Conventional vapor chamber for electronic products
The vapor chamber enclosure is a vacuum sealed envelope which houses the wick structure and refrigerant. Heat transfer is realized by the phase change of the refrigerant. The inner cavity is formed by the upper and lower cover plates through diffusion bonding. The cavity with copper mesh wick microstructure on the inner wall is made of oxygen-free copper (C1100/C1020), which could be customized. Due to the vacuum process, the refrigerant stays a saturated state, so that when the vapor chamber is heated, the liquid rapidly evaporates to form a saturated state again, reflecting the thermal sensitivity of the vapor chamber.
When the heat from heat source conducts to the evaporation zone, the refrigerant in the vacuum cavity begins evaporating. As the heat energy is absorbed, the refrigerant rapidly expands to fill the whole cavity. Condensation occurs when the vapor refrigerant meets the cooler region. By means of the condensation, the heat accumulated during evaporation is released, and the condensed coolant is returned to the evaporation zone through the capillary tube of the micro-structure. This operation is repeated in the cavity.
Based on the heat transfer process of rapid evaporation and condensation of the refrigerant inside the vapor chamber, the vapor chamber has the advantages of high thermal conductivity, nice temperature homogeneity and flexible heating position.
Different from the traditional heat pipe which can only meet the characteristics of radial heat transfer, the vapor chamber can also meet the characteristics of axial heat transfer, which makes it possible to configure the structure of evaporation at the bottom and condensation at the top. In addition to the use of copper, aluminum (6061) is also widely used in the vapor chambers. Based on the light weight and low cost of aluminum, the demand for aluminum vapor chambers is also increasing.