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Patent US5505367A successfully refreshed from Google Patents.
US5505367A
Expired / Lapsed
US
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Method for bumping silicon devices
Assignee: Bell Semiconductor LLC
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Filing: 1994-11-02
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Granted: 1996-04-09
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Expires: 2014-11-02
Abstract
Abstract The bonding pads (18) of a semiconductor chip (12) each may be provided with a solder bump (36) by first screen printing a pattern of solder paste (36) on a heat-resistant, non-wettable surface (24). The chip (12) is then placed on the surface (24) so each bonding pad (18) contacts a portion of the solder paste pattern (36). The solder paste is then reflowed, yielding molten solder that bonds to the bonding pads (18) of the chip, but not to the surface (24). After reflow, the chip, with its now-bumped pads, is removed from the surface for subsequent soldering to a wettable substrate.
Inventors
- 👤 Yinon Degani
- 👤 Thomas D. Dudderar
- 👤 John G. Spadafora
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 15:40
CPC Classifications
B; B23; B23K; B23K1/00; B23K1/0008; B23K1/0016; B23K2101/00; B23K2101/36
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
106 words
A method for providing solder on solder-wettable bond sites on a semiconductor chip, comprising the steps of: providing a non-wettable, heat-resistant surface that is printable with solder paste; printing a pattern of solder paste, corresponding to the pattern of bond sites on the chip, on the non-wettable, heat-resistant surface; placing the chip on the surface so that the bonding pads on the chip contact a portion of the pattern of solder paste; reflowing the pattern of solder paste to yield molten solder that wets and bonds to the bonding pads of the chip; and removing the chip from the surface once the molten solder has cooled.
Claim 2
Independent Claim
106 words
A method for providing solder on solder-wettable bond sites on a semiconductor chip, comprising the steps of: providing a non-wettable, heat-resistant surface that is printable with solder paste; printing a pattern of solder paste, corresponding to the pattern of bond sites on the chip, on the non-wettable, heat-resistant surface; placing the chip on the surface so that the bonding pads on the chip contact a portion of the pattern of solder paste; reflowing the pattern of solder paste to yield molten solder that wets and bonds to the bonding pads of the chip; and removing the chip from the surface once the molten solder has cooled.
Claim 3
Dependent Claim
57 words
The method according to claim 1 wherein the pattern of solder paste is printed by the steps of: placing a stencil, having a pattern of openings therein corresponding to the pattern of bonding pads on the chip, in face-to-face relationship with the surface; and forcing solder paste through the openings in the stencil and onto the surface.
Claim 4
Dependent Claim
29 words
The method according to claim 1 wherein the step of providing the non-wettable, heat-resistant surface comprises the step of: providing a silicon wafer having a mirrored, non-metallized major surface.
Claim 5
Dependent Claim
43 words
The method according to claim 1 wherein the step of providing the non-wettable, heat-resistant surface comprises the step of: providing a silicon wafer having metallization on a first major surface; and providing a non-wettable, heat-resistant layer over the major surface of the wafer.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-04-09 | 1999-10-09 | 2000-04-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-04-09 | 2003-10-09 | 2004-04-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-04-09 | 2007-10-09 | 2008-04-09 | $7700.00 | Window Closed / Lapsed |