In the application of LED industry, what are the advantages and disadvantages of thermal conductive silicone grease and thermal conductive silicone sheet?

Thermal grease Advantages: the material is pasty and the common thermal conductivity is 3-4w/m.k. the advantage is that the material has good adaptability, is suitable for aluminum substrates of various shapes, has good thermal conductivity and does not generate leftover materials. Disadvantages: large-area smearing operation part is convenient, which can be used in a long-term high-temperature state. free substances are separated out in the heat conductive paste, which pollutes the lamp lens and affects the light transmittance. when using such materials, attention should be paid to the performance of the materials in a long-term high-temperature state, and the less the escaped substances, the better. thermal silicon pad Advantages: The flexible gasket with single silicone base material is soft in material, good in compression performance, large in adjustable range of thickness, suitable for filling cavities, sticky on both sides, and strong in operability and maintainability. Disadvantages: when the heat conduction area is large, because this kind of material is relatively soft, when it comes to parts with size requirements such as mounting holes, it will lead to dimensional deviation and misalignment due to material deformation. moreover, because the two sides of the material are sticky, when the aluminum substrate cannot be accurately mounted to the heat dissipation base at one time and needs to be moved repeatedly, the material will wrinkle or even pull off, resulting in new cavities, thus affecting the heat conduction effect. when using this material, attention should be paid to the training of workers, or certain tools should be used to reduce the product problems caused by processing.