First,
thermal gel and thermal grease are both thermal interface materials. The
thermal gel is a new type of thermal interface material emerging in recent
years. However, thermal grease is a veteran of the thermal interface material
family. Both thermal interface materials are paste-like, and many customers
have been unclear about the difference between thermal gel and thermal grease.
Some people even default thermally conductive silicone to thermally conductive
silicone grease, but the name is different.
What
is thermally conductive gel?
Thermally
conductive gel is a high-viscosity thermally conductive material, which is
mixed with a variety of thermally conductive powders and thermally conductive
silicone after being fully cured. The entire production process is done under a
vacuum, so there is no air in the thermally conductive gel material. Most
thermal gels are packaged in syringes. It not only has excellent electrical
insulation, but also has excellent thermal conductivity, and has low oil
separation, high and low-temperature resistance, water resistance, ozone
resistance, and weather resistance.
The
thermally conductive gel will not cause the precipitation of silicone oil, and
the gel can be peeled off and reused. When the thermal conductive gel is
connected to the heat sink and the chip, it only needs a small working
pressure, generally less than 10psi, with low hardness, easy bending, and a
wide working temperature range.
What
is thermal grease?
Thermal
grease is a material used to fill the gap between the CPU and the heat sink.
Its function is to transfer heat from the CPU to the radiator, keep the CPU
temperature at a stable working level, prevent the CPU from being damaged due
to poor heat dissipation, and prolong its service life.
In
heat dissipation and thermal conduction applications, even two flat surfaces
with very smooth surfaces can create a gap when they encounter each other. The
air in these gaps is a poor conductor of heat and hinders the conduction of
heat to the heat sink. Thermal grease is a material that can fill these voids
for smoother and faster heat transfer. There are many kinds of silicone grease
on the market, and different parameters and physical properties determine
different uses.
1.
Different materials
Thermal
grease is a thermal grease compound made of silicone as the main raw material,
adding materials with excellent heat resistance and thermal conductivity
Thermally
conductive gel is a high-end thermally conductive compound
2.
Different characteristics
Thermal
grease has high thermal conductivity, excellent thermal conductivity, good
electrical insulation, a wide temperature range, good stability, low
consistency, and good construction performance.
The
thermally conductive gel releases low molecules through the condensation
reaction of moisture in the air to cause cross-linking and curing and then
vulcanizes into a high-performance elastomer. It has excellent heat and cold
resistance, aging resistance, and electrical insulation properties. And has
excellent moisture resistance, shock resistance, corona resistance, leakage
resistance and chemical resistance.
3.
Different uses
Thermal
paste is used for gap filling and heat transfer between high-power transistors
such as power amplifiers, transistors, electronic tubes, CPUs, switching tubes,
integrated circuits and other chips and heat sinks.
Thermally
conductive gel is widely used in LED chips, communication equipment, mobile
phone CPU, memory module, IGBT and other power modules, power semiconductors,
etc.
4.
Different construction methods
The
construction method of thermally conductive gel is better than that of
thermally conductive silicone grease.
The
conventional construction method of thermal grease is screen printing, and some
customers just apply and scrape it evenly. But such a simple construction
method must also be manually operated.
Thermally
conductive gel construction can be done directly from an automatic dispenser,
ending the history of thermal interface materials that could not be automated.
In this way, the thermally conductive gel has good contact with the electronic
product during the assembly process, has low contact thermal resistance, and
has good electrical insulation properties.
In
short, thermal gel can be built using a fully automated dispensing process,
while thermal grease can only be built manually.
5.
Different service life
Thermal
gel has a longer lifespan than thermal grease.
Thermal
gel does not dry for a long time and can be compressed infinitely. Can
guarantee the service life of more than 10 years. Some manufacturers refer to
thermally conductive gels as liquid thermally conductive silicone sheets.
But
thermal grease has a shorter lifespan than all thermally conductive interface
materials. After half a year of use, the thermal grease begins to dry slowly,
and can be completely turned into powder within 2 years. A pinch will turn into
dust, and thermal grease will also lose thermal conductivity. This is the end
of the life of thermal grease. This is also the situation that thermal grease
is often complained about, and it is also the fatal bottleneck for the
development of thermal grease.
