WO2016052654A1

WO2016052654A1 - Heat transfer spring and spring member

Info

Publication number: WO2016052654A1
Application number: PCT/JP2015/077820
Authority: WO
Inventors: 秀雅伊藤; 潤冨永
Original assignee: 日本発條株式会社
Priority date: 2014-09-30
Filing date: 2015-09-30
Publication date: 2016-04-07

Abstract

　A heat transfer spring according to the present invention is provided with: contact parts having a base end part at which one end of the contact part is curved at a first curvature radius and a distal end part at which the other end of the contact part is curved so as to be inverted with respect to the one end at a second curvature radius, the contact parts coming into contact, at each of the base end part and at the distal end part, with an object to be contacted; and a flat plate-shaped holding part for holding the base end parts. The first and the second curvature radii have values determined in accordance with the contact heat resistance with respect to the respective object to be contacted. A spring member according to the present invention connects two members, wherein the spring member is provided with: contact parts having a base end part at which one end of the contact part is curved and a distal end part at which the other end of the contact part is curved so as to be inverted with respect to the one end, the contact parts coming into contact, at each of the base end part and at the distal end part, with an object to be contacted; and a flat plate-shaped holding part for holding the base end parts; the holding part constituting 1/4 to 1/2 of the entire spring member when viewed from the direction orthogonal to the main surface of the holding part, and a thickness-direction through-hole being formed in the contact parts.

Description

Heat transfer spring and spring member

The present invention relates to a heat transfer spring that is interposed between a heat generating object and a heat radiating member and transmits heat generated by the heat generating object to the heat radiating member. The present invention also relates to a spring member interposed between two members.

Conventionally, in the automotive field and the precision equipment industry field, the connection between components has been required to follow vibration. As a member that is used for connection between constituent members and has a followability to vibration, a spring member that is interposed between the two members is known. The spring member is elastically deformed in response to vibration generated in one member, thereby suppressing vibration from being transmitted to the member such as the other member while maintaining the connection.

Also, in the automotive field and the precision equipment industry field, the component parts are required to have high heat dissipation, durability in a high temperature environment, and vibration followability. In order for the component parts to have high heat dissipation properties, it is necessary to use a heat transfer spring having high heat conductivity between the heat generating member and the cooling member. On the other hand, in order not to transmit the vibration generated in the heat generating member to a member such as a heat radiating member, the heat transfer spring needs to follow the generated vibration.

As such a spring member, a spring member (metal body) having a substantially flat frame portion and a contact portion (projection body) that comes up from a part of the frame portion and comes into contact with a member to be contacted ) Is disclosed (see, for example, Patent Document 1). Patent Document 1 discloses that a heat transfer spring that satisfies the above-described requirements is formed using a metal having thermal conductivity and has a protrusion. According to Patent Document 1, by disposing a metal plate between a semiconductor chip and an exterior cap, heat generated by the semiconductor chip is transmitted to the exterior cap, and heat is released to the outside by the exterior cap. Further, even when stress generated by heat or vibration generated between the heat generating member and the cooling member is applied, it can be absorbed by elastic deformation of the protrusion.

Japanese Patent Laid-Open No. 10-303340

However, if the contact surface of the protrusion with respect to the contact target is increased in order to increase the thermal conductivity, the portion that acts by elastic deformation becomes smaller. On the other hand, if the part which acts by elastic deformation is increased in order to improve the vibration followability, the contact surface is reduced and the contact thermal resistance is increased. Thus, it has been difficult to achieve both thermal conductivity and vibration followability in the heat transfer spring.

In addition to this, it is preferable to increase the contact area by increasing the number and size of the contact portions in order to improve followability. However, when the contact area between the contact portion and the member to be contacted is increased, the occupation ratio of the frame portion supporting the contact portion is reduced, and the rigidity between the contact portion and the frame portion is different. If there is a difference in rigidity between the contact part and the frame part, when the contact part is deformed due to the load applied from the outside, stress due to the deformation is applied to the frame part, and the stress causes the spring member to sag. End up. For this reason, the technique which suppresses the rigidity difference of a contact part and a frame part was desired.

The present invention has been made in view of the above, and an object thereof is to provide a heat transfer spring excellent in thermal conductivity and vibration followability.

Further, the present invention has been made in view of the above, and an object thereof is to provide a spring member that can suppress a difference in rigidity between a contact portion and a frame portion.

In order to solve the above-described problems and achieve the object, a heat transfer spring according to the present invention is formed using a substantially band-shaped member, and a base end portion having one end curved with a first radius of curvature; A distal end portion whose other end is curved in a reverse bending manner with respect to the one end, and a second curvature radius, and a contact portion that makes contact with a contact object at the proximal end portion and the distal end portion, A flat plate-like holding portion that holds the base end portion, and the first and second curvature radii have values determined according to contact thermal resistance with respect to each contact object.

In the heat transfer spring according to the present invention as set forth in the invention described above, the first and second curvature radii are extreme values of a curve indicating a relationship between the curvature radius and the contact thermal resistance, or a region in the vicinity of the extreme value. It is characterized by being determined according to the value.

Further, the heat transfer spring according to the present invention is characterized in that, in the above invention, the contact portion has a rectangular shape when viewed from a direction orthogonal to the main surface of the holding portion.

The heat transfer spring according to the present invention is characterized in that, in the above invention, the first and second radii of curvature are the same.

The heat transfer spring according to the present invention includes a plurality of the contact portions in the above invention, the holding portion includes a plurality of openings provided in a matrix shape, and the openings include a plurality of openings. Each base end portion of the contact portion is held.

In order to solve the above-described problems and achieve the object, a spring member according to the present invention is a spring member that connects two members, and is formed using a substantially band-shaped member, and one end is curved. A proximal end portion, and a distal end portion whose other end is curved in a reverse bending manner with respect to the one end, and the contact portion that contacts the contact object at the proximal end portion and the distal end portion, respectively, A flat holding portion for holding the base end portion, and the occupation ratio of the holding portion with respect to the entire spring member is ¼ or more and ½ or less when viewed from a direction orthogonal to the main surface of the holding portion. And the contact portion is formed with a through-hole penetrating in the thickness direction.

In the spring member according to the present invention, the area ratio S1 / S2 when the area of the through hole is S1 and the area of the contact part is S2 when the contact part is extended in a flat plate shape in the above invention. Is characterized by satisfying 1/2 or less.

The spring member according to the present invention is characterized in that, in the above invention, the through hole has a rhombus opening.

Further, the spring member according to the present invention is characterized in that, in the above invention, the contact portion has a rectangular shape when viewed from a direction orthogonal to the main surface of the holding portion.

In the above invention, the spring member according to the present invention includes a plurality of the contact portions, the holding portion includes a plurality of openings provided in a matrix shape, and the one or more openings are provided. Each base end portion of the contact portion is held.

According to the present invention, it is possible to realize a heat transfer spring having excellent thermal conductivity and vibration followability.

Further, according to the present invention, there is an effect that a difference in rigidity between the contact portion and the frame portion can be suppressed.

FIG. 1 is a side view schematically showing the configuration of the heat transfer spring according to the first embodiment of the present invention. FIG. 2 is a plan view showing a configuration of a main part of the heat transfer spring according to the first embodiment of the present invention. FIG. 3 is a side view showing the configuration of the main part of the heat transfer spring according to the first embodiment of the present invention. FIG. 4 is a partial cross-sectional view schematically showing the configuration of the main part of the heat transfer spring according to the first embodiment of the present invention, and is a diagram for explaining a case where a load is applied from the outside. FIG. 5 is a graph showing the contact surface pressure and the contact area with respect to the curved shape of the contact portion in the heat transfer spring according to the first embodiment of the present invention. FIG. 6 is a graph showing the contact thermal resistance and the contact area for the curved shape of the contact portion in the heat transfer spring according to the first embodiment of the present invention. FIG. 7 is a diagram for explaining an example of the method for manufacturing the heat transfer spring according to the first embodiment of the present invention. FIG. 8 is a diagram for explaining an example of the manufacturing method of the heat transfer spring according to the first embodiment of the present invention. FIG. 9 is a plan view showing the configuration of the heat transfer spring according to the modification of the first embodiment of the present invention. FIG. 10 is a side view schematically showing the configuration of the spring member according to the second embodiment of the present invention. FIG. 11: is a top view which shows the structure of the principal part of the spring member concerning Embodiment 2 of this invention. FIG. 12 is a side view showing the configuration of the main part of the spring member according to the second embodiment of the present invention. FIG. 13: is a fragmentary sectional view which shows typically the structure of the principal part of the spring member concerning Embodiment 2 of this invention, Comprising: It is a figure explaining the case where a load is added from the outside. FIG. 14 is a graph showing a spring constant ratio and a thermal resistance ratio per unit area in the spring member according to the second embodiment of the present invention and the spring member according to the comparative example. FIG. 15 is a graph showing the relationship between the spring height, the load, and the thermal resistance per unit area in the spring member according to the second embodiment of the present invention and the spring member according to the comparative example. FIG. 16 is a diagram for explaining an example of a spring member manufacturing method according to the second embodiment of the present invention. FIG. 17 is a perspective view showing the configuration of the heat transfer spring according to the third embodiment of the present invention.

In the following description, a heat transfer spring and a spring member will be described as modes for carrying out the present invention (hereinafter referred to as “embodiments”). Moreover, this invention is not limited by this embodiment. Furthermore, the same code | symbol is attached | subjected to the same part in description of drawing. Furthermore, the drawings are schematic, and it should be noted that the relationship between the thickness and width of each member, the ratio of each member, and the like are different from the actual ones. Moreover, the part from which a mutual dimension and ratio differ also in between drawings.

(Embodiment 1)
FIG. 1 is a side view schematically showing the configuration of the heat transfer spring according to the first embodiment of the present invention. The heat transfer spring 1 according to the first embodiment of the present invention is disposed between the opposing heat generating member and heat radiating member. The heat transfer spring 1 applies pressure to both the heat generating member and the heat radiating member by elastic force, and transmits heat generated by the heat generating member to the heat radiating member. The heat transfer spring 1 is formed using a flat member made of a material having elastic characteristics, for example, a copper-based alloy (for example, a Corson-based copper alloy).

The heat transfer spring 1 has a plate-like frame portion 10 having openings 10a provided in a matrix shape, and a belt shape in a direction rising from the inner peripheral surface of the opening portion 10a of the frame portion 10 with respect to the frame portion 10. The contact part 11 which extends and contacts a contact object is provided. The frame portion 10 has a function as a holding portion that holds the plurality of contact portions 11 in a predetermined arrangement.

FIG. 2 is a plan view showing a configuration of a main part of the heat transfer spring according to the first embodiment. FIG. 3 is a side view illustrating a configuration of a main part of the heat transfer spring according to the first embodiment, and is a diagram illustrating a state in which the heat transfer spring is placed on the heat radiating member. When the side where the contact part 11 extends with respect to the frame part 10 is located above the frame part 10, the contact part 11 has a base end part 11 a that has a curved surface convex downward with respect to the surface of the frame part 10, and a frame It has a curved surface that is convex upward with respect to the surface of the portion 10, and has a tip portion 11b that comes into contact with the contact target. The contact portion 11 has a rectangular projection shape viewed from above (a direction orthogonal to the main surface of the frame portion 10). The proximal end portion 11a and the distal end portion 11b have shapes that are curved in a curved manner opposite to each other with predetermined curvature radii (first and second curvature radii), respectively. In addition, the curvature radius of the base end part 11a and the front-end | tip part 11b in this Embodiment 1 means the curvature radius in the site | part (for example, a convex top part and a concave bottom part) where a curvature radius becomes the smallest.

As shown in FIG. 3, the heat transfer spring 1 has a frame portion 10 disposed on a heat radiating member 100 and a heat generating member 101 (see FIG. 4) disposed on the opposite side. At this time, both ends of the contact portion 11 are in contact with the heat radiating member 100 and the heat generating member 101, respectively. Specifically, the base end portion 11 a contacts the heat radiating member 100, and the tip end portion 11 b contacts the heat generating member 101.

FIG. 4 is a partial cross-sectional view schematically showing the configuration of the main part of the heat transfer spring according to the first embodiment of the present invention, and is a diagram illustrating a case where a load is applied from the outside. In addition, in FIG. 4, the shape of the contact part 11 in the state where the load is not applied to the front-end | tip part 11b is shown with the broken line Q. When the heat transfer section spring 1 is disposed between the heat radiating member 100 and the heat generating member 101, the base end portion 11 a contacts the heat radiating member 100 and the tip end portion 11 b contacts the heat generating member 101. As the distance between the heat radiating member 100 and the heat generating member 101 is reduced, a load is applied to the heat transfer spring 1. When a load starts to be applied to the heat transfer spring 1, the contact portion 11 gradually lies down with respect to the frame portion 10, while a portion of the frame portion 10 that is connected to the base end portion 11 a is separated from the surface of the heat radiating member 100. It rises.

Subsequently, the contact thermal resistance generated between the heat transfer spring 1 and the heat radiating member 100 or the heat generating member 101 will be described. In order to make the heat conduction between the heat transfer spring 1 and the heat radiating member 100 or the heat generating member 101 highly efficient, it is preferable to reduce the contact thermal resistance generated between them.

The contact thermal resistance R _c (m ² K / W) when the contact area is constant can be obtained by the following formulas (1) and (2) (The Japan Society of Mechanical Engineers Proceedings (A), Volume 76, 763 (2010-3), paper No. 09-0569 (p.344-350)).
The thermal contact resistance R _c is can be determined based on the following equation (1).

Here, h _c : contact heat transfer coefficient (W / m ² K), which can be obtained based on the following equation (2).

Here, P: contact surface pressure (MPa), λ: thermal conductivity of material (W / mK), Hv: Vickers hardness of material, Ra: center line average roughness (μm) of contact surface, c ₁ , c ₂ , c ₃ : Constant.
In Expression (2), the first term on the right side is a term related to a high temperature side member (for example, a heat generating member), and the second term is a term related to a low temperature side member (for example, a heat transfer spring).

By obtaining the contact thermal resistance R _c obtained from the equations (1) and (2), the contact thermal resistance R _cu per unit area can be obtained based on the following equation (3).

Here, A _c : contact area, A _sp : projected area of the heat transfer spring viewed from the direction orthogonal to the contact surface.

FIG. 5 is a graph showing the contact surface pressure and the contact area with respect to the curved shape of the contact portion in the heat transfer spring according to the first embodiment. The graph shown in FIG. 5 shows the contact thermal resistance and the contact area when the same load is applied to the contact portion 11, specifically, the plate width per contact portion 11 is 4.0 mm, the spring The case where the length (the length along the plate surface from the base end portion 11a to the tip end portion 11b) is 2.5 mm and the applied load is 1.4 N is shown as an example. As described above, when the contact surface of the contact target is a flat surface, the contact area between the contact portion 11 and the contact target increases as the radius of curvature (r) of the contact portion 11 increases. On the other hand, when the curvature radius (r) of the contact portion 11 increases, the contact surface pressure applied to the contact object by the contact portion 11 decreases.

FIG. 6 is a graph showing the contact thermal resistance and the contact area per unit area with respect to the curved shape of the contact portion in the heat transfer spring according to the first embodiment. The graph shown in FIG. 6 shows the contact thermal resistance and the contact area when the same load is applied to the contact portion 11. The dimensions of the contact portion 11 and the applied load are the same as those in the graph of FIG. For example, when the contact surface of the contact target is a flat surface, when the radius of curvature (r) of the contact portion 11 (the base end portion 11a or the tip end portion 11b) increases, the contact area between the contact portion 11 and the contact target increases. On the other hand, in the contact thermal resistance per unit area between the contact portion 11 and the contact target, a curve with respect to the curvature radius (r) of the contact portion 11 (base end portion 11a or tip end portion 11b) forms a parabola.

The contact thermal resistance per unit area with respect to the radius of curvature (r) of the contact portion 11 (base end portion 11a or tip end portion 11b) has an extreme value. In the graph shown in FIG. 6, r (mm) has an extreme value around 1.5 mm. The contact portion 11 with reduced contact thermal resistance is formed by setting the extreme value thus obtained and the value of r near the extreme value to the radius of curvature of the contact portion 11 (base end portion 11a or tip end portion 11b). be able to.

For example, the radius of curvature of the contact portion 11 may be r corresponding to the extreme value, may include the extreme value, and may be within a range within 5% of the extreme value, and the proximal end portion 11a and the distal end portion 11b. It may include a range (variation) of the radius of curvature (r) caused by a design tolerance in the formation of the curved shape (for example, a tolerance when r corresponding to an extreme value is a radius of curvature). Note that the curved shapes (first and second radii of curvature) of the proximal end portion 11a and the distal end portion 11b may be the same or different. The curved shapes of the base end portion 11a and the tip end portion 11b can be arbitrarily designed according to the contact target.

Next, an example of a method for manufacturing the heat transfer spring according to the first embodiment will be described with reference to the drawings. FIG. 7 is a diagram for explaining an example of the manufacturing method of the heat transfer spring according to the first embodiment. For example, a plurality of slits 201 are formed in a band-shaped base material 200 made of a Corson copper alloy (see FIG. 7). The slit 201 forms a hollow space having a substantially M shape in plan view. The slit 201 forms a frame portion 202, and a first tongue piece portion 203 and a second tongue piece portion 204 that extend from the frame portion 202 in a rectangular shape.

After the first tongue piece 203 and the second tongue piece 204 are formed, with respect to the first tongue piece 203 and the second tongue piece 204, the end on the side connected to the frame and the side connected to the frame 202 The contact portion 11 described above is formed by bending the end portions on the different sides from each other so as to have a predetermined radius of curvature. This radius of curvature is set based on the contact thermal resistance and contact surface pressure described above.

In this way, the slit 201 is formed, and the first tongue piece 203 and the second tongue piece 204 generated by the formation of the slit 201 are curved, whereby the transmission having the frame portion 10 and the contact portion 11 described above. The heat spring 1 can be produced. The slit 201 is substantially M-shaped in plan view, and the opening has been described as having two tongue pieces, but the opening may have one tongue piece, It may have three or more tongue pieces.

FIG. 8 is a diagram for explaining an example of the manufacturing method of the heat transfer spring according to the first embodiment. The formation width (d1 to d4) of the slit 201 is preferably as small as possible in terms of design from the viewpoint of the rigidity of the frame portion 202. In addition, the formation interval of the slits 201 is so small that the frame portion 202 is not deformed when the first tongue piece portion 203 and the second tongue piece portion 204 are curved. Is preferable. As described above, since the two contact portions 11 (the first tongue piece portion 203 and the second tongue piece portion 204) can be formed by the M-shaped slit 201, each contact portion 11 is formed on the frame portion 10. The heat transfer spring 1 can be downsized as compared with the case where it is surrounded.

According to the first embodiment described above, in the heat transfer spring 1, the contact portion 11 having a curved shape having a curvature radius (r) determined according to the contact thermal resistance and the contact surface pressure is formed. There is an effect that it is excellent in thermal conductivity and vibration followability.

Further, according to the first embodiment described above, since the contact portion 11 is formed by curving the tongue piece portion extending in a rectangular shape, the tongue piece portion having a tapered shape, for example, a weight shape, is curved. The heat transfer efficiency is higher than when the contact portion is formed. In general, when the contact portion is formed by bending the tongue piece portion, the tongue piece portion formed into a tapered shape is bent. However, as in this embodiment, the tongue piece portion having a rectangular shape is formed. By forming the contact portion based on the above, more efficient heat transfer can be performed.

Conventionally used heat transfer members include heat transfer grease and heat transfer sheet, but if the thickness of the heat transfer grease or heat transfer sheet is reduced from the viewpoint of the conductor thermal resistance, the followability to vibration is reduced. On the other hand, in the heat transfer grease, when the thickness of the heat transfer member is increased from the viewpoint of followability to vibration, it is difficult to control the thermal resistance because it is difficult to adjust the thickness. Further, in the heat transfer sheet, when the thickness of the heat transfer member is increased from the viewpoint of followability with respect to vibration, it is necessary to contain a large amount of high thermal conductive filler to reduce the conductor thermal resistance. It becomes hard and cannot follow the vibration. On the other hand, the heat transfer spring according to the present embodiment can achieve both high thermal conductivity and high vibration followability by having the above-described configuration.

In the above-described first embodiment, each contact portion 11 may have the same shape, or may have a different size or curved form. It is preferable to design appropriately depending on how the load is applied. Note that the same shape means the same shape in design and includes manufacturing errors.

Moreover, in Embodiment 1 mentioned above, although demonstrated as what has the some contact part 11, it comprises a rectangular flat plate shape, the frame part which has a rectangular opening, and one extension extended from a part of opening of a frame part It is good also as a heat-transfer spring which has a contact part (contact part 11). Also in this case, the curvature radius (first and second curvature radii) of the contact portion is determined according to the contact thermal resistance and the contact surface pressure as described above.

(Modification of Embodiment 1)
FIG. 9 is a plan view showing the configuration of the heat transfer spring according to the modification of the first embodiment. In Embodiment 1 mentioned above, although the contact part 11 demonstrated as what curves a rectangular tongue piece part, like the contact part 12 of the heat-transfer spring 1a concerning this modification 1, it is a trapezoidal tongue piece. The part may be curved. The contact portion 12 has a trapezoidal projection shape as viewed from above, and has a length (width) in a direction perpendicular to the extending direction from the frame portion 10 toward the tip.

(Embodiment 2)
Next, a second embodiment of the present invention will be described. FIG. 10 is a side view schematically showing the configuration of the spring member according to the second embodiment of the present invention. The spring member 2 according to the second embodiment is disposed between two opposing constituent members. The spring member 2 applies pressure to both of the two components by elastic force. The spring member 2 is formed using a flat member made of a material having elastic characteristics, for example, a copper-based alloy (for example, a Corson-based copper alloy).

The spring member 2 extends in a strip shape in a direction rising from the inner peripheral surface of the opening 20a of the frame 20 to the frame 20 with a flat frame 20 having openings 20a provided in a matrix. The contact part 21 which exists and contacts a contact object is provided. The frame portion 20 functions as a holding portion that holds the plurality of contact portions 21. Here, in the second embodiment, the occupation ratio of the frame part 20 with respect to the spring member 2 is ¼ or more and ½ or less in the projection shape seen from the direction orthogonal to the main surface of the frame part 20. In addition, when the occupation rate of the frame part 20 is larger than 1/2, since the frame part occupies half or more of the spring member, it is considered that there is no difference in rigidity between the frame part 20 and the contact part 21. .

FIG. 11 is a plan view showing the configuration of the main part of the spring member according to the second embodiment. FIG. 12 is a side view showing the configuration of the main part of the spring member according to the second embodiment, and shows a state where the spring member is placed on the heat dissipation member. When the side where the contact portion 21 extends with respect to the frame portion 20 is above the frame portion 20, the contact portion 21 has a base end portion 21 a that forms a curved surface that protrudes downward with respect to the surface of the frame portion 20, and a frame It has a curved surface that is convex upward with respect to the surface of the portion 20, and has a tip portion 21b that comes into contact with the contact target. The contact portion 21 has a rectangular projection shape viewed from above. The proximal end portion 21a and the distal end portion 21b are each curved with a predetermined radius of curvature. The radius of curvature (r) of the base end portion 21a and the tip end portion 21b in the second embodiment refers to the radius of curvature at a portion where the radius of curvature is the smallest (for example, a convex top portion or a concave bottom portion). .

Further, the contact portion 21 is formed with a through hole 21c penetrating in the plate thickness direction. In the through hole 21c, the shape of the opening (in the top view of the spring member 2) viewed from a direction orthogonal to the main surface of the frame portion 20 is substantially rhombus. For example, the short axis (or long axis) of the rhombus includes a straight line that passes through the center of each of the base end part 21 a and the front end part 21 b, and the opening is on a plane perpendicular to the main surface of the frame part 20. When the contact portion 21 is extended into a flat plate shape (for example, a first tongue piece portion 203 in FIG. 16 described later), the area of the through hole 21c is S1, and the area of the contact portion 21 is S2, the area ratio S1 / S2. Satisfies 1/2 or less (however, 0 is not included). When the occupation ratio of the frame part 20 is the minimum (1/4), the difference in rigidity between the frame part 20 and the contact part 21 can be adjusted by setting the area ratio S1 / S2 to 1/2. By forming the through hole 21c, the rigidity of the contact portion 21 can be reduced as compared with a contact portion having the same plate thickness where no through hole is formed. The size and shape of the through hole 21 c are determined in consideration of the rigidity of the frame portion 20 and the rigidity due to the shape of the contact portion 21. The contact portion 21 preferably has symmetry with respect to a straight line passing through the center of each of the base end portion 21a and the tip end portion 21b in the projected shape viewed from the direction orthogonal to the main surface of the frame portion 20.

As shown in FIG. 12, the spring member 2 arranges the frame portion 20 on the first component member 102, and arranges the second component member 103 (see FIG. 13) from the opposite side. At this time, both ends of the contact portion 21 are in contact with the first component member 102 and the second component member 103, respectively. Specifically, the proximal end portion 21 a contacts the first component member 102, and the distal end portion 21 b contacts the second component member 103.

FIG. 13 is a partial cross-sectional view schematically showing the configuration of the main part of the spring member according to the second embodiment of the present invention, and is a view for explaining a case where a load is applied from the outside. In FIG. 13, the shape of the contact portion 11 in a state where no load is applied to the distal end portion 21b is indicated by a broken line Q. When the spring member 2 is disposed between the first component member 102 and the second component member 103, the proximal end portion 21 a contacts the first component member 102, and the distal end portion 21 b contacts the second component member 103. To do. As the distance between the first component member 102 and the second component member 103 is reduced, a load is applied to the spring member 1. When a load starts to be applied to the spring member 2, the contact portion 21 gradually falls asleep against the frame portion 20. On the other hand, the frame portion 20 maintains flatness regardless of the load.

Subsequently, in the spring member having the same plate thickness, the spring constant in the case where the through hole is formed in the contact portion 21 and the case where the through hole is not formed, and the thermal resistance per unit area (contact thermal resistance) Will be described.

The thermal resistance per unit area is obtained by the sum of the thermal resistance of the conductor and the contact thermal resistance. The thermal resistance of the conductor is the same because the material used is the same in this comparison.

Regarding the contact thermal resistance, the contact thermal resistance R _c (m ² K / W) when the contact area is constant can be obtained by the above formulas (1) and (2). Here, in Expression (2), the first term on the right side is a term related to the high temperature side member (for example, the second component member), and the second term is a term related to the low temperature side member (for example, the spring member).

By obtaining the contact thermal resistance R _c obtained from the equations (1) and (2), the contact thermal resistance R _cu per unit area can be obtained based on the above equation (3). Here, A _sp is read as the projected area of the spring member viewed from the direction orthogonal to the contact surface.

FIG. 14 is a graph showing a spring constant ratio and a thermal resistance ratio per unit area in the spring member according to Embodiment 2 of the present invention and the spring member according to Comparative Example 1. In the graph shown in FIG. 14, when the spring member when the through hole 21 c is formed in the contact portion 21 is an example, the case where no through hole is formed is Comparative Example 1, and the value of Comparative Example 1 is 1. The ratios of the examples are shown. The characteristics of one contact portion when the same load is applied to the contact portion are compared. As shown in FIG. 14, the spring constant when the through hole 21c is formed is smaller than that when the through hole 21c is not formed. The spring constant k is given by k = P / δ (P is load (N), δ is displacement (mm)). When the same load is applied, the spring constant is smaller in the contact portion 21 in which the through-hole 21c is formed and the rigidity is lower than that in the first comparative example.

On the other hand, when the through hole 21c is formed, the contact thermal resistance is larger than when the through hole 21c is not formed. The contact thermal resistance R _cu per unit area increases when the difference between the rigidity of the frame portion 20 and the through hole 21c is reduced to reduce the rigidity of the contact portion 21. From this, when the difference between the rigidity of the frame part 20 and the through hole 21c and the rigidity of the contact part 21 is reduced, the sag of the spring member 2 is reduced by reducing the stress applied to the frame part 20. Therefore, it can be considered that the contact thermal resistance per unit area increases.

Thus, even when the spring member is formed using the material having the same plate thickness, the spring constant and the thermal resistance per unit area differ depending on whether or not the through hole 21c is formed. For example, by using a material having a plate thickness of 0.10 mm and forming a through hole 21c having the same spring constant and thermal resistance per unit area as a spring member not having the through hole 21c, the plate thickness is reduced to 0. It can be made using a 13 mm material. In this case, since the plate thickness of the frame portion 20 is 0.13 mm, the through hole 21c is formed while increasing the rigidity of the frame portion 20, and the same characteristics as the contact portion having a plate thickness of 0.10 mm are obtained. It can be set as the contact part which has.

FIG. 15 is a graph showing the relationship between the spring height, the load and the thermal resistance per unit area in the spring member according to the second embodiment of the present invention (Example) and the spring member according to Comparative Example 2. . The example shown in FIG. 15 is a spring member 2 made of a material having a plate thickness of 0.13 mm, and Comparative Example 2 is made of a material having a plate thickness of 0.10 mm and has a through hole. It is a spring member that does not. In addition, the spring constant of the spring member (contact part) concerning an Example and the comparative example 2 is the same. The spring height here refers to the height D from the bottom of the frame portion 20 to the top of the contact portion 21 in the spring member 2 shown in FIG. 12, and the more the load is applied, the smaller the spring height is. Become.

As shown in FIG. 15, when the spring member 2 according to the example is viewed at the same spring height, compared to the spring member of Comparative Example 2, the load relative to the spring height (load per contact portion ( N)) is large. This has shown that the spring member 2 concerning an Example has a small plastic strain compared with the spring member of the comparative example 2. FIG. In other words, it can be said that the spring member 2 according to the example has reduced initial settling compared to the spring member of the comparative example 2 for the same spring height. This is considered to be because the difference in rigidity between the frame portion 20 and the contact portion 21 is reduced by the formation of the through hole 21c. Thus, the spring member 2 according to the embodiment improves the elastic characteristics and the thermal characteristics as compared with the spring member having a thin plate thickness and no through-hole 21c even if the spring constant is the same. be able to.

In addition, regarding the thermal resistance per unit area, the spring member 2 according to the example has an initial settling reduced due to the formation of the through hole 21c. And thermal resistance is small.

Next, an example of a spring member manufacturing method according to the second embodiment will be described with reference to the drawings. FIG. 16 is a diagram illustrating an example of a method for manufacturing a spring member according to the second embodiment. For example, a plurality of slits 301 are formed in a strip-shaped base material 300 made of a Corson copper alloy. The slit 301 forms a hollow space having a substantially M shape in plan view. The slit 301 forms a frame portion 302 and a first tongue piece portion 303 and a second tongue piece portion 304 that extend from the frame portion 302 in a rectangular shape.

After forming the first tongue piece portion 303 and the second tongue piece portion 304, through

holes

303a and 304a having rhombus openings are formed. After forming the through

holes

303a and 304a, with respect to the first tongue piece portion 303 and the second tongue piece portion 304, an end portion on the side connected to the frame portion 302, and an end portion on a different side from the side connected to the frame portion 302 Are curved to have a predetermined radius of curvature, thereby forming the contact portion 21 described above.

Thus, the spring which has the frame part 20 and the contact part 21 mentioned above by forming the slit 301 and curving the 1st tongue piece part 303 and the 2nd tongue piece part 304 which were produced | generated by formation of the slit 301. FIG. The member 2 can be produced.

According to the second embodiment described above, in the projection shape viewed from the direction orthogonal to the main surface of the frame portion 20, the occupation ratio of the frame portion 20 to the spring member 1 is not less than 1/4 and not more than 1/2. Since the through hole 21c penetrating in the plate thickness direction is formed in the two contact portions 21, the difference in rigidity between the frame portion 20 and the contact portion 21 can be suppressed. As a result, when the spring member 2 is formed using a material having a uniform plate thickness, only the rigidity of the frame portion 20 is increased by changing the plate thickness, and the characteristics of the contact portion 21 before the plate thickness is changed are changed. It can be maintained.

Further, according to the above-described second embodiment, the contact portion 21 is a tongue piece extending in a rectangular shape, and is formed using a tongue piece having a through hole having a rhombus-shaped opening. , Heat transfer compared to the case where the contact portion is formed by curving a tongue-shaped portion having a tapered shape, for example, a conical shape, or when a through hole having an opening having another shape such as a circle is formed. High efficiency. In general, when the contact portion is formed by bending the tongue piece, the tongue piece formed into a tapered shape is bent. However, the tongue piece having a rectangular shape as in the second embodiment is used. By forming the contact portion based on the portion, more efficient heat transfer can be performed.

Conventionally used heat transfer spring members include heat transfer grease and heat transfer sheet, but if the thickness of the heat transfer grease or heat transfer sheet is reduced from the viewpoint of the conductor thermal resistance, the followability to vibration is reduced. On the other hand, in heat transfer grease, when the thickness of the spring member is increased from the viewpoint of followability with respect to vibration, it is difficult to control the thermal resistance because it is difficult to adjust the thickness. Further, in the heat transfer sheet, when the thickness of the spring member is increased from the viewpoint of followability with respect to vibration, it is necessary to contain a large amount of high thermal conductive filler in order to reduce the conductor thermal resistance, and it is harder to use the high thermal conductive filler. Therefore, the followability to vibration cannot be improved. On the other hand, the spring member concerning this Embodiment 2 can make high thermal conductivity and high vibration followability compatible by having the structure mentioned above.

In the above-described second embodiment, each contact portion 21 may have the same shape, or may have a different size or curved form. It is preferable to design appropriately depending on how the load is applied. Note that the same shape means the same shape in design and includes manufacturing errors.

Moreover, in Embodiment 2 mentioned above, it demonstrated as what has the some contact part 21, However, A rectangular flat plate shape is comprised, One part extended from a part of opening of a frame part which has a rectangular opening, and a frame part It is good also as a spring member which has a contact part (contact part 21). Also in this case, the size and shape of the through hole are determined according to the rigidity of the frame portion.

(Embodiment 3)
Next, a third embodiment of the present invention will be described. FIG. 17 is a perspective view showing the configuration of the heat transfer spring according to the third embodiment. In the first embodiment described above, the contact portion 11 is described as being formed by bending the flat tongue piece portion. However, like the contact portion 13 of the heat transfer spring 3 according to the third embodiment, the plate thickness A through hole 13a penetrating in the direction may be formed. In other words, the through holes 13a may be formed in the contact portions 11 of the heat transfer spring 1 shown in FIG. By forming the through-hole 13a, the rigidity of the contact portion 13 is reduced, so that the contact surface pressure can be reduced. For example, it is effective when the contact surface pressure is changed without changing the height of the contact portion 11 described above, or when the contact surface pressure of the contact portion 11 is partially changed (the rigidity of some contact portions 11 is changed). It is.

In

Embodiments

2 and 3 described above, the through hole has been described as having a rhombus-shaped opening, but it may be a through-hole having an opening that forms a circle, an ellipse, a triangle, or a polygon more than a pentagon. In addition to the heat transfer described above, the shape of the through hole can be appropriately changed depending on the application, such as a spring member provided between the two members and supporting the two members. In particular, for heat transfer, a through-hole having a diamond-shaped opening is preferable from the viewpoint of thermal characteristics, and considering the elastic characteristics of the contact portion, a through-hole having a circular opening is preferable from the viewpoint of elastic characteristics.

As described above, the heat transfer spring according to the present invention is suitable for obtaining a heat transfer spring having excellent thermal conductivity and vibration followability. The spring member according to the present invention is suitable for obtaining a spring member that suppresses a difference in rigidity between the contact portion and the frame portion.

1, 1a, 3 Heat transfer spring 2

Spring member

10, 20, 202, 302 Frame portion (holding portion)
11, 12, 13, 21

Contact part

11a, 21a

Base end part

11b,

21b Tip part

13a, 21c, 303a, 304a Through

hole

201, 301

Slit

203, 303 First

tongue piece part

204, 304 Second tongue piece part

Claims

A base end portion formed by using a substantially band-shaped member, one end of which is curved with a first radius of curvature, and the other end of which is curved with a reverse curvature with respect to the one end, and with a second radius of curvature. A contact portion that is in contact with a contact object at the base end portion and the tip end portion, respectively,
A plate-like holding part for holding the base end part;
With
The first and second radii of curvature have a value determined according to a contact thermal resistance with respect to each contact object.
The first and second curvature radii are respectively determined according to an extreme value of a curve indicating a relationship between the curvature radius and the contact thermal resistance or a value in a region near the extreme value. Heat transfer spring.
The heat transfer spring according to claim 1 or 2, wherein the contact portion has a rectangular shape when viewed from a direction orthogonal to the main surface of the holding portion.
The heat transfer spring according to any one of claims 1 to 3, wherein the first and second radii of curvature are the same.
A plurality of the contact portions,
The holding part has a plurality of openings provided in a matrix,
The heat transfer spring according to any one of claims 1 to 4, wherein the opening holds a base end portion of the plurality of contact portions.
A spring member connecting two members,
A base end portion formed using a substantially band-shaped member, and having a base end portion curved at one end and a tip end portion curved at an opposite end with respect to the one end, the base end portion and A contact portion that makes contact with the contact object at the tip,
A plate-like holding part for holding the base end part;
With
When viewed from the direction orthogonal to the main surface of the holding portion, the occupation ratio of the holding portion with respect to the entire spring member is ¼ or more and ½ or less,
The contact member is formed with a through-hole penetrating in the thickness direction.
The area ratio S1 / S2 satisfies 1/2 or less, where S1 is an area of the through hole when the contact portion is extended in a flat plate shape, and S2 is an area of the contact portion. 6. The spring member according to 6.
The spring member according to claim 6 or 7, wherein the through hole has a rhombus opening.
The spring member according to any one of claims 6 to 8, wherein the contact portion has a rectangular shape when viewed from a direction orthogonal to the main surface of the holding portion.
A plurality of the contact portions,
The holding part has a plurality of openings provided in a matrix,
The spring member according to any one of claims 6 to 9, wherein the opening holds each base end of one or a plurality of the contact portions.