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Hi-Flow

®

225U

Non-Reinforced Phase Change Thermal Interface Material Features and Benefits

TYPICAL PROPERTIES OF HI-FLOW 225U • Thermal impedance:0.07°C-in

2

/W (@25 psi)• Hi-Flow coating will resist dripping • Thermally conductive 55°C phase changecompound• Available in roll form with kiss-cut parts Hi-Flow 225U is designed for use as a thermalinterface material between a computer processor and a heat sink.The product consists of a thermally conductive 55°C phase change compound coated on a release liner and supplied on a carrier.Above its phase change temperature,Hi-Flow225U wets-out the thermal interface surfaces and flows to produce low thermal impedance. Hi-Flow 225U requires pressure of the assembly to cause flow.

PROPERTY IMPERIAL VALUE METRIC VALUE TEST METHOD Color Black Black Visual Reinforcement Carrier None None — Thickness (inch) / (mm) 0.0015 0.036 ASTM D374 Continuous Use Temp (°F) / (°C) 302 150 — Phase Change Temp (°F) / (°C) 131 55 ASTM D3418 ELECTRICAL Flame Rating V-O V-O U.L.94 THERMAL Thermal Conductivity (W/m-K) (1) 1.0 1.0 ASTM D5470 THERMAL PERFORMANCE vs PRESSURE Pressure (psi) 10 25 50 100 200 TO-220 Thermal Performance (°C/W) 0.53 0.47 0.39 0.34 0.32 Thermal Impedance (°C-in
2 /W) (2) 0.08 0.07 0.06 0.05 0.04
1) This is the measured thermal conductivity of the Hi-Flow coating.It represents one conducting layer in a three-layer laminate.TheHi-Flow coatings are phase change compounds.These layers will respond to heat and pressure induced stresses.The overall conductivityof the material in post-phase change,thin film products is highly dependent upon the heat and pressure applied.This characteristic isnot accounted for in ASTM D5470.Please contact Bergquist Product Management if additional specifications are required. 2) The ASTM D5470 test fixture was used and the test sample was conditioned at 70°C prior to test.The recorded value includes interfacial thermal resistance.These values are provided for reference only.Actual application performance is directly related to thesurface roughness,flatness and pressure applied.

Typical Applications Include:

• Computer and peripherals• High performance computer processors • Graphic cards • Power modules

HI-FLOW

Configurations Available:

• Roll form with tabs and kiss-cut parts – no holes Hi-Flow 225U is limited to a square or rectangular part design.Dimensional tolerance is+/- 0.020 inch (0.5mm).

Application Methods:

1.Hand-apply to 35°- 45°C heat sink.The heatsink is heated in an oven or via heat gun to between 35°- 45°C.The Hi-Flow 225U part is then applied like an adhesive pad.The heat sink is cooled to room temperature and packaged.A protective tab liner remains in place until the unit is ready for final assembly. The protective tab can be readily removed from the applied Hi-Flow 225U pad at a maximum temperature of 28°C.2.Automated equipment with 30-psi pressure.A pick-and-place automated dispensing unit can be used to apply the Hi-Flow 225U pad to a room-temperature heat sink.The placement head should have a silicone rubber pad,and should apply approximately 30-psi pressure to the pad on transfer to the 25° – 35°C heat sink.Once applied, the protective tab can be readily removed from the Hi-Flow 225U pad at a maximum temperature of 28°C.

Building a Part NumberStandard Options

––––11/500 NA = Selected standard option. If not selecting a standardoption, insert company name, drawing number, and revision level. HF225U = Hi-Flow 225U Phase Change Material HF225U0.001500NA Section ASection BSection CSection DSection E Standard thicknesses available: 0.0015"00 = No adhesive_ _ _ = Standard Hi-Flow 225U configuration,11/500 = 11" x 500' rolls, or 00 = custom configuration Note: To build a part number, visit our website at www.bergquistcompany.com. Hi- Flow
® : U.S. Patent 6,197,859 and others

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