Optimising solder paste application for manufacture of ultrafine pitch printed circuit boards

Electronic components are added to printed circuit boards using a process called Surface Mount Technology (SMT). Key components are a stencil, squeegee blade and solder paste which are housed in an automated printer for high volume production. Squeegee blade action forces solder paste from the top side of the stencil through the apertures to create a pattern on the circuit board which matches where the components are to be placed. As electronic devices get smaller and more powerful there is a need to install smaller components in a higher density - to do this the stencil apertures become smaller and closer together making it more difficult to deposit and control the small volumes of paste required. To date all innovation has been focused on the materials used and coatings for the board side of the stencil and the apertures themselves. Datum has developed an approach to modifying the characteristics of the squeegee side of the stencil as well as the apertures and independent tests have indicated a significant improvement in transfer of paste. The purpose of the grant is to understand the impact of changing the material characteristics of the stencil on the squeegee side and use this information to optimise the process. A positive outcome will improve the capability of electronics manufacturing and result in Datum selling materials to create the optimum surface finish on the squeegee side of the stencil.