Solid state relay

Abstract

A solid state relay (1) includes first and second lead frames (10, 20), first and second switching elements (3, 4), and a driving section (2). The first lead frame (10) has a first mounting portion (11) on which the first switching element (3) is mounted on an upper surface, and a first connecting portion (12) continuous with a lower surface of the first mounting portion (11). The second lead frame (20) has a second mounting portion (21) on which the second switching element (4) is mounted on an upper surface, and a second connecting portion (22) continuous with a lower surface of the second mounting portion (21). When viewed in a first direction along which the first and second lead frames (10, 20) are arranged, a first distance (D1) between the first and second switching elements (3, 4) is shorter than a second distance (D2) between the first and second connecting portions (12, 22).

Description

Technical Field

[0001] This disclosure relates to a solid-state relay. Background Technology

[0002] Previously, as a signal transmission device, a solid-state relay was known that, while isolating the input from the input terminal, outputs an output signal from the output terminal based on the input signal from the input terminal. Typically, this solid-state relay encapsulates its components in a resin package to achieve miniaturization.

[0003] For example, Patent Document 1 discloses a solid-state relay in which an optocoupler and a first and a second switching element for output are packaged in the same package. Existing technical documents Patent documents

[0004] Patent Document 1: Japanese Patent Application Publication No. 2022-126101 Summary of the Invention -The technical problem the invention aims to solve-

[0005] To improve the output of signals transmitted by solid-state relays, high voltage and high current are often used to drive the first and second switching elements on the output side. On the other hand, the miniaturization of solid-state relays is also required.

[0006] However, when the first and second switching elements, which are driven by high voltage and high current, are arranged in a small package, it is difficult to reliably insulate them from each other.

[0007] This disclosure was made to solve the above-mentioned technical problems, and its purpose is to provide a solid-state relay that can achieve miniaturization while ensuring insulation between the first switching element and the second switching element on the output side. - Technical solutions used to solve technical problems -

[0008] To achieve the above objectives, the solid-state relay disclosed herein includes a first lead frame, a second lead frame, a first switching element, a second switching element, and a driving unit. The first lead frame has a first mounting portion and a first connecting portion located below the first mounting portion. The second lead frame has a second mounting portion and a second connecting portion located below the second mounting portion. The first switching element is a metal-oxide-semiconductor field-effect transistor (MOSFET) located on the upper surface of the first mounting portion. The second switching element is also a MOSFET located on the upper surface of the second mounting portion. The driving unit is electrically connected to the first and second switching elements and drives them. The first and second mounting portions are arranged at intervals along a first direction, which is the direction in which the first and second lead frames are arranged. The first connecting portion and the second connecting portion are also arranged at intervals along the first direction. A first distance is shorter than a second distance, where the first distance is the interval between the first and second switching elements along the first direction, and the second distance is the interval between the first and second connecting portions along the first direction. The entire upper surface of the first connecting portion contacts the lower surface of the first placing portion, and the first connecting portion and the first placing portion are integrally formed. The entire upper surface of the second connecting portion contacts the lower surface of the second placing portion, and the second connecting portion and the second placing portion are integrally formed. -The effects of the invention-

[0009] According to this disclosure, the miniaturization of solid-state relays can be achieved while reliably isolating the first and second switching elements from the output side. Attached Figure Description

[0010] Figure 1 This is the equivalent circuit diagram of the solid-state relay involved in the first embodiment. Figure 2 This is a schematic diagram showing the main parts of the solid-state relay involved in the first embodiment as viewed from above. Figure 3 yes Figure 2 A cross-sectional view at line III-III. Figure 4 This is a schematic diagram showing the output side components of a solid-state relay as viewed from above. Figure 5 yes Figure 4 A cross-sectional view at the V-V line. Figure 6 This is a schematic diagram showing the main parts of the solid-state relay involved in the second embodiment as viewed from above. Figure 7 yes Figure 6 A sectional view along line VII-VII. Figure 8 This is the equivalent circuit diagram of the solid-state relay involved in the third embodiment. Figure 9 This is a schematic diagram showing the main parts of the solid-state relay involved in the third embodiment from above. Figure 10 yes Figure 9 A cross-sectional view at the X-X line. Detailed Implementation

[0011] The embodiments of this disclosure will now be described with reference to the accompanying drawings. It should be noted that the following description of preferred embodiments is merely illustrative and is not intended to limit this disclosure, its application, or its uses.

[0012] (First Implementation) [Circuit structure and operation of solid-state relay 1] Figure 1 This is the equivalent circuit diagram of the solid-state relay involved in the first embodiment.

[0013] like Figure 1 As shown, the solid-state relay 1 includes a drive unit 2, a first switching element 3, a second switching element 4, a first input terminal 6, a second input terminal 7, a first output terminal 8, and a second output terminal 9.

[0014] The drive unit 2 includes an oscillation circuit 2A, a boost circuit 2B, and a drive circuit 2C. The boost circuit 2B is a known charge pump type boost circuit with capacitors C1 and C2 and diodes Di1 to Di3. By connecting capacitors C1 and C2 in series between the oscillation circuit 2A and the boost circuit 2B, the input side of the solid-state relay 1, i.e., the first input terminal 6 and the second input terminal 7, is insulated from the output side, i.e., the first output terminal 8 and the second output terminal 9. It should be noted that the number and connection relationship of the diodes arranged in the latter part of the boost circuit 2B are not limited. Figure 1 The example shown.

[0015] It should be noted that in this embodiment, the driving unit 2 is an IC (integrated circuit) on a single semiconductor chip, comprising the oscillation circuit 2A, the boost circuit 2B, and the driving circuit 2C. However, it is not limited to this; for example, the oscillation circuit 2A, the boost circuit 2B, and the driving circuit 2C may be independent components connected by a metal wire 30 (see reference). Figure 2 Connect these three components together, or make these three components electrically connected on the printed circuit board.

[0016] The first switching element 3 and the second switching element 4 are both known vertical MOSFETs (metal-oxide-semiconductor field-effect transistors).

[0017] The operation of solid-state relay 1 will be explained below.

[0018] When an input signal is input between the first input terminal 6 and the second input terminal 7, the oscillation circuit 2A generates a first oscillation signal S1 and a second oscillation signal S2. The first oscillation signal S1 and the second oscillation signal S2 are pulse signals with a specified oscillation frequency and opposite phases.

[0019] In the boost circuit 2B, a signal is generated by superimposing the second oscillation signal S2, which has passed through capacitor C2 and diode Di2, onto the first oscillation signal S1 that has passed through capacitor C1 and diode Di1. This signal is then input to the drive circuit 2C.

[0020] The drive circuit 2C is a charging and discharging circuit that inputs a drive signal corresponding to the signal generated in the boost circuit 2B to the gates G of the first switching element 3 and the second switching element 4, respectively.

[0021] If the voltage of the drive signal output from the drive circuit 2C is higher than the threshold voltage of the first switching element 3 and the second switching element 4 respectively, the first switching element 3 and the second switching element 4 will be turned on, and the drain-source connection will be established. As a result, the first output terminal 8 and the second output terminal 9 will be connected, and the solid-state relay 1 will be closed (in the on state).

[0022] On the other hand, if there is no longer an input signal between the first input terminal 6 and the second input terminal 7, the oscillation circuit 2A will not operate, and no signal will be input from the boost circuit 2B to the drive circuit 2C. Therefore, the charge that has been charged to the gates G of the first switching element 3 and the second switching element 4 will be drawn away by the drive circuit 2C and discharged. As a result, the drain-source of the first switching element 3 and the second switching element 4 will become non-conductive, the connection between the first output terminal 8 and the second output terminal 9 will be blocked, and the solid-state relay 1 will be disconnected (become in the off state).

[0023] [Installation method of solid-state relay 1] Figure 2 This is a schematic diagram showing the main parts of the solid-state relay involved in the first embodiment as viewed from above. Figure 3 yes Figure 2 A cross-sectional view at line III-III. Figure 4 This is a schematic diagram showing the output side components of a solid-state relay as viewed from above. Figure 5 yes Figure 4 A cross-sectional view at the V-V line.

[0024] It should be noted that, for ease of explanation, in Figure 2 The illustrations of the first input terminal 6, the second input terminal 7, and the package 40 are omitted. Furthermore, the illustrations of the lead frame and / or metal wire 30 connecting the first input terminal 6 to the drive unit 2, and the lead frame and / or metal wire 30 connecting the second input terminal 7 to the drive unit 2, are also omitted. Additionally, the illustrations of the oscillation circuit 2A, the boost circuit 2B, and the drive circuit 2C within the drive unit 2 are also omitted.

[0025] Furthermore, in the following description, the stacking direction of the drive unit 2, the first switching element 3 and the second switching element 4, the first lead frame 10 and the second lead frame 20 in the solid-state relay 1 is sometimes referred to as the vertical direction. In the vertical direction, the side where the drive unit 2 is arranged is sometimes referred to as the upper side or above, and the side where the first lead frame 10 and the second lead frame 20 are arranged is sometimes referred to as the lower side or below. Also, when viewed from above, the direction in which the first lead frame 10 and the second lead frame 20 are arranged is referred to as the first direction. Furthermore, when the solid-state relay 1 is cut open with an imaginary plane that includes both the vertical direction and the first direction for observation, this is called a cross-sectional view.

[0026] In addition, Figure 4 The gate G and source S of the first switching element 3 and the second switching element 4 are omitted from the diagram.

[0027] like Figure 2 , 3 As shown, in the solid-state relay 1, the drive unit 2, the first switching element 3, the second switching element 4, the first lead frame 10, and the second lead frame 20 are housed in an encapsulation 40 formed of insulating resin. Furthermore, the first switching element 3 is mounted on the first lead frame 10, and the second switching element 4 is mounted on the second lead frame 20.

[0028] The first lead frame 10 is a conductive component made of a metal such as copper, having a first placement portion 11 and a first connecting portion 12. The first connecting portion 12 is located below the first placement portion 11, and the entire upper surface of the first connecting portion 12 is in contact with the lower surface of the first placement portion 11. Furthermore, the first placement portion 11 and the first connecting portion 12 are formed integrally.

[0029] Similarly, the second lead frame 20 is a conductive component made of a metal such as copper, having a second placement portion 21 and a second connecting portion 22. The second connecting portion 22 is located below the second placement portion 21, and the entire upper surface of the second connecting portion 22 is in contact with the lower surface of the second placement portion 21. Furthermore, the second placement portion 21 and the second connecting portion 22 are formed integrally.

[0030] The drains D of the first switching element 3 and the second switching element 4 respectively (in) Figures 2-5(Not shown) The first switching element 3 and the second switching element 4 are respectively disposed on the lower surface of their respective surfaces. The first switching element 3 is disposed on the upper surface of the first placement portion 11 of the first lead frame 10. The upper surface of the first placement portion 11 is electrically connected to the drain D via a conductive adhesive material (not shown), such as silver paste. The second switching element 4 is disposed on the upper surface of the second placement portion 21 of the second lead frame 20. The upper surface of the second placement portion 21 is electrically connected to the drain D via the aforementioned conductive adhesive material (not shown).

[0031] In addition, such as Figure 3 As shown, the lower surfaces of the first connecting portion 12 and the second connecting portion 22 are exposed from the lower surface of the package 40. The first connecting portion 12 and the second connecting portion 22 are electrically connected to the solder pad electrodes (not shown) provided on the component on which the solid-state relay 1 is mounted, such as a printed circuit board, via the aforementioned conductive adhesive material (not shown).

[0032] like Figures 2-5 As shown, viewed from above, the first lead frame 10 and the second lead frame 20 are arranged at intervals along a first direction. That is, the first mounting portion 11 and the second mounting portion 21 are arranged at intervals along the first direction. Furthermore, the first connecting portion 12 and the second connecting portion 22 are arranged at intervals along the first direction. Additionally, the first switching element 3 arranged on the first lead frame 10 and the second switching element 4 arranged on the second lead frame 20 are also arranged at intervals along the first direction.

[0033] In addition, such as Figure 3 , 5 As shown, in cross-section, on the side closest to the package 40, the side of the first placement portion 11 is flush with the side of the first connecting portion 12. Furthermore, when viewed along the first direction, the width of the first placement portion 11 is wider than the width of the first connecting portion 12. In other words, in cross-section, the first lead frame 10 is an L-shaped component. Similarly, in cross-section, on the side closest to the package 40, the side of the second placement portion 21 is flush with the side of the second connecting portion 22. Furthermore, when viewed along the first direction, the width of the second placement portion 21 is wider than the width of the second connecting portion 22. In other words, in cross-section, the second lead frame 20 is an L-shaped component.

[0034] Therefore, in cross-section, the distance between the first placement portion 11 and the second placement portion 21 along the first direction (third distance D3) is shorter than the distance between the first connecting portion 12 and the second connecting portion 22 along the first direction (second distance D2) (D3 < D2). It should be noted that the shapes of the first lead frame 10 and the second lead frame are obtained by etching a flat lead frame made of copper or the like. However, this is not a limitation; for example, the first lead frame 10 and the second lead frame can also be obtained by cutting a lead frame that has already been shaped into a strip.

[0035] In addition, such as Figure 2 , 4 As shown, the first switching element 3 is located inside the periphery of the first mounting section 11. The second switching element 4 is located inside the periphery of the second mounting section 21. Therefore, as... Figure 5 As shown in the cross-section, the distance between the first switching element 3 and the second switching element 4 along the first direction (first distance D1) is shorter than the aforementioned second distance D2. Furthermore, as... Figure 5 As clearly shown, the relationship D2 > D1 > D3 holds true.

[0036] It should be noted that the first switching element 3 can also be placed in the first mounting section 11 with the side of the first switching element 3 opposite to the second switching element 4 flush with the side of the first mounting section 11 opposite to the second mounting section 21. Similarly, the second switching element 4 can also be placed in the second mounting section 21 with the side of the second switching element 4 opposite to the first switching element 3 flush with the side of the second mounting section 21 opposite to the first mounting section 11. When both of these conditions are met, the relationship D2 > D1 = D3 holds true.

[0037] The drive unit 2 is arranged across the upper surfaces of the first switching element 3 and the second switching element 4 respectively. The drive unit 2 is bonded to the first switching element 3 and the second switching element 4 by an insulating adhesive material (not shown), and is electrically insulated at the bonding points.

[0038] The drive unit 2 has first terminals T1 to fourth terminals T4 on its upper surface. The first switching element 3 has a gate G and a source S on its upper surface. The second switching element 4 has a gate G and a source S on its upper surface.

[0039] The first terminal T1 is electrically connected to the gate G of the first switching element 3 via a metal line 30. The second terminal T2 is electrically connected to the gate G of the second switching element 4 via a metal line 30. The third terminal T3 is electrically connected to the source S of the first switching element 3 via a metal line 30. The fourth terminal T4 is electrically connected to the source S of the second switching element 4 via a metal line 30. The source S of the first switching element 3 and the source S of the second switching element 4 are electrically connected via a metal line 30. (This is achieved through...) Figure 2, 3 As shown, by connecting the drive unit 2, the first switching element 3, and the second switching element 4 via multiple metal wires 30, it is possible to achieve... Figure 1 The solid-state relay 1 is shown. Furthermore, by encapsulating the drive unit 2, the first switching element 3, and the second switching element 4 with an encapsulation 40 formed of insulating resin, these three components are electrically insulated from each other, except for the portion connected via the metal wire 30. Additionally, by encapsulating the first lead frame 10 and the second lead frame 20 with the encapsulation 40 formed of insulating resin while keeping them spaced apart, the first lead frame 10 and the second lead frame 20 are electrically insulated from each other.

[0040] [Effects, etc.] As described above, the solid-state relay 1 involved in this embodiment includes a first lead frame 10, a second lead frame 20, a first switching element 3, a second switching element 4, and a driving unit 2.

[0041] The first lead frame 10 has a first mounting portion 11 and a first connecting portion 12 located below the first mounting portion 11. The second lead frame 20 has a second mounting portion 21 and a second connecting portion 22 located below the second mounting portion 21. A first switching element 3 is located on the upper surface of the first mounting portion 11. A second switching element 4 is located on the upper surface of the second mounting portion 21. The driving unit 2 is electrically connected to the first switching element 3 and the second switching element 4, and drives the first switching element 3 and the second switching element 4.

[0042] The entire upper surface of the first connecting portion 12 of the first lead frame 10 contacts the lower surface of the first placement portion 11, and the first connecting portion 12 and the first placement portion 11 are integrally formed. The entire upper surface of the second connecting portion 22 of the second lead frame 20 contacts the lower surface of the second placement portion 21, and the second connecting portion 22 and the second placement portion 21 are integrally formed.

[0043] The first mounting portion 11 and the second mounting portion 21 are arranged at intervals along the direction in which the first lead frame 10 and the second lead frame 20 are arranged, i.e., the first direction. The first connecting portion 12 and the second connecting portion 22 are arranged at intervals along the first direction.

[0044] The first distance D1 between the first switching element 3 and the second switching element 4 along the first direction is shorter than the second distance D2 between the first connecting part 12 and the second connecting part 22 along the first direction.

[0045] In the solid-state relay 1, by making the second distance D2 longer than the first distance D1, the second distance D2 can be made relatively long. This second distance D2 is equivalent to the surface distance between the first lead frame 10 and the second lead frame 20 along the first direction. This allows for reliable electrical insulation between the first switching element 3 and the second switching element 4. Furthermore, in the first lead frame 10 and the second lead frame 20, the second distance D2 can be extended simply by shortening the amplitude of the first connecting portion 12 and the second connecting portion 22 along the first direction. In other words, the second distance D2 can be extended without increasing the length of the first lead frame 10 and the second lead frame 20 along the first direction, allowing for a reduction in the size of the solid-state relay 1 along the first direction. This means that miniaturization of the solid-state relay 1 is possible.

[0046] In addition, preferably, the distance between the first placement section 11 and the second placement section 21 along the first direction, i.e., the third distance D3, is shorter than the second distance D2.

[0047] By making the second distance D2 longer than the third distance D3, the aforementioned surface distance, i.e., the second distance D2, can be extended without increasing the length of the first lead frame 10 and the second lead frame 20 along the first direction. This allows for reliable electrical insulation between the first mounting section 11, which houses the first switching element 3, and the second mounting section 21, which houses the second switching element 4. Furthermore, the size of the solid-state relay 1 along the first direction can be reduced, enabling miniaturization of the solid-state relay 1.

[0048] Preferably, the first switching element 3 is located inside the periphery of the first mounting section 11, and the second switching element 4 is located inside the periphery of the second mounting section 21.

[0049] This allows the first distance D1 to be longer than the third distance D3. In other words, it ensures reliable insulation between the first switching element 3 and the second switching element 4.

[0050] Furthermore, when the first switching element 3 is placed and fixed to the first placement portion 11, using the aforementioned conductive adhesive material, by positioning the first switching element 3 inside the periphery of the first placement portion 11, it is possible to prevent the conductive adhesive material from overflowing from the first placement portion 11. Similarly, by positioning the second switching element 4 inside the periphery of the second placement portion 21, it is possible to prevent the conductive adhesive material from overflowing from the second placement portion 21. This prevents the insulation distance between the first placement portion 11 and the second placement portion 21 from becoming shorter. Additionally, it prevents the insulation distance between the first connecting portion 12 and the second connecting portion 22 from becoming shorter.

[0051] The drive unit 2 shown in this embodiment is located on the upper surface of the first switching element 3 and the upper surface of the second switching element 4. This ensures that the lengths of the metal wires (wiring) 30 connecting the drive unit 2 and the first switching element 3 are the same as the lengths of the metal wires (wiring) 30 connecting the drive unit 2 and the second switching element 4. This allows the amplitude and transmission time of the signals transmitted from the drive unit 2 to the first switching element 3 and the second switching element 4 to be similar, thereby improving the balance of the switching operation. For example, it can suppress the response delay of the solid-state relay 1 caused by the timing deviation of the turn-on and turn-off of each switching element.

[0052] In addition, by arranging the drive unit 2 on the upper surface of the first switching element 3 and the second switching element 4 respectively, the length of the metal wire 30 can be shortened, and signal transmission deviation and deformation of the metal wire 30 in the case of encapsulating the solid-state relay 1 with insulating resin can be suppressed.

[0053] The drive unit 2 shown in this embodiment has capacitors C1 and C2 inside the boost circuit 2B. Capacitor C1 is connected in series to one of a pair of conductive paths from the oscillation circuit 2A to the drive circuit 2C. Capacitor C2 is connected in series to the other of a pair of conductive paths from the oscillation circuit 2A to the drive circuit 2C.

[0054] The drive unit 2 has capacitors C1 and C2 at the aforementioned positions, thereby enabling electrical insulation between the input and output of the solid-state relay 1. Furthermore, as shown in this embodiment, when the first switching element 3 and the second switching element 4 are both MOSFETs, their respective gates G can be easily charged and discharged. In other words, the first switching element 3 and the second switching element 4 can be easily switched on and off.

[0055] Furthermore, the first lead frame 10, the second lead frame 20, the first switching element 3, the second switching element 4, and the drive unit 2 are housed in a package 40 formed of insulating resin. The lower surfaces of the first connecting portion 12 and the second connecting portion 22 are exposed from the lower surface of the package 40.

[0056] By configuring the solid-state relay 1 in this way, the mounting area when mounting the solid-state relay 1 on a circuit board, printed circuit board, etc. can be reduced. In addition, the distance between the first switching element 3 and the first connection portion 12, which are prone to heat generation, and the distance between the second switching element 4 and the second connection portion 22 can be shortened respectively, thus enabling efficient heat dissipation from the solid-state relay 1.

[0057] (Second Implementation) Figure 6 This is a schematic diagram showing the main parts of the solid-state relay involved in the second embodiment as viewed from above. Figure 7 yes Figure 6 A sectional view along line VII-VII. It should be noted that, for ease of explanation, [the following text is incomplete and requires further context: "in the sectional view along line VII-VII."] Figure 6 , 7 In the accompanying drawings shown thereafter, the same symbols are used for the same parts as in the first embodiment, and detailed descriptions are omitted.

[0058] exist Figure 6 , 7 In the solid-state relay 1 of this embodiment shown, the drive unit 2 is located on the upper surface of the first switching element 3, which is consistent with... Figure 2 , 3 The solid-state relay 1 shown in the first embodiment is different.

[0059] According to this embodiment, the first switching element 3 and the first mounting portion 11 function as supports for the drive portion 2 from below. As a result, the position of the drive portion 2 within the solid-state relay 1 is stable, thereby stabilizing the operation of the solid-state relay 1.

[0060] Furthermore, according to this embodiment, the same effects as the structure shown in the first embodiment can be achieved. That is, the surface distance, i.e., the second distance D2, can be extended, and the size of the solid-state relay 1 along the first direction can be reduced, thereby enabling the miniaturization of the solid-state relay 1.

[0061] Furthermore, the drive unit 2 has capacitors C1 and C2 at the aforementioned locations, thereby enabling electrical insulation between the input and output of the solid-state relay 1. Additionally, the first switching element 3 and the second switching element 4, which are MOSFETs respectively, can be easily switched on and off.

[0062] Furthermore, when the first switching element 3 is located inside the periphery of the first placement portion 11 and the second switching element 4 is located inside the periphery of the second placement portion 21, it is possible to prevent conductive adhesive material from overflowing from the first placement portion 11 and the second placement portion 21, respectively. This prevents the insulation distance between the first placement portion 11 and the second placement portion 21 from becoming shorter. Additionally, it prevents the insulation distance between the first connecting portion 12 and the second connecting portion 22 from becoming shorter.

[0063] It should be noted that in this embodiment, an example is shown where the driving part 2 is located on the upper surface of the first switching element 3, but the driving part 2 may also be located only on the upper surface of the second switching element 4.

[0064] In this case, the second switching element 4 and the second mounting section 21 function as supports for the drive section 2 from below. This stabilizes the position of the drive section 2 within the solid-state relay 1, thereby ensuring stable operation of the solid-state relay 1. Furthermore, in this case, the same effects as described above can be achieved as in the structure shown in the first embodiment.

[0065] (Third implementation method) [Circuit structure and operation of solid-state relay 50] Figure 8 This is the equivalent circuit diagram of the solid-state relay involved in the third embodiment.

[0066] exist Figure 8 In the solid-state relay 50 shown, the circuit structure of the drive unit 2 is similar to... Figure 1 The circuit structure of the first embodiment shown is different. That is to say, Figure 8 The driving unit 2 shown has a light-receiving unit 2D, which replaces... Figure 1 The oscillator circuit 2A and the boost circuit 2B are shown. It should be noted that... Figure 8 The driving circuit 2E shown is also related to Figure 1 Similarly, the driving circuit 2C shown is a charging and discharging circuit for the gates G of both the first switching element 3 and the second switching element 4. Furthermore, Figure 8 The solid-state relay 50 shown has a light-emitting element 5 positioned opposite the light-receiving part 2D. The light-emitting element 5 is connected in series between the first input terminal 6 and the second input terminal 7.

[0067] The operation of solid-state relay 50 will be explained below.

[0068] When an input signal is applied between the first input terminal 6 and the second input terminal 7, the light-emitting element 5 outputs a light signal. The light signal generated by the light-emitting element 5 is received by the light-receiving unit 2D.

[0069] The light-receiving part 2D has a photodiode array. In the photodiode array, the light signal is converted into current through photoelectric conversion, and the driving circuit 2E operates based on this current. The voltage signal corresponding to the amount of light from the light-emitting element 5, i.e., the driving signal, is applied to the gates G of the first switching element 3 and the second switching element 4 via the metal line 30.

[0070] If the voltage of the drive signal output from the drive circuit 2E is higher than the threshold voltage of the first switching element 3 and the second switching element 4 respectively, the first switching element 3 and the second switching element 4 will be turned on, and the drain-source connection will be established. As a result, the first output terminal 8 and the second output terminal 9 will be connected, and the solid-state relay 50 will be closed (in a conducting state).

[0071] On the other hand, if there is no longer an input signal between the first input terminal 6 and the second input terminal 7, the light emission from the light-emitting element 5 will also stop. Correspondingly, no current is generated in the photodiode array, and the drive signal from the drive circuit 2E also stops. Therefore, the charge that has been charged to the gates G of the first switching element 3 and the second switching element 4 is drawn away by the drive circuit 2E and discharged. As a result, the drain-source of the first switching element 3 and the second switching element 4 becomes non-conductive, the connection between the first output terminal 8 and the second output terminal 9 is blocked, and the solid-state relay 50 is disconnected (becomes in the off state).

[0072] In other words, Figure 1 The solid-state relay 1 shown is a solid-state relay that uses capacitors C1 and C2 to insulate between the input and the output. In contrast, the solid-state relay 50 of this embodiment is a solid-state relay that uses an optical coupler composed of a light-emitting element 5 and a light-receiving part 2D to insulate between the input and the output.

[0073] [Installation method of solid-state relay 50] Figure 9 This is a schematic diagram showing the main parts of the solid-state relay involved in the third embodiment from above. Figure 10 yes Figure 9 A cross-sectional view at the X-X line. It should be noted that... Figure 9 , 10 The diagram of the metal line 30 that transmits the input signal to the light-emitting element 5 and the wiring is omitted.

[0074] Figure 9 , 10 The mounting method of the solid-state relay 50 shown is the same as that shown below, except for the points indicated below. Figures 2-5 The solid-state relay 1 shown is installed in the same way.

[0075] First, in the solid-state relay 50, the drive unit 2, the first switching element 3, the second switching element 4, the first lead frame 10, the second lead frame 20, and the light-emitting element 5 are housed in a package 40 formed of insulating resin. That is, the solid-state relay 50 includes the light-emitting element 5, such as... Figure 10 As shown, the light-emitting element 5 is located above the driving unit 2. The driving unit 2 has a position relative to the light-emitting element 5 in the vertical direction. Figure 8 The light-receiving part 2D is shown.

[0076] As shown in this embodiment, by forming an optical coupler from the driving unit 2 and the light-emitting element 5, electrical insulation can be achieved between the input and output of the solid-state relay 50.

[0077] To further explain, the light-emitting element 5 is located on the upper surface of the driving unit 2. Specifically, the light-emitting element 5 is located on the upper surface of the light-receiving unit 2D (not shown). Wiring (not shown) is connected to the upper surface of the light-emitting element 5, and the first input terminal 6 or the second input terminal 7 is electrically connected to the light-emitting element 5 via this wiring. Furthermore, the lower surface of the light-emitting element 5 is the output surface for the light signal. The lower surface of the light-emitting element 5 is connected to the upper surface of the light-receiving unit 2D via a light-transmitting resin (not shown). This light-transmitting resin serves as the transmission path for the light signal. In this case, the insulating resin constituting the encapsulation body 40 is preferably a light-shielding resin. This prevents the light signal output from the light-emitting element 5 from leaking into the driving circuit 2E, the first switching element 3, or the second switching element 4 of the driving unit 2.

[0078] In addition, by arranging the light-emitting element 5 on the upper surface of the drive unit 2, the size of the solid-state relay 50 in the vertical direction can be reduced, and the solid-state relay 50 can be miniaturized.

[0079] Furthermore, according to this embodiment, the same effects as the structure shown in the first embodiment can be achieved. That is, the surface distance, i.e., the second distance D2, can be extended, and the size of the solid-state relay 1 along the first direction can be reduced, thereby enabling the miniaturization of the solid-state relay 1.

[0080] Furthermore, since the drive unit 2 is located on the upper surface of both the first switching element 3 and the second switching element 4, the lengths of the metal wires (wiring) 30 connecting the drive unit 2 and the first switching element 3 and the second switching element 4 can be made the same. This ensures that the amplitude and transmission time of the signals transmitted from the drive unit 2 to the first switching element 3 and the second switching element 4 are similar, thereby improving the balance of the switching operation. For example, it can suppress the response delay of the solid-state relay 50 caused by the timing deviation of the turn-on and turn-off of each switching element. Additionally, shortening the length of the metal wires 30 can suppress signal transmission deviations and deformation of the metal wires 30 when the solid-state relay 50 is encapsulated in insulating resin.

[0081] Furthermore, when the first switching element 3 is located inside the periphery of the first placement portion 11 and the second switching element 4 is located inside the periphery of the second placement portion 21, it is possible to prevent conductive adhesive material from overflowing from the first placement portion 11 and the second placement portion 21, respectively. This prevents the insulation distance between the first placement portion 11 and the second placement portion 21 from becoming shorter. Additionally, it prevents the insulation distance between the first connecting portion 12 and the second connecting portion 22 from becoming shorter.

[0082] (Other implementation methods) New embodiments can be constructed by appropriately combining the constituent elements shown in the first to third embodiments. For example, in the solid-state relay 50 shown in the third embodiment, the drive unit 2 can be arranged on the upper surface of either the first switching element 3 or the second switching element 4, just as in the solid-state relay shown in the second embodiment. In this case, when viewed from above, the light-emitting element 5 is arranged to overlap with the upper surface of either the first switching element 3 or the second switching element 4.

[0083] This achieves the same effect as the structure shown in the second embodiment. That is, either the first switching element 3 and the first mounting section 11, or the second switching element 4 and the second mounting section 21, functions as a support for the drive section 2 from below. Consequently, the position of the drive section 2 within the solid-state relay 50 is stable, and consequently, the operation of the solid-state relay 50 is stable. -Industry Applicability-

[0084] The solid-state relay disclosed herein is useful because it enables miniaturization of the solid-state relay while ensuring insulation between the first and second switching elements on the output side. - Symbol Explanation -

[0085] 1. 50 Solid State Relay 2 Drive Unit 2A oscillation circuit 2B boost circuit 2C driver circuit 2D light-receiving area 2E drive circuit 3. First switching element (MOSFET) 4. Second switching element (MOSFET) 5. Light-emitting elements 6 First Input Terminal 7 Second Input Terminal 8 First output terminal 9 Second output terminal 10 First lead frame 11 First Loading Section 12 First connecting part 20 Second lead frame 21 Second Loading Section 22 Second connecting part 30 Metal wire (wiring) 40 Encapsulation (insulating resin)

Claims

1. A solid-state relay, characterized in that: The solid-state relay includes a first lead frame, a second lead frame, a first switching element, a second switching element, and a driving unit. The first lead frame has a first placement portion and a first connecting portion located below the first placement portion. The second lead frame has a second mounting portion and a second connecting portion located below the second mounting portion. The first switching element is a metal-oxide-semiconductor field-effect transistor, located on the upper surface of the first amplifier section. The second switching element is a metal-oxide-semiconductor field-effect transistor, located on the upper surface of the second amplifier section. The driving unit is electrically connected to the first switching element and the second switching element, and drives the first switching element and the second switching element. The first mounting section and the second mounting section are arranged at intervals along a first direction, which is the direction in which the first lead frame and the second lead frame are arranged. The first connecting portion and the second connecting portion are arranged at intervals along the first direction. The first distance is shorter than the second distance. The first distance is the interval between the first switching element and the second switching element along the first direction, and the second distance is the interval between the first connecting portion and the second connecting portion along the first direction. The entire upper surface of the first connecting portion is in contact with the lower surface of the first placing portion, and the first connecting portion and the first placing portion are integrally formed. The entire upper surface of the second connecting portion contacts the lower surface of the second placing portion, and the second connecting portion and the second placing portion are integrally formed.

2. The solid-state relay according to claim 1, characterized in that: The third distance is shorter than the second distance, and the third distance is the interval between the first placement part and the second placement part along the first direction.

3. The solid-state relay according to claim 1 or 2, characterized in that: The first switching element is located inside the periphery of the first mounting section. The second switching element is located inside the periphery of the second mounting portion.

4. The solid-state relay according to any one of claims 1 to 3, characterized in that: The driving part is located on the upper surface of the first switching element or the upper surface of the second switching element.

5. The solid-state relay according to any one of claims 1 to 4, characterized in that: The driving part is located on the upper surface of the first switching element and the upper surface of the second switching element.

6. The solid-state relay according to any one of claims 1 to 5, characterized in that: The drive unit has a capacitor.

7. The solid-state relay according to any one of claims 1 to 5, characterized in that: The solid-state relay also includes a light-emitting element located above the driving unit. The driving unit has a light-receiving part.

8. The solid-state relay according to claim 7, characterized in that: The light-emitting element is located on the upper surface of the driving part.

9. The solid-state relay according to any one of claims 1 to 8, characterized in that: The first lead frame, the second lead frame, the first switching element, the second switching element, and the driving unit are housed in a package. The lower surfaces of both the first connecting portion and the second connecting portion are exposed from the lower surface of the package.

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