JP2009130007A - Semiconductor device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a semiconductor device capable of sharing a die for forming a case made of a resin among a plurality of products and stably and accurately performing the wire bonding of an electrode, and the semiconductor device manufactured by that. <P>SOLUTION: The semiconductor device includes a semiconductor element, a first electrode having a first plane, a wire for connecting the prescribed position of the semiconductor element and the prescribed position of the first plane, a second electrode bonded with the first electrode, and a resin case which covers the first electrode so as to be exposed to the surface at a bonding part which is the part where the wire is connected on the first plane at least and is constituted of the resin for directly or indirectly supporting the semiconductor element. Then, the resin is in contact with the shear droop surface of the first electrode and the resin is not in contact with the shear droop surface of the second electrode. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a semiconductor device in which an electrode and a semiconductor element can be connected by wire bonding and can cope with a plurality of different electrode layouts, and a manufacturing method thereof.

  A semiconductor device on which a semiconductor element is mounted is often provided with a metal electrode that mediates an electrical connection between an external device and the semiconductor element. Such an electrode may be provided with an external device connecting portion which is a portion connected to an external device, and a wire spotting surface which is a surface to be connected to a semiconductor element by wire bonding.

  Here, in order to perform the above-described wire bonding stably and accurately, the wire bonding needs to be performed in a state where the wire spotting surface of the electrode is fixed. Therefore, the above-mentioned electrode is placed in a mold for forming a resin case of the semiconductor device, and resin is injected into the mold to simultaneously form the case of the semiconductor device and place the electrode. The manufacture of such a resin case is called insert formation. According to the insert formation, since the electrode is fixed at a predetermined position with good adhesion to the resin, wire bonding can be performed stably and accurately.

JP 2000-196011 A JP 2001-144251 A JP 2002-359348 A JP 2007-027467 A

  By the way, the layout of the electrodes described above varies from product to product. Therefore, when the above-described insert formation is performed, the above-described mold needs to be prepared for each electrode layout, that is, for each product. Therefore, there is a problem that the cost is high. On the other hand, in order to avoid the mold manufacturing for each electrode layout, it is conceivable that after forming the resin case of the semiconductor device, the electrode is attached to the case by a method such as press fitting. However, in this case, although manufacturing of a mold for each electrode layout can be avoided, there is a problem that stable and accurate wire bonding cannot be performed because of insufficient fixing of electrodes during wire bonding.

  The present invention has been made to solve the above-described problems, and a resin case forming mold can be shared among a plurality of products, and electrode wire bonding can be performed stably and accurately. It is an object to provide a method for manufacturing a semiconductor device and a semiconductor device manufactured thereby.

  A semiconductor device according to the invention of the present application is joined to a semiconductor element, a first electrode having a first plane, a wire connecting a predetermined position of the semiconductor element and a predetermined position of the first plane, and the first electrode. A resin that covers the first electrode so that the second electrode and at least the bonding portion to which the wire on the first plane is connected are exposed on the surface and directly or indirectly support the semiconductor element And the resin is in contact with the sag surface of the first electrode, and the resin is not in contact with the sag surface of the second electrode.

  A method of manufacturing a semiconductor device according to the invention of the present application includes a first electrode placement step of placing a first electrode having a bonding portion to be wire-bonded in a molding die, and a bonding portion after the first electrode placement step. A resin injection step of injecting a resin covering the first electrode into the molding die so as not to contact, a cooling step of solidifying the resin after the resin injection step, and an external device after the cooling step A bonding step of bonding a second electrode having a connection portion to the first electrode, a semiconductor element mounting step of mounting a semiconductor element at a predetermined position of the case, and a predetermined position of the semiconductor element and the bonding portion by a wire And a wire bonding step of connecting.

  According to the present invention, a mold for forming a resin case of a semiconductor device can be shared among a plurality of products, and wire bonding of electrodes can be performed stably and accurately.

Embodiment 1
The present embodiment relates to a semiconductor device including wire-bonded electrodes, and more particularly to a semiconductor device that can cope with a plurality of electrode layouts and a manufacturing method thereof. The semiconductor device of this embodiment is a power device semiconductor device. First, the configuration of the power device semiconductor device of this embodiment will be outlined with reference to FIG.

  FIG. 1 is a perspective view for explaining the configuration of a power device semiconductor device 10 of the present embodiment. As shown in FIG. 1, the power device semiconductor device 10 of the present embodiment includes a base plate 11 to be the foundation. The base plate 11 is made of a material having a good heat dissipation property such as a metal and radiates heat from the power device semiconductor device 10. A resin case 12 is disposed on the base plate 11 in contact with the base plate 11. The resin case 12 is a case (housing) for the power device semiconductor device 10 of the present embodiment. The resin case 12 has a box shape having one open surface, and fixes or supports a semiconductor element, an electrode, and the like, which will be described later, inside the resin case 12.

  The power device semiconductor device 10 includes an insulating substrate 18. The insulating substrate 18 is mounted on the resin case 12 in order to insulate semiconductor elements described later. Further, the semiconductor element 15 is mounted on the insulating substrate 18. The semiconductor element 15 of the present embodiment is a power device such as an IGBT.

  The power device semiconductor device 10 further includes an external electrode 13 and an internal electrode 14. The external electrode 13 and the internal device 14 are connected to form an integral electrode. One end of this electrode is an end to be electrically connected to an external device (not shown) to which the power device semiconductor 10 is connected. On the other hand, the other end of this electrode is connected to the semiconductor element 15 by a wire 16. The above is the description of the overview of the power device semiconductor device 10 of the present embodiment. Hereinafter, a more detailed configuration of the present invention will be described with reference to FIG.

  FIG. 2 is an enlarged view for explaining the vicinity of the outer periphery of the resin case 12 included in the power semiconductor device 10. Here, the I part on the right side of the broken line in FIG. 2 will be described. As described above, the external electrode 13 and the internal electrode 14 are joined to form the electrode 64. This joining is performed by soldering the joining portion between the external electrode 13 and the internal electrode 14 with the solder 17. Thus, the external electrode 13 and the internal electrode 14 are joined to form an electrode 64. Here, a portion of the electrode 64 that was an external electrode before the above-described bonding is referred to as a post-bonding external electrode 65. Further, a portion of the electrode 64 that was an internal electrode before the above-described bonding is referred to as a post-bonding internal electrode 66. That is, the electrode 65 is formed by joining the external electrode 65 after bonding and the internal electrode 66 after bonding together.

  As can be seen from the part I in FIG. 2, the position of the post-joining external electrode 65 is fixed by the resin protrusion 24 in addition to being joined to the post-joining internal electrode 66 by the solder 17. The resin protrusion 24 is a part of the resin case 12 and is a protrusion having a bowl-shaped tip. On the other hand, after bonding, the internal electrode 66 is fixed by being disposed so as to be embedded by the resin case 12. Further, the arrangement position of the internal electrode 66 after bonding is also fixed by the longitudinal resin 22 which is a part of the resin case 12. In the present embodiment, the longitudinal resin 22 is disposed so as to longitudinally cut the surface (wire striking surface) exposed on the surface of the internal electrode 66 after bonding.

  The electrode 64 is fixed as described above. And the wire 20 is connected to predetermined positions other than the place where the longitudinal resin on the above-mentioned wire hitting surface is arrange | positioned. The wire 20 connects the semiconductor element 15 and a predetermined position on the wire striking surface.

  The power device semiconductor device 10 that is the semiconductor device of the present embodiment has the above-described configuration. A process for manufacturing such a power device semiconductor device will be described with reference to FIG. FIG. 3 is a flowchart for explaining a characteristic process among the manufacturing steps for manufacturing the power device semiconductor device described so far. First, in step 100, the internal electrode is disposed at a predetermined position of the molding die. Here, the molding die refers to a die used for injecting a molding resin into the inside to form a resin case.

  When the process of step 100 is completed, the process proceeds to step 102. In step 102, resin is injected into the above-described molding die. At this time, the internal electrode is disposed so as to be covered with the resin, but the resin is injected so that the resin does not adhere to a predetermined position on the wire striking surface where the wire is to be connected in the future. On the other hand, the resin is injected so that the longitudinal resin 22 adheres to the place where the longitudinal resin 22 on the wire striking surface is to be formed.

  When the process of step 102 is completed, the process proceeds to step 104. In step 104, the resin injected into the molding die in step 102 is cooled. This cooling may be performed using a cooler or air cooling. When this cooling is finished, the resin has been solidified, and a resin case having the above-mentioned internal electrodes at predetermined positions is molded. Hereinafter, such an arrangement of the (internal) electrode in the resin case simultaneously with the molding of the resin case by the solidification of the resin is referred to as “insert formation”. In the present embodiment, the internal electrode is formed by insert through the processes up to step 104.

  When the process of step 104 is completed, the process proceeds to step 106. In step 106, the insulating substrate is disposed at a predetermined position of the resin case, and the semiconductor element is mounted at a predetermined position on the insulating substrate.

  When the process of step 106 is finished, the process proceeds to step 108. In step 108, the predetermined position of the semiconductor element and the predetermined position of the wire spot surface provided in the internal electrode are connected by wire bonding.

  When the process of step 108 is completed, the process proceeds to step 110. In step 110, bonding (connection) of the external electrode to the internal electrode is performed. The connection of the external electrode to the internal electrode in step 110 will be described using the II part shown on the left side of the broken line in FIG. The internal electrode 14 in part II of FIG. 2 has a hole 26 into which an external terminal is to be inserted before step 110 processing. The external electrode 13 is inserted into the hole 26 so as to pass through the resin protrusion 24 from the outside of the resin case 12 as indicated by an arrow II in FIG. When this insertion is completed, the external electrode is pressed into the hole 26 with an arbitrary pressure. Thereafter, fixing with the solder 17 is performed in order to strengthen the bonding between the internal electrode 14 and the external electrode 13. When the above-described soldering is completed, an electrode 64 including a post-joining external electrode 65 and a post-joining internal electrode 66 is formed as shown in part I of FIG. Inserting and fixing an electrode from the outside of the resin case after the resin case is formed in this way is referred to as “outsert formation”. The external electrode of this embodiment is formed outsert as described above.

  Here, a comparative example will be described in order to understand the features of the present embodiment. FIG. 4 is a diagram for explaining a semiconductor device of a comparative example and a manufacturing method thereof. The external internal integrated electrode 62 which is an electrode of the semiconductor device of the comparative example is made of a continuous and integral material, and is not divided at the initial stage of the process as in this embodiment. Therefore, the electrode of the comparative example has no joint. This is as shown in part I of FIG. The position of the external internal integrated electrode 62 of the comparative example is fixed by fitting it into the resin protrusion 58 having a bowl-shaped portion and the groove 60 formed in the resin case 52. In addition, also in the comparative example, the point in which the electrode 62 is provided with a wire hitting surface is the same as the structure of this embodiment. Further, the point where the wire striking face and the predetermined position of the semiconductor element are connected by a wire is the same as the configuration of the present embodiment.

  Part II shown on the left side of the broken line in FIG. 4 is a diagram for explaining a method of arranging the external internal integrated electrode 62 of the comparative example. The external internal integrated electrode 62 of the comparative example is insert-formed in the direction indicated by the arrow in the II part of FIG. That is, the integrally formed external internal integrated electrode 62 is attached to the resin case after the resin case 52 is formed. Problems in the semiconductor device shown in the comparative example are as follows. That is, since the external internal integrated electrode having the wire striking surface is formed outsert, the external internal integrated electrode is not sufficiently fixed. If the fixing of the wire striking surface is insufficient, the wire striking surface may swing in the subsequent wire bonding step, which may cause problems such as poor connection of the wire.

  In order to solve the above-described problem of the comparative example, it is also conceivable to form an external internal integrated electrode. When the external internal integrated electrode is formed by insert, the above-mentioned problem can be solved since the wire striking surface is sufficiently fixed during wire bonding. However, in order to insert and form the external internal integrated electrode, a molding die must be prepared for each (external internal integrated) electrode layout. Therefore, when the electrode layout is arranged as required by the end user, or when manufacturing a plurality of products with different electrode layouts in series, the number of molds to be prepared increases, which is not preferable from the viewpoint of manufacturing cost. . In this way, the external internal integrated electrode has left a problem whether it is formed by insert insertion or outsert formation.

  The semiconductor device and the manufacturing method thereof according to this embodiment can solve the above-described problems. In the present embodiment, the electrode is divided into “internal electrode formed by insert” and “external electrode formed by outsert”, and both are joined in the course of the manufacturing process. And since the internal electrode is insert-formed and is fixed by the longitudinal resin, the wire striking surface does not swing during the wire bonding. Accordingly, wire bonding can be stably and accurately performed at a predetermined position on the wire striking surface. Here, the reason why stable and accurate wire bonding can be performed by forming the insert will be described with reference to FIGS. First, FIG. 5 will be described. FIG. 5 is a diagram illustrating the internal electrodes 14 and the like from the direction indicated by the black arrows in FIG. Here, the electrode is generally manufactured by pressing a metal plate into a desired size. Along with the pressing, a curved portion called a sag surface is generated at the corner of the electrode. The above-described sagging surface also occurs in the internal electrode 66 after bonding, and such sagging surface is expressed as the sagging surface 70. In this embodiment, since the internal electrode 66 after insertion is formed by insertion, the resin reaches the sag surface 70, and the sag surface 70 is in contact with and covered with the resin.

  On the other hand, FIG. 6 is a diagram illustrating a part of the semiconductor device of the comparative example, in which the external internal integrated electrode 62 and the like are drawn from the direction indicated by the black arrow in FIG. As in FIG. 5, the sagging surface of the external internal integrated electrode 62 is also illustrated as the sagging surface 70 in FIG. 6. Since the external internal integrated electrode 62 of the comparative example is formed outsert, the resin does not reach the sag surface 70. Accordingly, a gap 72 is generated between the sag surface 70 and the resin case 52. In this way, when the internal electrode is formed as an outsert, the resin does not reach the sag surface, but when the internal electrode is formed as an insert, the resin contacts (adheres) to the sag surface, so the internal electrode is firmly fixed by the resin case. It can be said that. Therefore, when the insert is formed, the electrode (in this case, the internal electrode) and the resin case are firmly fixed, and stable and accurate wire bonding can be performed.

  Further, according to the method for manufacturing a semiconductor device of the present embodiment, it is possible to insert a large number of internal electrodes and not join external electrodes to predetermined internal electrodes. That is, an internal electrode that can correspond to a plurality of electrode layouts is manufactured by insert formation, and the external electrode can be outserted so as to correspond to a specific electrode layout in the subsequent process of outsert the external electrode. . Therefore, it is possible to cope with a plurality of electrode layouts with one molding die. This is advantageous from the viewpoint of manufacturing cost because it is not necessary to prepare a molding die for each electrode layout.

  In addition, since the longitudinal resin of the present embodiment is arranged so as to longitudinally cut the internal electrode after joining, when joining the internal electrode and the external electrode by solder, the solder reaches the portion where the wire on the wire striking surface is joined. It can suppress spreading.

  The shapes of the internal electrode and the external electrode of this embodiment are not limited to those described in this embodiment. That is, since the internal electrode is insert-formed and the external electrode is outsert-formed, and wire bonding is performed on a part of the internal electrode, the effect of the present invention can be obtained, so the shape of the internal electrode and the external electrode is arbitrary. .

  In the present embodiment, the external terminals are outsert formed after wire bonding, but either of these may be performed first because the effect of the present invention can be obtained even if this order is reversed.

  In this embodiment, both press-fitting and soldering are used for joining the internal electrode and the external electrode. However, the present invention is characterized in that the internal terminal and the external terminal are divided and later both are joined. Therefore, the bonding method may be appropriately determined in consideration of necessary bonding strength.

  In this embodiment, the longitudinal resin is disposed for supplementary fixing of the internal electrodes and prevention of diffusion of the solder to the predetermined point of the wire striking surface, but this is not an essential component of the present invention. That is, if the longitudinal resin is disposed only for the purpose of fixing the internal electrode, the longitudinal resin may be disposed on the wire striking surface as “fixing resin” without vertically traversing the wire striking surface. Further, if the longitudinal resin is disposed only for the purpose of preventing the diffusion of solder, the longitudinal resin having a narrower width than that shown in FIG. 2 may be used, or it may be integrally formed linearly with the adjacent longitudinal resin. It may be a thing. Therefore, the shape of the longitudinal resin is not particularly limited.

2 is a diagram illustrating a configuration of a power device semiconductor device according to Embodiment 1. FIG. FIG. 3 is a diagram for explaining an electrode of the power device semiconductor device according to the first embodiment and its vicinity. The figure explaining the process of manufacturing the power device semiconductor device of Embodiment 1. FIG. It is a figure for demonstrating the semiconductor device of a comparative example, and its manufacturing method. 3A and 3B illustrate a sag surface according to Embodiment 1; The figure explaining the sagging surface of a comparative example.

Explanation of symbols

12 Resin Case 13 External Electrode 14 Internal Electrode 15 Semiconductor Element 17 Solder 20 Wire 22 Longitudinal Resin 70 Sag Surface

Claims (4)

A semiconductor element;
A first electrode comprising a first plane;
A wire connecting a predetermined position of the semiconductor element and a predetermined position of the first plane;
A second electrode joined to the first electrode;
A resin case made of a resin that covers the first electrode so that at least the bonding portion to which the wire on the first plane is connected is exposed on the surface and supports the semiconductor element directly or indirectly And
The resin contacts the sag surface of the first electrode,
A semiconductor device, wherein the resin does not contact the sagging surface of the second electrode.   The semiconductor device according to claim 1, wherein the resin is integrally formed so as to be disposed on the first plane excluding the bonding portion.   The semiconductor device according to claim 1, wherein the resin is disposed so as to cut the first plane vertically to the first plane excluding the bonding portion. A first electrode arrangement step of arranging a first electrode having a bonding part to be wire-bonded in a molding die;
After the first electrode placement step, a resin injection step of injecting a resin covering the first electrode into the molding die so as not to contact the bonding part,
After the resin injection step, a cooling step for solidifying the resin;
After the cooling step, a bonding step of bonding a second electrode having a connection portion with an external device to the first electrode;
A semiconductor element mounting step of mounting a semiconductor element at a predetermined position of the case;
A wire bonding step of connecting a predetermined position of the semiconductor element and the bonding portion with a wire;
A method for manufacturing a semiconductor device, comprising:

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