In my work, I make sure that Tenglikni o’rnatish does not have such errors. By welding hundreds of tiny components together, the PCB is less robust than you might think. If not handled properly, you may receive complaints from unsatisfied system installers because the circuits may not work properly.

Should PCB designers care about PCB handling?

Chances are, you might not want to make hundreds of PCBS with your own designs. The people who will be in contact with these PCBS are the assemblers, test engineers, installers, and maintenance personnel.

The fact that you won’t be involved in the post-production process doesn’t mean you can be complacent about PCB handling. It is important to understand the correct PCB handling process, otherwise it may lead to circuit failure.

More importantly, PCB designers should be aware of their role in optimizing PCB layouts in order to reduce problems associated with PCB handling. The last thing you want to do is rework your existing PCB when you should be challenging the next project.

How does improper PCB handling lead to damage

Given a choice, I would rather deal with damaged porcelain than problems caused by improper PCB handling. While the former is obvious, the damage caused by PCB handling problems is negligible. There are usually no obvious signs that a PCB will not work properly after deployment.

A common problem observed when careless handling of PCBS is the failure of active components due to personal electrostatic discharge (ESD). This occurs when handling PCBS in a non-ESD-safe environment. For ESD-sensitive components, less than 3,000 volts are needed to actually damage their internal circuitry.

If you look closely at a reflow welded PCB, you will see that very little solder holds the surface mount (SMD) assembly to the pad. Components such as SMD capacitors can cause one of their pads to break when mechanical forces are applied parallel to the PCB.

In other words, when you try to pick up the PCB with one hand, you press the PCB into yourself. This may cause the PCB to bend slightly and may cause some components to fall off its pad. To avoid this, it’s a good habit to pick up the PCB with both hands.

PCBS are often made into panels to reduce costs and improve efficiency. Once assembled, you need to disassemble the PCB. Even if they are supported by a minimal V score, you still need to exert some force to pull them apart. This process may also accidentally damage the welds of certain components.

It’s rare, but sometimes careless, and you drop the PCB as if it were on a China bowl. A sudden impact can damage larger components, such as electrolytic capacitors, or even the pads.

Design techniques to reduce PCB handling problems

PCB designers are not completely helpless when it comes to dealing with PCB handling problems. To a certain extent, implementing the right design strategy can help minimize defects associated with PCB handling.

Elektrostatik himoya

To prevent sensitive components from being damaged by ESD, you need to add protective components to suppress transients during ESD discharge. Varistors and Zener diodes are commonly used to handle rapid discharges of ESD. In addition, there are dedicated ESD protection devices that can provide better protection against this phenomenon.

Component placement

You cannot protect the PCB from mechanical stress. However, you can mitigate such problems by ensuring that components are placed in a certain way. For example, you know that placing SMD capacitors in a position consistent with the breaking force applied during decarbonization increases the risk of solder breakage.

Therefore, you need to position the SMD capacitor or similar parts parallel to the broken line to minimize the effect of the applied force. Also, avoid placing components near the curvature or curve line of the PCB, and avoid placing components near the outline of the board.