HDI PCB Design
With the rise of small, lightweight electronic devices in consumer products, healthcare and aerospace industries, HDI PCB design is essential. It enables smaller, lighter designs with exceptional performance.
When designing an HDI PCB, there are a few things that you must consider. These include traces and pads, vias and stackup.
Type I
HDI (high-density interconnect) PCBs are built to provide increased circuit density in a variety of applications. They are used in avionics, military, and high-speed telecommunications. These boards are also characterized by the use of advanced manufacturing technologies, such as micropore processing, to reduce the distance between components.
The main advantages of these types of boards are that they are easy to manufacture and have a lower total cost of ownership than traditional boards. They also have a longer life span, thanks to the reduced heat transfer between layers.
Several factors need to be considered when designing an HDI board. These include:
Materials: The type of materials you choose will affect your HDI design. It is best to select materials that are ultra-low loss, high speed, and suitable for your application.
These materials will help ensure your design is robust and able to withstand a variety hdi pcb design of conditions. For example, if your product is used for radiofrequency and microwave applications, you will need materials that have an extremely low loss.
Vias: The type of vias you choose will also impact your design. There are multiple via styles to choose from, including plated through hole (PLH) and blind vias. The choice of the right style for your design can have a significant impact on your PCB’s production and manufacturing costs.
Stackup: The stackup of your HDI board can have a major effect on hdi pcb design the performance of your PCB. It will determine your board’s routing efficiencies, parts placement, BGA fanout, and design rules.
A good stackup will have a minimum of two microvia layers. These should be placed on both sides of the board. This configuration can be used for many different types of HDI boards, such as stacked microvias, blind and buried vias, and plated through hole vias.
The aspect ratio of the vias should be less than 1. This value means that the diameter of the microvia is smaller than the height of the next layer that it penetrates. This helps increase your overall circuit density and decreases your production costs.
Dielectric Thickness: The thickness of your PCB’s dielectric is another important consideration when choosing a material for your HDI design. It needs to be thin enough to be delaminated in high-temperature soldering processes. It should also be able to withstand thermal shock from accelerated thermal cycles or multiple reflows.
Metalization: The final step of the HDI board fabrication process is metalization, or the placement of conductive material in and between the copper layers. This can be done through laser or a mechanical process.
The most common metals for HDI boards are FR-4, FR-4 lite, and FR-4 tin-lead. These materials are widely used for both high-frequency and microwave applications because of their low loss and excellent signal integrity.
EMI/EMC: The interference of electromagnetic radiation is one of the most important concerns when designing an HDI board. You will need to manage tight tolerances on dielectric layer thicknesses, spacings, and trace widths to ensure that the impedance does not have a negative impact on your signal.
