The Importance of Printed Circuit Board
Over the years, I heavily relied on my PCB suppliers to provide best circuit boards without worrying about PCB manufacturing details. However, the global economic factors influenced me a lot, and made me want to delve deeper into the manufacturing process and the reason why PCB is so important.
If your PCB contains packages like QFP, QFN or BGA, the accuracy of spacing and footprint is the top priority. Even minor misalignment in the manufacturing process could make component placement impossible. And silkscreen that seems blurry only shows that knowing how a PCB is manufactured allows you to choose the best supplier for your design.
PCB circuit boards are made of non-conductive substrates, usually made of glass fibers covering with epoxy resin. The substrate is then bonded to a thin copper plate, which forms a conductive layer to be etched in the later process. Coppers are known to suffer damage like corrosion, and a layer of solder mask is applied to copper that does not required to be exposed. The silkscreen layer for marking is then placed at the top of the solder mask.
The above process is how a standard PCB is manufactured. But when dealing with high-speed signals or high-power circuits, PCB material selection becomes your top priority. PCB circuit boards made of low-loss performance materials are critical to collision avoidance application especially in automotive circuitry.
When the efficiency of heat treatment is required, it is preferable to use a PCB circuit board made of a material with high thermal conductivity to avoid deterioration due to heat. This means the standard FR-4 material with 0.30 W/mK thermal conductivity is not suitable for high power applications.