PCB Assembly Process

In this article, EPCB outlines the importance of knowing the PCB assembly process for a  designer or engineer. Five different aspects are considered as follows: 

Inspection: Automatic optical inspection is used by most assembly companies. However, not every company really inspects samples or finished PCBs one by one, some of them just do sample inspection. A short or dry joint is really hard to check by visual, let alone many component packages have connections underneath the component body. So your assembler should check this with some kind of x-ray or specialist visual equipment.

Handling: The way your assembler handles electro static discharge and moisture sensitive components really matters. Though controlling static is often regarded as unnecessary, it is a real risk to components. The same applies to moisture sensitivity, you should be careful about which components are rated as moisture sensitive when designing.

Cleaning: The way a PCB is cleaned can affect components to some extent, so you should pay attention to what kind of cleaning process your assembler uses as standard. With the cleaning process there should be a drying process as well, making sure it’s sufficient to completely dry out the board this is especially needed if using Rogers materials.

Reflow: Generally, it is doesn’t matter what reflow process your assembler uses as standard, however some components can be damaged by vapor phase reflow processes. So have a good command of assembly process knowledge is a must, besides, be familiar with component datasheets is sometimes necessary.