Semiconductor device

Abstract

To provide a semiconductor device capable of improving a signal transmission characteristic.SOLUTION: A semiconductor device includes: a substrate having a first surface extending in a first direction and a second direction; a first transistor; a light receiving element; a light emitting element provided on the light receiving element; an input terminal provided on the first surface of the substrate; a first conductor electrically connecting a source end of the first transistor and a first electrode of the light receiving element; a second conductor electrically connecting a gate end of the first transistor and a second electrode of the light receiving element; and a third conductor that connects a third electrode of the light emitting element and an input terminal. The light emitting element and the input terminal are provided at positions overlapping in a third direction intersecting the first direction and the second direction, and the third conductor is provided inside the substrate.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The embodiments relate to a semiconductor device. [Background technology]

[0002] A photorelay device is a known semiconductor device. The photorelay device is a semiconductor relay device including a light-emitting element and a light-receiving element. The photorelay device is a contactless relay used to transmit AC or DC signals. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3505986 [Patent Document 2] Japanese Utility Model Application Publication No. 5-028059 [Patent Document 3] Patent No. 4121524 Summary of the Invention [Problem to be solved by the invention]

[0004] A semiconductor device capable of improving signal transmission characteristics is provided. [Means for solving the problem]

[0005] The semiconductor device of the embodiment comprises a substrate having a first surface extending in a first direction and a second direction, a first transistor, a light receiving element, a light emitting element provided on the light receiving element, an input terminal provided on the first surface of the substrate, a first conductor electrically connecting the source terminal of the first transistor and the first electrode of the light receiving element, a second conductor electrically connecting the gate terminal of the first transistor and the second electrode of the light receiving element, and a third conductor connecting the third electrode of the light emitting element and the input terminal, wherein the light emitting element and the input terminal are arranged at positions overlapping in a third direction that intersects the first direction and the second direction, and the third conductor is arranged inside the substrate. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a circuit diagram showing an example of a circuit configuration of a photorelay device according to a first embodiment. [Figure 2] FIG. 2 is a perspective view showing an example of the overall structure of the photorelay device according to the first embodiment. [Figure 3] FIG. 3 is a plan view showing an example of a planar layout of various elements included in the photorelay device according to the first embodiment. [Figure 4] 4 is a cross-sectional view taken along line IV-IV in FIG. 3, showing an example of the cross-sectional structure of the photorelay device according to the first embodiment. [Figure 5] 5 is a cross-sectional view taken along line VV in FIG. 3, showing an example of the cross-sectional structure of the photorelay device according to the first embodiment. [Figure 6] 6 is a cross-sectional view taken along line VI-VI in FIG. 3, showing an example of the cross-sectional structure of the photorelay device according to the first embodiment. [Figure 7] 7 is a cross-sectional view taken along line VII-VII in FIG. 3, showing an example of the cross-sectional structure of the photorelay device according to the first embodiment. [Figure 8] FIG. 8 is a cross-sectional view showing an example of a cross-sectional structure of the photorelay device according to the first embodiment during manufacturing. [Figure 9] FIG. 9 is a cross-sectional view showing an example of a cross-sectional structure of the photorelay device according to the first embodiment during manufacturing. [Figure 10] FIG. 10 is a cross-sectional view showing an example of a cross-sectional structure of the photorelay device according to the first embodiment during manufacturing. [Figure 11] FIG. 11 is a cross-sectional view showing an example of a cross-sectional structure of the photorelay device according to the first embodiment during manufacturing. [Figure 12] FIG. 12 is a cross-sectional view showing an example of a cross-sectional structure of the photorelay device according to the first embodiment during manufacturing. [Figure 13] FIG. 13 is a perspective view showing an example of the overall structure of a photorelay device according to a second embodiment. [Figure 14]FIG. 14 is a cross-sectional view showing an example of a cross-sectional structure of a photorelay device according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, embodiments will be described with reference to the drawings. In the following description, components having substantially the same functions and configurations are denoted by the same reference numerals.

[0008] In the following description, when a first element is "connected" to another second element, it includes the first element being indirectly connected to the second element via an intermediate element that is always or selectively conductive, or directly connected to the second element without an intermediate element.

[0009] A first embodiment will be described below. A photorelay device will be described below as an example of a semiconductor device according to the embodiment.

[0010] 1 is a circuit diagram showing an example of the circuit configuration of a photorelay device according to the first embodiment. An example of the circuit configuration of a photorelay device 1 according to the first embodiment will be described with reference to FIG.

[0011] As shown in FIG. 1, the photorelay device 1 includes two transistors 20a and 20b, a light receiving element 30, a light emitting element 50, input terminals 90 and 91, and output terminals 92a and 92b.

[0012] The transistors 20a and 20b are, for example, metal oxide semiconductor field effect transistors (MOSFETs). The following describes the case where the transistors 20a and 20b are MOSFETs (MOSFETs 20a and 20b).

[0013] The MOSFETs 20a and 20b are, for example, enhancement-type n-channel MOSFETs. The MOSFETs 20a and 20b are used to control the signals to be transmitted. The drain terminals of the MOSFETs 20a and 20b are connected to the output terminals 92a and 92b, respectively. The source terminals of the MOSFETs 20a and 20b are commonly connected to the cathode of the light-receiving element 30. The gate terminals of the MOSFETs 20a and 20b are commonly connected to the anode of the light-receiving element 30.

[0014] The light receiving element 30 is, for example, a PDA (Photo Diode Array) including a control circuit 30a and several to several tens of photodiodes 30b connected in series. Both ends of the series-connected photodiodes 30b are connected to the control circuit 30a. The control circuit 30a controls the MOSFETs 20a and 20b using the voltage applied from the photodiodes 30b as a power supply voltage. The light receiving element 30 may also be a phototransistor or the like. The following describes the case where the light receiving element 30 is a PDA.

[0015] The light emitting element 50 is, for example, an LED (Light Emitting Diode). The light emitting element 50 is connected to input terminals 90 and 91. A signal transmitted via the photorelay device 1 is input to the input terminals 90 and 91.

[0016] When a sufficient potential difference occurs between the input terminals 90 and 91, the light-emitting element 50 enters an ON state (light-emitting state). At this time, the light-receiving element 30 receives light from the light-emitting element 50 and generates a voltage of, for example, 7 V to several tens of volts. As a result, the MOSFETs 20a and 20b enter an ON state, and the output terminals 92a and 92b are connected to each other. On the other hand, when the potential difference between the input terminals 90 and 91 decreases and the light-emitting element 50 enters an OFF state (light-extinguishing state), the MOSFETs 20a and 20b enter an OFF state, and the output terminals 92a and 92b are insulated from each other.

[0017] The structure of the photorelay device according to the first embodiment is shown in FIGS. 2 and 3. FIG. 2 is a perspective view showing an example of the overall structure of the photorelay device according to the first embodiment. FIG. 3 is a plan view showing an example of the planar layout of various elements included in the photorelay device according to the first embodiment. Note that some conductors are omitted in FIG. 3. As shown in FIGS. 2 and 3, the photorelay device 1 further includes an adhesive layer 40 and conductors 60, 61, 62, 63, 70, 71, 72, 73, 74, 75, 77, and 78.

[0018] The MOSFETs 20a and 20b have, for example, a rectangular shape in a plan view, and are disposed so that their sides face each other. Hereinafter, the direction in which the MOSFETs 20a and 20b are aligned is referred to as the Y direction. The light-emitting element 50 is aligned with the MOSFETs 20a and 20b in a direction intersecting the Y direction. Hereinafter, the direction in which the light-emitting element 50 and the MOSFETs 20a and 20b are aligned is referred to as the X direction. The light-receiving element 30 is aligned with the light-emitting element 50 in a direction intersecting the X and Y directions. Hereinafter, the direction in which the light-receiving element 30 and the light-emitting element 50 are aligned is referred to as the Z direction, and the direction in which the light-receiving element 30 is aligned as viewed from the light-emitting element 50 is referred to as the upward direction, and the direction in which the light-emitting element 50 is aligned as viewed from the light-receiving element 30 is referred to as the downward direction. That is, the plan view shown in part (A) of FIG. 3 corresponds to the planar layout of the light-receiving element 30, the adhesive layer 40, and the light-emitting element 50 when the photorelay device 1 is viewed from above. Also, the plan view shown in part (B) of Figure 3 corresponds to the planar layout of the MOSFETs 20a and 20b, the conductors 60, 61, 62, and 63, the input terminals 90 and 91, and the output terminals 92a and 92b when the photorelay device 1 is viewed from below.

[0019] The MOSFET 20a includes electrodes 21a, 22a, and 23a. The electrode 21a is provided on the bottom surface of the MOSFET 20a and functions as the drain electrode of the MOSFET 20a. The electrode 22a is provided on the top surface of the MOSFET 20a and functions as the source electrode of the MOSFET 20a. The electrode 23a is provided on the top surface of the MOSFET 20a and functions as the gate electrode of the MOSFET 20a.

[0020] The MOSFET 20b includes electrodes 21b, 22b, and 23b. The electrode 21b is provided on the bottom surface of the MOSFET 20b and functions as the drain electrode of the MOSFET 20b. The electrode 22b is provided on the top surface of the MOSFET 20b and functions as the source electrode of the MOSFET 20b. The electrode 23b is provided on the top surface of the MOSFET 20b and functions as the gate electrode of the MOSFET 20b.

[0021] 2 and 3, electrodes 22a and 23a of MOSFET 20a and electrodes 22b and 23b of MOSFET 20b are arranged symmetrically with respect to the XZ plane. Electrode 23a is provided on the top surface of MOSFET 20a at a position along two sides: a side extending in the X direction on the side farther from MOSFET 20b and a side extending in the Y direction on the side closer to light-receiving element 30. Electrode 23b is provided on the top surface of MOSFET 20b at a position along two sides: a side extending in the X direction on the side farther from MOSFET 20a and a side extending in the Y direction on the side closer to light-receiving element 30.

[0022] The light receiving element 30 further includes a light receiving surface and electrodes 31, 32, 33, and 34. The light receiving surface of the light receiving element 30 is provided on the lower surface of the light receiving element 30. That is, the light receiving surface of the light receiving element 30 faces the side (downward) where the light emitting element 50 is arranged. The electrodes 31, 32, 33, and 34 are provided on the lower surface of the light receiving element 30. The electrodes 31 and 32 are provided so as to sandwich the light receiving surface of the light receiving element 30 in the Y direction. For example, the electrodes 31 and 32 are electrically connected by wiring (not shown) provided within the light receiving element 30. The electrodes 33 and 34 are provided so as to sandwich the light receiving surface of the light receiving element 30 in the Y direction. For example, the electrodes 33 and 34 are electrically connected by wiring (not shown) provided within the light receiving element 30.

[0023] The light-emitting element 50 is provided on the lower surface of the light-receiving element 30 via an adhesive layer 40. The adhesive layer 40 is made of a light-transmitting insulating material. The light-emitting element 50 includes a light irradiation surface and electrodes 51 and 52. The light irradiation surface of the light-emitting element 50 is provided on the upper surface of the light-emitting element 50. That is, the irradiation surface of the light-emitting element 50 faces the side (upward) where the light-receiving element 30 is arranged. The irradiation surface of the light-emitting element 50 faces the light-receiving surface of the light-receiving element 30 via the adhesive layer 40. The electrodes 51 and 52 are provided on the lower surface of the light-emitting element 50. One of the electrodes 51 and 52 is an anode electrode of the light-emitting element 50, and the other is a cathode electrode of the light-emitting element 50. In the example shown in FIGS. 2 and 3 , the electrode 52 corresponds to the anode electrode of the light-emitting element 50, and the electrode 51 corresponds to the cathode electrode of the light-emitting element 50.

[0024] The conductors 60 and 61 are provided below the MOSFETs 20a and 20b, respectively. The conductor 60 contacts the electrode 21a of the MOSFET 20a. The conductor 61 contacts the electrode 21b of the MOSFET 20b.

[0025] The conductors 62 and 63 are provided below the light emitting element 50 at approximately the same position in the Z direction as the conductors 60 and 61. The conductor 62 contacts the electrode 51. The conductor 63 contacts the electrode 52. The shapes of the conductors 62 and 63 are formed to correspond to the shapes of the electrodes 51 and 52.

[0026] Conductors 70, 71, 72, 73, 74, 75, 77, and 78 are wiring structures provided, for example, inside a substrate. Conductor 70 has a flat plate shape extending in the XY plane. Conductor 70 contacts electrode 22a of MOSFET 20a and electrode 22b of MOSFET 20b, connecting them to each other. The connection between conductor 70 and electrodes 22a and 22b is made as large as possible so as to cover the top surfaces of MOSFETs 20a and 20b as much as possible, excluding electrodes 23a and 23b. Conductor 71 has a U-shaped flat plate shape extending in the XY plane, including two portions extending in the X direction, and is provided so as to sandwich light-emitting element 50 in the Y direction. Conductor 71 contacts electrodes 31 and 32 of light-receiving element 30, connecting them to each other. Conductor 72 extends in the Z direction and connects conductors 70 and 71. That is, electrode 22a of MOSFET 20a, electrode 22b of MOSFET 20b, and electrodes 31 and 32 of light-receiving element 30 are connected to one another via conductors 70, 71, and 72. Conductor 73 has a flat plate shape extending in the XY plane. Conductor 73 contacts electrode 23a of MOSFET 20a. Conductor 74 has a flat plate shape extending in the X direction. Conductor 74 contacts electrode 33 of light-receiving element 30. Conductor 75 extends in the Z direction and connects conductors 73 and 74. That is, electrode 23a of MOSFET 20a and electrode 33 of light-receiving element 30 are connected via conductors 73, 74, and 75. Conductor 77 has a flat plate shape extending in the X direction. Conductor 77 contacts electrode 34 of light-receiving element 30. Conductor 78 extends in the Z direction and connects conductor 77 to a conductor (hereinafter referred to as conductor 76) that has a flat plate shape extending on the XY plane (not shown) and is in contact with electrode 23 b of MOSFET 20 b. In other words, electrode 23 b of MOSFET 20 b and electrode 34 of light receiving element 30 are connected via conductors 76, 77, and 78.

[0027] The input terminals 90 and 91 are provided below the conductors 62 and 63, respectively. That is, the input terminals 90 and 91 are provided at positions overlapping with the light-emitting element 50 in the Z direction. The input terminal 90 is connected to the conductor 62 via a conductor not shown. The input terminal 91 is connected to the conductor 63 via a conductor not shown. The input terminals 90 and 91 are connected to an external signal source not shown.

[0028] Output terminals 92a and 92b are provided below the conductors 60 and 61, respectively. Output terminal 92a is connected to conductor 60 via a conductor not shown. Output terminal 92b is connected to conductor 61 via a conductor not shown. Output terminals 92a and 92b are each connected to an external circuit or the like not shown. As described above, a signal is transmitted from a signal source to a circuit or the like via the photorelay device 1.

[0029] The cross-sectional structure of the photorelay device according to the first embodiment is shown in FIGS. 4 to 7. FIGS. 4 to 7 are cross-sectional views taken along lines IV-IV, VV, VI-VI, and VII-VII in FIG. 3, respectively, showing an example of the cross-sectional structure of the photorelay device according to the first embodiment. FIG. 4 corresponds to a YZ cross section of a portion of the photorelay device 1 including conductors 60, 61, 75, and 78, and a portion of conductor 72. FIG. 5 corresponds to a YZ cross section of a portion of the photorelay device 1 including conductors 62, 63, 71, 74, and 77. FIG. 6 corresponds to an XZ cross section of a portion of the photorelay device 1 including conductor 71. FIG. 7 corresponds to an XZ cross section of a portion of the photorelay device 1 including conductor 74.

[0030] First, the configuration of the photorelay device 1 will be described with reference to Figures 4 to 7. As shown in Figures 4 to 7, the photorelay device 1 further includes a substrate 10, conductors 93, 94, 95a, and 95b, and a sealing resin 100.

[0031] The substrate 10 is, for example, a flexible printed circuit (FPC) using polyimide, a resin substrate, a silicon substrate, or a polyimide substrate. The substrate 10 includes wiring layers 11, 13, 15, and 17, and insulator layers 12, 14, and 16. The substrate 10 has a seven-layer structure, for example, in which the wiring layer 11, the insulator layer 12, the wiring layer 13, the insulator layer 14, the wiring layer 15, the insulator layer 16, and the wiring layer 17 are stacked in this order from top to bottom. MOSFETs 20a and 20b are disposed in a layer corresponding to the insulator layer 14 of the substrate 10 so as to be embedded therein. That is, the MOSFETs 20a and 20b are disposed at positions intersecting with the substrate 10 in the XY plane. The substrate 10 also has an opening, which is a hole that penetrates the wiring layers 15 and 17 and the insulator layers 14 and 16 to reach the wiring layer 13. A light-emitting element 50 is disposed in the opening of the substrate 10. That is, the light emitting element 50 is provided at a position that intersects with the substrate 10 in the XY plane. The substrate 10 includes a plurality of conductors. The plurality of conductors serve as substrate wiring and appropriately connect between terminals provided in contact with the substrate 10.

[0032] The conductors 93, 94, 95a, and 95b are a wiring structure provided, for example, inside a substrate. The conductor 93 extends in the Z direction and connects the conductor 62 to the input terminal 90. The conductor 94 extends in the Z direction and connects the conductor 63 to the input terminal 91. The conductor 95a extends in the Z direction and connects the conductor 60 to the output terminal 92a. The conductor 95b extends in the Z direction and connects the conductor 61 to the output terminal 92b. Note that although three conductors 95a are provided in the examples of FIGS. 6 and 7, it is sufficient that there be one or more conductors 95a. Similarly, it is sufficient that there be one or more conductors 95b.

[0033] The sealing resin 100 is, for example, a molding resin having a light-blocking property. The sealing resin 100 covers the MOSFETs 20a and 20b, the light receiving element 30, and the light emitting element 50, thereby protecting them from physical or electrical disturbances.

[0034] Next, with reference to FIG. 4, a configuration for connecting the MOSFETs 20a and 20b to the output terminals 92a and 92b will be described.

[0035] The wiring layer 11 includes output terminals 92a and 92b. The insulator layer 12 includes conductors 95a and 95b and an insulator 12-1. The wiring layer 13 includes conductors 60 and 61 and an insulator 13-1. The insulator layer 14 includes an insulator 14-1. The conductor 95a functions as a via extending in the Z direction within the insulator 12-1 to connect the upper surface of the output terminal 92a and the lower surface of the conductor 60. The conductor 95b functions as a via extending in the Z direction within the insulator 12-1 to connect the upper surface of the output terminal 92b and the lower surface of the conductor 61. The insulator 13-1 insulates the conductor 60 from the conductor 61.

[0036] With the above configuration, the MOSFETs 20a and 20b are connected to the output terminals 92a and 92b.

[0037] Next, with reference to FIG. 5, a configuration for connecting the light emitting element 50 and the input terminals 90 and 91 will be described.

[0038] The wiring layer 11 further includes input terminals 90 and 91. The insulator layer 12 further includes conductors 93 and 94. The wiring layer 13 further includes conductors 62 and 63. The conductor 93 functions as a via extending in the Z direction within the insulator 12-1 to connect the upper surface of the input terminal 90 and the lower surface of the conductor 62. The conductor 94 functions as a via extending in the Z direction within the insulator 12-1 to connect the upper surface of the input terminal 91 and the lower surface of the conductor 63. The insulator 13-1 insulates the conductor 62, the conductor 63, and the conductors 60 and 61 from one another.

[0039] With the above-described configuration, the light emitting element 50 is connected to the input terminals 90 and 91 .

[0040] Next, a configuration for connecting the source terminal of the MOSFET 20a, the source terminal of the MOSFET 20b, and the electrodes 31 and 32 of the light receiving element 30 will be described with reference to FIGS.

[0041] The wiring layer 15 includes a conductor 70 and an insulator 15-1. The insulator layer 16 includes a conductor 72 and an insulator 16-1. The wiring layer 17 includes a conductor 71. The conductor 72 functions as a via extending in the Z direction within the insulator 16-1 to connect the upper surface of the conductor 70 and the lower surface of the conductor 71. Although two conductors 72 are shown in FIG. 4, one or more conductors 72 may be used. The source terminal of the MOSFET 20a, the source terminal of the MOSFET 20b, and the electrodes 31 and 32 of the light receiving element 30 are interconnected via the conductors 70, 71, and 72.

[0042] Next, with reference to FIGS. 4 and 7, a configuration for connecting the gate terminal of the MOSFET 20a and the electrode 33 of the light receiving element 30 will be described.

[0043] The wiring layer 15 further includes a conductor 73. The insulator layer 16 further includes a conductor 75. The wiring layer 17 further includes a conductor 74. The insulator 15-1 insulates the conductor 73 from the conductor 70. The conductor 75 functions as a via extending in the Z direction within the insulator 16-1 to connect the upper surface of the conductor 73 and the lower surface of the conductor 74. The gate terminal of the MOSFET 20a and the electrode 33 of the light-receiving element 30 are connected via the conductors 73, 74, and 75.

[0044] Although not shown, the gate terminal of MOSFET 20b and electrode 34 of light-receiving element 30 are connected in a similar manner to the connection between the gate terminal of MOSFET 20a and electrode 33 of light-receiving element 30. Specifically, they are connected via conductors 76, 77, and 78. As shown in FIG. 4 , wiring layer 15 further includes conductor 76. Insulator layer 16 further includes conductor 78. Wiring layer 17 further includes conductor 77. Conductor 78 functions as a via extending in the Z direction within insulator 16-1 to connect the upper surface of conductor 76 and the lower surface of conductor 77. Insulator 15-1 insulates conductor 76 from conductors 70 and 73.

[0045] A method for manufacturing the photorelay device according to the first embodiment will be described with reference to Figures 8 to 12. Figures 8 to 12 show an example of a cross-sectional structure of the photorelay device according to the first embodiment during manufacturing. The cross-sectional structure shown in Figures 8 to 12 also shows a portion (A) where the MOSFET is arranged, corresponding to Figure 4, and a portion (B) where the light receiving element and light emitting element are arranged, corresponding to Figure 5.

[0046] First, the MOSFETs 20a and 20b, the light receiving element 30, and the light emitting element 50 are individually formed. The light receiving element 30 and the light emitting element 50 are bonded via an adhesive layer 40 so that the light receiving surface of the light receiving element 30 faces the light emitting surface of the light emitting element 50. Furthermore, the substrate 10 is formed by laminating a wiring layer 11, an insulator layer 12, a wiring layer 13, and an insulator layer 14 in this order.

[0047] 8A, two holes are then formed through the insulator layer 14, for example by laser processing, in portions of the substrate 10 corresponding to where the MOSFETs 20a and 20b will be located. The laser processing exposes the conductors 60 and 61.

[0048] Next, as shown in part (A) of Fig. 9, electrode 21a of MOSFET 20a is bonded onto the upper surface of conductor 60. Electrode 21b of MOSFET 20b is bonded onto the upper surface of conductor 61. As a result, MOSFETs 20a and 20b are supported on substrate 10. The gaps between substrate 10 and MOSFETs 20a and 20b are filled with resin.

[0049] 10 , the wiring layer 15, the insulator layer 16, and the wiring layer 17 are provided in this order on the insulator layer 14 and the upper surfaces of the MOSFETs 20a and 20b. Specifically, in part (A), the electrode 22a of the MOSFET 20a and the electrode 22b of the MOSFET 20b are joined to the conductor 70 of the wiring layer 15. The electrode 23a of the MOSFET 20a is joined to the conductor 73 of the wiring layer 15. The electrode 23b of the MOSFET 20b is joined to the conductor 76 of the wiring layer 15.

[0050] 11B, openings penetrating the insulator layers 14 and 16 and the wiring layers 15 and 17 are formed by, for example, laser processing in the portions of the substrate 10 corresponding to the positions where the light emitting elements 50 are to be disposed. The laser processing exposes the conductors 62 and 63.

[0051] Next, as shown in part (B) of FIG. 12 , a light receiving element 30 and a light emitting element 50 are provided on the upper surface of the substrate 10 and in openings that penetrate the insulator layers 14 and 16 and the wiring layers 15 and 17, and bonded via an adhesive layer 40. At this time, the light emitting element 50 is provided on the upper surface of the wiring layer 13, and the light receiving element 30 is provided on the upper surface of the wiring layer 17. Specifically, electrodes 51 and 52 of the light emitting element 50 are bonded to conductors 62 and 63 of the wiring layer 13, respectively. Electrodes 31 and 32 of the light receiving element 30 are bonded to conductor 71 of the wiring layer 17. Furthermore, although not shown, electrodes 33 and 34 of the light receiving element 30 are bonded to conductors 74 and 77 of the wiring layer 17, respectively.

[0052] Finally, the structure obtained by the above steps, except for the lower part, is sealed with sealing resin 100. In this way, the photorelay device 1 is manufactured.

[0053] The configuration according to the first embodiment can improve the transmission characteristics of signals transmitted using the photorelay device 1. It can also achieve a smaller and thinner photorelay device. These will be described in detail below.

[0054] In the configuration according to the first embodiment, the electrodes of the MOSFETs 20a and 20b, the light receiving element 30, the light emitting element 50, the input terminals 90 and 91, and the output terminals 92a and 92b are connected by substrate wiring. This allows the length of the open stub to be shortened compared to when wires are used as wiring. This shifts the signal resonance frequency to the higher frequency side, thereby extending the communication band and improving the signal transmission characteristics.

[0055] Furthermore, in the configuration according to the first embodiment, the electrodes 31 to 34 of the light-receiving element 30 are directly connected to the conductors 71, 74, and 77 on the substrate 10. This eliminates the need for mounting pads for mounting the light-receiving element 30 on the substrate 10. As a result, no coupling capacitance occurs between the mounting pads and the input terminals 90 and 91, and between the mounting pads and the output terminals 92a and 92b. This makes it possible to suppress degradation of signal transmission characteristics in high frequency bands that would otherwise be caused by coupling capacitance.

[0056] Additionally, in the configuration according to the first embodiment, the electrode 22a of the MOSFET 20a and the electrode 22b of the MOSFET 20b are connected via a conductor 70 having as large an area as possible. This reduces the impedance of the circuit connecting the source electrodes of the MOSFETs 20a and 20b compared to when a wire or a thin conductor is used. This prevents deterioration of the signal transmission characteristics between the source electrodes of the MOSFETs 20a and 20b.

[0057] Furthermore, in the configuration according to the first embodiment, the conductors 62 and 63 for connecting the input terminals 90 and 91 to the light-emitting element 50 are provided directly below the light-emitting element 50. This reduces the area required for providing electrode pads corresponding to the conductors 62 and 63 on the substrate 10. Furthermore, in the configuration according to the first embodiment, the MOSFETs 20a and 20b and the light-receiving element 30 are provided at positions that do not intersect with each other in the XY plane. This allows the MOSFETs 20a and 20b to be positioned close to the light-receiving element 30 and the light-emitting element 50 in the X direction. As a result, the photorelay device 1 can be made smaller.

[0058] Additionally, since the configuration according to the first embodiment does not use wires, it is possible to reduce the height required for wires and thereby reduce the thickness of the photorelay device 1. Furthermore, since the process of connecting wires is not required, it is possible to reduce the number of steps required during manufacturing.

[0059] The photorelay device according to the first embodiment described above can be modified in various ways.

[0060] For example, a configuration is possible in which the conductor 71 is divided into a first portion that contacts the electrode 31 of the light-receiving element 30 and has a flat plate shape extending in the X direction, and a second portion that contacts the electrode 32 of the light-receiving element 30 and has a flat plate shape extending in the X direction. In this case, at least two or more conductors 72 must be provided. At least one of the multiple conductors 72 connects the first portion of the conductor 71 to the conductor 70. At least one of the multiple conductors 72 connects the second portion of the conductor 71 to the conductor 70.

[0061] Next, a second embodiment will be described, focusing mainly on the structure that differs from the first embodiment.

[0062] Fig. 13 is a perspective view showing an example of the overall structure of the photorelay device according to the second embodiment. Fig. 14 is a cross-sectional view showing an example of the cross-sectional structure of the photorelay device according to the second embodiment, corresponding to Fig. 5 in the first embodiment. The structure of the photorelay device 1A according to the second embodiment will be described using Figs. 13 and 14.

[0063] The photorelay device 1A according to the second embodiment includes a substrate 10A instead of the substrate 10, and further includes conductors 111, 112, and 113, as well as a conductor 114 (not shown). In addition to the components included in the substrate 10, the substrate 10A includes conductors 62A and 63A instead of the conductors 62 and 63 in the substrate 10, and further includes conductors 64, 65, 79, 80, 81, 82, 83, and 84.

[0064] Substrate 10A has a seven-layer structure in which, for example, wiring layer 11, insulator layer 12, wiring layer 13, insulator layer 14, wiring layer 15, insulator layer 16, and wiring layer 17 are stacked in this order from top to bottom. Substrate 10A does not include any openings.

[0065] The conductors 62A and 63A are provided in the wiring layer 13. The conductor 62A contacts the conductor 93 on its lower surface and the conductor 64 on its upper surface. The conductor 63A contacts the conductor 94 on its lower surface and the conductor 65 on its upper surface. The insulator 13-1 insulates the conductors 60, 61, 62A, and 63A from each other.

[0066] The conductors 64 and 65 are provided in the insulator layer 14. The conductor 64 functions as a via extending in the Z direction within the insulator 14-1 to connect between the upper surface of the conductor 62A and the lower surface of the conductor 79. The conductor 65 functions as a via extending in the Z direction within the insulator 14-1 to connect between the upper surface of the conductor 63A and the lower surface of the conductor 82. The insulator 14-1 insulates the conductors 64 and 65.

[0067] The conductors 79 and 82 are provided in the wiring layer 15. The conductor 79 contacts the conductor 64 on its lower surface and the conductor 81 on its upper surface. The conductor 82 contacts the conductor 65 on its lower surface and the conductor 84 on its upper surface. The insulator 15-1 insulates the conductors 70, 73, 76, 79, and 82 from one another. Conductors 81 and 84 are provided in the insulator layer 16. Conductor 81 functions as a via extending in the Z direction within the insulator 16-1 to connect between the upper surface of conductor 79 and the lower surface of conductor 80. Conductor 84 functions as a via extending in the Z direction within the insulator 16-1 to connect between the upper surface of conductor 82 and the lower surface of conductor 83. Insulator 16-1 insulates conductors 72, 75, 78, 81, and 84 from one another.

[0068] The conductors 80 and 83 are provided on the wiring layer 17. The conductor 80 contacts the conductor 81 on its lower surface and contacts the electrode 51 of the light-emitting element 50 on its upper surface. The conductor 83 contacts the conductor 84 on its lower surface and contacts the electrode 52 of the light-emitting element 50 on its upper surface.

[0069] With the above configuration, electrode 51 of light-emitting element 50 and input terminal 90 are connected via conductors 62A, 64, 79, 80, 81, and 93. Furthermore, electrode 52 of light-emitting element 50 and input terminal 91 are connected via conductors 63A, 65, 82, 83, 84, and 94.

[0070] The conductors 111, 112, 113, and 114 are, for example, metal spacers. The conductor 111 is provided between the electrode 31 of the light-receiving element 30 and the conductor 71, extending in the Z direction, to connect the two. The conductor 112 is provided between the electrode 32 of the light-receiving element 30 and the conductor 71, extending in the Z direction, to connect the two. The conductor 113 is provided between the electrode 33 of the light-receiving element 30 and the conductor 74, extending in the Z direction, to connect the two. The conductor 114 is provided between the electrode 34 of the light-receiving element 30 and the conductor 77, extending in the Z direction, to connect the two. The conductors 111, 112, 113, and 114 fix the substrate 10 and the light-receiving element 30 and support the light-receiving element 30.

[0071] With the above configuration, electrodes 31 and 32 of the light-receiving element are connected to electrode 22a of MOSFET 20a and electrode 22b of MOSFET 20b via conductors 70, 71, and 72, and conductors 111 and 112. Electrode 33 of the light-receiving element 30 is connected to electrode 23a of MOSFET 20a via conductors 73, 74, and 75, and conductor 113. Electrode 34 of the light-receiving element 30 is connected to electrode 23b of MOSFET 20b via conductors 76, 77, and 78, and conductor 114.

[0072] A method for manufacturing a photorelay device according to the second embodiment will be described. First, a substrate 10A in which MOSFETs 20a and 20b are embedded is formed by substantially the same steps as those for forming the substrate 10 shown in Fig. 10 in the first embodiment. In addition, a wiring layer 15 is provided so that conductors 79 and 82 are connected to conductors 64 and 65, respectively.

[0073] Thereafter, without performing laser processing, the light receiving element 30 and the light emitting element 50 are bonded onto the upper surface of the substrate 10A. Specifically, first, one end of each of the conductors 111, 112, 113, and 114 is bonded to the electrodes 31, 32, 33, and 34 of the light receiving element 30, respectively. Then, the light receiving element 30 and the light emitting element 50 are provided on the upper surface of the wiring layer 17, bonded via the adhesive layer 40, so that the light emitting element 50 corresponds to the electrode 31, 32, 33, and 34 of the light receiving element 30. The electrodes 51 and 52 of the light emitting element 50 are bonded to the conductors 80 and 83 of the wiring layer 17, respectively. The other ends of the conductors 111 and 112 are bonded to the conductor 71 of the wiring layer 17. The other ends of the conductors 113 and 114 are bonded to the conductors 74 and 77 of the wiring layer 17, respectively.

[0074] The process of bonding the light receiving element 30 and the light emitting element 50 to the upper surface of the substrate 10A is not limited to the above method. For example, the light receiving element 30 and the light emitting element 50 may be disposed on the substrate 10A first, and then the conductors 111, 112, 113, and 114 may be formed. Specifically, the light receiving element 30 and the light emitting element 50 are first provided on the upper surface of the wiring layer 17 so that the light emitting element 50 corresponds to the light receiving element 30 and the light emitting element 50 are bonded via the adhesive layer 40. The electrodes 51 and 52 of the light emitting element 50 are bonded to the conductors 80 and 83 of the wiring layer 17, respectively. Then, the conductors 111, 112, 113, and 114 are provided to connect the electrodes 31, 32, 33, and 34 of the light receiving element 30 to the conductors 71, 74, and 77 of the wiring layer 17. One end of the conductor 111 is bonded to the electrode 31, and the other end is bonded to the conductor 71. One end of conductor 112 is joined to electrode 32, and the other end is joined to conductor 71. One end of conductor 113 is joined to electrode 33, and the other end is joined to conductor 74. One end of conductor 114 is joined to electrode 34, and the other end is joined to conductor 77.

[0075] Finally, the structure obtained by the above steps, except for the lower part, is sealed with sealing resin 100. In this way, the photorelay device 1A is manufactured.

[0076] With the configuration of the second embodiment, as with the first embodiment, the length of the open stub can be shortened, the signal transmission characteristics can be improved, and degradation of the signal transmission characteristics due to coupling capacitance and high impedance can be suppressed.

[0077] Furthermore, with the configuration according to the second embodiment, as with the first embodiment, the area required for installing electrode pads corresponding to the conductors 62 and 63 on the substrate 10 can be reduced. Also, in the configuration according to the second embodiment, the light-emitting element 50 is provided at a position that does not intersect with the substrate 10A in the XY plane. Therefore, the light-receiving element 30 and the light-emitting element 50 can be positioned closer to the MOSFETs 20a and 20b in the X direction. As a result, the photorelay device 1A can be made smaller.

[0078] In addition, the configuration according to the second embodiment does not include an opening, which eliminates the need for laser processing to form an opening, thereby reducing the number of manufacturing steps.

[0079] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0080] 1, 1A...Photorelay device 10, 10A...board 11, 13, 15, 17...wiring layer 12, 14, 16...insulator layers 20a, 20b...Transistor (MOSFET) 21a, 21b, 22a, 22b, 23a, 23b, 31, 32, 33, 34, 51, 52...electrode 30...Photodetector 30a...Control circuit 30b...Photodiode 40...adhesive layer 50...Light emitting element 60, 61, 62, 62A, 63, 63A, 64, 65, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 93, 94, 95a, 95b, 111, 112, 113, 114...Conductor 90, 91...Input terminals 92a, 92b...Output terminals 100…Sealing resin

Claims

1. a substrate having a first surface extending in a first direction and a second direction; a first transistor; A light receiving element; a light-emitting element provided on the light-receiving element; an input terminal provided on the first surface of the substrate; a first conductor electrically connecting a source terminal of the first transistor and a first electrode of the light receiving element; a second conductor electrically connecting a gate terminal of the first transistor and a second electrode of the light receiving element; a third conductor connecting a third electrode of the light-emitting element and the input terminal; Equipped with the light-emitting element and the input terminal are provided at positions overlapping each other in a third direction intersecting the first direction and the second direction, the third conductor is provided inside the substrate; Semiconductor device.

2. the input terminal, the substrate, the light-emitting element, and the light-receiving element are arranged in this order in the third direction. The semiconductor device according to claim 1.

3. The light receiving surface of the light receiving element is provided to face the irradiation surface of the light emitting element. The semiconductor device according to claim 1.

4. the substrate further has a second surface extending in the first direction and the second direction and different from the first surface; the first conductor and the second conductor are provided inside the substrate and on the second surface; The semiconductor device according to claim 1.

5. an output terminal provided on the first surface of the substrate; a fourth conductor electrically connecting the output terminal and the drain terminal of the first transistor; Further provided with the fourth conductor is provided inside the substrate; The semiconductor device according to claim 1.

6. the first transistor is provided inside the substrate so as to be embedded in the substrate; The semiconductor device according to claim 1.

7. the substrate includes an opening recessed in the third direction on the second surface; the light-emitting element is provided in the opening of the substrate so as to be aligned with the first transistor in the first direction; the first electrode of the light receiving element is in contact with the first conductor on the second surface of the substrate; the second electrode of the light receiving element is in contact with the second conductor on the second surface of the substrate; 5. The semiconductor device according to claim 4.

8. the first conductor and the second conductor further have portions extending in the third direction outside the substrate; the third electrode of the light-emitting element is in contact with the third conductor on the second surface of the substrate; 5. The semiconductor device according to claim 4.

9. a second transistor arranged to be aligned with the first transistor in the second direction; a fifth conductor electrically connecting a gate terminal of the second transistor and a fourth electrode of the light receiving element; Further provided with the first conductor further electrically connects a source terminal of the second transistor to a source terminal of the first transistor and the first electrode of the light-receiving element; The semiconductor device according to claim 1.

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