US4120843A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Strippable solder mask material comprising polysulfone, silicon dioxide filler, and solvent
Assignee: International Business Machines Corp
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Filing: 1978-04-10
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Granted: 1978-10-17
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Expires: 1998-04-10
Abstract
Abstract A polysulfone base stop resist material to protect gold thermocompression bonding sites on a circuit module during a solder dipping operation. Along with the thermoplastic, thermostable strippable base of polysulfone, the resist includes a solvent for the polysulfone and a filler which holds the melted polysulfone in place during the solder dipping operation.
Inventors
- 👤 Joseph G. Ameen
- 👤 Glenn V. Elmore
- 👤 Anthony E. Peter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 00:21
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/0073; H05K3/0076; B; B23; B23K; B23K35/00; B23K35/22; B23K35/224; H05K2201/00; H05K2201/01; H05K2201/0104; H05K2201/0129; H05K2201/0137; H05K2201/0166; H05K2201/02; H05K2201/0203; H05K2201/0206; H05K2201/0209; H05K2203/00; H05K2203/07; H05K2203/0756; H05K2203/0769; H05K2203/0779; H05K2203/0783; H05K3/30; H05K3/32; H05K3/34; H05K3/3452
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
75 words
A solder mask material operative to protect gold thermocompression bonding sites on a ceramic module during a solder dipping operation, said mask material comprising a thermoplastic, thermostable strippable base of polysulfone, a solvent for the polysulfone, said solvent chosen from the group consisting of orthodichlorobenzene, monochlorobenzene, methylene chloride and trichloroethylene, and a filler of finely divided silicon dioxide particles, said filler being operative to hold the molten polysulfone in place during the solder dipping operation.
Claim 2
Dependent Claim
75 words
A solder mask material operative to protect gold thermocompression bonding sites on a ceramic module during a solder dipping operation, said mask material comprising a thermoplastic, thermostable strippable base of polysulfone, a solvent for the polysulfone, said solvent chosen from the group consisting of orthodichlorobenzene, monochlorobenzene, methylene chloride and trichloroethylene, and a filler of finely divided silicon dioxide particles, said filler being operative to hold the molten polysulfone in place during the solder dipping operation.
Claim 3
Dependent Claim
21 words
The invention according to claim 1 wherein there is between 20 and 40 grams of polysulfone per 100 mililiters of solvent.
Claim 4
Dependent Claim
27 words
The invention according to claim 1 wherein said filler consists of between 5 and 10 grams of finely divided silicon dioxide particles per 100 milliliters of solvent.
Claim 5
Dependent Claim
47 words
A strippable solder mask material operative to protect gold thermocompression bonding sites on a ceramic module during a solder dipping operation, said mask material comprising 30 grams of polysulfone dissolved in 100 milliliters of orthodichlorobenzene and mixed with 8 grams of finely divided particles of silicon dioxide.
Claim 6
Dependent Claim
47 words
A strippable solder mask material operative to protect gold thermocompression bonding sites on a ceramic module during a solder dipping operation, said mask material comprising 30 grams of polysulfone dissolved in 100 milliliters of orthodichlorobenzene and mixed with 8 grams of finely divided particles of silicon dioxide.
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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) | 1981-10-16 | 1982-04-17 | 1982-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-10-16 | 1986-04-17 | 1986-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-10-16 | 1990-04-17 | 1990-10-17 | $7700.00 | Window Closed / Lapsed |