Patent US5597110A successfully refreshed from Google Patents.
US5597110A
Expired / Lapsed
US
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Method for forming a solder bump by solder-jetting or the like
Assignee: NXP USA Inc
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Filing: 1995-08-25
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Granted: 1997-01-28
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Expires: 2015-08-25
Abstract
Abstract The present invention provides a method for forming a solder bump (24) on a substrate (20). The substrate (20) includes a bond pad (18) having a faying surface (19) composed of solder-wettable metal. The method includes coating the faying surface (19) with a plate (16) formed of a first metal having a first melting temperature, and projecting a discrete microdroplet (14) onto the plate (16). The microdroplet (14) is formed of a molten second metal and has a second melting temperature greater than the first melting temperature. The microdroplet (14) fuses to the plate (16) to form the solder bump (24).
Inventors
- 👤 Cynthia M. Melton
- 👤 Robert Pfahl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:36
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/3465; B; B23; B23K; B23K1/00; B23K1/20; H10; H10W; H10W70/00; H10W70/099; B23K2101/00; B23K2101/36; H05K2203/00; H05K2203/01; H05K2203/0104; H05K2203/013; H05K3/346; H05K3/3473
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
103 words
A method for forming a solder bump bonded to a bond pad on a substrate, said bond pad having a copper faying surface, said method comprising: coating the copper faying surface with a plate formed of a first metal having a first melting temperature; projecting a discrete microdroplet onto the plate, said microdroplet being formed of a molten second metal having a second melting temperature greater than the first melting temperature and fusible to the first metal to form a solder alloy, said microdroplet being projected onto the plate so as to fuse the microdroplet to the plate to form the solder bump.
Claim 2
Independent Claim
103 words
A method for forming a solder bump bonded to a bond pad on a substrate, said bond pad having a copper faying surface, said method comprising: coating the copper faying surface with a plate formed of a first metal having a first melting temperature; projecting a discrete microdroplet onto the plate, said microdroplet being formed of a molten second metal having a second melting temperature greater than the first melting temperature and fusible to the first metal to form a solder alloy, said microdroplet being projected onto the plate so as to fuse the microdroplet to the plate to form the solder bump.
Claim 3
Dependent Claim
15 words
The method of claim 1, wherein the first melting temperature is less than 160° C.
Claim 4
Dependent Claim
17 words
The method of claim 1, wherein the first melting temperature is not greater than about 120° C.
Claim 5
Dependent Claim
15 words
The method of claim 1, wherein the second melting temperature is at least 160° C.
Claim 6
Dependent Claim
15 words
The method of claim 1, wherein the second melting temperature is greater than 180° C.
Claim 7
Dependent Claim
20 words
The method of claim 1, wherein the step of projecting is comprised of jetting said microdroplet from a solder-jet device.
Claim 8
Dependent Claim
24 words
The method of claim 1, wherein the plate is composed of metal selected from the group consisting of indium, indium-base alloys, and tin-bismuth alloys.
Claim 9
Dependent Claim
25 words
The method of claim 1, wherein the microdroplet is composed of a molten solder selected from the group consisting of tin-base solders and lead-base solders.
Claim 10
Dependent Claim
55 words
The method of claim 1, wherein the solder bump is composed of an alloy comprising the second metal selected from the group consisting of tin-base and lead-base solders and the first metal selected from the group consisting of indium, indium-base alloy, and tin-bismuth alloy of said plate and is characterized by a substantially uniform composition.
Claim 11
Dependent Claim
31 words
The method of claim 1, further comprising projecting a second discrete microdroplet of the molten second metal onto said solder bump to fuse the second discrete microdroplet to said solder bump.
Claim 12
Independent Claim
85 words
A method for forming a solder bump on a substrate, said substrate comprising a bond pad having a faying surface composed of solder-wettable metal, said method comprising: coating the faying surface with a plate composed of metal selected from the group consisting of indium, indium-base alloys, and tin-bismuth alloys; and projecting a discrete microdroplet of a molten metal selected from the group consisting of tin-base metals and lead-base metals onto the plate to fuse the microdroplet to the plate and thereby form the solder bump.
Claim 13
Independent Claim
85 words
A method for forming a solder bump on a substrate, said substrate comprising a bond pad having a faying surface composed of solder-wettable metal, said method comprising: coating the faying surface with a plate composed of metal selected from the group consisting of indium, indium-base alloys, and tin-bismuth alloys; and projecting a discrete microdroplet of a molten metal selected from the group consisting of tin-base metals and lead-base metals onto the plate to fuse the microdroplet to the plate and thereby form the solder bump.
Claim 14
Dependent Claim
28 words
The method of claim 11, wherein the plate is formed of an alloy composed of between about 35 and 45 weight percent tin and the balance substantially bismuth.
Claim 15
Dependent Claim
17 words
The method of claim 11, wherein the microdroplet has a diameter between about 25 and 50 μm.
Claim 16
Dependent Claim
16 words
The method of claim 11, wherein the plate has a thickness of less than 50 μm.
Claim 17
Dependent Claim
16 words
The method of claim 11, wherein the molten metal is composed of a molten tin-base solder.
Claim 18
Dependent Claim
20 words
The method of claim 15, wherein the tin-base solder is formed of an alloy composed substantially of tin and lead.
Claim 19
Dependent Claim
29 words
The method of claim 16, wherein the tin-base solder is formed of an alloy composed of between about 55 to 65 weight percent tin and the balance substantially lead.
Claim 20
Dependent Claim
16 words
The method of claim 11, wherein the molten metal is composed of a molten lead-base solder.
Claim 21
Dependent Claim
26 words
The method of claim 18, wherein the lead-base solder is formed of an alloy composed of about 95 weight percent lead and the balance substantially tin.
Claim 22
Dependent Claim
19 words
The method of claim 11, wherein the plate is formed of an alloy composed substantially of tin and indium.
Claim 23
Dependent Claim
28 words
The method of claim 20, wherein the plate is formed of an alloy composed of between about 15 to 60 weight percent tin and the balance substantially indium.
Claim 24
Independent Claim
99 words
A method for forming a solder bump bonded to a bond pad on a substrate, said bond pad having a copper faying surface, said method comprising: coating the copper faying surface with a tin-indium plate having a melting temperature of less than about 120° C.; and solder-jetting a discrete microdroplet of a molten tin-lead solder having a diameter between about 25 and 50 μm and a melting temperature greater than about 180° C., whereupon the discrete microdroplet fuses to the tin-indium plate to form the solder bump, wherein the solder bump is characterized by a substantially uniform tin-lead-indium composition.
Claim 25
Independent Claim
99 words
A method for forming a solder bump bonded to a bond pad on a substrate, said bond pad having a copper faying surface, said method comprising: coating the copper faying surface with a tin-indium plate having a melting temperature of less than about 120° C.; and solder-jetting a discrete microdroplet of a molten tin-lead solder having a diameter between about 25 and 50 μm and a melting temperature greater than about 180° C., whereupon the discrete microdroplet fuses to the tin-indium plate to form the solder bump, wherein the solder bump is characterized by a substantially uniform tin-lead-indium composition.
References Cited (Backward Citations)
US2512743A
Cited
US3461462A
Cited
DE2906802A1
Cited
US4828886A
Cited
US5269453A
Cited
JPH06252536A
Cited
US5477419A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-01-28 | 2000-07-29 | 2001-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-01-28 | 2004-07-29 | 2005-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-01-28 | 2008-07-29 | 2009-01-28 | $7700.00 | Window Closed / Lapsed |