Browse Prior Art Database

Printed Circuit Board Etcher Spiral Conveyor

IP.com Disclosure Number: IPCOM000121046D
Original Publication Date: 1991-Jul-01
Included in the Prior Art Database: 2005-Apr-03
Document File: 2 page(s) / 56K

Publishing Venue

IBM

Related People

McAtee, DJ: AUTHOR

Abstract

Etching of printed circuit boards (PCBs) is commonly accomplished by use of horizontal conveyor with etchant solution sprays above and below the PCB. Etchant solution tends to "puddle" on top of the PCB while falling away from the bottom. This causes top-to-bottom difference in the size and shape of etched circuit features. This is especially troublesome as circuit features become smaller (fine line). To reduce these differences, PCBs may be inverted (flipped) part way through the etcher so that the top and bottom surfaces experience "equal" etching. Disclosed is a spiral conveyor which will invert PCBs in the etching process. Etchant spray nozzles may be fitted along the horizontal (1) and spiral (2) conveyor sections. Spiral conveyor features are: - Panel inversion without increasing etcher length.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Printed Circuit Board Etcher Spiral Conveyor

      Etching of printed circuit boards (PCBs) is commonly
accomplished by use of horizontal conveyor with etchant solution
sprays above and below the PCB.  Etchant solution tends to "puddle"
on top of the PCB while falling away from the bottom.  This causes
top-to-bottom difference in the size and shape of etched circuit
features.  This is especially troublesome as circuit features become
smaller (fine line).  To reduce these differences, PCBs may be
inverted (flipped) part way through the etcher so that the top and
bottom surfaces experience "equal" etching. Disclosed is a spiral
conveyor which will invert PCBs in the etching process.  Etchant
spray nozzles may be fitted along the horizontal (1) and spiral (2)
conveyor sections.
      Spiral conveyor features are:
      -    Panel inversion without increasing etcher length.
      -    No interruption of etching while inverting.
      -    Simple, reliable mechanism.  Same components and materials
as horizontal conveyor sections.
      Other applications:
      -    Vertical PCB processing - reorienting from/to horizontal.
      -    Other PCB chemical process where control of top/bottom
parameters is important.
      -    Reorient PCBs 90 degrees (1/2 spiral).
      -    Any conveyed item requiring reorientation