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UV-Laser Cut Embossing Die

IP.com Disclosure Number: IPCOM000119780D
Original Publication Date: 1991-Feb-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 1 page(s) / 53K

Publishing Venue

IBM

Related People

Reiley, TC: AUTHOR [+3]

Abstract

In microelectronic circuitry, semiconductor chips are often mounted on a multilayer ceramic (MLC) substrate. Electrical connections between various chips on the substrate are made by highly conductive connections between the chips or between the chips and intermediate conductive paths within the substrate. One technique for doing this is to emboss a pattern of indentations into the surface of a laminated stack of ceramic green (uncured) sheets and, after firing, to metalize the indentations. An improved embossing die is described for this process, where the die is comprised of a patterned layer of a polymer, such as polyimide.

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UV-Laser Cut Embossing Die

      In microelectronic circuitry, semiconductor chips are often
mounted on a multilayer ceramic (MLC) substrate.  Electrical
connections between various chips on the substrate are made by highly
conductive connections between the chips or between the chips and
intermediate conductive paths within the substrate.  One technique
for doing this is to emboss a pattern of indentations into the
surface of a laminated stack of ceramic green (uncured) sheets and,
after firing, to metalize the indentations.  An improved embossing
die is described for this process, where the die is comprised of a
patterned layer of a polymer, such as polyimide.

      The die is prepared by applying a thin layer of a plastic
material to a flat metal surface 10, such as stainless steel.  The
plastic material 12 is applied by, for example, spraying, rolling, or
laminating a thin film of the plastic to the metal 10.  The plastic
must withstand the embossing pressure and temperature (20-95@C)
without deformation.  Polyimide or polyesters such as Kapton H or
Mylar (trademarks of E.I. dupont deNemours co.) are suitable.  Metal
layer 10 can also be a sheet of molybdenum, copper, etc.

      The polyimide or plastic layer 12 is coated with a layer of
material which is opaque to and reflects ultraviolet radiation, such
as a layer of sputtered chromium of thickness approximately 400Ao .
The desired conductor pattern is photoetched into the chromium layer
by standa...