JP5203032B2 - Pressure contact type semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure contact semiconductor device, in which, as the whole semiconductor device, a low profile can be achieved, without preparing special another component, such as intermediate terminal board or the like, in the structure of the pressure contact semiconductor device, and the contact between semiconductor elements and a terminal board can be ensured, when a plurality of the semiconductor elements are mounted simultaneously by pressure contact, and the variation in the thickness of the semiconductor elements can be reduced, even if the variation in the thickness of the semiconductor elements is large. <P>SOLUTION: A pressure contact semiconductor device 10 has a structure with a plurality of semiconductor elements 11 and 12, and two terminal boards 22 and 23 which press to get in contact with each of a plurality of the semiconductor elements from both front and rear sides. A plurality of columnar electrode parts 21 are formed in the surfaces of electrodes 11A and 12A of the semiconductor elements, and heat sinks 57 and 59 hold two terminal boards, respectively, while pressing them. A plurality of columnar electrode parts 21 are plastically deformed to get in contact with the terminal board 22. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a pressure contact type semiconductor device, and in particular, when a plurality of vertical semiconductor elements are simultaneously pressure contact mounted, a pressure contact type semiconductor device capable of reliably ensuring a contact state between each semiconductor element and each terminal plate on the front and back surfaces thereof. About.

  A power semiconductor module is used in a power system electrical circuit for supplying necessary power to various electrical devices. An IGBT is included as an example of the power semiconductor module. An IGBT is a semiconductor device used as a switching element. An equivalent circuit of the IGBT is expressed by an electric circuit in which a bipolar transistor and a MOSFET are connected in parallel. Semiconductor elements such as IGBTs (also referred to as “semiconductor chips” or “chips”) have front and back chip surfaces. When the IGBT is turned on, a current flows in the front and back direction (vertical direction). In this sense, the IGBT or the like is called a vertical semiconductor element. The IGBT is separated into a plurality of chip elements having the same semiconductor structure when viewed from the surface, for example. The IGBT is configured as an aggregate of a plurality of chip elements. In the IGBT, each of a plurality of chip elements functions as a switching element, thereby turning on and off as a whole.

  In the structure of a power semiconductor module including a semiconductor element such as an IGBT or a diode, generally, the lower electrode (back surface side electrode) of the semiconductor element is bonded to the lower substrate by die soldering, and the upper electrode (front surface side electrode) of the semiconductor element is bonded. It is bonded to an external terminal provided on a resin case or the like by wire bonding.

  Conventional power semiconductor modules generally include a cooling structure that radiates heat only on the back side of the semiconductor element. According to this structure, the amount of current that can flow through the semiconductor element is limited depending on the heat dissipation performance. In order to increase the amount of current flowing through the semiconductor element, it is necessary to further improve the heat dissipation performance such as cooling both sides of the semiconductor element. In the semiconductor element of the power semiconductor module, a large number of bonding wires are connected to the electrode portions. When connecting to the electrode part of this semiconductor element, it takes time for the joining process. Further, when the above power semiconductor module is mounted on a vehicle such as an automobile, vibration is generated in a traveling vehicle, and thus it is required to improve reliability against the vibration.

2. Description of the Related Art A pressure contact type semiconductor device that satisfies the above requirements for a power semiconductor module is known. A pressure-contact type semiconductor device has a structure in which a terminal plate is brought into pressure contact with, for example, both front and back surfaces of a plurality of semiconductor elements to form electrical connection by surface contact. In a pressure-contact type semiconductor device, when a plurality of semiconductor elements are provided, each of the plurality of semiconductor elements (IGBT, diode, etc.) and an upper portion are removed in order to eliminate non-uniformity of the contact state caused by dimensional variation of the plurality of semiconductor elements. A structure in which an intermediate terminal body having conductivity and elasticity is arranged between the terminal board and the terminal board has been proposed (Patent Document 1).
Japanese Patent No. 2991010

  According to the structure of the semiconductor device disclosed in Patent Document 1, an intermediate terminal for reducing variation in thickness of each semiconductor element between each of a plurality of semiconductor elements (IGBT, diode, etc.) and the upper terminal plate. The body is placed. The plurality of intermediate terminal bodies are prepared as separate members with respect to the semiconductor element. Providing an intermediate terminal for each semiconductor element in the power semiconductor module increases the number of parts of the power semiconductor module, that is, the pressure contact type semiconductor device. Also, the production of the intermediate terminal body adds extra cost. The intermediate terminal body is formed into a specific shape using a member having a deformation characteristic due to elasticity in terms of material. By utilizing the elastic deformation of the material of the intermediate terminal body when pressed and pressed, the intermediate terminal body is deformed and the variation in the thickness of each semiconductor element is absorbed. For this reason, according to the structure of the pressure-contact type semiconductor device disclosed in Patent Document 1, the intermediate terminal body is thick and large as a component, and there is a possibility that the characteristics of electric resistance and thermal resistance are deteriorated.

  An object of the present invention is to realize a thin semiconductor device as a whole without preparing special separate parts such as an intermediate terminal board in the structure of a pressure-contact type semiconductor device in view of the above-described problems, and simultaneously a plurality of semiconductor elements. When mounting by pressure welding, the contact between the semiconductor element and the terminal plate is ensured, and even when the thickness variation of the semiconductor element is large, the thickness variation can be reduced, and the electrical resistance and thermal resistance characteristics can be improved. It is to provide a semiconductor device.

  In order to achieve the above object, a pressure contact type semiconductor device according to the present invention is configured as follows.

The first pressure-contact type semiconductor device (corresponding to claim 1) has a structure including a plurality of semiconductor elements and two terminal plates that press-contact each of the plurality of semiconductor elements from both the front and back surfaces. A plurality of columnar electrode portions are formed on the surfaces of the electrodes of the respective semiconductor elements, and each of the two terminal plates is provided with a heat radiating plate for holding it in a pressurized state, and the plurality of columnar electrode portions are plastically deformed. Each of the plurality of columnar electrode portions has a cylindrical shape, and the portion on the terminal plate side of the columnar electrode portion is configured such that the diameter decreases as it approaches the terminal plate. .

According to the structure of the first pressure-contact type semiconductor device, when two or more semiconductor elements (semiconductor chips) having different thicknesses are pressed and mounted by pressure as a power semiconductor module, the surface of each vertical semiconductor element or the like is mounted. A plurality of columnar electrode portions are formed in advance on the provided electrodes, and are brought into contact with the terminal board by utilizing plastic deformation of these columnar electrode portions. As a result, when there are variations in the thickness of the plurality of semiconductor elements, the variations are alleviated and the contact between the electrode of each semiconductor element and the terminal plate is ensured. In addition, since each of the plurality of columnar electrode portions has a cylindrical shape, the semiconductor element and the terminal plate can be pressure-welded and assembled with a low load. Furthermore, the diameter of the portion on the terminal plate side in the columnar electrode portion becomes smaller as it approaches the terminal plate, so that the semiconductor element and the terminal plate can be assembled by pressure contact with a low load, and the columnar electrode portion is less likely to collapse. Become.

  In the second press-contact type semiconductor device (corresponding to claim 2), in the above configuration, preferably, at least two semiconductor elements have different thicknesses, and surfaces of electrodes provided on surfaces of the two semiconductor elements, respectively. The columnar electrode portion is formed on the two terminal plates, and when the two terminal plates are pressure-welded, the difference in thickness between the two semiconductor elements is caused by plastic deformation of the columnar electrode portions of the electrodes on the surface side of each of the two semiconductor elements. It is characterized by absorbing. According to this configuration, when two semiconductor elements having different thicknesses are constructed as pressure contact type power semiconductor modules by pressure contact mounting, a plurality of columnar electrode portions are formed in advance on the surface of the electrode, and the plastic deformation is used to make 2 The difference in thickness between the two semiconductor elements is absorbed, and the contact between each semiconductor element and the terminal plate is ensured.

In the third press-contact type semiconductor device (corresponding to claim 3), in the above configuration, preferably, the plurality of columnar electrode portions formed on the surface of the electrode of the semiconductor element use the same metal material as the electrode, and It is formed on the surface of an electrode based on a film forming technique. According to this configuration, a plurality of columnar electrode portions can be formed with high accuracy on the surface of the electrode of the semiconductor element having a small shape, and the connectivity between the electrode and the columnar electrode portion is also improved.

In the fourth press-contact type semiconductor device (corresponding to claim 4), preferably, each of the plurality of columnar electrode portions is arranged at equal intervals between the adjacent columnar electrode portions. It is characterized by that. According to this structure, the contact by plastic deformation of each columnar electrode part is ensured by providing a gap between adjacent columnar electrode parts. In addition, this reduces the occurrence of contact between each semiconductor element and the terminal plate in the pressure contact state, can obtain a substantially uniform contact state, and biases the current flow between the front and back electrodes in the semiconductor element. Can be reduced.

The fifth pressure-contact type semiconductor device (corresponding to claim 5) has a structure comprising a plurality of semiconductor elements and two terminal plates that press- contact each of the plurality of semiconductor elements from both the front and back surfaces. A plurality of columnar electrode portions are formed on the surfaces of the electrodes of the respective semiconductor elements, and each of the two terminal plates is provided with a heat radiating plate for holding it in a pressurized state, and the plurality of columnar electrode portions are plastically deformed. The arrangement density of the plurality of columnar electrode portions on the electrode surface of the semiconductor element is higher than the arrangement density of the central portion of the electrode surface and the arrangement density of the peripheral portion of the electrode surface To do.

According to the structure of the fifth pressure-contact type semiconductor device, when two or more semiconductor elements (semiconductor chips) having different thicknesses are pressed as a power semiconductor module and pressure-welded and mounted on the surface of each vertical semiconductor element, etc. A plurality of columnar electrode portions are formed in advance on the provided electrodes, and are brought into contact with the terminal board by utilizing plastic deformation of these columnar electrode portions. As a result, when there are variations in the thickness of the plurality of semiconductor elements, the variations are alleviated and the contact between the electrode of each semiconductor element and the terminal plate is ensured. In addition, a substantially uniform temperature distribution is generated on the entire surface of the semiconductor element, so that deterioration in performance at the central part of the semiconductor element that becomes high temperature can be reduced, and the life of the semiconductor element can be improved.

A sixth pressure-contact type semiconductor device (corresponding to claim 6 ) has a structure including a plurality of semiconductor elements and two terminal plates that press- contact each of the plurality of semiconductor elements from both the front and back surfaces. A plurality of columnar electrode portions are formed on the surfaces of the electrodes of the respective semiconductor elements, and each of the two terminal plates is provided with a heat radiating plate for holding it in a pressurized state, and the plurality of columnar electrode portions are plastically deformed. The area of the cross section of the plurality of columnar electrode portions on the electrode surface of the semiconductor element is larger in the periphery of the electrode surface than the area of the columnar electrode portion located in the central portion of the electrode surface. The columnar electrode part located in the part has a large area.

According to the structure of the sixth pressure-contact type semiconductor device described above, when two or more semiconductor elements (semiconductor chips) having different thicknesses are pressed as a power semiconductor module and pressure-welded and mounted on the surface of each vertical semiconductor element, etc. A plurality of columnar electrode portions are formed in advance on the provided electrodes, and are brought into contact with the terminal board by utilizing plastic deformation of these columnar electrode portions. As a result, when there are variations in the thickness of the plurality of semiconductor elements, the variations are alleviated and the contact between the electrode of each semiconductor element and the terminal plate is ensured. In addition, a substantially uniform temperature distribution is generated on the entire surface of the semiconductor element, so that deterioration in performance at the central part of the semiconductor element that becomes high temperature can be reduced, and the life of the semiconductor element can be improved.

  According to the present invention, in a pressure contact type semiconductor device including at least two semiconductor elements, a plurality of columnar electrode portions are formed on the surface of the electrode of each semiconductor element, and the thickness is increased by plastic deformation of the columnar electrode portions during pressure contact mounting. Since adjustment is performed, the thickness of the entire semiconductor device is realized without preparing intermediate members such as intermediate terminal plates, and when a plurality of semiconductor elements are simultaneously pressed and mounted, the contact between the semiconductor elements and the terminal plate is achieved. Even if the semiconductor element has a large thickness variation, the thickness variation can be reduced. Furthermore, by using a columnar electrode portion made of the same material as the electrode, the electrical resistance and thermal resistance characteristics can be improved.

  DESCRIPTION OF EMBODIMENTS Preferred embodiments (examples) of the present invention will be described below with reference to the accompanying drawings.

  With reference to FIG. 1, a basic structure of a pressure contact type semiconductor device according to the present invention will be described. FIG. 1 is a longitudinal sectional view of a main part of a pressure contact type semiconductor device, and schematically and schematically showing a characteristic structure. Compared to an actual press-contact type semiconductor device, the size and thickness are exaggerated in the structure shown in FIG.

  The pressure contact type semiconductor device 10 shown in FIG. 1 shows a structural example in a state where pressure contact mounting is performed based on pressure applied from the upper and lower surfaces.

  In the example of FIG. 1, the press contact type semiconductor device 10 forming the power semiconductor module includes, for example, two semiconductor elements 11 and 12. The number of semiconductor elements is not limited to two and may be two or more. The semiconductor elements 11 and 12 are semiconductor elements as power devices, and are, for example, IGBTs or diodes. These semiconductor elements 11 and 12 are power devices and have a so-called vertical structure. In the semiconductor elements 11 and 12, electrodes 11A, 11B, 12A, and 12B are provided on the front surface (upper surface in FIG. 1) and the back surface (lower surface in FIG. 1), respectively. In each of the semiconductor elements 11 and 12, an arbitrary number of electrodes can be provided according to the element structure. However, in FIG. 1, for convenience of explanation, one electrode 11A, 11B, 12A, 12B is shown on each of the upper and lower surfaces of the semiconductor elements 11, 12. The material of the electrodes 11A, 11B, 12A, and 12B is a metal such as aluminum (Al) having conductivity.

  In the above, the planar shape of the semiconductor elements 11 and 12 is a rectangle. The electrodes 11A, 11B, 12A, and 12B are provided in desirable regions on the rectangular front and back surfaces of the semiconductor elements 11 and 12, respectively. The planar shape of each of the electrodes 11A, 11B, 12A, and 12B is also preferably rectangular.

  As shown in FIG. 1, since the two semiconductor elements 11 and 12 are different types of semiconductor elements, their thicknesses d1 and d2 (d1 <d2) are different. Usually, when the semiconductor device 10 includes two or more semiconductor elements, the thicknesses of the semiconductor elements are different. The thickness d1 of the semiconductor element 11 is, for example, 0.1 to 0.3 mm. On the other hand, the thickness d2 of the semiconductor element 12 has a dimension larger than the thickness d1.

  Regarding the relationship between the thicknesses of the respective electrodes 11A, 11B, 12A, 12B of the two semiconductor elements 11, 12, the following relationship is usually provided. The electrodes 11A and 12A on the surface side of the semiconductor elements 11 and 12 have substantially the same thickness, for example, 15 to 20 μm. The electrodes 11B and 12B on the back surface side of the semiconductor elements 11 and 12 preferably have substantially the same thickness. The thickness of the electrodes 11B and 12B may be the same as or different from the thickness of the electrodes 11A and 12A.

  In the structure example shown in FIG. 1, a plurality of columnar electrode portions 21 are further formed for the electrodes 11A and 12A on the surface side of the two semiconductor elements 11 and 12, respectively. In the illustrated example of FIG. 1, as described above, the pressure contact mounting is completed by the pressure contact terminal plate 22 located on the upper side and the electrode terminal plate 23 located on the lower side in FIG. It is in a state of being pressed against the columnar electrode portion 21. As a result, each of the plurality of columnar electrode portions 21 is formed with a crushed portion 21 a based on plastic deformation at a portion in contact with the terminal plate 22. The shape of the columnar electrode part 21 before the press contact is preferably a cylindrical body, and its axial length (height) is larger than 10 to 20 μm, for example, 15 to 25 μm. A plurality of columnar columnar electrode portions formed on each of the electrodes 11A and 12A are formed by the same technique described later using the same material as the electrode and have the same axial length. On the other hand, since the terminal plate 22 is simultaneously pressed against the columnar electrode portions 21 of the electrodes 11A and 12A at the time of pressure welding, a crushing portion 21a based on plastic deformation is formed at the upper end portions of the plurality of columnar electrode portions 21. Become. In FIG. 1, the dimension d3 is about 10-20 micrometers, for example. As a result, in the columnar electrode portion 21 of the electrode 11A, a collapsed portion 21a corresponding to the thickness d1 of the semiconductor element 11 is formed. Similarly, also in the columnar electrode portion 21 of the electrode 12A, a crushing portion 21a is formed depending on the thickness d2 of the semiconductor element 12 while being restricted by the dimension d3. Since the thickness d2 of the semiconductor element 12 is larger than the thickness d1 of the semiconductor element 11, the collapse amount of the collapsed portion 21a of the columnar electrode portion 21 of the electrode 12A is larger than the collapse amount of the collapsed portion 21a of the columnar electrode portion 21 of the electrode 11A. growing.

As described above, the electrode terminal plate 23 is arranged on the back surface side of the semiconductor elements 11 and 12, the electrodes 11 B and 12 B on the back surface side of the semiconductor elements 11 and 12 are brought into contact with it, and the surface side of the semiconductor elements 11 and 12 is contacted. The pressure contact terminal plate 22 is disposed and pressed against the columnar electrode portions 21 of the electrodes 11A and 12A on the surface side of the semiconductor elements 11 and 12, so that the pressure contact mounting is performed and the pressure contact type semiconductor device 10 is formed. . At this time, even when the semiconductor elements 11 and 12 have different thicknesses, the contact-side tip portions of the plurality of columnar electrode portions 21 formed on the surface-side electrodes 11A and 12A correspond to the thicknesses of the semiconductor elements 11 and 12, respectively. Then, it is crushed by an appropriate amount of crushing based on the plastic deformation, and the thickness between the terminal plates 22 and 23 is kept uniform and constant, and the contact between the electrodes 11A and 12A and the terminal plate 22 is ensured. The plurality of columnar electrode portions 21 formed on the surfaces of the electrodes 11A and 12A are surfaces based on a high film formation technique such as a sputtering method or a gas deposition method that is a semiconductor manufacturing process using the same material for the electrodes. It is formed by the processing method. Here, the gas deposition method is a method in which vaporized metal is aerosolized to form a metal film at a high film formation rate. When the pressure contact terminal plate 22 is, for example, molybdenum (Mo) or molybdenum copper (CuMo), the height of the columnar electrode portion 21 (the length in the axial direction) is at least about 10 to 20 μm using aluminum (Al). It is formed with the dimension. Actually, the height of the columnar electrode portion 21 is optimized to a value that can sufficiently absorb and mitigate the difference in thickness between the semiconductor elements 11 and 12 that are simultaneously pressed and mounted. In consideration of the purpose of causing the above-described plastic deformation, the area of the contact portion of each columnar electrode portion 21 with the terminal plate 22 is preferably as small as possible. However, considering the actual situation, it is necessary to optimize the area of the contact portion in accordance with the characteristics of the semiconductor element such as current density and calorific value.

  In general, the axial length (height), the cross-sectional diameter, the arrangement density, and the like of the columnar electrode unit 21 described above are plastic in the columnar electrode unit 21 when the columnar electrode unit 21 is pressed by the terminal plate 22. Optimized so that deformation can occur.

  In the description of the above-described embodiment, the example in which the plurality of columnar electrode portions 21 are formed on the electrodes 11A and 12A on the front surface side of the semiconductor elements 11 and 12 has been described, but a similar structure is provided on the electrodes 11B and 12B on the back surface side. Can also be provided.

  FIG. 2 shows an example of the arrangement of the plurality of columnar electrode portions 21 in the electrode 11 </ b> A on the surface side of the semiconductor element 11. In FIG. 2, the plurality of columnar electrode portions 21 formed on each of the plurality of electrodes 11 </ b> A are arranged so that the intervals between adjacent columnar electrode portions 21 are substantially equal. By this arrangement configuration, contact by plastic deformation of each columnar electrode portion 21 is ensured. Further, the columnar electrode portions 21 are arranged so that the distances between the columnar electrode portions 21 are substantially equal, and the columnar electrode portions 21 after being pressed and assembled and plastically deformed are separated from each other, whereby the semiconductor elements 11 and 12 and the terminal plate 22 in the pressure contact state are separated. And the occurrence of per-piece contact with each other can be reduced, and a substantially uniform contact state can be obtained.

  In addition, the arrangement density of the plurality of columnar electrode portions 21 on the surfaces of the electrodes 11A and 12A of the semiconductor elements 11 and 12 can be higher than the arrangement density of the central portion of the electrode surface. The temperature of the semiconductor element is higher in the central part than in the peripheral part. With this arrangement, the resistance of the peripheral part is made higher than that in the central part of the semiconductor element, so that the temperature distribution is substantially uniform over the entire surface of the semiconductor elements 11 and 12. Further, it is possible to reduce the performance deterioration at the central portion of the semiconductor element that becomes high temperature.

  Furthermore, regarding the size of the area of the cross section (cross section orthogonal to the axis) of the plurality of columnar electrode portions 21 on the surfaces of the electrodes 11A and 12A of the semiconductor elements 11 and 12, the columnar electrode portions located at the center of the electrode surface It is desirable that the area of the columnar electrode part located in the peripheral part of the electrode surface is larger than the area of. The temperature of the semiconductor element is higher in the central part than in the peripheral part, but according to this configuration, a substantially uniform temperature distribution is generated over the entire surface of the semiconductor element by increasing the resistance of the peripheral part from the central part of the semiconductor element. Therefore, it is possible to reduce the performance deterioration at the center of the semiconductor element that becomes high temperature.

  FIG. 3 shows four examples regarding the shape of the columnar electrode portion 21 described above. FIG. 3 shows a side view of the columnar electrode portion 21. 3A shows the columnar electrode portion 21 having the columnar shape described above, FIG. 3B shows the columnar electrode portion 21 having a truncated cone shape, and FIG. 3C shows a columnar shape having a substantially hemispherical tip portion. The electrode part 21 is shown, (D) has shown the columnar electrode part 21 in which a front-end | tip part has a truncated cone shape. The columnar electrode portions 21 of (B) to (D) have a tapered shape with a diameter that decreases as the upper terminal plate is approached. As a result, the semiconductor element and the terminal plate can be pressure-welded and assembled with a low load, and further falling can be prevented. Further, the columnar electrode portion 21 of (B) is the most suitable electrode shape because it can be easily formed by a general sputtering method as a film forming technique.

  Next, a specific power module structure of the pressure contact type semiconductor device according to the present invention will be described with reference to FIG. In FIG. 4, the longitudinal cross-sectional view of the principal part of a power module structure is shown.

  In FIG. 4, 31 is an IGBT which is a vertical semiconductor element, 32 is an emitter electrode formed on the upper surface of the IGBT 31, 33 is a collector electrode formed on the lower surface of the IGBT 31, and 34 is a gate electrode formed on the upper surface of the IGBT 31. is there. A plurality of columnar electrode portions 35 are formed on the surface of the emitter electrode 32. Reference numeral 41 denotes a diode which is another vertical semiconductor element, 42 denotes an anode electrode formed on the upper surface of the diode 41, and 43 denotes a cathode electrode formed on the lower surface of the diode 41. A plurality of columnar electrode portions 44 are formed on the surface of the anode electrode 42.

  The IGBT 31 and the diode 41, which are two semiconductor elements, are positioned in the horizontal direction by positioning frames 51, 52, and 53, and external terminals 54 and 55 are disposed on the upper and lower sides thereof, and these plate-like elements are arranged. The external terminals 54 and 55 are pressed and mounted. The plate-like external terminals 54 and 55 also serve as auxiliary heat sinks. The IGBT 31 and the diode 41 are pressed and sandwiched by the two upper and lower external terminals 54 and 55, and are pressed and mounted. The upper external terminal 54 is in pressure contact with each of the plurality of columnar electrode portions 35 and 44. In addition to the above structure, a heat radiating plate 57 is provided on the upper side via an insulating substrate 56, and a heat radiating plate 59 is provided on the lower side via an insulating substrate 58. Between the two heat sinks 57 and 59, for example, four fastening bolts 60 and fastening nuts 61 screwed to both ends thereof are provided, and are connected by these fastening means. The assembly incorporated in the portion between the insulating substrates 56 and 58 is surrounded and protected by the peripheral units 62 and 63. A gate signal external terminal 64 is provided on the lower insulating substrate 58. A gate signal wire 65 is connected between the gate signal external terminal 64 and the gate electrode 34. A bullet column imparting member such as a leaf spring may be disposed between the nut 61 and the heat radiating plate 59, and pressure contact assembly may be performed so as to maintain a predetermined pressure. Improves vibration resistance.

  According to the power module structure including the above-described pressure contact type semiconductor device, the plurality of columnar electrode portions 35 of the emitter electrode 32 and the plurality of columnar electrode portions 44 of the anode electrode 42 function as auxiliary heat sinks as terminal plates that pressurize and press contact. External terminals 54 and 55 are used. Further, when the pressure contact type semiconductor device is incorporated into the power module structure, the heat radiating plates 57 and 59 are attached to the part of the assembly including the pressure contact type semiconductor device. In addition, in said power module structure, it is not necessary to use the fastening bolt 60 grade | etc., And should just implement | achieve a box-shaped structure instead.

  Next, another embodiment of a specific power module structure of the pressure contact type semiconductor device according to the present invention will be described with reference to FIG. FIG. 5 shows a longitudinal sectional view of the main part of the power module structure, similar to FIG. In FIG. 5, elements that are substantially the same as those described in FIG. 4 are given the same reference numerals, and descriptions thereof are omitted.

  In the power module structure shown in FIG. 5, conductive pressure contacts 71 and 72 are provided as members for pressing the plurality of columnar electrode portions 35 and 44 against the IGBT 31 and the diode 41, respectively. An external terminal 73 that is also used as auxiliary heat dissipation is disposed on the upper side of these conductive pressers 71 and 72. In this example, since the thickness of the diode 41 is smaller than the thickness of the IGBT 31, the conductive pressure contacts 71 and 72 having different thicknesses are provided in order to absorb variations in the thickness of these semiconductor elements. I have to. The other structure is the same as the power module structure described with reference to FIG. According to the power module structure, the plurality of columnar electrode portions 35 and 44 are pressed against the IGBT 31 and the emitter electrode 32 and the anode electrode 42 of the diode 41, respectively, and have a thickness corresponding to the thickness of each semiconductor element. Since the dedicated conductive pressure contacts 71 and 72 are provided, it is possible to select an optimum material as the pressure contact material, and further ensure the contact with the columnar electrode portion and the pressure contact based on the plastic deformation of the columnar electrode portion. Can be done. Contact resistance can be made equal by making the amount of crushing by plastic deformation of the columnar electrode portions 35 and 44 substantially equal.

  The configurations, shapes, sizes, and arrangement relationships described in the above embodiments are merely schematically shown to the extent that the present invention can be understood and implemented, and the numerical values and the compositions (materials) of the respective components Is just an example. Therefore, the present invention is not limited to the described embodiments, and can be variously modified without departing from the scope of the technical idea shown in the claims.

  The pressure contact type semiconductor device according to the present invention is used as a built-in structure portion of a power semiconductor module mounted on an automobile or the like.

BRIEF DESCRIPTION OF THE DRAWINGS It is the longitudinal cross-sectional view of the principal part of a press-contact type semiconductor device which shows roughly the basic structure of the press-contact type semiconductor device which concerns on this invention. It is a figure which shows the example of arrangement | positioning of the several columnar electrode part in the electrode of the surface side of the press-contact type semiconductor element which concerns on this embodiment. It is a side view which shows four examples regarding the shape of the columnar electrode part in this embodiment. It is a longitudinal cross-sectional view of the principal part of the concrete power module structure of the press-contact type semiconductor device which concerns on this invention. It is a longitudinal cross-sectional view which shows the other Example of the concrete power module structure of the press-contact type semiconductor device based on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Pressure-contact type semiconductor device 11, 12 Semiconductor element 11A, 11B Electrode 12A, 12B Electrode 21 Columnar electrode part 21a Crush part 22 Pressure-contact terminal board 23 Electrode terminal board 31 IGBT
32 Emitter electrode 35 Columnar electrode part 41 Diode 42 Anode electrode 44 Columnar electrode part 57, 59 Heat sink 71, 72 Conductive pressure contactor

Claims (6)

A semiconductor device comprising a plurality of semiconductor elements and two terminal plates that press-contact each of the plurality of semiconductor elements from both front and back surfaces,
A plurality of columnar electrode portions are formed on the surface of the electrode of the semiconductor element,
A heat sink for holding each of the two terminal plates in a pressurized state;
A plurality of the columnar electrode portions are plastically deformed and contact the terminal plate ;
Each of the plurality of columnar electrode portions has a cylindrical shape, and a diameter of a portion of the columnar electrode portion on the terminal plate side decreases as the terminal plate is approached . At least two of the semiconductor elements have different thicknesses, and the columnar electrode portions are formed on the surfaces of the electrodes provided on the surfaces of the two semiconductor elements,
When the two terminal plates are mounted by pressure contact, the difference in thickness between the two semiconductor elements is absorbed by plastic deformation of the columnar electrode portion of the electrode on the surface side of each of the two semiconductor elements. The press-contact type semiconductor device according to claim 1. The plurality of columnar electrode portions formed on the surface of the electrode of the semiconductor element are formed on the surface of the electrode using the same metal material as the electrode and based on a film forming technique. 1 Symbol placement of pressure-contact type semiconductor device. Plurality of each of the columnar electrode portion, between the columnar electrode portion adjacent claim 1 Symbol placement of pressure-contact type semiconductor device characterized in that it is arranged at equal intervals. A semiconductor device comprising a plurality of semiconductor elements and two terminal plates that press-contact each of the plurality of semiconductor elements from both front and back surfaces,
A plurality of columnar electrode portions are formed on the surface of the electrode of the semiconductor element,
A heat sink for holding each of the two terminal plates in a pressurized state;
A plurality of the columnar electrode portions are plastically deformed and contact the terminal plate;
The arrangement density of the plurality of the columnar electrode part in the electrode surface of the semiconductor element, pressure contact type than the arrangement density of the central portion of the electrode surface you characterized by a high arrangement density of the peripheral portion of the electrode surface Semiconductor device. A semiconductor device comprising a plurality of semiconductor elements and two terminal plates that press-contact each of the plurality of semiconductor elements from both front and back surfaces,
A plurality of columnar electrode portions are formed on the surface of the electrode of the semiconductor element,
A heat sink for holding each of the two terminal plates in a pressurized state;
A plurality of the columnar electrode portions are plastically deformed and contact the terminal plate;
The size of the cross-sectional area of the plurality of columnar electrode portions on the electrode surface of the semiconductor element is located in the peripheral portion of the electrode surface rather than the area of the columnar electrode portion located in the central portion of the electrode surface pressure contact type you wherein an area of the columnar electrode portion is large for a semiconductor device.

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