JP7627561B2 - Electronics - Google Patents

Description

The present invention relates to an electronic device.

Patent Document 1 discloses an electronic device that includes a wiring board (printed circuit board) on which a wiring pattern is formed, and an electronic component (semiconductor element) connected to the wiring board. The electronic component is connected to the wiring board via a lead terminal extending from a main body. The entire lead terminal is bent into an L-shape, and the tip of the lead terminal is soldered to the wiring board with the tip inserted through the wiring board.

JP 2001-111271 A

In the electronic component described in Patent Document 1, the tip of the lead terminal is inserted into the wiring board to be positioned, and then the lead terminal is soldered to the wiring board. Therefore, until the lead terminal is soldered to the wiring board, the lead terminal is merely inserted into the wiring board but is not fixed there, which creates the problem that the positioning of the electronic component is not stable.

The present invention has been made to solve the above problems, and aims to stabilize the positioning of electronic components during manufacturing in electronic devices that include electronic components mounted on a wiring board.

An electronic device according to a first aspect of the present invention comprises a wiring board on which a wiring pattern is formed, and an electronic component having a main body and a lead portion extending from the main body, the electronic component having a shape in which the lead portion is folded back toward the main body, and the electronic component is mounted on the wiring board with an end side of the wiring board clamped between an upper surface of the main body and the lead portion.

In the electronic device according to the present invention, the electronic component is held on the wiring board by the main body and the lead portions, so that the electronic component is held on the wiring board and the positioning of the electronic component is stable. Therefore, when manufacturing the electronic device, the lead portions can be connected to the wiring pattern of the wiring board with the electronic component being stably positioned.

FIG. 2 is an exploded perspective view of the regulator device according to the embodiment. 1 is a circuit diagram showing a circuit configuration of a regulator device according to an embodiment of the present invention. 1 is a vertical cross-sectional view that typically illustrates a cross section of a regulator device according to an embodiment of the present invention. FIG. 2 is a perspective view of a circuit board according to the embodiment. FIG. 2 is an enlarged side view of the electronic component according to the embodiment. 6 is a partially enlarged side view of the electronic component according to the embodiment, seen from a different direction from that in FIG. 5 . FIG. 4 is an exploded perspective view showing a circuit board of a regulator device according to a first modified example of the present embodiment. FIG. 2 is an enlarged side view (partial cross-sectional view) of an electronic component according to a first modified example of the embodiment. FIG. 11 is an enlarged side view of an electronic component according to a second modified example of the embodiment.

Below, an embodiment of the present invention will be described with reference to Figs. 1 to 6. In this embodiment, a regulator device 1 shown in Fig. 1 will be described as an example of an electronic device according to the present invention. In this embodiment, for convenience of explanation, the directions indicated by the left and forward arrows shown appropriately in each figure will be defined as upward, left, and forward, respectively. Also, in each figure, some symbols may be omitted to make the drawings easier to read.

As shown in FIG. 1, the regulator device 1 includes a case 10, a circuit board 30 housed inside the case 10, and a connector 18 attached to the case 10. The regulator device 1 is a device that rectifies the current supplied to a battery from an AC generator mounted on a vehicle such as a motorcycle and suppresses voltage fluctuations.

The circuit board 30 includes a wiring board 31 in which conductor wiring is applied on the surface or inside of an insulating board, and a plurality of electronic components mounted on the wiring board 31. The wiring board 31 is equipped with a control unit 2 (see FIG. 2) including a plurality of circuit elements such as a CPU, six semiconductor elements 40, and three capacitors 5 as the plurality of electronic components. The control unit 2 and each semiconductor element 40 are electrically connected by wiring formed on the wiring board 31. As shown in FIG. 2, the six semiconductor elements 40 function as rectifying elements of a rectifying circuit and rectify the power output from the AC generator 3. The regulator device 1 charges the battery 4 with the power rectified by the six semiconductor elements 40. The six semiconductor elements 40 in this embodiment are, as an example, configured with thyristors. Note that the semiconductor elements 40 are not limited to thyristors, and may be configured with semiconductor elements such as diodes and MOSFETs, and the number of semiconductor elements may be appropriately changed depending on the circuit system.

As shown in FIG. 1, the case 10 is composed of a box-shaped case body 12 that opens upward, and a lid 14 that closes the opening of the case body 12. The lid 14 is not essential, and the case 10 may be composed of only the case body 12. The case body 12 is a rectangular box-shaped member made of metal and has an opening 13 that opens upward. The case body 12 has a front wall portion 12A, a rear wall portion 12B, a left wall portion 12C, a right wall portion 12D, and a bottom wall portion 12E. On the outer surfaces of the bottom wall portion 12E, the left wall portion 12C, and the right wall portion 12D, a plurality of heat dissipation fins 12F are provided to dissipate heat from the circuit board 30 (a plurality of electronic components) to the outside of the case body 12. The plurality of heat dissipation fins 12F are each formed in a plate shape extending in the left-right direction, and are arranged in a row in the front-rear direction on the outer surfaces of the bottom wall portion 12E, the left wall portion 12C, and the right wall portion 12D. The case 10 is composed of a metal such as aluminum or iron.

A connector mounting portion 16 is formed in the rear wall portion 12B of the case body 12. The connector mounting portion 16 is a groove portion that penetrates the rear wall portion 12B in the front-rear direction and opens upward. A connector 18 is attached to the connector mounting portion 16. The connector 18 has a housing 20 and a connection terminal 22 provided on the housing 20. One end of the connection terminal 22 is inserted into a through hole 32 of the circuit board 30 and electrically connected. A cable connector that is electrically connected to the AC generator 3, the battery 4, etc. is connected to the connector 18.

The bottom wall 12E of the case body 12 has a capacitor housing 24 formed in the front portion and a heat dissipation surface 26 formed in the rear portion. The capacitor housing 24 is configured as a recessed portion recessed downward. The capacitor housing 24 houses three capacitors 5 mounted on the front end side of the wiring board 31. The heat dissipation surface 26 is configured as a flat portion located above the bottom surface of the capacitor housing 24. The circuit board 30 is located above the heat dissipation surface 26 at a distance, and the heat dissipation surface 26 and the lower surface of the circuit board 30 (the mounting surface on which electronic components are mounted) are located opposite each other.

As shown in FIG. 3, the inside of the case 10 is filled with insulating resin 28. This resin 28 is a resin that has thermal conductivity. The resin 28 is filled between the circuit board 30 and the inner surface of the case 10, and ensures insulation between the circuit board 30 and the case 10. In addition, a plurality of semiconductor elements 40 that generate heat when electricity is passed through them are arranged on the underside of the circuit board 30, and the heat of the plurality of semiconductor elements 40 is dissipated to the outside of the case 10 via the resin 28, the heat dissipation surface portion 26, and the heat dissipation fins 12F.

As described above, the circuit board 30 includes a wiring board 31 and six semiconductor elements 40 mounted on the wiring board 31. As shown in FIG. 4, the wiring board 31 is a rectangular printed wiring board having a predetermined width in the front-rear and left-right directions and a thickness direction in the up-down direction. Three semiconductor elements 40 are mounted on each of the left and right ends of the wiring board 31. Three slits 36 are formed on each of the left and right ends of the wiring board 31 at positions where the semiconductor elements 40 are mounted. Each slit 36 is a groove that penetrates in the up-down direction and opens on the left and right end sides of the wiring board 31, and a number of grooves corresponding to the number of lead portions 44 of the semiconductor elements 40 described later are formed side by side in the front-rear direction.

As shown in Figures 5 and 6, the semiconductor element 40 has a block-shaped main body 42 and three lead portions 44 extending from the main body 42. The main body 42 is constructed by encapsulating a semiconductor chip (not shown) inside and molding the periphery of the semiconductor chip with a block-shaped resin. The semiconductor chip is electrically connected to the three lead portions 44. The exterior shape of the main body 42 is formed into a generally rectangular shape that is flat in the vertical direction. The upper surface of the main body 42 has a protrusion 42A that protrudes upward on the left side, forming a stepped shape.

The three lead portions 44 protrude outward from the side surface of the main body portion 42 (the left side surface in FIG. 5). Each lead portion 44 has a base end portion 46 protruding from the side surface of the main body portion 42, a folded portion 48 bent from the base end portion 46 into an approximately U-shape, and a tip portion 49 extending from the folded portion 48 in the opposite direction to the protruding direction of the base end portion 46. After protruding from the side surface of the main body portion 42, the lead portion 44 is folded back toward the main body portion 42 in an approximately U-shape to form a clip shape. The tip portion 49 folded back toward the main body portion 42 is arranged to extend facing the upper surface of the protruding portion 42A of the main body portion 42 with a predetermined gap therebetween.

The semiconductor element 40 is mounted on the wiring board 31 by inserting the end of the wiring board 31 between the main body 42 and the tip 49 of the lead 44. When the wiring board 31 is inserted between the main body 42 and the tip 49, the lead 44 is deformed against the elastic force, and the wiring board 31 is sandwiched between the main body 42 and the tip 49 by the restoring force. As a result, the semiconductor element 40 is held in a position on the wiring board 31. The semiconductor element 40 held in this manner is mounted on the wiring board 31 by soldering the tip 49 of the lead 44 to the wiring pattern formed on the upper surface of the wiring board 31.

When the semiconductor element 40 is mounted on the wiring board 31, the folded portions 48 of the three lead portions 44 are inserted into the three grooves of the slit portion 36 of the wiring board 31, respectively, and the semiconductor element 40 is prevented from moving forward and backward relative to the wiring board 31. The folded portions 48 of the lead portions 44 are inserted into the slit portion 36 so that they do not protrude outward from the end of the wiring board 31 and are configured to fit within the slit portion 36. The number, length, and external dimensions of the lead portions 44 of the semiconductor element 40 are set appropriately as needed, but in this embodiment, as an example, the lengths and external dimensions of the three lead portions 44 are the same.

When the semiconductor element 40 is mounted on the wiring board 31, the upper surface of the protruding portion 42A of the main body 42 is in surface contact with the lower surface of the wiring board 31. Meanwhile, as shown in FIG. 3, the lower surface of the main body 42 faces the heat dissipation surface 26 of the case body 12 at a predetermined distance. When the semiconductor chip inside the semiconductor element 40 generates heat due to the passage of electricity, the heat is transferred from the lower surface side of the main body 42 through the resin 28 to the bottom wall 12E and heat dissipation fins 12F of the case body 12, whereby the heat is dissipated. The lower surface of the main body 42 may be placed in direct contact with the heat dissipation surface 26 of the case body 12.

As described above, in this embodiment, the semiconductor element 40 is held by the main body 42 and the lead portion 44 at the end side of the wiring board 31, so that the semiconductor element 40 is held on the wiring board 31 and the positioning of the semiconductor element 40 is stable. Therefore, when manufacturing the electronic device 1, the lead portion 44 can be connected to the wiring pattern of the wiring board 31 with the semiconductor element 40 being stably positioned.

The semiconductor element can be positioned by a method of fastening the semiconductor element to the case side of the electronic device with screws or by a method of using a jig during the manufacturing process. However, these methods involve processing the case according to the fixing position of the semiconductor element and manufacturing a jig. In contrast, in this embodiment, the semiconductor element 40 is held and positioned by the wiring board 31, so there is no need for special processing of the case 10, adding fastening parts such as screws, or manufacturing a jig. As a result, it is possible to reduce component costs and improve assembly during the manufacturing of the electronic device 1. Furthermore, since the semiconductor element 40 is positioned relative to the wiring board 31, it is not necessary to perform a mounting process in which the semiconductor element 40 is soldered to the wiring board 31 immediately after the semiconductor element 40 is set in the case 10. Therefore, it is possible to perform the mounting process of the semiconductor element 40 together with the mounting process of other parts, and the processing cost can be reduced by making the soldering work more efficient.

In addition, in this embodiment, a slit portion 36 is formed at the end of the wiring board 31, and the end side of the wiring board 31 is clamped with the lead portion 44 inserted into the slit portion 36. Therefore, the semiconductor element 40 is restricted from moving in the front-rear direction relative to the wiring board 31, so that the positioning of the semiconductor element 40 is more stable. Furthermore, the folded portion 48 of the lead portion 44 is inserted into the slit portion 36, so that it does not protrude outward from the end of the wiring board 31 and is configured to fit within the slit portion 36. Therefore, even if the end of the wiring board 31 is disposed close to the inner surface of the case body 12 due to the miniaturization of the case body 12, contact between the lead portion 44 and the case body 12 can be avoided. As a result, the regulator device 1 can be miniaturized while suppressing short circuits of the lead portion 44.

In addition, in this embodiment, the wiring board 31 on which the semiconductor element 40 is mounted is housed in the case 10 with the semiconductor element 40 facing the inner surface of the bottom wall portion 12E of the case 10, and the wiring board 31 and the multiple electronic components mounted on the wiring board 31 are fixed inside the case 10 by the resin 28 filled inside the case 10. As a result, heat generated by the semiconductor element 40 is dissipated to the outside of the case 10 via the resin 28 and the bottom wall portion 12E. In addition, since multiple heat dissipation fins 12F are provided on the bottom wall portion 12E, the heat dissipation effect of the case 10 can be improved.

Below, a first modified example of the above embodiment will be described with reference to Figures 7 and 8. Note that the same components as those in the above embodiment are given the same numbers and their description will be omitted. As shown in Figures 7 and 8, this first modified example is characterized in that a convex portion 67 is provided on the lead portion 64 of the semiconductor element 60 mounted on the wiring board 31, and the convex portion 67 is inserted into a concave portion 72 of the wiring board 31. The other configurations are the same as those in the above embodiment.

In the first modified example, three recesses 72 are provided at each of the left and right ends of the wiring board 31 at positions where the semiconductor element 60 is mounted, instead of the slit portion 36 of the above embodiment. Each recess 72 is formed of a through hole that penetrates the wiring board 31 in the plate thickness direction, and the number of through holes corresponding to the number of lead portions 64 of the semiconductor element 60 are lined up in the front-rear direction. A conductive portion 74 formed by depositing a conductive material is formed on the inner surface of the recess 72. The conductive portion 74 is connected to a wiring pattern formed inside or on the surface of the wiring board 31.

The semiconductor element 60 has the above-mentioned main body 42 and three lead portions 64 extending from the main body 42. The three lead portions 64 protrude from the side of the main body 42 to the outside. Each lead portion 64 has a base end 66 protruding from the side of the main body 42, a folded portion 68 bent from the base end 46 into an approximately U-shape, and a tip portion 69 extending from the folded portion 68 in the opposite direction to the protruding direction of the base end 66. The lead portion 64 is bent into an approximately U-shape and folded back toward the main body 42 side after protruding from the side of the main body 42 to form a clip shape. The tip portion 69 folded back toward the main body 42 side is provided so as to extend in a state facing the upper surface of the protruding portion 42A of the main body 42 with a predetermined interval therebetween. The lead portion 64 has a protruding portion 67 protruding toward the main body 42 (protruding portion 42A) side by bending a part of the tip portion 69.

The semiconductor element 60 is mounted on the wiring board 31 by inserting the end of the wiring board 31 between the main body 42 and the tip 69 of the lead 64, similar to the semiconductor element 40. When the wiring board 31 is inserted between the main body 42 and the tip 69, the convex portion 67 of the lead 64 is inserted into the concave portion 72 of the wiring board 31. As a result, the convex portion 67 of the lead 64 engages with the concave portion 72 of the wiring board 31, and the semiconductor element 60 is held in a positioned state on the wiring board 31. When the convex portion 67 of the lead 64 engages with the concave portion 72 of the wiring board 31, the convex portion 67 comes into contact with the conductive portion 74, and the semiconductor element 60 and the wiring pattern of the wiring board 31 are electrically connected via the conductive portion 74. The tip portion 69 of the lead 64 may be soldered to the wiring pattern formed on the upper surface of the wiring board 31.

As described above, the first modified example basically follows the configuration of the above embodiment, and therefore the same action and effect can be obtained. Furthermore, in the first modified example, when the semiconductor element 60 is positioned and held on the wiring board 31, the convex portion 67 of the lead portion 64 is inserted into the concave portion 72 provided on the wiring board 31, so that the positioning of the semiconductor element 60 can be further stabilized. In addition, by inserting the convex portion 67 of the lead portion 64 into the concave portion 72 of the wiring board 31, the semiconductor element 60 and the wiring pattern of the wiring board 31 can be electrically connected. Therefore, the process of positioning the semiconductor element 60 on the wiring board 31 and the process of mounting it can be completed in a single process, and the number of steps during manufacturing can be reduced.

Below, a second modified example of the above embodiment will be described with reference to FIG. 9. Note that the same components as those in the above embodiment will be given the same reference numbers and their description will be omitted. As shown in FIG. 9, this second modified example is characterized in that the folded portion 88 of the lead portion 84 of the semiconductor element 80 mounted on the wiring board 31 is formed in an approximately C-shape. The other configurations are the same as those in the above embodiment.

The semiconductor element 80 has the above-mentioned main body 42 and three lead portions 84 extending from the main body 42. The three lead portions 84 protrude from the side of the main body 42 to the outside. Each lead portion 84 has a base end 86 protruding from the side of the main body 42, a folded portion 88 bent from the base end 86 into an approximately C-shape, and a tip portion 89 extending from the folded portion 88 in the opposite direction to the protruding direction of the base end 86. After protruding from the side of the main body 42, the lead portion 84 is folded back toward the main body 42 in an approximately C-shape to form a clip shape. The tip portion 89 folded back toward the main body 42 is provided so as to extend in a state facing the upper surface of the protruding portion 42A of the main body 42 with a predetermined interval therebetween. The folded portion 88 of the lead portion 84 is formed in a circular arc shape that bulges outward from the base end 86 and the tip portion 89 in a side view. As a result, when the wiring board 31 is inserted between the main body 42 and the tip 89 of the lead 84, the stress caused by the elastic deformation of the lead 84 is concentrated in the folded portion 88, reducing the stress burden on the base end 86.

As explained above, the second modified example basically follows the configuration of the above embodiment, and therefore can achieve the same effects and advantages. Furthermore, the second modified example reduces the stress burden on the base end 86 side associated with the elastic deformation of the lead portion 84, thereby reducing the risk of damage to the main body portion 42 and solder fatigue when the lead portion 84 is soldered.

In the above embodiment and each modified example, the present invention has been described as being applied to a regulator device mounted on a vehicle such as a motorcycle as an example of an electronic device according to the present invention, but the present invention is not limited to this. For example, the configuration of the present invention can also be applied to other electronic devices such as converters and inverters. In other words, the configuration of the present invention can be applied to any electronic component that is mounted on a board using a lead portion. Also, in the above embodiment and each modified example, a semiconductor element has been described as an example of an electronic component that is mounted on a board, but the present invention is not limited to semiconductor elements, and the configuration of the present invention can be applied to various electronic components that are mounted on a board using a lead portion.

In addition, in the above embodiment, the tip of the lead portion is soldered to the wiring board for mounting, but the present invention is not limited to this. If the force with which the lead portion holds the wiring board is sufficient, soldering etc. may be unnecessary.

In addition, in the first modified example, the recess 72 of the wiring board 31 is configured as a through hole, but the present invention is not limited to this. The recess may be configured as a through hole that does not have a conductive portion 74 on the inner surface. In this case, since the lead portion cannot be made conductive through the recess, the tip of the lead portion needs to be soldered to the wiring board. In addition, the recess is not limited to a through hole, and may be any depression formed on the surface of the wiring board and shaped so that the protrusion of the lead portion can engage with it.

In the above embodiment, the semiconductor element is positioned and held at the end of the wiring board, but the present invention is not limited to this. A configuration in which the semiconductor element is held at the center of the wiring board is also possible. In that case, for example, by providing a through hole in the wiring board and inserting the straight lead portion of the semiconductor element into the through hole, and then bending the lead portion into a clip shape, the semiconductor element can be held at any position on the wiring board, not just at the end of the wiring board. Alternatively, the wiring board may be provided with a slit that is continuous with the end (outer edge) of the wiring board and extends to any position on the wiring board. In that case, the number of slits may correspond to the number of lead portions, or one slit extending to any position may be provided, and one of the end faces of the wiring board facing the width direction of the slit may be clamped by the lead portion.

In addition, when the semiconductor element is disposed at any position on the wiring board by providing the through hole or slit, the dimensions of the through hole or slit may be formed so as to be included in the creepage distance (insulation distance) or spatial distance between the semiconductor element and other electronic components. This makes it possible to shorten the required distance between electronic components mounted on the wiring board, thereby improving the efficiency of the mounting space. In particular, in high-voltage electrical equipment through which a large current flows, it is necessary to ensure a large creepage distance and spatial distance between electronic components, so it is expected that the efficiency of the mounting space will lead to a reduction in the size of the entire device.

Furthermore, when the semiconductor element is disposed at any position on the wiring board by providing the through hole or slit, it is also possible to configure some of the leads extending from the main body of the semiconductor device to extend in a direction opposite to the tips of the other leads folded back in a clip shape. In this case, for example, some of the leads can be bent from the base end into a crank shape, and the tips of the leads can be inserted into the through hole or slit and placed on the mounting surface of the wiring board. That is, the leads folded in a clip shape clamp one side of the wiring board across the through hole or slit, while the other leads are supported on the other side of the wiring board across the through hole or slit. As a result, the positioning of the semiconductor element is more stable, and it is possible to prevent the semiconductor element from falling off the wiring board during the manufacture of the electronic device. Furthermore, compared to a configuration in which all the leads extend in the same direction (shape), it is possible to increase the distance between the leads arranged adjacent to each other on the wiring board, and it is possible to prevent solder bridges between the leads when soldering the leads to the wiring board. It also makes it easier to ensure the creepage distance between the wiring to which each lead is connected.

1 Regulator device (electronic device)
10 Case 28 Resin 31 Wiring board 36 Slit portion 40 Semiconductor element (electronic component)
42 Main body portion 44 Lead portion 60 Semiconductor element (electronic component)
64 Lead portion 67 Convex portion 72 Concave portion 80 Semiconductor element (electronic component)
84 Lead section

Claims (4)

A wiring board on which a wiring pattern is formed;
an electronic component having a body portion and a lead portion extending from the body portion;
The electronic component has a shape in which the lead portion is folded back toward the main body portion, and is mounted on the wiring board with the end side of the wiring board clamped between the upper surface of the main body portion and the lead portion. A slit portion is formed at an end of the wiring board,
2. The electronic device according to claim 1, wherein the end side of the wiring board is clamped with the lead portion of the electronic component inserted in the slit portion. The electronic device according to claim 1 or 2, wherein the lead portion has a protrusion that protrudes toward the main body portion at the tip side folded back toward the main body portion, and when the end side of the wiring board is sandwiched between the main body portion and the lead portion, the protrusion is inserted into a recess provided in the wiring board. a case that accommodates the wiring board and the electronic components;
the wiring board on which the electronic components are mounted is housed in the case with the electronic components facing an inner surface of the case;
4. The electronic device according to claim 1, wherein the wiring board and the electronic components are fixed inside the case by a resin that is filled in the case and has insulating and thermally conductive properties.