This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2015-242995, filed on Dec. 14, 2015, the entire contents of which are incorporated herein by reference.
Embodiments described herein relate generally to a semiconductor module and a semiconductor device.
In a field of a power converting apparatus such as an inverter device, a semiconductor module in which plural kinds of semiconductor elements are provided on one substrate is used. In such a semiconductor module, it is desired to have a structure which is as simple as possible in order to achieve miniaturization, enlargement of scale, reduction in inductance, reduction in cost etc.
A semiconductor module according to an embodiment has first and second wiring portions, first semiconductor devices and second semiconductor devices. The second wiring portion is provided to oppose the first wiring portion. The third wiring portion is provided to oppose the first wiring portion and apart from the second wiring portion. The first semiconductor devices are provided between the first wiring portion and the second wiring portion and are electrically connected with the first wiring portion and the second wiring portion respectively. Each of the first semiconductor devices has a first switching element, and an input or output terminal of the first switching element is electrically connected with the first wiring portion. The second semiconductor devices are provided between the first wiring portion and the third wiring portion and are electrically connected with the first wiring portion and the second wiring portion respectively. Each of the second semiconductor devices has a second switching element, and an output or input terminal of the second switching element is electrically connected with the first wiring portion in a connecting manner contrary to the first switching element.
Hereinafter, further embodiments will be described with reference to the drawings. In the drawings, the same reference numerals denote the same or similar portions respectively.
A semiconductor module having semiconductor devices according to a first embodiment will be described with reference to
As shown in
The substrate 101 is flat-plate-shaped and is formed of an insulating material. The substrate 101 can be formed of an inorganic material such as aluminum oxide or aluminum nitride i.e. a ceramic, or an organic material such as paper phenol or glass epoxy.
The substrate 101 may be a metal plate having a surface covered with an insulator. When such a metal plate having a surface covered with an insulator is used, the insulator may be composed of an organic material or an inorganic material.
When the substrate 101 is formed of an organic material such as glass epoxy, manufacturing cost of the semiconductor module 100 can be reduced. When the semiconductor device 1 have a characteristic of producing much heat, it is desirable that the substrate 101 is formed of a material having a high thermal conductivity in order to enhance heat dissipation. Specifically, it is desirable to form the substrate 101 of a ceramic such as aluminum oxide or aluminum nitride, or a metal plate having a surface covered with an insulator.
The substrate 101 is not always necessary and may be provided when needed. The substrate 101 can be omitted when the rigidity of the wiring portion 102 is high. When a metal plate having a surface covered with an insulator is not used, an insulating part such as an insulating sheet may be provided on a device, for example, an inverter device in which such a semiconductor module is provided, and the semiconductor module may be arranged on the insulating part.
The wiring portion 102 is provided on one main surface of the substrate 101. The planar shape of the wiring portion 102 can be the same as that of the substrate 101. For example, when the planar shape of the substrate 101 is a rectangle, the planar shape of the wiring portion 102 can also be a rectangle. The planar dimensions of the wiring portion 102 can also be the same as those of the substrate 101 or smaller. The wiring portion 102 can be provided on an entire area of a surface of the substrate 101.
The wiring portion 102 is formed of a conductive material. The wiring portion 102 can be formed of copper, a copper alloy, aluminum, an aluminum alloy etc. The wiring portion 102 can be formed on one main surface of the substrate 101 using a plating method etc. When the wiring portion 102 is formed using a plating method, the thickness of the wiring portion 102 can be made larger than that of a general wiring pattern. The thickness dimension of the wiring portion 102 can be 100 micrometers or more. Reduction of the impedance of the wiring portion 102 can be achieved by enlarging the thickness of the wiring portion 102. The wiring portion 102 may be a metal plate. When the wiring portion 102 is a metal plate, the substrate 101 can be omitted since the rigidity of the wiring portion 102 is high. The impedance of the wiring portion 102 can be further reduced by forming the wiring portion 102 with a metal plate.
The wiring portion 103 is a rectangle. The wiring portion 103 opposes the wiring portion 102. The planar shape of the wiring portion 103 can be a rectangle. In this case, a long side of the wiring portion 103 can be parallel to a long side of the wiring portion 102. The planar dimensions of the wiring portion 103 are smaller than those of the wiring portion 102. The wiring portion 103 is formed of a conductive material. The wiring portion 103 can be a metal plate. The wiring portion 103 can be formed of copper, copper alloy, aluminum, aluminum alloy etc. The wiring portion 103 can be a bus bar. A surface of the wiring portion 103 may be plated with nickel etc.
The wiring portion 104 is a rectangle. The wiring portion 104 opposes the wiring portion 102. The planar shape of the wiring portion 104 can be a rectangle. In this case, a long side of the wiring portion 104 can be parallel to the long side of the wiring portion 103. The planar shape and the planar dimensions of the wiring portion 104 can be the same as those of the wiring portion 103. The wiring portion 104 is formed of a conductive material. The material of the wiring portion 104 can be the same as that of the wiring portion 103. The wiring portion 104 can be a bus bar. A surface of the wiring portion 104 may be plated with nickel etc. The wiring portions 103, 104 are arranged to oppose the wiring portion 102. The wiring portions 102 to 104 are provided to oppose the plurality of semiconductor devices.
As shown in
The joining portions 106 are provided between the wiring portions 103, 104 and the semiconductor devices 1 respectively. The joining portions 106 connect the wiring portions 103, 104 and the semiconductor devices 1 electrically and mechanically, respectively.
The joining portions 106 can be formed of a conductive joining material such as a solder or a silver paste. The material of the joining portions 106 can be the same as the material of the joining portions 105 or the material different from the material of the joining portions 105.
The terminal 107 is a rectangle. The terminal 107 extends in a direction in which the wiring portion 103 extends. One end portion of the terminal 107 is provided on the wiring portion 103. The other end portion of the terminal 107 i.e. an end portion of the terminal 107 which opposes the wiring portion 103 is provided outside the substrate 101 in a planar view. The other end portion of the terminal 107 may be provided inside the substrate 101 in a planar view. A circular hole for wiring can be provided in the terminal 107 so that the circular hole may be positioned near the other end portion of the terminal 107 as shown in
The terminal 107 is connected to the wiring portion 103 electrically and mechanically. The terminal 107 can be welded to the wiring portion 103, be brazed to the wiring portion 103, be soldered to the wiring portion 103, or be attached to the wiring portion 103 with a screw. The terminal 107 and the wiring portion 103 may be made of a single body. The wiring portion 103 can be extended to form the terminal 107.
The terminal 107 is formed of a conductive material. The terminal 107 can be a metal plate. The terminal 107 can be formed of copper, copper alloy, aluminum, aluminum alloy etc. The material of the terminal 107 can be the same as that of the wiring portion 103.
The terminal 108 is rectangle. The terminal 108 extends in a direction in which the wiring portion 104 extends. One end portion of the terminal 108 is provided on the wiring portion 104. The other end portion of the terminal 108 i.e. an end portion of the terminal 108 which opposes the wiring portion 104 is provided outside the substrate 101 in a planar view. The other end portion of the terminal 108 may be provided inside the substrate 101 in a planar view. A circular hole for wiring can be provided in the terminal 107 so that the circular hole may be positioned near the other end portion of the terminal 107 as shown in
The terminal 108 is connected to the wiring portion 104 electrically and mechanically. The terminal 108 can be welded to the wiring portion 104, be brazed to the wiring portion 104, be soldered to the wiring portion 104, or be attached to the wiring portion 104 with a screw. The terminal 107 and the wiring portion 103 may be made of a single body. The wiring portion 103 can be extended to form the terminal 107. The terminal 108 is formed of a conductive material. The material of the terminal 108 may be the same as that of the terminal 107.
Each of the terminals 109 has a flat plate portion 109a, another flat plate portion 109b, and a bending portion 109c as shown in
The flat plate portion 109a is connected to the wiring portion 102 electrically and mechanically. The flat plate portion 109a can be welded to the wiring portion 102, be brazed to the wiring portion 102, be soldered to the wiring portion 102, or be attached to the wiring portion 102 with a screw. The other end portion of the flat plate portion 109b which opposes the bending portion 109c is provided outside the substrate 101 in a planar view. The other end portion of the flat plate portion 109b may be provided inside substrate 101 in a planar view.
A circular hole for wiring can be provided in the flat plate portion 109b near the other end portion of the flat plate portion 109b, as shown in
The terminals 109 and the wiring portion 102 may be formed of a single body. For example, when the wiring portion 102 is a metal plate, the terminal 109 can be formed by bending an end portion of the wiring portion 102.
In the above embodiment, two terminals 109 are provided, but one or more than two terminals 109 may be provided. In the above embodiment, a rectangular terminal 107, a rectangular terminal 108 and crank-shaped terminals 109 are used, but the shapes of these terminals may be changed appropriately. The shapes of the terminals 107, 108 and 109 can be changed according to a positional relationship etc. with a device or an apparatus arranged in the exterior of the semiconductor module 100.
A connected state and a structure of each semiconductor device 1 will be explained with reference to
Each semiconductor device 1 has an electrode 2 as a first electrode, an electrode 3 as a second electrode, a switching element 4, a rectifying element 5, two joining portions 6, two joining portions 7, a lead terminal 8, a wiring 9 and a sealing portion 10. The electrode 2 is flat-plate-shaped. The planar shape of the electrode 2 can be a rectangle. The electrode 2 is formed of a conductive material. The electrode 2 can be formed of copper, copper alloy, aluminum, aluminum alloy etc. A main surface 2a of the electrode 2 which is positioned at a side opposite to a side of both of the switching element 4 and the rectifying element 5 is arranged on the wiring portion 102 via the joining portion 105.
The electrode 3 opposes the electrode 2. A main surface 3b of the electrode 3 which is positioned at a side opposite to a side of both of the switching element 4 and the rectifying element 5 is provided on the wiring portion 103 or the wiring portion 104 via the joining portion 105. The planar shape of the electrode 3 can be a rectangle. A plurality of convex portions 3a is formed on a portion of the electrode 3 which opposes both of the switching element 4 and the rectifying element 5. The planar dimensions of each convex portion 3a are smaller than the planar dimensions of the switching element 4. A space for arranging the wiring 9 is provided in a side direction of the convex portion 3a. The convex portions 3a are provided in order to prevent short circuit between the electrode 3 and the wiring 9. For the purpose of preventing short circuit, the convex portions 3a may be projected at least toward the switching element 4. The electrode 3 is formed of a conductive material. The electrode 3 can be formed of copper, copper alloy, aluminum, aluminum alloy etc. The material of the electrode 3 may be the same as that of the electrode 2, or different from that of the electrode 2.
The switching element 4 is provided between the electrode 2 and the electrode 3. The switching element 4 may be an insulated gate bipolar transistor, a field effect transistor, a gate turn-off thyristor, a bipolar transistor etc. The kind of the switching element 4 is not limited to these elements. According to the embodiment, IGBT is used as the switching element 4.
The rectifying element 5 is formed between the electrode 2 and the electrode 3. The rectifying element 5 is connected in parallel with the switching element 4 via the electrode 2 and the electrode 3. The rectifying element 5 may be a diode.
One of the joining portions 6 is provided between the electrode 2 and the switching element 4, and the other of the joining portions 6 is provided between the electrode 2 and the rectifying element 5. The joining portions 6 connect the switching element 4 and rectifying element 5 with the electrode 2 electrically and mechanically. The joining portions 6 can be formed of a conductive joining material such as solder or a silver paste.
One of the joining portions 7 is provided between one of the convex portions 3a of the electrode 3 and the switching element 4, and the other of the joining portions 7 is provided between another one of the convex portions 3a and the rectifying element 5. The joining portions 7 connect the switching element 4 and the rectifying element 5 with the electrode 3 electrically and mechanically. The joining portions 7 can be formed of a conductive joining material such as solder or a silver paste. The material of the joining portions 7 may be same as that of the joining portions 6 or different from that of the joining portions 6. When the thicknesses of the switching element 4 and the rectifying element 5 are different, the thickness of the joining portions 6 and the joining portions 7 can be adjusted appropriately to match the switching element 4 and the rectifying element 5 with the heights of the electrodes 2, 3. In order to match the switching element 4 and the rectifying element 5 with the heights of the electrodes 2, 3, a conductive spacer (not illustrated) may be arranged between the switching element 4 or the rectifying element 5 and one of the convex portions 3a of the electrode 3.
The lead terminal 8 is line-shaped. One end portion of the lead terminal 8 is buried in the interior of the sealing portion 10 and is held at an approximately central position in a thickness direction of the sealing portion 10.
The lead terminal 8 may have a shape bending toward a side of the wiring portions 103, 104. The lead terminal 8 may be a shape of an L character. The lead terminal 8 is formed of a conductive material. The lead terminal 8 can be formed of copper, copper alloy, aluminum, aluminum alloy etc.
The wiring 9 may be a line-shaped body of a metal such as gold, copper or aluminum. The wiring 9 is provided between the lead terminal 8 and the switching element 4. One end portion of the wiring 9 is electrically connected to the lead terminal 8. The other end portion of the wiring 9 is electrically connected to a gate or a base of the switching element 4 which is a control terminal of the switching element 4. The wiring 9 may be joined to the lead terminal 8 and the gate or the base of the switching element 4 using a wire bonding method.
The sealing portion 10 seals the switching element 4 and the rectifying element 5 between the electrode 2 and the electrode 3 from a side direction. The sealing portion 10 is formed of an insulating material such as an epoxy resin. The sealing portion 10 may be formed using a transfer-molding method.
As shown in
In the semiconductor module 100, three of the semiconductor devices 1 are connected in parallel with one another via the wiring portion 102 and the wiring portion 103, and the remaining three of the semiconductor devices 1 are connected in parallel with one another via the wiring portion 102 and the wiring portion 104. In this case, as shown in
A leg of an inverter circuit can be composed of such semiconductor devices 1. Six semiconductor devices 1 are used to compose an inverter device for a three-phase motor,.
In the semiconductor module 100, part of the semiconductor devices 1 as the first semiconductor devices which are arranged between the wiring portion 102 and the wiring portion 103 face to the substrate 101 in a direction contrary to the remaining semiconductor devices 1 as are the second semiconductor devices which are arranged between the wiring portion 102 and the wiring portion 104. In other words, the direction of the input terminals or the output terminals of the first semiconductor devices connected to the electrodes 2 are contrary to that of the second semiconductor devices connected to the electrodes 2. For example, as shown in
The case 201 is rectangular-parallelepiped-shaped. The semiconductor module 100 is arranged in the interior of the case 201. The case 201 may be formed of an insulating material such as resin.
The driving circuit 202 is provided on an outer surface of the case 201. The driving circuit 202 is arranged to oppose a side of the substrate 101 of the semiconductor module 100, above the semiconductor module 100 for example. The driving circuit 202 applies a control signal to the gate or base of each switching element 4 via the lead terminal 8, for example. The semiconductor module 100 converts a direct-current electric power supplied from the direct-current power supply into a desired alternate-current electric power, based on a control signal from the driving circuit 202. The obtained alternate-current electric power is supplied to an apparatus (not illustrated) which is connected to the inverter device 200, a three-phase motor for example. The cooling portion 203 is provided on an outer surface of the case 201. The cooling portion 203 is provided on a side of the substrate 101 of the semiconductor module 100, below the semiconductor module 100 for example. The cooling portion 203 may be heat-radiating fins. As described above, the lead terminals 8 are L-character-shaped. Thus, the lead terminals 8 can be connected with the driving circuit 202 which are provided above the semiconductor module 100 easily.
As shown in
The wiring portions 302a to 302c are provided on one main surface of the substrate 101. The wiring portions 302a to 302c are patterned wirings. The wiring portions 303, 304 can be formed by bending a L-character-shaped metal plate into a shape of a crank. The terminals 307, 308 can be formed by bending a rectangular metal plate into a shape of a crank.
The semiconductor devices 1 of the comparative example are formed on the wiring portions 302b, 302c via the joining portions 105, respectively. The semiconductor devices 1 are connected in the same direction to the substrate 101. Specifically, all of the semiconductor devices 1 of the comparative example are mounted on the wiring portions 302b, 302c so that a collector of each switching element and a cathode of each rectifying element which compose a circuit similar to that shown in
Thus, the structure of the semiconductor module 300 of the comparative example becomes complicated. Further, the width of the wiring portion 302a which extends between one row of the semiconductor devices 1 and the other row of the semiconductor devices 1 becomes narrow, and the inductance may increase. In this case, the inductance can be small by enlarging the width of the wiring portion 302a, but it results in causing enlargement of the semiconductor module 300. On the other hand, when the semiconductor module 300 is made in a predetermined size, the number of the semiconductor devices to be arranged decreases, and enlargement of scale may not be achieved.
On the other hand, in the semiconductor module 100 according to the embodiment, part of the semiconductor devices 1 as the first semiconductor devices which are arranged between the wiring portion 102 and the wiring portion 104 face to the substrate 101 in a direction contrary to the remaining semiconductor devices 1 as the second semiconductor devices which are arranged between the wiring portion 102 and the wiring portion 103. The input or output terminals of the first semiconductor devices that are connected to the electrodes 2 are contrary to the output or input terminals of the second semiconductor devices. Further, the connections shown in
In the embodiment, the wiring portion 102 does not always need to be a patterned wiring, but may be a mere film body of a rectangular. Further, the wiring portion 103 and the wiring portion 104 can be formed of a rectangular metal plate. Accordingly, a semiconductor module 100 which has a simple structure is obtained. Since the cross-sectional area of the wiring portion 102 can be enlarged in a thickness direction with ease, the inductance can be reduced. Since the wiring portion 102 does not always need to be a patterned wiring, the distance between one row of the semiconductor devices 1 and the other row of the semiconductor devices 1 can be shortened. Thus, miniaturization and enlargement of scale of the semiconductor module 100 can be attained.
Part of the semiconductor devices 1 which are arranged between the wiring portions 102, 104 face to the substrate 101 in a direction contrary to the others of the semiconductor devices 1 which are arranged between the wiring portions 102, 103. Accordingly, part of the lead terminals 8 of the semiconductor devices 1 which are provided between the wiring portions 102, 104 bend in a direction contrary to the others of the lead terminals 8 which are provided between the wiring portions 102, 103. In this case, the end portions of these lead terminals 8 are held at an approximately center position in a thickness direction of the sealing portion 10. Thus, when the lead terminals 8 are made by bending, it is possible to use the same metallic mold. Further, the lead terminals 8 can be made by bending using a metallic mold which is employed when the sealing portion 10 is formed.
Heat produced in each switching elements 4 and each rectifying elements 5 is mainly transmitted to a side of the substrate 101. In this case, as shown in
The above embodiments use a semiconductor device which has a switching element and a rectifying element connected in parallel with the switching element. The semiconductor device may have the switching element excluding the rectifying element. In the semiconductor module 100 according to the above first embodiment, two joining portions 105, two joining portions 106 and six semiconductor devices 1 are employed, the numbers of joining portions and semiconductor devices are not limited to these.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions. These embodiments may be combined mutually to implement the inventions.
Number | Date | Country | Kind |
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2015-242995 | Dec 2015 | JP | national |