filled vias affect the overall performance of PCBs

Vias are the connection points between layers of a printed circuit board and allow for electrical signals to flow through the PCB. However, a via’s performance depends on the type of via fill that is used during the fabrication process. Conductive and non-conductive via fills are available, each with their own benefits and costs. In the past, some PCB designers have incorrectly specified the via type and this has impacted the overall performance of their boards. It is important to clearly state your via requirements so that you get the best possible performance out of your board.

The types of vias available are plated through holes and buried filled vias. Platted through holes are the most common type of via and support two kinds of components – passive and active. Active components, like transistors, ICs and diodes, require an external power source to operate. These components can modify or intensify electrical signals. They are typically used in amplification, switching and signal processing.

In contrast, passive components, such as resistors and capacitors, do not require an external power supply to operate. These components are often located on the surface of a PCB. They can be surrounded by other components or be sandwiched between layers of the board.

Plated through holes are typically filled with conductive copper or a conductive epoxy resin. Conductive via fills allow effective transfer of electrical signals and enhance the PCB’s thermal transfer properties. The conductive nature of the metal also wicks heat away from the components that are inserted into the PCB, helping to keep them cool and improving their longevity.

How do filled vias affect the overall performance of PCBs?

In addition to enhancing the performance of a printed circuit board, via fills can save space by allowing it to fit more components in a smaller package. This can be crucial in compact device designs and may also help to reduce the cost of the finished product.

Non-conductive epoxy vias can be a more affordable option, but they don’t offer the same level of performance as a conductive via fill. They do, however, stop impurities and solder wicking from entering the hole. They also provide structural support for a copper pad that, in the case of a via-in-pad, plates over the hole.

The bottom line is that it is essential to specify the correct via type and treatment when submitting your Gerber files for PCB fabrication. A lack of clarity can result in delays, higher manufacturing costs or even an unusable final product. The best way to ensure that your PCB is fabricated with the highest quality vias is to supply your contract manufacturer with detailed specifications for each component on your design.

At Fineline, we make sure to include the proper IPC-4761 via coverage for every PCB that goes through our production facilities. We understand that every detail counts and we are committed to delivering high-performance PCBs at a competitive price.