Thermal Conductivity of Polymer-Based Composites: Fundamentals and Applications

High temperature power electronics has become possible with the recent availability of silicon carbide devices. This material, as other wide-bandgap semiconductors, can operate at temperatures above 500 °C, whereas silicon is limited to 150-200 °C. Applications such as transportation or a deep oil and gas wells drilling can benefit. A few converters operating above 200 °C have been demonstrated, but work is still ongoing to design and build a power system able to operate in harsh environment (high temperature and deep thermal cycling).

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State of the art of high temperature power electronics

A release coating composition according to the present invention comprises an alkenyl functional polysiloxane (1), a silicon hydride functional polysiloxane (11) and a catalyst (111) comprising a platinum group metal. The alkenyl functional polysiloxane (1) is an alkenylterminated polysiloxane prepared by siloxane polycondensation and/or equilibration using a phosphazene base catalyst followed by neutralisation with an acidic neutralising agent. The level of catalyst (III) in the composition can be as low as 2-40 parts per million platinum group metal by weight.

Silicone release coating compositions

Heat fluxes in IC chips and other electronics equipment have reached the current limits of air-cooling technology. Some of the applications require heat fluxes well beyond the limit of 100 W/cm 2 , thus demanding advanced cooling solutions. Liquid cooling technology has also received attention as the advances in single-phase liquid cooling in microchannels have shown considerable promise. The extension of compact heat exchanger technology to microscale applications offers many new possibilities. The liquid cooling technology is expected to reach heat dissipation rates as high as 10 MW/m 2 (1 kW/cm 2 ) with enhanced microchannels and a junction-to-air temperature difference of 50°C. The challenges facing flow boiling systems are also evaluated. This paper reviews the fundamental technological developments in liquid cooling as well as flow boiling and presents possible solutions in integrating the cooling system with a building's HVAC unit in a large server-type application. The opportunities and challenges...

High Flux Heat Removal with Microchannels—A Roadmap of Challenges and Opportunities

A wafer level fan out package includes a semiconductor die having a first surface, a second surface, and a third surface. A stiffener is disposed on the third surface of the semiconductor die. A conductive via passes through the stiffener. First and second electrically conductive patterns electrically connected to the conductive via are disposed on the first and second surfaces of the semiconductor die and stiffener. Solder balls are electrically connected to the first or second electrically conductive patterns.

Fan-out semiconductor package

Thermally conductive compositions containing spherical boron nitride filler particles having an average aspect ration of less than 20 in a polymer matrix

Thermally conductive composition and method for preparing the same

A composition comprising at least one liquid metal having a melting point less than 35°C; at least one electrically insulating solid filler comprising thermally conducting materials; at least one resin is provided. The composition is both thermally conducting and electrically insulating and has utility in the preparation of electronic devices comprising heat generating and heat dissipating structures. In one instance a composition is provided which comprises a liquid metal selected from the group consisting of gallium, gallium alloys, and mixtures thereof, a boron nitride particulate filler, and a silicone resin, wherein said liquid metal and particulate filler are present in a volume ratio of about 1:0.4 to about 1: 10. A method of making and using such a composition is also provided.

Thermally conductive compositions and methods of making thereof

Thermal interface compositions (20) contain filler particles possessing a maximum particle size less than 25 microns in diameter blended with a polymer matrix. Such compositions enable lower attainable bond line thickness, which decreases in-situ thermal resistances that exist between thermal interface materials (20) and the corresponding mating surfaces.

Thin bond-line silicone adhesive composition and method for preparing the same

A power overlay (POL) structure includes a POL sub-module. The POL sub-module includes a dielectric layer and a semiconductor device having a top surface attached to the dielectric layer. The top surface of the semiconductor device has at least one contact pad formed thereon. The POL sub-module also includes a metal interconnect structure that extends through the dielectric layer and is electrically coupled to the at least one contact pad of the semiconductor device. A conducting shim is coupled to a bottom surface of the semiconductor device and a first side of a thermal interface is coupled to the conducting shim. A heat sink is coupled to a second side of the electrically insulating thermal interface.

Power overlay structure and method of making same

Thermal interface materials (TIMs) play a key role in the thermal management of microelectronics by providing a path of low thermal impedance between the heat generating devices and the heat dissipating components (heat spreader/sink). Thermal greases are TIM solutions that are widely utilized in the industry for the cooling of microelectronics. Thermal greases are expected to provide a very low thermal resistance path due to their ability to penetrate into the surface features of heat spreaders/sinks and silicon die. In addition, thermal greases do not require post-processing. However, some of the disadvantages associated with thermal greases are their tendency to "dry-out" and "pump-out" during prolonged periods of operation. These phenomena can drastically reduce the heat dissipation capability of the thermal grease layer. A "perfect" high thermal conductivity and low contact resistance TIM layer may become a voided and cracked layer on exposure to thermal and mechanical stresses. In this research, various tests are explored to determine the ability of thermal greases to deliver a reliable thermal interface, utilizing various thermal grease formulations, different TIM layer geometries, and testing conditions.

Arun Virupaksha Gowda

Papers

Thermally conductive composition and method for preparing the same

Thermally conductive compositions and methods of making thereof

Thin bond-line silicone adhesive composition and method for preparing the same

Power overlay structure and method of making same

Reliability testing of silicone-based thermal greases [IC cooling applications]