Multi-function LSI wafers

• US 3,984,860 A
• Filed: 12/13/1974
• Issued: 10/05/1976
• Est. Priority Date: 06/04/1973
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Logue, Joseph C.
• Primary Examiner(s): James, Andrew J.
• Application Number:
  US05/532,419
• Time in Patent Office: 662 Days
• Field of Search: 29/574, 29/578, 357/68, 357/75, 357/70
• US Class Current: 257/208
• CPC Class Codes: H01L 27/118 Masterslice integrated circuits

Abstract

A system that is to be placed on a wafer is partitioned into reasonably large functions, each provided with a set of I/O and power pads. The wafer design is called "design A"0 A second wafer design (design B) that is the mirror image of design A is also constructed. Wafers of designs A and B are tested and divided into two groups: group I wafers have relatively few functions that are inoperative; group II wafers have relatively few functions that are operative. Inoperative functions are removed from group I wafers and discarded; good functions are removed from group II wafers and retained. A given function on wafer A is the mirror image of the same function on wafer B. Therefore, a given function from a group II wafer A (or B) can be inverted and attached to a group I wafer B (or A) that has had the corresponding function removed from it. The I/O and power pads of the function removed from the group II wafer are joined to the I/O and power pads remaining on the group I wafer.

Claims

1. A multi-function, multi-island, wafer, comprising:

a first island which is electrically isolated from input-output connections to the other islands of said wafer; and

a second island that, with respect to certain input-output connections, is the mirror image of said first island;

said second island having said certain input-output connections electrically connected to corresponding input-output connections related to said first island;

said second island thereby replacing said first island on said wafer.

2. The multi-function, multi-island, wafer of claim 1 wherein:

said first is electrically isolated from said wafer by physical removal therefrom.

3. As an article of manufacture, materials for manufacturing a multi-function, multi-island, wafer, comprising:

wafers manufactured in accordance with a first design;

wafer islands manufactured in accordance with a second design;

said first and second designs being related in that each island of said second design is, with respect to input-output pads, the mirror image of an island of similar function of said first design;

a group of wafers, sorted from said manufactured wafers, each containing at least one island that is not satisfactory for use;

said one island being electrically isolated from the other islands of a wafer in said group while leaving its associated input-output pads connected to the other islands of the wafer;

said one island on said wafer being replaced by electrically connecting the input-output pads associated with an island of similar function, manufactured in accordance with said second design, to the input-output pads associated with said one island that was electrically isolated from said first wafer.

4. The article of manufacture of claim 3 wherein:

said one island is electrically isolated from said wafer by physical removal therefrom.