Heat dissipation module and its manufacturing method

Abstract

To suitably join a terminal to a heat pipe.SOLUTION: A heat radiation module includes a heat pipe and a terminal. The heat pipe includes a first plate, a second plate confronting the first plate via a refrigerant flow passage of the heat pipe, and a support member extending from the first plate to the second plate. The terminal is joined to a connected body of the first plate and the support member from the outside of the heat pipe. When being viewed along a thickness direction of the first plate, the support member is arranged within a range where the support member is superimposed with the joined portion of the terminal and the connected body.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The technology disclosed in this specification relates to a heat dissipation module and a manufacturing method thereof.

[0002] Patent Document 1 discloses a flat heat pipe, which can efficiently cool a semiconductor chip. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-044459 A Summary of the Invention [Problem to be solved by the invention]

[0004] When a heat pipe is used as a current path, a terminal may be joined to the heat pipe. When joining the terminal to the heat pipe, the terminal is pressurized toward the heat pipe. Because the heat pipe has a built-in refrigerant flow path, when the terminal is pressurized toward the heat pipe, the plate material constituting the outer wall of the heat pipe bends. When the plate material of the heat pipe bends, a gap occurs between the terminal and the plate material, and the terminal may not be properly joined to the plate material. This specification proposes a technique for appropriately joining the terminal to the heat pipe. [Means for solving the problem]

[0005] The heat dissipation module disclosed in this specification includes a heat pipe and a terminal. The heat pipe includes a first plate, a second plate facing the first plate via a refrigerant flow path of the heat pipe, and a support member extending from the first plate to the second plate. The terminal is joined to a connection body of the first plate and the support member from the outside of the heat pipe. When viewed along the thickness direction of the first plate, the support member is disposed within a range overlapping with a joint between the terminal and the connection body.

[0006] The above phrase "the terminal is joined to the connection between the first plate and the support member from the outside of the heat pipe" means that the terminal is joined to at least one of the first plate and the support member from the outside of the heat pipe. In other words, the terminal may be joined to the first plate, may be joined to the support member, or may be joined to both the first plate and the support member.

[0007] In this specification, the heat pipe includes a vapor chamber.

[0008] In this heat dissipation module, the terminal is joined to the connecting body so that the support member is positioned within a range that overlaps with the joint when viewed along the thickness direction of the first plate material. Therefore, when the terminal is joined to the connecting body (i.e., when the terminal is pressed toward the connecting body), the pressure is received by the support member. This prevents the connecting body from bending, and pressure is appropriately applied to the joint. Therefore, the terminal can be suitably joined to the connecting body.

[0009] This specification also proposes a method for manufacturing a heat dissipation module. The manufacturing method includes a step of joining a terminal to a heat pipe. The heat pipe includes a first plate material, a second plate material facing the first plate material via a refrigerant flow path of the heat pipe, and a support member extending from the first plate material to the second plate material. In the step of joining the terminal to the heat pipe, the terminal is joined to a connection body of the first plate material and the support member from the outside of the heat pipe. In the step of joining the terminal to the heat pipe, the terminal is joined to the connection body such that the support member is positioned within a range overlapping a joint between the terminal and the connection body when viewed along the thickness direction of the first plate material.

[0010] According to this manufacturing method, the terminal can be suitably joined to the connector. [Brief description of the drawings]

[0011] [Figure 1]FIG. [Diagram 2] FIG. 2 is a plan view of the connection structure according to the first embodiment. [Diagram 3] FIG. 2 is a cross-sectional view of the connection structure according to the first embodiment. [Figure 4] FIG. 4 is an explanatory diagram of a connection process according to the first embodiment. [Diagram 5] FIG. 11 is a plan view of a connection structure according to a second embodiment. [Figure 6] FIG. 6 is a cross-sectional view of a connection structure according to a second embodiment. [Figure 7] FIG. 13 is a plan view of a connection structure according to a first modified example of the second embodiment. [Figure 8] FIG. 13 is a plan view of a connection structure according to Modification 2 of the second embodiment. [Figure 9] FIG. 11 is a plan view of a connection structure according to a third embodiment. [Figure 10] FIG. 11 is a cross-sectional view of a connection structure according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] In the heat dissipation module of the example disclosed in the present specification, the support member may be disposed in the coolant flow path. In this case, the heat pipe may be provided with an injection path that extends from the first plate member to the support member and opens into the coolant flow path. The injection path may be sealed in the first plate member by a sealing member. The terminal may be disposed so as to cover the sealing member.

[0013] According to this configuration, when the terminal is joined to the connector, the joint portion can be supported by the support member disposed within the coolant flow path.

[0014] In the heat dissipation module disclosed in the present specification as an example, the support member may be a side wall that constitutes a side surface of the coolant flow path.

[0015] According to this configuration, when the terminal is joined to the connector, the joint portion can be supported by the side wall.

[0016] In one example heat dissipation module disclosed in the present specification, when viewed along the thickness direction of the first plate material, the area of ​​the overlapping portion where the joint and the support member overlap may be 20% or more of the area of ​​the joint.

[0017] According to this configuration, the support member is less likely to deform, so that the support member can more effectively suppress bending of the joint portion when the terminal is joined to the connector.

[0018] In the heat dissipation module disclosed in the present specification as an example, the terminal may be joined to the first plate member from outside the heat pipe.

[0019] In the heat dissipation module disclosed in the present specification as an example, the support member may be fixed to the first plate member by caulking, press fitting, or bonding.

[0020] FIG. 1 shows a heat dissipation module 10 for cooling a semiconductor chip 80. The heat dissipation module 10 has a heat pipe 20 and a bus bar 40. The heat pipe 20 has a flat box shape and has a refrigerant flow path through which a refrigerant circulates inside. The heat pipe 20 has an upper plate 22, a lower plate 24, and four side walls 26. The upper plate 22 is a metal plate constituting the upper surface 20a of the heat pipe 20. The lower plate 24 is a metal plate constituting the lower surface 20b of the heat pipe 20. Each side wall 26 is a metal plate constituting each side surface of the heat pipe 20. The space surrounded by the upper plate 22, the lower plate 24, and the four side walls 26 is the refrigerant flow path. A refrigerant (so-called working fluid) is sealed in the refrigerant flow path. The bus bar 40 is a metal plate and is joined to the upper surface 20a of the heat pipe 20. The bus bar 40 extends so as to protrude outward from the heat pipe 20. The heat pipe 20 and the bus bar 40 are made of, for example, copper. The semiconductor chip 80 is mounted on the upper surface 20a of the heat pipe 20. The heat pipe 20 functions as a heat dissipation member that cools the semiconductor chip 80. The heat pipe 20 is electrically connected to the semiconductor chip 80. That is, the bus bar 40 is electrically connected to the semiconductor chip 80 via the heat pipe 20. The bus bar 40 is a terminal for passing a current to the semiconductor chip 80. Although not shown, a wiring member is connected to the semiconductor chip 80 in addition to the heat pipe. An embodiment of the connection structure between the bus bar 40 and the heat pipe 20 will be described below. EXAMPLES

[0021] 2 and 3 show the connection structure of the first embodiment. As shown in FIG. 3, a refrigerant flow path 28 is formed between the upper plate 22 and the lower plate 24. That is, the lower plate 24 faces the upper plate 22 via the refrigerant flow path 28. A refrigerant is sealed in the refrigerant flow path 28. Although not shown, a wick for moving the liquid refrigerant by capillary action is arranged in the refrigerant flow path 28. The refrigerant in the refrigerant flow path 28 is heated and evaporated at the bottom of the semiconductor chip 80. The evaporated refrigerant flows to the outer periphery of the heat pipe 20, where it is cooled and condensed. The condensed refrigerant flows through the wick to the center of the heat pipe 20 (i.e., the bottom of the semiconductor chip 80). The refrigerant circulates in the refrigerant flow path 28 in this way, thereby cooling the semiconductor chip 80.

[0022] The upper plate 22 has a plate material 22a and a sealing member 22b. The plate material 22a constitutes a main part of the upper plate 22. The plate material 22a is provided with a through hole 22c. The sealing member 22b closes the through hole 22c.

[0023] The heat pipe 20 has a support member 30 disposed in the refrigerant flow path 28. The support member 30 has a cylindrical shape extending along the thickness direction of the heat pipe 20. The support member 30 extends from the upper plate 22 to the lower plate 24. The upper end of the support member 30 is bonded to the lower surface of the plate material 22a, and the lower end of the support member 30 is bonded to the upper surface of the lower plate 24. In the manufacturing process of the heat pipe 20, the support member 30 is bonded to the plate material 22a and the lower plate 24 by metal diffusion bonding, ultrasonic bonding, room temperature diffusion bonding, or the like. The center hole 30a of the support member 30 is connected to the through hole 22c provided in the plate material 22a. In other words, when viewed along the thickness direction of the upper plate 22, the through hole 22c is provided within a range surrounded by the support member 30. A through hole 30b is formed in the side surface of the support member 30. The through hole 30b penetrates the outer peripheral wall of the support member 30. Through hole 22c, center hole 30a, and through hole 30b form injection path 32 that extends from the upper surface of upper plate 22 to the inside of support member 30 and opens into refrigerant flow path 28. In the manufacturing process of heat pipe 20, refrigerant is injected into refrigerant flow path 28 through injection path 32, and then through hole 22c is sealed with sealing member 22b.

[0024] The bus bar 40 is disposed on the upper plate 22 at a position above the support member 30. The lower surface of the bus bar 40 is joined to the upper surface of the upper plate 22 within the joint 50. When viewed along the thickness direction of the upper plate 22 as shown in FIG. 2, the support member 30 is disposed at a position overlapping the joint 50. In the first embodiment, when viewed along the thickness direction of the upper plate 22 as shown in FIG. 2, the entire support member 30 is included in the joint 50. That is, as shown in FIG. 3, the support member 30 extends from the upper plate 22 to the lower plate 24 within a range overlapping with the joint 50. The bus bar 40 is disposed so as to cover the sealing member 22b. The bus bar 40 is joined to the sealing member 22b and is joined to the plate material 22a around the sealing member 22b. When viewed along the thickness direction of upper plate 22 as shown in FIG. 2, the area of ​​the overlapping portion where joint 50 and support member 30 overlap (i.e., the shaded area in FIG. 2) is 20% or more of the area of ​​joint 50.

[0025] FIG. 4 shows a bonding process for bonding the bus bar 40 to the upper plate 22 during the manufacture of the heat dissipation module of the first embodiment. In the bonding process, the bus bar 40 is bonded to the upper plate 22 by ultrasonic bonding. In the bonding process, the heat pipe 20 is first placed on the stage 90 so that the lower surface 20b of the heat pipe 20 is in contact with the stage 90. The bus bar 40 is also placed on the upper plate 22 so that the bus bar 40 overlaps the upper plate 22 at the upper part of the support member 30. Next, as shown by an arrow 92 in FIG. 4, ultrasonic waves are applied to the bus bar 40 at the pressure point while the bus bar 40 is pressed toward the upper plate 22 at the upper part of the support member 30. As a result, the bus bar 40 is bonded to the upper plate 22 at the upper part of the support member 30. More specifically, the bus bar 40 is bonded to the plate material 22a and the sealing member 22b at the upper part of the support member 30. As a result, a joint 50 is formed at the upper part of the support member 30.

[0026] When the busbar 40 is pressed toward the upper plate 22 in the joining process, if the upper plate 22 is bent by the pressure, a gap is generated between the busbar 40 and the upper plate 22. If such a gap is generated, the busbar 40 may not be joined to the upper plate 22, or the joining strength between the busbar 40 and the upper plate 22 may be weakened. In contrast, in the joining process of the first embodiment, the busbar 40 is pressed toward the upper plate 22 by the upper part of the support member 30. Since the support member 30 extends from the upper plate 22 to the lower plate 24, the support member 30 supports the upper plate 22 from below in the joining process. This suppresses the upper plate 22 from bending when pressure is applied to the upper plate 22. In particular, since the area of ​​the overlapping portion (shaded portion in FIG. 2 ) where the joint portion 50 and the support member 30 overlap is 20% or more of the area of ​​the joint portion 50, the support member 30 is less likely to deform due to the pressure, and the bending of the upper plate 22 can be more effectively suppressed. As a result, the occurrence of a gap between the bus bar 40 and the upper plate 22 is prevented, and the bus bar 40 is properly joined to the upper plate 22.

[0027] As described above, in the heat dissipation module having the connection structure of Example 1, bus bar 40 is appropriately joined to upper plate 22. Therefore, joint 50 between bus bar 40 and upper plate 22 has high strength.

[0028] In the first embodiment, the busbar 40 is joined to both the plate material 22a and the sealing member 22b, but the busbar 40 may be joined to the plate material 22a and not to the sealing member 22b. In addition, when the sealing member 22b is firmly fixed to the plate material 22a, the busbar 40 may be joined to the sealing member 22b and not to the plate material 22a. EXAMPLES

[0029] 5 and 6 show the connection structure of Example 2. In Example 2, the injection path 32 is not provided within the range overlapping with the joint 50. That is, in Example 2, the upper plate 22 is not provided with the through hole 22c within the range overlapping with the joint 50, and the support member 30 is not provided with the center hole 30a and the through hole 30b. Therefore, the support member 30 of Example 2 is a member dedicated to supporting the upper plate 22 in the joining process, and does not also serve as the injection path 32. The other configurations of the connection structure of Example 2 are the same as those of Example 1.

[0030] In the bonding process of the second embodiment, the heat pipe 20 is placed on the stage so that the lower surface 20b is in contact with the stage, as in the first embodiment. In addition, the bus bar 40 is pressed toward the upper plate 22 at the upper part of the support member 30, and ultrasonic waves are applied to the pressurized part. As a result, the bus bar 40 is bonded to the upper plate 22 at the upper part of the support member 30, and a joint part 50 is formed at the upper part of the support member 30. When the bus bar 40 is pressed toward the upper plate 22, the upper plate 22 is supported by the support member 30, so that the deflection of the upper plate 22 is suppressed. In particular, since the area of ​​the overlapping part (i.e., the hatched part in FIG. 5) where the joint part 50 and the support member 30 overlap is 20% or more of the area of ​​the joint part 50, the support member 30 has high strength and is unlikely to deform when pressed. Therefore, the deflection of the upper plate 22 is more effectively suppressed by the support member 30. Therefore, the bus bar 40 is appropriately bonded to the upper plate 22.

[0031] As described above, in the heat dissipation module having the connection structure of Example 2, bus bar 40 is also appropriately joined to upper plate 22. Therefore, joint 50 between bus bar 40 and upper plate 22 has high strength.

[0032] In the above-described second embodiment, the upper end of the support member 30 is joined to the lower surface of the upper plate 22. However, as shown in FIG. 7, the upper end of the support member 30 may be pressed into a fixing hole 22d provided in the upper plate 22, thereby fixing the support member 30 to the upper plate 22. Also, as shown in FIG. 8, the upper end of the support member 30 may be fixed to the fixing hole 22d by caulking. In the case of FIG. 7 or 8, the bus bar 40 may be joined to both the upper plate 22 and the support member 30, or the bus bar 40 may be joined to the upper plate 22 and not to the support member 30. Also, when the connection strength between the support member 30 and the upper plate 22 is high, the bus bar 40 may be joined to the support member 30 and not to the upper plate 22. In this way, when the upper plate 22 and the support member 30 are exposed on the surface of the heat pipe 20, the bus bar 40 may be joined to the connection body of the upper plate 22 and the support member 30 in any manner. Moreover, the fixing structure (ie, press-fitting or caulking) of the support member 30 and the upper plate 22 in FIGS. 7 and 8 may be applied to the first embodiment (ie, FIG. 3).

[0033] In addition, in Examples 1 and 2, the support member 30 extends from the upper plate 22 to the lower plate 24 within the range overlapping with the joint 50. With this configuration, the upper plate 22 within the joint 50 can be suitably supported by the support member 30 in the joining process. However, in some cases, the upper end of the support member 30 may be located within the range overlapping with the joint 50, and other parts of the support member 30 (for example, the lower end) may be located in a range not overlapping with the joint 50. EXAMPLES

[0034] 9 and 10 show a connection structure of Example 3. In Example 3, the bus bar 40 is joined to the upper plate 22 at an upper portion of the side wall 26. That is, in Example 3, the side wall 26 serves as a support member. The side wall 26 extends from the upper plate 22 to the lower plate 24 within a range overlapping with the joint 50. The other configurations of the connection structure of Example 3 are the same as those of Example 1.

[0035] In the bonding process of the third embodiment, the heat pipe 20 is placed on the stage so that the lower surface 20b is in contact with the stage, as in the first embodiment. In addition, the bus bar 40 is pressed toward the upper plate 22 at the upper part of the side wall 26, and ultrasonic waves are applied to the pressed part. As a result, the bus bar 40 is bonded to the upper plate 22 at the upper part of the side wall 26, and a joint 50 is formed at the upper part of the side wall 26. When the bus bar 40 is pressed toward the upper plate 22, the upper plate 22 is supported by the side wall 26, so that the deflection of the upper plate 22 is suppressed. In particular, since the area of ​​the overlapping part (i.e., the hatched part in FIG. 9 ) where the joint 50 and the side wall 26 overlap is 20% or more of the area of ​​the joint 50, the side wall 26 has high strength and is unlikely to deform when pressed. Therefore, the deflection of the upper plate 22 is more effectively suppressed. Therefore, the bus bar 40 is appropriately bonded to the upper plate 22.

[0036] As described above, in the heat dissipation module having the connection structure of Example 3, bus bar 40 is also appropriately joined to upper plate 22. Therefore, joint 50 between bus bar 40 and upper plate 22 has high strength.

[0037] In addition, in the third embodiment, the upper end of the side wall 26 is joined to the lower surface of the upper plate 22, but the upper plate 22 and the side wall 26 may be formed from a single plate material bent into an L shape.

[0038] The upper plate in the embodiment is an example of the first plate material, and the lower plate in the embodiment is an example of the second plate material. The bus bar of the embodiment is an example of a terminal. The support member 30 of the first and second embodiments and the side wall 26 of the third embodiment are an example of a support member.

[0039] Although the embodiments have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes to the specific examples exemplified above. The technical elements described in this specification or drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or drawings achieves multiple objectives simultaneously, and achieving one of the objectives itself has technical utility. [Explanation of symbols]

[0040] 10: heat dissipation module, 20: heat pipe, 22: upper plate, 24: lower plate, 26: side wall, 28: coolant flow path, 30: support member, 32: injection path, 40: bus bar, 50: joint, 80: semiconductor chip

Claims

1. A heat dissipation module (10) having a heat pipe (20) and a terminal (40) electrically connected to the heat pipe, The heat pipe, A first plate material (22); a second plate member (24) facing the first plate member across a refrigerant flow path (28) of the heat pipe; a support member (30) extending from the first plate to the second plate and disposed within the coolant flow path; having the terminal is joined to a connection body of the first plate member and the support member from an outside of the heat pipe, When viewed along the thickness direction of the first plate material, the support member is disposed within a range overlapping with a joint portion (50) of the terminal and the connector, The heat pipe is provided with an injection passage (32) that extends from the first plate member to the support member and opens into the refrigerant flow path, The injection passage in the first plate material is sealed by a sealing member (22b), The terminal is disposed so as to cover the sealing member. Heat dissipation module.

2. The heat dissipation module according to claim 1 , wherein an area of ​​an overlapping portion where the joint portion and the support member overlap is 20% or more of an area of ​​the joint portion when viewed along a thickness direction of the first plate member.

3. The heat dissipation module according to claim 1 , wherein the terminal is joined to the first plate member from outside the heat pipe.

4. 4. The heat dissipation module according to claim 1, wherein the support member is fixed to the first plate material by caulking, press fitting, or bonding.

5. A method for manufacturing a heat dissipation module having a heat pipe and a terminal electrically connected to the heat pipe, comprising: a step of joining the terminal to the heat pipe; The heat pipe, A first plate material; a second plate member facing the first plate member with a refrigerant flow path of the heat pipe therebetween; a support member extending from the first plate to the second plate and disposed within the coolant flow path; having the heat pipe is provided with an injection passage extending from the first plate member to the support member and opening into the coolant flow passage; The injection path in the first plate member is sealed by a sealing member, In the step of joining the terminal to the heat pipe, the terminal is joined to a connection body of the first plate member and the support member from outside the heat pipe, In the step of joining the terminal to the heat pipe, the terminal is joined to the connector such that the support member is disposed within a range overlapping a joint portion of the terminal and the connector when viewed along a thickness direction of the first plate material; In the step of joining the terminal to the heat pipe, the terminal is joined to the connector such that the terminal covers the sealing member. A method for manufacturing a heat dissipation module.

6. In the step of joining the terminal to the heat pipe, the terminal is joined to the connecting body such that an area of ​​an overlapping portion where the joint portion and the support member overlap is 20% or more of an area of ​​the joint portion when viewed along a thickness direction of the first plate material. The method according to claim 5 .

7. The manufacturing method according to claim 5 or 6, wherein in the step of joining the terminal to the heat pipe, the terminal is joined to the first plate member from outside the heat pipe.

8. The manufacturing method according to any one of claims 5 to 7, wherein the support member is fixed to the first plate material by caulking, press fitting, or bonding.

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