JP7223639B2 - electronic controller - Google Patents

Description

The present invention relates to electronic control units.

2. Description of the Related Art Electronic control devices used in electronic control devices for vehicles, etc., have been designed to be smaller and have higher performance.
For example, the electronic device disclosed in Patent Document 1 has a structure that ensures cooling performance. 1 of Patent Document 1, a thermal bonding material 22 is provided between a heat dissipation member 16 having fins and a heat transfer plate 20 having an inclined surface. A structure is known in which an electronic component 26 is inserted into a case 24 provided between the substrate 14 and the electronic component 26 to press the heat transfer plate 20 toward the heat radiating member 16 via an inclined surface. In this structure, since the heat transfer plate 20 contacts the electronic component 26 while being pressed, the contact thermal resistance between the heat transfer plate 20 and the electronic component 26 can be suppressed, and the heat of the electronic component 26 can be It is described that the heat can be efficiently transmitted to the heat radiating member 16 via the heat transfer plate 20 and the thermal bonding material 22 . In this structure, the area of the surface of the heat transfer plate 20 that contacts the electronic component 26 is formed smaller than the area of the electronic component 26 (see, for example, Patent Document 1).

JP 2018-195633 A

In the heat dissipation structure described in Patent Document 1, the area of the surface of the heat transfer plate 20 that contacts the electronic component 26 is smaller than the area of the electronic component 26 . In other words, the electronic component 26 has a region that does not contact the heat transfer plate 20 . For this reason, the heat dissipation from the area of the electronic component 26 not in contact with the heat transfer plate 20 is low, and the heat dissipation of the electronic control device as a whole is low.

According to the first aspect of the present invention, an electronic control device comprises: a heat radiating section; a substrate arranged on one surface side of the heat radiating section; a first heat transfer portion provided between the electronic component and the heat dissipation portion and thermally coupled to the electronic component; and a first heat transfer portion of the electronic component thermally coupled to the electronic component. a second heat transfer section thermally coupled to the electronic component and the first heat transfer section, having an interposed section provided between the non-removed region and the first heat transfer section .

According to the present invention, it is possible to improve the heat dissipation of the region of the electronic component that is not thermally coupled to the first heat transfer section, thereby improving the heat dissipation of the entire electronic component.

1 is an external perspective view of a first embodiment of an electronic control device of the present invention; FIG. FIG. 2 is a cross-sectional view taken along the line II-II of the electronic control device illustrated in FIG. 1; FIG. 3 is an enlarged cross-sectional view of region III of the electronic control unit illustrated in FIG. 2; FIG. 2 is a plan view of an assembly state of an electronic component and a heat transfer member according to the present invention, as viewed from above; 1 is an external perspective view showing Example 1 of an electronic control device based on a first embodiment of the present invention; FIG. FIG. 3 is an enlarged cross-sectional view showing a second embodiment of an electronic control device of the present invention and corresponding to FIG. 3 of the first embodiment; The figure which shows the modification 1 of the assembly|attachment state of the electronic component of this invention, and a heat-transfer member, and corresponds to FIG. 4 of 1st Embodiment. The figure which shows the modification 2 of the assembly|attachment state of the electronic component of this invention, and a heat-transfer member, and corresponds to FIG. 4 of 1st Embodiment. The figure which shows the modification 3 of the assembly|attachment state of the electronic component of this invention, and a heat-transfer member, and corresponds to FIG. 4 of 1st Embodiment. FIG. 4 is a diagram showing heat dissipation effects of Examples 1 and 2 of the present invention and a comparative example; FIG. 3 is a cross-sectional view of an assembled state of an electronic component and a heat transfer member in a comparative example, and corresponds to FIG. 3 of the first embodiment;

Embodiments of the present invention will be described below with reference to the drawings. The following description and drawings are examples for explaining the present invention, and are appropriately omitted and simplified for clarity of explanation. The present invention can also be implemented in various other forms. Unless otherwise specified, each component may be singular or plural.
The position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc., in order to facilitate understanding of the invention. As such, the present invention is not necessarily limited to the locations, sizes, shapes, extents, etc., disclosed in the drawings.

- 1st embodiment -
A first embodiment of the present invention will be described below with reference to FIGS. 1 to 4. FIG.
FIG. 1 is an external perspective view of an electronic control device of the present invention, and FIG. 2 is a cross-sectional view of the electronic control device shown in FIG. 1 taken along the line II-II.
The electronic control unit 100 has a housing composed of an upper housing 1 and a lower housing 2 . The upper housing 1 and the lower housing 2 are fixed by fastening members such as screws (not shown). One or a plurality of connectors 8 and a plurality of Ethernet (registered trademark) terminals 9 are arranged on the front of the housing. Inside the housing, there are a circuit board (substrate) 3, an electronic component 4 including a semiconductor element such as a microcomputer, a heat transfer material (first heat transfer part) 5 and a heat transfer member (second heat transfer part ) 7 and .

The upper housing 1 is made of a metal material with excellent thermal conductivity, such as aluminum (for example, ADC 12). The upper housing 1 can be made of sheet metal such as iron, or non-metallic materials such as resin material and CFRP, to reduce cost and weight. As shown in FIG. 2, the upper housing 1 is formed in a box-like shape having side walls on the periphery and an open bottom side (circuit board 3 side). The upper housing 1 is formed with a protrusion 12 that protrudes inward. Boss portions 10 protruding toward the circuit board 3 are provided at four corner portions or a central portion within the upper housing 1 . The circuit board 3 is fixed to the end surface of the boss portion 10 with screws 11 . A plurality of plate-like radiating fins 6 are provided on the upper surface of the upper housing 1 so as to protrude upward.

As shown in FIG. 1, the front side of the upper surface of the upper housing 1 is a flat portion, and each radiation fin 6 is flat as a whole in order to realize a low-profile structure of the electronic control device 100. It is formed at the same height as the part. The heat radiation fins 6, the boss portion 10 and the protruding portion 12 are formed integrally with the upper housing 1 by casting such as die casting. However, the radiation fins 6, the boss portion 10 and the protruding portion 12 may be manufactured as separate members from the upper housing 1 and attached to the upper housing.

A hole or notch (not shown) for inserting the connector 8 and the Ethernet terminal 9 is formed in the side wall on the front side of the upper housing 1, and the connector 8 and the Ethernet terminal 9 pass through the hole or notch. are connected to a wiring pattern (not shown) formed on the circuit board 3 . Power and control signals are transmitted and received between the outside and the electronic control unit 100 via the connector 8 and the Ethernet terminal 9 .

An electronic component 4 and a heat transfer member 7 are mounted on the circuit board 3 , and a protruding portion 12 protruding toward the circuit board 3 is formed on the upper inner surface of the upper housing 1 . The protruding portion 12 has a substantially trapezoidal cross-sectional shape with a wider skirt portion on the radiation fin 6 side than on the circuit board 3 side, and is formed to be thicker than its surroundings. A heat transfer material 5 is interposed between the protrusion 12 of the upper housing 1 and the electronic component 4 and between the protrusion 12 of the upper housing 1 and the heat transfer member 7 . The structures of the heat transfer material 5 and the heat transfer member 7 will be described later.

Similar to the upper housing 1, the lower housing 2 is made of a metal material such as aluminum having excellent thermal conductivity. Similarly to the upper housing 1, the lower housing 2 can be made of sheet metal such as iron or a non-metallic material such as a resin material to reduce cost and weight. A hole or notch for inserting the connector 8 or the Ethernet terminal 9 may be formed in the lower housing 2 . Alternatively, each of the upper housing 1 and the lower housing 2 may be formed with a notch that becomes one hole when both members are assembled.

FIG. 3 is an enlarged view of area III of the electronic control device illustrated in FIG. 2, showing details of the heat dissipation structure of the present embodiment.
The upper housing 1 made of a metal material with excellent thermal conductivity and having a plurality of heat radiating fins 6 constitutes a heat radiating section. As described above, the heat transfer material 5 is interposed between the protrusion 12 of the upper housing 1 and the electronic component 4 . The projecting portion 12 of the upper housing 1 has a rectangular shape with an area larger than that of the electronic component 4 in a plan view, and the electronic component 4 as a whole is arranged inside the outer periphery of the projecting portion 12 of the upper housing 1. It is The heat transfer material 5 is provided over substantially the entire surface of the projecting portion 12 of the upper housing 1 . Therefore, the entire electronic component 4 is arranged inside the outer periphery of the heat transfer material 5 .

The heat transfer material 5 is thermally coupled, ie thermally coupled, to the projecting portion 12 of the upper housing 1 . Also, the heat transfer material 5 is thermally coupled to the upper surface 4 a 1 of the upper portion 4 a of the electronic component 4 . That is, the heat transfer material 5 thermally couples the entire upper surface 4 a 1 of the upper portion 4 a of the electronic component 4 to the projecting portion 12 of the upper housing 1 .

Various kinds of materials such as grease-like, gel-like, and sheet-like materials are used for the heat transfer material 5 . Grease-like heat transfer materials are generally used, and include adhesive thermosetting resins and semi-hardening resins with low elasticity. The heat transfer material 5 contains a filler having good thermal conductivity made of metal, carbon, ceramic, or the like. The heat transfer material 5 is flexible at room temperature, and enters fine recesses such as the surface of the protrusion 12 of the upper housing 1 and the surface of the electronic component 4 to increase the bonding area. Therefore, the heat transfer material 5 improves the thermal conductivity between the electronic component 4 and the projecting portion 12 of the upper housing 1, thereby increasing the heat radiation effect. In addition, the heat transfer material 5 reduces the load acting on the electronic component 4 due to thermal deformation and vibration of the circuit board 3 . Furthermore, the heat transfer material 5 absorbs variations in the gap between the projecting portion 12 of the upper housing 1 and the upper surface 4a1 of the upper portion 4a of the electronic component 4 at the time of manufacture, so that the tolerance of the gap can be increased. The material of the heat transfer material 5 is preferably, for example, a semi-cured resin using a silicone-based resin containing a ceramic filler, but is not limited to this.

One or a plurality of electronic components 4 are mounted on the circuit board 3 as described above. Although not shown, passive elements such as capacitors are also mounted on the circuit board 3, and wiring patterns connecting these electronic parts with the connector 8 and the Ethernet terminal 9 are also formed. The circuit board 3 is made of, for example, an organic material such as an epoxy resin or a metal material, preferably an FR4 material. The circuit board 3 can be a single layer wiring board or a multilayer wiring board. In this embodiment, although not shown, a structure using a multilayer wiring board having a ground pattern formed as an inner layer is exemplified. By forming the ground pattern as an inner layer, the density of the wiring patterns provided on the front and back surfaces of the circuit board 3 can be increased.

Since the heat transfer material 5 is provided between the electronic component 4 and the projecting portion 12 of the upper housing 1 , a high frequency current flows to the upper housing 1 through the heat transfer material 5 , and the high frequency generated from the electronic component 4 The noise may radiate to the outside of the electronic control unit 100 and cause harm to peripheral electronic devices. Therefore, in this embodiment, a plurality of through holes 15 connected to a ground pattern formed as an inner layer are formed in the circuit board 3 , and the heat transfer member 7 is joined to each through hole 15 with a joining material 14 . The through hole 15 is also called a thermal via, and the inner diameter of the through hole of the substrate is plated with Cu or the like. Therefore, the high-frequency current flows through the ground pattern via the heat transfer member 7 and the through holes 15, so that radiation to the outside of the electronic control unit 100 can be suppressed. Through hole 15 is preferably formed around electronic component 4 .

The electronic component 4 has a stepped rectangular parallelepiped shape having an upper portion 4a and a lower portion 4b having a larger area than the upper portion 4a. In other words, the electronic component 4 has a structure in which the rectangular parallelepiped upper portion 4a is provided in the central portion of the rectangular parallelepiped low-back portion 4b. There is a step between the upper surface 4a1 of the upper portion 4a and the upper surface 4b1 of the lower portion 4b, which is the low-back portion, and the upper surface 4b1 of the lower portion 4b is positioned lower than the upper surface 4a1 of the upper portion 4a. The electronic component 4 includes a semiconductor element (not shown) that generates heat, such as a power semiconductor element. The electronic component 4 is preferably a semiconductor device in which a semiconductor element is packaged in a FCBGA (Flip Chip Ball Grid Array) type package, for example. In the FCBGA type semiconductor device, a semiconductor element (not shown) is flip-chip mounted on an interposer substrate (not shown) using a bonding material such as solder, and sealed together with the interposer substrate by resin. The electronic component 4 is joined to the circuit board 3 with a plurality of solder balls 13. As shown in FIG.
Note that the electronic component 4 is not limited to having a rectangular shape in plan view, and may have a polygonal shape in plan view.

The heat transfer member 7 has an interposed portion 7a, a mounting portion 7b, and an intermediate portion 7c. The interposed portion 7 a is arranged between the lower portion 4 b of the electronic component 4 and the heat transfer material 5 . The interposed portion 7a is coupled to the heat transfer material 5 so as to be heat conductive, that is, thermally coupled. Further, the interposed portion 7a is thermally coupled to the upper surface 4b1 of the lower portion 4b of the electronic component 4. As shown in FIG. That is, the interposed portion 7a of the heat transfer member 7 contacts the upper surface 4b1 of the lower portion 4b of the electronic component 4, which cannot be contacted by the heat transfer member 5, thereby causing the lower portion 4b of the electronic component 4 and the upper housing 1 to protrude. The part 12 is thermally coupled. Therefore, the upper surface 4 a 1 of the upper portion 4 a and the upper surface 4 b 1 of the lower portion 4 b , which are the entire surface of the electronic component 4 facing the projecting portion 12 of the upper housing 1 , are heated by the heat transfer member 5 and the heat transfer member 7 . is thermally coupled to the projection 12 of the . Therefore, according to the present embodiment, heat dissipation can be improved compared to a structure in which only the upper portion 4a of the electronic component 4 is thermally coupled to the projecting portion 12 of the upper housing 1. FIG.

As described above, the mounting portion 7b is joined to the circuit board 3 by the joining material 14 having thermal conductivity such as solder. The mounting portion 7 b is arranged at a position corresponding to each through hole 15 and electrically connected to the corresponding through hole 15 via the bonding material 14 . Therefore, the heat transfer member 7 has the same potential as the ground pattern of the circuit board 3 .

Although the mounting portion 7b is illustrated as being provided directly above the through hole 15, it may be arranged at a position shifted from the through hole 15. FIG. Although the bonding material 14 is shown as being divided directly under the mounting portion 7b, the bonding material 14 may be arranged over the entire surface directly under the mounting portion 7b. The point is that the mounting portion 7b and the bonding material 14 are electrically connected to the through holes 15 either directly or via a wiring pattern (not shown).
The intermediate portion 7c is a portion that connects the interposing portion 7a and the mounting portion 7b, and is formed so as to extend in a direction substantially orthogonal to each of the interposing portion 7a and the mounting portion 7b.

Since the mounting portion 7 b is bonded to the circuit board 3 via the bonding material 14 having thermal conductivity, the heat generated from the lower portion 4 b of the electronic component 4 is transferred to the circuit board 3 . That is, the heat generated from the electronic component 4 is transferred to the upper housing 1 via the interposed portion 7a of the heat transfer member 7 and the heat transfer material 5, and is transferred to the circuit through the mounting portion 7b of the heat transfer member 7. Heat is radiated to the substrate 3 . Therefore, according to this embodiment, the heat dissipation performance can be improved as compared with the structure in which the heat generated from the electronic component 4 is transferred only to the upper housing.

When solder is used as the bonding material 14 for bonding the mounting portion 7 b of the heat transfer member 7 to the circuit board 3 , the process of bonding the electronic component 4 to the circuit board 3 with the solder balls 13 can be performed at the same time. That is, a solder paste is applied on the connection pads for joining the mounting portions 7b of the electronic component 4 and the heat transfer member 7 of the circuit board 3, and the electronic component 4 and the heat transfer member 7 are respectively placed on the solder paste. and put it in the reflow oven. As a result, the solder paste melts, and the electronic component 4 and the heat transfer member 7 are respectively joined to the connection pads of the circuit board 3 . By using such a joining method, the efficiency of the joining process can be improved.

It is also possible to adopt a structure in which the upper surface of the interposed portion 7a of the heat transfer member 7 is directly thermally coupled to the projecting portion 12 of the upper housing 1 without the heat transfer material 5 interposed therebetween. However, if this is done, the effect of the heat transfer material 5 interposed between the thermally coupled members described above is lost, and heat conduction between the interposed portion 7a of the heat transfer member 7 and the protruding portion 12 of the upper housing 1 is reduced. In addition, the effect of reducing the load acting on the electronic component 4 due to thermal deformation and vibration of the circuit board 3 is lost.

FIG. 4 is a top plan view of an assembled electronic component and a heat transfer member according to the present invention.
The heat transfer member 7 includes a plurality of (four in this embodiment) split heat transfer members 71 arranged around the upper portion 4 a of the electronic component 4 . Each split heat transfer member 71 is provided to cover the corner portion of the electronic component 4 and its periphery. Each split heat transfer member 71 is spaced apart from the adjacent split heat transfer member 71 so that a gap 72 is formed. A gap 73 is formed between the inner end 7a1 of the interposed portion 7a of each split heat transfer member 71 and the side surface 4a2 of the upper portion 4a of the electronic component 4 .

The divided heat transfer member 71 of the embodiment is formed of a thin metal plate or the like having conductivity and flexibility. As the metal, for example, a Cu material having a high thermal conductivity and being plated with Ni is suitable, but the material is not limited to this. The divided heat transfer member 71 has flexibility, and the intermediate portion 7c and the interposed portion 7a are elastically deformed with respect to the mounting portion 7b. The interposed portion 7 a of each split heat transfer member 71 contacts the heat transfer material 5 and the upper surface 4 b 1 of the lower portion 4 b of the electronic component 4 . By imparting flexibility to the split heat transfer members 71 , when the mounting portions 7 b of the split heat transfer members 71 are mounted on the circuit board 3 , the interposed portions 7 a of the split heat transfer members 71 are placed on the electronic component 4 . It becomes unnecessary to contact the upper surface 4b1 of the lower portion 4b of the . The reason for this is that when the upper housing 1 and the lower housing 2 are assembled, the interposed portion 7a of each divided heat transfer member 71 is pressed by the projecting portion 12 of the upper housing 1 through the heat transfer material 5 and deformed. This is because the interposed portion 7a contacts the upper surface 4b1 of the lower portion 4b of the electronic component 4. As shown in FIG. Therefore, by imparting flexibility to the divided heat transfer member 71, the reliability of the electrical connection is improved, the assembly is facilitated, and the efficiency of the assembly is improved.

In the above-described embodiment, the upper surface 4b1 of the entire peripheral portion of the lower portion 4b is lower than the upper surface 4a1 of the upper portion 4a, so that the electronic component 4 has a structure in which the heat transfer material 5 cannot be directly contacted. However, the present invention can also be applied to an electronic component having a structure in which a part of the periphery of the lower portion 4b of the electronic component 4, for example, the upper surface 4b1 of one to three side edges is lower than the upper surface 4a1 of the upper portion 4a. can be done. Moreover, it can also be applied to an electronic component 4 in which the upper surface 4a1 of the electronic component 4 is locally recessed.

In the above-described embodiment, the heat transfer member 7 is illustrated as having a structure including the interposed portion 7a, the mounting portion 7b, and the intermediate portion 7c. The interposed portion 7a of the heat transfer member 7 is in contact with the upper surface 4b1 of the lower portion 4b of the electronic component 4 with which the heat transfer member 5 cannot contact, and the lower portion 4b of the electronic component 4 and the protruding portion 12 of the upper housing 1 are separated from each other. thermally couple with. Moreover, the mounting portion 7 b transfers heat generated from the lower portion 4 b of the electronic component 4 to the circuit board 3 . However, even if the heat transfer member 7 does not have the mounting portion 7b and has only the interposed portion 7a, the lower portion 4b of the electronic component 4, which the heat transfer material 5 cannot contact, is placed in the upper housing. It is thermally coupled to the projection 12 of the body 1 . Therefore, the heat transfer member 7 may have only the interposed portion 7a.

According to the said 1st Embodiment, there exist the following effects.
(1) The electronic control device 100 is provided between the electronic component 4 and the upper housing 1 (heat radiation portion), and includes a heat transfer material (first heat transfer portion) 5 thermally coupled to the electronic component 4, and an electronic The electronic component 4 has an interposing portion 7a provided between a region of the component 4 not thermally coupled to the heat transfer material 5 (an upper surface 4b1 of the lower portion 4b of the electronic component 4) and the heat transfer material 5. A heat transfer member (second heat transfer portion) 7 thermally coupled to the heat transfer material 5 is provided. Therefore, even from the area of the electronic component 4 that is not in contact with the heat transfer material 5 (the upper surface 4b1 of the lower portion 4b of the electronic component 4), the heat transfer member 7 and the heat transfer material 5 are interposed in the upper housing 1 (heat dissipation portion). The heat can be radiated to the outside, and the cooling performance of the electronic component 4 can be improved.

(2) The heat transfer member 7 has a mounting portion 7b that is formed integrally with the interposed portion 7a and that is mounted on the circuit board 3 . By assembling the upper housing 1 and the lower housing 2 with the heat transfer member 7 mounted on the circuit board 3 , the heat transfer member 7 can be connected to the heat transfer material 5 and the lower portion 4 b of the electronic component 4 . It becomes possible to intervene between them. In a structure in which the heat transfer member 7 does not have the mounting portion 7b, the interposed portion 7a cannot be fixed onto the lower portion 4b of the electronic component 4, and the interposed portion 7a of the heat transfer member 7 is not attached to the electronic component 4. It becomes difficult to accurately position and interpose between the lower part 4b of the heat transfer material 5 and the heat transfer material 5. That is, by providing the heat transfer member 7 with the mounting portion 7b integrally formed with the interposed portion 7a, the interposed portion 7a of the heat transfer member 7 is positioned between the lower portion 4b of the electronic component 4 and the heat transfer material 5. It is possible to improve the efficiency of the work provided in

(3) The heat transfer member 7 has flexibility. Therefore, when the heat transfer member 7 is mounted on the circuit board 3, even if the interposed portion 7a of the heat transfer member 7 is not in contact with the upper surface 4b1 of the lower portion 4b of the electronic component 4, the upper housing 1 and the lower housing are separated from each other. By assembling the body 2 , the interposed portion 7 a of the heat transfer member 7 contacts the upper surface 4 b 1 of the lower portion 4 b of the electronic component 4 . Therefore, the reliability of electrical connection is improved, the assembly is facilitated, and the efficiency of assembly is improved.

(4) The mounting portion 7b of the heat transfer member 7 is mounted on the circuit board 3 with the bonding material 14 having thermal conductivity. Thereby, the heat generated from the lower portion 4 b of the electronic component 4 is transferred to the circuit board 3 via the heat transfer member 7 . That is, the heat generated from the electronic component 4 is transferred to the upper housing 1 through the heat transfer material 5 and radiated to the circuit board 3 by the heat transfer member 7 . Therefore, according to this embodiment, the heat dissipation performance can be improved as compared with the structure in which the heat generated from the electronic component 4 is transferred only to the upper housing 1 .

(5) The circuit board (substrate) 3 is a multilayer wiring board having a ground pattern in its inner layer, and the heat transfer member 7 is provided in the circuit board 3 and electrically connected to the through holes 15 connected to the ground pattern. It is Therefore, the high-frequency current flows through the heat transfer member 7 and the through holes 15 to the ground pattern. can suppress radiation to Since the ground pattern is formed in the inner layer of the multilayer wiring board, the density of the wiring patterns provided on the front and back surfaces of the circuit board 3 can be increased.

(6) The heat transfer material 5 is a layer containing a resin that is flexible at room temperature, and enters fine recesses such as the surface of the protrusion 12 of the upper housing 1 and the surface of the electronic component 4 to increase the bonding area. do. Therefore, the heat transfer material 5 improves the thermal conductivity between the electronic component 4 and the projecting portion 12 of the upper housing 1, thereby increasing the heat radiation effect. In addition, the heat transfer material 5 reduces the load acting on the electronic component 4 due to thermal deformation and vibration of the circuit board 3 . Furthermore, the heat transfer material 5 absorbs variations in the gap between the projecting portion 12 of the upper housing 1 and the upper surface 4a1 of the upper portion 4a of the electronic component 4 at the time of manufacture, so that the tolerance of the gap can be increased.

[Example 1]
FIG. 5 is an external perspective view showing Example 1 of the electronic control device based on the first embodiment of the present invention.
As Example 1, an electronic control device 101 having the appearance shown in FIG. 5 was produced. The upper housing 1A of the electronic control device 101 is different from the upper housing 1 shown in FIG. 1, but is formed within the upper housing 1A and the lower housing 2 (not shown in FIG. 5). The cross-sectional structure is the same as in FIG. Also, the assembly structure of the electronic component 4 and the heat transfer member 7 of the electronic control unit 101 is the same as that shown in FIG.

An electronic control unit 101 was produced using the following members.
The outer shape of the housing formed by assembling the upper housing 1A and the lower housing was 110 mm×110 mm×30 mm (thickness). The circuit board 3 was fixed by screws 11 to bosses 10 provided at four corners of the upper housing 1A.
The electronic component 4 is an FCBGA (Flip Chip) of 31 mm x 31 mm x 3.2 mm (thickness).
It was formed as a ball grid array type semiconductor device and mounted in the center of the circuit board 3 by soldering.
The circuit board 3 was made of FR4 material with dimensions of 50 mm×50 mm×1.6 mm (thickness). The circuit board 3 is assumed to be an eight-layer laminated wiring board, and the equivalent thermal conductivity is 69.4 W/mK in the in-plane direction and 0.45 W/mK in the vertical direction.

The radiation fins 6 are formed integrally with the upper housing 1A with a thickness of 2 mm, a height of 13 mm, and a gap of 5 mm. The projecting portion 12 had a thickness of 2.9 mm and had the same planar shape as the heat transfer material 5 described below and was formed integrally with the upper housing 1A. The upper housing 1A, the lower housing 2, the heat radiation fins 6, and the projecting portion 12 are formed using an ADC 12 having a thermal conductivity of 96.3 W/mK and an emissivity of 0.5.

The heat transfer material 5 was formed using a low-elasticity heat transfer material having a thermal conductivity of 2 W/mK and containing a thermally conductive filler in silicon-based resin. The heat transfer material 5 was provided on the upper portion 4 a of the electronic component 4 and the upper portion of the interposed portion 7 a of the heat transfer member 7 . The outer shape of the heat transfer material 5 was 38 mm×38 mm×1.9 mm (thickness). The outer circumference of the heat transfer material 5 is outside the region where the lower portion 4 b of the electronic component 4 is projected onto the projecting portion 12 . In other words, a region obtained by projecting the lower portion 4b of the electronic component 4 onto the projecting portion 12 is arranged inside the outer periphery of the heat transfer material 5 .

As shown in FIG. 4, the heat transfer member 7 is configured by providing four split heat transfer members 71 at each corner portion and its periphery, spaced apart from the adjacent split heat transfer members 71. there is The thermal conductivity of each split heat transfer member 71 is 100 W/mK.

The through hole 15 has an outer diameter of 0.45 mm, an inner diameter of 0.4 mm, and a height of 1.6 mm, and the inner surface thereof is plated with Cu. A through-hole forming area of 6 mm x 6 mm is provided at the corner of each divided heat transfer member 71 corresponding to the four corners of the electronic component 4, and the through-holes 15 are arranged at a pitch of 0.85 mm in each through-hole forming area. arranged with The equivalent thermal conductivity in each through-hole forming region is 81.4 W/mK.

- Second Embodiment -
FIG. 6 shows a second embodiment of the electronic control device of the present invention, and is an enlarged sectional view corresponding to FIG. 3 of the first embodiment.
The electronic control unit 102 of the second embodiment differs from the first embodiment in that the lower housing 2A is configured as a heat dissipation member for dissipating heat generated from the electronic components 4. FIG.
As described in the first embodiment, the lower housing 2A is made of a metal material with excellent thermal conductivity, such as aluminum. Similarly to the upper housing 1, the lower housing 2A can be made of sheet metal such as iron, or non-metallic materials such as resin materials to reduce cost and weight. The lower housing 2A has a plurality of (four in the second embodiment) heat transfer parts 21 projecting toward the circuit board 3 .

The lower housing 2A having the heat transfer section 21 can be formed by sheet metal processing. However, the lower housing 2A may be formed by casting. When the heat transfer portion 21 is formed by casting, the heat transfer portion 21 may be formed as a boss portion. Moreover, when the heat transfer portion 21 is formed by casting, the heat transfer portion 21 may be formed as a thick protruding portion rising from the surroundings. moreover,
Radiation fins may be provided on the opposite side of the lower housing 2A to the circuit board 3 side.

The position of each heat transfer portion 21 corresponds to the through hole 15 of the circuit board 3 . In the present embodiment, only one electronic component 4 is illustrated, but in a structure in which a plurality of electronic components 4 and heat transfer members 7 are provided, heat transfer members 7 can be placed at positions corresponding to all the heat transfer members 7 . It is preferable to form the portion 21 . However, the heat transfer portion 21 may not be provided for the heat transfer member 7 that is thermally coupled to the electronic component 4 that generates a small amount of heat.

Each heat transfer portion 21 is joined to the through hole 15 by a heat transfer material 16 . That is, the heat transfer material 16 is thermally coupled, in other words, thermally coupled, to the through holes 15 provided in the circuit board 3 and the heat transfer portion 21 .

As with the heat transfer material 5, the heat transfer material 16 is made of various kinds of materials such as grease, gel, and sheet. The heat transfer material 16 has flexibility at room temperature and improves the thermal conductivity between the through holes 15 provided in the circuit board 3 and the heat transfer portion 21 . In addition, the heat transfer material 16 reduces the load acting on the electronic component 4 due to thermal deformation and vibration of the circuit board 3 . Furthermore, the heat transfer material 16 absorbs variations in the gap between the heat transfer part 21 of the lower housing 2A and the circuit board 3 during manufacturing, and allows the tolerance of the gap to have some margin.
As the material of the heat transfer material 16, for example, a semi-cured resin using a silicon-based resin containing a ceramic filler is preferable, but the material is not limited to this.

The heat transfer material 16 may be filled in the through holes 15 . By filling the heat transfer material 16 in the through hole 15, heat conduction in the through hole 15 is performed by both the metal layer provided on the inner surface of the through hole 15 and the heat transfer material 16. The internal heat conductivity is improved, and the heat dissipation effect of the lower housing 2A can be increased.
If an electronic component that generates a large amount of heat is mounted on the lower surface of the circuit board 3, the heat transfer material 16 may be extended to cover the surface of the electronic component.

In the second embodiment, as described above, the heat transfer material 16 is thermally coupled to the through hole 15 formed in the circuit board 3 and the heat transfer portion 21 of the lower housing 2A. Therefore, the heat generated from the electronic component 4 is conducted to the heat transfer section 21 through the heat transfer material 16 and radiated by the lower housing 2A.

Other structures of the second embodiment are similar to those of the first embodiment. Therefore, also in the second embodiment, the heat generated from the electronic component 4 is radiated by the upper housing 1 via the heat transfer member 5 and the heat transfer member 7 .
Therefore, in the second embodiment as well, the same effects as the effects (1) to (6) of the first embodiment are obtained.

Furthermore, according to the second embodiment, the following effects are obtained.
(7) The circuit board 3 and the heat transfer section 21 of the lower housing 2A are thermally coupled via the heat transfer material 16, and the heat generated from the electronic component 4 is transferred via the heat transfer material 16. The heat is conducted to the heat section 21 and radiated by the lower housing 2A. Since the heat generated from the electronic component 4 is radiated by both members of the upper housing 1 and the lower housing 2A, it is possible to further increase the heat dissipation capability.

(8) The circuit board 3 can be supported by the heat transfer section 21 joined by the heat transfer material 16 . As a result, a force that constrains the circuit board 3 acts in the vicinity of the electronic component 4 . Therefore, the deformation of the circuit board 3 due to heat and vibration and the load acting on the electronic component 4 can be reduced.

[Example 2]
An electronic control unit 102 of Example 2 based on the second embodiment of the present invention was produced.
The electronic control unit 102 of Example 2 has a cross-sectional structure illustrated in FIG.
The electronic control unit 102 of Example 2 has a structure in which the through hole 15 formed in the circuit board 3 and the heat transfer section 21 provided in the lower housing 2A are thermally coupled by the heat transfer material 16. , has a structure similar to that of the first embodiment.
Like the heat transfer member 5, the heat transfer member 16 is formed using a low-elasticity heat transfer material having a thermal conductivity of 2 W/mK and containing a thermally conductive filler in silicon resin. The outer shape of the heat transfer material 16 was set to 6 mm×6 mm×1.9 mm (thickness), and it was arranged at the same position as the forming area of the through hole 15 .

The heat transfer section 21 of the lower housing 2A was formed using an ADC 12 having a thermal conductivity of 96.3 W/mK and an emissivity of 0.5. The heat transfer part 21 has a thickness (plate thickness) of 1.5 mm and is formed integrally with the lower housing 2A with the same external size as the heat transfer material 16 .
The appearance of the electronic control unit 102 of the second embodiment and the internal structure from the circuit board 3 to the upper upper housing 1 are the same as those of the first embodiment.

FIG. 11 is a cross-sectional view of an assembled electronic component and a heat transfer member of a comparative example, and corresponds to FIG. 3 of the first embodiment.
An electronic control unit 100R of a comparative example was produced, and the heat dissipation effect was compared with that of the first and second examples.
The electronic control unit 100R of the comparative example has a structure in which the electronic component 4 and the projecting portion 12 of the upper housing 1 are thermally coupled by a heat transfer material 5A covering the upper surface 4a1 of the upper portion 4a and the upper surface 4b1 of the lower portion 4b of the electronic component 4. have. The electronic control unit 100R does not include the heat transfer member 7. As shown in FIG. Further, in the electronic control unit 100</b>R, the circuit board 3 is not formed with the through holes 15 , and the lower housing 2 is not provided with the heat transfer section 21 for thermally coupling to the circuit board 3 .

The outer size of the projecting portion 12 of the electronic control unit 100</b>R in plan view is the same as the size of the lower portion 4 b of the electronic component 4 projected onto the projecting portion 12 .
The heat transfer material 5A has the same thermal conductivity (2 W/mK) as the heat transfer material 5 of Examples 1 and 2, and has an external size of 26 mm×26 mm×1.9 mm (thickness). be.

FIG. 10 is a diagram showing the heat dissipation effect of Examples 1 and 2 of the present invention and a comparative example.
The heat radiation effect was evaluated by comparing the amount of temperature rise of the electronic component 4 . The amount of temperature rise represents the value obtained by subtracting the environmental temperature of 80° C. from the junction temperature (° C.) of the electronic component 4 . The junction temperature is the surface temperature of a silicon die (not shown) located in the internal JT of the electronic component 4 shown in FIG.
FIG. 10 shows the amount of temperature rise of the electronic component 4 in each of the electronic control devices of Example 1, Example 2, and Comparative Example.

The amount of temperature rise shown in FIG. 10 is the temperature in a windless environment and an environmental temperature of 80° C. when the heat generation amount of the electronic component 4 is 10 W. As shown in FIG. 10, the temperature rise amount of the electronic component 4 of Example 1 was able to be reduced more than the temperature rise amount of the electronic component 4 of the comparative example. Furthermore, the amount of temperature rise of the electronic component 4 of Example 2 could be reduced compared to the amount of temperature rise of the electronic component 4 of Example 1. FIG.

The electronic control device 101 of the first embodiment additionally includes a heat conducting path for conducting heat generated from the electronic component 4 to the circuit board 3, unlike the electronic control device 100R of the comparative example. From the results shown in FIG. 10, in the electronic control device 101 of Example 1, the heat generated from the electronic component 4 is conducted to the circuit board 3 by the heat transfer member 7, whereby the electronic control device 100R of the comparative example It can be seen that a greater heat dissipation effect can be obtained.

Further, unlike the electronic control device 101 of the first embodiment, the electronic control device 102 of the second embodiment transfers heat generated from the electronic component 4 through the through holes 15 and the heat transfer material 16 provided in the circuit board 3. A heat conduction path is additionally provided to conduct heat to the lower housing 2A. From the results shown in FIG. 10, in the electronic control device 102 of Example 2, the heat generated from the electronic component 4 is transferred to the lower housing 2A through the through holes 15 and the heat transfer material 16 provided in the circuit board 3. It can be seen that a greater heat dissipation effect than that of the electronic control device 101 of the first embodiment can be obtained by the heat conduction.

(Modification 1 of heat transfer member)
FIG. 7 shows Modification 1 of the assembled state of the electronic component and the heat transfer member of the present invention, and is a view corresponding to FIG. 4 of the first embodiment.
In the heat transfer member 7U shown in FIG. 7, adjacent split heat transfer members 71 are coupled by connecting portions 75, and the four split heat transfer members 71 form one member, forming an annular shape surrounding the outer periphery of the upper portion 4a of the electronic component 4. It has a structure integrally formed with the Each split connecting member 71 is similar to the heat transfer member 7 shown in FIG. 4 in that it is provided to cover the four corner portions of the electronic component 4 and their surroundings.
Since the heat transfer member 7U has a structure in which the four divided heat transfer members 71 are integrated as one member, the positioning becomes easy and the efficiency of assembly can be improved.
A heat transfer member 7U can be used instead of the heat transfer member 7 of the first and second embodiments.

(Modification 2 of heat transfer member)
FIG. 8 is a diagram corresponding to FIG. 4 of the first embodiment, showing Modification 2 of the assembled state of the electronic component and the heat transfer member of the present invention.
As with the heat transfer member 7U shown in FIG. 7, the heat transfer member 7V shown in FIG. 8 is a member in which four divided heat transfer members 71 are integrated as one member. A slit 76 is formed in a corner portion of the interposed portion 7a.
The slit 76 is formed by extending from the inner edge of the interposed portion 7a of the split heat transfer member 71 corresponding to the corner portion of the upper portion 4a of the electronic component 4 to the vicinity of the corner portion of the lower portion 4b of the electronic component 4. .
A heat transfer member 7V can be used instead of the heat transfer member 7 or the heat transfer member 7U of the first and second embodiments.

Even if the upper housing 1 is deformed by an external load and a load is applied to each split heat transfer member 71, the interposed portion 7a of the heat transfer member 7V is deformed at the slit 76, and the split heat transfer member 71 is deformed. is interposed between the upper surface 4 b 1 of the lower portion 4 b of the electronic component 4 and the projecting portion 12 of the upper housing 1 . That is, by providing the slit 76 in the interposed portion 7a of the heat transfer member 7V, the interposed portion 7a can flexibly follow the deformation of the upper housing 1 or the like.
A heat transfer member 7V can be used instead of the heat transfer member 7 or the heat transfer member 7U of the first and second embodiments.

(Modification 3 of heat transfer member)
FIG. 9 shows a modified example 3 of the assembled state of the electronic component and the heat transfer member of the present invention, and is a view corresponding to FIG. 4 of the first embodiment.
A heat transfer member 7W shown in FIG. 9 is, like the heat transfer member 7U shown in FIG. The mounting portion 7b has a comb-like shape in which formed portions 77 and non-formed portions 78 are alternately arranged.
Since the heat capacity of the mounting portion 7b is reduced by forming the mounting portion 7b into a comb-teeth shape, the mounting portion 7b can be easily heated when soldered to the circuit board 3, and the heat transfer member 7W and the circuit board 3 can be easily heated. Joining becomes easier.
A heat transfer member 7W can be used instead of the heat transfer member 7 or the heat transfer members 7U and 7V of the first and second embodiments.

In each of the above-described embodiments, the structure in which the upper housing 1 and the lower housing 2 constitute the housing is exemplified. However, an intermediate case may be interposed between the upper housing 1 and the lower housing 2 to form a housing with three or more cases.

In each of the above-described embodiments, the electronic component 4 is illustrated as an FCBGA type semiconductor device. However, the electronic component 4 may be of the BGA type other than the FCBGA type. Also, the electronic component 4 may be an electronic component other than the BGA type.

In each of the above-described embodiments, the heat transfer member 5 thermally couples the upper surface 4a1 of the upper portion 4a of the electronic component 4 and the protruding portion 12 of the upper housing 1, and the interposed portion 7a and the mounting portion 7b of the heat transfer member 7 , a structure in which a region of the electronic component 4 not thermally coupled to the heat transfer material 5 is thermally coupled to the heat transfer material 5 and the circuit board 3 . However, the heat transfer member 7 may have a structure in which the interposed portion 7a is not provided and only the mounting portion 7b is provided. In this structure, the upper surface 4 a 1 of the upper portion 4 a of the electronic component 4 and the upper housing 1 are thermally coupled by the heat transfer material 5 , and the area of the electronic component 4 not thermally coupled to the heat transfer material 5 is the heat transfer member 7 . It is thermally coupled to the circuit board 3 by the mounting portion 7b.

Although various embodiments and modifications have been described above, the present invention is not limited to these contents. Other aspects conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention.

1, 1A Upper housing (heat dissipation part)
2, 2A lower housing 3 circuit board (substrate)
4 Electronic component 4a Upper part 4a1 Upper surface 4b Lower part 4b1 Upper surface 6 Radiation fin 5 Heat transfer material (first heat transfer part)
7, 7U, 7V, 7W heat transfer member (second heat transfer section)
7a Interposed portion 7b Mounting portion 12 Protruding portion 14 Joining material 15 Through hole 16 Heat transfer member 21 Heat transfer portion 71 Divided heat transfer member 75 Connecting portions 100, 101, 102 Electronic control device

Claims (11)

a heat sink;
a substrate arranged on one surface side of the heat radiating part;
an electronic component mounted on a side of the substrate facing the one side of the heat radiating section;
a first heat transfer section provided between the electronic component and the heat dissipation section and thermally coupled to the electronic component;
an interposing portion provided between a region of the electronic component that is not thermally coupled to the first heat transfer portion and the first heat transfer portion, the electronic component and the first heat transfer portion; and a second heat transfer section thermally coupled to the section. In the electronic control device according to claim 1,
The electronic control device, wherein the second heat transfer section has a mounting section formed integrally with the interposing section and mounted on the substrate. In the electronic control device according to claim 2,
The second heat transfer section is a flexible electronic control device. In the electronic control device according to claim 2,
The electronic control device, wherein the mounting portion of the second heat transfer portion is mounted on the substrate with a bonding material having thermal conductivity. In the electronic control device according to claim 1,
The substrate is a multilayer wiring substrate having a ground pattern on an inner layer,
A through hole connected to the ground pattern is formed in the substrate,
The electronic control device, wherein the second heat transfer section is electrically connected to the through hole. In the electronic control device according to claim 1,
The substrate has a through hole penetrating from the front surface to the back surface of the substrate,
The electronic control device, wherein the through-hole is thermally coupled to a heat transfer portion disposed on the opposite side of the substrate from the heat dissipation portion. In the electronic control device according to claim 1,
the electronic component has an upper portion and a lower portion having a surface at a position lower than the upper surface of the upper portion;
The electronic control device, wherein the interposed portion of the second heat transfer portion is provided between the surface of the lower portion and the first heat transfer portion. In the electronic control device according to claim 7,
The electronic control unit, wherein the second heat transfer section includes a plurality of split heat transfer sections. In the electronic control device according to claim 8,
The electronic control unit, wherein the second heat transfer section has a connection section that connects and integrates the plurality of divided heat transfer sections. In the electronic control device according to claim 1,
The electronic control device, wherein the first heat transfer section is a layer containing a resin having flexibility at room temperature. In the electronic control device according to any one of claims 1 to 10,
The electronic control unit, wherein the heat dissipation section has a protrusion thermally coupled to the first heat transfer section, and a heat dissipation case having heat dissipation fins provided on a side opposite to the first heat transfer section.

Images