Assembly of Wafer Stacks

摘要

A method of forming a wafer stack includes providing a sub-stack comprising a first wafer and a second wafer. The sub-stack includes a first thermally-curable adhesive at an interface between the upper surface of the first wafer and the lower surface of the second wafer. A third wafer is placed on the upper surface of the second wafer. A second thermally-curable adhesive is present at an interface between the upper surface of the second wafer and the lower surface of the third wafer. Ultra-violet (UV) radiation is provided in a direction of the upper surface of the third wafer to cure a UV-curable adhesive in openings in the second wafer and in contact with portions of the third wafer so as to bond the third wafer to the sub-stack at discrete locations. Subsequently, the third wafer and the sub-stack are heated so to cure the first and second thermally-curable adhesives.

主权项

1. A method of forming a stack of wafers, the method comprising:
providing a sub-stack comprising a first wafer and a second wafer, each of which has a respective upper surface and lower surface, the sub-stack including a first thermally-curable adhesive at an interface between the upper surface of the first wafer and the lower surface of the second wafer; placing a third wafer on the upper surface of the second wafer, the third wafer having an upper surface and a lower surface, wherein a second thermally-curable adhesive is present at an interface between the upper surface of the second wafer and the lower surface of the third wafer; providing ultra-violet (UV) radiation in a direction of the upper surface of the third wafer to cure a UV-curable adhesive in openings in the second wafer and in contact with portions of the third wafer so as to bond the third wafer to the sub-stack at discrete locations; and subsequently heating the third wafer and the sub-stack so to cure the first and second thermally-curable adhesives.