US-20260126248-A1 - ULTRA-THIN HEAT PIPE AND MANUFACTURING METHOD OF THE SAME

US20260126248A1US 20260126248 A1US20260126248 A1US 20260126248A1US-20260126248-A1

Abstract

A heat dissipating device that includes a first plate and a second plate opposite the first plate and connected to the first plate by two opposite sidewalls. The first plate and the second plate are connected to each other at longitudinally opposite ends thereof, longitudinally extending ends of the first plate and the second plate are connected to each other by sidewalls, and the first plate, the second plate and the sidewalls enclosing an internal space of the heat dissipating device. The heat dissipating device also includes a first wick structure disposed in the internal space and contacting inner surfaces of at least one of the first plate and the second plate. The first wick structure extends longitudinally between the longitudinally opposite ends of the first plate and the second plate, and the first wick structure at least partially defines a first vapor flow channel of the heat dissipating device

Inventors

Jen-Chih CHENG

Assignees

COOLER MASTER CO., LTD.

Dates

Publication Date: 20260507
Application Date: 20260105

Claims (6)

1 . A method, comprising: arranging a first wick structure and a second wick structure in a metal pipe; flattening the metal pipe to obtain a heat dissipating device having a first plate; and a second plate opposite the first plate, wherein longitudinally extending ends of the first plate and the second plate are connected to each other by sidewalls, the first plate, the second plate and the sidewalls enclose an internal space of the heat dissipating device, and the first plate forms a top horizontal surface of the internal space, the second plate forms a bottom horizontal surface of the internal space, and each sidewall forms side surfaces of the internal space; sealing a first longitudinal end of the heat dissipating device to form a first transitional portion of the first plate that is sloped towards the second plate and connects to a first extended end of the second plate at the first longitudinal end; inserting a working pipe in the heat dissipating device via an opening at a second longitudinal end thereof; sealing the second longitudinal end of the heat dissipating device up to the working pipe; inserting working fluid in the internal space of the heat dissipating device via the working pipe; sealing an entire width of the heat dissipating device at a first location adjacent to the second longitudinal end to form a second transitional portion of the first plate that is sloped towards the second plate and connects to a second extended end of the second plate at the second longitudinal end; and removing excessive portions of the working pipe and the heat dissipating device at or adjacent to the second transitional portion away from the first longitudinal end, wherein the first wick structure and the second wick structure extend an entire length of the heat dissipating device and is absent in the first transitional portion and the second transitional portion.
2 . The method of claim 1 , further comprising vacuuming out air from the heat dissipating device prior to sealing the entire width of the heat dissipating device at the first location.
3 . The method of claim 1 , further comprising sintering the first wick structure and the second wick structure to an inner surface of the metal pipe prior to flattening the metal pipe.
4 . The method of claim 4 further comprising flattening the metal pipe such that the first wick structure and the second wick structure are spaced away from each other and contact inner surfaces of opposite sidewalls.
5 . The method of claim 1 , further comprising arranging a third wick structure in the metal pipe.
6 . The method of claim 5 , further comprising flattening the metal pipe such that the first wick structure and the second wick structure are spaced away from each other and contact inner surfaces of opposite sidewalls, and the third wick structure is disposed between the first and second wick structures.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This patent application is continuation of U.S. patent application No. 18/765,459, filed on July 8, 2024, which is a divisional application of U.S. patent application No. 16/845,663 filed on April 10, 2020, now U.S. Patent No. 12,066,256, which is a non-provisional application claims priority under 35 U.S.C. § 120 to U.S. provisional application No. 62/832,664 filed April 11, 2019, the entire contents of which are hereby incorporated by reference. BACKGROUND During operation of electronic devices, the heat generated by the processors must be dissipated quickly and efficiently to keep operating temperatures within manufacturer recommended ranges. As these electronic devices increase in functionality and applicability so does operating speed of the processors used therein. With each new generation of electronic devices being thinner and more compact, thermal management of these devices becomes challenging as spacing between the different heat sources in the electronic devices is reduced. Heat pipes are used to dissipate heat. In general, planar heat pipes are formed by flattening heat pipes to around 30% to 60% of their original diameter. Planar heat pipes are vacuum containers that carry heat from a heat source by evaporation of a working fluid which is spread by a vapor flow filling the vacuum, increasing the thermally connected surface area. The vapor flow eventually condenses over cooler surfaces, and, as a result, the heat is uniformly distributed from an evaporation surface (heat source interface) to a condensation surface (larger cooling surface area). Thereafter, condensed fluid flows back to the evaporation surface. A wick structure, such as a sintered powdered wick, is used to facilitate the flow of the condensed fluid by capillary force back to the evaporation surface, keeping the evaporation surface wet for large heat fluxes. The thermal performance of planar heat pipes is dependent on the effectiveness of the heat pipes to dissipate heat via the phase change (liquid-vapor-liquid) mechanism. The capillary force generated in the wick structure must overcome the liquid pressure drop in the wick and vapor pressure drop in the heat pipe. The capillary force generated is reduced when the vapor chambers are thin, as the liquid pressure drop and vapor pressure drop are higher when spacing is reduced. A sintered powdered wick can provide high capillary pressure, however it also has a high liquid pressure drop, leading to an adverse effect on the thermal performance of planar heat pipes. Furthermore, when the heat pipes are flattened, the structural integrity of the flattened structure is compromised. In addition, the flattened structure decreases thermal performance. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a plan view of an ultra-thin heat pipe, according to embodiments. FIG. 1B is a side view of the ultra-thin heat pipe, according to embodiments. FIG. 1C is a perspective view of the ultra-thin heat pipe, according to embodiments. FIG. 1D is a cross-sectional view of the ultra-thin heat pipe taken along line W-W in FIG. 1C, according to embodiments. FIG. 2 is a cross-sectional view of the ultra-thin heat pipe along lines W-W and L-L, according to embodiments. FIG. 3 is a flow chart of a method of manufacturing the ultra-thin heat pipe of FIGS. 1A-1D, according to embodiments. FIG. 4 is a perspective view of a conductive metal pipe following a series of operations of the method of FIG. 3, according to embodiments. FIG. 5 is a perspective view of the ultra-thin heat pipe of FIGS. 1A-1D obtained after a flattening operation performed in the manufacturing method, according to embodiments. FIG. 6 is a perspective view of the ultra-thin heat pipe of FIGS. 1A-1D after an operation of the manufacturing method, according to embodiments. FIG. 7 is a perspective view of the ultra-thin heat pipe of FIGS. 1A-1D following a series of operations of the manufacturing method, according to embodiments. FIG. 8 is a perspective view of the ultra-thin heat pipe of FIGS. 1A-1D following a series of operations of the manufacturing method, according to embodiments. FIG. 9 illustrates a comparison between the ultra-thin heat pipe of FIGS. 1A-1D manufactured according to the embodiments disclosed herein and an outline of an ultra-thin heat pipe manufactured according to existing manufacturing methods. FIG. 10A is a cross-sectional view of a wick structure including a plurality of wick fibers arranged in a circular manner. FIGS. 10B-10D illustrate different configurations of the wick structures of FIG. 10A. FIG. 10E is a cross-sectional view of a wick structure including multiple wick fibers arranged around a central wick fiber. FIGS. 10F, 10G, 10H, 10J, and 10K illustrate different configurations of the wick structures of FIG. 10E. FIG. 11 is a cross-sectional view of an ultra-thin heat pipe, according to embodiments. FIG. 12 is a cross-sectional view of an ultra-thin heat pipe, accordi