Semiconductor relay

Abstract

This semiconductor relay (100) comprises a light-emitting element (10), a light-receiving element (20), first and second switching elements (31, 32), first and second die pads (51, 52), first and second terminals (41, 42), and a package (60) that accommodates the elements, pads, terminals, and package therein. The light-receiving element (20) is positioned below the light-emitting element (10) and between the first switching element (31) and the second switching element (32). One-side ends of the first and second terminals (41, 42) are connected to the first and second die pads (51, 52), respectively, and the other-side ends are exposed to the outside of the package (60). In a top view, at least a part of the first and second die pads (51, 52) overlaps the first and second switching elements (31, 32), respectively.

Description

Solid State Relay

[0001] The present disclosure relates to solid state relays.

[0002] Conventionally, semiconductor relays, also known as MOSFET output photocouplers or optical MOSFETs, have been known as signal transmission means. Typically, these semiconductor relays are miniaturized by sealing each component in a resin package.

[0003] For example, Patent Document 1 discloses a semiconductor relay including a light-emitting element, an input terminal electrically connected to the light-emitting element, a light-receiving element provided in a position opposite the light-emitting element, a first switching element electrically connected to the light-receiving element, a first lead including a first mount bed on which the first switching element is mounted and a first output terminal electrically connected to the first switching element, and a resin package that encapsulates the light-emitting element, the light-receiving element, the first switching element, and the first mount bed of the first lead.

[0004] Japanese Patent Application Laid-Open No. 2022-126101

[0005] In the conventional semiconductor relay disclosed in Patent Document 1, the switching element generates a large amount of heat during operation, but Patent Document 1 does not disclose any measures to deal with this heat generation.

[0006] A semiconductor relay according to one aspect of the present disclosure includes: a light-emitting element; a light-receiving element located below the light-emitting element and facing the light-emitting element; a first switching element adjacent to the light-receiving element; a second switching element adjacent to the light-receiving element; a first die pad located above the first switching element; a second die pad located above the second switching element; a first terminal having one end connected to the first die pad; a second terminal having one end connected to the second die pad; and a package, wherein the light-receiving element is located between the first switching element and the second switching element and is arranged in a direction in which the first terminal and the second terminal are arranged. a first direction is a first direction, the other end of the first terminal is exposed to the outside of the package and extends downward from the package, the other end of the second terminal is exposed to the outside of the package and extends downward from the package, the light-emitting element, the light-receiving element, the first switching element, the second switching element, the first die pad, and the second die pad are located inside the package, and at least a portion of the first die pad overlaps with the first switching element in a top view, and at least a portion of the second die pad overlaps with the second switching element in a top view.

[0007] A semiconductor relay according to another aspect of the present disclosure includes a light-emitting element, a light-receiving element located below the light-emitting element and facing the light-emitting element, a first switching element adjacent to the light-receiving element, a second switching element adjacent to the light-receiving element, a first die pad located above the first switching element, a second die pad located above the second switching element, a first terminal having one end connected to the first die pad, a second terminal having one end connected to the second die pad, and a package. The first die pad is located between the first switching element and the second switching element, the direction in which the first terminal and the second terminal are aligned is defined as a first direction, the other end of the first terminal is exposed to the outside of the package and extends downward from the package, the other end of the second terminal is exposed to the outside of the package and extends downward from the package, at least a portion of the first die pad overlaps with the first switching element in a top view, and at least a portion of the second die pad overlaps with the second switching element in a top view. A semiconductor relay according to another aspect of the present disclosure further includes a third die pad on which the first switching element is arranged, a fourth die pad on which the second switching element is arranged, a third terminal having one end connected to the third die pad, and a fourth terminal arranged opposite the third terminal in the first direction, wherein the light-emitting element, the light-receiving element, the first switching element, the second switching element, and the first to third die pads are located inside the package, and the third terminal includes a third tip portion, a third intermediate portion connected to the third tip portion and exposed to the outside of the package, and a fourth terminal arranged opposite the third intermediate portion. and the third die pad and a third connection portion located inside the package, the third intermediate portion having a first portion connected to the third connection portion and a second portion extending downward from the first portion, when the direction in which the light-emitting element and the light-receiving element face each other is defined as a third direction, the shortest length of the third intermediate portion in the first direction is greater than the longest length of the third tip portion in the first direction, and a first axis which is the center line of the first portion along the third direction is farther from the fourth terminal than a second axis which is the center line of the third tip portion along the third direction.

[0008] According to the present disclosure, the path for dissipating heat generated during operation to the outside of the package can be strengthened, thereby improving heat dissipation.

[0009] FIG. 1A is a perspective view of the semiconductor relay according to the first embodiment. FIG. 1B is a side view of the semiconductor relay according to the first embodiment, as seen from the right. FIG. 1C is a side view of the semiconductor relay according to the first embodiment, as seen from the left. FIG. 1D is a top view of the semiconductor relay according to the first embodiment. FIG. 1E is a perspective view of the semiconductor relay according to the first embodiment, with the package omitted. FIG. 2 is a top view of the semiconductor relay according to the first embodiment, with the package omitted. FIG. 3 is a cross-sectional view of the semiconductor relay according to the first embodiment, taken along line III-III in FIG. 2. FIG. 4 is an equivalent circuit diagram of the semiconductor relay according to the first embodiment. FIG. 5A is a see-through view of the semiconductor relay according to the first embodiment, as seen from below. FIG. 5B is a see-through view of the semiconductor relay according to the first embodiment, as seen from above. FIG. 6A is a plan view of a first die pad according to the first embodiment. FIG. 6B is a plan view of a second die pad according to the first embodiment. FIG. 6C is a plan view showing another example of the first die pad. FIG. 6D is a plan view showing yet another example of the first die pad. FIG. 7A is a plan view of a first die pad and a first switching element. FIG. 7B is a plan view of a second die pad and a second switching element. FIG. 8A is a top view of a first terminal according to the first embodiment. FIG. 8B is a side view of the first terminal according to the first embodiment. FIG. 9A is a top view of a first terminal according to a comparative example. FIG. 9B is a side view of a first terminal according to a comparative example. FIG. 10A is an enlarged view of a portion surrounded by dashed line XA in FIG. 1C. FIG. 10B is an enlarged view of a portion surrounded by dashed line XB in FIG. 1C. FIG. 11A is a view corresponding to FIG. 10A according to a first modified example. FIG. 11B is a view corresponding to FIG. 10B according to the first modified example. FIG. 12A is a perspective view of a semiconductor relay according to a second modified example. FIG. 12B is a side view of a semiconductor relay according to the second modified example. FIG. 13 is a perspective view of a semiconductor relay according to the second embodiment, with the package omitted.

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The following description of the preferred embodiments is merely exemplary in nature and is not intended to limit the present invention, its applications, or uses.

[0011] In addition, in this disclosure, the terms "upper" and "lower" do not refer to the upper direction (vertically upper) and lower direction (vertically lower) in absolute spatial recognition, but are used as terms defined by the relative positional relationship of components in the semiconductor relay. Furthermore, the terms "upper" and "lower" are used not only when two components are arranged with a gap between them, but also when two components are arranged closely together and are in contact with each other. In the following description, the semiconductor relay 100 and its components viewed from above will be referred to as a top view.

[0012] First Embodiment [Overall Configuration of Semiconductor Relay 100] Hereinafter, a semiconductor relay 100 according to a first embodiment will be described.

[0013] An overview of the configuration of a semiconductor relay 100 according to this embodiment will be described with reference to FIGS. 1 to 3. FIG. 1A is a perspective view of the semiconductor relay according to the first embodiment. FIG. 1B is a side view of the semiconductor relay according to the first embodiment, viewed from the right. FIG. 1C is a side view of the semiconductor relay according to the first embodiment, viewed from the left. FIG. 1D is a top view of the semiconductor relay according to the first embodiment. FIG. 1E is a perspective view of the semiconductor relay according to the first embodiment, with the package omitted. FIG. 2 is a top view of the semiconductor relay according to the first embodiment. FIG. 3 is a cross-sectional view of the semiconductor relay according to the first embodiment, taken along line III-III in FIG. 2.

[0014] For the sake of convenience, in Fig. 1A and the following drawings, illustrations and detailed descriptions of metal wires connecting components of the semiconductor relay 100 are omitted. Also, in Fig. 1A and Fig. 1D, only lands 502a of the wiring 502 provided on the external mounting board 500 are illustrated.

[0015] In the following description, the arrangement and configuration of each component may be described using the terms front-to-back, left-to-right, and up-to-down in each figure. That is, the direction in which terminal 42 is arranged relative to terminal 41 is referred to as "front" or "forward," and the direction in which terminal 41 is arranged relative to terminal 42 is referred to as "back" or "rear." The direction in which terminals 41 to 46 protrude is referred to as "left" or "leftward," and the direction in which terminals 47 and 48 protrude is referred to as "right" or "rightward." The front-to-back direction may be referred to as "first direction." The left-to-right direction may be referred to as "second direction." The up-to-down direction may be referred to as "third direction." The first, second, and third directions are perpendicular to each other.

[0016] In addition, "terminal 41" may be referred to as "first terminal 41", "terminal 42" as "second terminal 42", "terminal 47" as "seventh terminal 47", and "terminal 48" as "eighth terminal 48".

[0017] The "seventh terminal 47" in the embodiment corresponds to the "third terminal" in the claims, and the "eighth terminal 48" in the embodiment corresponds to the "fourth terminal" in the claims.

[0018] In this specification, "orthogonal," "parallel," or "the same" means that the semiconductor relay 100 and its components are orthogonal, parallel, or the same, taking into account the processing tolerances and assembly tolerances of the semiconductor relay 100 and its components, and does not mean that the objects being compared are orthogonal, parallel, or the same in the strict sense.

[0019] 1A to 3, the semiconductor relay 100 includes a light-emitting element 10, a light-receiving element 20, first and second switching elements 31, 32, first to sixth die pads 51 to 56, terminals 41 to 48, and a package 60. The first to sixth die pads 51 to 56 and the terminals 41 to 48 are obtained by processing a metal plate such as copper.

[0020] The light emitting element 10 is disposed on the lower surface of the fifth die pad 55. The fifth die pad 55 is connected to the terminals 43 and 44. In this embodiment, the light emitting element 10 is a light emitting diode (LED).

[0021] The terminal 45 is electrically connected to the light-emitting element 10 via a metal wire. When a predetermined voltage is applied between the terminal 43 and the terminal 44 and the terminal 45, the light-emitting element 10 emits light and outputs an optical signal.

[0022] The light receiving element 20 is located below the light emitting element 10. The light receiving element 20 is disposed on the upper surface of the sixth die pad 56.

[0023] The first and second switching elements 31, 32 are adjacent to the light receiving element 20. The first and second switching elements 31, 32 are positioned on both sides of the light receiving element 20 along the first direction with a gap therebetween. That is, the light receiving element 20 is positioned between the first and second switching elements 31, 32. In this embodiment, the first and second switching elements 31, 32 are each a MOSFET (see FIG. 4 ), but are not particularly limited to this.

[0024] The first switching element 31 is disposed on the upper surface of the third die pad 53. The second switching element 32 is disposed on the upper surface of the fourth die pad .

[0025] The third die pad 53 has one end connected to the seventh terminal 47. The fourth die pad 54 has one end connected to the eighth terminal 48.

[0026] The package 60 is made of insulating resin and seals the light emitting element 10, the light receiving element 20, the first and second switching elements 31 and 32, and the first to sixth die pads 51 to 56. In addition, some of the terminals 41 to 48 are also sealed inside the package 60. In other words, the light emitting element 10, the light receiving element 20, the first and second switching elements 31 and 32, the first to sixth die pads 51 to 56, and some of the terminals 41 to 48 are located inside the package 60.

[0027] 1A to 1C, the shape of the package 60 is a rectangular parallelepiped. Although not shown, the package 60 may have a protrusion or a recess on its side.

[0028] Although not shown, the package 60 is made of an insulating light-transmitting resin and an insulating light-shielding resin. The light-transmitting resin covers the light-emitting element 10, the light-receiving element 20, the first and second switching elements 31 and 32, the first to sixth die pads 51 to 56, and parts of the terminals 41 to 48. The light-shielding resin is provided so as to cover the entire surface of the light-transmitting resin.

[0029] The first and second switching elements 31, 32 generate heat when the semiconductor relay 100 is in operation. When the first and second switching elements 31, 32 generate heat, the temperature inside the entire package 60 rises. This causes the package 60, which is made of a resin material, to expand, causing each element to peel from the package 60. This also causes the light-emitting element 10, the light-receiving element 20, and the first and second switching elements 31, 32 to peel from the third to sixth die pads 53 to 56. Furthermore, the expansion of the package 60 may cause each element to thermally run away or may cause the metal wires connecting each element to the third to sixth die pads 53 to 56 to become detached. As a result, the reliability of the light-emitting element 10, the light-receiving element 20, and the first and second switching elements 31, 32 may be reduced.

[0030] [Operation of the semiconductor relay 100] FIG. 4 is an equivalent circuit diagram of the semiconductor relay according to the first embodiment.

[0031] When an input signal is applied between terminals 43 and 45 or between terminals 44 and 45, light-emitting element 10 outputs an optical signal. The optical signal generated by light-emitting element 10 propagates through the light-transmitting resin and is received by light-receiving element 20.

[0032] The light receiving element 20 is composed of a photodiode array 21 and a control circuit 22 connected in parallel thereto. In the photodiode array 21, a current is generated by photoelectric conversion, and the control circuit 22 operates based on this current. A drive signal, which is a voltage signal corresponding to the amount of light emitted by the light emitting element 10, is applied via metal wires to the gate electrodes of the first switching element 31 and the second switching element 32, respectively.

[0033] When the voltage of the drive signal exceeds the respective threshold voltages of the first switching element 31 and the second switching element 32, the source (S)-drain (D) of the first switching element 31 and the source (S)-drain (D) of the second switching element 32 are turned on. Furthermore, a state of conduction is established between the terminals 47 and 48 via the first switching element 31 and the second switching element 32. This enables signal transmission between the terminals 47 and 48.

[0034] In the following description, the "terminal 47 (third terminal)" may be referred to as the "seventh terminal 41" and the "terminal 48 (fourth terminal)" may be referred to as the "eighth terminal 48".

[0035] When the input signal is stopped between terminals 43 and 45 or between terminals 44 and 45, light emission from the light-emitting element 10 also stops. In response to this, current is no longer generated in the photodiode array 21, and the control circuit 22 stops.

[0036] As a result, the voltage of the drive signal applied to the gate electrode of the first switching element 31 and the gate electrode of the second switching element 32 drops. When the voltage of the drive signal falls below the threshold voltage described above, the source (S)-drain (D) of the first switching element 31 and the source (S)-drain (D) of the second switching element 32 are both turned off. Furthermore, a non-conductive state is established between the seventh terminal 47 and the eighth terminal 48. This blocks signal transmission between the seventh terminal 47 and the eighth terminal 48.

[0037] [General Configuration of First and Second Die Pads 51, 52] The first die pad 51 is located above the first switching element 31. The second die pad 52 is located above the second switching element 32. As shown in Fig. 3, the semiconductor relay 100 is mounted on an external mounting board 500 located below.

[0038] 3, the external mounting substrate 500 is composed of a main substrate 501, wiring 502, and a ground electrode 503. The main substrate 501 is made of a dielectric material, and a plurality of wirings 502 are formed on the upper surface of the main substrate 501, and a ground electrode 503 is formed on the lower surface of the main substrate 501. Of the plurality of wirings 502, the wiring 502 having a land 502a at one end is a wiring for connection to the semiconductor relay 100 or an electronic component other than the semiconductor relay 100. The tip ends of the terminals 41 to 48, i.e., the tip ends 41a to 48a, are connected to the land 502a via a conductive adhesive (not shown). During operation of the semiconductor relay 100, heat generated in the semiconductor relay 100, particularly the first and second switching elements 31 and 32, is transmitted to the external mounting substrate 500, causing the external mounting substrate 500 to generate heat.

[0039] In addition, "tip portion 41a" may be referred to as "first tip portion 41a," "tip portion 42a" as "second tip portion 42a," "tip portion 47a" as "seventh tip portion 47a," and "tip portion 48a" as "eighth tip portion 48a."

[0040] The "seventh tip portion 47a" in the embodiment corresponds to the "third tip portion" in the claims, and the "eighth tip portion 48a" in the embodiment corresponds to the "fourth tip portion" in the claims.

[0041] Here, the path through which the heat generated in the first and second switching elements 31 and 32 is dissipated to the outside will be described in more detail.

[0042] A portion of the heat generated in the first switching element 31 is dissipated to the external mounting board 500 via the third die pad 53 and the seventh terminal 47. A portion of the heat generated in the first switching element 31 diffuses upward via the package 60 and is absorbed by the first die pad 51. A portion of the heat absorbed by the first die pad 51 is dissipated to the external mounting board 500 via the first terminal 41. A portion of the heat absorbed by the first die pad 51 diffuses upward via the package 60 and is dissipated to the outside from the top surface of the package 60.

[0043] 2 , one end of the first terminal 41 is connected to the first die pad 51 inside the package 60. The other end of the first terminal 41 is exposed to the outside of the package 60. With this configuration, heat absorbed by the first die pad 51 can be dissipated to the outside of the package 60 through the first terminal 41.

[0044] A portion of the heat generated in the second switching element 32 is dissipated to the external mounting board 500 via the fourth die pad 54 and the eighth terminal 48. A portion of the heat generated in the second switching element 32 is diffused upward via the package 60 and absorbed by the second die pad 52. A portion of the heat absorbed by the second die pad 52 is dissipated to the external mounting board 500 via the second terminal 42. A portion of the heat absorbed by the second die pad 52 is diffused upward via the package 60 and dissipated to the outside from the top surface of the package 60.

[0045] 2 , one end of the second terminal 42 is connected to the second die pad 52. The other end of the second terminal 42 is exposed to the outside of the package 60. With this configuration, heat absorbed by the second die pad 52 can be dissipated to the outside of the package 60 through the second terminal 42.

[0046] The second die pad 52 may be further connected to the terminal 46. With this configuration, the heat absorbed by the second die pad 52 can be dissipated to the outside of the package 60 not only through the second terminal 42 but also through the terminal 46.

[0047] No electronic components constituting the semiconductor relay 100 are disposed on the first and second die pads 51, 52. With this configuration, even if heat generated in the first and second switching elements 31, 32 is absorbed by the first and second die pads 51, 52, it does not affect the operation of the semiconductor relay 100. Furthermore, it does not have a significant effect on the operational reliability of the semiconductor relay 100. Note that metal wires may be connected to the first and second die pads 51, 52, respectively, to form part of the path through which current flows inside the semiconductor relay 100.

[0048] Furthermore, LEDs are generally more susceptible to heat than MOSFETs, and therefore, in this embodiment, the first die pad 51 on which the light emitting element 10 is disposed is disposed on the upper side inside the package 60, i.e., on the side with higher heat dissipation properties.

[0049] As shown in FIG. 2 , the first die pad 51 at least partially overlaps the first switching element 31 in a top view. This configuration allows the first die pad 51 to be in close proximity to the first switching element 31, which is one of the heat sources. When the first switching element 31 generates heat, the heat diffuses to the surrounding area through the surrounding resin. By reducing the distance between the first switching element 31 and the first die pad 51, the amount of heat that can be conducted from the first switching element 31 to the first die pad 51 can be increased. As described above, the first die pad 51 can efficiently absorb the heat generated by the first switching element 31. This configuration strengthens the path for dissipating heat generated during operation of the first switching element 31 to the outside of the package 60.

[0050] In particular, when the components constituting the semiconductor relay 100 are sealed with resin as in this embodiment, this effect is remarkable because the thermal conductivity of the resin is low.

[0051] As shown in FIG. 2 , at least a portion of the second die pad 52 overlaps with the second switching element 32 in a top view. This configuration allows the second die pad 52 to be in close proximity to the second switching element 32, which is one of the heat sources. When the second switching element 32 generates heat, the heat diffuses to the surrounding area through the surrounding resin. By reducing the distance between the second switching element 32 and the second die pad 52, the amount of heat that can be conducted from the second switching element 32 to the second die pad 52 can be increased. As described above, the second die pad 52 can efficiently absorb heat. This configuration strengthens the path for dissipating heat generated during operation of the second switching element 32 to the outside of the package 60.

[0052] In particular, when the components constituting the semiconductor relay 100 are sealed with resin as in this embodiment, this effect is remarkable because the thermal conductivity of the resin is low.

[0053] [Detailed Configuration of First and Second Die Pads 51, 52] Fig. 5A is a perspective view of the semiconductor relay according to the embodiment as seen from below. Fig. 5B is a perspective view of the semiconductor relay according to the embodiment as seen from above. The configuration of the first and second die pads 51, 52 will be described in detail below with reference to Fig. 5A and Figs. 6A and 6B described below.

[0054] 5A is the boundary between the first die pad 51 and the first terminal 41. In other words, the portion where the die pad 51 and the first terminal 41 start to become thicker is the boundary between the die pad 51 and the first terminal 41.

[0055] 5A is the boundary between the second die pad 52 and the second terminal 42. That is, the portion where the second die pad 52 and the second terminal 42 start to thicken is the boundary between the second die pad 52 and the second terminal 42.

[0056] The longest length L1 of the first die pad 51 in the front-rear direction (first direction) is greater than the longest length L2 of the first terminal 41. With this configuration, the first die pad 51 can be provided wider than when the first die pad 51 is the same thickness as or thinner than the first terminal 41.

[0057] The longest length L3 of the second die pad 52 in the front-to-rear direction is greater than the longest length L2 of the second terminal 42. In other words, the second die pad 52 is thicker than the second terminal 42. With this configuration, the second die pad 52 can be provided wider than when the second die pad 52 is the same thickness as or thinner than the second terminal 42.

[0058] The shortest distance W1 between the first die pad 51 and the second die pad 52 in the front-rear direction is shorter than the shortest distance W2 between the first terminal 41 and the second terminal 42 in the front-rear direction. When the light emitting element 10 is located between the first and second die pads 51 and 52 as in this embodiment, the first and second die pads 51 and 52 can be provided close to the light emitting element 10, which is one of the heat sources. With this configuration, the first and second die pads 51 and 52 can efficiently absorb the heat generated in the light emitting element 10 and diffused to the surrounding area.

[0059] The first die pad 51 protrudes further rearward than the first terminal 41. That is, the first die pad 51 protrudes in a direction approaching the second die pad 52. Moreover, the first die pad 51 shown in Fig. 5A protrudes into an empty area in the package 60, that is, into an area where no components of the semiconductor relay 100 are arranged. With this configuration, the first die pad 51 can be provided widely while effectively utilizing the space in the package 60.

[0060] The second die pad 52 protrudes further forward than the second terminal 42. That is, the second die pad 52 protrudes in a direction approaching the first die pad 51. The second die pad 52 shown in Fig. 5A protrudes into the aforementioned empty space in the package 60. With this configuration, the second die pad 52 can be provided widely while effectively utilizing the space in the package 60.

[0061] As shown in Fig. 5A , the first die pad 51 has a wide portion 51a. The wide portion 51a is configured such that the length of the first die pad 51 in the front-to-rear direction increases from the boundary between the first terminal 41 and the first die pad 51 toward the end of the first die pad 51. This configuration allows the first die pad 51 to be provided widely while effectively utilizing the space within the package 60. Here, the wide portion 51a includes not only the portion of the first die pad 51 from dotted line B to dotted line D shown in Fig. 5A , but also the portion from dotted line D to the end. In the following description, the wide portion 51a may be referred to as a width-changing portion 51a.

[0062] The second die pad 52 has a wide portion 52a. The wide portion 52a is configured so that the length of the second die pad 52 in the front-to-rear direction increases in the region from the boundary between the second terminal 42 and the second die pad 52 toward the end of the second die pad 52. This configuration allows the second die pad 52 to be provided widely while effectively utilizing the space within the package 60. In the following description, the wide portion 52a may be referred to as a width-changing portion 52a.

[0063] 6A is a plan view of the first die pad according to this embodiment. As shown in FIG. 6A, the length of the first die pad 51 in the front-rear direction at the end of the first die pad 51 is the longest length L1 of the first die pad 51 in the front-rear direction. The rectangular protruding portion of the wide portion 51a in the front-rear direction is referred to as a protruding portion 51b.

[0064] 6B is a plan view of the second die pad according to this embodiment. As shown in FIG. 6B, the length of the second die pad 52 in the front-rear direction at the end of the second die pad 52 is the longest length L3 of the second die pad 52 in the front-rear direction. The rectangular protruding portion of the second die pad 52 in the front-rear direction is referred to as a protruding portion 52b.

[0065] The shape of the first die pad 51 is not particularly limited to the shapes shown in FIGS. 1E, 2, and 5A, and may be, for example, the shape shown in FIG. 6C or 6D.

[0066] Fig. 6C is a plan view showing another example of the first die pad 51. In Fig. 6A, the length of the first die pad 51 in the front-rear direction at the end of the first die pad 51 is the longest length L1 of the first die pad 51 in the front-rear direction. On the other hand, in the first die pad 151 shown in Fig. 6C, the length L4 of the first die pad 151 in the front-rear direction at the end of the first die pad 151 is not the longest length L1 of the first die pad 151 in the front-rear direction. The wide portion 151a shown in Fig. 6C can also be expressed as a protruding portion 151b protruding in the front-rear direction or the left-right direction.

[0067] Fig. 6D is a plan view showing yet another example of a first die pad. The first die pad 151 shown in Fig. 6D has a width that varies stepwise in the front-to-rear direction. The multiple wide portions 151a shown in Fig. 6D can be expressed as multiple protruding portions 151b that protrude in the front-to-rear direction or the left-to-right direction. In the example shown in Fig. 6D, the length L5 of the first die pad 151 in the front-to-rear direction at the right end of the first die pad 151 is shorter than the length L6 of the first die pad 151 in the front-to-rear direction at the left end. Furthermore, the length L6 is also shorter than the longest length L1 of the first die pad 151 in the front-to-rear direction.

[0068] It is preferable to provide the first die pad 51 (151) as wide as possible while maintaining an insulating distance from the surrounding components. The wider the first die pad 51 (151), the more improved the heat dissipation performance of the semiconductor relay 100. The reason for this will be explained in detail below.

[0069] By providing the first die pad 51 widely, the surface area and volume of the first die pad 51 made of metal inside the package 60 can be increased compared to when the first die pad 51 is narrow. Therefore, the first die pad 51 can efficiently absorb heat inside the package 60. The heat absorbed by the first die pad 51 is released to the outside of the package 60 through the first terminal 41. As the first die pad 51 absorbs more heat and then conducts it to the first terminal 41, the amount of heat that can be released to the outside of the package 60 through the first terminal 41 increases. Therefore, by providing the first die pad 51 widely, heat dissipation can be improved compared to when the first die pad 51 is narrow.

[0070] It is also preferable to provide the second die pad 52 as wide as possible while maintaining an insulating distance from the surrounding components. The wider the second die pad 52, the more improved the heat dissipation performance of the semiconductor relay 100. The reason for this will be explained in detail below.

[0071] By providing the second die pad 52 widely, the surface area and volume of the metal inside the package 60 can be increased compared to when the second die pad 52 is narrow. Therefore, the second die pad 52 can efficiently absorb heat inside the package 60. The heat absorbed by the second die pad 52 is released to the outside of the package 60 through the second terminal 42. As the second die pad 52 absorbs more heat and then conducts it to the second terminal 42, the amount of heat that can be released to the outside of the package 60 through the second terminal 42 increases. Therefore, by providing the second die pad 52 widely, heat dissipation can be improved compared to when the second die pad 52 is narrow.

[0072] 7A is a plan view of the first die pad and the first switching element. 7B is a plan view of the second die pad and the second switching element. As shown in FIGS. 7A and 7B , the area where the first die pad 51 overlaps with the first switching element 31 is different from the area where the second die pad 52 overlaps with the second switching element 32 in a top view. The shape of the first die pad 51 is also different from the shape of the second die pad 52. This configuration allows the first and second die pads 51, 52 to have different heat dissipation efficiencies.

[0073] For example, in this embodiment, the area where the first die pad 51 overlaps with the first switching element 31 is smaller than the area where the second die pad 52 overlaps with the second switching element 32. Therefore, the second die pad 52 can absorb more heat than the first die pad 51. Therefore, the first switching element 31 that faces the first die pad 51 in the vertical direction becomes cooler than the first switching element 31 that faces the first die pad 51 in the vertical direction. With this configuration, when the package 60 is mounted on the external mounting board 500, elements that are sensitive to heat can be placed in front of the package 60.

[0074] 1A to 2, the terminals 41 to 46 are arranged in the first direction in the order of terminal 41, terminal 43, terminal 45, terminal 44, terminal 42, and terminal 46. As is clear from FIGS. 1A, 1E, and 2, the terminals 41 to 46 are bent downward inside the package 60, extend to the left, and are exposed to the outside of the package 60. Furthermore, outside the package 60, they extend downward along the outer surface of the package 60. Furthermore, they are bent to the left. In this embodiment, the shapes of the terminals 41 to 46 after they are bent downward inside the package 60 are the same. The configurations of the terminals 41 and 42 will be described below.

[0075] 1B, 8A, and 8B, the first terminal 41 includes a first tip portion 41 a, a first intermediate portion 41 b, and a first connecting portion 41 c.

[0076] In addition, the "tip portion 41a" may be referred to as the "first tip portion 41a", the "intermediate portion 41b" as the "first intermediate portion 41b", and the "connection portion 41c" as the "first connection portion 41c".

[0077] 1A to 1D, the first terminal 41 is mounted on an external mounting substrate 500 at a first tip portion 41a. The first tip portion 41a is a portion of the first terminal 41 that is exposed to the outside of the package 60 and extends parallel to the bottom surface of the package 60. The first intermediate portion 41b is a portion that is connected to the first tip portion 41a and exposed to the outside of the package 60. The first connection portion 41c is a portion that connects the first intermediate portion 41b and the first die pad 51 and is located inside the package 60.

[0078] 9A and 9B are top and side views of a first terminal according to a comparative example, respectively. The shape of the first terminal 41 according to this embodiment will be described in detail below, in comparison with the first terminal 141 of the comparative example.

[0079] 8A , in the first terminal 41, the shortest length D1 of the first connecting portion 41 c in the front-rear direction is greater than the longest length D2 of the first tip portion 41 a in the front-rear direction. In contrast, as shown in FIG. 9A , in the first terminal 141, the shortest length D11 of the first connecting portion 141 c is equal to the longest length D12 of the first tip portion 141 a in the front-rear direction. The lengths D2 and D12 of the first tip portion 41 a and the first tip portion 141 a in the front-rear direction correspond to the length of the land of the external mounting board 500 in the front-rear direction, and length D2 is equal to length D12.

[0080] That is, outside the package 60 , the first terminal 41 can improve heat dissipation compared to the first terminal 141 .

[0081] The heat dissipation properties of the first connecting portion 41c of the present disclosure will be described in further detail below, in comparison with the first connecting portion 141c of the comparative example.

[0082] The first connection portion 41c of the present disclosure can have a larger surface area inside the package 60 than the first connection portion 141c of the comparative example. Therefore, the first connection portion 41c of the present disclosure can absorb heat inside the package 60 more efficiently than the first connection portion 141c of the comparative example. As the first connection portion 41c absorbs more heat, the amount of heat that can be released outside the package 60 increases.

[0083] Furthermore, the first connection portion 41c of the present disclosure can have a larger volume inside the package 60 than the first connection portion 141c of the comparative example. Therefore, the first connection portion 41c of the present disclosure can have higher thermal conductivity than the first connection portion 141c of the comparative example. Heat absorbed by the first die pad 51 is conducted through the first connection portion 41c to the first intermediate portion 41b exposed to the outside of the package 60. Furthermore, the heat absorbed by the first connection portion 41c is conducted to the first intermediate portion 41b exposed to the outside of the package 60. The first connection portion 41c absorbs more heat and then conducts it to the first intermediate portion 41b exposed to the outside of the package 60, thereby increasing the amount of heat that can be released to the outside of the package 60. From the above, the first connection portion 41c of the present disclosure can improve heat dissipation compared to the first connection portion 141c of the comparative example.

[0084] As shown in Fig. 8B, the shortest length D3 of the first intermediate portion 41b is greater than the longest length D2 of the first tip portion 41a in the front-to-rear direction. In contrast, as shown in Fig. 9B, the shortest length D13 of the first intermediate portion 141b is equal to the longest length D12 of the first tip portion 141a in the front-to-rear direction. With this configuration, the first terminal 41 can have improved heat dissipation properties compared to the first terminal 141.

[0085] The heat dissipation properties of the first intermediate portion 41b of the present disclosure will be described in further detail below in comparison with the first intermediate portion 141b of the comparative example.

[0086] The first intermediate portion 41b of the present disclosure shown in Fig. 8B can have a larger surface area than the first intermediate portion 141b of the comparative example shown in Fig. 9B. In other words, the first intermediate portion 41b of the present disclosure has a larger surface area exposed to the outside air than the first intermediate portion 141b of the comparative example. Therefore, heat can be efficiently released from the first intermediate portion 41b to the outside air.

[0087] Furthermore, the first intermediate portion 41b of the present disclosure can have a larger volume inside the package 60 than the first intermediate portion 141b of the comparative example. Therefore, the first intermediate portion 41b of the present disclosure can have higher thermal conductivity than the first intermediate portion 141b of the comparative example. Heat absorbed by the first die pad 51 is conducted to the first intermediate portion 41b through the first connection portion 41c. Furthermore, heat absorbed by the first connection portion 41c is conducted to the first intermediate portion 41b. Since the first intermediate portion 41b conducts more heat, the amount of heat that can be released to the outside of the package 60 increases. As a result, the first intermediate portion 41b of the present disclosure can have improved heat dissipation performance compared to the first intermediate portion 141b of the comparative example.

[0088] As shown in FIGS. 1B, 8A, and 8B, the second terminal 42 is composed of a second tip portion 42a, an intermediate portion 42b, and a connecting portion 42c.

[0089] In addition, the "tip portion 42a" may be referred to as the "second tip portion 42a", the "intermediate portion 42b" as the "second intermediate portion 42b", and the "connection portion 42c" as the "second connection portion 42c".

[0090] 1A to 1D, the second terminal 42 is mounted on an external mounting substrate 500 at the second tip portion 42a. The second tip portion 42a is a portion of the second terminal 42 that is exposed to the outside of the package 60 and extends parallel to the bottom surface of the package 60. The second intermediate portion 42b is a portion that is connected to the second tip portion 42a and exposed to the outside of the package 60. The second connection portion 42c is a portion that connects the second intermediate portion 42b and the second die pad 52 and is located inside the package 60.

[0091] The configuration of the second terminal 42 is similar to that of the first terminal 41 described with reference to FIGS. 8A and 8B.

[0092] In the second terminal 42, the shortest length D1 of the second connection portion 42c in the front-rear direction is greater than the longest length D2 of the second tip portion 42a in the front-rear direction. As described with respect to the first terminal 41, this configuration enables the second terminal 42 to improve heat dissipation.

[0093] The shortest length D3 of the second intermediate portion 42b in the front-rear direction is greater than the longest length D2 of the second tip portion 42a in the front-rear direction. As described with respect to the first terminal 41, this configuration enables the second terminal 42 to improve heat dissipation.

[0094] [Configuration of Seventh and Eighth Terminals 47, 48] As described above, the first and second switching elements 31, 32 generate heat. Furthermore, as shown in FIGS. 1E and 2, the first and second switching elements 31, 32 are mounted on the third and fourth die pads 53, 54, respectively, and the third and fourth die pads 53, 54 are connected to the seventh and eighth terminals 47, 48, respectively. This configuration also allows heat generated in the first and second switching elements 31, 32 to be released to the outside of the package 60 from the seventh and eighth terminals 47, 48. As shown in FIGS. 1C and 5B, the seventh terminal 47 includes a seventh tip portion 47a, a seventh middle portion 47b, and a seventh connection portion 47c.

[0095] The "seventh terminal 47" in the embodiment corresponds to the "third terminal" in the claims, and the "eighth terminal 48" in the embodiment corresponds to the "fourth terminal" in the claims.

[0096] Furthermore, the "seventh tip portion 47a," "seventh intermediate portion 47b," and "seventh connecting portion 47c" in the embodiment correspond to the "third tip portion," "third intermediate portion," and "third connecting portion" in the claims, respectively.

[0097] Furthermore, in the embodiment, the "eighth tip portion 48a," the "eighth intermediate portion 48b," and the "eighth connecting portion 48c" correspond to the "fourth tip portion," the "fourth intermediate portion," and the "fourth connecting portion" in the claims, respectively.

[0098] 1A to 1D, the seventh terminal 47 is mounted on an external mounting substrate 500 at a seventh tip portion 47a. The seventh tip portion 47a is a portion that is exposed to the outside of the package 60 and extends parallel to the bottom surface of the package 60. The seventh middle portion 47b is a portion that is connected to the seventh tip portion 47a and is exposed to the outside of the package 60. The seventh connection portion 47c is a portion that connects the seventh middle portion 47b and the third die pad 53 and is located inside the package 60.

[0099] 5B , the shortest length D1 of the seventh connection portion 47 c in the front-to-rear direction is greater than the longest length D2 of the seventh tip portion 47 a in the front-to-rear direction. As described with respect to the first terminal 41, this configuration allows the seventh terminal 47 to have improved heat dissipation properties, similar to the first terminal 41.

[0100] 1C , the shortest length D3 of the seventh intermediate portion 47 b in the front-to-rear direction is greater than the longest length D2 of the seventh tip portion 47 a in the front-to-rear direction. As described with respect to the first terminal 41, this configuration enables the seventh terminal 47 to improve heat dissipation.

[0101] As shown in FIGS. 1C and 5B, the eighth terminal 48 is composed of an eighth tip portion 48a, an eighth intermediate portion 48b, and an eighth connecting portion 48c.

[0102] 1A to 1D, the eighth terminal 48 is mounted on an external mounting substrate 500 at an eighth tip portion 48a. The eighth tip portion 48a is a portion that is exposed to the outside of the package 60 and extends parallel to the bottom surface of the package 60. The eighth middle portion 48b is a portion that is connected to the eighth tip portion 48a and is exposed to the outside of the package 60. The eighth connection portion 48c is a portion that connects the eighth middle portion 48b and the fourth die pad 54 and is located inside the package 60.

[0103] 5B , the shortest length D1 of the eighth connection portion 48 c in the front-to-rear direction is greater than the longest length D2 of the eighth tip portion 48 a in the front-to-rear direction. As described with respect to the first terminal 41, this configuration enables the eighth terminal 48 to improve heat dissipation.

[0104] 1C , the shortest length D3 of the eighth intermediate portion 48 b in the front-to-rear direction is greater than the longest length D2 of the eighth tip portion 48 a in the front-to-rear direction. As described with respect to the first terminal 41, this configuration enables the eighth terminal 48 to improve heat dissipation.

[0105] 1B, the lower portions of the intermediate portions 41b to 46c are wider on both sides in the front-to-rear direction, whereas the lower portions of the seventh and eighth intermediate portions 47b and 48b are wider on only one side in the front-to-rear direction, as shown in FIG. 1C. Specifically, the lower portion of the seventh intermediate portion 47b is wider on the side farther from the eighth intermediate portion 48b, in this case, toward the rear. The lower portion of the eighth intermediate portion 48b is wider on the side farther from the seventh intermediate portion 47b, in this case, toward the front.

[0106] To ensure sufficient insulation between the first and second switching elements 31, 32, a sufficiently large creepage distance is required. Here, creepage distance refers to the shortest distance along the surface of the insulator located between two conductors. In the semiconductor relay 100, the surface of the resin package 60 is significantly affected by discharge. For this reason, the creepage distance W3 (see FIGS. 1C and 5B ) on the output side of the semiconductor relay 100 corresponds to the shortest distance in the front-to-rear direction between the seventh terminal 47 and the eighth terminal 48.

[0107] Because the lands 502a are arranged at equal intervals in the front-rear direction, the positions of the seventh and eighth tip portions 47a, 48a cannot be changed. Therefore, as shown in FIG. 1C , by widening the lower portions of the seventh and eighth intermediate portions 47b, 48b only on the sides farther from each other, the shortest distance between the seventh tip portion 47a and the eighth tip portion 48a in the front-rear direction can be made the same as the creepage distance W3. This prevents the creepage distance W3 from becoming shorter, ensuring insulation between the seventh terminal 47 and the eighth terminal 48, and ultimately between the first switching element 31 and the second switching element 32.

[0108] The semiconductor relay 100 in this embodiment is surface-mounted on an external mounting substrate 500. That is, the tip portions 41a to 48a extend outside the package 60, along the underside of the package 60, and parallel to the underside, and are surface-mounted on the external mounting substrate 500. Furthermore, in order to ensure the creepage distance W3, the shapes of the seventh terminal 47 and the eighth terminal 48 are further specified. Fig. 10A is an enlarged view of the portion surrounded by the dashed line XA in Fig. 1C. Fig. 10B is an enlarged view of the portion surrounded by the dashed line XB in Fig. 1C.

[0109] As shown in FIG. 10A, in the seventh tip portion 47a of the seventh terminal 47, the side surface facing the eighth terminal 48 is referred to as the first surface 47a1, and the side surface facing the first surface 47a1 in the front-to-rear direction is referred to as the second surface 47a2.

[0110] The seventh intermediate portion 47b of the seventh terminal 47 is composed of multiple portions according to its shape. Specifically, the seventh intermediate portion 47b is composed of a first portion 47ba connected to the seventh connecting portion 47c, a second portion 47bb extending downward from the first portion 47ba, and a third portion 47bc extending downward from the second portion 47bb and connecting to the seventh tip portion 47a. As shown in FIG. 10A , the length of the third portion 47bc in the front-to-rear direction corresponds to the shortest length D3 of the seventh intermediate portion 47b. The side surface of the third portion 47bc facing the eighth terminal 48 in the front-to-rear direction is referred to as the third surface 47bc3, and the side surface facing the third surface 47bc3 is referred to as the fourth surface 47bc4.

[0111] Similarly, in the first and second portions 47ba, 47bb, the side surfaces facing the eighth terminal 48 in the front-rear direction are referred to as third surfaces 47ba3, 47bb3, and the side surfaces facing the third surfaces 47ba3, 47bb3 are referred to as fourth surfaces 47ba4, 47bb4.

[0112] Also, as shown in Figure 10B, in the eighth tip portion 48a of the eighth terminal 48, the side surface facing the seventh terminal 47 is called the fifth surface 48a1, and the side surface facing the fifth surface 48a1 in the front-to-back direction is called the sixth surface 48a2.

[0113] The eighth intermediate portion 48b of the eighth terminal 48 is composed of multiple portions according to its shape. Specifically, the eighth intermediate portion 48b is composed of a fourth portion 48ba connected to the eighth connecting portion 48c, a fifth portion 48bb extending downward from the fourth portion 48ba, and a sixth portion 48bc extending downward from the fifth portion 48bb and connecting to the eighth tip portion 48a. As shown in FIG. 10B , the length of the sixth portion 48bc in the front-to-rear direction corresponds to the shortest length D3 of the eighth intermediate portion 48b. The side surface of the sixth portion 48bc facing the seventh terminal 47 in the front-to-rear direction is referred to as the seventh surface 48bc3, and the side surface facing the seventh surface 48bc3 is referred to as the eighth surface 48bc4.

[0114] Similarly, in the fourth and fifth portions 48ba, 48bb, the side surfaces facing the eighth terminal 48 in the front-rear direction are referred to as seventh surfaces 48ba3, 48bb3, and the side surfaces facing the seventh surfaces 48ba3, 48bb3 are referred to as eighth surfaces 48ba4, 48bb4.

[0115] 10A , in the seventh terminal 47, the first axis A1, which is the center line of the first portion 47ba along the up-down direction, is farther away from the eighth terminal 48 in the front-to-rear direction than the second axis A2, which is the center line of the seventh tip end portion 47a along the up-down direction. This prevents the front-to-rear distance between the seventh intermediate portion 47b and the eighth terminal 48 from being too short compared to the front-to-rear distance between the seventh tip end portion 47a and the eighth terminal 48, ensuring the creepage distance W3 described above.

[0116] The shape of the seventh terminal 47 is designed so that the first surface 47a1 of the seventh tip portion 47a and the third surface 47bc3 of the third portion 47bc of the seventh intermediate portion 47b are flush with each other. This makes it possible to make the distance in the front-to-rear direction between the seventh intermediate portion 47b and the eighth terminal 48 the same as the distance in the front-to-rear direction between the seventh tip portion 47a and the eighth terminal 48 at a location close to the external mounting board 500, thereby ensuring the creepage distance W3 described above.

[0117] 10B , in the eighth terminal 48, the third axis A3, which is the center line of the fourth portion 48ba along the up-down direction, is farther away from the seventh terminal 47 in the front-to-rear direction than the fourth axis A4, which is the center line of the eighth tip end portion 48a along the up-down direction. This prevents the front-to-rear distance between the eighth intermediate portion 48b and the seventh terminal 47 from being too short compared to the front-to-rear distance between the eighth tip end portion 48a and the seventh terminal 47, thereby ensuring the creepage distance W3 described above.

[0118] The shape of the eighth terminal 48 is designed so that the fifth surface 48a1 of the eighth tip portion 48a and the seventh surface 48bc3 of the sixth portion 48bc of the eighth intermediate portion 48b are flush with each other. This makes it possible to make the distance in the front-to-rear direction between the eighth intermediate portion 48b and the seventh terminal 47 the same as the distance in the front-to-rear direction between the eighth tip portion 48a and the seventh terminal 47 at a location close to the external mounting board 500, thereby ensuring the creepage distance W3 described above.

[0119] <First Modification> Fig. 11A is a diagram corresponding to Fig. 10A according to a first modification. Fig. 11B is a diagram corresponding to Fig. 10B according to the first modification. In Figs. 11A and 11B and the following drawings, parts similar to those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

[0120] The seventh terminal 47 shown in Fig. 11A differs from the semiconductor relay 100 of the first embodiment shown in Fig. 10A in that the third surfaces 47ba3, 47bb3, and 47bc3 of the first to third portions 47ba, 47bb, and 47bc are flush with each other. The seventh terminal 47 shown in Fig. 11A also differs from the semiconductor relay 100 of the first embodiment shown in Fig. 10A in that the fourth surfaces 47ba4, 47bb4, and 47bc4 of the first to third portions 47ba, 47bb, and 47bc are flush with each other in the seventh intermediate portion 47b.

[0121] In other words, the first to third portions 47ba, 47bb, and 47bc can be regarded as a single member having a common third surface 47bb3 and fourth surface 47bb4, and in this modification, the seventh intermediate portion 47b is also referred to as the seventh intermediate portion 47bb. In addition, when viewed from the left-right direction, the third surface 47bb3 of the seventh intermediate portion 47bb is flush with the first surface 47a1 of the seventh tip portion 47a.

[0122] The eighth terminal 48 shown in Fig. 11B differs from the semiconductor relay 100 of the first embodiment shown in Fig. 10A in that, in the eighth intermediate portion 48b, seventh surfaces 48ba3, 48bb3, and 48bc3 of the fourth to sixth portions 48ba, 48bb, and 48bc are flush with each other. The eighth terminal 48 shown in Fig. 11B differs from the semiconductor relay 100 of the first embodiment shown in Fig. 10B in that, in the eighth intermediate portion 48b, eighth surfaces 48ba4, 48bb4, and 48bc4 of the fourth to sixth portions 48ba, 48bb, and 48bc are flush with each other.

[0123] In other words, the fourth to sixth portions 48ba, 48bb, and 48bc can be regarded as a single member having a common seventh surface 48bb3 and an eighth surface 48bb4, and in this modification, the eighth intermediate portion 48b is also referred to as the eighth intermediate portion 48bb. In addition, when viewed from the left-right direction, the seventh surface 48bb3 of the eighth intermediate portion 48bb is flush with the fifth surface 48a1 of the eighth tip portion 48a.

[0124] By configuring the seventh intermediate portion 47b and the eighth intermediate portion 48b in this manner, the distance in the front-to-rear direction between the seventh terminal 47 and the eighth terminal 48 can be made the same over the entire portion exposed to the outside of the package 60, and the creepage distance W3 described above can be sufficiently ensured. Furthermore, according to this modification, the spatial insulation distance between the seventh terminal 47 and the eighth terminal 48 can be ensured.

[0125] 12A and 12B are perspective and side views of a semiconductor relay according to a second modification.

[0126] As shown in this modification, the semiconductor relay 200 may be of an insertion mounting type that is inserted into an external mounting board 500. In this modification, the tip portions 41 a to 48 a extend along the side surface of the package 60 and parallel to the side surface to the outside of the package 60. Although not shown, the internal structure of the package 60 in the semiconductor relay 200 of this modification is the same as that shown in the first embodiment.

[0127] This modification can achieve the same effects as the configuration shown in the first embodiment. That is, by providing the first and second die pads 51, 52, heat generated by the first and second switching elements 31, 32 and the light emitting element 10 during operation of the semiconductor relay 200 can be efficiently absorbed and conducted to the outside of the package 60. In other words, the path for dissipating heat generated during operation of the semiconductor relay 200 to the outside of the package 60 can be strengthened, thereby improving heat dissipation.

[0128] Generally, a surface mount type element has a larger contact area with the external mounting board 500 than an insertion mount type element, and therefore has higher heat dissipation properties. Therefore, the insertion mount type semiconductor relay 200 shown in this modification has lower heat dissipation properties than the semiconductor relay 100 of the first embodiment.

[0129] Second Embodiment FIG. 13 is a perspective view of a semiconductor relay according to a second embodiment, with the package omitted.

[0130] In the semiconductor relay 300 according to the second embodiment, a first terminal 341 and a second terminal 342 are different from the first terminal 41 and the second terminal 42 of the semiconductor relay 100 according to the first embodiment. Apart from this, the external appearance of the semiconductor relay 300 including the package 60, the configuration of each component inside the package 60, and the arrangement of each component are similar to those of the semiconductor relay 100.

[0131] 13 , the first terminal 341 is pulled out from the middle of the package 60 in the vertical direction to the outside of the package 60, bent, and extends downward along the side of the package 60, and is further bent and extends along the bottom surface of the package 60 substantially parallel to the bottom surface. The first terminal 341 is not bent inside the package 60 but extends substantially parallel to the top surface of the package 60. The second terminal 342 has the same shape as the first terminal 341.

[0132] In this embodiment, compared to the first embodiment, the distance between the first die pad 51 and the third die pad 53 is shorter than the distance between the fifth die pad 55 and the sixth die pad 56. In addition, the distance between the second die pad 52 and the fourth die pad 54 is shorter than the distance between the fifth die pad 55 and the sixth die pad 56.

[0133] With this configuration, the distance between the first switching element 31 and the first die pad 51 is shorter than in the first embodiment. When the first switching element 31 generates heat, the heat diffuses to the surrounding area through the surrounding resin. By shortening the distance between the first switching element 31 and the first die pad 51, the amount of heat that can be conducted from the first switching element 31 to the first die pad 51 can be increased. This effect is particularly pronounced when the components constituting the semiconductor relay 300 are resin-encapsulated, because the thermal conductivity of the resin is low. As described above, in this embodiment, the first die pad 51 can more efficiently absorb the heat generated by the first switching element 31 and conduct it to the outside of the package 60 through the first terminal 341, compared to the first embodiment.

[0134] Furthermore, in this embodiment, the distance between the second switching element 32 and the second die pad 52 is shorter than in the first embodiment. When the second switching element 32 generates heat, the heat diffuses to the surrounding area through the surrounding resin. By shortening the distance between the second switching element 32 and the second die pad 52, the amount of heat that can be conducted from the second switching element 32 to the second die pad 52 can be increased. This effect is particularly pronounced when the components constituting the semiconductor relay 300 are resin-encapsulated because the resin has low thermal conductivity. As described above, in this embodiment, the second die pad 52 can more efficiently absorb the heat generated by the first switching element 31 and conduct it to the outside of the package 60 through the second terminal 342 than in the first embodiment.

[0135] These features further strengthen the path for dissipating heat generated during operation of the semiconductor relay 300 to the outside of the package 60, thereby improving heat dissipation.

[0136] Like the terminal 341, the terminals 43 to 46 may extend parallel to the upper surface of the package 60 without being bent inside the package 60.

[0137] (Summary) The semiconductor relay 100 of the present disclosure has the following configuration.

[0138] The semiconductor relay 100 of the first aspect includes at least a light-emitting element 10, a light-receiving element 20 located below the light-emitting element 10 and facing the light-emitting element 10, a first switching element 31 adjacent to the light-receiving element 20, and a second switching element 32 adjacent to the light-receiving element 20. The semiconductor relay 100 also includes a first die pad 51 located above the first switching element 31, a second die pad 52 located above the second switching element 32, a first terminal 41 having one end connected to the first die pad 51, a second terminal 42 having one end connected to the second die pad 52, and a package 60.

[0139] The light-receiving element 20 is located between the first switching element 31 and the second switching element 32. The direction in which the first terminal 41 and the second terminal 42 are aligned is defined as a first direction, and the other end of the first terminal 41 is exposed to the outside of the package 60 and extends downward from the package 60, while the other end of the second terminal 42 is exposed to the outside of the package 60 and extends downward from the package 60. The light-emitting element 10, the light-receiving element 20, the first switching element 31, the second switching element 32, the first die pad 51, and the second die pad 52 are located inside the package 60, and at least a portion of the first die pad 51 overlaps the first switching element 31 in a top view, and at least a portion of the second die pad 52 overlaps the second switching element 32 in a top view.

[0140] In the second aspect of the semiconductor relay 100, the longest length L1 of the first die pad 51 in the first direction is greater than the longest length L2 of the first terminal 41 in the first direction, and the longest length L3 of the second die pad 52 in the first direction is greater than the longest length L2 of the second terminal 42 in the first direction.

[0141] In the semiconductor relay 100 of the third aspect, the shortest distance W1 between the first die pad 51 and the second die pad in the first direction is shorter than the shortest distance W2 between the first terminal 41 and the second terminal 42 in the first direction.

[0142] In the semiconductor relay 100 of the fourth aspect, the first die pad 51 has a wide portion (width-changing portion) 51a, and the wide portion (width-changing portion) 51a is configured so that the length of the first die pad 51 in a first direction increases from the boundary between the first terminal 41 and the first die pad toward the end of the first die pad 51.

[0143] In the fifth aspect of the semiconductor relay 100, when the direction in which the first terminal 41 and the second terminal 42 each protrude and the direction perpendicular to the first direction is defined as the second direction (left-right direction), the first die pad 51 has a protrusion that protrudes in the first direction or the second direction.

[0144] In the semiconductor relay 100 of the sixth aspect, the area where the first die pad 51 overlaps with the first switching element 31 is different from the area where the second die pad 52 overlaps with the second switching element 32 in a top view.

[0145] In the semiconductor relay 100 of the seventh aspect, the first terminal 41 is composed of a first tip portion 41 a, a first intermediate portion 41 b connected to the first tip portion 41 a and exposed to the outside of the package 60, and a first connection portion 41 c connecting the first intermediate portion 41 b and the first die pad 51 and located inside the package 60. The shortest length D1 of the first connection portion 41 c in the first direction is greater than the longest length D2 of the first tip portion 41 a in the first direction. The second terminal 42 is composed of a second tip portion 42 a, a second intermediate portion 42 b connected to the second tip portion 42 a and exposed to the outside of the package 60, and a second connection portion 42 c connecting the second intermediate portion 42 b and the second die pad 52 and located inside the package 60. The shortest length D1 of the second connecting portion 42c in the first direction is greater than the longest length D2 of the second tip portion 42a in the first direction.

[0146] In the eighth aspect of the semiconductor relay 100, the shortest length D3 of the first intermediate portion 41b in the first direction is greater than the longest length D2 of the first tip portion 41a in the first direction, and the shortest length D3 of the second intermediate portion 42b in the first direction is greater than the longest length D2 of the second tip portion 42a in the first direction.

[0147] The semiconductor relay 100 of the ninth aspect further includes a third die pad 53 on which the first switching element 31 is arranged, a fourth die pad 54 on which the second switching element 32 is arranged, a terminal 47 having one end connected to the third die pad 53, and a terminal 48 having one end connected to the fourth die pad 54. The terminal 47 is composed of a tip portion 47a, an intermediate portion 47b connected to the tip portion 47a and exposed to the outside of the package 60, and a connection portion 47c located inside the package 60 and connecting the intermediate portion 47b to the first die pad 51. The shortest length D1 of the connection portion 47c in the first direction is greater than the longest length D2 of the tip portion 47a in the first direction. Terminal 48 is composed of a tip portion 48a, an intermediate portion 48b connected to tip portion 48a and exposed to the outside of package 60, and a connection portion 48c connected to intermediate portion 48b and second die pad 52 and located inside package 60. The shortest length D1 of connection portion 48c in the first direction is greater than the longest length D2 of tip portion 48a in the first direction.

[0148] In the semiconductor relay 100 of the tenth aspect, the shortest length D3 of the intermediate portion 47b in the first direction is greater than the longest length D2 of the tip portion 47a in the first direction, and the shortest length D3 of the intermediate portion 48b in the first direction is greater than the longest length D2 of the tip portion 48a in the first direction.

[0149] A creepage distance W3 between the intermediate portion 47b and the intermediate portion 48b in the first direction is equal to the shortest distance between the tip portion 47a and the tip portion 48a in the first direction.

[0150] The semiconductor relay 200 is an insertion mounting type in which the tip portions 41 a to 48 a extend along the side surface of the package 60 and parallel to the side surface to the outside of the package 60, and are inserted and mounted on an external mounting board 500. Apart from this, the configuration of the semiconductor relay 200 is similar to the configuration of the semiconductor relay 100.

[0151] The semiconductor relay 300 includes a fifth die pad 55 having a lower surface and a light-emitting element 10 disposed on the lower surface, and a sixth die pad 56 having an upper surface and a light-receiving element 20 disposed on the upper surface.

[0152] Except for the following points, the configuration of the semiconductor relay 300 is similar to the configuration of the semiconductor relay 100. In the semiconductor relay 300, the distance between the first die pad 51 and the third die pad 53 is shorter than the distance between the fifth die pad 55 and the sixth die pad 56, and the distance between the second die pad 52 and the fourth die pad 54 is shorter than the distance between the fifth die pad 55 and the sixth die pad 56.

[0153] The semiconductor relays 100, 200, and 300 can enhance the heat dissipation performance by strengthening the path for dissipating heat generated during operation to the outside of the package 60.

[0154] Although the present specification has been described using the optically coupled semiconductor relays 100, 200, and 300 as examples, the present invention is not limited to this. The shapes and positional relationships of the first to sixth die pads 51-56 and terminals 41-48 may also be applied to magnetically coupled or capacitively coupled semiconductor relays. In this case, too, the path for dissipating heat generated during operation to the outside of the package 60 can be strengthened, thereby improving the heat dissipation performance of the semiconductor relay.

[0155] The semiconductor relay of the present disclosure is useful because it enhances the path for dissipating heat generated during operation to the outside of the package, thereby improving heat dissipation.

[0156] 10 Light-emitting element 20 Light-receiving element 21 Photodiode array 22 Control circuit 31 First switching element 32 Second switching element 41 Terminal (first terminal) 41a Tip portion (first tip portion) 41b Intermediate portion (first intermediate portion) 41c Connection portion (first connection portion) 42 Terminal (second terminal) 42a Tip portion (second tip portion) 42b Intermediate portion (second intermediate portion) 42c Connection portion (second connection portion) 43 Terminal 44 Terminal 45 Terminal 46 Terminal 47 Terminal (third terminal in claims) 47a Tip portion (third tip portion in claims) 47a1 First surface 47a2 Second surface 47b Intermediate portion (third intermediate portion in claims) 47ba First portion 47ba3 Third surface 47ba4 Fourth surface 47bb Second portion 47bb3 Third surface 47bb4 Fourth surface 47bc Third portion 47bc3 Third surface 47bc4 Fourth surface 47c Connection portion (third connection portion in claims) 48 Terminal (fourth terminal in claims) 48a Tip portion (fourth tip portion in claims) 48a1 Fifth surface 48a2 Sixth surface 48b Middle portion (fourth middle portion in claims) 48ba Fourth portion 48ba3 Seventh surface 48ba4 Eighth surface 48bb Fifth portion 48bb3 Seventh surface 48bb4 Eighth surface 48bc Sixth portion 48bc3 Seventh surface 48bc4 Eighth surface 48c Connection portion (fourth connection portion in claims) 51, 151 First die pad 51a, 151a: Wide portion (width-changing portion) 51b, 151b: Projection portion 52: Second die pad 53: Third die pad 54: Fourth die pad 55: Fifth die pad 56: Sixth die pad 60: Package 100: Semiconductor relay 200: Semiconductor relay 300: Semiconductor relay 341: First terminal 342: Second terminal 500: External mounting substrate 501: Main body substrate 502: Wiring 502a: Land 503: Ground electrode

Claims

1. A semiconductor device comprising: a light-emitting element; a light-receiving element located below the light-emitting element and facing the light-emitting element; a first switching element adjacent to the light-receiving element; a second switching element adjacent to the light-receiving element; a first die pad located above the first switching element; a second die pad located above the second switching element; a first terminal having one end connected to the first die pad; a second terminal having one end connected to the second die pad; and a package, wherein the light-receiving element is located between the first switching element and the second switching element, a direction in which the first terminal and the second terminal are arranged is a first direction, the other end of the first terminal is exposed to the outside of the package and extends downward from the package, and the other end of the second terminal is exposed to the outside of the package and extends downward from the package, the light-emitting element, the light-receiving element, the first switching element, the second switching element, the first die pad, and the second die pad are located inside the package, the first die pad at least partially overlaps with the first switching element in a top view, and the second die pad at least partially overlaps with the second switching element in a top view.

2. A semiconductor relay as described in claim 1, wherein the longest length of said first die pad in said first direction is greater than the longest length of said first terminal in said first direction, and the longest length of said second die pad in said first direction is greater than the longest length of said second terminal in said first direction.

3. A semiconductor relay as described in claim 1 or 2, wherein the shortest distance between the first die pad and the second die pad in the first direction is shorter than the shortest distance between the first terminal and the second terminal in the first direction.

4. A semiconductor relay as described in any one of claims 1 to 3, wherein the first die pad has a width-changing portion, and the width-changing portion is configured so that the length of the first die pad in the first direction increases from the boundary between the first terminal and the first die pad toward the end of the first die pad.

5. A semiconductor relay as claimed in any one of claims 1 to 4, wherein when a direction in which the first terminal and the second terminal each protrude and a direction perpendicular to the first direction are defined as a second direction, the first die pad has a protrusion that protrudes in the first direction or the second direction.

6. A semiconductor relay as claimed in any one of claims 1 to 5, wherein an area where the first die pad overlaps with the first switching element in a top view is different from an area where the second die pad overlaps with the second switching element.

7. A semiconductor relay as claimed in any one of claims 1 to 6, wherein the first terminal is composed of a first tip portion, a first intermediate portion connected to the first tip portion and exposed to the outside of the package, and a first connection portion connecting the first intermediate portion and the first die pad and located inside the package, and a shortest length of the first connection portion in the first direction is greater than a longest length of the first tip portion in the first direction, and the second terminal is composed of a second tip portion, a second intermediate portion connected to the second tip portion and exposed to the outside of the package, and a second connection portion connecting the second intermediate portion and the second die pad and located inside the package, and a shortest length of the second connection portion in the first direction is greater than a longest length of the second tip portion in the first direction.

8. A semiconductor relay as described in claim 7, wherein a shortest length of the first intermediate portion in the first direction is greater than a longest length of the first tip portion in the first direction, and a shortest length of the second intermediate portion in the first direction is greater than a longest length of the second tip portion in the first direction.

9. The semiconductor device further comprises a third die pad on which the first switching element is arranged, a fourth die pad on which the second switching element is arranged, a third terminal having one end connected to the third die pad, and a fourth terminal having one end connected to the fourth die pad, wherein the third terminal is composed of a third tip portion, a third intermediate portion connected to the third tip portion and exposed to the outside of the package, and a third connection portion connecting the third intermediate portion and the third die pad and located inside the package, wherein the shortest length of the third connection portion in the first direction is greater than the longest length of the third tip portion in the first direction, and the fourth terminal is composed of a fourth tip portion, a fourth intermediate portion connected to the fourth tip portion and exposed to the outside of the package, and a fourth connection portion connecting the fourth intermediate portion and the fourth die pad and located inside the package, wherein the shortest length of the fourth connection portion in the first direction is greater than the longest length of the fourth tip portion in the first direction. The semiconductor relay according to any one of claims 1 to 8.

10. A semiconductor relay as described in claim 9, wherein the shortest length of the third intermediate portion in the first direction is greater than the longest length of the third tip portion in the first direction, and the shortest length of the fourth intermediate portion in the first direction is greater than the longest length of the fourth tip portion in the first direction.

11. A semiconductor relay as described in claim 9 or 10, wherein the third intermediate portion has a first portion connected to the third connection portion and a second portion extending downward from the first portion, and when the direction in which the light-emitting element and the light-receiving element face each other is defined as a third direction, a first axis which is a center line of the first portion along the third direction is farther away from the fourth terminal than a second axis which is a center line of the third tip portion along the third direction.

12. A semiconductor device comprising: a light-emitting element; a light-receiving element located below the light-emitting element and facing the light-emitting element; a first switching element adjacent to the light-receiving element; a second switching element adjacent to the light-receiving element; a first die pad located above the first switching element; a second die pad located above the second switching element; a first terminal having one end connected to the first die pad; a second terminal having one end connected to the second die pad; and a package, wherein the light-receiving element is located between the first switching element and the second switching element, a direction in which the first terminal and the second terminal are arranged is a first direction, the other end of the first terminal is exposed to the outside of the package and extends downward from the package, and the other end of the second terminal is exposed to the outside of the package and extends downward from the package, and at least a portion of the first die pad overlaps with the first switching element in a top view, the second die pad at least partially overlaps with the second switching element in a top view, and further comprising: a third die pad on which the first switching element is arranged; a fourth die pad on which the second switching element is arranged; a third terminal having one end connected to the third die pad; and a fourth terminal arranged to face the third terminal in the first direction, wherein the light-emitting element, the light-receiving element, the first switching element, the second switching element, and the first to third die pads are located inside the package, and the third terminal is composed of: a third tip portion, a third intermediate portion connected to the third tip portion and exposed to the outside of the package, and a third connection portion connecting the third intermediate portion and the third die pad and located inside the package, and the third intermediate portion has a first portion connected to the third connection portion and a second portion extending downward from the first portion, and a minimum length of the third intermediate portion in the first direction is greater than a maximum length of the third tip portion in the first direction;a first axis that is a center line of the first portion along the third direction is farther away from the fourth terminal than a second axis that is a center line of the third tip portion along the third direction.

13. A semiconductor relay as described in claim 12, wherein the third tip portion has a first surface facing the fourth terminal and a second surface that is spaced further away from the fourth terminal in the first direction than the first surface; the third intermediate portion has a third surface facing the fourth terminal and a fourth surface that is spaced further away from the fourth terminal in the first direction than the third surface; and the first surface is flush with the third surface.

14. The solid-state relay according to claim 13, wherein the third surface of the first portion is flush with the third surface of the second portion.

15. A semiconductor relay as claimed in claim 13 or 14, wherein the fourth surface of the first portion is flush with the fourth surface of the second portion.

16. A semiconductor relay as described in any one of claims 9 to 15, comprising: a fifth die pad having a lower surface, the light-emitting element being arranged on the lower surface; and a sixth die pad having an upper surface, the light-receiving element being arranged on the upper surface; the distance between the first die pad and the third die pad being shorter than the distance between the fifth die pad and the sixth die pad; and the distance between the second die pad and the fourth die pad being shorter than the distance between the fifth die pad and the sixth die pad.

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