Thermal Interface Materials - Phase Change Thermal Interface Material(PCTIM)

Introduction				Typical Characteristics
Heat Technology, Inc.(HTI)'s phase change thermal interface provides an extremely high thermal conductivity bond between a heat sink and hot IC component. The thermal resistance of this bond can be 0.03C-in2/W or lower depending upon attachment pressure.
Description
This product consists of a pre-applied pattern of Phase Change Thermal Interface Material (PCTIM). It does not contain a substrate of non-melting material. It is dry-to-the-touch and flexible at room temperature. When placed on a rough surface and heat (>52OC) and pressures (4.5psi) are applied, the following occur:
When the heat exceeds 52OC (either from electronic component heat-up or because of externally applied heat) the PCTIM becomes a soft flowable under low closure force. The physical pressure on the component causes the PCTIM to flow into the micro pores of the component and heat sink, expulsing air from these pores. The distance from the component to the heat sink decreases as the PCTIM enters the pores and surface irregularities. Excess material is extruded from under the component and forms a “bead” around the perimeter of the component. The thinnest possible interface is created.
				PCTIM does not require high mounting forces. Typically 4.5 psi is quite sufficient. Clips can be used to hold the semiconductor in place. Since only low mounting forces are required, it is practical to contact large surface areas.
This material is Thermoplastic and exhibits RAB (reversible adhesive bonding). When the material has reflowed under heat and pressure between component and heat sink and then recools below the phase change temperature it adheres the component and heat sink to each other. By reheating the material again beyond its reflow temperature, you can reverse the adhesion and separate the component and heat sink. This process can be carried out an unlimited number of times. This product feature can be used to adhere components to heat sinks to replace mechanical fasteners. A version of the material also melts at 100OC for use in higher temperature applications. When selecting a product of this type please be aware of the following: Always check to see at what closure force the thermal resistance measurements were made. Products tested using ASTM 5470-95 as the test method use 438 psi. You cannot obtain this with normal electronic components and fasteners. Beware of phase change products that melt at temperatures less than 52°C as they can melt in transit.
Summary
HTI’s Phase Change Thermal Interface Material (PCTIM) offer many advantages. These advantages include: Lowest available thermal resistance: 0.03 OC/W/in2 at very low closure force Low mounting force so you can use clips, not screws Controlled particulate morphology for superior void filling Organo-metallic wetting action promotes laminar flow Controlled thixotropicity eliminates migration Thermoplastic adhesion can eliminate fasteners Reversible Adhesive Bond (RAB) characteristics Easy to handle – "manufacturing friendly" Excellent solvent resistance Available in a wide range of thickness Environmentally friendly/Non Toxic
Options
Available in melting temperature grades of 52 OC and 100 OC. Available with Zero ∆T PSA (Pressure Sensitive Adhesive).
Ordering Information
Due to trade secret, HTI’s Phase Change Thermal Interface Material (PCTIM) can only be purchased with the PCTIM applied onto the heat sink by HTI ourselves. Please contact Heattechnology Inc. for pricing, availability and/or questions.