Browse Prior Art Database

Combined Laser Processing of Vias and Circuitry in Flex-Circuits

IP.com Disclosure Number: IPCOM000115614D
Original Publication Date: 1995-May-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 2 page(s) / 53K

Publishing Venue

IBM

Related People

Roth, E: AUTHOR [+4]

Abstract

Disclosed is a laser-based process sequence to produce fine line electrical circuitry on a dielectric foil as well as vertical via-connections from front to back surface. Such structured foils can be assembled to multi-layer flex-circuits. For structuring of the vias and the fine line circuitry two different laser process steps are involved in a suitable manner. The process sequence does not involve any lithography/development, no vacuum processing nor metal-wet-etch processes, and is therefore a flexible, short process sequence with low environmental impact and offers roll-to-roll processing capability.

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Combined Laser Processing of Vias and Circuitry in Flex-Circuits

      Disclosed is a laser-based process sequence to produce fine
line electrical circuitry on a dielectric foil as well as vertical
via-connections from front to back surface.  Such structured foils
can be assembled to multi-layer flex-circuits.  For structuring of
the vias and the fine line circuitry two different laser process
steps are involved in a suitable manner.  The process sequence does
not involve any lithography/development, no vacuum processing nor
metal-wet-etch processes, and is therefore a flexible, short process
sequence with low environmental impact and offers roll-to-roll
processing capability.

      Flexible circuits are of growing importance for the packaging
of small, portable devices like FAX, phones, displays, data storage,
etc., where the core is being reduced to thin foils (some 25 &mu.m)
of non-reinforced polymeric materials like polyimide, polyester etc.
Instead of mechanical drilling of these foils either plasma- or
laser-drilling is presently being used.

      The processed material is a foil, or roll of polymeric
material.

      Process step 1: Produce vias of appropriate diameter and
location in the foil 1 with laser ablation.  Via diameters down to 6
&mu.m can be produced with present laser optics.  The number of vias,
as well as the density of vias on the foil determine whether a
projection excimer laser, or a direct write (frequency multiplied)
solid s...