WO1999053256A1

WO1999053256A1 - Plate type heat pipe and its installation structure

Info

Publication number: WO1999053256A1
Application number: PCT/JP1999/001841
Authority: WO
Inventors: Masaaki Yamamoto; Masami Ikeda; Tatsuhiko Ueki; Hitoshi Sho
Original assignee: Furukawa Electric Co., Ltd.
Priority date: 1998-04-15
Filing date: 1999-04-07
Publication date: 1999-10-21
Also published as: DE19980819T1; CN1179188C; JP4278720B2; CN1263592A; TW414854B; GB2342152B; GB9928393D0; GB2342152A

Abstract

A plate type heat pipe, comprising an enclosed container having principal plane parts (A) and (B) opposed to each other, at least one heat transfer block for heat transfer installed in the container so that the inner wall of the principal plane part (A) is connected through the heat transfer block to the inner wall of the principal plane part (B), a wick disposed in the container at at least one part of the heat transfer block, and a working fluid sealed in the container.

Description

Specification

Plate type heat pipe and its mounting structure

The present invention relates to a plate-type heat pipe for effectively cooling electric and electronic components such as semiconductor elements, and a mounting structure using the same. Background art

Electric and electronic components such as semiconductor devices mounted on various devices such as personal computers and electric and electronic equipment such as power equipment generate heat to some extent by their use. If the temperature of such electrical-electronic components rises excessively, their performance will be reduced or their life will be shortened. In recent years, the miniaturization of electric devices such as personal computers has been progressing, and attention has been paid to the development of technology for cooling electric and electronic components mounted on electric devices.

As a method of cooling electric and electronic elements that need to be cooled (hereinafter referred to as “cooled parts”), for example, an air-cooled type, that is, a fan etc. There is known a method of preventing the temperature of a component to be cooled from excessively rising by cooling an atmosphere in a housing. This method is particularly effective for relatively large electrical equipment.

In addition to the air-cooling method described above, in recent years, a method of connecting a heat sink and fins to a component to be cooled and dissipating heat via the heat sink has become effective. Interpose a heat pipe between the heat sink or fin and the part to be cooled! ) In some cases. Also, there is known a technology in which an electric fan is used to blow the heat sink and fins to achieve higher cooling efficiency.

Hereinafter, the heat pipe will be described. The heat pipe has a sealed cavity. In the heat pipe, heat is transferred by the phase transformation and movement of the working fluid contained in the cavity. There is also heat transfer that conducts heat through the container (container) that constitutes the heat pipe, but it is usually relatively small compared to the above-mentioned heat transfer by phase transformation and movement of the working fluid. Next, the operation of the heat pipe will be briefly described. Taking a rod-shaped heat pipe as an example, a heat-generating component (cooled component) is connected near one end, and a fin for heat dissipation is mounted near the other end. The part to which the component to be cooled is attached

In the “heat-absorbing section or heat-absorbing side”), the working fluid evaporates due to the heat of the part to be cooled transmitted through the thick part of the container by heat conduction, and the vapor is attached to the fins ( (Hereinafter referred to as “radiator or radiator”). Then, the vapor returns to the liquid phase again in the heat radiating section, and the heat is released to the outside from the cavity almost through the fins. In this way, heat is transferred from the heat absorbing section to the heat radiating section. In order for the above-mentioned heat transfer to be performed continuously, the working fluid that has returned to the liquid phase on the heat radiation side must be moved (refluxed) to the heat absorption side again. In the case of a gravity-type heat pipe, the heat-absorbing side may be located below the heat-radiating side (this form is called bottom heat). In this case, the working fluid that has changed to a liquid phase due to phase transformation on the heat radiation side returns to the heat absorption side due to gravity. However, when the heat-absorbing side is located above the heat-dissipating side (this form is called top heat), the working fluid is not sufficiently recirculated to the heat-absorbing side, and a phenomenon called dry-out occurs. May be confused.

By the way, the shape of a heat pipe has attracted attention in recent years, in addition to a typical round pipe shape, a plate-shaped heat pipe. Plate-type heat pipes are sometimes referred to as flat-type heat pipes, flat-type heat pipes, and the like; depending on the shape, the plate-type heat pipe has a large area with components to be cooled such as semiconductor elements. There are advantages such as easy contact.

That is, the plate-type heat pipe has an advantage that it can contact the component to be cooled on its wide main surface. Even in the case of using a plate-type heat pipe, it is desirable to use it in the bottom heat mode in order to further ensure the recirculation of the working fluid, as in the case of a round pipe-shaped heat pipe. Therefore, as a desirable mounting structure, a plate-type heat pipe is arranged so that one main surface faces downward, the component to be cooled contacts the lower main surface, and a heat sink is attached to the other upper main surface. Structure is conceivable. In this way, the lower main surface part is on the heat absorbing side, The part of the upper main surface where the heat sink is attached is the heat radiation side, and it is in the bottom heat mode.

However, in recent years, miniaturization of computers and the like has progressed, and the scope of electric and electronic devices on which components to be cooled are mounted has been expanding from stationary to portable. In particular, in the case of a small computer, etc., it may be assumed that it is used with a certain inclination. Under these circumstances, a plate-type heat pipe that can maintain a certain level of performance even in the top heat mode has been demanded. Disclosure of the invention

The inventors have intensively studied to overcome the above-mentioned conventional problems. As a result, a heat transfer block for transferring heat is provided inside the container so as to connect between the inner wall of the main surface portion A and the inner wall of the main surface portion B, and at least a part of the heat transfer block. By disposing the wicks in the tub, it was found that a plate-type heat pipe that can be used at an angle and can maintain the cooling performance efficiently even in the top heat mode can be provided.

The plate-type heat pipe of the present invention has been made based on the above findings, and a first embodiment of the plate-type heat pipe of the present invention is a plate-type heat pipe including the following members:

(1) A sealed container having opposed main surface portions A and B,

(2) At least one heat transfer block for transmitting heat, which is provided to connect between the inner wall of the main surface portion A and the inner wall of the main surface portion B inside the container,

(3) Dick disposed on at least a part of the heat transfer block inside the container, and

(4) Working fluid sealed in the container.

A second aspect of the plate heat pipe of the present invention is characterized in that the main surface portion A and the main surface portion B are made of a flat plate-like material.

A third aspect of the plate-type heat pipe of the present invention is that the main surface portion A or the main surface portion Any one of B has at least one convex portion extending outwardly of the container.

A fourth aspect of the plate-type heat pipe of the present invention is characterized in that the protrusions extend outward at different heights from the container.

A fifth aspect of the plate-type heat pipe of the present invention is characterized in that the protrusions extend at the same height toward the outside of the container.

A sixth aspect of the plate-type heat pipe of the present invention is characterized in that the heat transfer block is provided so as to be connected to each of the at least one projection.

In a seventh aspect of the plate-type heat pipe of the present invention, the heat transfer block has a cylindrical shape or a prismatic shape, and the entire heat transfer block is formed by metal bonding, and the inner wall of the main surface portion A is formed. And a connection between the inner walls of the main surface portion B.

In an eighth aspect of the plate heat pipe of the present invention, the wick is formed on at least one part of the inner wall of the main surface part A, the inner wall of the main surface part B, and the side wall of the heat transfer block. It is characterized by being provided.

A ninth aspect of the plate-type heat pipe of the present invention is characterized in that the wick is further provided on the entire surface of one of the inner wall of the main surface portion A and the inner wall of the main surface portion B. It is.

According to a tenth aspect of the plate heat pipe of the present invention, the wick further includes an entire surface of one of an inner wall of the main surface portion A and an inner wall of the main surface portion B, and an entire surface of a side wall of the heat transfer block. Are provided.

According to a first aspect of the plate-type heat pipe of the present invention, the wick is not provided on the entire surface, and the wick is provided on the inner wall of the main surface portion A or the inner wall of the main surface portion B. It is characterized by being bent at the connection portion with the side wall.

According to a twelfth aspect of the plate heat pipe of the present invention, the wick includes at least an inner wall of the main surface portion A, an inner wall of the main surface portion B, and a side wall of the heat transfer block. It is characterized by being provided in contact with or joined to one. A thirteenth aspect of the plate-type heat pipe of the present invention is characterized in that the wick is fixed by a side surface of the heat transfer block and an inner wall of the projection.

A fourteenth aspect of the plate-type heat pipe of the present invention is characterized in that a component to be cooled is mounted on an outer wall of the projection provided so as to be connected to the heat transfer block. is there.

A fifteenth aspect of the plate heat pipe of the present invention is characterized in that fins are provided on one of the inner wall of the main surface portion A and the inner wall of the main surface portion B. is there.

According to a sixteenth aspect of the plate heat pipe of the present invention, the plate heat pipe is disposed so as to face a substrate on which a component to be cooled is mounted, and the heat transfer block is provided in at least one position. Is a mounting structure of a plate-type heat pipe to which the component to be cooled is connected. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an explanatory view showing an example of a plate-type heat pipe according to the present invention.

FIG. 2 is an explanatory view showing an example of a plate-type heat pipe according to the present invention.

FIG. 3 is a partially enlarged explanatory view of FIG. BEST MODE FOR CARRYING OUT THE INVENTION

The plate heat pipe of the present invention is a plate heat pipe capable of maintaining excellent performance even in the top heat mode.

The plate-type heat pipe of the present invention includes the following members. (1) a sealed container having opposed main surface portions A and B,

(2) At least one heat transfer block for transmitting heat, which is provided so as to connect between the inner wall of the main surface portion A and the inner wall of the main surface portion B inside the container. At least part of the heat transfer block inside the container (4) The working fluid enclosed in the container. Further, in the plate-type heat pipe of the present invention, the main surface portion A and the main surface portion B are made of a flat plate-like material. Further, in the plate-type heat pipe of the present invention, one of the main surface portion A and the main surface portion B may have at least one convex portion extending outwardly of the container. Good. In the plate-type heat pipe of the present invention, the above-mentioned convex portions may extend outward of the container at different heights. Further, in the plate-type heat pipe of the present invention, the above-mentioned projections may extend outward of the container at the same height.

Further, in the plate heat pipe of the present invention, a heat transfer block may be provided so as to be connected to each of the at least one projection.

Further, in the plate-type heat pipe of the present invention, the heat transfer block has a cylindrical shape or a prismatic shape, and the heat transfer block is formed between the inner wall of the main surface portion A and the inner wall of the main surface portion B by metal bonding. May be connected.

Further, in the plate-type heat pipe of the present invention, the wick is at least a part of the heat transfer block, preferably at least each of the inner wall of the main surface portion A, the inner wall of the main surface portion B, and the side wall of the heat transfer block. It is provided in one part. In the plate-type heat pipe of the present invention, the wick may be further provided on the entire surface of one of the inner wall of the main surface portion A and the inner wall of the main surface portion B. In the plate heat pipe of the present invention, the wick may be further provided on the entire surface of one of the inner wall of the main surface portion A and the inner wall of the main surface portion B, and on the entire surface of the side wall of the heat transfer block.

In the plate-type heat pipe of the present invention, further, the wick is not provided on the entire surface, and the wick is bent at the connection portion with the side wall of the heat transfer block on the inner wall of the main surface portion A or the inner wall of the main surface portion B. It may be provided.

Further, in the plate heat pipe of the present invention, the wick is provided so as to be in contact with or in contact with at least one of the inner wall of the main surface portion A, the inner wall of the main surface portion B, and the side wall of the heat transfer block. It is a feature.

In the plate-type heat pipe of the present invention, the wick may be fixed by a side surface of the heat transfer block and an inner wall of the projection. In the plate-type heat pipe of the present invention, a component to be cooled may be mounted on an outer wall of the projection provided to connect the heat transfer block.

In the plate-type heat pipe of the present invention, fins may be provided on any one of the inner wall of the main surface portion A and the inner wall of the main surface portion B.

Furthermore, in the mounting structure of the plate-type heat pipe of the present invention, the above-described plate-type heat pipe is arranged so as to be opposed to the substrate on which the component-to-be-cooled is mounted, and at least one of the positions provided with the heat transfer blocks is provided. Is a mounting structure to which the component to be cooled is connected.

With reference to the drawings, the plate-type heat pipe of the present invention will be described in more detail. FIG. 1 is an explanatory diagram schematically showing an example of a plate-type heat pipe of the present invention and an example of a mounting structure thereof. A substrate 30 is assumed to be a printed circuit board or the like, on which a cooled component 40 such as a semiconductor element is provided. Has been implemented. Reference numeral 31 in the figure indicates a lead.

The plate-shaped heat pipe 1 is arranged so as to be in contact with the upper surface side of the component to be cooled 40. The component to be cooled 40 and the plate-type heat pipe 1 may be brought into contact with each other with direct interposition of heat transfer grease or the like as necessary, in addition to direct contact. In some cases, these may be joined by soldering or the like. The material of the container 10 constituting the plate-type heat pipe 1 is not particularly limited, but if a material having excellent thermal conductivity such as copper material or aluminum material is used, the plate-type heat pipe 1 having excellent thermal performance can be used. And it is desirable. Copper material is JIS standard C100, C110, etc.Alluminum material is also JTS standard A110, A300, A500, A500 60000 system and the like.

An appropriate amount of working fluid (not shown) is accommodated in the hollow portion 13 of the plate-type heat pipe 1. Working fluids include water, alternative chlorofluorocarbons, ammonia, alcohol, acetone, etc.

The heat transfer block 11 is provided in the cavity 13 at a position corresponding to a portion where the component to be cooled 40 is connected to the plate-shaped heat pipe 1. The heat transfer block 11 is in contact with the inner wall of the hollow portion 13 corresponding to both the upper and lower main surfaces of the container 10. The heat transfer block 11 may be metal-joined to its inner wall by soldering or brazing. If the heat transfer block 11 is joined to the inner wall by metal joining, This is desirable because the thermal resistance between them will be smaller.

The cavity 13 is provided with a wick 12. The wick 12 is arranged along the inner wall of a portion corresponding to the upper surface of the container 10 (the upper main surface of the container 10). It extends to the inner wall corresponding to the lower part of container 10 (the lower main surface of container 10), and its tip contacts the inner wall. In the case of the embodiment shown in FIG. 1, the wick 12 is brought into contact with the inner wall corresponding to the lower surface while bending the heat transfer block 11 such that the tip is bent. By doing so, a connection state with lower thermal resistance between the wick 12 and the inner wall is realized. The tip of the wick 12 may be metal-joined to its inner wall. With metal bonding, the thermal resistance between them will be even lower.

When the temperature of the cooled component 40 rises, the heat of the cooled component 40 is transmitted to the upper surface of the plate-shaped heat pipe 1 by the operation of the heat pipe, and the heat is generally released to the outside via the fins 14. Become like In this way, cooling of the cooled component 40 is realized. As long as the bottom heat mode is as shown in FIG. 1, the working fluid (not shown) in the plate-shaped heat pipe 1 can be expected to return by gravity. However, in the case of the plate heat pipe 1, even if the plate heat pipe 1 is greatly inclined and the top heat mode is set, the reflux of the working fluid is maintained by the capillary action of the wick 12 according to the plate heat pipe of the present invention. .

In particular, since the wick 12 is also in contact with or joined to the inner wall on the side where the component to be cooled 40 is mounted, the working fluid is reliably returned. If the wick 12 is brought into contact with or joined to the heat transfer block 11, the reflux of the wick 12 is further ensured. In particular, in the case of the embodiment shown in FIG. 1, since the heat transfer block 11 is arranged at the connection position of the component to be cooled 40, the heat of the component to be cooled 40 is directly transmitted to the heat transfer block through the container 10. The heat transferred to the heat transfer block returns to the working fluid flowing through the wick 12.

(Liquid phase) cools the heat transfer block on the wide side surface.

Next, another embodiment of the present invention will be described with reference to FIGS. The plate-shaped heat pipe 2 is composed of a plurality of components to be cooled 41 to 3 mounted on the substrate 30 through the leads 31.

(Three parts to be cooled are shown in this figure) It has 20 containers. In this embodiment, the container 20 is formed by joining an upper container member 201 and a lower container member 202 in the figure. As shown in the figure, the three convex portions are formed by previously performing press working or the like on the container member 202. An appropriate amount of working fluid (not shown) is stored in the hollow portion 22 inside the container 20. A heat sink 50 is attached to the upper surface of the plate-shaped heat pipe 2. The heat sink 50 is applied, for example, a heat radiating work made of aluminum.

At least one of the one or more protrusions (all three in the example of this figure) has heat transfer blocks 23 to 25 disposed therein. A wick 21 is provided in the hollow portion 22. The wick 21 is in contact with the upper inner wall, and further along the heat transfer blocks 23 to 25, comes into contact with the bottom surface of the lower inner wall, or the convex portion. Are joined. The wick 21 may also be in contact with or joined to the heat transfer block 24.

As for the method of bringing the wick 21 into contact with the lower inner wall or the method of joining them, the metal may be joined by, for example, a brazing method. As shown in Fig. 2, when the container 20 has a convex portion and the heat transfer blocks 23, 24, and 25 are arranged inside the container, the heat transfer blocks 23 to 25 and the container 20 It is also effective to fix the wick 21 by sandwiching it between and. FIG. 3 is an enlarged view of the vicinity of the heat transfer block 24, showing a state in which the wick 21 is fixed so as to be sandwiched between the heat transfer block 24 and the inner wall of the container member 202 which forms the convex portion. Is shown. By fixing the wick 21 in this way, it is possible to connect the wick 21 to the inner wall and further to the heat transfer block 24 with low thermal resistance without the need for a separate step such as brazing. It is practical.

The plate heat pipe 2 shown in FIG. 2 also maintains the reflux of the working fluid in the top heat mode, similarly to the plate heat pipe 1 (FIG. 1) described above. Also, in this case, the cooling structure for multiple components to be cooled with different heights can be handled by one plate-type heat pipe because the components to be cooled have protrusions according to the height of 23 to 25. It has practical advantages and is practical. Example

Example 1

Using a copper plate material having a thickness of 1 mm, a plate-type heat pipe having a length of 10 O mm, a width of 7 O mm, and a thickness of 6 mm shown in FIG. 1 was produced. One heat transfer block made of copper, 25 mm long x 25 mm wide x 4 mm high, was placed in the cavity at the position where the parts to be cooled are connected. The heat transfer blocks are made of metal by brazing the upper and lower inner walls of the cavity.

Hi Hi!

Furthermore, as shown in Fig. 1, wicks were placed on the entire inner wall of the upper surface in the cavity, on the entire side surface of the heat transfer block, and on a part of the lower surface in the cavity in contact with the component to be cooled. . Furthermore, the pressure inside the cavity was reduced, and water as a working fluid was sealed.

MPU as a component to be cooled was brought into contact with the plate-shaped heat pipe thus produced via heat transfer grease. When this plate-type heat pipe was used at an angle from the horizontal plane, excellent cooling performance was obtained without dry-out. Example 2

A plate-type heat pipe as shown in Fig. 2 by joining a lmm thick copper upper plate and a 1mm thick copper lower plate with three convex parts formed by pressing. Was made. The three projections were formed so that the central part was higher and the both sides were relatively lower, corresponding to the height of the component to be cooled. The container formed in this way is 10 O mm long x 7 O mm wide x 6 mm wide, and the width including the convex part is 9 mm at the central convex part and 8 mm at the convex parts on both sides. Met.

A copper heat transfer block of 25 mm (length) x 25 mm (width) x 7 mm (height) is placed in the central convex part by a copper heat transfer block (length 25 mm x width 25 mm x height 6 mm). The heat blocks were placed in the protrusions on both sides, respectively, and the heat transfer blocks were each metal-bonded by brazing to the upper and lower inner walls of the cavity.

Furthermore, as shown in Fig. 2, wicks were placed all over the inner wall of the upper surface inside the cavity and all over the side surfaces of the heat transfer block. Furthermore, as shown in FIG. The wick was sandwiched between the side wall and the heat transfer block.

Furthermore, the pressure inside the cavity was reduced, and water as a working fluid was sealed.

MPUs having different heights provided on the substrate were brought into contact with the plate-shaped heat pipe manufactured as described above as heat-receiving parts via heat transfer grease. When this plate-type heat pipe was used at an angle of 60 degrees from the horizontal plane, excellent cooling performance was obtained without causing dryout. Industrial applicability

As described above, according to the plate-type heat pipe of the present invention, it is possible to provide a plate-type heat pipe capable of maintaining excellent performance even in the top heat. For this reason, the mounting structure using the plate-type heat pie of the present invention can be used, for example, if the plate-type heat pipe of the present invention is used in an electric or electronic device on which a component to be cooled such as a semiconductor element to be cooled is mounted. Excellent cooling performance can be maintained even when the top heat mode is set, for example, when the air conditioner is used at an angle.

Claims

The scope of the claims

1. Plate heat pipe with the following components:

(1) A sealed container having opposed main surface portions A and B,

(2) Inside the container, at least one heat transfer workpipe for transmitting heat, which is provided to connect between the inner wall of the main surface portion A and the inner wall of the main surface portion B,

(3) a wick arranged at least in part of the heat transfer block inside the container, and

(4) Working fluid sealed in the container.

2. The plate-type heat pipe according to claim 1, wherein the main surface portion A and the main surface portion B are made of a flat plate-like material.

3. The method according to claim 1, wherein at least one of the main surface portion A and the main surface portion B includes at least one convex portion extending outwardly of the container. The plate-shaped heat pipe as described.

4. The plate-type heat pipe according to claim 3, wherein the convex portions extend outwardly of the container at different heights.

5. The plate-shaped heat pipe according to claim 3, wherein the protrusions extend at the same height toward the outside of the container.

6. The plate-type heat pipe according to claim 3, wherein the heat transfer block is provided so as to be connected to that of the at least one convex portion.

7. The plate-type heat pipe according to claim 3, wherein the heat transfer block is provided so as to be connected to at least one of the protrusions.

8. The heat transfer block has a cylindrical or prismatic shape, and all the heat transfer blocks connect between the inner wall of the main surface portion A and the inner wall of the main surface portion B by metal bonding. The plate-shaped heat pipe according to claim 2, wherein

9. The wick is provided on at least one of the inner wall of the main surface portion A, the inner wall of the main surface portion B, and the side wall of the heat transfer block. The plate-type heat pipe according to claim 1, wherein

10. The plate-type heat pipe according to claim 9, wherein the wick is provided on an entire surface of one of the inner wall of the main surface portion A and the inner wall of the main surface portion B.

11. The wick is characterized in that it is provided on the entire surface of one of the inner wall of the main surface portion A and the inner wall of the main surface portion B, and on the entire surface of the side wall of the heat transfer block. Item 10. A plate-type heat pipe according to item 9.

12. On the inner wall of the main surface portion A or the inner wall of the main surface portion B where the wick is not provided on the entire surface, the wick is provided by being bent at a connection portion with the side wall of the heat transfer block. 10. The plate-shaped heat pipe according to claim 10, wherein:

13. The wick is provided so as to be in contact with or joined to at least one of the inner wall of the main surface portion A, the inner wall of the main surface portion B, and the side wall of the heat transfer block. Item 13. A plate-type heat pipe according to any one of Items 9 to 12.

14. The plate-type heat pipe according to claim 10, wherein the wick is fixed by a side surface of the heat transfer work and an inner wall of the projection.

15. The plate-type heat paper according to claim 6 or 7, wherein a component to be cooled is mounted on an outer wall of the projection provided to connect the heat transfer block. H.

16. The plate-type heat pipe according to claim 1, wherein a 7-pin is provided on one of an outer wall of the inner surface of the main surface portion A and an inner wall of the main surface portion B. 17.

17. The plate-shaped heat pipe according to any one of claims 1 to 7, wherein the plate-shaped heat pipe is arranged to face a substrate on which a component to be cooled is mounted, and at least one of the positions where the heat transfer block is provided. One is a mounting structure of a plate-shaped heat pipe to which the component to be cooled is connected.