A Thermal Performance Characterization Method for Thin Vapor Chambers by Photonics Technologies

This study presents a novel thermal performance characterization method for the thin vapor chambers by photonics technologies. It is proposed and experimentally demonstrated using a laser as the heat source, and the infra-red (IR) thermal radiation sensors as the thermometers. The laser heat source and the IR thermometers used in this system are all optical and therefore it is a non-contact detection device. The laser heat source enjoys the advantages of nearly complete and instantaneous power transfer from the laser output to the device under test. Arbitrary heat power waveforms can be generated by the laser heat source by controlling the driving current of the diode laser. The temperature measurement capabilities of this system include not only the temperature uniformity on the condenser but also the temperature on the evaporator of the vapor chamber. The advantages of this non-contact system including the much faster steady-state temperature uniformity measurement speed and the ability to the transient performance analysis of the vapor chamber are experimentally confirmed. For steady-state temperature uniformity measurement, the test time for the non-contact measurement system by natural convection is less than 30 seconds, while it takes several minutes for the contact measurement system. Using a 1-s rectangular heat pulse as the input, the temperature of the vapor chamber stays 37.4% and 51.1% cooler than the copper plate by comparing the magnitude of temperature rise when the input heat power is 5 W (below Q
max
) and 10 W (beyond Q
max
), respectively. This method offers an accurate and fast characterization of the thin vapor chambers.