1. There are various problems that occur in the PCB process, and process engineers often take on the responsibility of forensic autopsy (analysis of the causes of defects and solutions) Therefore, the main purpose of initiating this discussion question is to discuss one by one in the equipment area, including personnel, machinery, materials, and possible problems that may arise under certain conditions

　　2. Processes that use pre-treatment equipment, such as inner pre-treatment lines, electroplating copper pre-treatment lines, D/F, solder mask (solder mask) Wait a minute

　　3. Taking the pre-treatment line for solder mask (solder mask) on hard board PCB as an example (different manufacturers may have differences): brush grinding * 2 groups ->water washing ->acid washing ->water washing ->cold air knife ->drying section ->sun disk collection ->discharge collection

　　4. Generally, steel brushes with brush wheels of # 600 and # 800 are used, which can affect the roughness of the board surface and thus affect the adhesion between the ink and the copper surface After long-term use, if the brush wheel is not evenly placed on both sides of the product, it is easy to produce dog bones, which can lead to uneven surface roughness and even deformation of the circuit, as well as different color differences between the copper surface and INK after printing. Therefore, the entire brush operation is required Before brushing and grinding operations, a brush mark test (with a water break test added for D/F) is required. The width of the brush marks should be measured to be approximately 0.8-1.2mm, which may vary depending on the product. After updating the brush, the level of the brush wheel needs to be corrected, and lubricating oil needs to be added regularly If water is not boiled during grinding or the spray pressure is too small to form a fan-shaped angle with each other, it is easy to produce copper powder. Mild copper powder can cause micro short circuits (dense wire areas) or failure of high-voltage testing during finished product testing