JPH05218509A - Optical semiconductor device - Google Patents

Abstract

(57) [Summary] [Purpose] When soldering the conductor pattern on the outer surface of the plastic package to the conductor of the printed circuit board, a short circuit does not occur between the conductor patterns. [Structure] A plurality of protrusions are provided on a surface to be mounted on a printed circuit board or the like, and a conductor pattern connected to each electrode of an optical semiconductor chip is guided to the surface of the protrusion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical semiconductor chip mounted on the bottom surface of the inside of the recess of a plastic package having a recess at the center, and each electrode of the optical semiconductor chip is provided on the surface of the plastic package. The present invention relates to an optical semiconductor device, which is connected to a conductor pattern reaching the outer surface of the package from above the bottom surface inside the recess, and in which the inside of the recess is filled with a light-transmissive sealing resin.

[0002]

2. Description of the Related Art FIG. 5 shows the structure of an example of a conventional optical semiconductor device of this type. On the surface of the plastic package 1 having a recess in the center, the package 1 is
Two conductor patterns 2 reaching the back surface of the optical semiconductor chip 3 are die-bonded to one conductor pattern 2 on the bottom surface inside the recess, and the electrodes on the upper surface of the optical semiconductor chip 3 and the conductor pattern are electrically connected. After the separate conductive pattern 2 is electrically connected with the gold wire 4, the inside of the recess of the package 1 is filled with the light-transmissive sealing resin 5 to be formed. In this type of optical semiconductor device, one end of the conductor pattern 2 is guided to the back surface of the package 1, and the conductor pattern 2 portion on the back surface is soldered and mounted on a printed circuit board or the like.

[0003]

When the back surface of the package 1 remains flat as described above, there is no gap between the back surface of the package 1 and the printed board or the like during mounting on the printed board or the like. However, there is a problem that the package 1 is completely crushed on the back surface and spreads over a wide area, the electrodes are short-circuited by the solder paste, and the package 1 is lifted due to the gas generated when the solder paste is cured. Then, as the distance between the electrodes becomes narrower, there is a concern that a short circuit between the electrodes may occur, and there is a problem that it is not suitable for a fine pitch (narrow pitch). The present invention aims to solve the above problems.

[0004]

An optical semiconductor device of the present invention has a plurality of optical semiconductor devices mounted on a substrate so that a gap is provided between the substrate mounted surface and the substrate mounted surface. Providing individual protrusions, guide the conductor pattern connected to each electrode of the optical semiconductor chip to any surface of the protrusion, and solder the conductor pattern covering the surface of the protrusion to a conductor such as a printed circuit board. It is mounted so that the solder paste is not crushed and spreads to unnecessary areas on the substrate.

FIG. 1 is an explanatory view showing an embodiment of the present invention.
FIG. 1A shows a sectional structure and FIG. 1B shows a back surface structure. In the figure, reference numerals 1, 2, 3, 4, and 5 are the same as or correspond to the same reference numerals in FIG. 5, and 6 is a hemispherical protrusion provided on the back surface of the package 1.

Hemispherical projections 6 are provided on the four corners of the back surface of the package 1, an optical semiconductor chip 3 having two electrodes is mounted, and a conductor pattern 2 connected to each electrode of the optical semiconductor chip 3 is mounted. Are arranged so as to reach the surface of the protrusion 6 from the bottom surface inside the recess. When the conductor pattern 2 covering the surface of the hemispherical protrusion 6 is soldered to a printed circuit board or the like, as shown in FIG. 2, the solder paste is securely attached without being crushed and spread to an unnecessary area. .. In the figure, 7 is a printed circuit board,
8 is a solder paste.

When the projecting portions 6 have the above-mentioned shape, at least three projecting portions 6 are required to keep the posture of the package 1 stable at the time of mounting, and the number of electrodes of the mounted optical semiconductor chip is two. In this case, the protruding portion 6 that does not need to be provided with the electrode leading conductor pattern 2 is formed on the surface. In this case,
As shown in (b), if a conductor pattern covering these protrusions 6 is provided and all the protrusions are soldered, more reliable mounting can be obtained.

Conventionally, in this type of optical semiconductor device, a mounting method has been adopted in which the back surface is mounted on a printed circuit board or the like and only the space above the board is operated. However, the space below the board is operated. It may be more convenient to have a configuration. In this case, a method may be adopted in which a portion of the substrate corresponding to the operation region of the optical semiconductor device is opened, and the upper surface of the side wall portion around the recess of the package is mounted on the substrate. FIG. 3 is an explanatory view showing an embodiment of the present invention in which the upper surface of the side wall portion around the recess of the package is mounted on the substrate and mounted. FIG. 3 (a) shows the cross section and the structure inside the recess, and FIG. ) Indicates the mounting state. In the figure, reference numerals 1, 2, 3, 4, 5, 7, and 8 indicate the same or corresponding parts with the same reference numerals in FIGS. 1 and 2, and 6a represents a strip-shaped strip provided on the upper surface of the side wall around the recess of the package 1. It is a protrusion. The conductor patterns 2 connected to the respective electrodes of the optical semiconductor chip 3 are arranged so as to cover the surfaces of the protrusions 6a provided on the upper surfaces of the opposing side walls, and the conductor pattern 2 covering the protrusions 6a is printed. It is mounted by being soldered to a conductor such as the board 7. When the protrusion 6a has the above-described shape, the posture of the package 1 at the time of mounting is kept sufficiently stable by the two protrusions 6a. And FIG.
As shown in FIG. 3, the solder paste 8 is reliably soldered without spreading on an unnecessary region on the substrate 7.

When the mounting method as described above is adopted,
There is no need to provide a space between the board 7 and the surface on which the package 1 is mounted, and the protrusion 6b is inserted into the hole 9 provided in the board 7 as shown in FIGS. 4 (a) and 4 (b). The mounting method may be such that it is embedded and soldered. In this case, the protrusion 6b does not need to have a strip shape, and the two protrusions 6b
It is also possible to adopt a different shape to make a structure that does not confuse the directionality during mounting.

[0010]

As described above, according to the present invention,
This makes it possible to reduce the distance between the electrodes, enable stable soldering, and facilitate the mounting so that the operation direction is directed downwardly on the printed circuit board or the like. In addition, the shape of the protrusion is changed to prevent an error in directionality during mounting.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an effect of a protrusion of the embodiment shown in FIG.

FIG. 3 is an explanatory view showing another embodiment of the present invention.

FIG. 4 is an explanatory diagram showing another embodiment of the present invention.

FIG. 5 is an explanatory diagram showing the structure of an example of a conventional optical semiconductor device of this type.

[Explanation of symbols]

 1 Plastic Package 2 Conductor Pattern 3 Optical Semiconductor Chip 4 Gold Wire 5 Light Transmissive Sealing Resin 6 Projection 7 Printed Circuit Board 8 Solder Paste 9 Hole

Claims (1)

[Claims] 1. An optical semiconductor chip is mounted on the bottom surface of the inside of the recess of a plastic package having a recess at the center, and each electrode of the optical semiconductor chip is provided inside the recess provided on the surface of the plastic package. An optical semiconductor device in which a light-transmissive sealing resin is filled inside the recess after being connected to a conductor pattern reaching from the bottom surface to the outer surface of the plastic package, which is mounted on the substrate when mounting on the substrate. A plurality of protrusions are provided on the surface, the conductor pattern connected to each electrode of the optical semiconductor chip is guided to the surface of the protrusion, and the conductor pattern is soldered to the conductor portion of the substrate. Optical semiconductor device.