In the welding process, what is the difference between tin beads, residue, false welding, cold welding, missing welding and virtual welding?
1. False welding, usually means that it looks like it is welded on the surface, but in fact it is not welded at all. Sometimes when you pull it out by hand, the lead wire will be pulled out from the solder joint.
2. Insufficient soldering means that there is only a small amount of tin soldering at the solder joint, causing poor contact and intermittent on and off. Virtual welding and false welding basically mean that the surface of the weldment is not coated with tin layer in many aspects, and the weldments are not fixed by tin. The main reason is that the surface of the weldment is not cleaned, or too little flux is used.
3. Missing welding means that the solder joints should be welded but not welded. Too little solder paste, the problem of the part itself, the location of the part, and the long time after tin printing... etc. can also cause solder leakage.
4. Cold welding, usually the tin-eating interface of the part does not have the tin-eating strip, (that is, the phenomenon of poor soldering). The flow soldering temperature is too low, the flow soldering time is very short, tin-eating problems... etc. can also cause cold soldering.
5. Tin beads usually refer to some other solder balls. Before the solder paste is soldered, the solder paste may exceed the printed pad itself due to a series of factors such as collapse and extrusion. When performing soldering, these The solder paste beyond the pad is not fused with the solder paste on the pad during the soldering process and is formed independently on the body of the electronic component or next to the pad. However, the vast majority of solder beads occur on the chip on both sides of the electronic components.
6. Tin connection usually means that several or more solder joints are combined by solder, causing adverse phenomena in appearance and effect.
7. Not tinned, usually means that when the solder paste is soldered, the electronic components that should have been covered are only covered with a part of them, and they are not completely soldered.
8. Fried tin, that is to say, in the solder paste welding process, after the furnace is passed, the solder paste often cracks explosively, causing the undesirable phenomenon of displacement of electronic components.
9. Tombstone, that is to say, in the reflow soldering process of the surface mount process, the SMD components may have defects of desoldering due to standing up.
10. Residue, usually refers to the impurity residue deposited on the electronic board or stencil after solder paste soldering.
