JP5939754B2 - Structure of plate heat pipe - Google Patents

Description

The present invention relates to a structure of a plate heat pipe and a method for manufacturing the plate heat pipe, and in particular, by joining a metal material and a ceramic material, thermal fatigue ( The present invention relates to a plate-type heat pipe structure that prevents cracks from being generated due to thermal fatigue and a method for manufacturing the same.

With the progress of semiconductor technology, the volume of integrated circuits is gradually reduced. Further, in order to allow the integrated circuit to process a larger amount of data, the integrated circuit is loaded with a number of arithmetic elements several times that of the conventional circuit. However, as the number of arithmetic elements in the integrated circuit increases, more heat is generated when the arithmetic elements are operated. Taking the CPU as an example, the heat generated from the CPU in maximum operation is a sufficient amount of heat to burn out the entire CPU. Therefore, the heat dissipation device of the integrated circuit is very important.

Since the CPU unit and the chip in the electronic device are heat sources, heat is generated when the electronic device is operated. The external package of the CPU unit and the chip is mainly made of a ceramic material. Ceramic materials have a low thermal expansion coefficient, are insulating materials, and have a thermal expansion coefficient close to that of a chip, so that they are used in large quantities as package materials and semiconductor materials.

In general, an aluminum material and a copper material are used as a material for the heat dissipation device. Moreover, the heat radiation effect is enhanced by combining heat radiating members such as a fan and a heat pipe. However, adopting a fan and a heat pipe reduces the reliability of the entire heat dissipation device.

In general, the simpler the overall structure of the heat dissipation device, the higher the reliability. Moreover, the thermal conductivity can be directly improved by using a material having a heat dissipation structure that is superior to the heat dissipation capability of copper.

The problem of thermal stress between the heat dissipation device and the heat source is another problem related to the reliability of the product. Product reliability is ensured by sealing the chip with a ceramic material having a low thermal expansion coefficient such as AlN (aluminum nitride) or SiC (silicon carbide) because the heat expansion coefficient of the heat source (for example, the chip in the CPU) is low. Increases sex.

For example, regarding the heat dissipation of the LED, the thermal expansion coefficient of the aluminum material and the copper material is much higher than that of sapphire. Therefore, when a high-intensity LED is used for a long period of time, due to thermal fatigue, a crack is likely to occur in the joint portion between the aluminum material and the copper material and sapphire, and the thermal resistance of the joint surface is likely to increase. When the thermal resistance at the heat dissipation interface increases, heat accumulates in the high-brightness LED product, which may damage the LED chip and damage the light emitter.

Therefore, there is a need for an immediate solution to the problem of cracking due to thermal fatigue caused by the difference in thermal expansion coefficient at the joint between the ceramic material arranged outside the heat source and the heat dissipation device made of a metal material. It was.

JP 2005-95944 A JP 2009-283559 A JP 2005-510357 A

A main object of the present invention is to provide a structure of a plate heat pipe that prevents a crack from being generated due to thermal fatigue at a joint portion between the plate heat pipe and a heat generation source.
Another object of the present invention is to provide a method for manufacturing a plate heat pipe that prevents cracks due to thermal fatigue from occurring at the joint between the plate heat pipe and the heat source.

In order to solve the above problems, according to a first embodiment of the present invention, a plate-type heat pipe structure including a main body, wherein the main body includes a metal plate body and a ceramic plate body, and the metal plate The body and the ceramic plate are opposed to each other and their peripheral edges are joined to each other , thereby defining a space serving as a chamber between them, forming a wick structure on the inner wall surface of the chamber and joining a plurality of copper pillars with soft solder A support structure in which the ceramic plate and the metal plate are joined by hard solder joining, diffusion joining, ultrasonic welding or copper direct joining, and the chamber is filled with a working fluid. A package for sealing the outside of the ceramic substrate is formed of a ceramic substrate, and the thermal expansion coefficient of the ceramic plate of the main body is substantially equal to the thermal expansion coefficient of the ceramic substrate of the package, The structure of the plate type heat pipe to heat conduction is provided a ceramic plate member directly bonded to the ceramic substrate of the package.

  The wick structure is preferably a powder sintered body, a net-like body, or a plurality of grooves.

The ceramic plate is preferably made of silicon nitride, zirconium oxide or aluminum oxide.

Moreover, it is preferable that the said support structure is joined to the said ceramic plate body and the said metal plate body by soft solder joining, hard solder joining, diffusion joining, ultrasonic welding, or copper direct joining.

The support structure is preferably a copper pillar.

Moreover, it is preferable that the said metal plate body consists of material which was excellent in copper material, aluminum material, stainless steel, or heat dissipation and heat conductivity.

In order to solve the above problems, according to a second embodiment of the present invention, a step of preparing a metal plate body and a ceramic plate body, and a surface of the metal plate body and the ceramic plate body on opposite sides of each other are provided. The step of providing a wick structure and a support structure, and the metal plate body and the ceramic plate body are bonded to each other to form a space between them, and then the chamber is evacuated and evacuated. Then, after filling the chamber with a working fluid, and finally sealing to form a plate heat pipe, a package for sealing the outside of the heat source is configured with a ceramic substrate, The thermal expansion coefficient of the ceramic plate body is substantially equal to the thermal expansion coefficient of the ceramic substrate of the package, and the ceramic plate body is directly joined to the ceramic substrate of the package to transfer heat. Method for producing a plate-type heat pipe letting is provided.

  The wick structure is preferably a powder sintered body, a net-like body, or a plurality of grooves.

The ceramic plate is preferably made of silicon nitride, zirconium oxide or aluminum oxide.

Moreover, it is preferable that the said support structure is joined to the said ceramic plate body and the said metal plate body by soft solder joining, hard solder joining, diffusion joining, ultrasonic welding, or copper direct joining.

The support structure is preferably a copper pillar.

Further, after the metal plate body and the ceramic plate body are connected to each other, the chamber is evacuated, and then the chamber is filled with a working fluid, and finally sealed to form a plate heat pipe. During the step, the metal plate body and the ceramic plate body are preferably joined by soft solder joining, hard solder joining, diffusion joining, ultrasonic welding, or copper direct joining.

The structure of the plate heat pipe of the present invention is configured by directly bonding a ceramic substrate that seals the outside of the heat source and a ceramic plate that forms part of the plate heat pipe . When used, the ceramic plate body and the ceramic substrate of the package that seals the outside of the heat generation source are directly bonded to each other, which is caused by the difference in thermal expansion coefficient at the bonding portion between the plate type heat pipe and the heat generation source. by the thermal fatigue land rack can be prevented from being generated.

It is a disassembled perspective view which shows the structure of the plate-type heat pipe by 1st Embodiment of this invention. It is a perspective view which shows the structure of the plate-type heat pipe by 1st Embodiment of this invention. It is sectional drawing which shows the structure of the plate-type heat pipe by 1st Embodiment of this invention. It is sectional drawing which shows the structure of the plate-type heat pipe by 2nd Embodiment of this invention. It is sectional drawing which shows the structure of the plate-type heat pipe by 3rd Embodiment of this invention. It is a flowchart which shows the manufacturing method of the plate-type heat pipe by one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited thereby.

(First embodiment)
Please refer to FIG. As shown in FIGS. 1 to 3, the structure of the plate heat pipe according to the first embodiment of the present invention includes a main body 1.

  The main body 1 includes a metal plate 11 and a ceramic plate 12. The metal plate 11 is bonded to the ceramic plate 12 so as to face each other, and a space serving as a chamber 13 is defined between the metal plate 11 and the ceramic plate 12 facing each other. A wick structure 14 and a support structure 15 are formed in the chamber 13. The wick structure 14 is formed on the inner wall surface of the chamber 13, and the support structure 15 is disposed between the metal plate body 11 and the ceramic plate body 12 in the space of the chamber and connects the two to form a flat chamber space. To support. The chamber 13 is filled with a working fluid 16.

  The wick structure 14 will be described by exemplifying a powder sintered body, but is not limited thereto.

The ceramic plate 12 is made of silicon nitride (Si ₃ N ₄ ), zirconium oxide (ZrO ₂ ), or aluminum oxide (Al ₂ O ₃ ).

  The support structure 15 is bonded to the ceramic plate 12 by soft solder bonding, hard solder bonding, diffusion bonding, ultrasonic welding, or direct bonding copper (DBC).

  The support structure 15 is a copper pillar. The metal plate 11 is made of a copper material, an aluminum material, stainless steel, or a material excellent in heat dissipation and thermal conductivity.

(Second Embodiment)
Please refer to FIG. As shown in FIG. 4, the structure of the plate heat pipe according to the second embodiment of the present invention is the same as the structure of the plate heat pipe according to the first embodiment in part and the connection relationship. Will not be repeated here. The heat radiating device according to the second embodiment of the present invention is different from the first embodiment in that the wick structure 14 is a net-like body.

(Third embodiment)
Please refer to FIG. As shown in FIG. 5, the structure of the plate-type heat pipe according to the third embodiment of the present invention is the same as the structure of the plate-type heat pipe according to the first embodiment. Will not be repeated here. The heat dissipation device according to the third embodiment of the present invention is different from the first embodiment in that the wick structure 14 is a plurality of grooves.

  Please refer to FIG. As shown in FIGS. 1-6, the manufacturing method of the plate-type heat pipe by one Embodiment of this invention consists of the following steps S1-S3.

  S1: A metal plate and a ceramic plate are prepared.

In S1, the metal plate 11 and the ceramic plate 12 are prepared. The metal material of the metal plate 11 is a copper material, an aluminum material, stainless steel, or a material excellent in heat dissipation and thermal conductivity. In this embodiment, a copper material will be described as an example. The ceramic material of the ceramic plate 12 is silicon nitride, zirconium oxide or aluminum oxide. In the present embodiment, aluminum oxide will be described as an example.

S2: A wick structure and a support structure are provided on one surface of the metal plate body and the ceramic plate body facing each other.

In S2, the wick structure 14 and the support structure 15 are provided on the surfaces of the metal plate body 11 and the ceramic plate body 12 facing each other. The wick structure 14 is a powder sintered body, a net-like body, or a plurality of grooves. When a powder sintered body is selected for the wick structure 14, the powder sintered body is formed on the metal plate body 11 and the ceramic plate body 12 by sintering.

When the wick structure 14 is a network body, the network body is bonded to the ceramic plate body 12 and the metal plate body 11 by soft solder bonding, hard solder bonding, diffusion bonding, ultrasonic welding, or copper direct bonding.

When the wick structure 14 is a plurality of grooves, the grooves are provided in the metal plate body 11 and the ceramic plate body 12 in advance by machining. Machining is milling, routering, laser cutting or etching.

The support structure 15 is a copper pillar. The support structure 15 is bonded to the ceramic plate 12 in advance by soft solder bonding, hard solder bonding, diffusion bonding, ultrasonic welding, or copper direct bonding, or is bonded to the metal plate 11 in advance.

  S3: The metal plate body and the ceramic plate body are bonded to each other and a space serving as a chamber is formed therebetween, and then the chamber is evacuated and evacuated. Next, the chamber is filled with a working fluid and then sealed to complete a plate heat pipe.

  The metal plate 11 and the ceramic plate 12 are connected to each other by soft solder bonding, hard solder bonding, diffusion bonding, ultrasonic welding, or copper direct bonding. Next, the inside of the chamber 13 is evacuated. Next, the chamber 13 is filled with the working fluid 16 and then sealed to form a plate heat pipe.

In the structure of the plate heat pipe of the present invention, a package that seals the outside of the heat source is formed of a ceramic substrate, and heat is conducted by contacting the ceramic plate 12 with the ceramic substrate of the package . Ceramic plate body 12 to conduct heat in contact with the package of the ceramic substrate to cover the direct heat source. Since the thermal expansion coefficient of the ceramic plate 12 is close to the thermal expansion coefficient of the ceramic package that seals the outside of the heat source, the heat generated by the difference in the thermal expansion coefficient at the joint between the plate heat pipe and the heat source. It is possible to prevent the problem of cracks from occurring due to fatigue, and the application range of the plate heat pipe as a heat radiating member can be expanded.

While the preferred embodiments of the present invention have been disclosed above, as may be appreciated by those skilled in the art, they are not intended to limit the invention in any way. Various changes and modifications can be made without departing from the spirit and scope of the present invention. Accordingly, the scope of the claims of the present invention should be construed broadly including such changes and modifications.

DESCRIPTION OF SYMBOLS 1 Main body 11 Metal plate body 12 Ceramic plate body 13 Chamber 14 Wick structure 15 Support structure 16 Working fluid

Claims (4)

The structure of a plate-type heat pipe provided with a main body,
The body is composed of a metal plate member及beauty ceramic plate member, by joining respective peripheral to face and said said metal plate ceramic plate body defining a space of a chamber therebetween Forming a wick structure on the inner wall surface of the chamber and joining a plurality of copper pillars to the ceramic plate and the metal plate by soft solder bonding, hard solder bonding, diffusion bonding, ultrasonic welding or copper direct bonding. A support structure, and the chamber is filled with a working fluid ,
A package for sealing the outside of the heat source is formed of a ceramic substrate, and the thermal expansion coefficient of the ceramic plate body is substantially equal to the thermal expansion coefficient of the ceramic substrate of the package, and the ceramic plate body is A plate-type heat pipe structure that is directly bonded to a ceramic substrate to conduct heat.   The plate-type heat pipe structure according to claim 1, wherein the wick structure is a powder sintered body, a net-like body, or a plurality of grooves.   The structure of the plate-type heat pipe according to claim 1, wherein the ceramic plate body is made of silicon nitride, zirconium oxide or aluminum oxide.   The plate-type heat pipe structure according to claim 1, wherein the metal plate is made of a copper material, an aluminum material, or stainless steel.

Images