US3929532A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for etching apertured work piece
Assignee: RCA Licensing Corp
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Filing: 1974-07-17
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Granted: 1975-12-30
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Expires: 1994-07-17
Abstract
Abstract Method for etching an apertured work piece, such as a shadow mask for a color television picture tube, comprises coating opposite major surfaces of a thin metal sheet with etch-resistant patterns. The pattern on one major surface comprises an array of larger open areas surrounded by etch-resistant material, and the pattern on the opposite major surface comprises smaller open areas of similar shape and registered with the larger open areas on the one major surface. Each of the smaller open areas has therein a still-smaller solid area of etch-resistant material. The coated sheet is then etched from both sides to produce the desired apertures, and then the coatings are removed from the sheet.
Inventors
- 👤 Henry William Kuzminski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 08:45
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/02; H01J9/14; H01J9/142; C; C23; C23F; C23F1/00; C23F1/02
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
140 words
A METHOD FOR PRODUCING AN ARRAY OF TAPERED APERTURES IN A THIN METAL SHEET COMPRISING A. COATING OPPOSITE MAJOR SURFADES OF SAID SHEET WITH ETCHRESISTANT PATTERNS, THE PATTERN ON ONE MAJOR SURFACE COMPRISING AN ARRAY OF OPEN AREAS SURROUNDED BY ETCH-RESISTANT MATERIAL, AND THE PATTERN ON THE OPPOSITE MAJOR SURFACE COMPRISING OPEN AREAS OF SMALLER SHAPE BUT SMALLER THAN THE OPEN AREAS ON SAID ONE MAJOR SURFACE AND REGISTERED WITH SAID LARGE OPEN AREAS, EACH OF SAID SMALLER OPEN AREAS HAVING THEREIN A SOLID AREA OF ETCH-RESISTANT MATERIAL THAT IS STILL SMALLER THAN SAID SMALLER OPEN AREA, EACH STILL-SMALLER SOLID AREA BEING CONTINUOUS AND UNBROKEN BY OPEN AREAS, B. SIMULTANEOUSLY ETCHING BOTH SIDES OF SAID COATED SHEET UNTIL SAID TAPERED APERTURES ARE PRODUCED IN SAID SHEET, C. AND THEN REMOVING SAID ETCH-RESISTANT PATTERNS FROM BOTH MAJOR SURFACES OF SAID SHEET.
Claim 2
Independent Claim
140 words
A METHOD FOR PRODUCING AN ARRAY OF TAPERED APERTURES IN A THIN METAL SHEET COMPRISING A. COATING OPPOSITE MAJOR SURFADES OF SAID SHEET WITH ETCHRESISTANT PATTERNS, THE PATTERN ON ONE MAJOR SURFACE COMPRISING AN ARRAY OF OPEN AREAS SURROUNDED BY ETCH-RESISTANT MATERIAL, AND THE PATTERN ON THE OPPOSITE MAJOR SURFACE COMPRISING OPEN AREAS OF SMALLER SHAPE BUT SMALLER THAN THE OPEN AREAS ON SAID ONE MAJOR SURFACE AND REGISTERED WITH SAID LARGE OPEN AREAS, EACH OF SAID SMALLER OPEN AREAS HAVING THEREIN A SOLID AREA OF ETCH-RESISTANT MATERIAL THAT IS STILL SMALLER THAN SAID SMALLER OPEN AREA, EACH STILL-SMALLER SOLID AREA BEING CONTINUOUS AND UNBROKEN BY OPEN AREAS, B. SIMULTANEOUSLY ETCHING BOTH SIDES OF SAID COATED SHEET UNTIL SAID TAPERED APERTURES ARE PRODUCED IN SAID SHEET, C. AND THEN REMOVING SAID ETCH-RESISTANT PATTERNS FROM BOTH MAJOR SURFACES OF SAID SHEET.
Claim 3
Dependent Claim
33 words
The method defined in claim 1 wherein said still-smaller solid area is, in at least one dimension thereof, at least 1.0-mil wide and at least 2.0 mils smaller than said smaller open area.
Claim 4
Dependent Claim
34 words
The method defined in claim 2 wherein, in said one dimension, said smaller open areas are about 6 to 10 mils wide and said still-smaller solid area is about 2 to 3 mils wide.
Claim 5
Dependent Claim
38 words
The method defined in claim 1 wherein said larger open areas are substantially circular areas about 12 to 20 mils in diameter, and said smaller open areas arE substantially circular areas about 6 to 10 mils in diameter.
Claim 6
Dependent Claim
38 words
The method defined in claim 4 wherein said still-smaller solid areas are circular and concentrically placed within said smaller open circular areas, said smaller open areas being about 2 mils in diameter larger than said still-smaller solid areas.
Claim 7
Dependent Claim
45 words
The method defined in claim 1 wherein said larger open areas are substantially rectangular areas about 12 to 20 mils wide and said smaller open areas are substantially rectangular areas about 4 to 10 mils wide in the same dimension as said larger rectangular areas.
Claim 8
Dependent Claim
21 words
The method defined in claim 6 wherein said smaller open areas are about 2 mils wider than said still-smaller solid areas.
Claim 9
Dependent Claim
24 words
The method defined in claim 6 wherein the lengths of said still-smaller solid areas are equal to the lengths of said smaller open areas.
Claim 10
Dependent Claim
28 words
The method defined in claim 6 wherein the lengths of said still-smaller solid areas are ar least 2 mils shorter than the lengths of said smaller open areas.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-29 | 1979-06-30 | 1979-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-29 | 1983-06-30 | 1983-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-29 | 1987-06-30 | 1987-12-30 | $7700.00 | Window Closed / Lapsed |