The Application of the Pin-in-Paste Reflow ProcessThe Pin-in-Paste (PIP) reflow process, also called through-hole (TH) reflow or pin-in-hole (PIH) reflow technology, has become more popular because it eliminates time-consuming processes, such as hand and traditional wave soldering, without losing the advantages that through hole components can offer.
The benefits of the pin-in-paste reflow process include:
- Use of the same SMT equipment for both SMT and TH components
- Elimination of hand and wave soldering processes
- Reduction of machine setup time
- Reduction of production turn around space and time
- Elimination of the board cleaning process since it is unnecessary to clean TH components
- Are the components PIP ready? Not all TH components, especially the connector’s plastic housing, can withstand reflow temperatures up to 260°C over several seconds. The component’s geometry such as pin length and free space also need to be reviewed in order to make the right decision.
- Is the layout designed for the PIP process? If the PCB hole diameter is too big, it will require too much solder to fill it up. If it is too small, it is very difficult to fill the hole properly with paste during solder paste printing. Also, low solder volume can cause solder defects.
- Is the stencil designed for the PIP process? To get enough paste to fill up the pin hole, the stencil aperture must be designed bigger than the solder pad size depending upon the paste volume calculation.
- Is reflow profile optimized for the PIP process? Consider a delta type reflow profile first in order to reduce most of the defects. This profile has a slow ramp up of 0.5 to 1°C per second, a slight dwell at the liquidus temperature, a minimum time above liquidus, and a rapid ramp down of 4° C per second or less.
- Pin-in-Paste Reflow Calculations and Special Cases
- How the modern solder reflow oven works?
- Lead-free Reflow Profile: Soaking type vs. Slumping type
- How to optimize the reflow profile?
- How to Maintain a Reflow Oven?