How to Ensure Quality of PCBA Manufacturing Process?
Before we start PCBA manufacturing, engineers have to review PCB gerber files and BOM list and try to figure out critical aspects of PCB manufacturing and SMT assembly process, such as copper plating, exposure, surface finish, solder paste printing, oven temperature curve etc. Now we start to talk about the quality control methods separately.
PCBA Flow Chart
1. Gerber files
Engineer has to confirm the specific parameters of PCB fabrication, including laminate thickness and dimension, copper thickness, surface finish, line spacing and width, other special requirements of impedance, blind via, buried via etc. The key points to ensure quality of common PCBs are uniformity of copper plating and circuit printing. In terms of impedance, engineer should calculate the value and place related manufacturing requirements to production team.
2. BOM List
Through the BOM list, we have to find out the most key components, including IC, display, connector etc. and their package method. We have to config advanced SMT mounter to do assembly for 0201 chips. At mean time, to confirm the timeline of purchase is huge important for whole PCBA manufacturing process. Some are out of stock and some should be imported internationally.
3. SMT Assembly Process
Before SMT assembly process, we have to inspect all incoming materials before they are placed onto production lines. Through checks of shape, dimension, value and brand, we can ensure all components are in compliance with the BOM list. Regarding some replacement component, we have to raise conversation with customer design engineers before making purchase decision. At stage of solder paste, engineer has to make sure of the laser stencil is OK and solder paste on PCB pads is in uniformity and good shape for first test board. High precision advanced SMT mounter is also a key to guarantee the quality. Subsequently, we have to set right oven temperature curve and use AOI to make online test. At last phase, ICT or FCT is necessary before delivery. We can find problems of soldering, vibration or test under severe conditions.
4. Team Management
Machine is one thing, man is the other. Perfect team management almost does everything for quality control of PCBA manufacturing process. We have to implant corporate culture into minds of everybody and the internal acceptance would impulse the team to take care of every job. Also, to make appropriate incentives is crucial.
PCBA manufacturing process is not so easy as above mentioned. It involves many technical aspects and professional operations. This article is mainly aimed to offer a rough sketch of whole PCBA manufacturing process.