JP2007012979A - Semiconductor element and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that for a semiconductor element formed by mounting an optical semiconductor chip on a lead frame, the method of mounting the semiconductor chip in a recess surrounded with a mold resin on the frame is proposed but, because of a poor thermal conductivity of the mold resin, it is difficult to escape much heat well around from a high power laser diode. <P>SOLUTION: The front end of a lead frame is bent to improve the heat radiation with protecting a laser diode chip. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a semiconductor element including a laser diode and a method for manufacturing the same.

Japanese Patent No. 3186684 describes a technique for mounting a semiconductor chip in a recess surrounded by a mold resin on a frame.
Japanese Patent Application Laid-Open No. 4-280487 describes a technique for forming a recess by bending a frame.
In the design registration 1236059, only the semiconductor chip mounting portion is thickened so that a part of the frame is exposed on the back surface.

Japanese Patent No. 3186684 JP-A-4-2804877 Design Registration No. 123605

With respect to the technique described in Japanese Patent No. 3186684, it is difficult to efficiently release the large heat generated by the high-powered laser diode to the surroundings because the heat conduction of the mold resin is poor.
In JP-A-4-280487, when such a semiconductor element is attached, the frame surface (submount interface side) is often attached as a reference surface. However, this method cannot use heat radiation from this surface.
In addition, regarding the design registration No. 123605, since a normal lead frame is thinly processed by rolling, it is difficult to provide a large step so that the mold resin can enter, and even if possible, it is necessary to go through an expensive process. there were.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a semiconductor device with improved protection and heat dissipation of a laser diode chip.

  A semiconductor element according to the present invention is a semiconductor element formed by mounting a light emitting semiconductor chip on a frame, wherein a portion near the light emitting point of the light emitting semiconductor chip at the end of the frame is bent. It is.

  In the semiconductor element according to the present invention, in the semiconductor element formed by mounting the light emitting semiconductor chip on the frame, the protrusion is formed in the mold part so as to enter at least part of the plurality of wire bonds. It is characterized by.

  The semiconductor element according to the present invention is a semiconductor element formed by mounting a light emitting semiconductor chip on a frame, wherein the lead portion of the frame has a step with respect to the semiconductor chip mounting portion, and the mold resin is a frame. It is characterized by not projecting from the back surface.

  The method for manufacturing a semiconductor device according to the present invention includes a step of mounting a light emitting semiconductor chip on a frame, and a step of injecting mold resin from a mold resin injection hole of a mold for forming a mold. The injection hole of the mold is disposed at a portion other than the lead portion of the frame, the lead portion of the frame has a step with respect to the semiconductor chip mounting portion, and the mold resin protrudes from the back surface of the frame It is characterized by not.

As described above, according to the present invention, it is possible to protect the laser diode chip and improve the heat dissipation by bending the end of the frame near the light emitting point of the semiconductor chip.
Further, by forming the partition portion in the mold portion so as to enter at least a part of the plurality of wire bonds, it is possible to prevent an electrical short circuit at the time of wire bond deformation due to impact or contact.
In addition, since the lead part of the frame has a step with respect to the laser diode chip mounting part, and the mold resin does not protrude from the back surface of the laser diode chip mounting part of the frame, the degree of adhesion to the equipment housing and heat spreader is improved when mounting the equipment. In addition, heat dissipation from the back surface of the frame is facilitated.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof may be simplified or omitted.

Embodiment 1 FIG.
FIG. 1 is a schematic diagram for explaining a semiconductor device according to a first embodiment for carrying out the present invention. FIG. 1 (a) is an overhead view, (b) is a top view, and (c) and (d). Is a front view.

In FIG. 1, 101 is a lead frame, 103 is a mold resin, 105 is a lead, 107 is a submount, 109 is a laser diode chip, 111 is a bent portion, and 113 is a wire bond.
A center lead and electrically independent left and right leads are formed on a Cu lead frame 101 having a thickness of 0.25 mm. A laser diode chip 109 (GaAs, 0.2 mm × 1.5 mm × 0.1 mm) mounted on a submount 107 (AlN, 0.6 mm × 1.5 mm × 0.25 mm) at a portion connected to the central lead ), A mold resin 103 is formed around the periphery, and independent leads 105 are fixed. The laser diode 109 and the submount 107 are bonded in advance with AuSn solder (melting point 280 ° C.), and a conductive adhesive (acrylic resin in which Ag filler is diffused) is used for the lead frame 101. In addition, wire bond 113 (Au thickness 30 μm) is used for electrical connection. At the front end portion of the frame 101, two protrusions having a width W of 0.5 mm, a length L of 0.7 mm, and an interval S of 0.7 mm are bent to the diode chip side by molding to form a bent portion 111. Has been. Its height H1 is 0.6 mm from the surface of the frame, and is the same as the height of the mold resin 103. The total height of the submount 107 and the laser diode chip 109 is 0.35 mm or the maximum of the Au wire bond loop. The height is larger than 0.5 mm.

  In this embodiment, the bent portion 111 is formed by bending in the direction in which the fold line is perpendicular to the long side of the diode chip 109, that is, the side parallel to the laser beam to be emitted. As long as a heat dissipation effect can be obtained with respect to the wind, the same effect can be obtained regardless of the direction of bending.

  FIG. 2 is a schematic diagram for explaining another example of the first embodiment of the present invention. As shown in FIG. 2, by bending the left and right ends of the lead frame 101 in the direction of a surface that is not used at the time of assembly, it is possible to increase surface rigidity and ensure flatness.

  Also, as shown in FIG. 2, the protection capability of the laser diode chip 109 can be further enhanced by connecting the upper ends of the bent portions 111 on the left and right.

  In addition, it is possible to facilitate the bending by thinning only the bent portion 111 at the front end portion of the first embodiment by half etching or pressing.

  In the first embodiment described above, it is possible to protect the laser diode chip and improve heat dissipation by bending the end of the frame near the light emitting point of the semiconductor chip.

In addition, the height of the bent portion 111, which is a part of the bent frame, is formed so as to be at least higher than the position of the upper surface of the mounted semiconductor chip, thereby preventing contact when it is turned over. Is possible.
In addition, when the semiconductor element of the present invention is used in a pickup device such as a CD-R or DVD-R, the fold direction of the bent portion 111 is generally perpendicular to the long side of the semiconductor chip. In particular, efficient air cooling is possible by receiving the rotating wind of the media flowing parallel to the long side of the laser diode chip.

Embodiment 2. FIG.
FIG. 3 is a schematic diagram for explaining a semiconductor element according to the second embodiment for carrying out the present invention.

  In FIG. 3, 101 is a lead frame, 103 is a mold resin, 105 is a lead, 107 is a submount, 109 is a laser diode chip, 111 is a bent portion, and 113 is a wire bond.

  In contrast to the first embodiment, the mold resin 103 does not exist in the portion parallel to the long side of the laser diode chip 109, but is disposed only in the peripheral portion of the lead 105, and the space between the submount 107 and the frame 101 is AuSn solder. (Melting point: 280 ° C.)

  In the second embodiment described above, since the mold resin is not disposed in the portion parallel to the long side of the chip, a bonding process higher than the heat resistance temperature of the mold resin is possible for bonding between the submount and the frame. Therefore, AuSn solder or the like excellent in heat conduction can be used.

Embodiment 3 FIG.
4A and 4B are schematic views for explaining a semiconductor element according to the third embodiment for carrying out the present invention. FIG. 4A is an overhead view and FIG. 4B is a top view.

In FIG. 4, 101 is a lead frame, 2 is a mold resin, 3 is a lead, 4 is a submount, 5 is a laser diode chip, 6 is a bent portion, and 7 is a wire bond.
In contrast to the second embodiment, the bent portion 111 is extended to the portion where the laser diode chip 109 exists. Also in the third embodiment, as in the first embodiment, the height H2 of the bent portion 111 from the upper surface of the lead frame is 0.6 mm.

  In this embodiment, the bent portion 111 has a simple rectangular parallelepiped shape, but it is possible to further improve the heat dissipation by giving a fin shape or the like.

  Further, by extending the bent portion 111 so as to be applied to the mold resin 103, it is possible to suppress deformation due to impact.

  In the third embodiment described above, a part of the bent frame extends to a portion where the semiconductor chip is present, so that the laser diode chip can be more reliably protected.

Embodiment 4 FIG.
5 (a) and 5 (b) are schematic diagrams for explaining a semiconductor element according to the fourth embodiment for carrying out the present invention.

  5A and 5B, 101 is a lead frame, 103 is a mold resin, 105 is a lead, 107 is a submount, 109 is a laser diode chip, 113 is a wire bond, and 511 is a bent portion.

  In contrast to the first embodiment, by injecting the mold resin 103 so as to press the front end portion of the frame 101 against the wall surface of the mold into which the mold resin 103 is injected, the bent portion 511 bites into the mold resin 103, and The bent portion 511 is formed so as to be exposed on the front end surface.

  In this embodiment, the bent portion 511 is bent so that the fold line is parallel to the long side of the laser diode chip 109, but it is possible to expose part of the bent portion 511 even if it is bent vertically. .

  Further, as shown in FIG. 5B, the bending process can be facilitated by thinning only the bent part 511 by half etching or pressing.

  In the fourth embodiment described above, a part of the folded frame bites into the mold resin, and the frame is exposed at the front end surface, thereby increasing the adhesion of the mold resin to the frame, and Heat dissipation can be ensured by exposing a part of the frame.

Embodiment 5 FIG.
FIG. 6 is a schematic diagram for explaining a semiconductor device according to a fifth embodiment for carrying out the present invention.

  In FIG. 6, 101 is a lead frame, 103 is a mold resin, 105 is a lead, 107 is a submount, 109 is a laser diode chip, 111 is a bent portion, 113 is a wire bond, and 601 is a projection of the mold.

  With respect to the first embodiment, the projection 601 of the mold resin 103 is formed so as to reach a straight line connecting the joints on the frame side of the wire bond 113.

  In the fifth embodiment described above, an electrical short circuit at the time of deformation of the wire bond due to impact or contact is prevented by forming the protruding portion on the mold portion so as to enter at least part of the plurality of wire bonds 113. It becomes possible to do. Further, by forming the protrusion 601 of the mold resin 103 up to a position that reaches a straight line connecting the joints on the frame side of the wire bond 113, the effect of preventing a short circuit can be further increased.

Embodiment 6 FIG.
7A and 7B are schematic views for explaining a semiconductor device according to a sixth embodiment for carrying out the present invention. FIG. 7A is a view showing a frame, FIG. 7B is a top view, and FIG. 7C is a front view. FIG. 4D is a bottom view.

  In FIG. 7, 101 is a lead frame, 103 is a mold resin, 107 is a submount, 109 is a laser diode chip, 113 is a wire bond, 705 is an opening of the frame, 707 is an exposed portion of the lead back surface, and 703 (a). Is a center lead, 703 (b) is a signal lead, and 701 is a laser diode chip mounting portion.

  Compared to the first embodiment, a portion connecting the center lead 703 (a) and the laser diode chip mounting portion 701 is bent, and a step H3 of 0.3 mm is provided. Further, the back surface of the laser diode mounting portion of the frame 101 is pressed against the mold resin injection mold, and the mold resin 103 is injected from the opening 705 of the frame 101 so that the back surface of the laser diode chip mounting portion is exposed. Mold resin formation is performed. The opening 705 of the frame 101 is circular with a maximum diameter of 0.6 mm. The mold injection hole of the mold resin injection mold is arranged at a position other than the lead portion of the frame 101. In the present embodiment, the mold injection hole of the mold resin injection mold communicates with the opening 705 of the frame 101.

  The opening portion 705 of the frame 101 is punched from the upper surface to the lower surface by press punching so that the opening area of the opening portion 705 is formed so that the lower surface is larger than the upper surface. It is possible to increase the adhesion strength.

  In this embodiment, the opening 705 is formed by punching. However, even in the formation by etching, the area near the lower surface can be maximized by optimizing the mask pattern and the etching rate.

  Further, by thinning only the bent portion of the center lead 703 (a) by half etching or pressing, the bending workability is improved.

  Further, by forming the lead back surface exposed portion 707 as shown in FIG. 7D, the frame is directly supported by using a projection or the like at the time of wire bonding, so that heat conduction and ultrasonic transmission are stabilized, and the condition likelihood. Wide wire bondability can be ensured.

  The same effect can be obtained even if the lead connected to the laser diode chip mounting portion 701 is not the center but the left and right leads.

  In addition, when the heat radiation is sufficient only by the rear surface of the laser diode mounting portion, there is no problem even if the portions extending to the left and right of the frame are deleted.

In the sixth embodiment described above, since the lead portion of the frame has a step with respect to the laser diode chip mounting portion, the mold resin enters the lower side of the lead having the step to support the lead. The mold resin is contained in the gap between the lead under the lead and the frame, and does not enter the back surface of the frame. Since the mold resin does not protrude from the back surface of the laser diode chip mounting portion of the frame in this way, the degree of adhesion to the device casing and the heat spreader increases when the device is mounted, and heat dissipation from the back surface of the frame becomes easy.
In addition, by disposing the mold resin injection hole outside the position corresponding to the lead portion of the frame and avoiding the position corresponding to the lead portion of the frame, the resin is likely to be in the vicinity of the injection hole. ) Due to individual differences in heat conduction and changes in ultrasonic transmission can be suppressed.
Further, by injecting the mold through the opening formed in the frame, it is possible to increase the degree of adhesion of the resin to the frame and reduce the outer shape of the package.

FIG. 3 is a simulation diagram showing the semiconductor element of the first embodiment. 6 is a simulation diagram showing another example of the semiconductor element of the first embodiment. FIG. FIG. 6 is a simulation diagram showing a semiconductor element of a second embodiment. FIG. 10 is a simulation diagram showing a semiconductor element of a third embodiment. FIG. 10 is a simulation diagram showing a semiconductor element of a fourth embodiment. FIG. 10 is a simulation diagram showing a semiconductor element of a fifth embodiment. FIG. 10 is a simulation diagram showing a semiconductor element of a sixth embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Lead frame 103 Mold resin 105 Lead 109 Laser diode chip 111 Bending part 113 Wire bond 115 Light emitting point 511 Bending part 601 Projection part 701 Laser diode chip mounting part 703 Lead 705 Opening part 707 Lead back surface exposed part

Claims (11)

In a semiconductor element formed by mounting a light emitting semiconductor chip on a frame,
A semiconductor element, wherein a portion of the end of the frame that is close to a light emitting point of the light emitting semiconductor chip is bent. The semiconductor device according to claim 1,
A semiconductor element, wherein at least a part of a bent portion of the frame is formed to be higher than an upper surface of a semiconductor chip. The semiconductor device according to claim 1,
A semiconductor element, wherein a direction in which the frame is bent is parallel to a long side of the light emitting semiconductor chip. The semiconductor device according to claim 1,
A semiconductor element, wherein a mold resin is not disposed in a portion parallel to the long side of the light emitting semiconductor chip. The semiconductor device according to claim 1,
At least a part of the bent portion of the frame extends to a portion where the light emitting semiconductor chip is mounted. The semiconductor device according to claim 1,
A semiconductor element, wherein at least a part of a bent portion of the frame bites into the mold resin, and a front end surface of the frame is exposed from the mold resin. In a semiconductor element formed by mounting a light emitting semiconductor chip on a frame,
A projecting portion is formed in a mold portion so as to enter at least part of a plurality of wire bonds. In a semiconductor element formed by mounting a light emitting semiconductor chip on a frame,
A semiconductor element, wherein the lead portion of the frame has a step with respect to the semiconductor chip mounting portion, and the mold resin does not protrude from the back surface of the frame. The semiconductor device according to claim 8,
A semiconductor element, wherein an opening for injecting a mold is formed in a frame. Mounting the light emitting semiconductor chip on the frame;
A step of injecting mold resin from an injection hole of a mold for forming a mold,
The injection hole of the mold is disposed at a portion other than the portion facing the lead of the frame, the lead portion of the frame has a step with respect to the semiconductor chip mounting portion, and the mold resin is on the back surface of the frame A method for manufacturing a semiconductor device, characterized by not protruding further. It is a manufacturing method of the semiconductor device according to claim 10,
The method of manufacturing a semiconductor device, wherein the injection hole of the mold is arranged to communicate with an opening formed in the frame.

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