JP2011103312A - Semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device that secures high reliability at even a high temperature region by: decreasing a thermal resistance in a peripheral region of a semiconductor element; and also decreasing a thermal stress of the semiconductor element. <P>SOLUTION: Two electrodes are provided on both sides of the semiconductor device, respectively, and a plurality of slits are provided on each of the sides thereof opposite to the junction surface of the two electrodes. Bending rigidity is lowered and the directions of the slits of the two electrodes are displaced by 90° to be vertical. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a semiconductor device, and more particularly to a semiconductor device suitable for a rectifier of a vehicular rotary generator.

  FIG. 4 shows a general structure of a semiconductor device which is a rectifier of a vehicular rotary generator.

  As shown in the figure, the semiconductor device includes a semiconductor element 1, a first electrode 3 and a second electrode 5 having conductivity, and bonding materials 2 and 4 for bonding them are stacked, and the periphery is sealed. The structure is covered with a stopper 6.

  The semiconductor element 1 has a very small coefficient of linear expansion, and the first and second electrodes 3 and 5 often have a coefficient of linear expansion several times that of the semiconductor element 1. Therefore, when a temperature change is given to the semiconductor device, the semiconductor element 1 and the bonding material 6 generate thermal stress due to the difference in linear expansion coefficient between the semiconductor element 1 and the first and second electrodes 3 and 5. However, if an excessive thermal stress is applied to the semiconductor element 1 or the bonding materials 2 and 4, they may be broken.

  As a structure for ensuring the reliability of the joint portion, as shown in Patent Document 1, a structure in which a component having a linear expansion coefficient intermediate between the semiconductor element and the component is inserted and thermal stress is dispersed, or as shown in Patent Document 2 is shown. Thus, a structure for reducing the rigidity of the electrode has been proposed.

U.S. Pat. No. 4,349,831 JP 2006-190728 A

  In recent years, in the field of power semiconductors, there has been an increasing demand for operation in a higher temperature range than in the past due to the acceleration of the electrification of automobiles and the development of next-generation semiconductor elements. As the operating temperature of the power semiconductor device increases, the thermal stress generated in the semiconductor element is expected to increase more than ever.

  On the other hand, development of lead-free products is being promoted to realize an environmental society. Since lead-free bonding materials tend to be harder as the heat resistance is higher, selecting a lead-free bonding material that can withstand higher operating temperatures in the future inevitably increases the thermal stress generated in the semiconductor element. As a result, the present situation is that the reliability of the semiconductor element cannot be sufficiently ensured only by structural measures as shown in Patent Documents 1 and 2.

  Accordingly, an object of the present invention is to provide a semiconductor device that can ensure high reliability even in a high temperature region by reducing the thermal resistance of the periphery of the semiconductor element and reducing the thermal stress of the semiconductor element. is there.

  In order to achieve the above object, a semiconductor device of the present invention includes a semiconductor element, a first electrode bonded to the semiconductor element via a bonding material, and a semiconductor element opposite to the first electrode. In a semiconductor device comprising a second electrode bonded via a bonding material, a slit is provided in parallel to the opposite side of the bonding surface of the semiconductor element in the first electrode, and in the second electrode A slit is provided in parallel to the side opposite to the semiconductor element bonding surface, and the direction of the slit of the first electrode and the direction of the slit of the second electrode is orthogonal or shifted by 90 degrees. To do.

  According to the present invention, even when the temperature of the semiconductor device rises and each member around the connection portion thermally expands, the bending rigidity of the electrodes on both sides is shifted by 90 degrees, so that warpage deformation occurs on both sides of the semiconductor element. Since the direction is shifted by 90 degrees and the force can be released without restraining the warp deformation of each other, the thermal resistance of the periphery of the semiconductor element can be reduced, and the thermal stress of the semiconductor element can also be reduced. However, a semiconductor device that can ensure high reliability can be obtained.

1 is a perspective view showing a semiconductor device according to a first embodiment of the present invention and a partial enlarged sectional view thereof. The semiconductor device in the 2nd example of the present invention is shown, (a) is a section front view and (b) is a section side view. The semiconductor device in the 3rd example of the present invention is shown, (a) is a section front view and (b) is a section side view. It is principal part sectional drawing which shows the conventional semiconductor device.

  A structure that can reduce the thermal resistance of the periphery of the semiconductor element and reduce the thermal stress of the semiconductor element can be realized with a simple configuration.

  FIG. 1 shows a semiconductor device according to a first embodiment of the present invention.

  The semiconductor device of the first embodiment shown in FIG. 1 includes a semiconductor element 1, a conductive first electrode 3 and a second electrode 5 as in the prior art, and a bonding material 2 for bonding them. , 4 are stacked and the periphery is covered with a sealing material (not shown).

  In this embodiment, a slit 3 a is provided in parallel to the opposite side of the first electrode 3 to the bonding surface of the semiconductor element 1, and on the opposite side of the second electrode 5 to the bonding surface of the semiconductor element 1. Also, slits 5a are provided in parallel, and the slits 3a and 5a are provided so as to be orthogonal to each other, that is, shifted by 90 degrees. It should be noted that module mounting parts are not omitted.

  Here, although Si is used for the semiconductor element 1, the effect of the present invention is not lost even in the case of SiC or GaN. In addition, although Ag sintered material is used for the joining materials 2 and 4, Sn—Sb solder, Sn—Cu solder, Bi—Ag solder, Zn—Al solder, Ag and Cu solder are used. Even in the case of materials, sintered materials, and paste materials, the effects of the present invention are not lost. Although the first and second electrodes 3 and 5 are made of Cu, Ag or other materials may be used.

  With the configuration of this embodiment, even if the temperature of the semiconductor device rises and each member around the connection portion thermally expands, the bending rigidity of the electrodes on both sides is shifted by 90 degrees. The direction of the warp deformation is shifted by 90 degrees on both sides of the element, and the force can be released without restraining the warp deformation. Furthermore, it is possible to increase the heat capacity and reduce the temperature rise of the semiconductor element compared to the case where the electrode is uniformly thinned by slitting the electrode and providing a part with a large plate thickness. It becomes. As a result, it is possible to reduce the thermal stress generated in the semiconductor element.

  FIG. 2 shows a semiconductor device according to the second embodiment of the present invention.

  The semiconductor device of the second embodiment shown in FIG. 2 has substantially the same structure as that of the first embodiment shown in FIG. 1 except that the first electrode material 3 has a terminal connection region. 3b is provided, and the second electrode 5 is provided with a wall 5b for press-fitting into the radiating fin.

  Even in this configuration, the effect of this embodiment is the same as that of the first embodiment described above.

  A present Example is an example which shows that it can apply to the rectifier of a rotary generator for vehicles, etc.

  FIG. 3 shows a semiconductor device according to a third embodiment of the present invention.

  The difference from the second embodiment shown in FIG. 2 is that the second electrode 5 is connected to the case material 7 because it is press-fitted into the radiation fin. The second electrode 5 and the case material 7 can obtain the same effect by either direct bonding such as welding or indirect bonding via a bonding material.

  Here, the second electrode 5 and the case material 7 are preferably made of the same material.

DESCRIPTION OF SYMBOLS 1 Semiconductor element 2, 4 Bonding material 3 1st electrode 3a, 5a Slit 3b Area | region 5 for terminal connection 2nd electrode 5b, 7a Wall part 6 Sealing material 7 Case material

Claims (5)

A semiconductor element; a first electrode bonded to the semiconductor element via a bonding material; and a second electrode bonded to the semiconductor element opposite to the first electrode via a bonding material. In semiconductor devices
A slit is provided in parallel to the opposite side of the bonding surface of the semiconductor element in the first electrode, a slit is provided in parallel to the opposite side of the bonding surface of the semiconductor element in the second electrode, and the first The semiconductor device is characterized in that the direction of the slit of the electrode and the direction of the slit of the second electrode are orthogonal. A semiconductor element; a first electrode bonded to the semiconductor element via a bonding material; and a second electrode bonded to the semiconductor element opposite to the first electrode via a bonding material. In semiconductor devices
A slit is provided in parallel to the opposite side of the bonding surface of the semiconductor element in the first electrode, a slit is provided in parallel to the opposite side of the bonding surface of the semiconductor element in the second electrode, and the first The semiconductor device is characterized in that the orientation of the slit of the electrode and the slit of the second electrode is shifted by 90 degrees. The semiconductor device according to claim 1 or 2,
A region for connecting a terminal is provided in the first electrode material, and a wall portion is provided in the second electrode for press-fitting into a radiation fin. The semiconductor device according to claim 1 or 2,
The semiconductor device, wherein the second electrode is connected to a case material for press-fitting into the heat radiation fin. The semiconductor device according to claim 4,
The semiconductor device, wherein the second electrode and the case material are the same material.

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