HDI PCB Design-Create the Most Suitable for Your Needs

You know enough about printed circuit boards to be certain HDI PCB is the right choice for your application.

It is important to emphasize that your search for an ideal printed circuit board doesn’t end there. You will want to choose the right materials and make crucial design and manufacturing decisions to create an ideal high-density PCB.

If you want to know more about how to create the most suitable HDI board for your needs, take a look at our detailed guide below!

1、Why HDI PCB Is the Right Choice for Your Application

A high-density printed circuit board's basic principle is to ensure maximum performance while keeping the size as compact as possible. In other words, the idea is to fit the preferred components in as little space as you can while keeping the quality and performance of the board at their maximum.

Those are the critical advantages of high-density PCBs and why people choose them over standard units.

Here is a brief overview of the benefits that come with choosing HDI boards:

• Uncompromised and extremely stable performance

• Reduced size and compact design that makes it more fitting for small-sized products

• Overall optimization of costs and confirmation you will get the most value for your money

Image 1: A person holding a PCB chip assembly

2、Where Can You Use HDI PCBs?

Image 2: A close up of circuit boards in a tray

Most people consider HDI boards to be a step forward compared to the ordinary units. Their compact size and enhanced performance make them extremely versatile and suitable for many industries. These are only some suggestions on where you can use a high-density PCB, but don’t hesitate to be creative with its use:

• Smartphones–thanks to thin HDI boards, we can use thin smartphones today. However, phones are only a portion of electronic products that use PCBs as tablets, and other devices also use them.

• Smartwatches – if you are wearing an Apple Watch or Samsung Gear smartwatch, the chances are you have a printed circuit board on your hand. Additionally, you can find an HDI PCB in VR headsets and other wearable technology.

• Healthcare – you probably heard of a pacemaker, a small life-saving device that utilizes PCBs. You can also find HDI boards in miniature cameras that can observe the patient’s organs from the inside and other products.

Apart from these industries, you can also find HDI boards in the automotive, aerospace, military industry, etc. You can check this video to learn more about how PCBs work.

3、HDI PCB Design – Overview

Image 3: A group of electronic printed circuit boards

Before you start designing the HDI PCB, you should know that the process can be rather complex. That is why it is vital to know what you are doing or trust a professional with your needs.

The core idea of the HDI PCB design is to prepare everything for manufacturing. During the process, it is essential to foresee the potential problems that may appear during assembly. You want to design your board in a way that the machines can produce. The goal is to put in extra effort and minimize the potential risk of making changes during the manufacturing process.

The industry experts suggest a line width/space to be at least 100um to ensure optimal stability. The manufacturers will use plasma and laser drilling during the process and dielectrics that are photo-imageable, which should help make blind vias. Thanks to that, it will be possible to achieve the desired density of the board.

When it comes to your concerns, you probably have the desired board size in mind and preferences when it comes to performance. All these are important to mention to the expert who is working on the design on your board. The PCB should fit into the planned space for it on your product and perform up to the expectations to ensure the item’s optimal longevity.

4、Additional Tips for Designing an HDI PCB

Image 4: PCB component soldering

Here are some extra tips that you can use during the process of designing and manufacturing a high-density HDI printed circuit board:

• Use as little components as possible – it is extremely important to add each component to the board for a reason. Carefully choosing the components to include will reduce the size and weight of the board and decrease your overall cost and delivery time.

• Pick the right via types – you can choose between buried or blind micro vias, or go with a via-in-pad approach. The latter may make the process more complex and increase the costs, so make sure you have a good reason if you use it.

• Use small trace widths – this is another benefit that comes from using HDI PCBs. Thanks to minimal trace widths, you can reduce the boards' size and minimize the integrity issues of the signal.

5、Crucial Considerations in HDI PCB Manufacturing

Image 5: PCB manufacturing factory

Now that you know the basics of PCB design let's discuss the manufacturing process of these boards. It would help if you keep several factors in mind when it comes to interconnecting PCBs high-density, and we are listing them below.

1.1.Aperture

The overall definition of the aperture is that it is an opening or hole where light should pass. When it comes to manufacturing HDI boards, we consider the aperture ratio one of the crucial parameters.

It would help if you kept this ratio in mind while designing the blind and through holes. If you use an old-fashioned mechanical driller, keep the aperture at approximately 0.15mm, but make sure that the board's overall thickness and the aperture ratio is 8:1 or more.

On the other hand, if you use a laser driller, you should use a different approach. In that case, the opening's aperture should be at least 3mm, but no more than 6mm. At the same time, keep the aperture ratio level at about 1:1.

1.2.PCB Stack Up

The next thing to consider is the process of stacking up your board. While doing this, you should take care of various factors, including but not limited to pressure and temperature. You want to distribute the stress equally throughout the board, which is why you should consider the asymmetric design.

However, a non-symmetric design is also possible, but an experienced designer must be handling the job. That way, you will avoid any problems during the manufacturing process and ensure that your board is working flawlessly.

1.3.Process Flow

It is interesting to note that high-density boards are not that different from standard ones when processing flow. For example, if you have a high-density PCB with six layers and a couple of stacks, the only difference compared to a standard unit will be the sequence of drilling holes.

Those who use a laser driller will make blind holes in the boards with extreme temperatures that sever to melt the hole's walls. If you use a two-layer HDI board, you should consider plating and filling blind holes. However, keep in mind that the process can be costly.

6、What Is the Right Material for Your PCB?

Image 6: A close up of an electronic PCB

It is needless to say that the preferred material selection for your application will depend on multiple factors. Some of them include:

• The desired application – some materials may be more suitable for specific applications than others, which is why you should keep in mind how you plan to use the board.

• Quality and durability - you only want to use high-quality materials. Because they ensure that your PCB works flawlessly and ensure that it has the most extended life.

• Budget – it is only natural to consider the budget for your board and the project overall. However, keep in mind that it is important to save, but it is also vital to secure the optimal performance of your HDI PCB.

As for the materials that you can use, the industry experts advise going with dielectric components. You can choose the desired speed and loss level, depending on your application. Some of the suggested material choices include FR4, fiberglass, metal, etc.

7、Why You Should Choose OurPCB to Design Your HDI PCB

Image 7: White Solder Mask

Here is an overview of some requests that users have from a PCB manufacturer:

• Superb quality – the users' primary demand is usually to design a top-quality printed circuit board. That involves using premium materials and manufacturing techniques that guarantee extended durability and reliable performance.

• Optimal cost – on top of adequate performance, the companies should ensure affordable prices. The idea is to secure maximum value for the user’s investment.

• Quick delivery time – most clients are looking forward to seeing their HDI PCBs in action as soon as possible. That is why the manufacturers should ensure to deliver the boards in the shortest possible timeframe.

• Someone to ask any question a user might have – the chances are you have a dilemma or two regarding your PCB's manufacturing process. Conclusion: that is why a company should have experts ready to provide insightful answers and help make the right choice for your application.

If you are looking for a company that meets all the above criteria, you should contact OurPCB. The manufacturer has years of experience in assembling various board types for its customers. Regardless of the task's complexity, they will be on your side throughout the entire process and ensure to deliver the boards quickly while ensuring excellent performance and reliability.

8、Conclusion

We hope that you learned everything regarding how to create the most suitable HDI PCB for your needs. As you could see, some considerations depend on your desired applications.

However, the general rule of designing reliable and durable boards you can trust for a long time remains. That is why it is important to pick a trustworthy manufacturer. It is the right way to ensure that you will receive an HDI board that will perform impeccably regardless of how you plan to use it!