Substrate mounted on on-board device, and method for manufacturing substrate

Abstract

This substrate is mounted on an on-board device and has a side through hole formed therein. The substrate is formed by cutting a substrate source member having a circular through hole formed therein. The through hole is filled with solder. By cutting the substrate source member, the through hole is formed into the side through hole which is semicircular, and the solder filled in the through hole remains in the side through hole.

Description

Substrate mounted on in-vehicle device and method for manufacturing substrate

[0001] The present disclosure relates to a substrate mounted on an in-vehicle device and a method for manufacturing the substrate. The present application claims priority based on Japanese Patent Application No. 2025-029157 filed on February 26, 2025, and incorporates all the contents described in the Japanese application by reference.

[0002] Patent Document 1 discloses a vehicle communication device that receives a differential signal represented by a voltage difference between two electrical signals respectively propagating through two conductive wires. In this communication device, noise is removed from the two electrical signals with the potential of a first conductor as a reference potential. Further, the differential signal represented by the voltage difference between the two electrical signals from which noise has been removed is converted into a voltage signal whose reference potential is the potential of a second conductor. In the communication device, a voltage whose reference potential is the potential of the first conductor is applied via a connector. The applied voltage is converted into a voltage whose reference potential is the potential of the second conductor. The converted voltage is applied to a conversion unit that converts a differential signal into a voltage signal. Accordingly, power is supplied to the conversion unit.

[0003] Japanese Unexamined Patent Publication No. 2020-167536

[0004] A substrate according to an aspect of the present disclosure is a substrate that is mounted on an in-vehicle device and has a side through-hole formed therein, and is formed by cutting an original substrate member having a circular through-hole formed therein, the through-hole is filled with solder, the through-hole is formed into the semicircular side through-hole by cutting the original substrate member, and the solder filled in the through-hole remains in the side through-hole.

[0005] These are schematic diagrams illustrating an outline of an in-vehicle device mounted on a vehicle, a substrate, and the like; they are explanatory diagrams illustrating a method for manufacturing a substrate mounted on an in-vehicle device; they are perspective views of a main substrate and an SIP substrate included in an in-vehicle device; they are exploded views of a main substrate and an SIP substrate included in an in-vehicle device; they are cross-sectional views of a main substrate and an SIP substrate; they are partially enlarged views of a main substrate and an SIP substrate; they are a bottom view of an SIP substrate and a front view of a main substrate.

[0006] [Problems to be Solved by This Disclosure] In the communication device described in Patent Document 1, the point of suitably applying solder to the side through holes in a substrate that is mounted on an in-vehicle device and has side through holes formed therein has not been considered.

[0007] This disclosure has been made in view of the above circumstances, and its purpose is to provide a substrate in which solder is suitably applied to the side through holes, which are mounted on an in-vehicle device.

[0008] [Effects of this disclosure] According to one aspect of this disclosure, it is possible to provide a substrate that is mounted in an in-vehicle device and has side through holes formed therein, in which solder is suitably applied to the side through holes.

[0009] [Description of Embodiments of the Disclosure] First, embodiments of the Disclosure will be listed and described. At least some of the embodiments described below may be combined in any way.

[0010] (1) A substrate according to one aspect of the present disclosure is a substrate mounted on an in-vehicle device and having side through-holes formed on it, which is formed by cutting a substrate base member having circular through-holes formed on it, and the through-holes are filled with solder, and by cutting the substrate base member, the through-holes are formed into semicircular side through-holes, and the solder that was filled in the through-holes remains in the side through-holes.

[0011] In this embodiment, an in-vehicle device such as an ECU mounted in a vehicle is fitted with a substrate having side through-holes formed on it. The side through-holes are formed on the side, for example, on the side surface that forms the thickness of the substrate, the outer peripheral surface, or the inner peripheral surface of a through-hole formed in the substrate, and consist of a semicircular notch cut out along the thickness direction of the substrate. The side through-hole, which consists of the semicircular notch, includes a semicircular side cut out in the substrate and a copper pattern (semi-ring copper land) provided along the inner peripheral surface of the semicircular side. Solder is provided inside the side through-hole, that is, inside the semicircular copper pattern (semi-ring copper land). The solder provided inside the side through-hole is the solder that was filled into the circular through-hole of the substrate base material when the substrate base material was cut. In other words, in a substrate base member with a circular through-hole formed therein, after solder is filled into the through-hole, the substrate base member is cut, including the area where the through-hole is formed, to form a substrate. At this time, the circular through-hole is also cut, and a semicircular side through-hole is formed by the cut through-hole. In this case, the side through-hole is formed on the cut surface of the cut substrate base member, and this cut surface corresponds to the side of the substrate, the outer surface, or the inner surface of a through-hole formed in the substrate. By cutting the solder-filled circular through-hole so as to pass through the center of the through-hole, a side through-hole can be formed in which the filled solder remains, and the solder can be evenly applied inside the side through-hole. In this way, by cutting the through-hole to form a side through-hole, it is possible to efficiently prevent or suppress insufficient soldering in the side through-hole, and a substrate can be provided in which solder is suitably applied to the side through-hole.

[0012] (2) In one embodiment of the present disclosure, the substrate base member has a plurality of through holes arranged in a straight line, and the substrate base member is cut along the plurality of through holes to form a plurality of side through holes.

[0013] In this embodiment, the substrate base member has a plurality of through-holes arranged in a straight line; that is, the centers of these circularly formed through-holes are arranged in a straight line on the substrate base member. In this case, the substrate base member is cut along the plurality of through-holes, that is, along the straight line connecting the centers of each of these through-holes. This makes it possible to efficiently manufacture a substrate with a plurality of side through-holes. Since solder that was filled into the through-holes remains inside each of the formed side through-holes, it is possible to efficiently prevent or suppress insufficient soldering in these side through-holes.

[0014] (3) A substrate according to one aspect of the present disclosure, wherein the in-vehicle device includes a main substrate and a SIP substrate detachably mounted on the main substrate, the substrate being the SIP substrate, the side through holes being formed on the side surface of the SIP substrate, and the SIP substrate and the main substrate being electrically connected by the solder remaining in the side through holes of the SIP substrate and a conductor formed on the main substrate.

[0015] In this embodiment, the in-vehicle device includes a main board and a SIP board that is detachably mounted on the main board, and the board is configured as a SIP board. In this case, side through holes are formed on the side surface of the SIP board, and these side through holes are formed by cutting the substrate base material in which the through holes are formed. Solder is filled into these through holes, and by cutting the solder-filled through holes, solder-filled side through holes can be formed, effectively preventing or suppressing insufficient soldering in the side through holes. Through this manufacturing process, SIP boards with properly filled solder inside the side through holes can be efficiently manufactured.

[0016] (4) A substrate according to one aspect of the present disclosure, wherein the in-vehicle device includes a main substrate and a SIP substrate detachably mounted on the main substrate, the substrate being the main substrate, the main substrate having through holes that penetrate in the thickness direction of the main substrate, the side through holes formed on the inner circumferential surface of the through holes, and the SIP substrate and the main substrate being electrically connected by the solder remaining in the side through holes of the main substrate and a conductor formed on the SIP substrate.

[0017] In this embodiment, the in-vehicle device includes a main board and a SIP board that is detachably mounted on the main board, with the board being configured as the main board. In this case, side through holes are formed on the sides (outer circumferential surfaces) of the main board, or on the inner circumferential surfaces of through holes formed in the main board, which constitute the thickness of the main board. These side through holes are formed by cutting the substrate base material in which the through holes are formed. Solder is filled into these through holes, and by cutting the solder-filled through holes, solder-filled side through holes can be formed, effectively preventing or suppressing insufficient soldering in the side through holes. Through this manufacturing process, a main board with properly filled solder inside the side through holes can be efficiently manufactured.

[0018] (5) A method for manufacturing a substrate according to one aspect of the present disclosure is a method for manufacturing a substrate to be mounted on an in-vehicle device and having side through-holes formed thereon, comprising the steps of: forming circular through-holes in a plate-shaped substrate base member; filling the inside of the formed through-holes with solder; cutting the substrate base member including the through-holes filled with solder; and using the cut substrate base member to form the semicircular side through-holes filled with solder.

[0019] In this embodiment, the substrate is manufactured through a series of steps, which include a step of forming through-holes in the substrate base material, a step of filling the through-holes with solder, a step of cutting the solder-filled through-holes (a step of cutting the substrate base material), and a step of forming the substrate (a substrate including solder-filled semicircular side through-holes) using the cut substrate base material. In this way, since the substrate is manufactured by a manufacturing method using a through-hole cutting method that cuts the substrate base material including solder-filled side through-holes, it is possible to efficiently manufacture a substrate in which solder is properly applied inside the side through-holes.

[0020] [Details of Embodiments of the Invention] The present disclosure will be described in detail with reference to the drawings illustrating its embodiments. A substrate 11 mounted on an in-vehicle device 1 according to an embodiment of the present disclosure will be described below with reference to the drawings. However, the present disclosure is not limited to these examples and is intended to include all modifications within the meaning and scope of the claims, as indicated by the claims.

[0021] (Embodiment 1) Hereinafter, embodiments will be described based on the drawings. Figure 1 is a schematic diagram illustrating the outline of an in-vehicle device 1 and circuit board etc. mounted on a vehicle. Vehicle C is equipped with the in-vehicle device 1, an in-vehicle ECU 91 and a power supply device 92. The in-vehicle device 1 is mounted on vehicle C and is connected to a plurality of in-vehicle ECUs 91 so as to be able to communicate via an in-vehicle network. The communication protocol used in the in-vehicle network is, for example, LIN (Local Interconnect Network), CAN (Controller Area Network), CAN-FD, or Ethernet (registered trademark), and therefore the in-vehicle network is composed of communication cables such as a LIN bus, a CAN bus, or an Ethernet cable.

[0022] The in-vehicle device 1 includes one or more connectors 93 to which these communication cables are connected. The connectors 93 may include, for example, a LIN connector, a CAN connector, and an Ethernet connector, and may also include a power connector. Power cables extending from a power supply unit 92 are connected to the connectors 93. The power supply unit 92 is composed of, for example, a lead-acid battery or alternator mounted on the vehicle C.

[0023] The in-vehicle device 1 comprises a main board 2 and a SIP board 4 that is detachably mounted on the main board 2. The SIP board 4 is a board composed of modules in which multiple die chips are sealed in a single package, and is, for example, a stack-type SIP module in which multiple chips (electrical components) are stacked vertically. The SIP board 4 and the main board 2 are electrically connected by a conductor 3 (see Figure 5), which will be described later. These SIP boards 4 and the main board 2 correspond to boards manufactured by a manufacturing method using a through-hole cutting method, which will be described later.

[0024] Figure 2 is an explanatory diagram illustrating a method for manufacturing a substrate 11 to be mounted on an in-vehicle device 1. In this embodiment, the substrate 11 is manufactured by a through-hole cutting method that cuts a substrate base member 10, which is the source material for processing. The substrate 11 thus formed corresponds to at least one of the main substrate 2 or SIP substrate 4 provided in the in-vehicle device 1. That is, the main substrate 2 and SIP substrate 4 may also be manufactured by the said through-hole cutting method.

[0025] In the illustrations of this embodiment, a method for manufacturing the substrate 11 corresponding to the main substrate 2 or SIP substrate 4 (through-hole cutting method) will be described. The substrate 11 is manufactured through a plurality of steps, which include a step of forming through-holes 101 in the substrate base member 10, a step of filling the inside of the through-holes 101 with solder 103, a step of cutting the through-holes 101 filled with solder 103 (a step of cutting the substrate base member 10), and a step of molding the substrate 11 using the cut substrate base member 10.

[0026] The manufacturing method for the substrate 11 includes the step of forming circular through-holes 101 in a plate-shaped substrate base member 10. The substrate base member 10 corresponds to the processing base member of the substrate 11. One or more through-holes 101 (in this embodiment, five through-holes 101) are formed in a straight line on the substrate base member 10. The through-holes 101 are formed by drilling circular holes through the substrate base member 10 and applying copper lands 102 to the inner surface of the holes and to annular regions along the circumference of the holes on the front and back surfaces of the substrate base member 10. The copper lands 102 may extend from the through-holes 101 so as to be connected to terminals of mounted components 5.

[0027] In this embodiment, the method for manufacturing the substrate 11 includes the step of forming a circular through-hole 101 in the substrate base member 10, but is not limited to this, and may be replaced by the step of preparing a substrate base member 10 in which a circular through-hole 101 has already been formed. In this case, the substrate base member 10 in which the circular through-hole 101 has been formed may be supplied by a parts manufacturer such as a supplier. Thus, the through-hole cutting method does not include the step of forming a through-hole 101 in the substrate base member 10, but may also include the step of preparing a substrate base member 10 in which a through-hole 101 has already been formed.

[0028] The manufacturing method for the substrate 11 includes a step of filling the formed through-holes 101 with solder 103. The step of filling the through-holes 101 with solder 103 is performed after the step of forming the through-holes 101 in the substrate base member 10. Solder 103 is filled into each of the multiple through-holes 101 by paste, coating, or injection. In this case, the solder 103 may be filled at a filling rate such that the volume of the filled solder 103 is, for example, 90% or more of the internal volume of the through-hole 101.

[0029] If solder 103 is applied or pasted to the inside of a side through-hole 111 after it has been formed, there is a concern that the solder 103 may not adhere properly. In contrast, by filling the inside of the through-hole 101, which forms a cylindrical space, it is possible to efficiently ensure that the filling rate of solder 103 inside the through-hole 101, that is, the ratio of the volume of filled solder 103 to the volume of the internal space of the through-hole 101, is, for example, 90% or more.

[0030] The manufacturing method for the substrate 11 includes a step of cutting the substrate base member 10, including the through-holes 101 filled with solder 103. The step of cutting the through-holes 101 filled with solder 103 (the step of cutting the substrate base member 10) is performed after the step of filling the inside of the through-holes 101 with solder 103. The substrate base member 10 is cut in a direction along the multiple through-holes 101 that are arranged in a straight line. Therefore, the virtual cutting line when cutting the substrate base member 10 (shown as a dashed line in the illustration in this embodiment) passes through the center of the multiple through-holes 101 that are arranged in a straight line.

[0031] Since the through-hole 101 to be cut is filled with solder 103, cutting the through-hole 101 also cuts (divides) the solder 103 that is filled inside the through-hole 101. That is, the solder 103 located inside the through-hole 101 is cylindrical, and by cutting (dividing) this cylindrical solder 103, a semicircular piece of solder 103 remains inside the side through-hole 111. In this embodiment, cutting is performed along multiple through-holes 101 that are arranged in a straight line, but the invention is not limited to this, and it is also possible to cut only a single through-hole 101.

[0032] The manufacturing method for the substrate 11 includes a step of forming a substrate 11 including semicircular side through-holes 111 filled with solder 103 using a cut substrate base member 10. The forming step of the substrate 11 (substrate 11 including semicircular side through-holes 111 filled with solder 103) is performed after the cutting step of the through-holes 101 filled with solder 103 (cutting step of the substrate base member 10). By cutting the circular through-hole 101 so as to pass through the center of the through-hole 101, a semicircular side through-hole 111 is formed. The cutting of the through-hole 101 also cuts the solder 103 filled inside the through-hole 101, and the cut solder 103 remains inside the semicircular side through-hole 111.

[0033] The cut substrate base member 10 will, for example, constitute two substrates 11. In this case, the cut surface of the cut substrate base member 10 corresponds to the side portion, such as the side surface, that constitutes the thickness of the substrate 11. Alternatively, if the substrate base member 10 is cut rectangularly to form a rectangular through hole 21, a main substrate 2 with the through hole 21 formed thereon will be formed, and the cut surface of the cut substrate base member 10 will correspond to the side portion, such as the inner circumferential surface 211 of the through hole 21 formed in the main substrate 2. In this case, the semicircular side through hole 111 is formed on the cut surface of the substrate base member 10, for example, on the side surface (outer circumferential surface) of the SIP substrate 4 or the main substrate 2, or on the inner circumferential surface 211 of the through hole 21 in the main substrate 2. Since solder 103 that was filled inside the through-hole 101 remains inside the semicircular side through-hole 111, it is possible to efficiently prevent or suppress insufficient solder 103 upflow in the side through-hole 111, and to efficiently manufacture a substrate 11 in which solder 103 is properly applied inside the side through-hole 111.

[0034] Figure 3 is a perspective view of the main substrate 2 and SIP substrate 4 of the in-vehicle device 1. Figure 4 is an exploded view of the main substrate 2 and SIP substrate 4 of the in-vehicle device 1. Figure 5 is a cross-sectional view of the main substrate 2 and SIP substrate 4. Figure 5 shows a cross-sectional view when the main substrate 2 and SIP substrate 4 shown in Figure 3 are cut along the line I-I. In this embodiment, the substrate 11 manufactured by the through-hole cutting method includes the main substrate 2 and the SIP substrate 4. Hereafter, the structure, arrangement configuration, etc. of the main substrate 2 and SIP substrate 4 will be described as an example of the substrate 11. In this case, the side through-holes 111 of the substrate 11 correspond to, for example, the notches 212 of the main substrate 2. The solder 103 provided inside the side through-holes 111 corresponds to, for example, the conductor 31 inside the notches of the main substrate 2.

[0035] The main board 2 and the SIP board 4 are detachably mounted on each other. The SIP board 4 corresponds to one of the electrical components mounted on the main board 2. For example, connectors, power supply circuits, conductors, and connecting elements are further mounted on the main board 2. In this embodiment, the main board 2 and SIP board 4 are shown as rectangular, but are not limited to this. The main board 2 and SIP board 4 may be circular, elliptical, or have other shapes.

[0036] A rectangular through-hole 21 is formed in the main substrate 2, penetrating in the thickness direction of the main substrate 2. The through-hole 21 is not limited to being formed in a rectangular shape, but may also be formed in a circular or elliptical shape.

[0037] A notch 212 is formed on the inner circumferential surface 211 of the through hole 21, cut out along the thickness direction of the main substrate 2. The notch 212 corresponds to the side through hole 111. Multiple notches 212 are formed over the entire area of ​​the inner circumferential surface 211. In Figure 4, multiple notches 212 are formed over the entire rectangular inner circumferential surface 211. Multiple notches 212 may be formed on a part of the four inner surfaces that make up the inner circumferential surface 211 (for example, the first inner surface, the second inner surface, and the third inner surface).

[0038] The SIP substrate 4 comprises an opposing surface 41 facing the main substrate 2 and a non-opposing surface 42 on the back side of the opposing surface 41. The opposing surface 41 includes an exposed surface 411 that is exposed through the through hole 21. That is, the exposed surface 411 corresponds to a portion of the opposing surface 41. The inner circumference of the through hole 21 partitions the outer circumference of the exposed surface 411, thereby defining the region of the exposed surface 411, which is a portion of the opposing surface 41. The main substrate 2 and the SIP substrate 4 are electrically connected by a conductor 3 formed from the notch 212 of the main substrate 2 to the exposed surface 411 of the SIP substrate 4. The conductor 3 provided in the notch 212 corresponds to solder 103.

[0039] The rectangular SIP substrate 4 has an outer periphery, which forms the thickness of the SIP substrate 4. Multiple notches are formed on at least a portion of the outer periphery, cut out along the thickness direction of the SIP substrate 4. The notches on the outer periphery correspond to side through holes 111. The main substrate 2 and the SIP substrate 4 are electrically connected by a conductor formed in the notches on the outer periphery (see Figure 5) and a conductor formed on the opposite surface of the main substrate 2 located directly below the notches on the outer periphery (see Figure 5). The conductor formed in the notches on the outer periphery corresponds to solder 103.

[0040] As described above, by forming the conductor 3 between the notch 212 of the main substrate 2 and the exposed surface 411 of the SIP substrate 4, the exposed surface 411, the notch 212 of the main substrate 2, and the inner surface 211 of the through hole 21 of the main substrate 2 can be utilized as areas for placing the conductor 3, such as lands or wiring patterns. Furthermore, this configuration ensures the expandability or availability of the SIP substrate 4. Moreover, when the SIP substrate 4 is mounted on the main substrate 2, the connection points of the conductor 3 between the main substrate 2 and the SIP substrate 4 become visible from the outside through the through hole 21 of the main substrate 2. This makes it possible to efficiently carry out quality control work to confirm the electrical connection between the SIP substrate 4 and the main substrate 2, including confirmation of the connectivity of the conductor 3 during the production process of the main substrate 2.

[0041] Furthermore, the SIP board 4 includes mounted components 5 and a heat sink 6. Mounted components 5 are arranged on the exposed surface 411 and the non-facing surface 42 of the SIP board 4. Mounted components 5 include, for example, relays, switches, sensors, integrated circuits (ICs), transistors, or heat-generating components 51. Heat-generating components 51 include, for example, resistive elements, connecting elements (common mode choke coils and inductors, etc.), capacitors (ceramic capacitors and variable capacitors, etc.), or transformers, etc.

[0042] A heat-generating component 51 is placed on the non-opposing surface 42, which is the back side of the exposed surface 411. In the illustration of this embodiment, one heat-generating component 51 is placed on the non-opposing surface 42, but this is not limited to this. Multiple heat-generating components 51 may be placed on the non-opposing surface 42. By placing the heat-generating component 51 on the non-opposing surface 42 which is perpendicular to the perpendicular direction (thickness direction) of the exposed surface 411, the heat emitted from the heat-generating component 51 is transferred from the non-opposing surface 42 to the exposed surface 411 and dissipated from the exposed surface 411. This makes it possible to dissipate the heat emitted from the heat-generating component 51 through the exposed surface 411.

[0043] Mounted components 5 and heat sinks 6 are placed on the exposed surface 411. In Figure 5, multiple mounted components 5 and heat sinks 6 are placed on the exposed surface 411. Multiple mounted components 5 and heat sinks 6 are placed on the exposed surface 411 so as not to overlap. The height in the thickness direction of the mounted components 5 and heat sinks 6 is less than or equal to the height in the thickness direction of the main substrate 2. By placing the heat sinks 6 on the exposed surface 411 which is the back side of the non-opposing surface 42 on which the heat-generating component 51 is placed, heat from the heat-generating component 51 is dissipated through the heat sinks 6. As a result, the heat emitted from the heat-generating component 51 is transferred to the heat sinks 6 directly or indirectly via the exposed surface 411, and dissipated through the heat sinks 6.

[0044] The opening area of the through-hole 21 is, for example, 70% or less relative to the area of the SIP substrate 4. Further, the opening area of the through-hole 21 is, for example, 10 to 30% or more relative to the area of the SIP substrate 4. When the opening area of the through-hole 21 is 10% or more and 70% or less of the area of the SIP substrate, an increase in the opening area of the through-hole 21 is suppressed, and the mounting area on the main substrate is secured. Further, by changing the opening area of the through-hole 21 within the above range according to the area of the SIP substrate, SIP substrates of various sizes suitable for applications can be mounted, and the scalability or availability of the SIP substrate 4 can be ensured.

[0045] FIG. 6 is a partially enlarged view of the main substrate 2 and the SIP substrate 4. This drawing shows a portion enclosed by a square indicated by a two-dot chain line in FIG. 5. The conductor 3 includes an in-notch conductor 31 formed in the notch 212, and an on-exposed-surface conductor 32 formed on the exposed surface 411. When the SIP substrate 4 is mounted on the main substrate 2, an end portion of the in-notch conductor 31 located on the SIP substrate 4 side abuts or is in close contact with the on-exposed-surface conductor 32. That is, the on-exposed-surface conductor 32 of the SIP substrate 4 and the in-notch conductor 31 of the main substrate 2 are aligned and formed so as to contact each other when the SIP substrate 4 is mounted on the main substrate 2. As a result, the main substrate 2 and the SIP substrate 4 are electrically connected by the plurality of in-notch conductors 31 formed in the notches 212 and the plurality of on-exposed-surface conductors 32 formed on the exposed surface 411.

[0046] Note that any mounted component (not shown) to be mounted on the main substrate 2 is connected to the end opposite to the end located on the SIP substrate 4 side of the in-notch conductor 31. Any mounted component (not shown) to be mounted on the SIP substrate 4 is connected to the end opposite to the end located on the through-hole 21 side of the on-exposed-surface conductor 32. A part of the on-exposed-surface conductor 32 including the opposite end may be interposed between the opposing surface 41 of the SIP substrate 4 and the main substrate 2, and sandwiched between the opposing surface 41 of the SIP substrate 4 and the main substrate 2.

[0047] FIG. 7 is a bottom view of the SIP substrate 4. This figure illustrates the opposing surface 41 side of the SIP substrate 4 shown in FIG. 5. The broken line portion in FIG. 7 is the outer peripheral portion of the exposed surface 411 when the main substrate 2 and the SIP substrate 4 are detachably placed, and coincides with the inner peripheral portion of the through hole 21. A plurality of exposed-surface conductors 32 are formed on the outer peripheral portion of the exposed surface 411. A plurality of side through holes 111 (notches on the outer peripheral surface) are formed on the side surfaces (outer peripheral surface: left and right side surfaces in the present embodiment) of the SIP substrate 4, and a semi-cylindrical solder 103 (a conductor formed in the notch on the outer peripheral surface) is provided inside (on the inner side of) the side through holes 111.

[0048] FIG. 8 is a front view of the main substrate 2. FIG. 8 illustrates a surface of the main substrate 2 shown in FIG. 5 that faces the SIP substrate 4. Each of the plurality of in-notch conductors 31 (solder 103) is formed in each of the plurality of notches 212 (side through holes 111). That is, one in-notch conductor 31 is formed in one notch 212. The broken line portion in FIG. 8 coincides with the outer peripheral surface of the SIP substrate 4 when the main substrate 2 and the SIP substrate 4 are detachably placed. A plurality of conductors that electrically connect the main substrate 2 and the SIP substrate 4 are formed in the broken line portion. The positions of the plurality of conductors formed in the broken line portion correspond to the positions of the plurality of conductors formed in the notches on the outer peripheral surface of the SIP substrate 4. Similarly to the side surface (outer peripheral surface) of the SIP substrate 4, a plurality of side through holes 111 are also formed on the side surface (outer peripheral surface) of the main substrate 2, and the solder 103 may be provided inside (on the inner side of) the side through holes 111.

[0049] From FIG. 7 and FIG. 8, the number of in-notch conductors 31 formed in the plurality of notches 212 is equal to the number of exposed-surface conductors 32 formed on the exposed surface 411. By matching the number of the in-notch conductors 31 and the exposed-surface conductors 32, the number of conductors 3 that electrically connect the SIP substrate 4 and the main substrate 2, that is, the number of current-carrying paths can be increased.

[0050] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of this disclosure is indicated by the claims and not in the sense described above, and all modifications within the meaning and scope equivalent to the claims are intended.

[0051] With respect to the multiple claims described in the claims, they may be combined with each other regardless of the form of reference. Multiple dependent claims that depend on multiple claims may be described in the claims. Multiple dependent claims that depend on multiple dependent claims may be described. Even if multiple dependent claims that depend on multiple dependent claims are not described, this does not limit the description of multiple dependent claims that depend on multiple dependent claims.

[0052] C Vehicle 1 In-vehicle equipment 10 Base board component 101 Through-hole 102 Copper land 103 Solder 11 Board 111 Side through-hole 2 Main board 21 Through-hole 211 Inner surface 212 Notch (side through-hole) 3 Conductor 31 Conductor inside notch (solder) 32 Conductor on exposed surface 4 SIP board 41 Opposing surface 411 Exposed surface 42 Non-opposing surface 5 Mounted components 51 Heat-generating components 6 Heat sink 91 In-vehicle ECU 92 Power supply unit 93 Connector

Claims

1. A substrate mounted in an in-vehicle device, having side through-holes formed thereon, which is formed by cutting a substrate base member having circular through-holes formed thereon, the through-holes being filled with solder, the through-holes being formed into semi-circular side through-holes by cutting the substrate base member, and the solder that filled the through-holes remaining in the side through-holes.

2. The substrate according to claim 1, wherein a plurality of through-holes arranged in a straight line are formed in the substrate base member, and the plurality of side through-holes are formed by cutting the substrate base member along the plurality of through-holes.

3. The in-vehicle device includes a main board and a SIP board detachably mounted on the main board, wherein the board is the SIP board, the side through holes are formed on the side surface of the SIP board, and the SIP board and the main board are electrically connected by the solder remaining in the side through holes of the SIP board and a conductor formed on the main board, as described in claim 1 or claim 2.

4. The in-vehicle device includes a main board and a SIP board detachably mounted on the main board, wherein the board is the main board, the main board has through holes formed therein in the thickness direction of the main board, the inner circumferential surface of the through holes has the side through holes, and the SIP board and the main board are electrically connected by the solder remaining in the side through holes of the main board and a conductor formed on the SIP board.

5. A manufacturing method for a substrate to be mounted in an in-vehicle device and having side through-holes formed thereon, comprising the steps of: forming circular through-holes in a plate-shaped substrate base member; filling the inside of the formed through-holes with solder; cutting the substrate base member including the through-holes filled with solder; and using the cut substrate base member to form the semicircular side through-holes filled with solder.

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