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AssigneeCredence Systems Corporation
InventorsChun-Cheng Tsao, John Valliant
Estimating the term…
A reliable, inexpensive “back side” thinning process and apparatus therefor, capable of globally thinning an integrated circuit die to a target thickness of 10 microns, and maintaining a yield of at least 80%, for chip repair and/or failure analysis of the packaged die. The flip-chip packaged die is exposed at its backside and mounted on a lapping machine with the backside exposed. The thickness of the die is measured at at least five locations on the die. The lapping machine grinds the exposed surface of the die to a thickness somewhat greater than the target thickness. The exposed surface of the die is polished. The thickness of the die is again measured optically with high accuracy. Based on the thickness data collected, appropriate machine operating parameters for further grinding and polishing of the exposed surface are determined. Further grinding and polishing are performed. These steps are repeated until the target thickness is reached.
An apparatus for measurement of remaining semiconductor substrate thickness of at least a portion of a semiconductor wafer, said portion having a thickness less than 50 micrometers, said measurement having an accuracy at least as good as about 100 nm, said apparatus comprising:
A method of forming a thickness map of the remaining thickness of a semiconductor wafer portion comprising the steps of:
A method for mounting a semiconductor wafer portion having a top surface and a back surface onto a lapping puck to achieve uniform lapping of said top surface by a lapping platen opposing said lapping puck, comprising the steps of:
A method of providing a uniform thickness to a thinned semiconductor wafer portion comprising the steps of:
A fixture for mounting a lapping puck having a semiconductor wafer portion thereon, said fixture positioned on an optical tool selected from the group consisting of:
Dependencies are inferred from the claim text.