Compositions – Frost-preventing – ice-thawing – thermostatic – thermophoric,...
Reexamination Certificate
2002-10-17
2004-08-31
Green, Anthony J. (Department: 1755)
Compositions
Frost-preventing, ice-thawing, thermostatic, thermophoric,...
C165S185000, C165S104150, C252S502000, C252S511000, C252S512000, C252S521300, C257S706000, C257S712000, C257S791000, C257SE23106, C257SE23107, C257SE23120, C361S706000, C361S707000, C361S708000, C361S709000, C361S712000, C361S713000, C428S447000, C524S404000, C524S406000, C524S424000, C524S428000, C524S430000, C524S432000, C524S433000, C524S436000, C524S439000, C524S442000
Reexamination Certificate
active
06783692
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a heat softening thermally conductive (HSTC) composition and methods for preparation and use of the same. More particularly, this invention relates to a HSTC composition comprising a silicone resin system and a thermally conductive filler. The HSTC composition can be used as a thermal interface material (TIM).
BACKGROUND
Electronic components such as semiconductors, transistors, integrated circuits (ICs), discrete devices, and others known in the art are designed to operate at a normal operating temperature or within a normal operating temperature range. However, the operation of an electronic component generates heat. If sufficient heat is not removed, the electronic component will operate at a temperature significantly above its normal operating temperature. Excessive temperatures can adversely affect performance of the electronic component and operation of the device associated therewith and negatively impact mean time between failures.
To avoid these problems, heat can be removed by thermal conduction from the electronic component to a heat sink. The heat sink can then be cooled by any convenient means such as convection or radiation techniques. During thermal conduction, heat can be transferred from the electronic component to the heat sink by surface contact between the electronic component and the heat sink or by contact of the electronic component and heat sink with a TIM.
Surfaces of the electronic component and the heat sink are typically not completely smooth, therefore, it is difficult to achieve full contact between the surfaces. Air spaces, which are poor thermal conductors, appear between the surfaces and increase impedance. These spaces can be filled by inserting a TIM between the surfaces. The lower the thermal resistance of the TIM, the greater the flow of heat from the electronic component to the heat sink.
Some commercially available TIMs are elastomers filled with thermally conductive fillers. However, elastomers suffer from the drawbacks that a high pressure is required to reduce the thermal interfacial contact resistance and promote effective heat transfer between the substrate and the TIM.
Silicone greases with conductive fillers have also been proposed as TIMs. However, greases suffer from the drawbacks that they can be messy to apply and can flow out of the spaces after application.
HSTC compositions are advantageous in solving the above problems because they can be handled as a solid at low temperatures and soften at an elevated temperature. The softening temperature can be equal to or above the normal operating temperature of the electronic component.
HSTC compositions can comprise organic materials such as waxes, and conductive fillers. However, organic waxes suffer from the drawback that they can flow out of the spaces after application, during operation of the electronic component. Organic waxes may also be brittle at room temperature.
SUMMARY OF THE INVENTION
This invention relates to a heat softening thermally conductive (HSTC) composition and methods for its preparation and use. The HSTC composition comprises a matrix and a thermally conductive filler. The matrix comprises a silicone resin.
REFERENCES:
patent: 4282346 (1981-08-01), Sharkey
patent: 4299715 (1981-11-01), Whitfield et al.
patent: 4501861 (1985-02-01), Woodbrey
patent: 4558110 (1985-12-01), Lee
patent: 4604442 (1986-08-01), Rich
patent: 4631329 (1986-12-01), Gornowica et al.
patent: 4793555 (1988-12-01), Lee et al.
patent: RE33141 (1990-01-01), Gornowicz et al.
patent: 5015413 (1991-05-01), Nagaoka
patent: 5250228 (1993-10-01), Baigrie et al.
patent: 5380527 (1995-01-01), Legrow et al.
patent: 5493041 (1996-02-01), Biggs et al.
patent: 5563197 (1996-10-01), Donatelli et al.
patent: 5688862 (1997-11-01), Kondou et al.
patent: 5904796 (1999-05-01), Freuler et al.
patent: 5912805 (1999-06-01), Freuler et al.
patent: 5929164 (1999-07-01), Zhang
patent: 5930893 (1999-08-01), Eaton
patent: 5950066 (1999-09-01), Hanson et al.
patent: 5981680 (1999-11-01), Petroff et al.
patent: 6051216 (2000-04-01), Barr et al.
patent: 6054198 (2000-04-01), Bunyan et al.
patent: 6150446 (2000-11-01), Numata
patent: 6169142 (2001-01-01), Nakano et al.
patent: 6197859 (2001-03-01), Green et al.
patent: 6284817 (2001-09-01), Cross et al.
patent: 6286212 (2001-09-01), Eaton
patent: 6605238 (2003-08-01), Nguyen et al.
patent: 6620515 (2003-09-01), Feng et al.
patent: 6652958 (2003-11-01), Tobita
patent: 2002/0007035 (2002-01-01), Nguyen et al.
patent: 2003/0164223 (2003-09-01), Cross et al.
patent: 2004/0026670 (2004-02-01), Nguyen et al.
patent: 198 39 603 (1999-03-01), None
patent: 0 558 044 (1993-09-01), None
patent: WO 98/35360 (1998-08-01), None
patent: 1 101 167 (1999-07-01), None
patent: 0 987 757 (2000-03-01), None
patent: 1 067 164 (2001-01-01), None
patent: WO 01/68363 (2001-09-01), None
patent: 1 174 462 (2002-01-01), None
patent: 1 197 972 (2002-04-01), None
patent: WO 02/082468 (2002-10-01), None
patent: WO 02/086911 (2002-10-01), None
patent: WO 03/017289 (2003-02-01), None
patent: 63-230781 (1987-03-01), None
patent: 2002-329989 (2002-11-01), None
American Chemical Society, “Effect of Stabilization of Polypropylene During Processing and Its Influence on Long-Term Behavior Under Thermal Stress,” Hans Sweifel, 1996, pp. 375-396, no month.
Encyclopedia of Polymer Science and Engineering, Scattering to Structural Foams, “Silicones”, pp. 242-245, 298-308, Vo. 15, no date.
EIII Semi-Therm Symposium, “Measurements of Adhesive Bondline Effective Thermal Conductivity and Thermal Resistance Using the Laser Flash Method,” Robert C. Campbell, Stephen E. Smith and Raymond L. Dietz, pp. 83-97, 1999, no month.
Polymer Bulletin, “Siloxane-Urea Segmented Copolymers,” I. Yilgor, J.Riffle, G.Wilkes, J.McGrath, 8, 535-542, 1982, no month.
Thermal Conductivity 25, Thermal Expansion 13, “Laser Flash Diffusivity Measurements of Filled Adhesive Effective Thermal Conductivity and Contact Resistance Using Multilayer Methods,” R.C. Campbell, S.E. Smith and R.L. Dietz, Jun. 13-16, 1999, 191-202.
Thermal Trends, “Parameter Optimization for Measuring Thermal Properties of Electronic Materials Using the Transient Plane Source Technique”, Craig Dixon, Michael Strong and S. Mark Zhang, vol. 7, No. 5, pp. 1-10, 2000, no month.
Thesis, “The Thermal, Dynamic Mechanical and Morphological Properties of Silicone Adhesives,” by Bruce Campbell Copley, submitted to the Faculty of the Graduate School of the University of Minnesota, Master of Science Degree, Mar. 1984.
ITherm abstract, “Silicone Organic Phase Change Materials for TIM”. M.Zhang, D.Swarthout and J. Feng, no date.
A. Polym. Preprints, “Dynamic Mechanical Properties of Interpenetrating Polymer Networks of Trimethylsiloxy Silicates (MQ) and Polydimethyl Siloxanes (PDMS),” Jeffrey H. Wengrovius, Timothy B. Burnell, Michael A. Zumbrum, and Mary A. Krenceski, 1998, 39(1), pp. 512-513, no month.
ITherm abstract, “Novel Silicone Based Phase Change Thermal Interface Materials”, Bhagwagar, Nguyen, Mojica, no date.
“Alkyl Methyl Silicone Phase Change Materials for Thermal Interface Applications,” Zhang, Swarthout, Feng, Petroff, Noll, Gelderbloom, Houtman and Wall, no date.
ASTM Standards, “Standard Test Methdo for Thermal Diffusivity by the Flash Method”, pp. 1-13, no date.
The Polymeric Materials Encyclopedia, “Siloxane-Containing Polymers”, Bogdan Simionescu, Valeria Harabagiu and Cristofer Simionescu, CRC Press, Inc. 1996, no month.
Thermoplastic Elastomers, A Comprehensive Review, “Research on Thermoplastic Elastomers”, James E. McGrath, Hanser Publishers, 1987, no month.
Brown Catherine U.
Dow Corning Corporation
Green Anthony J.
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