Substrate structure and method of manufacturing a substrate structure

Abstract

To apply a press-fit terminal to a metal substrate.SOLUTION: The substrate structural body 1 includes a substrate 2 including a base layer 21 formed of a metallic material, an insulating layer 22 provided on a main surface 21a of the base layer, and a copper layer 23 provided on a main surface 22a of the insulating layer, a front surface connection plate 3 fixed to the main surface 23a of the copper layer and provided with a connection plate terminal hole 3T, a portion in contact with the main surface 23a of the copper layer and an inner peripheral surface of the connection plate terminal hole 3T being electrically conducted, and press-fit terminals 5 inserted into the connection plate terminal hole 3T and fixed to the front surface connection plate 3 by generating a pressing force against the inner peripheral surface of the connection plate terminal hole 3T.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a substrate structure and a method for manufacturing a substrate structure. [Background technology]

[0002] Patent Documents 1 to 5 disclose structures for connecting electronic components to a substrate.

[0003] The manufacturing process of electric motors and the like includes a process of mounting chip components and the like on an electronic board using reflow soldering and a process of connecting the mounted components to electrical components such as coils. Traditionally, soldering has been the mainstream method for electrically connecting these components. The soldering connection process is expensive. Furthermore, soldered connection structures may deteriorate over time due to thermal cycles, repeated loads, and other factors. Given these circumstances, there has been a demand in recent years for connection methods that do not use solder. Press-fit is attracting attention as a solder-free connection method. For example, Patent Document 1 discloses a structure in which press-fit terminals are directly inserted into through-holes in a board. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2008 / 163247 [Patent Document 2] Japanese Patent Application Laid-Open No. 60-102793 [Patent Document 3] Japanese Patent Application Publication No. 2018-14273 [Patent Document 4] Japanese Patent Application Laid-Open No. 2007-266249 [Patent Document 5] Japanese Patent Application Laid-Open No. 2008-294234 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, the current flowing through electronic boards has tended to increase, and as a result, the importance of the board's heat dissipation has increased. As a method of improving the heat dissipation of electronic boards, the use of so-called metal boards, in which layers formed from resin materials such as glass epoxy have been replaced with metal materials with high thermal conductivity, is becoming more common.

[0006] When press-fit terminals are pressed into the through-holes, they are pressed against the inner periphery of the through-holes. This pressure mechanically fixes the terminals and ensures electrical connection. The through-holes in conventional glass epoxy boards can easily be plated to make their inner periphery conductive.

[0007] On the other hand, in the case of a metal substrate, it is necessary to ensure electrical insulation between the metal substrate and the press-fit terminals, but it has been difficult to perform the desired surface treatment on the holes provided in the metal substrate.

[0008] Therefore, the present disclosure provides a substrate structure that allows press-fit terminals to be applied to a metal substrate, and a method for manufacturing the substrate structure. [Means for solving the problem]

[0009] A substrate structure that is one form of the present invention comprises: a substrate including a base layer formed of a metal material, an insulating layer provided on a main surface of the base layer, and a conductive layer provided on the main surface of the insulating layer; a connection plate that is fixed to the main surface of the conductive layer and has a connection plate terminal hole that is a through hole, and whose portion in contact with the main surface of the conductive layer is electrically conductive with the inner surface of the connection plate terminal hole; and a press-fit terminal that is inserted into the connection plate terminal hole and is fixed to the connection plate by generating a pressing force against the inner surface of the connection plate terminal hole.

[0010] This substrate structure mechanically and electrically connects the press-fit terminal to the substrate via the connection plate, so that the press-fit terminal can be applied to a metal substrate including a base layer formed from a metal material.

[0011] In the above substrate structure, the press-fit terminal may include a terminal shank protruding from the rear surface of the connecting plate, the substrate may include a substrate side surface facing the side surface of the terminal shank, and the side surface of the terminal shank and the substrate side surface may be electrically insulated. With this configuration, the press-fit terminal can be electrically insulated from the base layer formed of a metal material.

[0012] In the above substrate structure, the press-fit terminal may include a terminal shank protruding from the rear surface of the connecting plate, the substrate may include a substrate side surface facing the side surface of the terminal shank, and a gap may be formed between the side surface of the terminal shank and the substrate side surface. This configuration also allows electrical insulation between the press-fit terminal and the base layer made of a metal material.

[0013] In the above substrate structure, the substrate may include substrate terminal holes penetrating the conductive layer, the insulating layer, and the base layer, the connecting plate may be disposed so that the connecting plate terminal holes overlap the substrate terminal holes, and the side surface of the substrate may be the inner peripheral surface of the substrate terminal holes. With this configuration, press-fit terminals can be applied to one substrate.

[0014] The above substrate structure may further include a second substrate adjacent to the first substrate, the second substrate including a second substrate side surface facing the first substrate side surface of the first substrate, the connecting plate being disposed across the first and second substrates, and the side surface of the terminal shaft portion facing each of the first substrate side surface and the second substrate side surface. With this configuration, a press-fit terminal can be applied to the substrate structure in which the first substrate and the second substrate are connected by the connecting plate.

[0015] In the above substrate structure, the connection plate may be disposed on the substrate so as to protrude from a side surface of the substrate so that the connection plate terminal hole does not overlap with the substrate, and the side surface of the terminal shaft may face the side surface of the substrate from which the connection plate protrudes. With this configuration, a press-fit terminal can be applied to a substrate structure having a connection plate provided so as to protrude from the substrate.

[0016] A method for manufacturing a substrate structure, which is another form of the present invention, includes the steps of: preparing a substrate including a base layer formed of a metal material, an insulating layer provided on a main surface of the base layer, and a conductive layer provided on the main surface of the insulating layer; fixing a connection plate, which has a connection plate terminal hole that is a through hole, to the main surface of the conductive layer, and which has a portion that contacts the main surface of the conductive layer and is electrically conductive between the inner surface of the connection plate terminal hole; and inserting a press-fit terminal into the connection plate terminal hole of the connection plate to generate a pressing force against the inner surface of the connection plate terminal hole, thereby fixing the press-fit terminal to the connection plate.

[0017] According to this method, a substrate structure can be obtained that allows press-fit terminals to be applied to a metal substrate. [Effects of the Invention]

[0018] According to the present invention, there is provided a method for manufacturing an electronic substrate and a substrate structure that allows press-fit terminals to be applied to a metal substrate. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a cross-sectional perspective view showing a substrate structure according to an embodiment. [Figure 2] 2(a) and 2(b) are perspective views showing the manufacturing process for obtaining the substrate structure shown in FIG. [Figure 3] 3(a) and 3(b) are perspective views showing the manufacturing process for obtaining the substrate structure shown in FIG. 1, following FIG. 2. In FIG. [Figure 4] FIG. 4 is a cross-sectional perspective view showing the substrate structure of the first modification. [Figure 5] 5(a) and 5(b) are perspective views showing the manufacturing process for obtaining the substrate structure of the first modified example shown in FIG. [Figure 6] 6(a) and 6(b) are perspective views showing the manufacturing process for obtaining the substrate structure of Modified Example 1 shown in FIG. 4, following FIG. 5. In FIG. [Figure 7]FIG. 7 is a cross-sectional perspective view showing a substrate structure according to the second modification. [Figure 8] 8(a) and 8(b) are perspective views showing the manufacturing process for obtaining the substrate structure of the second modification shown in FIG. [Figure 9] 9(a) and 9(b) are perspective views showing the manufacturing process for obtaining the substrate structure of Modified Example 2 shown in FIG. 7, following FIG. DETAILED DESCRIPTION OF THE INVENTION

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are designated by the same reference numerals, and duplicated explanations will be omitted.

[0021] 1 is a cross-sectional perspective view of a substrate structure 1 according to a first embodiment. The substrate structure 1 is a part of an electronic board on which a plurality of electronic components, such as resistor elements and transistor elements, are mounted. The substrate structure 1 includes a substrate 2, a surface connecting plate 3, a fastening component 4, and a press-fit terminal 5.

[0022] The substrate 2 is a so-called metal substrate. The substrate 2 includes a base layer 21, an insulating layer 22, and a copper layer 23 (conductive layer). The substrate 2 may include other functional layers as needed. The substrate 2 has a substrate main surface 2a and a substrate back surface 2b. Various electronic components are arranged on the substrate main surface 2a, forming a desired electronic circuit. The substrate back surface 2b may be in contact with a housing that houses an electronic substrate including the substrate structure 1, for example.

[0023] The base layer 21 is the main body of the substrate 2. The base layer 21 is made of a metal material. For example, the base layer 21 may be a plate material made of aluminum. The base layer 21 may also be a plate material made of copper. The base layer 21 made of a metal material can improve the heat dissipation properties of the substrate 2. The base layer 21 has a base layer main surface 21a and a base layer back surface 21b.

[0024] The insulating layer 22 is a base for forming a desired electronic circuit on the base layer 21. The insulating layer 22 is made of an electrically insulating resin material such as epoxy resin or polyimide resin. The thickness of the insulating layer 22 is thinner than the thickness of the base layer 21. The insulating layer 22 is provided on the base layer main surface 21a. That is, the insulating layer 22 has an insulating layer main surface 22a and an insulating layer back surface 22b, and the insulating layer back surface 22b is in contact with the base layer main surface 21a.

[0025] The copper layer 23 electrically connects electronic components attached to electrodes exposed from the insulating layer main surface 22a. The copper layer 23 is a so-called wiring pattern formed on the insulating layer main surface 22a. The copper layer 23 is a thin copper film (copper foil). The copper layer 23 is provided on the insulating layer main surface 22a. The copper layer 23 has a copper layer main surface 23a and a copper layer back surface 23b, and the copper layer back surface 23b is in contact with the insulating layer main surface 22a. In FIG. 1, the copper layer 23 is provided on the entire insulating layer main surface 22a, but the copper layer 23 may be provided on only a part of the insulating layer main surface 22a. In other words, the surface of the substrate 2 includes the insulating layer main surface 22a and the copper layer main surface 23a.

[0026] The substrate 2 has substrate terminal holes 2T formed from the substrate main surface 2a to the substrate back surface 2b. The substrate terminal holes 2T are for press-fit terminals 5. When viewed from above, the substrate terminal holes 2T have a circular shape. The substrate terminal holes 2T include copper layer terminal holes 23T formed in the copper layer 23, insulating layer terminal holes 22T formed in the insulating layer 22, and base layer terminal holes 21T formed in the base layer 21. Because the copper layer terminal holes 23T, insulating layer terminal holes 22T, and base layer terminal holes 21T form a single substrate terminal hole 2T, their diameters are the same.

[0027] The board terminal hole 2T can be defined as a space surrounded by the board terminal hole inner surface 2Ts (see FIG. 2(b)). Since the board terminal hole 2T includes the copper layer terminal hole 23T, the insulating layer terminal hole 22T, and the base layer terminal hole 21T, the board terminal hole 2T can also be said to be an area surrounded by the copper layer terminal inner surface 23Ts, the insulating layer terminal inner surface 22Ts, and the base layer terminal hole inner surface 21Ts.

[0028] Furthermore, board fastening holes 2C are formed in board 2, extending from board main surface 2a to board back surface 2b. Board fastening holes 2C are for fastening components 4. When viewed from above, board fastening holes 2C are circular in shape. Board fastening holes 2C include copper layer fastening holes 23C formed in copper layer 23, insulating layer fastening holes 22C formed in insulating layer 22, and base layer fastening holes 21C formed in base layer 21. Copper layer fastening holes 23C, insulating layer fastening holes 22C, and base layer fastening holes 21C form a single board fastening hole 2C, and therefore have the same diameter.

[0029] Two board fastening holes 2C are provided in the board 2. A board terminal hole 2T is provided between the two board fastening holes 2C. In other words, the board terminal hole 2T is sandwiched between the two board fastening holes 2C. The distances from the central axes of the board terminal holes 2T to the board fastening holes 2C may be the same. Furthermore, the inner diameter of the board terminal hole 2T is larger than the inner diameter of the board fastening hole 2C.

[0030] The surface connecting plate 3 is used to attach the press-fit terminals 5 to the substrate 2. "Attaching" here refers to both mechanically fixing the press-fit terminals 5 to the substrate 2 and electrically connecting the press-fit terminals 5 to the copper layer 23. The surface connecting plate 3 is a plate-shaped member having desired strength and electrical conductivity. The surface connecting plate 3 may be a metal plate such as aluminum or copper. A surface connecting plate 3 using a metal plate can be easily produced. The surface connecting plate 3 may also be a plate made of a resin material with a metal plating formed on its surface. More specifically, a plating layer may be provided to electrically connect the portion of the surface connecting plate 3 that contacts the copper layer 23 to the inner surface of the connecting plate terminal hole 3T. A surface connecting plate 3 made of a resin material can be made lighter.

[0031] The surface connecting plate 3 is fixed to the copper layer 23. In the example shown in FIG. 1, the surface connecting plate 3 is fixed to the substrate 2 by fastening parts 4. However, the manner in which the surface connecting plate 3 is fixed to the substrate 2 is not limited to fastening. For example, the surface connecting plate 3 may be fixed to the substrate 2 by reflow soldering, ultrasonic bonding, laser welding, resistance welding, or other welding or bonding methods. Such bonding methods can be implemented during the manufacturing process of the substrate alone. Therefore, they can be implemented more easily than when used to connect the substrate 2 to an electrical component.

[0032] The front-side connecting plate 3 has a connecting-plate main surface 3a and a connecting-plate back surface 3b, and the connecting-plate back surface 3b is in contact with the copper layer main surface 23a. The front-side connecting plate 3 includes connecting-plate terminal holes 3T and connecting-plate fastening holes 3C. The positional relationship between the connecting-plate terminal holes 3T and the connecting-plate fastening holes 3C is the same as the positional relationship between the board terminal holes 2T and the board fastening holes 2C described above. In other words, the connecting-plate terminal hole 3T is provided between two connecting-plate fastening holes 3C. In other words, the connecting-plate terminal hole 3T is sandwiched between two connecting-plate fastening holes 3C. The distances from the central axes of the connecting-plate terminal holes 3T to the connecting-plate fastening holes 3C may be the same. Furthermore, the inner diameter of the connecting-plate terminal hole 3T is larger than the inner diameter of the connecting-plate fastening holes 3C.

[0033] Furthermore, the diameter of the connection plate terminal hole 3T is smaller than the diameter of the board terminal hole 2T. The diameters of the connection plate terminal hole 3T and the board terminal hole 2T are determined by the dimensions of the press-fit terminal 5. The diameter of the connection plate terminal hole 3T is slightly smaller than the width (outer diameter) of the press-fit terminal 5 so that the press-fit terminal 5 is press-fitted. On the other hand, the diameter of the board terminal hole 2T is larger than the width (outer diameter) of the press-fit terminal 5 so that it does not come into contact with the press-fit terminal 5. Therefore, the diameter of the connection plate terminal hole 3T is smaller than the diameter of the board terminal hole 2T. In other words, the diameter of the board terminal hole 2T is larger than the diameter of the connection plate terminal hole 3T.

[0034] The connecting plate terminal hole 3T overlaps with the board terminal hole 2T. More specifically, it can be said that the central axis of the connecting plate terminal hole 3T coincides with the central axis of the board terminal hole 2T. Similarly, the connecting plate fastening hole 3C overlaps with the board fastening hole 2C. More specifically, it can be said that the central axis of the connecting plate fastening hole 3C coincides with the central axis of the board fastening hole 2C.

[0035] The fastening parts 4 are used to secure the surface connecting plate 3 to the substrate 2. The fastening parts 4 may be, for example, bolts and nuts. The fastening parts 4 are inserted, for example, from the substrate main surface 2a side into the connecting plate fastening holes 3C and the substrate fastening holes 2C and protrude from the substrate back surface 2b. Axial force is generated in the fastening parts 4 by a nut 43 that is screwed onto the head 41 of the fastening part 4 and the neck 42 protruding from the substrate back surface 2b. This axial force mechanically secures the surface connecting plate 3 to the substrate 2. In other words, the fastening parts 4 contact the connecting plate main surface 3a and the base layer back surface 21b (substrate back surface 2b). The necks of the fastening parts 4 are inserted into the connecting plate fastening holes 3C and the substrate fastening holes 2C. The outer peripheral surfaces of the necks 42 of the fastening parts 4 may contact the inner peripheral surfaces of the connecting plate fastening holes 3C and the substrate fastening holes 2C, respectively, or may be slightly spaced apart.

[0036] The fastening parts 4 must be made of an electrically insulating material. An electrically insulating fastening part 4 prevents a short circuit between the conductive surface connecting plate 3 and the base layer 21, which is also conductive. In other words, the fastening parts 4 are intended to mechanically fix the surface connecting plate 3 to the substrate 2, and do not play any role in electrical connection. The entire fastening part 4 may be made of an electrically insulating material, or an insulating layer may be provided in the portion that contacts the surface connecting plate 3 and / or the portion that contacts the base layer 21.

[0037] The press-fit terminals 5 are used to electrically connect, for example, an electronic board including the substrate structure 1 to another counterpart electronic board. What is connected to the press-fit terminals 5 is not limited to an electronic board, but may also be an electric machine such as a motor. In this example, the electronic board including the substrate structure 1 is an inverter that provides three-phase AC to the motor, and what is connected to the electronic board by the press-fit terminals 5 is the motor.

[0038] The press-fit terminal 5 has a terminal head portion 51 and a terminal shaft portion 52. These are integrally formed components.

[0039] The terminal head 51 is a portion that is electrically connected to the aforementioned mating electronic board. In Fig. 1, the terminal head 51 is shown in a low rectangular parallelepiped shape, but this shape is merely an example. The shape of the terminal head 51 can be changed as appropriate depending on the mating electronic board, etc.

[0040] The terminal shank 52 is press-fit into the connection plate terminal hole 3T. More specifically, the terminal side surface 52s of the terminal shank 52 is pressed against the inner peripheral surface of the connection plate terminal hole 3T. Furthermore, the terminal shank 52 is inserted into the board terminal hole 2T. More specifically, the terminal side surface 52s of the terminal shank 52 does not contact the inner peripheral surface of the board terminal hole 2T.

[0041] From a functional perspective, the press-fit terminal 5 is mechanically fixed to the surface connecting plate 3 by pressing the terminal side surface 52s of the terminal shank 52 against the inner peripheral surface 3Ts of the connecting plate terminal hole 3T. Furthermore, the press-fit terminal 5 is electrically connected to the surface connecting plate 3 by pressing the terminal side surface 52s of the terminal shank 52 against the inner peripheral surface 3Ts of the connecting plate terminal hole 3T. Furthermore, the terminal shank 52 does not contact the inner peripheral surface 2Ts of the board terminal hole 2T, so the terminal shank 52 is not directly electrically connected to the board 2. More specifically, the press-fit terminal 5 is electrically insulated from the base layer 21.

[0042] Electrical insulation between the press-fit terminal 5 and the base layer 21 is ensured by the formation of a gap (air layer) between the terminal side surface 52s of the terminal shaft portion 52 and the base layer terminal hole inner peripheral surface 21Ts of the base layer terminal hole 21T. As long as electrical insulation is ensured, an electrically insulating resin material or the like may be filled between the press-fit terminal 5 and the base layer 21.

[0043] Furthermore, the distance from the terminal side surface 52s of the terminal shank 52 to the base layer terminal hole inner surface 21Ts of the base layer terminal hole 21T affects two performance factors. The first factor is the electrical insulation between the press-fit terminal 5 and the base layer 21. For example, when a high voltage is applied to the press-fit terminal 5, if the distance from the terminal side surface 52s of the terminal shank 52 to the base layer terminal hole inner surface 21Ts of the base layer terminal hole 21T is short, sufficient electrical insulation cannot be ensured. In this case, the diameter of the board terminal hole 2T can be increased so that the distance from the terminal side surface 52s of the terminal shank 52 to the base layer terminal hole inner surface 21Ts of the base layer terminal hole 21T increases.

[0044] On the other hand, increasing the distance from the terminal side surface 52s of the terminal shank 52 to the base layer terminal hole inner surface 21Ts of the base layer terminal hole 21T means reducing the area of ​​the base layer 21 for ensuring heat dissipation. Therefore, if heat dissipation is important, the diameter of the board terminal hole 2T can be reduced so that the distance from the terminal side surface 52s of the terminal shank 52 to the base layer terminal hole inner surface 21Ts of the base layer terminal hole 21T becomes shorter.

[0045] In other words, depending on the specifications required for the electronic board, a structure that prioritizes voltage resistance or heat dissipation can be adopted. Moreover, the balance between voltage resistance and heat dissipation can be adjusted simply by selecting the diameter of the board terminal hole 2T. Since the board terminal hole 2T is a simple circular hole in the example shown in Figure 1, it is relatively easy to drill a through hole with the desired diameter.

[0046] <Method for manufacturing substrate structure> Next, a method for manufacturing the substrate structure 1 will be described. As shown in FIG. 2(a), a substrate 2 is prepared (S11). Next, as shown in FIG. 2(b), substrate terminal holes 2T and substrate fastening holes 2C are formed in the substrate 2 (S12). Note that if the surface connecting plate 3 is to be soldered, drilling for the substrate fastening holes 2C may be omitted. Next, as shown in FIG. 3(a), a surface connecting plate 3 is placed on the substrate main surface 2a (S13). Note that the surface connecting plate 3 may already have the connecting plate terminal holes 3T and the connecting plate fastening holes 3C formed therein. Next, as shown in FIG. 3(b), the surface connecting plate 3 is fixed to the substrate 2 (S14). In the example shown in FIG. 3(b), fastening components 4 are inserted into the connecting plate fastening holes 3C and the substrate fastening holes 2C. Note that in the step (S14) of fixing the surface connecting plate 3 to the substrate 2, the surface connecting plate 3 may be soldered to the copper layer 23 of the substrate 2. Then, the press-fit terminals 5 are press-fitted into the connection plate terminal holes 3T (FIG. 1, S15), thereby obtaining the substrate structure 1 shown in FIG.

[0047] <Action and effect> The substrate structure 1 comprises a substrate 2 including a base layer 21 formed of a metal material, an insulating layer 22 provided on the base layer main surface 21a, and a copper layer 23 provided on the insulating layer main surface 22a, a surface connecting plate 3 fixed to the copper layer main surface 23a and provided with a connecting plate terminal hole 3T, such that the portion in contact with the copper layer main surface 23a is electrically conductive with the inner surface of the connecting plate terminal hole 3T, and a press-fit terminal 5 inserted into the connecting plate terminal hole 3T and fixed to the surface connecting plate 3 by generating a pressing force against the inner surface of the connecting plate terminal hole 3T.

[0048] This substrate structure 1 mechanically and electrically connects the press-fit terminal 5 to the substrate 2 via the surface connecting plate 3, so that the press-fit terminal 5 can be applied to the substrate 2, which is a metal substrate including a base layer 21 formed from a metal material.

[0049] The press-fit terminal 5 includes a terminal shaft 52 that protrudes from the rear surface 3b of the connecting board. The substrate 2 includes an inner peripheral surface 2Ts of the substrate terminal hole, which is the substrate side surface facing the side of the terminal shaft 52. There is electrical insulation between the side surface of the terminal shaft 52 and the inner peripheral surface 2Ts of the substrate terminal hole. This configuration allows electrical insulation between the press-fit terminal 5 and the base layer 21 formed of a metal material.

[0050] A gap is formed between the side surface of the terminal shaft portion 52 and the inner peripheral surface 2Ts of the board terminal hole. This configuration also makes it possible to electrically insulate the press-fit terminal 5 from the base layer 21 made of a metal material.

[0051] The substrate 2 includes substrate terminal holes 2T that penetrate the copper layer 23, the insulating layer 22, and the base layer 21. The surface connecting plate 3 is arranged so that the connecting plate terminal holes 3T overlap the substrate terminal holes 2T. The substrate terminal hole inner surface 2Ts is the inner surface of the substrate terminal hole 2T. With this configuration, press-fit terminals 5 can be applied to one substrate 2.

[0052] The method for manufacturing the substrate structure 1 includes the steps of: preparing a substrate 2 (S11) including a base layer 21 formed of a metal material, an insulating layer 22 provided on the base layer main surface 21a, and a copper layer 23 provided on the insulating layer main surface 22a; fixing a surface connecting plate 3 to the copper layer main surface 23a (S14), the surface connecting plate 3 having a connecting plate terminal hole 3T and having an electrically conductive portion in contact with the copper layer main surface 23a and the inner surface of the connecting plate terminal hole 3T; and fixing the press-fit terminal 5 to the surface connecting plate 3 by inserting the press-fit terminal 5 into the connecting plate terminal hole 3T of the surface connecting plate 3, thereby generating a pressing force against the inner surface of the connecting plate terminal hole 3T.

[0053] In other words, the substrate structure 1 of the embodiment includes a surface connecting plate 3, which is a surface connecting component, and a fastening component 4, which is an insulating fastening component, in order to electrically connect an electronic component to the copper layer 23 of the substrate 2. At least the portion of the surface connecting plate 3 that contacts the copper layer 23 of the substrate 2 and the press-fit terminal 5 is conductive. Therefore, the surface connecting plate 3 has a connecting plate terminal hole 3T, which is a through hole that can be mechanically held by press-fitting the press-fit terminal 5. The substrate 2 has a substrate terminal hole 2T, which is a through hole that is larger than the connecting plate terminal hole 3T.

[0054] By fastening the surface connecting plate 3, into which the press-fit terminals 5 are press-fitted, and the substrate 2 with the fastening parts 4, an electrical connection between the substrate 2 and the electronic component is achieved. The fastening parts 4 are insulating, and the inner diameter of the substrate terminal holes 2T, which are through holes in the substrate 2, is larger than the inner diameter of the connecting plate terminal holes 3T in the surface connecting plate 3. Therefore, even if the substrate 2 is a metal-based substrate, there is little chance of a short circuit occurring in the base layer 21, and the load on the substrate 2 is also small. No special equipment or tools are required for mounting, so mounting can be done at room temperature and in the atmosphere.

[0055] From another perspective, in the substrate structure 1 of the embodiment, the press-fit terminals are inserted into components suitable for press-fit that are already connected to the substrate, rather than into the substrate itself. Specifically, components that are electrically connected to the copper layer that is the surface layer of the substrate are placed on a part of the substrate.

[0056] As a result, the substrate structure 1 of the embodiment can achieve solder-free even on substrates where direct press-fitting is difficult. Therefore, the load on the substrate can be reduced. In addition, since it is directly connected to the copper layer on the surface, it can be used on a variety of substrates. Furthermore, through-hole plating or special insulation treatment is not required. As a result, the substrate structure 1 of the embodiment can be manufactured at low cost.

[0057] The substrate structure and the method for manufacturing the substrate structure according to the present invention are not limited to the above-described embodiment, and various modifications are possible within the scope of the present invention.

[0058] <Variation 1> As shown in FIG. 4, the substrate structure 1A may electrically connect a first substrate 2A and a second substrate 2B to each other and may also electrically connect them to a counterpart substrate (not shown).

[0059] The first substrate 2A and the second substrate 2B are formed by laminating a base layer 21, an insulating layer 22, and a copper layer 23, similar to the substrate 2. Furthermore, the first substrate 2A and the second substrate 2B are provided with one substrate fastening hole 2C (see FIG. 5(b)). However, the first substrate 2A and the second substrate 2B are not provided with a substrate terminal hole 2T. The first substrate 2A is adjacent to the second substrate 2B. The first substrate 2A has a first substrate side surface 2As facing the second substrate 2B. Similarly, the second substrate 2B has a second substrate side surface 2Bs facing the first substrate side surface 2As.

[0060] The shape of the surface connecting plate 3A alone is the same as that of the surface connecting plate 3A of the embodiment. In Modification 1, one end of the surface connecting plate 3A is disposed on the first substrate 2A, and the other end of the surface connecting plate 3A is disposed on the second substrate 2B. In other words, the surface connecting plate 3A is disposed across the first substrate 2A and the second substrate 2B. As a result, the copper layer 23 of the first substrate 2A is electrically connected to the copper layer 23 of the second substrate 2B.

[0061] In addition to a portion overlapping the first substrate 2A and a portion overlapping the second substrate 2B, the surface connecting plate 3A also includes a portion that does not overlap either the first substrate 2A or the second substrate 2B. The portion overlapping the first substrate 2A is provided with a first connecting plate fastening hole 3C. The portion overlapping the second substrate 2B is provided with a second connecting plate fastening hole 3C. The portion that does not overlap either the first substrate 2A or the second substrate 2B is provided with a connecting plate terminal hole 3T.

[0062] The press-fit terminal 5 press-fitted into the connecting plate terminal hole 3T is disposed between the first substrate 2A and the second substrate 2B. More specifically, the terminal shaft portion 52 of the press-fit terminal 5 is disposed between the first substrate side surface 2As and the second substrate side surface 2Bs.

[0063] In this case, the gaps (air layers) for ensuring electrical insulation between the press-fit terminals 5 and the base layer 21 described in the embodiment correspond to the gaps between the first board-side surface 2As and the shank-side surface 52s1 of the terminal shank 52 and the gaps between the second board-side surface 2Bs and the shank-side surface 52s2 of the terminal shank 52, respectively. As in the embodiment, if emphasis is placed on voltage resistance, it is sufficient to increase the gap between the first board-side surface 2As and the shank-side surface 52s1 of the terminal shank 52 and the gap between the second board-side surface 2Bs and the shank-side surface 52s2 of the terminal shank 52. These gaps can be adjusted by changing the longitudinal length of the surface connecting plate 3A.

[0064] <Method for manufacturing substrate structure according to modified example 1> Next, a method for manufacturing the substrate structure of Modification 1 will be described. As shown in FIG. 5(a), a first substrate 2A and a second substrate 2B are prepared (S21). Next, as shown in FIG. 5(b), first substrate fastening holes 2C are formed in the first substrate 2A, and second substrate fastening holes 2C are also formed in the second substrate 2B (S22). Next, as shown in FIG. 6(a), a surface connecting plate 3A is arranged so as to span from the first substrate 2A to the second substrate 2B (S23). Next, as shown in FIG. 6(b), the surface connecting plate 3A is fixed to the first substrate 2A by first fastening components 4 (S24). Similarly, the surface connecting plate 3A is fixed to the second substrate 2B by second fastening components 4 (S24). Then, press-fit terminals 5 are press-fitted into the connecting plate terminal holes 3T (FIG. 4, S25). As a result, the substrate structure 1A shown in FIG. 4 is obtained.

[0065] <Effects of Modification Example 1> The substrate structure 1A of the first modification includes a first substrate 2A and a second substrate 2B adjacent to the first substrate 2A. The second substrate 2B includes a second substrate side surface 2Bs facing the first substrate side surface 2As. The surface connecting plate 3A is disposed across the first substrate 2A and the second substrate 2B. The shank side surface 52s1 of the terminal shank 52 faces the first substrate side surface 2As. The shank side surface 52s2 of the terminal shank 52 faces the second substrate side surface 2Bs. With this configuration, a press-fit terminal 5 can be applied to the substrate structure in which the first substrate 2A and the second substrate 2B are connected by the surface connecting plate 3A.

[0066] That is, even with the substrate structure 1A of the first modification, it is possible to obtain the same effects as those of the substrate structure 1A of the embodiment.

[0067] <Variation 2> In Modification 1, the surface connecting plate 3A is arranged so that the first substrate 2A spans the second substrate 2B. This configuration electrically connects the first substrate 2A to the second substrate 2B. For example, as shown in FIG. 7, the second substrate 2B may be omitted and the surface connecting plate 3B may be attached only to the first substrate 2A, as in substrate structure 1B of Modification 2. This configuration can be used in a configuration in which the first substrate 2A is an inverter and a motor is connected to the press-fit terminals 5.

[0068] The first substrate 2A is the same as the first substrate 2A of Modification 1, and therefore a detailed description thereof will be omitted. The surface connecting plate 3B includes one connecting plate fastening hole 3C and one connecting plate terminal hole 3T (see FIG. 9(b)). In other words, the substrate structure 1B of Modification 2 does not include a second substrate 2B, and therefore the surface connecting plate 3B does not include a second connecting plate fastening hole 3C.

[0069] In Modification 2, the gap for ensuring electrical insulation between the press-fit terminal 5 and the base layer 21 described in the embodiment corresponds to the gap between the first board-side surface 2As and the shank-side surface 52s1 of the terminal shank 52. As in the embodiment, if priority is given to voltage resistance, the gap between the first board-side surface 2As and the shank-side surface 52s1 of the terminal shank 52 can be increased. In order to increase the gap between the first board-side surface 2As and the shank-side surface 52s1 of the terminal shank 52, the distance from the connecting plate terminal hole 3T to the connecting plate fastening hole 3C can be increased.

[0070] <Method for manufacturing substrate structure according to modified example 2> Next, a method for manufacturing the substrate structure of Modification 2 will be described. As shown in FIG. 8(a), a first substrate 2A is prepared (S31). Next, as shown in FIG. 8(b), first substrate fastening holes 2C are formed in the first substrate 2A (S32). Next, as shown in FIG. 9(a), a surface connecting plate 3B is placed on the first substrate 2A (S33). Next, as shown in FIG. 9(b), the surface connecting plate 3B is fixed to the first substrate 2A with first fastening components 4 (S34). Then, press-fit terminals 5 are press-fitted into the connecting plate terminal holes 3T (FIG. 7, S35). As a result, the substrate structure 1B shown in FIG. 7 can be obtained.

[0071] <Effects of Modification Example 2>

[0072] In the substrate structure 1B of the second modification, the surface connecting plate 3B is disposed on the substrate 2A so as to protrude from the first substrate side surface 2As so that the connecting plate terminal holes 3T do not overlap with the substrate 2A. The shaft side surface 52s1 of the terminal shaft 52 faces the first substrate side surface 2As from which the surface connecting plate 3B protrudes. With this configuration, a press-fit terminal 5 can be applied to a substrate structure including the surface connecting plate 3B provided so as to protrude from the substrate 2. In other words, the substrate structure 1B of the second modification can also achieve the same effects as the substrate structure 1 of the embodiment. [Explanation of symbols]

[0073] 1, 1A, 1B Substrate structure 2 boards 2A First board 2B Second board 2a Main surface of substrate 2As First substrate side 2b Back side of the board 2Bs Second board side 2Ts PCB terminal hole inner surface 2C PCB fastening hole 2T board terminal hole 21 Base Layer 22 Insulating layer 23 Copper layer (conductive layer) 3,3A,3B Surface connection plate 3C Connection plate fastening hole 3T connection plate terminal hole 4 Fastening parts 5 Press-fit terminals 52s1,52s2 Shaft side

Claims

1. a substrate including a base layer formed of a metal material, an insulating layer provided on a main surface of the base layer, and a conductive layer provided on the main surface of the insulating layer; a connection plate fixed to a main surface of the conductive layer and having a connection plate terminal hole as a through hole, the portion of the connection plate contacting the main surface of the conductive layer electrically conducting with an inner peripheral surface of the connection plate terminal hole; a press-fit terminal that is inserted into the connection plate terminal hole and fixed to the connection plate by generating a pressing force against the inner surface of the connection plate terminal hole.

2. the press-fit terminal includes a terminal shaft portion protruding from the rear surface of the connection plate, the substrate includes a substrate side surface facing a side surface of the terminal shank, The substrate structure according to claim 1 , wherein the side surface of said terminal shaft portion is electrically insulated from the side surface of said substrate.

3. the press-fit terminal includes a terminal shaft portion protruding from the rear surface of the connection plate, the substrate includes a substrate side surface facing a side surface of the terminal shank, The substrate structure according to claim 1 , wherein a gap is formed between the side surface of the terminal shaft portion and the side surface of the substrate.

4. the substrate includes substrate terminal holes penetrating through the conductive layer, the insulating layer, and the base layer, the connection plate is arranged so that the connection plate terminal holes overlap the substrate terminal holes; The substrate structure according to claim 2 or 3, wherein the substrate side surface is an inner peripheral surface of the substrate terminal hole.

5. Further comprising a second substrate adjacent to the first substrate, the second substrate includes a second substrate side surface facing the first substrate side surface of the first substrate, the second substrate side surface being the substrate side surface; the connecting plate is disposed across the first substrate and the second substrate, 4. The substrate structure according to claim 2, wherein a side surface of the terminal shaft portion faces each of the first substrate side surface and the second substrate side surface.

6. the connection plate is disposed on the substrate so as to protrude from a side surface of the substrate and so that the connection plate terminal hole does not overlap with the substrate; 4. The substrate structure according to claim 2, wherein a side surface of said terminal shaft portion faces a side surface of said substrate from which said connecting plate projects.

7. A step of preparing a substrate including a base layer formed of a metal material, an insulating layer provided on a main surface of the base layer, and a conductive layer provided on the main surface of the insulating layer; a step of fixing a connection plate, which has a connection plate terminal hole that is a through hole, to the main surface of the conductive layer, the connection plate having a portion that contacts the main surface of the conductive layer and an inner peripheral surface of the connection plate terminal hole that is electrically conductive; a step of inserting a press-fit terminal into a connection plate terminal hole of the connection plate to generate a pressing force against the inner surface of the connection plate terminal hole, thereby fixing the press-fit terminal to the connection plate.

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