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Dry Film Protective Coating Process

IP.com Disclosure Number: IPCOM000090049D
Original Publication Date: 1969-Jan-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Galloway, WD: AUTHOR

Abstract

Application of a dry film protective coating to a pinned printed circuit board is facilitated in the following manner. PROCESS.

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Dry Film Protective Coating Process

Application of a dry film protective coating to a pinned printed circuit board is facilitated in the following manner. PROCESS.

The film is die cut to proper size, but is not removed from the backer sheet until immediately before use. The backer sheet is removed and the film is registered before piercing with pins approximately 1.5 times the size of the pins over which it is placed.

The printed circuit board is then registered under the vacuum head holding the film. The head is brought down placing the film over the board. The vacuum is released and the head retracted to leave the film on the board. The printed circuit board with film applied is then placed between preheated platens. The platens are then placed in a hydraulic press where a pressure of 173 psi is applied at a temperature of 335 degrees +/- 5 degrees F for two minutes + 30 seconds. The printed circuit board is then removed with the film adhered to the board and partially cured.

PROCESS.

A vapor blast using #400 grit is applied to the stiffener board. A rollet coater is used to apply Bostik 7026 cement, a product of United Shoe Machine Corporation, Bostik Division, on the stiffener to a minimum thickness of 1.5 mils of cement. The cement prepared is an approximate mix of 2 parts Bostik 7026 to 1 part methanol., The viscosity is adjusted to 347 cps by adding either methanol or Bostik cement. After the cement is applied, the stiffener is air-dried for 30 minutes. Th...