Advanced Institute Technology explains the advantages and disadvantages of commonly used thermal conductive materials for you

In some mechanical processing and electronic component production processes, there may be certain gaps and grooves between chips, which contain a large amount of air. However, air is a poor conductor of heat and can seriously affect the heat dissipation efficiency between chips. Sometimes it can also affect the effectiveness of heat sinks. Therefore, the use of thermal conductive materials is very necessary. There are many commonly used thermal conductive materials, and below we will analyze the advantages and disadvantages of some of the seven commonly used thermal conductive materials?

1. Advantages and disadvantages of thermal conductive silicone gasket

Thermal padMainly used to fill the gap between the heating element and the heat sink, this gasket has good flexibility and elasticity, so it can be used in various uneven space gaps. Heat is conducted from the separation device or the entire PCB to the metal casing or diffusion board, thereby improving the efficiency and service life of the heat generating electronic components. In the use of gaskets, pressure and temperature are mutually constrained. As the temperature increases, after a period of equipment operation, the gasket material undergoes softening, creep, and stress relaxation, and the mechanical strength also decreases, resulting in a decrease in sealing pressure.

(1) Pre formed thermal conductive materials have the convenience of installation, testing, and reusability.

(1) The thickness and shape are pre-set and will be limited during use

(2) Soft and elastic, with good compressibility, capable of covering very uneven surfaces.

(2) The thermal conductive silicon film with a thickness of less than 0.5mm has a complex process and relatively high thermal resistance.

(3) It has the effect of buffering, shock absorption and sound absorption under low pressure.

(3) Compared to thermal grease, thermal pads have slightly lower thermal conductivity.

(4) Good thermal conductivity and high-grade pressure insulation.

(4) Compared to thermal grease, the price of thermal pads is slightly higher.

(5) Stable performance, no oil leakage at high temperatures, high cleanliness.

2. Advantages and disadvantages of phase change thermal conductive materials

Phase change thermal conductive materialThis mainly refers to the fact that this type of thermal conductive material can change its form according to different temperature changes, from liquid to solid, and vice versa. Under normal circumstances, the temperature variation of this thermal conductive material is 45 degrees Celsius, and its thermal conductivity is also relatively superior.

(1) Repackable, reusable, coating thickness and shape can be controlled as needed

There are no obvious drawbacks yet.

(2) At room temperature, it is a solid, but during equipment operation, it melts and fills micro gaps (without vertical flow).

(3) The thermal conductivity effect is equivalent to traditional thermal grease, with better performance.

(4) An excellent substitute for silicone grease, without the phenomenon of traditional silicone oil evaporating, drying and aging.

(5) There is no overflow phenomenon of general silicone grease.

(6) Compared with thermal grease, there is no "inflation" effect, and long-term use has high reliability.

(7) Glue dispensing, screen printing, manual coating, fully automated operation, significantly increasing production volume.

3. Advantages and disadvantages of thermal conductive silicone grease

THERMAL GREASEAlso known as thermal paste, it is currently a widely used thermal conductive medium. This material mostly appears in a paste like liquid form, with silicone oil as the main raw material, and some thickeners and other fillers added to it. It can effectively fill between various electronic components, playing a role in heat dissipation.

(1) It exists in liquid form and has good wetting properties.

(1) It does not have a good effect on large-scale application.

(2) Good thermal conductivity, high temperature resistance, and good aging resistance.

(2) The long-term stability of the product is poor, and after continuous thermal cycling, it will cause liquid migration, leaving only the filling material and losing surface wettability, which may ultimately lead to failure.

(3) Insoluble in water and not easily oxidized.

(3) Due to the different thermal expansion rates of the materials on both sides of the interface, a "inflation" effect is caused, resulting in an increase in thermal resistance and a decrease in heat transfer efficiency.

(4) Has certain lubricity and electrical insulation properties.

(4) Always in liquid state, difficult to control during processing, easily causing pollution to other components and material waste, increasing costs.

(5) Low cost.

4. Advantages and disadvantages of thermal conductive sealant

Thermal conductive sealing adhesive is commonly divided into organic silicone rubber system, epoxy system, and polyurethane system. Thermal conductive sealing adhesive belongs to a liquid state before curing, with fluidity. The viscosity of the adhesive liquid varies depending on the performance, material, and production process of the product. The thermal conductive electronic sealing adhesive can only realize its use value after it is completely cured. After curing, it can play a role in waterproofing, moisture resistance, thermal conductivity, confidentiality, corrosion prevention, dust prevention, insulation, temperature resistance, and shock resistance.

(1) Has excellent waterproof sealing effect;

(1) The thermal conductivity effect is average.

(2) Excellent electrical and insulation performance

(2) The process is relatively complex.

(3) After solidification, it can be disassembled and repaired;

(3) Poor adhesion performance

(4) The cleanliness is average.

5. Advantages and disadvantages of thermal conductive gel

Thermal conductive gel is a two-component preformed thermal conductive silicone grease product. The thermal conductive gel mainly meets the requirements of low pressure and high compression modulus when the product is used. It can realize automatic production, and has good contact with electronic products during assembly, showing low contact thermal resistance and good electrical insulation characteristics. It is widely used in electronic components.

(1) Excellent flexibility and compressibility.

(1) Not reusable.

(2) After curing, it becomes an elastic body, resistant to impact and vibration. (2) Poor adhesion.

(3) The cured material has good thermal conductivity and heat dissipation functions.

(4) Excellent high and low temperature resistance and electrical performance.

(5) Long service life.

6. Advantages and disadvantages of thermal conductive double-sided tape

Thermal conductive double-sided tape, also known as thermal conductive adhesive tape, is composed of acrylic polymer filled with thermal conductive ceramic powder and compounded with organic silicone adhesive. Has high thermal conductivity and insulation properties, as well as flexibility, compressibility, conformity, and strong adhesion. Adapting to a wide temperature range, it can fill uneven surfaces, tightly and firmly adhere to heat source devices and heat sinks, and quickly dissipate heat.

(1) Simultaneously possessing thermal conductivity and adhesive properties.

(1) The thermal conductivity coefficient is relatively low, and the thermal conductivity is average.

(2) Has good joint filling performance.

(2) Unable to bond and fix heavy objects.

(3) The appearance is similar to double-sided tape, and the operation is simple.

(3) Once the thickness of the tape exceeds, effective heat transfer cannot be achieved between it and the heat sink.

(4) Generally used for surfaces of electronic components and chips with low heat generation.

(4) Once used, it is not easy to disassemble and there is a risk of damaging the chip and surrounding components, making it difficult to disassemble completely.

(5) The surface requirements for bonding are high, and printing and electroplating surfaces are not suitable.

7. Advantages and disadvantages of thermally conductive graphite sheets

Thermal conductive graphite sheet is a new type of thermal and heat dissipation material that conducts heat uniformly in two directions, shielding heat sources and components while improving the performance of consumer electronic products. High heat dissipation efficiency, small space occupation, light weight, uniform heat conduction along two directions, eliminating "hot spot" areas, shielding heat sources and components while improving the performance of consumer electronics products.

(1) High thermal conductivity.

(1) Not insulated.

(2) The material is relatively thin.

(2) The material is relatively brittle and experiences significant losses during punching.

(3) High cost-effectiveness.

(4) The longitudinal thermal conductivity is extremely strong, which can quickly eliminate hot spots.