JP2023142259A - Electronic device - Google Patents

Abstract

To obtain an electronic device that reduces the amount of sealing resin used, reduces weight, and meets the requirements for vibration-proofing and waterproofing of a substrate.SOLUTION: A case member 10 of an electronic device 1 includes a partition wall 12 that partitions an internal space of the case member 10 into a first housing space S1 and a second housing space S2. A first substrate 30 is accommodated in a first housing space S1 with an annular first seal portion 40 sandwiched between the first substrate and one surface of the partition wall 12, a second substrate 32 is accommodated in a second housing space S2 with the annular second seal portion 42 sandwiched between the second substrate and the other surface of the partition wall 12, a first sealed space SX1 in which the sealing resin 50 does not enter is formed in the space between the partition wall 12 and the first substrate 30 surrounded by the first seal portion 40, and a second sealed space SX2 in which the sealing resin 50 does not enter is formed in a space between the partition wall 12 and the second substrate 32, which is surrounded by the second seal portion 42.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to electronic devices.

Patent Document 1 discloses a control box in which a first board is arranged on one side of a case with the bottom surface interposed therebetween, and a second board is arranged on the other side. In this control box, the amount of potting material used can be reduced by embedding only the first board in the potting material within the case and attaching and fixing the second board to the case.

Japanese Patent Application Publication No. 7-321472

A structure in which the substrate is attached to the case without being embedded in a potting material (sealing resin) like the second substrate described above may not be able to meet the requirements for vibration-proofing properties and waterproof properties of the substrate. On the other hand, if the second substrate is also embedded in potting material and fixed to the case, there is a problem that the amount of potting material used increases and the device becomes heavier.

The present invention has been made to solve the above problems, and is an electronic device that reduces the amount of sealing resin used, reduces weight, and meets the requirements for vibration-proofing and waterproofing of the board. The purpose is to provide equipment.

An electronic device according to a first aspect of the present invention includes a first substrate, a second substrate electrically connected to the first substrate, and a case member that accommodates the first substrate and the second substrate. An electronic device comprising: a partition that partitions an internal space of the case member into a first accommodation space in which the first board is accommodated and a second accommodation space in which the second board is accommodated. a first annular seal portion having a wall portion and disposed on one side of the partition wall portion; a second annular seal portion disposed on the other side of the partition wall portion; a first housing space and a sealing resin injected into the second housing space, the first substrate sandwiching the first seal part between one side surface of the partition wall part. The second substrate is housed in the first housing space, and the second substrate is housed in the second housing space with the second seal sandwiched between the second substrate and the other surface of the partition wall. A first sealed space in which the sealing resin does not enter is formed in a space between the partition wall portion surrounded by a seal portion and the first substrate, and the partition wall portion is surrounded by the second seal portion. A second sealed space in which the sealing resin does not enter is formed between the second substrate and the second substrate.

The electronic device according to the present invention includes a case member that houses a first board and a second board electrically connected to the first board. The first substrate and the second substrate are protected from vibration and adhesion of water droplets by being sealed with a sealing resin in the internal space of the case member. Further, the case member has a partition wall portion, and the partition wall portion divides the internal space of the case member into a first accommodation space in which the first board is accommodated and a second accommodation space in which the second board is accommodated. It is divided into two parts. Therefore, an amount of sealing resin optimized according to the circuit element configuration of the board to be accommodated is injected into each of the first accommodation space and the second accommodation space. Furthermore, since the first substrate is housed with the first seal section sandwiched between the partition wall section and the first substrate, a first sealing section is provided in which the sealing resin does not enter between the partition wall section and the first substrate. A space is formed. Similarly, the second board is housed with the second seal part sandwiched between it and the partition wall, so there is a second seal that prevents the sealing resin from entering between the partition wall and the second board. A space is formed. With this configuration, waterproof performance is ensured in the space between the partition wall portion and each substrate without injecting sealing resin, so the amount of resin can be reduced. In this way, the amount of sealing resin injected into the case member is optimized, making it possible to reduce the weight of the electronic device and also meet the requirements for vibration-proofing and waterproofing of the board.

FIG. 1 is an exploded perspective view of an electronic device according to an embodiment. FIG. 1 is a cross-sectional view of an electronic device according to an embodiment. FIG. 1 is a partially enlarged sectional view of an electronic device according to an embodiment. FIG. 3 is an exploded perspective view showing the positional relationship between the first housing space and the first seal portion of the case member according to the embodiment. FIG. 3 is a plan view of the first housing space of the electronic device according to the embodiment, viewed from above. FIG. 1 is a block diagram schematically showing an electronic device according to an embodiment.

A first embodiment of the present invention will be described with reference to FIGS. 1 to 6. In this embodiment, for convenience of explanation, the directions indicated by the up-down, left-right, and front-back arrows shown as appropriate in each figure are defined as the up-down direction, the left-right direction, and the front-back direction of the electronic device 1, respectively.

In this embodiment, an electronic device 1 that mutually converts power between direct current and alternating current will be described as an example of an electronic device according to the present invention. As shown in FIG. 6, the electronic device 1 includes a first substrate 30 having a power conversion circuit section 2 and a second substrate 32 electrically connected to the first substrate 30. The second substrate 32 is provided with a control section 3 that is electrically connected to the power conversion circuit section 2 and controls mutual conversion of power between direct current and alternating current. This second board 32 also has a first power port 4 and a second power port that constitute ports for power supplied (input) to the power inverter circuit section 2 and power output from the power inverter circuit section 2. 5 is provided. The first power port 4 is a power port for DC power that enables input/output of DC current, and can be used for inputting DC power supplied from an external DC power supply or for power conversion. The circuit unit 2 outputs the electric power converted to direct current. The second power port 5 is a power port for AC power that enables input/output of AC power, and inputs AC power supplied from an external AC power supply or power converted to AC by the power conversion circuit unit 2. is output.

The power inverter circuit section 2 includes an inverter circuit section 2A and a converter circuit section 2B. The inverter circuit unit 2A has a function of converting DC power supplied from the first power port 4 into AC power, and has a plurality of switching elements (semiconductor elements 52 to be described later) composed of MOSFETs, IGBTs, etc. include. The inverter circuit unit 2A controls the on-state and off-state of a plurality of switching elements based on the control signal output from the control unit 3, and converts DC power into AC power. The power converted into alternating current by the inverter circuit section 2A can be supplied to an external load via the second power port 5. The converter circuit unit 2B has a function of converting AC power supplied from the second power port 5 into DC power, and includes a plurality of semiconductor elements (semiconductor elements 52 to be described later) including rectifying diodes and the like. including. The converter circuit unit 2B converts AC power into DC power by rectifying the power based on a control signal output from the control unit 3. The power converted to direct current by the converter circuit section 2B can be supplied to a battery or an external load via the first power port 4.

As shown in FIGS. 1 to 3, the first substrate 30 and the second substrate 32 are housed inside the box-shaped case member 10. The case member 10 includes a partition wall 12 that partitions an internal space, a first side wall 14 that stands on one side (upper side in FIG. 1) from the periphery of the partition wall 12, and a first side wall 14 that extends from the periphery of the partition wall 12. It has a second side wall portion 16 erected on the other side (lower side in FIG. 1). The first substrate 30 is housed inside the case member 10 in a first housing space S1 formed by the partition wall part 12 and the first side wall part 14. The second board 32 is accommodated in a second accommodation space S2 formed by the partition wall portion 12 and the second side wall portion 16 inside the case member 10. Note that in FIG. 1, circuit elements mounted on the first substrate 30 and the second substrate 32 are omitted.

Although the material for molding the case member 10 is not particularly limited, for example, the case member 10 can be molded using a metal material or a resin material. The case member 10 of this embodiment is formed by molding a resin material, for example. By molding the case member 10 from a resin material, the first substrate 30 and the second substrate 32 are arranged in the internal space of the case member 10 with the partition wall 12 having insulation properties separated. Thereby, insulation between the first substrate 30 and the second substrate 32 can be easily ensured, and the distance between the substrates can be shortened. Furthermore, the weight of the case member 10 can be reduced.

In the first accommodation space S1 of the case member 10, a rising portion 18 is formed on the upper surface of the partition wall portion 12 and is one step higher than the upper surface. The rising portion 18 is formed in an annular shape along the inner surface of the first side wall portion 14 . A first substrate 30 is fixed to this annular rising portion 18 . The rising portion 18 has a plurality of mount portions 20 provided at predetermined intervals in the circumferential direction of the rising portion 18, and a seal groove 22 formed in a concave shape on the upper surface of the rising portion 18. The seal groove 22 is formed in an annular shape over the entire circumference of the rising portion 18 . The mount portion 20 is provided outside the seal groove 22 on the upper surface of the rising portion 18 . Each mount portion 20 is formed with a through hole penetrating toward the second accommodation space S2 side. The first board 30 has a bolt 24 inserted through a mounting hole (numerical omitted) formed through the end of the board and a through hole of the mount section 20, and a nut 26 attached to the tip of the bolt 24 protruding into the housing space on the opposite side. It is fixed to the case member 10 by screwing them together. Note that a female thread may be formed on the inner peripheral surface of the through hole of the mount portion 20.

Here, the bolts 24 and nuts 26 used as fastening members for the first board 30 are also used in the second accommodation space S2 as fastening members for the second board 32. The bolt 24 inserted into the through hole of the mount portion 20 is also inserted into a mounting hole (numerical omitted) formed through the end of the second board 32 in the second housing space S2. Thereby, the first board 30 and the second board 32 are fastened together using the common bolts 24 and nuts 26, and the number of parts of the fastening member and the number of mounting parts provided on the case member 10 can be reduced.

Further, when the first substrate 30 and the second substrate 32 are formed of printed wiring boards, measures are required to suppress the intrusion of noise from outside the substrate and the emission of noise from within the substrate. To counter these noises, a GND pattern is generally provided at the edge of the substrate. The GND pattern includes a copper pattern formed to surround the edge of the substrate, and vias provided at equal intervals in the copper pattern. By arranging a control signal line (wiring pattern) inside the GND pattern, the intrusion of noise from outside the board and the emission of noise from within the board are suppressed. In this embodiment, when the first substrate 30 and the second substrate 32 are formed of printed wiring boards, a metal fastening member is arranged along the edge of the substrate where the GND pattern is provided. Therefore, the GND of the substrate is strengthened, and noise resistance performance can be improved.

As shown in FIG. 4, the first seal portion 40 is inserted into an annular seal groove 22 formed in the rising portion 18 on one side (upper surface) of the partition wall portion 12. As shown in FIG. The first seal part 40 is made of an elastic material such as a rubber material, and has an annular part 46 inserted into the seal groove 22 and a plurality of protruding pieces 48 provided along the extending direction of the annular part 46. ing. The annular portion 46 is formed in the shape of an O-ring and has a circular cross section. The outer diameter of this circular cross section is set larger than the depth of the seal groove 22. Therefore, when the annular portion 46 is inserted into the seal groove 22, the tip side protrudes from the seal groove 22. Each of the plurality of protruding pieces 48 is a small plate-shaped piece that is integrally formed with the annular portion 46 . Each protruding piece 48 is provided to protrude outward from the annular portion 46 and is configured to be fitted into a positioning recess 23 formed integrally with the seal groove 22 . In this state, the plurality of mount parts 20 are arranged outside the first seal part 40 so as to surround the first seal part 40.

The first substrate 30 is accommodated in the first accommodation space S<b>1 with the first seal portion 40 sandwiched between the first substrate 30 and the upper surface of the partition wall portion 12 . As shown in FIG. 5, when accommodated in this manner, the plurality of protruding pieces 48 formed on the first seal portion 40 protrude outward from the outer peripheral end of the first substrate 30, so that the first substrate It can be visually observed from the upper side of 30. The position of the protruding piece 48 allows the assembling worker to grasp the fit of the first seal portion 40 in the case member 10. Therefore, when the protrusion piece 48 is in the prescribed position, it can be determined that the sealing performance between the partition wall part 12 and the first substrate 30 is satisfied by the first seal part 40. Therefore, when the first seal portion 40 falls off from the seal groove 22, it can be discovered that the sealing performance is impaired.

As shown in FIG. 2, when the end of the first substrate 30 is fixed to the mount section 20, the first seal section 40 inserted into the seal groove 22 is crushed and tightly attached to the opposing surface of the first substrate 30. do. As a result, a first sealed space SX1 is formed between the partition wall section 12 surrounded by the first seal section 40 and the first substrate 30. The first substrate 30 is partially or completely embedded and sealed in the sealing resin 50 injected into the first housing space S1, so that vibrations when the electronic device 1 is used and water droplets that have entered the inside can be prevented. protected from etc.

The first sealed space SX1 between the partition wall part 12 and the first substrate 30 is sealed by the first seal part 40, and is a space in which the sealing resin does not enter. Furthermore, in the first sealed space SX1, the mounting surface of the first substrate 30 facing the partition wall 12 can be protected from water droplets that have entered the inside of the electronic device 1. In this way, the first accommodation space S1 does not require a sealing resin for sealing one side of the first substrate 30, so the amount of resin injected into the first accommodation space S1 can be reduced. I can do it.

The internal space of the case member 10 has the same configuration as the first housing space S1 also in the second housing space S2 on the opposite side across the partition wall portion 12. That is, in the second accommodation space S2, the second seal part 42 having the same configuration as the first seal part 40 is arranged on the other side (lower surface) of the partition wall part 12. The second board 32 is housed with the second seal part 42 sandwiched between the bottom surface of the partition wall part 12 and the space between the partition wall part 12 surrounded by the second seal part 42 and the second board 32. A second sealed space SX2 in which the sealing resin 50 does not enter is formed. This second substrate 32 is also partially or completely sealed with the sealing resin 50 injected into the second housing space S2, so that it is protected from vibrations when the electronic device 1 is used, water droplets that have entered the inside, etc. protected.

By the way, the above-mentioned power inverter circuit section 2 is provided on the mounting surface (the upper surface in FIG. 2) of the first substrate 30 on the opposite side to the surface facing the partition wall section 12. A plurality of semiconductor elements 52 constituting the power conversion circuit section 2 are mounted on the first substrate 30 while being fixed to a block-shaped heat sink 54 in order to efficiently release heat generated by energization during operation. . A plurality of smoothing capacitors 56 are also mounted on the same mounting surface. With this configuration, relatively tall components are arranged in a concentrated manner on the mounting surface of the first board 30. On the other hand, the control unit 3, the first power port 4, and the second power port 5 are mounted on the mounting surface (lower surface in FIG. 2) of the second board 32 opposite to the surface facing the partition wall 12. There is. The control unit 3 is composed of a small control IC composed of a CPU (Central Processing Unit) and the like. With this configuration, relatively short components are arranged in a concentrated manner on the mounting surface of the first board 30.

Since a large current flows through the power conversion circuit section 2 compared to the current flowing through the control IC of the second substrate 32, for example, in order to ensure insulation between the lead section of the semiconductor element 52 and the mounting surface of the first substrate 30, , it is necessary to provide the sealing resin 50 with a sufficient thickness. Therefore, as shown in FIG. 3, the thickness T1 of the sealing resin 50 injected into the first accommodation space S1 is set larger than the thickness T2 of the sealing resin 50 injected into the second accommodation space S2. .

A through hole 60 is formed in the partition wall portion 12 to penetrate inside the first and second seal portions 40 and 42 and communicate the first housing space S1 and the second housing space S2. A terminal member 62 that electrically connects the signal line of the power conversion circuit section 2 of the first substrate 30 and the control section 3 of the second substrate 32 is inserted into the through hole 60 . Although the type of the terminal member 62 is not limited, in this embodiment, the terminal member 62 is configured with a floating connector that facilitates absorption of tolerances during assembly. The terminal member 62 includes, for example, a female connector 66 in which a male connector 64 having a plurality of conductor pins is connected to the first board 30 side, and the tips of the conductor pins of the male connector 64 are arranged on the opposing surface of the second board 32. It is connected to the.

(action and effect)
As described above, the electronic device 1 of this embodiment includes the case member 10 that accommodates the first board 30 and the second board 32 that is electrically connected to the first board 30. The first substrate 30 and the second substrate 32 are protected from vibration and adhesion of water droplets by being sealed with a sealing resin 50 in the internal space of the case member 10.

Further, in the electronic device 1, the case member 10 has the partition wall 12, and the partition wall 12 divides the internal space of the case member 10 into a first accommodation space S1 in which the first substrate 30 is accommodated, and a first accommodation space S1 in which the first substrate 30 is accommodated. It is partitioned into a second accommodation space S2 in which two substrates 32 are accommodated. Therefore, an amount of sealing resin optimized according to the circuit element configuration of the board to be accommodated is injected into each of the first accommodation space S1 and the second accommodation space S2. Furthermore, since the first substrate 30 is accommodated with the first seal portion 40 sandwiched between it and the partition wall portion 12, there is no sealing resin between the partition wall portion 12 and the first substrate 30. A first sealed space SX1 that cannot be entered is formed. Similarly, the second substrate 32 is accommodated with the second seal portion 42 sandwiched between it and the partition wall portion 12, so there is no sealing resin between the partition wall portion 12 and the second substrate 32. A second sealed space SX2 that cannot be entered is formed. With this configuration, waterproof performance is ensured in the space between the partition wall portion 12 and each substrate without injecting the sealing resin 50, so that the amount of resin can be reduced. In this way, the amount of sealing resin 50 injected into the case member 10 is optimized, making it possible to reduce the weight of the electronic device 1 and to meet the requirements for vibration-proofing and waterproofing of the board. can.

The protruding pieces 48 provided on the first seal section 40 and the second seal section 42 are arranged so that the first seal section 40 and the second seal section 42 are arranged along the edge side of the corresponding substrate. It is configured to protrude outward from the outer peripheral end. As a result, even when the substrate is stacked on the first seal section 40 and the second seal section 42, it is possible to grasp the fit of the first seal section 40 and the second seal section 42 based on the position of the protruding piece 48. It is possible to visually check whether the first sealed space SX1 and the second sealed space SX2 satisfy the desired sealing properties. Furthermore, among the plurality of protruding pieces 48 , some of the protruding pieces 48 used as a reference for positioning during accommodation are shaped differently from other protruding pieces 48 , so that the protruding pieces 48 can be used as reference points for positioning when accommodated in the case member 10 . A configuration may be adopted in which the orientation of the first seal portion 40 and the second seal portion 42 is intuitively communicated to the operator.

The first substrate 30 and the second substrate 32 separated by the partition wall 12 are electrically connected via the terminal member 62 inserted into the through hole 60 of the partition wall 12, so that a connection line between the substrates is formed. It is possible to shorten the time and increase wiring efficiency.

A power conversion circuit section 2 including a plurality of switching elements (semiconductor elements 52) is provided on the first substrate 30, and a control section 3 for controlling the on-state and off-state of the switching elements is provided on the second substrate 32. Thereby, the heat generated by the switching element is blocked by the partition wall part 12, and the control part 3 can be protected from the heat generated by the switching element.

Since the first power port 4 that allows input/output of DC power and the second power port 5 that allows input/output of AC power are provided on the second board 32 together with the control unit 3, the power supply and external load ( connection to the power supply target) can be made all at once from one side of the case member 10. Therefore, it is excellent in assembly workability and maintainability.

By molding the case member 10 with resin, it is possible to easily ensure an insulating distance between the substrates separated by the partition wall portion 12.

The first board 30 and the second board 32 are fixed to the case member 10 by common fastening members (bolts 24 and nuts 26) via a mount part 20 formed on the partition wall part 12. Thereby, the number of parts of the fastening member and the number of mount parts provided on the case member 10 can be reduced, and it is possible to reduce the manufacturing cost and the working time required for assembly.

The first substrate 30 and the second substrate 32 are fixed at their end sides by a plurality of fastening members made of metal material. Therefore, when the first board 30 and the second board 32 are configured with printed wiring boards, a metal fastening member is placed along the outer peripheral edge of the board where the GND pattern is provided, so that the GND of the board is strengthened. It is possible to improve noise resistance performance. Moreover, the noise resistance performance can be further improved by arranging the plurality of fastening members at finer intervals.

[supplementary explanation]
In the embodiment described above, the first seal portion 40 is formed of an elastic material such as a rubber material, but the present invention is not limited to this. The first seal portion 40 can also be configured by arranging a metal gasket, a foam adhesive, a silicone liquid adhesive (CIPG), etc. in an annular shape.

1 Electronic device 2 Power conversion circuit section 3 Control section 4 First power port 5 Second power port 10 Case member 12 Partition wall section 20 Mount section 24 Bolt (fastening member)
26 Nut (fastening member)
30 First board 32 Second board 40 First seal part 42 Second seal part 50 Sealing resin 60 Through hole 62 Terminal member S1 First housing space S2 Second housing space SX1 First sealed space SX2 Second sealed space

Claims (5)

An electronic device comprising a first substrate, a second substrate electrically connected to the first substrate, and a case member housing the first substrate and the second substrate,
The case member has a partition wall portion that partitions the internal space of the case member into a first storage space in which the first board is stored and a second storage space in which the second board is stored,
an annular first seal portion disposed on one side of the partition wall portion;
an annular second seal portion disposed on the other side surface of the partition wall portion;
A sealing resin injected into the first accommodation space and the second accommodation space,
The first substrate is accommodated in the first accommodation space with the first seal section sandwiched between the first substrate and one surface of the partition wall section,
The second substrate is accommodated in the second accommodation space with the second seal section sandwiched between the second substrate and the other surface of the partition wall section,
A first sealed space in which the sealing resin does not enter is formed in a space between the partition wall portion surrounded by the first seal portion and the first substrate;
An electronic device, wherein a second sealed space in which the sealing resin does not enter is formed in a space between the partition wall portion surrounded by the second seal portion and the second substrate. The first and second seal portions are composed of annular seal members and have a plurality of protruding pieces provided at predetermined intervals in the extending direction,
The plurality of protruding pieces extend outward from an edge on the outer peripheral side of each substrate, with the first and second seal portions being respectively disposed between the first and second substrates and the partition wall portion. 2. The electronic device of claim 1, wherein the electronic device is adapted to protrude. The partition wall portion has a through hole that is formed to penetrate inside the first and second seal portions and communicates the first storage space and the second storage space,
3. The electronic device according to claim 1, wherein a terminal member for electrically connecting the first substrate and the second substrate is inserted into the through hole. a power conversion circuit section that includes a plurality of switching elements and performs mutual conversion of power between direct current and alternating current;
a control unit that controls an on state and an off state of the switching element;
a first power port that enables input and output of DC power;
A second power port that enables input and output of AC power,
The power conversion circuit section is provided on the first substrate,
The control unit, the first power port, and the second power port are provided on the second board and electrically connected to the power conversion circuit unit via the terminal member. electronic devices. The case member is formed by molding a resin material,
a plurality of mount portions formed through the partition wall portion outside the first and second seal portions;
a plurality of fastening members that fix the first and second substrates to the case member via the mount section,
The fastening member is formed by molding a metal material, is inserted into the mounting hole of the first board from the first housing space side, protrudes to the second housing space side via the mount part, and is inserted into the mounting hole of the first board from the side of the first housing space, and protrudes into the second housing space side through the mount part. The electronic device according to any one of claims 1 to 4, which is inserted into the mounting hole.