Thermal module and joining method for hermetically sealed enclosure of a thermal module using a capillary joint

Abstract

A thermal module includes parts with diverging or divergent walls that cause a capillary pressure gradient in a bonding paste used to secure the parts together. Based in part on the capillary pressure, the bonding paste is drawn in between the divergent walls, including small gaps between the walls. Additionally, during a reflow operation of the bonding paste, particles and/or air bubbles can egress from the bonding paste, allowing the bonding paste to freeze and form a homogeneous structure. By removing particles and air bubbles, the bonding paste can form a more robust structural joint and a hermetic seal for the thermal module. The multiple parts of the thermal module can be formed into their respective shapes prior to be joined together by the bonding paste. As a result, the formation of the thermal module is less likely to damage other structures, such as wick structures.