Print Performance Studies Comparing Electroform And Laser-Cut Stencils
Authors: Rachel Miller Short and William E. Coleman Ph.D.; and Joseph Perault Company: Photo Stencil and Parmi Date Published: 10/13/2013
Abstract: There has been recent activity and interest in Laser-Cut Electroform blank foils as an alternative to normal Electroform stencils. The present study will investigate and compare the print performance in terms of % paste transfer as well the dispersion in paste transfer volume for a variety of Electroform and Laser-Cut stencils with and without post processing treatments. Side wall quality will also be investigated in detail. A Jabil solder paste qualification test board will be used as the PCB test vehicle. This board has a wide range of pads ranging from 75 micron (3 mil) squares and circles up to 300 micron (12 mil) squares and circles. There are also long rectangular pads with spacing’s as low as 75 micron (3 mil). A total of 12 stencils, four stencils of different stencil technologies with three different coating configurations, will be tested as described in 1-4 below: 1- Electroform (E-FAB) w/o Nano Coat and with and Nano Coat A and Nano Coat B 2- Laser-Cut Electroform foil (NiCut) w/o Nano-Coat and with Nano Coat A and Nano Coat B 3- Laser-Cut SS (Laser FG) w/o Nano Coat and with Nano Coat A and Nano Coat B 4- Laser-Cut SS with Electropolish and Nickel plating (NicAlloy), w/o Nano Coat and with Nano Coat A and Nano Coat B A 100 micron (4 mil) thick stencil is used for all 12 stencils yielding Area Ratios ranging from .31 to .1.21.