Electronic control device and method for manufacturing the same

Abstract

The present invention provides an electronic control device configured to efficiently dissipate heat from multiple chips of different heights, and a method for manufacturing the same. [Solution] The electronic control unit 1 comprises a plurality of chips 17A, 17B, a cooling unit 21, and a heat dissipation member 23. The cooling unit 21 has an inner wall surface 41 provided along the periphery of the range corresponding to the plurality of chips 17A, 17B, and a space 43 is formed inside the inner wall surface 41. The heat dissipation member 23 is disposed within the space 43 and is configured to contact the upper surface of each of the plurality of chips 17A, 17B, and to contact the side surface of at least one of the plurality of chips 17A, 17B.

Description

Technical Field

[0001] The present disclosure relates to an electronic control device and a method for manufacturing the same.

Background Art

[0002] For example, as described in Patent Document 1, a technique of interposing a metal sponge body between a plurality of semiconductor chips having different heights and heat radiation fins is known. By using such a metal sponge body, the variation in the height of the semiconductor chips can be absorbed by the metal sponge body, and the heat of the semiconductor chips can be transmitted to the heat radiation fins via the metal sponge body.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the case of the technique described in Patent Document 1 above, the metal sponge body is configured to contact the upper surface of the semiconductor chip. Therefore, heat cannot be transmitted from locations other than the upper surface of the semiconductor chip to the metal sponge body, and there is room for improvement from the viewpoint of promoting heat dissipation of the semiconductor chip.

[0005] In one aspect of the present disclosure, it is desirable to provide an electronic control device configured to be able to efficiently dissipate heat from a plurality of chips having different heights and a method for manufacturing the same.

Means for Solving the Problems

[0006] One aspect of the present disclosure is an electronic control device (1) comprising a housing (11), a substrate (13), an interposer (15), a plurality of chips (17A, 17B), a stiffener (19), a cooling unit (21), and a heat dissipation member (23). The substrate is mounted inside the housing. The interposer is mounted on the substrate. The chips are mounted on the interposer. The stiffener is mounted on the interposer and positioned to surround the plurality of chips. The cooling unit is positioned with a gap between it and the plurality of chips. The heat dissipation member is positioned between the plurality of chips and the cooling unit and is in contact with each of the plurality of chips and the cooling unit, and when each of the plurality of chips generates heat, it promotes heat dissipation from each of the plurality of chips to the cooling unit. The cooling section has inner wall surfaces (41, 61, 65, 71, 75, 81) positioned along the periphery of a range corresponding to multiple chips, with spaces (43, 63, 67, 73) formed inside the inner wall surfaces. The multiple chips and stiffeners are arranged such that a portion of each chip and a portion of the stiffener are located within the spaces. The heat dissipation member is positioned within the spaces and is configured to contact the upper surface of each of the multiple chips, and, for at least one of the multiple chips, to contact the side surface of that chip.

[0007] With the electronic control device configured as described above, the heat dissipation component mentioned above is in contact not only with the top surface of the chip but also with the sides of the chip, thus improving the heat dissipation performance from the chip.

[0008] One aspect of the present disclosure is an electronic control device comprising a housing (11), a substrate (13), a plurality of chips (87A, 87B, 87C, 87D), a cooling unit (21), and a heat dissipation member (23). The substrate is mounted inside the housing. The chips are mounted on the substrate. The cooling unit is positioned with a gap between it and the plurality of chips. The heat dissipation member is positioned between the plurality of chips and the cooling unit, and is in contact with each of the plurality of chips and the cooling unit, and promotes heat dissipation from each of the plurality of chips to the cooling unit when each of the plurality of chips generates heat. The cooling unit has an inner wall surface (41) provided along the periphery of the area corresponding to the plurality of chips, and a space (43) is formed inside the inner wall surface. The plurality of chips have a top surface, side surfaces and a bottom surface, and are bonded to the substrate on the bottom side, and are arranged so that a part of each of the plurality of chips is located in the space. The heat dissipation member is positioned within the space and is configured to contact the upper surface of each of the multiple chips, and, for at least one of the multiple chips, to contact the side surface of that chip.

[0009] With the electronic control device configured as described above, the heat dissipation component mentioned above is in contact not only with the top surface of the chip but also with the sides of the chip, thus improving the heat dissipation performance from the chip.

[0010] One aspect of the present disclosure is a method for manufacturing an electronic control device, and more particularly, a method for manufacturing an electronic control device (1). The electronic control device further comprises a housing (11), a substrate (13), an interposer (15), a plurality of chips (17A, 17B), a stiffener (19), a cooling unit (21), and a heat dissipation member (23). The substrate is mounted inside the housing. The interposer is mounted on the substrate. The chips are mounted on the interposer. The stiffener is mounted on the interposer and positioned to surround the plurality of chips. The cooling unit is positioned with a gap between it and the plurality of chips. The heat dissipation member is positioned between the plurality of chips and the cooling unit and is in contact with each of the plurality of chips and the cooling unit, and when each of the plurality of chips generates heat, it promotes heat dissipation from each of the plurality of chips to the cooling unit. The cooling section has inner wall surfaces (41, 61, 65, 71, 75, 81) located along the periphery of the area corresponding to multiple chips, with spaces (43, 63, 67, 73) formed inside the inner wall surfaces. The multiple chips and stiffeners are arranged such that a portion of each chip and a portion of the stiffener are located within the spaces. The heat dissipation member is positioned within the spaces and is configured to contact the upper surface of each of the multiple chips, and to contact the side surface of at least one of the chips. In the pre-mounted state before the substrate is attached to the housing, the thickness of the heat dissipation member is set to thickness T1. In the mounted state after the substrate is attached to the housing, the distance between the multiple chips and the cooling section is the maximum distance, which is defined as distance T2. The thickness T1 of the heat dissipation member is set to satisfy the inequality T1 > T2, and when sandwiched at the location of distance T2, it is compressed to a thickness matching distance T2.

[0011] According to the manufacturing method for the electronic control unit configured as described above, it is possible to manufacture an electronic control unit in which the heat dissipation member described above is in contact not only with the top surface of the chip but also with the side surface of the chip. Therefore, it is possible to manufacture an electronic control unit with improved heat dissipation performance from the chip. [Brief explanation of the drawing]

[0012] [Figure 1]Figure 1 is an explanatory diagram showing the schematic structure of the electronic control device in the first embodiment. [Figure 2] Figure 2 is an enlarged view of part II shown in Figure 1. [Figure 3] Figure 3 is an explanatory diagram for comparing the shapes and dimensions of the stiffener, interposer, and heat dissipation component. [Figure 4] Figure 4 is a bottom view of the enclosure. [Figure 5] Figure 5 is an explanatory diagram showing the state before the circuit board is attached to the housing. [Figure 6] Figure 6 is an enlarged view of section VI shown in Figure 5. [Figure 7] Figure 7 is an explanatory diagram showing the shape of the inner wall surface of the electronic control device in the second embodiment. [Figure 8] Figure 8 is an explanatory diagram showing the shape of the inner wall surface of the electronic control device in the third embodiment. [Figure 9] Figure 9 is an explanatory diagram showing the shape of the inner wall surface of the electronic control device in the fourth embodiment. [Figure 10] Figure 10 is a bottom view of the housing in the fifth embodiment. [Figure 11] Figure 11 is a bottom view of the housing in the sixth embodiment. [Figure 12] Figure 12 is an explanatory diagram showing the shape of the protrusion of the electronic control device in the seventh embodiment. [Figure 13] Figure 13 is an explanatory diagram showing the structure of the electronic control device in the eighth embodiment. [Figure 14] Figure 14 is an explanatory diagram showing the shape of the inner wall surface of the electronic control device in the eighth embodiment. [Modes for carrying out the invention]

[0013] Next, the above-mentioned electronic control device will be described with reference to exemplary embodiments. (1) First Embodiment [Configuration of the electronic control unit] As shown in FIGS. 1 and 2, the electronic control device 1 includes a housing 11, a substrate 13, an interposer 15, a plurality of chips 17A, 17B, a stiffener 19, a cooling unit 21, and a heat dissipation member 23. The housing 11 is a die-cast product made of an aluminum alloy in this embodiment. The substrate 13 is attached inside the housing 11 by a fixture 31. The interposer 15 is mounted on the substrate 13. The plurality of chips 17A, 17B are mounted on the interposer 15.

[0014] On the interposer 15, wirings for electrically connecting between the plurality of chips 17A, 17B and wirings for electrically connecting the plurality of chips 17A, 17B and the substrate 13 are formed. The interposer 15 and the substrate 13 are electrically connected via solder balls 33 arranged in a grid pattern. Further, side fills 35 are provided at the peripheries of the interposer 15 and the substrate 13 to reinforce the bonding strength between the interposer 15 and the substrate 13.

[0015] The stiffener 19 is mounted on the interposer 15. The stiffener 19 is a reinforcing material for increasing the rigidity of the interposer 15. When viewed from the direction indicated by arrow A1 in FIG. 2, the stiffener 19 and the interposer 15 are arranged overlapping each other at positions as shown in FIG. 3. In this embodiment, the stiffener 19 is configured in a rectangular frame shape as shown in FIG. 3. The plurality of chips 17A, 17B shown in FIGS. 1 and 2 are arranged at positions surrounded by the frame-shaped stiffener 19.

[0016] As shown in FIG. 3, the shape and dimensions of the stiffener 19 are configured such that the outer periphery of the stiffener 19 is arranged inside the outer periphery of the interposer 15 over the entire circumference. That is, the stiffener 19 is configured to be slightly smaller than the interposer 15.

[0017] Figure 3 also shows the positions where the heat dissipation members 23 are stacked, indicated by dashed lines. The shape and dimensions of the heat dissipation members 23 are configured such that the outer circumference of the heat dissipation members 23 is positioned outside the outer circumference of the interposer 15 throughout its entire circumference. In other words, the heat dissipation members 23 are made to be slightly larger than the interposer 15.

[0018] In this embodiment, the cooling unit 21 has a water-cooled structure. Specifically, a portion is provided in the lower center of the housing 11 that protrudes downward, and this protruding portion is the cooling unit 21. A cavity is formed inside the cooling unit 21, and it is configured so that cooling water, which serves as a refrigerant, can be introduced into the cooling unit 21. As shown in Figure 4, an inlet 37 and an outlet 39 for the cooling water are provided on the front of the housing 11.

[0019] Cooling water introduced into the cooling unit 21 from the inlet 37 absorbs heat transferred to the underside of the cooling unit 21, and the heated cooling water is discharged to the outside of the housing 11 from the outlet 39. The heated cooling water may be cooled down by passing it through, for example, a heat exchanger (not shown) before being circulated back into the cooling unit 21. In this embodiment, the cooling unit 21 is a water-cooled structure, but a cooling unit 21 other than a water-cooled type may also be used.

[0020] The cooling unit 21 is positioned at intervals between the multiple chips 17A and 17B. The cooling unit 21 has an inner wall surface 41 provided along the periphery of the range corresponding to the multiple chips 17A and 17B. Inside the inner wall surface 41, a space 43 is formed surrounded by the inner wall surface 41. In this embodiment, a recess 47 is formed on the lower surface of the cooling unit 21, having the aforementioned inner wall surface 41 and a ceiling surface 45. The recess 47 is recessed in the direction away from the substrate 13. That is, the recess 47 is recessed upward from the lower surface of the cooling unit 21.

[0021] A heat dissipation member 23 is positioned within the space 43. The heat dissipation member 23 is positioned between the multiple chips 17A, 17B and the cooling unit 21, and is in contact with each of the multiple chips 17A, 17B and the cooling unit 21. When the substrate 13 is attached to the housing 11, the heat dissipation member 23 is compressed in the thickness direction. As a result, the heat dissipation member 23 is configured to be in contact with the upper surface of each of the multiple chips 17A, 17B, and to be in contact with the side surface of at least one of the multiple chips 17A, 17B.

[0022] In the mounting state in which the circuit board 13 is attached to the housing 11, a portion of each of the multiple chips 17A and 17B is positioned within the space 43. That is, a portion of the upper end of each of the multiple chips 17A and 17B is located above the lower end of the inner wall surface 41 and is located within the space 43 surrounded by the inner wall surface 41. A portion of each of the multiple chips 17A and 17B is in contact with the heat dissipation member 23 within the aforementioned space 43.

[0023] The heat dissipation member 23 is made of a flexible material with high thermal conductivity. Examples of such flexible materials include silicone resin, epoxy resin, and acrylic resin. In this embodiment, the heat dissipation member 23 is made of a flexible silicone resin with high thermal conductivity. These flexible materials may be blended with a thermally conductive filler made of a material with high thermal conductivity, such as alumina particles.

[0024] When arranging the heat dissipation member 23 within the space 43 surrounded by the inner wall surface 41, an amorphous composition can be applied to the space 43 surrounded by the inner wall surface 41. Alternatively, the heat dissipation member 23, cut into the desired shape from a plate-shaped or sheet-shaped molded product, can be housed within the space 43 surrounded by the inner wall surface 41.

[0025] The heat dissipation member 23 is constructed to be extremely low in hardness. Specifically, the hardness of the heat dissipation member 23 is adjusted so that when the heat dissipation member 23 is sandwiched between the cooling unit 21 and the multiple chips 17A and 17B, the heat dissipation member 23 deforms very flexibly, and the deformed portion bulges into the gap between the multiple chips 17A and 17B. When the heat dissipation member 23 is compressed in the thickness direction, the heat dissipation member 23 tends to expand in a direction perpendicular to the compression direction.

[0026] However, in the electronic control device 1 of this embodiment, the heat dissipation member 23 is surrounded by the inner wall surface 41 described above. Therefore, although the contact pressure between the heat dissipation member 23 and the inner wall surface 41 increases, the heat dissipation member 23 does not expand in a direction perpendicular to the compression direction. As a result, when the heat dissipation member 23 is compressed in the thickness direction between the multiple chips 17A, 17B and the cooling unit 21, it deforms in a direction that causes it to bulge into the gap between the multiple chips 17A, 17B.

[0027] The heat dissipation member 23 has a portion that bulges into the gap between the multiple chips 17A and 17B, and this portion is in contact with the side surface of at least one of the chips 17A and 17B. In this embodiment, the heat dissipation member 23 is in contact with the side surface of each of the multiple chips 17A and 17B. When each of the multiple chips 17A and 17B generates heat, heat is transferred from the top and side surfaces of the chips 17A and 17B to the heat dissipation member 23 for at least one chip 17A and 17B whose side surface is in contact with the heat dissipation member 23. Therefore, compared to the case where the heat dissipation member 23 is in contact only with the top surface of each of the multiple chips 17A and 17B, the amount of heat transfer can be increased by the amount of heat transferred from the side surfaces of the chips 17A and 17B to the heat dissipation member 23.

[0028] Furthermore, the heat dissipation member 23 repeatedly heats up and dissipates heat as the electronic control unit 1 is activated and deactivated. In an environment where such a heating and cooling cycle is repeated, the heat dissipation member 23 repeatedly expands and contracts. If the inner wall surface 41 described above were not present, the heat dissipation member 23, which repeatedly expands and contracts, may gradually shift position. However, in this embodiment, since the heat dissipation member 23 is located in the space 43 surrounded by the inner wall surface 41, the shifting position of the heat dissipation member 23 can be suppressed.

[0029] Furthermore, in this embodiment, a portion of the stiffener 19 is positioned within the space 43 and is in contact with the heat dissipation member 23 within the space 43. As shown in Figure 3, the heat dissipation member 23 is configured to be slightly larger than the interposer 15 and the stiffener 19, so the upper side of the stiffener 19 is sealed by the heat dissipation member 23. Therefore, unlike structures in which there is a gap on the upper side of the stiffener 19, it is possible to prevent foreign matter from entering from the upper side of the stiffener 19, and to prevent such foreign matter from reaching the vicinity of the chips 17A and 17B located on the inner circumference side of the stiffener 19.

[0030] Furthermore, the heat dissipation member 23 contacts the cooling section 21 over an area slightly larger than that of the interposer 15 and stiffener 19, and also contacts the heat source side by wrapping around the outer circumference of the stiffener 19. Therefore, compared to the case where a smaller area heat dissipation member 23 is used, the heat dissipation from the heat source side can be improved.

[0031] When the circuit board 13 is attached to the housing 11, if the upper surface of the stiffener 19 comes into close contact with the heat dissipation member 23, air will be trapped inside the stiffener 19. Therefore, in this embodiment, as shown in Figure 2, the interposer 15 is provided with through holes 51 that penetrate in the thickness direction of the interposer 15. With such through holes 51 provided, the air trapped inside the stiffener 19 will escape to the bottom of the interposer 15 through the through holes 51.

[0032] Therefore, unlike in cases where there is no through-hole 51, the air trapped inside the stiffener 19 will not enter the space between the chips 17A, 17B and the heat dissipation member 23 as bubbles. Thus, it is possible to suppress the reduction in heat dissipation performance caused by such bubbles. Alternatively, instead of providing a through-hole 51 in the interposer 15, a similar effect can be expected by forming holes or grooves in a part of the stiffener 19 to serve as air vents.

[0033] As shown in Figures 5 and 6, the heat dissipation member 23 is not compressed in the thickness direction in the pre-installation state where the substrate 13 is attached to the housing 11. The thickness of the heat dissipation member 23 at this time is defined as thickness T1, as shown in Figure 6. As shown in Figures 1 and 2, the heat dissipation member 23 becomes compressed in the thickness direction when the substrate 13 is attached to the housing 11. The distance at the point where the distance between the multiple chips 17A, 17B and the cooling unit 21 is maximum at this time is defined as distance T2, as shown in Figure 2.

[0034] Distance T2 is determined based on the number of chips 17A and 17B used in the electronic control unit 1. In the case of the multiple chips 17A and 17B exemplified in Figure 2, the distance between the chips 17A and 17B and the cooling unit 21 is greatest at the location where the lower-profile chip 17A is mounted.

[0035] Therefore, once the distance T2 is determined, the thickness T1 of the heat dissipation member 23 is adjusted based on the distance T2 so that the thickness satisfies the inequality T1 > T2. By adjusting the heat dissipation member 23 to such a thickness T1, the heat dissipation member 23 is compressed between the multiple chips 17A, 17B and the cooling unit 21 even at the point where the distance between the multiple chips 17A, 17B and the cooling unit 21 is maximum.

[0036] Therefore, the adhesion between the heat dissipation member 23 and the multiple chips 17A, 17B, and between the heat dissipation member 23 and the cooling unit 21 can be improved, and the heat dissipation from the multiple chips 17A, 17B, which are the heat source side, can be improved. If the thickness of the heat dissipation member 23 can be partially changed, the thickness T1 of the heat dissipation member 23 may be less than or equal to the distance T2 in areas other than the area where the distance between the multiple chips 17A, 17B and the cooling unit 21 is maximum.

[0037] In this embodiment, the heat dissipation member 23 is configured not to come into contact with the substrate 13. This suppresses the transfer of heat from the heat dissipation member 23 to the substrate 13, and thus prevents such heat from being transferred to components on the substrate 13.

[0038] [effect] With the electronic control unit 1 configured as described above, the heat dissipation member 23 is in contact not only with the upper surface of the chips 17A and 17B but also with the sides of the chips 17A and 17B, thereby improving the heat dissipation performance from the chips 17A and 17B.

[0039] Furthermore, in this embodiment, since the upper surface of the stiffener 19 is in close contact with the heat dissipation member 23, it is possible to suppress the intrusion of foreign matter into the vicinity of the chips 17A and 17B which are arranged on the inner circumference side of the stiffener 19.

[0040] Furthermore, in this embodiment, the thickness T1 of the heat dissipation member 23 is configured to satisfy the inequality T1 > T2, based on the distance T2 at the point where the distance between the multiple chips 17A, 17B and the cooling unit 21 is maximum. Therefore, the heat dissipation member 23 can be properly pressed and brought into contact with low-profile chips 17A.

[0041] Furthermore, in this embodiment, since the heat dissipation member 23 is in contact with the sides of each of the multiple chips 17A and 17B, the heat dissipation performance can be improved compared to the case where some chips 17A and 17B are not in contact with the heat dissipation member 23 on their sides. Even if the heights of the multiple chips 17A and 17B are different from each other, the heat dissipation member 23 can be in contact with each of the multiple chips 17A and 17B, so heat can be dissipated from each chip 17A and 17B regardless of the height difference between the multiple chips 17A and 17B.

[0042] Furthermore, in this embodiment, since the heat dissipation member 23 is made of silicone resin, it is a heat dissipation member 23 with excellent flexibility, and can be configured to easily wrap around the sides of the chips 17A and 17B.

[0043] Furthermore, in this embodiment, since the heat dissipation member 23 is positioned in a recess 47 having an inner wall surface 41 and a ceiling surface 45, it becomes easier to bring the heat dissipation member 23 into contact with the upper and side surfaces of the chips 17A and 17B, thereby improving heat dissipation performance. Note that, as long as the heat dissipation member 23 can be sufficiently brought into contact with the upper and side surfaces of the chips 17A and 17B, the space 43 in which the heat dissipation member 23 is positioned is not limited to the space 43 surrounded by the inner wall surface 41 and the ceiling surface 45. For example, the heat dissipation member 23 may be held in a holding portion of a through-structure that has an inner wall surface 41 but no ceiling surface 45, and the heat dissipation member 23 may be configured to contact the chips 17A and 17B.

[0044] Furthermore, in this embodiment, since the cooling unit 21 has a water-cooling structure, it can achieve higher cooling performance compared to other cooling structures such as air-cooling. Furthermore, in this embodiment, since the interposer 15 is provided with through holes 51, when attaching the substrate 13 to the housing 11, it is possible to prevent air from entering the contact area between the heat dissipation member 23 and the chips 17A and 17B.

[0045] Furthermore, in this embodiment, the heat dissipation member 23 is configured with a shape and dimensions such that its outer circumference is positioned outside the outer circumference of the interposer 15 over its entire circumference. Therefore, the entire array of chips 17A, 17B and stiffeners 19 can be brought into proper contact with the heat dissipation member 23, thereby improving heat dissipation.

[0046] (2) Second Embodiment Next, the second embodiment will be described. Note that each embodiment from the second embodiment onward only modifies a part of the configuration exemplified in the first embodiment. Therefore, the differences from the first embodiment will be described in detail, and detailed explanations of parts similar to the first embodiment will be omitted.

[0047] In the second embodiment, as shown in Figure 7, an inner wall surface 61 with a different shape from the inner wall surface 41 of the first embodiment is adopted. Specifically, in the second embodiment, the inner wall surface 61 is an inclined surface that is tilted in such a way that the space 63 surrounded by the inner wall surface 61 expands towards the bottom.

[0048] By adopting an inner wall surface 61 with such an inclination, the space 63 enclosed by the inner wall surface 61 expands towards the bottom. Therefore, when the heat dissipation member 23 placed in this space 63 is compressed, the heat dissipation member 23 deforms in a direction that expands laterally. Thus, the heat dissipation member 23 can be deformed to protrude laterally, increasing the contact area with the chips 17A and 17B.

[0049] (3) Third Embodiment Next, a third embodiment will be described. In the third embodiment, as shown in Figure 8, an inner wall surface 65 with a different shape from the inner wall surface 41 of the first embodiment is adopted. Specifically, in the third embodiment, the inner wall surface 65 is a curved surface that curves in a direction in which the space 67 surrounded by the inner wall surface 65 expands towards the bottom.

[0050] By adopting such a curved inner wall surface 65, the space 67 enclosed by the inner wall surface 65 expands towards the bottom. Therefore, when the heat dissipation member 23 placed in this space 67 is compressed, the heat dissipation member 23 deforms in a direction that expands laterally. Thus, the heat dissipation member 23 can be deformed to protrude laterally, increasing the contact area with the chips 17A and 17B.

[0051] (4) Fourth Embodiment Next, a fourth embodiment will be described. In the fourth embodiment, as shown in Figure 9, an inner wall surface 71 with a different shape from the inner wall surface 41 of the first embodiment is adopted. Specifically, in the fourth embodiment, the inner wall surface 71 is a stepped surface. More specifically, the inner wall surface 71 comprises a first inner wall surface 71A, a second inner wall surface 71B, and an intermediate surface 71C. The first inner wall surface 71A and the second inner wall surface 71B are surfaces located on the inner circumference side and constitute a part of the inner wall surface 71. The intermediate surface 71C is a surface facing the substrate 13 side and constitutes a part of the inner wall surface 71.

[0052] The second inner wall surface 71B is located further from the substrate 13 than the first inner wall surface 71A, and when viewed from the substrate 13 side, it is located on the inner circumference side than the first inner wall surface 71A. The intermediate surface 71C is located between the first inner wall surface 71A and the second inner wall surface 71B, and the outer edge of the intermediate surface 71C is connected to one end of the first inner wall surface 71A, forming a recessed corner between it and the first inner wall surface 71A. Also, the inner edge of the intermediate surface 71C is connected to one end of the second inner wall surface 71B, forming a protruding corner between it and the second inner wall surface 71B.

[0053] If the inner wall surface 71 is configured in this way, the space 73 surrounded by the inner wall surface 71 will be larger in the portion surrounded by the first inner wall surface 71A than in the portion surrounded by the second inner wall surface 71B. Therefore, when the heat dissipation member 23 placed in this space 73 is compressed, the heat dissipation member 23 will deform in a direction that expands laterally in the portion surrounded by the first inner wall surface 71A. Thus, the heat dissipation member 23 can be deformed to protrude laterally, thereby increasing the contact area with the chip. In addition, since the heat dissipation member 23 can be allowed to escape laterally in the portion surrounded by the first inner wall surface 71A, it is possible to suppress the heat dissipation member 23 from bulging excessively toward the substrate 13 and to prevent the heat dissipation member 23 from coming into contact with the substrate 13 or components on the substrate 13.

[0054] (5) Fifth embodiment Next, a fifth embodiment will be described. In the fifth embodiment, as shown in Figure 10, an inner wall surface 75 with a different shape from the inner wall surface 41 of the first embodiment is adopted. Specifically, in the fifth embodiment, the inner wall surface 75 is provided with relief portions 77 that are recessed further outward from the inner wall surface 75, forming a relief space inside the recessed area. In the inner wall surface 75 illustrated in Figure 10, two relief portions 77 are formed on each of the four sides of the rectangular inner wall surface 75 when viewed from the bottom.

[0055] By providing such relief sections 77, when the heat dissipation member 23 is compressed in the area where the relief section 77 is located, it bulges into the relief section 77, thereby reducing the pressing force acting on the chips near the relief section 77. Therefore, for example, if a relief section 77 is provided near a location where a chip 17B with a higher product height is placed, it is possible to suppress excessive load on the chip 17B with a higher product height.

[0056] (6) Sixth Embodiment Next, a sixth embodiment will be described. In the sixth embodiment, as shown in Figure 11, an inner wall surface 81 with a different shape from the inner wall surface 41 of the first embodiment is adopted. Specifically, in the sixth embodiment, the inner wall surface 81 is configured to be circular when viewed from the bottom direction.

[0057] With such an inner wall surface 81, there are no recessed corners on the inner wall surface 81. Therefore, when arranging the heat dissipation member 23, if an irregularly shaped composition is to be applied to the space 43 surrounded by the inner wall surface 41, the irregularly shaped composition can be applied more easily compared to an inner wall surface with recessed corners.

[0058] (7) Seventh Embodiment Next, a seventh embodiment will be described. In the seventh embodiment, as shown in Figure 12, a ceiling surface 83 with a different shape from the ceiling surface 45 of the first embodiment is adopted. Specifically, in the case of the seventh embodiment, a convex portion 85 that protrudes downward is formed on the ceiling surface 83.

[0059] By providing such protrusions 85, the heat dissipation member 23 can be crushed by the protrusions 85, allowing the heat dissipation member 23 to adhere more strongly to the protrusions 85 and the chips located opposite the protrusions 85. Figure 12 shows an example in which the heat dissipation member 23 has approximately equal thickness in the area with the protrusions 85 and the area around the protrusions 85, but the heat dissipation member 23 may be partially modified. For example, the lower surface of the heat dissipation member 23 may be made flat so that the heat dissipation member 23 is thinner in the area with the protrusions 85 than in the area around the protrusions 85. In this case, since the heat dissipation member 23 is thinner in the area with the protrusions 85, the amount of flexible material used to make up the heat dissipation member 23 can be reduced, thereby reducing material costs and weight.

[0060] (8) Eighth embodiment Next, the eighth embodiment will be described. In the eighth embodiment, as shown in Figure 13, a configuration is adopted in which multiple chips 87A, 87B, 87C, and 87D are directly mounted on the substrate 13. In other words, in the eighth embodiment, there is no configuration equivalent to the interposer 15 exemplified in the first embodiment. Even when such a configuration is adopted, heat can be transferred from the top and side surfaces of the multiple chips 87A to 87D to the cooling unit 21 by interposing a heat dissipation member 23 between the cooling unit 21 and the multiple chips 87A to 87D.

[0061] (9) Ninth Embodiment Next, a ninth embodiment will be described. In the ninth embodiment, as shown in Figure 14, a rectangular tubular projection 90 is provided on the lower surface of the cooling unit 21, thereby creating a space 93 surrounded by the inner wall surface 91. In other words, a space 93 for arranging the heat dissipation member 23 can be created not only by providing a recess as exemplified in the other embodiments, but also by providing a projection 90. (10) Other embodiments Although the electronic control device 1 has been described above with reference to exemplary embodiments, the above-described embodiments are merely illustrative examples of one aspect of the present disclosure. In other words, the present disclosure is not limited to the above-described exemplary embodiments and can be implemented in various forms without departing from the technical idea of ​​the present disclosure.

[0062] For example, in the fourth embodiment described above, an example was shown in which the inner wall surface 71 is a stepped surface. However, in the inner wall surfaces shown in embodiments other than the fourth embodiment, a stepped surface similar to that of the fourth embodiment may also be formed.

[0063] Furthermore, although the fifth embodiment described above shows an example in which a relief portion 77 is provided on the inner wall surface 75, a relief portion 77 similar to that of the fifth embodiment may also be formed on the inner wall surface shown in embodiments other than the fifth embodiment.

[0064] Furthermore, multiple functions realized by one component as exemplified in the above embodiment may be realized by multiple components. One function realized by one component as exemplified in the above embodiment may be realized by multiple components. Multiple functions realized by multiple components as exemplified in the above embodiment may be realized by one component. One function realized by multiple components as exemplified in the above embodiment may be realized by one component. Some of the configurations exemplified in the above embodiment may be omitted. At least a part of the configuration exemplified in one of the above embodiments may be added to or replaced with the configuration exemplified in the other embodiments. [Explanation of symbols]

[0065] 1...Electronic control unit, 11...Housing, 13...Circuit board, 15...Interposer, 17A,17B,87A,87B,87C,87D...Chip, 19...Stiffener, 21...Cooling section, 23...Heat dissipation member, 31...Fixing device, 33...Solder ball, 35...Side fill, 37...Inlet, 39...Outlet, 41,61,65,71,75,81,91...Inner wall surface, 43,63,67,73,93...Space, 45,83...Ceiling surface, 47...Recess, 51...Through hole, 71A...First inner wall surface, 71B...Second inner wall surface, 71C...Intermediate surface, 77...Relief section, 85,90...Protrusions.

Claims

1. The enclosure (11) and A circuit board (13) is mounted inside the aforementioned housing, An interposer (15) mounted on the aforementioned substrate, Multiple chips (17A, 17B) are mounted on the interposer, The interposer is equipped with a stiffener (19) positioned to surround the plurality of chips, A cooling unit (21) is positioned with a gap between it and the plurality of chips, A heat dissipation member (23) is positioned between the plurality of chips and the cooling unit, and is in contact with each of the plurality of chips and the cooling unit, and when each of the plurality of chips generates heat, it promotes the dissipation of heat from each of the plurality of chips to the cooling unit. Equipped with, The cooling section has inner wall surfaces (41, 61, 65, 71, 75, 81) provided along the periphery of the range corresponding to the plurality of chips, and spaces (43, 63, 67, 73) are formed inside the inner wall surfaces. The plurality of chips and the stiffener are arranged such that a portion of each of the plurality of chips and a portion of the stiffener are located within the space. The heat dissipation member is arranged in the space and is configured to contact the upper surface of each of the plurality of chips, and to contact the side surface of at least one of the plurality of chips. Electronic control unit (1).

2. The enclosure (11) and A circuit board (13) is mounted inside the aforementioned housing, Multiple chips (87A, 87B, 87C, 87D) mounted on the aforementioned substrate, A cooling unit (21) is positioned with a gap between it and the plurality of chips, A heat dissipation member (23) is positioned between the plurality of chips and the cooling unit, and is in contact with each of the plurality of chips and the cooling unit, and when each of the plurality of chips generates heat, it promotes the dissipation of heat from each of the plurality of chips to the cooling unit. Equipped with, The cooling section has an inner wall surface (41) provided along the periphery of the range corresponding to the plurality of chips, and a space (43) is formed inside the inner wall surface. The plurality of chips have a shape having an upper surface, a side surface and a lower surface, and are bonded to the substrate on the lower surface side, and a portion of each of the plurality of chips is positioned within the space, The heat dissipation member is arranged in the space and is configured to contact the upper surface of each of the plurality of chips, and to contact the side surface of at least one of the plurality of chips. Electronic control unit.

3. An electronic control device according to claim 1 or claim 2, Let the thickness of the heat dissipation member in an uncompressed state in the thickness direction be thickness T1, and the distance T2 be the distance between the plurality of chips and the cooling section at the point where the distance is maximum. The thickness T1 is configured such that it satisfies the inequality T1 > T2 based on the distance T2. Electronic control unit.

4. An electronic control device according to claim 1 or claim 2, The heat dissipation member is configured to contact the side surface of each of the plurality of chips. Electronic control unit.

5. The electronic control device according to claim 1, The heat dissipation member is configured to be in contact with the stiffener. The electronic control device according to claim 1.

6. An electronic control device according to claim 1 or claim 2, The heat dissipation member is made of silicone resin. Electronic control unit.

7. An electronic control device according to claim 1 or claim 2, The cooling section has a recess (47) formed in which it is recessed in a direction away from the substrate, and whose inner circumferential surface is the inner wall surface. Electronic control unit.

8. An electronic control device according to claim 1 or claim 2, The cooling unit has a water-cooling structure. Electronic control unit.

9. The electronic control device according to claim 1, The interposer is provided with a through hole (51) that penetrates the interposer in the thickness direction. Electronic control unit.

10. The electronic control device according to claim 1, The heat dissipation member is configured with a shape and dimensions such that its outer circumference is positioned outside the outer circumference of the interposer over its entire circumference. Electronic control unit.

11. An electronic control device according to claim 1 or claim 2, The aforementioned inner wall surface is A first inner wall surface (71A) that forms a part of the inner wall surface on the inner circumferential side, A second inner wall surface (71B) is located on the inner circumference side, forming a part of the inner wall surface, and is further from the substrate than the first inner wall surface, and when viewed from the substrate side, it is on the inner circumference side than the first inner wall surface. An intermediate surface (71C) is formed by a surface facing the substrate side and is located between the first inner wall surface and the second inner wall surface, with its outer peripheral end connected to one end of the first inner wall surface, forming a recessed corner with the first inner wall surface, and its inner peripheral end connected to one end of the second inner wall surface, forming a protruding corner with the second inner wall surface, Equipped with, The heat dissipation member is positioned on the inside of the second inner wall surface. Electronic control unit.

12. An electronic control device according to claim 1 or claim 2, The inner wall surfaces (61, 65) are inclined or curved such that the space narrows as it moves further away from the substrate. Electronic control unit.

13. An electronic control device according to claim 1 or claim 2, The inner wall surface (75) is provided with a relief portion (77) that is further recessed outward from the inner wall surface, forming a relief space inside the recessed portion. Electronic control unit.

14. A method for manufacturing an electronic control device (1), The aforementioned electronic control device is The enclosure (11) and A circuit board (13) is mounted inside the aforementioned housing, An interposer (15) mounted on the aforementioned substrate, Multiple chips (17A, 17B) are mounted on the interposer, The interposer is equipped with a stiffener (19) positioned to surround the plurality of chips, A cooling unit (21) is positioned with a gap between it and the plurality of chips, A heat dissipation member (23) is positioned between the plurality of chips and the cooling unit, and is in contact with each of the plurality of chips and the cooling unit, and when each of the plurality of chips generates heat, it promotes the dissipation of heat from each of the plurality of chips to the cooling unit. Equipped with, The cooling section has inner wall surfaces (41, 61, 65, 71, 75, 81) provided along the periphery of the range corresponding to the plurality of chips, and spaces (43, 63, 67, 73) are formed inside the inner wall surfaces. The plurality of chips and the stiffener are arranged such that a portion of each of the plurality of chips and a portion of the stiffener are located within the space. The heat dissipation member is arranged in the space and is configured to contact the upper surface of each of the plurality of chips, and to contact the side surface of at least one of the plurality of chips. In the pre-installation state before attaching the substrate to the housing, the thickness of the heat dissipation member is configured to be thickness T1. In the mounted state after the substrate has been attached to the housing, the distance T2 is defined as the maximum distance between the plurality of chips and the cooling unit, and the thickness T1 of the heat dissipation member is such that the inequality T1 > T2 is satisfied, and when sandwiched at the location of the distance T2, it is compressed to a thickness that matches the distance T2. A method for manufacturing electronic control devices.

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