Stencil printing is far more complex than most people think. There are 37 different stencil printing parameters that must be optimized on an SMT printer. Because of this complexity, the typical SMT line only runs at 90-95% yield. With proper stencil printing, SMT lines can run at 99%+ yields. In other words, fix your stencil printing process and you fix almost all of your other PCB assembly problems. The key to better printing is to get rid of the alcohol used during stencil cleaning. That’s right: wipe dry! The #1 cause of bad printing is the solvent used with the paper. The alcohol leaves residues on the stencil that mix with the solder paste and change its viscosity. Get rid of the alcohol and improve your printing. The benefits of this improvement are stunning: faster production, higher throughput, higher yields, less scrap, less rework, fewer warranty claims, and so on. Your company is far more profitable and competitive.