Electronic control device and method for manufacturing same

Abstract

An electronic control device (10) is provided with longitudinal members (30) having a longitudinal shape and provided along two longitudinal edges (22, 22) of a printed circuit board (20). The longitudinal members (30) are each constructed such that when viewed from a direction along the longitudinal edges (22), a bonded part (31) that is bonded to a resin sealing member (13) sealing the printed circuit board (20), and a protruding part (35) that is integrated with the bonded part (31) and protrudes from the sealing member (13) are integrated.

Description

Electronic control device and manufacturing method thereof

[0001] The present invention relates to an electronic control device having a printed circuit board sealed with resin.

[0002] Vehicles such as four-wheeled vehicles and two-wheeled vehicles are provided with electronic control devices applicable to engine control units, etc. A conventional electronic control device is disclosed in Patent Document 1. The electronic control device disclosed in Patent Document 1 includes a printed circuit board on which electronic components are mounted, and a connector attached to the edge of the printed circuit board and capable of being connected to an external device.

[0003] Japanese Patent Application Laid-Open No. 2020-188175

[0004] Electronic control units mounted on vehicles are required to have waterproof and dustproof functions, so it is necessary to seal the electronic components and printed circuit boards. This electronic control unit further includes a case that houses the printed circuit board excluding the connector, and a resin sealing member that is filled in the case and seals the electronic components and printed circuit board. It is desirable to be able to manufacture the electronic control unit at low cost. An object of the present invention is to provide an electronic control unit that can be manufactured at low cost.

[0005] First, an electronic control device is provided, comprising: a rectangular plate-shaped printed circuit board having a widthwise edge extending in the width direction and two lengthwise edges extending in a lengthwise direction L perpendicular to the widthwise direction; a connector mounted on the widthwise edge of the printed circuit board and connectable to an external device; a resin sealing member sealing the printed circuit board; and a longitudinal member having a longitudinal shape provided along the lengthwise edge, wherein, when viewed from a direction along the lengthwise edge, the longitudinal member is integrally formed with a joint joined to the sealing member and a protrusion that is integrated with the joint and protrudes from the sealing member.

[0006] Secondly, preferably, in the electronic control device described in the first aspect, the protrusion has a first protrusion extending along the longitudinal edge and a second protrusion located at the end of the first protrusion and protruding further than the first protrusion.

[0007] Thirdly, in the electronic control device according to the first or second aspect, the joint portion preferably has a fitting recess that is recessed so that the longitudinal edge of the printed circuit board fits into the fitting recess.

[0008] Fourthly, there is provided a method for manufacturing an electronic control device, the method comprising: a preparation step of preparing a rectangular plate-shaped printed circuit board having a widthwise edge on which a connector connectable to an external device is mounted and two lengthwise edges extending in a direction perpendicular to the widthwise edge, and a longitudinal member extending along the lengthwise edge; an arrangement step of arranging the longitudinal member and the printed circuit board inside a molding die having a first mold and a second mold divided in the thickness direction of the printed circuit board; and a filling step of filling the inside of the molding die with molten resin, wherein the molding die has a support portion that is recessed so as to be able to support the longitudinal member in the arrangement step, and the support portion is formed from the first mold to the second mold.

[0009] Fifth, preferably, in the method for manufacturing an electronic control device described in the fourth aspect, the longitudinal member has a mating recess that is recessed so that the longitudinal edge of the printed circuit board fits into it, and in the placement process, first, the longitudinal edge of the printed circuit board is fitted into the mating recess of the longitudinal member to obtain a printed circuit board with the longitudinal member, and then the printed circuit board with the longitudinal member is fitted into the support portion of the molding die.

[0010] Sixth, preferably, in the method for manufacturing an electronic control device described in the fourth, the longitudinal member has a mating recess that is recessed so that the longitudinal edge of the printed circuit board fits into it, and in the positioning step, first, the longitudinal member is fitted into the support portion of the molding die, and then the longitudinal edge is slid along the mating recess of the longitudinal member to position the printed circuit board inside the molding die.

[0011] The present invention can provide an electronic control device with reduced manufacturing costs.

[0012] FIG. 1A is a perspective view of an electronic control device according to an embodiment. FIG. 1B is a view taken along the line 1B in FIG. 1A. FIG. 1C is a view taken along the line 1C in FIG. 1A. FIG. 2A is a cross-sectional view taken along the line 2A-2A in FIG. 1B. FIG. 2B is a cross-sectional view of an end of the electronic control device. FIG. 2C is a view taken along the line 2C in FIG. 2B. FIG. 3A is a diagram illustrating a preparation step. FIG. 3B is a perspective view of a printed circuit board with longitudinal members. FIG. 4A is a diagram illustrating an arrangement step. FIG. 4B is an enlarged view of a support portion of a molding die. FIG. 4C is a diagram illustrating the configuration of a longitudinal member supported by the support portion. FIG. 5A is a diagram illustrating a filling step. FIG. 5B is a diagram illustrating a demolding step. FIG. 6A is a diagram illustrating a demolding step according to the prior art. FIG. 6B is a diagram illustrating the operation according to an embodiment. FIG. 7A is a diagram illustrating a method of attaching a longitudinal member to a support portion of a molding die. FIG. 7B is a diagram illustrating a method of attaching a printed circuit board to the support portion.

[0013] An embodiment will be described with reference to the accompanying drawings. Fig. 1A shows an electronic control device 10 according to the embodiment. This electronic control device 10 can be applied to, for example, an engine control unit, and can be attached to the body of a vehicle (for example, a four-wheeled vehicle or a two-wheeled vehicle).

[0014] The electronic control device 10 comprises a printed circuit board 20 on which electronic components 11, 11 are mounted, a connector 12 mounted on the printed circuit board 20 and capable of electrically connecting to an external device (not shown), and a resin sealing member 13 that seals the electronic components 11, 11 and the printed circuit board 20.

[0015] (Printed Circuit Board) See Figures 1A to 1C. The printed circuit board 20 is a rectangular plate. The direction in which one of the edges of the printed circuit board 20 extends is defined as the width direction W, and the direction perpendicular to the width direction W is defined as the length direction L. The direction along the thickness of the printed circuit board 20 is defined as the thickness direction T.

[0016] 3A , the printed circuit board 20 has two surfaces 20a and 20b, of which the surface to which the connector 12 is attached is referred to as the connector surface 20a, and the surface opposite the connector surface 20a is referred to as the opposite surface 20b. The printed circuit board 20 has a widthwise edge 21 extending in the width direction W and two lengthwise edges 22 extending in the lengthwise direction L.

[0017] (Connector) The connector 12 is provided on the widthwise edge 21 and protrudes from the widthwise edge 21. The insertion direction of the connector 12 is the length direction of the printed circuit board 20. The shape and insertion direction of the connector 12 can be changed as appropriate.

[0018] (Longitudinal Members) See Figures 1A and 2A. Two longitudinal members 30 are provided adjacent to each longitudinal edge 22 of the printed circuit board 20. The two longitudinal members 30 sandwich the printed circuit board 20 in the width direction W. The material of the longitudinal members 30 may be, for example, a resin such as PBT or the same material as the sealing resin 13, and any material may be used as long as it has a predetermined rigidity. The length of the longitudinal members 30 may be longer or shorter than the length of the longitudinal edges 22 of the printed circuit board 20.

[0019] 2B , when viewed in a direction along the longitudinal edge 22 of the longitudinal member 30, each longitudinal member 30 has a joint portion 31 joined to the sealing member 13 and a protrusion 35 that is integral with the joint portion 31 and protrudes from the end surface 13 a of the sealing member 13.

[0020] (Joint Portion) The joint portion 31 is a portion embedded in the sealing member 13, and its surface is joined to the sealing member 13. The cross-sectional shape of the joint portion 31 is not limited to a rectangle and can be changed as appropriate.

[0021] (Mating recess) The inner surface 32 of the joint portion 31 (the surface facing the center of the width direction W of the printed circuit board 20) has a mating recess 33 that is recessed so as to fit over the longitudinal edge 22 of the printed circuit board 20. With the thickness direction T of the printed circuit board 20 as the reference, the mating recess 33 is located in the center.

[0022] 1A and 1B, the protrusion 35 has a first protrusion 40 extending along the longitudinal edge 22 and two second protrusions 50, 50 located at both ends of the first protrusion 40 in the longitudinal direction and protruding further than the first protrusion 40.

[0023] (Space) See Figures 2B and 2C. Due to the difference in the protrusion amounts between the first protrusion 40 and the two second protrusions 50, 50, a space S is formed to the side of the first protrusion 40 (in the direction in which the end surface 22a of the longitudinal edge 22 faces). This space S is surrounded by a plane including the side surface 51 of the second protrusion 50, a plane including the top surface 52 (the surface in the direction in which the connector surface 20a faces), a plane including the bottom surface 53 (the surface in the direction in which the opposite surface 20b faces), and the side surface 41 of the first protrusion 40. Note that the up-down direction is used for the purpose of explaining the embodiment and does not limit the orientation of the electronic control device 10 during manufacture, installation, or use.

[0024] The side surface 41 of the first protrusion 40 has a convex shape that protrudes laterally from its center (based on the thickness direction T of the printed circuit board 20), so the space S is approximately U-shaped. Note that the side surface 41 of the first protrusion 40 may be flat. If the side surface 41 is flat, the space S will be rectangular.

[0025] 2C, the upper surface 52 of the second protrusion 50 and the upper surface 42 of the first protrusion 40 are located on the same plane. The lower surface 53 of the second protrusion 50 and the lower surface 43 of the first protrusion 40 are located on the same plane.

[0026] (Method of Manufacturing Electronic Control Device) (Preparation Step) Referring to Fig. 3A, first, a printed circuit board 20 on which electronic components 11, 11 and a connector 12 are mounted, and two longitudinal members 30 each having a longitudinal shape extending along a longitudinal edge 22 of the printed circuit board 20 are prepared.

[0027] 3A and 3B, the fitting recesses 33 of the longitudinal members 30 are fitted into the longitudinal edges 22 of the printed circuit board 20. The printed circuit board 20 and the longitudinal members 30 are fixed to each other. In this way, a printed circuit board 20A with longitudinal members is obtained.

[0028] (Mold, First Mold, Second Mold) See Figures 4A and 4B. See Figure 4A. Next, a mold 60 having a cavity 60A is prepared. The mold 60 includes a first mold 61 and a second mold 62 that are separated in the thickness direction T of the printed circuit board 20.

[0029] 4A and 4B . The molding die 60 has two support portions 63, 63 that are recessed so as to be able to support the longitudinal member 30. Each support portion 63 is formed from the first die 61 to the second die 62. The area where the first die 61 and the second die 62 overlap is defined as an overlapping portion 64. The support portion 63 has a bottom surface 65 that includes an end portion 64a on the inside (cavity 60A side) of the overlapping portion 64 and extends along the thickness direction T of the printed circuit board 20, and a first wall surface 66 and a second wall surface 67 that extend from both ends of the bottom surface 65 along the width direction W of the printed circuit board 20.

[0030] 4A, the printed circuit board 20A with the longitudinal members is then fitted into the support portions 63, 63. As a result, the longitudinal members 30, 30 and the printed circuit board 20 are placed inside the molding die 60.

[0031] (Configuration of Support Portion and Longitudinal Member) See Fig. 4C . When the longitudinal member 30 is supported by the support portion 63, the side surface 51 of the second protruding portion 50 is in surface contact with the bottom surface 65. The upper surface 52 of the second protruding portion 50 and the upper surface 42 of the first protruding portion 40 are in surface contact with the first wall surface 66. The lower surface 53 of the second protruding portion 50 and the lower surface 43 of the first protruding portion 40 are in surface contact with the second wall surface 67. The area surrounded by the bottom surface 65, the first wall surface 66, the second wall surface 67, and the side surface 41 of the first protruding portion 40 forms a space S.

[0032] (Filling Step) See Figure 5A. Next, the cavity 60A of the molding die 60 is filled with the molten resin R. The method of filling the molten resin R can be selected as appropriate. For example, as shown in Figure 5A, the opening 60A of the molding die 60 may be directed upward, and the molten resin R may simply be poured in without applying pressure. Alternatively, pressure may be applied to the molten resin R to fill the cavity 60A with the molten resin R.

[0033] (Mold Release Process) See FIG. 5B. Finally, the first mold 61 and the second mold 62 are moved away from each other to obtain the electronic control device 10. A parting line 13C extending in the width direction W is formed on the end surface 13b of the sealing member 13 opposite the connector 12. See FIG. 1C. When viewed along the longitudinal edge 22, the parting line 13C is located between the two longitudinal members 30, 30.

[0034] 1A and 2A , an electronic control device 10 includes a rectangular printed circuit board 20 having a widthwise edge 21 extending in a width direction W and two lengthwise edges 22 extending in a lengthwise direction L perpendicular to the widthwise direction W, a connector 12 mounted on the widthwise edge 21 of the printed circuit board 20 and connectable to an external device, a resin sealing member 13 sealing the printed circuit board 20, and two longitudinal members 30 provided along each of the lengthwise edges 22 and sandwiching the printed circuit board 20 in the widthwise direction W.

[0035] 2B , when viewed in a direction along the longitudinal edge 22, each longitudinal member 30 is integrally formed with a joint portion 31 joined to the sealing member 13 and a protrusion portion 35 that is integral with the joint portion 31 and protrudes from the sealing member 13. The electronic control device 10 does not include a case, which reduces manufacturing costs.

[0036] (Second Effect) See Figure 6A. In the demolding process of the prior art, there is a process of pulling out the electronic control device 100 from the molding die 101. On the side opposite the opening 101a of the molding die 101, closed spaces 103, 103 are formed between the sealing member 104 of the electronic control device 10 and the molding die 60. The pressure in the closed spaces 103, 103 becomes negative, making it difficult to pull out the electronic control device 100.

[0037] The manufacturing method of the electronic control device 10 according to the embodiment includes a preparation process (see Figure 3A) of preparing a printed circuit board 20 and two longitudinal members 30, an arrangement process (see Figures 3B and 4A) of arranging the longitudinal members 30 and the printed circuit board 20 inside a molding die 60 having a first die 61 and a second die 62 divided in the thickness direction T of the printed circuit board 20, and a filling process (see Figure 5A) of filling molten resin inside the molding die 60.

[0038] Referring to Fig. 4A, the molding die 60 has two recessed support portions 63 that can support the longitudinal member 30 during the placement process. Referring to Fig. 4B, each support portion 63 is formed across the first die 61 and the second die.

[0039] 6B , after the resin is filled and cooled, the first mold 61 and the second mold 62 are moved away from each other (demolding process), thereby obtaining the electronic control device 10. The electronic control device 10 does not have a case, which reduces manufacturing costs.

[0040] Air flows into the molding die 60 through the gap at the overlapping portion 64, and branches off into the mounting surface side and the opposite surface side. No negative pressure is generated, making it easier to remove the electronic control device 10 from the molding die 60.

[0041] (Third Effect) See Figure 4C. The protruding portion 35 has a first protruding portion 40 extending along the longitudinal edge 22 and two second protruding portions 50 located at both ends of the first protruding portion 40 and protruding further than the first protruding portion 40. Therefore, when the longitudinal member 30 is supported by the supporting portion 63, a space S is formed between the supporting portion 63 and the longitudinal member 30. Compared to an example in which the space S is not provided and the longitudinal member 30 has a rectangular cross section, air is more likely to enter the interior of the molding die 60.

[0042] 2A and 2B , the joint portion 31 of the longitudinal member 30 has a fitting recess 33 that is recessed so that the longitudinal edge 22 of the printed circuit board 20 fits therein. Therefore, the longitudinal member 30 can be fixed to the printed circuit board 20.

[0043] (Fifth Effect) In the placement step, first, the longitudinal edge 22 of the printed circuit board 20 is fitted into the fitting recess 33 formed in the longitudinal member 30. Next, the longitudinal member 30 to which the printed circuit board 20 is attached is fitted into the support portion 63 of the molding die 60. The printed circuit board 20 and the longitudinal member 30 can be placed in the molding die 60 at one time.

[0044] 7A and 7B , in the placement step, the printed circuit board 20 may be placed inside the mold 60 by first fitting the longitudinal member 30 into the support portion 63 of the longitudinal member 30, and then sliding the longitudinal edge 22 along the fitting recess 33 of the longitudinal member 30.

[0045] It should be noted that the present invention is not limited to the examples provided that the functions and effects of the present invention are achieved.

[0046] REFERENCE SIGNS LIST 10...Electronic control device 11...Electronic component 12...Connector 13...Sealing member 20...Printed circuit board, 20A...Printed circuit board with longitudinal member 21...Width direction edge 22...Length direction edge 30...Longitudinal member 31...Joint portion 33...Fitting recess 35...Protrusion 40...First protrusion 50...Second protrusion 60...Molding die 61...First die 62...Second die 63...Support portion

Claims

1. a rectangular printed circuit board having a widthwise edge extending in a width direction and two lengthwise edges extending in a lengthwise direction perpendicular to the widthwise direction; a connector mounted on the widthwise edge of the printed circuit board and connectable to an external device; a resin sealing member that seals the printed circuit board; a longitudinal member provided along the longitudinal edge; When viewed along the longitudinal edge, An electronic control device, wherein the longitudinal member is integrally formed of a joint portion joined to the sealing member and a protrusion portion that is integral with the joint portion and protrudes from the sealing member.

2. 2. The electronic control device according to claim 1, wherein the protrusion has a first protrusion extending along the longitudinal edge and a second protrusion located at an end of the first protrusion and protruding further than the first protrusion.

3. 3. The electronic control device according to claim 1, wherein the joint portion has a mating recess that is recessed so that the longitudinal edge of the printed circuit board fits into the mating recess.

4. a preparation step of preparing a rectangular printed circuit board having a widthwise edge on which a connector connectable to an external device is mounted and two lengthwise edges extending in a direction perpendicular to the widthwise edge, and a longitudinal member extending along the lengthwise edges; an arrangement step of arranging the elongate member and the printed circuit board inside a molding die having a first die and a second die which are divided in a thickness direction of the printed circuit board; a filling step of filling the inside of the molding die with molten resin, the molding die has a recessed support portion capable of supporting the longitudinal member in the placing step, A method for manufacturing an electronic control device, wherein the support portion is formed across the first mold and the second mold.

5. the longitudinal member has a fitting recess that is recessed so that the longitudinal edge of the printed circuit board fits into the fitting recess, In the placing step, First, the longitudinal edge of the printed circuit board is fitted into the fitting recess of the longitudinal member to obtain a printed circuit board with the longitudinal member; The method for manufacturing an electronic control unit according to claim 4, further comprising the step of fitting the printed circuit board with the longitudinal members into the support portion of the molding die.

6. the longitudinal member has a fitting recess that is recessed so that the longitudinal edge of the printed circuit board fits into the fitting recess, In the placing step, First, the elongate member is fitted into the support portion of the mold; The method for manufacturing an electronic control unit according to claim 4 , further comprising the step of: sliding the longitudinal edge along the fitting recess of the elongate member to place the printed circuit board inside the molding die.