switching power supply

Abstract

A switching power supply (10) comprising a high-side switching element (11) and a low-side switching element (12) connected in series with the high-side switching element (11); wherein the switching power supply (10) comprises: a base plate (20) having an insulating layer (21) and a conductive layer (22), the conductive layer (22) being provided on a surface of the insulating layer (21); a plurality of high-side transistors (110) provided on the conductive layer (22), the high-side transistors (110) being connected in parallel to form the high-side switching element (11); and a plurality of low-side transistors (120) provided on the conductive layer (22), the low-side transistors (120) being connected in parallel to form the low-side switching element (12), and a smoothing capacitor section (13) provided on the conductive layer (22), wherein the smoothing capacitor section (13) comprises a plurality of capacitors (130) provided on the conductive layer (22), the plurality of capacitors (130) corresponding to a sum of the plurality of high-side transistors (110) and the plurality of low-side transistors (120), and each of the plurality of capacitors (130) is arranged adjacent to a corresponding transistor (110, 120), the corresponding transistor (110, 120) being one of the plurality of high-side transistors (110) and the plurality of low-side transistors (120), wherein the plurality of high-side transistors (110) are arranged in series next to the plurality of low-side transistors (120).

Description

Technical field

[0001] The present disclosure relates to switching power supplies. Technical background

[0002] Switching power supplies are already known. For example, Patent Document 1 discloses a base-mounted inverter device in which a semiconductor chip is mounted on a surface of a metal substrate with a ceramic-based substrate in between. (The semiconductor chip includes switching elements and diodes that form an inverter.) In this device, the three-phase inverter has an upper arm and a lower arm; the upper arm includes a switching element (high-side switching element), and the lower arm includes a switching element (low-side switching element). A collector of the high-side switching element is mounted on a wiring pattern on the upper arm side, and an emitter of the low-side switching element is mounted on a wiring pattern on the lower arm side.The emitter of the high-side switching element is connected to the collector of the low-side switching element via a beam lead electrode to connect the upper and lower arms.

[0003] Patent Document 2 describes a conductive layer on a surface of an insulating layer comprising a power source-side conductor track, a ground-side conductor track, and an output-side conductor track. A first switching element is surface-mounted on the power source-side conductor track and connected to the output-side conductor track. A second switching element is surface-mounted on the output-side conductor track and connected to the ground-side conductor track. A capacitor is surface-mounted on the ground-side conductor track and connected to the power source-side conductor track or the output-side conductor track.

[0004] Patent document 3 describes a circuit arrangement comprising at least two electrical components and an energy storage device, which are arranged on electrically conductive plates in such a way that the shortest possible current paths with a minimum parasitic inductance are created.

[0005] Patent Document 4 describes an electrical power module including power transistors and control components for controlling the power transistors, wherein the module is cooled, in particular, by conduction cooling. The module also includes an AMB / Si3N4 type main substrate supporting the power transistors. This main substrate itself forms a heat-dissipating base plate for dissipating the heat generated by the power transistors by being arranged in the module in direct contact with the support structure, which ensures conduction cooling when the module is in place. A ceramic substrate supporting the control components is also included. This ceramic substrate is itself supported by the main substrate. BibliographyPatent literature Patent Document 1: Unexamined Japanese Patent Publication No. 2001-286156 (JP 2001- 286 156 A) Patent specification 2: DE 11 2016 006 651 T5 Patent specification 3: DE 102 55 629 A1 Patent specification 4: US 2015 / 0 077 942 A1 Summary of the inventionTechnical problem

[0006] In a switching power supply as disclosed in Patent Document 1, a high-side switching element and a low-side switching element are each expected to include a plurality of transistors. If the plurality of transistors (high-side transistors) constituting the high-side switching element are densely arranged and the plurality of transistors (low-side transistors) constituting the low-side switching element are also densely arranged, heat may concentrate on the high-side switching element or low-side switching element. For example, during a period when the high-side switching element is in an ON state and the low-side switching element is in an OFF state, the plurality of high-side transistors are heated. As a result, heat may concentrate on the accumulation of the plurality of high-side transistors (i.e., the high-side switching element).During a period when the high-side switching element is in an OFF state and the low-side switching element is in an ON state, the plurality of low-side transistors heats up. As a result, heat may concentrate on the accumulation of the plurality of low-side transistors (i.e., the low-side switching element). Solution to the task

[0007] A switching power supply according to one aspect of the present disclosure is a switching power supply according to claim 1. Advantageous effect of the invention

[0008] According to the present disclosure, it is possible to reduce heat concentration on a high-side switching element and a low-side switching element. Short description of the drawing Fig. 1 is a circuit diagram illustrating an arrangement of a switching power supply according to a first exemplary embodiment. Fig. 2 is a plan view illustrating the arrangement of the switching power supply according to the first exemplary embodiment. Fig. 3 is a sectional view illustrating the arrangement of the switching power supply according to the first exemplary embodiment. Fig. 4 is a sectional view illustrating the arrangement of the switching power supply according to the first exemplary embodiment. Fig. 5 is a sectional view illustrating a first modification of a connecting structure of a connecting member. Fig. 6 is a sectional view showing a second modification of the connecting structure of the connecting member. Fig. 7 is a sectional view showing a third modification of the connection structure of the connecting member. Fig. 8 is an exploded perspective view showing the third modification of the connection structure of the connecting member. Fig. 9 is a sectional view showing a fourth modification of the connecting structure of the connecting member. Fig. 10 is a plan view illustrating an arrangement of a switching power supply according to a second exemplary embodiment. Fig. 11 is a plan view illustrating an arrangement of a switching power supply according to a third exemplary embodiment. Fig. 12 is a plan view illustrating an arrangement of a switching power supply according to a first modification of the third exemplary embodiment. Fig. 13 is a plan view illustrating an arrangement of a switching power supply according to a second modification of the third exemplary embodiment. Fig. 14 is a plan view illustrating an arrangement of a switching power supply according to a third modification of the third exemplary embodiment. Description of embodiments

[0009] Exemplary embodiments are described in detail below with reference to the accompanying drawings. It should be noted that identical or equivalent parts are designated by identical reference numerals, and the description of such parts will not be repeated. (First exemplary embodiment)

[0010] Fig. 1 illustrates a configuration of the switching power supply 10 according to an exemplary embodiment. The switching power supply 10 performs a switching operation to convert electric power supplied from a power supply (in this example, a DC power supply P) into output electric power, and then supplies this output electric power to a target object to be driven (in this example, a motor M). In this example, the motor M may be a three-phase AC motor, and the switching power supply 10 may serve as an inverter that converts DC power into three-phase AC power.

[0011] The switching power supply 10 includes a power supply line LP, a ground line LG, one or more output lines LO, one or more switching sections SW, and a smoothing capacitor section 13. The smoothing capacitor section 13 is connected between the power supply line LP and the ground line LG. Each of the switching sections SW includes a high-side switching element 11 and a low-side switching element 12 connected in series between the power supply line LP and the ground line LG. An intermediate point of each switching section SW (i.e., a node between the high-side switching element 11 and the low-side switching element 12) is connected to the target object to be controlled (in this example, the motor M) via a corresponding output line LO. In the figure, a freewheeling diode is connected in parallel to each of the high-side switching elements 11 and the low-side switching elements 12.This freewheeling diode corresponds to parasitic diodes that are parasitic in the high-side switching elements 11 and low-side switching elements 12.

[0012] In this example, the switching power supply 10 includes three output lines (a first output line LOu, a second output line LOv, and a third output line LOw) and three switching parts (a first switching part SWu, a second switching part SWv, and a third switching part SWw). One end (the positive electrode) of the DC power supply P is connected to the power supply line LP, while the other end (the negative electrode) of the DC power supply P is connected to the ground line LG.

[0013] The first switching part SWu includes a first high-side switching element 11u and a first low-side switching element 12u. A node between the first high-side switching element 11u and the first low-side switching element 12u is connected to a U-phase winding (not shown) of the motor M via the first output line LOu.

[0014] The second switching part SWv includes a second high-side switching element 11v and a second low-side switching element 12v. A node between the second high-side switching element 11v and the second low-side switching element 12v is connected to a V-phase winding (not shown) of the motor M via the second output line LOv.

[0015] The third switching part SWw includes a third high-side switching element 11w and a third low-side switching element 12w. A node between the third high-side switching element 11w and the third low-side switching element 12w is connected to a W-phase winding (not shown) of the motor M via the third output line LOw. [Structure of the switching power supply]

[0016] Next, a description will be given of a structure of the switching power supply 10 according to the first exemplary embodiment with reference to Fig. 2, Fig. 3 and Fig. 4. Fig. 2 is a schematic plan view illustrating a planar structure of the switching power supply 10. Fig. 3 and Fig. 4 are each schematic sectional views illustrating a part of a sectional structure of the switching power supply 10. Fig. 3 corresponds to a sectional view along the line III-III in Fig. 2; Fig. 4 corresponds to a sectional view along the line IV-IV in Fig. 2. The switching power supply 10 is provided with a base plate 20. <grundplatte>

[0017] The base plate 20 includes an insulating layer 21, a conductive layer 22, and a heat dissipating layer 23. In this example, the base plate 20 is formed in a rectangular, flat shape. In the example of Fig. 2, a longitudinal direction of the base plate 20 corresponds to a first direction X (direction from right to left in Fig. 2), while a lateral direction of the base plate 20 corresponds to a second direction Y (direction from top to bottom in Fig. 2).

[0018] The insulating layer 21 made of an insulating material (e.g., an epoxy resin plate) is formed in a flat shape. The conductive layer 22 made of a conductive material (e.g., copper) is provided on one surface of the insulating layer 21 and formed into a thin film. The heat dissipation layer 23 made of a heat-conducting material (e.g., aluminum) is provided on the other surface of the insulating layer 21.

[0019] In this example, the thickness of the insulating layer 21 is smaller than those of the conductive layer 22 and the heat dissipation layer 23. The heat dissipation layer 23 has a greater thickness than the conductive layer 22. For example, the thickness of the insulating layer 21 may be set to about 100 µm, the thickness of the conductive layer 22 may be set to about 200 µm, and the thickness of the heat dissipation layer 23 may be set in a range from about 1 mm to about 3 mm. A thermal conductivity of the insulating layer 21 is lower than a thermal conductivity of one of the conductive layer 22 and the heat dissipation layer 23. The thermal conductivity of the conductive layer 22 is higher than the thermal conductivity of the heat dissipation layer 23. <Wärmeableitelement>

[0020] In this example, the heat dissipation layer 23 is bonded and fixed to a heat dissipation member 24. For example, the heat dissipation member 24 corresponds to a part of a housing (not shown) that houses the base plate 20. The heat dissipation member 24 is cooled by air cooling (air-cooled) or liquid cooling (cooled with a liquid such as cooling water or cooling oil). <befestigungsschraube>

[0021] The base plate 20 is fixed to the heat dissipation member 24 with a plurality (six in this example) of fixing screws 25. The fixing screws 25 penetrate the base plate 20 and are fixed to the heat dissipation member 24. More specifically, insertion holes (not shown) through which the fixing screws 25 pass are provided in the base plate 20. Threaded holes (not shown) are provided in the heat dissipation member 24, into which the fixing screws 25 are fixed. The fixing screws 25 pass through the insertion holes in the base plate 20 and are fixed in the threaded holes in the heat dissipation member 24. In this case, gaps are formed between the threaded portions of the fixing screws 25 and the corresponding insertion holes in the base plate 20.In addition, insulating members (not shown), such as insulating paper members, are provided between the heads of the fastening screws 25 and the conductive layer 22 of the base plate 20. This arrangement reliably electrically insulates the conductive layer 22 of the base plate 20 from both the heat dissipation layer 23 and the heat dissipation member 24. <verdrahtungsmuster>

[0022] Wiring patterns are formed in the conductive layer 22. More specifically, an output pattern 30, a power supply pattern 40, and a ground pattern 50 are formed in the conductive layer 22. The output pattern 30, the power supply pattern 40, and the ground pattern 50 are formed with a predetermined distance therebetween so that the output pattern 30, the power supply pattern 40, and the ground pattern 50 are not short-circuited. <ausgangsmuster>

[0023] The output pattern 30 is provided to connect high-side switching elements 11 with corresponding low-side switching elements 12 in series in the switching part SW. In short, the output pattern 30 is a part that connects the intermediate points (nodes between the high-side switching elements 11 and the low-side switching elements 12) in the Fig. 1 forms the switching part SW.

[0024] In this example, the output pattern 30 includes a first output region 301 to a third output region 303, each corresponding to a first switching part SWu to a third switching part SWw. Hereinafter, the first output region 301 to the third output region 303 are collectively referred to as "output regions 300." The output regions 300 are configured to extend in the first direction X. More specifically, the first output region 301 to the third output region 303 have configurations described below.

[0025] The first output portion 301 to the third output portion 303 are formed to extend in the first direction X and are spaced apart in the second direction Y, which is perpendicular to the first direction X. In this example, the first direction X refers to a direction along the longitudinal direction of the base plate 20, while the second direction Y refers to a direction along the lateral direction of the base plate 20. The first output portion 301 is near one end (the lower end in Fig. 2) of the base plate 20 in the lateral direction. The second output region 302 is arranged in a center of the base plate 20 in the lateral direction. The third output region 303 is arranged near the other end (the upper end in Fig. 2) of the base plate 20 in the lateral direction. <stromversorgungsmuster>

[0026] The power supply pattern 40 is provided to connect the power supply (DC power supply P in this example) to high-side switching elements 11 of the switching parts SW. In short, the power supply pattern 40 is a part that covers a region of the Fig. 1, which forms the power supply line LP. < <stromversorgungsbereich>>

[0027] In this example, the power supply pattern 40 includes six wiring areas (a first power supply area 401 to a sixth power supply area 406). Hereinafter, the first power supply area 401 to the sixth power supply area 406 are collectively referred to as "power supply areas 400."

[0028] The plurality of power supply regions 400 are lined up at intervals in an extending direction of the output regions 300 and are opposed to corresponding output regions 300 with predetermined intervals therebetween in a direction perpendicular to the extending direction of the output regions 300. More specifically, the first power supply region 401 to the sixth power supply region 406 have configurations described below.

[0029] Both the first power supply region 401 and the second power supply region 402 are arranged between the first output region 301 and the second output region 302 and are lined up at a distance in an extending direction (first direction X) of the first output region 301. In this example, the first power supply region 401 and the second power supply region 402 are arranged in this order from one end side to the other end side (the left side to the right side in Fig. 2) in the extension direction of the first output region 301. Furthermore, both the first power supply region 401 and the second power supply region 402 are opposite to the first output region 301 with a predetermined distance therebetween in a direction (second direction Y) perpendicular to the extension direction of the first output region 301.

[0030] Both the third power supply region 403 and the fourth power supply region 404 are arranged between the second output region 302 and the third output region 303 and are lined up at a distance in an extending direction (first direction X) of the second output region 302. In this example, the third power supply region 403 and the fourth power supply region 404 are arranged in this order from one end side to the other end side (the left side to the right side in Fig. 2) in the extension direction of the second output region 302. Furthermore, both the third power supply region 403 and the fourth power supply region 404 are opposite to the second output region 302 with a predetermined distance therebetween in a direction (second direction Y) perpendicular to the extension direction of the second output region 302.

[0031] Both the fifth power supply region 405 and the sixth power supply region 406 are arranged between the second output region 302 and the third output region 303 and are lined up at a distance in an extending direction (first direction X) of the second output region 303. In this example, the fifth power supply region 405 and the sixth power supply region 406 are arranged in this order from one end side to the other end side (the left side to the right side in Fig. 2) in the extension direction of the third output region 303. Furthermore, both the fifth power supply region 405 and the sixth power supply region 406 are opposite to the third output region 303 with a predetermined distance therebetween in a direction (second direction Y) perpendicular to the extension direction of the third output region 303. < <stromversorgungs-zwischenverbindungsbereich>>

[0032] In this example, the power supply pattern 40 includes a power supply interconnection region 410. The power supply interconnection region 410 is electrically connected to one end (the positive electrode) of the DC power supply P. In this example, the power supply interconnection region 410 is near an edge part (right edge part in Fig. 2) of the base plate 20 in the longitudinal direction. In this example, the first power supply portion 401 to the sixth power supply portion 406 are electrically connected to the power supply interconnection portion 410 via interconnection elements 200 (first power supply interconnection element 41 to the third power supply interconnection element 43), which will be described below. < <extra-stromversorgungsbereich>>

[0033] In this example, the power supply pattern 40 includes an extra power supply region 421. The extra power supply region 421 is formed along an edge portion (upper edge portion in Fig. 2) of the base plate 20 in the lateral direction and connected to the power supply interconnection portion 410. <massemuster>

[0034] The ground pattern 50 is provided to connect the power supply (DC power supply P in this example) to low-side switching elements 12 in the switching parts SW. In short, the ground pattern 50 is a part that covers a portion of the Fig. 1, which forms the ground line LG. < <massebereich>>

[0035] In this example, ground pattern 50 contains nine wiring areas (first ground area 501 to ninth ground area 509). Hereinafter, the first ground area 501 to ninth ground area 509 are collectively referred to as "ground areas 500."

[0036] Similar to the plurality of power supply portions 400, the plurality of ground portions 500 are arrayed at intervals in the extending direction of the output portions 300 and oppose respective output portions 300 with predetermined intervals therebetween in the direction perpendicular to the extending direction of the output portions 300. More specifically, the first ground portion 501 to the ninth ground portion 509 have configurations described below.

[0037] The first ground region 501 to the third ground region 503 are arranged between the first output region 301 and the second output region 302 and are arranged at a distance in the extension direction (first direction X) of the first output region 301. In this example, the first ground region 501, the second ground region 502, and the third ground region 503 are arranged in this order from one end side to the other end side (the left side to the right side in Fig. 2) are arranged in the extension direction of the first output region 301. Furthermore, the first ground region 501 to the third ground region 503 are opposite the first output region 301 with a predetermined distance therebetween in a direction (second direction Y) perpendicular to the extension direction of the first output region 301.

[0038] The fourth ground region 504 to the sixth ground region 506 are arranged between the second output region 302 and the third output region 303 and are arranged at a distance in the extension direction (first direction X) of the second output region 302. In this example, the fourth ground region 504, the fifth ground region 505, and the sixth ground region 506 are arranged in this order from one end side to the other end side (the left side to the right side in Fig. 2) in the extension direction of the second output region 302. Furthermore, the fourth ground region 504 to the sixth ground region 506 are opposite the second output region 302 with a predetermined distance therebetween in a direction (second direction Y) perpendicular to the extension direction of the second output region 302.

[0039] The seventh ground region 507 to the ninth ground region 509 are arranged between the second output region 302 and the third output region 303 and are arranged at a distance in the extension direction (first direction X) of the third output region 303. In this example, the seventh ground region 507, the eighth ground region 508, and the ninth ground region 509 are arranged in this order from one end side to the other end side (the left side to the right side in Fig. 2) in the extension direction of the third output region 303. Furthermore, the seventh ground region 507 to the ninth ground region 509 are disposed opposite the third output region 303 with a predetermined distance therebetween in the direction (second direction Y) perpendicular to the extension direction of the third output region 303. < <masse-zwischenverbindungsbereich>>

[0040] In this example, the ground pattern 50 includes the ground interconnection region 510. The ground interconnection region 510 is electrically connected to the other end (the negative electrode) of the DC power supply P. In this example, the ground interconnection region 510 is near an edge part (right edge part in Fig. 2) of the base plate 20 in the longitudinal direction. The ground interconnection region 510 and the power supply interconnection region 410 are arranged with a predetermined distance therebetween in the lateral direction of the base plate 20. < <masseverbindungsbereich>>

[0041] In this example, the ground pattern 50 includes the first ground connection region 511 to the third ground connection region 513.

[0042] The first ground connection region 511 is formed to extend in a first direction X and is arranged between the first output region 301 and the second output region 302. The first power supply region 401, the second power supply region 402, and the first ground region 501 to the third ground region 503 are arranged between the first output region 301 and the first ground connection region 511. In addition, both the first power supply region 401 and the second power supply region 402 oppose the first ground connection region 511 with a predetermined distance therebetween in the direction (second direction Y) perpendicular to the extending direction of the first ground connection region 511. The first ground region 501 to the third ground region 503 are connected to the first ground connection region 511.

[0043] The second ground connection region 512 is formed to extend in a first direction X and is arranged between the second output region 302 and the third output region 303. The third power supply region 403, the fourth power supply region 404, and the fourth ground region 504 to the sixth ground region 506 are arranged between the second output region 302 and the second ground connection region 512. In addition, both the third power supply region 403 and the fourth power supply region 404 oppose the second ground connection region 512 with a predetermined distance therebetween in the direction (second direction Y) perpendicular to the extending direction of the second ground connection region 512. The fourth ground region 504 to the sixth ground region 506 are connected to the second ground connection region 512.The fifth power supply region 405, the sixth power supply region 406, and the seventh ground region 507 to the ninth ground region 509 are arranged between the second ground connection region 512 and the third output region 303. Furthermore, both the fifth power supply region 405 and the sixth power supply region 406 oppose the second ground connection region 512 with a predetermined distance therebetween in the direction (second direction Y) perpendicular to the extension direction of the second ground connection region 512. The seventh ground region 507 to the ninth ground region 509 are connected to the second ground connection region 512.

[0044] The third ground connection region 513 is formed to extend in the second direction Y and is disposed between the second output region 302 and the power supply interconnection region 410. Furthermore, the third ground connection region 513 connects the ground interconnection region 510 and the first connection region 511 and the second connection region 512. < <extra-massebereich>>

[0045] In this example, the ground pattern 50 includes an extra ground region 521. The extra ground region 521 is arranged along an edge portion (lower edge portion in Fig. 2) of the base plate 20 in the lateral direction and connected to the ground interconnection portion 510. <Anordnung von Stromversorgungsbereichen und Massebereichen>

[0046] The plurality of power supply regions 400 and the plurality of ground regions 500 are alternately arrayed in a direction along the extending direction of output regions 300. Further, the plurality of power supply regions 400 and the plurality of ground regions 500 are arrayed such that adjacent pairs of power supply regions 400 and ground regions 500 are opposed to each other with a predetermined distance therebetween.

[0047] More specifically, between the first output region 301 and the second output region 302 (between the first output region 301 and the first ground connection region 511 in the example of Fig. 2) the first ground region 501, the first power supply region 401, the second ground region 502, the second power supply region 402 and the third ground region 503 in this order from one end side to the other end side (the left side to the right side in Fig. 2) arranged in the first direction X, which lies along the extension direction of the first output region 301. The first power supply region 401 faces both the first ground region 501 and the second ground region 502 with a predetermined distance therebetween. Likewise, the second power supply region 402 faces both the second ground region 502 and the third ground region 503 with a predetermined distance therebetween.

[0048] Between the second output region 302 and the third output region 303 (between the second output region 302 and the second ground connection region 512 in the example of Fig. 2) the fourth ground area 504, the third power supply area 403, the fifth ground area 505, the fourth power supply area 404 and the sixth ground area 506 are arranged in this order from one end side to the other end side (the left side to the right side in Fig. 2) arranged in the first direction X, which lies along the extension direction of the second output region 302. The third power supply region 403 faces both the fourth ground region 504 and the fifth ground region 505 with a predetermined distance therebetween. Likewise, the fourth power supply region 404 faces both the fifth ground region 505 and the sixth ground region 506 with a predetermined distance therebetween.

[0049] Between the second output region 302 and the third output region 303 (between the second ground connection region 512 and the third output region 303 in the example of Fig. 2) are the seventh ground area 507, the fifth power supply area 405, the eighth ground area 508, the sixth power supply area 406 and the ninth ground area 509 in this order from one end side to the other end side (the left side to the right side in Fig. 2) arranged in the first direction X, which lies along the extension direction of the third output region 303. The fifth power supply region 405 faces both the seventh ground region 507 and the eighth ground region 508 with a predetermined distance therebetween. Likewise, the sixth power supply region 406 faces both the eighth ground region 508 and the ninth ground region 509 with a predetermined distance therebetween. <High-Side-Schaltelement und High-Side-Transistor>

[0050] In the switching power supply 10, high-side switching elements 11 are provided on the conductive layer 22 of the base plate 20. Each of the high-side switching elements 11 includes a plurality of high-side transistors 110. More specifically, the plurality of high-side transistors 110 are connected in parallel to form the high-side switching element 11. In short, the switching power supply 10 includes the plurality of high-side transistors 110 that form the high-side switching elements 11.

[0051] The high-side transistors 110 are connected to the power supply pattern 40 and the output pattern 30. In this example, the high-side transistors 110 are mounted on one surface of the power supply pattern 40 and connected to the output pattern 30. More specifically, the high-side transistors 110 are mounted on the power supply pattern 40. One end (drain) of each of the high-side transistors 110, formed into a flat shape, is arranged on a bottom of the main body of the high-side transistor 110 and connected to the surface of the power supply pattern 40 by soldering. Another end (source) of each of the high-side transistors 110 extends from one side of the main body of the high-side transistor 110 to the output pattern 30 and is connected to the surface of the output pattern 30 by soldering. A gate of each of the high-side transistors 110 is electrically connected to a gate wire (not shown).For example, each of the high-side transistors 110 may be a surface-mounted type of field-effect transistor (FET).

[0052] More specifically, in this example, the first high-side switching element 11u to the third high-side switching element 11w are provided on the conductive layer 22 of the base plate 20. Each of the first high-side switching element 11u to the third high-side switching element 11w includes four high-side transistors 110.

[0053] Four high-side transistors 110 constituting the first high-side switching element 11u are spaced apart in the first direction X, which is along the extending direction of the first output region 301. Of these four high-side transistors 110, two high-side transistors 110 are mounted on a surface of the first power supply region 401 and connected to the first output region 301, and two remaining high-side transistors 110 are mounted on a surface of the second power supply region 402 and connected to the first output region 301.

[0054] Four high-side transistors 110 constituting the second high-side switching element 11v are spaced apart in the first direction X, which is along the extension direction of the second output region 302. Of these four high-side transistors 110, two high-side transistors 110 are mounted on a surface of the third power supply region 403 and connected to the second output region 302, and two remaining high-side transistors 110 are mounted on a surface of the fourth power supply region 404 and connected to the second output region 302.

[0055] Four high-side transistors 110 constituting the third high-side switching element 11w are spaced apart in the first direction X, which is along the extension direction of the third output region 303. Of these four high-side transistors 110, two high-side transistors 110 are mounted on a surface of the fifth power supply region 405 and connected to the third output region 303, and two remaining high-side transistors 110 are mounted on a surface of the sixth power supply region 406 and connected to the third output region 303. <Low-Side-Schaltelement und Low-Side-Transistor>

[0056] In the switching power supply 10, low-side switching elements 12 are provided on the conductive layer 22 of the base plate 20. The low-side switching elements 12 include a plurality of low-side transistors 120. More specifically, the plurality of low-side transistors 120 are connected in parallel to form the low-side switching element 12. In short, the switching power supply 10 includes the plurality of low-side transistors 120 that form the low-side switching elements 12.

[0057] The low-side transistors 120 are connected to the ground pattern 50 and the output pattern 30. In this example, the low-side transistors 120 are mounted on the surface of the output pattern 30 and connected to the ground pattern 50. More specifically, the low-side transistors 120 are mounted on the output pattern 30. One end (drain) of each of the low-side transistors 120, formed into a flat shape, is arranged on a bottom of the main body of the low-side transistor 120 and connected to the surface of the output pattern 30 by soldering. Another end (source) of each of the low-side transistors 120 extends from one side of the main body of the low-side transistor 120 to the ground pattern 50 and is connected to the surface of the ground pattern 50 by soldering. A gate of each of the low-side transistors 120 is electrically connected to a gate wire (not shown).For example, each of the low-side transistors 120 may be a surface-mounted type of field-effect transistor (FET).

[0058] More specifically, in this example, the first low-side switching element 12u to the third low-side switching element 12w are provided on the conductive layer 22 of the base plate 20. Each of the first low-side switching element 12u to the third low-side switching element 12w includes four low-side transistors 120.

[0059] Four low-side transistors 120 constituting the first low-side switching element 12u are spaced apart in the first direction X, which is along the extension direction of the first output region 301. Of these four low-side transistors 120, one low-side transistor 120 is mounted on a surface of the first output region 301 and connected to the first ground region 501; two low-side transistors 120 are mounted on the surface of the first output region 301 and connected to the second ground region 502; and a remaining low-side transistor 120 is mounted on the surface of the first output region 301 and connected to the third ground region 503.

[0060] Four low-side transistors 120 constituting the second low-side switching element 12v are spaced apart in the first direction X, which is along the extension direction of the second output region 302. Of these four low-side transistors 120, one low-side transistor 120 is mounted on a surface of the second output region 302 and connected to the fourth ground region 504; two low-side transistors 120 are mounted on the surface of the second output region 302 and connected to the fifth ground region 505; and a remaining low-side transistor 120 is mounted on the surface of the second output region 302 and connected to the sixth ground region 506.

[0061] Four low-side transistors 120 constituting the third low-side switching element 12w are spaced apart in the first direction X, which is along the extension direction of the third output region 303. Of these four low-side transistors 120, one low-side transistor 120 is mounted on a surface of the third output region 303 and connected to the seventh ground region 507; two low-side transistors 120 are mounted on the surface of the third output region 303 and connected to the eighth ground region 508; and a remaining low-side transistor 120 is mounted on the surface of the third output region 303 and connected to the ninth ground region 509. <Anordnung der High-Side-Transistoren und Low-Side-Transistoren>

[0062] In the switching power supply 10, the plurality of high-side transistors 110 constituting a single high-side switching element 11 are sequentially arranged next to the plurality of low-side transistors 120 constituting a single low-side switching element 12 in the first direction X, which is along the extension direction of the output regions 300. In this case, a direction in which the terminals of the low-side transistors 120 (terminals projecting from the sides of the main parts to ground regions 500) are aligned is opposite to a direction in which the terminals of the high-side transistors 110 (terminals projecting from the sides of the main parts to output regions 300) are aligned.

[0063] More specifically, four high-side transistors 110 constituting the first high-side switching element 11u and four low-side transistors 120 constituting the first low-side switching element 12u are arrayed in the first direction X along the extending direction of the first output region 301, such that one low-side transistor 120, two high-side transistors 110, two low-side transistors 120, two high-side transistors 110, and one low-side transistor 120 are arranged in this order from one side to the other side (the left side to the right side in Fig. 2) are arranged in the first direction X.

[0064] More specifically, four high-side transistors 110 constituting the second high-side switching element 11v and four low-side transistors 120 constituting the second low-side switching element 12v are arrayed in the first direction X along the extending direction of the second output region 302, such that one low-side transistor 120, two high-side transistors 110, two low-side transistors 120, two high-side transistors 110, and one low-side transistor 120 are arranged in this order from one side to the other side (the left side to the right side in Fig. 2) are arranged in the first direction X.

[0065] More specifically, four high-side transistors 110 constituting the third high-side switching element 11w and four low-side transistors 120 constituting the third low-side switching element 12w are arrayed in the first direction X along the extending direction of the third output region 303, such that one low-side transistor 120, two high-side transistors 110, two low-side transistors 120, two high-side transistors 110, and one low-side transistor 120 are arranged in this order from one side to the other side (the left side to the right side in Fig. 2) are arranged in the first direction X. <Glättungskondensatorabschnitt und Kondensator>

[0066] In the switching power supply 10, a smoothing capacitor section 13 is provided on the conductive layer 22 of the base plate 20. The smoothing capacitor section 13 includes a plurality of capacitors 130. In short, the switching power supply 10 includes the plurality of capacitors 130 that form the smoothing capacitor section 13.

[0067] The plurality of capacitors 130 are connected to the power supply pattern 40 and the ground pattern 50. In this example, the capacitors 130 are mounted on the surfaces of the power supply pattern 40 and the ground pattern 50. More specifically, the capacitors 130 are mounted extending from the power supply pattern 40 and the ground pattern 50. One end (the positive electrode) of each capacitor 130 is connected to the surface of the power supply pattern 40 by soldering, while the other end (the negative electrode) of each capacitor 130 is connected to the surface of the ground pattern 50 by soldering. For example, each of the capacitors 130 may be an electrolytic capacitor, a plastic capacitor, or a ceramic capacitor.

[0068] The plurality of capacitors 130 corresponds to the plurality of high-side transistors 110 and the plurality of low-side transistors 120. Each of the plurality of capacitors 130 is arranged adjacent to its corresponding transistor among the plurality of high-side transistors 110 and the plurality of low-side transistors 120. In this example, the plurality of capacitors 130 are spaced apart in the first direction X, which lies along an array direction (extension direction of the output regions 300) of the plurality of high-side transistors 110 and the plurality of low-side transistors 120.In the second direction Y, perpendicular to the first direction X, which lies along the array direction (extension direction of the output regions 300) of the plurality of high-side transistors 110 and the plurality of low-side transistors 120, each of the plurality of capacitors 130 is arranged adjacent to its corresponding transistor among the high-side transistors 110 and the plurality of low-side transistors 120. In other words, the plurality of high-side transistors 110, the plurality of low-side transistors 120, and the plurality of capacitors 130 are arranged such that pairs each including a high-side transistor 110 and its corresponding capacitor 130 are positioned adjacent to pairs each including a low-side transistor 120 and its corresponding capacitor 130.

[0069] More specifically, in this example, 24 capacitors 130 are provided, corresponding to 12 high-side transistors 110 and 12 low-side transistors provided on the conductive layer 22 of the base plate 20.

[0070] Four capacitors 130 corresponding to respective four high-side transistors 110 constituting the first high-side switching element 11u are spaced apart in the first direction X along the array direction of these four high-side transistors 110 (extension direction of the first output region 301) and are provided near the four high-side transistors 110. Of the four capacitors 130, two capacitors 130 are mounted on the surfaces of the first power supply region 401 and the first ground connection region 511, and two remaining capacitors 130 are mounted on the surfaces of the second power supply region 402 and the first ground connection region 511.

[0071] Four capacitors 130 corresponding to respective four high-side transistors 110 constituting the second high-side switching element 11v are spaced apart in the first direction X along the array direction of these four high-side transistors 110 (extension direction of the second output region 302) and are provided near the four high-side transistors 110. Of the four capacitors 130, two capacitors 130 are mounted on the surfaces of the third power supply region 403 and the second ground connection region 512, and two remaining capacitors 130 are mounted on the surfaces of the fourth power supply region 404 and the second ground connection region 512.

[0072] Four capacitors 130 corresponding to respective four high-side transistors 110 constituting the third high-side switching element 11w are spaced apart in the first direction X along the array direction of these four high-side transistors 110 (extension direction of the third output region 303) and are provided near the four high-side transistors 110. Of the four capacitors 130, two capacitors 130 are mounted on the surfaces of the fifth power supply region 405 and the second ground connection region 512, and two remaining capacitors 130 are mounted on the surfaces of the sixth power supply region 406 and the second ground connection region 512.

[0073] Four capacitors 130, corresponding to respective four low-side transistors 120 constituting the first low-side switching element 12u, are spaced apart in the first direction X, which is along the array direction of these four low-side transistors 120 (extension direction of the first output region 301), and are provided near the four low-side transistors 120. Of these four capacitors 130, one capacitor 130 is mounted on the surfaces of the first power supply region 401 and the first ground region 501; one capacitor 130 is mounted on the surfaces of the first power supply region 401 and the second ground region 502; one capacitor 130 is mounted on the surfaces of the second power supply region 402 and the second ground region 502; and a remaining capacitor 130 is mounted on the surfaces of the second power supply region 402 and the third ground region 503.

[0074] Four capacitors 130, corresponding to respective four low-side transistors 120 constituting the second low-side switching element 12v, are spaced apart in the first direction X along the array direction of these four low-side transistors 120 (extension direction of the second output region 302), and are provided near the four low-side transistors 120. Of these four capacitors 130, one capacitor 130 is mounted on the surfaces of the third power supply region 403 and the fourth ground region 504; one capacitor 130 is mounted on the surfaces of the third power supply region 403 and the fifth ground region 505; one capacitor 130 is mounted on the surfaces of the fourth power supply region 404 and the fifth ground region 505; and a remaining capacitor 130 is mounted on the surfaces of the fourth power supply region 404 and the fifth ground region 505.

[0075] Four capacitors 130 corresponding to respective four low-side transistors 120 constituting the third low-side switching element 12w are spaced apart in the first direction X along the array direction of these four low-side transistors 120 (extension direction of the third output region 303) and are provided near the four low-side transistors 120. Of these four capacitors 130, one capacitor 130 is mounted on the surfaces of the fifth power supply region 405 and the seventh ground region 507; one capacitor 130 is mounted on the surfaces of the fifth power supply region 405 and the eighth ground region 508; one capacitor 130 is mounted on the surfaces of the sixth power supply region 406 and the eighth ground region 508; and and a remaining capacitor 130 is mounted on the surfaces of the sixth power supply region 406 and the ninth ground region 509. <verbindungselement>

[0076] In the switching power supply 10, at least one of the power supply pattern 40 and the ground pattern 50 includes a plurality of wiring portions (portions of the wiring patterns formed in the conductive layer 22) electrically connected via interconnecting elements 200. In this example, the power supply pattern 40 includes the first power supply portion 401 to the sixth power supply portion 406, which are electrically connected via the first power supply interconnecting element 41 to the third power supply interconnecting element 43 (interconnecting elements 200). Fig. 2 illustrates the first power supply connector 41 to third power supply connector 43 (connectors 200) with lines of one long and two short dashes.

[0077] The first power supply connecting element 41 electrically connects the power supply interconnection region 410, the first power supply region 401, the second power supply region 402, the third power supply region 403, and the fourth power supply region 404. The second power supply connecting element 42 electrically connects the third power supply region 403 to the fifth power supply region 405. The third power supply connecting element 43 electrically connects the fourth power supply region 404 to the sixth power supply region 406.

[0078] In this example, each of the connecting elements 200 consists of a conductor (a so-called bus bar) having a flat shape. More specifically, each connecting element 200 includes a main part 201 and tabs 202; the main part 201 is formed in a flat shape and faces the conductive layer 22 with a gap therebetween; and each of the tabs 202 extends from the main part 201 to each of the plurality of wiring regions in the conductive layer 22.For example, the power supply connecting member 41 includes a main part 201 and five tabs 202; the main part 201 opposes the second output region 302 with a space therebetween, and the tabs 202 extend from the main part 201 to respective five wiring regions (power supply interconnection region 410, first power supply region 401, second power supply region 402, third power supply region 403, and fourth power supply region 404) of the power supply pattern 40.

[0079] In this example, the connecting elements 200 are connected by soldering to the plurality of wiring regions in the conductive layer 22. For example, five tabs 202 of the first power supply connecting element 41 are connected by soldering to the respective five wiring regions (power supply interconnection region 410, first power supply region 401, second power supply region 402, third power supply region 403, and fourth power supply region 404) of the power supply pattern 40.

[0080] In this example, a material of the connecting members 200 may be the same type as a material of the heat dissipation layer 23. In this example, parts of each connecting member 200 that are connected to the plurality of wiring regions by soldering may be subjected to plating to enable solder connection. For example, each of the first power supply connecting member 41 and the heat dissipation layer 23 may be made of aluminum. In the first power supply connecting member 41, five tabs 202 that are connected to the five wiring regions (power supply interconnection region 410, first power supply region 401, second power supply region 402, third power supply region 403, and fourth power supply region 404) of the power supply pattern 40 by soldering are plated with nickel (a material that enables solder connection). [Effect of the first exemplary embodiment]

[0081] In the switching power supply 10, as described above, high-side transistors 110 are arranged in series next to the plurality of low-side transistors 120. With this configuration, when heat is generated in one of the high-side transistors 110 and 120 arranged side by side, the generated heat can be transferred to the other transistor via the base plate 20. More specifically, during a period in which the high-side switching element 11 is in an ON state and the low-side switching element 12 is in an OFF state, heat generated in the high-side transistors 110 in the ON state can be transferred to the low-side transistors 120 in the OFF state via the base plate 20.During a period in which the high-side switching element 11 is in an OFF state and the low-side switching element 12 is in an ON state, heat generated in the low-side transistors 120 in the ON state can be transferred to the high-side transistors 110 in the OFF state via the base plate 20. In this way, it is possible to reduce heat concentration in the high-side switching elements 11 and the low-side switching elements 12.

[0082] High-side transistors 110 and low-side transistors 120, as well as a smoothing capacitor section 13, are provided on the conductive layer 22 of the base plate 20. This configuration can shorten wiring paths between the smoothing capacitor section 13 and the high-side transistors 110, and between the smoothing capacitor section 13 and the low-side transistors 120, compared with a configuration in which no smoothing capacitor section 13 is provided on the conductive layer 22 of the base plate 20 (for example, a configuration in which the smoothing capacitor section 13 is provided on a base plate different from the base plate 20 on which the high-side transistors 110 and the low-side transistors 120 are mounted).Consequently, it is possible to reduce parasitic inductance of the wiring paths between the smoothing capacitor section 13 and the high-side transistors 110 and between the smoothing capacitor section 13 and the low-side transistors 120, and thereby reduce voltage surges caused by switching operations of the high-side transistors 110 and the low-side transistors 120.

[0083] The plurality of capacitors 130 constituting the smoothing capacitor section 13 are arranged so that high-side transistors 110 are adjacent to the plurality of low-side transistors 120. This configuration can shorten the wiring paths between capacitors 130 and high-side transistors 110 (or low-side transistors 120). Consequently, it is possible to reduce voltage surges caused by the switching operations of high-side transistors 110 and low-side transistors 120.

[0084] The plurality of high-side transistors 110, the plurality of low-side transistors 120, and the plurality of capacitors 130 are arranged such that pairs each including a high-side transistor 110 and its corresponding capacitor 130 are positioned adjacent to pairs each including a low-side transistor 120 and its corresponding capacitor 130. This configuration can shorten the wiring paths formed between high-side transistors 110 and capacitors 130 and between low-side transistors 120 and capacitors 130. Consequently, it is possible to reduce voltage surges caused by the switching operations of high-side transistors 110 and low-side transistors 120.

[0085] In the switching power supply 10, the plurality of high-side transistors 110 are arranged sequentially next to the plurality of low-side transistors 120 in the first direction X. Further, each of the plurality of capacitors 130 is arranged next to its corresponding transistor among the high-side transistors 110 and the plurality of low-side transistors 120 in the second direction Y, which is perpendicular to the first direction X. This configuration can reduce differences in wiring lengths between the plurality of capacitors 130 and transistors (high-side transistors 110 or low-side transistors 120). In this way, it is possible to reduce uneven heat in the plurality of capacitors 130 (to prevent electric current from being concentrated in some of the capacitors 130 and heating these capacitors 130).

[0086] In this example, the power supply pattern 40 includes the plurality of wiring regions (in this example, the first power supply region 401 to the sixth power supply region 406) connected via interconnection elements 200 (in this example, the first power supply interconnection element 41 to the third power supply interconnection element 43). This arrangement improves a degree of freedom in designing the power supply pattern 40 (of wiring patterns). Consequently, it is possible to improve a degree of freedom in arranging the high-side transistors 110 and the low-side transistors 120.

[0087] Each of the connecting elements 200 (the first power supply connecting element 41 to the third power supply connecting element 43 in this example) is formed from a conductor having a flat shape. This configuration can radiate heat transferred to the wiring portions (the first power supply portion 401 to the sixth power supply portion 406 in this example) of the conductive layer 22 via the connecting elements 200. Thus, it is possible to improve heat dissipation performance.

[0088] Each of the connectors 200 (the first power supply connector 41 to the third power supply connector 43 in this example) is made of a material of the same type as a type of the material of the heat dissipation layer 23. Thus, thermal expansion coefficients of the connectors 200 and the heat dissipation layer 23 can be made consistent with each other. Consequently, it is possible to deform the connectors 200 in accordance with a shape of the heat dissipation layer 23 upon a temperature rise, thereby improving the reliability of the switching power supply 10.

[0089] Connecting elements 200 (in this example, the first power supply connecting element 41 to the third power supply connecting element 43) are connected to the wiring portions (in this example, the first power supply portion 401 to the sixth power supply portion 406) of the conductive layer 22 by soldering. This configuration can achieve a simple connection structure of the connecting elements 200 compared to a configuration in which connecting elements 200 are fixed to the wiring portions of the conductive layer 22 by screws.

[0090] Portions of connecting elements 200 (in this example, the first power supply connecting element 41 to the third power supply connecting element 43) to be connected by soldering to the wiring portions (in this example, the first power supply portion 401 to the sixth power supply portion 406) are subjected to plating to enable soldering. This configuration can connect connecting elements 200 to the wiring portions of the conductive layer 22 by soldering, even when connecting elements 200 are made of a material unsuitable for soldering. Consequently, it is possible to improve the degree of freedom in selecting a material of connecting elements 200. (First modification of a connection structure of a connecting element)

[0091] Fig. 5 shows a first modification of a connection structure of a connecting element 200. In Fig. 5, the connection structure of the first power supply connection element 41 and the third power supply region 403 is shown as an example.

[0092] In this example, each of the connectors 200 (the first power supply connector 41 in the example of Fig. 5) a conductor (a so-called bus bar) having a flat shape. More specifically, each connecting element 200 has a main part 201 and tabs 202; the main part 201 is formed in a flat shape and faces the conductive layer 22 with a space therebetween; and each of the tabs 202 projects from the main part 201 to one of the plurality of wiring areas (the third power supply area 403 in the example of Fig. 5) in the conductive layer 22.

[0093] First through-holes 21h, second through-holes 22h, and third through-holes 23h are provided in the base plate 20. Each of the first through-holes 21h penetrates the insulating layer 21 in a thickness direction. Each of the second through-holes 22h is formed to respectively pass one of the plurality of wiring regions (the third power supply region 403 in the example of Fig. 5) penetrates the conductive layer 22 in the thickness direction and communicates with a corresponding first through-hole 21h. Each of the third through-holes 23h penetrates the heat dissipation layer 23 in the thickness direction and communicates with a corresponding first through-hole 21h.

[0094] The tabs 202 of the connecting elements 200 (of the first power supply connecting element 41 in the example of Fig. 5) are connected by soldering (solder connection 26) to wiring areas (the third power supply area 403 in the example of Fig. 5) connected to second through-holes 22h, which are some of the plurality of wiring portions in the conductive layer 22, while being inserted into the first through-holes 21h, the second through-holes 22h, and the third through-holes 23h.

[0095] The third through-holes 23h have a larger opening area than an opening area of the first through-holes 21h, so that tabs 202 of the connecting element 200 (the first power supply connecting element 41 in the example of Fig. 5) inserted into the first through-hole 21h, the second through-hole 22h and the third through-hole 23h do not make contact with inner walls of the third through-holes 23h.

[0096] In this example, a material of each connecting element 200 (the first power supply connecting element 41 in the example of Fig. 5) may be of the same type as a type of material of the heat dissipation layer 23. In this example, parts of the connecting elements 200 (tabs 202 of the first power supply connecting element 41 in the example of Fig. 5) connected to the plurality of wiring portions by soldering may be subjected to plating to enable soldering.

[0097] As described above, connecting elements 200 (the first power supply connecting element 41 in the example of Fig. 5) by soldering to the wiring portions (the third power supply portion 403 in the example of Fig. 5) of the conductive layer 22. This configuration can achieve a simple connection structure of the connecting elements 200, compared with a configuration in which the connecting elements 200 are fixed to the wiring portions of the conductive layer 22 by screws. (Second modification of a connection structure of a connecting element)

[0098] Fig. 6 shows a second modification of a connecting structure of a connecting element 200. In Fig. 6 shows an example of the connection structure of the first power supply connection element 41 and the third power supply region 403.

[0099] In this example, each of the connectors 200 (the first power supply connector 41 in the example of Fig. 6) of a conductor (a so-called bus bar) having a flat shape. The switching power supply 10 has nuts 27 and screws 28; each of the nuts 27 is connected by soldering (solder point 26) to one of the plurality of wiring areas (the third power supply area 403 in the example of Fig. 6) in the conductive layer 22, and each of the screws 28 penetrates the connecting element 200 (the first power supply connecting element 41 in the example of Fig. 6) and is attached to the corresponding nut 27.

[0100] In this example, a material of each connecting element 200 (the first power supply connecting element 41 in the example of Fig. 6) be of the same type as a type of material of the heat dissipation layer 23.

[0101] As described above, nuts 27 are connected by soldering to the wiring portions (the third power supply portion 403 in the example of Fig. 6) in the conductive layer 22, and screws 28 penetrate the connecting elements 200 (the first power supply connecting element 41 in the example of Fig. 6) and are fixed to the nuts 27. This configuration can connect the connecting elements 200 to the wiring portions of the conductive layer 22 by soldering, even when the connecting elements 200 are made of a material unsuitable for soldering. Consequently, it is possible to improve the degree of freedom in selecting a material for the connecting elements 200. (Third modification of a connection structure of a connecting element)

[0102] Fig. 7 and Fig. 8 each represent a third modification of the connection structure of a connecting element 200. In Fig. 7 and Fig. 8, the connection structure of the first power supply connection element 41 and the third power supply region 403 is shown as an example.

[0103] The connection structure of the connecting elements 200 (the first power supply connecting element 41 in the example of Fig. 7 and Fig. 8) is a structure in which the connecting elements 200 are fixed to the base plate 20 (more precisely, the conductive layer 22) by coupling screws 60. This connecting structure includes supports 71, insulating elements 72, washers 73, and coupling screws 60.

[0104] The supports 71, each made of a conductive material (for example, metal), are provided on the conductive layer 22. More specifically, the supports 71 are provided in connecting parts between the connecting elements 200 and the conductive layer 22. (The connecting parts correspond to parts to which the connecting elements 200 are connected, that is, the third power supply region 403 in the example of Fig. 7).

[0105] In this example, each of the supports 71 has a mounting surface (upper surface in Fig. 8) formed into a rectangular shape. Provided at a center of each support 71 is an insertion hole through which a corresponding coupling screw 60 passes. The insertion holes of the supports 71 have a larger diameter than an outer diameter of threaded portions of the coupling screws 60.

[0106] The corresponding connecting element 200 is mounted on the mounting surface of each of the supports 71. In this example, connecting elements 200, each formed into a flat shape, are mounted on the mounting surfaces of the supports 71. Each connecting element 200 has an insertion hole through which the corresponding coupling screw 60 passes. The insertion holes in the connecting elements 200 have a larger diameter than an outer diameter of the threaded portions of the coupling screws 60.

[0107] A height of the supports 71 (height from a surface of the conductive layer 22 to the mounting surface of the supports 71) is greater than a height of high-side transistors 110 and low-side transistors 120 mounted on the conductive layer 22 (height relative to the surface of the conductive layer 22). This configuration can prevent interconnect elements 200 mounted on the mounting surfaces of supports 71 from making contact with high-side transistors 110 and low-side transistors 120 provided on the conductive layer 22.

[0108] Insulating members 72, each formed in a flat shape, are mounted on the connecting members 200 mounted on the brackets 71. For example, each of the insulating members 72 may be made of insulating paper (quality paper or kraft paper coated with an insulating varnish). In this example, the insulating members 72 are formed in accordance with a flat shape of the mounting surfaces of the brackets 71 (that is, formed in a rectangular flat shape). At a center of each insulating member 72, an insertion hole is provided through which a corresponding coupling bolt 60 passes. A diameter of the insertion holes in the insulating members 72 is larger than the outer diameters of the threaded portions of the coupling bolts 60, but smaller than the diameter of the insertion holes in the connecting member 200 and the bracket 71.Each insulating member 72 has an annular protrusion 72a provided on its inner peripheral portion surrounding the insertion hole. For example, each annular protrusion 72a may be formed by die-cutting the inner peripheral portion of the corresponding insulating member 72 surrounding the insertion hole.

[0109] Washers 73, each formed in a flat shape, are mounted on the insulating members 72 mounted on the connecting members 200. In this example, each washer 73 is formed into a flat U-shape (a plate shape bent into a U-shape). Each washer 73 is designed to cover the corresponding bracket 71, with the connecting member 200 and the insulating member 72 sandwiched between the washer 73 and the mounting surface of the bracket 71. An insertion hole is provided at a center of each washer 73 through which a corresponding coupling bolt 60 passes. The insertion holes in the washers 73 have a larger diameter than the outer diameter of the threaded portions of the coupling bolts 60.

[0110] Insertion holes through which coupling screws 60 pass are provided in the conductive layer 22 and the insulating layer 21 in the base plate 20. A diameter of the insertion holes in the conductive layer 22 and the insulating layer 21 is larger than any one of the outer diameter of the threaded portions of the coupling screws 60 and the diameter of the insertion holes in the insulating member 72. Threaded holes 61 into which the coupling screws 60 are inserted are provided in the heat dissipation layer 23 of the base plate 20.

[0111] The coupling screws 60 penetrate the washers 73, the insulating elements 72, the connecting elements 200, the supports 71, the conductive layer 22, and the insulating layer 21 and are fixed to the heat dissipation layer 23. More specifically, the coupling screws 60 pass through the insertion holes in the washers 73, the insulating elements 72, the connecting elements 200, the supports 71, the conductive layer 22, and the insulating layer 21 and are fixed in the heat dissipation layer 23. In this case, clearances are provided between the threaded portions of the coupling screws 60 and the insertion holes in the connecting elements 200, the supports 71, the conductive layer 22, and the insulating layer 21. Furthermore, the washers 73 and insulating elements 72 are provided between the heads of the coupling screws 60 and the connecting elements 200. This arrangement reliably insulates the connecting elements 200 from the heat dissipation layer 23.

[0112] As described above, by using coupling screws 60 penetrating the conductive layer 22 and the insulating layer 21 and fixed to the heat dissipation layer 23, the connecting elements 200 are fixed to the connecting parts (the third power supply region 403 in the example of Fig. 7) between the connecting elements 200 and the conductive layer 22 by screws. Contact between the insulating layer 21 and the heat dissipation layer 23 can thereby be improved. This configuration facilitates heat transfer from the high-side transistors 110 and the low-side transistors 120 to the heat dissipation layer 23 via the conductive layer 22 and the insulating layer 21. As a result, the heat dissipation property of the base plate 20 can be improved. Thus, the configuration can suppress a temperature rise caused by the switching operations of the high-side transistors 110 and the low-side transistors 120. (Fourth modification of a connecting structure of a connecting element)

[0113] Fig. 9 shows a fourth modification of a connecting structure of a connecting element 200. In Fig. 9, the connection structure of the first power supply connection element 41 and the third power supply region 403 is shown as an example.

[0114] As in Fig. 9, the switching power supply 10 may be configured such that coupling screws 60 penetrate the conductive layer 22, the insulating layer 21, and the heat dissipation layer 23 and are fixed to the heat dissipation element 24. More specifically, by using coupling screws 60 that penetrate the conductive layer 22, the insulating layer 21, and the heat dissipation layer 23 and are fixed to the heat dissipation element 24, the connecting elements 200 (the first power supply connecting element 41 in the example of Fig. 9) at the connecting parts (the third power supply area 403 in the example of Fig. 9) between the connecting elements 200 and the conductive layer 22.

[0115] In the example of Fig. 9, insertion holes are provided in each of the conductive layer 22, the insulating layer 21, and the heat dissipation layer 23, through which coupling screws 60 pass. Threaded holes 61 are provided in the heat dissipation member 24, into which coupling screws 60 are inserted. The coupling screws 60 pass through the insertion holes in the washers 73, the insulating members 72, the connecting members 200, the supports 71, the conductive layer 22, the insulating layer 21, and the heat dissipation layer 23. Further, the coupling screws 60 are inserted into threaded holes 61 in the heat dissipation member 24 and fastened therein. In this case, clearances are provided between the threaded portions of the coupling screws 60 and the insertion holes in the connecting members 200, supports 71, the conductive layer 22, the insulating layer 21, and the heat dissipation layer 23. In addition, the washers 73 and the insulating elements 72 are provided between the heads of the coupling screws 60 and the connecting elements 200.This design reliably insulates the connecting elements 200 from the heat dissipation element 24.

[0116] As described above, by using coupling screws 60 that penetrate the conductive layer 22, the insulating layer 21 and the heat dissipation layer 23 and are fixed to the heat dissipation member 24, the connecting members 200 are fixed to the connecting parts (the third power supply portion 403 in the example of Fig. 9) is secured between the connecting elements 200 and the conductive layer 22. Contact between the insulating layer 21 and the heat dissipation layer 23, as well as between the heat dissipation layer 23 and the heat dissipation element 24, can thereby be improved. This configuration facilitates heat transfer from the high-side transistors 110 and the low-side transistors 120 to the heat dissipation element 24 via the conductive layer 22, the insulating layer 21, and the heat dissipation layer 23. As a result, the heat dissipation property of the base plate 20 can be improved. Thus, the configuration can suppress a temperature rise caused by the switching operations of the high-side transistors 110 and the low-side transistors 120.

[0117] Furthermore, by using coupling screws 60 that penetrate the conductive layer 22, the insulating layer 21 and the heat dissipation layer 23 and are fixed to the heat dissipation member 24, the connecting members 200 are fixed to the connecting parts (the third power supply region 403 in the example of Fig. 9) is secured between the connecting elements 200 and the conductive layer 22. Warpage of the base plate 20 can thereby be suppressed. The design in which the base plate 20 and the heat dissipation element 24 are secured to each other via coupling screws 60 can reduce the number of components in the switching power supply 10. (Second exemplary embodiment)

[0118] Fig. 10 illustrates a structure of the switching power supply 10 according to a second exemplary embodiment. The switching power supply 10 according to the second exemplary embodiment differs from the switching power supply 10 according to the first exemplary embodiment in configurations of the power supply pattern 40, the ground pattern 50, and the connection elements 200, and arrangements of the high-side transistors 110, the low-side transistors 120, and the capacitors 130. <stromversorgungsmuster>

[0119] In the second exemplary embodiment, the power supply pattern 40 includes: six wiring regions (a first power supply region 401 to a sixth power supply region 406); and a power supply interconnection region 410. < <stromversorgungsbereich>>

[0120] The second exemplary embodiment is similar to the first exemplary embodiment in that the plurality of power supply sections 400 are lined up at intervals in an extending direction of the output sections 300 and oppose respective output sections 300 with predetermined intervals therebetween in a direction perpendicular to the extending direction of the output sections 300. More specifically, the first power supply section 401 to the sixth power supply section 406 have configurations described below.

[0121] The first power supply region 401 to the third power supply region 403 are arranged between the first output region 301 and the second output region 302 and are lined up at a distance in an extending direction (first direction X) of the first output region 301. In this example, the first power supply region 401, the second power supply region 402, and the third power supply region 403 are arranged in this order from one end side to the other end side (the left side to the right side in Fig. 10) are arranged in the extension direction of the first output region 301. The first power supply region 401 to the third power supply region 403 are opposite the first output region 301 with a predetermined distance therebetween in a direction (second direction Y) perpendicular to the extension direction of the first output region 301.

[0122] The fourth power supply region 404 to the sixth power supply region 406 are arranged between the second output region 302 and the third output region 303 and are lined up at a distance in an extending direction (first direction X) of the second output region 302 and the third output region 303. In this example, the fourth power supply region 404, the fifth power supply region 405, and the sixth power supply region 406 are arranged in this order from one end side to the other end side (the left side to the right side in Fig. 10) are arranged in the extension direction of the second output region 302 and the third output region 303. The fourth power supply region 404 to the sixth power supply region 406 are opposed to the second output region 302 with a predetermined distance therebetween in a direction (second direction Y) perpendicular to the extension direction of the second output region 302. Furthermore, the fourth power supply region 404 to the sixth power supply region 406 are opposed to the third output region 303 with a predetermined distance therebetween in a direction (second direction Y) perpendicular to an extension direction of the third output region 303. < <stromversorgungs-zwischenverbindungsbereich>>

[0123] In the second exemplary embodiment, the power supply interconnection portion 410 is formed to extend in the second direction Y, which is along a lateral direction of the base plate 20, and is located near an edge part (right edge part in Fig. 10) of the base plate 20 in the longitudinal direction. The third power supply region 403 and the sixth power supply region 406 are connected to the power supply interconnection region 410. In the second exemplary embodiment, the first power supply region 401, the second power supply region 402, the fourth power supply region 404, and the fifth power supply region 405 are electrically connected to the power supply interconnection region 410 via interconnection members 200 (a first power supply interconnection member 41 and a second power supply interconnection member 42) described below. <massemuster>

[0124] In the second exemplary embodiment, the ground pattern 50 includes four wiring regions (a first ground region 501 to a fourth ground region 504) and a ground interconnection region 510. < <massebereich>>

[0125] The second exemplary embodiment is similar to the first exemplary embodiment in that the plurality of ground regions 500 are lined up at intervals in an extending direction of the output regions 300 and oppose respective output regions 300 with predetermined intervals therebetween in a direction perpendicular to the extending direction of the output regions 300. More specifically, the first ground region 501 to the fourth ground region 504 have configurations described below.

[0126] Both the first ground region 501 and the second ground region 502 are arranged between the first output region 301 and the second output region 302 and are lined up with a distance in the extension direction (first direction X) of the first output region 301. In this example, the first ground region 501 and the second ground region 502 are arranged in this order from one end side to the other end side (the left side to the right side in Fig. 10) in the extension direction of the first output region 301. Furthermore, both the first ground region 501 and the second ground region 502 are opposite to the first output region 301 with a predetermined distance therebetween in the direction (second direction Y) perpendicular to the extension direction of the first output region 301.

[0127] Both the third ground region 503 and the fourth ground region 504 are arranged between the first output region 301 and the second output region 302 and are lined up with a distance in the extension direction (first direction X) of the second output region 302 and output region 303. In this example, the third ground region 503 and the fourth ground region 504 are arranged in this order from one end side to the other end side (the left side to the right side in Fig. 10) in the extension direction of the second output region 302 and the third output region 303. Furthermore, both the third ground region 503 and the fourth ground region 504 oppose the second output region 302 with a predetermined distance therebetween in the direction (second direction Y) perpendicular to the extension direction of the second output region 302. Likewise, both the third ground region 503 and the fourth ground region 504 oppose the third output region 303 with a predetermined distance therebetween in the direction (second direction Y) perpendicular to the extension direction of the third output region 303. < <masse-zwischenverbindungsbereich>>

[0128] In the second exemplary embodiment, the ground interconnection region 510 is near an edge part (right edge part in Fig. 10) of the base plate 20 in the longitudinal direction. In the second exemplary embodiment, the first ground region 501 to the fourth ground region are electrically connected to the ground interconnection region 510 via a connecting member 200 (ground connecting member 51), which will be described later. <Anordnung von Stromversorgungsbereichen und Massebereichen>

[0129] The second exemplary embodiment is similar to the first exemplary embodiment in that the plurality of power supply regions 400 and the plurality of ground regions 500 are alternately arrayed in the direction along the extending direction of output regions 300. Further, the plurality of power supply regions 400 and the plurality of ground regions 500 are arrayed such that each power supply region 400 and its adjacent ground region 500 oppose each other with a predetermined distance therebetween.

[0130] More specifically, between the first output region 301 and the second output region 302, the first power supply region 401, the first ground region 501, the second power supply region 402, the second ground region 502 and the third power supply region 403 are arranged in this order from one side to the other (the left side to the right side in Fig. 10) in the first direction X, which lies along the extension direction of the first output region 301. The first ground region 501 faces both the first power supply region 401 and the second power supply region 402 with a predetermined distance therebetween. Likewise, the second ground region 502 faces both the second power supply region 402 and the third power supply region 403 with a predetermined distance therebetween.

[0131] Between the second output region 302 and the third output region 303, the fourth power supply region 404, the third ground region 503, the fifth power supply region 405, the fourth ground region 504 and the sixth power supply region 406 are arranged in this order from one side to the other side (the left side to the right side in Fig. 10) is arranged in the first direction X, which lies along the extension direction of the second output region 302 and the third output region 303. The ground region 503 faces both the fourth power supply region 404 and the fifth power supply region 405 with a predetermined distance therebetween. Likewise, the fourth ground region 504 faces both the fifth power supply region 405 and the sixth power supply region 406 with a predetermined distance therebetween. <High-Side-Schaltelement und High-Side-Transistor>

[0132] The second exemplary embodiment is similar to the first exemplary embodiment in that the first high-side switching element 11u to the third high-side switching element 11w are provided on the conductive layer 22 of the base plate 20. Each of the first high-side switching element 11u to the third high-side switching element 11w includes four high-side transistors 110.

[0133] Four high-side transistors 110 constituting the first high-side switching element 11u are spaced apart in the first direction X, which is along the extending direction of the first output region 301. Of these four high-side transistors 110, one high-side transistor 110 is mounted on a surface of the first power supply region 401 and connected to the first output region 301; two high-side transistors 110 are mounted on a surface of the second power supply region 402 and connected to the first output region 301; and a remaining high-side transistor 110 is mounted on a surface of the third power supply region 403 and connected to the first output region 301.

[0134] Four high-side transistors 110 constituting the second high-side switching element 11v are spaced apart in the first direction X, which is along the extension direction of the second output region 302. Of these four high-side transistors 110, one high-side transistor 110 is mounted on a surface of the fourth power supply region 404 and connected to the second output region 302; two high-side transistors 110 are mounted on a surface of the fifth power supply region 405 and connected to the second output region 302; and a remaining high-side transistor 110 is mounted on a surface of the sixth power supply region 406 and connected to the second output region 302.

[0135] Four high-side transistors 110 constituting the third high-side switching element 11w are spaced apart in the first direction X, which is along the extension direction of the third output region 303. Of these four high-side transistors 110, one high-side transistor 110 is mounted on a surface of the fourth power supply region 404 and connected to the third output region 303; two high-side transistors 110 are mounted on the surface of the fifth power supply region 405 and connected to the third output region 303; and a remaining high-side transistor 110 is mounted on the surface of the sixth power supply region 406 and connected to the third output region 303. <Low-Side-Schaltelement und Low-Side-Transistor>

[0136] The second exemplary embodiment is similar to the first exemplary embodiment in that the first low-side switching element 12u through the third low-side switching element 12w are provided on the conductive layer 22 of the base plate 20. Each of the first low-side switching element 12u through the third low-side switching element 12w includes four low-side transistors 120.

[0137] Four low-side transistors 120 constituting the first low-side switching element 12u are spaced apart in the first direction X, which is along the extension direction of the first output region 301. Of these four low-side transistors 120, two low-side transistors 120 are mounted on a surface of the first output region 301 and connected to the first ground region 501, and two remaining low-side transistors 120 are mounted on a surface of the first output region 301 and connected to the second ground region 502.

[0138] Four low-side transistors 120 constituting the second low-side switching element 12v are spaced apart in the first direction X, which lies along the extension direction of the second output region 302. Of these four low-side transistors 120, two low-side transistors 120 are mounted on one surface of the second output region 302 and connected to the third ground region 503, and two remaining low-side transistors 120 are mounted on the surface of the second output region 302 and connected to the fourth ground region 504.

[0139] Four low-side transistors 120 constituting the third low-side switching element 12w are spaced apart in the first direction X, which is along the extension direction of the third output region 303. Of these four low-side transistors 120, two low-side transistors 120 are mounted on one surface of the third output region 303 and connected to the third ground region 503, and two remaining low-side transistors 120 are mounted on the surface of the third output region 303 and connected to the fourth ground region 504. <Anordnung der High-Side-Transistoren und Low-Side-Transistoren>

[0140] The second exemplary embodiment is similar to the first exemplary embodiment in that the plurality of high-side transistors 110 constituting a single high-side switching element 11 are arranged sequentially next to the plurality of low-side transistors 120 constituting a single low-side switching element 12 in the first direction X, which is along the extension direction of the output regions 300. In this case, a direction in which the terminals of the low-side transistors 120 (terminals projecting from the main part sides to the ground regions 500) are aligned is opposite to a direction in which the terminals of the high-side transistors 110 (terminals projecting from the main part sides to the output regions 300) are aligned.

[0141] More specifically, the four high-side transistors 110 constituting the first high-side switching element 11u and the four low-side transistors 120 constituting the first low-side switching element 12u are lined up in the first direction X, which is along the extending direction of the first output region 301, such that one high-side transistor 110, two low-side transistors 120, two high-side transistors 110, two low-side transistors 120, and one high-side transistor 110 are arranged in this order from one side to the other side (the left side to the right side in Fig. 10) are arranged in the first direction X.

[0142] The four high-side transistors 110 constituting the second high-side switching element 11v and the four low-side transistors 120 constituting the second low-side switching element 12v are lined up in the first direction X, which is along the extending direction of the second output region 302, such that one high-side transistor 110, two low-side transistors 120, two high-side transistors 110, two low-side transistors 120, and one high-side transistor 110 are arranged in this order from one side to the other side (the left side to the right side in Fig. 10) are arranged in the first direction X.

[0143] The four high-side transistors 110 constituting the third high-side switching element 11w and the four low-side transistors 120 constituting the third low-side switching element 12w are lined up in the first direction X, which is along the extending direction of the third output region 303, such that one high-side transistor 110, two low-side transistors 120, two high-side transistors 110, two low-side transistors 120, and one high-side transistor 110 are arranged in this order from one side to the other side (the left side to the right side in Fig. 10) are arranged in the first direction X. <Glättungskondensatorabschnitt und Kondensator>

[0144] The switching power supply 10 according to the second exemplary embodiment is similar to the switching power supply 10 according to the first exemplary embodiment in that the smoothing capacitor section 13 is provided on the conductive layer 22 of the base plate 20. The smoothing capacitor section 13 includes a plurality of capacitors 130.

[0145] The second exemplary embodiment is similar to the first exemplary embodiment in that the plurality of capacitors 130 corresponds to the plurality of high-side transistors 110 and the plurality of low-side transistors 120. Each of the plurality of capacitors 130 is arranged adjacent to its corresponding one of the plurality of high-side transistors 110 and the plurality of low-side transistors 120. In other words, the plurality of high-side transistors 110, the plurality of low-side transistors 120, and the plurality of capacitors 130 are arranged such that pairs each including a high-side transistor 110 and its corresponding capacitor 130 are positioned adjacent to pairs each including a low-side transistor 120 and its corresponding capacitor 130.

[0146] More specifically, the second exemplary embodiment is similar to the first exemplary embodiment in that 24 capacitors 130 are provided, corresponding to 12 high-side transistors 110 and 12 low-side transistors 120 provided on the conductive layer 22 of the base plate 20.

[0147] Four capacitors 130, corresponding to respective four high-side transistors 110 constituting the first high-side switching element 11u, are spaced apart in the first direction X along the array direction of these four high-side transistors 110 (extension direction of the first output region 301), and are provided near the four high-side transistors 110. Of these four capacitors 130, one capacitor 130 is mounted on the surface of the first power supply region 401 and one surface of the first ground region 501; one capacitor 130 is mounted on the surfaces of the second power supply region 402 and the first ground region 501; one capacitor 130 is mounted on the surface of the second power supply region 402 and one surface of the second ground region 502; and a remaining capacitor 130 is mounted on the surfaces of the third power supply region 403 and the second ground region 502.

[0148] Four capacitors 130, corresponding to respective four high-side transistors 110 constituting the second high-side switching element 11v, are spaced apart in the first direction X along the array direction of these four high-side transistors 110 (extension direction of the first output region 302), and are provided near the four high-side transistors 110. Of these four capacitors 130, one capacitor 130 is mounted on the surface of the fourth power supply region 404 and one surface of the third ground region 503; one capacitor 130 is mounted on the surfaces of the fifth power supply region 405 and the third ground region 503; one capacitor 130 is mounted on the surface of the fifth power supply region 405 and one surface of the fourth ground region 504; and and a remaining capacitor 130 is mounted on the surfaces of the sixth power supply region 406 and the fourth ground region 504.

[0149] Four capacitors 130 corresponding to respective four high-side transistors 110 constituting the third high-side switching element 11w are spaced apart in the first direction X along the array direction of these four high-side transistors 110 (extension direction of the third output region 303) and are provided near the four high-side transistors 110. Of these four capacitors 130, one capacitor 130 is mounted on the surface of the fourth power supply region 404 and one surface of the third ground region 503; one capacitor 130 is mounted on the surfaces of the fifth power supply region 405 and the third ground region 503; one capacitor 130 is mounted on the surface of the fifth power supply region 405 and one surface of the fourth ground region 504; and and a remaining capacitor 130 is mounted on the surfaces of the sixth power supply region 406 and the fourth ground region 504.

[0150] Four capacitors 130, corresponding to respective four low-side transistors 120 constituting the first low-side switching element 12u, are spaced apart in the first direction X along the array direction of these four low-side transistors 120 (extension direction of the first output region 301), and are provided near the four low-side transistors 120. Of these four capacitors 130, one capacitor 130 is mounted on the surface of the first power supply region 401 and one surface of the first ground region 501; one capacitor 130 is mounted on the surfaces of the second power supply region 402 and the first ground region 501; one capacitor 130 is mounted on the surface of the second power supply region 402 and one surface of the second ground region 502; and a remaining capacitor 130 is mounted on the surfaces of the third power supply region 403 and the second ground region 502.

[0151] Four capacitors 130, corresponding to respective four low-side transistors 120 constituting the second low-side switching element 12v, are spaced apart in the first direction X along the array direction of these four low-side transistors 120 (extension direction of the second output region 302), and are provided near the four low-side transistors 120. Of these four capacitors 130, one capacitor 130 is mounted on the surface of the fourth power supply region 404 and one surface of the third ground region 503; one capacitor 130 is mounted on the surfaces of the fifth power supply region 405 and the third ground region 503; one capacitor 130 is mounted on the surface of the fifth power supply region 405 and one surface of the fourth ground region 504; and and a remaining capacitor 130 is mounted on the surfaces of the sixth power supply region 406 and the fourth ground region 504.

[0152] Four capacitors 130, corresponding to respective four low-side transistors 120 constituting the third low-side switching element 12w, are spaced apart in the first direction X along the array direction of these four low-side transistors 120 (extension direction of the third output region 303), and are provided near the four low-side transistors 120. Of these four capacitors 130, one capacitor 130 is mounted on the surface of the fourth power supply region 404 and one surface of the third ground region 503; one capacitor 130 is mounted on the surfaces of the fifth power supply region 405 and the third ground region 503; one capacitor 130 is mounted on the surface of the fifth power supply region 405 and one surface of the fourth ground region 504; and and a remaining capacitor 130 is mounted on the surfaces of the sixth power supply region 406 and the fourth ground region 504. <verbindungselement>

[0153] The second exemplary embodiment is similar to the first exemplary embodiment in that at least one of the power supply pattern 40 and the ground pattern 50 includes a plurality of wiring regions (portions of the wiring patterns formed in the conductive layer 22) that are electrically connected via interconnects 200. In this example, the power supply pattern 40 includes the first power supply region 401, the second power supply region 402, the fourth power supply region 404, and the fifth power supply region 405, which are electrically connected via the first power supply interconnect 41 and the second power supply interconnect 42 (interconnect 200). The ground pattern 50 includes the first ground region 501 to the fourth ground region 504, which are electrically connected via the ground interconnect 51 (interconnect 200). Fig. 10 illustrates the first power supply connection element 41, the second power supply connection element 42 and the ground connection element 51 with lines of one long and two short dashes.

[0154] The first power supply connection element 41 electrically connects the power supply interconnection region 410, the first power supply region 401, and the second power supply region 402. The second power supply connection element 42 electrically connects the power supply interconnection region 410, the fourth power supply region 404, and the fifth power supply region 405. The ground connection element 51 electrically connects the ground interconnection region 510, the first ground region 501, the second ground region 502, the third ground region 503, and the fourth ground region 504.

[0155] The second exemplary embodiment is similar to the first exemplary embodiment in that each of the connecting elements 200 is composed of a conductor (a bus bar) having a flat shape. More specifically, each connecting element 200 includes a main portion 201 and tabs 202; the main portion 201 is formed in a flat shape and faces the conductive layer 22 with a space therebetween; and each of the tabs 202 extends from the main portion 201 to each of the plurality of wiring regions in the conductive layer 22.For example, the ground interconnection member 51 includes a main portion 201 and five tabs 202; the main portion 201 opposes the second output portion 302 with a space therebetween, and the tabs 202 extend from the main portion 201 to respective five wiring portions (ground interconnection portion 510, first ground portion 501, second ground portion 502, third ground portion 503, and fourth ground portion 504) of the ground pattern 50.

[0156] The second exemplary embodiment is similar to the first exemplary embodiment in that the connecting elements 200 are connected by soldering to the plurality of wiring regions in the conductive layer 22. For example, five tabs 202 of the ground connecting element 51 are connected by soldering to the five respective wiring regions (the ground interconnection region 510, the first ground region 501, the second ground region 502, the third ground region 503, and the fourth ground region 504) of the ground pattern 50.

[0157] The second exemplary embodiment is similar to the first exemplary embodiment in that a material of the connecting members 200 may be of the same type as a material of the heat dissipation layer 23. In this example, parts of each connecting member 200 that are connected to the plurality of wiring regions by soldering may be subjected to plating to enable solder connection. For example, each of the ground connecting member 51 and the heat dissipation layer 23 may be made of aluminum. In the ground connecting member 51, five tabs 202 that are connected to the five wiring regions (the ground interconnection region 510, the first ground region 501, the second ground region 502, the third ground region 503, and the fourth ground region 504) of the ground pattern 50 by soldering are plated with nickel (a material that enables solder connection). [Effect of the second exemplary embodiment]

[0158] The switching power supply 10 according to the second exemplary embodiment can achieve substantially the same effect as the switching power supply 10 according to the first exemplary embodiment. For example, it is possible to reduce heat concentration in the high-side switching elements 11 and the low-side switching elements 12. (Third exemplary embodiment)

[0159] Fig. 11 illustrates a configuration of the switching power supply 10 according to a third exemplary embodiment. The switching power supply 10 according to the third exemplary embodiment differs from the switching power supply 10 according to the first exemplary embodiment in configurations of the output pattern 30, the power supply pattern 40, the ground pattern 50, and the connection elements 200, and configurations of the high-side transistors 110, the low-side transistors 120, and the capacitors 130. <ausgangsmuster>

[0160] In the third exemplary embodiment, the output pattern 30 includes a first output region 301 to a third output region 303, which correspond to a first switching part SWu to a third switching part SWw, respectively. The first output region 301 to the third output region 303 are formed to extend in the first direction X and are spaced apart in the first direction X. In this example, the first output region 301 to the third output region 303 are arranged at a center of the base plate 20 in its lateral direction.

[0161] The first output portion 301 to the third output portion 303 are electrically connected to the first output connector 81 to the third output connector 83. For example, each of the first output connector 81 to the third output connector 83 may be formed from a conductor (a bus bar) having a flat shape. Fig. 11 illustrates a first output connection element 81 to a third output connection element 83 with lines of one long and two short dashes. <stromversorgungsmuster>

[0162] In the third exemplary embodiment, the power supply pattern 40 includes a first power supply region 401, a second power supply region 402, and a power supply connection region 430. < <stromversorgungsbereich>>

[0163] The first power supply section 401 and the second power supply section 402 extend in an extension direction (first direction X) of the first output section 301 to the third output section 303. The first power supply section 401 opposes the first output section 301 to the third output section 303 with a predetermined distance therebetween in a direction (second direction Y) perpendicular to the extension direction of the first output section 301 to the third output section 303. The second power supply section 402 is arranged to oppose the first power supply section 401, with the first output section 301 to the third output section 303 and the second ground section 502, which will be described later, interposed therebetween in the direction (second direction Y) perpendicular to the extension direction of the first output section 301 to the third output section 303.In addition, the second power supply portion 402 is electrically connected to one end (the positive electrode) of the DC power supply P. < <stromversorgungsverbindungsbereich>>

[0164] The power supply connection portion 430 is formed to extend in the second direction Y and connects the first power supply portion 401 to the second power supply portion 402. In this example, the power supply connection portion 430 is near an edge part (right edge part in Fig. 11) of the base plate 20 in the longitudinal direction. <massemuster>

[0165] In the third exemplary embodiment, the ground pattern 50 includes a first ground region 501, a second ground region 502, a first ground tail region 531, and a second ground tail region 532. < <massebereich>>

[0166] The first ground region 501 and the second ground region 502 extend in an extending direction (first direction X) of the first output region 301 to the third output region 303. Furthermore, the first ground region 502 opposes the first output region 301 to the third output region 303 with a predetermined distance therebetween in a direction (second direction Y) perpendicular to the extending direction of the first output region 301 to the third output region 303. The first ground region 501 is arranged to oppose the second ground region 502, with the first power supply region 401 and the first output region 301 to the third output region 303 interposed therebetween in the direction (second direction Y) perpendicular to the extending direction of the first output region 301 to the third output region 303. Furthermore, the first ground region 501 is electrically connected to the other end (the negative electrode) of the DC power supply P. <<Masseausläuferbereich> >

[0167] The first ground tail portion 531 and the second ground tail portion 532 are formed to extend in the direction (second direction Y) perpendicular to the extending direction of the first output portion 301 to the third output portion 303. The first ground tail portion 531 is disposed between the first output portion 301 and the second output portion 302, while the second ground tail portion 532 is disposed between the second output portion 302 and the third output portion 303. Furthermore, both the first ground tail portion 531 and the second ground tail portion 532 are connected to the second ground portion 502, opposing the first power supply portion 401 with a predetermined distance therebetween. <Anordnung von Stromversorgungsbereichen und Massebereichen>

[0168] In the third exemplary embodiment, a plurality of power supply regions 400 and a plurality of ground regions 500 are arranged to oppose each other at a predetermined distance in a direction perpendicular to an extending direction of the output regions 300.

[0169] More specifically, the first ground region 501, the first power supply region 401, the first output region 301 to the third output region 303, the second ground region 502, and the second power supply region 402 are arranged in this order from one end side to the other end side (a lower side to an upper side in the example of Fig. 11) in the lateral direction of the base plate 20. Furthermore, the first power supply region 401 opposes the first ground region 501 with a predetermined distance therebetween, while the second power supply region 402 opposes the second ground region 502 with a predetermined distance therebetween. <High-Side-Schaltelement und High-Side-Transistor>

[0170] The third exemplary embodiment is similar to the first exemplary embodiment in that the first high-side switching element 11u to the third high-side switching element 11w are provided on the conductive layer 22 of the base plate 20. Each of the first high-side switching element 11u to the third high-side switching element 11w includes four high-side transistors 110.

[0171] The four high-side transistors 110 constituting the first high-side switching element 11u are spaced apart in the first direction X, which lies along the extension direction of the first output region 301. These high-side transistors 110 are mounted on a surface of the first power supply region 401 and connected to the first output region 301. The four high-side transistors 110 constituting the second high-side switching element 11v are spaced apart in the first direction X, which lies along the extension direction of the second output region 302. These high-side transistors 110 are mounted on the surface of the first power supply region 401 and connected to the second output region 302. The four high-side transistors 110 forming the third high-side switching element 11w are arranged at a distance in the first direction X, which lies along the extension direction of the third output region 303.These high-side transistors 110 are mounted on the surface of the first power supply region 401 and connected to the third output region 303. <Low-Side-Schaltelement und Low-Side-Transistor>

[0172] The third exemplary embodiment is similar to the first exemplary embodiment in that the first low-side switching element 12u through the third low-side switching element 12w are provided on the conductive layer 22 of the base plate 20. Each of the first low-side switching element 12u through the third low-side switching element 12w includes four low-side transistors 120.

[0173] The four low-side transistors 120 forming the first low-side switching element 12u are spaced apart in the first direction X, which lies along the extension direction of the first output region 301. These low-side transistors 120 are mounted on a surface of the first output region 301 and connected to the second ground region 502. The four low-side transistors 120 forming the second low-side switching element 12v are spaced apart in the first direction X, which lies along the extension direction of the second output region 302. These low-side transistors 120 are mounted on a surface of the second output region 302 and connected to the second ground region 502. The four low-side transistors 120 forming the third low-side switching element 12w are arranged at a distance in the first direction X, which lies along the extension direction of the third output region 303.These low-side transistors 120 are mounted on a surface of the third output region 303 and connected to the second ground region 502. <Anordnung der High-Side-Transistoren und Low-Side-Transistoren>

[0174] In the third exemplary embodiment, the plurality of high-side transistors 110 constituting a single high-side switching element 11 and the plurality of low-side transistors 120 constituting a single low-side switching element 12 are arranged in the direction (first direction X) along the extending direction of the output regions 300 such that a high-side transistor 110 is arranged adjacent to a corresponding low-side transistor 120 in the direction (second direction Y) perpendicular to the extending direction of the output regions 300.

[0175] More specifically, the four high-side transistors 110 constituting the first high-side switching element 11u are sequentially opposed to the four low-side transistors 120 constituting the first low-side switching element 12u in the second direction Y perpendicular to the extension direction of the first output region 301. Likewise, the four high-side transistors 110 constituting the second high-side switching element 11v are sequentially opposed to the four low-side transistors 120 constituting the second low-side switching element 12v in the second direction Y perpendicular to the extension direction of the second output region 302. The four high-side transistors 110 constituting the third high-side switching element 11w are sequentially opposed to the four low-side transistors 120 constituting the third low-side switching element 12w in the second direction Y perpendicular to the extension direction of the third output region 303. <Glättungskondensatorabschnitt und Kondensator>

[0176] The switching power supply 10 according to the third exemplary embodiment is similar to the switching power supply 10 according to the first exemplary embodiment in that the smoothing capacitor section 13 is provided on the conductive layer 22 of the base plate 20. The smoothing capacitor section 13 includes a plurality of capacitors 130.

[0177] The third exemplary embodiment is similar to the first exemplary embodiment in that the plurality of capacitors 130 corresponds to the plurality of high-side transistors 110 and the plurality of low-side transistors 120. Each of the plurality of capacitors 130 is arranged adjacent to its corresponding one of the plurality of high-side transistors 110 and the plurality of low-side transistors 120. In other words, the plurality of high-side transistors 110, the plurality of low-side transistors 120, and the plurality of capacitors 130 are arranged such that pairs each including a high-side transistor 110 and its corresponding capacitor 130 are positioned adjacent to pairs each including a low-side transistor 120 and its corresponding capacitor 130.

[0178] In this example, the plurality of capacitors 130 corresponding to the plurality of high-side transistors 110 are spaced apart in the first direction X, which is along a line-up direction of the plurality of high-side transistors 110 (which is along the extension direction of the output regions 300). Furthermore, these capacitors 130 are arranged adjacent to the plurality of high-side transistors 110 in a direction (second direction Y) perpendicular to the line-up direction of the plurality of high-side transistors 110. The plurality of capacitors 130 corresponding to the plurality of low-side transistors 120 are spaced apart in the first direction X, which is along a line-up direction of the plurality of low-side transistors 120 (which is along the extension direction of the output regions 300).In addition, these capacitors 130 are arranged adjacent to the plurality of low-side transistors 120 in the direction (second direction Y) perpendicular to the array direction of the plurality of low-side transistors 120. In this example, the capacitors 130 corresponding to high-side transistors 110, high-side transistors 110, low-side transistors 120, and capacitors 130 corresponding to low-side transistors 120 are arranged in this order from one side to the other side (from the lower side to the upper side in . Fig. 11) of the base plate 20 in the lateral direction.

[0179] Specifically, four capacitors 130 corresponding to four high-side transistors 110 constituting the first high-side switching element 11u are spaced apart in the first direction X along the array direction of these four high-side transistors 110 (extension direction of the first output region 301) and are provided near the four high-side transistors 110. The four capacitors 130 corresponding to four high-side transistors 110 are mounted on surfaces of the first power supply region 401 and the first ground region 501.An arrangement of four capacitors 130 corresponding to respective four high-side transistors 110 constituting the second high-side switching element 11v and an arrangement of four capacitors 130 corresponding to respective four high-side transistors 110 constituting the third high-side switching element 11w are the same as the arrangement of four capacitors 130 corresponding to respective four high-side transistors 110 constituting the first high-side switching element 11u.

[0180] Four capacitors 130 corresponding to respective four low-side transistors 120 constituting the first low-side switching element 12u are spaced apart in the first direction X along the array direction of these four low-side transistors 120 (along the extension direction of the first output region 301) and are provided near the four low-side transistors 120. The four capacitors 130 corresponding to respective four low-side transistors 120 are mounted on surfaces of the second power supply region 402 and the second ground region 502.An arrangement of four capacitors 130 corresponding to respective four low-side transistors 120 constituting the second low-side switching element 12v and an arrangement of four capacitors 130 corresponding to respective four low-side transistors 120 constituting the third low-side switching element 12w are the same as the arrangement of four capacitors 130 corresponding to respective four low-side transistors 120 constituting the first low-side switching element 12u. <verbindungselement>

[0181] The third exemplary embodiment is similar to the first exemplary embodiment in that at least one of the power supply pattern 40 and the ground pattern 50 includes a plurality of wiring regions (portions of the wiring patterns formed in the conductive layer 22) electrically connected via interconnection elements 200. In this example, the ground pattern 50 includes a first ground region 501, a first ground extension region 531, and a second ground extension region 532, which are electrically connected via the first ground connection element 55 and the second ground connection element 56 (interconnection elements 200). Fig. 11 illustrates a first ground connection element 55 and second ground connection element 56 with lines of one long and two short dashes.

[0182] The first ground connection element 55 electrically connects the first ground region 501 to the first ground extension region 531. The second ground connection element 56 electrically connects the first ground region 501 to the second ground extension region 532.

[0183] The third exemplary embodiment is similar to the first exemplary embodiment in that each of the connecting elements 200 is composed of a conductor (a bus bar) having a flat shape. More specifically, each connecting element 200 includes a main part 201 and tabs 202; the main part 201 is formed in a flat shape and faces the conductive layer 22 with a gap therebetween; and each of the tabs 202 extends from the main part 201 to each of the plurality of wiring regions in the conductive layer 22. For example, the first ground connecting element 55 includes a main part 201 and two tabs 202; the main part 201 faces the first power supply region 401 with a gap therebetween, and the tabs 202 extend from the main part 201 to each of the two wiring regions (the first ground region 501 and the first ground extension region 531) of the ground pattern 50.

[0184] The third exemplary embodiment is similar to the first exemplary embodiment in that the connecting elements 200 are connected by soldering to the plurality of wiring regions in the conductive layer 22. For example, two tabs 202 of the first ground connecting element 55 are connected by soldering to the two respective wiring regions (the first ground region 501 and the first ground extension region 531) of the ground pattern 50.

[0185] The third exemplary embodiment is similar to the first exemplary embodiment in that a material of the connecting members 200 may be of the same type as a material of the heat dissipation layer 23. In this example, parts of each connecting member 200 that are connected to the plurality of wiring regions by soldering may be subjected to plating to enable solder connection. For example, each of the first ground connecting member 55 and the heat dissipation layer 23 may be made of aluminum. In the first ground connecting member 55, two tabs 202 that are connected to the two wiring regions (the first ground region 501 and the first ground tail region 531) of the ground pattern 50 by soldering are plated with nickel (a material that enables solder connection). [Effect of the third exemplary embodiment]

[0186] The switching power supply 10 according to the third exemplary embodiment can achieve substantially the same effect as the switching power supply 10 according to the first exemplary embodiment. For example, it is possible to reduce heat concentration in the high-side switching elements 11 and the low-side switching elements 12. (First Modification of the Third Exemplary Embodiment)

[0187] Fig. 12 illustrates a configuration of a switching power supply 10 according to a first modification of the third exemplary embodiment. The switching power supply 10 according to a first modification of the third exemplary embodiment differs from the switching power supply 10 according to the third exemplary embodiment in configurations of the output pattern 30, the power supply pattern 40, the ground pattern 50, and the connection elements 200, as well as configurations of the high-side transistors 110, the low-side transistors 120, and the capacitors 130. <ausgangsmuster>

[0188] In the first modification of the third exemplary embodiment, the output pattern 30 includes a first output region 301 to a third output region 303, which correspond to a first switching part SWu to a third switching part SWw, respectively, and further includes a fourth output region 304 to a sixth output region 306, which correspond to a first switching part SWu to a third switching part SWw, respectively. The first output region 301 to the third output region 303 are formed to extend in the first direction X and are spaced apart in the first direction X. Likewise, the fourth output region 304 to the sixth output region 306 are formed to extend in the first direction X and are spaced apart in the first direction X.The fourth output region 304 to the sixth output region 306 are arranged to oppose the first output region 301 to the third output region 303, respectively, with a distance therebetween in the second direction Y which is perpendicular to the first direction X.

[0189] Both the first output region 301 and the fourth output region 304 are electrically connected to the first output connector 81; both the second output region 302 and the fifth output region 305 are electrically connected to the second output connector 82; and both the third output region 303 and the sixth output region 306 are electrically connected to the third output connector 83. Fig. 12 illustrates a first output connection element 81 to a third output connection element 83 with lines of one long and two short dashes. <stromversorgungsmuster>

[0190] In the first modification of the third exemplary embodiment, the power supply pattern 40 includes a first power supply region 401, a second power supply region 402, a power supply interconnection region 410, a first power supply connection region 431, a second power supply connection region 432, and a third power supply connection region 433. < <stromversorgungsbereich>>

[0191] The first power supply region 401 and the second power supply region 402 extend in an extension direction (first direction X) of the first output region 301 to the third output region 303. The first power supply region 401 opposes the first output region 301 to the third output region 303 with a predetermined distance therebetween in a direction (second direction Y) perpendicular to the extension direction of the first output region 301 to the third output region 303. The second power supply region 402 is arranged to oppose the first power supply region 401, with the first ground region 501, described later, interposed therebetween in the direction (second direction Y) perpendicular to the extension direction of the first output region 301 to the third output region 303. < <stromversorgungs-zwischenverbindungsbereich>>

[0192] The power supply interconnection region 410 is formed to extend in the extension direction (first direction X) of the first output region 301 to the third output region 303 and is arranged to oppose the first power supply region 401, with the first output region 301 to the third output region 303 therebetween in the direction (second direction Y) perpendicular to the extension direction of the first output region 301 to the third output region 303. In this example, the power supply interconnection region 410 is near an edge part (lower edge part in Fig. 12) of the base plate 20 in the lateral direction. Furthermore, the power supply interconnection portion 410 is electrically connected to the end (positive electrode) of the DC power supply P. < <stromversorgungsverbindungsbereich>>

[0193] The first power supply connection portion 431 and the second power supply connection portion 432 are formed to extend in the direction (second direction Y) perpendicular to the extension direction of the first output portion 301 to the third output portion 303. The first power supply connection portion 431 is disposed between the first output portion 301 and the second output portion 302, while the second power supply connection portion 432 is disposed between the second output portion 302 and the third output portion 303. Furthermore, both the first power supply connection portion 431 and the second power supply connection portion 432 connect the first power supply portion 401 to the power supply interconnection portion 410.

[0194] The third power supply connection portion 433 is formed to extend in the second direction Y and connects the first power supply portion 401 to the second power supply portion 402. In this example, the third power supply connection portion 433 is near an edge part (right edge part in Fig. 12) of the base plate 20 in the longitudinal direction. <massemuster>

[0195] In the first modification of the third exemplary embodiment, the ground pattern 50 includes a first ground region 501, a second ground region 502, a ground interconnection region 510, a first ground connection region 511, and a second ground connection region 512. < <massebereich>>

[0196] The first ground region 501 and the second ground region 502 extend in an extension direction (first direction X) of the fourth output region 304 to the sixth output region 306. The second ground region 502 opposes the fourth output region 304 to the sixth output region 306 with a predetermined distance therebetween in a direction (second direction Y) perpendicular to the extension direction of the fourth output region 304 to the sixth output region 306. The first ground region 501 is arranged to oppose the second ground region 502, with the second power supply region 402 interposed therebetween in the direction (second direction Y) perpendicular to the extension direction of the fourth output region 304 to the sixth output region 306. < <masse-zwischenverbindungsbereich>>

[0197] The ground interconnection region 510 is formed to extend in the extension direction (first direction X) of the fourth output region 304 to the sixth output region 306, and is arranged to oppose the second ground region 502, with the fourth output region 304 to the sixth output region 306 interposed in the direction (second direction Y) perpendicular to the extension direction of the fourth output region 304 to the sixth output region 306. In this example, the ground interconnection region 510 is near an edge part (upper edge part in Fig. 12) of the base plate 20 in the lateral direction. Furthermore, the ground interconnection portion 510 is electrically connected to the other end (the negative electrode) of the DC power supply P. < <masseverbindungsbereich>>

[0198] The first ground interconnection region 511 and the second ground interconnection region 512 are formed to extend in the direction (second direction Y) perpendicular to the extension direction of the fourth output region 304 to the sixth output region 306. The first ground interconnection region 511 is disposed between the fourth output region 304 and the fifth output region 305, while the second ground interconnection region 512 is disposed between the fifth output region 305 and the sixth output region 306. Both the first ground interconnection region 511 and the second ground interconnection region 512 connect the second ground region 502 to the ground interconnection region 510. <Anordnung von Stromversorgungsbereichen und Massebereichen>

[0199] The first modification of the third exemplary embodiment is similar to the third exemplary embodiment in that a plurality of power supply portions 400 and a plurality of ground portions 500 are arranged to oppose each other at a predetermined interval in a direction perpendicular to an extending direction of the output portions 300.

[0200] More specifically, the power supply interconnection region 410, the first output region 301 to the third output region 303, the first power supply region 401, the first ground region 501, the second power supply region 402, the second ground region 502, the fourth output region 304 to the sixth output region 306, and the ground interconnection region 510 are arranged in this order from one end side to the other end side (the lower side to the upper side in the example of Fig. 12) in the lateral direction of the base plate 20. In addition, the first power supply region 401 opposes the first ground region 501 with a predetermined distance therebetween, while the second power supply region 402 opposes the second ground region 502 with a predetermined distance therebetween. <High-Side-Schaltelement und High-Side-Transistor>

[0201] The first modification of the third exemplary embodiment is similar to the third exemplary embodiment in that the first high-side switching element 11u to the third high-side switching element 11w are provided on the conductive layer 22 of the base plate 20. Each of the first high-side switching element 11u to the third high-side switching element 11w includes four high-side transistors 110.

[0202] The first modification of the third exemplary embodiment is similar to the third exemplary embodiment in that the four high-side transistors 110 constituting the first high-side switching element 11u are spaced apart in the first direction X along the extension direction of the first output region 301. These high-side transistors 110 are mounted on a surface of the first power supply region 401 and connected to the first output region 301. The four high-side transistors 110 constituting the second high-side switching element 11v are spaced apart in the first direction X along the extension direction of the second output region 302. These high-side transistors 110 are mounted on the surface of the first power supply region 401 and connected to the second output region 302.The four high-side transistors 110 constituting the third high-side switching element 11w are spaced apart in the first direction X, which lies along the extension direction of the third output region 303. These high-side transistors 110 are mounted on the surface of the first power supply region 401 and connected to the third output region 303. <Low-Side-Schaltelement und Low-Side-Transistor>

[0203] The first modification of the third exemplary embodiment is similar to the third exemplary embodiment in that the first low-side switching element 12u to the third low-side switching element 12w are provided on the conductive layer 22 of the base plate 20. Each of the first low-side switching element 12u to the third low-side switching element 12w includes four low-side transistors 120.

[0204] In the first modification of the third exemplary embodiment, the four low-side transistors 120 constituting the first low-side switching element 12u are spaced apart in the first direction X along an extension direction of the fourth output region 304. These low-side transistors 120 are mounted on a surface of the fourth output region 304 and connected to the second ground region 502. The four low-side transistors 120 constituting the second low-side switching element 12v are spaced apart in the first direction X along an extension direction of the fifth output region 305. These low-side transistors 120 are mounted on a surface of the fifth output region 305 and connected to the second ground region 502.The four low-side transistors 120 forming the third low-side switching element 12w are spaced apart in the first direction X, which lies along the extension direction of the sixth output region 306. These low-side transistors 120 are mounted on a surface of the sixth output region 306 and connected to the second ground region 502. <Anordnung der High-Side-Transistoren und Low-Side-Transistoren>

[0205] In the first modification of the third exemplary embodiment, the plurality of high-side transistors 110 constituting a single high-side switching element 11 and the plurality of low-side transistors 120 constituting a single low-side switching element 12 are arranged in the direction (first direction X) along the extending direction of the output regions 300 such that a high-side transistor 110 is disposed adjacent to a corresponding low-side transistor 120, with capacitors 130, which will be described later, disposed therebetween in the direction (second direction Y) perpendicular to the extending direction of the output regions 300. <Glättungskondensatorabschnitt und Kondensator>

[0206] The switching power supply 10 according to the first modification of the third exemplary embodiment is similar to the switching power supply 10 according to the third exemplary embodiment in that the smoothing capacitor section 13 is provided on the conductive layer 22 of the base plate 20. The smoothing capacitor section 13 includes a plurality of capacitors 130.

[0207] The first modification of the third exemplary embodiment is similar to the third exemplary embodiment in that the plurality of capacitors 130 corresponds to the plurality of high-side transistors 110 and the plurality of low-side transistors 120. Each of the plurality of capacitors 130 is arranged adjacent to its corresponding one of the plurality of high-side transistors 110 and the plurality of low-side transistors 120. In other words, the plurality of high-side transistors 110, the plurality of low-side transistors 120, and the plurality of capacitors 130 are arranged such that pairs each including a high-side transistor 110 and its corresponding capacitor 130 are positioned adjacent to pairs each including a low-side transistor 120 and its corresponding capacitor 130.

[0208] In this example, the plurality of capacitors 130 corresponding to the plurality of high-side transistors 110 constituting a single high-side switching element 11 are arranged in sequence next to the plurality of capacitors 130 corresponding to the plurality of low-side transistors 120 constituting a single low-side switching element 12 in a direction (second direction Y) perpendicular to an array direction of the plurality of high-side transistors 110 (extension direction of output regions 300). More specifically, in this example, high-side transistors 110, capacitors 130 corresponding to high-side transistors 110, capacitors 130 corresponding to low-side transistors 120, and low-side transistors 120 are arranged in this order from one side to the other side (the lower side to the upper side in Fig. 12) of the base plate 20 in the lateral direction. <verbindungselement>

[0209] The first modification of the third exemplary embodiment is similar to the third exemplary embodiment in that the ground pattern 50 has a first ground region 501 and a second ground region 502 that are electrically connected via the first ground connecting member 55 and the second ground connecting member 56 (connecting members 200). Fig. 12 illustrates a first ground connection element 55 and a second ground connection element 56 with lines of one long and two short dashes. Both the first ground connection element 55 and the second ground connection element 56 electrically connect the first ground region 501 to the second ground region 502. [Effect of the first modification of the third exemplary embodiment]

[0210] The switching power supply 10 according to the first modification of the third exemplary embodiment can achieve substantially the same effect as the switching power supply 10 according to the third exemplary embodiment. For example, it is possible to reduce heat concentration in the high-side switching elements 11 and the low-side switching elements 12. (Second Modification of the Third Exemplary Embodiment)

[0211] Fig. 13 illustrates a configuration of a switching power supply 10 according to the second modification of the third exemplary embodiment. The switching power supply 10 according to the second modification of the third exemplary embodiment differs from the switching power supply 10 according to the third exemplary embodiment in configurations of the output pattern 30, the power supply pattern 40, the ground pattern 50, and the connection elements 200, and configurations of the high-side transistors 110, the low-side transistors 120, and the capacitors 130. <ausgangsmuster>

[0212] In the second modification of the third exemplary embodiment, the output pattern 30 includes a first output region 301 to a third output region 303, which correspond to a first switching part SWu to a third switching part SWw, respectively, and further includes a fourth output region 304 to a sixth output region 306, which correspond to a first switching part SWu to a third switching part SWw, respectively. The first output region 301 to the third output region 303 are formed to extend in the first direction X and are spaced apart in the first direction X. Likewise, the fourth output region 304 to the sixth output region 306 are formed to extend in the first direction X and are spaced apart in the first direction X.The fourth output region 304 to the sixth output region 306 are arranged to oppose the first output region 301 to the third output region 303, respectively, with a distance therebetween in the second direction Y which is perpendicular to the first direction X.

[0213] Both the first output region 301 and the fourth output region 304 are electrically connected to the first output connector 81; both the second output region 302 and the fifth output region 305 are electrically connected to the second output connector 82; and both the third output region 303 and the sixth output region 306 are electrically connected to the third output connector 83. Fig. 13 illustrates a first output connection element 81 to a third output connection element 83 with lines of one long and two short dashes. <stromversorgungsmuster>

[0214] In the second modification of the third exemplary embodiment, the power supply pattern 40 includes a first power supply region 401, a second power supply region 402, and a power supply connection region 430. < <stromversorgungsbereich>>

[0215] The first power supply section 401 and the second power supply section 402 extend in an extending direction of the first output section 301 to the third output section 303. The first power supply section 401 opposes the first output section 301 to the third output section 303 with a predetermined distance therebetween in a direction (second direction Y) perpendicular to the extending direction of the first output section 301 to the third output section 303. The second power supply section 402 is arranged to oppose the first power supply section 401, with the first output section 301 to the third output section 303 interposed in the direction (second direction Y) perpendicular to the extending direction of the first output section 301 to the third output section 303. Furthermore, the first power supply section 401 is electrically connected to one end (the positive electrode) of the DC power supply P. < <stromversorgungsverbindungsbereich>>

[0216] The power supply connection portion 430 is formed to extend in the second direction Y and connects the first power supply portion 401 to the second power supply portion 402. In this example, the power supply connection portion 430 is near an edge part (right edge part in Fig. 13) of the base plate 20 in the longitudinal direction. <massemuster>

[0217] In the second modification of the third exemplary embodiment, the ground pattern 50 includes a first ground region 501 and a second ground region 502. < <massebereich>>

[0218] The first ground region 501 and the second ground region 502 extend in an extension direction (first direction X) of the fourth output region 304 to the sixth output region 306. The second ground region 502 opposes the fourth output region 304 to the sixth output region 306 with a predetermined distance therebetween in a direction (second direction Y) perpendicular to the extension direction of the fourth output region 304 to the sixth output region 306. The first ground region 501 is arranged to oppose the second ground region 502, with the first power supply region 401, the first output region 301 to the third output region 303, and the second power supply region 402 interposed in the direction (second direction Y) perpendicular to the extension direction of the fourth output region 304 to the sixth output region 306. <Anordnung von Stromversorgungsbereichen und Massebereichen>

[0219] The second modification of the third exemplary embodiment is similar to the third exemplary embodiment in that a plurality of power supply portions 400 and a plurality of ground portions 500 are arranged to oppose each other at a predetermined interval in a direction perpendicular to an extending direction of the output portions 300.

[0220] More specifically, the first ground region 501, the first power supply region 401, the first output region 301 to the third output region 303, the second power supply region 402, the second ground region 502, and the fourth output region 304 to the sixth output region 306 are arranged in this order from one end side to the other end side (a lower side to an upper side in the example of Fig. 13) in the lateral direction of the base plate 20. In addition, the first power supply region 401 opposes the first ground region 501 with a predetermined distance therebetween, while the second power supply region 402 opposes the second ground region 502 with a predetermined distance therebetween. <High-Side-Schaltelement und High-Side-Transistor>

[0221] The second modification of the third exemplary embodiment is similar to the third exemplary embodiment in that the first high-side switching element 11u to the third high-side switching element 11w are provided on the conductive layer 22 of the base plate 20. Each of the first high-side switching element 11u to the third high-side switching element 11w includes four high-side transistors 110.

[0222] The second modification of the third exemplary embodiment is similar to the third exemplary embodiment in that the four high-side transistors 110 constituting the first high-side switching element 11u are spaced apart in the first direction X along the extending direction of the first output region 301. These high-side transistors 110 are mounted on a surface of the first power supply region 401 and connected to the first output region 301. The four high-side transistors 110 constituting the second high-side switching element 11v are spaced apart in the first direction X along the extending direction of the second output region 302. These high-side transistors 110 are mounted on the surface of the first power supply region 401 and connected to the second output region 302.The four high-side transistors 110 constituting the third high-side switching element 11w are spaced apart in the first direction X, which lies along the extension direction of the third output region 303. These high-side transistors 110 are mounted on the surface of the first power supply region 401 and connected to the third output region 303. <Low-Side-Schaltelement und Low-Side-Transistor>

[0223] The second modification of the third exemplary embodiment is similar to the third exemplary embodiment in that the first low-side switching element 12u to the third low-side switching element 12w are provided on the conductive layer 22 of the base plate 20. Each of the first low-side switching element 12u to the third low-side switching element 12w includes four low-side transistors 120.

[0224] In the second modification of the third exemplary embodiment, the four low-side transistors 120 constituting the first low-side switching element 12u are spaced apart in the first direction X along an extension direction of the fourth output region 304. These low-side transistors 120 are mounted on a surface of the fourth output region 304 and connected to the second ground region 502. The four low-side transistors 120 constituting the second low-side switching element 12v are spaced apart in the first direction X along an extension direction of the fifth output region 305. These low-side transistors 120 are mounted on a surface of the fifth output region 305 and connected to the second ground region 502.The four low-side transistors 120 forming the third low-side switching element 12w are spaced apart in the first direction X, which lies along the extension direction of the sixth output region 306. These low-side transistors 120 are mounted on a surface of the sixth output region 306 and connected to the second ground region 502. <Anordnung der High-Side-Transistoren und Low-Side-Transistoren>

[0225] In the second modification of the third exemplary embodiment, the plurality of high-side transistors 110 constituting a single high-side switching element 11 and the plurality of low-side transistors 120 constituting a single low-side switching element 12 are arranged in the direction (first direction X) along the extending direction of the output regions 300 such that a high-side transistor 110 is disposed adjacent to a corresponding low-side transistor 120, with a capacitor 130 described below interposed therebetween in the direction (second direction Y) perpendicular to the extending direction of the output regions 300. <Glättungskondensatorabschnitt und Kondensator>

[0226] The switching power supply 10 according to the second modification of the third exemplary embodiment is similar to the switching power supply 10 according to the third exemplary embodiment in that the smoothing capacitor section 13 is provided on the conductive layer 22 of the base plate 20. The smoothing capacitor section 13 includes a plurality of capacitors 130.

[0227] The second modification of the third exemplary embodiment is similar to the third exemplary embodiment in that the plurality of capacitors 130 corresponds to the plurality of high-side transistors 110 and the plurality of low-side transistors 120. Each of the plurality of capacitors 130 is arranged adjacent to its corresponding one of the plurality of high-side transistors 110 and the plurality of low-side transistors 120. In other words, the plurality of high-side transistors 110, the plurality of low-side transistors 120, and the plurality of capacitors 130 are arranged such that pairs each including a high-side transistor 110 and its corresponding capacitor 130 are positioned adjacent to pairs each including a low-side transistor 120 and its corresponding capacitor 130.

[0228] In this example, the plurality of capacitors 130 corresponding to the plurality of high-side transistors 110 constituting a single high-side switching element 11 are arranged in sequence next to the plurality of capacitors 130 corresponding to the plurality of low-side transistors 120 constituting a single low-side switching element 12 in a direction (second direction Y) perpendicular to an array direction of the plurality of high-side transistors 110 (extension direction of output regions 300). More specifically, in this example, capacitors 130 corresponding to high-side transistors 110, high-side transistors 130, capacitors 130 corresponding to low-side transistors 120, and low-side transistors 120 are arranged in this order from one side to the other side (from the lower side to the upper side in Fig. 13) of the base plate 20 in the lateral direction. <verbindungselement>

[0229] The second modification of the third exemplary embodiment is similar to the third exemplary embodiment in that the ground pattern 50 has a first ground region 501 and a second ground region 502 that are electrically connected via the first ground connecting member 55 and the second ground connecting member 56 (connecting members 200). Fig. 13 illustrates a first ground connection element 55 and second ground connection element 56 with lines of one long and two short dashes. Both the first ground connection element 55 and the second ground connection element 56 electrically connect the first ground region 501 to the second ground region 502. [Effect of the second modification of the third exemplary embodiment]

[0230] The switching power supply 10 according to the second modification of the third exemplary embodiment can achieve substantially the same effect as the switching power supply 10 according to the third exemplary embodiment. For example, it is possible to reduce heat concentration in the high-side switching elements 11 and the low-side switching elements 12. (Third Modification of the Third Exemplary Embodiment)

[0231] Fig. 14 illustrates a configuration of a switching power supply 10 according to the third modification of the third exemplary embodiment. The switching power supply 10 according to the third modification of the third exemplary embodiment differs from the switching power supply 10 according to the third exemplary embodiment in a configuration of the power supply pattern 40. <stromversorgungsmuster>

[0232] In the third modification of the third exemplary embodiment, the power supply pattern 40 includes a first power supply connection region 431 and a second power supply connection region 432 instead of the first power supply connection region 431 shown in FIG. Fig. 11 shown power supply connection area 430. < <stromversorgungsverbindungsbereich>>

[0233] Both the first power supply connection portion 431 and the second power supply connection portion 432 are formed to extend in the second direction Y and connect the first power supply portion 401 to the second power supply portion 402. In this example, the first power supply connection portion 431 is near an edge part (right edge part in Fig. 14) of the base plate 20 in the longitudinal direction, while the second power supply connection area 432 is arranged near the other edge part (left edge part in Fig. 14) of the base plate 20 in the longitudinal direction. In this example, the first power supply region 401, the second power supply region 402, the first power supply connection region 431, and the second power supply connection region 432 are connected to form a continuous annular path. In short, in this example, the power supply pattern 40 has a continuous annular path. [Effect of the third modification of the third exemplary embodiment]

[0234] The switching power supply 10 according to the third modification of the third exemplary embodiment can achieve substantially the same effect as the switching power supply 10 according to the third exemplary embodiment. For example, it is possible to reduce heat concentration in the high-side switching elements 11 and the low-side switching elements 12.

[0235] In the switching power supply 10 according to the third modification of the third exemplary embodiment, the power supply pattern 40 has the continuous annular path. This arrangement can improve the degree of freedom in selecting a current path (shortest current path) between components (e.g., high-side transistors 110 and capacitors 130) provided in the power supply pattern 40. Consequently, it is possible to shorten the current paths between the components and thereby reduce parasitic inductances of the current paths between the components. Therefore, it is possible to reduce surge voltages (e.g., surge voltages caused by switching operations of the switching elements) acting on the components constituting the switching power supply 10.

[0236] In the switching power supply 10 according to the third modification of the third exemplary embodiment, the ground pattern 50 may also have a continuous annular path. In short, at least one of the power supply pattern 40 and the ground pattern 50 may have a continuous annular path. (Other exemplary embodiments)

[0237] The above description is made regarding a case where each connecting member 200 is formed from a bus bar (a conductor having a flat shape); however, a structure of each connecting member 200 is not limited to this example. As an alternative example, each connecting member 200 may be formed from a conductive metal wire.

[0238] The above description is presented with respect to an exemplary case in which materials of connecting elements 200 and heat dissipation layer 23 are of the same type; however, materials of connecting elements 200 and heat dissipation layer 23 may be of different types.

[0239] The above description is made with respect to a case where the number of capacitors 130 constituting the smoothing capacitor section 13 is equal to the total number of high-side transistors 110 and low-side transistors 120 mounted on the base plate 20; however, the number of capacitors 130 is not limited to this example. As an alternative example, the number of capacitors 130 constituting the smoothing capacitor section 13 is different from the total number of high-side transistors 110 and low-side transistors 120 mounted on the base plate 20.

[0240] Two or more of the exemplary embodiments and modifications described above may be combined and implemented as appropriate. The exemplary embodiments and modifications described above are merely preferred examples and are not intended to limit the scope of the disclosure or its application and use. Commercial applicability

[0241] As described above, the present disclosure is applicable to switching power supplies.< / stromversorgungsverbindungsbereich> < / stromversorgungsmuster> < / verbindungselement> < / massebereich> < / massemuster> < / stromversorgungsverbindungsbereich> < / stromversorgungsbereich> < / stromversorgungsmuster> < / ausgangsmuster> < / verbindungselement> < / masseverbindungsbereich> < / massebereich> < / massemuster> < / stromversorgungsverbindungsbereich> < / stromversorgungsbereich> < / stromversorgungsmuster> < / ausgangsmuster> < / verbindungselement> < / massebereich> < / massemuster> < / stromversorgungsverbindungsbereich> < / stromversorgungsbereich> < / stromversorgungsmuster> < / ausgangsmuster> < / verbindungselement> < / massebereich> < / massemuster> < / stromversorgungsbereich> < / stromversorgungsmuster> < / verbindungselement> < / masseverbindungsbereich> < / massebereich> < / massemuster> < / stromversorgungsbereich> < / stromversorgungsmuster> < / ausgangsmuster> < / verdrahtungsmuster> < / befestigungsschraube> < / grundplatte>

Claims

[1] A switching power supply (10) comprising a high-side switching element (11) and a low-side switching element (12) connected in series with the high-side switching element (11); the switching power supply (10) comprising: a base plate (20) having an insulating layer (21) and a conductive layer (22), the conductive layer (22) being provided on a surface of the insulating layer (21); a plurality of high-side transistors (110) provided on the conductive layer (22), the high-side transistors (110) being connected in parallel to form the high-side switching element (11); and a plurality of low-side transistors (120) provided on the conductive layer (22), the low-side transistors (120) being connected in parallel to form the low-side switching element (12), and a smoothing capacitor section (13) provided on the conductive layer (22), wherein the smoothing capacitor section (13) comprises a plurality of capacitors (130) provided on the conductive layer (22), the plurality of capacitors (130) corresponding to a sum of the plurality of high-side transistors (110) and the plurality of low-side transistors (120), and each of the plurality of capacitors (130) is arranged adjacent to a corresponding transistor (110, 120), the corresponding transistor (110, 120) being one of the plurality of high-side transistors (110) and the plurality of low-side transistors (120), wherein the plurality of high-side transistors (110) are arranged in series next to the plurality of low-side transistors (120). [2] Switching power supply (10) according to claim 1, wherein the plurality of capacitors (130) are each arranged individually next to the corresponding transistor (110, 120). [3] Switching power supply (10) according to claim 1, wherein the plurality of high-side transistors (110) are arranged sequentially next to the plurality of low-side transistors (120) in a first direction, and each of the plurality of capacitors (130) is arranged adjacent to the corresponding transistor (110, 120) in a second direction perpendicular to the first direction, wherein the corresponding transistor (110, 120) is one of the plurality of high-side transistors (110) and the plurality of low-side transistors (120). [4] The switching power supply (10) of claim 2, wherein the plurality of high-side transistors (110), the plurality of low-side transistors (120), and the plurality of capacitors (130) are arranged such that a pair including one of the plurality of high-side transistors (110) and a corresponding one of the plurality of capacitors (130) is respectively arranged adjacent to a pair including the plurality of low-side transistors (120) and a corresponding one of the plurality of capacitors (130). [5] The switching power supply (10) of claim 4, wherein one of the plurality of capacitors (130) corresponding to one of the plurality of high-side transistors (110) and one of the plurality of capacitors (130) corresponding to one of the plurality of low-side transistors (120) are arranged to be adjacent to each other. [6] Switching power supply (10) according to claim 4 or 5, wherein none of the high-side transistors (110) and none of the low-side transistors (120) is arranged between one of the plurality of capacitors (130) corresponding to one of the plurality of high-side transistors (110) and one of the plurality of capacitors (130) corresponding to one of the plurality of low-side transistors (120). [7] Switching power supply (10) according to one of claims 1 to 6, wherein an output pattern (30), a power supply pattern (40) and a ground pattern (50) are located in the conductive layer (22), the plurality of high-side transistors (110) are electrically connected to the output pattern (30) and the power supply pattern (40), the plurality of low-side transistors (120) are electrically connected to the output pattern (30) and the ground pattern (50), and at least one of the power supply pattern (40) and the ground pattern (50) has a plurality of wiring areas (401 to 406; 410; 501 to 509; 510; 531) which are electrically connected via a connecting element (200). [8] The switching power supply (10) according to claim 7, wherein parts of the power supply pattern (40) and the ground pattern (50) include opposing regions which are respectively interleaved, and the plurality of capacitors (130) are electrically connected to the opposing regions. [9] Switching power supply (10) according to claim 7 or 8, wherein the connecting element (200) is formed from a conductor having a flat shape. [10] Switching power supply (10) according to claim 9, wherein in the base plate (20), the insulating layer (21), the conductive layer (22) is provided on a first surface of the insulating layer (21), and a heat dissipation layer (23) is provided on a second surface of the insulating layer (21) opposite the first surface, and a material of the connecting element (200) is of the same type as a material of the heat dissipation layer (23). [11] Switching power supply (10) according to claim 9 or 10, wherein the connecting element (200) is connected to the plurality of wiring portions (401 to 406; 410; 501 to 509; 510; 531) by soldering. [12] Switching power supply (10) according to claim 9, wherein the base plate (20) contains the insulating layer (21), the conductive layer (22) on the first surface of the insulating layer (21) and a heat dissipation layer (23) provided on a second surface of the insulating layer (21) opposite the first surface, the connecting element (200) has a main part (201) in a planar shape, which faces the conductive layer (22) with a distance between the main part (201) and the conductive layer (22), and a tab (202) extending from the main part (201) to one of the plurality of wiring areas (401 to 406; 410; 501 to 509; 510; 531), a first through-hole (21h), a second through-hole (22h), and a third through-hole (23h) are provided in the base plate (20), the first through-hole (21h) penetrating the insulating layer (21), the second through-hole (22h) penetrating one of the plurality of wiring regions (401 to 406; 410; 501 to 509; 510; 531) to communicate with the first through-hole (21h), the third through-hole (23h) penetrating the heat dissipation layer (23) to communicate with the first through-hole (21h), the tab (202) of the connecting element (200) is connected by soldering to one of the plurality of wiring areas (401 to 406; 410; 501 to 509; 510; 531) in which the second through-hole (22h) is provided, while being inserted into the first through-hole (21h), the second through-hole (22h) and the third through-hole (23h), and the third through-hole (23h) has a larger opening area than an opening area of the first through-hole (21h) in order to prevent the tab (202) of the connecting element (200) inserted into the first through-hole (21h), the second through-hole (22h) and the third through-hole (23h) from coming into contact with an inner wall of the third through-hole (23h). [13] Switching power supply (10) according to claim 11 or 12, wherein parts of the connecting element (200) which are connected to the plurality of wiring regions (401 to 406; 410; 501 to 509; 510; 531) by soldering are subjected to metallization for the solder connection. [14] Switching power supply (10) according to claim 9 or 10, further comprising a nut (27) connected by soldering to one of the plurality of wiring portions (401 to 406; 410; 501 to 509; 510; 531); and a screw (28) which penetrates the connecting element (200) and is fastened to the nut (27). [15] Switching power supply (10) according to claim 1, wherein an output pattern (30), a power supply pattern (40) and a ground pattern (50) are located in the conductive layer (22), the plurality of high-side transistors (110) are electrically connected to the output pattern (30) and the power supply pattern (40), the plurality of low-side transistors (120) are electrically connected to the output pattern (30) and the ground pattern (50), and at least one of the power supply pattern (40) and the ground pattern (50) has a continuous annular path. [16] Switching power supply (10) according to one of claims 1 or 4 to 13, wherein an occupied area of each of the plurality of high-side transistors (110), an occupied area of each of the plurality of low-side transistors (120) and an occupied area of each of the plurality of capacitors (130) on the base plate (20) are less than twice and more than half of each other.

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