US5238709A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrostatic spray coating method
Assignee: MacDermid Acumen Inc
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Filing: 1991-04-26
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Granted: 1993-08-24
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Expires: 2011-04-26
Abstract
Abstract A method and apparatus are provided for electrostatically applying a coating, such as solder mask, to a substrate such as a circuit board. A grounded conveyor system includes electrically conductive means for suspending the substrate from the conveyor and grounding the substrate. An atomizing spray nozzle provides an atomized, electrically charged spray of the coating material in the direction of the grounded substrate. A focusing element is positioned to confine the spray to a desired pattern, and a receiving backplate, which carries a charge opposite that of the spray, is positioned behind the substrate to attract the charged coating particles that do not impinge on the substrate.
Inventors
- 👤 Robert R. Wilkie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:10
CPC Classifications
B; B05; B05B; B05B5/00; B05B5/08; B05B14/00; H; H05; H05K; H05K3/00; H05K3/0091; H05K2203/00; H05K2203/10; H05K2203/105; H05K2203/13; H05K2203/1333; H05K2203/1366; H05K2203/15; H05K2203/1518; Y; Y02; Y02P; Y02P70/00; Y02P70/10
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
146 words
A method of electrostatically coating a plurality of grounded, spaced apart substrates comprising: a. spraying a charged coating material from a charged nozzle means directed to a spray area; b. confining said charged coating material to a desired spray pattern by means of a charged spray focusing means; c. conveying said substrates in a path longitudinally spaced from said nozzle means and wherein the longitudinal axis of symmetry of said spray pattern is normal to said path so that said substrates approach, enter and leave said spray area; and d. providing receiving backplate means for attracting said charged coating material, said backplate means being longitudinally spaced from said substrates so that said substrates are conveyed between said nozzle means and said backplate means, whereby, as said substrates approach and leave said spray area, charged coating material not impinging on said substrates impinges on said backplate means.
Claim 2
Independent Claim
146 words
A method of electrostatically coating a plurality of grounded, spaced apart substrates comprising: a. spraying a charged coating material from a charged nozzle means directed to a spray area; b. confining said charged coating material to a desired spray pattern by means of a charged spray focusing means; c. conveying said substrates in a path longitudinally spaced from said nozzle means and wherein the longitudinal axis of symmetry of said spray pattern is normal to said path so that said substrates approach, enter and leave said spray area; and d. providing receiving backplate means for attracting said charged coating material, said backplate means being longitudinally spaced from said substrates so that said substrates are conveyed between said nozzle means and said backplate means, whereby, as said substrates approach and leave said spray area, charged coating material not impinging on said substrates impinges on said backplate means.
Claim 3
Dependent Claim
18 words
The method of claim 1 wherein said coating material is solder mask and said substrates are circuit boards.
Claim 4
Dependent Claim
19 words
The method of claim 1 wherein said coating material is primary resist and said backplate means comprises metal foil.
Claim 5
Dependent Claim
22 words
The method of claim 1 wherein said backplate means bears a charge opposite to that of said charge on said coating material.
Claim 6
Dependent Claim
12 words
The method of claim 1 wherein said coating material is negatively charged.
Claim 7
Dependent Claim
41 words
The method of claim 1 wherein said spray focusing means comprises an electrically charged element having a charge corresponding in polarity to that of said coating material, said electrically charged element being spaced from and substantially encircling said spray nozzle means.
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) | 1996-08-23 | 1997-02-22 | 1997-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-08-23 | 2001-02-22 | 2001-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-08-23 | 2005-02-22 | 2005-08-24 | $7700.00 | Window Closed / Lapsed |