Sealing unit for rectification element module

Abstract

To provide a sealing unit for a rectification element module capable of suppressing adverse influences upon a rectification element module constituting a rectification circuit.SOLUTION: A sealing unit 100 for a rectification element module comprises: a rectification element module 10 including rectification elements; a first substrate 20 which is tabular and includes a first front face 21 and a first back face 22 and in which the rectification element module 10 is disposed on the first front face 21; a second substrate 30 which is tabular, includes a second front face 31 and a second back face 32 and is disposed with respect to the first substrate 20 in such a manner that the second front face 31 faces the first front face 21; and a side wall part 40 which covers a region open laterally between the first substrate 20 and the second substrate 30, thereby forming a sealing space Sp in which the rectification element module 10 is disposed together with the first substrate 20 and the second substrate 30.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a sealing unit for a rectifier module. [Background technology]

[0002] A power conversion device includes, for example, a primary circuit that receives an input voltage, a secondary circuit that outputs an output voltage, and a transformer that magnetically connects the primary and secondary circuits. The secondary circuit is provided with a rectifier circuit that rectifies the voltage waveform generated in the secondary winding of the transformer. Patent Document 1 discloses a power conversion device in which a switching element serving as a primary circuit, a rectifier circuit serving as a secondary circuit, a primary-side input capacitor, a secondary-side output capacitor, and various control circuits are arranged on the surface of a multi-layer substrate. In addition, a pattern coil is formed on the substrate using a copper foil pattern or the like, and this pattern coil and a magnetic core form a transformer, etc. A cooler is arranged on the back surface of the substrate to cool the heat generated by the rectifier circuit, etc.

[0003] Such a substrate is formed with a heat dissipation pattern, and heat transferred in the planar direction between the various elements and the pattern coil is dissipated to the cooler via the heat dissipation pattern. This suppresses thermal interference between the various elements on the substrate, allowing the various elements to be arranged closely together, thereby reducing the area of ​​the substrate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2018 / 105465 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the configuration of Patent Document 1, the substrate is exposed with the rectifier circuit and other components arranged thereon, and therefore, depending on the contamination state of the exposed space, such as dust, humidity, and chemical atmosphere, dust may adhere to components such as the rectifier circuit and wiring on the substrate, causing corrosion of the components. This may result in adverse effects such as malfunction, damage, and shortened lifespan of the rectifier circuit. Therefore, there is a need to suppress adverse effects on the rectifier element module that constitutes the rectifier circuit.

[0006] SUMMARY OF THE INVENTION Therefore, a primary object of the present invention is to provide a sealing unit for a rectifier module that can suppress adverse effects on the rectifier module that constitutes a rectifier circuit. [Means for solving the problem]

[0007] The sealing unit of the rectifier module of this invention comprises a rectifier module having a rectifier element, a plate-shaped first substrate having a first surface and a first back surface, with the rectifier module arranged on the first surface, a plate-shaped second substrate having a second surface and a second back surface, with the second surface arranged relative to the first substrate so that the second surface faces the first surface, and a side wall portion that covers the area open laterally between the first and second substrates, thereby forming a sealed space in which the rectifier module is arranged together with the first and second substrates.

[0008] According to the above configuration, it is possible to provide a sealing unit for a rectifier module that can suppress adverse effects on the rectifier module that constitutes the rectifier circuit. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a sealing unit for a rectifier module that can suppress adverse effects on the rectifier module that constitutes a rectifier circuit.

[0010] The above and other objects, features, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments of the present invention, which proceeds with reference to the accompanying drawings. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 2 is a top view of a sealing unit of the rectifier circuit according to the embodiment of the present invention. [Figure 2] 2 is a top view of FIG. 1 with the upper second substrate removed. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 1 is a circuit diagram of a power conversion device having a synchronous rectification circuit. [Figure 5] FIG. 1(a) is a top perspective view of a rectifying element module, and FIG. 1(b) is a rear perspective view of FIG. [Figure 6] 2 is a current path diagram showing the flow of current in a sealing unit of the rectifier module of FIG. 1. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] 1. Embodiment (1) Structure of the encapsulation unit of the rectifier module The configuration of a sealing unit 100 of a rectifier module according to an embodiment of the present invention will be described below with reference to the drawings. Fig. 1 is a top view of a sealed unit of a rectifier circuit according to an embodiment of the present invention, Fig. 2 is a top view of Fig. 1 with a second upper substrate removed, and Fig. 3 is a cross-sectional view taken along line III-III in Fig. 1.

[0013] The rectifier module sealing unit 100 includes at least one rectifier module 10, a first substrate 20, a second substrate 30, and a sidewall portion 40. Each rectifier module 10 has a switching function and includes rectifier elements that generate a rectified output voltage. In this embodiment, the rectifier modules 10 are divided into two groups, a first group and a second group, facing each other in the x-direction across a first wiring board 51 (described later). The first group includes multiple rectifier modules 10a, and the second group includes multiple rectifier modules 10b. The first substrate 20 is plate-shaped and has a first surface 21 and a first rear surface 22. The rectifier modules 10 are disposed on the first surface 21. The second substrate 30 is plate-shaped and has a second surface 31 and a second rear surface 32. The second substrate 30 is disposed relative to the first substrate 20 such that the second surface 31 faces the first surface 21. The sidewall 40 covers the area that is open laterally between the first substrate 20 and the second substrate 30. As a result, a sealed space Sp in which the rectifying element module 10 is disposed is formed by the space surrounded by the first substrate 20, the second substrate 30, and the sidewall 40. The sealed space Sp is a closed space isolated from the external space other than the space surrounded by the first substrate 20, the second substrate 30, and the sidewall 40.

[0014] The sealed unit 100 of the rectifier module further includes a first wiring board 51, a second wiring board 52, a cooling unit 60, an insulating heat dissipation sheet 65, and a connector 70. The cooling unit 60 is disposed below the first substrate 20 and cools the first substrate 20. The first wiring board 51 and the insulating heat dissipation sheet 65 are disposed between the first substrate 20 and the cooling unit 60. The first wiring board 51 electrically connects the first substrate 20 to the cooling unit 60. The insulating heat dissipation sheet 65 electrically insulates a predetermined portion of the first substrate 20 from the cooling unit 60 and transfers heat from the first substrate 20 to the cooling unit 60 for heat dissipation. The second wiring board 52 electrically connects the rectifier module 10 to at least one of the elements on the second substrate 30 and an external circuit. The connector 70 electrically connects the first substrate 20 to the second substrate 30.

[0015] 1 to 3, the direction in which the rectifier modules 10a face each other across the first wiring board 51 is defined as the x direction. The direction in which the rectifier modules 10a are arranged in the first and second groups of the rectifier modules 10 is defined as the y direction. In FIGS. 1 to 3, the y direction is also the direction in which the first wiring board 51 extends between the rectifier modules 10a. The direction perpendicular to the x and y directions is defined as the z direction, and may also be referred to as the vertical direction, up, or down. A plane parallel to the xy plane is defined as the horizontal plane. In this embodiment, the first substrate 20 and the second substrate 30 are aligned along the horizontal plane. Each component will be described below.

[0016] The rectifier module 10 includes a rectifier for generating a rectified output voltage. The rectifier constitutes a synchronous rectifier circuit. Such a synchronous rectifier circuit is used in the power converter 1. Figure 4 is a circuit diagram of a power converter having a synchronous rectifier circuit.

[0017] There are many different types of power conversion devices that use synchronous rectification circuits, but as an example, a center-tapped power conversion device 1 will be described here. As shown in FIG. 3, the power conversion device 1 includes a transformer 2, a primary circuit 3, and a secondary circuit 4. The primary circuit 3 generates an AC voltage from a DC voltage and supplies the AC voltage to a primary winding 2b of the transformer 2. A magnetic field is generated when a current flows through the primary winding 2b, and electromagnetic induction of this magnetic field induces a current in the secondary windings 2c and 2d of the transformer 2. As a result, an output voltage according to the turns ratio is obtained from the secondary windings 2c and 2d.

[0018] The transformer 2 has a core 2a, a primary winding 2b, and secondary windings 2c and 2d. The primary winding 2b is wound around the core 2a from a primary winding start end 2b1 to a primary winding end 2b2. The secondary windings 2c and 2d are wound around the core 2a and have a first partial winding 2c and a second partial winding 2d. The first partial winding 2c is wound around the core 2a from a first partial winding start end 2c1 to a first partial winding end 2c2. The second partial winding 2d is wound around the core 2a from a second partial winding start end 2d1 to a second partial winding end 2d2. The first partial winding end 2c2 and the second partial winding start end 2d1 are connected so that the first partial winding 2c and the second partial winding 2d are connected in series. The first partial winding start end 2c1 and the second partial winding end 2d2 are connected to the secondary output (-) line Vout(-) via the secondary circuit 4. The connection between the first partial winding end end 2c2 and the second partial winding start end 2d1 is commonly connected to the secondary output (+) line Vout(+). An output voltage induced in the first partial winding 2c and the second partial winding 2d is output from the secondary output (+) line Vout(+).

[0019] The primary circuit 3 is not limited as long as it can receive a DC voltage input from the primary input (+) line Vin(+) and the primary input (-) line Vin(-) and generate an AC voltage from the DC voltage. For example, the primary circuit 3 includes a plurality of transistors that receive the DC voltage from the primary input (+) line Vin(+) and the primary input (-) line Vin(-). By switching the plurality of transistors, the primary circuit 3 can generate an AC voltage from the DC voltage.

[0020] The secondary circuit 4 rectifies the output voltage induced in the secondary windings 2c and 2d. The secondary circuit 4 includes first and second transistors Q1 and Q2 (an example of a rectifying element). The first transistor Q1 includes a first gate terminal G1, a first source terminal S1, and a first drain terminal D1. The second transistor Q2 includes a second gate terminal G2, a second source terminal S2, and a second drain terminal D2. A first gate signal g1 is input to the first gate terminal G1, and a second gate signal g2 is input to the second gate terminal G2. The first and second drain terminals D1 and D2 are connected to the secondary windings 2c and 2d. Specifically, the first drain terminal D1 is connected to the second portion winding end 2d2, and the second drain terminal D2 is connected to the first portion winding start end 2c1. The first and second source terminals S1 and S2 are commonly connected to a secondary output (-) line Vout(-).

[0021] In this secondary circuit 4, the first and second transistors Q1 and Q2 perform switching operations based on the voltage difference applied to the first and second gate terminals G1 and G2, the first and second source terminals S1 and S2, and the first and second drain terminals D1 and D2. In the example of FIG. 3, the first and second transistors Q1 and Q2 alternately turn on and off. As a result, the output voltage from the first partial winding 2c and the output voltage from the second partial winding 2d are alternately output from the secondary output (+) line Vout(+), resulting in a rectified output voltage being output from the secondary output (+) line Vout(+). In this embodiment, the first and second transistors Q1 and Q2 form a synchronous rectifier circuit 4a.

[0022] Furthermore, the secondary circuit 4 may include a circuit related to rectification, such as a smoothing circuit, in addition to the synchronous rectifier circuit 4a.

[0023] In the present embodiment, the transistor is, for example, a MOSFET transistor (metal oxide semiconductor field effect transistor), although an IGBT (insulated gate bipolar transistor) or the like can also be used instead of the MOSFET transistor.

[0024] Next, a rectifier module 10 having first and second transistors Q1 and Q2 (an example of a rectifier) ​​will be described. In Fig. 5, (a) is a top perspective view of the rectifier module, and (b) is a rear perspective view of (a).

[0025] As shown in FIG. 5, the rectifier module 10 has an element body 11, a first lead terminal 12, and a second module terminal 13. The element body 11 has a transistor (first transistor Q1 or second transistor Q2) disposed therein and sealed with resin. The element body 11 has an element body rear surface 11a, an element body front surface 11b, and an element body side surface 11c. In this embodiment, the element body 11 has a generally rectangular parallelepiped shape, the element body rear surface 11a being the rear surface of the element body 11, the element body front surface 11b being the front surface of the element body 11 facing the element body rear surface 11a, and the element body side surface 11c being the side surface excluding the element body rear surface 11a and the element body front surface 11b.

[0026] In the following, the rectifier module 10 will be described assuming that the first transistor Q1 is disposed inside the element body 11.

[0027] In this embodiment, a first lead-out terminal 12 extends from the element body 11. The first lead-out terminal 12 is formed of a conductive material, for example, a metal containing copper as a main component. The first lead-out terminal 12 has, for example, six pins 12a to 12f, including a gate pin 12a, pins 12b to 12e, and a first module terminal 12f. The six pins 12a to 12f extend in order from the element body side surface 11c along the element body back surface 11a. The first module terminal 12f is electrically connected to the first source terminal S1. The gate pin 12a is electrically connected to the first gate terminal G1. The gate pin 12a and the first module terminal 12f extend from one of the element body side surfaces 11c to the outside of the element body 11 and toward the element body back surface 11a. Although not limited to this, in the present embodiment, the gate pin 12a and the first module terminal 12f have a portion that extends from the element body side surface 11c along the element body back surface 11a, and a portion that is bent or curved from the tip of the portion and extends toward the element body back surface 11a. Furthermore, one of the element body side surfaces 11c from which the gate pin 12a and the first module terminal 12f are drawn out is a surface that faces the side where a part of the second module terminal 13 protrudes from the element body 11. In other words, the direction in which the first draw-out terminal 12 extends from the element body 11 is opposite to the direction in which the second module terminal 13 protrudes from the element body 11.

[0028] The second module terminal 13 is electrically connected to the first drain terminal D1. The second module terminal 13 is arranged with at least a portion in contact with the element body rear surface 11a. In this embodiment, the second module terminal 13 is plate-shaped extending along the element body rear surface 11a, and a portion is arranged in surface contact with the element body rear surface 11a. The second module terminal 13 is arranged so as to be flush with the element body rear surface 11a. The remaining portion of the second module terminal 13 that is not in contact with the element body rear surface 11a extends from one of the element body side surfaces 11c toward the outside of the element body 11, along the element body rear surface 11a in a direction opposite to the direction in which the first module terminal 12f extends from the element body 11. Such a second module terminal 13 is formed of a conductive material, for example, a metal containing copper as a main component.

[0029] In the rectifier module 10, the first module terminal 12f extends outside the device body 11 and toward the device body rear surface 11a, and the second module terminal 13 is disposed with at least a portion thereof in contact with the device body rear surface 11a. The rectifier module 10 is, for example, a surface-mounted component in which the above-described state is the standard state. Therefore, the rectifier module 10 can be attached to the first substrate 20 in the standard state, eliminating the need for additional work beyond normal attachment.

[0030] As shown in FIGS. 1 to 3 , the first substrate 20 is used to mount the rectifying element module 10. The first substrate 20 is formed in a plate shape and has a first surface 21 and a first rear surface 22. The first substrate 20 is disposed along the mounting surface 61 of the cooling unit 60. Here, the first substrate 20 is disposed along a horizontal plane, and the first surface 21 and the first rear surface 22 are also along the horizontal plane. The rectifying element module 10 is disposed on the first surface 21 side of the first substrate 20. In the example of FIGS. 1 to 3 , a first group including a plurality of rectifying element modules 10a and a second group including a plurality of rectifying element modules 10b are disposed on the first substrate 20 so as to face each other with the center of the first substrate 20 in the x direction as the center. A first connector 71 is disposed on the first surface 21 between the rectifying element module 10a and the rectifying element module 10b.

[0031] In each rectifying element module 10, the first module terminal 12f extends from the element body side surface 11c of the element body 11 along the element body rear surface 11a, and its tip extending toward the element body rear surface 11a is attached to the first substrate 20. In the present embodiment, the first module terminal 12f extends from the element body side surface 11c in the x-direction and downward in the z-direction and is attached to the first substrate 20. Furthermore, the first module terminal 12f is electrically connected to the first wiring board 51 via a penetrating member (not shown). The penetrating member is made of a conductive member that penetrates the first substrate 20 in the thickness direction (z-direction) from the first surface 21 to the first rear surface 22. Furthermore, like the first module terminal 12f, the gate pin 12a extends along the element body rear surface 11a and its tip extending toward the element body rear surface 11a is attached to the first substrate 20. The gate pin 12a is electrically connected to a gate signal circuit (not shown) via, for example, a wiring (not shown) on the first substrate 20, and receives a first gate signal g1.

[0032] The element body 11 and the second module terminal 13 are in contact with each other along the first surface 21. The second module terminal 13 is electrically connected to the second wiring board 52.

[0033] A rectifier module 10 is disposed on the first surface 21 of the first substrate 20 as a first-substrate-side component. The first-substrate-side component is not limited to the rectifier module 10, and may include various electronic components other than the rectifier module 10, wiring other than the wiring for the rectifier module 10, etc. Examples of first-substrate-side components other than the rectifier module 10 include electronic components that are not adversely affected, such as malfunction or destruction, by heat generated by the rectifier module 10. Examples of first-substrate-side components other than the rectifier module 10 include chip ceramic capacitors for smoothing power supply and suppressing noise, chip resistors for gate resistors, etc., and various connectors for connecting wiring for inputting and outputting gate signals, power supplies, etc.

[0034] The second substrate 30 is disposed opposite the first substrate 20, with the second surface 31 of the second substrate 30 facing the first surface 21 of the first substrate. The second substrate 30 is formed in a plate shape and has the second surface 31 and a second back surface 32. The second substrate 30 is disposed along the first substrate 20. Here, the second substrate 30 is disposed along a horizontal plane, with the second surface 31 and the second back surface 32 also along the horizontal plane. Second-substrate components 35 are disposed on the second surface 31 of the second substrate 30. The second-substrate components 35 can form the secondary-side circuit 4 together with, for example, the rectifier module 10 of the first substrate. The first substrate 20 and the second substrate 30 are electrically connected via, for example, a connector 70, and the first-substrate components including the rectifier module 10 are electrically connected to the second-substrate components 35. In addition, a second connector 72 is disposed on the second surface 31 in correspondence with the first connector 71. The first connector 71 and the second connector 72 are coupled to form a connector 70, and the first substrate 20 and the second substrate 30 are electrically connected.

[0035] It is preferable that second-substrate-side components 35 and wiring, etc., which may be adversely affected, such as malfunction or destruction, by heat generated by the rectifier module 10, are arranged on the second surface 31 of the second substrate 30. For example, examples of second-substrate-side components 35 arranged on the second surface 31 include chip ceramic capacitors for smoothing the power supply and for noise suppression, electrolytic capacitors for smoothing the power supply and for reverse bias circuits, various connectors for connecting wiring for inputting and outputting gate signals, abnormal signals, power supplies, etc., high-speed diodes (FRDs) as protection circuits, Zener diodes as protection circuits and constant-voltage sources, photocouplers for transmitting gate signals, drive circuits for transmitting gate signals, chip resistors such as gate resistors, etc.

[0036] The first substrate 20 may be a relatively inexpensive resin substrate such as glass epoxy resin, a ceramic substrate, or the like. The first substrate 20 may be relatively thin, for example, having a thickness of 1.6 mm or more and 2.0 mm or less. The second substrate 30 may be a relatively inexpensive resin substrate such as glass epoxy resin, for example. The second substrate 30 may be relatively thin, for example, having a thickness of 1.6 mm or more and 2.0 mm or less.

[0037] The sidewall portion 40 covers a laterally open area between the first substrate 20 and the second substrate 30, which are arranged horizontally and face each other. The sidewall portion 40 is plate-shaped and arranged perpendicular to the first substrate 20 and the second substrate 30. The sidewall portion 40 is formed, for example, from an insulating material. In the example of FIG. 3 , the sidewall portion 40 extends in the z direction from the cooling portion 60 at positions corresponding to both edges of the first and second substrates 20, 30. A sealed space Sp is formed by the space surrounded by the first substrate 20, the second substrate 30, and the sidewall portion 40. The first surface 21 of the first substrate 20, the second surface 31 of the second substrate 30, the rectifying element module 10, a portion of the second wiring board 52, and the like are located in the sealed space Sp.

[0038] 3, the sealed space Sp may include the area from the arrangement surface 61 of the cooling unit 60 to the second surface 31 of the second substrate 30. Therefore, the first substrate 20, the second surface 31 of the second substrate 30, the arrangement surface 61 of the cooling unit 60, the rectifier module 10, the first wiring board 51, part of the second wiring board 52, and the insulating heat dissipation sheet 65 may be located in the sealed space Sp.

[0039] The first wiring board 51 is disposed between the first substrate 20 and the cooling unit 60 in contact with the first back surface 22 of the first substrate 20 and the mounting surface 61 of the cooling unit 60. In the example of FIGS. 2 and 3 , the first wiring board 51 is plate-shaped, extends longitudinally in the y direction, and is formed of a conductive material such as Cu or Al. The first group of rectifier element modules 10a and the second group of rectifier element modules 10b are disposed on the first substrate 20, facing each other with the first wiring board 51 extending in the y direction interposed therebetween. The first lead-out terminals 12 of the rectifier element modules 10a and the first lead-out terminals 12 of the rectifier element modules 10b face each other across the center of the first substrate 20 in the x direction. In this case, the first module terminal 12f of the first group of rectifier element modules 10a and the first module terminal 12f of the second group of rectifier element modules 10b face each other with the first wiring board 51 interposed therebetween. The first module terminal 12f of the rectifier module 10a extends toward the first wiring board 51 and penetrates the first substrate 20 via a penetration member to be connected to the first wiring board 51. Similarly, the first module terminal 12f of the rectifier module 10b extends toward the first wiring board 51 and penetrates the first substrate 20 via a penetration member to be connected to the first wiring board 51. The first wiring board 51 connects the first module terminal 12f of the rectifier module 10 to the secondary-side output (-) line Vout(-) via the cooling unit 60, for example.

[0040] The second wiring board 52 is disposed on the first surface 21 of the first substrate 20 and extends outside the sealing unit 100 of the rectifier module. In the example of FIGS. 2 and 3 , the second wiring board 52 includes a second wiring board 52 corresponding to the rectifier module 10a of the first group and a second wiring board 52 corresponding to the rectifier module 10b of the second group. The second wiring boards 52 are disposed opposite each other with respect to the center in the x direction. Each second wiring board 52 has a plate shape bent in the xz plane and extends in the y direction. The second wiring board 52 is formed of a conductive material such as Cu or Al. One of the bent portions of the second wiring board 52 is disposed on the first surface 21 of the first substrate 20, and the other bent portion of the second wiring board 52 is disposed along the side wall 40. The second wiring board 52 extends upward along the side wall 40 to the outside of the sealing unit 100 of the rectifier module. The second wiring boards 52 are electrically connected to the second module terminals 13 of the rectifier element modules 10 on the first substrate 20. Each second wiring board 52 connects, for example, the second module terminals 13 of the rectifier element modules 10 to the secondary output (+) line Vout(+).

[0041] The first wiring board 51 may electrically connect the first module terminal 12f and the secondary output (+) line Vout(+), and the second wiring board 52 may electrically connect the second module terminal 13 and the secondary output (-) line Vout(-).

[0042] The cooling unit 60 cools at least the first substrate 20. The cooling unit 60 is made of a conductive material such as Cu or Al. In the example of FIG. 3 , the cooling unit 60 has an arrangement surface 61, which is a horizontal surface and serves as the upper surface of the cooling unit 60. The cooling unit 60 has a first wiring board 51 and an insulating heat dissipation sheet 65 arranged on the arrangement surface 61. The cooling unit 60 has the first substrate 20 arranged on it, with the first wiring board 51 and the insulating heat dissipation sheet 65 interposed therebetween. The insulating heat dissipation sheet 65 is divided into two. One insulating heat dissipation sheet 65 is arranged on the cooling unit 60 in a position corresponding to the portion of the first substrate 20 where the rectifying element modules 10a of the first group are arranged. The other insulating heat dissipation sheet 65 is arranged on the cooling unit 60 in a position corresponding to the portion of the first substrate 20 where the rectifying element modules 10b of the second group are arranged. This makes it possible to insulate the rectifier module 10a of the first group from the rectifier module 10b of the second group and to dissipate heat generated by the first substrate 20 and the rectifier module 10. Note that the insulating heat dissipation sheet 65 may be disposed corresponding to either the rectifier module 10a of the first group or the rectifier module 10b of the second group.

[0043] When the rectifier module 10 includes the first transistor Q1, the cooling unit 60 primarily cools heat generated by a first current passing through the first source terminal S1 and a second current passing through the second drain terminal D1. Because relatively large first and second currents flow through the rectifier module 10, the heat generated by the first and second currents is also relatively large. The heat generated by the first and second currents may occur in the rectifier module 10 or in the first substrate 20 through which the first and second currents pass. The cooling unit 60 can cool the heat generated by the first and second currents in the first substrate 20 and the rectifier module 10.

[0044] The cooling unit 60 is not limited in configuration as long as it can cool the first substrate 20 and the rectifying element module 10. Examples of the cooling unit 60 include a water-cooled heat sink made up of one or more fins and conduits that allow a liquid such as water to flow through, and an air-cooled heat sink made up of one or more fins that can dissipate heat.

[0045] The above explanation relates to a rectifier module 10 in which a first transistor Q1 is arranged inside the rectifier module 10. Below, we will briefly explain a rectifier module 10 in which a second transistor Q2 is arranged, focusing on the differences.

[0046] The first module terminal 12f is electrically connected to the second source terminal S2. The gate pin 12a is electrically connected to the second gate terminal G2. The second module terminal 13 is electrically connected to the second drain terminal D2.

[0047] The first module terminal 12f extends to the outside of the element body 11 and also extends toward the element body rear surface 11a, and is attached to the first substrate 20. The first module terminal 12f penetrates the first substrate 20 via a penetrating member and is electrically connected to the cooling unit 60. The gate pin 12a extends to the outside of the element body 11 and also extends toward the element body rear surface 11a, and is attached to the first substrate 20. The gate pin 12a is electrically connected to a gate signal circuit (not shown), for example, via wiring (not shown) on the first substrate 20, and is supplied with a second gate signal g2.

[0048] The second source terminal S2 is electrically connected to the secondary output (-) line Vout(-), and the cooling unit 60 mainly cools the heat generated by the first current passing through the second source terminal S2. The second drain terminal D2 is electrically connected to the first partial winding starting end 2c1 of the first partial winding 2c, and the cooling unit 60 mainly cools the heat generated by the second current passing through the second drain terminal D2.

[0049] (2) Overall layout and configuration of the sealing unit of the rectifier module Next, the arrangement and configuration of the rectifier module 10, the first substrate 20, the second substrate 30, the side wall portion 40, the first wiring board 51, the second wiring board 52, the cooling portion 60, the insulating heat dissipation sheet 65, and the connector 70 in the sealing unit 100 of the rectifier module will be summarized and further explained.

[0050] In the sealed unit 100 of the rectifier module of this embodiment, the cooling unit 60 is disposed at the bottom. A pair of insulating heat dissipation sheets 65 are disposed opposite the mounting surface 61 of the cooling unit 60, sandwiching the first wiring board 51 in the x-direction. A first substrate 20 is disposed on the upper surfaces of the first wiring board 51 and the pair of insulating heat dissipation sheets 65. A rectifier module 10a is disposed on the first substrate 20 corresponding to one of the insulating heat dissipation sheets 65, and a rectifier module 10b is disposed corresponding to the other insulating heat dissipation sheet 65. The first module terminals 12f of the rectifier modules 10a and 10b are disposed facing each other in the x-direction. The first module terminals 12f penetrate the first substrate 20 via a penetration member (not shown) and are electrically connected to the first wiring board 51. The first wiring board 51 is electrically connected to the secondary-side output (-) line Vout(-) via the cooling unit 60. The pair of second wiring boards 52 are disposed opposite each other with respect to the center in the x-direction. Each second wiring board 52 is electrically connected to the second module terminal 13 of each rectifier module 10a, 10b. The second substrate 30 is disposed opposite the first substrate 20. The second wiring board 52 along the side wall portion 40 penetrates the end of the second substrate 30, is drawn out to the outside, and is electrically connected to the secondary output (+) line Vout(+).

[0051] With this configuration, a sealed space Sp is formed that is surrounded by the first substrate 20, the second substrate 30, and the sidewall portion 40. At least the rectifying element module 10 is disposed in the sealed space Sp, and also the first surface 21 of the first substrate 20, the second surface 31 of the second substrate 30, a part of the second wiring board 52, etc. are disposed therein.

[0052] In this embodiment, a connector 70 that electrically connects the first substrate 20 and the second substrate 30 is disposed in the center of the first substrate 20, that is, between the rectifying element modules 10a and 10b. The connector 70 is also disposed, for example, in the central portions of the first substrate 20 and the second substrate 30.

[0053] In this embodiment, as shown in Figure 2, multiple rectifier modules 10 are arranged side by side in the y direction on the first surface 21. Each rectifier module 10 has a first or second transistor Q1 or Q2 as appropriate. The configuration and arrangement of each rectifier module 10 are the same as those described above.

[0054] (3) Current path Next, a description will be given of the current flow in the sealing unit 100 of the rectifier module. Whether the first transistor Q1 or the second transistor Q2 is arranged inside the rectifier module 10, the current flow in the sealing unit 100 of the rectifier module is the same.

[0055] FIG. 6 is a current path diagram showing the flow of current in the sealing unit of the rectifier module of FIG. A part of a first current path 90 of the first current extending from the first source terminal S1 (or the second source terminal S2) via the first module terminal 12f to the secondary-side output (-) line Vout(-) is composed of a first through current path 91 through which the first current passes through the first substrate 20 from the first surface 21 to the first rear surface 22. The length of the first through current path 91 is equal to the thickness t of the first substrate 20 extending from the first surface 21 to the first rear surface 22. The part of the first current path 90 further includes a first wiring board current path 92 through which the first current passes through the first wiring board 51.

[0056] A part of the second current path 80 of the second current, which runs from the first drain terminal D1 (or the second drain terminal D2) through the second module terminal 13 and the second partial winding 2d (or the first partial winding 2c) to the secondary output (+) line Vout(+), includes a second wiring board current path 81 through which the second current passes through the second wiring board 52.

[0057] When the first transistor Q1 is on and the second transistor Q2 is off, a signal from the secondary output (-) line Vout(-) is transmitted as a first current to the first source terminal S1 via a first current path 90 including a first through current path 91 and a first wiring plate current path 92, and a current flows from the first source terminal S1 to the first drain terminal D1. Next, a second current flows from the first drain terminal D1 to the second partial winding end 2d2 of the second partial winding 2d via a second current path 80 including a second wiring plate current path 81. Then, an output voltage induced in the second partial winding 2d is output from the second partial winding start end 2d1 and the secondary output (+) line Vout(+).

[0058] On the other hand, when the second transistor Q2 is on and the first transistor Q1 is off, a signal from the secondary output (-) line Vout(-) is transmitted as a first current to the second source terminal S2 via a first current path 90 including a first through current path 91 and a first wiring plate current path 92, and a current flows from the second source terminal S2 to the second drain terminal D2. Next, a second current flows from the second drain terminal D2 to the first partial winding start end 2c1 of the first partial winding 2c via a second current path 80 including a second wiring plate current path 81. Then, an output voltage induced in the first partial winding 2c is output from the first partial winding end 2c2 and the secondary output (+) line Vout(+).

[0059] (4) Action and effect (4-1) According to the above configuration, since the rectifier module 10 is disposed in the sealed space Sp, it is possible to isolate the rectifier module 10 from the external environment contaminated by dust, humidity, chemical atmosphere, etc. This will be further explained below.

[0060] Here, the rectifier circuit that generates a rectified output voltage is configured, for example, by combining multiple rectifier element modules 10 as described above. Each rectifier element module 10 may have first and second transistors Q1 and Q2 (an example of rectifier elements) having a switching function and module terminals 12f and 13 for inputting and outputting signals to the first and second transistors Q1 and Q2 (an example of rectifier elements). The first and second transistors Q1 and Q2 (an example of rectifier elements) are configured, for example, as an element body 11 molded with molding resin or the like with the first and second transistors Q1 and Q2 (an example of rectifier elements) disposed therein. The module terminals 12f and 13 are terminals electrically connected to the first and second transistors Q1 and Q2 (an example of rectifier elements) and extend from the element body 11 to the outside. The module terminals 12f and 13 input and output signals between wiring for the rectifier element module 10 and the first and second transistors Q1 and Q2 (an example of rectifier elements).

[0061] According to the above configuration, since the rectifier module 10 is disposed in the sealed space Sp, the rectifier module 10 can be isolated from a highly polluted external environment. This can prevent contamination, corrosion, and dust from adhering to the rectifier module 10. This can prevent adverse effects such as malfunction, damage, and shortened lifespan of the first and second transistors Q1 and Q2 (an example of a rectifier element) in the rectifier module 10, and ultimately of the rectifier circuit. In particular, the module terminals 12f, 13, etc., which are not covered with mold resin, can be isolated from the highly polluted external environment.

[0062] The rectifier module 10 may be used in a highly polluted environment, such as a metal plating site (factory). The rectifier module 10 is cooled by drawing in air from this highly polluted environment. Therefore, if the rectifier module 10 is not placed in the sealed space Sp, the rectifier module 10 will be actively exposed to the highly polluted environment, which may adversely affect the rectifier circuit formed by the rectifier module 10, such as malfunctioning. The sealing unit 100 for the rectifier module described above can isolate the rectifier circuit from the highly polluted external environment.

[0063] Furthermore, wiring and the like for the rectifier module 10 can be formed on the first surface 21 of the first substrate 20. Because the first surface 21 is also located in the sealed space Sp, contamination, corrosion, dust adhesion, and the like to the wiring and the like for the rectifier module 10 can be suppressed. This makes it possible to suppress adverse effects such as signal interruption due to damage or disconnection of the wiring and the like for the rectifier module 10, and noise being introduced into the signal. Note that by arranging wiring and the like other than the wiring for the rectifier module 10 in the sealed space Sp, adverse effects on the wiring can be suppressed.

[0064] Furthermore, in the above-described sealed unit 100 of the rectifier module, the rectifier module 10 is formed on the first substrate 20, so that the sealed unit 100 of the rectifier module can be made smaller and less expensive. This will be specifically described below.

[0065] As described above, the external environment in which the rectifier module 10 is used may be highly polluted. Therefore, it is necessary to prevent the rectifier circuit from malfunctioning due to contamination. Therefore, to isolate the relatively large rectifier elements currently used, which are composed of diodes, from the external environment, the rectifier elements are encapsulated in a molded resin, resulting in a relatively large molded component. Furthermore, the connection between the molded component and other components is not performed using wiring on a substrate, but rather using, for example, thick and wide copper wiring coated with an insulating material. Therefore, although the rectifier circuit, which is composed of the molded component and the copper wiring coated with an insulating material, is not exposed to the external environment, it results in increased size and cost. On the other hand, in the above-described configuration, the relatively small rectifier module 10 mounted on the first substrate 20 is disposed in the sealed space Sp together with the first substrate 20. Furthermore, connections between the rectifier modules 10 and between the rectifier module 10 and other components can be performed using relatively thin wiring formed on the first substrate 20. Furthermore, the first substrate 20 itself is plate-shaped and thin. Therefore, by employing the above-described sealing unit 100 of the rectifier module, it is possible to achieve a reduction in size and cost.

[0066] (4-2) According to the above configuration, the rectifier module 10 is disposed on the first substrate 20, while the second-substrate-side components 35, wiring, etc., whose performance tends to deteriorate due to the influence of heat generated by the rectifier module 10, are disposed on the second substrate 30, separate from the first substrate 20. This allows components that are susceptible to the influence of heat to be isolated from the rectifier module 10. Therefore, the influence of heat on the components that are susceptible to the influence of heat can be suppressed compared to when the rectifier module 10 and the components that are susceptible to the influence of heat are disposed on the same substrate.

[0067] Furthermore, since the second surface 31 of the second substrate 30 is also located inside the sealed space Sp, it is possible to prevent the second substrate side components 35 and wiring, etc., which are easily affected by heat and are arranged on the second substrate 30, from being adversely affected by the external environment, such as malfunction, damage, shortened lifespan, etc.

[0068] Furthermore, since the first substrate 20 and the second substrate 30 are opposed to each other, electrical connection between the first substrate 20 and the second substrate 30 can be easily ensured.

[0069] (4-3) According to the above configuration, the rectifier module 10 is included in the secondary circuit 4 connected to the transformer 2, and a large current flows therethrough, which tends to generate a large amount of heat. According to the above configuration, the second-substrate-side components 35 and wiring, which are susceptible to the effects of heat, can be arranged on the second substrate 30 and isolated from the first substrate 20 on which the rectifier module 10 is arranged. This makes it possible to protect the components, etc., on the second substrate 30 that are susceptible to the effects of heat from the effects of heat. Therefore, the above-described sealed unit 100 of the rectifier module is useful when applied to the secondary circuit 4 of the transformer 2.

[0070] (4-4) According to the above configuration, the rectifying element module 10 is disposed on the first surface 21 of the first substrate 20, and the cooling unit 60 is provided on the first back surface 22 side of the first substrate 20. Therefore, the heat generated by the first substrate 20 on which the rectifying element module 10 is disposed can be easily cooled by the cooling unit 60.

[0071] (4-5) According to the above configuration, a portion of the first current path 90 for the current flowing through the rectifier module 10 is formed by the first through-current path 91. Therefore, compared to when the entire first current path 90 is formed as wiring on the first substrate 20, heat generation in the first substrate 20 due to the current flowing through the rectifier module 10 can be suppressed. In other words, by reducing the length of the wiring through which the current flows on the first substrate 20, heat generation in the first substrate 20 due to the current flowing through the wiring can be suppressed. This makes it possible to suppress heat generation in the rectifier module 10 due to the influence of heat generated by the first substrate 20. Furthermore, the heat generated by the first substrate 20 and the rectifier module 10 is cooled by the cooling unit 60. As a result, damage to the rectifier module 10 due to heat generation can be suppressed.

[0072] (4-6) According to the above configuration, the connector 70 can support the first substrate 20 and the second substrate 30 in a state where they face each other, and can also electrically connect these substrates 20, 30 together.

[0073] (4-7) According to the above configuration, since the side wall portion 40 is formed from an insulating material, it is possible to prevent current from flowing through the side wall portion 40 and to form a desired current path.

[0074] As described above, the embodiment of the present invention has been disclosed in the above description, but the present invention is not limited to this. In other words, various modifications can be made to the above-described embodiments in terms of mechanism, shape, material, quantity, position, arrangement, etc. without departing from the scope of the technical idea and purpose of the present invention, and these modifications are included in the present invention.

[0075] 2. Variations (1) About the sealed space Sp In the sealed unit 100 of the rectifying element module shown in the above embodiment, the sealed space Sp is formed by combining the first substrate 20, the second substrate 30, and the side wall portion 40. However, the side wall portion 40 may be omitted as long as the sealed space Sp can be formed. For example, the sealed space Sp can be formed by the first substrate 20 and the second substrate 30 by bending the edge of the first substrate 20 or by bending the edge of the second substrate 30 to function as the side wall portion 40. In the above embodiment, the sidewall 40 is formed of an insulating material. However, the sidewall 40 may be formed of the same material as the first substrate 20 and the second substrate 30, for example, a substrate.

[0076] (2) Rectifier module In the above embodiment, in the rectifier element module 10, the first lead-out terminal 12 is led out from the element body side surface 11c, and the second module terminal 13 extends along the element body back surface 11a. However, in the rectifier element module 10, the second module terminal 13 on the element body back surface 11a may not be used as a terminal, and only the first lead-out terminal 12 may be used as a terminal. For example, the first lead-out terminal 12 includes a gate pin 12a that receives a gate signal input, a first module terminal 12f electrically connected to the first source terminal S1, and a second module terminal 12d electrically connected to the first drain terminal D1. The second module terminal 12d is electrically connected to the second wiring board 52. In this case, the second module terminal 12d is used in place of the second module terminal 13 in the above embodiment.

[0077] The rectifier module 10 is a surface-mounted component, but the form of the rectifier module 10 is not limited thereto, and it may be, for example, a discrete component.

[0078] (3) Electronic components on the second board In the above embodiment, second-board-side components 35 are arranged on second board 30. However, it is not necessary for components to be arranged on second board 30.

[0079] (4) Rectifier circuit In the above embodiment, the secondary circuit 4 includes a synchronous rectifier circuit using the first and second transistors Q1 and Q2. However, the secondary circuit 4 may include a rectifier circuit instead of a synchronous rectifier circuit, as long as it can rectify the output voltage induced in the secondary windings 2c and 2d. The rectifier circuit may include, for example, a diode (an example of a rectifier element) instead of the first and second transistors Q1 and Q2 as a rectifier element. The diode has an anode (an example of a first element terminal) and a cathode (an example of a second element terminal). Current flows in the forward direction from the anode to the cathode, but not in the reverse direction from the cathode to the anode. Therefore, the diode performs switching operation based on the voltage difference applied to the anode and cathode. The rectified output voltage due to the rectification action of the diode is obtained as the output of the rectifier circuit. [Explanation of symbols]

[0080] 1: Power conversion device 2: Transformer 2a: Core 2b: Primary winding 2c, 2d: Secondary winding, first partial winding, second partial winding 3: Primary side circuit 4:Secondary side circuit 4a:Synchronous rectifier circuit 10, 10a, 10b: Rectifier element module 11: Element body 11a: Back of the device body 11b: Front of element body 11c: Side of the element body 12: 1st extraction terminal 12a: Gate pin 12b~12e: Pin 12f: 1st module terminal 12d, 13: Second module terminal 20: First board 21 :1st surface 22: 1st back 30: Second board 31: 2nd surface 32: 2nd back 35: Second board side components 40: Side wall 51: 1st wiring board 52: 2nd wiring board 60: Cooling section 61: Placement surface 65: Insulating heat dissipation sheet 70: Connector 71, 72: 1st and 2nd connectors 80: Second current path 81: Second wiring board current path 90: First current path 91: First through current path 92: First wiring board current path 100: Sealing unit for rectifier module D1, D2: First and second drain terminals G1, G2: First and second gate terminals Q1, Q2: First and second transistors Sp: Sealed space S1, S2: 1st to 4th source terminals (1st element terminals) Vin(+): Primary side input (+) line Vin(-): Primary side input (-) line Vout(+): Secondary output (+) line Vout(-): Secondary output (-) line g1, g2: 1st and 2nd gate signals

Claims

1. a rectifier module having a rectifier; a first substrate having a plate shape, a first surface and a first back surface, the rectifier module being disposed on the first surface; a second substrate having a plate shape, a second front surface and a second back surface, and disposed relative to the first substrate such that the second surface faces the first surface; A sealing unit for a rectifying element module comprising: a side wall portion that covers an area that is open laterally between the first substrate and the second substrate, thereby forming a sealed space in which the rectifying element module is disposed together with the first substrate and the second substrate.

2. The sealing unit of the rectifying element module described in claim 1, wherein a component electrically connected to the first substrate and whose performance tends to deteriorate due to the influence of heat generated by the rectifying element module is arranged on the second surface of the second substrate.

3. 3. The sealed unit of a rectifier module according to claim 1, wherein the rectifier module is included in a secondary circuit connected to a transformer.

4. 3 . The sealing unit of the rectification element module according to claim 1 , further comprising a cooling portion arranged on the first rear surface side of the first substrate, for cooling the first substrate.

5. The cooling portion is formed from a conductive material, 5. The sealing unit of a rectifier module according to claim 4, wherein a part of a current path of a current flowing through the rectifier module is constituted by a through current path penetrating the first substrate from the first front surface to the first rear surface.

6. 3 . The sealing unit of the rectifier module according to claim 1 , further comprising a connector that supports the second substrate relative to the first substrate and electrically connects the first substrate and the second substrate.

7. 3. The sealing unit of a rectifier module according to claim 1, wherein the side wall portion is formed of an insulating material.

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