Flexible customized 3d heat pipe and its preparation method and application

A preparation method for a customized three dimensional (3D) heat pipe, wherein the customized 3D heat pipe is disposed in an electronic device and partially contacts a control chip of the electronic device, and comprises a flexible housing, a flexible wick, and a working fluid;

• wherein the flexible housing forms a working fluid circulation groove therein, the flexible wick is disposed within the working fluid circulation groove, and on any cross-section perpendicular to an extending direction of the working fluid circulation groove, the flexible wick contacts both a top surface and a bottom surface of the working fluid circulation groove;
• the working fluid circulates within the working fluid circulation groove, the flexible wick absorbs a liquid working fluid through capillary action, and the liquid working fluid absorbs heat dissipated by the control chip and evaporates into a gaseous state, then dissipates heat through the top surface and the bottom surface of the working fluid circulation groove to condense into liquid and flow back onto the flexible wick;
• the preparation method comprises the following steps:
• (1) converting a target model into point cloud data, and then planning a morphological trajectory of the customized 3D heat pipe along its two-phase circulation direction based on the point cloud data;
• wherein the flexible housing is obtained by sealingly covering an upper housing and a lower housing, the upper housing and the lower housing forming two ports after being covered;
• and the upper housing and the lower housing each are provided with a thermally sealable edge at their outer periphery except at positions corresponding to the ports;
• the morphological trajectory comprises sealable edges and regions where a curvature of the customized 3D heat pipe changes abruptly;
• (2) extracting three-dimensional point coordinates from the morphological trajectory, generating a three-dimensional surface from three-dimensional sheets along adjacent morphological trajectories in a three-dimensional modeling software, unfolding and converting the three-dimensional surface into a two-dimensional unfolded plane using a two-dimensional mapping algorithm, then preparing an upper housing sheet, a lower housing sheet, a wick sheet, and a flexible heater having the same shape as the sealable edges along the two-dimensional unfolded plane;
• (3) generating a three-dimensional model of a shaping mold for the flexible wick and a three-dimensional model of a pre-encapsulation mold for the customized 3D heat pipe by combining the three-dimensional surface and the morphological trajectory, and then printing the shaping mold and the pre-encapsulation mold using light-curing 3D printing technology;
• wherein the shaping mold comprises an upper shaping mold and a lower shaping mold, and a middle portion of mating surfaces of the upper shaping mold and the lower shaping mold has the same shape as the flexible wick;
• and
• the pre-encapsulation mold comprises an upper pre-encapsulation mold and a lower pre-encapsulation mold, and a middle portion of mating surfaces of the upper pre-encapsulation mold and the lower pre-encapsulation mold forms a shape identical to that of the customized 3D heat pipe;
• (4) stacking multiple pieces of the wick sheet and placing them between the upper shaping mold and the lower shaping mold, mating of the upper shaping mold and the lower shaping mold applying a normal force to wick sheets to obtain a three-dimensional wick, and subjecting the three-dimensional wick to hydrophilic treatment to obtain the flexible wick;
• (5) sequentially stacking the upper pre-encapsulation mold, the flexible heater, the upper housing sheet, the flexible wick, the lower housing sheet, and the lower pre-encapsulation mold, mating of the upper pre-encapsulation mold and the lower pre-encapsulation mold applying a normal force to the upper housing sheet and the lower housing sheet, heating the flexible heater to seal the sealable edges, and obtaining a pre-encapsulated heat pipe, an outer periphery of the pre-encapsulated heat pipe not sealed by the sealable edges forming the two ports;
• and
• (6) performing a drainage port treatment on one of the ports, then sealing the other port, evacuating and filling the pre-encapsulated heat pipe with the working fluid from a port subjected to the drainage port treatment, finally sealing the port subjected to the drainage port treatment, and obtaining the customized 3D heat pipe.