The reason for the heat sink pad solder joint

- Aug 30, 2018-

In a certain circuit board product, the power amplifier is poorly grounded. The soldering iron is used to melt the soldering of the soldering pins, and the soldering pad can be removed gently, indicating that the heat sinking pads are not actually soldered.

Why is this happening?

The Pcb used in power amplifier products is relatively thin, the heat capacity is small, and the temperature during soldering is higher than the temperature of the components. Therefore, the solder will flow into the heat dissipation holes (capillary action) so that the heat sink pads are less tinned and soldered.

multilayer pcb

We generally take the following measures:

The heat sink pad is often soldered, and it is often not noticed. However, for some components with high grounding requirements, layout, opening, and soldering must be carefully considered.

1. Improvement measures: soldering plug hole is used at the bottom of the heat dissipation hole

2. Adjust the temperature profile or use tooling to raise the component temperature before the PCB.

This case has a typical meaning. We generally notice the wicking effect, but it is difficult to think that the heat sink pad of the heat sink component will have this problem. The thickness of the pcb has an influence on the soldering quality of some components.


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