Arctic Silver Thermal Adhesive is a two part epoxy that
forms a very strong bond between IC chip and heatsink. For use in applications
where it is not possible to use a mechanical mounting mechanism. This adhesive
will securely mount your heatsink. Most importantly, Arctic Silver Thermal
Adhesive will efficiently conduct heat between chip and heatsink.
Features
- Forms an extremely strong bond
- Thermally conductive adhesive
- Comes in part A and part B tubes
- Each tube is 3.5grams
- Thermal conductivity greater than 7.0 W/m-K !
CAUTION!
Arctic Silver Thermal Adhesive is a very strong adhesive. Be very sure that the
components you are attaching are ones you want to stay attached.
Application
Instructions
Cure Stages - Mixing the resin
and the curing agent begins a chemical reaction that transforms the
combined liquid ingredients to a solid. The time it takes for this
transformation is the cure time. As it cures the adhesive passes from the liquid
state, through a gel state, before it reaches a solid state.
Liquid-Open - Liquid-Open time
(also "working time") is the portion of the cure time, after mixing,
that the resin/curing agent mixture remains a liquid and is workable and
suitable for application. All assembly and clamping should take place during the
open time to assure a dependable bond.
Gel-Initial Cure - The mixture
passes into an initial cure phase (also called the green stage) when it begins
to gel, or "kick-off. The adhesive is no longer workable and will no longer
feel tacky. During this stage it progresses from a soft gel consistency to the
firmness of hard rubber, You will be able to dent it with your thumbnail
Solid-Final Cure - The adhesive mixture has cured to a solid.
You should not be able to dent it with
your thumbnail. At this point the adhesive has reached about 90% of its ultimate
strength, so clamps or other retention aids can be removed. It will continue to
cure over the next several hours at room temperature.
Understanding and Controlling Cure Time
Pot Life - Pot life is a
term used to compare the usable life of different hardeners. It is the amount of
time 100 grams at 72 F remains a liquid. Because pot life is a measure of the
cure speed of a specific contained mass (volume) of adhesive rather than a thin
film, a hardener's pot life is much shorter than its open time.
Curing Temperature -The warmer the
temperature, the faster the adhesive will cure. The cure temperature is
determined by the ambient temperature plus the exothermic heat generated during
cure. Ambient temperature is the temperature of the air or material in contact
with the adhesive. Air temperature is most often the ambient temperature unless
the adhesive is applied to a surface with a different temperature. Generally,
the adhesive cures faster when it is warmer. Exothermic heat is produced by the
chemical reaction during cure. The amount of heat produced depends on the
thickness and surface area of mixed adhesive. In a thicker mass, more heat is
retained, causing a faster reaction and more heat. A contained mass of curing
adhesive can quickly generate enough heat raise its temperature significantly
above the ambient level and increase the curing rate. However, if the same
quantity is-spread into a thin layer, exothermic heat is dissipated, and the
ambient temperature determines the adhesive’s cure time. The thinner the layer
of curing adhesive, the less it is affected by exothermic heat, and the slower
it cures.
Controlling Cure Time - In warm
conditions mix smaller batches that can be used up quickly, or keep the mixture
in a thin layer thereby allowing exothermic heat to dissipate and extending open
time. The sooner the mixture is transferred or applied (after thorough mixing),
the more of the mixture's useful open time will be available for assembly.
In cool conditions use supplemental heat to raise the adhesive temperature above
the curing agents minimum recommended application temperature. Use a hot air
gun, heat lamp or other heat source to warm the resin and curing agent before
mixing or after the adhesive is applied. At room temperature, supplemental heat
is useful when a quicker cure is desired.
CAUTION!
Heating adhesive that has not gelled will lower its viscosity, allowing the
adhesive to run or sag more easily on vertical surfaces. Never heat mixed
adhesive in a liquid state over 120F(49C). Regardless of what steps are
taken to control the cure time, thorough planning of the application and
assembly will allow you to make maximum use of the adhesive's open time and
cure time.
Specific
Application Instructions
1. CAUTION!
Even though Arctic Silver Thermal Adhesive is specifically engineered for high
electrical resistance, you should keep it away from processor, memory, and
motherboard traces, pins and leads. The cured adhesive is slightly
capacitive and can cause problems if it bridges two close-proximity electrical
paths.
2. ONLY Arctic
Silver Thermal Adhesive should be between the chip and the heatsink.
Remove any old adhesive, thermal grease, pads, tape, or other interface
materials from the heatsink and chip before attaching the heatsink with
the Arctic Silver Thermal Adhesive.
3. Verify that
the heatsink will fit on the chip without interference from any surrounding
components.
4. Clean the
mating surfaces completely with a low residual solvent (isopropyl alcohol will
work) and a low lint cloth. (Medical type alcohol pads are excellent.) If the
heatsink surface has had thermal compound previously applied, the surface should
be thoroughly scrubbed and cleaned with a quality degreaser. Wipe the
surface with paper towels before the solvent dries and then follow with the
alcohol cleaning step. It is important to keep the surfaces free of foreign
materials and NOT to touch the surfaces. (A hair, piece of lint, and even
dead skin cells can affect the thermal interface performance. )
5. Arctic Silver
Thermal Adhesive is designed to be mixed 1:1, that is equal amounts of Part A
and Part B. Varying the ratio of the mix will not significantly affect the
curing time, but may affect the strength of the final bond. DO NOT attempt to
alter the cure time by altering the ratio. An accurate ratio is essential for a
proper cure and full development of physical properties. Mixed in the proper
ratios, Arctic Silver Thermal Adhesive has a pot life of 3 to 4 minutes at
normal room temperatures.
Dispense the
proper proportions of resin and curing agent onto a clean plastic, metal or
wax-free paper sheet. Only use as much as you will be able to mix and apply in
approximately three minutes. Stir the two ingredients together thoroughly with
the supplied mixing stick. To assure thorough mixing, scrape the mixing sheet as
you mix. If you have adhesive left over after the application, do not dispose of
the mixture until the reaction is complete and has cooled.
6. Use the mixing
stick to apply the adhesive to the top of the chip in a thin layer. Be careful
to keep the adhesive away from traces, pins, and leads.
The flatter the mating surfaces, the thinner the layer that is required. Stock
processors and/or heatsinks with normal surface irregularities or that are
slightly concave or convex will require a layer 0.004" to 0.008 thick to
fill the resultant gaps. (Equal to the thickness of 1 to 2 sheets of
standard weight paper.) Properly lapped processors and heatsinks will
require a thinner layer.
7. RECHECK to
make sure no foreign contaminants are present on either mating surface, and
place the heatsink on the chip.
Clamp or secure
the components. Attach clamps as necessary to hold the components in place. Use
enough pressure to insure that the adhesive is making good contact with both
mating surfaces. Avoid using too much clamping pressure, which can damage
components.
Any method of
clamping is suitable as long as the parts to be joined are held so that movement
will not occur. Methods of clamping include spring clamps, "C" clamps,
rubber bands, nylon-reinforced packaging tape, applying weights, and vacuum
bagging. When placing clamps near adhesive-covered areas, use wax paper under
the clamps so they don't inadvertently bond to the surface.
8. Remove or
shape any excess adhesive that squeezes out of the joint as soon as the joint is
secured with clamps. The mixing stick can be wiped off with a paper towel and
used to keep the adhesive away from chip leads and other sensitive areas.
9. Wipe the
remaining adhesive off the mixing stick with a paper towel and wait patiently
for the adhesive to cure. After half an hour or so, remove the clamps and marvel
at the incredibly neat job you did.
Do not put undue
stress on the connection until the adhesive has several hours to completely set.
