First we will elaborate on our topic, that is, how important PCB design is to the SMT patch process. In connection with the content we have analyzed before, we can find that most of the quality problems in SMT are directly related to the problems of the front-end process. It’s just like the concept of “deformation zone” we put forward today.
This is mainly for PCB. As long as the bottom surface of the PCB is bent or uneven, the PCB may be bent during the screw installation process. If a few consecutive screws are distributed in a line or close to the same research area, the PCB will be bent and deformed due to the repeated action of stress during the management of the screw installation process. We call this repeatedly bent area the deformation zone.
If the chip capacitors, BGAs, modules, and other stress change sensitive components are placed in the deformation zone during the placement process, then a solder joint may not be cracked or broken.
The fracture of the module power supply solder joint in this case is of this situation
(1) Avoid placing stress-sensitive components in areas that are easy to bend and deform during PCB assembly.
(2) Use the bottom bracket tooling during the assembly process to flatten the PCB where a screw is installed to avoid bending of the PCB during assembly.
(3) Reinforce the solder joints.
Post time: May-28-2021
