HDI PCB Design and Layout Guidelines
HDI PCB Design and Layout Guidelines is a set of guidelines to help you design HDI boards in the most efficient way possible. It will show you how to organise your layout for easy assembly, reduce the number of components needed, and save on costs by using high-density techniques.
HDI PCB Design and Layout Guidelines is useful for designers who want to learn more about designing with HDIs or those just starting out with designing their own board.
This article will cover some of the basic rules that should be followed when designing an HDI PCB board.
What Is HDI PCB Layout?
Designers and engineers are always looking for new ways to create equipment with more electronics in a smaller space. High-Density Interconnect (HDI) is one of these newer technologies that has allowed people to make boards while maintaining high connectivity, component density, and low signal paths or resistance on the board.
High-density interconnection technology enables designers and engineers alike who need additional room for components but want them all connected neatly together so they can communicate effectively through less complicated lines without risking any impedance.
High density interconnect (HDI) is used to reduce PCB trace widths below 8 mils in order to increase component density. This allows you to keep your board size small while increasing the number of components on it by using HDI design strategies without sacrificing quality for compatibility due to these smaller traces and spaces between them.
Not all boards require an HDI layout technique, as there are other ways towards increased circuit count that don't rely on such precise spacing. However, some types of components will need this type of treatment so they can be routed more easily within tight spaces.
Trace Sizes and Vias
A HDI board is specially made to make space for the fine-pitch components. It uses smaller vias in order to provide more room which makes it an excellent choice for a BGA component, or any other product that has a lot of small traces on one side and larger connections on the opposite side.
The HDI layout has a few features that make it stand out from other layouts. These typically include:
- Thin Traces: The thin traces on an HDI pcb board allow for higher trace density, which in turn leads to lower cost manufacturing costs because the process requires fewer layers than traditional PCBs.
- Small Vias: Micro-vias are used to create the smallest and densest boards possible. These vias go through many design changes in order to keep up with industry demands for smaller electronics, whether on a board or within an individual component.
- Lower Signal Levels: HDI boards are the perfect solution for digital circuit design that needs to avoid ESD and high temperature rise.
- Higher Layer Count: This is an area where the HDI board really shines. It's easy to count up to 20 layers of boards when you're working with high-density components like FPGAs, but this can be a ridiculously difficult thing for other types of PCBs.
HDI PCB Design Guidelines
Fine-pitch BGA and HDI layouts go hand in hand. A good layout starts with a clean schematic, especially if it's for an HDI board. The first step is to lay out all components on one side of the PCB without any traces yet connecting them together by using power or ground planes.
Next, identify which signals are needed internally within each block of functional circuits, so that these connections can be routed directly underneath those blocks when they're placed onto their own layer later on. Finally, after routing has been completed around your circuit blocks but before adding vias into this signal plane.
Manufacturer’s HDI PCB Capabilities
The HDI constraints can be a huge headache if you don't do your research beforehand and check with the manufacturer to see what they are capable of. With so many different capabilities for manufacturers, there is no one-size-fits-all solution when it comes to planning an HDI design.
While PCB design is generally more forgiving than manufacturing, there are still ways to mess up that will make it harder for a manufacturer. One of the most overlooked areas in this field is spacing between traces and pads, which matter because they affect how easy or hard your board can be manufactured.
In order to avoid solder bridging, keep track of spacing between traces and pads. This idea also applies as far as 1 mm pitch BGAs are concerned. Solder mask clearance values depend on your trace width.
Number of Layers
Keep your board simpler and less expensive by using fewer layers. Your final product will be cheaper with assembly being faster because there are more steps to finish the process of manufacturing a high layer count board.
The design of your HDI board layout has to be more precise than on a normal PCB because signal integrity is crucial for high-speed transmission. If the impedance isn't consistent, data will get corrupted and that can cause major malfunctions in sensitive equipment such as medical instrumentation or military hardware.
To ensure consistency with these standards, it's best if you carefully plan out where each trace goes beforehand before actually laying down anything else. This will ensure that nothing gets crossed over by accident later on when soldering connections together and routing cables through various parts of the circuit board.
HDI boards are an excellent way to optimize your circuit design. They can be used with many different components and in a variety of applications. To create the best board, it is important to follow the above mentioned basic rules when designing one.
Hemeixin is one of the first companies to provide HDI PCB boards and we are experts in this field. If you have any questions or want us to help with your project, contact us today.