In fact, the red glue process can improve the efficiency of post-soldering. There are still many people who do this process. Anyone who does PCB patch processing knows it. Let's take a look at how the red glue process is done.

　　As the name suggests, the red glue process is to use red glue for patching. When opening the stencil, it is not to open the pad position of the component, but to open a slot in the middle of the component, brush the red glue, and then put the component on the SMT, In this way, the components are glued to the PCB circuit board by red glue. After the plug-in material is inserted, the pads of the components will be soldered in the tin furnace.

　　There will be some problems in the red glue process: as can be seen from Figure 1, the red glue will have a certain thickness, and the components will be raised during the hardening process, so that the pads of the components and the pads on the PCB circuit board are easy to There is a gap. Once there is a gap, it is easy to cause poor tinning to form virtual soldering; in addition, the red glue will become very hard after passing through the tin furnace, and it will be very troublesome if the components need to be replaced for maintenance; When the temperature is too high in the tin furnace, it is easy to remove parts, especially IC is more likely to occur.

　　Today, the editor of Zhongke Circuit Board Factory introduced this method to you to avoid these problems in the red glue process. Let’s look at a few pictures first.

　　There are some holes and slots on the jig: the holes are the positions where post-soldering is required, and the pins of the plug-in material can pass through these holes. When the jig is placed on the tin furnace, only the positions of these holes can contact the solder. ; The slot corresponds to various components after the PCB SMD. If the components are large, dig larger ones, and if the components are small, dig smaller ones, so that the PCB circuit board with the SMD components attached can be placed flat on the fixture.

　　PCB circuit boards for fixtures

　　There are two larger chips on each PCB board, one close to a square and the other a rectangle. Use these two chips to match the slot in Figure 2, and you will know that the PCB circuit board with the patch components attached is in the fixture. How is it flattened.

　　The fixture is placed on the bottom surface of the SMD PCB

　　Figure 4 shows the bottom surface of the board with the patch components attached to the fixture. It can be clearly seen that the pad vias of the plug-in components are exposed, and the pins of the components pass through the pad vias. Come here, put this side on the tin stove, can you solder all the plug-in materials at once?

　　The fixture is placed on the back of the SMD PCB circuit board

　　Let's take a look at the back, I don't need to explain that everyone knows that this can be easily done. This method can significantly increase the post-soldering efficiency, but there can be no other patch materials near the pad of the plug-in material. If it is too close, the pad cannot be exposed, and manual repair welding is required later.

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