Method for Applying Adhesives to Surface-Mounted-Technology-Type Modules
Original Publication Date: 1987-Apr-01
Included in the Prior Art Database: 2005-Feb-01
A new stencil design is described which removes the problem of smearing which occurs when an adhesive is applied by a screening technique to a panel on which solder paste has been applied. There are many advantages to using a screening technique to apply adhesives to panels rather than the prior-art syringe application technique. All the adhesive dots can be applied at substantially the same time at a very fast rate. This results in lower cost of the circuit panels. The 10- to 12-mil thick stencil used for solder paste is increased to about a 30-mil thickness, and the stainless steel or polyester mesh is also removed to prevent the stencil from deflecting too much when the adhesive is squeezed through the stencil. Screening is done by fixing the snap-off to be equal to the adhesive height needed.