JP2023106647A - Heat conduction member - Google Patents

Abstract

To improve joint strength between a first housing part and a second housing part of a heat conduction member.SOLUTION: A housing 101 of a heat conduction member 100 has: a plate-like first housing part 1; a plate-like second housing part 2: and a joint part 3. Between the first housing part and the second housing part, a working medium is enclosed and an internal space 1010, in which a wick structure is disposed, are disposed. The first housing part has: a first plate 11 made of a metal; and a first metal layer 12. The first metal layer is disposed on a second housing part side surface of the first plate. A fusion point of the first metal layer is lower than a fusion point of the first plate. The second housing part has a second plate 21 made of a metal. The joint part is disposed along an outer edge part of the internal space when viewed in a vertical direction from one of the first housing part and the second housing part to the other. A first surface at the second housing part side of the first metal layer and a second surface at the first housing part side of the second housing part are joined.SELECTED DRAWING: Figure 2

Description

The present invention relates to heat conducting members.

2. Description of the Related Art Conventionally, a vapor chamber formed in a thin flat plate shape is known as a thermally conductive member for cooling a heating element. For example, a vapor chamber has an upper metal sheet and a lower metal sheet. The upper metal sheet is provided on the lower metal sheet. A heating element is attached to the lower surface of the lower metal sheet. Between the upper metal sheet and the lower metal sheet, a closed space containing hydraulic fluid is formed. In the closed space, the working fluid that has been evaporated by receiving heat from the heating element is cooled by the outside through the upper metal sheet. The upper metal sheet and the lower metal sheet can be formed using a metal material such as stainless steel. (For example, see Japanese Patent Laid-Open No. 2019-158323)

JP 2019-158323 A

However, when the upper metal sheet is provided on the lower metal sheet to form an enclosed space, if the metal materials are a combination that is difficult to bond directly, such as stainless steel, sufficient bonding strength can be obtained between the two. There is a risk that it will not be

An object of the present invention is to improve the bonding strength between a first housing portion and a second housing portion of a heat conducting member.

An exemplary heat-conducting member of the present invention comprises a housing with a working medium enclosed in an interior space. A wick structure is disposed within the interior space. The housing includes a plate-shaped first housing portion, a plate-shaped second housing portion, and a joint portion. The internal space is arranged between the first housing portion and the second housing portion. The first housing part has a metal first plate and a first metal layer. The first metal layer is arranged on the surface of the first plate on the side of the second housing. The melting point of the first metal layer is lower than the melting point of the first plate. The second housing part has a second plate made of metal. The joint portion is arranged along the outer edge portion of the internal space when viewed in a vertical direction from one of the first housing portion and the second housing portion to the other. The joining portion joins a first surface of the first metal layer on the side of the second casing and a second surface of the second casing on the side of the first casing.

According to the exemplary heat-conducting member of the present invention, it is possible to improve the joint strength between the first housing portion and the second housing portion of the heat-conducting member.

FIG. 1 is a perspective view of a heat conducting member. FIG. 2 is a cross-sectional view showing a configuration example of the heat conducting member according to the embodiment. FIG. 3 is a cross-sectional view showing a first configuration example of a joint portion according to the embodiment. FIG. 4A is a cross-sectional view showing a second configuration example of the joint portion according to the embodiment. FIG. 4B is a cross-sectional view showing a third configuration example of the joint according to the embodiment; FIG. 5A is a cross-sectional view showing a configuration example of a joint. FIG. 5B is a cross-sectional view showing another configuration example of the joint. FIG. 6 is a cross-sectional view showing another configuration example of the heat conducting member according to the embodiment. FIG. 7A is a cross-sectional view showing a first configuration example of a joint portion according to a first modification. FIG. 7B is a cross-sectional view showing a second configuration example of the joint according to the first modification. FIG. 8A is a cross-sectional view showing a configuration example of a heat conducting member according to a second modification. FIG. 8B is a cross-sectional view showing another configuration example of the heat conducting member according to the second modification.

Exemplary embodiments are described below with reference to the drawings.

In this specification, in the heat conducting member 100, the facing direction of the first housing portion 1 and the second housing portion 2, which will be described later, is referred to as the "vertical direction". Among the vertical directions, the direction from the first housing portion 1 to the second housing portion 2 is called “downward”, and the direction from the second housing portion 2 to the first housing portion 1 is called “upward”. . In each component, the lower end is called the "lower end" and the upper end is called the "upper end". In addition, in the surface of each component, the surface facing downward is called "lower surface", and the surface facing upward is called "upper surface". However, these names are merely used for explanation, and are not intended to limit actual positional relationships, directions, and names.

<1. embodiment>
<1-1. Heat-conducting member>
FIG. 1 is a perspective view of the heat conducting member 100. FIG. FIG. 2 is a cross-sectional view showing a configuration example of the heat conducting member 100 according to the embodiment. 2 shows a cross-sectional structure of the heat conducting member 100 along line AA in FIG.

The heat conducting member 100 is a so-called vapor chamber, and is a member for cooling a heat source (not shown). Note that the heat source is, for example, an arithmetic processing unit such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit). The heat-conducting member 100 includes a housing 101 in which a working medium (not shown) is enclosed in an internal space 1010 . A wick structure (not shown) is arranged in the internal space 1010 . The wick structure has a capillary structure. The interior of the wick structure is permeable to the liquefied working medium. In this embodiment, the wick structure is a porous metal sintered body such as a sintered body of metal powder such as copper. However, the wick structure is not limited to these examples.

Further, although the working medium is pure water in this embodiment, it may be a medium other than water. For example, the working medium may be any of alcohol compounds such as methanol and ethanol, alternative fluorocarbons such as hydrofluorocarbons, hydrocarbon compounds such as propane and isobutane, fluorohydrocarbon compounds such as difluoromethane, ethylene glycol, and the like. good. The working medium can be used according to the usage environment of the heat conducting member 100 .

The working medium is vaporized by the heat transferred from the heat source in the vicinity of the portion of the housing 101 that is in contact with the heat source, and evaporates into the internal space 1010 . Here, preferably, the sealed internal space 1010 is decompressed and its internal pressure is lower than the atmospheric pressure. This makes it easier for the working medium to vaporize. The working medium is cooled and liquefied in a portion of the housing 101 away from the heat source. The liquefied working medium permeates the inside of the wick structure and is returned to the vicinity of the portion in contact with the heat source. Due to the cycle of vaporization and liquefaction of the working medium as described above, the heat transfer member 100 can transmit the heat transferred from the heat source to the portion of the housing 101 distant from the heat source and dissipate the heat.

<1-2. Housing>
The housing 101 has a plate-like first housing portion 1 , a plate-like second housing portion 2 , and a joint portion 3 . An internal space 1010 is arranged between the first housing portion 1 and the second housing portion 2 . One of the "first housing portion 1" and "second housing portion 2" described in this specification corresponds to the "first housing portion" of the present invention, and the other corresponds to the "first housing portion" of the present invention. It corresponds to the "second casing section".

<1-2-1. First Casing Part, Second Casing Part>
The first housing portion 1 is arranged over the second housing portion 2 . The first housing part 1 has a recess 10 . The recessed portion 10 is arranged at the lower end portion of the first housing portion 1 and is recessed upward. A sealed internal space 1010 is formed inside the housing 101 by joining the outer peripheral edges of the first housing section 1 and the second housing section 2 to each other. In this embodiment, the recessed part 10 becomes the internal space 1010 . It should be noted that the second housing portion 2 may have a recess that is arranged at the upper end portion of the second housing portion 2 and is recessed downward, without being limited to this example. For example, the recess may overlap the recess 10 when viewed from above and below. In other words, the internal space 1010 may be composed of the recessed portion 10 of the first housing portion 1 and the recessed portion of the second housing portion 2 . Alternatively, the first housing portion 1 may not have the recess 10 and the recess of the second housing portion 2 may be the internal space 1010 .

The first housing part 1 has a metal first plate 11 and a first metal layer 12 . The first metal layer 12 is arranged on the surface (that is, the lower surface) of the first plate 11 on the second housing part 2 side. The melting point of the first metal layer 12 is lower than the melting point of the first plate 11 . This makes it easier to join the first housing portion 1 to the second housing portion 2 compared to the case where the first plate 11 and the second plate 21 are directly joined.

The second housing part 2 has a second plate 21 made of metal. The second housing part 2 further has a second metal layer 22 . The second metal layer 22 is arranged on the surface (that is, the upper surface) of the second plate 21 on the side of the first casing part 1 . The melting point of the second metal layer 22 is lower than the melting point of the second plate 21 . This makes it easier to join the first housing portion 1 and the second housing portion 2 together.

One of the "first plate 11" and "second plate 21" described in this specification corresponds to the "first plate" of the present invention, and the other corresponds to the "second plate" of the present invention. do. Furthermore, one of the "first metal layer 12" and "second metal layer 22" described herein corresponds to the "first metal layer" of the present invention, and the other corresponds to the "second metal layer" of the present invention. Corresponds to "Layer". For example, the "first housing part 1" described in this specification corresponds to the "first housing part" of the present invention, and the "second housing part 2" described in this specification corresponds to the " In the case of corresponding to the "second housing portion", the "first plate 11" and "first metal layer 12" described in this specification respectively correspond to the "first plate" and "first metal layer" of the present invention. In addition, the "second plate 21" and "second metal layer 22" described in this specification respectively correspond to the "second plate" and "second metal layer" of the present invention. Conversely, the “first housing portion 1” described in this specification corresponds to the “second housing portion” of the present invention, and the “second housing portion 2” described in this specification corresponds to the “second housing portion” of the present invention. When corresponding to the "first casing", the "first plate 11" and "first metal layer 12" described in this specification correspond to the "second plate" and "second metal layer" of the present invention, respectively. Correspondingly, the "second plate 21" and "second metal layer 22" described in this specification respectively correspond to the "first plate" and "first metal layer" of the present invention.

The first housing part 1 is joined to the second housing part 2 outside the internal space 1010 when viewed from the vertical direction from one of the first housing part 1 and the second housing part 2 to the other. be done. In the present embodiment, the thickness T1 of the first housing portion 1 at the portion joined to the second housing portion 2 in the first housing portion 1 is It is thinner than the thickness T2 of the first housing part 1 at the portion overlapping the internal space 1010 when viewed. Further, the thickness T3 of the second housing portion 2 at the portion joined to the first housing portion 1 of the second housing portion 2 is It is thinner than the thickness T4 of the second housing section 2 at the portion overlapping with the space 1010 .

That is, the thickness of the portion of one of the housings that is joined to the other housing is the same as the thickness of the portion of the one of the housings that overlaps the internal space 1010 when viewed in the vertical direction. thinner than the thickness of one of the casing parts in One of the housing parts is one of the first housing part 1 and the second housing part 2 . The other housing part is the other of the first housing part and the second housing part.

By doing so, the thermal resistance of the joint portion of one of the housings becomes greater than the thermal resistance of the portion of the one of the housings that overlaps the internal space 1010 . In other words, the thermal resistance of the portion of one of the housings that overlaps with the internal space 1010 becomes smaller. For example, if T1<T2, the thermal resistance of the portion of first casing 1 overlapping internal space 1010 is smaller than the thermal resistance of the joint portion of first casing 1 . Further, if T3<T4, the thermal resistance of the portion of the second housing portion 2 that overlaps with the internal space 1010 is smaller than the thermal resistance of the joint portion of the second housing portion 2 . Therefore, heat is easily transferred through the portion of the housing 101 that overlaps with the internal space 1010 . Therefore, since heat can be transferred through a heat transfer path having a shorter path length, the heat transfer performance of the heat transfer member 100 is improved.

In this embodiment, T1<T2 and T3<T4. However, the size relationship between the thickness of the portion of the housing 101 overlapping the internal space 1010 and the thickness of the joint portion of the housing 101 is not limited to this example. In one of the first housing part 1 and the second housing part 2, the thickness of the joint part is thinner than the thickness of the part overlapping the internal space 1010, while the first housing part 1 and the second housing part In the other of the two, the thickness of the joint portion may not be thinner than the thickness of the portion overlapping the internal space 1010 . For example, T3≧T4 while T1<T2. Alternatively, T1≧T2 while T3<T4.

Next, the thickness ta of the first metal layer 12 at the portion of the first metal layer 12 that is joined to the second casing 2 is the same as the inner space 1010 of the first metal layer 12 when viewed from above and below. It is thinner than the thickness tb of the first metal layer 12 at the overlapping portion. Since ta<tb, the thermal resistance of the joint portion of the first metal layer 12 is greater than the thermal resistance of the portion of the first metal layer 12 overlapping the internal space 1010 . That is, the thermal resistance of the portion of the first casing 1 that overlaps with the internal space 1010 becomes smaller. Therefore, between the outside of the housing 101 and the internal space 1010 inside the housing 101, heat is more easily transferred via this portion. Therefore, since heat can be transferred through a heat transfer path having a shorter path length, the heat transfer performance of the heat transfer member 100 is improved.

In addition, the thickness tc of the second metal layer 22 at the portion of the second metal layer 22 that is joined to the first housing portion 1 overlaps the internal space 1010 of the second metal layer 22 when viewed from above and below. It is thinner than the thickness td of the second metal layer 22 at the part. Since tc<td, the thermal resistance of the joint portion of the second metal layer 22 is greater than the thermal resistance of the portion of the second metal layer 22 overlapping the internal space 1010 . That is, the thermal resistance of the portion of the second housing 2 that overlaps with the internal space 1010 becomes smaller. Therefore, between the outside of the housing 101 and the internal space 1010 inside the housing 101, heat is more easily transferred via this portion. Therefore, since heat can be transferred through a heat transfer path having a shorter path length, the heat transfer performance of the heat transfer member 100 is improved.

Next, the first plate 11 and the second plate 21 spread in a direction perpendicular to the vertical direction. A material with high mechanical strength is adopted as the material of the first plate 11 and the second plate 21 . For example, in this embodiment, the materials of the first plate 11 and the second plate 21 are each stainless steel. By using stainless steel with a high Young's modulus as the material of the first plate 11 and the second plate 21, the mechanical strength of the housing 101 can be improved. Therefore, the durability of the heat conducting member 100 can be improved. However, the material of the first plate 11 and the second plate 21 is not limited to the above examples, and may be any metal such as iron, aluminum, zinc, silver, gold, magnesium, manganese, and titanium, or , alloys containing these metals (brass, duralumin, etc.) can be used.

The material of the first metal layer 12 has higher thermal conductivity than the material of the first plate 11 . For example, in this embodiment, the material of the first metal layer 12 is either copper or a copper alloy. By using copper or a copper alloy having high thermal conductivity for the first metal layer 12, the thermal conductivity of the first casing 1 can be improved. Therefore, the heat conducting performance of the heat conducting member 100 can be improved. Also, the material of the second metal layer 22 has higher thermal conductivity than the material of the second plate 21 . For example, in this embodiment, the material of the second metal layer 22 is either copper or a copper alloy, like the first metal layer 12 . By using copper or a copper alloy having high thermal conductivity for the second metal layer 22, the thermal conductivity of the second housing 2 can be improved. Also, since the first metal layer 12 and the second metal layer 22 are made of the same material, they can be easily joined together, and the joining strength can be improved. Metal materials other than copper and copper alloys may be employed for the first metal layer 12 and the second metal layer 22 without being limited to the above-described examples.

Further, in the present embodiment, the first metal layer 12 covers the entire surface of the first plate 11 on the side of the second housing part 2 . For example, by forming the first metal layer 12 with a material having a higher thermal conductivity than the first plate 11, the thermal conductivity of the first casing 1 can be increased. Therefore, the heat conducting performance of the heat conducting member 100 can be improved. Similarly, the second metal layer 22 covers the entire surface of the second plate 21 on the side of the first housing part 1 . For example, by forming the second metal layer 22 with a material having a higher thermal conductivity than the second plate 21, the thermal conductivity of the second housing 2 can be increased. Therefore, the heat conducting performance of the heat conducting member 100 can be improved. Note that at least one metal layer of the first metal layer 12 and the second metal layer 22 is not limited to the above-described examples, and the first housing portion 1 and the second housing portion 2 of the above-described surfaces may be covered only where they touch each other.

Further, in the present embodiment, the first metal layer 12 is a metal plating layer arranged on the surface of the first plate 11 on the side of the second housing portion 2 . Similarly, the second metal layer 22 is a metal plating layer arranged on the surface of the second plate 21 on the side of the first casing 1 . By forming the first metal layer 12 as a metal plated layer, the thickness of the first metal layer 12 can be made thinner than the thickness of the first plate 11 . Similarly, by forming the second metal layer 22 as a metal plated layer, the thickness of the second metal layer 22 can be made thinner than the thickness of the second plate 21 . Therefore, the thickness of the joint portion 3 can be made thinner. Moreover, since a metal plate having a metal plating layer formed on the surface thereof can be used for the first housing portion 1 and the second housing portion 2, the number of manufacturing steps of the heat conducting member 100 can be reduced. Therefore, the productivity of the heat conducting member 100 can be improved.

The forms of the first metal layer 12 and the second metal layer 22 are not limited to the above examples. For example, the first housing portion 1 may be a clad material, and for example, the first metal layer 12 may be roll-bonded to the surface of the first plate 11 on the second housing portion 2 side. And/or, the second housing portion 2 may be a clad material, and the second metal layer 22 may be roll-bonded to the surface of the second plate 21 on the first housing portion 1 side. For example, since a roll-joined clad material can be used for the first housing part 1 and/or the second housing part 2, the number of manufacturing steps of the heat conducting member 100 can be reduced. Therefore, the productivity of the heat conducting member 100 can be improved.

<1-2-2. Joint>
Next, the joint portion 3 will be described with reference to FIGS. 1 to 3. FIG. FIG. 3 is a cross-sectional view showing a first configuration example of the joint portion 3 according to the embodiment. In addition, FIG. 3 is the figure which expanded the cross-sectional structure of junction part 3 vicinity in embodiment.

The joint portion 3 is a portion of the housing 101 where the first housing portion 1 and the second housing portion 2 are jointed to each other. The joint portion 3 is arranged along the outer edge of the internal space 1010 when viewed in the vertical direction from one of the first casing portion 1 and the second casing portion 2 to the other (see FIG. 1). The joint portion 3 is arranged in an annular shape when viewed from above and below. For example, since the joints 3 can be arranged seamlessly along the outer edge of the internal space 1010, the sealing of the internal space 1010 can be ensured.

For example, as shown in FIG. 3 , joint 3 joins first surface 120 and second surface 20 . The first surface 120 is the surface of the first metal layer 12 on the second housing part 2 side. The second surface 20 is the surface of the second housing portion 2 on the side of the first housing portion 1 . Specifically, the joint portion 3 joins the lower surface of the first metal layer 12 to the upper surface of the second metal layer 22 . By bonding the two together, the first plate 11 can be connected to the second plate 21 via metal layers such as the first metal layer 12 and the second metal layer 22 . As described above, the melting point of the first metal layer 12 is lower than that of the first plate 11 and the melting point of the second metal layer 22 is lower than that of the second plate 21 . Therefore, compared to the case where the first plate 11 and the second plate 21 are directly joined, it becomes easier to join the first housing portion 1 to the second housing portion 2 . Therefore, even if the materials of the first plate 11 and the second plate 21 are a combination that makes it difficult to directly bond the two, the indirect fixation of the two via the above-described metal layer enables a close connection between the two. It can be done easily. For example, even if both the material of the first plate 11 and the material of the second plate 21 are stainless steel, they can be firmly connected. Therefore, the bonding strength between the first housing portion 1 and the second housing portion 2 can be improved.

Preferably, the joint portion 3 joins the entire area of the lower surface of the first housing portion 1 that contacts the second housing portion 2 to the second housing portion 2 . For example, the joining portion 3 joins the entire region of the first surface 120 of the first metal layer 12 that contacts the second surface 20 of the second housing portion 2 to the second surface 20 . Specifically, as shown in FIG. 3 , the bonding portion 3 bonds the entire region of the bottom surface of the first metal layer 12 that is in contact with the top surface of the second metal layer 22 to the second metal layer 22 . In this way, a large joint area can be secured between the two, so that the joint strength between the two can be improved. Furthermore, the airtightness of the internal space 1010 can be ensured.

In addition, in FIG. 3, the second surface 20 is the surface of the second metal layer 22 on the side of the first casing part 1 . That is, the joint portion 3 joins the first surface 120 of the first metal layer 12 on the side of the second housing portion 2 to the upper surface of the second metal layer 22 (that is, the second surface 20). Since both the first housing part 1 and the second housing part 2 have metal layers for bonding, the bonding strength between the first housing part 1 and the second housing part 2 can be further improved.

Moreover, in the above description, both the first metal layer 12 and the second metal layer 22 are arranged in the housing 101 according to the present embodiment. However, the present invention is not limited to these examples, and either the first metal layer 12 or the second metal layer 22 may not be arranged on the housing 101 as shown in FIGS. 4A and 4B. FIG. 4A is a cross-sectional view showing a second configuration example of the joint 3 according to the embodiment. FIG. 4B is a cross-sectional view showing a third configuration example of the joint 3 according to the embodiment. In addition, FIG. 4A and FIG. 4B are the figures which expanded the cross-sectional structure of junction part 3 vicinity.

For example, as shown in FIG. 4A, the first housing portion 1 may have the first metal layer 12 while the second housing portion 2 may not have the second metal layer 22 . In this case, the joint portion 3 joins the lower surface of the first metal layer 12 and the upper surface of the second plate 21 . By joining the two, the first plate 11 can be connected to the second plate 21 via the first metal layer 12, so that the joint strength between the first housing part 1 and the second housing part 2 can be improved. can be done. Preferably, the joining portion 3 joins the entire area of the lower surface of the first metal layer 12 that contacts the upper surface of the second plate 21 to the second plate 21 . In this way, a large joint area can be secured between the two, so that the joint strength between the two can be improved. Furthermore, the airtightness of the internal space 1010 can be ensured.

Alternatively, as shown in FIG. 4B, the second housing portion 2 may have the second metal layer 22 while the first housing portion 1 may not have the first metal layer 12 . In this case, the joint portion 3 joins the upper surface of the second metal layer 22 and the lower surface of the first plate 11 . By joining the two, the first plate 11 can be connected to the second plate 21 via the second metal layer 22, so that the joint strength between the first housing part 1 and the second housing part 2 can be improved. can be done. Preferably, the joining portion 3 joins the entire region of the upper surface of the second metal layer 22 that is in contact with the lower surface of the first plate 11 to the first plate 11 . In this way, a large joint area can be secured between the two, so that the joint strength between the two can be improved. Furthermore, the airtightness of the internal space 1010 can be ensured.

<1-2-2-1. Joining method>
Next, with reference to FIGS. 5 and 5B, a method of joining the joints 3 will be described. FIG. 5A is a cross-sectional view showing a configuration example of the joint 3. FIG. FIG. 5B is a cross-sectional view showing another configuration example of the joint 3. As shown in FIG.

The first housing part 1 and the second housing part 2 are joined together by applying pressure in the vertical direction while being heated in a state in which they are stacked vertically. Hereinafter, a process in which heating and pressurization are performed at the same time will be referred to as a "heating and pressurizing process." The heating and pressurizing treatment gradually reconstructs the metal structure of the contact portion where the first housing portion 1 and the second housing portion 2 are in contact with each other. For example, the metal atoms of the first metal layer 12 diffuse into the metal structure of the second metal layer 22 and the metal atoms of the second metal layer 22 diffuse into the metal structure of the first metal layer 12 . As a result, the joint portion 3 is formed at the contact portion of the first housing portion 1 and the second housing portion 2 .

In this embodiment, by appropriately adjusting the conditions of the heating and pressurizing process, as shown in FIG. 5A, the boundary between the first housing part 1 and the second housing part 2 at the contact portion is partially eliminated. As a result, due to the reconstruction of the metallographic structure at the contact portion, crystal grains Cr are generated at a portion of the boundary between the first housing portion 1 and the second housing portion 2 and straddling the boundary. In this case, the joint portion 3 having the first area A1 and the second area A2 is formed at the contact portion between the first housing portion 1 and the second housing portion 2 .

In the first region A1, crystal grains Cr are generated by reconstruction of the metal structure at the contact portion. For example, in FIG. 5A, crystal grains Cr exist across a part of the boundary between the first metal layer 12 and the second metal layer 22 of the second housing 2 . In addition, the crystal grain Cr arranged in each first region A1 is singular in FIG. 5A, but is not limited to this illustration and may be plural.

On the other hand, in the second region A2, the contact surface where the first housing part 1 and the second housing part 2 are in contact with each other remains without reconstructing the metal structure. For example, the joint portion 3 further has an interface 31 where the first surface 120 of the first metal layer 12 and the second surface 20 of the second housing portion 2 are in direct contact. At interface 31 , first metal layer 12 is bonded to second housing portion 2 . For example, in FIG. 5A, first metal layer 12 is joined with second metal layer 22 at interface 31 . Since the two are bonded together, it is possible to sufficiently suppress permeation of a liquid such as a liquid working medium and a gas such as a vaporized working medium through the interface 31 . Therefore, the airtightness of the internal space 1010 can be further improved.

It should be noted that the contact portions of the first casing portion 1 and the second casing portion 2 may be joined by completely eliminating the boundary therebetween, without being limited to the example shown in FIG. 5A. In this case, the joint portion 3 having only the first region A1 is formed at the contact portion between the first housing portion 1 and the second housing portion 2 by the heating and pressurizing process. In other words, in the joint portion 3, the crystal grains Cr generated by reconstructing the metal structure at the contact portion extend over the entire boundary between the first housing portion 1 and the second housing portion 2. exist. For example, in FIG. 5B, crystal grains Cr exist across the boundary between the first metal layer 12 and the second metal layer 22, straddling the boundary. In addition, although the crystal grain Cr is singular in FIG. 5B, it is not limited to this illustration and may be plural.

In other words, the joint portion 3 has crystal grains Cr existing across at least a portion of the boundary between the first metal layer 12 and the second housing portion 2 . Since the joining portion 3 has the crystal grains Cr, the first housing portion 1 and the second housing portion 2 can be joined to each other without using other materials.

Moreover, by eliminating part of the boundary as shown in FIG. 5A, both can be bonded to each other under more preferable conditions than when the boundary is completely eliminated. For example, the first housing part 1 and the second housing part 2 can be bonded to each other under lower temperature conditions and in a shorter processing time than in the case of completely eliminating the boundary described above. Alternatively, the temperature conditions can be kept the same and the processing time can be further shortened compared to the case where the boundary is completely eliminated. In this way, the time required to join the first housing part 1 and the second housing part 2 together can be shortened. Alternatively, the processing time can be the same and the temperature conditions can be further reduced compared to the case where the boundary is completely eliminated. By doing so, it is possible to reduce the amount of energy consumed when joining the first housing portion 1 and the second housing portion 2 to each other.

Further, by completely eliminating the boundary as shown in FIG. 5B, the entire boundary between the first casing portion 1 and the second casing portion 2 can be firmly joined. Therefore, liquid such as a liquid working medium and gas such as a vaporized working medium can be reliably prevented from permeating through the joint 3 . Therefore, the airtightness of the internal space 1010 can be significantly improved.

In addition, as described above, the joint portion 3 is arranged along the outer edge portion of the internal space 1010 when viewed in the vertical direction. Preferably, in the joint portion 3 , the single or multiple crystal grains Cr are arranged annularly along the outer edge portion of the internal space 1010 when viewed from above and below. For example, the first area A1 and the second area A2 in FIG. 5A are arranged annularly as described above when viewed from the vertical direction. Alternatively, the first area A1 in FIG. 5B is arranged annularly as described above when viewed from above and below. Since the inner space 1010 can be surrounded by the crystal grains Cr arranged in a continuous ring, it is possible to further ensure that the liquid such as the liquid working medium and the gas such as the vaporized working medium can pass through the joint 3. can be prevented. Therefore, the airtightness of the internal space 1010 can be greatly improved. However, the arrangement of crystal grains Cr is not limited to this example. For example, the crystal grains Cr may extend annularly along the outer edge of the internal space 1010 with some interruptions.

<1-2-3. Pillar>
Next, the housing 101 further has a pillar portion 4 and a third metal layer 5 (see FIG. 2).

The column portion 4 protrudes from the first plate 11 toward the second housing portion 2 and is arranged inside the internal space 1010 . More specifically, the pillar 4 protrudes downward from the bottom surface of the recess 10 . In this embodiment, the pillars 4 are plural and arranged integrally with the first plate 11 . In other words, the column 4 and the first plate 11 are each different parts of a single member.

In this embodiment, the tip portion of the column portion 4 is in direct contact with the upper surface of the second housing portion 2 via the third metal layer 5 . Alternatively, the tip portion may directly contact the upper surface of the second housing portion 2, or indirectly or directly contact the wick structure. Thereby, the pillar part 4 supports the first housing part 1 and the second housing part 2 between them. Therefore, even if a downward force acts on the upper surface of the first housing part 1 or an upward force acts on the lower surface of the second housing part 2, the housing 101 is less likely to deform. Narrowing of the internal space 1010 due to deformation of the housing 101 can be suppressed. In addition, at least a portion of the column portion 4 may protrude from the upper surface of the second housing portion 2 , and may protrude from the upper surface of the second plate 21 , for example.

The third metal layer 5 is arranged on the surface of the pillar 4 (see FIG. 2). That is, the surface of the pillar portion 4 is covered with the third metal layer 5 . In this embodiment, the third metal layer 5 and the first metal layer 12 are different parts of a single member. However, it is not limited to this example, and the third metal layer 5 may be separate from the first metal layer 12 . The thermal conductivity of the third metal layer 5 is higher than that of the column portion 4 . By disposing the third metal layer 5 having a higher thermal conductivity than the column 4 on the surface of the column 4, the thermal conductivity of the column 4 with respect to the working medium in the internal space 1010 can be improved. Therefore, the heat conducting performance of the heat conducting member 100 can be improved. However, it is not limited to these examples, and the surface of the pillar portion 4 may not be covered with the third metal layer 5 . For example, as shown in FIG. 6, at least the side surfaces of the pillars 4 may be exposed to the internal space 1010 .

<1-3. First modification>
Next, the 1st modification of embodiment is demonstrated. Configurations different from the above-described embodiment will be described below. Moreover, the same code|symbol may be attached|subjected to the component similar to the above-mentioned embodiment, and the description may be abbreviate|omitted.

7A and 7B are enlarged views of the cross-sectional structure around the joint 3 in the first modified example. FIG. 7A is a cross-sectional view showing a first configuration example of the joint portion 3 according to the first modification. FIG. 7B is a cross-sectional view showing a second configuration example of the joint portion 3 according to the first modification. Note that both the first metal layer 12 and the second metal layer 22 are arranged on the housing 101 in FIGS. 7A and 7B. However, the present invention is not limited to these examples, and one of the first metal layer 12 and the second metal layer 22 may not be arranged on the housing 101, for example, as in FIGS. 4A and 4B.

In the first modification, the joint 3 further has an intermediate connector 32 . The intermediate connector 32 is made of metal, and is a copper or copper alloy plate in this embodiment. However, the material of the intermediate connector 32 is not limited to this example, and other metal materials may be used.

The intermediate connector 32 is arranged between the first housing part 1 and the second housing part 2, and indirectly connects the lower surface of the first housing part 1 and the second surface 20 of the second housing part 2. connect to. For example, the intermediate connector 32 is arranged between the first metal layer 12 and the second housing portion 2 . The first surface 120 of the first metal layer 12 is connected to the second surface 20 of the second housing part 2 via the intermediate connector 32 . 7A and 7B, the intermediate connector 32 is arranged between the first metal layer 12 and the second metal layer 22. In FIG. The first surface 120 of the first metal layer 12 is connected to the top surface of the second metal layer 22 via the intermediate connector 32 . By doing so, the bonding strength between the first housing portion 1 and the second housing portion 2 can be improved. Therefore, permeation of a liquid such as a liquid working fluid medium and a gas such as a vaporized working medium can be sufficiently suppressed. Therefore, the airtightness of the internal space 1010 can be further improved.

The upper surface of the intermediate connector 32 is preferably joined to the entire area of the lower surface of the first housing 1 that contacts the intermediate connector 32 . For example, in FIGS. 7A and 7B, the upper surface of intermediate connector 32 is bonded to the entire region of the lower surface of first metal layer 12 that contacts intermediate connector 32 . Similarly, the lower surface of the intermediate connector 32 is preferably joined to the entire area of the second surface 20 of the second housing part 2 that contacts the intermediate connector 32 . For example, in FIGS. 7A and 7B, the lower surface of intermediate connector 32 is bonded to the entire area of the upper surface of second metal layer 22 that contacts intermediate connector 32 . In this way, a large bonding area can be secured between the first housing portion 1, the second housing portion 2, and the intermediate connector 32, so that the bonding strength between them can be improved. Furthermore, the airtightness of the internal space 1010 can be ensured.

In the first modified example, the first casing portion 1, the intermediate connector 32, and the second casing portion 2 are joined by heating and pressurizing in a state in which they are stacked in order from top to bottom. be done. In the first modification, the metallographic structure of the contact portion between the first metal layer 12 and the intermediate connector 32 and the metallographic structure of the contact portion between the second metal layer 22 and the intermediate connector 32 are gradually changed by the heating and pressurizing treatment. reconfigured.

For example, as shown in FIG. 7A, in the first region A1 (see FIG. 5A) of the joint 3, a first crystal grain Cr1 and a second crystal grain Cr2 are generated by restructuring of the metal structure at the contact portion described above. do. That is, the joint portion 3 has the first crystal grains Cr1 and the second crystal grains Cr2. The first crystal grains Cr1 exist across a part of the boundary between the first housing part 1 and the intermediate connector 32, and in FIG. Straddle. The second crystal grains Cr2 exist across a part of the boundary between the second housing part 2 and the intermediate connector 32, and in FIG. Straddle. In addition, in each first region A1, the number of the first crystal grain Cr1 and the number of the second crystal grain Cr2 may be singular or plural.

Alternatively, as shown in FIG. 7B, in the first region A1 (see FIG. 5A) of the joint portion 3, the first casing portion 1, the intermediate connector 32, and the The second housing part 2 may be connected by a single crystal grain Cra in the vertical direction. That is, the joint portion 3 has crystal grains Cra. The crystal grains Cra exist across the boundary between the first casing portion 1 and the intermediate connector 32 , the intermediate connector 32 , and the boundary between the intermediate connector 32 and the second casing portion 2 . More specifically, the crystal grains Cra exist across a portion of the boundary between the first metal layer 12 of the first casing 1 and the intermediate connector 32 . Also, the crystal grains Cra exist across the intermediate connector 32 in the vertical direction. Furthermore, the crystal grains Cra exist across a portion of the boundary between the intermediate connector 32 and the second metal layer 22 of the second housing portion 2 . In addition, in each 1st area|region A1, the crystal grain Cra may be singular and may be plural.

Alternatively, the joint portion 3 may have at least two of the first crystal grains Cr1, the second crystal grains Cr2, and the crystal grains Cra.

On the other hand, in the second region A2 (see FIG. 5A) of the joint portion 3, the contact surface where the first metal layer 12 and the intermediate connector 32 are in contact with each other, the second metal layer 22 and the intermediate connector 32, and the metal structure is not reconstructed. A contact surface remains where the connections 32 contact each other. That is, the joint 3 further has a first interface 311 and a second interface 312 . At the first interface 311, the first surface 120 of the first metal layer 12 of the first casing 1 and the surface of the intermediate connector 32 on the first casing 1 side are in direct contact. At the second interface 312, the second surface 20 of the second housing portion 2 and the surface of the intermediate connector 32 on the side of the second housing portion 2 are in direct contact. The upper surface and the lower surface of the intermediate connector 32 are in direct contact. The intermediate connector 32 is joined to the first metal layer 12 of the first housing 1 at the first interface 311 . Further, the intermediate connector 32 is joined to the second housing part 2 at the second interface 312, and joined to the second metal layer 22 in FIGS. 7A and 7B. Bonding at the first interface 311 and the second interface 312 can sufficiently prevent a liquid such as a liquid working fluid medium and a gas such as a vaporized working medium from passing through the first interface 311 and the second interface 312 . . Therefore, the airtightness of the internal space 1010 can be further improved.

7A and 7B, the bonding portion 3 (see FIG. 5B) having only the first region A1 is formed into the first housing portion 1 and the second housing portion 2 by the heat and pressure treatment. may be formed at the contact portion of the In other words, in the joint portion 3, at least one of the crystal grains Cr1, Cr2, and Cra generated by reconstructing the metal structure at the contact portion is formed between the first housing portion 1 and the second housing portion 2. may be present straddling the boundary in the entire area of the boundary.

For example, when the joint portion 3 has the first crystal grains Cr1 and the second crystal grains Cr2 (see FIG. 7A), the first crystal grains Cr1 are formed between the first metal layer 12 and the intermediate connector 32 of the first housing portion 1. may be present straddling the boundary in the entire area of the boundary. And/or, the second crystal grains Cr2 may exist across the entire boundary between the second metal layer 22 of the second casing 2 and the intermediate connector 32 . At least one of the first crystal grains Cr1 and the second crystal grains Cr2 may be singular or plural.

That is, the joint portion 3 further has the first crystal grains Cr1 and the second crystal grains Cr2. The first crystal grains Cr1 exist across at least part of the boundary between the first metal layer 12 and the intermediate connector 32 . The second crystal grain Cr2 exists across at least part of the boundary between the second metal layer 22 and the intermediate connector 32 . In this way, since the joint portion 3 has the first crystal grains Cr1 and the second crystal grains Cr2, the first housing portion 1 and the second housing can be connected via the intermediate connector 32 without using other materials. 2 can be connected to each other.

Further, by eliminating a part of the boundary between the first housing part 1 and the intermediate connection body 32 and/or a part of the boundary between the second housing part 2 and the intermediate connection body 32, the above-mentioned boundary can be eliminated. Both can be bonded to each other under more favorable conditions than when they are completely eliminated. For example, the first casing 1 and the second casing 2 can be connected under lower temperature conditions and in a shorter processing time than when the boundary is completely eliminated. Alternatively, the temperature conditions can be kept the same and the processing time can be further shortened compared to the case where the boundary is completely eliminated. In this way, the time required to connect the first housing portion 1 and the second housing portion 2 can be shortened. Alternatively, the processing time can be the same and the temperature conditions can be further reduced compared to the case where the boundary is completely eliminated. By doing so, it is possible to reduce the amount of energy consumed when connecting the first housing portion 1 and the second housing portion 2 .

Alternatively, by completely eliminating the boundary between the first casing portion 1 and the intermediate connector 32 and/or the boundary between the second casing portion 2 and the intermediate connector 32, the first casing portion 1 and the second The entire boundary of the two housing parts 2 can be firmly joined. Therefore, liquid such as a liquid working medium and gas such as a vaporized working medium can be reliably prevented from permeating through the joint 3 . Therefore, the airtightness of the internal space 1010 can be significantly improved.

Further, when the joint portion 3 has crystal grains Cra (see FIG. 7B), the crystal grains Cra straddle the entire boundary between the first metal layer 12 of the first housing portion 1 and the intermediate connector 32. may exist. And/or the crystal grains Cra may exist across the entire boundary between the second metal layer 22 of the second housing 2 and the intermediate connector 32 . In this case, the number of crystal grains Cra may be singular or plural.

That is, the joint portion 3 has crystal grains Cra. The crystal grains Cra exist across at least a part of the boundary between the first metal layer 12 of the first casing 1 and the intermediate connector 32, and exist across the intermediate connector 32. At least a portion of the boundary between the intermediate connector 32 and the second housing portion 2 is present across the boundary. In this way, not only the bonding between the first metal layer 12 and the second housing portion 2 of the first housing portion 1 and the intermediate connector 32 but also the bonding between the first metal layer 12 of the first housing portion 1 and the intermediate connector 32 can be achieved. A direct connection with the second housing portion 2 can also be achieved by the crystal grains Cra. In other words, the first metal layer 12 and the second housing portion 2 can be bonded by the crystal grains Cra. Therefore, the first housing portion 1 and the second housing portion 2 can be connected more firmly through the intermediate connector 32 . Further, by eliminating a part of the boundary between the first housing part 1 and the intermediate connection body 32 and/or a part of the boundary between the second housing part 2 and the intermediate connection body 32, the above-mentioned boundary can be eliminated. Compared to the case of completely eliminating them, both can be joined to each other under more favorable conditions as in the case of FIG. 7A. Alternatively, by completely eliminating the boundary between the first casing part 1 and the intermediate connector 32 and/or the boundary between the second casing part 2 and the intermediate connector 32, as in FIG. 7A, It is possible to reliably prevent a liquid such as a liquid working medium and a gas such as a vaporized working medium from permeating through the joint 3 .

Note that the joint portion 3 is arranged along the outer edge portion of the internal space 1010 when viewed from the vertical direction. Preferably, in the joint portion 3, the single or multiple crystal grains Cr1, Cr2, and Cra are arranged annularly along the outer edge portion of the internal space 1010 when viewed from above and below.

For example, at least one of the first crystal grains Cr1 and the second crystal grains Cr2 in FIG. 7A is arranged annularly along the outer edge of the internal space 1010 when viewed from above. In FIG. 7A, since the first crystal grains Cr1 and/or the second crystal grains Cr2 can be continuously arranged in an annular shape to surround the internal space 1010, liquid such as liquid working medium and vaporized working medium can be of gas can be sufficiently prevented from permeating through the joint 3 . Therefore, the airtightness of the internal space 1010 can be improved. However, the arrangement of the first crystal grains Cr1 and the second crystal grains Cr2 is not limited to this example. For example, at least one of the first crystal grains Cr1 and the second crystal grains Cr2 may extend annularly along the outer edge of the internal space 1010 with a partial break.

Alternatively, the crystal grains Cra in FIG. 7B are arranged annularly along the outer edge of the internal space 1010 when viewed from above and below. In FIG. 7B , since the crystal grains Cra arranged in an annular shape without interruption can surround the internal space 1010 , liquid such as a liquid working medium and gas such as a vaporized working medium can pass through the joint 3 . can be reliably prevented. Therefore, the airtightness of the internal space 1010 can be improved. However, the arrangement of crystal grains Cra is not limited to this example. For example, the crystal grains Cra may extend annularly along the outer edge of the internal space 1010 with some interruptions.

Alternatively, the region A1 in which the first crystal grains Cr1 and the crystal grains Cra are present may be arranged annularly along the outer edge of the internal space 1010 when viewed from above and below. And/or, the region A1 in which the second crystal grains Cr2 and the crystal grains Cra are present may be arranged annularly along the outer edge of the internal space 1010 when viewed from above.

<1-4. Second modification>
Next, a second modified example of the embodiment will be described. Configurations different from the above-described embodiment will be described below. Moreover, the same code|symbol may be attached|subjected to the component similar to the above-mentioned embodiment, and the description may be abbreviate|omitted.

FIG. 8A is a cross-sectional view showing a configuration example of a heat conducting member 100 according to a second modified example. FIG. 8B is a cross-sectional view showing another configuration example of the heat conducting member 100 according to the second modified example.

In the second modification, one of the first metal layer 12 and the second metal layer 22 is arranged on the housing 101 .

For example, as shown in FIG. 8A, the first metal layer 12 is placed on the housing 101, but the second metal layer 22 is not. The third metal layer 5 may or may not be arranged on the surface of the columnar portion 4 as shown in FIG. 8A. Furthermore, the material of the first metal layer 12 is different from the material of the first plate 11 and the same as the material of the second plate 21 . For example, in FIG. 8A, the material of the first plate 11 is stainless steel, and the material of the first metal layer 12 and the material of the second plate 21 are both copper or copper alloy. These materials are not limited to the above examples. For example, the first plate 11 can be made of a material having higher mechanical strength than the first metal layer 12 . Furthermore, a material having a higher thermal conductivity than the first plate 11 can be used for the first metal layer 12 and the second plate 21 . In this way, since the same materials are joined together at the joining portion 3, the joining strength between the first metal layer 12 and the second plate 21 of the first housing portion 1 can be improved. Therefore, the airtightness of the internal space 1010 can be further improved.

Alternatively, as shown in FIG. 8B, the second metal layer 22 is disposed on the housing 101, but the first metal layer 12 and the third metal layer 5 are not disposed. Furthermore, the material of the second metal layer 22 is different from the material of the second plate 21 and the same as the material of the first plate 11 . For example, in FIG. 8B, the material of the first plate 11 and the material of the second metal layer 22 are both copper or copper alloy, and the material of the second plate 21 is stainless steel. These materials are not limited to the above examples. For example, the second plate 21 can be made of a material having a mechanical strength higher than that of the second metal layer 22 . Furthermore, a material having a higher thermal conductivity than the second plate 21 can be used for the first plate 11 and the second metal layer 22 . In this way, since the same materials are joined together at the joining portion 3, the joining strength between the first plate 11 and the second metal layer 22 of the second housing portion 2 can be improved. Therefore, the airtightness of the internal space 1010 can be further improved.

<2. Others>
The embodiment of the present invention and its first and second modifications have been described above. Note that the above-described embodiment and its first and second modifications are examples. It should be understood by those skilled in the art that various modifications can be made to the combination of each component and each process and are within the scope of the present invention.

INDUSTRIAL APPLICABILITY The present invention is useful, for example, as a member that dissipates heat from a heat source.

DESCRIPTION OF SYMBOLS 100... Heat-conducting member, 101... Case, 1010... Internal space, 1... First case part, 10... Recessed part, 11... First plate, 12... First metal layer 120 First surface 2 Second casing 20 Second surface 21 Second plate 22 Second metal layer 3. .. Joining portion 31 .. Interface 311 .. First interface 312 .. Second interface 32 .. Intermediate connector 4 .. Column 5 .. Third metal layer , Cr, Cra... crystal grains, Cr1... first crystal grains, Cr2... second crystal grains

Claims (17)

A heat conducting member comprising a housing in which a working medium is enclosed in an internal space, and a wick structure disposed in the internal space,
The housing has a plate-shaped first housing portion, a plate-shaped second housing portion, and a joint portion,
The internal space is arranged between the first housing portion and the second housing portion,
The first housing part has a metal first plate and a first metal layer,
The first metal layer is arranged on the surface of the first plate on the second housing part side,
The melting point of the first metal layer is lower than the melting point of the first plate,
The second housing part has a metal second plate,
The junction is
arranged along the outer edge of the internal space when viewed in the vertical direction from one of the first casing portion and the second casing portion to the other;
A thermally conductive member that joins a first surface of the first metal layer on the side of the second casing and a second surface of the second casing on the side of the first casing. 2. The thermally conductive member according to claim 1, wherein said first metal layer is a metal plating layer disposed on a surface of said first plate on the side of said second housing portion. 2. The thermally conductive member according to claim 1, wherein said first housing portion is a clad material. 4. The thermally conductive member according to any one of claims 1 to 3, wherein the material of said first metal layer is either copper or a copper alloy. The heat conducting member according to any one of claims 1 to 4, wherein the material of the first plate and the material of the second plate are each stainless steel. 6. The method according to any one of claims 1 to 5, wherein the bonding portion bonds an entire region of the first surface of the first metal layer that is in contact with the second surface of the second housing portion to the second surface. The thermally conductive member according to any one of items 1 to 3. The heat transfer member according to any one of claims 1 to 6, wherein the joint portion is arranged annularly when viewed from the up-down direction. 8. The bonding portion according to any one of claims 1 to 7, wherein at least a part of a boundary between the first metal layer and the second casing portion has crystal grains existing across the boundary. A thermally conductive member as described. 9. The heat conducting member according to claim 8, wherein said crystal grains are annularly arranged along an outer edge of said internal space when viewed from above and below. The joint further has an intermediate connector,
the intermediate connector is disposed between the first metal layer and the second housing,
8. The method according to any one of claims 1 to 7, wherein said first surface of said first metal layer is connected to said second surface of said second housing via said intermediate connector. thermally conductive member. The junction is
a first crystal grain extending over at least part of a boundary between the first metal layer and the intermediate connector;
a second crystal grain extending over at least a portion of a boundary between the second housing portion and the intermediate connector;
11. The thermally conductive member of claim 10, further comprising: 12. The heat conducting member according to claim 11, wherein at least one of said first crystal grains and said second crystal grains is annularly arranged along an outer edge of said internal space when viewed from above and below. . The joint further has crystal grains,
The crystal grains are present across at least a part of a boundary between the first metal layer and the intermediate connector, and are present across the intermediate connector. 11. The thermally conductive member according to claim 10, existing across at least a portion of the boundary with the second housing portion. 14. The heat conducting member according to claim 13, wherein said crystal grains are annularly arranged along an outer edge of said internal space when viewed from above and below. 10. The heat conducting member according to any one of claims 1 to 9, wherein the material of the first metal layer is different from the material of the first plate and the same as the material of the second plate. the second housing further includes a second metal layer disposed on a surface of the second plate facing the first housing,
The heat conduction member according to any one of claims 1 to 14, wherein the second surface is a surface of the second metal layer on the first housing portion side. The housing further has a pillar and a third metal layer,
the column protrudes from the first plate toward the second housing and is disposed in the internal space;
The third metal layer is arranged on the surface of the pillar,
The thermally conductive member according to any one of claims 1 to 16, wherein thermal conductivity of said third metal layer is higher than thermal conductivity of said column portion.

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