US4282311A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for fabricating flyleads for video disc styli
Assignee: RCA Corp
•
Filing: 1979-10-03
•
Granted: 1981-08-04
•
Expires: 1999-10-03
Abstract
Abstract A method of making flyleads for video disc playback cartridges wherein a dry film resist is coated on both sides of a metal sheet, one side is exposed through a patterned mask, the patterned side is developed and etched, and the remaining photoresist is removed.
Inventors
- 👤 Joseph R. Dinardo, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 23:12
CPC Classifications
G; G11; G11B; G11B3/00; G11B3/44; G11B3/46
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
94 words
A method for preparing a flylead for video disc pickup cartridges consisting essentially of the steps of laminating a dry film photoresist to both sides of a thin metal sheet between about 0.0002 and 0.0008 inches thick, exposing the first side to light through a mask so that the pattern on the mask is transferred to the photoresist, developing the patterned side with a solvent developer to selectively remove photoresist thereby exposing the underlying metal sheet, etching the exposed metal sheet, and removing the remaining photoresist from both sides of the etched metal sheet.
Claim 2
Independent Claim
94 words
A method for preparing a flylead for video disc pickup cartridges consisting essentially of the steps of laminating a dry film photoresist to both sides of a thin metal sheet between about 0.0002 and 0.0008 inches thick, exposing the first side to light through a mask so that the pattern on the mask is transferred to the photoresist, developing the patterned side with a solvent developer to selectively remove photoresist thereby exposing the underlying metal sheet, etching the exposed metal sheet, and removing the remaining photoresist from both sides of the etched metal sheet.
Claim 3
Dependent Claim
14 words
The method of claim 1 wherein the etchant is an aqueous ferric chloride solution.
Claim 4
Dependent Claim
17 words
The method of claim 2 wherein the density of the ferric chloride solution is about 32°-42° Baume.
Claim 5
Dependent Claim
13 words
The method of claim 1 wherein the photoresist is a negative working photoresist.
Claim 6
Dependent Claim
13 words
The method of claim 1 wherein the photoresist is a positive working photoresist.
Claim 7
Dependent Claim
14 words
The method of claim 1 wherein the metal sheet comprises a beryllium copper alloy.
Claim 8
Dependent Claim
18 words
The method of claim 4 which includes the additional step of flood exposing the second side to light.
References Cited (Backward Citations)
US3539259A
Cited
US3469982A
Cited
GB1275471A
Cited
US3842194A
Cited
US3767398A
Cited
US3952147A
Cited
US3960561A
Cited
US4077050A
Cited
US4162510A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-08-03 | 1985-02-02 | 1985-08-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-03 | 1989-02-02 | 1989-08-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-03 | 1993-02-02 | 1993-08-04 | $7700.00 | Window Closed / Lapsed |