What is Pin-in-Paste (PIP) Technology?

The existing mixed PCB assembly process i.e assembling a board with both surface mount and through-hole components consists of two main steps for component placement and soldering. First, the PCB is populated with surface mount devices (SMDs) and soldered by the reflow process. In the second step, the Through Hole components are mounted and soldered by hand or wave soldering process. 

Pin-in-Paste (PIP) technology is an alternative to the mixed PCB assembly in which both the through-hole components and surface mount components are soldered to the board using the reflow soldering process. This technology skips the wave soldering step altogether, thereby saving considerable amounts of time and making PCB Assembly less expensive. This process was developed in about 1985 and since then has been used extensively for mixed component PCB Assembly.

How does it work?

In the Pin-in-Paste (PIP) process, the solder paste is pressed into the through-contacted holes. The amount of solder paste used must be balanced to provide the final solder joint. After solder application, the component is placed in the holes. The board then undergoes reflow soldering in order to strengthen the solder joint.

This process is also known as Through-Hole Reflow Technology.