Patent Application
20070022603
This non-provisional application claims priority under U.S.C.ยง 119(A) on patent application No. 094125806, filed in Taiwan, Republic of China on Jul. 29, 2005, the entire contents of which are hereby incorporated by reference.
1. Field of the Invention
The invention relates in general to cooling apparatuses and in particular to a method for manufacturing vapor chambers.
2. Description of the Related Art
With progress in IC fabrication, while the number of transistors per unit area within an electronic component has greatly increased, more heat is generated during its operation. Heat pipes are widely used in heat dissipation of electronic devices because its simple structure and high efficiency. The heat pipes dissipate heat by using a working fluid continuously transferring between the liquid phase and the gas phase so as to carry heat away from the heat source.
Vapor chambers are a specific type of heat pipes, applying similar heat exchange to conventional heat pipes. Generally, as vapor chambers provide lager conductive surface and smaller dimensions than conventional heat pipes, they are suitable for compact electronic products having large heat dissipation surface. Various types of planar vapor chambers have been disclosed, and most of which use a top plate and a bottom plate to form a closed chamber, wherein capillary structures are formed on the inner surfaces of the plates. The capillary structures can be made by sintered powder, such as copper powder.
Referring to
As conventional vapor chambers are produced by welding two plates, the long welding path may reduce fabrication reliability and the capillary structures cannot be continuously formed on the inner surfaces of the two plates. As conventional welding fabrication requires many parts and complex molding technologies, production costs are potentially increased. Further, since the top and bottom plates must be produced individually with specific profiles, it is difficult to produce the two plates of different dimensions simultaneously during a single sintering process.
Thus, a method for manufacturing vapor chambers is provided, formed by copper extrusion or drawing. A capillary structure is formed on an inner surface of a hollow tube by sintering, wherein the capillary structure includes a metal spring, groove, pillar, mesh or metal powder porous structure.
Subsequently, an end of the hollow tube is sealed by welding, soldering, fusing or other mechanical process. A working fluid is filled into the hollow tube. The hollow tube is evacuated with the other end of the tube sealed.
According to the method for manufacturing a vapor chamber, the top and bottom plates can be integrally formed as a single piece, rather than using conventional welding method so as to avoid long welding path and improve reliability. Further, as continuous capillary structure facilitates movement of the working fluid, thermal transmission pathway is improved, as compared with the discontinuous capillary structure of conventional vapor chambers.
The method for manufacturing vapor chamber of the invention is suitable for single sintering process, wherein the dimension of the vapor chamber is adjustable by demand, thereby reducing mold cost and simplifying manufacturing processes. In summary, the method for manufacturing vapor chamber is cheap and flexible, producing various shapes of vapor chambers.
The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
In a method for manufacturing vapor chambers, a hollow tube is integrally formed by copper extrusion or drawing. The hollow tube may be circular, elliptical, half-circular, rectangular, triangular, square, trapezoid, pentagonal, hexagonal, octagonal, equilateral or inequilateral in cross-section. The hollow tube is made of aluminum, copper, titanium, molybdenum, or a metal with a high thermal conductivity. Subsequently, a capillary structure is formed on the inner surface of the hollow tube and the surface of the partition 25 by sintering. Specifically, the capillary structure is formed by a porous spring, groove, pillar, mesh or metal powder porous structure.
One end of the hollow tube is sealed by welding, soldering, fusing or other mechanical process, and a working fluid is filled into the hollow tube. The working fluid is such as inorganic compounds, water, alkane, alcohol, liquid metal, ketone, Freon or organic compounds. After the working fluid is filled, the hollow tube is evacuated and completely sealed by sealing the other end of the hollow tube.
According to the method for manufacturing vapor chambers, the top and bottom plates can be integrally formed as a single piece, unlike conventional vapor chambers whose top and bottom plates are combined by welding. As the result, this avoids long welding path and improves reliability of the vapor chambers. Further, as continuous capillary structure facilitates movement of a working fluid, thermal transferring effect is improved over the discontinuous capillary structure of conventional vapor chambers.
Also, the method for manufacturing vapor chambers of the invention is suitable for single sintering process, wherein the dimensions of the vapor chamber are adjustable by demand, thereby reducing mold costs and simplifying manufacturing. In summary, the method for manufacturing vapor chamber is cheap and flexible to produce various shapes of vapor chambers.
While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation to encompass all such modifications and similar arrangements.
| Number | Date | Country | Kind |
|---|---|---|---|
| 94125806 | Jul 2005 | TW | national |
