Consumer PCB

Today we shall explore consumer PCBs.

First, you will learn the basic definition, advantages, disadvantages and applications. Second, we shall focus on the components, design and fabrication of consumer PCBs.

Thereafter, we will delve into consumer PCB prototyping and how these PCBs work. Again, you will learn about the materials for making the PCBs, followed by a deeper understanding on the types of consumer PCBs.

Finally, we’ll study the application and use of consumer PCBs.

Let’s dive right in:

What is Consumer PCB?

Printed Circuit Board (PCB) is the board base which physically supports and makes wiring of components possible.

The support is done using conductive tracks pads and other features etched from one or more sheet layers of copper.

Laptop mother board

The copper is laminated onto and/or between sheet layers of non-conductive substrate.

Components are therefore generally soldered onto the PCB to both electrically connect and mechanically fasten them to it.

The most common circuit boards are made of plastic or glass-fiber and resin composites and use copper, but a wide variety of other materials may be used.

Most PCBs are flat and rigid but flexible substrates can allow boards to fit in convoluted spaces.

Components are mounted through surface-mount, commonly known as SMD, or through–hole methods.

Printed Circuit Board is sometimes called Circuit Board, PC Board, or just abbreviated as PCB. A company manufacturing printed circuit board is called a Board House.

Advantages and Disadvantages of Consumer PCBs

Now, before you buy consumer PCB, here are a few things you should know:

Advantages of Consumer Printed Circuit Board

Consumer PCB

1.Compact Size and Saving of Wire

The copper tracks enable the PCB to harbor interconnection between the components. The copper tracks are used as an alternative to current carrying wires.

This results into a less bulky interconnection.

The components hereby are very small in size.

Without the printed circuit board, it would be impossible to connect these components together using wires.

On a distinctively printed circuit board, a platform on which the electronic components can be arranged in an efficient manner is availed.

Within the small form factors, a big and complicated electronic circuit can be created. This results into space efficiency in electronic devices.

2.Ease of Repair and Diagnostic

With consumer PCBs, it is easier to verify and substitute a particular component that has failed. In properly designed boards, the electronic components and their polarities are clearly labeled.

As such, convenience is assured during both the installation and the repair process. Signal paths can easily be traced during diagnostics of the problem.

3.No Need to Worry Over Short Circuits

The material used in the manufacture of PCBs makes short circuiting of the whole device impossible.

This implies, when one part stops working, then you are in a position to do a replacement with another exact part.

You can put in a substitute into it with a lot of ease and make it keep on ticking without worrying over all the other parts being damaged as well.

4.Time Saving

The conservative technique of circuit connections takes a long period of time to connect the components.

On the other hand, printed circuit board takes comparatively less time in the assembly process.

5.Immune to Movement

All components on a printed circuit board are tightly held on the board.

The solder flux essence prevents them from moving on the board regardless of the movements of the board itself.

6.Tight connections

Copper tracks ensure that the connections are made automatically. In this process, it is unlikely that there will be loose connections.

7.Low Electronic Noise

A properly laid out printed circuit board ensures that there is reduction in noise from the electronic. If the layout is not done properly, then there are high chances that the noise will hamper the performance of the circuit.

Electrical components on PCBs are organized in a way that the path lengths of the electrical current between them are as less as possible.

This translates into low radiation and pickup of electromagnetic waves. It means there is lower crosstalk in between components and in between varied traces which usually is a major concern in electronic circuits.

The electrical noise can be released in the form of heat, radiation, or flickering sound.

8.Low Cost

When you have high demand of circuits, then you should not look further from the printed circuit boards. Large scale production of these circuits is guaranteed at low costs. You will therefore be saving on both the cost and time factors.

Mass production is therefore guaranteed at cost friendly terms.

9.Reliability

All the above translate into reliability in how the circuit performs.

10.  Streamlined Production

PCB Prototypes can take a significant period of testing time to develop until they’re ready to be used.

This is because each issue must be individually diagnosed and addressed by hand.

Section of consumer electronic PCB

However, the automated design checks used during the engineering process alert the designer to any potential issues.

The testers therefore know what to look for. This intuitive design process means that PCBs are often ready to go into production sooner than PTP constructs.

Disadvantages of Consumer PCBs

Even as you plan to invest in consumer printed circuit boards, there are a few things that you will have to deal with.

These include:

Section of consumer electronic PCB

1.Complicated Repair Process

It is near impossible to repair a damaged printed circuit board. This gives manually made bread boards an upper hand over PCBs.

However, you won’t need to worry about this if you take utmost care of the board.

2.Fixed and specific use

A printed circuit board can only perform the function for which it is designed. It can never be programmed or updated after its production.

One should design the boards he intends to use.

3.Environmental degradation

Environmental concerns are likely to arise due to the technology and chemicals used to produce printed circuit boards.

Companies should thus produce only what can be consumed in the market to avoid further degradation. Recycling is also an effective remedy.

4.Limited Use

Since copper tracks are very thin they can only carry less current.

This implies that most PCBs can only be used in the manufacture of electronics which require less current. Heavy currents will heat up the strips and cause problems.

To avoid these heat ups, the PCBs should be restricted to electronics requiring less current.

Components of Consumer PCB

Copper traces are the skeleton of the PCB. It is backed up by the components which are the vital organs. These components PCB play different roles making the printed circuit board achieve its intended purpose.

PCB Components

Different components are needed for different circuits depending on the device. These components are a wide range of electronic parts.

The battery provides the voltage to the circuit. The resistors control flow of electric currents as it passes through them.

Color codes are accorded to them to help determine their value.

Light emitting diode lights up when currents flow through it and directs current flow in one direction. The transistor simplifies charge, while the capacitors harbor electrical charge.

The inductor has the responsibility of storing charge and regulates stops and change in current. Diode allows current to pass in one direction only thus blocking the other.

Switches allow current or block depending if they are closed or open.

Consumer PCB Design Process

PCBs functions as the backbone. In so doing, it keeps everything connected and compacted in a form that is easy to use.

PCB designs process

Circuit boards are thin, plastic, rectangular plates or polyester film. Most are blue or tan.

The most commonly used raw material for printed circuit boards is fiber glass epoxy resin with a copper foil attached on to one or both sides.

In some instances, PCBs are made from paper reinforced phonetic resin with bonded copper foil. This is mainly used because bonded copper foils are inexpensive and are a preference in household electrical devices.

Printed circuit boards can also be made of copper. Here, copper is either plated or etched away on the surface of the substrate to leave the pattern desired.

Copper circuits are coated with a layer of tin-lead, then nickel and finally gold for excellent conductivity.

Let us now have a look at the design and fabrication process for a consumer PCB.

For more on design process, here is a complete guide for you: PCB Designs and Layout: The Ultimate Guide.

Consumer PCB Fabrication

Do you wish to know how to make a consumer PCB, well, here is a simple guide you can follow:

Making the substrate for consumer PCB

PCB Substrate

Step 1: Saturation of glass fiber

From a roll, woven glass fiber is winded down into a process station where it is soaked with epoxy resin. You can do this through either dipping or spraying.

The saturated glass fiber is then passed through rollers which fabricate it to the required thickness for the finished substrate. This process further removes any excess deposits.

Step 2: Semi-Curing of glass fiber

In order to strengthen it, pass the saturated fiber glass obtained from the first step through an oven.

Flex PCB

Cut the resultant material into large panels.

Step 3: Binding of copper to substrate material

In this step, heap the panels in layers, alternating with layers of adhesive-backed copper foil. The stacks are then placed in a press.

Here, they are subjected to temperatures of about 340°F (170°C) and pressures of 1500 psi for an hour or more. This fully strengthens the resin and tightly bonds the copper foil to the surface of the substrate material.

Drilling and plating the holes

Here is what this process entails:

Step 4: Drilling of holes

Several panels of substrate are stacked on top of each other and pinned together to keep them from moving. The stacked panels are placed in a Numerical Control machine.

Drilling holes on PCB

Holes are then drilled according to the pattern determined when the boards were laid out. To remove any excess material clinging to the edges, the holes are de-burred.

Step 5: Plaiting of the holes

Coat the inside surfaces of the holes designed to provide conductive circuit from one side of the board to the other with copper.

Plating PCB holes

Non-conducting holes are plugged to keep them from being plated or are drilled after the individual boards are cut from the larger panel.

Creating the printed circuit pattern on the substrate

To create the printed circuit pattern, you can use either subtractive or additive process.

In the additive process, copper is coated on substrate’s surface in the desired pattern. The rest of the surface remains un-plated.

In the subtractive process, the entire surface of the substrate is first plated. The areas that are not part of the desired pattern are then etched away, or subtracted.

Step 6: Irradiation of photo-resist material

Here, we first degrease the foil surface of the substrate. The panels pass through a vacuum chamber where a layer of positive photo-resist material is pressed firmly onto the entire surface of the foil.

A positive photo-resist material is a polymer that has the property of becoming more soluble when exposed to ultraviolet light.

The vacuum ensures that no air bubbles are trapped between the foil and the photo-resist.

The printed circuit pattern mask is laid on top of the photo-resist and the panels are exposed to an intense ultraviolet light.

Because the mask is clear in the areas of the printed circuit pattern, the photo-resist in those areas is irradiated and becomes very soluble.

Step 7: Preparation for electroplating

After the removal of the mask, spray the surface of the panels with an alkaline developer. This will melt the irradiated photo-resist in the areas of the printed circuit pattern.

The copper foil therefore remains exposed on the surface of the substrate.

Step 8: Copper plaiting

The foil on the surface of the substrate acts as the cathode in this process.

Remember, the copper is plated in the exposed foil areas to a thickness of about 0.001-0.002 inches (0.025-0.050 mm).

Plating PCB

The areas still covered with photo-resist cannot act as a cathode, so they are not plated.

To prevent copper from oxidizing, either tin-lead or a different shielding coating is plated on top of the copper plating. This will also act as a resist for the next manufacturing step.

Step 9: Protecting the copper plating

The photo-resist is stripped from the boards with a solvent to expose the substrate’s copper foil between the plated printed circuit patterns.

The boards are sprayed with an acid solution which clears out the copper foil.

The copper plating on the printed circuit pattern is protected by the tin-lead coating and is unaffected by the acid.

Step 10: Attaching the contact fingers

Now we will attach the contact fingers to the edge of the substrate to connect with the printed circuit.

Mask off the fingers from the rest of the board and then plate them. Plating is done with three metals: first tin-lead, next nickel, and then gold.

Step 11: Fusing the tin-lead coating

The tin-lead coating on the surface of the copper printed circuit pattern is very porous and is easily oxidized.

Pass the panels through a “reflow” oven or hot oil bath, causing the tin-lead to melt, or reflow, into a shiny surface.

Sealing, stenciling, and cutting the panels

PCB Stencil

Step 12: Sealing and stenciling

Each panel is sealed with epoxy to protect the circuits from being damaged while components are being attached. Instructions and other markings are stenciled onto the boards.

Step 13: Cutting the panels

This step involves cutting the panels into individual boards and smoothing the edges.

Mounting the components

PCB is not complete without components.

PCB with components

Step 14: Chip shooting and robotic mounting

Individual boards pass through several machines which place the electronic components in their proper location in the circuit. I

f you are using surface mount technology to mount the components, the boards first pass through an automatic solder paste machine.

This machine places a dab of solder paste at each component contact point. Very small components may be placed by a “chip shooter”.

The shooter rapidly places, or shoots, the components onto the board.

Larger components may be robotically placed. Some components may be too large or odd-sized for robotic placement and must be manually placed and soldered later.

Step 15: Soldering of Components

Here, the components are soldered to the circuits. With surface mount technology, the soldering is done by passing the boards through another reflow process.

 Soldering PCB

This causes the solder paste to melt and make the connection.

Step 16: Cleaning of the residue

The flux residue from the solder is cleaned with water or solvents depending on the type of solder used.

Step 17: Packaging

Unless the printed circuit boards are going to be used immediately, they are individually packaged in protective plastic bags for storage or shipping.

Quality Control

Visual and electrical inspections are made throughout the manufacturing process to detect flaws. Some of these flaws are generated by the automated machines.

For example, components are sometimes misplaced on the board or shifted before final soldering.

PCB testing lab

Other flaws are caused by the application of too much solder paste. This can cause excess solder to flow, or bridge, across two adjacent printed circuit paths.

Heating the solder too quickly in the final reflow process can cause a “tombstone” effect. When this happens, one end of a component lifts up off the board and doesn’t make contact.

Completed boards are also tested for functional performance to ensure their output is within the desired limits.

Some boards are subjected to environmental tests to determine their performance under extremes of heat, humidity, vibration, and impact.

Consumer PCB Prototyping

PCB prototypes are used by engineers in the early design process to test the functions of a PCB-based solution.

Often, multiple runs are conducted in order to test redesigns or to even test a single function before transition into a more complex design.

Consumer PCB prototyping

Prototyping therefore assists in prediction of success and to avoid failure of the consumer PCB. In simpler terms, consumer PCB prototypes have a fast turnaround time. There is also the ability to detect flaws early.

Prototyping also provides room testing components individually. It also gives an accurate representation of standard PCB performance leading to efficient project completion.

This ultimately reduces overall costs of the project by helping the designer fix flaws sooner.

At the end of it all, there is an improved final product.

Again, here, there are important guides you should read: Prototype PCB Assembly – The Ultimate Guide and PCB Prototypes – The Ultimate Guide.

How Consumer PCBs Work

Consumer PCB allows signals and power to be routed between physical devices. This is made possible by its various components that play a number of roles.

Since a consumer PCB has to provide a platform on which interconnection of components should take place, copper tracks are used.

Just as any other electrical device, there is usually need for a battery. The currents can fluctuate from time to time.

The resistors in the consumer PCB help control the flow of electric currents. These currents are then directed in one direction by the light emitting diode.

The diode thus ensures that all currents flow in only one direction therefore blocking the others.

Color codes accorded to light emitting diode helps in determining their value. When the charge is too much, they are simplified by the transistor.

Fully assembled PCB

Capacitors harbor the electrical charge. Storage of the charge, its regulation in the Consumer PCB and the change in current is done by the inductor.

Switches on the consumer PCB allow current or block the current depending if they are open or closed.

These components therefore function effectively to meet the expectations of the designers of the consumer PCB in question. The function that the PCB is going to play determines the design.

Materials for Consumer PCB

PCBs can be made from fiberglass or resin derived from paper. Copper, solder mask and silk layers are also used.

The four layers of a PCB are hence made of substrate, copper, solder and silkscreen.

Generally, the substrate is made of fiberglass also known as FR4 where FR refers to fire retardant.

This forms the foundation of the PCB. It is the thickest layer in any PCB. It thus offers rigidity to the PCB.

PCB Material

Other materials that have been used to make the substrate include epoxy and phenolics.

Copper is the next layer which gets bonded with the help of industrial adhesive or heat. The copper used in PCB is referred to by weight and presented in ounces per square foot. In most PCBs, the copper content is 1 ounce per square foot.

Solder mask then is applied over the copper layer so that they don’t come in contact with other electrical parts. Atop the solder mask, a silkscreen layer is provided to create marks and labels for placement of various components.

Types of Consumer PCBs

In order to classify PCBs, we will look at characteristics like frequency, number of layers and the substrates used.  On this basis, let us see some of the most common types.

Turnkey PCB Assembly

· Single Sided PCBs

These are the most basic types of printed circuit boards. Just as the name suggests, they are composed of a single layer of substrate or base material.

They are coated with a thin layer of metal, such as copper which is a good conductor of electricity.

Single sided PCBs also possess a protective solder mask. This is applied atop the copper layer together with a silk screen coat.

Single sided PCBs are beneficial because of their low cost implication which is a major consideration during mass production.

They are also the most effective in production of simple circuits such as power sensors, relays and electronic toys.

·Double Sided PCBs’

In this type of PCBs, either phases of the substrate feature a metal conductive layer. Attachment of metal parts on this type of PCB can be done from one side to the other. This is made possible by the holes on the circuit board.

As a result, connection on either side by either of the two mounting schemes, namely surface mounts technology and through-hole technology is made possible.

In through-hole technology, lead components are inserted through pre-drilled holes on the circuit board. These are then soldered to the pads on the opposite sides.

The surface mount technology on the other hand involves direct placement of electrical components on the surface of the circuit boards.

This is advantageous because surface mounting allows more circuits to be attached to the board as compared to through-hole mounting.

Double sided PCBs are also utilized in a wide range of applications including mobile phone system, power monitoring, test equipment and amplifiers.

·Multi-layer PCBs

Just as the name suggests, multi layered printed circuit boards comprise more than two copper layers. Such include 4L, 6L, 8L, where the “L” denotes the number of layers.

They therefore widen the technology used in double sided PCB’s. Substrate board and insulating materials are used to demarcate the layers in this type of PCBs.

They are compact sized, and come with the advantages of heaviness and space.

One of the benefits of this type of PCB that it enables design flexibility and play an important role in high speed circuits. They are also capable of providing additional room for conductor pattern and power.

· Rigid PCBs

These are a type of PCBs whose bases are built from nonflexible material. The obvious feature in this case therefore is that their bases cannot be bent.

Due to this compactness, they ensure crafting of a wide range of multifaceted circuitry on them. They are also beneficial because, they offer effortless mending and preservation.

·Flexible PCBs

As opposed to rigid PCBs, flexible PCBs are created on a flexible base material. This type of PCBs comes in single sided, double-sided and multilayer formats. Flexibility assists in dropping the snags associated with the device assemblage.

Flexible PCBs have a fair share of advantages. Apart from reduction in overall board weight, flexible PCBs promptly save on the use of space.

Flexible PCBs also help to effectively decrease the board size. This makes it perfect for a variety of applications in which high signal trace density is needed. They are the most preferred for conditions where temperature and density are the main concern

·Rigid-Flex-PCBs

A combination of rigid and flexible circuit boards results into rigid-flex PCBs.  They are comprised of multiple layers of flexible circuits put together on a number of rigid boards.

These PCBs are accurately built to suit special uses as opposed to other general purpose PCBs. They are commonly used in medical and military applications.

The main advantage that comes with this kind of PCB is that it is light in weight and makes economical use of space.

·High-Frequency PCBs

This type of PCBs is used in frequencies ranging 500MHz to 2GHz. This makes it suitable for use in a wide range of frequency critical applications.

Examples of these include micro-strips, communication systems, microwave PCBs among others.

·Aluminum backed PCBs

These PCBs are usually utilized in high power electrical applications. This is due the fact that the aluminum construction assists in heat debauchery.

Aluminum backed PCBs are known to offer high level of rigidity and low level of thermal increase. This makes them perfect for applications having high mechanical tolerance.

The PCBs are used for LEDs and power supplies.

·High speed PCB

This is any PCB with a physical design which gives attention to features that enhance integrity of your signals.

With this design, where you are placing the traces, their proximity to signals and the nature of connected components are given a priority.

·HDI PCB

High density interconnect PCB refers to a circuit board with higher wiring density per unit area as opposed to the conventional board.

They make more room on your PCB thus resulting into efficiency and faster transmission.

·LED PCB

In this type of PCB, LED is soldered to the circuit board and features a chip that produces light when electrically connected.

·RF PCB

Radio frequency PCBs are designed to operate on signals in the megahertz to gigahertz frequency ranges.

These frequencies are important communication signals in everything from cell-phones to military radars.

·Metal Core PCB

In this kind of PCB the base of the material for the PCB is the metal.

Metals such as aluminium or copper are used to make the base. They are most commonly used for LED products.

·Thick Copper PCB

They are circuits with copper thickness of more that 4oz per square foot (ft2). These are used extensively in power electronic devices and power supply systems.

·Gold Finger PCB

Gold fingers are gold-plated columns which connect edges of PCBs. Its main purpose is to connect secondary PCB to the motherboard of a computer.

Gold is preferred because of the alloy’s superior conductivity. They therefore protect the PCB from wear and tear.

·Ceramic PCB

This is most commonly used when you are looking for substrates for electronic circuits with high thermal conductivity and low expansion co-efficient.

Application and Use of Consumer PCBs

There are many applications of consumer PCBs in various industries. These include:

·Medical devices

A number of PCBs are continuously being used in the healthcare sector. PCBs are used in devices used for diagnostic, monitoring, treatment and more. PCBs used in medical applications can be classified in different categories

CT Scan

Monitors of heart rate, blood pressure and blood glucose depend on electronic components to obtain accurate readings. Infusion pumps such as insulin and patient controlled analgesia pumps  are also made of PCBs.

Other equipments classified as pacemakers also use small PCBs to function.

·LEDs

Light-emitting diodes are popularly being used for residential and commercial lighting.

They are also used in other industries including the automotive, medical and computer technology sectors.

LED lights

LEDs are favored for their long life, efficiency and compactness. You will therefore find LED PCBs in residential lighting, storefront lighting, automotive displays, computer displays and in medical lighting.

·Consumer Electronics

Computers, smart phones and other consumer products that people use daily require PCBs to function.

These products can be classified as communication devices which include smart-watches, radios and other communication products.

Consumer electronics

Computers for both personal and business feature rely on PCBs. Other entertainment-related products such as television, stereos and video-games all rely on PCBs.

PCBs are also used in home appliances including refrigerators, microwaves and coffee makers.

·Industrial Equipment

Electronic components power much of the equipment in manufacturing and distribution centers as well as other types of industrial facilities.

These can be categorized as manufacturing equipment, which include electric drills and presses used in manufacturing.

PLC System

Another category of electronics in this sectors that use PCBs is power equipment. These include DC-to-AC power inverters, solar power cogeneration equipment and more.

Measuring equipment also rely on PCBs. These are equipment that measure and control pressure and temperature.

·Automotive Components

A number of electronic components are today used in manufacture of vehicles. Earlier, only windshield wipers and headlight switches used PCBs.

Car dashboard

Today PCBs are used in different automotive components including entertainment and navigation systems.

They include stereos and system integrated navigations. Sensors and control systems in the automotives also use PCB.

·Aerospace Components

Electronics used in aerospace applications have similar requirements to those used in automotive sector though they work under tougher conditions.

PCBs are used in various aerospace equipment including planes, space shuttles, satellites and radio communication systems.

Boeing cockpit

Power supplies to control towers, satellites and other systems use PCBs.

PCBs are also used in monitoring equipment such as accelerometers and pressure sensors. Yet another area of PCB application is communication equipment which is vital for safe air travel.

·Maritime Applications

All maritime vessels and systems rely on PCBs to function appropriately.

Regardless of whether they are large cargo ships, submarines, small vessels, communication system and navigation equipment, they all rely on PCBs.

Ship control room

Areas where PCB s are used in this sector include navigation systems, communication systems, and control systems.

·Safety and Security Equipment

Most of the aspects of security systems for businesses, homes and government buildings rely heavily on PCBs. They are an integral part of our security.

Here, PCBs are used in Security cameras and equipment used to monitor security footage, Smoke detectors, carbon monoxide detectors.

·Telecommunications Equipment

PCBs are a critical part of the telecommunication industry. They are necessary for devices such as smart phones but also for the infrastructure that enables those devices to work.

Telecom equipments such as telecom towers, office communications equipment and LED displays and indicators requires PCBs

Military and Defense Applications

The military uses PCBs for a wide range of applications. For communication, PCBs are used by the military in radio communication systems.

 Anti-aircraft missile system

For control systems, the military uses PCBs in a various types of equipment including radar jamming systems and missile detection systems.

PCBs are also used by the military to monitor threats, to conduct military operations and to operate equipment.

Conclusion

Consumer PCBs have become an inevitable part of every sector. In fact, PCBs are the drivers of most of what is called technology today.

Due to the availability of the different types of PCBs and the different fabrication and assembly methods, there are now very small, yet so effective devices and appliances.

The production of different PCB types such as the flex and rigid flex has made it easier to use the PCBs in areas such as the aerospace industry.