Interface can delaminate Void can form if line is in tension metal can be extruded as hillocks througl racks in the overcoat outions control thermal cycling during processing, choose materials with compatible thermal expansion control film stress(by deposition method) use adhesion layer, eg that reacts with silica to form an oxide, making a chemical bond to the substrate ll/703 3.155J6.l52J Thermal Old IBM multi-chip module More than 30 layers ceramic green sheet Containing x, y lines and vias and 100 chips mounted with solder balls signals in and Optimal dielectric( no electrical breaks, robust ll/703 3.155J6.l52JThermal management in packaging: Old IBM multi-chip module More than 30 layers of ceramic “green sheet” Fired Containing x, y lines and vias and 100 chips mounted with solder balls x y vias Power, signals in and out How pick ceramic, conductors to co-fire without warp (thermal expansion), Optimal dielectric constant for speed, no electrical breaks, robust… And hermetically sealed with helium and heat sinks contacting each chip 11/17/03 3.155J/6.152J 24 12 Void can form if line is in tension. Dielectric Metal line Substrate Interface can delaminate In compression, metal can be extruded as ‘hillocks’ through cracks in the overcoat. Solutions: control thermal cycling during processing, or choose materials with compatible thermal expansion control film stress (by deposition method) use adhesion layer, eg that reacts with silica to form an oxide, making a chemical bond to the substrate. 11/17/03 3.155J/6.152J 21