Many friends of wave soldering have tin-connected situations when using wave soldering, which is very troublesome. The main reasons for this situation are the following:
Flux activity is not enough.
Flux does not wet enough.
The amount of flux applied is too small.
Uneven flux application.
The circuit board area cannot be coated with flux.
There is no tin on the circuit board area.
Some pads or solder feet are severely oxidized.
Circuit board wiring is unreasonable (unreasonable distribution of components).
The direction of walking is wrong.
The tin content is not enough, or the copper exceeds the standard; [excessive impurities cause the melting point (liquidus) of the tin liquid to rise] the foaming tube is blocked, and the foaming is uneven, resulting in uneven coating of the flux on the circuit board.
The air knife setting is not reasonable (flux is not blown evenly).
The board speed and preheating are not well matched.
Improper operation method when dipping tin by hand.
The inclination of the chain is unreasonable.
The crest is uneven.
Since connecting the tin will cause a short circuit of the pcb, it must be repaired before it can continue to be used. The repair method is to point a little flux (that is, rosin oil solvent), and then use high-temperature ferrochrome to heat the position of the connecting tin to melt it, and the position of the connecting tin Under the action of surface tension, it will retract and no longer short circuit.
Solutions
1. The flux is not enough or not uniform enough, increase the flow.
2. Lianxi speeds up the speed and enlarges the track angle.
3. Do not use 1 wave, use 2 waves of single wave, the height of the tin does not have to be 1/2, it is enough to just touch the bottom of the board. If you have a tray, the tin side should be on the highest side of the tray hollow.
4. Is the board deformed?
5. If the 2-wave single shot is not good, use 1 wave to punch, and the 2-wave hits low enough to touch the pin, so that the shape of the solder joint can be repaired, and it will be fine when it comes out.
For the above reasons, you can also check whether the wave soldering machine has the following problems:
1. Peak height distance.
2. Whether the chain speed is appropriate.
3. Temperature.
4. Whether the amount of tin in the tin furnace is sufficient.
5. Is the wave crest out of the tin even?
Post time: May-31-2023