The Science Lab
A Closer Look at the Importance of Stencil Cleaning
Most solder defects, some estimate up to 70%, can be attributed to the stencil printing process. This means that having a clean stencil can be critical.
As PCB assemblies become denser and miniaturization drives electronic component size ever smaller, the more important it has become that solder paste deposits and volume transfer are consistent and reproducible from board to board in the printing process. A number of factors can negatively affect these important attributes. For example, proper solder paste transfer efficiency is especially critical for small pad features, because it reduces defects due to poor solder joints. In this case, solder paste builds up onto the aperture walls and bottom side of the stencil over time leading to insufficient or inconsistent transfer onto the pads. Periodic cleaning of the built-up paste with a KYZEN stencil cleaning fluid designed for your application will improve print quality and process yield.
Depending on your manufacturing process needs, choosing the best stencil cleaning method can be key. Whether it is manual (handwipe), on printer (under stencil wipe) or an off-line cleaning machine process KYZEN will work with you to make sure you get the best solder print and placement. In fact, our experts have taken the time to host a collection of presentations taking a deeper dive into this topic! You can find a playlist of their videos below. Additionally, you can download our free cutsheet explaining the best chemistries for stencil cleaning.
Why Your Inline Process Needs AQUANOX A4382
Consistent cleaning underneath components with low gaps including QFN’s, BGAs, and chip caps is imperative to avoid flux contamination. Skipping this could result in a very costly field failure.
In the latest case study conducted by our KYZEN Clean Team, we set out to discover if using our award-winning AQUANOX A4382 with lower surface tension and better solubility will improve cleaning underneath AVX component devices.
The goal was to ensure that the chemistry was a consistent and reliable final product that would improve both reliability and throughput, while reducing rework and warranty liability.