ESD (Electro-Static discharge) came from the human body, environment and even electronic devices can cause various damage to sophisticated semiconductor chips, such as: penetrate the thin insulation layer inside the components. Damage the grid of MOSFET and CMOS components; Trigger lock in CMOS device; PN junction of short circuit reversal; Short circuit forward biased PN junction; Melt the welding line or aluminum wire inside the active device. To eliminate the interference and destruction of electronic devices by electrostatic discharge (ESD), various technical protections to be made.
During PCB design stage, PCB's anti-esd can be realized from layering, proper layout, installation and during production. Here are some common precautions:
1. Try to select multi-layer boards compared with double-sided PCB;
2. For double-sided PCB, choose tight interlaced power and ground grids;
3. Be sure that all the circuit be compact enough;
4. Try to layout as putting the components to one side;
5. Introduce the power cord from the center of the board if possible;
6. On all PCB layers below the connector that leads to the chassis, populate the wide chassis or polygonal filling and connect them through VIA at approximately 13mm space.
7. Put a ground wire to each signal to all those areas hit directly by ESD.
8. All I/O circuit be near related connectors.
9. Be sure that the signal wire as short as possible;
10. A ground wire to be created if the signal wire is longer than 300mm;
11. A high frequency bypass capacitance be hold for each 80mm connectors, etc.
In spite of the above, proper actions to be taken during PCBA assembly to ensure ESD protection as well, and this is what our FastPCBA have been focusing on.
Any PCB or PCBA inquiries, or would you like to know more about our ESD protection? Contact us as below freely:
Factory address: 3/F. 1/B, 18-2 Yuquan East Rd. Yulv Village. Guangming New district. Shenzhen. China.