Question:

After PCB electronics are installed, it is often found that there are defective devices on the PCB. After one failure, six 101A bipolar operational amplifiers were found to have failed, with the failure mode being an increase in input offset voltage to 40mV. The mode of failure was that the input offset voltage increased to 40mV, and the characteristics of the inputs were abnormal when tested with a Characteristic Curve Mapper. After dissecting the devices, it was found that the inputs of the chips showed traces of flying arc discharge.

Solution:

1. It was found that PCBs are subjected to static voltages of 300 to 800 V due to various reasons on the assembly line.

2. Enterprises have taken static neutralization measures on assembly lines to better solve this problem.