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US4897141A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for preparing semiconductor wafers

Assignee: Valtech Corp
•
Filing: 1988-06-09
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Granted: 1990-01-30
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Expires: 2008-06-09
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Abstract

Abstract Profound improvements and advantages are realized in the process of cutting semiconductor ingots to provide wafers if the adhesive used to bond said ingot to a mounting or cutting beam contains hollow microspheres.

Inventors

  • 👤 Richard T. Girard

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 13:02
CPC Classifications
B; B28; B28D; B28D5/00; B28D5/0058; B28D5/0082; B24; B24D; B24D3/00; B24D3/02; B24D3/20; B24D3/28; B24D3/32; B24D3/34; B24D3/342; B24D3/344; Y; Y10; Y10S; Y10S156/00; Y10S156/918; Y10S156/93; Y10T; Y10T156/00; Y10T156/10; Y10T156/1052; Y10T156/11; Y10T29/00; Y10T29/49; Y10T29/49789; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249971; Y10T428/249974

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 224 words
The process of preparing semiconductor wafers from ingots by bonding said ingots to a cutting beam with an epoxy adhesive and slicing the ingot into wafers, said process comprising the steps of: a. mixing hollow microspheres of an average diameter of 1 to 500 micrometers as the single additive that prevents or ameliorates thermally induced stress and the clogging problem during slicing with the resin part of an epoxy adhesive, wherein sufficient hollow microspheres are used to provide 2 to 35% (wt/wt) of the total adhesive, wherein the hollow microspheres are formed from silicate glass melts or from a homogeneous solution of alkali metal silicate and a polysalt selected from the group consisting of ammonium pentaborate, sodium pentaborate and sodium hexametaphosphate; b. mixing a sufficient amount of a hardener for the epoxy adhesive with the mixture of step a. to provide a set time of 4 to 12 hours; c. spreading the mixed adhesive system on said cutting beam and/or semiconductor liquid; d. placing said cutting beam and silicon ingot in contact with each other; e. allowing the adhesive to set; f. slicing the ingot into wafers with an inside diameter diamond or wire saw that penetrates the ingot, adhesive and part of the cutting beam; and g. recovering the wafers by breaking the adhesive bond between the semiconductor wafer and the cutting means.
Claim 2
Dependent Claim 224 words
The process of preparing semiconductor wafers from ingots by bonding said ingots to a cutting beam with an epoxy adhesive and slicing the ingot into wafers, said process comprising the steps of: a. mixing hollow microspheres of an average diameter of 1 to 500 micrometers as the single additive that prevents or ameliorates thermally induced stress and the clogging problem during slicing with the resin part of an epoxy adhesive, wherein sufficient hollow microspheres are used to provide 2 to 35% (wt/wt) of the total adhesive, wherein the hollow microspheres are formed from silicate glass melts or from a homogeneous solution of alkali metal silicate and a polysalt selected from the group consisting of ammonium pentaborate, sodium pentaborate and sodium hexametaphosphate; b. mixing a sufficient amount of a hardener for the epoxy adhesive with the mixture of step a. to provide a set time of 4 to 12 hours; c. spreading the mixed adhesive system on said cutting beam and/or semiconductor liquid; d. placing said cutting beam and silicon ingot in contact with each other; e. allowing the adhesive to set; f. slicing the ingot into wafers with an inside diameter diamond or wire saw that penetrates the ingot, adhesive and part of the cutting beam; and g. recovering the wafers by breaking the adhesive bond between the semiconductor wafer and the cutting means.

References Cited (Backward Citations)

US3652486A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-01-29 1993-07-31 1994-01-30 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-01-29 1997-07-31 1998-01-30 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-01-29 2001-07-31 2002-01-30 $7700.00 Window Closed / Lapsed

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