US4632295A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reduction atmosphere workpiece joining
Assignee: International Business Machines Corp
•
Filing: 1985-08-12
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Granted: 1986-12-30
•
Expires: 2005-08-12
Abstract
Abstract A workpiece is joined to a substrate by employing solder and applying diol and/or polyol and/or ether derivative thereof to the substrate. The workpiece is placed in contact with the diol and/or polyol and the resulting assembly is heated in a reducing atmosphere.
Inventors
- 👤 Vlasta A. Brusic
- 👤 Peter J. Elmgren
- 👤 Charles J. Owen
- 👤 David W. Sissenstein, Jr.
- 👤 Helen L. Yeh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:17
CPC Classifications
B; B23; B23K; B23K35/00; B23K35/22; B23K35/38; B23K35/36; B23K35/3612; H; H05; H05K; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/3489
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
106 words
A process for joining a workpiece to a substrate which comprises: a. applying solder to the area of said substrate where the workpiece is to be joined, or to said workpiece, or to both; b. applying to at least a portion of the area of said substrate where the workpiece is to be joined, a material selected from the group of dihydric alcohols, polyhydric alcohols, ether derivatives thereof, or mixtures thereof; c. positioning a workpiece on said substrate in contact with at least a portion of said material; d. heating the resulting assembly in a reducing atmosphere; and e. thereby joining said workpiece to said substrate.
Claim 2
Dependent Claim
106 words
A process for joining a workpiece to a substrate which comprises: a. applying solder to the area of said substrate where the workpiece is to be joined, or to said workpiece, or to both; b. applying to at least a portion of the area of said substrate where the workpiece is to be joined, a material selected from the group of dihydric alcohols, polyhydric alcohols, ether derivatives thereof, or mixtures thereof; c. positioning a workpiece on said substrate in contact with at least a portion of said material; d. heating the resulting assembly in a reducing atmosphere; and e. thereby joining said workpiece to said substrate.
Claim 3
Dependent Claim
13 words
The process of claim 1 wherein said workpiece is an integrated circuit chip.
Claim 4
Dependent Claim
12 words
The process of claim 2 wherein said substrate is a ceramic substrate.
Claim 5
Dependent Claim
12 words
The process of claim 1 wherein said substrate is a ceramic substrate.
Claim 6
Dependent Claim
23 words
The process of claim 1 wherein said reducing atmosphere is a hydrogen atmosphere wherein the amount of oxygen is less than 10 ppm.
Claim 7
Dependent Claim
16 words
The process of claim 5 wherein the temperature is about 300° C. to about 500° C.
Claim 8
Dependent Claim
18 words
The process of claim 6 wherein said heating is carried out for about 1 to about 3 minutes.
Claim 9
Dependent Claim
18 words
The process of claim 6 wherein said reducing atmosphere is hydrogen containing less than 1 ppm of oxygen.
Claim 10
Dependent Claim
12 words
The process of claim 6 wherein said reducing atmosphere is 100% hydrogen.
Claim 11
Dependent Claim
16 words
The process of claim 6 wherein said temperature is about 350° C. to about 450° C.
Claim 12
Dependent Claim
22 words
The process of claim 1 wherein said material is a saturated aliphatic alcohol or ether thereof containing 2 to 6 hydroxyl groups.
Claim 13
Dependent Claim
14 words
The process of claim 11 wherein said material contains 20 carbon atoms or less.
Claim 14
Dependent Claim
14 words
The process of claim 11 wherein said material contains 10 carbon atoms or less.
Claim 15
Dependent Claim
11 words
The process of claim 1 wherein said material is a 1,3-propanediol.
Claim 16
Dependent Claim
10 words
The process of claim 1 wherein said material is 1,2-propanediol.
Claim 17
Dependent Claim
19 words
The process of claim 1 which further comprises inserting input/output pins into the substrate prior to applying the solder.
Claim 18
Dependent Claim
32 words
The process of claim 16 wherein after insertion of the pins and prior to applying the solder the assembly is subjected to heating in a reducing atmosphere in order to remove oxide.
Claim 19
Dependent Claim
18 words
The process of claim 17 wherein said reducing atmosphere is hydrogen containing less than 10 ppm of oxygen.
Claim 20
Dependent Claim
18 words
The process of claim 17 wherein said reducing atmosphere is hydrogen containing less than 1 ppm of oxygen.
Claim 21
Dependent Claim
16 words
The process of claim 18 wherein the temperature is about 300° C. to about 500° C.
Claim 22
Dependent Claim
16 words
The process of claim 18 wherein said temperature is about 350° C. to about 450° C.
Claim 23
Dependent Claim
20 words
The process of claim 20 wherein the assembly is subjected to the heating for about 1 to about 3 minutes.
Claim 24
Dependent Claim
36 words
The process of claim 11 which further includes applying solder, to the pin heads which protrude from the top side of the substrate and simultaneously joining the chip to the substrate and soldering the pin heads.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-12-29 | 1990-06-30 | 1990-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-29 | 1994-06-30 | 1994-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-29 | 1998-06-30 | 1998-12-30 | $7700.00 | Window Closed / Lapsed |