The pinhole formation process of wave soldering joint. How to prevent the second-hand wave soldering pinhole?
Author:Panna Time:2021-06-06 14:39 Browse(821)
The pinhole formation process of wave soldering joint. How to prevent pinholes in second-hand wave soldering joints, Touch screen and OLED Forum
The pin hole of wave soldering joint is the hole on the solder joint, which usually appears near the through hole of wave soldering joint of circuit board.
next, Zhichi technology will briefly introduce how to prevent the pin hole of wave soldering joint.

The pinhole formation process of wave soldering joint. How to prevent the second-hand wave soldering pinhole?

% '# T: m (I1 s. \. M "~ 6] 4 u# Z9 |9 n% ]" s* j0 WDue to the gas inside the PCB.
the wave soldering joint of the PCB is pinhole shaped.
the inside of the PCB absorbs water.
in particular, cheaper substrate materials or rougher drilling methods are used, and the through holes of the pad are easier to absorb water during storage. In the process of insertion or storage, the pinhole formation process of the wave soldering joint of the PCB:) | 7 x & D_ 3 X4 p+ h+ L    Y5 g# e3 VIn the process of high temperature welding, the vapor formed due to the above reasons will produce high pressure effect, and the escape path is mainly through holes of PCB; The second is that the mismatch of expansion coefficient between materials may lead to the damage of through-hole copper layer.
the gas generated in the welding process is easy to enter the solder alloy through the broken copper layer.
the surface of solder joint solidifies first.
then pinhole phenomenon occurs during the gas escape.
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B7 H8 Z1 Q7 t preventive measures for pin holes in wave soldering joints of circuit boards:/Y9 x0 w # g / Z: S ${(d (T 1, select appropriate PCB board;' {1 x0 b    u: X: b 0 w 2. The board is well stored;# H0 ^: d' W! [ 1 e$ z      3. Bake the plate before welding,Generally, it is dried at 120 ℃ for about 2 hours. If it is effective, it should be used as air leakage test of printed circuit board& l2 b( b! r9 S% e. N4. The processor needs to ensure that the copper thickness of the through hole is reduced by 25 μ m;* i) k# F* U! \. j8 X5 E5. Clean PCB or lead surface with solvent" E: d6 F6 c7 b    u- ]# T$ j   ^' ` 8 H6 h" ~) t3 s4 G# D& u.
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