US5973406A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic device bonding method and electronic circuit apparatus
Assignee: Hitachi Ltd
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Filing: 1997-08-25
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Granted: 1999-10-26
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Expires: 2017-08-25
Abstract
Abstract An electronic device is solder bonded properly without using fluxes nor precise positioning with respect to a substrate. A bond pad with a size about twice the size of terminal pad of the electronic device is formed in a region on the substrate where the electronic device is to be mounted. After placing the electronic device of the substrate surface, the whole unit is heated in a nitrogen atmosphere to melt a bump formed on the terminal pad of the electronic device. The molten solder wets and spreads over the bond pads formed on the substrate, thereby establishing reflow soldering between the bond pads and the terminal pads. The position of the electronic device with respect to the substrate is spontaneously corrected due to a self-alignment function induced by wetting and spreading of the molten solder over the bond pad of the substrate.
Inventors
- 👤 Masahide Harada
- 👤 Toru Nishikawa
- 👤 Ryohei Satoh
- 👤 Osamu Yamada
- 👤 Takayuki Uda
- 👤 Mitsugu Shirai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 12:13
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/341; H05K3/3431; H05K3/3436; H05K2201/00; H05K2201/09; H05K2201/09209; H05K2201/09654; H05K2201/09781; H05K2201/20; H05K2201/2036; H05K2203/00; H05K2203/01; H05K2203/0182; H05K2203/08; H05K2203/086; H10; H10W; H10W72/00; H10W72/071; H10W72/072; H10W72/07221; H10W72/07227; H10W72/07231; H10W72/07236; H10W72/20; H10W72/251; H10W72/252; H10W72/261; H10W72/263; H10W72/267; Y; Y02; Y02P; Y02P70/00; Y02P70/50
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
157 words
An electronic device bonding method by which bumps formed on terminal pads of an electronic device are melted to form solder joints so as to connect said bond pads of device mounting pattern formed on a substrate and said terminal pads of said electronic device, comprising the steps of: fabricating said device mounting pattern which comprises a plurality of said bond pads, each having a surface area about twice a size of a corresponding one of said terminal pads of said electronic device, within a surface region of said substrate where said electronic device is to be mounted; and melting said bumps formed on said terminal pads of said electronic device while said bumps contact with the corresponding bond pads of said device mounting pattern fabricated on said substrate so as to form solder joints connecting between said bond pads of said device mounting pattern fabricated on said substrate and said terminal pads of said electronic device.
Claim 2
Dependent Claim
157 words
An electronic device bonding method by which bumps formed on terminal pads of an electronic device are melted to form solder joints so as to connect said bond pads of device mounting pattern formed on a substrate and said terminal pads of said electronic device, comprising the steps of: fabricating said device mounting pattern which comprises a plurality of said bond pads, each having a surface area about twice a size of a corresponding one of said terminal pads of said electronic device, within a surface region of said substrate where said electronic device is to be mounted; and melting said bumps formed on said terminal pads of said electronic device while said bumps contact with the corresponding bond pads of said device mounting pattern fabricated on said substrate so as to form solder joints connecting between said bond pads of said device mounting pattern fabricated on said substrate and said terminal pads of said electronic device.
Claim 3
Dependent Claim
227 words
An electronic device bonding method by which bumps formed on a plurality of terminal pads of an electronic device are melted to form solder joints so as to connect bond pads of a device mounting pattern formed on a substrate and said terminal pads of said electronic device, comprising the steps of: fabricating said device mounting pattern which comprises a plurality of said bond pads, each having a larger surface area than a corresponding terminal pad of said electronic device, within a surface region of said substrate where said electronic device is to be mounted; melting said bumps formed on said terminal pads of said electronic device while said bumps contact with corresponding bond pads of said device mounting pattern fabricated on said substrate so as to form solder joints connecting between said bond pads of said device mounting pattern fabricated on said substrate and said terminal pads of said electronic device; and, wherein at least one of said bumps formed on at least one of the plurality of said terminal pads of said electronic device is an electronic device push-up bump, which contacts with a surface region of said substrate where no bond pad is formed when said electronic device is mounted on said substrate, and the melted push-up bump pushes said electronic device up by its surface tension during the formation of said solder joints.
Claim 4
Dependent Claim
227 words
An electronic device bonding method by which bumps formed on a plurality of terminal pads of an electronic device are melted to form solder joints so as to connect bond pads of a device mounting pattern formed on a substrate and said terminal pads of said electronic device, comprising the steps of: fabricating said device mounting pattern which comprises a plurality of said bond pads, each having a larger surface area than a corresponding terminal pad of said electronic device, within a surface region of said substrate where said electronic device is to be mounted; melting said bumps formed on said terminal pads of said electronic device while said bumps contact with corresponding bond pads of said device mounting pattern fabricated on said substrate so as to form solder joints connecting between said bond pads of said device mounting pattern fabricated on said substrate and said terminal pads of said electronic device; and, wherein at least one of said bumps formed on at least one of the plurality of said terminal pads of said electronic device is an electronic device push-up bump, which contacts with a surface region of said substrate where no bond pad is formed when said electronic device is mounted on said substrate, and the melted push-up bump pushes said electronic device up by its surface tension during the formation of said solder joints.
Claim 5
Dependent Claim
51 words
The electronic device bonding method in accordance with claim 2, wherein, said surface region of said substrate, where no bond pad is formed and to which said electronic device push-up bump contacts, includes areas in the center and the periphery of the region where said electronic device is to be mounted.
Claim 6
Dependent Claim
45 words
The electronic device bonding method in accordance with claim 2, wherein, said solder joints, which bond between said bond pads formed on said substrate and a part of said terminal pads on which said push-up bump has not been formed, form a drum type shape.
Claim 7
Dependent Claim
63 words
An electronic circuit apparatus in which solder joints are formed between bonds pads of a device mounting pattern formed on a substrate and terminal pads of an electronic device using a flip-chip method, wherein: said bond pad of said device mounting pattern formed on said substrate has a surface area about twice a size of a corresponding terminal pad of said electronic device.
Claim 8
Dependent Claim
63 words
An electronic circuit apparatus in which solder joints are formed between bonds pads of a device mounting pattern formed on a substrate and terminal pads of an electronic device using a flip-chip method, wherein: said bond pad of said device mounting pattern formed on said substrate has a surface area about twice a size of a corresponding terminal pad of said electronic device.
Claim 9
Dependent Claim
163 words
An electronic circuit apparatus in which solder joints are formed between bonds pads of a device mounting pattern formed on a substrate and a plurality of terminal pads of an electronic device using a flip-chip method, wherein: said bond pad of said device mounting pattern formed on said substrate has a larger surface area than a corresponding terminal pad of said electronic device; at least one of said bumps formed on the plurality of said terminal pads said electronic device is an electronic device push-up bump, which contacts with a surface region of said substrate where no bond pad is formed when said electronic device is mounted on said substrate, and the melted push-up bump pushes said electronic device up by its surface tension during the formation of said solder joints; and, said solder joints, which bond between said bond pads formed on said substrate and said terminal pads on which said push-up bump has not been formed, form a drum type shape.
Claim 10
Dependent Claim
163 words
An electronic circuit apparatus in which solder joints are formed between bonds pads of a device mounting pattern formed on a substrate and a plurality of terminal pads of an electronic device using a flip-chip method, wherein: said bond pad of said device mounting pattern formed on said substrate has a larger surface area than a corresponding terminal pad of said electronic device; at least one of said bumps formed on the plurality of said terminal pads said electronic device is an electronic device push-up bump, which contacts with a surface region of said substrate where no bond pad is formed when said electronic device is mounted on said substrate, and the melted push-up bump pushes said electronic device up by its surface tension during the formation of said solder joints; and, said solder joints, which bond between said bond pads formed on said substrate and said terminal pads on which said push-up bump has not been formed, form a drum type shape.
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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) | 2002-10-25 | 2003-04-26 | 2003-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-10-25 | 2007-04-26 | 2007-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-10-25 | 2011-04-26 | 2011-10-26 | $7700.00 | Window Closed / Lapsed |