Substrate unit

Abstract

To provide a substrate unit that can be downsized.SOLUTION: A substrate unit according to the embodiment has a first substrate and a second substrate. The first substrate is mounted with electronic components for control. The second substrate is mounted with electronic components for the power supply and is arranged so that the surface on which the electronic components for the power supply are mounted is opposite the first substrate. The first substrate has an opening that can accommodate electronic components for the power supply.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The disclosed embodiments relate to a substrate unit.

Background Art

[0002] In recent years, with the miniaturization of products, there has been a demand to miniaturize the electronic substrates included in the products. Also, various techniques related to the miniaturization of such electronic substrates have been proposed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, electronic substrates include, for example, a substrate on which control electronic components are mounted and a substrate on which power supply electronic components are mounted. By combining these substrates into a unit, miniaturization may be achieved. However, there has been room for improvement in the prior art in terms of miniaturizing a substrate unit including such substrates.

[0005] One aspect of the embodiment aims to provide a substrate unit capable of achieving miniaturization.

Means for Solving the Problems

[0006] A substrate unit according to one aspect of the embodiment includes a first substrate on which control electronic components are mounted, and a second substrate on which power supply electronic components are mounted and which is arranged such that the surface on which the power supply electronic components are mounted faces the first substrate. The first substrate includes an opening capable of accommodating the power supply electronic components.

[0007] Thus, even when the first substrate and the second substrate are arranged so as to overlap each other, the power supply electronic component of the second substrate is housed in the opening and thus does not come into contact with the first substrate. Therefore, the clearance between the first and second substrates can be reduced, the height when the first and second substrates are combined can be lowered, and thus the size of the substrate unit can be reduced.

[0008] Also, even when the first and second substrates are coated, since the height when the first and second substrates are combined is low, the coating height is also such that coating up to a height where there is concern about the intrusion of the coating material is unnecessary, and it will not reach a height where unnecessary parts are coated. That is, it becomes possible to appropriately coat the parts that require coating. In this way, by appropriately coating the electronic components, while relaxing the insulation distance, the distance (height) between the substrates can be shortened to achieve further miniaturization.

[0009] Further, the first substrate is arranged so as to be in contact with the second substrate on the surface on which the power supply electronic component is mounted.

[0010] Thereby, the clearance between the first and second substrates can be further reduced, the height when the first and second substrates are combined can be further lowered, and thus the size of the substrate unit can be reduced.

[0011] Further, the opening is a through hole.

[0012] Thereby, the strength of the first substrate can be ensured while forming the opening. Also, since the opening is a through hole, the opening can be easily formed.

[0013] Further, the opening is covered by the second substrate.

[0014] Thus, since the opening is covered by the second substrate, a portion overlapping with the second substrate is formed around the opening of the first substrate. By forming a connecting member for connecting the first substrate and the second substrate, for example, at this overlapping portion, the first substrate and the second substrate can be easily connected.

[0015] Further, in a plan view of the first substrate, the shape of the opening is formed to be different from the shape of the second substrate.

[0016] Thereby, it becomes possible to make the area of the opening relatively large in a plan view. When the area of the opening becomes relatively large, for example, even when a design change is made to the power supply electronic component such as an increase in the number of power supply electronic components accommodated in the opening or a change in the mounting position, it is possible to cope without changing the shape of the opening.

Advantages of the Invention

[0017] According to one aspect of the embodiment, miniaturization can be achieved in the substrate unit.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0019] Hereinafter, with reference to the accompanying drawings, embodiments of the substrate unit disclosed in the present application will be described in detail. Note that the present invention is not limited by the embodiments shown below.

[0020] (Embodiment) The substrate unit according to the embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a plan view of the substrate unit according to the embodiment, and FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1. Note that FIGS. 1, 2, and FIGS. 4 and later are all schematic diagrams.

[0021] Also, in FIGS. 1 and 2, for convenience of explanation, a three-dimensional orthogonal coordinate system defined by the X-axis direction, Y-axis direction, and Z-axis direction that are orthogonal to each other is illustrated. Such an orthogonal coordinate system may also be shown in other drawings used in the following explanation. Note that in the following explanation, expressions such as "X-axis direction", "Y-axis direction", and "Z-axis direction" are used, which mean the "X-axis direction", "Y-axis direction", and "Z-axis direction" when the substrate unit is in the illustrated state, and do not limit the arrangement direction of the substrate unit, etc.

[0022] The substrate unit 1 is mounted on a product (not shown) and performs control of such a product, power supply to the product, etc. Note that the product may be any product on which the substrate unit 1 can be mounted. Examples of the product include, but are not limited to, a toilet device, a bidet device, an electric appliance, an electronic device, etc.

[0023] As shown in FIGS. 1 and 2, the substrate unit 1 includes a first substrate 10, a second substrate 20, and a case 30.

[0024] The first substrate 10 is, for example, flat and is formed in a rectangular or substantially rectangular shape in a plan view (viewed in the Z-axis direction). Note that the shape of the first substrate 10 shown in FIG. 1 is an example and is not limiting.

[0025] On the first substrate 10, control electronic components 11, a voltage conversion section 12, a connector 13, a load driving section 14, a load 15, etc. are mounted. The control electronic components 11 include a microcomputer or the like that controls the load driving section 14 and the like. The voltage conversion section 12 steps down the DC voltage supplied from the second substrate 20 as described later, and supplies power to the load 15, the control electronic components 11, an external load (not shown) connected to the connector 13, etc. As the voltage conversion section 12, a switching regulator IC or the like can be used.

[0026] An external load (not shown) is connected to the connector 13. Examples of the external load include, but are not limited to, a motor, a display device (display), a lighting device, etc. The load driving section 14 is a component (e.g., a switching element (e.g., a transistor)) that drives the load 15 in response to a driving instruction from the control electronic components 11, for example. Examples of the load 15 include, but are not limited to, a buzzer.

[0027] In this way, the first substrate 10 is configured such that components related to the control of the load and the like and components related to the power supply such as voltage conversion are mounted on a single substrate.

[0028] In the examples shown in FIGS. 1 and 2, each component such as the control electronic components 11 is mounted on the front surface 10a of the first substrate 10, but it is not limited to this, and a part of each component may be mounted on the back surface 10b of the first substrate 10. Also, each component mounted on the first substrate 10 described above is an example and is not limited, and a configuration in which a part of each component is not mounted on the first substrate 10 may be adopted. Also, in the first substrate 10, the positions where each component is mounted are also examples and are not limited. Also, the mounting of each component on the first substrate 10 may be surface mounting connected via pads or the like provided on the surface of the first substrate 10, or insertion mounting in which the leads are inserted into the through holes of the first substrate 10 and connected. Also, the control electronic components 11, the voltage conversion section 12, and the load driving section 14 may include electronic components such as resistors and capacitors.

[0029] In addition, the first substrate 10 is formed with insertion holes 16 (see FIG. 2) through which the connection connectors 23 of the second substrate 20 described later can be inserted. The first substrate 10 and the second substrate 20 are electrically connected when the connection connectors 23 are inserted into the insertion holes 16. Note that the connection connectors 23 and the insertion holes 16 can also be said to be connecting members that connect the first substrate 10 and the second substrate 20.

[0030] The second substrate 20 is, for example, flat and is formed in a rectangular shape or a substantially rectangular shape in a plan view (view in the Z-axis direction). Further, the second substrate 20 is formed so that its area is smaller than the area of the first substrate 10 in a plan view. Note that the shape of the second substrate 20 shown in FIG. 1 is an example and is not limited.

[0031] Various components for controlling the power supply supplied to the product are mounted on the second substrate 20. The second substrate 20 on which these various components are mounted is a so-called power module in which the power components corresponding to the product are modularized.

[0032] Here, the power module 120 will be described with reference to FIG. 3. FIG. 3 is a block diagram showing a configuration example of the power module 120.

[0033] As shown in FIG. 3, the power module 120 includes an input unit 121, a filter unit 122, a smoothing unit 123, an SW unit (switch unit) 124, an output unit 125, a voltage detection unit 126, and a control unit 127.

[0034] The input unit 121 receives, for example, an alternating current from an AC power supply A and outputs the input alternating current to the filter unit 122. The filter unit 122 removes noise from the input alternating current and outputs it to the smoothing unit 123. The smoothing unit 123 converts the alternating current input from the filter unit 122 into a direct current and outputs it to the SW unit 124. The SW unit 124 steps down the voltage of the direct current input from the smoothing unit 123 and outputs it to the output unit 125. The output unit 125 outputs the direct current stepped down by the SW unit 124 to the first substrate 10 via the above-described connection connector 23 (see FIG. 2).

[0035] The voltage detection unit 126 detects the voltage of the direct current output from the output unit 125 and outputs a signal indicating the detected voltage value to the control unit 127. The control unit 127 controls the SW unit 124 and the like based on various signals such as the signal indicating the voltage value. Note that the power supply module 120 may be configured without some elements such as the input unit 121.

[0036] The above-described input unit 121, filter unit 122, smoothing unit 123, SW unit 124, output unit 125, voltage detection unit 126, and control unit 127 include electronic components such as capacitors, transformers, varistors, resistors, and switching regulator ICs. Since these electronic components are components related to the power supply supplied to the product, they are described as "electronic components 21 for power supply" in this specification. Such electronic components 21 for power supply are mounted on the second substrate 20 as described above. As a configuration example of the power supply module 120 including the second substrate 20, there is one described in Japanese Patent Application Laid-Open No. 2023-500268 of the Japan Institute of Invention and Innovation.

[0037] Next, the second substrate 20 on which the electronic components 21 for power supply are mounted will be described with reference to FIGS. 4 to 6. FIG. 4 is a plan view when the second substrate 20 is viewed from the front surface 20a. FIG. 5 is a side view of the second substrate 20, and FIG. 6 is a bottom view when the second substrate 20 is viewed from the back surface 20b.

[0038] As shown in FIGS. 4 to 6, the electronic components 21 for power supply are mounted on the front surface 20a and the back surface 20b of the second substrate 20, respectively. Hereinafter, the electronic components 21 for power supply mounted on the front surface 20a may be described as "electronic components 21a for power supply", and the electronic components 21 for power supply mounted on the back surface 20b may be described as "electronic components 21b for power supply".

[0039] In addition, in the second substrate 20 shown in FIGS. 4 to 6, the positions where the power supply electronic components 21a and 21b are mounted are examples and are not limited. Also, the mounting of the power supply electronic components 21a and 21b on the second substrate 20 may be surface mounting connected via pads or the like provided on the surface of the second substrate 20, or may be insertion mounting in which leads are inserted into through holes of the second substrate 20 for connection.

[0040] Further, the second substrate 20 includes the above-described connection connector 23. A plurality (for example, four) of connection connectors 23 are provided at the four corners of the second substrate 20 in a plan view. The connection connector 23 has a pin shape and is formed to protrude from the back surface 20b of the second substrate 20.

[0041] Returning to the description of FIGS. 1 and 2, the case 30 is a rectangular parallelepiped housing with an open upper (positive Z-axis direction) surface. The first substrate 10 and the second substrate 20 are disposed in the internal space B, and the first substrate 10 and the second substrate 20 are housed. Specifically, the second substrate 20 is disposed above (in the positive Z-axis direction) the first substrate 10, and the first substrate 10 and the second substrate 20 are housed in the case 30 in a state where they overlap.

[0042] As described above, in the substrate unit 1 according to the present embodiment, the first substrate 10 on which the control electronic components 11 and the like are mounted and the second substrate 20 on which the power supply electronic components 21 are mounted are combined and unitized. Thereby, the substrate unit 1 can be miniaturized.

[0043] Here, in an electronic substrate, regulations are defined regarding the distance (insulation distance) between pattern lines between different poles on the substrate. In such regulations, the insulation distance required when the components subject to the regulations are coated with resin or the like is defined to be shorter than the insulation distance required when they are not coated. This is because when the components are coated, it becomes difficult for dust to enter the components and it also becomes difficult for metal powder to adhere to the components.

[0044] If the distance (insulation distance) between the pattern lines between different poles on the substrate can be shortened in this way, further miniaturization of the substrate unit 1 can be achieved. Therefore, it is conceivable to apply a coating to the substrate unit 1 according to this embodiment. In FIG. 2, the coating portion is indicated by dots.

[0045] Here, in the second substrate 20 that overlaps the first substrate 10, a power supply electronic component 21 is mounted on the back surface 20b side. Specifically, in the second substrate 20, a power supply electronic component 21b is mounted on the back surface 20b side, which is the surface facing the first substrate 10.

[0046] Therefore, for example, if the first substrate 10 and the second substrate 20 are simply arranged to overlap each other, it is necessary to prevent the power supply electronic component 21b on the back surface 20b from coming into contact with the first substrate 10. Specifically, it is necessary to arrange a spacer between the first substrate 10 and the second substrate 20 to secure a space for arranging the power supply electronic component 21b. However, when such a spacer is provided, the height in the Z-axis direction when the first and second substrates 10 and 20 are combined becomes the value obtained by adding the height of the spacer to the thickness of the first substrate 10 and the thickness of the second substrate 20, so it becomes higher by the thickness of the spacer.

[0047] In this way, when the height in the Z-axis direction when the first and second substrates 10 and 20 are combined becomes high, in order to sufficiently coat the components that require coating, the coating height also becomes high. When the coating height becomes high, there is a risk that even the portions that do not require coating will be coated, leading to a deterioration in the quality of the substrate unit 1. On the other hand, if the coating height is lowered so as not to coat the portions that do not require coating, there is a risk that the components that require coating cannot be sufficiently coated.

[0048] Therefore, in the substrate unit 1 according to the present embodiment, the first and second substrates 10 and 20 are combined and unitized to achieve miniaturization, and by appropriately coating the electronic components, the distance between the electronic components can be shortened to further reduce the size.

[0049] Hereinafter, such a configuration will be described with reference to FIG. 7. FIG. 7 is a plan view when the first substrate 10 is viewed from the front surface 10a.

[0050] As shown in FIG. 7, the first substrate 10 is provided with an opening 18. The opening 18 is formed in a rectangular or substantially rectangular shape in a plan view (viewed in the Z-axis direction). The opening 18 is configured to accommodate the power supply electronic component 21 of the second substrate 20 (see FIG. 2). Specifically, the opening 18 is configured to accommodate the power supply electronic component 21b mounted on the back surface 20b of the second substrate 20.

[0051] Specifically, as shown by the dashed line in FIG. 7, the front surface 10a, which is the main surface of the first substrate 10, is divided into a mounting region 19a and a substrate overlapping region 19b. The mounting region 19a is a region where the control electronic component 11, the transformer section 12, the connector 13, the load driving section 14, and the load 15 are mounted. The substrate overlapping region 19b is a region where the combined second substrate 20 overlaps.

[0052] The opening 18 is formed in the substrate overlapping region 19b of the first substrate 10. Specifically, the opening 18 is formed at a position corresponding to the power supply electronic component 21b mounted on the back surface 20b of the second substrate 20 when the second substrate 20 overlaps the first substrate 10. In other words, in the plan view of the first substrate 10, the opening 18 is formed at a position including the portion of the power supply electronic component 21b mounted on the back surface 20b of the second substrate 20 when the second substrate 20 overlaps. In FIGS. 1 and 6, the opening 18 is shown as an imaginary line for understanding the positional relationship between the opening 18 and the power supply electronic component 21b.

[0053] Thus, the first substrate 10 according to this embodiment is configured to include an opening 18 capable of accommodating the power supply electronic component 21 (21b). Thereby, even when the first substrate 10 and the second substrate 20 are arranged to overlap each other, the power supply electronic component 21b on the back surface 20b of the second substrate 20 is accommodated in the opening 18, so it does not come into contact with the first substrate 10, and a spacer between the first substrate 10 and the second substrate 20 can be made unnecessary. Therefore, the clearance between the first and second substrates 10 and 20 can be reduced, and the height H1 (see FIG. 2) in the Z-axis direction when the first and second substrates 10 and 20 are combined can be lowered, thus enabling miniaturization of the substrate unit 1.

[0054] Also, even when the first and second substrates 10 and 20 are coated, since the height H1 when the first and second substrates 10 and 20 are combined is low, the coating height H2 is also such that coating up to the height where there is concern about the intrusion of the coating material is unnecessary, and it does not reach a height where unnecessary parts are coated. That is, it becomes possible to appropriately coat the parts that require coating. In this way, by appropriately coating the electronic components, while relaxing the insulation distance, the distance (height) between the substrates can be shortened to achieve further miniaturization.

[0055] Also, as shown in FIG. 2, the first substrate 10 is arranged to contact the surface on which the power supply electronic component 21 is mounted with respect to the second substrate 20. Specifically, the first substrate 10 is arranged such that the front surface 10a contacts the back surface 20b on which the power supply electronic component 21b of the second substrate 20 is mounted. In other words, the first substrate 10 and the second substrate 20 are connected such that the clearance between the first and second substrates 10 and 20 becomes zero or substantially zero.

[0056] Thereby, the clearance between the first and second substrates 10 and 20 can be further reduced, and the height H1 in the Z-axis direction when the first and second substrates 10 and 20 are combined can be further lowered, thus enabling miniaturization of the substrate unit 1.

[0057] Further, as shown in FIGS. 2 and 7, etc., the opening 18 is a through hole. In other words, the opening 18 is a through hole formed by punching through the first substrate 10.

[0058] Thereby, while ensuring the strength of the first substrate 10, the opening 18 can be formed. Also, since the opening 18 is a through hole, the opening 18 can be easily formed.

[0059] Note that, in the above, an example where the opening 18 is a through hole has been shown, but it is not limited to this. That is, the opening 18 may be a notch or the like formed by notching the first substrate 10.

[0060] Further, as shown in FIG. 1, etc., the opening 18 is covered by the second substrate 20. That is, in a plan view, the second substrate 20 is formed such that its area is larger than the area of the opening 18. Conversely, in a plan view, the opening 18 is formed such that its area is smaller than the area of the second substrate 20.

[0061] Thus, since the opening 18 is covered by the second substrate 20, a portion overlapping with the second substrate 20 is generated around the opening 18 of the first substrate 10. By forming a connecting member (here, the connection connector 23 and the insertion hole 16) for connecting the first substrate 10 and the second substrate 20 at this overlapping portion, the first substrate 10 and the second substrate 20 can be easily connected.

[0062] (Modification example) Next, a modification example of the embodiment will be described with reference to FIG. 8. FIG. 8 is a plan view when the first substrate 10 according to the modification example of the embodiment is viewed from the front surface 10a. Note that hereinafter, the same components as those in the embodiment may be denoted by the same reference numerals and the description thereof may be omitted.

[0063] In the first substrate 10 according to the embodiment, in a plan view, the shape of the opening 18 is formed to be the same as the shape of the second substrate 20, that is, a rectangular shape or a substantially rectangular shape. In the first substrate 10 according to the modification, as shown in FIG. 8, in a plan view, the shape of the opening 18a is formed to be different from the shape of the second substrate 20 (rectangular shape or substantially rectangular shape).

[0064] Specifically, the opening 18a is formed to have a shape excluding a portion 16a where a connecting member (here, the insertion hole 16) connecting to the second substrate 20 is formed from the substrate overlapping region 19b of the first substrate 10.

[0065] Thereby, the area of the opening 18a can be made relatively large in a plan view. When the area of the opening 18a becomes relatively large, for example, even when a design change is made to the power supply electronic component 21b such that the number of power supply electronic components 21b accommodated in the opening 18a increases or the mounting position changes, it is possible to cope without changing the shape of the opening 18a.

[0066] In the above-described embodiment and the like, the length L1 (see FIG. 7) of the side (short side) of the first substrate 10 in a plan view and the length L2 (see FIG. 4) of the side (short side) of the second substrate 20 are set to be the same or substantially the same, but the present invention is not limited thereto, and the length L1 of the side of the first substrate 10 and the length L2 of the side of the second substrate 20 may be set to be different. That is, for example, the length L1 of the side of the first substrate 10 may be set to be longer than the length L2 of the side of the second substrate 20 (L1 > L2).

[0067] Also, the positions of the connection connector 23 and the insertion hole 16 shown in FIGS. 4 and 7 are merely examples and are not limited. That is, the positions of the connection connector 23 and the insertion hole 16 may be different from the positions shown in FIGS. 4 and 7.

[0068] <Appendix> (1) A first substrate on which a control electronic component is mounted, A second substrate on which electronic components for power supply are mounted and which is arranged such that the surface on which the electronic components for power supply are mounted faces the first substrate and the first substrate includes an opening capable of accommodating the electronic components for power supply is a substrate unit (2) The first substrate is arranged to be in contact with the second substrate on the surface on which the electronic components for power supply are mounted The substrate unit according to (1). (3) The opening is a through hole The substrate unit according to (1) or (2). (4) The opening is covered by the second substrate The substrate unit according to any one of (1) to (3). (5) In a plan view of the first substrate, the shape of the opening is formed to be different from the shape of the second substrate The substrate unit according to any one of (1) to (4). The substrate unit according to claim 1

[0069] Further effects and modifications can be easily derived by those skilled in the art. Therefore, the broader aspects of the present invention are not limited to the specific details and representative embodiments described and represented as above. Accordingly, various changes can be made without departing from the spirit or scope of the general inventive concept defined by the appended claims and their equivalents

Explanation of reference numerals

[0070] 1 Substrate unit 10 First substrate 18, 18a Opening 20 Second substrate

Claims

1. A first substrate on which a control electronic component is mounted, A second substrate on which a power supply electronic component is mounted and which is arranged such that the surface on which the power supply electronic component is mounted faces the first substrate, comprising: The first substrate includes an opening capable of accommodating the power supply electronic component. A substrate unit.

2. The first substrate is arranged to contact the second substrate on the surface on which the power supply electronic component is mounted. The substrate unit according to Claim 1.

3. The opening is a through-hole. The substrate unit according to Claim 1.

4. The opening is covered by the second substrate. The substrate unit according to Claim 1.

5. In a plan view of the first substrate, the shape of the opening is formed to be different from the shape of the second substrate. The substrate unit according to Claim 1.

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