Browse Prior Art Database

Microstructured Solder Mask by Means of Laser Ablation

IP.com Disclosure Number: IPCOM000106575D
Original Publication Date: 1993-Nov-01
Included in the Prior Art Database: 2005-Mar-21
Document File: 2 page(s) / 53K

Publishing Venue

IBM

Related People

Arnold, H: AUTHOR [+3]

Abstract

Disclosed is a process that allows the manufacture of solder masks by adding the step of laser ablation to the standard process of manufacturing printed circuit boards (PCB).

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This is the abbreviated version, containing approximately 58% of the total text.

Microstructured Solder Mask by Means of Laser Ablation

      Disclosed is a process that allows the manufacture of solder
masks by adding the step of laser ablation to the standard process of
manufacturing printed circuit boards (PCB).

      In contrast to the photolitographical exposure, the structuring
of a probimer material by means of laser ablation does not depend on
the particle size of the photosensitive probimer component.

      For polymer materials such as probimer, pulsed excimer lasers
are especially useful.  The irradiated material nearly completely
turns into the gaseous state by means of photochemical/photothermal
processes.

      Solid reaction products which deposit as carbon-consisting
layers in the environment of the ablated areas, can be removed either
by standard oxygen plasma etching or by a subsequent short flood
exposure with an excimer laser using low power densities.

      By means of laser ablation it is easily possible to create
structures down to about 10 ffm for the necessary layer thicknesses of
about 40 mu m, e.g., by projection of suitable mask structures.

      The vertical profiles of the produced trenches (between about
30º  and 89º, i.e., nearly vertical walls) can be
manufactured either by the choice of adequate masks or by the choice
of suitable laser power densities.

      Laser ablation can easily be carried out in such a way that the
ablation process stops automatically after breaking through th...