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Note: This thermal material is not
electrically conductive but contains no substrate to prevent metal
to metal contact between component and heat sink.
Thermaps
thermal materials do 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.
Description: Thermaphase "Thermaps"
are solid rods of thixotropic (FSF-52) material which can be used
for manual or automatic attachment of components to heat sinks (or
PC boards).
When
the rod material is touched briefly to a heated surface, this
thermal interface material becomes a soft thixotropic
substance. The molten thermal material adheres to the heated
surface when the Thermap is removed. When a component is
pressed down into the molten material, it flows into the
micropores of component and heat sink, expulsing air from the
pores. The distance between component and heat sink decreases
as the thermal compound flows into the pores and surface
irregularities. Excess FSF 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.
The excess material at the component perimeter forms a seal around
the component. Thermaphase FSF material is not electrically
conductive, but has no barrier in it to prevent metal to metal
contact between component and heat sink.
This
material is Thermoplastic and exhibits RAB (Reversible Adhesive
Bonding). When the material has reflowed under heat and
pressure and then recools below the phase change temperature, it
bonds the component to the heat sink. The component can be
removed at any time by reheating. This can be done an
unlimited number of times. This product feature can be used to
adhere components to heat sinks replacing mechanical
fasteners.
You
can use these "Thermaps" for prototype work by simply "painting"
pads onto heat sinks or other flat surfaces. For production
work, the "Thermaps" is brought down vertically each time and prints
the heat sink with a thermal pad similar to the rod cross sectional
shape. The tip of the rod retains its cross sectional shape
because the thermal material is thixotropic, non-flowing. When
the component is pressed onto the heat sink and the thermal
interface material allowed to change again to the solid state, the
component is firmly adhered to the heat sink (tensile strength
>25psi). |