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The main reasons for solder joints not full are as follows:
1. The activity of the flux in the solder paste is not enough, and the oxidized
substances on the PCB pads or SMD solder joints are not completely removed.
2. The moisture retention of the flux in the solder paste is not good.
3. PCB pads or SMD soldering positions have serious oxidation.
4. During reflow soldering, the preheating time is too long or the preheating
temperature is too high, cause the failure of flux activity in the solder paste.
5. If the solder paste has not been fully stirred or the flux and tin powder have not
been fully fused. If, there will be insufficient tin on some solder joints.
6. The soldering zone temperature is too low.
7. Insufficient amount of solder paste at the solder joint.
8.2 Precautions
*Keep a certain distance of more than 100mm when PCB size exceeds 100mm.
*If the PCB length is longer than the ESD tray, the ESD tray needs to be replaced by
other suitable carriers to place the soldered PCB.
*For your personal safety, after opening the incubator, the incubator must be supported
by the support rod before proceeding to the next step.
*The upper cover and incubator can only be opened after the bottom caster is lay down.
*The power board and control board should not be touched when the power is on.
Support Rod
keep distance of
more than 100mm