EP0092041A2
Expired / Lapsed
EP
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Method for stress relieving in mounted circuit chips
Assignee: International Business Machines Corp
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Filing: 1983-02-23
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Granted: —
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Expires: 2003-02-23
Abstract
Abstract A method of relieving the stresses in elastically deformed semiconductor chips (10) soldered (20) to a substantially rigid substrate (15) by heating the assembly to and maintaining it at a temperature within the single phase region of the solder alloy employed to complete grain boundary sliding in the solder to thus permit the chip (10) to be restored to an unstressed state.
Inventors
- 👤 David Perry Fouts
- 👤 Jasvier Singh Jaspal
- 👤 James Robert Lloyd
- 👤 Walden Bennett Roush
- 👤 Michael James Sullivan
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 19:49
CPC Classifications
H; H10; H10W; H10W72/00; H10W72/071; H10W72/072; H05; H05K; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/341; H05K3/3431; H05K3/3436; H10W72/07231; H10W72/07236
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
100 words
Method of relieving stresses in a circuit chip fastened by means of a plurality of discrete solder joints to a dielectric substrate rigid with respect to the chip, wherein the chip has become elastically deformed and such deformation is maintained by the plastic flow of the solder, characterized by the steps of: heating the soldered assembly to a temperature within the single phase region of the solder employed, and maintaining the assembly at the selected temperature for a time sufficient to effect substantially complete grain boundary sliding in said solder to thus restore said chip to a substantially unstressed state.
Claim 2
Dependent Claim
100 words
Method of relieving stresses in a circuit chip fastened by means of a plurality of discrete solder joints to a dielectric substrate rigid with respect to the chip, wherein the chip has become elastically deformed and such deformation is maintained by the plastic flow of the solder, characterized by the steps of: heating the soldered assembly to a temperature within the single phase region of the solder employed, and maintaining the assembly at the selected temperature for a time sufficient to effect substantially complete grain boundary sliding in said solder to thus restore said chip to a substantially unstressed state.
Claim 3
Dependent Claim
42 words
Method according to claim 2, characterized in that the said temperature lies midway between the liquidus temperature and the temperature of the single phase to two phase transition for the solder used to effect the interconnection of the chip and the substrate.
Claim 4
Dependent Claim
14 words
Method according to claim 2, characterized in that the temperature is 200°C ± 10°C.
Claim 5
Dependent Claim
29 words
Method according to claim 3, characterized in that the time at which the assembly is maintained at the elevated temperature is in the range from 20 to 30 minutes.
References Cited (Backward Citations)
No citation records indexed.
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