PCB Design Layout
Venture PCB Design & Layout services team had been offered high-quality PCB Design & Layout for over 200 customers all around the world,with our full range of experiences and up-to-date technology. We had been focused on high-speed PCB design, SI/PI/EMC analysis and also consulting.
Venture Offer Different Types of PCB
Venture has the full selection of design software, such as Cadence Allegro\ORCAD, Mentor WG\PADS, Protel99\ Altium Designer (AD)..etc. Please let us know which EDA tools you want use in your project, our most frequently used software are Eagle, Altium Designer, Protel( protel pcb design), PADS.
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Venture is not only a PCB fabrication manufacturer but also a PCB design company in China, we provide PCB custom design (advanced PCB design) services and PCB fabrication all under one roof, we offer high performance and high-reliability PCB design, high speed, and high-density PCB design, A/D mixed PCB design, Analog, RF PCB design to meet customer’s different PCB Design & Layout requirements.
- 100+ PCB Design & Layout projects per year
- Outstanding designers with 10+ working experiences.
- 7/24 Live sales & tech support
- Complete Design Software such as Cadence Allegro\ORCAD, Mentor WG\PADS..etc
- 6 hours PCB Layout expedite services
Through our 2 hours rapid response services from our 24/7 sales and tech support team, and excellent after-sales service, we will be your expert PCB Design & Layout partner in China.
From PCB Design To Layout
Venture PCB design capability can support :
- Min.trace width 2.5mil,
- Min trace spacing 2.5mil,
- Min vias 6mil ( 4mil laser drilling),
- Max layer count 32 layers,
- Min BGA spacing 0.4mm,
- Max BGA Pin 2500pin,
- Max High speed signal 12G differential signal,
- HDI highest Layer count 18 layers,
- fastest delivery time 6 hours per item.
If you have detailed requirement ideas in mind, and want to request a circuit design in schematic file, Venture Design team will be here for you;
If you want to request a PCB Gerber file design drawings that match to your schematic file, Venture Layout engineers are here for you;
If you have obsolete printed circuit board looking for PCB Copy or PCB clone or BOM list making, Venture design & Layout service will be your perfect choice.
No matter you are an electrical engineer, a product designer, a system integrator or a maker looking for a low cost PCB design, Venture design & Layout team will be here to help you develop your PCB design projects.
At Venture we can answer any PCB Design & Layout questions that you may have, please feel free to contact us anytime for your custom PCB design projects.
Product types: Data communication products
- Optical network products
- Multimedia products
- Network products
- Medical products
- Aerospace products
- Industrial control products
Chip types: Network processing series
- Intel server series
- Freescale Power P-C series
- Samsung ARM series
- DDR 3 & DDR 4 series
Design software:
- Cadence Allegro\ORCAD, Mentor WG\ PADS, Protel 99\ Altium Designer ( AD)
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Download the FREE PCB & Assembly Catalog online today! Venture will be your best partner on the way of bring your idea to market.
PCB Design & Layout Capabilities
Min.trace width: | 2.5mil | Min.trace spacing | 2.5mil |
Min.Vias: | 6mil(4mil laser drilling) | Max.layer | 48L |
Min.BGA spacing | 0.35mm | Max.BGA Pin | 3600pin |
Max.high-speed signal | 40 GBPS | Fastest delivery time | 6 Hours/ Item |
HDI Highest layer | 22 L | HDI Highest layer | 14 L any layer HDI |
PCB Design & Layout Delivery Capabilities
Delivery Time | ||
Item | Normal | Expedited |
300pin | 1 day | 6 hours |
1000pin | 3 days | 2 days |
2000pin | 5 days | 3 days |
5000pin | 10 days | 7 days |
10000pin | 20 days | 14 days |
20000pin | 30 days | 20 days |
Quick Response | |
Time | Service |
2 Hours | Data veriy and quote |
7*24 Hours | Technical support |
7*24 Hours | Order service |
7*24 Hours | After sale services |
PCB Design & Layout: The Ultimate Guide
Do you have trouble accessing information on the complete guide on printed circuit board design and layout?
Maybe, you wonder how you can get the printed circuit board and the process of making it is quite challenging.
Well, worry no more as you are about to learn more about the whole printed circuit board and layout.
- PCB Design Basics
- Choose PCB Design Software
- Understand PCB Layout Design Rules
- PCB Design Steps – How to Create a PCB Layout from Schematic
- High-Speed Design Features and Process
- What to Pay Attention During PCB design & Layout
- PCB Design Courses – Your Ultimate Learning for PCB Design & Layout
- FAQs on PCB Design & Layout
- Conclusion
Chapter 1: PCB Design Basics
Are you new PCB designs?
Well, in this section, I will walk you through the PCB design and layout.
What is a PCB Layout Design?
A printed circuit board layout design is a very important element that you should consider in designing electronic products.
In many cases, a design engineer is responsible for designing the electronic circuit.
A printed circuit board layout designer is responsible for taking the PCB layout and design from the given schematic.
PCB
The PCB layout and design is a special skill that requires you to have knowledge of the basic software.
The type of software that you should have knowledge of is inclusive of the CAD system plus a variety of techniques.
The standards that you will use will ensure a successful transfer of the circuit board to the printed circuit board.
It will also ensure success in the process of manufacturing the printed circuit board in a manufacturing environment.
For a successful manufacture of a printed circuit board, you should have guidelines that you will follow in the process.
There are experts who have experience in the system and are able to design a layout without a guideline.
When it comes to the process of making a printed circuit board design, different software is available for use.
It is important to choose software that many people in the designing industry prefer to use.
Remember, this is an important factor to consider when doing team designs as the software will enhance the skill of engineers.
The printed circuit board layout and design software that many people use include Xpedition, PADS, Altium and Cadence Allegro.
The software is suitable for the job of designing the PCB layouts but some do better jobs than others.
The programs that you will use range from simple products to products that have very high sophistication.
Types of PCB Designs
There are quite a number of printed circuit board designs that you can choose from depending on the application.
Continue reading and find out more about the most common types of PCB designs that you can use.
1. Flex PCB Design
A flex PCB design is a type of printed circuit board that is able to bend at different angles.
The material that you will use in making the flex PCB should have the ability to bend round different corners.
Flex PCB design
The main materials in a flex PCB design are copper and flexible substrate materials put together using pressure, heat and adhesives.
The substrate that many manufacturers use is the polyimide which is a flexible and strong thermosetting polymer.
Examples of polyimides that you can use are Kapton, Apical, VTEC PI, UPILEX, Kaptrex and Norton TH.
It is, therefore, a pattern of different conductors on an insulating film that is flexible
2.Rigid Flex PCB Design
As the name suggests, it is a printed circuit board with a rigid circuit and a flexible circuit operating together.
The rigid-flex design is important as it has the benefits of the rigid and flexible circuits.
The rigid circuit carries most of the components of the PCB while the flexible area acts as the connections.
The flexible area is meant to save weight and space and is components of portable devices such as cell phones.
It also helps in the reduction of packaging complexity as it eliminates the need of doing interconnect wirings.
3.Multilayer PCB Design
A multilayer PCB is a design of a printed circuit board that has three or more layers.
It has more than three layers of conductors which you will find at the centre of the material.
It is an essential component of aerospace printed circuit boards and critical crosstalk levels equipment.
Multilayer PCB design
You can also find it in applications such as computers, data storage, file servers, cell phone transmitters and repeaters.
Other applications include weather analysis equipment, atomic accelerators, equipment for a space probe, and the fire alarm control system.
The advantages of using it include smaller size, high assembly density, increase in flexibility, easy incorporation and reduction in interconnections.
4.High-Speed PCB Design
A high-speed PCB design is any type of printed circuit board that involves the interruption of the equipment signals.
The interruption of the signals is by physical characteristics of the circuit board such as packaging, layout and interconnections.
High speed PCB design
It involves issues such as reflection crosstalk, delays or emissions whenever you initiate the designing of the boards.
It is one of the most distinct designs due to the kind of attention it receives. You can use one to design a board where the main focus is on component routing and placement.
With designs of high speed, it is important to:
- Know the exact place for putting the traces
- Know how close the traces are to the signals
- Note the exact nature of the items you will connect.
Such considerations are important for taking the design to a new level of functionality.
5.High Power PCB Design
The most significant rule that you should look at is knowing the power path of the printed circuit board.
The amount of power and the location of the circuit is another significant consideration to focus on high power PCB designs.
High power PCB
Apart from these factors, there are other factors to consider in high power PCB designs which include:
- The quantity of power that flows through the circuit
- Ambient temperature resulting around the board and the design
- The quantity of airflow around the board and the device
- The material you will use in making the board
- The density of the IC on the board
You will use this type of printed circuit board in devices that require the use of high power.
Since devices are becoming smaller and smaller by the day, PCB designs should be high power tolerant.
6.HDI PCB Design
High-Density Interconnect printed circuit boards is one of the fastest growing technologies for the PCB designs.
HDI PCB’s contain buried and/or blind vias and microvias that are less than a diameter thick usually 0.006 micrometres.
HDI PCB design
The circuitry density of this board is higher than the normal densities of the printed circuit boards.
High-Density Interconnect boards are available in six different types which include:
- The through vias extending from one surface to another surface
- A board with both buried and through vias
- Multilayer high density interconnect that have through vias
- Passive substrates that do not have any electrical connections
- Coreless construction of the HDI printed circuit boards using layer pairs
- An alternate construction of the HDI printed circuit boards using layer pairs
The benefits of using this type of printed circuit board include:
- It gives an allowance for placing more components on the two sides of the printed circuit board
- The multiple via process available allow the manufacturer to place smaller components very close to other components
- The decrease in pitch and size of the components allow for an increase in I/O in geometries of smaller sizes
- Allows for fast transmission of signals and reduces crossing delays and signal loss significantly.
5.LED PCB Design
Light Emitting Diode printed circuit board is an advancement in technology for the LED lighting. It features the connection of the LED to the circuit board and a chip producing light whenever the electric current flows.
Bonding of the chips is possible through the use of ceramic bases and thermal heat sinks.
The heat it generates is very high thus cooling through traditional means is very difficult.
You will, therefore, find metal cores in LED PCB’s because of the ability to release heat.
The most common piece of metal you will find in the LED PCB is aluminium.
LED PCB design
An aluminium PCB will include a thin layer of dielectric material that is able to conduct enough heat.
It is able to conduct and transfer heat from the system making it better than the traditionally printed circuit boards.
You will find the LED PCB design in different applications due to the following excellent abilities:
- It is energy efficient
- It is cost effective and you will save a lot for this type of design
- The design offers for maximum flexibility when you are using it
The applications that require the LED PCB include automotive headlights, military lighting applications, airport runway lighting, and street lighting.
Other applications are lighting in the highway tunnels, photovoltaic or solar lighting, lanterns and flashlights, signals and traffic lightings.
You may also find it in hospital lightings such as the theatre or operating rooms and growing plant lightings among others.
6.RF PCB Design
Radiofrequency printed circuit board designs is one of the most exciting pieces’ engineers have been working on.
You are likely to find the high-frequency boards in the upcoming technological inventions such as smartphones, robotics and sensors.
The high complexity of the design makes it an extremely difficult design to come up with.
The Industry of the printed circuit boards will consider any PCB operating above 100MHz as a radio frequency PCB.
RF PCB design
The devices that use the RF PCBs are complex and can accommodate both analog and digital signals.
There are certain devices that can accommodate different configurations of 60 layers.
7. High Voltage PCB Design
The high voltage printed circuit board design is common in different applications that require very high voltages.
It is important to have enough space and suitable clearances when designing the high voltage printed circuit board.
High voltage PCB design
It helps in the elimination of any electrical breakdowns or electrical arcing.
When you are planning to come up with the high voltage PCB, there are certain considerations to look at.
The considerations include altitude, clearance, creepage distance, double insulation, reinforced insulation, basic insulation, supplementary insulation, and functional insulation.
The grade of insulating material, the altitude, environment, and type of PCB affect the creepage and clearance.
8.Amplifier PCB Design
You are most likely to find amplifier PCB designs in devices that produce sound with low to high-frequency audio devices.
The aspects of designing a complete functional audio circuit have been a challenge since it is very complex.
Amplifier PCB design
It is therefore important to have a specific layout that you will follow during the designing process.
The factors to consider when designing an amplifier PCB design are:
- The power supply and the grounds for power supply where transformers are the best
- Signals where you will avoid the in and out signals flowing to and from the IC
- Interfacing should be according to the design layout of the particular amplifier PCB design
- Capacitors where the audio signals will be passing through
- Op Amp circuits which will help in inverting of audio signals to achieve simple circuits
9. Metal Core PCB Design
Metalcore printed circuit boards or MCPCB are boards that use metal as the base material to spread the heat.
The base metals come as alternatives for CEM3 or FR4 boards as it disseminates heat faster and better.
Metal core will spread the heat to other fewer heat areas such as the metallic core or heatsink backing.
Metal Core PCB design
The type of metal material you can use in making the metal core printed circuit board will vary accordingly.
The most common metal materials are aluminium, copper or different mixtures of metal alloys. Again, the thickness of the metal core should range from 30 mils to 125 mils even though the thickness varies.
The advantages of using the metal core printed circuit board are as follows:
- It has the ability to integrate dielectric polymer layers that have high thermal conductivity for low thermal resistance
- It transfers heat 8 to 9 times faster in comparison to other materials such as the FR4
- It also laminates decapitate heat and keeps the heat generating components cool thus increased performance and longevity of life
Understand PCB Design Terminology
You might decide that you want to design your own printed circuit board and come up with your own design.
To get more information on your design, you might decide to visit the internet for the right guidelines.
In the process, you meet certain terminologies that are difficult to understand.
The terminologies you will encounter are common terms that design engineers use when designing different types of printed circuit boards.
Continue reading and find out more about the terminologies and abbreviation of designing PCB’s.
Different types of PCB
·PCB
It is an abbreviation for printed circuit boards. You will also come across other abbreviations for materials.
The most common abbreviations for materials are FR-1, FR-2, CEM-3, and CEM-1.
· FR
It is an abbreviation for flame retardant which means that the material is flame retardant.
CEM is an abbreviation for composite epoxy material which means that the material has such properties.
Apart from these, there are other terminologies that you will come across as follows.
·Layers
Every detail that you will draw will be on a layer and different layers have different physical attributes.
The top layer is for the layout of the components while the inner or bottom layers are for making connections.
There are many other functions that are present for different layers as you will find out in the designing process.
·Footprints
Footprints are collections of outlines and pads that contribute to the making of an individual component on the PCB design.
A PCB software will come with a whole library or unit of footprints you will use for different components.
It is important to note that the number of footprints is not as sufficient as you might expect.
The advancements of technology in the recent past has led to the emergence of smaller devices.
It has also led to the shrinking of the components manufacturers use in making the printed circuit boards.
It is, therefore, sometimes mandatory to come up with your own footprints for your device.
·Solder mask
When observing a PCB, you will come across masks or coatings of different colours such as green, red, blue or white.
The coating you have always been observing is the solder mask.
Masking is important for the PCB to prevent accidents or damage from accidentally dropping solders.
It also makes the soldering of the PCB components to become easy thus preventing short circuits among the close tracks.
As a beginner, you might use excess solder which eventually leads to shorts on the entire system.
The solder mask will prevent such problems and you easily remove the excess solders without melting.
It is among the non-conducting layers that you will find in a printed circuit board.
·Silkscreen
The silkscreen on the printed circuit board is important for the identification of the name of the components.
The user will use the silk screen to know the value of the component guide him through the soldering process.
It has been one of the best practices many manufacturers use in designing printed circuit boards.
You can do silk screening on every side of the printed circuit board which are the copper or component side.
It can also help you in identifying the name of the company or the manufacturer.
It is one of the non-conducting parts of a printed circuit board.
· Jumper
The jumper wire will form the connections between two different points of the printed circuit board.
In case tracks overlap in the process of designing the printed circuit board, you will use jumper wires.
The tracks may overlap one another as you attempt to make connections thus prompting the use of jumpers.
· Pads
Pads make different connections between the track and components using a solder.
They are small copper surfaces that you will find available on the printed circuit boards.
They are important for soldering leads of components to strengthen the mechanical bonds.
You will use different types of pads to mount the components of the surface and that of the through hole.
The size and shape of the components vary thus bringing the great difference in the types of pads.
·Copper traces
When you observe a printed circuit board, you will see red, blue or green lines connecting the vias and pads.
These lines are the copper traces and their function is to connect the pads and the vias.
They are the paths where electric current will flow between the vias and the pads, or two pads or two vias.
The width of the track or the copper traces will vary in accordance with the amount of current flowing.
·Via
In a multilayer printed circuit board, you will come across connections connecting the different layers.
The connections between the different layers of the printed circuit boards are possible because of the vias.
Apart from acting as connectors, they also conduct electric current through the different boards.
In a multilayer PCB, different colours represent different layers of the printed circuit board.
The explanation of the different colours representing different layers is as follows.
- Green colour represents the top and the bottom solder mask
- Red colour represents the top layer
- Violet colour will represent the second layer
- The yellow colour is a representative of the third layer
- Blue colours will represent the bottom layers
· Blind Via
Generally, in a more complex circuit, such as designing integrated circuits using more power planes then vias come into play.
The vias are seen only on the top and the second layer of the printed circuit board but not in the layer at the bottom.
The vias that you see are the blind vias as it is simple to make direct connections of the power planes.
The power planes are beneath the chips instead of finding alternative long tracks.
Blind vias come in handy for connecting layers on the external side to the internal side of the PCB.
The PCBs usually have very minimum heights thus blind vias are more suitable for connection purposes.
It is possible to get the difference between the through vias and the blind vias by exposing the PCB to light.
If you are unable to see light passing through then it is a blind via. Its light is able to pass through the vias then it is a through hole via.
The process is important when you have limited space for placing the components and for the routing process.
Using through-hole vias will force you to create more space for the vias on both sides.
·Buried Vias
They have very close similarities to the blind vias except for the fact that they are for connecting inner layers.
It is a more expensive technique in comparison to the through vias which are cheaper.
It also smaller and saves a lot of space so one can choose to stuck more components.
·Gerber
A Gerber is a type of file that the user will send to the manufacturer so that he can make the PCB.
When designing a PCB layout, I might use a different software from that of the manufacturer.
So I will use a Gerber file to transmit my design to the manufacturer for easier interpretation.
A Gerber file is important as it is the most universal type of software that the manufacturers can easily interpret.
For example, I might make my PCB on an eagle software which my manufacturer may not have.
It should not be a problem because when I transmit my design using Gerber software, the manufacturer will easily interpret.
The manufacturer does not have the freedom of making any changes on the Gerber file making it more secure.
It contains different types of information such as hole size and location, how to connect the tracks and naming components.
·BOM
BOM is an abbreviation for the bill of materials. It contains the list of the components that are available on the printed circuit board.
You will, therefore, calculate the estimated cost and thus you can make an order for the products.
It will also help in reminding you about the components that you might forget when shopping.
Know PCB Design Cost
The cost of designing a PCB will vary according to different factors of doing the designs.
Printed circuit board
The factors that will determine the cost of the PCB include:
- Cost of the material as different materials are of different prices
- Size of the PCB as bigger printed circuit boards cost a lot more
- The number of components as more components will increase the price of the design
- The type of designs will either increase or decrease the cost
- As the numbers of layers’ increase, so will the cost of designing
Apart from the factors on the list, there are other factors that you will come across when doing calculations.
When using a PCB design calculator, you will realize that there are many varying factors.
The cost calculator will also show you the time it will take for you to get your design.
When using the PCB cost and time calculator, you will first fill the following details.
The details that you need to key in are:
- PCB dimensions in inches and make sure that the approximations are okay. Some of the dimensions that you will key in are length and width in inches.
- You will also key in the number of pats you need for your printed circuit board design
- Key in the number of layers that you need for your printed circuit board
The calculator will also have optional fields that you might fill if need be. The optional fields are inclusive of:
- The delivery schedule requirements such as the economy, standard, expedited or priority
- The shape of the printed circuit board outline which can either be rectangular, irregular, round, flex or rigid-flex among others.
- The special features or constraints of the design that will apply to your requirements. The special features on the calculator that you can tick are high pin count, differential pairs, and sensitive analog circuitry. Others are RF traces, high current routing, high voltage traces, and the test points for testing them in circuits.
After filling in the details, you will submit the form and get the response in time.
From this point, you will, therefore, make a budget on how you will proceed with the plan.
Specify PCB Design Application
Electronics play a huge role in the daily routine of a human being living in this modern world.
At the centre of operations of every electronic appliance, there is the printed circuit board.
It is the foundation that makes every type of modern electronics that you will come across today.
The components have a wide range of configurations that allow them to perform different functions.
As developments in the electronics sector continue, developments in the PCB technology also improves.
It is easy to identify a printed circuit board whenever you see it and you can find them in the following applications.
·Medical Devices
There are many electronics that you can see in the medical industry functioning as monitoring, diagnostic and treatment devices.
Infusion pump
As technology advances, you will also see endless advancements in medical devices.
At the centre of the devices are highly specialized PCBs that will fit the demands of the devices.
You expect to find high density interconnect (HDI) PCBs, with flexible base materials.
It allows the PCB to stretch and flex during the applications thus making it essential for internal and external use.
Because it has some health implications, the medical PCBs have improved capabilities restricted under the strict medical regulations.
The main electronic devices that you will find in hospitals are:
- Monitors such as healthcare and personal monitors for testing heart rates, glucose content, blood pressure monitors among other types.
- Scanning Technology such as ultrasonic technology and CT scanners
- Control Systems such as equipment for fluid infusion, where dispensation ad rate of flow is under electrical controls.
- Internal devices such as the pacemaker of the heart and other internal devices
- Scientific instrumentation for studying diseases and patient outcomes
·Consumer electronics
These are the devices that we commonly use in our daily activities such as computers and smartphones.
You will find printed circuit boards within these applications even in the most modern refrigerators.
Phone PCB
The high volume of producing these appliances expects production of exact copies of PCBs.
The cost of producing the PCBs in bulk will help in reducing the cost of production.
It will also reduce the cost of the final product but the challenge comes when you have to do maintenance.
The maintenance of quality and uniformity of the PCBs have to be in compliance with the industrial standards and consumer standards.
The main consumer electronics with printed circuit boards are:
- Mobile devices such as tablets and cell phones
- Computer electronics such as laptops and desktops
- Recording devices such as digital cameras, camcorders and microphones
- Entertainment systems including everything in your entertainment system such as TV, radio, home theatre systems, DVD among others.
- Home appliances such as microwaves, alarm clocks, coffee makers and refrigerators
·Industrial Applications
The high powered PCBs control the electronics and machines that you will find in the big manufacturing and processing industries.
PLC PCB
They have the challenge of facing the difficult conditions of the industrial environment such as harsh chemicals and high temperatures.
In these challenging conditions, manufacturers develop PCB that can withstand the harsh environment such as the thick copper PCB.
You will find the applications in different industrial applications such as:
- Industrial equipment such as electric presses and drills
- Measuring equipment for measuring and controlling pressure
- Power Equipment such as DC to Ac power inverters and solar panels
·Automotive applications
Cars rely on the use of printed circuit boards more unlike in the past when it was on the headlights.
Advancements in technology make it possible to incorporate different types of printed circuit boards in cars.
PCBs such as RF and microwave that require high frequencies are available in modern cars.
The PCBs have led to improved safety on the roads and better experiences in driving.
The applications of the printed circuit boards in the automobiles are as follows:
- Surrounding monitors that help in different calculations of distance and proximities among others.
- Control systems such as fuel and engine management systems and power supplies among other applications.
- Navigation devices such as the GPS computers,
- Video and Audio devices you will see on the dashboards of the modern vehicles.
·Aerospace applications
Just like the applications on automotive, PCBs on aerospace equipment require the right precision and durability.
Figure 19 Aluminum PCB
The turbulence that these aerospace jets go through while in the air are enough to cause damages on the PCBs.
Manufactures develop flexible PCBs that are light in weight and can withstand vibration.
The PCBs on jets are durable and should also be functioning well and precisely to avoid any technical issues.
This will ensure the safety of the jet and the crew that is on board.
The PCB is available in different applications on the jet such as:
- Monitoring equipment and instrumentations such as pressure sensors, accelerometers, microphones, pressure sensors among other vital equipment. They are important for use in the cockpit and the engines of the aeroplanes for monitoring functions and communication.
- Testing equipment for checking the functionality of the air vehicles during the process of development. The equipment collects and transmits data with PCBs being at the core of its functions.
·Lighting Applications
The PCB provides a versatile base that manufacturers use in making different varieties of LED lighting systems.
It has led to various advantages such as low power consumption, the good output of light and impressive efficiency.
LED PCB
LEDs that have PCBs work better and improves the versatility of the lighting device.
It improves the functionality of the indicators and the display signs. Some of the common applications with PCBs are:
- Telecommunications industry use PCBs to control the LED displays and indicators. The PCBs in use are light in weight and are durable.
- Automotive industry found on dashboards, brake light and headlights among other key applications.
- Computer technology found in laptop and desktop indicators and they use aluminium-based PCB for high-temperature resistance.
- Medical industry for the lighting tools for surgery purposes to improve the visibility of the physician among other applications.
- Residential applications and business premises in the form of signage applications and different displays.
·Other Applications
There are other general applications where you will find the printed circuit boards in use.
The applications are too many for mention except for the following:
- Firearm applications where PCBs are in the equipment manufacturers use to test the firearms. It ensures the functionality and safety of the equipment before releasing it to the market.
- Marine applications such as underwater submarines and sailing boats on the surface of the water. You can find it in equipment that controls navigation, power distribution and engine management.
- Security applications use the PCBs in different equipment that controls and detect the presence of intruders. It is essential in fire, smoke and burglar alarms triggering sounds whenever there is a problem.
- Telecommunication and broadcasting applications especially on high frequency and filtering equipment or amplifiers. You will find them at booster stations, frequency boards, receivers, microphones and mixing decks.
Identify PCB Design Service Provider
In the pursuit for a good printed circuit board that will fit the specifications you desire, you have to get a designer.
The PCB design service provider is responsible for giving you the right details about the type of design you need.
They will guide you through the steps you need to follow when outsourcing for good printed circuit board.
Rigid flex PCB design
A good PCB design provider should have the relevant experience in the making of printed circuit board designs.
He should have the relevant machinery, tools and equipment which he will use in making the design.
The provider should also have a relevant employee base of engineers with enough experience to help in the production of a good design.
Most PCB design service providers are available online and have customer care services ready to care for your needs.
Most of the reliable but it is important to get a reference from somebody who knows them better.
With the reference, you will know how reliable and competent such companies are to take care of your needs.
After identifying a reliable PCB service provider, you should take care of the business you require of them.
Look at their profile and see if they can provide the type of services that you require for your design.
You can speak to one of their customer care representatives who are always available all the time.
Apart from that, reliable design service providers should have an online form for you to fill to get a quotation.
The quotation will help you in knowing the rough estimate of the cost of coming up with your design.
With the quote, you can compare with other service providers and choose the one that will be favorable for you.
Chapter 2: Choose PCB Design Software
A PCB design software is an open source and free suite for electronic design automation in making printed circuit boards.
It is the software that you will use in making the designs and layouts of the printed circuit boards.
There are many software available in the market today due to the advancements in technology.
Many of the software that you might prefer to use are available online while others require special permission to access.
PCB Design Software
You should be careful when making decisions about software online because you might meet fraudsters.
You might also fall in the hand s of people who will sell you uncertified software that may be obsolete.
There are different types of software that perform different types of design functions.
When choosing a software, make sure you look at the type of software that will perform your design duties.
You can choose a software that has overall functions and can help you design any type of printed circuit board.
A good software should have essential features such as:
- Scalable fonts
- Layer groups
- Gerber
- NC drill
- Encapsulated postscript
- Postscript output
It should also have a centroid, flags for vias and pins, auto router, netlist window, trace optimizers and rats nest. It should be inclusive of snap to pads and pins, centroid data output, add-on device drivers, among other things.
Popular PCB Design Software
PCB design software is available in different forms and names for you to choose from.
You should note that the software performs different functions so choose carefully.
Choose the software that will help you make the kind of design you need better.
Some of the most popular design software that manufacturers use is cadence allegro, Protel 99 and Altium designer among others.
They are the most popular because they are reliable and provides different types of functionality.
Continue reading and find out more about the different design software.
1. Cadence Allegro
This type of software takes the complex and simple designs of printed circuit boards all the way from concept to production.
It is inclusive of the cost of designing making sure it is functional.
It has scalable technology that enables designers to match current and future methodological and technological needs for different complexities.
The benefits of using this type of software include:
- It ensures that the design is complete in time for placement, routing and manufacturing
- It has very powerful features for designs such as RF design capabilities, design partitioning, and interconnect design planning
- It has been proven to be reliable in mass production of designs and engineers can ramp up to volume productions
- It is also safe for use as it has the relevant certification such as TUV SUD “Fit for Purpose – TCL1”. These certifications make it preferable as it also meets the ISO 26262 certification for automotive functional safety.
2. Protel 99
This is another type of software that many PCB designers and manufacturers use to come up with a good design.
The software enables you to do a lot of things on the design including the relevant details for the design.
It is a reliable software that you can comfortably use with relevant training on using the software.
It also provides a workspace for editing particular areas of printed circuit board design on the PCB editor panel. Some of the areas that it provides for editing include:
- The browse section which has components such as, nets, libraries, net classes, and component classes. It also provides the design rules and the design rules violations.
- Mini viewer which provides for planning, changing of the view window, and magnifiers to improve the designing experience.
- It provides a panel browse which you can use for the purposes of browsing nets, components’, libraries, and net classes. It also has provisions for browsing component classes, design rule violations, design rules and exercises such as using the mini-viewer
The procedure for using the software will include:
- Creating a new printed circuit board using the PCB wizard
- Transfer of the information on the design to the printed circuit board
- Setting up the layers of the printed circuit board
- Setting up the rules for the design
- Using the component placement tools to do various functions such as moving the components.
- Routing and polygon processes
- Checking the rules of the design
- Printing the final design
- Going through the CAM manager to determine BOM, DRC, Gerber, NC drill, Pick and place and test point report.
3. Altium Designer
This type of software bridges all the facets of the process of printed circuit designing.
It is a design software package that has electronic automation for designing printed circuit boards.
The features of this software encompass four main design areas such as:
- Schematic capture
- 3D printed circuit board design
- Field programmable gate array (FPGA)
- The release of data management
The advantages of using Altium design for the printed circuit board design include:
- Decreased time of making the designs
- It provides the ability to create accurate 3D models so that one can have a better view of the design
- The schematic approach and integrated capture for the designs makes it the best type of software
- It continuously comes up with new and better innovations that the customer might prefer to use
- It has a wide range of materials in the library that a designer can easily refer
- It also supports track lengths during the process of 3D modelling
The software has the relevant tools for all the types of designs such as HDL design capture, and signal integrity analysis.
Others include circuit simulation, PCB designs, and the FPGA base that is within the system development and design. The environment of an Altium designer should consist of:
- Editing area of the main document of the Altium designer
- Workspace panels
- The software is a rival for many other types of software due to its originality and functionality. It is among the software that you can easily identify and you will not regret. The process of making a printed circuit board design in Altium follows the following procedure:
- Creating a new project with the idea of the kind of PCB design layout you need
- Creating the schematic parts by opening the schematic file and select from the libraries.
- Update the printed circuit board from the schematic by validating the changes before execution of the changes
- After that, you should determine the shape of the board and the type and number of layers.
- The next step involves checking on the rules and routing
- Look at the signal layers and the internal planes
- After that take care of the mounting holes before generating the files as the final step of the process.
4.PCBWeb designer
This is a CAD application that is free for the designing of PCBs before giving it out to the manufacturer. It can help in designing multi-layer PCB schematics with fast and easily usable software.
PCB Web
It also provides for routing of the multi-layer boards with support for the copper pours and checking of the DRC.
It also provides for other important areas of designing such as the integrated Digi-Key parts catalogue and management of BOM.
5. ZenitPCB
This is an excellent printed circuit board layout designing software for creating professional PCBs.
It is a CAD program that is flexible and easy to use allowing to get the final project in a limited time period. You can start the project either from the schematic or from the layout.
6. TinyCAD
This is program or software that will assist you in drawing or making circuit diagrams. It has symbol libraries that you can use to start the designing process right away.
It simplifies the print of the designs and publishes the design on a word document or save it as PNG bitmap.
7. Osmond PCB
This is another flexible software or tool that you will find easily for use in designing printed circuit boards.
The program runs on the Macintosh operating system and has many features to bring your PCB design to form. The features of the software include:
- Virtually unlimited sizes for the boards
- A range of different numbers for the PCB boards
- Number of parts
- Support for the through holes and surface mounting parts
8. KiCad
This is an open source type of design software that you can use to create electronic schematics and PCB artwork.
It is a software that abides by the GNU’s GPL copyright agreements.
It also uses the graphical user interface making it very easy software to work with.
9. PADS (PowerPCB)
It is the software many people know as the king of CAD on the lower side suitable for the small companies.
It is among the best types of EDA among the EDA that is available as it is easy to learn and use. The quality of the design is top notch just like the ones you get from Allegro.
Other types of software that you will get in the market include ORCARD, WG, Eagle, EasyEda among others.
They are as efficient as any other type of software but with varying complexities. The procedure of using every software is simple and vary from one software to another.
Chapter 3: Understand PCB Layout Design Rules
To come up with a design that is perfect on paper and will be equally good after manufacture requires certain guidelines.
At the end of your design, you should make sure that it is properly functioning, durable and reliable.
Many of the new designers make the common mistake of leaving the PCB design guidelines and focus more on designing.
RF PCB design layout
At the end of the day, you may come up with a design that does not fit the digital layout.
The physical layout may not be as good and functional as it was on the digital representation.
Apart from that, it might pose more problems to the manufacturer when he attempts to create the physical design.
The key to coming up with a design that is realistic both on the board and on paper id to follow the guidelines.
The most important guidelines that you need to know when designing are as follows.
· Fine Tuning the component placement
Placing the components on your PCB is a science and an art that requires a lot of experience and expertise.
There are particular considerations that you will have to pay close attention to ensure you get the perfect outcome.
It is a challenging process that will determine the ease of manufacturing the physical PCB design.
Components on PCB
It will also determine if the original requirements that you have been on the final product.
There are general guidelines that you will follow when designing the layout such as the type of PCB, and power circuits.
Other considerations are critical circuits and precision circuits among other general considerations.
The specific considerations that you have to adhere to are:
- The orientation of similar components in similar directions as it will help in the process of soldering.
- Placement of components on the solder side is not right especially if it will rest behind the plated through hole components.
- The organization requires you to place the surface mount components on the same side of the board. Place the through hole components on the top as it minimizes the assembly steps.
· Placing the ground, power and signal traces
After placing your components, it is important to have ground, power and signal traces in place.
It ensures that the signals have a clear path that is deficient of numerous problems for travelling purposes.
Signal traces on PCB
The following are the things to keep in mind during this process of placing the ground, power and signal traces.
i.The orientation of the ground and power planes
You should have the ground and power planes on the inner side of the board making sure it is centered and symmetrical.
It prevents the damages such as breaking and affects the proper positioning of the elements. Use common rails to power the ICs, and make sure you have wide and solid traces and avoid daisy-chaining of power-lines.
ii. Connecting the signal traces
Connect the signal traces and ensure they match the schematic guidelines by placing them short and direct to the components.
If the races force a horizontal face on one side, then place a vertical face on the other side of the board.
iii. Defining the net widths
The design might require different nets carrying a wide range of current dictating the net width. Provide a 0.010 inch for the low current digital and analog signals.
When the traces are carrying more than 0.03 amps, increase the width to fit the new condition.
· Keeping the components separate
The high and low voltages sometimes interfere with the current flow in the printed circuit board. To get rid of such problems, there are particular guidelines that you need to follow.
Flex PCB layout
i.Separation
Make sure that the power ground and the control ground are separate for every stage of the power supply.
In case you have to tie them together, make sure it is at the end of the path of a supply.
ii.Placement
Placing the ground plane in the middle layer requires a small impedance path.
The impedance path will reduce the risk of power circuit interference and protect the control signals.
You can follow the same rule to make sure that the analog and digital signals are separate.
iii.Coupling
To get rid of capacitive coupling, cross the analog with another analog signal.
·Combating issues of heating
There are incidences when you have had to look back at the starting line because your device cannot work anymore.
The device might be destroyed by high temperatures that increase when you are testing your device.
The reason for this damage is a failure of taking care of heat dissemination in the designing process.
High power PCB
To help combat heating issues there are certain guidelines that you need to follow during the designing process. The rules to take care of are:
i.Identifying the components that cause the problems
The first step is finding out the component that is likely to dissipate a lot of heat on your board.
You can achieve this by finding the thermal resistance of the different components on your device.
Then follow the guidelines that will assist in dissipating the heat from the device.
You can also add cooling devices such as fans and heat sinks to help in cooling down the device.
Remember to put the critical resources away from the areas of high temperatures.
ii.Adding thermal reliefs
Thermal reliefs are important additions to the devices that have more than one layer of boards.
It is also important for devices that have wave soldering applications on the copper content.
You can also use thermal reliefs on the components of the through holes to ease the process of soldering.
Use the thermal reliefs for the vias or holes that have direct connections to the ground or power supply.
Adding teardrops on the places where the pads join the traces will also assist in making the device stronger.
It will help in reducing thermal and mechanical stress in the long run.
iii.Checking the complete work
It is a common practice for many designers to be joyous when approaching the end of their designs.
It is important to check your device two or three times to make sure it is good enough for manufacturing.
To make sure that you don’t mess up at this stage, there are guidelines that can assist you.
The first thing to do is to observe the electrical rule check and the design rule checks.
This will help you make sure that all the constraints you were working on are in check.
It will help you enforce trace widths, gap widths, manufacturing setups, short circuits and high-speed requirements.
When the DRC and ERC produce good results, you can check the routing of the system.
Go through the whole process of routing buy checking one wire at a time more than once.
Make sure that all the dimensions match the original schematic as you probe the masking features.
Rounding the whole process up is the final process of the design rules that you have to look at. You will be in the right position of providing your design to the manufacturer.
Chapter 4: PCB Design Steps – How to Create a PCB Layout from Schematic
There is much software that you can choose from to assist you in making a good schematic complete.
The software will guide you through every step to help you come up with the right schematic. The schematic will play a huge role, in the final design and it has to be perfect.
You are able to develop the schematic using the schematic capture that lies deep in the heart of designing software.
Amplifier PCB layout
It has a combination of a powerful environment that will assist in design re-use and a complete bill of materials.
The process of creating a PCB layout from a schematic will follow the process below.
Step 1: Use Software to Design a Circuit Diagram
The first step is designing a circuit diagram using the different software available for the purpose.
You can either decide to use SmartDraw to help you in making the drawing of a schematic. It is one of the software that you can easily download and use freely without serious tuition.
Sample PCB Design Software
It has many examples and templates that will assist you in making the first start in the process of drawing.
You will select the type of schematic that you would like to use from the wide library of schematics available.
SmartDraw is a powerful tool that you can use to make the schematic drawing in very little time.
Other advantages of using SmartDraw include:
- It has quick start drawing templates for the schematic
- It has a very big library for you to choose from especially when looking for the right diagram
- Intelligent formatting for the large schematics
- It also offers free support for the designers
- It also offers for effortless collaborations so that you can share and work on a design together
- It also offers smart integration so that you can use it wherever you are as long as you have internet access.
The software is among many other types of software that you can use in making the schematic diagram.
Step 2: Make a PCB Film – Transfer PCB Design File to Film
The second step in making a printed circuit board film by transferring the PCB design on to a film. It involves printing the PCB schematic on either one or more films.
PCB Film transfer
Once the diagram of the schematic is on the film, you can advance to the next step.
In many cases, the film gets a transfer onto actual boards which may have different films for different physical components.
Step 3: Prepare PCB Material
The third step is the preparation of the printed circuit board material especially the boards and copper material.
The material will, however, differ depending on the type of printed circuit board that you intend to create.
Preparation can involve collecting and dusting the material that you will use in the process.
It can also involve creating a bill of materials so that you don’t forget anything when the manufacturer gets the material.
Sample PCB Material
Measuring and cutting the material into the right dimensions are all part of the preparation process.
It is important to do all the preparations according to the guidelines that you have.
Step 4: Drill Holes
There are special machines that you can use to drill holes, especially on the circuit board.
You can choose to use the X-ray drill to make the reference holes, especially for the leaded components.
It is the method you will use for making the vias holes that will link the copper layers together.
Drilling holes on PCB
You will have to put the material you want to drill on the drill bed to avoid any damages.
The drilling machine is under the influence of a machine using a particular drilling program.
It will guide the machine on the best mode and speed of drilling considering the axis for drilling.
It is a slow process as the machine will drill one hole at a time.
You can stack up one to three boards together and make a hole through them.
The number of layers you will stack up will depend on the type and size of the drilling machine.
Step 5: Print PCB
The next step after drilling the holes on the board is to print the printed circuit board. Other people may prefer to identify it as legend printing which is on one side or both sides of the PCB.
It contains component designators, test points, switch settings, and different indications for assembly purposes.
Printing PCB
There are three methods you can use in printing the printed circuit board including:
- Silkscreen printing
- Liquid photo imaging which is a more accurate process
- Inkjet printing increasingly gaining fame in the printing industry
Step 6: Stripping and Etching Process
The etching process involves removing layers of copper to the substrate on either one or both sides of the plate.
It involves removing excess layers of copper leaving the traces you need on the board.
There are many ways by which you can carry out the process of etching on the printed circuit board.
The most common type of etching is by using ferric chloride or hydrochloric acid as they are economical.
It is the main process of tracing the design of the circuit on the copper plate. The steps to follow when etching is:
- Designing the circuit
- Print circuit design on the transfer paper
- Rub sand on the copper plate as a method of preparing the clean it using water or alcohol
- Cut the copper pieces into shape and pass them through lamination process several times
- Pass it through a bathing process and make sure it is cooled and dry at the end of the process.
- After that, you can take it through the stripping process which involves covering it using lead or tin. From that point, you can use nitric acid to clean the plate and get rid of the tin and preserve the copper traces.
Step 7: Test and Validate Quality of PCB
The last step is testing the circuit board to check if it is free of defects and it is working well.
There are many testing types of equipment available in the modern world that you can choose from.
PCB testing equipment
Some of the equipment include ATG testing machines that have flying probes and fixtureless testers.
You can also use them for the universal grid tests on the printed circuit boards.
Remember, electrical tests are critical when manufacturing PCB.
Chapter 5: High-Speed Design Features and Process
At this point, you have a lot of information about the processes and considerations of standard printed circuit boards.
Well, the mention of facts such as crosstalk, signal integrity and reflections may make feel like you are lost.
These are the kind of terminologies you will come across when you are dealing with high-speed PCB designs.
High speed PCB
Therefore, high-speed PCB design is any type of printed circuit board design where signal integrity begins with physical characteristics.
It means that the physical characteristics of your board will be the main factors that affect signal integrity.
Physical characteristics such as layer stack up, packaging, layout, and interconnections among others will affect the signal integrity of your PCB.
Whenever you are designing a printed circuit board and you come across certain issues, do not worry yet.
The issues, such as attenuation, delays, reflection, emissions, crosstalk are some of the factors that you should look at.
In case, these are the issues affecting your design then you are welcome to the world of high-speed PCBs.
The amount of attention engineers pays to these issues make the high speed printed circuit board most important.
PCB Assembly
Routing and component placement is often the main points of focus when designing the standard printed circuit boards.
High speed printed circuit boards, on the other hand, requires to focus on factors such as:
- The exact point of placement for the traces
- The width of the traces
- The proximity of the traces to other signals
- The type of components you will connect to the traces
Such considerations will lead you to a whole new level of designing printed circuit boards.
We know that a good high-speed design deals with signal issues, let’s have a look at these factors.
Signal and Signal Integrity
No matter the type of design you are working on, it is important to note that it will transfer signals.
The signals will be moving from the source through the copper length traces to the final destination. The signal can either be digital or analog as you are about to learn.
· Digital Signals
A digital signal is a clock signal or a square wave that you will find in most digital appliances you know. It has a simple representation of the values, unlike the analog counterpart. The signals consist of low and high points, 1 and 0, or on and off.
·Analog signals
Analog signals, on the other hand, have a range of negative and positive values to determine its existence.
It has a wide range of results depend on the signal frequency and signal strength.
The fact that the analog and digital signals have interference will bring in the issue of signal integrity.
Whenever the environment of the signal affects the signal, then you have to consider the issues arising.
There are many factors that can interfere with the transmission of signals from the transmitter to the receiver.
The issues that may affect the transmission of signals from the transmitter to the receiver are:
- The signal reflection which involves the reflection of some of the signals on the transmission line back to the transmitter. The signal does not complete the journey from the transmitter to the receiver.
- Signal ringing involves the unwanted shifting of the power or voltage of the traces. It leads to the flow of extra current and delays the arrival of the signals to the receiver.
- Signal noise involves other signals on the board affecting the integrity of the signals that are closer to it. in case of too much noise affecting the signal, there is a chance of damage of other signals.
- Signal crosstalk is the situation where two traces are in very close proximity to one another. Electromagnetic radiation can cause disruption to occur in other signals thus corrupting the data.
- Signal timing involves delaying of signals from reaching the receiver in time to unite with the clock signals. It might lead to the misinterpretation of the signals as you may confuse 0 signals for 1.
PCB Turnkey Solution
These are some of the problems that you may face when dealing with high speed printed circuit boards.
The role of the engineer responsible for the high-speed PCBs is to make sure such issues never occur.
It means that when the signal leaves the transmitter it should arrive at the destination with the same wavelength.
Please note that there are numerous problems that you will encounter when designing a high-speed PCB.
It is, however, important to take note of the main three issues which are:
- Timing involves the delay of the signals from arriving at the destination at the right time. All the signals are under the control of a clock and there are situations when the signals don’t match time. In this case, you should know that the data you receive may be corrupt
- Integrity involves a different look of the signals from the transmitter to the receiver. In other words, the signals from the transmitter look different from the ones at the receiver. If they do not match, then the signal has certain interferences affecting its integrity.
- Noise involves the interference that signals pass through in the transmission process. Every PCB has to encounter interference in the process of transmission of signals. In case the interference is too much, then the data you receive must be corrupt.
Rigid Flex PCB
The main problems affecting the transmission of signals in the high speed printed circuit board also has solutions.
The solutions to these problems are impedance, spacing and matching.
- Impedance affects the quality of the signals you will be transmitted from the transmitter to the receiver. Proper impedance will not only have better signal quality but also affect the sensitivity of signals to noise.
- Matching the lengths of the traces will ensure that the signals arrive in time and at the same wavelength. The arrival of the signal will also be in sync with the clock rates of the printed circuit boards. It is a solution to SATA, DDR, HDMI, PCI Express and USB applications.
- Spacing involves leaving considerable space between the traces and other components.
High-Speed Design Process
The process of making a high speed printed circuit board is not as diverse as that of making the standard PCBs.
The process will involve specific considerations for specific information and processes in the designing process.
So, what should you do?
PCB with LED
· Have a plan for designing the high speed printed circuit board
The most important factor to consider when thinking of designing a high speed printed circuit board is a good plan.
Without a proper plan, it is possible to encounter unexpected issues, respins and setbacks along the way.
You will need a checklist of some of the things you need to avoid missing the point.
Some of the things that you need to look at are:
- System organization requires you to have a diagram that will help you visualize the design you need. You will be able to recognize how the sub-circuits interconnect and how the return currents establish.
- Signal speed involves knowing the fastest rise time and highest frequency of every signal you intend to use.
- Power supply involves considering documentation of power and voltage requirements such as the ICs and splitting of the power planes.
- Sensitive signals involve planning for differential signals, trace lengths, controlled impedance and trace propagation.
These are some of the factors that will get you started on your project and make sure you involve your manufacturer.
They will advise you on the minimum tolerance requirements of their products.
Remember to have a strategy that will reduce the level of noise on the high-speed signals.
·Document all the details of the board stack up
This involves a thorough documentation and review of the details you will need in the making of the design.
Your manufacturer will assist you in making the right choices on the type of material you need among other important factors.
The kind of material that you may need include FR-4, Megtron, SI or Nelco, and Rogers.
PCB assembly
Apart from the material, there are other factors that you need to put in mind including:
- Have the signal layer next to the plane layer to provide an efficient return path for your signals.
- Consider routing the high-speed signals on the inner layer of the board between the planes. This will provide a shield against external radiations.
- Use multiple ground planes on the stack up helping to lower impedance and reduce common mode radiation.
§ Floor Planning
This involves organizing the board into logical sections among them being component placement.
Consider where you will place all the sub-circuits in the whole design. It is important for the digital and analog signals to get the right isolation to reduce interference.
§ Know the use of the ground and power planes
The ground plane should be complete and not split with any other routed signals. Splitting the ground power planes will lead to certain interference that you did not expect.
Add a 0-ohm resistor just in case you need to split the ground power planes.
§ The size of the land patterns should be at a minimum
In this case, saving of space is very important as you will need to fit every detail on the board.
This will force you to keep the size of the patterns at minimum usually 0 to 5% of the component pin size.
The standard PCBs often requires 30% of the size of the pins making this case different.
Saving space will improve the mechanical strength, reduce parasitic capacitance, important for high frequencies.
It also gives room for differential pairs, vias, and high pin counts like ICs and FPGAs.
§ Route the signals to help in maximum shielding
To maximize shielding benefits and avoid conflicts on the board follow these guidelines:
- Keep parallel and long signals at the minimum to avoid signal crosstalk and coupling
- Keep distance between the signal traces and route signals on separate layers
- Route the signals orthogonally to one another meaning one layer will have vertical signals and the other horizontal signals.
- Provide a path for the return of current
Every signal on high-speed designs requires a route from the path all the way to sink without any form of impedance.
To ensure the success of the transmission, you will need to use vias to allow smooth flow.
Without the vias, the current might spread around the splits on the ground plane thus leading to loss of signal integrity.
To ensure on-time arrival of the signals uses tightly coupled impedance differential vias.
The return vias should also be as close to the signal vias as possible to minimize travelling distance.
PCB design and layout
Use the 3W rule that minimizes coupling between the traces
The 3W rule will guide you on the distance you need to keep between the traces of your high-speed PCB.
It states that the space between the traces should be triple the size of a single trace from centre to centre. You can increase the spacing to ten times the size of one trace to get better results.
Use the 20H rule to reduce the plane coupling
To reduce the risk of coupling between the ground and power planes, use the 20H rule on the high-speed layout.
The process of coupling between the power and ground planes may lead to fringing on the circuit. To reduce fringing, make the power plane next to the ground plane smaller.
It will lead to the absorption of the fringing planes to the ground instead of letting it cause further interference.
You will make the size of the power plane 20 times smaller than the dielectric thickness between the ground and power planes.
Finish off with the general guidelines for routing
Finishing off the process are the guidelines for routing which you need to look at keenly. The guidelines for routing the high speed printed circuit boards are:
- Avoid the 90-degree bends when working on the traces as they may lead to signal reflection
- Maintain the same gap and length between the differential pairs to enjoy the benefits of electronic field cancellation.
- Design the transmission lines carefully using stripline traces or microstrips. Microstrips provide one reference plane in separation with a dielectric.
Chapter 6: What to Pay Attention During PCB design & Layout
Many of the designers usually pay more attention to the latest components, circuits, and code as important parts.
Many of them neglect the very important parts of the printed circuit board which is the layout. Poor layouts can lead to reliability and function problems of the printed circuit board.
PCB Layout
The factors that you need to pay close attention to when designing a good layout are:
§ Sizing traces
To control resistance on the printed circuit board, designers will focus on the sizes of the traces.
This involves controlling the width, length and thickness of the copper traces to control resistance.
You can use the PCB trace calculator to determine the size of the trace for your design.
§ Make the loops smaller
You should try and make the loops very small especially if the loops are for high frequency printed circuit boards.
Small loops reduce the resistance and inductance of the printed circuit board. Placing the loop over the ground plane will reduce inductance to a greater extent
§ Decoupling capacitor placement
To increase decoupling efficiency, place the decoupling capacitors as close as possible to the ground and power pins. Increasing the distance between the capacitors will introduce stray inductance of the printed circuit board system. Many vias from the pins of the capacitor to the ground plane will reduce inductance.
§ Kelvin Connections
These are very important measurements that you will make at the exact place to deduce stray inductance and resistance.
§ Keep the noisy and digital traces away from the analog traces
Place the traces and conductors parallel and far from one another to reduce the coupling of the signals.
Keep the noisy traces away from the traces that do not need any noise interference.
§ The ground is not ground
You should route the noisy signals away from the quiet signals and remember that the ground is not a good conductor.
Make the ground traces wider to carry the flowing current and place the ground plane under signal traces. This will reduce the ideal impedance of the traces.
§ Via number and size
Use many vias to route traces from one side of the PCB to another side to reduce resistance and inductance.
When grounding high current node and filter capacitors use large vias to reduce resistance. You can use a via size calculator to know the exact size of the via you will use.
§ Use the PCB as a heat sink
Placing extra copper around the surface mount will provide more surface area to dissipate heat efficiently.
Some of the datasheets of the components have guidelines on how to use the PCB as heatsinks.
§ Thermal Vias
You can use vias to move the heat from one side of the board to another side. It is important especially when you mount the PCB on a material that dissipates heat.
Larger vias will dissipate more heat in comparison to the smaller vias.
§ Thermal relief
It is the process of making a connection between the fill or trace and any component to make the process of soldering easy. The small connection is very short and reduces any impact on resistance from electricity.
§ The distance between the traces and the mounting holes
Leave enough room between the copper fills or traces and the mounting holes to help prevent shock hazards. Solder masks are not reliable insulators so keep distance between copper and the mounting hardware.
§ Heat sensitive components
Keep the heat sensitive material away from the areas that produce a lot of heat. The sensitive components that are heat sensitive include electrolytic capacitors, and thermocouples. It will lead to life extension for the components and better working conditions for the components.
Chapter 7: PCB Design Courses – Your Ultimate Learning for PCB Design & Layout
There are many courses that you can try and learn how to design a printed circuit board. These causes are available online at your disposal.
All you need to do is log in to any of the websites and follow the instructions.
Apart from that, there are many schools that offer electrical engineering courses.
You can as well register and have training on the subject of designing printed circuit boards.
You can as well take an online course on the same subject and train on becoming a good designer.
PCB with components
The courses that are available online will guide you through specific guidelines on different forms of designs.
Apart from that, you will get complete insights into the advantages of using the different types of PCBs.
In this section, you will go through a sample of the courses on making a custom PCB from a breadboard prototype.
It is an important guideline that will take you through the process of making multiple copies of a circuit board.
It will also enable you to polish the experience you have in making printed circuit boards.
Apart from that, such courses will elevate your project to better levels of fabrication and design.
Taking your time and maximizing your concentration will lead you to a better learning experience.
It will also take you through the process of using different design software to improve your experience.
After the training and a successful design of your own, you will never regret taking the course.
Some of the Lessons you will go through in this course are:
§ PCB materials and Concepts
You will learn about the basic terminologies and concepts of making the circuit boards. You will also look at the materials and tools for making the design.
§ Preparing a Schematic
Before you indulge in making the design for the board, there are particular preparations you need to consider. This lesson will prepare you using a breadboard and take you through to the digital schematic.
§ Laying out the board
After dealing with the schematic, it will be very easy for you to come up with the circuit board. You will learn how to draw on the components, layout the different parts, and draw the traces for your circuit board.
§ Manufacturing
This lesson will take you through the process of validation and how to get a reliable manufacturer.
§ Assembling the board
The final board will be the assembly of the board and figure out if it will work well. We will also take you through troubleshooting techniques that will help you find out the problem on the design.
This is a sample of the course outline that you will meet whenever you are online studying different design concepts.
You can consider this type of learning or take other types, of course, available for you to choose from.
Apart from that, there is an allowance to have direct chats so that you can ask questions for direct answers.
Find more PCB learning resources from here:
- PCB Design Tutorial for Beginners (Video)
- Advanced PCB Layout (Video)
- Circuit Board Design Class
- Learn PCB Design Process
- PCB Design and Manufacturing
Chapter 8: FAQs on PCB Design & Layout
In case you have questions on PCB design & layout, I will walk you through some frequently asked questions and answers.
This will enlighten you on PCB design and layout – let’s dive right in:
PCB design and assembly
1)How do I get a quote for my printed circuit board design and layout?
You will get a quote when you provide a schematic and a few details about the type of design and layout you need.
There are a few questions you will need to answer so that we can have all the information right.
There might be a form you will need to fill to make the work easier and remember to include the contact details properly.
You will get your quote on the type of layout you desire within a short period of receiving your request.
2)How long will it take before I receive my quote?
In case the board is simple and require little specializations, you will get the quote within a few hours.
In case you are in a rush, you can make direct calls to the customer service and receive faster treatment. Different companies have different policies and many will work on the project as soon as you acknowledge the quote.
3)Are you going to Auto-route, my boards?
This is not a practice that we encourage within our organization as our team of experts review the designs well.
They spend their time to focus on the originality of the design and keep it within the right specs and standards.
They know how to create the product to the best quality standards that will pass the quality tests.
4)How fast can you make my layout?
Depending on the complexity of the design, the layout may take a considerable amount of time to manufacture.
We take our time to make the design that you need with the exact precision to satisfy your needs.
We promise to take the least time possible and you will not wait for long to get your product.
5)What can I do if the quote seems excessive?
Do not panic about the cost of the quote but give us a call and we will discuss the issue together.
We have been in business for a very long time and we offer the best prices for the designs.
In case of an excessive quote, we will have to review it and give you better terms.
6)How can I get a netlist?
We are available to offer such services to you depending on the type of schematic you have. We will take you through every process and show you how to complete the transaction.
7) How can I be sure that the board is ready for manufacture?
This is an issue that we will need to sort with our team of engineers and explain the manufacturing issues. We will review your board on functionality issues and reliability before giving you a feedback.
8)Do you offer any other form of engineering help?
When it comes to printed circuit boards, we are the experts, and we can help you with any problem. Just contact us and we will be ready to offer the help that you need.
9) What are some of the PCB/CAD tools I can use for a layout?
The tools you will use for a layout include:
- Cadence Allegro
- Mentor Graphics expedition
- Valor Enterprise 3000
- Custom programs
10)Do factors other than the complexity of the design affects the cost of development
There are many factors that will affect the cost of developing a printed circuit board layout.
Apart from the complexity you need to look at the size of the design, type and number of components and type and number of materials.
Certain materials are more expensive because of the quality and increase in number increases cost.
11)What is centroid data?
It is a machine that includes the X, Y, Theta, top and side of the board and the reference designators.
You can as well refer to it as the XYRS data, pick and place data, or the XY data.
12)Do you have overseas clientele and how far can you ship the products?
Due to our long-time experience in the industry, we have clients from all over the world.
We speak online so that the client can cancel the possibility of travelling.
Apart from that, we send them samples to approve before we manufacture and later ship.
13) Do you have free shipping for the products?
We might consider doing after sales services to you so that you don’t feel the burden of transporting the product.
Our rates are favorable and they include the cost of shipping to your destination.
Do not hesitate as we will bring the product all the way to the address you will provide.
14) What are some of the documents that you will need before you start the assembly of my PCB?
The documents that we will require from you are very few and easy to find.
Most of the forms we need are available online for you to access and fill. Some of the key documents you will present are:
- Assembly order type
- Assembly type
- Customer and company information
The documents have certain points that will require you to fill with the right information before submitting.
Conclusion
You have everything you need about the printed circuit board design and layout. You can make the choice of making the right designs with the guidelines available.
You can as well get more information by contacting different companies with lines open 24/7.