Semiconductor relay

Abstract

This semiconductor relay (1) comprises an output circuit (OPC) which includes a first MOSFET element (3) and a second MOSFET element (4) and which controls signal transmission between a first output terminal (8) and a second output terminal (9) on the basis of a second drive signal output from a drive circuit (DRC). A first metal bump (13A) is provided on a surface of a first source electrode (3e) of the first MOSFET element (3), and a second metal bump (14A) is provided on a surface of a second source electrode (4e) of the second MOSFET element (4). The connection conductor (12) is joined to the first metal bump (13A) and the second metal bump (14A). The first source electrode (3e) and the second source electrode (4e) are electrically connected to each other via the first metal bump (13A), the second metal bump (14A), and the connection conductor (12).

Description

Semiconductor Relay

[0001] The present disclosure relates to a semiconductor relay.

[0002] Conventionally, semiconductor relays, also called MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) output photocouplers or optical MOSFETs, have been known as signal transmission means. In such semiconductor relays, an increase in insertion loss has been an issue along with the higher frequency of transmission signals. More specifically, when the inductance component of the output circuit in a semiconductor relay is large, insertion loss tends to increase.

[0003] To solve this problem, configurations disclosed in Patent Documents 1 and 2, for example, have been proposed. For example, Patent Document 1 discloses a configuration of an optically coupled semiconductor relay in which a connection conductor is provided on the back surface of a light-receiving driving element, and the light-receiving driving element is arranged to cover the respective surfaces of two MOSFET elements. Further, a first connection body and a second connection body, which are conductors, are respectively provided between the connection conductor and the source electrodes. The two source electrodes are electrically connected to each other via the connection conductor, the first connection body, and the second connection body. Patent Document 2 discloses a configuration of an optically coupled semiconductor relay in which the source electrodes of two MOSFET elements constituting an output circuit are connected to each other by plated wiring. In either case, the width of the wiring connecting the source electrodes of the two MOSFET elements can be increased, so that the inductance component of the output circuit in the semiconductor relay, and consequently the insertion loss, can be reduced.

[0004] International Publication No. 2024 / 190452; Japanese Unexamined Patent Application Publication No. 2002-359392

[0005] In the conventional configuration disclosed in Patent Document 1, the connecting conductor is a layered or sheet-like conductive material. In this case, the connection resistance between the first or second connector and the connecting conductor may become high. For example, if the resistivity of the first or second connector and the connecting conductor differs significantly, the aforementioned connection resistance may become high. Furthermore, depending on the materials of the first or second connector and the connecting conductor, the interfacial resistance between the first or second connector and the connecting conductor may become high. These tendencies become more pronounced when the connecting conductor is a conductive die attach film mixed with a conductive filler.

[0006] Furthermore, in cases where the connecting conductor is a flexible conductive sheet, the connecting conductor may deform due to prolonged use or external environmental factors such as temperature changes in which the semiconductor relay is located. Such deformation may cause the connecting conductor to come into contact with the MOSFET element of the output circuit, potentially adversely affecting the output characteristics of the MOSFET element.

[0007] Furthermore, in the configuration disclosed in Patent Document 2, there is a risk that the plated wiring may deform and come into contact with the MOSFET element. Also, Patent Document 2 does not disclose how the source electrode and the plated wiring are connected, and under certain conditions, the connection resistance between the source electrode and the plated wiring may become high.

[0008] The semiconductor relay according to this disclosure comprises an input circuit, a drive circuit, an output circuit, and a connecting conductor made of a metallic material and in the shape of a plate. The input circuit and the output circuit are electrically insulated from each other. The input circuit has a first input terminal, a second input terminal, and an input element, and outputs a first drive signal to the drive circuit based on an input signal input between the first input terminal and the second input terminal. The drive circuit outputs a second drive signal to the output circuit based on the first drive signal. The output circuit has at least a first output terminal, a second output terminal, and an output element, and either makes the first output terminal and the second output terminal conductive or non-conductive based on the second drive signal. The output element has a first MOSFET element and a second MOSFET element, each electrically connected to the drive circuit. The first MOSFET element has a first gate electrode and a first source electrode formed on its surface, and a first connector is provided on the surface of the first source electrode. The second MOSFET element has a second gate electrode and a second source electrode formed on its surface, and a second connector is provided on the surface of the second source electrode. The first connector and the second connector are each metal bumps. The first connector and the second connector are each joined to the connecting conductor. The first connector, the connecting conductor, and the second connector electrically connect the first and second source electrodes to each other.

[0009] According to this disclosure, in the connection between the connecting conductor and the connector that connects the source electrodes of the output element, the connection resistance can be reduced and the connection reliability can be improved.

[0010] This is a perspective view of a semiconductor relay according to Embodiment 1. This is a view of the semiconductor relay from direction A shown in Figure 1. This is a partially exploded perspective view of the semiconductor relay. This is a perspective view of the light-emitting element. This is a perspective view of the light-receiving driving element. This is a perspective view of the first MOSFET element. This is a plan view of the connecting conductor. This is a view of the first and second MOSFET elements and the connecting conductor inside the semiconductor relay from direction B shown in Figure 1. This is a schematic cross-sectional view of the connecting conductor connected to the source electrode. This is a schematic cross-sectional view of another connecting conductor connected to the source electrode. This is an equivalent circuit diagram of the semiconductor relay according to Embodiment 1. This is a schematic cross-sectional view showing the positional relationship between the connecting conductor and the first MOSFET element when there are burrs on the connecting conductor. This is a plan view of another connecting conductor. This is a diagram corresponding to Figure 2 of the semiconductor relay according to Modification 1. This is a diagram corresponding to Figure 2 of the semiconductor relay according to Modification 2. This is an equivalent circuit diagram of the semiconductor relay according to Embodiment 2. This is a perspective view of the semiconductor relay. This is a view of the semiconductor relay from above. This is a view of the semiconductor relay from direction C shown in Figure 16.

[0011] Embodiments of the present disclosure will be described below with reference to the drawings. The following description of preferred embodiments is illustrative in nature and is not intended to limit the present disclosure, its applications, or its uses.

[0012] (Embodiment 1) [Configuration of Semiconductor Relay] Figure 1 shows a perspective view of the semiconductor relay according to this embodiment, and Figure 2 shows a side view of the semiconductor relay as seen from direction A shown in Figure 1. Figure 3 is a partially exploded perspective view of the semiconductor relay. Figure 4 is a perspective view of the light-emitting element. Figure 5 is a perspective view of the light-receiving driving element. Figure 6 is a perspective view of the first MOSFET element.

[0013] For the sake of clarity, in Figures 1 and 2, the outlines of the housing 10 and the light-shielding resin 10a and light-transmitting resin 10b that constitute it are shown with dashed lines. Also, in Figures 1 to 6, the shapes of each component are simplified. For example, the shapes of the first metal bump 13A and the second metal bump 14A shown in Figure 3 differ from the actual shapes.

[0014] In the following explanation, the direction perpendicular to the surface 12a of the connecting conductor 12 (see Figures 3 and 8) may be referred to as the first direction. Also, in this embodiment, the X direction is the direction in which the light-emitting element 2 and the light-receiving driving element 5 face each other, and is also the first direction. The direction in which the first output terminal 8 and the second output terminal 9 are aligned may be referred to as the Y direction. The Y direction is also the direction in which the first input terminal 6 and the second input terminal 7 are aligned. The direction perpendicular to both the X direction and the Y direction may be referred to as the Z direction.

[0015] In this specification, "orthogonal" or "parallel" means that the processing tolerances and manufacturing tolerances of each component constituting the semiconductor relay 1, as well as the assembly tolerances between the components, are orthogonal or parallel. It does not mean that the comparison objects themselves are orthogonal or parallel in a strict sense.

[0016] In this embodiment, the X direction is also the direction in which the light-receiving driving element 5, the first MOSFET element 3, and the second MOSFET element 4 are aligned. In the Z direction, the side where the first MOSFET mounting section 82 is located may be referred to as "up" or "upper," and the side where the first output side external terminal section 81 is located may be referred to as "down" or "lower." In this specification, the terms "up" and "down" are purely relative and do not, for example, mean "up" or "down" along the vertical direction.

[0017] Furthermore, the terms "front" and "back" in this specification are defined as follows. First, in the light-emitting element 2, the surface on which the anode electrode 2c is formed is the front surface 2a, and the surface on which the cathode electrode 2d is formed is the back surface 2b (see Figure 4). In the light-receiving driving element 5, the surface on which the source electrode 5c and drain electrode 5d are formed is the front surface 5a, and the surface opposite to the front surface 5a is the back surface 5b. In the first MOSFET element 3 and the second MOSFET element 4, the surfaces on which the first and second gate electrodes 3d and 4d and the first and second source electrodes 3e and 4e are formed are the front surfaces 3a and 4a, respectively, and the surfaces opposite to the front surfaces 3a and 4a are the back surfaces 3b and 4b. Also, in the first and second source electrodes 3e and 4e, the surfaces on which the first connector 13 and the second connector 14 are arranged are called the front surfaces.

[0018] Furthermore, in the connecting conductor 12, the surface that is joined to the respective ends of the first connector 13 and the second connector 14 is called the front surface 12a, and the surface opposite to the front surface 12a is called the back surface 12b. In each of the first input terminal 6, second input terminal 7, first output terminal 8, and second output terminal 9, the surface on which the element is placed or the surface to which the wire 11 is connected is called the front surface 6a, 7a, 8a, and 9a, and the surface opposite to the front surfaces 6a, 7a, 8a, and 9a is called the back surface 6b, 7b, 8b, and 9b.

[0019] As shown in Figures 1 and 2, the semiconductor relay 1 comprises a light-emitting element 2, a light-receiving driving element 5, a first MOSFET element 3, and a second MOSFET element 4. The semiconductor relay 1 also comprises a first input terminal 6, a second input terminal 7, a first output terminal 8, a second output terminal 9, and a housing 10.

[0020] The light-emitting element 2 is a known LED (Light Emitting Diode) element. As shown in Figure 4, an anode electrode 2c is formed on the surface 2a of the light-emitting element, and a cathode electrode 2d is formed on the back surface 2b. The cathode electrode 2d is connected and fixed to the surface 7a of the light-emitting element mounting portion 72 of the second input terminal 7 via a conductive adhesive (not shown), such as silver paste. In other words, the cathode electrode 2d is electrically connected to the second input terminal 7.

[0021] The light-receiving driving element 5 includes a light-receiving element 51 and a control circuit 52 (see Figure 10). The light-receiving element 51 is, for example, made up of an array of known photodiodes. As shown in Figures 3 and 5, a source electrode 5c and a drain electrode 5d are formed on the surface 5a of the light-receiving driving element 5. The drain electrode 5d is provided at two locations on the surface 5a that are spaced apart from each other. Although the light-receiving element 51 is also formed on the surface 5a of the light-receiving driving element 5, it is omitted from the illustration for the sake of explanation.

[0022] Furthermore, as shown in Figures 1, 2, and 9A, a connecting conductor 12 is arranged on the back surface 5b of the light-receiving driving element 5. As shown in Figures 3 and 7, the connecting conductor 12 is a flat conductive member. The shape and function of the connecting conductor 12 will be explained later.

[0023] As shown in Figures 1-3, the source electrode 5c of the light-receiving driving element 5 and the first source electrode 3e of the first MOSFET element 3 are electrically connected via a wire 11. One of the two drain electrodes 5d, 5d of the light-receiving driving element 5 is electrically connected to the first gate electrode 3d of the first MOSFET element 3 via a wire 11. The other of the two drain electrodes 5d, 5d is electrically connected to the second gate electrode 4d of the second MOSFET element 4 via a wire 11.

[0024] The first MOSFET element 3 is formed by forming a known vertical MOSFET on a semiconductor substrate. The first MOSFET element 3 is usually composed of multiple vertical MOSFETs connected in series or in parallel. However, it may also be a single vertical MOSFET. As shown in Figure 6, a first gate electrode 3d and a first source electrode 3e are formed on the surface 3a of the first MOSFET element 3, and a first drain electrode 3f is formed on the back surface 3b. The first drain electrode 3f is formed over the entire surface of the back surface 3b of the first MOSFET element 3.

[0025] As shown in Figure 6, the first source electrode 3e has a first electrode body portion 3e1 and a first enlarged electrode portion 3e2. As shown in Figures 1 to 3, inside the semiconductor relay 1, the longitudinal direction of the first electrode body portion 3e1 is the Z direction. The first enlarged electrode portion 3e2 is formed continuously with the first electrode body portion 3e1. Also, when viewed along the X direction, the first electrode body portion 3e1 has a portion that overlaps with the light-receiving driving element 5 (see Figures 1 to 3).

[0026] Furthermore, the second MOSFET element 4 has the same structure as the first MOSFET element 3 (see Figure 6). Therefore, the arrangement and shape of the second gate electrode 4d, the second source electrode 4e, and the second drain electrode 4f are the same as those of the first MOSFET element 3. In other words, the second source electrode 4e also has a second electrode body portion 4e1 and a second expanded electrode portion 4e2, and their shapes and arrangements are the same as those of the first electrode body portion 3e1 and the first expanded electrode portion 3e2, respectively. For example, when viewed along the X direction, the second electrode body portion 4e1 has a portion that overlaps with the light-receiving driving element 5 (see Figures 1-3).

[0027] Furthermore, as is clear from Figure 3, a first connector 13 is provided on the surface of the first electrode body portion 3e1 of the first source electrode 3e. A second connector 14 is provided on the surface of the second electrode body portion 4e1 of the second source electrode 4e.

[0028] Furthermore, the portions of the surface 3a of the first MOSFET element and the surface 4a of the second MOSFET element 4 on which the light-receiving driving element 5 is mounted are sometimes referred to as the first mounting portion 3a1 and the second mounting portion 4a1, respectively, while the portions on which the light-receiving driving element 5 is not mounted are sometimes referred to as the first non-mounting portion 3a2 and the second non-mounting portion 4a2, respectively.

[0029] The first mounting portion 3a1 is provided with the first electrode body portion 3e1 of the first source electrode 3e, and the second mounting portion 4a1 is provided with the second electrode body portion 4e1 of the second source electrode 4e. The first non-mounting portion 3a2 is provided with the first enlarged electrode portion 3e2 and the first gate electrode portion 3d of the first source electrode 3e, and the second mounting portion 4a1 is provided with the second enlarged electrode portion 4e2 and the second gate electrode portion 4d of the second source electrode 4e.

[0030] Furthermore, as shown in Figure 2, the first drain electrode 3f of the first MOSFET element 3 is fixed to the surface 8a of the first MOSFET mounting portion 82 of the first output terminal 8 with a conductive adhesive such as silver paste (not shown). Although not shown, similar to the first drain electrode 3f, the second drain electrode 4f of the second MOSFET element 4 is fixed to the surface 9a of the second MOSFET mounting portion 92 of the second output terminal 9 with a conductive adhesive.

[0031] As shown in Figure 3, the first connector 13 is composed of a plurality of first metal bumps 13A, and the second connector 14 is composed of a plurality of second metal bumps 14A. In this case, a plurality of first metal bumps 13A are formed on the surface of the first electrode body portion 3e1 of the first source electrode 3e, and the first connector 13 is provided. A plurality of second metal bumps 14A are formed on the surface of the second electrode body portion 4e1 of the second source electrode 4e.

[0032] The first input terminal 6 and the second input terminal 7 are conductive members obtained by processing a metal plate. For example, the material of the metal plate is copper. Alternatively, another metal film, such as a nickel-containing metal film (not shown), may be plated onto the surface of the copper plate to form a metal plate. Furthermore, the material of the metal film is not particularly limited.

[0033] In this embodiment, components such as the light-emitting element 2, the first MOSFET element 3, the second MOSFET element 4, and the light-receiving driving element 5 are mounted on a lead frame (not shown) made of a metal plate, and the lead frame and each component are resin-sealed with a light-shielding resin 10a. The semiconductor relay 1 is obtained such that the first input terminal 6, the second input terminal 7, the first output terminal 8, and the second output terminal 9 are formed by a part of the lead frame. In addition, a light-transmitting resin 10b is filled between the light-receiving driving element 5 and the light-emitting element 2.

[0034] The first input terminal 6 has a first input side external terminal portion 61, a wire connection portion 62, and a branch portion 63. The second input terminal 7 has a second input side external terminal portion 71, a light-emitting element mounting portion 72, and branch portions 73a to 73c. ​​In the semiconductor relay 1, the first input terminal 6 is arranged side by side with the second input terminal 7 in the Y direction, while being spaced apart from the second input terminal 7.

[0035] As shown in Figures 1 and 2, the first input terminal 6 and the second input terminal 7 each extend downward along the Z direction from one end located inside the housing 10, are bent near the bottom surface of the housing 10, and the other end extends along the X direction from the side surface of the housing 10 and further protrudes outside the housing 10. In each of the first input terminal 6 and the second input terminal 7, the parts that protrude outside the housing 10 are the first and second input side external terminal portions 61 and 71.

[0036] At the first input terminal 6, one end of the wire 11 is connected to the surface of the wire connection portion 62, and the other end of the wire 11 is connected to the anode electrode 2c of the light-emitting element 2. The branch portion 63 protrudes from the wire connection portion 62 in the Y direction and on the opposite side from the second input terminal 7. The tip of the branch portion 63 is exposed on the side surface of the housing 10. The branch portion 63 is a part of the aforementioned lead frame that remained at the first input terminal 6 when the semiconductor relay 1 was disconnected.

[0037] As described above, the light-emitting element 2 is placed on the surface 7a of the light-emitting element mounting portion 72 of the second input terminal 7. Also, the branch portions 73a to 73c are, like the branch portion 63, parts of the lead frame that remained on the second input terminal 7 when the semiconductor relay 1 was disconnected. The tips of the branch portions 73a to 73c are exposed on the side surface of the housing 10.

[0038] The first output terminal 8 has a first output side external terminal section 81, a first MOSFET mounting section 82, and a branching section 83. The second output terminal 9 has a second output side external terminal section 91, a second MOSFET mounting section 92, and a branching section 93.

[0039] As shown in Figure 2, the first output terminal 8 and the second output terminal 9 each extend downward along the Z direction from one end located inside the housing 10, are bent near the bottom surface of the housing 10, and the other end extends along the Y direction from the side surface of the housing 10 and further protrudes outside the housing 10. In the first output terminal 8, the portion that protrudes outside the housing 10 is the first output side external terminal portion 81. In the second output terminal 9, the portion that protrudes outside the housing 10 is the second output side external terminal portion 91.

[0040] The first MOSFET mounting section 82 and the second MOSFET mounting section 92 are each located inside the housing 10. The first MOSFET element 3 is mounted on the surface 8a of the first MOSFET mounting section 82, and the second MOSFET element 4 is mounted on the surface 9a of the second MOSFET mounting section 92. The first output terminal 8 is positioned alongside the second output terminal 9 in the Y direction, while being spaced apart from the second output terminal 9.

[0041] As shown in FIG. 2, the first MOSFET mounting portion 82 and the second MOSFET mounting portion 92 face each other in the X direction at a predetermined distance from the light-emitting element mounting portion 72 of the second input terminal 7.

[0042] Further, when viewed from the Z direction, the first output-side external terminal portion 81 faces the first input-side external terminal portion 61 of the first input terminal 6 in the Y direction. The second output-side external terminal portion 91 faces the second input-side external terminal portion 71 of the second input terminal 7 in the Y direction.

[0043] The housing 10 seals the first input terminal 6, the second input terminal 7, the first output terminal 8, and the second output terminal 9, and fixes their respective positions. It goes without saying that the light-emitting element 2 mounted on the second input terminal 7, the first MOSFET element 3 mounted on the first output terminal 8, the second MOSFET element 4 mounted on the second output terminal 9, and further the light-receiving driving element 5 are sealed by the housing 10 and their respective positions are fixed. As described above, the first output-side external terminal portion 81, the second output-side external terminal portion 91, the first input-side external terminal portion 61, and the second input-side external terminal portion 71 each protrude to the outside of the housing 10.

[0044] As shown in FIG. 2, the housing 10 is composed of an insulating light-shielding resin 10a and a translucent resin 10b. The light-shielding resin 10a is, for example, an epoxy resin containing a black pigment. However, the material is not particularly limited thereto, and any material that shields light may be used. The translucent resin 10b is provided between the light-receiving driving element 5 and the light-emitting element 2, and is sealed by the light-shielding resin 10a. The translucent resin 10b is, for example, a transparent silicone resin. However, it is not particularly limited thereto, and any insulating resin that is transparent to at least the light emitted by the light-emitting element 2 may be used. The translucent resin 10b constitutes an optical coupling portion that optically couples the light-receiving element 51 of the light-receiving driving element 5 and the light-emitting element 2.

[0045] Furthermore, the first input terminal 6 and the second input terminal 7, and the first output terminal 8 and the second output terminal 9 are electrically isolated from each other by the housing 10. In addition, the light-emitting element 2 and the light-receiving driving element 5 are optically coupled. In other words, the semiconductor relay 1 is an input / output isolated type semiconductor relay that switches the output signal on and off by optical coupling while the input circuit IPC and the output circuit OPC (see Figure 10 for both) are electrically isolated.

[0046] [Connection structure between connecting conductor and first and second connecting elements] Figure 7 is a plan view of the connecting conductor. Figure 8 is a view of the first and second MOSFET elements inside the semiconductor relay and the connecting conductor from direction B shown in Figure 1. Figure 9A is a schematic cross-sectional view of the connecting conductor connected to the source electrode. Figure 9B is a schematic cross-sectional view of another connecting conductor connected to the source electrode. For the sake of explanation, the connecting conductor 12 is shown with a dashed line in Figure 8. Also, in Figures 7, 9A, and 9B, the shapes of each component are simplified. For example, the shapes of the first metal bump 13A and the second metal bump 14A shown in Figures 9A and 9B are different from the actual shapes.

[0047] The connecting conductor 12 is obtained, for example, by processing a lead frame made of nickel or copper. Also, as shown in Figures 7 and 9A, the connecting conductor 12 has first to third connecting conductor portions 121 to 123. The first connecting conductor portion 121 is the portion of the connecting conductor 12 that is positioned between the light-receiving driving element 5 and the first electrode body portion 3e1 of the first source electrode 3e and is electrically connected to the first connector 13. The second connecting conductor portion 122 is the portion of the connecting conductor 12 that is positioned between the light-receiving driving element 5 and the second electrode body portion 4e1 of the second source electrode 4e and is electrically connected to the second connector 14. The third connecting conductor portion 123 is the portion of the connecting conductor 12 that electrically connects the first connecting conductor portion 121 and the second connecting conductor portion 122 and overlaps with the light-receiving driving element 5 when viewed along the X direction.

[0048] Further, two extending portions 12c are provided on the connecting conductor 12. As shown in FIGS. 7 and 9A, one extending portion 12c is physically connected to the first connecting conductor portion 121 and protrudes in the Y direction from a side surface of the first connecting conductor portion 121. The other extending portion 12c is physically connected to the second connecting conductor portion 122 and protrudes in the Y direction from a side surface of the second connecting conductor portion 122. When viewed along the first direction, the two extending portions 12c are arranged so as not to overlap the first MOSFET element 3 and the second MOSFET element 4. Note that one of the two extending portions 12c may be omitted.

[0049] As shown in FIG. 8, the first connection body 13, that is, six first metal bumps 13A, are provided on a surface of the first electrode main body portion 3e1 of the first source electrode 3e. More specifically, three of the six first metal bumps 13A are arranged in a row at the same interval P in the Z direction, and the remaining three first metal bumps 13A are also arranged in a row at the same interval P in the Z direction. However, the two rows of first metal bumps 13A arranged in the Y direction are provided on the surface of the first electrode main body portion 3e1 in a manner shifted by P / 2 in the Z direction.

[0050] Similarly, the second connection body 14, that is, six second metal bumps 14A, are provided on a surface of the second electrode main body portion 4e1 of the second source electrode 4e. More specifically, three of the six second metal bumps 14A are arranged in a row at the same interval P in the Z direction, and the remaining three second metal bumps 14A are also arranged in a row at the same interval P in the Z direction. However, the two rows of second metal bumps 14A arranged in the Y direction are provided on the surface of the second electrode main body portion 4e1 in a manner shifted by P / 2 in the Z direction.

[0051] Further, the connecting conductor 12 is attached to the first connection body 13 and the second connection body 14 such that a center line CL2 of the connecting conductor 12 in the Y direction coincides with respective center lines of the first connection body 13 and the second connection body 14 in the Y direction. When viewed along the X direction, the first connection body 13 and the second connection body 14 are each arranged symmetrically with respect to a center line CL1 of the housing 10 in the Z direction.

[0052] The number of first metal bumps 13A and second metal bumps 14A is not particularly limited to the example shown in Figure 8 and can be changed as appropriate. However, when two or more first metal bumps 13A are arranged, it is preferable that they be arranged in two rows in the Y direction and at different positions along the Z direction. Also, when three or more first metal bumps 13A are arranged, it is preferable that they be arranged at the same intervals along the Z direction. These also apply to the second metal bumps 14A. However, even in these cases, the two rows of first metal bumps 13A aligned in the Y direction are provided on the surface of the first electrode body 3e1 with a shift of P / 2 in the Z direction.

[0053] Furthermore, as shown in Figure 8, when the width of the first connector 13 and the second connector 14 along the Z direction is W2, and the width of the connecting conductor 12 along the Z direction is W1, it is preferable that the relationship shown in equation (1) is satisfied.

[0054] 0.5 × W1 ≤ W2 < W1 ... (1) Also, the length of the connecting conductor 12 in the Y direction is wider than the distance between the first connecting body 13 and the second connecting body 14 along the Y direction.

[0055] As explained above, by defining the arrangement and size of the first metal bump 13A, the second metal bump 14A, and the connecting conductor 12, the tilt of the connecting conductor 12 can be suppressed when attaching the connecting conductor 12 to the first connector 13 and the second connector 14. In addition, it is possible to prevent the connecting conductor 12 from contacting the first MOSFET element 3 and / or the second MOSFET element 4, thereby preventing short-circuit failures.

[0056] In this embodiment, the first metal bump 13A and the second metal bump 14A are gold bumps and stud bumps. However, the material of the first metal bump 13A and the second metal bump 14A is not particularly limited. Also, depending on the size of the first source electrode 3e and the second source electrode 4e, the first connector 13 may be one first metal bump 13A and the second connector 14 may be one second metal bump 14A.

[0057] As shown in Figure 9A, the tips of a plurality of first metal bumps 13A formed on the surface of the first electrode body portion 3e1 of the first source electrode 3e of the first MOSFET element 3 are metal-bonded to the surface 12a of the connecting conductor 12. Similarly, the tips of a plurality of second metal bumps 14A formed on the surface of the second electrode body portion 4e1 of the second source electrode 4e of the second MOSFET element 4 are metal-bonded to the surface 12a of the connecting conductor 12. As a result, the first source electrode 3e of the first MOSFET element 3 and the second source electrode 4e of the second MOSFET element 4 are electrically connected via the plurality of first metal bumps 13A and second metal bumps 14A and the connecting conductor 12.

[0058] The connecting conductor 12 and the first metal bump 13A and the second metal bump 14A are joined, for example, by the following procedure.

[0059] First, the connecting conductor 12 is moved above the first metal bump 13A on the first MOSFET element 3 and the second metal bump 14A on the second MOSFET element 4 using a suction tool (not shown). After the connecting conductor 12 is brought into contact with the tips of the first metal bump 13A and the second metal bump 14A, a pressurizing and heating process is performed to attach the connecting conductor 12 to the first MOSFET element 3 and the second MOSFET element 4. Next, the connecting conductor 12 is attached to the light-receiving driving element 5 so that the back surface 12b of the connecting conductor 12 is in contact with the back surface 5b of the light-receiving driving element 5.

[0060] During the pressurization and heating process, a solid-phase diffusion reaction proceeds at the interface between the metal constituting the connecting conductor 12 and the first metal bump 13A and the second metal bump 14A, resulting in metal bonding between the connecting conductor 12 and the first metal bump 13A, and between the connecting conductor 12 and the second metal bump 14A.

[0061] Furthermore, the portion of the connecting conductor 12 that is metal-jointed with the first metal bump 13A and the second metal bump 14A, that is, the surface side of the connecting conductor 12, may be made of the same type of metal as the first metal bump 13A and the second metal bump 14A. For example, as shown in Figure 9B, the connecting conductor 12 may have a three-layer structure. For the sake of explanation, in Figure 9B, only the first connecting conductor portion 121 of the connecting conductor 12 is shown, and only the first MOSFET element 3 and the first metal bump 13A are shown. Although not shown, the configuration of the second connecting conductor portion 122 and the connection method between the second connecting conductor portion 122 and the second metal bump 14A are the same as shown in Figure 9A.

[0062] In the example shown in Figure 9B, the first metal layer 12d, the third metal layer 12f, and the second metal layer 12e are laminated in this order from the back surface 12b to the front surface 12a. The first metal layer 12d is, for example, mainly composed of copper and has the thickness necessary to ensure the strength of the connecting conductor 12 and to achieve a desired electrical resistance. The second metal layer 12e is made of the same material as the first metal bump 13A, i.e., gold. The third metal layer 12f is made of nickel and functions as a seed layer when the second metal layer 12e is formed on the first metal layer 12d by a plating method. Furthermore, by providing the third metal layer 12f, the second metal layer 12e can be reliably adhered to the first metal layer 12d, and the diffusion of gold into the first metal layer 12d can be prevented. The thickness of the second metal layer 12e is set to a value necessary for reliably forming a metal bond with the first metal bump 13A and the second metal bump 14A.

[0063] Furthermore, if the adhesion between the first metal layer 12d and the second metal layer 12e is good, or if a seed layer is not required to form the second metal layer 12e, the third metal layer 12f can be omitted.

[0064] [Circuit Configuration and Operation of Semiconductor Relay] Figure 10 is an equivalent circuit diagram of a semiconductor relay according to Embodiment 1. Note that the inductance L1 shown in Figure 8 is the parasitic inductance between the source (S) of the first MOSFET element 3 and the source (S) of the second MOSFET element 4, and is not an actual component of the semiconductor relay 1.

[0065] As shown in Figure 10, the input circuit IPC of the semiconductor relay 1 has a first input terminal 6, a second input terminal 7, and a light-emitting element 2. The output circuit OPC has a first output terminal 8, a second output terminal 9, a first MOSFET element 3, and a second MOSFET element 4. The connecting conductor 12, the first connector 13, and the second connector 14 are also included in the output circuit OPC. The drive circuit DRC has a light-receiving element 51 and a control circuit 52.

[0066] When an input signal is input between the first input terminal 6 and the second input terminal 7, the light-emitting element 2 outputs an optical signal of a predetermined wavelength. The optical signal generated by the light-emitting element 2 is the first drive signal, and the first drive signal propagates inside the light-transmitting resin 10b and is received by the light-receiving element 51.

[0067] In the light-receiving element 51, a current is generated by photoelectric conversion, and the control circuit 52 operates based on this current. A second drive signal, which is a voltage signal corresponding to the light intensity of the light-emitting element 2, is applied via the wire 11 to the first gate electrode 3d of the first MOSFET element 3 and the second gate electrode 4d of the second MOSFET element 4, respectively.

[0068] When the voltage of the second drive signal exceeds the threshold voltages of the first MOSFET element 3 and the second MOSFET element 4, the source (S)-drain (D) junctions of the first MOSFET element 3 and the source (S)-drain (D) junctions of the second MOSFET element 4 are turned ON. Furthermore, the first output terminal 8 and the second output terminal 9 become conductive through the first MOSFET element 3 and the second MOSFET element 4. As a result, a signal is transmitted between the first output terminal 8 and the second output terminal 9.

[0069] When no input signal is received between the first input terminal 6 and the second input terminal 7, the light emission from the light-emitting element 2 also stops. Accordingly, no current is generated in the light-receiving element 51, and the control circuit 52 stops.

[0070] As a result, the voltage of the second drive signal applied to the first gate electrode 3d of the first MOSFET element 3 and the second gate electrode 4d of the second MOSFET element 4 decreases. When the voltage of the second drive signal falls below the threshold voltage mentioned above, the source (S)-drain (D) junction of the first MOSFET element 3 and the source (S)-drain (D) junction of the second MOSFET element 4 are turned off. Furthermore, the connection between the first output terminal 8 and the second output terminal 9 becomes non-conductive. This interrupts signal transmission between the first output terminal 8 and the second output terminal 9.

[0071] [Effects, etc.] As described above, the semiconductor relay 1 according to this embodiment comprises at least an input circuit IPC, a drive circuit DRC, and an output circuit OPC, and the input circuit IPC and the output circuit OPC are electrically isolated from each other.

[0072] The input circuit IPC has at least a first input terminal 6, a second input terminal 7, and an input element, a light-emitting element 2. Based on the input signal input between the first input terminal 6 and the second input terminal 7, the input circuit IPC outputs an optical signal, which is a first drive signal, to the photodetector 51 of the drive circuit DRC.

[0073] The drive circuit DRC outputs a second drive signal to the output circuit OPC based on the first drive signal.

[0074] The output circuit OPC has at least a first output terminal 8, a second output terminal 9, and an output element, and based on a second drive signal, it either makes the first output terminal 8 and the second output terminal 9 conductive or non-conductive.

[0075] The output element comprises a first MOSFET element 3 and a second MOSFET element 4, both electrically connected to the drive circuit DRC.

[0076] The first MOSFET element 3 has a first gate electrode 3d and a first source electrode 3e formed on its surface 3a, and a first connector 13 is provided on the surface of the first source electrode 3e.

[0077] The second MOSFET element 4 has a second gate electrode 4d and a second source electrode 4e formed on its surface 4a, and a second connector 14 is provided on the surface of the second source electrode 4e.

[0078] The first connector 13 and the second connector 14 are each at least one metal bump.

[0079] The semiconductor relay 1 is joined to the ends of the first connector 13 and the second connector 14, and further has a plate-shaped connecting conductor 12 made of a metal material.

[0080] The first source electrode 3e and the second source electrode 4e are electrically connected via the first connector 13, the connecting conductor 12, and the second connector 14.

[0081] According to this embodiment, the connecting conductor 12 and the first connector 13 and the second connector 14 are metal-jointed, which increases the connection strength between the connecting conductor 12 and the first connector 13 and the second connector 14. In addition, by ensuring that the connecting conductor 12 and the first connector 13 and the second connector 14 are securely connected, the connection resistance between the first source electrode 3e of the first MOSFET element 3 and the second source electrode 4e of the second MOSFET element 4 can be reduced, thereby improving connection reliability.

[0082] Furthermore, according to this embodiment, the parasitic inductance component can be reduced by connecting the first source electrode 3e of the first MOSFET element 3 and the second source electrode 4e of the second MOSFET element 4 with a connecting conductor 12. Normally, the wire diameter of the wire 11 is about 0.0 mm, while the width W1 in the Z direction of the connecting conductor 12 is several to more than 10 times larger than this value. For this reason, the inductance per unit length along the signal path inside the semiconductor relay 1 is smaller in the semiconductor relay 1 of this embodiment using the connecting conductor 12 than in the case using the wire 11.

[0083] In other words, according to this embodiment, the parasitic inductance component can be reduced, and as a result, insertion loss can be reduced. Furthermore, by reducing the inductance along the signal path, the mismatch in the characteristic impedance of the signal path can be reduced. This improves the reflection characteristics within the signal path, and consequently, insertion loss can be further reduced.

[0084] Furthermore, it is preferable that the first metal bump 13A constituting the first connector 13 and the second metal bump 14A constituting the second connector 14 are gold bumps. By doing so, the electrical resistance of the first connector 13 and the second connector 14, and consequently the connection resistance between the first source electrode 3e and the second source electrode 4e, can be further reduced. Note that the gold may contain unavoidable impurities that are mixed in during the manufacturing process. In other words, the first metal bump 13A and the second metal bump 14A can be metal bumps in which gold is the main constituent metal.

[0085] It is preferable that the connecting conductor 12, the first connector 13, and the second connector 14 each contain the same type of metal. By doing so, the joint structure between the connecting conductor 12, the first connector 13, and the second connector 14 becomes a joint of the same type of metal, thereby reducing contact resistance and further reducing the connection resistance between the first source electrode 3e and the second source electrode 4e.

[0086] Furthermore, the thermal expansion coefficient of the connecting conductor 12 can be made closer to that of the first connector 13 and the second connector 14, making it less likely for distortion and stress to occur in the joint structure between the connecting conductor 12 and the first connector 13 and the second connector 14 due to temperature changes. This improves the reliability of the connection between the first source electrode 3e and the second source electrode 4e.

[0087] Furthermore, since the connecting conductor 12, the first connecting body 13, and the second connecting body 14 are made of the same type of metal, electrochemical corrosion due to contact between dissimilar metals does not occur at the metal joint portion, thereby improving corrosion resistance.

[0088] Preferably, the first connector 13 is composed of a plurality of first metal bumps 13A, and the second connector 14 is composed of a plurality of second metal bumps 14A. This arrangement suppresses the tilting of the connecting conductor 12 when attaching it to the first connector 13 and the second connector 14. It also prevents the connecting conductor 12 from contacting the first MOSFET element 3 and / or the second MOSFET element 4, thus preventing short-circuit failures. Furthermore, by increasing the contact area between the connecting conductor 12 and the first connector 13, and further increasing the contact area between the connecting conductor 12 and the second connector 14, the connection resistance between the first source electrode 3e and the second source electrode 4e can be reduced.

[0089] The connecting conductor 12 includes at least a first metal layer 12d and a second metal layer 12e. The first connector 13 and the second connector 14 are joined to the surface of the first metal layer 12d, i.e., the surface 12a of the connecting conductor 12. The second metal layer 12e is provided in contact with the back surface of the first metal layer 12d either directly or via a third metal layer 12f. The material of the second metal layer 12e is different from the material of the first metal layer 12d.

[0090] In this way, it is possible to ensure the strength of the connecting conductor 12 while strengthening the metal joint between the first metal layer 12d and the first connector 13 and the second connector 14. For example, by making the material of the first metal layer 12d the same as the material of the first connector 13 and the second connector 14, contact resistance, stress, and strain can be reduced. In addition, the corrosion resistance of the metal joint can be improved.

[0091] When the first metal layer 12d is gold, it is preferable that the second metal layer 12e be mainly composed of copper, nickel, or silicon (Si). This ensures the strength of the connecting conductor 12. In particular, when the second metal layer 12e is copper, the resistance of the connecting conductor 12 can be reduced. Note that the copper, nickel, and silicon may contain unavoidable impurities introduced during the manufacturing process.

[0092] The connecting conductor 12 has a first connecting conductor portion 121, a second connecting conductor portion 122, a third connecting conductor portion 123, and an extended portion 12c. When viewed along the first direction described above, the first connecting conductor portion 121 overlaps the first MOSFET element 3, and the second connecting conductor portion 122 overlaps the second MOSFET element 4. The third connecting conductor portion 123 is located between the first connecting conductor portion 121 and the second connecting conductor portion 122, and electrically connects the first connecting conductor portion 121 to the second connecting conductor portion 122. Also, when viewed along the first direction, the third connecting conductor portion 123 does not overlap the first MOSFET element 3 and the second MOSFET element 4. In the example shown in Figure 9A, the first to third connecting conductor portions 121 to 123 and the extended portion 12c each have the same thickness along the X direction. However, the invention is not limited to this, and the first to third connecting conductor portions 121 to 123 and the extended portion 12c may each have different thicknesses, or two or more portions may have the same thickness.

[0093] The extended portion 12c is physically connected to the first connecting conductor portion 121 and / or the second connecting conductor portion 122, and when viewed along the first direction, the extended portion 12c does not overlap the first MOSFET element 3 and the second MOSFET element 4.

[0094] The connecting conductor 12 is a plate-shaped metal plate, and a simple method for obtaining it is to cut the lead frame, as is done with the first input terminal 6 and the first output terminal 8. This also reduces the manufacturing cost of the connecting conductor 12. In this case, the connecting portion of the lead frame remains on the connecting conductor 12 as an extended portion 12c.

[0095] Furthermore, if the connecting conductor 12 is obtained by processing a lead frame, burrs may form on the punched or cut end face. In this case, if the burrs come into contact with the first MOSFET element 3 or the second MOSFET element 4, it may cause a short circuit failure or form an unintended current path inside the semiconductor relay 1, leading to performance defects.

[0096] To prevent this, even if burrs occur on the connecting conductor 12, it is necessary to impose restrictions on their size.

[0097] Figure 11 is a schematic cross-sectional view showing the positional relationship between the connecting conductor and the first MOSFET element when there are burrs on the connecting conductor.

[0098] In the example shown in Figure 11, a burr (first projection) 12g is formed that protrudes in the X direction toward the first MOSFET element 3 from the extended portion 12c connected to the first connecting conductor portion 121. In addition, a burr (second projection) 12h is formed that protrudes in the X direction toward the second MOSFET element 4 from the extended portion 12c connected to the second connecting conductor portion 122.

[0099] In order to prevent contact between the connecting conductor 12 and the first MOSFET element 3 and the second MOSFET element 4, the following conditions must be met. First, the height h3 of the burr 12g along the X direction, with respect to the surface 12a1 of the first connecting conductor portion 121, must be lower than the height h1 of the first connector 13 along the X direction, with respect to the surface 3a of the first MOSFET element 3. Furthermore, the height h4 of the burr 12h along the X direction, with respect to the surface 12a2 of the second connecting conductor portion 122, must be lower than the height h2 of the second connector 14 along the X direction, with respect to the surface 4a of the second MOSFET element 4.

[0100] Even if burrs 12g and 12h occur, limiting their respective heights h3 and h4 as described above can reduce the occurrence of short-circuit failures and performance defects in the semiconductor relay 1.

[0101] Furthermore, if the shape of the connecting conductor 12 differs from the shape shown in Figure 7, it is necessary to limit the height of burrs that occur at other locations as described above.

[0102] Figure 12 is a plan view of another connecting conductor. The connecting conductor 12 shown in Figure 12 differs from the connecting conductor 12 shown in Figure 7 in that it is physically connected to the third connecting conductor portion 123 and has an extended portion 12i that protrudes from the side surface of the third connecting conductor portion 123 along the Z direction. Similar to the extended portion 12c, when viewed along the X direction, the extended portion 12i does not overlap the first connecting conductor portion 121 and the second connecting conductor portion 122. In addition, in the connecting conductor 12 shown in Figures 7 and 12, when viewed along the Z direction, the burrs are located outside the Y-direction sides of the first MOSFET element 3 and the second MOSFET element 4. Furthermore, the connecting conductor 12, including the extended portions 12c and 12i, is located inside the housing 10 and is completely covered by the light-shielding resin 10a.

[0103] If the shape of the connecting conductor 12 is as shown in Figure 12, not only burrs protruding in the X direction from the side surface of the extended portion 12i, but also burrs protruding in the X direction from the side surface of the first connecting conductor portion 121 and the side surface of the second connecting conductor portion 122 may cause short-circuit failures. Therefore, in the latter case as well, it is necessary to limit the height of the burrs so as to satisfy the aforementioned conditions.

[0104] The drive circuit DRC is provided on the light-receiving drive element 5, and the light-receiving drive element 5 is mounted on the back surface 12b of the connecting conductor 12. This allows for miniaturization of the semiconductor relay 1.

[0105] Furthermore, the light-receiving driving element 5 is positioned to cover the surfaces of the first MOSFET element 3 and the second MOSFET element 4, respectively. By doing so, the first MOSFET element 3 and the second MOSFET element 4 and the light-receiving driving element 5 can be placed in close proximity, thereby further miniaturizing the semiconductor relay 1.

[0106] Furthermore, in the semiconductor relay 1, the light-emitting element 2 and the light-receiving element 51 are arranged facing each other with a predetermined distance between them in the X direction. This arrangement suppresses the increase in size of the semiconductor relay 1 in the Z direction, enabling a lower profile and miniaturization of the semiconductor relay 1.

[0107] Furthermore, in the drive circuit DRC, the photodetector, which receives the optical signal as the first drive signal from the light-emitting element 2, generates a current corresponding to the magnitude of the first drive signal, that is, the magnitude of the light intensity of the optical signal. Based on this current, the control circuit 52 outputs a second drive signal to the output circuit OPC.

[0108] In this way, the input circuit IPC and the output circuit OPC can be electrically isolated while the output signal can be switched on and off by optical coupling.

[0109] <Modification 1> Figure 13 is a diagram corresponding to Figure 2 of the semiconductor relay according to Modification 1. In Figure 13 and the subsequent drawings, the same reference numerals are used for parts that are the same as in Embodiment 1, and detailed explanations are omitted.

[0110] The semiconductor relay 1 shown in Figure 13 differs from the semiconductor relay 1 shown in Embodiment 1 in that it further includes an adhesive sheet 15 interposed between the light-receiving driving element 5 and the connecting conductor 12.

[0111] By providing the adhesive sheet 15 in the aforementioned position, the back surface 12b of the connecting conductor 12 can be securely bonded to the back surface 5b of the light-receiving driving element 5. This fixes the position of the connecting conductor 12 and ensures that the connecting conductor 12 is securely attached to the first connector 13 and the second connector 14.

[0112] <Modification 2> Figure 14 is a diagram corresponding to Figure 2 of the semiconductor relay according to Modification 2.

[0113] The semiconductor relay 1 shown in Figure 14 differs from the semiconductor relay 1 shown in Embodiment 1 in the following respects. First, the second input terminal 7 and the second output terminal 9 are flat plates whose surface normals are aligned in the Z direction. Although not shown, the first input terminal 6 and the first output terminal 8 are also flat plates whose surface normals are aligned in the Z direction. The back surfaces of the first input terminal 6, the second input terminal 7, the first output terminal 8, and the second output terminal 9 are exposed to the outside from the back surface of the housing 10. In other words, the back surfaces of the first input terminal 6, the second input terminal 7, the first output terminal 8, and the second output terminal 9 correspond to the first input side external terminal portion 61, the second input side external terminal portion 71, the first output side external terminal portion 81, and the second output side external terminal portion 91 shown in Embodiment 1.

[0114] Furthermore, the first MOSFET element 3, the second MOSFET element 4, the connecting conductor 12, the light-receiving driving element 5, and the light-emitting element 2 are stacked in this order along the Z direction. Therefore, the first direction in this modified example is the Z direction. As in Embodiment 1, a first connector 13 is interposed between the first MOSFET element 3 and the connecting conductor 12, and a second connector 14 is interposed between the second MOSFET element 4 and the connecting conductor 12. On the other hand, in this modified example, the light-emitting element 2 is placed on the surface of the light-receiving element 51 of the light-receiving driving element 5 via a light-transmitting resin 10b.

[0115] According to this embodiment, the semiconductor relay 1 can be miniaturized in the Z direction. Furthermore, this embodiment can achieve the same effects as the configuration shown in Embodiment 1. Specifically, the connection resistance between the first source electrode 3e of the first MOSFET element 3 and the second source electrode 4e of the second MOSFET element 4 can be reduced, thereby improving connection reliability. In addition, the parasitic inductance component on the output side of the semiconductor relay 1 can be reduced, thereby reducing insertion loss.

[0116] In addition, a transparent plate such as a glass plate may be interposed between the surface of the light-receiving element 51 and the light-emitting element 2, rather than the light-transmitting resin 10b. In other words, the light-emitting element 2 may be placed on the surface of the light-receiving element 51 via a light-transmitting material.

[0117] (Embodiment 2) Figure 15 is an equivalent circuit diagram of a semiconductor relay according to Embodiment 2. Figure 16 is a perspective view of the semiconductor relay. Figure 17 is a view of the semiconductor relay from above. Figure 18 is a view of the semiconductor relay from direction C shown in Figure 16.

[0118] The semiconductor relay described in this specification is not limited to the optically coupled semiconductor relay shown in Embodiment 1. In this embodiment, a semiconductor relay 20 that switches an output signal on and off by capacitive coupling while the input circuit IPC and the output circuit OPC are electrically isolated will be described.

[0119] As shown in Figure 15, the semiconductor relay 20 of this embodiment differs from the semiconductor relay 1 of Embodiment 1 in that an oscillation circuit 31 is provided instead of a light-emitting element 2 as the input circuit IPC. Furthermore, it differs from the semiconductor relay 1 of Embodiment 1 in that it has a boost circuit 32 and a control circuit 33 as the drive circuit DRC.

[0120] The boost circuit 32 is a known charge pump type boost circuit having capacitors C1 and C2 and diodes Di1 to Di3. Capacitors C1 and C2, which are connected in series between the oscillator circuit 31 and the boost circuit 32, isolate the input circuit IPC and the output circuit OPC of the semiconductor relay 20. The number of diodes and their connection relationships arranged after the boost circuit 32 are not particularly limited to the example shown in Figure 15.

[0121] In this embodiment, the driving element 30 is an IC in which the oscillation circuit 31, the boost circuit 32, and the control circuit 33 are integrated on a single semiconductor chip. However, it is not limited to this, and for example, the oscillation circuit 31, the boost circuit 32, and the control circuit 33 may each be separate components, and the three components may be connected by wires 11 or electrically connected on a printed circuit board. Alternatively, the boost circuit 32 and the control circuit 33 may be integrated on a single semiconductor chip, and the oscillation circuit 31 and this semiconductor chip may be connected by wires 11 or electrically connected on a printed circuit board.

[0122] The operation of the semiconductor relay 20 will be described below.

[0123] When an input signal is input between the first input terminal 6 and the second input terminal 7, the oscillation circuit 31 generates a first oscillation signal S1 and a second oscillation signal S2, which are pulse signals having a predetermined oscillation frequency and inverted phases relative to each other. The first oscillation signal S1 and the second oscillation signal S2 correspond to the first drive signal in Embodiment 1.

[0124] In the boost circuit 32, a signal is generated by adding the second oscillation signal S2, which has passed through capacitor C2 and diode Di2, to the first oscillation signal S1, which has passed through capacitor C1 and diode Di1. This signal is input to the control circuit 33.

[0125] The control circuit 33 is a charge / discharge circuit, and it inputs a second drive signal corresponding to the signal generated by the boost circuit 32 to the gate electrodes G of the first MOSFET element 3 and the second MOSFET element 4, respectively.

[0126] When the voltage of the second drive signal output from the control circuit 33 becomes higher than the threshold voltages of the first MOSFET element 3 and the second MOSFET element 4, the first MOSFET element 3 and the second MOSFET element 4 turn on, respectively. As a result, the first output terminal 8 and the second output terminal 9 become conductive. This allows a signal to be transmitted between the first output terminal 8 and the second output terminal 9.

[0127] On the other hand, when no input signal is input between the first input terminal 6 and the second input terminal 7, the oscillation circuit 31 does not operate, and the second drive signal is not input from the boost circuit 32 to the control circuit 33. As a result, the control circuit 33 extracts and discharges the charge stored in the gate electrodes G of the first MOSFET element 3 and the second MOSFET element 4. Consequently, the first MOSFET element 3 and the second MOSFET element 4 are turned off, and the connection between the first output terminal 8 and the second output terminal 9 becomes non-conductive. This interrupts signal transmission between the first output terminal 8 and the second output terminal 9.

[0128] Furthermore, as shown in Figures 16 to 18, in the semiconductor relay 20, the drive element 30, the first MOSFET element 3, and the second MOSFET element 4 are arranged with a gap in the X direction so that their sides face each other.

[0129] The surface 30a of the driving element 30 has a first electrode 30c, a second electrode 30d, two third electrodes 30e, and a fourth electrode 30f formed on the surface 30a of the driving element 30. The first electrode 30c is electrically connected to the surface 6a of the first input terminal 6 via a wire 11. The second electrode 30d is electrically connected to the surface 7a of the second input terminal 7 via a wire 11. One of the two third electrodes 30e is electrically connected to the first gate electrode 3d of the first MOSFET element 3 via a wire 11, and the other is electrically connected to the second gate electrode 4d of the second MOSFET element 4 via a wire 11. The fourth electrode 30f is electrically connected to the second source electrode 4e of the second MOSFET element 4 via a wire 11.

[0130] Furthermore, an insulating adhesive sheet 30g is formed on the back surface 30b of the drive element 30, and the adhesive sheet 30g is exposed to the outside from the back surface of the housing 10.

[0131] Furthermore, a first MOSFET element 3 is positioned on the surface 8a of the first output terminal 8, and a second MOSFET element 4 is positioned on the surface 9a of the second output terminal 9. Although not shown in the figures, a first connector 13 consisting of six first metal bumps 13A is provided on the first source electrode 3e of the first MOSFET element 3, and a second connector 14 consisting of six second metal bumps 14A is provided on the second source electrode 4e of the second MOSFET element 4. The arrangement of the first metal bumps 13A relative to the first source electrode 3e and the arrangement of the second metal bumps 14A relative to the second source electrode 4e are the same as those shown in Figure 8.

[0132] The connecting conductor 12 is positioned above the first MOSFET element 3 and the second MOSFET element 4, and is connected to the first metal bump 13A and the second metal bump 14A, respectively. However, the connecting conductor 12 and the driving element 30 are spaced apart in the X direction.

[0133] According to this embodiment, the same effects as those achieved by the configuration shown in Embodiment 1 can be achieved. Specifically, the connection resistance between the first source electrode 3e of the first MOSFET element 3 and the second source electrode 4e of the second MOSFET element 4 can be reduced, thereby improving connection reliability. Furthermore, the parasitic inductance component on the output side of the semiconductor relay 20 can be reduced, thereby reducing insertion loss.

[0134] Furthermore, according to this embodiment, the output signal can be switched on and off by capacitive coupling while the input circuit IPC and the output circuit OPC are electrically isolated from each other.

[0135] Alternatively, the semiconductor relay 20 may be a magnetically coupled type. In this case, a pair of inductors (not shown) are used instead of capacitors C1 and C2. One inductor is connected in parallel to the oscillation circuit 31. The other inductor is connected in parallel to the boost circuit 32. The oscillation circuit 31 outputs a first drive signal that varies periodically over time. The first drive signal is transmitted to the boost circuit 32 via the magnetic coupling between the pair of inductors.

[0136] In this case, the output signal can be switched on and off by the magnetic coupling of a pair of inductors while the input circuit IPC and the output circuit OPC are electrically isolated from each other.

[0137] The semiconductor relay of this disclosure is useful because it can reduce connection resistance and has high connection reliability in the connection between the connecting conductor and the connector that connects the source electrodes of the output element.

[0138] 1. Semiconductor relay 2. Light-emitting element 3. First MOSFET element 3a Front surface 3a1 First mounting area 3a2 First non-mounting area 3b Back surface 3d First gate electrode 3e First source electrode 3e1 First electrode body 3e2 First enlarged electrode 3f First drain electrode 4. Second MOSFET element 4a Front surface 4a1 Second mounting area 4a2 Second non-mounting area 4b Back surface 4d Second gate electrode 4e Second source electrode 4e1 Second electrode body 4e2 Second enlarged electrode 4f Second drain electrode 5. Light-receiving driving element 5a Front surface 5b Back surface 51 Light-receiving element 52 Control circuit 6. First input terminal 61 First input side external terminal 62 Wire connection part 63 Branch part 7. Second input terminal 71 Second input side external terminal 72 Light-emitting element mounting section 73 Branch section 73a-73c Branch section 8 First output terminal 81 First output side external terminal section 82 First MOSFET mounting section 83 Branch section 9 Second output terminal 91 Second output side external terminal section 92 Second MOSFET mounting section 93 Branch section 10 Housing 10a Light-shielding resin 10b Light-transmitting resin 11 Wire 12 Connecting conductor 121 First connecting conductor section 122 Second connecting conductor section 123 Third connecting conductor section 12a Surface (surface of connecting conductor) 12a1 Surface (surface of first connecting conductor section) 12a2 Surface (surface of second connecting conductor section) 12b Back (back of connecting conductor) 12c Extended section (first extended section, second extended section) 12d First metal layer 12e Second metal layer 12f Third metal layer 12g Burr (first protrusion) 12h Burr (second protrusion) 12i Extending part (third extending part) 13 First connector 13A First metal bump 14 Second connector 14A Second metal bump 15 Adhesive sheet 30 Driving element 31 Oscillator circuit 30a Front surface 30b Back surface 30c-30f First to fourth electrodes 30g Adhesive sheet 32 ​​Boost circuit 33 Control circuit

Claims

1. The device comprises an input circuit, a drive circuit, an output circuit, and a connecting conductor made of a metal material and in the shape of a plate, wherein the input circuit and the output circuit are electrically insulated from each other, the input circuit has a first input terminal, a second input terminal and an input element, and outputs a first drive signal to the drive circuit based on an input signal input between the first input terminal and the second input terminal, the drive circuit outputs a second drive signal to the output circuit based on the first drive signal, the output circuit has a first output terminal, a second output terminal and an output element, and either makes the first output terminal and the second output terminal conductive or non-conductive based on the second drive signal, the output element has a first MOSFET element and a second MOSFET element electrically connected to the drive circuit, the first MOSFET element has a first gate electrode and a first source electrode formed on its surface, and a first connector is provided on the surface of the first source electrode, The second MOSFET element has a second gate electrode and a second source electrode formed on its surface, a second connector provided on the surface of the second source electrode, each of the first and second connectors being a metal bump, each of the first and second connectors being joined to the connecting conductor, and the first and second source electrodes being electrically connected to each other via the first connector, the connecting conductor, and the second connector, in a semiconductor relay.

2. The semiconductor relay according to claim 1, wherein each of the first and second connectors has gold as its main constituent metal.

3. The semiconductor relay according to claim 1 or 2, wherein the first connector, the second connector, and the connecting conductor each contain the same type of metal.

4. The semiconductor relay according to any one of claims 1 to 3, wherein each of the first connector and the second connector is composed of a plurality of metal bumps, and each of the plurality of metal bumps is a metal bump.

5. The semiconductor relay according to any one of claims 1 to 4, wherein the connecting conductor includes a first metal layer and a second metal layer, the first connector and the second connector are bonded to the surface of the first metal layer, the second metal layer is provided in contact with the back surface of the first metal layer either directly or via a third metal layer, and the material of the second metal layer is different from the material of the first metal layer.

6. The semiconductor relay according to claim 5, wherein the material of the first metal layer is the same as the material of the first connector and the material of the second connector.

7. The semiconductor relay according to claim 5 or 6, wherein the second metal layer is mainly composed of copper, nickel, or silicon.

8. The semiconductor relay according to any one of claims 1 to 7, wherein the connecting conductor comprises: a first connecting conductor portion; a second connecting conductor portion; a third connecting conductor portion located between the first connecting conductor portion and the second connecting conductor portion and electrically connecting the first connecting conductor portion and the second connecting conductor portion; a first extension portion physically connected to the first connecting conductor portion; and a second extension portion physically connected to the second connecting conductor portion, wherein the direction perpendicular to the surface of the connecting conductor is defined as the first direction, and when viewed along the first direction, the first connecting conductor portion overlaps the first MOSFET element, the second connecting conductor portion overlaps the second MOSFET element, and the third connecting conductor portion, the first extension portion, and the second extension portion do not overlap the first MOSFET element and the second MOSFET element, respectively.

9. The semiconductor relay according to any one of claims 1 to 7, wherein the connecting conductor comprises: a first connecting conductor portion; a second connecting conductor portion; a third connecting conductor portion located between the first connecting conductor portion and the second connecting conductor portion, electrically connecting the first connecting conductor portion and the second connecting conductor portion to each other; and a third extension portion physically connected to the third connecting conductor portion, wherein the direction perpendicular to the surface of the connecting conductor is defined as the first direction, and when viewed along the first direction, the first connecting conductor portion overlaps the first MOSFET element, the second connecting conductor portion overlaps the second MOSFET element, and the third extension portion does not overlap the first MOSFET element and the second MOSFET element.

10. The semiconductor relay according to claim 8, wherein the connecting conductor further comprises: a first projection protruding from the surface of the first connecting conductor portion toward the first MOSFET element; and a second projection protruding from the surface of the second connecting conductor portion toward the second MOSFET element, wherein the height of the first projection along the first direction with respect to the surface of the first connecting conductor portion is lower than the height of the first connector along the first direction with respect to the surface of the first MOSFET element; and the height of the second projection along the first direction with respect to the surface of the second connecting conductor portion is lower than the height of the first connector along the first direction with respect to the surface of the second MOSFET element.

11. The semiconductor relay according to any one of claims 1 to 10, wherein the drive circuit is provided on the drive element, and the drive element is mounted on the back surface of the connecting conductor.

12. The semiconductor relay according to claim 11, further comprising an adhesive sheet interposed between the driving element and the connecting conductor.

13. The semiconductor relay according to claim 11 or 12, wherein the input element is a light-emitting element, the driving element includes a light-receiving element and a control circuit, the light-receiving element, upon input of the first driving signal, generates a current corresponding to the magnitude of the first driving signal, and the control circuit outputs the second driving signal to the output circuit based on the current.

14. The semiconductor relay according to any one of claims 1 to 10, wherein the drive circuit is provided on a drive element, the drive element includes a capacitor, and the input circuit and the output circuit are electrically isolated by the capacitor.

15. The semiconductor relay according to any one of claims 1 to 10, wherein the drive circuit is provided on a drive element, the drive element includes a pair of inductors, and the input circuit and the output circuit are electrically isolated from each other by the pair of inductors.

16. The semiconductor relay according to claim 13, wherein the drive element is arranged so as to cover the respective surfaces of the first MOSFET element and the second MOSFET element.

17. The semiconductor relay according to claim 16, wherein the light-emitting element and the light-receiving element are arranged opposite each other with a predetermined distance between them, in a direction perpendicular to the surface of the connecting conductor.

18. The semiconductor relay according to claim 13 or 16, wherein the light-emitting element is arranged on the surface of the light-receiving element via a light-transmitting material.

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