How much do you know about thermal gel (heat dissipation gel) ? What is it and where to apply?
Aqui está o esboço:
What is thermal gel?
What are the characteristics of thermal gel?
Application of thermal gel
What will happen to the thermal gel during the application process?
Compared with thermal pads and thermal grease, what are the advantages and disadvantages of thermal gel?
Why choose thermal gel？
O que é gel térmico?
Thermal gel (also known as thermal conductive gel, heat sink gel, CPU gel and processor gel ect.) is a gel-like silicone based thermally conductive material formed by stirring, mixing and encapsulating silicone resin, crosslinking agent, thermally conductive filler and curing agent.
It has one part and two parts thermal conductive silicone gel. Among them, the two-component thermal gel is divided into A and B components. The A component is composed of silicone resin, crosslinking agent and filler, and the B component is composed of silicone resin, catalyst and filler. After the two are mixed and cured, it will become thermal silica gel.
Quais são as características do gel térmico?
Thermally conductive gel has almost no hardness, is soft and has a strong surface affinity. It can be compressed into a very thin variety of shapes and spread on the surface of various types of non-smooth electronic components, significantly improving the heat transfer efficiency of electronic components.
Thermally conductive gel has viscosity and adhesion, will not be oily and dry, and has very superior reliability.
Thermal gel has a weak adhesion to the surface of the substrate and can be peeled off from the substrate. Therefore, the electronic components filled with it are reworkable.
Aplicação de gel térmico
Thermal conductive gel is widely used in LED chips, communication equipment, CPU and other semiconductor fields.
It is applied to the contact surface between the heating element (power tube, thyristor, electric heating pile, etc.) in various electronic products and electrical equipment and the heat dissipation facility (heat sink, shell) to transfer heat Intermediate action and moisture-proof, dust-proof, anti-corrosion, anti-vibration and other properties.
O que acontecerá com o gel térmico durante o processo de aplicação?
Since thermal gel has a large proportion of thermally conductive fillers and the viscosity of the rubber is high, the thermal conductive gel is prone to air bubbles during the production and packaging of the rubber tube. The generation of bubbles will cause the rubber to solidify and form a cavity, which affects the appearance of heat transfer gel and reduce the thermal conductivity.
If there are bubbles in one component of the two-component thermal gel, it will also affect the mixing ratio of the AB glue and affect the performance of all aspects of the product.
During the dispensing test of thermal conductive gel, if the glue outlet is too small, the extrusion pressure or the viscosity of the heat conductive gel are too high, the glue will overflow from the end of the hose. One of the main reasons is that in the process of squeezing the glue by the tail cover, the glue also reversely squeezes the tail cover. When the pressure is too high, the tail cover cannot withstand the deformation and overflows. the second is that the gel thermal squeezes the packaging tube which causes the packaging tube to deform and overflow.
Before the two-component thermal gel is cured, the components in the AB tube are mainly a combination of oil and powder. When the oil and powder are not well combined, they are very easy to stratify (separate out.) resulting in the upper and lower parts of the processor gel are not uniform, and oil is prone to appear.
Nota:
When the A+B components are mixed and cured into a gel, the silicone oil and the cross-linking agent react to form a tight spatial network structure, and the product hardly produces oil at this time.
Em comparação com as almofadas térmicas e graxa térmica (pasta térmica), quais são as vantagens e desvantagens do gel térmico?
Thermal gel belongs to thermal interface materials (TIM) like thermal paste and thermal pad.
Gel térmico:
Advantages：
- Pode ser comprimido em várias formas, e o mínimo pode ser comprimido para algumas centenas de mícrons, o que reduz a resistência térmica do gel e melhora a eficiência de transferência de calor do elemento eletrônico;
- Pode utilizar dispensador para operação contínua;
- Não vai óleo e secar
Disadvantage：
The powder filling amount is limited, and the current maximum can reach 6w/m.k.
Almofada térmica:
Advantages：
- A mais alta condutividade térmica, pode atingir 10-20 w/m.k
- Pode ser feito em várias formas;
Disadvantages：
- Cada forma requer um molde específico;
- Incapaz de operar continuamente, é necessário usar cada junta para unir os componentes eletrônicos, é fácil enrugar e produzir cavidades durante o processo de colagem, e o processo de operação é complicado
Graxa térmica:
Advantages：
- Pode ser impresso em tela ou chapa de aço, ou pintado diretamente, o que é fácil de operar
- A operação pode ser contínua.
- A quantidade de cola é a mais fina e pode ser escovada em poucos mícrons
Disadvantages：
- Facilmente oleosos e secos, estabilidade e confiabilidade a longo prazo são insuficientes;
- A condutividade térmica da graxa de silicone não é muito diferente da do gel térmico, que é muito menor do que a da almofada térmica
Por que escolher o gel térmico?
The most serious problem of thermal conductive silicone grease is the precipitation of silicone oil after long-term use. However, the precipitation of silicone oil will cause short-circuit failure of surrounding electronic devices, and at the same time, the thermal conductivity will drop sharply
Although the thermal pad has a long service life, it has a high thermal resistance and requires a higher working pressure.
Thermal gel combines the advantages of thermal grease and thermal pad, while avoiding the shortcomings of both. Thermal conductive gel is a silicone grease mixed with high thermal conductivity particles (such as alumina, silver powder, etc.), and then through a heat treatment process to cross-link low-molecular-weight siloxane, and then form a gel.
Thermal gap filler is a gel state substance between liquid and solid. It not only has the characteristics of shape recovery, strong material cohesion, high heat resistance, good long-term thermal stability and etc., but also has extremely low thermal resistance like thermal conductive silicone grease that can fill gaps, and has high adhesion.
Modelo de produto de gel térmico bicomponente Antas
ZS-GF-5299B gel de dissipação de caloris a kind of paste-like two-component addition molding high thermally conductivity silicone gel, which can be cured by heating, and has the characteristic that the higher the temperature, the faster the curing.
This thermal gap filler does not produce any by-products in the curing reaction. It is suitable for PC, PP, ABS, PVC and other materials and metal surfaces and It can be used in an environment of -40°C to 200°C and fully meets the requirements of EU ROHS and REACH directives.
Jointas chemical is listed company specialized in R&D, manufacture and sale of Eco-friendly silicone sealant, thermal gel, thermal grease and water based paints&coatings founded in 1989, China. Get FREE sample to test the quality now! Email:oversea@jointas.com
