CN103203606A - Method for producing multi-cavity phase change temperature-equalization plate - Google Patents

Abstract

The invention discloses a method for manufacturing a multi-cavity phase change uniform temperature plate, comprising the following steps: A) processing an aluminum alloy plate into an aluminum alloy lower shell with multiple cavities; An aluminum alloy upper casing that matches the lower casing; C) making a plurality of aluminum foam panels that match the plurality of cavities; D) installing the plurality of aluminum foam panels into corresponding multiple aluminum alloy lower casings In each cavity, an aluminum alloy lower shell assembly having multiple aluminum foam cavities is formed; E) fastening the aluminum alloy upper shell to the aluminum alloy lower shell assembly and performing sealing treatment. The present invention realizes reliability redundancy by forming a plurality of completely independent and sealed cavities inside the uniform temperature plate, and can meet the heat transfer requirements of multiple heat sources.

Description

A method of manufacturing a multi-cavity phase-change vapor chamber

technical field

The invention relates to a method for manufacturing a uniform temperature plate.

Background technique

With the rapid development of electronics, IT, communications, LED, solar energy and other industries, the heating power of electronic components used in them is also increasing, and the heat flux density is greatly increased. Transmission problems, especially in the field of heat dissipation such as IGBT (Insulated Gate Bipolar Transistor, insulated gate bipolar transistor), communication power amplifiers, and high-power LED street lights.

The traditional heat dissipation mostly uses the heat dissipation mode of the heat source plus the heat sink, and the heat is lost through the heat exchange between the heat sink and the air, but due to the limitations of its structural space, material heat transfer characteristics, weight, structural strength and reliability of the heat dissipation , when encountering high power and high heat flux density, the traditional heat dissipation mode cannot meet the heat dissipation requirements. At the same time, for the IGBT, communication and military electronics high-power cooling fields, the reliability and redundancy of the radiator must be considered.

The working principle of the traditional phase change vapor chamber (Vapor Chamber) is shown in Figure 1. The typical design is a single sealed cavity composed of a closed shell 1, a liquid-absorbing core and a working fluid, and the inside of the tube is pumped into a 1.3×(10 ^-2 ~ 10 ^{- 3} )Pa negative pressure, filled with an appropriate amount of working liquid, so that the capillary core of the liquid-absorbing core close to the inner wall of the cavity is filled with liquid and then sealed. One end of the cavity is the evaporation section (heating section), and the other end is the condensation section (cooling section). When one end of the cavity is heated, the liquid in the capillary wick evaporates and vaporizes, and the steam flows in the steam channel 3 to the other end under a small pressure difference to release heat and condenses into a liquid, and the liquid flows back in the fluid channel 4 by capillary force or gravity evaporation section. In this endless cycle, heat is transferred from one end of the Vapor Chamber to the other.

The heat flux of the traditional Vapor Chamber can reach 200W/cm2~300W/cm2, and its thermal resistance is 0.03W/℃~0.08W/℃. Compared with the heat pipe, it has a larger heat transfer capacity and can meet the heat dissipation requirements of multi-point heat sources. However, the traditional vapor chamber generally has only one sealed cavity. If the vapor chamber is partially damaged or fails, it will cause the problem that all electronic components (heat sources) in contact with the vapor chamber cannot dissipate heat normally, especially in military electronics, communication and other equipment. In order to ensure the normal operation of the equipment, corresponding redundant protection measures should be added to a system. When one of the power amplifiers or IGBTs has a problem, the redundantly designed circuit or power supply will replace the problematic one. components to ensure the normal use of communication or power systems.

If all these heating elements share a single-chamber chamber, the purpose of reliability redundancy cannot be achieved. Therefore, it is urgent to develop a new type of redundant multi-chamber phase-change chamber.

Contents of the invention

The purpose of the present invention is to provide a method for manufacturing a multi-cavity phase-change vapor chamber, which can better solve the problem that all heating elements in a system share a single-chamber vapor chamber and cannot achieve reliability redundancy.

According to one aspect of the present invention, a method for manufacturing a multi-cavity phase change chamber is provided, comprising the following steps:

A) processing the aluminum alloy plate into an aluminum alloy lower shell with multiple cavities;

B) making an aluminum alloy upper case that matches the aluminum alloy lower case;

C) making a plurality of aluminum foam boards matching the plurality of cavities;

D) installing the plurality of aluminum foam panels into corresponding plurality of cavities in the aluminum alloy lower housing to form an aluminum alloy lower housing assembly having a plurality of aluminum foam cavities;

E) Fasten the aluminum alloy upper shell to the aluminum alloy lower shell assembly, and perform sealing treatment.

Further, in the step A), the aluminum alloy lower shell has a side wall processed with sealing steps, and a supporting structure for forming a plurality of cavities.

Further, in the step B), the aluminum alloy upper shell has welding sides and welding grooves respectively matched with the sealing step and the supporting structure, and corresponding to the plurality of cavities Multiple craft holes.

Further, said step C) includes:

C1) cutting out a plurality of aluminum foam boards matching the plurality of cavities;

C2) Press-molding the cut aluminum foam boards.

Further, said step C) also includes:

C3) After implementing the step C2), decontaminate, degrease, and dry the plurality of aluminum foam boards by using ultrasonic waves, and perform surface grinding and roughening treatment on the obtained plurality of aluminum foam boards to remove surface oxide layer.

Using different abrasive belts of 60-100 mesh, roughening the surface of the plurality of aluminum foam boards.

Further, the step D) includes:

D1) After cleaning the plurality of aluminum foam boards whose surfaces have been roughened, they are soaked in aluminum brazing flux and dried;

D2) After the aluminum alloy lower shell is cleaned by ultrasonic waves, the surface is sprayed with aluminum brazing flux or soaked in aluminum brazing flux and dried;

D3) Adjust the temperature of the brazing furnace to 450-650°C, and under the protection of gas, the aluminum alloy lower shell and the aluminum foam board are sealed and brazed in the brazing furnace to form a multi-aluminum foam cavity Aluminum alloy lower shell assembly.

Further, said step E) includes:

E1) inserting a plurality of process tubes into the plurality of process holes of the aluminum alloy upper shell;

E2) welding the process tube and the aluminum alloy upper shell together by argon arc welding;

E3) Fasten the aluminum alloy upper shell with a plurality of process tubes installed on the aluminum alloy lower shell assembly and use friction stir welding to weld the welding groove of the aluminum alloy upper shell and the The welded sides are respectively welded to the supporting structure and the sealing step of the aluminum alloy lower shell assembly.

Further, said step E) also includes:

E4) After implementing the step E3), use the process tube to vacuumize and inject working fluid into a plurality of aluminum foam cavities.

E5) After implementing the step E4), the process tube is sealed and welded by argon arc welding.

Compared with the prior art, the beneficial effect of the present invention is that: the present invention realizes reliability redundancy by forming multiple completely independent and sealed cavities inside the vapor chamber, and can meet the heat transfer requirements of multiple heat sources.

Description of drawings

Fig. 1 is a working principle diagram of a traditional phase change vapor chamber provided by the prior art;

Fig. 2 is a structural diagram of an aluminum alloy lower case provided by an embodiment of the present invention;

Fig. 3 is a structural diagram of an aluminum alloy upper shell provided by an embodiment of the present invention;

Fig. 4 is a structural view of the cut aluminum foam board provided by the embodiment of the present invention;

Fig. 5 is a structural diagram of the pressed aluminum foam board provided by the embodiment of the present invention;

Fig. 6 is a structural diagram of an aluminum alloy lower shell assembly provided by an embodiment of the present invention;

Fig. 7 is a welding structure diagram of an aluminum alloy shell provided by an embodiment of the present invention;

Fig. 8 is a schematic diagram of the application of the multi-cavity phase change chamber provided by the embodiment of the present invention.

Explanation of reference numerals: 1-housing; 2-capillary structure; 3-steam channel; 4-fluid channel; 51a-first cavity; 51b-second cavity; 51c-third cavity; 51d-fourth Cavity; 52a-the first aluminum foam board; 52b-the second aluminum foam board; 52c-the third aluminum foam board; 52d-the fourth aluminum foam board; 53a-the first aluminum foam cavity; 53b-the second aluminum foam Cavity; 53c-third aluminum foam cavity; 53d-fourth aluminum foam cavity; 6-side wall; 7-support structure; 8-sealing step; 9-welding side; 10-welding groove; 11- Process hole; 12-side seam groove; 13a-first heat source; 13-second heat source; 13c-third heat source.

Detailed ways

The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described below are only used to illustrate and explain the present invention, and are not intended to limit the present invention.

As shown in Figures 2 to 7, the method for manufacturing a multi-cavity phase-change chamber of the present invention includes the following steps:

A) Processing the aluminum alloy plate into an aluminum alloy lower shell with multiple cavities. The aluminum alloy lower shell has a side wall 6 processed with a sealing step 8, and a supporting structure 7 for forming a plurality of cavities 51a-51d.

B) making an aluminum alloy upper shell matching the aluminum alloy lower shell. The aluminum alloy upper shell has welding sides 9 and welding grooves 10 respectively matched with the sealing step 8 and the support structure 7, and a plurality of process holes corresponding to the plurality of cavities 51a-51d 11.

C) Fabricate a plurality of aluminum foam panels 52a-52d to fit the plurality of cavities 51a-51d. Specifically, a plurality of aluminum foam boards 52a-52d matching the plurality of cavities 51a-51d are first cut out, and then the cut-out plurality of aluminum foam boards 52a-52d are subjected to molding processing. After the molding process, the plurality of aluminum foam boards 52a-52d are decontaminated, degreased, cleaned and dried using ultrasonic waves, and the obtained multiple aluminum foam boards 52a -52d surface roughening treatment to remove the surface oxide layer.

D) Install the plurality of aluminum foam plates 52a-52d into the corresponding plurality of cavities 51a-51d in the aluminum alloy lower shell to form an aluminum alloy lower shell assembly with a plurality of aluminum foam cavities 53a-53d . Specifically, firstly, the plurality of aluminum foam boards 52a-52d whose surface has been roughened are cleaned, soaked in aluminum brazing flux and dried, and the aluminum alloy lower shell is cleaned by ultrasonic waves. Spray aluminum brazing flux on the surface or soak and dry in aluminum brazing flux, then adjust the temperature of the brazing furnace to 450-650°C, and under gas protection, make the aluminum alloy lower shell Seal brazing with aluminum foam plates 52a-52d in a brazing furnace to form an aluminum alloy lower shell assembly with multiple aluminum foam cavities 53a-53d.

E) Fasten the aluminum alloy upper shell to the aluminum alloy lower shell assembly, and perform sealing treatment. Specifically, first insert a plurality of process tubes into the plurality of process holes 11 of the aluminum alloy upper shell respectively, use argon arc welding to weld the process tubes and the aluminum alloy upper shell together, and then The aluminum alloy upper shell with a plurality of process tubes installed is fastened to the aluminum alloy lower shell assembly, and the welding groove 10 of the aluminum alloy upper shell is welded to the welding groove 10 by friction stir welding. The sides 9 are respectively welded to the support structure 7 and the sealing step 8 of the aluminum alloy lower shell assembly, and finally, a plurality of aluminum foam cavities 53a-53d are vacuumed and injected with a process tube. Process and seal weld the process tubes using argon arc welding.

Taking four cavities as examples below, the above-mentioned manufacturing method will be described in detail with reference to FIGS. 2 to 7 .

1. Fabrication of multi-cavity phase change uniform temperature plate aluminum shell

Through the aluminum die-casting process or the use of CNC processing technology, the aluminum alloy lower shell of the multi-cavity phase change uniform temperature plate as shown in Figure 2 is produced with an aluminum alloy plate, and the aluminum alloy lower shell is made of the support structure 7 therein. The casing is divided into four cavities, forming an aluminum alloy lower casing with a first cavity 51a, a second cavity 51b, a third cavity 51c and a fourth cavity 51d. Wherein, the support structure 7 can not only strengthen the structure of the phase change chamber, but also serve as steps for welding and sealing the four cavities 51a-51d. The surrounding side walls 6 of the aluminum alloy lower shell are processed with sealing steps 8 , and the sealing steps 8 are at the same height as the supporting structure 7 .

According to the size of the sealing step 8 of the aluminum alloy lower shell of the multi-cavity phase change chamber, the aluminum alloy plate is cut and processed to produce an aluminum alloy upper shell as shown in Figure 3, and its surface is processed with welding grooves 10 and Welded sides 9 with bevels. That is to say, the manufactured aluminum alloy upper shell should match the aluminum alloy lower shell, and have welded side edges 9 and welded grooves 10 matched with the sealing step 8 and the support structure 7 respectively. . Further, four process holes 11 are opened at the four corners of the aluminum alloy upper shell, and the process holes 11 are used for welding process tubes for exhausting and filling working fluid for each cavity.

2. Aluminum foam forming:

According to the design requirements of different products, aluminum foam (80-120 mesh) with different meshes is selected, and according to the heat transfer requirements of the product, the first aluminum foam board 52a (1# cavity foam board), the second aluminum foam board 52b (2# cavity foam board), the third aluminum foam board 52c (3# cavity foam board), the fourth aluminum foam board 52d (4# cavity foam board) , to match the dimensions of the cavities 51a-51d of the multi-cavity phase change vapor chamber aluminum alloy lower shell.

For the aluminum foam boards 52a-52d obtained by cutting, the aluminum foam cavity shapes corresponding to the multiple cavities 51a-51d as shown in Figure 5 are respectively processed by using a die, and then decontamination and degreasing cleaning are performed by ultrasonic waves, and then drying.

3. Surface roughening of aluminum foam

Use different abrasive belts of 60-100 meshes to grind and roughen the contact surfaces of the aluminum foam boards 52a-52d and the aluminum alloy shell to increase the contact area between the aluminum foam boards 52a-52d and the aluminum alloy shell, and to Remove the oxide layer on the surface of the aluminum foam boards 52a-52d.

4. Aluminum foam board pretreatment:

Clean the roughened aluminum foam boards 52a-52d, then immerse the aluminum foam boards 52a-52d in the aluminum brazing flux liquid, and make the aluminum foam boards 52a-52d swing back and forth in the aluminum brazing flux, and Vibrate up and down so that the surface of the aluminum foam boards 52a-52d can be fully soaked in the aluminum brazing flux liquid, take them out and dry them in the drying tunnel.

5. Aluminum alloy shell pretreatment

Ultrasonic cleaning is performed on the aluminum alloy lower shell, and then aluminum brazing flux is used to spray or soak the surface of the shell, and finally it is taken out and dried in a drying tunnel.

6. Assembly of aluminum foam board and aluminum alloy lower shell

Assemble the cleaned and dried aluminum foam boards 52a-52d and the aluminum alloy lower shell, as shown in Figure 6, and lock the brazing mandrel (maintain a certain pressure, 10kg/cm ² ) to the corresponding Aluminum foam cavities 53a-53d, and protect the process hole 11.

7. Aluminum alloy lower shell and aluminum foam board are brazed

Adjust the temperature of the brazing furnace (between 450 and 650°C), and under the gas protection of nitrogen (or other protective gas), the aluminum brazing workpiece is brazed in the gas shielded brazing furnace, and the aluminum alloy lower shell and the The aluminum foam panels are welded together in a one-time seal. Then cool down to below 45 degrees under gas protection conditions and take out the workpiece.

8. Accessory assembly

Assemble the process tube (vacuum tube and injection tube) and the four process holes 11 of the aluminum alloy upper shell. During the assembly process, the fit gap between the shell and the shell welding gap is well controlled, and the fit gap is generally less than 0.08mm. Then, the process tube and the aluminum alloy upper shell are welded together by argon arc welding.

9. Shell sealing welding

Friction Stir Welding (FSW) technology is adopted. During the welding process, the welding head rotates and extends into the joint of the workpiece according to the curves of the welding groove 10 and the side seam groove 12 as shown in Figure 7. The frictional heat between the head and the workpiece causes the aluminum alloy material in front of the welding head to undergo strong plastic deformation, and then as the welding head moves, the highly plastically deformed material flows to the back of the welding head, sealing the edge seam and the groove gap for welding . So that each aluminum foam cavity achieves a completely independent sealing effect.

10. Vacuuming and injection

Vacuumize each sealed and welded aluminum shell cavity through the process tube of each independent aluminum foam cavity (<1.3X10 ^-2 ~5.0X10 ^-3 Pa), and according to product design requirements, in each aluminum foam cavity Inject different amounts of working fluid (141b, acetone, ethylene glycol, etc.).

11. The process tube is sealed.

After injecting a corresponding amount of working fluid, use argon arc welding to seal and weld the process tubes of each aluminum foam cavity.

12. Seal detection of welded shell:

Use helium mass spectrometry to detect the seal of each sealed aluminum alloy shell, and perform air pressure detection (5-15kgf/cm2) according to different product structure designs and different requirements, or use helium mass spectrometry to perform seal detection (according to product design requirements, cavity The microleakage is controlled at 3.0X10 ^-10 ~ 1.0X10 ^-11 Pa.m ³ /S) depending on the size of the body, the working fluid material, and the service life.

13. Performance testing

The fabricated aluminum temperature chamber was tested for heat transfer, temperature uniformity, thermal resistance and other performance tests.

Figure 8 shows a schematic diagram of the application of the multi-cavity phase change chamber provided by the embodiment of the present invention. As shown in Figure 8, in one power module, there are three heat sources at the same time, namely the first heat source 13a and the second heat source 13b. The third heat source 13c. The three heat sources are located below the multi-chamber phase change vapor chamber and are in close contact with the plane of the vapor chamber. In order to ensure that the heat generated by the three heat source modules can be safely and reliably transmitted to the cooling end by the multi-chamber phase change chamber, a redundant design is adopted, that is, each heat source is simultaneously connected to two independently sealed chambers of the chamber Contact, as shown in Figure 8, the first heat source 13a is located under the first aluminum foam cavity 53a and the second aluminum foam cavity 53b, and the second heat source 13b is located under the second aluminum foam cavity 53b and the third aluminum foam cavity Below the foam cavity 53c, the third heat source 13c is located below the third aluminum foam cavity 53c and the fourth aluminum foam cavity 53d, that is, the heat generated by the first heat source 13a can be absorbed by the first aluminum foam cavity 53a and the second aluminum foam cavity. The working medium (working fluid) in the two independent sealed cavities of the aluminum foam cavity 53b is transmitted to the cooling end. Similarly, the heat generated by the second heat source 13b can be transferred to the cooling end by the working fluid in the two independent sealed cavities of the second aluminum foam cavity 53b and the third aluminum foam cavity 53c; the heat generated by the third heat source 13c can be The working fluid in the two independent sealed cavities of the third aluminum foam cavity 53c and the fourth aluminum foam cavity 53d is transmitted to the cooling end.

Its reliability shows that when one of the independent sealed chambers, such as the first aluminum foam chamber 53a, leaks or other damage occurs, the working fluid in the second aluminum foam chamber 53b can still convert the heat produced by the first heat source 13a The heat is taken away, thereby ensuring that the first heat source 14a can be used normally, and enhancing the reliability and safety of the power module.

In summary, the present invention has the following technical effects:

1. It can meet the heat transfer requirements of multiple heat sources at the same time;

2. Multiple aluminum foam cavities can be used to meet the design requirements of redundant reliability;

3. The multi-cavity phase change chamber has better structural strength;

4. The manufacturing process is simple, and the cost of uniform temperature of copper can be greatly reduced;

5. It can effectively reduce the weight of the radiator.

Although the present invention has been described in detail above, the present invention is not limited thereto, and various modifications can be made by those skilled in the art based on the principle of the present invention. Therefore, any modifications made according to the principles of the present invention should be understood as falling within the protection scope of the present invention.

Claims (10)

1. a method of making multi-cavity body phase transformation temperature-uniforming plate is characterized in that, may further comprise the steps:

A) aluminium alloy plate is processed into the aluminium alloy lower house with a plurality of cavitys;

B) make the aluminium alloy upper shell that matches with described aluminium alloy lower house;

C) make a plurality of aluminum foam plates that match with described a plurality of cavitys;

D) described a plurality of aluminum foam plates are respectively installed in the interior corresponding a plurality of cavitys of aluminium alloy lower house, form the aluminium alloy lower house assembly with a plurality of aluminum foam cavitys;

E) described aluminium alloy upper shell is fastened on the described aluminium alloy lower house assembly, and carry out encapsulation process.

2. method according to claim 1 is characterized in that, in described steps A) in, described aluminium alloy lower house has the sidewall of the sealed step of processing, and the supporting construction that is used for forming a plurality of cavitys.

3. method according to claim 2, it is characterized in that, at described step B) in, described aluminium alloy upper shell has respectively welding side and the welding groove that matches with described sealed step and described supporting construction, and a plurality of fabrication holes corresponding with described a plurality of cavitys.

4. method according to claim 3 is characterized in that, described step C) comprising:

C1) cut out a plurality of aluminum foam plates that match with described a plurality of cavitys;

C2) described a plurality of aluminum foam plates that will cut out carry out the mold pressing processing.

5. according to claim or 4 described methods, it is characterized in that described step C) also comprise:

C3) implementing described step C2) after, utilize ultrasonic wave, described a plurality of aluminum foam plates are carried out decontamination, cleaning by degreasing and oven dry handle, and a plurality of aluminum foam plates that will obtain carry out the surface finish roughening treatment, the removal surface oxide layer.

6. method according to claim 5 is characterized in that, utilizes the different abrasive bands of 60-100 purpose, and described a plurality of aluminum foam plates are carried out the surface finish roughening treatment.

7. according to any described method of claim 1-6, it is characterized in that described step D) comprising:

D1) described a plurality of aluminum foam plates of surface finish alligatoring are cleaned after, in aluminum brazing flux, carry out immersion treatment and oven dry;

D2) utilize ultrasonic wave that described aluminium alloy lower house is cleaned after, carry out the processing of surface spraying aluminum brazing flux or in aluminum brazing flux, carry out immersion treatment and the oven dry;

D3) the soldering oven temperature is adjusted between 450～650 ℃, under gas shield, made aluminium alloy lower house and aluminum foam plate in soldering oven, carry out sealed welding, form the aluminium alloy lower house assembly with a plurality of aluminum foam cavitys.

8. method according to claim 7 is characterized in that, described step e) comprising:

E1) a plurality of process duct are inserted respectively in a plurality of fabrication holes of described aluminium alloy upper shell;

E2) utilize argon arc welding that described process duct and described aluminium alloy upper shell are welded together;

E3) the aluminium alloy upper shell that a plurality of process duct will be installed fastens on the described aluminium alloy lower house assembly and utilizes friction stir welding, on the described supporting construction and described sealed step that described welding groove and the described welding side of described aluminium alloy upper shell is welded to described aluminium alloy lower house assembly respectively.

9. method according to claim 8, described step e) also comprise:

E4) implementing described step e 3) afterwards, utilize process duct that a plurality of aluminum foam cavitys are vacuumized, annotate working medium and handle.

10. method according to claim 9, described step e) also comprise:

E5) implementing described step e 4) afterwards, utilize the described process duct of argon arc welding soldering and sealing.

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