1. There are three major possibilities for the green paint to fall off. The first is that the nature of the green paint itself is not enough to withstand the test of the tin furnace. This may be due to the expiration of the green paint or poor operation. The green paint used by the industry almost always undergoes test procedures such as heat resistance and reliability, so there should be no normal problems. In this regard, it is necessary to review whether the material itself has changed or the process has changed.

    2. The second possibility is the influence of external force, including flux supply and mechanical collision, etc., especially under high temperature conditions, the green paint characteristics are no longer as high as the normal temperature environment, and the green paint surface of the circuit board is impacted by any external force. are prone to scratches and peeling.

    3. The third possibility is that the circuit board bursts due to moisture absorption before the green paint is applied or during storage. When the water vapor is heated and vaporized, the volume expands by nearly 300 times, and the temperature rises instantly and the green paint softens. , it is very easy for the green paint to peel off. Such problems will occur in the tin spraying process of circuit board production, and may also occur in assembly processes such as wave soldering and reflow soldering.

    4. There are several possibilities for SMPEELING after gold formation. The first may be that the treatment in front of the copper is not ideal, the second may be insufficient drying before S/M coating, and the third may be that the stagnation time is too long to produce an oxide layer. The fourth possibility is that the material of the green paint itself is not suitable for the chemical gold process. The fifth possibility is that the polymerization degree of the green paint is insufficient. Sixth, if you have done more than one high temperature process, such as: gold and gold plating Or two gold immersion, it is also possible. Because there are many possibilities, you must do a detailed analysis to clarify each item, but in general it is very important to use the S/M type.