Patent US5249732A successfully refreshed from Google Patents.
US5249732A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of bonding semiconductor chips to a substrate
Assignee: National Semiconductor Corp
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Filing: 1993-02-09
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Granted: 1993-10-05
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Expires: 2013-02-09
Abstract
Abstract In a method of bonding a pad on a semiconductor chip to a corresponding pad on a carrier, a wire ball is attached to the pad on the chip by bonding one end of a low melting temperature aluminum alloy bond wire to the chip pad. The wire is then broken off at the bond. A bead is formed on the chip pad by heating the ball to a temperature slightly above the melting point of the bond wire material for a predetermined period of time. The melted bead is then placed into contact with a corresponding pad on the carrier.
Inventors
- 👤 Michael E. Thomas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 14:53
CPC Classifications
H; H10; H10W; H10W72/00; H10W72/01; H10W72/012; H10W72/071; H10W72/072; H10W72/07231; H10W72/07236; H10W72/20; H10W72/251; H10W72/90; H10W72/951; H10W72/952
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
114 words
A method for bonding a pad on a semiconductor chip to a corresponding pad on a carrier comprising the steps of: 1) providing a bond wire comprising a low melting temperature aluminum alloy material; 2) forming a wire ball attached to a pad on the chip by bonding one end of the bond wire to the pad on the chip; 3) breaking the wire off at the bond; 4) forming a bead on the chip pad by heating the ball to a temperature slightly above the melting point of the bond wire material for a predetermined period of time; and 5) placing the melted bead into contact with a corresponding pad on the carrier.
Claim 2
Independent Claim
114 words
A method for bonding a pad on a semiconductor chip to a corresponding pad on a carrier comprising the steps of: 1) providing a bond wire comprising a low melting temperature aluminum alloy material; 2) forming a wire ball attached to a pad on the chip by bonding one end of the bond wire to the pad on the chip; 3) breaking the wire off at the bond; 4) forming a bead on the chip pad by heating the ball to a temperature slightly above the melting point of the bond wire material for a predetermined period of time; and 5) placing the melted bead into contact with a corresponding pad on the carrier.
Claim 3
Dependent Claim
19 words
The method in accordance with claim 1 wherein said low melting temperature aluminum alloy material comprises an aluminum-germanium alloy.
Claim 4
Dependent Claim
19 words
The method in accordance with claim 1 wherein said low melting temperature aluminum alloy material comprises an aluminum-magnesium alloy.
Claim 5
Dependent Claim
19 words
The method in accordance with claim 1 wherein said low melting temperature aluminum alloy material comprises an aluminum-copper alloy.
Claim 6
Dependent Claim
20 words
The method in accordance with claim 1 wherein steps 4 and 5 are carried out under reducing or inert conditions.
Claim 7
Independent Claim
94 words
A method for bonding a pad on a semiconductor chip to a corresponding pad on a carrier comprising the steps of: 1) forming a bead on the pad on the chip by dispensing a ball of molten bonding material comprising a low melting temperature aluminum alloy from a heated capillary tube onto the pad on the chip; 2) heating the bead to a temperature slightly above the melting point of the bonding material for a predetermined period of time; and 3) placing the melted bead into contact with a corresponding pad on the carrier.
Claim 8
Independent Claim
94 words
A method for bonding a pad on a semiconductor chip to a corresponding pad on a carrier comprising the steps of: 1) forming a bead on the pad on the chip by dispensing a ball of molten bonding material comprising a low melting temperature aluminum alloy from a heated capillary tube onto the pad on the chip; 2) heating the bead to a temperature slightly above the melting point of the bonding material for a predetermined period of time; and 3) placing the melted bead into contact with a corresponding pad on the carrier.
Claim 9
Dependent Claim
18 words
The method in accordance with claim 6 wherein said low melting temperature aluminum alloy comprises an aluminum-germanium alloy.
Claim 10
Dependent Claim
18 words
The method in accordance with claim 6 wherein said low melting temperature aluminum alloy comprises an aluminum-magnesium alloy.
Claim 11
Dependent Claim
18 words
The method in accordance with claim 6 wherein said low melting temperature aluminum alloy comprises an aluminum-copper alloy.
Claim 12
Dependent Claim
20 words
The method in accordance with claim 6 wherein steps 2 and 3 are carried out under reducing or inert conditions.
Claim 13
Independent Claim
162 words
A method for bonding a pad on a semiconductor chip to a corresponding pad on a carrier comprising the steps of: 1) forming at least one aluminum bond pad on a semiconductor chip; 2) forming a protective layer over the surface of the semiconductor chip and said at least one bond pad; 3) forming a window in the protective layer for each aluminum pad exposing said aluminum; 4) providing a bond wire comprising a low melting temperature aluminum alloy material; 5) forming a wire bond ball attached to a pad on the chip by bonding one end of the bond wire to the pad on the chip; 6) breaking the bond wire off at the bond; 7) forming a bead on the chip pad by heating the ball to a temperature slightly above the melting point of the bond wire material for a predetermined period of time; and 8) placing the melted bead into contact with a corresponding pad on the carrier.
Claim 14
Independent Claim
162 words
A method for bonding a pad on a semiconductor chip to a corresponding pad on a carrier comprising the steps of: 1) forming at least one aluminum bond pad on a semiconductor chip; 2) forming a protective layer over the surface of the semiconductor chip and said at least one bond pad; 3) forming a window in the protective layer for each aluminum pad exposing said aluminum; 4) providing a bond wire comprising a low melting temperature aluminum alloy material; 5) forming a wire bond ball attached to a pad on the chip by bonding one end of the bond wire to the pad on the chip; 6) breaking the bond wire off at the bond; 7) forming a bead on the chip pad by heating the ball to a temperature slightly above the melting point of the bond wire material for a predetermined period of time; and 8) placing the melted bead into contact with a corresponding pad on the carrier.
Claim 15
Dependent Claim
19 words
The method in accordance with claim 11 wherein said low melting temperature aluminum alloy material comprises an aluminum-magnesium alloy.
Claim 16
Dependent Claim
19 words
The method in accordance with claim 11 wherein said low melting temperature aluminum alloy material comprises an aluminum-germanium alloy.
Claim 17
Dependent Claim
19 words
The method in accordance with claim 11 wherein said low melting temperature aluminum alloy material comprises an aluminum-copper alloy.
Claim 18
Dependent Claim
19 words
The method in accordance with claim 11 wherein steps 7 and 8 are performed under reducing or inert conditions.
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) | 1996-10-04 | 1997-04-05 | 1997-10-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-10-04 | 2001-04-05 | 2001-10-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-10-04 | 2005-04-05 | 2005-10-05 | $7700.00 | Window Closed / Lapsed |