Microvias achieved High-Density Interconnection What is Microvia?
A Blind structure with a maximum aspect ratio of 1:1, terminating on a target land with a total depth of no more than 0.25mm measured from the structure’s capture land foil to the target land named Microvia .
The Role of Microvias
●Space saving on PCB
●Faster signal transfer
●Low resistance and capacitance
●Reduced weight of final PCB
Mircovias Types we can support
Tree Types Of HDI PCB structures
In IPC-2226, the structure of HDI is defined by type, and there are three types, as following
●Type 1 :It for Single layer,the Mircrovias in one side or both sides of the core.it used Microvias and the PTH Hole for interconnection.This structure only uses for blind holes .
●Type 2:Same as Type 1 ,Microvias local in one or both sides ,but for interconnection It uses blind holes and buried holes.
●Type 3 :This type with high demanding for factoriers ,because it the most complex .there are contain at least two layers of microvia on one or both sides of the core .it uses blind holes, buried vias, through holes.
Venture can provide professional technology and large-scale HDI PCB products.
HDI PCB Material Requirements
There are three typical material for HDI PCS is Resin-coated-copper(RCC),cost Polyimide film, Polyimide Metallized film and Pure polyimide film.
The Features of HDI material include:
With the development of HDI technology, HDI PCB materials have to meet more requirements.Venture can provide HDI PCB materials with high heat resistance, good flatness, high dielectric constant, low dielectric loss, low coefficient of thermal expansion, high welding stability.
Your Valuable HDI PCB Manufacturer And Supplier
HDI PCB (High-density interconnect printed circuit board)is a fast growing part of the PCB industry, nowadays our devices are getting more and more portable, at the same time components inside are getting smaller and more lightweight, but providing better performance, all these requirements are needed to be functional into a smaller area, this is just what an HDI PCB can offer.
16L M6 3 Step HDI PCB(PANASONIC MEGTRON 6R-5775M)
HDI PCBs have higher circuitry density per unit than traditional PCBs. HDI PCB uses a combination of buried vias and blind vias, as well as micro vias, with our state-of-the-art laser drilling machine( Mitsubishi), laser direct imaging ( LDI), we are able to provide you fast delivery services for HDI PCB prototypes.
16L 3 Step HDI PCB FPGA 2
In the past, computers used to fill up an entire room, but now, with HDI technology, You can find HDI boards in laptops, cellphones, and watches, as well as other portable consumer electronics such as digital cameras and GPS devices. HDI PCBs had played an important role in providing us with a more efficient life.
Venture has been manufacturing HDI PCB boards for more than 10 years, below table is our HDI PCB capabilities.
HDI PCB Feature
|layers counts||4 – 30 layers|
|HDI builds||1+N+1, 2+N+2, 3+N+3,4+N+4, any layer in R&D|
|Materials||FR4, Halogen free FR4, Rogers|
|Copper weights (finished)||18μm – 70μm|
|Minimum track and gap||0.075mm / 0.075mm|
|PCB thickness||0.40mm – 3.20mm|
|Maximum dimensions||610mm x 450mm|
|Surface finishes available||OSP, Immersion Gold(ENIG), Immersion tin, Immersion silver, Electrolytic gold, Gold fingers|
|Minimum mechanical drill||0.15mm|
|Minimum laser drill||0.1mm advanced|
We’re happy to share everything we know from our 10 years experiences, as trusted by thousands of electronic engineers all around the world through our100% quality guaranteed policy. With our 2 hours rapid response services from our 24/7 sales and tech support team and excellent after-sales service, we will be your valued HDI PCB supplier in China. At Venture we can answer any HDI PCB questions that you may have, pls feel free to contact us anytime.
Your Valuable HDI PCB Manufacturer And Supplier
HDI PCB: The Ultimate Guide
Do you want small scale or mass fabrication of HDI PCB?
Here is the right guide you’ve been looking for.
It covers both basic and advanced aspects about HDI printed circuit boards, from definition, design, benefits, design, applications, and many more.
By the end of this guide, you’ll be an expert in the HDI PCBs.
Take a look.
Chapter 1: What is an HDI PCB?
What do we mean when we are talking of HDI PCB?
What is HDI PCB definition?
In basic terms, HDI PCB stands for High-Density Interconnector Printed Circuit Board.
Their main characteristic?
The boards have high wiring density per unit surface area.
HDI Printed circuit board
When using these PCBs, you will notice that they have fine lines and spaces, capture pads, minor vias, and high connection pad density.
These serve the function of facilitating the electrical performance as well as minimizing the size and weight of the application.
The effectiveness of these boards serves as an alternative to the use of high- layer laminated boards which are expensive.
As we shall see later on, the characteristics of these boards such as lightweight, high electrical speed and frequency are what makes it ideal for several applications.
Chapter 2: Benefits of an HDI PCB
Using HDI Printed Circuit Boards in your application comes with a wide variety of advantages. These advantages are what makes various manufacturers use these HDI PCB.
But what are these benefits that you will experience when using HDI PCB?
Well, here is a look at these benefits.
HDI with reduced heat transfer
·Reduced heat transfer
One of the benefits of having an HDI PCB is that there will be a minimal transfer of heat. This is because heat travels for a short distance before escaping the HDI PCB.
The design of the HDI PCB enables it to go through a high thermal expansion which in turn increases the lifespan of the PCB.
Thermal expansion on circuit boards
·Managing thermal conductivity
The availability of vias helps the HDI PCB to transmit current between the components. You can fill the vias with either conductive or non- conductive materials.
You can also improve the functionality of the HDI PCB by placing the blind vias and via- in- pad components together.
Reducing the transmission distance between the components reduces the transmission times as well as the crossing delays.
The result of this is a strong signal for your HDI PCB.
·Smaller form factors
HDI PCB is the ideal PCBs when it comes to saving space. You can quickly minimize the number of layers when designing your HDI PCB.
For instance, you can easily replace a PCB that has 8- layer through hole with a 4-layer HDI that has via- in- pad solution.
Different layers of HDI PCB
By doing so, you end up with a smaller PCB that has vias which are somehow visible to a person and one that increases performance.
·Minimal power usage
One of the benefits of having an HDI PCB is that it will consume less of the battery power. This is due to the technology used in the manufacturing process.
Such technology includes keeping the electrical components together which minimizes loss of energy.
The effect of this is that there is an extension of the lifespan of your battery.
The use of vias instead of through holes also makes HDI PCB ideal at reducing power usage.
·Incorporation of components
Since you can minimize the space on the PCB for the components, you can incorporate as many details as you may want on the board.
Also, you can reduce or increase the number of layers depending on the design of your PCB.
The other consideration that you can use to incorporate the components is by populating both sides of the boards. This, of course, will depend on the design as well as the application of your HDI PCB.
By using HDI PCB, you can have different designs for your application. HDI PCB comes in different types that you can choose for your application.
Unique design of HDI PCB
For instance, you can have flexible, rigid or a combination of the two for your application. Later on, in this guide, we will discuss each of these types of HDI PCB that you can select when designing your PCB.
Chapter 3: HDI PCB Manufacturing Process
Manufacturing HDI PCBs is one of the most straightforward processes that you can quickly learn.
Even though there are a few technical steps that you will encounter, you can counter them by understanding all the requirements.
Here are the steps that you need to follow when manufacturing HDI PCB.
1.HDI PCB Designs and Layout
There are various designs and layouts that you can have for your HDI PCB.
However, there are several considerations that you have to check when selecting the PCB design and layout which will fit on your application.
PCB design and layout
First, you have to check on the size of your application. This is in terms of dimensions to ensure that all the angles fit perfectly fine.
The other consideration that you need to check is the environment that your HDI PCB will operate in.
This is essential to determine which materials you are going to use especially if the environment is of high temperature.
Lastly, most HDI PCBs don’t consume a lot of electricity.
You, therefore, need to check on the energy output requirement levels for your application to ensure that you design the correct HDI PCB.
1.HDI PCB Fabrication Process
The following are the steps that you can follow when fabricating your HDI PCB.
HDI PCB Fabrication
·Design and output
The first step in the manufacturing of your HDI PCB is to come up with a plan that will fit your application. Various software exists that you can use to design your HDI PCB.
You are identifying which software will inform your manufacture of the production procedure to use.
You, therefore, need to inform your manufacturer of the software that you will be using.
·Checking on the signal frequency that your HDI PCB requires
The next step involves identifying the correct power and voltage needs of the various electrical components on the board.
This includes checking if you can accommodate trace length and controlled impedance on the board.
Checking signal frequency
Your manufacturer will come in handy here to ensure that you accurately know what they have as the minimum tolerance needs for the PCB.
At the same time, ensure that you have a plan on how you will minimize noise coming from the HDI PB.
·Documenting the board stack up a plan for manufacturing purposes
In this step, you will need to keep a record of all that you will require for stacking up plan. Again, in this step, a manufacturer will be of help in determining the specifications for your HDI PCB.
Among the details to check includes the type of material to use and the constraints specified for your HDI PCB.
You can either have FR-4, Nelco or Rodgers types of material for your HDI PCB.
Rodgers PCB Material
Other strategies that you can have for the stacking up plan includes the use of a signal layer. This you can place side by side to the adjacent layer which will offer an efficient return path for the signals.
Another option that you can have is to route the high- frequency signals present on the inner layers of the HDI PCB between the planes.
The importance of this is to protect against any radiation that the signals emitted externally.
On your stack up, you can have ground planes. This is important as it reduces the reference hinderance which then minimizes the radiation effect on the circuit.
The crucial step of your HDI PCB manufacturing process. Here, you will have to partition your PCB into logical parts.
Among the consideration to note when you are partitioning is if you are going to place all the subcircuits separately or into a larger design.
This step is essential, especially when dealing with analog and digital sections which need isolation to reduce interference. Also, you need to identify the direction of the circuit.
·Understanding the ground and power planes
This step involves understanding the details of your HDI PCB. You will have to identify and understand the ground plane and check if it is complete.
The routed signal should not divide your ground plane. Division on the ground plane will force you to rotate the void available which may affect the EMI as well as the signal timings.
In case it is a must that you divide the ground plane, you need to include a resistor on the signal trace. The function of this is to facilitate the signal by creating a bridge so that there can be the facilitation of the return path.
·Check on the size of the land patterns
You need to ensure that you have the correct land pattern for your PCB. The right size requires to provide accommodation of all the components to function correctly.
Generally, the size of your PCB pad needs to be around 30% the size of the component pins. The advantage of this is that it will offer mechanical strength to your PCB while minimizing the parasitic capacitance.
·Routing high-frequency signals
By routing high-frequency signals, you will maximize the shielding effect of your HDI PCB. High-frequency signals emit high levels of radiations while moving from the source.
This radiation can interfere with two different signals. There are two ways that you can route the frequency signals to avoid this interference.
One is that you can reduce the long and parallel signals which will minimize coupling of the signals. The second option is increasing the distance of the traces of the signals.
Alternatively, if they are noisy, you can route the signal to a different layer. Routing of the frequency signals on different layers must be orthogonal to each other.
For instance, on a signal layer, you can include traces that are either vertical or horizontal.
·Ensure you have an efficient return path
You need to ensure that every signal has a route originating from the source and ending at the sing via the path. The path needs to have a minimum of obstruction.
The use if via might be necessary for certain situations to ensure that there is a smooth path. The via minimizes chances of the current spreading over the splits that are on your PCB.
This can lead to loss of quality of the signal. If you use the via for reversing the current to the source, ensure you have tight coupling.
Tight coupling ensures the timely arrival of the signals. You can place the reverse via near the signal via to minimize the distance the signal needs to travel.
·Use the 3W rule to minimize trace coupling
Line coupling can affect the quality of signal transmission. However, you can prevent this by using a 3W valve.
This rule states that the distance of separation between traces should be thrice the width of one single trace measured from end to end. This rule increases the distance between the traces which in turn minimizes the coupling effect.
To increase the gains of reducing line coupling, you need to increase the separation distance to ten from three.
·Use 20H rule to minimize coupling of the plane
Coupling happens between the ground plane and the power which poses a risk to your HDI PCB. The coupling allows for the absorption of fringe to the ground plane instead of radiating out externally.
The 20H rule indicates that you should ensure that the thickness of the dielectric between the adjacent power plane and the ground is 20 times thicker than the power plan.
·Check the routing guidelines
Lastly, you need to ensure that you have followed the routing guidelines for your HDI PCB. To start with, avoid the use of the 90- degree bends on the traces because they can bring about the single reflections of the frequencies.
Also, check to ensure you have all the signals from the different pairs being of the same signal and gap. The advantage of this is that it will increase the cancellation of the electromagnetic field.
Lastly, as you design your transmission lines, ensure that you use microstrip traces. The purpose of these traces is to offer a single reference plane which is separated using a dielectric.
Chapter 4: HDI PCB Working Principle
Understanding how an HDI PCB works can be a bit hectic for beginners. All one can see are green shapes and tons of different parts assembled.
However, if you are keen, it is easy to understand how this board functions. Let me simplify this for you. To start, when you are viewing the board, you need to look at it from the perspective of a city. Another way of looking at it is to take a flight and look down.
HDI PCB design
All that you can see is a well-organized city which is different to when you are walking on the streets. You can view roads, buildings, people and vehicles which all interact to form a city.
Now translate that perspective to the HDI PCBs. These PCBs are a complete system with components that interact in a harmonized way.
Let’s use the analogy of the city and its components to see how the PCB functions.
·Talk of HDI PCB Traces (Let’s Equate this to Roads and Cars)
When you look at the PCB, you will observe that there are lines which run on the entire board while connecting different components. Just like roads in which cars move around, there are electrons which run along these lines transferring power from one element to another.
PCB Traces – Photo courtesy: Macro Fab
These lines are made of copper, and they are known as traces when we are talking of HDI PCBs.
·Integrated Circuits (Let’s Equate this to Downtown)
In a city, the downtown area is that section where a lot of activities take place. Here, you have all sorts of businesses from big offices to small businesses and even markets.
Downtown also exists when we are talking of PCBs. Here, they are the square black shapes that are on the PCB. They are called Integrated Circuits.
During fire calculation activities, it is here where all the work takes place.
·Components on HDI PCB
The design of HDI PCB is such that you will fix various components on the board.
Normally, the nature of the components will depend on the main application of function of the DDI PCB.
For example, you can have:
- Capacitors, etc.
HDI PCB with components – Photo courtesy: JPS
·HDI PCB Pads
These are areas on the HDI PCB, where you can solder components on the board.
Or, you can talk of it as a section that support components on the PCB.
It looks like this:
PCB Pads – Photo courtesy: Electro Soft Engineering
·Silkscreen on HDI PCB
They are all the white or at times gold paintings that you will see on the PCB.
They are known as the silkscreen.
They serve the function of directing the people who are fixing or assembling the PCB to know which part is for a particular location.
In most cases, they are on the component side, and have vital information such as component interface, identifiers, settings, etc.
These are holes that allow for interconnecting various section of the PCB or components.
For instance, vias allows you to connect various layers of the PCB.
Besides, you can join pads or traces.
It looks like this:
Different kinds of vias
Chapter 5: Types of HDI PCB
There are different types of HDI PCBs available in the market. These HDI PCBs though different in terms of designs, they all serve the same function.
However, the choice of which type of HDI PCB that you select will depend on your application.
So, what are these types?
Here is the answer to this question
Different kinds of HDI PCB
1)Flex HDI PCB
The composition of this kind of HDI PCB is a flexible plastic. It is this material that allows the board to shape into different shapes which is advantageous to when you compare to the rigid boards.
The flexibility of the board allows you to bend or move easily during application process without damaging the circuits which are on the board.
The only disadvantage you have with this type of board is that it is expensive to design and manufacture. However, they have numerous advantages.
For instance, you can replace the heavy wiring available in advanced equipment such satellites with these PCBs. The fact that they utilize little space and are lighter makes them ideal for such use.
The other advantage you have with this board is that it comes in different designs such as double-sided, single-sided or multilayer designs.
2)Rigid HDI PCB
The difference with this type of HDI PCB is that in addition to the number of sides and layers that it has, you can have it in different rigidities. Rigid HDI PCB constitutes a rigid but solid substrate material like fiberglass.
Such a material prevents the HDI board from bending. However, when mentioning these PCBs, most consumers tend to think they are the circuit boards.
An example of a typical application of this HDI PCB is the tower on most of the desktop.
3)Rigid- Flex HDI PCB
Rigid-flex HDI PCB combines both stiff and flex circuit HDI board technology. The rigid-flex HDI PCB consists of a circuit board that is rigid that attaches to a circuit board that is flexible.
The complexity of the design depends on your application.
4)Multilayer HDI PCB
Multilayer HDI PCB incorporates the advanced technology of the double-sided board. These boards have multiple layers of substrate boards with insulating material separating each of these layers.
Just like double- sided HDI PCBs, you can either use through holes or vias to connect the electrical circuits in the board.
The advantage you have by using a multilayer HDI PCB is that it consumes less space than a double-sided HDI board.
The most common types of Multilayer HDI PCB include ones that have 4, 6,8 or even ten layers. However, you can have a multilayer HDI PCB with more layers as per your specification.
The standard applications that utilize this type of HDI boards include servers, medical machinery, computers, and handheld devices.
5)Double-Sided HDI PCB
Double-sided HDI PCBs have the characteristics of having electrically conductive metal layers on both sides. Also, attachment of the conductive components and circuits are on both sides.
By having holes on both sides, electrical circuits on one side connected to electrical circuits on the opposite side of the HDI PCB. There are two methods through which the electrical circuits can connect.
You can connect by using ether surface mount technology or through-hole technology. Through- hole technology entails feeding tiny wires also known as leads through the holes.
You then solder each of these holes to the relevant circuit or component. On the other hand, surface technology excludes the use of wires.
Instead, you solder the leads directly onto the HDI PCB.
Surface technology gives you the freedom of using more circuits even when you have a small space on the HDI PCB.
The implication of this is that the HDI PCB can perform many functions at a lesser weight and a faster speed than through-hole boards.
6)Single- Sided HDI PCB
The main characteristics of this HDI PCB are that it has only one layer of the base material or substrate. A thin layer of metal which is usually copper covers one side of the board.
The use of copper is mainly due to it being an excellent conductor of electricity.
On top of the metal, you will have a protective solder mask, and then you can have a silkscreen coat on top of the protective solder mask.
The purpose of the silkscreen is to label the parts of the HDI PCB. Single- sided HDI PCBs usually have electronic circuits and components on one side of the board.
You can conveniently use this board for simple electronic applications. You can easily design and manufacture this PCB at home since it is less costly and complicated.
However, since they are common in basic applications, it is rare to find these boards in large scale use.
Chapter 6: Definition of HDI PCB terms
There are various terms that you will encounter while handling HDI PCBs.
Some of these terms may appear difficult to understand at first, but in due process, you will find them comfortable.
Let me take you through these terms so that you can be in a position to understand them.
The buried via refers to a connection between two or more inner layers of the PCB. However, this via does not pass through the outer layer of the PCB.
There are several advantages that you can have when selecting a buried via for your PCB your application.
First, it allows you to perform more functions on the board on a little space since the vias don’t pass through the outer layer.
Secondly, buried vias is a cost-effective method of designing your HDI board. Actually, a lot of manufacturers prefer the use of buried vias when manufacturing the HDI PCB.
Micro-via is the minute holes that a laser drill on the HDI PCB.
These holes are essential in generating an electrical link between the layers of a multilayer HDI PCB.
Once the laser drills these holes, you can fill them with different types of materials depending on the design of your HDI PCB.
For instance, you can use epoxy resin, conductive and non- conductive material or electroplated copper.
The use of micro- via can lead to an increase in the component design of your HDI PCB. However, the reliability structure of the HDI PCB is the main limitation of the application of micro- vias.
A blind via is a connection between the outer layer of the PCB and one or more inner layers. However, this connection does not pass through the whole board.
In basic terms, via will consists of a barrel, a pad, and an anti-pad. While drilling the blind via, you will have to put into consideration several factors.
First, you have to check on the depth that you want the via to have.
Also, you need to check on the quality of the plating of the PCB.
Lastly, you need to select which build up plan you are going to use when drilling the vias.
· SBU (Sequential Build-Up)
This is a technology whose use is common in the manufacturing of HDI PCBs.
It consists of subsequent building up of multilayer boards having a minimum of 2 pressing steps.
What happens is that you can add several layers in sequence to a board that already has multiple layers.
While using this technology, blind and buried vias play an essential role in the combining of layers to the board.
There are several advantages that you can have by using sequential build-up technology on your HDI PCB.
They include cost-effective benefits, the ability to add more components on the board as well as using little space on the board.
Chapter 7: Applications of an HDI PCB
Having come all this way, you might be wondering where to apply these crucial pieces of boards.
The truth is there is a vast area of application that you can use HDI PCBs.
This ranges from basic applications to complex ones. Here are some of the applications that you can use HDI PCBs.
Consumer electronics refers to the basic devices that you will find very many people using.
They include laptops, computers and smartphones, entertainment systems, home appliances as well as recording devices.
Due to the nature of some of these gadgets, there is a need to have PCBs that are lighter. These boards need to carry still the same electrical components maintaining their flexibility.
Since HDI PCBs meet these qualities, they are commonly used by different manufacturers to produce these gadgets.
However, manufacturers need to adhere strictly to the regulations in place.
This avoids situations where they come up with different designs that affect the quality of the devices.
· Medical equipment
Electronics play a significant role in the well being of our health. However, the PCB components of this equipment that are always understated.
There is a high specialization of the PCBs that are in the medical industry to ensure that they meet the standards.
This includes having a small size of these HDI PCBs incorporate all the details that will be useful.
Also, they must adhere to the health standards set to ensure the safety of the patients. There are several devices that you will find HDI PCB important.
They include monitors, scanners, internal devices such as heart pacemakers, control systems as well as scientific instruments.
HDI PCBs are standard in high- powered industrial applications due to their nature of consuming less energy while ensuring maximum output.
Also, they can withstand the harsh environment in which they are as they perform their functions.
Industrial automation system
Most of the HDI PCBs incorporate thick copper on the boards which aid in faster battery charging and high current application. You can find these PCBs in a variety of industrial applications.
They include industrial equipment such as electric drills, measuring equipment that is used to measure pressure and temperature.
Also, they are present in power equipment such as solar power panels and generators.
Automotive is the other area of application where you can find HDI PCBs in use. Most automotive rely on electronic parts to function correctly.
You can apply a combination of HDI PCBs and a few other technologies like high-frequency signals present in RF to sensor applications which are common in automotive.
Other technologies such as radar technology are also finding their way in the automobile industry. All these technologies depend on HDI PCBs to function.
Among the common applications include car control systems such as engine management systems. Others applications include navigation devices, audio, and video devices and surrounding motors.
The durability and precision that HDI offers make them an ideal in most aerospace applications. The harsh and turbulent environment that airplanes and jets go through require equipment that can stand such stress.
To find a solution for this, most airplanes use flexible HDI PCBs which are small in size while being light in weight.
They are also resistant to the vibration effect.
These HDIs need to meet certain standards to be used in the aerospace industry since the safety of the airplanes relies on them.
Among the common applications include monitoring equipment such as accelerometers and pressure sensors.
Also, you can find them in testing equipment which collects information during flight testing.
HDI PCBs have everyday use in a wide range of LED applications. LED are increasingly becoming popular due to the change in technology.
The advantage of these lights is that they consume less power and are highly efficient. At the core of LED, you will find HDI PCBs.
LED Street lights
The features that make these lights stand out to include the HDI PCB using little space; hence they will be small in size. Also, the fact that the components are close together means that less energy is lost to the surrounding thus ensuring maximum output.
LED are common in a wide range of industries. They include automotive lights, home lights as well as in medical theatres.
In summary, I hope I was able to address all your concerns about HDI PCBs. Of importance when selecting an HDI PCB for your application is to check on the specifications.
Specifications that you can check on include the materials that you are using and the design of your HDI PCB.
Also, there are various manufacturers of HDI PCB in the market. However, not all of them are genuine. As such, always ensure that you check on the details of the manufacturer before engaging them to manufacturer your HDI PCB.
Actually, you can avoid all the speculation by engaging us to manufacturer your HDI PCB. We assure you of our quality and timelines in manufacturing your HDI PCB.