US5207372A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for soldering a semiconductor device to a circuitized substrate
Assignee: International Business Machines Corp
•
Filing: 1991-09-23
•
Granted: 1993-05-04
•
Expires: 2011-09-23
Abstract
Abstract A method for bonding a semiconductor device onto a substrate (e.g., a printed circuit board) such that solder elements on the device are connected, respectively, to circuit elements on the substrate. The solder elements are heated by passing hot gas onto an opposing surface of the device such that, by heat transference, the solder elements become partially molten to form the desired connections. Pressure is also applied onto the device during this formation to assure planarity at the connection sites. Following formation, cooling of the connections is accomplished. By directing heated gas onto only the semiconductor device and not onto the solder element-circuit member locations (and thus onto the substrate), direct semiconductor device bonding to lower melting point temperature substrates (e.g., those circuit boards containing fiberglass reinforced epoxy resin as a dielectric) may be achieved.
Inventors
- 👤 Joseph Funari
- 👤 Ronald J. Moore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 13:28
CPC Classifications
B; B23; B23K; B23K1/00; B23K1/012; H; H05; H05K; H05K13/00; H05K13/04; H05K13/046; H05K13/0465; H10; H10W; H10W72/00; H10W72/071; H10W72/0711
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
167 words
A method of soldering a semiconductor device having a plurality of solder elements located along a first surface thereof to a substrate having a plurality of circuit members thereon, said method comprising: aligning said semiconductor device relative to said substrate such that selected ones of said solder elements are aligned with respective ones of said circuit members on said substrate; engaging a second surface of said semiconductor device to apply force onto said second surface sufficient to cause said selected solder elements to engage said aligned respective circuit elements; applying heat directly onto only said second surface of said semiconductor device, said semiconductor device conducting said heat to said selected solder elements, said solder elements heated by primarily conductor heat during said application of force to cause at least partial reflow of said selected solder elements engaging said respective circuit elements; cooling said selected solder elements to cause at least partial solidification thereof during said application of said force; and removing said force from said semiconductor device.
Claim 2
Independent Claim
167 words
A method of soldering a semiconductor device having a plurality of solder elements located along a first surface thereof to a substrate having a plurality of circuit members thereon, said method comprising: aligning said semiconductor device relative to said substrate such that selected ones of said solder elements are aligned with respective ones of said circuit members on said substrate; engaging a second surface of said semiconductor device to apply force onto said second surface sufficient to cause said selected solder elements to engage said aligned respective circuit elements; applying heat directly onto only said second surface of said semiconductor device, said semiconductor device conducting said heat to said selected solder elements, said solder elements heated by primarily conductor heat during said application of force to cause at least partial reflow of said selected solder elements engaging said respective circuit elements; cooling said selected solder elements to cause at least partial solidification thereof during said application of said force; and removing said force from said semiconductor device.
Claim 3
Dependent Claim
24 words
The method according to claim 1 wherein said aligning of said semiconductor device is accomplished by applying a suction force on said semiconductor device.
Claim 4
Dependent Claim
30 words
The method according to claim 2 wherein said suction force is applied on said semiconductor device during said application of said force onto said second surface of said semiconductor device.
Claim 5
Dependent Claim
23 words
The method according to claim 3 wherein said suction force is applied on said semiconductor device during said heating of said semiconductor device.
Claim 6
Dependent Claim
24 words
The method according to claim 4 wherein said suction force is applied on said semiconductor device during said cooling of said selected solder elements.
Claim 7
Dependent Claim
33 words
The method according to claim 1 wherein said applying said heat to said semiconductor device is accomplished by applying heated gas onto said second surface of said device for a predetermined time period.
Claim 8
Dependent Claim
14 words
The method according to claim 6 wherein said heated gas is an inert gas.
Claim 9
Dependent Claim
11 words
The method according to claim 7 wherein said gas is nitrogen.
Claim 10
Dependent Claim
33 words
The method according to claim 6 wherein said heating of said semiconductor device heats said first surface of said semiconductor device to a temperature slightly below the melting point of said solder elements.
Claim 11
Dependent Claim
28 words
The method according to claim 9 wherein said heated gas applied to said second surface is at a temperature slightly above the melting point of said solder elements.
Claim 12
Dependent Claim
37 words
The method according to claim 10 wherein said predetermined time period said heated gas is applied onto said second surface of said semiconductor device is within the range of from about 0.1 seconds to about 5.0 seconds.
Claim 13
Dependent Claim
23 words
The method according to claim 1 wherein said cooling of said selected solder elements is accomplished by applying cooling gas onto said elements.
Claim 14
Dependent Claim
14 words
The method according to claim 12 wherein said cooling gas is an inert gas.
Claim 15
Dependent Claim
12 words
The method according to claim 13 wherein said cooling gas is nitrogen.
Claim 16
Dependent Claim
33 words
The method according to claim 1 further including heating said substrate and said circuit members thereon to an established temperature prior to said applying heat to said second surface of said semiconductor device.
Claim 17
Dependent Claim
23 words
The method according to claim 1 further including applying a predetermined weight onto said selected solder elements during said applying of said heat.
Claim 18
Dependent Claim
29 words
The method according to claim 16 wherein said predetermined weight is within the range of from about three to about ten grams per each of said selected solder elements.
References Cited (Backward Citations)
DE2351056A1
Cited
US4887760A
Cited
US4735354A
Cited
US4844325A
Cited
US4787548A
Cited
US4799617A
Cited
US4967950A
Cited
US5115964A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-05-03 | 1996-11-02 | 1997-05-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-05-03 | 2000-11-02 | 2001-05-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-05-03 | 2004-11-02 | 2005-05-04 | $7700.00 | Window Closed / Lapsed |