Thermal pads, particularly those made from robust materials like graphite, are quite age-resistant. However, they do have an expiration date. A point in time at which they lose their thermal conductivity and cooling capabilities. This article assesses the varying lifespans of different thermal pads, the causes of degradation, and the signs to watch for.

Typical Lifespan of Thermal Pads

Thermal pads are generally made from various materials, which explains the variation in key performance metrics such as thermal conductivity, compressibility, and age resistance. You will find that the material used essentially determines the key applications of the thermal pads.

For instance, graphite thermal pads thrive in industrial and high-power computers and laptops while silicone thermal pads work best in consumer laptops and tablets. The table below compares the thermal pad service life of distinct thermal pads.

What Causes Thermal Pads to Degrade

· Heat Cycling

Laptops and computers tend to heat up when powered on and cool down once turned off. This repeated heating and cooling causes heat cycling, which consequently degrades thermal pad lifespan. This is often demonstrated by the hardening and development of microscopic cracks on the thermal pads.

In some instances, you will notice that thermal pads tend to lose their elasticity and thickness, resulting in loose contact between the thermal pad, the heat-generating components, and the heat sink. Such pads become less effective and age prematurely.

· Compression Set

Thermal pads that are compressed heavily tend to age much faster, resulting in untimely damage. Such pads experience a significant loss of compressibility and increased thermal resistance, resulting in overheating, which ultimately wears out key computer components such as the CPU. Further, laptops experiencing compression set tend to suffer from thermal throttling, which causes slow operating speeds. Such thermal pads also lose their thermal absorption capabilities.

· Silicone Oil Bleed

Thermal pads generally operate under high heat, and this persistent exposure to extreme heat results in silicone oil bleed. This is quite common in silicone-based and silicone-filled ceramic thermal pads, and it often results in the leaking of silicone oil.

This silicone oil spills over to the contacted components, and it can cause component failure or even short circuiting. Excessive silicone oil bleeding will reduce your thermal performance of the thermal pads whilst damaging the pads’ mechanical integrity.

· Mechanical Damage

Although cases of mechanical damage are quite rare, especially in graphite and ceramic-based thermal pads, they are not unheard of. Thermal pads may become damaged due to excessive compression and surface contamination, resulting in increased thermal impedance.

Computers suffering any form of mechanical damage, for instance tearing or compression set, tend to overheat due to the reduced contact between the thermal pads and the respective component surfaces.

· Improper Storage

Unused thermal pads are also susceptible to degradation if improperly stored. They should be stored while enclosed in protective films to safeguard them from environmental elements such as UV light and dust.

When you expose thermal pads to excessive UV light, they are likely to dry out and lose compressibility, resulting in reduced thermal pad durability. Furthermore, they should not be subjected to excessive weight, which can cause mechanical damage.

· Oxidation Contamination

Metal-based thermal pads, particularly thermal pads laced with aluminum or silver, may experience premature degradation due to oxidation. These metal particles are susceptible to oxidation due to persistent exposure to high temperatures and ambient oxygen.

This reduces their heat-transfer capabilities, resulting in overheating laptops or PCs. Such pads may have an uneven surface, consequently increasing the chances of loose connections. To avert oxidation in metal-based thermal pads, manufacturers recommend storing the pads in protective coatings.

FAQ

Which equipment requires earlier thermal pad replacement?

Electronic devices such as computers and laptops under heavy use may necessitate regular thermal pad replacement, unlike lightly used devices. This is because they are subjected to high temperatures for extended periods, and this can reduce their durability by several years.

How can you tell if a thermal pad is failing?

There are several signs that point to a failing thermal pad. The most obvious sign is system overheating. Other signs to watch out for include abnormal system shutdowns, thermal throttling, loss of compressibility, and reduced device or equipment performance.

Can old thermal pads be reused?

Whereas old thermal pads, particularly those in perfect condition, can be reused, reusing old thermal pads often does not end well. This is because most old thermal pads have degraded and are less likely to match the thermal performance of new thermal pads. Furthermore, new thermal pads are quite affordable, and they guarantee optimal heat-transfer capacities.

How long will a thermal pad last in equipment?

Thermal pads, particularly those installed in lightly used equipment and electronic devices, are generally long-lasting. However, their durability is mainly dependent on the construction material and degree of usage. Graphite thermal pads offer the most durability, lasting over 10 years. Silicone-based thermal pads, in contrast, last between 2 and 5 years.

Can thermal pads fail without physical damage?

Yes. Whilst physical damage is the leading cause of thermal pad failure, it is possible for thermal pads to degrade as a consequence of other causes. This includes oxidation, heat cycling, and compression set.

Should thermal pads be replaced during maintenance?

Thermal pad replacement should be undertaken once the equipment or device in question starts overheating or experiencing reduced performance levels. One should not necessarily wait for the next maintenance cycle.

Can thermal pads lose thermal conductivity?

Yes. Thermal pads may lose their optimal thermal conductivity prematurely due to a number of reasons. This includes physical damage, natural aging, silicone oil bleed, and heat cycling.

Final Thoughts

Thermal pads do not fail overnight; however, their performance may decline gradually due to thermal cycling, material aging, environmental exposure or compression set.

At Gallop, we help you choose the right thermal interface material according to your unique application requirements. Contact us today, and our team will help you choose the right material specifications.