Browse Prior Art Database

Bubble Removal Bumper Machine

IP.com Disclosure Number: IPCOM000050645D
Original Publication Date: 1982-Nov-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 2 page(s) / 71K

Publishing Venue

IBM

Related People

Canestaro, MJ: AUTHOR [+5]

Abstract

An epoxy-glass panel is periodically subjected to vertical and transverse reciprocal motion to remove hydrogen bubbles trapped in holes formed in the panel that are being processed into blind or via plated through holes (PTHs) in a laminated multilayer printed circuit board (PCB) structure.

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Bubble Removal Bumper Machine

An epoxy-glass panel is periodically subjected to vertical and transverse reciprocal motion to remove hydrogen bubbles trapped in holes formed in the panel that are being processed into blind or via plated through holes (PTHs) in a laminated multilayer printed circuit board (PCB) structure.

Prior to plating the walls of the drilled holes, a particular additive solution is used to preclean the holes. During plating, a hydrogen by-product forms from any solution residual which may become trapped as gas bubbles in the holes. These bubbles inhibit the plating action.

To remove the offending bubbles, one or more of the panels (not shown) are mounted vertically in an appropriate holding frame (not shown). The frame, in turn, is supported on parallel lift bars 1 of the bumper machine with the planes of the panels parallel to the ZY plane. Bars 1 are repeatedly lifted and dropped in the Z direction against the parallel bumpers or stops 2 by the pneumatically driven mechanism 3 for a certain time period. Concurrently, the assembly 1-3 is reciprocated in the X direction by the pneumatically driven agitation mechanism unit 4. The vertical and reciprocal motion is done with the panel(s) completely immersed in the plating bath. The combined bumping and agitation action effectively removes the trapped bubbles.

Typical approximate bumping rate parameters are, to wit: ten horizontal strokes per minute in the X direction, and sixty per minute in the...