KR100755572B1 - Method for case's bonding of flat plate heat spreader based on brazing and Apparatus manufactured using the same - Google Patents

Abstract

The present invention discloses a case joining method of a plate heat transfer apparatus. According to the present invention, first, a first case having an upper side and a first side wall forming a first storage space at an edge thereof is prepared. Subsequently, a second case having an edge having a second side wall forming a second storage space in which an upper portion of the first case is opened and in which an opening surface of the first case is inserted is prepared. Then, a gap is formed between the first side wall and the second side wall by inserting the open surface of the first case into the second storage space of the second case with the heat transfer medium inserted into the first storage space of the first case. The first and second cases are assembled to form this. Finally, the first and second cases are joined by seating a welding base material along the gap and melting the welding base material.

According to the present invention, the inside of the case can be prevented from being contaminated during the case joining process, the process time is small, a smooth welding surface can be obtained, and the plane shape of the case is not affected.

Description

Method for case bonding of plate heat transfer apparatus and apparatus manufactured by the method {Method for case's bonding of flat plate heat spreader based on brazing and Apparatus manufactured using the same}

The following drawings attached to this specification are illustrative of preferred embodiments of the present invention, and together with the detailed description of the invention to serve to further understand the technical spirit of the present invention, the present invention is a matter described in such drawings It should not be construed as limited to.

1 is an exemplary view of a case bonding process by a TIG or laser welding method according to the prior art.

Figure 2 is an illustration of a case bonding process by the soldering method according to the prior art.

3A and 3B are cross-sectional views of the first and second cases respectively used in the bonding process of the present invention.

3C is a cross-sectional view of the case assembly after the first and second cases are assembled.

Figure 3d is a cross-sectional view of the case assembly after the welding base material is seated on the edge of the case assembly.

Figure 3e is a partial perspective view showing that the refrigerant injection tube is inserted into the case assembly, the rib is bent in the direction of the welding base material.

4A and 4B are process diagrams illustrating a process of joining a case by performing a brazing welding process according to the present invention.

5 is a cross-sectional view of the case after the case bonding process according to the present invention is completed.

The present invention relates to a method of manufacturing a plate heat transfer apparatus, and more particularly, to a method of joining a case of a plate heat transfer apparatus and a plate heat transfer apparatus manufactured by the method.

In recent years, electronic devices such as notebook computers and PDAs have become smaller and smaller in thickness due to the development of high integration technology. In addition, the demand for high responsiveness and functional improvement of electronic equipment is increasing, the power consumption is also gradually increasing.

Accordingly, a lot of heat is generated from the electronic components therein during the operation of the electronic equipment, various plate heat transfer devices are used to release the heat to the outside.

In the plate heat transfer apparatus, a heat transfer medium such as a screen mesh is inserted between the lower case and the upper case to form a case assembly, joining the lower case and the upper case with only the refrigerant inlet, and then injecting the refrigerant into the case and closing the refrigerant inlet. Production is completed by final sealing. At this time, a TIG welding method, a laser welding method or a soldering method is mainly used as a joining method of the lower case and the upper case.

1 is an exemplary view of a conventional case bonding process using a TIG welding method or a laser welding method.

According to the bonding process shown, first, the case assembly 30 is fixed between the upper jig 10 and the lower jig 20. Then, the upper case 30a and the lower case 30b are applied by applying a pulse current to the TIG welding rod or the laser welding rod 60 while pressing the jigs 10 and 20 with the upper and lower press cylinders 40 and 50. Weld the boundary that is in contact.

However, the above welding method is a spot welding method using the instantaneous pulse current, there is a problem that the welding surface is not continuous and not suitable for case welding of a complicated shape. In addition, due to the occurrence of fine leaks, it is difficult to completely bond the upper case 30a and the lower case 30b and there is a limit in that the process time is long.

Figure 2 is an illustration of another conventional case bonding process using a soldering method.

According to the illustrated bonding process, the soldering material 70 is inserted between the contact surfaces of each case when the upper case 30a and the lower case 30b are assembled. Then, the case assembly 30 is fixed between the upper jig 10 and the lower jig 20 using the press cylinders 40 and 50, and the edge of the case assembly 30 is heated. Then, the upper case 30a and the lower case 30b are bonded while the soldering material is melted.

By the way, the above joining method has the advantage that the welding surface is smooth and the processing time is fast due to the characteristics of the line welding, regardless of the shape of the case, but impurities such as flux contained in the soldering material penetrate into the inside of the case. There is a disadvantage of degrading the performance.

The present invention was devised to overcome the above-mentioned problems of the prior art, while preventing contamination of the inside of the case in the case bonding process of the plate heat transfer device. The purpose of the present invention is to provide a case joining method and a plate heat transfer device manufactured by the method, which can manufacture a cooling module of a high heat generation product and reduce the size of the plate heat transfer device by improving the heat transfer capacity, and to produce a more compact cooling module. .

According to another aspect of the present invention, there is provided a method of joining a case of a plate heat transfer apparatus, the method including: (a) preparing a first case having an upper side at an edge thereof with an open first side wall forming a first storage space; (b) preparing a second case having a second side wall at an edge thereof, the second side wall forming a second storage space of which an upper side is opened and an opening surface of the first case is inserted; (c) a gap between the first side wall and the second side wall by inserting the open surface of the first case into the second storage space of the second case with the heat transfer medium inserted into the first storage space of the first case; Assembling the first and second cases so that the first and second cases are formed; And (d) bonding the first and second cases by seating a weld base material along the gap and melting the weld base material.

Preferably, forming an opening to be inserted into the refrigerant injection tube on the first side wall and the second side wall; And inserting a refrigerant injection tube through the opening to the inside of the first storage space.

On the other hand, a flange extending outward is formed on the first side wall of the first case, and the gap is formed by the flange when the first case and the second case are assembled.

At this time, the flange is in close contact with the bottom surface of the second case to maintain the airtightness of the first storage space.

According to the present invention, the step (d) may include: mounting the case assembly between an upper jig and a lower jig; And bonding the case assembly by applying a high frequency power to a coil installed in the jig to melt the welding base material by high frequency induction heating.

Preferably, in the step (d), argon gas or nitrogen gas is supplied to the case assembly surface to prevent oxidation of the case assembly surface during the high frequency induction heating.

Preferably, the method further includes circulating a refrigerant through a cooling tube installed in the jig to cool the bonded case assembly.

Preferably, the upper jig and the lower jig have grooves that match the shape of the case assembly to fix the case assembly.

Preferably, the welding base material is a welding wire that is bent or pressed to correspond to the edge shape of the case assembly provided with the gap and does not contain flux.

In the present invention, the second case further comprises a plurality of ribs extending from the second side wall, it is preferable to fix the welding base material by bending the ribs in the direction of the welding base material seated in the gap.

According to the invention, the step (d), the step of placing the case assembly in a heating furnace; And melting the welding base material by applying heat to the heating furnace to bond the case assembly.

Preferably, the interior of the furnace is vacuum or full of at least one gas selected from hydrogen, nitrogen and ammonia.

According to another aspect of the present invention, there is provided a plate heat transfer apparatus comprising: a heat transfer medium; A first case having a first side wall defining a first storage space for receiving the heat transfer medium; A second case defining a second storage space for accommodating the first case and having a second side wall formed to form a gap between the first side wall; A refrigerant injected into an accommodation space accommodating the heat transfer medium; And a joining member fused along the gap between the first side wall and the second side wall to join the first and second cases.

Here, the first case has a flange extending from the side wall, the flange is preferably in close contact with the bottom surface of the second case is formed a gap between the first side wall and the second side wall.

In addition, the second case is preferably provided with a plurality of ribs extending to a predetermined length on the side wall, the plurality of ribs are bent in the direction of the joining member.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the present specification and claims should not be construed as being limited to the common or dictionary meanings, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

In the case bonding method of the plate-shaped heat transfer apparatus of the present invention, as shown in FIG. 3A, a first case A having a sidewall S ₁ formed at an edge thereof to form a first storage space 100 having an open upper portion. Prepare. In this case, the first case A is a member corresponding to one side wall of the plate-shaped heat transfer apparatus to be manufactured and includes a flange 110 having a predetermined width extending outward from the side wall S ₁ . In addition, the sidewall S ₁ is provided with an opening 120 into which the refrigerant injection tube of the plate heat transfer device is inserted.

Then, as shown in Figure 3b, the second case (B) is combined with the first case (A) to form the other side wall of the plate-shaped heat transfer device. The second case has a sidewall S ₂ formed at an edge thereof to open a top thereof to form a second storage space 130 in which the first case A is accommodated. The second storage space of the second case is large enough to accommodate an open surface formed with a flange of the first case, and the side wall S ₂ has a plurality of ribs 135 extending to a predetermined length. Formed. The opening 140 is located at a position corresponding to the opening 120 formed in the side wall S ₁ of the first case A for insertion of a refrigerant injection tube into the side wall S ₂ of the second case B. ) Is provided.

When the first and second cases A and B are prepared, as shown in FIG. 3C, the heat transfer medium 150 is inserted into the first storage space 100 and the first and second cases A, Assemble B). In this case, the first case A is assembled such that its open surface is inserted into the second storage space 130 of the second case B. In this assembled state, since the flange 110 is formed at the edge of the first case (A) as shown, the outer surface of the first case side wall (S ₁ ) and the inner surface of the second case side wall (S ₂ ) A gap 160 is formed in between.

Preferably, the gap 160 is continuously provided around the case assembly A-B. When the first and second cases A and B are assembled, the flange 110 provided in the first case A is in close contact with the bottom surface of the second case B (see 170).

The heat transfer medium 150 is composed of a metal screen mesh having good thermal conductivity. The screen mesh simultaneously provides a diffusion passage of the vaporized refrigerant and a flow passage of the liquefied refrigerant. The heat transfer medium 150 is preferably composed of a composite layer of coarse mesh and dense mesh in order to increase heat transfer efficiency.

After the first and second cases A and B are assembled, the welding base material 180 is seated along the gap 160, as shown in FIG. 3D. Welding base material 180 is preferably bent or pressed wire shape according to the shape of the gap 160. As the material, a brazing welding base material containing no welding flux is employed. Preferably, the welding base material is a silver lead alloy. At this time, the plurality of ribs 135 formed on the side wall (S ₂ ) of the second case (B) to fix the welding base material 180 as shown in FIG. Bend to 180). In addition, the plurality of ribs 135 are bent in the direction of the welding base material 180 to compress the first case A to bring the first case A and the second case B into close contact with each other.

When the welding base material 180 is seated, the refrigerant is injected through the openings 120 and 140 provided in the sidewalls S ₁ and S _{2 of} the first and second cases A and B, as shown in the drawing. Insert the tube (190). At this time, the end of the tube 190 reaches to the first storage space 100 of the first case (A).

When the assembly of the first case (A) and the second case (B) is completed, the cases are coupled to each other by welding.

Preferably, as shown in Figure 4a, the case assembly (A-B) is mounted to the lower jig 200 of the brazing welding equipment. The upper part of the lower jig 200 is provided with a rectangular groove 210 into which the lower part of the case assembly A-B is closely inserted. Therefore, the case assembly A-B is inserted along the sidewall of the groove 210 and tightly fixed to the lower jig 200.

The lower jig 200 includes a high frequency generating coil 220 and a cooling tube 230. Preferably, the coil 220 and the tube 230 is inserted along the edge of the lower jig 200. In a subsequent step, a high frequency current is applied to the coil 220, and a refrigerant is circulated in the cooling tube 230.

Subsequently, as shown in FIG. 4B, the upper jig 240 of the brazing welding equipment is moved to the press cylinder 250 to cover the case assembly A-B. Preferably, the lower surface of the upper jig 240 is provided with a rectangular groove in which the upper part of the case assembly (A-B) is closely inserted like the lower jig 200. Therefore, when the upper jig 240 covers the case assembly A-B, an upper portion of the case assembly A-B is inserted along the sidewall of the groove to be tightly fixed to the upper jig 240. Thereafter, pressure is applied to the press 250 to closely contact the flange 110 of the first case A with the bottom surface of the second case B (see 170 of FIG. 3C), thereby providing a heat transfer medium 150. The airtightness of the inserted first storage space 100 is maintained.

Brazing welding is performed in a state where the airtightness of the first storage space 100 is maintained as above. That is, a high frequency current is applied to the high frequency generating coil 220 to melt the welding base material 180 seated in the gap 160 by high frequency induction heating.

Preferably, argon gas or nitrogen gas is supplied to the surface of the case assembly A-B to prevent oxidation of the surface of the case assembly A-B during the high frequency induction heating.

In another embodiment in which the assembled first case (A) and the second case (B) are bonded to each other by welding in the case joining method of the plate-shaped heat transfer device of the present invention, the case assembly (AB) may be a heating furnace ( And the welding base material 180 is melted by applying heat to the heating furnace.

At this time, the inside of the furnace is preferably vacuum or filled with at least one gas selected from hydrogen, nitrogen and ammonia.

Then, as shown in FIG. 5, the first and second cases (the capillary phenomenon caused by the viscous movement of the molten weld base material 180 'and the contact interface between the first and second cases A and B) A and B) are joined. By the same principle, the refrigerant injection tube 190 is also joined to the opening provided in the side walls of the first and second cases A and B. Melting of the welding parent material 180 occurs substantially simultaneously along the edge of the case assembly (A-B). Thereby, line welding characteristic can be acquired. That is, the welding time can be shortened and a smooth welding surface can be obtained.

In the process of welding, since the first storage space 100 into which the heat transfer medium 150 is inserted is hermetically maintained by the pressure of the press, the first storage space 100 by the molten welding base material 180 ′. ) Can be prevented from being contaminated. In addition, since the flux is not included in the welding base material 180, contamination of the first storage space 100 due to the flux does not occur.

When the brazing welding is completed, the case assembly A-B is cooled by circulating a refrigerant, for example, water, through a cooling tube 230 installed in the lower jig 200. Thereby, the bonding process of 1st and 2nd case A, B is complete | finished.

After the bonding process is completed, the pressure of the first storage space 100 is reduced to a vacuum state using a vacuum pump, a refrigerant (eg, distilled water) is injected through the refrigerant injection tube, and the tube 190 is sealed. The plate heat transfer device is completed.

The present inventors compared the performance of the plate heat transfer apparatus manufactured by applying the present invention to the performance of the plate heat transfer apparatus manufactured by applying the conventional laser welding method. At this time, only the bonding method of the case is different and all other conditions are the same.

As a result, the plate heat transfer device to which the present invention was applied was about 33% better than the plate heat transfer device to which the laser welding method was applied, and the heat conduction performance was about 20%.

As described above, although the present invention has been described by way of limited embodiments and drawings, the present invention is not limited thereto and is intended by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalents of the claims to be described.

According to the present invention, since the airtightness of the space where the heat transfer medium is inserted during the case bonding process is maintained, it is possible to prevent contamination inside the case. In addition, since the flux is not contained in the welding base material used for the case joining, the contamination problem due to the flux does not occur at all. In addition, since the welding base material is simultaneously melted at the edge of the case by high frequency induction heating and heating using a heating furnace, line welding characteristics can be obtained. Therefore, process time can be shortened and a smooth welding surface can be obtained, and it is not limited to the planar shape of a case. Furthermore, it is possible to manufacture a cooling module of a high heat generation product by improving the heat transfer capacity, and it is possible to manufacture a more compact cooling module by reducing the size of the plate heat transfer device.

Claims (16)

(a) preparing a first case having an edge at which a first side wall is opened and a first storage space is formed; (b) preparing a second case having a second side wall at an edge thereof, the second side wall forming a second storage space of which an upper side is opened and an opening surface of the first case is inserted; (c) a gap between the first side wall and the second side wall by inserting the open surface of the first case into the second storage space of the second case with the heat transfer medium inserted into the first storage space of the first case; Assembling the first and second cases so that the first and second cases are formed; And and (d) joining the first and second cases by seating a welding base material along the gap and melting the welding base material. The method of claim 1, Forming openings into the first side wall and the second side wall to insert a refrigerant injection tube; And And inserting a refrigerant injection tube through the opening to the inside of the first storage space. The method of claim 2, The first side wall of the first case is formed with a flange extending outward, And the gap is formed by the flange when the first case and the second case are assembled. The method of claim 3, And the flange is in close contact with the bottom surface of the second case to maintain the airtightness of the first storage space. The method of claim 1, wherein step (d) Mounting a case assembly, which is an assembly of the first case and the second case, between an upper jig and a lower jig; And And applying the high frequency power to the coil installed in the jig to melt the welding base material by high frequency induction heating to bond the case assembly. The method of claim 5, And argon gas or nitrogen gas is supplied to the surface of the case assembly to prevent oxidation of the surface of the case assembly during the high frequency induction heating. The method of claim 5, The jig further includes a cooling tube of the refrigerant circulation type, And circulating a coolant through the cooling tube to cool the bonded case assembly. The method of claim 5, And the upper jig and the lower jig have grooves matching the shape of the case assembly to fix the case assembly. The method of claim 1, The welding base material is a case joining method of the plate-shaped heat transfer device, characterized in that the welding wire bent or pressed to correspond to the edge shape of the case assembly which is the assembly of the first case and the second case, the gap is provided. delete The method of claim 1, The second case further includes a plurality of ribs extending from the second side wall, And bending the rib in the direction of the weld base material seated in the gap to fix the weld base material. The method of claim 1, wherein step (d) Putting a case assembly, which is an assembly of the first case and the second case, into a heating furnace; And And applying heat to the heating furnace to melt the welding base material to bond the case assembly. The method of claim 12, The inside of the furnace is a vacuum or case bonding method of the plate-type heat transfer device, characterized in that any one or more gases selected from hydrogen, nitrogen and ammonia is filled. Heat transfer medium; A first case having a first side wall defining a first storage space for receiving the heat transfer medium; A second case forming a second storage space for accommodating the first case and having a second side wall formed to form a gap between the first side wall; A refrigerant injected into an accommodation space accommodating the heat transfer medium; And And a joining member fused along the gap between the first side wall and the second side wall to join the first and second cases. The method of claim 14, The first case has a flange extending from the side wall, The flange is in close contact with the bottom surface of the second case plate heat transfer device, characterized in that a gap is formed between the first side wall and the second side wall. The method of claim 14, The second case has a plurality of ribs extending to a predetermined length on the side wall, And said plurality of ribs are bent in the direction of said joining member.

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