1. There are various problems that occur during the PCB manufacturing process, and process engineers often take on the responsibility of forensic autopsy (analysis of the causes of defects and solutions). The main purpose is to discuss the potential issues that may arise in terms of personnel, machinery, materials, and conditions in the equipment area one by one. We hope that everyone can participate and provide their own opinions and opinions.

　　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 resistance (solder mask) of 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 unqualified high-voltage testing during finished product testing.