The use of temporary bonding in manufacturing flexible and rigid substrates

Thin substrate manufacturing is one of the highest growth areas in electronics. Fragile substrates of 100um or less supported by a carrier until the process is complete and are removed by simple and reliable means. The demands for temporary bonding of electronics vary from rigid wafers, flexible films, to components with solder bumps. Substrate type, topography, thermal budget, processing, and removal, all influence the choice of bond & de-bonding. The handling of wafers and the choice of adhesive commonly operate within single-wafer processing equipment. Batch processing exists with perforated carriers or DaeBond 3D whereby debond occurs by passive means in a green chemical bath while thinned device wafers remain affixed to film frames. Flexible display manufacturing uses thin substrates as polyimide (PI) and metal foil. Much is focused on transparent materials with high thermal resistance. Adhesive choice depends upon the substrate being a liquid casting or solid film; removal is by peeling. Tuning adhesion enables simple removal without challenge to substrate integrity. This presentation will discuss temporary adhesives spanning a range of substrates, adhesives, and processes. Daetec will discuss our challenges in handling 4um Si, interposers with bumps, and flexible PI, as well as thermal resistance to 600C.