Orcus Inc., Datasheets, 98°C Thermaphase on Kapton®

Thermaphase on Kapton® 98°C

(Thermally Conductive Electrical Insulators)

Advantages:

Lowest available thermal resistance for High Temp Phase Change 0.06°C/W/in² at 10psi(MTI)
Low mounting force so you can use clips, not screws
Differential Phase Change Characteristic allows one or two-phase operation
Controlled particulate morphology for superior void filling
Organo-metallic wetting action promotes lamellar flow
Controlled Thixotropicity eliminates migration
Thermoplastic adhesion can eliminate fasteners
Reversible Adhesive Bond (RAB) characteristic eliminates outgassing
Easy to handle - "manufacturing friendly"
Excellent solvent resistance
Precision metered coating 0.5 to 6.0 mils thick
Available with different compound thickness on each side of Kapton
Environmentally friendly/Non Toxic
Available with Zero DT adhesive backing
Dielectric strength up to 11000 Volts

Description:
Thermaphase on Kapton 98°C was developed in response to industry demand for a Thermaphase with a higher phase change temperature. In some applications, it is advantageous to have a material which can operate in the solid state at temperatures up to 80°C. Thermaphase 98°C can change state once at initial heat up and then return to the solid state during normal semiconductor operation. The heat to reflow this 98°C material can be supplied externally or from the component itself. The graph below shows the dramatic difference between pre-phase change thermal resistance and operation in the solid state after initial reflow. This new material is available in 1, 2, and 3 mil Kapton substrates.

This product consists of Dupont Kapton precoated on both sides with ORCUS 98°C Thermaphase Differential Phase Change Material. The material is dry-to-the-touch and flexible. This is the original material that started the Phase Change Material revolution years ago. When this material is placed between two rigid, rough, uneven surfaces and heat (>98°C) and pressure (10psi) are applied the following occurs:

1) When the heat exceeds 98°C (either from electronic component heat-up or because of externally applied heat) the Thermaphase material becomes a soft, thixotropic
2)The physical pressure on the component causes the Thermaphase material to flow into the micropores of the component and heat sink, expulsing air from these pores. The distance from the component to the Kapton and from the Kapton to the heatsink decreases as the Thermaphase material enters the pores and surface irregularities. Excess material is extruded from under the component and forms a "bead" of material around the perimeter of the component. The thinnest possible interface is created.
3) The Kapton provides electrical insulation. The Thermaphase compound provides a heat transfer medium that fills the surface pores of component and heat sink.

This material is Thermoplastic and exhibits RAB (reversible adhesive bonding). When the material has reflowed under heat and pressure between component and heatsink and then recools below the phase change temperature it adheres the component and heatsink to each other. By reheating the material again beyond its reflow temperature, you can reverse the adhesion and separate the component and heat sink. These process can be carried out an unlimited number of times. This product feature can be used to adhere components to heatsinks to replace mechanical fasteners.

Typical Characteristics

Thermal Characteristics	Units	1 mil Kapton	2 mil Kapton	3 mil Kapton
Overall Thermal Resistance at 10psi. See graph of Thermal Resistance vs Closure Force (See Test Procedure)	°C/W/in²	0.06	0.08	0.09
Thermal Conductivity of Kapton Substrate	W/M²/K	0.45	0.45	0.45
Phase Change Temperature	°C	98	98	98
Use Temperature	°C	-60 to +200	-60 to +200	-60 to +200
Mechanical Characteristics	Units	1 mil Kapton	2 mil Kapton	3 mil Kapton
Substrate Material	----	MT Polyimide	MT Polyimide	MT Polyimide
Substrate Thickness	inches	0.001	0.002	0.003
Coating Thickness	mils	0.5 to 6.0 mils	0.5 to 6.0 mils	0.5 to 6.0 mils
Moisture Absorption (substrate)	%	5	5	5
Viscosity (Thermaphase compound) at 150°C	Poise	>100	>100	>100
Density of Thermaphase Compound	g/cc	2.1	2.1	2.1
Electrical Characteristics	Units	1 mil Kapton	2 mil Kapton	3 mil Kapton
Volume Resistivity (substrate + thermal coating)	W-cm	10¹⁴	10¹⁴	10¹⁴
Dielectric Strength	Volts AC	3900	7800	11000
Dissipation Factor	----	0.003	0.003	0.003
Dielectric Constant (1KHz/50% humidity)	%	5	5	5

Thermal Resistance versus Closure Force

OPTIONS:

1) Thickness of Kapton can be 1, 2, or 3 mils thick
    The thicker the Kapton, the higher the dielectric strength
    The thicker the Kapton, the higher the cost
    The thicker the Kapton, the higher the Thermal Resistance
    The thicker the Kapton, the greater the mechanical resistance to "cut-through"

2) The thickness of the Thermaphase coating can be varied from 0.5 mils up to 6 mils per side.
The coating thickness can be different on the two sides of the Kapton. This is useful if you have a very smooth, flat electronic component on one side and a rough, uneven heatsink on the other side.

3) This material is available with ORCUS' unique Zero DT Fiberized Pressure Sensitive Adhesive (FPSA) which does not increase thermal resistance.

4) Available with ORCUS' unique Zero DT Repositionnable Thermal Adhesive (PSTA) which allows adjusting position of the part after it is applied to the heat sink.

How to Use:

Place Thermaphase on Kapton material on heat sink. Install component using clips, screws, spring-loaded screws, or Bellville washers. Use at least 4.5psi of closure force during initial reflow of Thermaphase compound. Heat component/heat sink by using component operating temperature, or externally applied heat. You can use more or less than 4.5 psi closure force. The thermal resistance decreases with increasing closure force. (See graph above).

Product Availability:

Standard Sheets: 12" x 12"
Standard rolls: 12" x 500 ft.
Standard die-cut parts: Pads for all standard case sizes are available. Contact us for outline drawings of standard parts. We have cut thousands of special die-cut parts. We may already have what you need.

For detailed information on "Specials", contact ORCUS with information on your application. We will be pleased to assist you in selecting the material having the best thermal, electrical, and mechanical characteristics.