JPH11307809A - Optical semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate and downsize optical devices such as a prism by sealing semiconductor chips serving as a light emitting section and a light receiving section into an optical semiconductor device and by forming a groove having a reflecting and transmitting surface on a resin sealing body transparent to light of a predetermined wavelength. SOLUTION: A leadframe comprises islands 21 and leads 22. A semiconductor chip 23 serving as a light emitting section and a semiconductor chip 24 serving as a light receiving section are fixed onto the islands 21 and the leads 22 through solder or the like. Further, bonding pads are formed around the chips 23 and 24. The plurality of leads 22 extend outside from the peripheries of the chips so as to correspond to the bonding pads, and the leads 22 are connected to the chips 23 and 24 through fine metal wires. The ends of the leads 22 and the chips 23 and 24 are sealed with a sealing body 25 that is transparent to a predetermined wavelength. The body 25 is provided with a groove 27 having a surface 26 that reflects and transmits light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical semiconductor device, and more particularly to an optical semiconductor device having a thin structure and emitting (or entering) light from a thin side surface thereof.・ Thinning is realized.

[0002]

2. Description of the Related Art Recently, multimedia equipment such as a sub-notebook personal computer, a portable information terminal, and an electronic still camera has been remarkably developed.

[0003] Moreover, 7 million portable devices are sold annually, and about 80% adopt the infrared system of the IrDA (InfraredData Association) standard. That is, transmission / reception between the external device and the main body via an infrared signal is required, and a light emitting element that emits infrared light and a light receiving element that receives infrared light are required.

An optical head used in an optical recording / reproducing apparatus such as an MD or a CD irradiates an optical recording medium with a beam and detects a modulated beam from the optical recording medium, thereby recording and reproducing information. I do. Also here, a light emitting element and a light receiving element are required.

However, these light emitting elements and light receiving elements have not been reduced in size.

For example, FIG. 3 illustrates a technique disclosed in Japanese Patent Publication No. Hei 7-28085, in which a semiconductor laser 1 is directly connected to a semiconductor substrate 2 and a prism 3 having a trapezoidal cross section is fixed to the semiconductor substrate 2. ing. Reference numeral 4 denotes an optical recording medium. The inclined surface 5 of the prism 3 facing the semiconductor laser 1 is a semi-transmissive reflecting surface, and the prism surface 6 in contact with the semiconductor substrate 2 has a portion other than the photodetector (light receiving element) 7. The prism surfaces 8 facing each other are reflection surfaces.

[0007] A beam 9 emitted from the semiconductor laser 1 and incident on the prism 3 from the inclined surface 5 is reflected by the reflecting surfaces 6 and 8 and detected by the photodetector 7.

FIG. 4 shows an infrared data communication module 11, which includes an infrared LED, an LED driver, a PIN photodiode, an amplifier, and the like. For example, the LED is mounted on a substrate, and light emitted from the LED is emitted to the outside through a lens 12, and the photodiode mounted on the substrate enters the mold 11 through a lens 13.

[0009]

In the modules shown in FIGS. 3 and 4, an optical device is mounted on a semiconductor substrate, and a lens is further mounted on a module on which a semiconductor substrate is molded. The set incorporating these has a problem that miniaturization cannot be realized.

[0010]

SUMMARY OF THE INVENTION The present invention is directed to a light emitting semiconductor chip for emitting light, a light receiving semiconductor chip having an upper surface as a light receiving surface, and a transparent light for sealing the light emitting and light receiving semiconductor chips. And a surface that intersects the optical path of the light emitted from the light emitting semiconductor chip at a predetermined angle, and is formed on the light receiving semiconductor chip and on the surface of the resin sealed body. A first groove,
The light from the light emitting semiconductor chip is emitted by being reflected by the groove, and the light incident from the outside is transmitted through the groove and received by the light receiving semiconductor chip.

In particular, a half mirror is formed on the surface of the groove.

Further, the light emitting semiconductor chip is characterized in that a side surface thereof is a light emitting surface. In particular, the height of the light emitting semiconductor chip is set such that the emitted light is applied to the surface of the groove.

Further, an upper surface of the light emitting semiconductor chip is a light emitting surface. Furthermore, the light emitting semiconductor chip has a surface which intersects at a predetermined angle so that an optical path of light emitted from the light emitting semiconductor chip is directed toward the first groove, and is provided on the light emitting semiconductor chip and the resin sealing. And a second groove formed on the surface of the stationary body.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

For the sake of understanding, the drawings are made by integrating the two drawings. The upper part is a plan view of the optical semiconductor device, and the lower part is a cross-sectional view taken along line AA in the above-mentioned plan view.

First, there is a lead frame. This lead frame includes an island 21 and a lead 22 indicated by a two-dot chain line.
Here, a semiconductor chip 23 indicated by an alternate long and short dash line serving as a light emitting portion and a semiconductor chip 24 indicated by an alternate long and short dash line serving as a light receiving portion are fixed via Cu or other fixing means. Also, the semiconductor chips 23 and 24
, A plurality of leads 22 are extended from the periphery of the chip to the outside, and the chips 23 and 24 and the leads 22 are connected by thin metal wires. .

The tip of the lead and the semiconductor chip are sealed with a sealing body 25 transparent to light of a predetermined wavelength. The sealing body 25 has a surface 2 on which light is reflected and transmitted.
A groove 27 having 6 is provided.

The feature of the present invention resides in the surface 26. The surface 26 is formed by forming a groove in the sealing body 25, and emits light emitted from the side surface of the light emitting portion 23 as indicated by a dotted arrow. The light is reflected from the surface 26 and emitted from the upper surface X of the sealing body 25, and the light incident on the upper surface X of the sealing body 25 is
The light can be transmitted through the light receiving unit 6 and received by the light receiving unit 24.

The light emitting section 23 shown in FIG. 1 is a semiconductor chip that emits light from its side. When the light emitting section 23 and the light receiving section 24 are mounted on a frame having the same height, the light is transmitted to the groove 27 because the depth of the groove is about half the thickness of the sealing body 25.
Cannot be irradiated on the surface 26 of the resin sealing body 25, and as a result, light cannot be emitted from the upper surface X of the resin sealing body 25. Therefore, by increasing the height of the frame on which the light emitting unit 23 is mounted so that the emitted light is irradiated on the surface 26,
The emitted light is reflected by the surface 26 and the upper surface X of the resin sealing body 25 is reflected.
It is possible to eject from.

The light emitting section 23 shown in FIG. 1 emits light from the side of the semiconductor chip. Therefore, the embodiment shown in FIG. 1 is suitable for a semiconductor chip which emits laser light.

FIG. 2 is a view showing another embodiment. For the sake of understanding, the figure is one in which two figures are integrated as in FIG. 1, and the upper part is a plan view of the optical semiconductor device, and the lower part is. A in the plan view
It is sectional drawing in the -A line. The lead frame includes an island 21 and a lead 22 as shown in FIG. 1, and a semiconductor chip 23 serving as a light emitting unit and a semiconductor chip 24 serving as a light receiving unit are mounted on the island 21. A bonding pad is formed around the semiconductor chips 23 and 24, and a plurality of leads 22 are extended from the periphery of the chip to the outside corresponding to the bonding pads. Are connected by a thin metal wire.

The tips of the leads and the semiconductor chip are also sealed with a sealing body 25 transparent to light of a predetermined wavelength. The sealing body 25 is provided with a first groove 27 having a surface 26 through which light is reflected and transmitted, and a second groove 29 having a reflecting surface 28.

The feature of the present invention lies in the surface 26 and the reflection surface 27. The surface 26 is formed by forming a groove 27 in the sealing body 25, and the reflection surface 28 is formed by a groove 29 in the sealing body 25.
Is formed. In FIG. 2, light emitted from the upper surface of the light emitting unit 23 is first reflected by the reflecting surface 28, and light from the light emitting unit 23 is
To be irradiated. The light reflected on the reflection surface 28 is further reflected on the surface 26, and the light is emitted from the upper surface X of the sealing body 25. On the other hand, light incident on the upper surface X of the sealing body 25 passes through the surface 26 and can be received by the light receiving unit 24.

The light emitting section 13 in FIG. 2 emits light from the upper surface of the semiconductor chip. Therefore, the embodiment of FIG. 2 is suitable for use in a semiconductor chip that emits infrared light.

In general, a prism or a lens is formed on a semiconductor chip forming a light emitting section or a light receiving section to form a semiconductor device.
Since the thickness of the set itself is increased, and optical devices are arranged on and around the set, it is difficult to make the set thin and small. However, since the surface 26 that is a part of the groove allows light to enter and exit from the upper surface X of the sealing body, no prism is required. Therefore, the thickness of the device itself can be reduced.

In this case, the thickness of the lead frame is about 0.
125 mm, the thickness of the semiconductor chip is, for example, 250 to
It is about 300 μm. The sealing body 25 is made of a transparent epoxy material, for example, by transfer molding, and has a total thickness of about 1 mm to 1.5 mm. The mold is also provided with a portion for forming a groove, and the groove is formed simultaneously when the semiconductor chip is transfer-molded with the resin sealing body.

Here, the grooves 27 and 29 have a thickness of about half, here about 750 μm, and at least the portions constituting the reflecting surfaces 26 and 28 are at 45 °. The reflecting surface here becomes both a transmitting surface and a reflecting surface due to the difference between the refractive index of the air on both sides of the interface and the refractive index of the epoxy material. If it is desired to increase the reflection efficiency, a half mirror may be formed on the reflection surface with a metal film. As the coating method, vapor deposition and sputter deposition used in semiconductor technology can be considered, and plating can also be considered.

The tips of the grooves 27 and 29 are formed at an acute angle, but may be rounded. In this case, the durability when a force is applied to the resin sealing body 25 from the outside is improved.

FIG. 5 shows an application example in which the optical semiconductor device of FIGS. 1 and 2 is incorporated in an optical pickup of an optical recording medium reproducing apparatus. Light emitted from the groove of the optical semiconductor device 50 according to FIGS. 1 and 2 is emitted. The emitted light is the lens 51
Is irradiated onto the optical disk 52. The light emitted by the lens 51 is collected on an optical disk. On the optical disc, the irradiated light is reflected or not reflected according to the shape of the disc corresponding to "1" or "0". Optical disc 52 is CD, M
D, LD, DVD and the like. For example, in a CD, light reflection is caused by the presence or absence of pits formed on the CD. The reflected light is collected by the lens 51 and then returns to the groove of the optical semiconductor device 50. The reflected light is detected by the light receiving unit of the optical semiconductor device 50, and a binary signal is detected by the light receiving unit depending on the presence or absence of the reflected light.

In a conventional optical pickup, a semiconductor device that emits light, a prism that changes the optical path of the emitted light,
A semiconductor device for receiving light is required. On the other hand, in the optical semiconductor device 50 of the present invention, the semiconductor chips to be the light emitting unit and the light receiving unit are sealed in one sealing body, and a groove having a reflection and transmission surface is formed on the sealing body. ing. Therefore, a prism is not required, and the number of semiconductor devices can be reduced.
As a result, the size of the optical pickup can be reduced.

[0031]

According to the present invention, in an optical semiconductor device,
Since a semiconductor chip serving as a light emitting unit and a light receiving unit is sealed and a groove having a reflection and transmission surface is formed on a resin sealing body transparent to light of a predetermined wavelength, light is transmitted from the upper surface of the optical semiconductor device. Incoming and outgoing can be performed. Therefore, the number of optical devices such as prisms can be reduced, and the size can be reduced.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing another embodiment of the present invention.

FIG. 3 is a schematic view showing a combination of a conventional optical semiconductor device and an optical device.

FIG. 4 is a schematic view showing a combination of a conventional optical semiconductor device and an optical device.

FIG. 5 is a schematic view showing an application example of the optical semiconductor of the present invention to an optical pickup.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tsutomu Ishikawa 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Satoshi Sekiguchi 2-5-2 Keihanhondori, Moriguchi-shi, Osaka No. 5 Sanyo Electric Co., Ltd. (72) Inventor Hiroshi Kobori 2-5-5 Keihan Hondori, Moriguchi-shi, Osaka Pref. Sanyo Electric Co., Ltd. (72) Inventor Hiroki Seyama 2 Keihan-hondori, Moriguchi-shi, Osaka 5-5, Sanyo Electric Co., Ltd.

Claims (6)

[Claims] A light-emitting semiconductor chip that emits light; a light-receiving semiconductor chip having an upper surface as a light-receiving surface; a resin sealing body that is transparent to light that seals the light-emitting and light-receiving semiconductor chips; It has a surface that intersects the optical path of light emitted from the light emitting semiconductor chip at a predetermined angle and has a first groove formed on the light receiving semiconductor chip and on the surface of the resin sealing body. Light emitted from the light emitting semiconductor chip is reflected by the groove, and light incident from the outside is transmitted through the groove and received by the light receiving semiconductor chip. Semiconductor device. 2. The optical semiconductor device according to claim 1, wherein a half mirror is formed on the surface of the groove. 3. The optical semiconductor device according to claim 1, wherein a side surface of the light emitting semiconductor chip is a light emitting surface. 4. The optical semiconductor device according to claim 3, wherein the height of the light emitting semiconductor chip is set so that emitted light is irradiated to the surface of the groove. 5. The optical semiconductor device according to claim 1, wherein an upper surface of the light emitting semiconductor chip is a light emitting surface. 6. A light emitting device according to claim 1, further comprising: a surface that intersects a light path of light emitted from the light emitting semiconductor chip at a predetermined angle so as to face the direction of the first groove. The optical semiconductor device according to claim 5, further comprising a second groove formed on a surface of the resin sealing body.