Abstract: An integrated circuit/substrate interconnect apparatus and method are provided. Included is an integrated circuit including a plurality of bond pads, and a substrate including a plurality of landing pads and a mask. Such mask is spaced from the landing pads for defining areas therebetween. Further provided is a plurality of interconnects connected between the bond pads of the integrated circuit and the landing pads of the substrate. The interconnects include metal projections extending from the bond pads and a solder material for connecting the metal projections and the landing pads of the substrate.

Abstract: A method of assembling a substrate and die in a flip chip configuration using a no clean flux. The no clean fluxes have sufficient chemical activity to activate solder bumps contacting bond pads to form reliable solder joints, sufficient tackiness to hold the substrate and die in alignment with the solder bumps contacting the bond pads, and a viscosity to enable a high volume manufacturing process to be used. The no clean fluxes leave a minimal amount of residue during a reflow process that does not interfere with an underfill operation and does not adversely affect the solder joints. The no clean fluxes that can be used for this application are RM1919 from Alpha Metals, Co. and H208 from Indium Company.

Abstract: A method of assembling a substrate and die in a flip chip configuration uses a non-hazardous cleaning solvent to clean the flux residue. The non-hazardous cleaning solvent utilized is Ionox obtained from Kyzen Corporation. Optimized process parameters are: time 10-30 minutes, temperature 70-90.degree. C., pressure 40-70 psi, rotation speed and reversals 100-1000 rpm and 24-100 reversal cycles.