Electronic control unit

Abstract

To provide an electronic control apparatus configured to suppress contact between a chip component and a main circuit board.SOLUTION: An electronic control apparatus 101 includes an MCM 10 equipped with an MCM substrate 11 having one surface S1 and an opposite surface S2, a heat generating component 12 mounted on the one surface, and a back side chip 13 mounted on the opposite surface. The electronic control apparatus includes a mother board 20 mounted so as to face the opposite surface, and an enclosure 30 for housing the MCM and the mother board. The electronic control apparatus includes: a flexible heat dissipation gel 40 in contact with the heat generating component and the enclosure; and an operation member 50 disposed between the opposite surface and the mother board and repulsively acting against stress applied to the MCM due to thermal expansion of the heat dissipation gel.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to an electronic control device.

Background Art

[0002] Patent Document 1 discloses an example of an electronic control device. In the electronic control device, a heat conductive material having flexibility is disposed between an electronic component and a housing. The electronic control device dissipates heat generated in the electronic component through the heat conductive material.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, an electronic control device may be configured to include a circuit board having a heat generating component mounted on one surface and a chip component mounted on the opposite surface, a main circuit board on which the circuit board is mounted, and a housing that houses the main circuit board on which the circuit board is mounted. When the heat conductive material described in Patent Document 1 is applied to this electronic control device, a configuration in which the heat conductive material is disposed between the heat generating component and the housing can be considered. In this case, the circuit board will be mounted on the main circuit board with the chip component and the main circuit board facing each other.

[0005] The heat conductive material thermally expands due to the heat generated from the heat generating component. Therefore, in the electronic control device, the circuit board may be pressed and distorted due to the thermal expansion of the heat conductive material. When the circuit board is distorted in the electronic control device, there is a risk that the chip component contacts the main circuit board.

[0006] One object of the disclosure is to provide an electronic control device in which contact between a chip component and a main circuit board is suppressed.

Means for Solving the Problems

[0007] The electronic control device disclosed herein is A wiring board (11) having one side (S1) and the opposite side (S2), a circuit board (10) comprising at least one heat-generating component (12) mounted on one side and at least one chip component (13) mounted on the opposite side, The main circuit board (20) is mounted facing the opposite side, with the circuit board electrically connected, A housing (30) that houses the circuit board and the main circuit board, A heat-generating component and a flexible thermal conductive material (40) that is in contact with the opposing part of the housing that faces the heat-generating component, It is characterized by having an acting member (50) provided between the opposite surface and the main circuit board, which repels the stress applied to the circuit board due to the thermal expansion of the thermal conductive material.

[0008] Thus, the electronic control unit has an action member provided between the opposite side and the main circuit board. The action member is a component that repels the stress applied to the wiring board due to the thermal expansion of the thermal conductive material. Therefore, the action member can suppress the distortion of the wiring board through the stress caused by the repulsion. As a result, the electronic control unit can suppress contact between chip components and the main circuit board by having the action member suppress the distortion of the wiring board.

[0009] The various embodiments disclosed in this specification employ different technical means to achieve their respective objectives. The claims and the reference numerals in parentheses in this section are illustrative in their correspondence with the embodiments described later and are not intended to limit the technical scope. The objectives, features, and effects disclosed in this specification will become clearer by referring to the subsequent detailed description and the accompanying drawings. [Brief explanation of the drawing]

[0010] [Figure 1] This is a plan view showing the schematic configuration of the electronic control device in the first embodiment. [Figure 2]This is a cross-sectional view along the line II-II in Figure 1. [Figure 3] This is a cross-sectional view showing the schematic configuration of the electronic control device in the comparative example. [Figure 4] This is a plan view showing the schematic configuration of the electronic control device in the second embodiment. [Figure 5] This is a cross-sectional view along the line V-V in Figure 4. [Figure 6] This is a plan view showing the schematic configuration of the electronic control device in the third embodiment. [Figure 7] This is a cross-sectional view along the line VII-VII in Figure 6. [Figure 8] This is a plan view showing the schematic configuration of the electronic control device in the fourth embodiment. [Figure 9] This is a cross-sectional view along the IX-IX line in Figure 8. [Modes for carrying out the invention]

[0011] In the following, several embodiments for implementing this disclosure will be described with reference to the drawings. In each embodiment, parts corresponding to matters described in a previous embodiment may be denoted by the same reference numerals, and redundant explanations may be omitted. In each embodiment, if only a part of the configuration is described, the other parts of the configuration can be referred to and applied to other embodiments described in advance. In the following, the three mutually orthogonal directions will be referred to as the X direction, Y direction, and Z direction.

[0012] (First Embodiment) The electronic control unit 101 of this embodiment will be described with reference to Figures 1, 2, and 3. The electronic control unit 101 is configured to be mounted on a vehicle, for example. The electronic control unit 101 includes an MCM 10, a motherboard 20, a housing 30, a heat dissipation gel 40, and working members 50. These components will be described below. MCM is an abbreviation for multi-chip module.

[0013] <mcm> As shown in FIGS. 1 and 2, the MCM 10 includes an MCM substrate 11, a heat-generating component 12, a back surface chip 13, a front surface chip 14, an MCM terminal 15, etc. In FIG. 1, the front surface chip 14 is omitted for simplicity of the drawing. The MCM 10 corresponds to a circuit board. The MCM substrate 11 corresponds to a wiring board. The back surface chip 13 corresponds to a chip component. The MCM terminal 15 corresponds to a connection terminal.

[0014] The MCM substrate 11 has a conductive wiring pattern formed on an electrically insulating base material. The MCM substrate 11 has, for example, a rectangular shape in the XY plane. The MCM substrate 11 has one surface S1 and the opposite surface S2 of the one surface S1. The wiring pattern includes a surface layer wiring provided on the surface of the base material and an inner layer wiring provided inside the base material. A part of the surface layer wiring constitutes a land on which circuit components to be described later are mounted.

[0015] A plurality of circuit components are mounted on the MCM substrate 11. The circuit components are mounted on the MCM substrate 11 via a conductive connection member such as solder. That is, the circuit components are electrically connected to the lands of the MCM substrate 11 via the connection member. The circuit components are, for example, the heat-generating component 12 mounted on the one surface S1, the front surface chip 14, and the back surface chip 13 mounted on the opposite surface S2. Each circuit component is connected via the wiring pattern.

[0016] The heat-generating component 12 is a circuit component that generates heat when operating. Also, it can be said that the heat-generating component 12 is a circuit component in which the heat generated by the operation is more prominent than that of the front surface chip 14 and the back surface chip 13. Furthermore, it can be said that the heat-generating component 12 is a circuit component that generates heat to such an extent that cooling (heat dissipation) is required. The heat-generating component 12 is, for example, any one of a system on chip, a memory device, and a power circuit. Note that a system on chip has functions necessary for the operation of the system implemented on one semiconductor chip. The system on chip can adopt, for example, one having a communication function.

[0017] In FIGS. 1 and 2, one heat-generating component 12 is illustrated. However, at least one heat-generating component 12 may be mounted on the MCM substrate 11. Therefore, a plurality of heat-generating components 12 may be mounted on the MCM substrate 11. That is, the MCM substrate 11 may have a plurality of heat-generating components 12 of different types (functions) mounted thereon. For example, the MCM substrate 11 may have all of a system-on-chip, a memory device, and a power circuit mounted thereon as the heat-generating component 12.

[0018] The back chips 13 and the front chips 14 are resistive elements, capacitors, or the like. However, the back chips 13 and the front chips 14 are not limited thereto and may be other elements.

[0019] Also, in the present embodiment, as an example, an example in which a plurality of back chips 13 and a plurality of front chips 14 are mounted on the MCM substrate 11 is adopted. However, the present disclosure is not limited thereto. The MCM substrate 11 only needs to have at least one back chip 13 mounted on the opposite surface S2. Also, the MCM substrate 11 may not have a front chip 14 mounted on one surface S1, or may have one front chip 14 mounted on one surface S1.

[0020] As shown in FIGS. 1 and 2, at least some of the back chips 13 are arranged in the facing region of the heat-generating component 12. The facing region here is the facing region of the heat-generating component 12 in the Z direction. Therefore, at least some of the back chips 13 are arranged to face the heat-generating component 12 in the Z direction.

[0021] As shown in FIG. 2, the MCM terminals 15 are provided on the opposite surface S2. The MCM terminals 15 are electrically connected to the lands of the MCM substrate 11. The MCM terminals 15 are conductive connection members such as solder balls. The MCM terminals 15 are terminals for electrically connecting the MCM 10 and the mother board 20.

[0022] The MCM10 is mounted on the motherboard 20 via the MCM terminals 15. Furthermore, the MCM10 is stacked on the motherboard 20 in the Z direction. The MCM terminals 15 are electrically connected to the lands on the motherboard 20. The MCM10 is mounted on the motherboard 20 via the MCM terminals 15 by methods such as reflow soldering. This electrically connects the MCM10 to the motherboard 20. Note that the opposite side S2 of the MCM10 faces the mounting surface S3 of the motherboard 20, which will be explained later.

[0023] Furthermore, the MCM10 is mounted on the motherboard 20 such that the back chip 13 does not come into contact with the motherboard 20. In other words, the MCM10 is mounted such that, in a state where the working member 50 (explained later) is not present and the heat dissipation gel 40 is not affected by thermal expansion, a gap is formed between the back chip 13 and the motherboard 20 in the Z direction. This gap can also be called the initial gap.

[0024] <Motherboard> The motherboard 20 is a printed circuit board in which multiple wirings, mainly composed of conductive materials, are provided on an electrically insulating substrate such as resin or ceramics. The motherboard 20 has a mounting surface S3 on which the MCM 10 is mounted. Some of the wiring is exposed on the mounting surface S3 and forms lands.

[0025] Figures 1 and 2 illustrate a motherboard 20 on which one MCM10 is mounted. However, the motherboard 20 may have multiple MCM10s mounted on it. Furthermore, the motherboard 20 may have circuit components other than the MCM10 mounted on it. In addition, the motherboard 20 may have circuit components mounted on the opposite side (back side) of the mounting surface S3. The motherboard 20 corresponds to the main circuit board.

[0026] <Enclosure> As shown in Figure 2, the enclosure 30 houses the MCM 10 and the motherboard 20. The enclosure 30 is mainly composed of metal such as aluminum. The enclosure 30 can be, for example, one that comprises two components: a base and a cover. In this case, the enclosure 30 can form the housing space for the MCM 10 and the motherboard 20 by assembling the base and the cover. However, the enclosure 30 is not limited to this.

[0027] The housing 30 is provided with a protruding portion 31 as a facing portion that faces the heat-generating component 12. The protruding portion 31 is a part that protrudes more than the surrounding area. Furthermore, the protruding portion 31 protrudes in the Z direction from a part of the housing 30 that faces one surface S1.

[0028] The protruding portion 31 is provided so as not to come into contact with the heat-generating component 12 when the MCM 10 and the motherboard 20 are housed in the casing 30. This is so that the heat-dissipating gel 40, which will be explained later, can be placed between the heat-generating component 12 and the protruding portion 31.

[0029] The protruding portion 31 has a facing surface that faces the heat-generating component 12. The facing surface is a surface that aligns with the XY plane. The area of ​​the facing surface can be, for example, about the same as the area of ​​the heat-generating component 12. This makes it easier for the housing 30 to dissipate heat from the heat-generating component 12 to the housing 30 via the heat-dissipating gel 40. It can also be said that the electronic control unit 101 can efficiently dissipate the heat emitted from the heat-generating component 12 to the housing 30. The area of ​​the heat-generating component 12 is the area of ​​the upper surface of the heat-generating component 12, that is, the surface that aligns with the XY plane and faces the protruding portion 31.

[0030] Furthermore, the housing 30 does not necessarily have to have a protruding portion 31. The housing 30 may have a heat dissipation gel 40 placed between the opposing portion facing the heat-generating component 12 and the heat-generating component 12. In addition, the housing 30 may be made mainly of resin material, but may also have heat dissipation paths provided in the opposing portion or elsewhere. In other words, the housing 30 may have heat dissipation paths made of metal in part of the resin material.

[0031] <Heat dissipation gel> As shown in Figure 2, the heat dissipation gel 40 is provided between the heat-generating component 12 and the protrusion 31. The heat dissipation gel 40 is provided in contact with the heat-generating component 12 and the protrusion 31. The heat dissipation gel 40 is provided to dissipate the heat generated from the heat-generating component 12 to the housing 30. The heat dissipation gel 40 is flexible. The heat dissipation gel 40 can be made of a material mainly composed of silicon, etc. The heat dissipation gel 40 is equivalent to a thermal conductive material.

[0032] The heat dissipation gel 40's temperature rises due to the heat generated by the heat-generating component 12. The heat dissipation gel 40 then expands thermally in response to this temperature rise. This thermal expansion applies stress to the heat-generating component 12 and the housing 30, as indicated by the white arrow E1. The heat dissipation gel 40 applies stress to the heat-generating component 12 and the housing 30 in the Z direction. In the following, the stress caused by the thermal expansion of the heat dissipation gel 40 may also be referred to as expansion stress.

[0033] Therefore, the expansion stress of the MCM 10 is also applied to the MCM substrate 11 via the heat-generating component 12. As a result, the MCM substrate 11 is subjected to expansion stress in the direction from the opposite side S2 toward the mounting side S3.

[0034] <Operating member> As shown in Figure 2, the working member 50 is provided between the opposite surface S2 and the motherboard 20. The working member 50 is a member that resists the expansion stress applied to the MCM substrate 11.

[0035] The working member 50 is mainly composed of resin. Like the heat dissipation gel 40, the working member 50 expands with increasing temperature. The working member 50 can be made of a material mainly composed of silicon, for example. Therefore, the working member 50 may be made of the same material as the heat dissipation gel 40. The working member 50 can also be described as an electrically insulating resin member.

[0036] The working member 50 expands thermally together with the heat dissipation gel 40 in response to the temperature rise. As a result, the working member 50 repels the expansion stress, as shown by the white arrow E2. Therefore, the working member 50 applies stress to the MCM 10 and the motherboard 20 in response to thermal expansion. In the following, the stress due to the thermal expansion of the working member 50 may also be referred to as the repulsive stress. However, the working member 50 is not limited to this, and any member that repels the expansion stress is acceptable.

[0037] Furthermore, as shown in Figures 1 and 2, the example adopted is in which the working member 50 is provided over the entire opposing region of the opposite surface S2. In this case, the working member 50 can also be called an underfill. The working member 50 may or may not protrude from the opposing region of the opposite surface S2. Note that the working member 50 can be provided between the opposite surface S2 and the motherboard 20 by pouring it between the opposite surface S2 and the motherboard 20 when the MCM 10 is mounted on the motherboard 20.

[0038] <Effects> Here, the effects of the electronic control device 101 will be explained using the comparative example electronic control device 10x. As shown in Figure 3, the electronic control device 10x uses the same reference numerals for the same components as the electronic control device 101. The electronic control device 10x differs from the electronic control device 101 in that it does not have an operating member 50.

[0039] The electronic control unit 10x is equipped with a heat dissipation gel 40 to dissipate heat from the heat-generating component 12. As a result, expansion stress is applied to the MCM substrate 11, as shown by the white arrow E3. In other words, the MCM substrate 11 is deformed by the expansion stress so that the opposite side S2 moves closer to the motherboard 20. Due to the deformation of the MCM substrate 11, the back surface chip 13 of the MCM 10 moves closer to the motherboard 20. Also, as shown in Figure 3, depending on the magnitude of the expansion stress and the initial spacing, the back surface chip 13 and the motherboard 20 may come into contact. Note that the direction from the opposite side S2 toward the motherboard 20 can also be described as downward.

[0040] Thus, the electronic control unit 10x is at risk of damaging the wiring if the back chip 13 comes into contact with the motherboard 20. Therefore, it is conceivable that the electronic control unit 10x could design the wiring layout so that even if the back chip 13 comes into contact with the motherboard 20, there will be no electrical effect on the motherboard 20, that is, no effect on the circuit operation. However, this would impose constraints on the wiring layout of the electronic control unit 10x.

[0041] In contrast, the electronic control unit 101 has an action member 50 provided between the opposite surface S2 and the motherboard 20. The action member 50 is a member that repels the expansion stress applied to the MCM substrate 11 due to the thermal expansion of the heat dissipation gel 40. Therefore, the action member 50 suppresses the distortion of the MCM substrate 11 by repelling the stress. By suppressing the distortion of the MCM substrate 11, the action member 50 suppresses contact between the back surface chip 13 and the motherboard 20.

[0042] Therefore, even if expansion stress occurs, the electronic control unit 101 can suppress contact between the back chip 13 and the motherboard 20. In other words, the electronic control unit 101 can dissipate heat from the heat-generating component 12 using the heat dissipation gel 40 while suppressing contact between the back chip 13 and the motherboard 20.

[0043] Furthermore, the electronic control unit 101 does not need to design the wiring layout of the motherboard 20 in such a way that the back chip 13 and the motherboard 20 may come into contact. Therefore, the electronic control unit 101 can suppress a decrease in the degree of freedom of the wiring layout on the motherboard 20.

[0044] In this embodiment, as an example, the working member 50 is provided over the entire area of ​​the opposing region on the opposite surface S2. By providing the working member 50 over the entire area of ​​the opposing region on the opposite surface S2, the electronic control unit 101 can suppress distortion throughout the entire MCM substrate 11. Therefore, the electronic control unit 101 can suppress contact between the back surface chip 13 and the motherboard 20 over the entire area of ​​the opposite surface S2.

[0045] Furthermore, the distortion of the MCM substrate 11 is caused by the heat-generating component 12 being pressed downward by expansion stress. In other words, the back chip 13, which is located in the region opposite the heat-generating component 12, is likely to come into contact with the motherboard 20. Therefore, the working member 50 may be provided only in the region opposite the heat-generating component 12. This allows the electronic control unit 101 to place the working member 50 only where necessary, and efficiently suppress contact between the back chip 13 and the motherboard 20. The position of the working member 50 should be such that it can suppress contact between the back chip 13 and the motherboard 20 even if expansion stress occurs.

[0046] Furthermore, the working member 50 may have a coefficient of linear expansion equivalent to that of the heat dissipation gel 40. "Equivalent" includes the fact that both coefficients of linear expansion are the same. Even if the two coefficients of linear expansion are different, they can be considered equivalent as long as they are within the margin of error, within the tolerance, or within a predetermined reference value. This allows the electronic control unit 101 to balance expansion stress and rebound stress. Therefore, the electronic control unit 101 can reliably suppress contact between the back surface chip 13 and the motherboard 20.

[0047] Furthermore, the working member 50 is made of resin. Therefore, even with the configuration in which the working member 50 is provided, the electronic control unit 101 can ensure electrical insulation between the MCM 10 and the motherboard 20. Thus, the electronic control unit 101 does not need to devise the wiring layout of the motherboard 20 in order to ensure electrical insulation. Thus, the electronic control unit 101 can provide the working member 50 without reducing the design flexibility of the motherboard 20.

[0048] Furthermore, the working member 50 can be any member that repels expansion stress. Therefore, the working member 50 can be, for example, a spring member. The working member 50 is mainly composed of resin. Furthermore, it is preferable that the working member 50 can maintain its shape and function even at the reflow soldering temperature of the MCM 10. In this case, the working member 50 can be placed between the opposite surface S2 and the motherboard 20 before reflow soldering of the MCM 10. Therefore, the electronic control unit 101 can easily place the working member 50 between the opposite surface S2 and the motherboard 20. In addition, the electronic control unit 101 can easily position the working member 50 with respect to the opposite surface S2 and the motherboard 20.

[0049] Furthermore, the working member 50 can be made of a material whose shape and function change with reflow temperature, as long as it is placed between the opposite surface S2 and the motherboard 20 after reflow soldering. In addition, the working member 50 may be mainly composed of metal, as long as it can be electrically insulated from the MCM 10 and the motherboard 20.

[0050] Preferred embodiments of the present disclosure have been described above. However, the present disclosure is not limited in any way to the above embodiments, and various modifications are possible without departing from the spirit of the present disclosure. Below, second to fourth embodiments of the present disclosure are described as other forms of the present disclosure. The above embodiments and second to fourth embodiments can be implemented individually, but they can also be implemented in various combinations as appropriate. The present disclosure can be implemented in various combinations, not limited to the combinations shown in the embodiments.

[0051] (Second Embodiment) The electronic control unit 102 of the second embodiment will be described using Figures 4 and 5. Here, we will mainly describe the differences between the electronic control unit 102 and the electronic control unit 101. The electronic control unit 102 differs from the electronic control unit 101 mainly in the position of the working member 50 and the configuration of the MCM terminal 15.

[0052] As shown in Figure 4, the MCM substrate 11 is provided with a first terminal group 15a and a second terminal group 15b as MCM terminals 15. The first terminal group 15a is provided in an annular shape along the outer circumference of the MCM substrate 11. The first terminal group 15a includes multiple MCM terminals 15. The second terminal group 15b is provided in a position surrounded by the first terminal group 15a. The second terminal group 15b includes multiple MCM terminals 15.

[0053] As shown in Figures 4 and 5, the operating member 50 is provided at least at one location between the first terminal group 15a and the second terminal group 15b. In this embodiment, as an example, the operating member 50 is provided in an annular shape surrounding the area facing the heat-generating component 12 and the second terminal group 15b. The operating member 50 may be divided into sections.

[0054] Furthermore, the operating member 50 is provided without contacting the back surface chip 13. The operating member 50 is provided so as not to come into contact with the back surface chip 13 even when expansion stress and rebound stress are generated.

[0055] Therefore, the electronic control unit 102 can prevent repulsive stress from being applied to the back chip 13. Thus, the electronic control unit 102 can suppress the occurrence of cracks or other damage to the back chip 13. Furthermore, the electronic control unit 102 can also suppress the occurrence of cracks or other damage to the connection between the back chip 13 and the MCM substrate 11. In addition, the electronic control unit 102 can have fewer working members 50 than the electronic control unit 101. Moreover, like the electronic control unit 101, the electronic control unit 102 can suppress contact between the back chip 13 and the motherboard 20, and can suppress a decrease in the degree of freedom of wiring layout.

[0056] (Third embodiment) The electronic control unit 103 of the third embodiment will be described with reference to Figures 6 and 7. Here, we will mainly describe the differences between the electronic control unit 103 and the electronic control unit 102. The electronic control unit 103 differs from the electronic control unit 102 mainly in the position of the working member 50 and the configuration of the MCM 10.

[0057] As shown in Figure 6, the MCM10 does not have a back surface chip 13 in the center of the opposite surface S2. In other words, the MCM10 has multiple back surface chips 13 surrounding the center of the opposite surface S2.

[0058] Furthermore, as shown in Figure 6, the heat-generating component 12 is positioned at an off-center location at the corner of the first terminal group 15a. For this reason, the heat-generating component 12 is provided adjacent to the opposing region of the first terminal group 15a. In addition, the two side walls of the heat-generating component 12 are positioned along the opposing region of the first terminal group 15a.

[0059] In other words, the heat-generating component 12 is positioned such that its two side walls align with a virtual ring line that defines the region enclosed by the first terminal group 15a. That is, the heat-generating component 12 is positioned such that its two side walls align with two edges that connect via a corner in the virtual ring line. The virtual ring line can also be described as a virtual line that defines the region enclosed by the opposing regions of the first terminal group 15a. The heat-generating component 12 may be positioned such that its two side walls coincide with two edges in the virtual ring line, and its corner coincides with a corner in the virtual ring line. Furthermore, a portion of the heat-generating component 12 may be positioned on the opposing region of the first terminal group 15a.

[0060] As shown in Figures 6 and 7, the working member 50 is provided in the area facing the heat-generating component 12 and around the area facing the heat-generating component 12. In other words, the working member 50 is provided in the center of the opposite surface S2 without contacting the back surface chip 13. Furthermore, the working member 50 is provided in two locations along the areas facing two side walls different from the two side walls mentioned above on the heat-generating component 12. Note that the working member 50 may be further divided.

[0061] When expansion stress is applied to the MCM substrate 11, the electronic control unit 103 can suppress the distortion of the MCM substrate 11 by using the MCM terminals 15 of the first terminal group 15a in addition to the working members 50. Therefore, the electronic control unit 103 can reduce the number of working members 50 compared to the electronic control unit 102. The electronic control unit 103 can achieve the same effects as 102.

[0062] The third embodiment can also be implemented in combination with the second embodiment. For example, if multiple heat-generating components 12 are provided, the position of the operating member 50 may be varied according to the position of the heat-generating components 12. The configuration combining the electronic control unit 103 and the electronic control unit 102 results in a configuration in which heat-generating components 12 are positioned biased towards the corners of the first terminal group 15a and in the center of the MCM substrate 11. In this configuration, the operating member 50 is positioned as in this embodiment to correspond to the heat-generating component 12 biased towards the corners of the first terminal group 15a. Also, the operating member 50 is positioned as in the second embodiment to correspond to the heat-generating component 12 in the center of the MCM substrate 11. As a result, the electronic control unit 103 can suppress contact between the back chip 13 and the motherboard 20 regardless of the position of the heat-generating components 12.

[0063] (Fourth Embodiment) The electronic control unit 104 of the fourth embodiment will be described using Figures 8 and 9. Here, we will mainly describe the differences between the electronic control unit 104 and the electronic control unit 103. The electronic control unit 104 differs from the electronic control unit 103 mainly in the position of the working member 50 and the configuration of the MCM 10.

[0064] As shown in Figure 8, the MCM10 does not have multiple back surface chips 13 across the entire area of ​​the opposite surface S2. In other words, the MCM10 also has a back surface chip 13 in the center of the opposite surface S2.

[0065] As shown in Figures 8 and 9, the operating member 50 is provided without contacting the back surface chip 13. Furthermore, the operating member 50 is provided along the opposing regions of two side walls that are different from the two side walls of the heat-generating component 12.

[0066] The electronic control unit 104 can achieve the same effects as the electronic control unit 103. Furthermore, the fourth embodiment can be implemented in combination with the second and third embodiments. In other words, the position of the operating member 50 may be varied depending on the configuration of the heat-generating component 12 and the position of the heat-generating component 12 on the MCM substrate 11.

[0067] This disclosure is described in accordance with embodiments, but it is understood that this disclosure is not limited to such embodiments or structures. This disclosure also includes various modifications and variations within the scope of equivalents. In addition, while various combinations and forms are shown in this disclosure, other combinations and forms that include one, more, or fewer of those elements also fall within the scope and idea of ​​this disclosure. [Explanation of symbols]

[0068] 10…MCM, 11…MCM substrate, 12…Heat-generating component, 13…Backside chip, 14…Frontside chip, 15…MCM terminals, 15a…First terminal group, 15b…Second terminal group, S1…One side, S2…Opposite side, 20…Motherboard, S3…Mounting side, 30…Housing, 31…Protruding part, 40…Heat dissipation gel, 50…Working member, 101~104…Electronic control unit< / mcm>

Claims

1. A wiring board (11) having one side (S1) and the opposite side (S2) of the one side, a circuit board (10) comprising at least one heat-generating component (12) mounted on the one side and at least one chip component (13) mounted on the opposite side, A main circuit board (20) mounted facing the opposite side and with the circuit board electrically connected, A housing (30) that houses the circuit board and the main circuit board, A flexible thermal conductive material (40) in contact with the heat-generating component and the opposing portion of the housing that faces the heat-generating component, An electronic control device comprising an acting member (50) provided between the opposite surface and the main circuit board, which resists the stress applied to the circuit board due to the thermal expansion of the heat conductive material.

2. The electronic control device according to claim 1, wherein the housing is provided with a protruding portion (31) that protrudes more than the periphery of the opposing portion.

3. The electronic control device according to claim 2, wherein the operating member is mainly composed of resin.

4. The electronic control device according to claim 3, wherein the working member has a coefficient of linear expansion equivalent to that of the thermal conductive material.

5. The electronic control device according to claim 2, wherein the operating member is a spring member.

6. The circuit board comprises a plurality of the aforementioned chip components, The electronic control device according to claim 2, wherein at least some of the chip components are arranged in the region opposite to the heat-generating component.

7. The electronic control device according to any one of claims 1 to 6, wherein the operating member is provided in the region opposite to the heat-generating component.

8. The electronic control device according to any one of claims 1 to 6, wherein the operating member is provided over the entire area of ​​the opposing region on the opposite side.

9. The electronic control device according to any one of claims 1 to 6, wherein the operating member is provided without contacting the chip component mounted on the opposite side.

10. The circuit board and the main circuit board are provided in the opposing region and are equipped with a plurality of connection terminals (15) that electrically connect the circuit board and the main circuit board, The plurality of connection terminals include a first group of terminals arranged in an annular shape along the outer circumference of the circuit board, and a second group of terminals (15b) surrounded by the first group of terminals (15a). The electronic control device according to any one of claims 1 to 6, wherein the operating member is provided at least at one location between the first terminal group and the second terminal group.

11. The electronic control device according to any one of claims 1 to 6, wherein the heat-generating component is a system-on-a-chip, a memory device, and a power supply circuit.

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