Electronic control device and method for manufacturing the same

Abstract

The electronic control device of the present invention and the manufacturing method thereof can improve reliability. The electronic control device of the present invention comprises: a control substrate (2) for mounting an electronic component (1); and a frame (3) for sealing the control substrate (2) with a sealing resin (5), the frame (3) being shaped such that the resin volume on one surface side of the control substrate (2) is larger than the resin volume on the other surface side, the frame (3) being formed with a gate mark (21a), the length of the gate mark (21a) in the thickness direction of the control substrate (2) being larger than the thickness of the control substrate (2), the control substrate (2) being located in the projection area of ​​the gate mark (21a) in a manner that a part of the side surface overlaps, and the control substrate (2) being arranged closer to the other surface side than the center of the gate mark (21a).

Description

Technical Field

[0001] The invention relates to an electronic control device and a method for manufacturing the electronic control device. Background Art

[0002] Vehicles are equipped with electronic control devices such as engine control units and automatic transmission control units. In recent years, with environmental and energy issues as the background, the electrification of automobiles has accelerated, and the number of electronic control devices installed has increased significantly. Therefore, the installation locations of electronic control devices are limited, and in automobiles, they have to be installed in the engine room with a harsh environment. On the other hand, with the improvement of automobile comfort and the expansion of cabin space, the engine room has become smaller. In this way, a large number of electronic control devices and wiring harnesses that electrically connect them are arranged in the miniaturized engine room, so the reduction in layout freedom, the increase in weight, and the increase in costs associated with them become problems. Therefore, miniaturization, lightness, and low cost are required for electronic control devices.

[0003] In addition, the wiring harness tends to be shortened. Along with this, for example, if the engine control device is mounted closer to the engine, there is a risk of being affected by the high heat and high vibration of the engine. Therefore, it is necessary to improve the heat resistance and vibration resistance of the electronic control device. As a countermeasure, there is a known structure for resin-sealing a control substrate on which electronic components are installed (Patent Document 1). By resin-sealing the control substrate, the influence of heat on the electronic components can be reduced, and the deflection of the control substrate can be suppressed in a vibrating environment.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2007-273796 Summary of the invention

[0007] Problems to be solved by the invention

[0008] The circuit substrate of the module of Patent Document 1 is fixed to the metal substrate by screws, and the molding is completed by filling the sealing resin from one end of the circuit substrate. However, in the future, in order to reduce the weight and cost of electronic control devices, the miniaturization of the metal substrate will become necessary, and the fixing area of ​​the circuit substrate will become smaller. Therefore, when filling the sealing resin, there is a risk that the circuit substrate will bend and deform due to the molding pressure of the sealing resin. If the circuit substrate is warped, the reliability of the electronic control device will be reduced.

[0009] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electronic control device with improved reliability.

[0010] Technical means to solve problems

[0011] In order to solve the above-mentioned problems, an electronic control device involved in one viewpoint comprises: a control substrate, which is used to mount electronic components; and a frame, which seals the control substrate with resin, the frame being in a shape in which the resin volume on one surface side of the control substrate is larger than the resin volume on the other surface side, the frame being formed with a gate mark, the length of the gate mark in the thickness direction of the control substrate being formed to be larger than the thickness of the control substrate, the control substrate being located in a projection area of ​​the gate mark in a manner that a portion of the side overlaps, and the control substrate being arranged closer to the other surface side than the center of the gate mark.

[0012] Effects of the Invention

[0013] According to the present invention, it is possible to provide an electronic control device with improved reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a cross-sectional view of the electronic control device according to the first embodiment.

[0015] Figure 2 It is an explanatory diagram showing the assembly procedure of the electronic control device according to the first embodiment.

[0016] Figure 3 It is a side view of the electronic control device according to the first embodiment.

[0017] Figure 4 It is an explanatory diagram showing the assembly procedure of the electronic control device according to the second embodiment.

[0018] Figure 5 It is a side view of the electronic control device according to the second embodiment.

[0019] Figure 6 It is a cross-sectional view of an electronic control device according to a third embodiment.

[0020] Figure 7 This is a flowchart showing the molding procedure of the electronic control device according to the third embodiment. DETAILED DESCRIPTION

[0021] Several embodiments are described below using the drawings. In addition, the embodiments described below do not limit the inventions involved in the patent claims, and the elements and combinations thereof described in the embodiments are not all essential to the solution means of the invention.

[0022] Example 1

[0023] Figure 1 It is a cross-sectional view showing the electronic control device according to the first embodiment. Figure 2 It is an explanatory diagram showing the assembly procedure of the electronic control device according to the first embodiment.

[0024] like Figure 1 , Figure 2 As shown, the electronic control device 30 includes a control substrate 2 on which an electronic component 1 such as a microprocessor is mounted, a connector 4, and a frame 3. The frame 3 is formed with a gate mark 21a on the side opposite to the side on which the connector is formed. It is arranged in a manner that a part of the side of the control substrate 2 is located within the projection area of ​​the gate mark 21a. In other words, in the thickness direction of the frame (the thickness direction of the control substrate 2), the thickness of the control substrate 2 is smaller than the height of the gate mark 21a (the length in the thickness direction of the control substrate 2), and the frames are arranged in an overlapping manner. The frame 3 is shaped so that the volume of the side on which the connector 4 is formed relative to the control substrate 2 is larger than the volume of the side on which the connector 4 is not formed. Moreover, the control substrate 2 is arranged in a manner that is closer to the side on which the connector 4 is not formed than the center of the gate mark 21a in the thickness direction of the frame 3.

[0025] like Figure 2 As shown in (a), the connector 4 includes a terminal 10 for connecting the vehicle-side wiring harness to the control substrate 2, and a housing 11 for arranging and holding the terminals 10 at a predetermined pitch. The material of the terminal 10 is preferably copper or a copper alloy from the viewpoints of conductivity, miniaturization, and cost. As the material of the housing 11, it is preferred to use a resin such as PBT (Polybutylene Terephthalate), PA (Polyamide) 66, or PPS (Polyphenylene Sulfide) from the viewpoint of light weight and excellent heat resistance.

[0026] Then, if Figure 2 As shown in (b), a plurality of electronic components 1 such as a microprocessor are mounted on both the front and back surfaces of a control substrate 2. A resin wiring board based on a glass epoxy resin or the like is used as the control substrate 2. When connecting the electronic components 1 to the control substrate 2, for example, a lead-free solder such as Sn-Cu solder, Sn-Ag-Cu solder, or Sn-Ag-Cu-Bi solder is used.

[0027] Next, if Figure 2 As shown in (c), the connector 4 is mounted on the end of the control substrate 2. As for the connection between the terminal 10 of the connector 4 and the control substrate 2, a lead-free solder such as Sn-Cu solder, Sn-Ag-Cu solder, or Sn-Ag-Cu-Bi solder is used to connect the through-hole portion 12 of the control substrate 2, and the terminal 10 is inserted into the control substrate 2. In addition, the type of the connector 4 may be either a surface mounting type or a press-fit type.

[0028] like Figure 2As shown in (d), the component 20 thus produced is set in a mold 17 for resin sealing. The mold 17 includes an upper mold 18 and a lower mold 19 covering both sides in the thickness direction of the control substrate 2. In this embodiment, after the component 20 is set in the upper mold 18 as a movable mold, the upper mold 18 is made movable and set in the lower mold 19 as a fixed mold.

[0029] Figure 3 It is a side view of the electronic control device according to the first embodiment.

[0030] Also refer to Figure 3 , an injection port of the sealing resin 5 as an example of "resin", namely a gate portion 21, is provided between the upper mold 18 and the lower mold 19. The gate portion 21 has a rectangular opening, and is provided near one end 26 of the control substrate 2 in a manner opposite thereto. Thus, the sealing resin 5 injected from the gate 2 into the mold 17 flows parallel to the plane direction of the control substrate 2. Furthermore, the height of the opening (cross section) of the gate portion 21 (the length in the thickness direction of the control substrate 2) is formed to be larger than the thickness of the control substrate 2. In addition, an example is shown in which the width of the opening of the gate portion 21 (the length in the surface direction of the control substrate 2) is formed to be smaller than the width of the control substrate 2, but it is not limited to this.

[0031] Back to Figure 2 (d). Figure 2 (d) shows the middle of the filling process of the sealing resin 5 injected from the gate portion 21. The height of the cross section of the gate portion 21 is greater than the thickness of the control substrate 2. Thus, the sealing resin 5 flows smoothly into the mold 17.

[0032] Furthermore, the connector 4 is provided on the downstream side of the resin flow path A on the upper surface side of the control substrate 2. In other words, the connector 4 is formed on the opposite side of the gate mark 21a in the control substrate 2. Thus, compared with the case where the connector 4 is provided on the upstream side of the resin flow path A, the generation of a gap caused by the terminal 10 can be suppressed.

[0033] Here, the connector 4 is mounted on one surface (hereinafter, the upper surface) side of the control substrate 2. Since the connector 4 also needs to be sealed with the sealing resin 5, the volume of the sealing resin 5 on the surface (hereinafter, the lower surface) side opposite to the upper surface of the control substrate 2 is small. In this case, the filling completion times of the sealing resin 5 on the upper and lower surface sides of the control substrate 2 in the mold 17 are different, so a pressure difference of the sealing resin 5 is generated between the upper and lower surfaces of the control substrate 2. As a result, the control substrate 2 warps. If the filling of the sealing resin 5 is completed in a state where the control substrate 2 is warped, the control substrate 2 generates residual deformation. Due to this residual deformation, cracks are generated in the solder connection part during manufacturing, and the yield rate deteriorates. Therefore, in the present embodiment, in order to suppress the warping of the control substrate 2, when the sealing resin 5 is filled in the mold 17, the pressure difference of the sealing resin 5 between the upper and lower surfaces of the control substrate 2 is reduced. That is, it is only necessary to reduce the time difference in the filling completion of the sealing resin 5 between the upper and lower surface sides of the control substrate 2. More preferably, the sealing resin 5 is filled and completed in the mold 17 at the same time on the upper and lower surface sides of the control substrate 2.

[0034] In the present embodiment, the volume of the sealing resin 5 on the upper surface side is larger than that on the lower surface side of the control substrate 2. Therefore, in order to reduce the difference in the filling completion times of the sealing resin 5 between the upper and lower surface sides of the control substrate 2, the cross-sectional area (S1') of the resin flow path A on the upper surface side of the control substrate 2 is set to be larger than the cross-sectional area (S2') of the resin flow path B on the lower surface side of the control substrate 2. The control substrate 2 is arranged in the mold 17 such that the relationship between the area (S1) on the upper surface side of the control substrate 2 and the area (S2) on the lower surface side in the gate portion 21 is S2 < S1.

[0035] More preferably, the filling is completed in the mold 17 at the same time on the upper and lower sides of the control substrate 2. That is, the ratio of the cross-sectional areas of the two resin flow paths A and B is set such that the sealing resin 5 injected from the resin flow path A and the sealing resin 5 injected from the resin flow path B are filled and completed in the mold 17 at the same time on the upper and lower surface sides of the control substrate 2.

[0036] For example, the volume ratio of the sealing resin 5 on the upper surface side of the control substrate 2 to the resin volume (V2 < V1) on the lower surface side of the control substrate 2 is approximately equal to the area ratio of the cross-sectional area (S1) on the upper surface side of the control substrate 2 to the cross-sectional area (S2 < S1) on the lower surface side in the gate portion 21. That is, the control substrate 2 is arranged in the mold 17 such that the relationship of V1:V2 ≒ S1:S2 is established.

[0037] The width of the cross section of the resin flow path A is substantially equal to the width of the cross section of the resin flow path B. As a result, the expansion of the sealing resin 5 during filling is equal on both surfaces of the control substrate 2, and the balance is good. Therefore, the height 22 of the cross section of the resin flow path A is made higher than the height 23 of the cross section of the resin flow path B.

[0038] In addition, in order to ensure the fluidity of the sealing resin 5, the sealing resin 5 is filled throughout the fine parts of the mold 17, and the mold 17, the assembly 20, and the sealing resin 5 are preferably preheated. The sealing resin 5 can also be a thermosetting epoxy resin, an unsaturated polyester resin, or a thermoplastic resin. As the sealing implementation method, it can be transfer molding, compression molding, injection molding, or hot melting. The sealing resin 5 preferably has a linear expansion coefficient of 10 to 30×10 -6 / °C, and the thermal conductivity is 0.5 to 3 W / mK. Thus, it is possible to suppress the separation of the sealing resin 5 and the control substrate 2.

[0039] After the sealing resin 5 is filled into the mold 17, the sealing resin 5 is cured in the mold 17. After curing, the mold 17 is opened to take out the resin molded product. After removing the excess area of ​​the gate portion 21, the molding is completed. Figure 2 The electronic control device 30 shown in (e) When the redundant area of ​​the gate portion 21 is removed, the gate mark 21a is formed.

[0040] In this embodiment, the resin frame 3 is shaped such that the resin volume on one surface side of the control substrate 2 is larger than the resin volume on the other surface side, the length of the control substrate 2 in the thickness direction of the gate mark 21a is formed to be larger than the thickness of the control substrate 2, the control substrate 2 is located in the projection area of ​​the gate mark 21a in a manner that a part of the side overlaps, and the control substrate 2 is arranged closer to one surface side than the center of the gate mark 21a. According to this structure, the difference in the resin filling time between one surface side and the other surface side of the control substrate 2 during molding can be reduced, the warping of the control substrate 2 during molding can be suppressed, and the reliability of the electronic control device 30 can be improved. Furthermore, the control substrate 2 is sealed with resin, so that the electronic control device 30 can be miniaturized, lightweight, and low-cost.

[0041] Furthermore, it is more preferable that, in order to make the resin filling timing the same (to substantially eliminate the difference), the area ratio (S1 / S2) of the area S1 of the gate mark 21a on the one surface side relative to the control substrate 2 to the area S2 of the gate mark 21a on the other surface side relative to the control substrate 2, and the volume ratio (V1 / V2) of the volume V1 of the frame body 3 on the one surface side relative to the control substrate 2 to the volume V2 of the frame body 3 on the other surface side relative to the control substrate 2 are substantially equal. By doing so, the warping of the control substrate 2 can be further suppressed, and the reliability can be further improved.

[0042] Furthermore, the resin flow paths A and B branch from one end 26 of the control substrate 2 to the upper and lower surfaces of the control substrate 2, so by changing the configuration and shape of the gate portion 21 and the control substrate 2, the pressure of the sealing resin 5 and 5 injected into these resin flow paths A and B can be adjusted.

[0043] The height 22 of the cross-sectional area of ​​the resin flow paths A and B is set to be larger than the thickness of the control substrate 2. The control substrate 2 is configured so that one end 26 is opposite to the resin flow paths A and B. Therefore, the configuration of one end 26 of the control substrate 2 is changed, thereby adjusting the pressure of the sealing resin 5 and 5 filled in these resin flow paths A and B.

[0044] The cross-sectional area (S1′) of the resin flow path A on the side where the connector 4 is arranged on both surfaces of the control substrate 2 is larger than the cross-sectional area (S2′) of the resin flow path B on the side where the connector 4 is not arranged, so the connector 4 can be sealed and the warping of the control substrate 2 can be suppressed.

[0045] Example 2

[0046] The second embodiment will be described in comparison with the first embodiment. The mold 27 of the second embodiment is different from the mold 17 of the first embodiment only in the structure of the gate portion, and the other structures are the same as the mold 17 of the first embodiment. Therefore, the description will be centered on the differences from the first embodiment.

[0047] Figure 4 It is an explanatory diagram showing the assembly procedure of the electronic control device according to the second embodiment.

[0048] In the first embodiment, if Figure 2 As shown in (d) of FIG. 1 , the gate portion 21 is a single body structure, but in the second embodiment, as shown in FIG. Figure 4 As shown in (d) of FIG. 8 , the gate portion 21 has a double structure including a first gate portion 24 and a second gate portion 25 .

[0049] That is, the mold 27 is provided with the first gate 24 and the second gate 25 so as to sandwich the control board 2. The size (area) of the first gate 24 is larger than the size (area) of the second gate 25.

[0050] Figure 5 It is a side view of the electronic control device according to the second embodiment.

[0051] like Figure 4As shown in (d), the first gate portion 24 is provided in the upper mold 18, and the second gate portion 25 is provided in the lower mold 19. After the sealing resin 5 is filled into the mold 27, the sealing resin 5 is hardened in the mold 27. After hardening, the mold 27 is opened, the resin molded product is taken out, and after removing the redundant areas of the first gate portion 24 and the second gate portion 25, the molding is completed. Figure 4 The electronic control device 40 shown in (e) of FIG. 1 is a schematic diagram showing an example of an electronic control device 40. The gate marks 24a and 25a are formed on the frame body 3 by the removal step.

[0052] like Figure 4 As shown in (e), the frame body 3 is formed with a first gate mark 24a and a second gate mark 25a. The first gate mark 24a is formed on the surface side of the control substrate 2 in the frame body 3 where the connector 4 is arranged, and the second gate mark 25a is formed on the surface side of the control substrate 2 in the frame body 3 where the connector 4 is not arranged. The frame body 3 is shaped such that the volume of the side where the connector 4 is formed relative to the control substrate 4 is larger than the volume of the side where the connector 4 is not formed relative to the control substrate 2, and the size (area) of the first gate mark 24a is larger than the size (area) of the second gate mark 25a.

[0053] In the present embodiment, the resin frame 3 is a shape in which the resin volume on one surface side of the control substrate 2 is larger than the resin volume on the other surface side, and the frame 3 has a first gate mark 24a formed on one surface side of the control substrate 2, and a second gate mark 25a formed on the other surface side of the control substrate 2, and the first gate mark 24a is larger than the second gate mark 25a. According to this structure, as in the first embodiment, the warping of the control substrate 2 can be suppressed, and the reliability can be improved. Furthermore, the gate is divided so that the one end 26 of the control substrate 2 does not overlap in the projection area, so that the sealing resin 5 is not easy to collide with the one end 26 of the control substrate, and it is easier to control the flow of the sealing resin 5. As a result, the warping of the control substrate 2 is easier to suppress than in the first embodiment.

[0054] In addition, as a more preferred example, the volume ratio of the volume of one surface side of the control substrate 2 of the frame 3 to the volume of the other surface side of the control substrate 2 of the frame 3, and the area ratio of the area of ​​the first gate mark 24a to the area of ​​the second gate mark 25a are roughly equal, so that the filling timing of the upper and lower parts (one surface side and the other surface side) of the control substrate 2 is the same, which can further suppress the warping of the substrate and improve the reliability.

[0055] In addition, the length of the first gate mark 24a in the thickness direction of the control substrate 2 is made larger than the length of the second gate mark 25a in the thickness direction of the control substrate 2, so that the length of the first gate mark 24a in the surface direction of the control substrate 2 is roughly equal to the length of the second gate mark 25a in the surface direction of the control substrate 2, and the size of the first gate part 24 and the second gate part 25 in the height direction is changed, so that the upper and lower resin injection speeds can be efficiently adjusted, and a low profile can be achieved.

[0056] Example 3

[0057] The third embodiment will be described in comparison with the first embodiment. The mold 37 of the third embodiment is different from the mold 17 of the first embodiment only in the structure of the gate portion, and the other structures are the same as the mold 17 of the first embodiment. Therefore, the description will be centered on the differences from the first embodiment.

[0058] Figure 6 It is a cross-sectional view of an electronic control device according to a third embodiment.

[0059] The die 37 is newly provided with a pair of movable pins 31 and 32. More specifically, the upper die 38 is provided with a through hole 33, and the movable pin 51 is inserted into the through hole 33. Furthermore, the lower die 39 is provided with a through hole 34, and the movable pin 52 is inserted into the through hole 34.

[0060] Figure 7 This is a flowchart showing the molding procedure of the electronic control device according to the third embodiment.

[0061] Next, the molding sequence of the electronic control device 50 is described. First, in a state where a pair of movable pins 31 and 32 are respectively inserted into a pair of through holes 33 and 34, the upper and lower surface sides of the control substrate 3 are arranged between the upper mold 38 and the lower mold 39, and the mold 37 is closed (S701). After that, the pair of movable pins 31 and 32 are brought close to the control substrate 2, and the control substrate 2 is supported from the upper and lower sides by the pair of movable pins 31 and 32 (S702), and the sealing resin 5 is injected from the gate portion 21 (S703). Next, it is determined whether the injection of the sealing resin 5 is completed (S704). In the case where the judgment of S704 is affirmative (S704: Yes), after the sealing resin 5 is hardened, the pair of movable pins 31 and 32 are separated from the control substrate 2 and pulled out from the upper mold 38 and the lower mold 39. (S705). Finally, the upper mold 38 and the lower mold 39 are separated (S706).

[0062] According to this configuration, since the pair of movable pins 31 and 32 support the control substrate 2 , it is possible to suppress the control substrate 2 from being warped while being filled with the sealing resin 5 .

[0063] As mentioned above, the embodiment of the electronic control device of the present invention is described in detail, but the present invention is not limited to the above embodiment, and various design changes can be made without departing from the scope of the spirit of the present invention described in the patent claims.

[0064] Explanation of symbols

[0065] 1…Electronic components, 2…Control board, 3…Frame, 4…Connector, 5…Sealing resin,

[0066] 10…terminal, 17…mold, 21…gate, 21a…gate mark,

[0067] 22 ... height of the cross section of the resin flow path A, 23 ... height of the cross section of the resin flow path B,

[0068] 24... the first gate, 24a... the gate mark, 25... the second gate,

[0069] 25a…gate mark, 26…one end, 27…mold,

[0070] 30...electronic control device, 31...movable pin, 32...movable pin, 37...mold,

[0071] 40 ... electronic control unit, A ... resin flow path, B ... resin flow path.

Claims

1. An electronic control device, characterized in that: have: a control substrate for mounting electronic components; and a frame body that seals the control substrate with resin, The frame is shaped such that the resin volume on one surface side of the control substrate is larger than the resin volume on the other surface side. The frame is formed with a gate mark, The length of the gate mark in the thickness direction of the control substrate is formed to be larger than the thickness of the control substrate. The control substrate is located in the projection area of ​​the gate mark in a manner that a part of the side surface overlaps. The control substrate is arranged closer to the other surface than the center of the gate mark. The area ratio of the area of ​​the gate mark closer to the one surface side than the control substrate to the area of ​​the gate mark closer to the other surface side than the control substrate, and the volume ratio of the volume of the frame closer to the one surface side than the control substrate to the volume of the frame closer to the other surface side than the control substrate are formed to be equal.

2. The electronic control device according to claim 1, characterized in that: A connector having a terminal electrically connected to the control substrate and mounted on one surface side of the control substrate, The gate mark is formed on a side surface of the frame body opposite to a side on which the connector is formed.

3. The electronic control device according to claim 2, characterized in that: The linear expansion coefficient of the resin is 10 to 30×10 -6 / ℃, thermal conductivity is 0.5~3.0W / mK.

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