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Irradiation of Low Dielectrics for Improved Performance

IP.com Disclosure Number: IPCOM000103063D
Original Publication Date: 1990-May-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 1 page(s) / 38K

Publishing Venue

IBM

Related People

Chu, MC: AUTHOR [+4]

Abstract

Disclosed is an approach for tailoring the thermal expansion behaviors of certain fluorocarbon polymers by irradiation with a high-energy beam in vacuum. The use of vacuum is necessary to prevent material degradation.

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Irradiation of Low Dielectrics for Improved Performance

      Disclosed is an approach for tailoring the thermal expansion
behaviors of certain fluorocarbon polymers by irradiation with a
high-energy beam in vacuum.  The use of vacuum is necessary to
prevent material degradation.

      The fluorocarbon polymers studied included RO-2500* and
RO-2800* films.  The high-energy beam used was gamma-ray. For each
material, both the differential scanning calorimetry (DSC) and
thermal mechanical analysis (TMA) were performed before and after
irradiation at a dose of typically around 4Mrad.  The DSC was used to
determine the true melting point (DSC melting point) and the heat
absorbed per unit weight of the sample during melting (a measure of
crystallinity).  The TMA, on the other hand, was used to measure the
thermal expansion coefficient in the plane of the film and the TMA
melting point at which the thermal expansion coefficient increased
abruptly.

      The results indicated that irradiation not only increased the
crystallinity in the fluorocarbons studied but also shifted the high
thermal expansion behaviors to higher temperatures.  These occurred
with the DSC melting points practically unchanged.  As an example,
the TMA melting point of the RO-2800 increased from 327 to 391oC
while its DSC melting point remained at around 326oC upon
irradiation.
*from Rogers Corporation

      Disclosed anonymously.