Housing structure and method for manufacturing same

Abstract

The present invention provides a housing structure that houses a heat-generating component which is capable of effectively dissipating heat generated in the heat-generating component to the outside and can be easily manufactured while achieving weight reduction. The housing structure according to the present invention is characterized by comprising a housing including a heat-dissipating resin and a heat-generating component housed in the housing, and is characterized in that: the housing has, on an inner surface thereof, a partition wall portion integrally formed by resin molding toward the heat-generating component and surrounding the heat-generating component; a portion surrounded by the partition wall portion and the housing is set as a heat-generating component housing portion capable of housing the heat-generating component; and in the heat-generating component housing portion, heat transfer grease is interposed between opposing surfaces of the heat-generating component and the partition wall portion.

Description

Housing structure and manufacturing method thereof

[0001] The present invention relates to a housing structure and a manufacturing method thereof.

[0002] Conventionally, electric vehicles, such as electric vehicles or hybrid vehicles, that use a motor as one of their drive sources, are equipped with power conversion devices. Examples of power conversion devices include a charger that converts a commercial AC power source into DC power to charge a high-voltage battery, a DC / DC converter that converts the DC power of the high-voltage battery into the voltage of a battery for auxiliary equipment, and an inverter that converts DC power from the battery into AC power for the motor.

[0003] Power conversion devices used in electric vehicles use many electronic components, such as semiconductor switching elements, various resistors, aluminum electrolytic capacitors, reactors, and transformers. Many of these electronic components are heat-generating components that generate heat when conducting electricity. The heat generated by these components creates a high-temperature environment inside the power conversion device. Therefore, power conversion devices are required to efficiently dissipate heat from the heat-generating components to the outside from the housing to cool the heat-generating components.

[0004] Patent Document 1 discloses a power conversion device that includes a printed wiring board, an electromagnetic induction device electrically connected to the printed wiring board, a cooling section that is arranged opposite the printed wiring board via the electromagnetic induction device and cools the electromagnetic induction device, and a case that has a U-shaped cross section, is thermally conductive, and electrically insulating, and that houses the electromagnetic induction device.

[0005] JP 2015-89179 A

[0006] In the power converter, the cooling unit and the case, which are thermally conductive and electrically insulating, are formed separately, and grease, which is a heat dissipation material, is interposed between the cooling unit and the case. The cooling unit, the case, and the grease have different expansion coefficients when heated. Therefore, when heat is generated from the heat-generating components of the power converter, the difference in the degree of expansion of the cooling unit, the case, and the grease reduces the adhesion between these components, creating gaps. Furthermore, heat conductivity is reduced at the interfaces between the cooling unit, the case, and the grease, which are adjacent components. This causes a problem in that the heat generated by the heat-generating components cannot be smoothly transferred to the case and dissipated to the outside.

[0007] Since the case is arranged in contact with the printed wiring board via an adhesive, the heat generated by the heat-generating component is transmitted to the printed wiring board via the case, causing the problem that the circuits arranged on the printed wiring board are affected by the heat.

[0008] The above-mentioned power conversion device requires a case to be placed between the opposing surfaces of the cooling unit and the printed wiring board, with the heat-generating components housed in this case and connected to both the cooling unit and the printed wiring board.This requires a complex manufacturing process, which results in low production efficiency.

[0009] Furthermore, in the power conversion device mounted on an electric vehicle, the housing is made of metal with excellent heat conductivity in order to efficiently dissipate heat generated from heat-generating components to the outside.

[0010] If the housing is made of metal, the weight of the power conversion device increases, which causes problems such as poor fuel economy of an electric vehicle equipped with the power conversion device, and therefore there is a demand for lighter power conversion devices.

[0011] The present invention provides a housing structure for accommodating heat-generating components, which can effectively dissipate heat generated by the heat-generating components to the outside and which is lightweight and easy to manufacture.

[0012] The housing structure of the present invention is characterized by having a housing containing a heat-dissipating resin, a heat-generating component housed within the housing, a partition wall portion integrally formed by resin molding on the inner surface of the housing facing the heat-generating component and surrounding the heat-generating component, a heat-generating component storage portion consisting of a portion surrounded by the partition wall portion and the housing and capable of storing the heat-generating component, and heat-conductive grease interposed within the heat-generating component storage portion between the opposing surfaces of the heat-generating component and the partition wall portion.

[0013] The housing structure of the present invention comprises a housing containing a heat-dissipating resin and a heat-generating component housed within the housing, wherein the housing has a partition wall portion on its inner surface that is integrally formed by resin molding toward the heat-generating component and surrounds the heat-generating component, the portion surrounded by the partition wall portion and the housing is a heat-generating component housing portion that can house the heat-generating component, and the heat-conductive grease is interposed between the opposing surfaces of the heat-generating component and the partition wall portion in the heat-generating component housing portion.

[0014] The manufacturing method of the housing structure of the present invention is characterized by comprising: a heat-generating component disposing step of disposing and fixing a heat-generating component in one housing side containing a heat-dissipating resin and having an opening; a grease supplying step of supplying fluid heat-transferring grease into a heat-generating component accommodating section formed by the partition wall section and the other housing part surrounded by the partition wall section in the other housing side which has an opening and has a partition wall section integrally formed by resin molding on its inner bottom surface and which contains heat-dissipating resin; an embedding step of inserting the heat-generating component disposed and fixed in the one housing side into the heat-generating component accommodating section of the other housing side, and embedding at least a portion of the heat-generating component of the one housing side in the heat-transferring grease in the heat-generating component accommodating section of the other housing side; and a heat-transferring grease fixation step of solidifying or hardening the heat-transferring grease.

[0015] The housing structure of the present invention has a partition wall portion that is integrally formed by resin molding on the inner surface of the housing toward the heat-generating component and surrounds the heat-generating component, and the heat generated by the heat-generating component can be effectively dissipated to the outside through the partition wall portion and the housing via the thermally conductive grease.

[0016] The housing structure includes a housing containing a heat dissipating resin, and therefore, unlike a case where a housing made of metal is used, the weight of the housing structure can be reduced.

[0017] The housing and the partition wall are integrally formed with each other through resin molding without any connecting interface, so there is no reduction in heat transfer between the housing and the partition wall, and heat generated by heat-generating components can be transferred from the partition wall to the housing and smoothly dissipated from the housing to the outside.

[0018] Furthermore, since the housing and the partition wall do not have a connection interface at their connection points, the housing and the partition wall will not accidentally separate due to heat generated by the heat-generating components; the housing and the partition wall are always integrated, and the heat generated by the heat-generating components can be smoothly transferred to the housing through the partition wall.

[0019] In the above-mentioned housing structure, heat-conductive grease is interposed between the opposing surfaces of the heat-generating component and the housing facing the heat-generating component in the heat-generating component storage section, so that the heat generated by the heat-generating component can be smoothly transmitted to the partition wall section and the housing via the heat-conductive grease and released to the outside.

[0020] In the above-described housing structure, when heat-generating components are arranged on the printed wiring board, the heat-generating components arranged on the printed wiring board can be arranged and fixed inside the housing, and measures for cooling the heat-generating components can be easily taken.

[0021] In the above-mentioned housing structure, if a gap is formed between the partition wall portion and the printed wiring board facing the partition wall portion, the heat generated from the heat-generating component can be easily dissipated outside the compartment containing the heat-generating component, and the heat-generating component can be cooled smoothly.

[0022] Since a gap is formed between the partition wall and the printed wiring board, the effect of heat transferred from the heat-generating components to the partition wall on the printed wiring board can be reduced, and the printed wiring board can be protected from heat.

[0023] Since a gap is formed between the partition wall portion and the printed wiring board, there is no need to provide a space on the printed wiring board for connecting the partition wall portion, and the printed wiring board can be made smaller, thereby making it possible to make the housing structure smaller.

[0024] In the above-mentioned housing structure, if heat dissipation fins are integrally formed on the inner surface of the heat-generating component accommodating section by resin molding, the heat generated by the heat-generating component can be effectively dissipated to the outside through the housing, thereby improving the cooling effect of the heat-generating component.

[0025] In the above-mentioned housing structure, if heat-conductive grease is arranged between the heat-dissipating fins, the contact area between the heat-dissipating fins and the heat-conductive grease can be increased, and the heat generated from the heat-generating components can be smoothly dissipated to the outside through the housing, thereby smoothly cooling the heat-generating components.

[0026] In the above-mentioned housing structure, the housing includes a first housing and an second housing that are divided into two parts, and is configured by overlapping the opening of the first housing with the opening of the second housing. When the opening end of the first housing and the opening end of the second housing are integrated with an adhesive, the housing structure can be made lighter.

[0027] Since the manufacturing method of the housing structure of the present invention includes the steps described above, it is possible to fill the space between at least a portion of the heat-generating component and the opposing surface of the partition wall with heat-generating grease by a simple process of inserting a heat-generating component arranged and fixed in one housing into the fluid heat-transfer grease in the heat-generating component accommodating portion of the other housing, burying at least a portion of the heat-generating component in the heat-transfer grease, and then solidifying or curing the heat-transfer grease. As a result, heat generated from the heat-generating component can be smoothly released to the outside through the heat-transfer grease, the partition wall, and the housing, providing an excellent cooling effect for the heat-generating component.

[0028] In the manufacturing method of the above-mentioned housing structure, if there is a bonding step in which the opening end of one housing and the opening end of the other housing are bonded together around their entire circumference with an adhesive, the one housing and the other housing can be bonded together with the adhesive, and the resulting housing structure has excellent lightweight properties.

[0029] In the manufacturing method of the above-mentioned housing structure, if a label indicating the required amount of fluid heat-conductive grease is formed on the inner surface of the partition wall of the other housing, an appropriate amount of heat-conductive grease can be supplied into the heat-generating component accommodating section, and the heat-conductive grease can be reliably filled between the opposing surfaces of at least a portion of the heat-generating component and the partition wall opposite it.Therefore, the heat generated from the heat-generating component can be more smoothly released to the outside through the heat-conductive grease, the partition wall and the housing, providing an excellent cooling effect for the heat-generating component.

[0030] FIG. 1 is a cross-sectional view showing a housing structure of the present invention. FIG. 1 is a cross-sectional view showing a part of a manufacturing process of the housing structure of the present invention. FIG. 2 is a perspective view showing an example of the other housing. FIG. 3 is a cross-sectional view showing another example of the housing structure. FIG. 4 is a cross-sectional view showing another example of the housing structure. FIG. 5 is a cross-sectional view showing another example of the housing structure. FIG. 6 is a cross-sectional view showing another example of the housing structure. FIG. 7 is a cross-sectional view showing a housing structure serving as a comparative example.

[0031] An example of a housing structure of the present invention will be described with reference to the drawings. As shown in FIGS. 1 to 3 , housing structure A includes housing 1, which is divided into two parts: one housing 11 and the other housing 12. The one housing 11 and the other housing 12 are manufactured using a general-purpose resin molding method such as injection molding or blow molding. The one housing 11, the partition wall and heat dissipation fins 12h and 12i (described later), and the other housing 12 are made of a heat-dissipating resin, providing excellent heat conductivity for housing 1. The heat-dissipating resin is formed by incorporating a heat-conducting material with higher heat conductivity than the synthetic resin into a synthetic resin. Examples of heat-conducting materials include heat-conducting microparticles such as graphite, carbon black, and metal microparticles, and heat-conducting fibers such as carbon fiber and metal fiber.

[0032] It is preferable that one or both of the first housing 11 and the second housing 12 are manufactured by a single resin molding process in which raw resin is thermoformed into a desired shape. By manufacturing the first housing 11 and / or the second housing 12 by a single resin molding process, the first housing 11 and / or the second housing 12 can be molded products that are entirely free of adhesive or heat-sealed parts, and have excellent heat conductivity.

[0033] The thermal conductivity of the heat-dissipating resin is preferably 2.0 W / m K or more, more preferably 4.0 W / m K or more, and even more preferably 8.0 W / m K or more. The thermal conductivity of the heat-dissipating resin is preferably 50.0 W / m K or less. The thermal conductivity of the heat-dissipating resin is a value measured at 25°C using the laser flash method.

[0034] One side housing 11 has a bottom 11a and a peripheral wall 11b integrally formed around the entire outer periphery of this bottom 11a, and one side housing 11 has a space 11c formed in the area surrounded by bottom 11a and peripheral wall 11b, which has an opening 11d that is open all the way and in which electronic components including heat-generating component B can be placed.

[0035] The other housing 12 has a bottom 12a and a peripheral wall 12b integrally formed around the entire outer periphery of the bottom 12a, and the other housing 12 has a space 12c formed in the area surrounded by the bottom 12a and the peripheral wall 12b, in which electronic components including a heat-generating component B can be arranged and which has an opening 12d that is open all the way.

[0036] Opening 11d of space 11c of one housing 11 and opening 12d of space 12c of the other housing 12 are formed to be identical to each other, and when one housing 11 and the other housing 12 are placed together with openings 11d, 12d of spaces 11c, 12c facing each other, the frame-shaped edges of peripheral wall 11b of one housing 11 and the frame-shaped edges of peripheral wall 12b of the other housing 12 are aligned along the entire periphery, thereby closing spaces 11c, 12c of one housing 11 and the other housing 12, and forming electronic component housing 1a capable of housing electronic components by spaces 11c, 12c of one housing 11 and the other housing 12. The frame-shaped edges of peripheral wall 11b of one housing 11 and the frame-shaped edges of peripheral wall 12b of the other housing 12 are bonded together via adhesive G, resulting in an excellent lightweight housing structure. In addition, a cooling medium flow passage I is formed in one housing 11 and / or the other housing 12, as necessary, to circulate a cooling medium (e.g., water, air, etc.) for cooling one housing 11 and / or the other housing 12.

[0037] Electronic components C including a heat-generating component B are disposed and fixed in the space 11c of the one housing 11. The heat-generating component B is a component that generates heat when used, and examples thereof include a reactor, a transformer, a coil, and a capacitor. The electronic components C may be the heat-generating component B alone, or the heat-generating component B may be disposed and fixed on a printed wiring board D in a state where the heat-generating component B is electrically connected thereto.

[0038] 2 and 3 , one or more partition walls 12f are integrally formed on the inner surface of the bottom 12a of the other-side housing 12, protruding toward the heat-generating component B disposed and fixed in the one-side housing 11 and surrounding the heat-generating component B partially or entirely. The partition walls 12f of the other-side housing 12 are formed integrally with the bottom 12a and protrude from the bottom 12a during resin molding of the other-side housing 12, and no connection interface exists between the partition walls 12f and the bottom 12a. Therefore, when the housing structure is in use, the partition walls 12f and the bottom 12a will not separate from each other due to deformation caused by heat generated by the heat-generating component B, and no reduction in heat transfer due to the connection interface occurs when heat is transferred from the partition walls 12f to the bottom 12a. Therefore, heat generated by the heat-generating component B can be smoothly dissipated from the bottom 12a to the outside via the partition walls 12f. In the present invention, "there is no connection interface between two components" means that when two components are integrated together, there is no adhesive or heat-sealed portion at the boundary between the two components. "There is no connection interface between the partition wall 12f and the bottom 12a" means that there is no adhesive or heat-sealed portion at the boundary between the partition wall 12f and the bottom 12a. It is preferable that the bottom 12a of the other housing 12 and the partition wall 12f integrated with the bottom 12a are simultaneously thermoformed by a resin molding process in which raw resin is thermoformed into a desired shape. For example, when the other-side housing 12 is molded by injection molding, raw resin is supplied into the cavity of a mold for molding the other-side housing 12, and the bottom 12a of the other-side housing 12 and the partition wall portion 12f integrated with the bottom portion 12a are simultaneously thermally formed, thereby making it possible to manufacture the other-side housing 12 without there being a connection interface between the bottom portion 12a and the partition wall portion 12f.

[0039] The inner surface of the partition wall 12f of the other housing 12 and the inner surface of the bottom 12a surrounded by this partition wall 12f form a heat-generating component housing 12g that is fully open at the tip end and can partially or completely house a heat-generating component B. This heat-generating component housing 12g is sized to house a part or all of the heat-generating component B disposed and fixed in the one housing 11. The shape of the partition wall 12f is not particularly limited. The shape of the partition wall 12f is appropriately adjusted to match the shape of the heat-generating component B to be housed, and examples include a cylindrical shape (a rectangular cylindrical shape or a cylindrical shape). Adjacent partition walls 12f may be connected and integrated with each other by sharing a portion of the partition wall.

[0040] The heat-generating component B disposed and fixed in the space 11c of the one-side housing 11 is accommodated in part or in whole in the heat-generating component accommodating section 12g of the other-side housing 12. One heat-generating component accommodating section 12g may accommodate one heat-generating component B (one type), or multiple heat-generating components B (multiple types) may be accommodated in one heat-generating component accommodating section 12g.

[0041] The space formed between the heat-generating component B and the inner surface of the partition wall 12f facing it and the inner surface of the bottom 12a of the other-side housing 12 is filled with thermally conductive grease F in a solidified or hardened state. The thermally conductive grease is composed of a matrix of organopolysiloxane, poly-α-olefin, or the like, which is liquid when uncured, and contains a thermally conductive filler such as metal oxide powder, metal nitride powder, metal carbide powder, or metal hydroxide powder. For applications requiring electrical insulation, metal oxide powder, metal nitride powder, metal carbide powder, or metal hydroxide powder is preferably used as the thermally conductive filler. Examples of metal oxides include aluminum oxide, magnesium oxide, zinc oxide, and silicon oxide. Examples of metal hydroxides include aluminum hydroxide and magnesium hydroxide. Examples of metal nitrides include aluminum nitride, silicon nitride, and boron nitride. Other examples of the thermally conductive filler include metal powders such as aluminum and copper, as well as graphite and carbon fiber. A hardening type heat conductive grease is preferable because it prevents leakage to the surrounding area.

[0042] The thermal conductivity of the thermal conductive grease is preferably 2.0 W / m K or more, more preferably 3.0 W / m K or more, and even more preferably 4.5 W / m K or more. The thermal conductivity of the thermal conductive grease is preferably 40.0 W / m K or less. The thermal conductivity of the thermal conductive grease is a value measured at 25°C using the laser flash method.

[0043] It is not necessary for the entire space formed between the heat-generating component B and the inner surface of the partition wall portion 12f facing the heat-generating component B and the inner surface of the bottom 12a of the other-side housing 12 to be filled with heat-conductive grease F; it is also possible for the heat-conductive grease F to be filled only in a portion of the space. However, since the heat generated in the heat-generating component B can be directly transferred to the bottom 12a of the other-side housing 12 via the heat-conductive grease F and smoothly dissipated to the outside, it is preferable for the entire space formed between the heat-generating component B and the inner surface of the bottom 12a of the other-side housing 12 facing it to be filled with heat-conductive grease F.

[0044] The opening end of the partition wall portion 12f of the other-side housing 12 does not reach the base material to which the heat-generating component B is fixed, i.e., the bottom 11a of the one-side housing 11 or the printed wiring board D, and a gap E is formed between the opening end (tip) of the partition wall portion 12f and the base material (the bottom 11a of the one-side housing 11 or the printed wiring board D) facing this opening end (tip).

[0045] The heat generated by the heat-generating component B housed in one heat-generating component housing portion 12g is dissipated to the outside through the bottom 12a of the other-side housing 12 via the thermally conductive grease F and the partition wall 12f constituting the heat-generating component housing portion 12g, and then flows out of the one partition wall 12f through the gap E formed between the one partition wall 12f and the base material, and is then dissipated to the outside through the bottom 12a of the other-side housing 12 via another partition wall 12f disposed in the electronic component housing portion 1a of the housing 1. Thus, the heat generated by the heat-generating component B can be dissipated to the outside via the multiple partition walls 12f, improving the cooling effect of the heat-generating component B.

[0046] Furthermore, when the heat-generating component B is disposed on the printed wiring board D, an electric circuit is formed on the printed wiring board D. When the tip of the partition wall portion 12f does not reach the printed wiring board D and a gap E is formed, the effect of the heat transmitted to the partition wall portion 12f on the printed wiring board D can be reduced, and the printed wiring board D can be prevented from being damaged by the heat generated by the heat-generating component B.

[0047] Furthermore, since the partition wall portion 12f does not contact the printed wiring board D, there is no need to provide an area for the partition wall portion 12f to abut against the printed wiring board D, and unnecessary parts can be eliminated from the printed wiring board D, thereby making the printed wiring board D smaller, and ultimately making the housing structure A smaller and lighter.

[0048] It is preferable that a plurality of heat dissipation fins 12h are integrally provided on the inner surface of the bottom 12a portion surrounded by the inner surface of the partition wall 12f of the other-side housing 12, protruding toward the heat-generating component accommodating portion 12g. It is not necessary for the heat dissipation fins 12h to be integrally provided on the entire inner surface of the bottom 12a portion surrounded by the inner surface of the partition wall 12f of the other-side housing 12; the heat dissipation fins 12h may be integrally provided on a portion of the inner surface. The heat dissipation fins 12h are provided on the inner surface of the bottom 12a during resin molding of the other-side housing 12, and are integrally formed with the bottom 12a. There is no connection interface between the heat dissipation fins 12h and the bottom 12a. The heat dissipation fins 12h are formed from a heat-dissipating resin. Furthermore, thermally conductive grease F is filled between the opposing surfaces of the plurality of heat dissipation fins 12h. Therefore, when the housing structure A is in use, the heat dissipation fins 12h and the bottom 12a do not separate from each other due to deformation caused by heat generated by the heat-generating component B, and there is no reduction in heat transfer due to the connection interface when heat is transferred from the heat-generating component B to the bottom 12a. Therefore, the heat generated by the heat-generating component B is smoothly dissipated from the bottom 12a to the outside via the heat dissipation fins 12h and the thermally conductive grease F. "No connection interface exists between the heat dissipation fins 12h and the bottom 12a" means that there is no adhesive or heat-sealed portion at the boundary between the heat dissipation fins 12h and the bottom 12a. It is preferable to simultaneously thermoform the bottom 12a of the other housing 12 and the heat dissipation fins 12h integrated with the bottom 12a using a resin molding process in which raw resin is thermoformed into a desired shape. For example, when the other-side housing 12 is molded by injection molding, raw resin is supplied into the cavity of a molding die for molding the other-side housing 12, and the bottom 12a of the other-side housing 12 and the heat dissipation fins 12h integrated with the bottom 12a are thermally formed simultaneously, thereby making it possible to manufacture the other-side housing 12 without there being a connection interface between the bottom 12a and the heat dissipation fins 12h.

[0049] 4, a plurality of heat dissipation fins 12i may be integrally provided on the outer surface of the housing 1 (preferably, on the outer surface of the other housing 12). The heat dissipation fins 12i are provided on the outer surface of the housing 1 (preferably, the bottom 12a of the other housing 12) during resin molding of the housing 1 (preferably, the other housing 12). The heat dissipation fins 12i are integrally formed with the housing 1 (preferably, the bottom 12a of the other housing 12). There is no connection interface between the heat dissipation fins 12i and the housing 1 (preferably, the bottom 12a of the other housing 12). The heat dissipation fins 12i are formed from a heat-dissipating resin. Therefore, when the housing structure A is in use, the heat dissipation fins 12i and the housing 1 will not separate from each other due to deformation caused by heat generated by the heat-generating component B. Furthermore, there is no reduction in heat transfer due to the connection interface when heat is transferred from the heat dissipation fins 12i to the housing 1. Therefore, the heat generated by the heat-generating component B can be more effectively dissipated to the outside from the heat dissipation fins 12i. "No connection interface exists between the heat dissipation fins 12i and the housing 1" means that there is no adhesive or heat-sealed portion at the boundary between the heat dissipation fins 12i and the housing 1. It is preferable to simultaneously thermoform the housing 1 and the heat dissipation fins 12i integrated with the housing 1 through a resin molding process in which raw resin is thermoformed into a desired shape. For example, when molding the housing 1 by injection molding, raw resin is supplied into the cavity of a molding die for molding the housing 1, and the housing 1 and the heat dissipation fins 12i integrated with the housing 1 are thermoformed simultaneously, whereby the housing 1 can be manufactured without any connection interface existing between the housing 1 and the heat dissipation fins 12i.

[0050] It is preferable that some of the heat dissipation fins 12i formed on the outer surface of the housing 1 are formed on the outer surface of the other housing 12 or the outer surface of the bottom 12a, located on the opposite side of the other housing 12 or its bottom 12a from the partition wall 12f. It is preferable that the heat dissipation fins 12i are formed in a portion where the partition wall 12f is projected onto the outer surface of the housing 1 in the direction opposite to the formation direction of the partition wall 12f. Heat generated by the heat-generating component B can be efficiently dissipated to the outside of the housing 1 via the partition wall 12f and the heat dissipation fins 12i.

[0051] Next, a manufacturing method of the housing structure will be described. Electronic components C including heat-generating components B are arranged and fixed in the space 11c of one housing 11 in a general manner (heat-generating component arrangement step).

[0052] On the other hand, as shown in Figure 2, the other-side housing 12 is placed on any mounting surface H with the heat-generating component housing 12g, formed by being surrounded by the partition wall 12f, open upward. Fluid thermally conductive grease F is supplied into the heat-generating component housing 12g of the other-side housing 12. If the heat-generating grease F is normally solid, it must be heated to make it fluid. A label such as a scale or step to indicate the required amount of heat-generating grease F is preferably formed on the inner surface of the partition wall 12f of the other-side housing 12, and the fluid thermally conductive grease F is supplied into the heat-generating component housing 12g up to the required amount indicated on the label (grease supplying process).

[0053] 2, the one-side housing 11 is turned upside down so that the opening 11d of the space 11c of the one-side housing 11 faces the opening 12d of the space 12c of the other-side housing 12. Then, the heat-generating components B of the one-side housing 11 are positioned above the heat-generating component housings 12g of the other-side housing 12, and are embedded in the thermally conductive grease F inside the heat-generating component housings 12g.

[0054] Thereafter, the one-side housing 11 is displaced in a direction (downward) approaching the other-side housing 12, so that the frame-shaped edges of the peripheral wall portion 11b of the one-side housing 11 and the frame-shaped edges of the peripheral wall portion 12b of the other-side housing 12 are aligned around the entire circumference, and part or all of each heat-generating component B fixed to the one-side housing 11 is embedded in the heat-conductive grease F in each heat-generating component accommodating portion 12g of the other-side housing 12 (embedding process). The heat-generating component B is inserted from above into the heat-conductive grease F stored in each heat-generating component storage section 12g of the other-side housing 12 and is thereby buried, which can be done in a simple manner. Furthermore, the heat-conductive grease F can be filled without any gaps into the space formed between at least the tip of the heat-generating component B and the opposing partition wall section 12f and bottom section 12a, so that the heat generated in the heat-generating component B can be efficiently guided through the heat-conductive grease F to the partition wall section 12f and bottom section 12a and dissipated to the outside.

[0055] An adhesive G is applied over the entire area between the opposing surfaces of the frame-shaped edge of the peripheral wall portion 11b of the one housing 11 and the frame-shaped edge of the peripheral wall portion 12b of the other housing 12, and the one housing 11 and the other housing 12 are integrated together by the adhesive G. In this state, the spaces 11c, 12c of the one housing 11 and the other housing 12 form an electronic component accommodating portion 1a, and electronic components C, including heat-generating components B, are accommodated in this electronic component accommodating portion 1a.

[0056] On the other hand, the heat-conductive grease F in each heat-generating component accommodating section 12g of the other housing 12 is cooled, solidified, or hardened to lose its fluidity and become solid (heat-conductive grease fixation process), and the heat-generating component B is fixed in a state where it is partially or entirely buried in the heat-conductive grease F, thereby manufacturing the housing structure A.

[0057] As described above, the housing structure A can be easily manufactured by simply supplying fluid heat-conductive grease F into each heat-generating component accommodating section 12g of the other-side housing 12, and then burying part or all of the heat-generating components B arranged and fixed to the one-side housing 11 in this heat-conductive grease from above.

[0058] When the housing structure A is used, heat is generated in the heat-generating component B housed in the electronic component housing portion 1a. This heat is smoothly dissipated to the outside through the partition wall portion 12f (and further the heat dissipation fins 12i, 12h) made of heat-conductive grease F and / or heat-dissipating resin, and through the bottom portion 12a of the other housing 12 made of heat-dissipating resin, thereby efficiently cooling the electronic component C.

[0059] As described above, the housing structure A can smoothly dissipate heat generated by the heat-generating component B to the outside of the housing 1, protecting the electronic component C disposed within the housing 1 from heat and enabling stable operation of the electronic component C. Furthermore, since the housing structure A is lightweight, it can be used by accommodating a power conversion device or the like and mounting it on an electric vehicle or the like.

[0060] The present invention will be described in more detail below using examples, but the present invention is not limited thereto. Specific numerical values ​​of the blending ratios (content ratios), physical property values, parameters, etc. used in the following description can be replaced with the upper limit values ​​(numeric values ​​defined as "equal to or less than") or lower limit values ​​(numeric values ​​defined as "equal to or more than" or "exceeding") of the corresponding blending ratios (content ratios), physical property values, parameters, etc. described in the "Description of Embodiments."

[0061] 5, a housing 11 was prepared, which had a bottom 11a and a peripheral wall 11b integrally formed around the entire periphery of the bottom 11a. The housing 11 had a space 11c in the area surrounded by the bottom 11a and the peripheral wall 11b, in which electronic components including a heat-generating component B could be placed, and which had an opening 11d that was completely open. One housing 11 was made of a heat-dissipating resin (thermal conductivity: 12.3 W / m K) containing 100 parts by mass of polypropylene (manufactured by Japan Polypropylene Corporation, product name "BC10HRF"), 100 parts by mass of expanded graphite (manufactured by Fuji Graphite Industries Co., Ltd., product name "EXP-80S220", expansion ratio: 200 mL / g, volume average particle size: 180 μm), and 100 parts by mass of flake graphite (manufactured by Chuetsu Graphite Industries Co., Ltd., product name "CPB-100", volume average particle size: 100 μm).

[0062] An other-side housing 12 was prepared, which had a bottom 12a and a peripheral wall 12b integrally formed around the entire outer periphery of the bottom 12a. The other-side housing 12 had a space 12c formed in the area surrounded by the bottom 12a and the peripheral wall 12b, which had an opening 12d that was fully open and capable of accommodating electronic components including a heat-generating component B. The other-side housing 12 was made of the same heat-dissipating resin as the one-side housing 11.

[0063] When the one-side housing 11 and the other-side housing 12 were placed one on top of the other with the openings 11d, 12d of the spaces 11c, 12c facing each other, the spaces 11c, 12c of the one-side housing 11 and the other-side housing 12 were closed, and the spaces 11c, 12c of the one-side housing 11 and the other-side housing 12 formed an electronic component housing section 1a capable of housing electronic components. The frame-shaped edge of the peripheral wall section 11b of the one-side housing 11 and the frame-shaped edge of the peripheral wall section 12b of the other-side housing 12 were bonded together with adhesive G. The one-side housing 11 and the other-side housing 12 constituted the housing 1.

[0064] A heat-generating component B was disposed and fixed in the space 11c of the one-side housing 11. The heat-generating component B was fixed on a printed wiring board D. A single cylindrical partition wall 12f was integrally formed on the inner surface of the bottom 12a of the other-side housing 12, protruding in the direction of the heat-generating component B disposed and fixed to the one-side housing 11 and partially surrounding the heat-generating component B. The partition wall 12f of the other-side housing 12 was formed integrally with the bottom 12a and protruded from the bottom 12a during resin molding of the other-side housing 12, with no connection interface existing between the partition wall 12f and the bottom 12a. The partition wall 12f was made of the same heat-dissipating resin as the one-side housing 11.

[0065] The inner surface of partition wall 12f of the other-side housing 12 and the inner surface of bottom 12a surrounded by partition wall 12f formed heat-generating component accommodating section 12g, which was fully open at the tip and capable of partially or completely accommodating heat-generating component B. Heat-generating component accommodating section 12g of the other-side housing 12 accommodated part or all of heat-generating component B, which was disposed and fixed in space 11c of one-side housing 11.

[0066] A plurality of heat dissipation fins 12h were integrally provided on the inner surface of the bottom 12a portion surrounded by the inner surface of the partition wall 12f of the other-side housing 12, protruding toward the heat-generating component accommodating portion 12g. The heat dissipation fins 12h were made of the same heat dissipation resin as the one-side housing 11. There was no connection interface between the heat dissipation fins 12h and the bottom 12a. The heat dissipation fins 12h were made of the same heat dissipation resin as the other-side housing 12.

[0067] Furthermore, multiple heat dissipation fins 12i were integrally provided on the outer surface of the other-side housing 12. The heat dissipation fins 12i were provided on the outer surface of the bottom 12a during resin molding of the other-side housing 12 and were integrally formed with the bottom 12a, with no connection interface between the heat dissipation fins 12i and the bottom 12a. The heat dissipation fins 12i were made of the same heat dissipation resin as the other-side housing 12. Some of the heat dissipation fins 12i were formed on the outer surface of the bottom 12a of the other-side housing 12, on the opposite side of the partition wall 12f across the bottom 12a of the other-side housing 12. Specifically, some of the heat dissipation fins 12i were formed on the portion of the partition wall 12f projected onto the outer surface of the housing 1 in the opposite direction from its formation direction (upward in FIG. 5).

[0068] The space formed between the heat-generating component B and the inner surface of the partition wall 12f facing it and the inner surface of the bottom 12a of the other-side housing 12 was filled with thermally conductive grease F (thermal conductivity: 6 W / m·K) in a solid state. The open end of the partition wall 12f of the other-side housing 12 did not reach the printed wiring board D to which the heat-generating component B was fixed.

[0069] The heat-generating component B in the housing structure A (FIG. 5) configured as described above was driven. The temperature T of the surface of the heat-generating component B was measured 10 minutes after the heat-generating component B was driven. The temperature T is shown in Table 1.

[0070] Example 2 A housing structure A (FIG. 6) was prepared, which had the same structure as the housing structure of Example 1, except that the heat dissipation fins 12h were not formed on the inner surface of the bottom 12a of the other housing 12 and the inner surface of the bottom 12a was formed as a smooth surface. Heat-generating component B in housing structure A was driven. The temperature T of the surface of heat-generating component B was measured 10 minutes after driving heat-generating component B. The temperature T is shown in Table 1.

[0071] Example 3 A housing structure A (FIG. 7) was prepared, which had the same structure as the housing structure of Example 1, except that the heat dissipation fins 12i were not formed on the outer surface of the bottom 12a of the other housing 12 and the outer surface of the bottom 12a was formed as a flat surface. Heat-generating component B in housing structure A was driven. The temperature T of the surface of heat-generating component B was measured 10 minutes after driving heat-generating component B. The temperature T is shown in Table 1.

[0072] Example 4 A housing structure A (FIG. 8) was prepared, which had the same structure as the housing structure of Example 1, except that the heat dissipation fins 12h, 12i were not formed on the inner and outer surfaces of the bottom 12a of the other housing 12 and the inner and outer surfaces of the bottom 12a were formed flat. Heat-generating component B in housing structure A was driven. The temperature T of the surface of heat-generating component B was measured 10 minutes after driving heat-generating component B. The temperature T is shown in Table 1.

[0073] (Comparative Example 1) A housing structure A (Fig. 9) was prepared, which had the same structure as the housing structure of Example 4, except that no partition wall was formed on the inner surface of the bottom 12a of the other housing 12, and no thermally conductive grease was used. An air layer was formed in the space formed between the inner surface of housing 1 and heat-generating component B, and housing 1 and heat-generating component B were not in contact. Heat-generating component B in housing structure A was driven. The temperature T of the surface of heat-generating component B was measured 10 minutes after driving heat-generating component B. The temperature T is shown in Table 1.

[0074]

[0075] (Cross-reference to related applications) This application claims priority based on Japanese Patent Application No. 2023-104542, filed on June 26, 2023, the disclosure of which is incorporated herein by reference in its entirety.

[0076] According to the housing structure of the present invention, heat generated by heat-generating components can be effectively dissipated to the outside through the partition wall and the housing via the thermally conductive grease, and the housing is lightweight, making it suitable for use in power conversion devices used in electric vehicles, etc.

[0077] REFERENCE SIGNS LIST 1 casing 1a electronic component storage section 11 one-side casing 11a bottom 11b peripheral wall 11c space 11d opening 12 other-side casing 12a bottom 12b peripheral wall 12c space 12d opening 12f partition wall 12g heat-generating component storage section 12h heat dissipation fin A casing structure B heat-generating component C electronic component D printed wiring board E gap F thermally conductive grease G adhesive

Claims

1. A housing structure comprising: a housing containing a heat dissipating resin; a heat-generating component housed within the housing; a partition wall portion integrally formed by resin molding on an inner surface of the housing facing the heat-generating component and surrounding the heat-generating component; a heat-generating component storage portion composed of an area surrounded by the partition wall portion and the housing and capable of storing the heat-generating component; and heat-conductive grease disposed between opposing surfaces of the heat-generating component and the partition wall portion within the heat-generating component storage portion.

2. The case structure according to claim 1, wherein in said heat generating component storage section, heat conductive grease is interposed between the heat generating component and the opposing surface of said case facing said heat generating component.

3. A housing structure according to claim 1 or 2, characterized in that the heat generating member is disposed on a printed wiring board.

4. The housing structure according to claim 3, wherein a gap is formed between the partition wall and the printed wiring board facing the partition wall.

5. A housing structure according to claim 1 or 2, characterized in that the inner surface of the heat generating component housing section has heat dissipation fins formed integrally with the heat generating component housing section by resin molding.

6. The housing structure according to claim 5, further comprising thermally conductive grease disposed between said heat dissipation fins.

7. The housing structure according to claim 1, characterized in that the housing includes one housing and the other housing that are divided into two parts, the opening of the one housing and the opening of the other housing are butted together and integrated, and the open end of the one housing and the open end of the other housing are integrated with an adhesive.

8. The housing structure according to claim 1 or 2, characterized in that the heat-generating component is at least one heat-generating component selected from the group consisting of a reactor, a transformer, a coil and a capacitor.

9. A housing structure according to claim 1 or 2, characterized in that a heat dissipating fin is formed on the outer surface of the housing projected on the opposite side to the formation direction of the partition wall.

10. A method for manufacturing a housing structure comprising the steps of: a heat-generating component disposing step of disposing and fixing a heat-generating component in one housing containing heat-dissipating resin and having an opening; a grease supplying step of supplying flowable heat-conductive grease into a heat-generating component accommodating section formed by the partition wall and the other housing part surrounded by the partition wall in the other housing having an opening, a partition wall integrally formed on the inner bottom surface by resin molding and containing heat-dissipating resin; an embedding step of inserting the heat-generating component disposed and fixed in the one housing into the heat-generating component accommodating section of the other housing and embedding at least a portion of the heat-generating component of the one housing in the heat-conductive grease in the heat-generating component accommodating section of the other housing; and a heat-conductive grease fixation step of solidifying or hardening the heat-conductive grease.

11. The method for manufacturing a housing structure according to claim 10, characterized in that the inner surface of the heat generating component housing portion has heat dissipation fins formed integrally with the inner surface by resin molding.

12. A method for manufacturing a housing structure as described in claim 10 or 11, characterized in that the embedding step includes the steps of: placing the other-side housing on a mounting surface with an opening of its heat-generating component accommodating portion open upward; arranging the heat-generating component arranged in the one-side housing above the other-side housing so that it faces the opening of the heat-generating component accommodating portion of the other-side housing; and bringing the one-side housing and the other-side housing close to each other, inserting the heat-generating component arranged and fixed in the one-side housing into the heat-generating component accommodating portion of the other-side housing, and embedding at least a portion of the heat-generating component in the one-side housing in the thermally conductive grease in the heat-generating component accommodating portion of the other-side housing.

13. A method of manufacturing a housing structure as set forth in claim 10 or 11, further comprising a bonding step of bonding the open end of said one housing and the open end of said other housing together over their entire periphery with an adhesive.

14. A method for manufacturing a housing structure as described in claim 10 or 11, characterized in that a label is formed on the inner surface of the partition wall of the other housing to indicate the amount of fluid heat conductive grease that needs to be supplied.

15. The manufacturing method of the housing structure according to claim 14, wherein the label is a scale or step provided on the inner surface of the partition wall.

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