DocID15852 Rev 3

11/15

TN0107

Reflow

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3.3

Pin-in-paste

Another technique used to solder THDs is to print solder paste onto a PCB near or over drill

holes through which the leads are then inserted. The reflow of the solder paste is done

together with soldering the SMDs, which therefore have to go through the reflow

temperature profile. This has two consequences:

1.

The temperature is nearly the same for the whole package in contrast to wave

soldering.

2.

The time for which the peak temperature is applied to the package is much longer

compared to wave soldering.

THDs are qualified for wave soldering and not for reflow soldering. Therefore, pin-in-paste

soldering techniques are not recommended for the SLLIMM.

3.4

Heatsink mounting by reflow soldering

In special applications the heatsinks of high-power THDs can be mounted to the board by

solder paste printing, pick-and-place, and reflow soldering. In this case, the packages

undergo a reflow profile. THDs are qualified for wave soldering and not for the reflow

soldering. Therefore, reflow soldering should not be used for the heatsink mounting for the

SLLIMM.