JP2000133822A - Optical semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable miniaturization of a module or a set including a light- emitting element and a light-receiving element by making external forms of the elements as thin as possible. SOLUTION: Semiconductor chips 21, 22 are a light-emitting element and a light-receiving element. A resin sealing body 24 sealing the elements is composed of optically transparent material. On a region where a light is outputted from the element and a region where a light enters the element, a recessed part 25 is formed, on which a reflecting surface 26 is constituted. As a result, exiting and incidence of a light are made possible via a side surface E. A wide sensitivity region can be obtained due to the form of the side surface.

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 an optical semiconductor module mounting the same.
In particular, the structure of the optical semiconductor device is made thinner, and light is emitted (or made incident) from the thinner side surface, thereby realizing miniaturization and thinning of a device using the same.

[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 a beam onto an optical recording medium to detect 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.
The technique described in Japanese Patent Application Publication No. 8085 is described in which a semiconductor laser 1 is directly disposed on a semiconductor substrate 2 and a prism 3 having a trapezoidal cross section is fixed to the semiconductor substrate 2. 4
An optical recording medium. The inclined surface 5 of the prism 3 facing the semiconductor laser 1 is a transflective surface, and the prism surface 6 facing the semiconductor substrate 2 is a photodetector (light receiving element) 7.
The prism surface 8 whose other parts are opposite to the surface 6
Are both reflective surfaces.

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. 10 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 12 is mounted on a substrate, and light emitted from the LED 12 is emitted to the outside via the lens 13. The photodiode 14 mounted on the substrate has a lens 15
And enters the mold 11.

[0008]

In the above-mentioned module, in FIG. 9, since an optical device is mounted above the semiconductor substrate, there is a problem that a very advanced technique is required and the price is high. .

In FIG. 10, light needs to be put in and out of the mold body, and it is necessary to set another optical semiconductor device at the opposing position. There was a problem that could not be realized.

In FIG. 10, if light is to be taken in and out in the horizontal direction, the lead 16 of the optical semiconductor device 11 must be bent at 90 degrees as shown in FIG.
Depending on how the optical semiconductor device 11 is bent,
There was a problem with stability.

Further, the conventional optical semiconductor device can transmit and receive light only in a direction perpendicular to the semiconductor substrate.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has an object to seal a semiconductor chip having a light receiving element and / or a light emitting element, which is transparent to at least light having a predetermined wavelength. The sealing body has a cylindrical portion having a concave portion with a reflection surface formed above the semiconductor chip, and an optical path of light is incident on the cylindrical portion or emitted from the cylindrical portion. And an optical semiconductor device that passes through the sealing body and is reflected by the reflection surface.

[0013] Further, the optical semiconductor device is characterized in that the side surface of the cylindrical portion is mirror-finished.

A drive circuit for driving the light-receiving element and / or the light-emitting element is sealed in a portion other than the cylindrical portion of the sealing body, and has a lead connected to the drive circuit. And / or the light emitting element is an optical semiconductor device characterized by being formed with a drive circuit interposed therebetween.

Further, the drive circuit is formed concentrically with the light receiving element and / or the light emitting element and has a lead connected to the drive circuit, and the lead is formed radially from the cylindrical portion. Optical semiconductor device.

Further, the drive circuit has an electrode formed concentrically with the light receiving element and / or the light emitting element and connected to the drive circuit, and this electrode is formed on the lower surface of the optical semiconductor device. It is an optical semiconductor device characterized by the following.

Further, the optical semiconductor device is characterized in that a curved surface having a predetermined curvature is formed in the cylindrical portion.

An upper lens having a refractive index different from that of the sealing body is formed in the concave portion. Light incident from above the upper lens is also incident on the light receiving surface, or light emitted from the light emitting element is emitted from the light receiving element. A part is an optical semiconductor device which is emitted from the upper lens.

Further, the optical semiconductor device is characterized in that the recess has a bottom surface which is a substantially horizontal plane.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIG. FIG. 1 (a)
FIG. 1B is a plan view of the optical semiconductor device, and FIG.
FIG. 1 (c) is a cross-sectional view taken along line A of FIG.
It is sectional drawing in the -B line. FIG. 1D is a perspective view for understanding the shape of the optical semiconductor device of the present embodiment.

Reference numerals 21 and 22 are semiconductor chips. The semiconductor chip 21 is a light receiving element such as a photodiode, and the semiconductor chip 22 is a drive circuit of the semiconductor chip 21. The semiconductor chip 21 may be, for example, a light emitting element of an infrared LED, or both a light receiving element and a light emitting element may be formed. Hereinafter, the light receiving element will be described, but the same applies to a light emitting element. Further, the light receiving element 21 and its driving circuit 22 may of course be formed integrally.

Reference numeral 23 is a lead. The lead 23 is made of, for example, Cu, and is connected to a bonding pad (not shown) provided in a predetermined region of the semiconductor chip 21 or 22 by a thin metal wire or solder (not shown).

The semiconductor chips 21 and 22 and one end of the lead 23 are sealed by a sealing body 24. Here, the sealing material may be any material that is transparent to light, such as a transparent epoxy resin, and the material is not particularly limited. In addition, since LEDs generally use infrared light,
What is necessary is just to transmit this infrared ray, and it is not necessary to be transparent to visible light. That is, it suffices if it is at least transparent to predetermined light. A recess 25 having a reflection surface 26 is formed in the sealing body 24.

A feature of the present invention resides in the reflection surface 26,
The reflection surface 26 is formed by forming a concave portion 25 in the sealing body 24, and thereby light can be incident from the side surface of the sealing body 24 as shown by an arrow.

In general, a semiconductor chip constituting a light emitting section and a light receiving section constitutes a semiconductor device by forming a prism and a lens on the semiconductor chip. Therefore, a module or a set using the semiconductor chip is arranged in a vertical direction of the set itself. Since the thickness is increased, and optical devices are arranged on and around this, it is difficult to reduce the thickness and size. However, the reflecting surface 26 which is a part of the concave portion 25 of the sealing body allows light to enter and exit from the side surface of the sealing body, so that a prism is unnecessary. Therefore, the thickness of the device itself can be reduced. Moreover, the conventional optical semiconductor device has sensitivity only in the direction in which the lens is directed (although it is slightly wider depending on the lens).

On the other hand, the optical semiconductor device of this embodiment is
As shown in the drawing, the shape of the reflection surface 26 is such that the concave portion 25 is formed by cutting out a cone, and is formed in a mortar shape.
It is 7. The side surface of the cylindrical portion 27 and the reflecting surface 26 are mirror-finished, and light incident on the cylindrical portion 27 is reflected by the reflecting surface 2.
6 and is incident on the semiconductor chip 21. Therefore,
Light incident on the cylindrical portion 27 from the horizontal direction (the direction of the paper surface in FIG. 1A) of the optical semiconductor device is incident on the semiconductor chip 21 from any direction.

The thickness of the substrate holding the semiconductor chips 21 and 22 is about 125 μm, and the thickness of the semiconductor chips 21 and 22 is, for example, about 250 μm to 300 μm. The sealing body 24 is formed by, for example, transfer molding, and has a total thickness of about 1 mm to 1.5 mm. It goes without saying that if the thickness of the chip is reduced, it can be further reduced. Here, the concave portion 25 may have a reflecting surface without exposing the semiconductor chip. For example, the concave portion 25 has a depth of about half of the thickness, here, about 750 μm. °. The height of the cylindrical portion 27 is formed to be approximately the same as or slightly higher than the depth of the concave portion 25. Thereby, the cylindrical portion 27
Is horizontally reflected by the reflecting surface 26,
It reaches the semiconductor chip 21. Cylindrical part 27 of sealing body 24
Is formed so thin that the semiconductor chip 22 is not exposed. In this case, the thickness was about 750 μm, which is about half of the entire thickness.

The reflecting surface 26 becomes a reflecting surface due to the difference in the refractive index between the air on both sides of the interface and the transparent resin. However, not all light is reflected, and a metal film may be formed on the reflection surface to further increase the reflectance. As the coating method, vapor deposition and sputter deposition used in semiconductor technology can be considered, and plating can also be considered. A point to be noted here is a short circuit with the coating material formed on the sealing body 24. In the former two coating methods,
Around the lead, on the side of the cylindrical part 27 where light enters, etc.
Requires a mask. When the whole is dipped in a solution by, for example, electroless plating, a resin is applied to the lead 22 of the lead-out part and the sealing body 24 around the lead-out part, and thereafter, plating is performed to remove the resin. I just need. In addition to the dip method, the solution may be dropped only on the concave portion to perform plating. Gold, A
1, nickel and the like are conceivable.

As described above, the reflection surface 26 does not totally reflect light but transmits a part of the light. This means that, conversely, light that is vertically incident on the optical semiconductor device,
This means that the light can be incident on the light receiving element.

Since the lead 23 is made of a metal such as Cu as described above, it reflects light. In order to prevent a malfunction due to the reflected light, the lead 23 is preferably installed as far as possible from the light receiving portion 21 and the side surface of the cylindrical portion 27 where light enters. For example, the drive circuit 22 is interposed between the light receiving unit 21 and the lead 23 is provided on the opposite side.

Next, a second embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. The optical semiconductor device of FIG. 2 differs from the first embodiment in that the angle of the reflecting surface 26 is shallower than 45 °, for example, 40 ° with respect to the light receiving surface. When the reflection surface 26 is at an angle of 45 °, the light horizontally incident on the optical semiconductor device is reflected by the reflection surface 26 in the vertical direction, and the light receiving element located immediately below the reflection surface 26 detects this. On the other hand, by forming the reflecting surface 26 to be shallow, the light reflected by the reflecting surface 26 is condensed at the central portion of the semiconductor chip 21 as shown by the arrow in the drawing, so that the light receiving element is made smaller. can do. In general, when the incident angle of light with respect to the reflecting surface becomes shallow,
The reflectance increases, and total reflection occurs at a certain angle as a boundary. When the light is not totally reflected, part of the incident light passes through the reflection surface 26 and does not enter the light receiving element.
Therefore, by forming the angle of the reflecting surface 26 to be shallow, the reflectance of the reflecting surface 26 can be made higher, and the sensitivity of the optical semiconductor device can be made higher. Also,
Conversely, the reflectance decreases with respect to light that is incident on the optical semiconductor device in the vertical direction, so that more light can be transmitted, and the sensitivity can be increased with respect to light in the vertical direction.

Next, a third embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. The optical semiconductor device of FIG. 3 differs from the first embodiment in that the opening of the concave portion 25 having the reflection surface 26 is rectangular. The recess 25 has a reflection surface 26 along four sides. The optical semiconductor device of the present embodiment has central sensitivity regions in four directions, that is, in the direction of the reflection surface 26, and has low sensitivity in other directions. The optical semiconductor device of the present embodiment is useful when the light incident on the optical semiconductor device is limited to a predetermined direction. Although illustration is omitted, the shape of the concave portion 25 is similarly triangular, trapezoidal,
Various settings can be made according to the direction in which the sensitivity area is to be provided, such as a hexagon. These optical semiconductor devices can prevent unnecessary optical noise that enters from a direction not facing the reflection surface 26 from entering the light receiving region. In addition, the sealing body 24
A curved surface may be provided on the side surface to add a function as a lens, or a lens provided in a conventional optical semiconductor device may be provided.

Next, a fourth embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. In the optical semiconductor device of FIG. 4, a drive circuit 22 is formed concentrically around a semiconductor chip 21 having a light receiving portion and / or a light emitting portion, and leads 23 are radially arranged around the optical semiconductor device. Of course, the semiconductor chips 21 and 22 may be integrated.
The sealing body 24 has a cylindrical shape, and light is incident or emitted radially from the side surface of the sealing body 24. By forming in this manner, the size of the optical semiconductor device can be further reduced, and the conditions for incidence of light over the entire circumference are substantially equal.
Variation in sensitivity of the optical semiconductor device depending on the incident direction is small. The leads 23 connected to the drive circuit are formed radially from the outer periphery of the sealing body to disperse the influence of light reflection by the leads 23 and reduce variations in sensitivity of the optical semiconductor device.

Next, a fifth embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. The optical semiconductor device of FIG.
P (Chip size package), for example, PGA (Pin Grid
Array), BGA (Ball Grid Array), LGA (Land
It is formed using a package method such as a grid array that takes out electrodes from the lower surface of the semiconductor chip.
The semiconductor chips 21 and 22 are formed concentrically as in the fourth embodiment. On the lower surface of the optical semiconductor device, an electrode 28 is formed instead of the lead 23, and the semiconductor chip 2
1, 22 are electrically connected to predetermined positions. In the figure, a hemispherical electrode 28 is illustrated by exemplifying a BGA.
Of course, in the case of PGA, the electrodes are pin-shaped, and LGA
Then, it becomes a grid-like electrode. As shown in FIG.
Is radially formed, reflection of light there may cause a malfunction of the optical semiconductor device. So, CS
The advantage of using P is, of course, that the size of the optical semiconductor device can be reduced as compared with the case where the leads 23 are formed.
By forming 8 on the lower surface of the optical semiconductor device, a malfunction due to light reflection is prevented. In the optical semiconductor device of FIG. 4, there are cases where the optical semiconductor device passes over the lead 23 and where the lead 23 does not exist, depending on the optical path of light, whereby the sensitivity of the optical semiconductor device may vary depending on the direction of intrusion. There is. On the other hand, FIG.
Has the same sensitivity to light coming from any angle.

The semiconductor chips 21 and 22 are not limited to the shape shown in FIG. 5, but may be, for example, a square. Further, as shown in FIG.
1 with the semiconductor chip with the drive circuit down,
They may be arranged three-dimensionally.

As shown in FIG. 7, the sealing body 24 has a curved surface on the optical path and a side lens 29.
The incident light is collected, and the light receiving sensitivity is further improved. The side lenses 29 are uniformly formed around the cylindrical portion 27.
FIG. 7 is a view in which the side lens 29 is formed in the fifth embodiment. The side lens 29 is, of course, provided on the side surface of the cylindrical portion 27 of the optical semiconductor device of the first to fourth embodiments. Can also be formed.

FIG. 8 shows an optical semiconductor device having sensitivity to light from above. As described above, the reflection surface 26 of the concave portion 25 provided on the sealing body 24 reflects light due to a difference in refractive index inside and outside the sealing body.
In the optical semiconductor device of FIG. 8, the concave portion 25 is filled with a transparent substance having a reflectance different from that of the sealing body 24 to form the upper lens 30. Since the upper lens 30 has a different refractive index from the sealing body 24, the light incident from the side faces
Is reflected by As described in the second embodiment, since the reflection surface 26 is formed to have a small angle, light incident from the side surface has a small penetration angle and a high reflectance. On the other hand, light incident from above is collected by the upper lens 30 and
The light passes through the reflection surface 26 and enters the semiconductor chip 21. Part of the light incident from above is, of course, reflected by the reflection surface 26, but since the reflection surface 26 is formed with a small angle, the light incident from above has a large penetration angle,
The reflectance is low.

At the lower end of the reflection surface 26, a bottom 25a of a concave portion is formed. Since the concave portion 25a is substantially horizontal, light from above is not reflected so much, and therefore, it is more sensitive to light in the vertical direction.

The upper lens 30 and the bottom 25a may be formed in the optical semiconductor device according to the first to fifth embodiments, and in such a case, the same effect is obtained.

The shape of the optical semiconductor device of the present invention is not limited to the above-described examples, but can be variously modified. Further, it is of course possible to implement an optical semiconductor device having the features of the optical semiconductor device exemplified in each embodiment.

[0041]

As described above, the present invention provides a semiconductor chip having a light receiving element and / or a light emitting element, and a sealing body for sealing the semiconductor chip, which is transparent to at least light of a predetermined wavelength. The sealing body has a cylindrical portion above the semiconductor chip, a concave portion provided on the cylindrical portion of the sealing body, and the concave portion has a light receiving surface of the light receiving element or the light emitting portion. It has a reflecting surface that intersects a perpendicular line of the light emitting surface of the element at a predetermined angle, and at least a part of the optical path of light incident on the light receiving element or emitted from the light emitting element is incident on the cylindrical portion, or Since the optical semiconductor device is emitted from the cylindrical portion, passes through the sealing body, and is reflected by the reflection surface, the optical semiconductor device has sensitivity over the entire circumference to light incident from the horizontal direction, or emits light. Optical semiconductor equipment It is.

Furthermore, according to the second aspect of the present invention, since the side surface of the cylindrical portion is mirror-finished, irregular reflection of light on the side surface of the cylindrical portion is small and light loss is small, so that higher sensitivity is achieved. Have or can emit more intense light.

Further, according to a third aspect of the present invention, a light receiving element and / or a driving circuit for driving the light emitting element is sealed in a portion other than the cylindrical portion of the sealing body. The lead electrically connected to the element and / or the light emitting element is formed with the drive circuit separated from the light receiving element and / or the light emitting element. Errors can be prevented.

Further, according to a fourth aspect of the present invention, the driving circuit for driving the light receiving element and / or the light emitting element is formed concentrically with the light receiving element and / or the light emitting element. In addition, since the lead electrically connected to the light emitting element is formed radially from the cylindrical portion, reflection of light on the lead can be dispersed, and malfunction or communication error of the device can be prevented.

Further, according to a fifth aspect of the present invention, in the driving circuit for driving the light receiving element and / or the light emitting element, the driving circuit is formed concentrically with the light receiving element and / or the light emitting element. Since the electrode electrically connected to the light emitting element is formed on the lower surface of the optical semiconductor device, malfunction of the device or communication error due to reflection of light on the lead can be prevented. Further, the actual phase area of the device can be reduced.

Further, in the invention according to claim 6, since a curved surface having a predetermined curvature is formed in a portion on the optical path on the side surface of the cylindrical portion, the light is condensed and higher sensitivity is obtained. Have or can emit more intense light.

Further, according to the present invention, an upper lens having a refractive index different from that of the sealing member is formed in the concave portion, and light incident from above the upper lens also enters the light receiving surface or is emitted from the light emitting element. Since part of the emitted light is emitted from the upper lens, higher sensitivity or stronger light can be emitted to the upper surface of the device.

Further, in the invention according to claim 8, since the concave portion has the bottom surface which is a substantially horizontal plane, the concave portion can emit light having higher sensitivity or stronger light to the upper surface of the device.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an optical semiconductor device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an optical semiconductor device according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram of an optical semiconductor device according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram of an optical semiconductor device according to an embodiment of the present invention.

FIG. 5 is an explanatory diagram of an optical semiconductor device according to an embodiment of the present invention.

FIG. 6 is a cross-sectional view of an optical semiconductor device according to an embodiment of the present invention.

FIG. 7 is an explanatory diagram of an optical semiconductor device according to an embodiment of the present invention.

FIG. 8 is an explanatory diagram of an optical semiconductor device according to an embodiment of the present invention.

FIG. 9 is an explanatory diagram of a conventional optical semiconductor device.

FIG. 10 is a schematic view of a conventional optical semiconductor device.

FIG. 11 is a diagram in which a conventional optical semiconductor device is mounted on a circuit board.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Koichi Ochiai 2-5-2-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Hiroshi Inoguchi 2-5-2 Keihanhondori, Moriguchi-shi, Osaka No. 5 Sanyo Electric Co., Ltd. (72) Inventor Tsutomu Ishikawa 2-5-5 Keihan Hondori, Moriguchi City, Osaka Prefecture (72) Inventor Satoshi Sekiguchi 2 Keihanhondori, Moriguchi City, Osaka Prefecture 5-5-5 Sanyo Electric Co., Ltd. (72) Inventor Hiroshi Kobori 2-5-5 Keihanhondori, Moriguchi-shi, Osaka F-term in Sanyo Electric Co., Ltd. 5F041 AA04 AA06 AA14 AA31 AA47 CB32 CB33 DA17 DA44 DA57 DA83 FF14 5F088 AA03 BA01 BA03 BA15 BA20 BB01 CB06 CB07 CB20 EA07 EA09 JA02 JA06 JA20 KA01 KA02 LA01

Claims (8)

[Claims] 1. A semiconductor chip having a light-receiving element and / or a light-emitting element, and a sealing body that seals the semiconductor chip and that is transparent to at least light having a predetermined wavelength. Having a cylindrical portion above the semiconductor chip,
A concave portion provided on the cylindrical portion of the sealing body, the concave portion having a reflecting surface intersecting a perpendicular to a light receiving surface of the light receiving element or a light emitting surface of the light emitting element at a predetermined angle; At least, the optical path of at least a part of the light emitted from the light emitting element is incident on the cylindrical portion, or emitted from the cylindrical portion, passes through the sealing body,
An optical semiconductor device reflected by the reflection surface. 2. The optical semiconductor device according to claim 1, wherein a mirror surface treatment is performed on a side surface of the cylindrical portion. 3. The optical semiconductor device according to claim 1, wherein a drive circuit for driving the light receiving element and / or the light emitting element is sealed in a portion of the sealing body other than the cylindrical portion. A lead electrically connected to the driving circuit or the light receiving element and / or the light emitting element, wherein the lead is formed with the driving circuit separated from the light receiving element and / or the light emitting element. An optical semiconductor device, comprising: 4. The optical semiconductor device according to claim 1, wherein the driving circuit for driving the light receiving element and / or the light emitting element is formed concentrically with the light receiving element and / or the light emitting element. An optical semiconductor device having a circuit or a lead electrically connected to the light receiving element and / or the light emitting element, wherein the lead is formed radially from the cylindrical portion. 5. The optical semiconductor device according to claim 1, wherein the driving circuit for driving the light receiving element and / or the light emitting element is formed concentrically with the light receiving element and / or the light emitting element. An optical semiconductor device having an electrode electrically connected to a circuit or the light receiving element and / or the light emitting element, wherein the electrode is formed on a lower surface of the optical semiconductor device. 6. The optical semiconductor device according to claim 1, wherein a curved surface having a predetermined curvature is formed in a portion on an optical path on a side surface of the cylindrical portion. apparatus. 7. The optical semiconductor device according to claim 1, wherein an upper lens having a refractive index different from that of the sealing body is formed in the recess, and the light incident from above the upper lens is also received. An optical semiconductor device, wherein a part of light incident on a surface or emitted from the light emitting element is emitted from the upper lens. 8. The optical semiconductor device according to claim 1, wherein the recess has a bottom surface that is a substantially horizontal plane.