US3791028A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ultrasonic bonding of cubic crystal-structure metals
Assignee: International Business Machines Corp
•
Filing: 1971-09-17
•
Granted: 1974-02-12
•
Expires: 1991-09-17
Abstract
Abstract Improved corrosion resistant, high ductility ultrasonic bonds are formed between two cubic structure metallic members such as a copper wire and a copper clad printed circuit board. Each of the members is coated, preferably by plating with a smooth layer of dead soft gold prior to bonding. The coated members are then ultrasonically bonded together. The bond formed is preferably a gold-to-gold joint with no contact between the cubic structure metallic members. This bond is unexpectedly much stronger than the dead soft gold of which it is comprised. Preferred plating and bonding parameters are discussed and analyzed.
Inventors
- 👤 L Missel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:36
CPC Classifications
H; H10; H10P; H10P72/00; H10P72/04; H10P72/0444; B; B23; B23K; B23K20/00; B23K20/10; B23K35/00; B23K35/001; H05; H05K; H05K3/00; H05K3/30; H05K3/32; H05K3/328; H05K2201/00; H05K2201/10; H05K2201/10227; H05K2201/10287; H05K2203/00; H05K2203/02; H05K2203/0285; H10W; H10W72/00; H10W72/01; H10W72/015; H10W72/01565; H10W72/071; H10W72/075; H10W72/07531; H10W72/07532; H10W72/07533; H10W72/50; H10W72/521; H10W72/522; H10W72/531; H10W72/5363; H10W72/551; H10W72/552; H10W72/5522; H10W72/5524; H10W72/5525; H10W72/90; H10W72/951; H10W72/952; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/49155; Y10T29/49162
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
91 words
A method of connecting terminals on a copper-clad printed circuit board comprising the steps of: gold plating the terminals of said circuit board with a layer of deadsoft, smooth gold; gold plating a copper wire with a layer of dead-soft, smooth; placing in contact with the gold-plated terminal the gold-plated copper wire; applying pressure to the wire against the board to maintain a gold-to-gold contact; ultrasonically vibrating the wire relative to the the board until a gold-to-gold bond is formed between the wire and the board thereby making an electrical connection.
Claim 2
Independent Claim
91 words
A method of connecting terminals on a copper-clad printed circuit board comprising the steps of: gold plating the terminals of said circuit board with a layer of deadsoft, smooth gold; gold plating a copper wire with a layer of dead-soft, smooth; placing in contact with the gold-plated terminal the gold-plated copper wire; applying pressure to the wire against the board to maintain a gold-to-gold contact; ultrasonically vibrating the wire relative to the the board until a gold-to-gold bond is formed between the wire and the board thereby making an electrical connection.
Claim 3
Dependent Claim
22 words
The method of claim 1 wherein the plating steps are performed in a neutral bath to provide maximum gold density and purity.
Claim 4
Dependent Claim
51 words
The method of claim 1 wherein each plating step comprises: cleaning the members to remove adhesion-impairing and contaminating materials; plating a gold strike coating onto the member in a gold strike plating bath; and plating gold accumulation layer on the member over the gold strike coating in an efficient plating bath.
Claim 5
Dependent Claim
37 words
The method of claim 3 wherein the plating of the accumulation layer on the circuit board is performed with a plating current of between 2 and 6 amperes per square foot of the area to be plated.
Claim 6
Dependent Claim
36 words
The method of claim 3 wherein the plating of the accumulation layer on the wire is performed with a plating current of between 2 and 15 amperes per square foot of the area to be plated.
Claim 7
Dependent Claim
18 words
The method of claim 5 Wherein the copper wire is made of fully annealed oxygen-free, high conductivity copper.
References Cited (Backward Citations)
US2946119A
Cited
GB845112A
Cited
US3458921A
Cited
US3617818A
Cited
US3609472A
Cited
US3593412A
Cited
US3662454A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |