CN202734632U - Microcrack flat heat pipe - Google Patents

Abstract

The utility model discloses a micro-cracked flat heat pipe, which comprises a pipe body and a porous capillary layer attached to the inner wall of the pipe body. The surface of the porous capillary layer has a plurality of grooves distributed uniformly along the inner wall of the pipe body; the processing method is to The sintered mandrel is placed in the middle of the tube body, and there is a gap between the tube body and the sintered mandrel; shrink one end of the tube body, and then derust and degrease the tube body and the sintered mandrel as a whole; fill the metal powder into In the gap between the tube body and the sintering mandrel, put the tube body together with the sintering furnace into a high-temperature sintering furnace for sintering; take out the tube body after sintering, take out the sintering mandrel after cooling to room temperature, and then vacuumize the other end of the tube body, Infusion of working fluid and sealing; flattening of the pipe body; the utility model adopts the phase change flattening process and the continuous and large porous capillary layer obtained by the sintered mandrel induction method, that is, the micro-crack channel space, which provides steam The channel significantly improves the heat transfer and mass transfer performance of the flat heat pipe.

Description

A microcrack flat heat pipe

technical field

The utility model relates to a cooling component in the electronic field, in particular to a micro-crack flat heat pipe.

Background technique

With the rapid development of high-performance electronic chip technology and the continuous improvement of electronic packaging and integration, the heat flux density of the chip will increase sharply and the effective heat dissipation space will become increasingly narrow. The traditional heat dissipation methods can no longer meet the heat dissipation requirements. The cooling system is developed and optimized. Because the flat heat pipe has the characteristics of fast heat transfer and small space occupation, it is widely used in electronic products in these small spaces.

Traditional micro heat pipes with liquid-absorbent cores mainly include grooved heat pipes, sintered metal powder heat pipes, wire mesh heat pipes, and fiber-type liquid-absorbent core heat pipes. The grooved liquid-absorbing core has a high permeability, and the working fluid return resistance is much lower than that of the sintered liquid-absorbing core. It has a relatively large steam flow channel under the same pipe diameter, but its capillary force is small, and it is susceptible to Gravity affects. However, the sintered wick has high capillary force, but has high thermal resistance and low permeability.

Contents of the invention

The purpose of the utility model is to overcome the shortcomings and deficiencies of the prior art, to provide a micro-cracked flat heat pipe with simple structure and convenient processing, and to solve the problem of insufficient heat dissipation capacity of the existing heat pipe.

The utility model is realized through the following technical solutions:

A micro-crack flat heat pipe comprises a pipe body and a porous capillary layer attached to the inner wall of the pipe; the surface of the porous capillary layer has a plurality of grooves uniformly distributed along the inner wall of the pipe body.

The tube body is a metal flat heat pipe; the tube body is filled with deionized distilled water or ethanol.

A method for manufacturing a microcrack flat heat pipe, comprising the steps of:

(1) Prepare a pipe body and a sintered mandrel. The diameter of the sintered mandrel is smaller than the inner diameter of the pipe body. Place the sintered mandrel in the middle of the pipe body. There is a gap between the pipe body and the sintered mandrel; One end of the body is shrinked, and then the pipe body and the sintered mandrel are derusted and degreased as a whole;

(2) Preparation of porous capillary layer: Fill the metal powder into the gap between the tube body and the sintered mandrel, the metal powder covers the entire gap, and then put the tube body together with the tube body into a high-temperature sintering furnace at 850°C to 950°C for sintering. The final metal powder is attached to the inner wall of the tube to form a porous capillary layer;

(3) After the sintering is completed, take out the tube body, take out the sintered mandrel after cooling down to room temperature naturally, then vacuumize the other end of the tube body, pour working fluid and seal it; Flattening to obtain micro-cracked flat heat pipes;

In the above step (3), the pipe body is finally flattened and formed by the phase change flattening device. The phase change flattening device includes an upper plate mold and a lower plate mold. The lower plate mold has a plurality of holes, and the A heating rod is inserted into the hole to heat the lower platen; the upper platen is also provided with multiple holes, and a cooling water pipe is connected to the hole, and the upper platen is continuously cooled by the cooling water, and then the upper platen and the lower platen are passed Flatten the tube body to the desired flat shape.

In the above step (1), grooves are also opened on the inner surface of the pipe body, and the surface of the sintered mandrel is smooth.

In the above step (1), the inner surface of the pipe body may also be a smooth surface, and the surface of the sintered mandrel may be a surface covered with multiple grooves.

The working medium in the above step (3) is deionized distilled water or ethanol.

Compared with the prior art, the utility model has the following advantages:

A porous capillary layer is attached to the inner wall of the pipe body of the utility model, and the surface of the porous capillary layer has a plurality of grooves, which are evenly distributed along the inner wall of the pipe body in the circumferential direction, and has high permeability and low backflow resistance. The phase change flattening process is adopted, and the sintered mandrel with a grooved surface is used to induce the porous capillary layer to crack naturally along the grooves formed on the porous capillary layer during the flattening process, and the cracked grooves are in the porous capillary layer Microcracks are formed on the surface, and a continuous and sufficiently large porous capillary layer is obtained. This microcrack provides a steam channel and significantly improves the heat transfer and mass transfer performance of the flat heat pipe.

The utility model adopts the phase-change flattening process, which prevents buckling on the central axis of the pipe body and ensures the quality of the flat surface of the heat pipe.

The technical means of the utility model is simple and easy to implement, the cost is low, and it is convenient to popularize and apply.

Description of drawings

Fig. 1 is a kind of structural sectional schematic diagram of the utility model;

Fig. 2 is a schematic cross-sectional structure diagram of one of the sintered mandrels of the present invention;

Fig. 3 is a schematic diagram of the manufacturing process flow in Fig. 1;

Fig. 4 is the second schematic diagram of the manufacturing process flow in Fig. 1;

Fig. 5 is a schematic cross-sectional view of another structure of the utility model;

Fig. 6 is a schematic diagram of the manufacturing process of Fig. 5;

FIG. 7 is a second schematic diagram of the manufacturing process flow in FIG. 5;

Detailed ways

Below in conjunction with specific embodiment the utility model is described in further detail.

Example 1

As shown in Figures 1 to 4. The micro-crack flat heat pipe of the utility model comprises a pipe body 1 and a porous capillary layer 2 attached to the inner wall of the pipe body 1; the surface of the porous capillary layer 2 has a plurality of grooves, which are evenly distributed along the inner wall of the pipe body 1; The tube body 1 adopts a metal flat heat pipe, and the tube body 1 is filled with deionized distilled water or ethanol.

The utility model micro-crack flat heat pipe manufacturing method can be realized through the following steps:

(1) Prepare a tube body 1 (circular metal heat pipe) and a sintered mandrel 3, the diameter of the sintered mandrel is smaller than the inner diameter of the tube body 1, place the sintered mandrel in the middle of the tube body 1, and the tube body There is a gap between 1 and the sintered mandrel 3; one end of the tube body 1 is retracted, and then the tube body 1 and the sintered mandrel 3 are derusted and degreased as a whole;

(2) Preparation of porous capillary layer: Fill the metal powder into the gap between the tube body 1 and the sintered mandrel 3, the metal powder covers the entire gap, and then put the tube body 1 into a high-temperature sintering furnace at 850°C to 950°C Sintering, the sintered metal powder is attached to the inner wall of the tube body 1 to form a porous capillary layer;

(3) After the sintering is completed, take out the tube body 1, take out the sintered mandrel 3 after cooling down to room temperature naturally, then vacuumize the other end of the tube body 1, pour working fluid, and seal it; The tube body 1 is flattened to obtain a flat heat pipe with microcracks;

In the above step (3), the pipe body 1 is finally flattened and formed by the phase change flattening device. The phase change flattening device includes an upper plate mold 4 and a lower plate mold 5, and the lower plate mold 5 has a plurality of holes ( 5 are shown in the figure), and a heating rod is inserted into the hole to heat the lower plate mold 5; the upper plate mold 4 is also provided with a plurality of holes (5 are shown in the figure), and a cooling water pipe is connected to the hole , the upper plate mold 4 is continuously cooled by cooling water, and then the pipe body 1 is flattened to the required flat shape by the upper plate mold 4 and the lower plate mold 5 .

In the above step (1), the inner surface of the pipe body 1 is a smooth surface, and the surface of the sintered mandrel is a surface covered with a plurality of grooves (see FIG. 2 ). After the sintering process is completed, the sintered mandrel with this structure will correspondingly form a corresponding groove structure on the inner surface of the porous capillary layer. Therefore, during the flattening process of the tube body 1, along the inner surface of the porous capillary layer The groove is naturally cracked, and the cracked groove forms a continuous steam channel, thereby obtaining a micro-cracked flat heat pipe;

The working medium in the above step (3) is deionized distilled water or ethanol.

The metal powder is copper, aluminum metal powder, etc., and the mesh size is 200-400 mesh.

The material of the sintered mandrel 3 can be stainless steel, nickel-based alloy, etc.

Example 2

This embodiment is the same as Embodiment 1 except for the following features.

As shown in Figure 5 to Figure 7. In the above step (1), grooves are opened on the inner surface of the pipe body 1 , and the surface of the sintered mandrel is a smooth surface (not shown in the figure).

As mentioned above, the utility model can be better realized.

The above-mentioned embodiment is only the preferred implementation mode of the present utility model, but the implementation mode of the present utility model is not limited by the above-mentioned embodiment, and any other changes, modifications and substitutions made without departing from the spirit and principle of the present utility model , combination, and simplification, all should be equivalent replacement methods, and are all included in the protection scope of the present utility model.

Claims (4)

1. A microcrack flat heat pipe is characterized in that it comprises a pipe body and a porous capillary layer attached to the inner wall of the pipe. 2 . The microcracked flat heat pipe according to claim 1 , characterized in that, the surface of the porous capillary layer has a plurality of grooves uniformly distributed along the inner wall surface of the pipe body. 3 . 3. The microcrack flat heat pipe according to claim 1 or 2, characterized in that the pipe body is a metal flat heat pipe. 4. The microcracked flat heat pipe according to claim 1 or 2, characterized in that, the pipe body is filled with deionized distilled water or ethanol.

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