The problem of
low-temperature tin wire dropping is a problem that is usually encountered when using low-temperature tin wire products. The main reason is that its tin wire metal composition is tin-bismuth alloy. More bismuth in the solder paste can lower the melting point, but the same solder joints are very brittle, making it easy to drop parts when soldering.
So how to avoid such problems? Let's talk about it below:
①The cooling speed of the tin wire should not be too fast, and do not touch it until the room temperature is reached.
②When selecting tin wire, you can use tin-bismuth-silver tin wire with a higher melting point to replace it. Although the melting point of tin-bismuth-silver tin wire is higher, the solder joints are much stronger.
③ Special attention should be paid when splitting the board. It is best to use a splitting machine to minimize stress and reduce deformation of the board.
④ Check the temperature curve, pay attention to the cooling slope.
⑤This kind of board is usually an aluminum substrate, so pay attention to the cooling treatment after reflow. After it is out of the oven, add cooling air to cross the bridge.
⑥Protect the reflow through the furnace with a jig.