A parametric study on the performance of vapor chamber in association with pillar distribution

• Effect of geometric features on vapor chamber performance is experimentally studied. • Pillar distribution plays a key role in determining liquid return and vapor flow. • X-wing pillar distribution provided a minimum thermal resistance of 0.19 K W −1. • A 2 × 200 mesh offered a minimum thermal resistance of 0.18 K W −1 at 161 W. • Increasing number of pillars may not always reduce the thermal resistance. The performance of vapor chamber is significantly affected by the wick structure, height of the vapor cavity, pillar structure, working fluid, filling ratio, and heat source area. Besides, it can also be influenced by the pillar distribution, which has not been extensively studied in prior literature. Therefore, the present study investigates the influence of pillar distribution on the vapor chamber performance. Totally 11 different vapor chamber models are fabricated and tested, and water is selected as a working fluid for all the samples. The examined geometric features include different mesh layers, mesh sizes, wick structure in condenser surface, pillar distributions, and vapor core space. The results showed that the evaporator with a single-layered mesh provided the thermal resistance of 0.19 K W −1 , while triple-layered mesh yielded a thermal resistance of 0.24 K W −1 . Moreover, the 2 × 200 mesh offered a maximum heating load of 161 W with a thermal resistance of 0.18 K W −1 against the maximum heating load of 120 W and 75.6 W by the 2 × 150 and 2 × 100 mesh, respectively. The experimental results showed that increasing the pillar numbers alone may not always reduce the thermal resistance, a better pillar distribution can help to direct the vapor flow and improve the performance of the vapor chamber. The proposed vapor chamber with a novel X-wing patterned pillar distribution can offer a thermal resistance of 0.19 K W −1 at a heating load of 146.6 W.