Please check now if your PCB is bent?

Please check now if your PCB is bent?

Especially for large-sized boards, PCBs are prone to warping.

However, generally speaking, the acceptable warpage for rigid PCBs is 0.75%.

How to measure it?

Place the PCB on a flat marble countertop or a glass plate with a thickness greater than 5MM, and use a plug gauge to measure the maximum size of the corner.

Then measure the lengths of the diagonals of the PCB with a ruler and divide the two numbers.

According to the IPC standard, if the PCB warpage is greater than 0.75%, it is considered unqualified.

A warpage of less than 0.75% is considered qualified.

What consequences will there be if the PCB is overly bent?

1. Solder joint failure: The solder joint between the component lead and the pad cracked, peeled off, causing an open circuit and poor contact.

2. Damage to the inner and outer layers of the circuit causes a short circuit

3. Component damage, such as pin deformation, chip packaging cracking, and wafer damage, etc.

4. Assembly and connection deviations affect the structural stability of the PCBA

5. Reliability declines. Even if the initial function is normal, the probability of failure increases under subsequent vibration and temperature and humidity cycles.

How to prevent PCB from bending? We will talk about it in the next article.