Patent US4179802A successfully refreshed from Google Patents.
US4179802A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Studded chip attachment process
Assignee: International Business Machines Corp
•
Filing: 1978-03-27
•
Granted: 1979-12-25
•
Expires: 1998-03-27
Abstract
Abstract A plurality of metal studs are plated on a chip carrier surface in a pattern to match a terminal metal footprint on a chip to be joined. The studs are of sufficient height to permit flux cleaning, if necessary. After the studs are in place, the chip is aligned with the carrier and attached thereto, the chip pads containing a small amount of solder to provide the connecting joints. The carrier and chip are made of materials having nearly equal thermal expansion characteristics.
Inventors
- 👤 Kailash C. Joshi
- 👤 Ronald N. Spaight
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:40
CPC Classifications
H; H10; H10W; H10W72/00; H10W72/01; H10W72/012; H10W72/071; H10W72/072; H10W72/07231; H10W72/07236; H10W72/20; H10W72/251; H10W72/252; H10W72/90; H10W72/951; H10W72/952; Y; Y10; Y10S; Y10S505/00; Y10S505/825; Y10S505/917; Y10S505/923; Y10S505/927; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/49126; Y10T29/49147; Y10T29/49149; Y10T29/49155; Y10T29/49156
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
143 words
A method of bonding a first integrated circuit device having a number of connecting points to a second integrated circuit device having a like number of connecting pads, both first and second devices having approximately equal thermal expansion characteristics, said method comprising the steps of: fabricating a metal stud at each of said connecting points of said first integrated circuit device, the top of each stud providing a bondable surface; applying a amount of solder not exceeding 4×10 -3 centimeters thick to each of said connecting pads of said second integrated circuit devices; aligning said first and second integrated circuit devices so that each metal stud of said first device is positioned proximate its respective connecting pad of said second device; and applying sufficient pressure and temperature to the studs and pads to bond each of said studs to its respective connecting pad.
Claim 2
Independent Claim
143 words
A method of bonding a first integrated circuit device having a number of connecting points to a second integrated circuit device having a like number of connecting pads, both first and second devices having approximately equal thermal expansion characteristics, said method comprising the steps of: fabricating a metal stud at each of said connecting points of said first integrated circuit device, the top of each stud providing a bondable surface; applying a amount of solder not exceeding 4×10 -3 centimeters thick to each of said connecting pads of said second integrated circuit devices; aligning said first and second integrated circuit devices so that each metal stud of said first device is positioned proximate its respective connecting pad of said second device; and applying sufficient pressure and temperature to the studs and pads to bond each of said studs to its respective connecting pad.
Claim 3
Dependent Claim
28 words
The invention according to claim 1 including fabricating said first and second integrated circuit devices as a circuitized semiconductor chip and a matched expansion chip carrier substrate, respectively.
Claim 4
Dependent Claim
28 words
The invention according to claim 1 including fabricating said first and second integrated circuit devices as a matched expansion chip carrier substrate and a circuitized semiconductor chip, respectively.
Claim 5
Dependent Claim
20 words
The invention according to claims 2 or 3 including both first and second integrated circuit devices from a silicon base.
Claim 6
Dependent Claim
14 words
The invention according to claim 1 including forming said studs of the metal copper.
Claim 7
Dependent Claim
106 words
The invention according to claim 5 wherein said copper studs are fabricated by the steps of: depositing a thin layer of conductive metal over the areas encompassing the positions for each of said studs on the surface of said first device; depositing a layer of photoresist over the surface of said first device; exposing and developing the photoresist to define the stud areas on the surface of said first device; electroplating copper in the stud areas defined in said photoresist to form said studs; removing the photoresist; and flash etching the surface of said first device to remove the exposed thin layer of conductive metal therefrom.
Claim 8
Dependent Claim
40 words
The invention according to claim 1 inducing fabricating said metal studs by evaporating metal through openings in a pattern placed over the surface of said first device, said openings corresponding to the stud locations on the surface of said device.
Claim 9
Dependent Claim
31 words
The invention according to claim 6 including fabricating said studs to cylindrical shape having a height of 8 to 12×10 -3 centimeters and a diameter of 6 to 9×10 -3 centimeters.
References Cited (Backward Citations)
US3330026A
Cited
US3403438A
Cited
US3373481A
Cited
US3591839A
Cited
US3816270A
Cited
US3901770A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-12-24 | 1983-06-25 | 1983-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-24 | 1987-06-25 | 1987-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-24 | 1991-06-25 | 1991-12-25 | $7700.00 | Window Closed / Lapsed |