Adhesion Promoters and Adhesion Primers improve adhesion between substrates and coatings or adhesives by creating an interface for additional covalent bonds. This increases adhesion and the bond between the substrate and the coating or adhesive: improving the performance of the coating or adhesive.
One of the most common applications for adhesion promoters is to enhance the adhesion strength and performance of die attach between the die, the die attach, and the substate or copper lead-frame. Adhesion Promoters can be used for copper foil applications for the adhesion of low dielectric resins to copper for printed circuit boards and chip scale packaging. By pretreating the intended copper surface with an adhesion promoter significantly higher peel strengths can be obtained. Aculon has demonstrated superior performance to silane adhesion promoters in terms of peel strength on smooth copper (600 hours in autoclave).
Different adhesion promoters have different base chemistries but all of them work on a molecular level. For example Aculons Primers contain self- assembled monolayers of phosphonates (SAMPs) which improve the adhesion of metals to polymeric coatings. They do this by using reactive groups to create strong bonds with coatings that contain functional groups such as epoxies, polyurethanes, acrylates, and oxide particles.
Examples of the Adhesion Promoters with different base chemistries can be seen in Aculon’s range of adhesion promoters and primers. Thiol based primers promote adhesion between substrates and epoxy (meth)acyrlics. Acrylate primers promote adhesion between substrates and (meth)acrylates, amines, and thiol based coatings. Hydroxyls primers promote adhesion between substrates and polyurethanes, iso-cyanates, melamine formaldehydes, phenolic epoxy based coatings.