- The stencil must be designed such that the correct amount of solder paste can be printed onto the through-holes to form an acceptable joint after reflow.
- The solder paste should be amenable to the PiP process.
- The stencil printing process should be optimized.
- The through-hole components selected must be able to withstand reflow soldering temperatures.
- The through-hole component leads must be rounded at the end.
- The through-hole component leads must be of the correct length to form a good solder joint.
- The through-hole components must be mounted correctly.
- The reflow profile will be acceptable.
- The greatest challenge in the PiP process is stencil design. The stencil must deliver the correct amount of solder paste to the through-hole in the printing process. To achieve this goal, the amount of solder needed must be determined. The figure which shows the geometry of an acceptable solder joint helps to understand how to calculate the solder volume for through-hole parts.
