JP2014154770A - Semiconductor device and semiconductor device manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor device capable of suppressing increase in size and cost and reducing inductance, and a method for manufacturing the semiconductor device.
In a semiconductor device, switching elements (10, 20) joined to both ends (41, 43) of a single flat output bus bar (40) are stacked together by bending the output bus bar (40). Arranged. Further, the overlapping portion 45 of the output bus bar 40 extends from the mold resin A when modularized. For this reason, it is not necessary to join another member to the output bus bar 40 further. Therefore, it is possible to suppress the increase in size and cost by arranging the switching elements 10 and 20 close to each other. Furthermore, it is possible to reduce the parasitic inductance by arranging the positive electrode bus bar 14 and the negative electrode bus bar 24 close to each other.
[Selection] Figure 2

Description

  The present invention relates to a semiconductor device including a pair of switching elements and a method for manufacturing the semiconductor device.

  Patent Document 1 describes a semiconductor device in which a pair of IGBT (Insulated Gate Bipolar Transistor) elements arranged opposite to each other is molded with a resin. In the semiconductor device described in Patent Document 1, the output bus bar is joined by screwing to a metal wiring board that electrically connects the emitter of one IGBT element and the collector of the other IGBT element.

Japanese Patent No. 4878520

  In the semiconductor device described in Patent Document 1, as described above, the output bus bar is screwed and joined to the metal wiring board that connects the IGBT elements. For this reason, it is necessary to provide a tool gap or the like for screwing at these joint portions. Therefore, since the IGBT elements are separated from each other by the amount of the tool gap, the apparatus is increased in size, and the necessary amount of mold resin is increased, resulting in an increase in material cost.

  In addition, since the current path formed by the metal wiring board and the output bus bar is made redundant by the amount of the tool gap, resistance and inductance increase. Furthermore, since the high voltage bus bar connected to the collector of one IGBT element and the low voltage bus bar connected to the emitter of the other IGBT element are arranged apart from each other by the amount of the tool gap, parasitic inductance increases.

  The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a semiconductor device capable of suppressing an increase in size and cost, and capable of reducing inductance, and a method for manufacturing the semiconductor device. To do.

  In order to solve the above problems, a semiconductor device according to the present invention is a semiconductor device including a pair of switching elements, and electrically connects a predetermined terminal of one switching element and a predetermined terminal of the other switching element. A single intermediate electrode to be connected is provided, and switching elements bonded to both ends of the substantially flat intermediate electrode are arranged so as to be stacked on each other by bending the intermediate electrode, and then sealed with a mold resin. Thus, the overlapping portion of the intermediate electrode produced by bending the intermediate electrode protrudes from the mold resin and extends.

  In order to solve the above-described problem, a manufacturing method of a semiconductor device according to the present invention is a manufacturing method of a semiconductor device including a pair of switching elements, and includes a predetermined terminal of one switching element and a switching element of the other switching element. A first step of preparing a single intermediate electrode for electrically connecting to a predetermined terminal, and after the first step, a switching element is joined to each of both ends of the substantially flat plate-like intermediate electrode. After the second step, after the second step, the intermediate electrode is bent to arrange the switching elements so as to be stacked on each other. After the third step, the switching element is sealed with a mold resin. A fourth step of stopping and modularizing, and the overlapping portion of the intermediate electrode produced by bending the intermediate electrode is formed by molding resin the switching element in the fourth step. It extends projecting from the molding resin when sealed more sealing, characterized in that.

  In the semiconductor device and the method for manufacturing the semiconductor device, the switching elements bonded to both ends of the single flat plate-like intermediate electrode are arranged so as to be stacked on each other by bending the intermediate electrode. And the overlapping part of the intermediate electrode protrudes and extends from the mold resin at the time of modularization. Therefore, it is not necessary to further join an output bus bar or the like made of another member to the intermediate electrode (that is, no tool gap or the like for joining is necessary).

  Therefore, since it is possible to arrange the switching elements close to each other, it is possible to suppress an increase in the size of the apparatus, and it is possible to reduce the required amount of the mold resin and suppress an increase in cost. Furthermore, since the positive electrode bus bar and the negative electrode bus bar for connecting the pair of switching elements between the positive electrode and the negative electrode can be arranged close to each other, the parasitic inductance can be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the semiconductor device which can suppress enlargement and cost increase, and can reduce an inductance, and the manufacturing method of a semiconductor device can be provided.

It is a figure which shows the structure of one Embodiment of the semiconductor device which concerns on this invention. It is sectional drawing of the semiconductor device shown by (a) of FIG. It is a figure which shows the main processes of the manufacturing method of the semiconductor device shown by FIG. It is a figure which shows the main processes of the manufacturing method of the semiconductor device shown by FIG. It is a figure which shows the main processes of the manufacturing method of the semiconductor device shown by FIG.

  Hereinafter, a semiconductor device and a method for manufacturing the semiconductor device according to the present invention will be described in detail with reference to the drawings. In the description of the drawings, the same elements or corresponding elements are denoted by the same reference numerals, and redundant description is omitted. Moreover, in each drawing, the dimension ratio of each part may differ from an actual thing.

  FIG. 1A is a plan view of one embodiment of a semiconductor device according to the present invention, and FIG. 1B is a circuit diagram of an inverter including one embodiment of a semiconductor device according to the present invention. . 2A is a sectional view taken along line IIA-IIA in FIG. 1A, and FIG. 2B is taken along line IIB-IIB in FIG. FIG.

  As shown in FIGS. 1 and 2, the semiconductor device 1 according to this embodiment includes a pair of switching elements 10 and 20. In the present embodiment, the switching elements 10 and 20 are mainly described as IGBTs. However, for example, the switching elements 10 and 20 may be a pair of an IGBT and a diode, a pair of a MOS and a diode, only a MOS, an RC (Reverse Conducting) -IGBT, or the like.

  The switching elements 10 and 20 are sealed and molded by the mold resin A in a state where they are arranged so as to be laminated in the vertical direction. The mold resin A is, for example, a thermosetting epoxy. In addition, although the diode etc. can be integrally modularized with the switching elements 10 and 20, it abbreviate | omits here.

  The switching elements 10 and 20 are connected in series between the positive electrode P and the negative electrode N together with the diodes D1 and D2 connected in antiparallel to each other, and constitute, for example, the U phase of the three-phase inverter I. The collector C1 of the switching element 10 is connected to the positive electrode P. The emitter (predetermined terminal) E1 of the switching element 10 is connected to the collector (predetermined terminal) C2 of the switching element 20.

  The emitter E2 of the switching element 20 is connected to the negative electrode N. A U-phase output terminal U is provided at a connection point between the emitter E1 of the switching element 10 and the collector C2 of the switching element 20. The switching element 10 is a switching element on the upper arm side, and the switching element 20 is a switching element on the lower arm side.

  The switching element 10 has a lower surface 10a on which a collector C1 is formed and an upper surface 10b on which an emitter E1 and a gate G1 are formed. A heat radiating plate 11 is joined to the lower surface 10 a of the switching element 10 by a conductive adhesive 12 such as solder. The heat sink 11 is made of a conductive material such as metal, and is electrically connected to the collector C1 of the switching element 10 via the conductive adhesive 12. Therefore, the heat sink 11 functions as a positive electrode. Note that at least a portion (here, the lower surface) of the heat radiating plate 11 is exposed from the mold resin A for heat radiation.

  A positive electrode bus bar (lead frame) 14 is joined to the heat radiating plate 11 by a conductive adhesive 13 such as solder. Therefore, the positive electrode bus bar 14 is electrically connected to the collector C <b> 1 of the switching element 10 through the conductive adhesive 13, the heat sink 11, and the conductive adhesive 12. The positive electrode bus bar 14 is made of, for example, a thin copper plate, and extends from one end portion of the heat radiating plate 11 and protrudes from the mold resin A. Note that the gate G1 formed on the upper surface 10b of the switching element 10 is electrically connected to the gate signal terminal B1 by a wire W1 made of, for example, gold or copper.

  The switching element 20 has an upper surface 20a on which a collector C2 is formed, and a lower surface 20b on which an emitter E2 and a gate G2 are formed. A heat radiating plate 21 is joined to the upper surface 20 a of the switching element 20 by a conductive adhesive 22 such as solder. The heat sink 21 is made of a conductive material such as metal and is electrically connected to the collector C <b> 2 of the switching element 20 via a conductive adhesive 22. Therefore, the heat sink 21 functions as an output electrode (for example, U phase). At least a part (here, the upper surface) of the heat radiating plate 21 is exposed from the mold resin A for heat radiation.

  A negative electrode bus bar (lead frame) 24 is joined to the lower surface 20 b of the switching element 20 by a conductive adhesive 23 such as solder. The negative electrode bus bar 24 is electrically connected to the emitter E <b> 2 of the switching element 20 through the conductive adhesive 23. The negative electrode bus bar 24 is made of, for example, a thin copper plate, extends from the lower surface 20 b of the switching element 20 along the positive electrode bus bar 14, and protrudes from the mold resin A. The gate G2 formed on the lower surface 20b of the switching element 20 is electrically connected to the gate signal terminal B2 by a wire W2 made of, for example, gold or copper.

  Most of the positive electrode bus bar 14 and the negative electrode bus bar 24 are arranged so as to face each other in close proximity (to run side by side). An insulating plate 30 is interposed between the positive electrode bus bar 14 and the negative electrode bus bar 24. Therefore, the positive electrode bus bar 14 and the negative electrode bus bar 24 are electrically insulated from each other by the insulating plate 30. The insulating plate 30 is formed in a long plate shape having a thickness of about 0.2 mm, for example, with a resin such as glass epoxy, ceramic, or the like.

  Here, the semiconductor device 1 further includes an output bus bar (lead frame: intermediate electrode) 40. The output bus bar 40 is formed in a substantially U-shaped plate shape by a single conductive member. One end 41 of the output bus bar 40 is joined to the upper surface 10b of the switching element 10 by a conductive adhesive 42 such as solder. The other end 43 of the output bus bar 40 is joined to the heat sink 21 by a conductive adhesive 44 such as solder.

  Therefore, the emitter E1 of the switching element 10 and the collector C2 of the switching element 20 are electrically connected via the conductive adhesive 42, the output bus bar 40, the conductive adhesive 44, and the heat sink 21. . That is, the semiconductor device 1 includes a single output bus bar 40 that electrically connects the emitter E1 formed on the upper surface 10b of the switching element 10 and the collector C2 formed on the upper surface 20a of the switching element 20. .

  As will be described later, the switching elements 10 and 20 are joined to both end portions 41 and 43 of the flat output bus bar 40 and then stacked in the vertical direction by bending the output bus bar 40 into a substantially U shape. And sealed with a mold resin A to form a module. An overlapping portion 45 generated when the output bus bar 40 is bent in a substantially U shape extends along the positive electrode bus bar 14 and the negative electrode bus bar 24 and protrudes from the mold resin A in the same manner as the positive electrode bus bar 14 and the negative electrode bus bar 24. Yes.

  Subsequently, a method for manufacturing the semiconductor device 1 will be described. 3, 4, and 5 are diagrams for explaining main steps of the method for manufacturing the semiconductor device shown in FIGS. 1 and 2. 3 to 5 are side views except that FIG. 4B is a plan view.

  In the method for manufacturing the semiconductor device 1 according to the present embodiment, first, as shown in FIG. 3A, the switching element 10 is joined to the heat sink 11 with the conductive adhesive 12, and the switching element 20 is It joins to the heat sink 21 with the conductive adhesive 22 (process S101). At this time, the collector C1 formed on the lower surface 10a of the switching element 10 is electrically connected to the heat radiating plate 11, and heat is radiated to the collector C2 formed on the upper surface (lower surface in FIG. 3) 20a. The plate 21 is electrically connected.

  Subsequently, the positive electrode bus bar 14, the negative electrode bus bar 24, the output bus bar 40, and the gate signal terminals B1 and B2 are prepared (first step). At this time, the output bus bar 40 is not bent into a substantially U shape, and has a substantially flat plate shape. Further, the positive electrode bus bar 14, the negative electrode bus bar 24, the output bus bar 40, and the gate signal terminals B1 and B2 are integrally formed with each other by being joined to a predetermined frame material.

  Subsequently, as shown in FIG. 3B, the positive electrode bus bar 14 is joined to one end portion of the heat radiating plate 11 by the conductive adhesive 13, and the lower surface (upper surface in FIG. 3) 20 b of the switching element 20. The negative electrode bus bar 24 is joined to the conductive adhesive 23 (step S102). In this step S102, one end 41 of the flat output bus bar 40 is joined to the upper surface 10b of the switching element 10 by the conductive adhesive 42, and the other end 43 is joined by the conductive adhesive 44 to the heat sink 21. (Step S102: second step).

  That is, in this process S102, the switching elements 10 and 20 are joined to the both ends 41 and 43 of the output bus bar 40 together with the joining of the positive electrode bus bars 14 and 15, respectively. Thereby, the emitter E1 of the switching element 10 and the collector C2 of the switching element 20 are electrically connected by the output bus bar 40.

  Subsequently, as shown in FIG. 4, the gate signal line B1 is electrically connected to the gate G1 of the switching element 10 by the wire W1, and the gate signal line B2 is electrically connected to the switching element 20 gate G2 by the wire W2. Connect (step S103).

  As described above, the positive electrode bus bar 14, the negative electrode bus bar 24, the output bus bar 40, and the gate signal terminals B1 and B2 are integrally formed of a predetermined frame material. For this reason, in this process S102 and process S103, the positive electrode bus bar 14, the negative electrode bus bar 24, the output bus bar 40, and the gate signal terminals B1 and B2 can be simultaneously disposed at predetermined positions and mounted from the same surface side. .

  Subsequently, the output bus bar 40 is bent by approximately 180 ° at a fold line (substantially central position in the longitudinal direction of the output bus bar 40) L shown in FIG. , 20 are arranged so as to be stacked in the vertical direction (step S104: third step). As a result, the positive electrode bus bar 14 and the negative electrode bus bar 24 run close to each other.

  In order to shorten the current path formed by the output bus bar 40, it is preferable to short-circuit the output bus bar 40 at the overlapping portion 45 of the output bus bar 40. For this purpose, for example, the overlapping portions 45 of the output bus bars 40 can be clamped so as to contact each other, or the overlapping portions 45 can be joined together by welding or the like.

  Subsequently, as shown in FIG. 2, after the insulating plate 30 is interposed between the positive electrode bus bar 14 and the negative electrode bus bar 24, the switching elements 10 and 20 are sealed with the mold resin A to form a module ( Fourth step). At this time, the overlapping portion 45 of the output bus bar 40 protrudes from the mold resin A.

  Thereafter, the positive electrode bus bar 14, the negative electrode bus bar 24, the output bus bar 40, and the gate signal terminals B1 and B2 are separated from the frame material and separated from each other, whereby the semiconductor device 1 is obtained. In addition, when each member is separated from the frame material, the cut portion may be exposed from the mold resin A. In this manufacturing method, the arrangement is such that exposure of the cut portion does not become a problem. However, in some cases, the cut portion may be sealed by potting or the like.

  As described above, in the semiconductor device 1 and the method for manufacturing the semiconductor device 1 according to the present embodiment, the switching element 10 bonded to each of the both end portions 41 and 43 of the single flat output bus bar 40, 20 are arranged so as to be stacked on each other by bending the output bus bar 40. And the overlapping part 45 of the output bus-bar 40 protrudes and extends from the mold resin A at the time of modularization.

  Therefore, it is not necessary to further join another member or the like to the output bus bar 40 (that is, no tool gap or the like is necessary for joining). Therefore, since it is possible to arrange switching elements 10 and 20 close to each other, it is possible to suppress an increase in the size of the apparatus, and it is possible to reduce the required amount of the mold resin A and suppress an increase in cost. . Furthermore, since the positive electrode bus bar 14 and the negative electrode bus bar 24 for connecting the switching elements 10 and 20 between the positive electrode P and the negative electrode N can be disposed close to each other, the coupling ratio between the positive electrode bus bar 14 and the negative electrode bus bar 24 By raising the parasitic inductance, it is possible to reduce the parasitic inductance.

  Furthermore, in the method for manufacturing the semiconductor device 1 according to the present embodiment, from one side (from the upper side in the figure) of the switching element 10 (heat radiation plate 11) and the switching element 20 (heat radiation plate 21), the positive electrode bus bar 14, the negative electrode bus bar. 24. The output bus bar 40 can be joined, and the workability is good. For the same reason, the positive electrode bus bar 14, the negative electrode bus bar 24, and the bus bar 40 integrated with each other by the frame material can be used (that is, they can be configured by the same lead frame). ), Workability is further improved.

  The above embodiment describes one embodiment of the semiconductor device and the method for manufacturing the semiconductor device according to the present invention. Therefore, the semiconductor device and the method for manufacturing the semiconductor device according to the present invention are not limited to the semiconductor device 1 and the method for manufacturing the semiconductor device 1 described above. The semiconductor device and the method for manufacturing the semiconductor device according to the present invention may be arbitrarily changed from the above-described ones within the scope not changing the gist of each claim.

  For example, although the said embodiment demonstrated the example which applied this invention when comprising the U phase of a three-phase inverter, the aspect of application of this invention is not limited to this. The present invention can be applied to any semiconductor device (for example, a converter) including a pair of switching elements that are electrically connected to each other.

  DESCRIPTION OF SYMBOLS 1 ... Semiconductor device, 10, 20 ... Switching element, 40 ... Output bus-bar (intermediate electrode), 41 ... One end part, 43 ... Other end part, 45 ... Overlapping part, A ... Mold resin.

Claims (2)

A semiconductor device comprising a pair of switching elements,
A single intermediate electrode that electrically connects a predetermined terminal of one of the switching elements and a predetermined terminal of the other switching element;
The switching elements joined to both ends of the substantially flat intermediate electrode are arranged so as to be stacked on each other by bending the intermediate electrode, and then sealed with a mold resin to be modularized. ,
The overlapping portion of the intermediate electrode generated by bending the intermediate electrode extends from the mold resin,
A semiconductor device. A method of manufacturing a semiconductor device comprising a pair of switching elements,
A first step of preparing a single intermediate electrode for electrically connecting a predetermined terminal of one of the switching elements and a predetermined terminal of the other switching element;
After the first step, a second step of bonding the switching element to each of both ends of the substantially flat intermediate electrode;
A third step of arranging the switching elements so as to be stacked on each other by bending the intermediate electrode after the second step;
After the third step, a fourth step of sealing the switching element with a mold resin to form a module,
The overlapping portion of the intermediate electrode generated by bending the intermediate electrode extends and protrudes from the mold resin when the switching element is sealed with the mold resin in the fourth step.
A method for manufacturing a semiconductor device.

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