| abstract |
A chip is provided by an encapsulant underfill material having a plurality of solder columns separated therein to provide a simplified method of flip chip mounting the chip to a substrate. Pre-coat 10 to eliminate the conventional capillary flow downfill process. Such a structure allows a plurality of remeltable layers to be accommodated for rework, testing or repair. This also allows for accommodation of the electrical redistribution layer. In one embodiment, the chip 10 and the pre-coated encapsulant are placed at a predetermined angle to the substrate, contacted with the pre-coated substrate, and then the chip 10 and the pre-coated encapsulant are contacted with the first Any gas from between them is evacuated until the solder bumps 14 on the chip are in full contact with the substrate 20 by placing them on an axis along the contact point of. Provided is a flip chip device with a compatible solder and flexible encapsulant substructure that generally deforms laterally with respect to the substrate 20 when the substrate 20 undergoes expansion and contraction. With this arrangement, the underlying structure of compatible solder and flexible encapsulant absorbs the strain created by the substrate without deforming the chip 10 and substrate 20. |