In order to get good solder paste release properties, there are several factors that the PCB assembler needs to control. While the solder paste printing process needs to have the right controls in terms of squeegee speed/pressure, snap off height, stable board support and proper squeegee material; there are other metal stencil parameters which can positively influence the print quality.
The solder paste release properties of the stencil come into play in specifying a stencil for manufacturing purposes. The stencil’s material choice as well as the laser cutting source are important to insuring repeatable performance. Stencil metals with small grain structure and the ability to maintain stable dimensional stability are important in getting the paste to release consistently.
BEST supplies high end
Tension™ stainless steel as part of its standard stencils. This alloy provides the properties mentioned for good and consistent paste release. When the stainless steel stencil is cut by the BEST fiber laser source, heat is imparted as part of the cutting process. This generated heat can cause dimensional instability which can result in warpage. A warped stencil will not sit properly on the surface of the PCB during the printing process. The BEST Tension™ stainless steel stencil will.
Call Chris E at
224-387-4302 or send her files to try one of these stencils at
cedwards@solder.net.
