JP2012222239A - Semiconductor module and pressing force dispersion member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the operation stability of a semiconductor module by making the pressing force of an elastic member act uniformly by each member constituting the semiconductor module.SOLUTION: In the semiconductor module including electrode terminals 3, 4 being connected electrically with the electrode layer of IGBT elements 2, 2, a spring electrode 6 is provided between the IGBT element 2 and the electrode terminal 4. The spring electrode 6 is constituted by holding a disc spring 5 between flat plate parts 8a, 8a formed by folding a conductive plate member 8. Furthermore, in order to disperse the pressing force of the disc spring 5, dispersion plates 7, 7 (pressing force dispersion members) are provided, respectively, between the flat plate part 8a and the disc spring 5.

Description

  The present invention relates to a semiconductor module that electrically connects an electrode layer and an electrode terminal of a semiconductor element by pressure contact, and a pressing force dispersion member provided in the semiconductor module.

  In recent years, high-voltage, high-capacity IGBTs (Insulated Gate Bipolar Transistors) are used for insulated power semiconductor modules used in fields such as industrial and vehicle systems, substation equipment, and power converters such as inverters. Has been applied. Standards for “green green power semiconductor modules” or “Isolated power semiconductor devices” typified by this IGBT module are established in JEC-2407-2007 and IEC60747-15, respectively.

  In a general green-type power semiconductor module, a semiconductor element such as an IGBT or a diode as a switching element has a copper circuit on a DBC (Direct Bond Copper) substrate (or DCB substrate) with an electrode layer provided on the lower surface of the semiconductor element. It is provided by soldering on a foil (for example, Non-Patent Document 1). The DBC substrate is obtained by directly bonding a copper circuit foil to an insulating plate made of ceramics or the like.

  An aluminum wire is connected to the electrode layer provided on the upper surface of the semiconductor element by a method such as ultrasonic bonding, and is electrically connected to, for example, a copper circuit foil on a DBC substrate. A copper terminal (lead frame or bus bar) for connecting electricity from the copper circuit foil of the DBC substrate to the outside is connected to the copper circuit foil by soldering. Furthermore, this area is surrounded by a (super) engineering plastic case and filled with silicon gel or the like for electric green.

  As the power density increases year by year, the bonding temperature between the electrode on the semiconductor element and the aluminum wire increases, and the shear stress of the solder and the stress of the aluminum wire increase. On the other hand, it is necessary to design the structure of the semiconductor module so that the influence of thermal expansion does not become apparent over the period until the design life of the semiconductor module is reached. With the advent of wideband cap semiconductor elements that can be used at high temperatures such as SiC and GaN, there is a demand for further reduction of the effects of thermal expansion. As described above, the operating temperature of the semiconductor element is increasing, and when the operating temperature is 175 ° C. to 200 ° C., this temperature is close to the melting point of the solder material, so that the conventional solder material may not be used. is there. Therefore, as a material to be replaced with solder, for example, metal-based high-temperature solder (Bi, Zn, Au), compound-based high-temperature solder (Sn—Cu), low-temperature sintered metal (Ag powder, nanoAg), and the like have been proposed. In addition, operation | movement at 250-300 degreeC is reported for SiC which is a next-generation semiconductor element.

  In order to comply with RoHS (Restriction of Hazardous Substances), lead-free solder and to improve the reliability of temperature cycle, power cycle, etc. There exists a subject, such as reducing the stress which acts between members.

  In order to solve the problem of lead-free solder, use of lead-free solder and semiconductor module structures not using solder are being studied. For example, as a lead-free solder material, Sn-Ag-based or Sn-Cu-based materials as described above are being studied.

  On the other hand, for the problem of improving the reliability such as temperature cycle and power cycle, it is necessary to improve the problem caused by the difference in thermal expansion coefficient of each member (semiconductor, metal, ceramics, etc.) constituting the semiconductor module. . That is, between the substrate and the copper base, between the substrate and the copper terminal, the shear stress acts on the solder between the copper and ceramics due to the difference in the thermal expansion coefficient, causing cracks in the solder, increasing the thermal resistance, and peeling the terminals. There is a risk of Furthermore, cracks may also occur in the solder between the semiconductor element and the substrate. In addition, stress may be generated due to the difference in thermal expansion between aluminum and the semiconductor element at the connection portion of the aluminum wire on the semiconductor element, and the aluminum wire may be fatigued.

  As a semiconductor module that solves these two problems, a semiconductor module structure that does not use solder, that is, a flat pressure contact structure package has been proposed (Patent Document 1, Non-Patent Documents 1 and 2).

  In this flat pressure contact structure package, a guide for positioning the semiconductor element and the contact terminal is generally provided at the end of the semiconductor element (for example, IGBT, diode, etc.). Then, the semiconductor element is provided on a substrate (Mo substrate, DBC substrate, etc.) with the upper electrode layer of the semiconductor element in contact with the contact terminal. The contact terminals and the substrate are provided in the semiconductor module in a state of being pressed so as to sandwich the semiconductor element. In the flat type pressure contact structure package, since each member is connected by pressure contact, solder is not used, and stress due to a difference in thermal expansion coefficient of each member can be relieved.

  In such a flat pressure contact structure package, the contact terminal and the semiconductor element are connected and the semiconductor element and the substrate are connected by pressure contact. Therefore, in order to use this flat pressure contact structure package, force is applied to the electrode portions (contact terminals and external connection terminals) at both ends provided in the semiconductor module from the outside of the semiconductor module, and the electrode portion and the electrode of the semiconductor element It is necessary to perform pressure contact with the layer. Therefore, in general, a flat semiconductor module is provided with an elastic member such as a spring in order to press-contact the semiconductor module.

US Pat. No. 6,320,268 JP-A-9-139148

IEEJ Technical Committee on High Performance and High Performance Power Devices and Power ICs, “Power Device and Power IC Handbook”, Corona, July 1996, p289, p336 Hiroshi Mori, Yasukazu Seki, “Recent Advances in Large Capacity IGBTs”, The Institute of Electrical Engineers of Japan, The Institute of Electrical Engineers of Japan, May 1998, Vol. 118 (5), pp. 274-277

  In the semiconductor module having this pressure contact structure, it is necessary to assemble the semiconductor module so that the pressure contact force is equally applied to each semiconductor element or the like. That is, the pressure contact of each member constituting the semiconductor module electrically insulates between the upper and lower electrode terminals of the pressure contact structure package, and the pressure contact force of the pressure contact structure package by the elastic member is equally applied to the electrode posts of the pressure contact structure package. It is necessary to do so.

  If the pressure contact is poor, the semiconductor element may be destroyed due to an increase in on-resistance or an increase in the temperature of the semiconductor element.

  Therefore, an object of the present invention is to contribute to causing the pressing force of the elastic member provided in the semiconductor module to act more uniformly on the electrode surface of the semiconductor element.

  The semiconductor module of the present invention that achieves the above object is characterized by including a pressing force dispersion member that disperses the pressing force of an elastic member provided in the semiconductor module. Further, the pressing force dispersion member of the present invention is characterized in that the position of the pressing force dispersion member or the elastic member is controlled so as to maintain the initially provided position.

  That is, the semiconductor module of the present invention that achieves the above object is a semiconductor module comprising a semiconductor element and an electrode terminal electrically connected to an electrode layer of the semiconductor element, wherein the semiconductor element and the electrode terminal An electrode member configured by folding a conductor flat plate and providing an elastic member between the folded conductor flat plates, a first pressing force dispersion member provided between one end of the elastic member and the conductor flat plate, And a second pressing force dispersion member provided between the other end of the elastic member and the conductive flat plate.

  Moreover, the semiconductor module of the present invention that achieves the above object is characterized in that, in the semiconductor module, the first pressing force distribution member has a sliding portion that slides on the second pressing force distribution member.

  In the semiconductor module of the present invention that achieves the above object, in the semiconductor module, the first pressing force distribution member includes a loose fitting portion that loosely fits the second pressing force distribution member, and the second pressing force distribution. And a contact portion that contacts the side surface of the member.

  The semiconductor module of the present invention that achieves the above object is characterized in that, in the semiconductor module, the abutting portion abuts a side surface of the conductor flat plate when the elastic member is elastically deformed.

  Moreover, the semiconductor module of the present invention that achieves the above object is characterized in that in the semiconductor module, the semiconductor module has an intermediate portion that connects the first pressing force distribution member and the second pressing force distribution member.

  The semiconductor module of the present invention that achieves the above object is characterized in that, in the semiconductor module, a fitting portion into which the elastic member is fitted is formed in the first pressing force distribution member and the second pressing force distribution member. It is characterized by.

  The pressing force distribution member of the present invention that achieves the above object is a pair of pressing force distribution members that sandwich an elastic member, and one pressing force distribution member slides on the other pressing force distribution member. It has a sliding part.

  The pressing force distribution member of the present invention that achieves the above object is a pair of pressing force distribution members that sandwich an elastic member, and one of the pressing force distribution members is loosely fitted to the other pressing force distribution member. It has a fitting part and an abutting part which abuts on the other pressing force distribution member.

  The pressing force distribution member of the present invention that achieves the above object is a pair of pressing force distribution members that sandwich an elastic member, and is an intermediate that connects one pressing force distribution member and the other pressing force distribution member. It has the part.

  According to the above invention, it contributes to making the pressing force of the elastic member with which a semiconductor module is provided act on the electrode surface of a semiconductor element more uniformly.

It is principal part sectional drawing of the semiconductor module which concerns on Embodiment 1 of this invention. It is a perspective view of the electrode member concerning Embodiment 1 of the present invention. It is a perspective view of the electrode member which concerns on Embodiment 2 of this invention, (a) The figure which shows a state when the pressure concerning an electrode member is weak, (b) The figure which shows a state when the pressure concerning an electrode member is strong . It is a perspective view of the electrode member which concerns on Embodiment 3 of this invention, (a) The figure which shows a state when the pressure concerning an electrode member is weak, (b) The figure which shows a state when the pressure concerning an electrode member is strong . It is a side view of the electrode member which concerns on Embodiment 4 of this invention, (a) The figure which shows a state when the pressure concerning an electrode member is weak, (b) The figure which shows a state when the pressure concerning an electrode member is strong . It is a perspective view of the electrode member which concerns on Embodiment 5 of this invention.

(Embodiment 1)
A semiconductor module and a pressing force dispersion member according to Embodiment 1 of the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, the semiconductor module 1 according to Embodiment 1 of the present invention includes an IGBT element 2 (semiconductor element), a collector electrode terminal 3 electrically connected to an electrode layer of the IGBT element 2, and an IGBT element 2. The emitter electrode terminal 4 is electrically connected to the electrode layer, and the spring electrode 6 is provided between the IGBT element 2 and the emitter electrode terminal 4.

  The spring electrode 6 is configured by folding the conductive plate member 8 and sandwiching the disc spring 5 between the flat plate portions 8 a and 8 a formed by folding the conductive plate member 8. Furthermore, in order to disperse the pressing force of the disc spring 5, dispersal plates 7 and 7 (pressing force dispersing members) are provided between the flat plate portion 8a and the disc spring 5, respectively.

  As shown in FIG. 2, a pair of dispersion plates 7 are provided in the direction in which the disc spring 5 is elastically deformed, and a pair of dispersion plates 7 and 7 sandwiching the disc spring 5 are provided between the flat plate portions 8a and 8a. The dispersion plate 7 has substantially the same size as the flat plate portion 8a, and the plurality of disc springs 5 press one dispersion plate 7, and the distribution plate 7 presses the flat plate portion 8a. As the dispersion plate 7, for example, a plate made of a known hard metal such as a stainless steel plate, a molybdenum (Mo) plate, or a tungsten (W) plate is used (the same applies to the dispersion plates according to other embodiments).

  The conductive plate member 8 is made of a conductive material such as copper or aluminum. The folded portion 8b of the conductive plate member 8 can be folded back as long as the disc spring 5 and the dispersion plate 7 can be sandwiched, such as a folded shape of both ends of the conductive plate member 8 in addition to the folded shape of the U shape. Also good.

  The IGBT element 2 is provided on a collector (cathode) electrode terminal 3 via a molybdenum contact electrode 9 as shown in FIG. Although not shown, the IGBT element 2 has an emitter and a gate (control electrode) formed on the top surface and a collector formed on the bottom surface. That is, the collector electrode terminal 3 is electrically connected to the collector of the IGBT element 2 through the contact electrode 9. In the description of the embodiment, for convenience, the top surface and the bottom surface are used, but the vertical direction does not limit the present invention. The connection between the gate (control electrode) and the control circuit is not shown because a conventional connection method may be used.

  As the collector electrode terminal 3 (and the emitter electrode terminal 4), an electrode terminal made of a known electrode material can be used. For example, in order to improve the heat dissipation of the semiconductor module 1 (IGBT element 2), a metal having good thermal conductivity such as copper is used as the material of the collector electrode terminal 3 (and the emitter electrode terminal 4).

  As the contact electrode 9 (and a contact electrode 10 described later), a contact electrode used in a semiconductor module is appropriately selected and used. For example, the material of the IGBT element 2 (for example, Si, SiC, GaN) is used as a material for the contact electrode 9 (contact electrode 10). When used, the contact electrode 9 (contact electrode 10) acts as a buffer plate for the thermal stress between the IGBT element 2 and the collector electrode terminal 3 (spring electrode 6), thereby improving the reliability of the semiconductor module 1 with respect to the temperature cycle. it can.

  An emitter electrode terminal 4 is provided on the emitter of the IGBT element 2 via a contact electrode 10 and a spring electrode 6. That is, the emitter electrode terminal 4 is electrically connected to the emitter of the IGBT element 2 through the contact electrode 10 and the spring electrode 6.

  Further, cooling plates 11 and 12 are provided on the collector electrode terminal 3 and the emitter electrode terminal 4 via the insulating plates 13 and 13 so as to press the collector electrode terminal 3 and the emitter electrode terminal 4 in the direction of the IGBT element 2. . The cooling plates 11 and 12 are fixed in a state where the collector electrode terminal 3 and the emitter electrode terminal 4 are pressed in the direction of the IGBT element 2.

  As the cooling plates 11 and 12, a metal plate such as copper or aluminum or a ceramic plate having high thermal conductivity is used. The semiconductor module 1 is cooled by connecting a heat sink to the cooling plates 11 and 12 or bringing a cooling medium (gas or liquid) into direct contact with the cooling plates 11 and 12. Although the cooling plates 11 and 12 can be used as a housing of the semiconductor module 1, the IGBT element 2 sandwiched between the cooling plates 11 and 12 may be housed in a housing not shown. Further, the insulating plates 13 and 13 are not provided, and the cooling plates 11 and 12 can be used as external connection electrodes connected to an external circuit of the semiconductor module 1.

  In the semiconductor module 1 having the above configuration, the cooling plates 11 and 12 are provided so as to press the collector electrode terminal 3 and the emitter electrode terminal 4 in the direction of the IGBT element 2, so that elastic energy is accumulated in the disc spring 5 of the spring electrode 6. Is done. The spring electrode 6 presses the emitter electrode terminal 4 and the insulating plate 13 in the direction of the cooling plate 12 and the contact electrode 10 in the direction of the IGBT element 2 (emitter of the IGBT element 2) by the elastic force of the disc spring 5. Further, the collector electrode terminal 3 and the insulating plate 13 are pressed in the direction of the cooling plate 11 by the pressing of the spring electrode 6, and the collector electrode terminal 3 causes the contact electrode 9 to be connected to the IGBT element 2 (IGBT element 2) by the reaction force of the pressing force. Press in the direction of the collector. Thus, the balance of the force which presses each member inside the semiconductor module 1 is maintained, and an appropriate pressure contact force works between each member.

  Then, by providing the dispersion plate 7 between the disc spring 5 and the flat plate portion 8a, the pressing force of the disc spring 5 is evenly applied to the flat plate portion 8a. That is, since the contact area of the portion that contacts the disc spring 5 decreases, the pressing force of the portion that is in contact with the disc spring 5 is increased, and a dent may be generated in the portion that is in contact with the disc spring 5. . If a dent arises, the press by the disk spring 5 will be canceled. In the semiconductor module 1, the dispersion plate 7 is provided at both ends of the disc spring 5, so that even if the elastic force of the disc spring 5 is concentrated at the contact portion between the dispersion plate 7 and the disc spring 5, the dispersion plate 7 is not deformed. The flat plate portion 8a can be evenly applied without impairing the elastic force of the disc spring 5.

  As described above, according to the semiconductor module 1 according to the first embodiment of the present invention, by providing the dispersion plates 7 at both ends of the disc spring 5, the elastic force of the disc spring 5 is increased to the conductive plate member 8 (flat plate portion 8a). The force of pressing on the connection surface between the spring electrode 6 and the emitter electrode terminal 4 (or the contact electrode 10) becomes more uniform.

  Further, only by providing the semiconductor module 1 with the spring electrode 6, an appropriate pressure contact force can be applied to each member provided in the semiconductor module 1, such as an electrode surface of the semiconductor element. As a result, the assembling work of the semiconductor module 1 is facilitated, and the performance degradation of the semiconductor module 1 and the destruction of the semiconductor element 2 due to improper assembly can be prevented. Furthermore, since each member which comprises the semiconductor module 1 is connected by press-contact, the solder free semiconductor module 1 can be obtained.

  Further, when the temperature of the semiconductor module 1 is lowered or raised during the storage or operation of the semiconductor module 1, the fluctuation width of the distance between the members due to the thermal contraction or thermal expansion of the internal components is determined by the disc spring 5 (spring electrode 6). It can be relieved by the shape change, and the pressing force acting between the members can be maintained at a predetermined pressing force. That is, the electrical connection between the IGBT element 2 and each electrode terminal 3, 4 is kept good, so that the operational stability of the semiconductor module 1 is improved, and each electrode terminal 3, 4 and the cooling members 11, 12 are Is ensured, and the heat dissipation of the semiconductor module 1 is improved.

  Since the spring electrode 6 is formed so that the conductive plate member 8 wraps the disc spring 5, the conductive plate member 8 acts as a heat diffusion plate, and the heat dissipation of the semiconductor module 1 is improved.

(Embodiment 2)
A semiconductor module and a pressing force dispersion member according to Embodiment 2 of the present invention will be described in detail with reference to FIG. The semiconductor module according to the second embodiment will be described with reference to FIG. 1 except that the shape of the dispersion plates 15 and 16 (pressing force dispersion member) provided in the semiconductor module is different from that of the dispersion plate 7 according to the first embodiment. This is the same as the semiconductor module 1 according to the first embodiment. Therefore, in the description of the embodiment, the dispersion plates 15 and 16 (and the spring electrode 14) will be described in detail, the same components as those in the first embodiment will be denoted by the same reference numerals, and detailed description thereof will be omitted (implementation). The same applies to Forms 3 to 5.)

  As shown in FIG. 3A, the spring electrode 14 according to the second embodiment of the present invention is a disc spring between the flat plate portions 8 a and 8 a formed by folding the conductive plate member 8 and folding the conductive plate member 8. 5 is configured. Further, distribution plates 15 and 16 (pressing force distribution members) are provided between the flat plate portion 8a and the disc spring 5, respectively. That is, a pair of dispersion plates 15 and 16 are provided in a direction in which the disc spring 5 is elastically deformed, and a pair of dispersion plates 15 and 16 sandwiching the disc spring 5 are provided between the flat plate portions 8a and 8a.

  The dispersion plate 15 provided at one end of the disc spring 5 includes a central portion 15a that contacts the disc spring 5 or the flat plate portion 8a and a pair of side portions 15b and 15b formed at the side ends of the central portion 15a. The side part 15b is formed integrally with the central part 15a, and the thickness of the side part 15b is formed thinner than the thickness of the central part 15a. And the sliding part which the dispersion | distribution plate 16 provided in the other end of the disk spring 5 slides is formed by bending the side part 15b in the disk spring 5 direction.

  The disc spring 5 is provided between the dispersion plate 15 and the dispersion plate 16 in a state in which the sliding portion of the dispersion plate 15 is engaged with the dispersion plate 16. That is, the disc spring 5 is provided between the dispersion plate 15 and the dispersion plate 16, and the dispersion plate 16 is provided between the side portions 15 b and 15 b of the dispersion plate 15.

  The dispersion plates 15 and 16 according to the second embodiment of the present invention having the above-described configuration are relative positions of the dispersion plate 15 and the dispersion plate 16 when the dispersion plate 16 slides on the sliding portion of the dispersion plate 15. The relationship is maintained in place. In addition, the relative positional relationship between the dispersion plate 15 and the dispersion plate 16 is maintained at a predetermined position, so that the disc spring 5 provided between the dispersion plate 15 and the dispersion plate 16 is in a direction perpendicular to the pressure contact direction. The action of force is suppressed, and the disc spring 5 is prevented from being displaced. In addition, since the inner peripheral surface of the side part 15b slides with the side surface of the dispersion | distribution plate 16 with the displacement of the disc spring 5, the displacement of the disc spring 5 is prevented by contact with the side part 15b and the side surface of the dispersion | distribution plate 16. Absent.

  As shown in FIG. 3B, when a force that reduces the distance between the flat plate portions 8a and 8a is applied to the spring electrode 14, the side portion 15b is further slid with the side surface of the flat plate portion 8a. If the length of the disc spring 5 is set, the relative position between the dispersion plate 15 and the flat plate portion 8a can be controlled to maintain the initially provided position by the displacement of the disc spring 5. Further, even if the relative position between the dispersion plate 15 and the flat plate portion 8a is shifted, the relative position between the dispersion plate 15 and the flat plate portion 8a is obtained by sliding the side portion 15b along the side surface of the flat plate portion 8a. Can be corrected. In addition, the end of the side portion 15b is tapered so that the movement of the side portion 15b is not hindered at the boundary between the dispersion plate 16 and the flat plate portion 8a (the tip of the side portion 15b is closer to the side surface of the dispersion plate 16). You may form so that distance may spread.

  When forming the sliding portion, if the gap 15c is formed between the central portion 15a and the side portion 15b, the flexibility in the normal direction of the surface in contact with the dispersion plate 16 of the side portion 15b is improved. Therefore, even when a difference occurs between the distance between the side portions 15b and 15b and the width of the dispersion plate 16 due to the coefficient of thermal expansion of each member constituting the semiconductor module, the side portion 15b prevents the disc spring 5 from being displaced. Absent.

  As described above, according to the dispersion plates 15 and 16 according to the second embodiment of the present invention, the relative positions of the dispersion plate 15 and the dispersion plate 16 can be controlled so as to maintain the initially provided position. it can. Therefore, it is possible to suppress the occurrence of displacement of the dispersion plates 15 and 16 and the disc spring 5 and to appropriately apply the pressure contact force by the disc spring 5 to each member constituting the semiconductor module.

  Therefore, in the semiconductor module 1 shown in FIG. 1, the semiconductor module provided with the spring electrode 14 according to the second embodiment of the present invention instead of the spring electrode 6 is the disc spring 5 (and the dispersion plate 15) provided in the spring electrode 14. 16) can be prevented from being displaced. As a result, in addition to the effects exhibited by the semiconductor module 1 according to the first embodiment, a more uniform pressure contact force can be applied to each member (such as an electrode layer of a semiconductor element) constituting the semiconductor module.

  In addition, in this embodiment, although it is the form which formed the sliding part in the dispersion | distribution board 15, it is good also as a form which forms a sliding part in the dispersion | distribution board 16, and makes the dispersion | distribution board 15 slide to this sliding part.

(Embodiment 3)
A semiconductor module and a pressing force dispersion member according to Embodiment 3 of the present invention will be described in detail with reference to FIG. The semiconductor module according to the third embodiment will be described with reference to FIG. 1 except that the shape of the dispersion plates 18 and 19 (pressing force dispersion member) provided in the semiconductor module is different from that of the dispersion plate 7 according to the first embodiment. This is the same as the semiconductor module 1 according to the first embodiment. Therefore, in the description of the embodiment, the spring electrode 17 provided with the dispersion plates 18 and 19 will be described in detail.

  As shown in FIG. 4A, the spring electrode 17 according to the third embodiment of the present invention is a disc spring between the flat plate portions 8a and 8a formed by folding the conductive plate member 8 and folding the conductive plate member 8. 5 is configured. Further, dispersion plates 18 and 19 are provided between the flat plate portion 8a and the disc spring 5, respectively. That is, a pair of dispersion plates 18 and 19 are provided in a direction in which the disc spring 5 is elastically deformed, and a pair of dispersion plates 18 and 19 sandwiching the disc spring 5 are provided between the flat plate portions 8a and 8a.

  The dispersion plate 18 provided at one end of the disc spring 5 includes a central portion 18a that contacts the disc spring 5 or the flat plate portion 8a and a pair of side portions 18b and 18b formed at the side ends of the central portion 18a. The side part 18b is formed integrally with the central part 18a, and the thickness of the side part 18b is formed thinner than the thickness of the central part 18a. Then, by bending the side portion 18b in the direction of the disc spring 5, a loose fitting portion in which the dispersion plate 19 provided at the other end of the disc spring 5 is loosely fitted is formed. That is, the side portions 18 b and 18 b are folded back so that the distance between the bent side portions 18 b and 18 b is wider than the width of the dispersion plate 19. Further, the side portion 18b is mountain-folded so as to be convex in the direction of the dispersion plate 19, and an abutting portion 18c is formed. When the contact portion 18c is formed in this way, slopes 18d and 18e are formed on the side portion 18b.

  Then, the dispersion plate 19 is loosely fitted to the loose fitting portion of the dispersion plate 18 so that the contact portion 18 c of the dispersion plate 18 slides on the side surface of the dispersion plate 19. A disc spring 5 is provided between them. That is, the disc spring 5 is provided between the dispersion plate 18 and the dispersion plate 19, and the dispersion plate 19 is provided between the side portions 18 b and 18 b of the dispersion plate 18.

  As shown in FIG. 4B, when a force that reduces the distance between the flat plate portions 8a and 8a is applied, the contact portion 18c is formed so that the contact portion 18c slides on the side surface of the flat plate portion 8a. The position is set.

  According to the dispersion plates 18 and 19 according to the third embodiment of the present invention having the above-described configuration, the abutment portion 18c slides on the side surface of the dispersion plate 19 as the disc spring 5 is displaced. The relative position with respect to the dispersion plate 19 can be maintained in a predetermined state. Further, the abutting portion 18c slides on the side surface of the flat plate portion 8a in accordance with the displacement of the disc spring 5, so that the relative positions of the dispersion plate 18 and the flat plate portion 8a are controlled so as to maintain the initially provided position. can do.

  Further, the contact portion 18c is formed by folding the side portion 18b bent in the direction of the disc spring 5 so as to be further convex in the direction of the dispersion plate 19, so that the contact portion 18c and the dispersion plate 19 ( Alternatively, the contact area with the side surface of the flat plate portion 8a) is small, and the displacement of the disc spring 5 is not hindered by the sliding of the contact portion 18c and the dispersion plate 19 (or the flat plate portion 8a).

  If a shift occurs in the relative position between the dispersion plate 18 and the flat plate portion 8a, the flat plate portion 8a is corrected to a predetermined state by moving the contact portion 18c with the displacement of the disc spring 5. At this time, the flat plate portion 8a is guided to a predetermined position by the inclined surface 18e. Similarly, when the relative position between the dispersion plate 18 and the dispersion plate 19 is shifted, the dispersion plate 19 is guided to a predetermined position by the inclined surface 18d.

  As described above, according to the dispersion plates 18 and 19 according to the third embodiment of the present invention, the relative positions of the dispersion plate 18 and the dispersion plate 19 (and the flat plate portion 8a) are the positions initially provided. It can be controlled to maintain. Therefore, similarly to the second embodiment of the present invention, the occurrence of displacement of the dispersion plates 18 and 19 and the disc spring 5 is suppressed, and the pressure contact force by the disc spring 5 is used to form each member (electrode layer of the semiconductor element) of the semiconductor module. Etc.).

  Therefore, in the semiconductor module 1 shown in FIG. 1, the semiconductor module provided with the spring electrode 17 according to Embodiment 3 of the present invention instead of the spring electrode 6 is the disc spring 5 (and the dispersion plate) provided in the spring electrode 17. 18, 19) can be prevented from being displaced. As a result, in addition to the effect produced by the semiconductor module 1 according to the first embodiment, a more uniform pressure contact force can be applied to each member constituting the semiconductor module.

  In addition, in this embodiment, although it is the form which formed the loose fitting part and the contact part 18c in the dispersion | distribution board 18, the same effect is acquired also as a form which forms the loose fitting part and the contact part in the dispersion | distribution board 19. Can do.

  In addition, when a plurality of abutting portions are formed on the side portion 18b of the dispersion plate 18 in the displacement direction of the disc spring 5, and each abutting portion abuts on the side surface of the dispersion plate 19 or the side surface of the flat plate portion 8a, Regardless of the displacement of the spring 5, the relative positions of the dispersion plate 18, the dispersion plate 19, and the flat plate portion 8a can be maintained at a predetermined position.

(Embodiment 4)
A semiconductor module and a pressing force dispersion member according to Embodiment 4 of the present invention will be described in detail with reference to FIG. The semiconductor module according to the fourth embodiment will be described with reference to FIG. 1 except that the shape of the dispersion plates 21 and 22 (pressing force dispersion members) provided in the semiconductor module is different from that of the dispersion plate 7 according to the first embodiment. This is the same as the semiconductor module 1 according to the first embodiment. Therefore, in description of embodiment, the spring electrode 20 with which the dispersion plates 21 and 22 are provided is demonstrated in detail.

  As shown in FIG. 5 (a), the spring electrode 20 according to the fourth embodiment of the present invention is a disc spring between the flat plate portions 8a and 8a formed by folding the conductive plate member 8 and folding the conductive plate member 8. 5 is configured. Further, dispersion plates 21 and 22 are provided between the flat plate portion 8a and the disc spring 5, respectively. That is, a pair of dispersion plates 21 and 22 are provided in a direction in which the disc spring 5 is elastically deformed, and a pair of dispersion plates 21 and 22 sandwiching the disc spring 5 is provided between the flat plate portions 8a and 8a.

  The dispersion plate 21 and the dispersion plate 22 are connected via an intermediate portion 23. The dispersion plate 21, the intermediate portion 23, and the dispersion plate 22 are integrally formed, and the thickness of the intermediate portion 23 is formed thinner than the thickness of the dispersion plate 21 (dispersion plate 22). Then, the intermediate portion 23 is folded back, and the disc spring 5 is provided between the dispersion plate 21 and the dispersion plate 22.

  As described above, in the dispersion plates 21 and 22 according to the fourth embodiment of the present invention, the dispersion plate 21 and the dispersion plate 22 are integrally formed via the intermediate portion 23. Therefore, the dispersion plate 21 and the dispersion plate 22 are integrated. The relative position is fixed in advance. Further, since the displacement of the dispersion plates 21 and 22 is prevented, the force in the direction perpendicular to the press-contact direction of the disc spring 5 is suppressed from acting on the disc spring 5, and the disc spring 5 is prevented from being displaced. Can do. As a result, the pressure contact force by the disc spring 5 can be made to act appropriately on each member (such as the electrode layer of the semiconductor element) constituting the semiconductor module.

  As shown in FIG. 5 (b), since the thickness of the intermediate portion 23 is formed thinner than the thickness of the dispersion plates 21 and 22, when a force that reduces the distance between the flat plate portions 8a and 8a is applied, The part 23 is bent and the displacement of the disc spring 5 is not hindered.

  Therefore, in the semiconductor module 1 shown in FIG. 1, the semiconductor module including the spring electrode 20 according to the fourth embodiment of the present invention instead of the spring electrode 6 includes the dispersion plates 21 and 22 (and The displacement of the disc spring 5) can be prevented. As a result, in addition to the effects of the semiconductor module 1 according to the first embodiment, a more uniform pressure contact force can be applied to each member constituting the semiconductor module.

  In the present embodiment, the intermediate portion 23 that connects the dispersion plate 21 and the dispersion plate 22 is integrally formed. However, if the dispersion plate 21 and the dispersion plate 22 can be connected, an intermediate portion 23 is provided. The shape, material, and the like of the portion 23 are not particularly limited. Also, the location where the intermediate portion 23 is formed is not particularly limited as long as the side surfaces of the dispersion plate 21 and the dispersion plate 22 are connected, and the same effect as the semiconductor module described in the fourth embodiment can be obtained. Can do.

(Embodiment 5)
A semiconductor module and a pressing force dispersion member according to Embodiment 5 of the present invention will be described in detail with reference to FIG. The semiconductor module according to the fifth embodiment will be described with reference to FIG. 1 except that the shape of the dispersion plates 25 and 26 (pressing force dispersion member) provided in the semiconductor module is different from that of the dispersion plate 7 according to the first embodiment. This is the same as the semiconductor module 1 according to the first embodiment. Therefore, the spring electrode 24 provided with the dispersion plates 25 and 26 will be described in detail.

  As shown in FIG. 6, the spring electrode 24 according to the fifth embodiment of the present invention folds the conductive plate member 8 and sandwiches the disc spring 5 between the flat plate portions 8 a and 8 a formed by folding the conductive plate member 8. Configured. Further, dispersion plates 25 and 26 are provided between the conductive plate member 8 and the disc spring 5, respectively. That is, a pair of dispersion plates 25 and 26 are provided in the direction in which the disc spring 5 is elastically deformed, and a pair of dispersion plates 25 and 26 sandwiching the disc spring 5 is provided between the flat plate portions 8a and 8a.

  The dispersion plate 26 is formed with a fitting groove 26 a in which the disc spring 5 is fitted on the surface of the dispersion plate 26 that contacts the disc spring 5. The disc spring 5 is fixed to the dispersion plate 26 by providing the disc spring 5 in the fitting groove 26a. Similarly, a fitting groove 25a for fitting the disc spring 5 is formed on the surface of the dispersion plate 25 in contact with the disc spring 5, and the disc spring 5 is provided in the fitting groove 25a. The relative position of the dispersion plate 26 can be controlled to be a predetermined position. The widths and shapes of the fitting grooves 25a and 26a are set to widths and shapes that do not hinder the elastic deformation of the disc spring 5.

  As described above, according to the dispersion plates 25 and 26 according to the fifth embodiment of the present invention, the disc spring 5 is fixed to the dispersion plate 26, so that the disc spring 5 can be prevented from being displaced. Further, it is possible to maintain the relative position of the dispersion plate 25 and the dispersion plate 26 with respect to the disc spring 5 as a predetermined position. As a result, the pressure contact force by the disc spring 5 can be appropriately applied to each member (semiconductor element or the like) constituting the semiconductor module.

  Therefore, in the semiconductor module 1 shown in FIG. 1, the semiconductor module including the spring electrode 24 according to the fifth embodiment of the present invention instead of the spring electrode 6 is the disc spring 5 (and the dispersion plate) provided in the spring electrode 24. 25, 26) can be prevented. As a result, in addition to the effects of the semiconductor module 1 according to the first embodiment, a more uniform pressure contact force can be applied to each member constituting the semiconductor module.

  In addition, by combining the dispersion plates 25 and 26 according to Embodiment 5 with the dispersion plates described in Embodiments 2 to 4, it is possible to further prevent the disc spring 5 and the dispersion plate from being displaced.

  As described above, according to the semiconductor module of the present invention, the pressing force dispersion member is provided at both ends of the elastic member provided in the semiconductor module, so that the pressing force of the elastic member can be applied uniformly to the semiconductor element.

  Moreover, since the pressing force dispersion member of the present invention can control the position of the pressing force dispersion member and the elastic member so as to maintain the initially provided position, the pressure contact force acting on each member constituting the semiconductor module. Can be made more uniform.

  When the electrode member is configured by wrapping the conductive plate member with an elastic member as in the embodiment, the heat generated in the semiconductor element diffuses in the conductive plate member, so that the heat dissipation of the semiconductor module is improved. Therefore, in a semiconductor module that takes advantage of the performance of a semiconductor element that can be used at a high temperature, such as SiC and GaN, reliability such as temperature cycle and power cycle can be improved.

  However, when the conductive plate member is folded, the folded portion formed by folding the conductive plate member and the opening formed by folding the conductive plate member may have different resistance to the same force. Such a difference in drag between the folded portion and the opening portion may cause a positional shift of the elastic member or the pressing force dispersing member.

  In a semiconductor module in which each member such as a semiconductor element is connected by pressure contact, if the position of the pressing force dispersion member or the elastic member is deviated from a predetermined position due to the influence of vibration or displacement of the elastic member, the semiconductor module is There is a possibility that variation occurs in the pressure contact force of the elastic member acting on each component member.

  Therefore, the semiconductor module provided with the pressing force dispersion member of the present invention is controlled so that the pressing force dispersion member and the elastic member are in a predetermined position, and the pressing force distribution member and the elastic member are shifted from the predetermined position. However, it can be corrected so as to be a predetermined position.

  Therefore, the semiconductor module provided with the pressing force dispersion member of the present invention maintains the pressing force dispersion member and the elastic member at a predetermined position, thereby further increasing the pressure contact force acting on each member constituting the semiconductor module. It can be made uniform.

  As a result, the reliability such as the temperature cycle and power cycle of the semiconductor module that press-contacts each member provided in the semiconductor module by the elastic force of the electrode member is improved. That is, an insulating power semiconductor module that is easy to use without using solder bonding or wire bonding can be obtained, and high reliability, environmental friendliness, and convenience of the semiconductor module can be realized at the same time.

  The semiconductor module and the pressing force dispersion member of the present invention are not limited to the above-described first to fifth embodiments, and can be appropriately changed in design without impairing the characteristics of the present invention. It is a semiconductor module and a pressing force dispersion member according to the present invention.

  For example, in the embodiment, a semiconductor module having a flat pressure contact structure including an IGBT element has been described as an example. However, the present invention is not limited to this embodiment, and the electrode layer of the semiconductor element and the outside (or the outside (or The present invention can be applied to a semiconductor module that is electrically connected to an electrode terminal for connection to another internal circuit.

  The semiconductor element provided in the semiconductor module is not limited to the IGBT element, and a semiconductor element such as a thyristor (GTO thyristor, etc.), a transistor (MOSFET, etc.), an FWD element, or the like can be appropriately selected and used.

  Further, in the embodiment of the present invention, the pressing force dispersion member that disperses the elastic force of the elastic member provided on the electrode member has been described as an example. However, the elastic member has an effect of dispersing the pressing force of the elastic member. If it is a place, an installation place will not be specifically limited.

  Further, the elastic member is not limited to the disc spring 5, and a wave plate spring, a convex spring, a mesh spring, or the like can be used. Further, the number of the disc springs 5 is not particularly limited, and the number of the disc springs 5 is set according to the pressure contact force applied to each member constituting the semiconductor module.

  Moreover, although it is good also as a form which provides a press dispersion plate with respect to each disc spring 5, by providing one dispersion plate with respect to each disc spring 5, the characteristic of each disc spring 5 or the disc spring 5 of FIG. The dispersion plate can press the conductive plate member 8 more evenly regardless of the difference in elastic force due to the difference in the provided position.

DESCRIPTION OF SYMBOLS 1 ... Semiconductor module 2 ... Semiconductor element 3 ... Collector electrode terminal (electrode terminal)
4. Emitter electrode terminal (electrode terminal)
5 ... Belleville spring (elastic member)
6, 14, 17, 20, 24 ... Spring electrode (electrode member)
7,15,16,18,19,21,22,25,26 ... dispersion plate (pressing force dispersion member)
8 ... Conductive plate member (conductive plate)
8a ... Flat plate portion 8b ... Folded portions 15a, 18a ... Central portions 15b, 18b ... Side portions 18c ... Abutting portions 23 ... Intermediate portions 25a, 26a ... Fitting grooves

Claims (9)

A semiconductor module comprising a semiconductor element and an electrode terminal electrically connected to the electrode layer of the semiconductor element,
An electrode member configured by folding a conductive plate between the semiconductor element and the electrode terminal, and providing an elastic member between the folded conductive plates;
A first pressing force dispersion member provided between one end of the elastic member and the conductor flat plate;
A semiconductor module, comprising: a second pressing force dispersion member provided between the other end of the elastic member and the conductor flat plate. 2. The semiconductor module according to claim 1, wherein the first pressing force dispersing member has a sliding portion that slides on the second pressing force dispersing member. The first pressing force dispersing member is
A loosely fitting portion loosely fitted to the second pressing force dispersing member;
The semiconductor module according to claim 1, further comprising a contact portion that contacts a side surface of the second pressing force dispersion member. The semiconductor module according to claim 3, wherein the abutting portion abuts against a side surface of the conductor flat plate when the elastic member is elastically deformed. 2. The semiconductor module according to claim 1, further comprising an intermediate portion that connects the first pressing force distribution member and the second pressing force distribution member. 6. The fitting portion according to claim 1, wherein a fitting portion into which the elastic member is fitted is formed in the first pressing force distribution member and the second pressing force distribution member. Semiconductor module. A pair of pressing force dispersion members sandwiching the elastic member,
One pressing force distribution member has a sliding portion that slides on the other pressing force distribution member. A pair of pressing force dispersion members that sandwich the elastic member,
One pressing force dispersion member is
A loosely fitting portion loosely fitted to the other pressing force dispersing member;
And a contact portion that contacts the other pressing force dispersion member. A pair of pressing force dispersion members that sandwich the elastic member,
A pressing force dispersing member having an intermediate portion for connecting one pressing force dispersing member and the other pressing force dispersing member.

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