JP2008103382A - Semiconductor device and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device in which junction between a metal plate and a semiconductor element is hardly peeled, and to provide a manufacturing method thereof. <P>SOLUTION: The semiconductor device 10 is provided with a semiconductor element having front and rear surfaces; at least a pair of metal plates 12 respectively joined to the front and rear surfaces of the semiconductor element, and configuring an external electrode; and a sealing portion 14 provided so as to expose surfaces 12a opposite to junction surfaces of the pair of metal plates where the semiconductor element is joined, and cover the other portion. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a semiconductor device and a manufacturing method thereof.

  Conventionally, there is a semiconductor device in which a plurality of semiconductor elements are sandwiched between a pair of metal plates and separated by dicing (see, for example, Patent Document 1).

However, such a semiconductor device has a problem that the metal plate and the semiconductor element are easily peeled off when thermal stress is applied. Further, in this method of manufacturing a semiconductor device, since there is a blade cutting step, the semiconductor device is likely to fall down due to a load during cutting, so that it may be detached from the dicing tape or cut into a distorted shape.
JP 2004-14811 A

  An object of the present invention is to provide a semiconductor device in which the bonding between a metal plate and a semiconductor element is difficult to peel off, and a method for manufacturing the same.

  According to one aspect of the present invention, a semiconductor element having a front surface and a back surface, at least a pair of metal plates that are respectively joined to the front surface and the back surface of the semiconductor element and constitute an external electrode, and the pair of metal plates There is provided a semiconductor device comprising: a sealing portion that is provided so as to expose a surface opposite to a bonding surface with respect to a semiconductor element and to cover other portions.

  According to another aspect of the present invention, a step of collectively bonding a semiconductor element to each main surface of the plurality of first metal plates; a second surface on each main surface of the semiconductor element; A step of bonding metal plates together to form a plurality of laminates, a step of attaching a sealing material to each peripheral side surface of the plurality of laminates, and the semiconductor element of the second metal plate And a step of removing the sealing material adhering to the opposite main surface. A method of manufacturing a semiconductor device is provided.

  According to the present invention, it is possible to provide a semiconductor device in which the metal plate and the semiconductor element are hardly separated from each other.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a perspective view showing an embodiment of a semiconductor device of the present invention, FIG. 2 is a longitudinal side view, and FIG. 3 is a cross-sectional view taken along line AA of FIG.

  The semiconductor device 10 includes a semiconductor element 11, a pair of metal plates 12 and 13 made of a metal such as copper bonded to the front and back surfaces of the semiconductor element 11, and the outer periphery of the semiconductor element 11 and the metal plates 12 and 13. And a sealing portion 14 that is sealed so that only the surfaces 12a and 13a of the metal plates 12 and 13 are exposed.

  For example, a PN junction diode is used as the semiconductor element 11. The metal plate 12 is electrically and mechanically joined to one surface of the semiconductor element 11 over almost the entire surface, and metal bumps 15 are provided on the opposite surface, and another metal plate 13 is attached to the metal bump 15. It is joined. A sealing portion 14 made of an insulating material is formed in the outer peripheral surface of the semiconductor element 11 and each metal plate 12 and the gap 16 around the metal bump 15. As a result, only the surfaces (surfaces opposite to the bonding surface to the semiconductor element 11) 12a, 13a of the metal plates 12, 13 are exposed surfaces, and the other portions are sealed. As a sealing material for the sealing portion 14, an insulating material such as resin, glass, or ceramic can be used.

  The semiconductor device 10 can be mounted by connecting the metal plates 12 and 13 to the substrate 35 via the solder 36. According to the present embodiment, the metal plates 12 and 13 having substantially the same size as the semiconductor element 11 are bonded to both surfaces of the semiconductor element 11, and as a result, an extremely compact semiconductor device having the same size as the semiconductor element 11 can be realized. . In addition, since the peripheral side surface is sealed with resin or the like until reaching the side surfaces of the metal plates 12 and 13, it is possible to prevent the bonded metal plates 12 and 13 from being peeled off due to thermal stress, etc. Durability is also improved and high reliability can be obtained.

  4 and 5 show the manufacturing process of the semiconductor device 10 of the first embodiment.

  As shown in FIG. 4A, a metal plate 13 made of a conductor such as copper is aligned with the first chuck jig 21, and the first chuck jig 21 is fed and sucked. The chuck jig 21 is preferably an electrostatic chuck, but the type of the chuck jig is not limited as long as it can hold an article with an attractive force. When the chuck jig 21 is an electrostatic chuck, an attracting force generating electrode is built in, and is supplied with power through a power feeding terminal (not shown), and by means such as a built-in heater. A heating mechanism for uniformly heating the surface is also incorporated.

  Next, as shown in FIG. 4B, the semiconductor element 11 to which the metal bumps 15 such as gold and solder are joined is aligned with the second chuck jig 22 at the same pitch as the first metal plate 13. Adsorb.

  Next, as shown in FIG. 4C, the second chuck jig 22 is opposed to the upper side of the first chuck jig 21 with the semiconductor element 11 facing downward. At this time, both the first and second chuck jigs 21 and 22 are heated to a bonding temperature of about 200 ° C., and the metal bumps 15 and the first metal plate 13 are brought into pressure contact with each other for electrical and mechanical use. Jointly.

  Next, the power supply to the second chuck jig 22 is turned off, and the second chuck jig 22 is removed from the semi-finished product, and as shown in FIG. After the metal plate 12 is aligned and adsorbed to the third chuck jig 23, the third chuck jig 23 is rotated, and the metal plate 12 faces downward so as to cover the semiconductor element 11 and join. At this time, the chuck jigs 21 and 23 are set in the vicinity of the eutectic temperature of the back surface of the semiconductor element 11 and the metal plate 12 (for example, about 350 ° C.). In this way, a plurality of laminated bodies each formed of the metal plates 12 and 13 and the semiconductor element 11 are formed.

  Next, as shown in FIG. 5 (e), the laminated body 10 a with the first chuck jig 21 removed is a sealing material having a viscosity of, for example, several poises in the resin tank 25. Immerse in resin 24.

  Next, as shown in FIG. 5F, when the semiconductor device main body 10a is pulled up from the resin tank 25 after a predetermined time (for example, several seconds), the resin 24 adheres only to the periphery of the stacked body 10a due to its surface tension. . The resin 25 is cured by placing it in an oven (not shown) set at a temperature of about 150 ° C. or by raising the temperature of the third chuck jig 23 to about 150 ° C.

  Next, the resin burr 24a attached to the surface of the metal plate 13 in this sealing process is removed by a deburring process such as honing (not shown), as shown in FIG. 5 (g) and FIG. Thus, the semiconductor device 10 in which the sealing portion 14 made of the resin 24 is formed on the peripheral surfaces of the metal plates 12 and 13 and the semiconductor element 11 is obtained.

  Ni—Au plating is applied to the bonding surface side (semiconductor element 11 side) of the metal plates 12 and 13 to ensure the bonding between the metal plate 13 and the metal bump 15 and between the metal plate 12 and the semiconductor element 11. Can do. In addition, the adhesion of the resin can be minimized by making the surface (outer surface) opposite to the Ni—Au plating bonding surface of the metal plates 12 and 13 Ni-plating that is difficult to adhere to the resin. At the same time, the resin can be easily removed in the deburring step.

FIG. 6 shows another sealing method.
After the bonding step of FIG. 5D, instead of immersing in the resin tank 25, the third chuck jig 23 is rotated so that the semiconductor device body 10a faces upward, and the resin nozzle 24 is applied to each semiconductor device by the coating nozzle 26. Supply to the main body 10a and apply. In this case, the surface of the third chuck jig 23 is covered with a fluorine-based surface treatment or a fluorine-based sheet that does not easily adhere to the resin, so that the chuck jig 23 is difficult to get wet with the resin, and the adjacent semiconductor device body It can prevent that resin connects between 10a.

  In addition, although the example which uses resin 24 as a sealing material was demonstrated in the said sealing process, insulating materials, such as glass and a ceramic other than resin, can be used as a sealing material.

  Prior to the step of bonding the metal plates 12 and 13 to the semiconductor element 11, impurities on the surfaces of the metal plates 12 and 13 are removed by a method such as plasma cleaning, so that a plurality of the plates are securely bonded together. Can do.

  7 and 8 are plan views of the semiconductor device according to the second embodiment, and are examples in the case where the semiconductor element 11 is a transistor having three electrodes.

  As shown in the figure, the semiconductor element 11 is a transistor including, for example, a drain electrode 27 on one surface and, for example, a gate electrode 28 and a source electrode 29 on the other surface. As shown in the figure, a first metal plate 30 is electrically and mechanically joined to the drain electrode 27 side, and a second metal plate 31 is joined to the gate electrode 28 and source electrode 29 side. And the third metal plate 32 is electrically and mechanically joined to the source electrode 29. The substrate mounting surfaces (upper and lower surfaces in FIG. 7) of the metal plates 30, 31, and 32 are the same plane, and the mounting surfaces can be brought into contact with the substrate 35 for mounting.

  Also in this embodiment, the size of the semiconductor device completed by joining the metal plates 30, 31, and 32 is approximately the same as that of the semiconductor element 11, and a so-called chip-sized compact semiconductor device can be realized.

  FIG. 9 shows, as a comparative example, a method for manufacturing a small-sized semiconductor device having metal plates to be external electrodes on both sides of a semiconductor element.

  This semiconductor device is manufactured as follows. A long metal plate 41 is bonded to one surface of the semiconductor element 40, and a long metal plate 43 is bonded to the other surface via metal bumps 42. A sealing material such as a resin is formed between the metal plates 41 and 43. By forming the sealing part 44 by this, a long semi-finished product is produced, this is mounted on the dicing tape 45, and it cut | disconnects with the blade 46, and the semiconductor device 47 is obtained.

  In such a semiconductor device, when the outer dimension is 060303 (0.6 × 0.3 × 0.3 mm), the vertical and horizontal dimensions W of the metal plates 41 and 43 are 0.3 mm, and the height H is 0. .6 mm, which is a vertically long dimension, the semiconductor device 47 is likely to fall during cutting with the blade 46, so that it may come off the dicing tape 45 or be cut into a distorted shape. In the completed semiconductor device 47, the sealing portion 44 is only between the metal plates 41 and 43, and the bonding area of the sealing material is small. Therefore, the metal plates 41 and 42 and the semiconductor element 40 are detached when thermal stress occurs. Cheap.

  On the other hand, in the semiconductor device of the present embodiment, the metal plates 12, 13 or the metal plates 30, 31, 32 are directly joined to both side surfaces of the semiconductor element 11, and the metal plates 12, 13, 30, 31, 32 are joined. Since the sealing portion 14 is formed so as to expose only the surface opposite to the bonding surface to the semiconductor element 11 and cover the other portions, the metal plates 12, 13, 30, 31, 32 serving as external electrodes are formed. Is enclosed by the sealing portion 14, and when the thermal stress is applied, the resistance to stress that the metal plates 12, 13, 30, 31, 32 and the semiconductor element 11 are likely to come off can be increased.

  Further, in the semiconductor device manufacturing method of this embodiment, the individual semiconductor device main bodies 10a are manufactured and sealed in units of these semiconductor device main bodies 10a, so that the cutting step by the blade can be eliminated. As shown in FIG. 9, the phenomenon of cutting into a distorted shape is eliminated, and a highly accurate semiconductor device is obtained.

1 is a perspective view of a semiconductor device according to an embodiment of the present invention. It is a vertical side view of the semiconductor device concerning a 1st embodiment. It is the sectional view on the AA line of FIG. It is a manufacturing process figure of the semiconductor device concerning a 1st embodiment. FIG. 5 is a manufacturing process diagram for the semiconductor device according to the first embodiment, following FIG. 4; It is a sealing process figure which shows the other example of the sealing method. It is a vertical side view of the semiconductor device concerning 2nd Embodiment. FIG. 8 is a sectional view taken along line BB in FIG. It is sectional drawing which shows the manufacturing method of the general semiconductor device by a blade dicing method.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Semiconductor device, 11 Semiconductor element, 12, 13, 30, 31, 32 Metal plate, 12a, 13a Exposed surface, 14 Sealing part, 15 Metal bump, 21 1st chuck jig 22 2nd chuck jig, 23 Third chuck jig 16 Resin (sealing material), 27 Drain electrode, 28 Gate electrode, 29 Source electrode

Claims (5)

A semiconductor element having a front surface and a back surface;
At least a pair of metal plates bonded to the front surface and the back surface of the semiconductor element, respectively, and constituting an external electrode;
A sealing portion provided so as to expose a surface opposite to a bonding surface of the pair of metal plates with respect to the semiconductor element, and to cover other portions;
A semiconductor device comprising:   2. The semiconductor device according to claim 1, wherein a size of the pair of metal plates viewed from a direction perpendicular to the surface is substantially the same as a size of the semiconductor element.   The semiconductor device according to claim 1, wherein at least one of the pair of metal plates is bonded to the semiconductor element via a bump.   2. At least one of the pair of metal plates is characterized in that a main surface on a side to which the semiconductor element is bonded and a main surface on the opposite side are coated with different metals. The semiconductor device according to any one of? A step of collectively bonding the semiconductor elements to the main surfaces of the plurality of first metal plates;
A step of collectively bonding a second metal plate to each main surface of the semiconductor element to form a plurality of stacked bodies;
Attaching a sealing material to each peripheral side surface of the plurality of laminates;
Removing the sealing material adhering to the main surface of the second metal plate opposite to the semiconductor element;
A method for manufacturing a semiconductor device, comprising:

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