Sold to our customers since 1996, Heat Technology’s patented MicroPin™ adhesive interface material provides an easy to use, effective thermal interface between the heat source and heat spreaders or heat sinks. It has excellent thermal conductivity and bonding characteristics, allowing for the heat source and heat sink/spreader to be bonded together without the use of mechanical fasteners or thermal grease.
Low to Medium Power Thermal Solutions
Controlling Boards
BGA Applications
Fastener-free Attachment
ROHS Compliant
Description
Application Instructions
A peel and stick material with double-sided adhesive, Heat Technology Inc (HTI)’s MicroPin Interface Material™ consists of a compliant metallized polymer matrix that is impregnated with a pressure-sensitive resin. The peel and stick silicone copolymer resin is compatible with chip mold release agents for additional strength. The metal matrix consists of a copper base and a nickel surface, which provides a corrosion barrier against aluminum.
The theme of MicroPin™ is to give the designer an additional option when bonding two surfaces together without using screws or clamps, yet still assisting in the heat transfer. It has three major advantages over the Peel and Stick market due to its construction. The HTI material is mostly high conductivity metal whereas the other tapes primarily are composed of poorly conductive rubbers and fillers. This metal matrix is volume compressible, like a sponge; while the others are not compressible, like a hydraulic fluid. The HTI material can expand and contract without affecting the thermal conductivity while following the contour of the, generally, out-of-flat chips.
Prep area of heatsink application by making free of dirt, any oils etc…by using acetone, toluene, or MEK as the cleaning agent
Use Kim-wipe or similar tissue wet with solvent to clean area.
Wipe dry with clean Kim-wipe to remove residual contamination.
Peel off clear release sheet from interface material.
Center heatsink foot on chip package and/or heat spreader.
Apply 30 pounds per square inch of pressure for 30 seconds for optimal performance. If 30 psi exceeds the structural integrity of the chip package then apply the maximum allowed by the manufacturer.
Advantages
The first advantage is the thermal conductivity of the HTI material is superior due to its metal matrix.
Second, the product conformance optimizes contact for greater adhesion. The greater the contact coverage, the stronger the more durable the bond. In the real world out-of-flat parts multiply the advantages of this flexible metal matrix.
Third, this structure promotes incremental increases in the thickness of the thermal adhesive (from 5 mil to 10 mil) to accommodate greater out of flat conditions while maintaining its high thermal conductive performance.
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Note 1: A pneumatic fixture is often used in production to assure uniform bonds.
Note 2: Cross-cut extruded heatsinks need to be installed with the more open side facing airflow for optimal performance.
Removal Instructions
Carefully insert an industrial grade single edge razor blade into the bond line at a corner between the device and the bonding surface.
Slowly rotate the razor to provide a slight upward pressure
As the two surfaces begin to separate, move the razor deeper into the bond, continuing the upward pressure until surfaces are completely apart.
Follow application instructions above to re-use components
Shear Strength Test
Figure 1: The Thermal Impedance per area as a function of test pressure
Figure 2: 3 lap shear test curves for the 5mil MicroPin™ material. The red line indicates the average lap shear strength, 32.3 N/cm2 (46.9psi).
Figure 3: 5 lap shear test curves for the 10mil MicroPin™ material. The red line indicates the average lap shear strength, 35.5 N/cm2 (51.5psi).
Summary:
Independent testing has shown that the Micropin Interface Material has many advantages over traditional adhesives and mechanical fasteners. It can be consistently applied to meet design level thermal and mechanical requirements.
Mechanically, the adhesive must meet a minimum internal lap shear test of 15 pounds at 20 deg C, before being released to production. It has met the earthquake spec of 10G’s. The adhesive has supported 10 times the weight of the heatsink for 1 week as well as 200 times the weight of the heatsink for 10 minutes.
Thermally, the adhesive has a minimum conductance of 0.6 degrees C per watt per square inch and has been tested as 0.3 degrees C per watt per square inch.
Ordering Information:
Micro Pin™ is available in sheet form (8in. x 10in.) and custom die cut parts. Samples are available upon request.
