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Ultra high resolution flexible circuit boards
Process
overview
Board
layout/design |
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Photomask
printing |
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Embossing
tool fabrication |
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Coating
and UV embossing |
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Electroplating |
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Lamination
of base carrier film |
Instead
of defining the pattern of tracks on the board using a photoresist, our
process embosses the tracks into the dielectric polymer resin material
in which the conducting tracks eventually become embedded. The process
is the same type used to make high definition holograms. The high precision
and small feature size of the track pattern is built into the embossing
tool. The embossing tool is made of either nickel (for hard tooling) or
a proprietary polymer material (for soft tooling). In both cases a conventional
photoresist pre-form is used to make the tool. Once embossed the tracks
are electroplated with one or more metals to give the required board finish
and track composition. The depth of the embossing defines the thickness
of the metallisation on the board. The plated circuit is laminated with
the desired base carrier film at the end of the process. This allows a
wide choice of carrier substrate/adhesive combinations to be used depending
on the end use requirements of the boards.
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