Method for non-destructive removal of semiconductor devices
Method of manufacturing a repairable multi-chip module
Method of securing surface-mounted devices to a substrate Patent #: 5220724
ApplicationNo. 988638 filed on 12/10/1992
US Classes:156/94, Reclaiming, renewing or repairing articles for reuse29/831, Assembling formed circuit to base156/297, Of discrete laminae to single face of additional lamina257/E21.505, Insulative mounting semiconductor device on support (EPO)438/118Including adhesive bonding step
ExaminersPrimary: Ball, Michael W.
Assistant: Robey, Robert W.
Foreign Patent References
International ClassesB32B 035/00
AbstractAn integrated circuit is reworkably attached to a circuit board in a manner that forms a compliant bond which is stable under conditions of high thermal stress and thermal coefficient of expansion mismatch. A thermoplastic adhesive having a melting temperature higher than integrated circuit operating temperature is coated on the integrated circuit and dried. The adhesive is then cured. The coated integrated circuit is bonded to the circuit board with a thermosetting epoxy having a low curing temperature, such that curing the adhesive does not damage the circuit board. The integrated circuit is readily removed from the circuit board without damaging the board by heating the integrated circuit to soften the bond between the integrated circuit and the circuit board at the thermoplastic adhesive interface. An alternate embodiment of the invention provides a copper plate interface that is soldered to the circuit board, and to which an integrated circuit is permanently bonded. Reworkability is achieved by flowing the solder bond and removing the copper plate/integrated circuit assembly.
Field of SearchReclaiming, renewing or repairing articles for reuse
With removal of defective area to be repaired
Of discrete laminae to single face of additional lamina
With coating or impregnating a face to be adhered
Coating solidified; e.g., by drying, etc., before assembly
Of laminae having a different coating on at least two mating surfaces
On flat or curved insulated base, e.g., printed circuit, etc.
Assembling formed circuit to base
Assembling to base an electrical component, e.g., capacitor, etc.
Directly attached to semiconductor device
Chip mounted on chip