JPH0521818A - Light receiver - Google Patents

Abstract

PURPOSE:To provide a light receiver which can disconnect light receiving parts such as an optical fiber, a light receiving element array, etc., from one another and enables the easy alignment between these parts. CONSTITUTION:This light receiver is constituted, being equipped with a first package body F and a second package body P. Hereupon, the first package body F holds an optical fiber 2a integrally in place with the emission end thereof being exposed to the outside. Moreover, a second package body P is equipped with a first substrate 5, where a light receiving part 5b which receives the light from the optical fiber 2a and outputs an electric signal and a first electrode which is connected to the light receiving part 5b and takes out the electric signal are made on the rear, a V groove, and a flat part 6b, and further the second electrode connected with the first electrode is made on the incline 6a of the V groove. Furthermore, this includes a second substrate 6, where the third electrode 6g connected with an outer lead 7 is made in the flat part 6b, and a third substrate 9, which catches the end of the outer lead 7 on the third electrode of the second substrate 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light receiving device composed of a pair of package bodies positioned by uniting.

[0002]

2. Description of the Related Art As a conventional light receiving device, "High Uniform
ity, Low Cost Packaging of Multi-Channel InGaAs Pho
todetector Arrays for Parallel-Bus Optical Interco
nnects ”(LEOS '90 Conference Digest,
p.168) and EP.0138630B1.

The light receiving device shown in the paper is composed of a substrate integrally held by a resin member, an optical fiber, and a light receiving element array. An inclined surface is formed on the substrate, and the emitting surface of the optical fiber and the light receiving surface of the light receiving element are arranged symmetrically with respect to an axis orthogonal to the inclined surface. Since the reflecting film is formed on the surface of the inclined surface, the light from the optical fiber is reflected by the reflecting surface of the substrate and enters the light receiving surface of the light receiving element. The light receiving element is connected to the receiving circuit formed on the substrate by wire bonding.

Further, the light receiving device shown in EP.0.138630B1 is composed of a two-sided L-shaped package body in which a light receiving element is mounted on a vertical surface and an optical fiber is fixed on a horizontal surface.

[0005]

In the light receiving device shown in the paper, the structure before the package is unstable and the housing process is not easy. In this device, since the optical fiber and the light receiving element array are integrally resin-molded, there is a problem that the optical fiber cannot be connected to the connector.

Further, the light receiving device shown in EP · 0.138630B1 has a drawback that it is difficult to align the parts.

In view of this, the present invention provides a light-receiving device in which the optical fiber and the light-receiving element are separately configured so that the light-receiving element such as the light-receiving element array can be separated from each other, and the alignment between these parts can be facilitated. The purpose is to provide.

[0008]

A light receiving device according to the present invention comprises a first package and a second package. Here, the first package body positions the optical fiber and integrally holds the optical fiber in a state where the emitting end face of the optical fiber is exposed to the outside. Also, the second
The package body includes a light receiving portion that receives the transmitted light from the optical fiber and outputs an electric signal, and a first substrate that is connected to the light receiving portion and that has a first electrode formed on the back surface to take out the electric signal, a V groove, and a flat portion. A second substrate having a second electrode connected to the first electrode formed on the slope of the V-shaped groove, a third electrode connected to the receiving circuit and the external lead formed on a flat portion, and an end portion of the external lead. A first substrate, a second substrate including a third substrate sandwiched on a third electrode of the second substrate, the first substrate being held in a V groove of the second substrate and the first electrode and the second electrode being electrically connected;
The substrate and the third substrate are integrally held.

[0009]

According to the present invention, the first package body holding the optical fiber and the second package body holding the light receiving portion are separate bodies, and the optical fiber and the second package held in the first package body by the combination. The light receiving portion held by the body is in a state of being optically coupled. The external lead is sandwiched between the second substrate and the third substrate, and is connected to the third electrode without a wire.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A light receiving device according to an embodiment of the present invention will be described below with reference to the accompanying drawings. In the description, the same elements will be denoted by the same reference symbols, without redundant description.

FIG. 1 (a) is a plan view showing a light receiving device using a multi-core optical fiber and a light receiving element array as an embodiment of the present invention, and FIG. 1 (b) is an AA line in FIG. 1 (a). 2 is an end view showing the internal structure taken along the line ', FIG. 2 is an exploded perspective view of the first substrate and the second substrate before packaging, and FIG. 3 shows the first substrate held on the slope of the second substrate. FIG. 4 is a side view showing a state before packaging, and FIG. 4 is a perspective view showing a state before packaging including a second substrate holding a first substrate and a third substrate.

In this embodiment, the first package F and the second package
The first package body F is configured to include the package body P.
The first package body F and the second package body P are coupled to each other by fitting the pair of guide pins formed so as to project from the side surface of the second package body P into the pair of guide holes h formed on the side surfaces of the first package body F and the second package body P. To do.

The first package F has an alignment substrate 1 such as Si having a plurality of V-grooves formed on the surface thereof, and a part of the coating having a plurality of optical fibers 2a aligned with these V-grooves is removed. Multi-core optical fiber core 2, multiple optical fibers 2
It has a so-called multi-core connector structure including a fixing substrate 3 such as Si for fixing a, and has a plurality of optical fibers 2a.
The aligning substrate 1, the multi-core optical fiber core wire 2 and the fixing substrate 3 are integrally held by the resin member 4 in a state where the emitting end faces of are exposed in a line. A pair of guide holes h are formed in the optical axis direction on the emission surface of the first package F where the emission end surface of the optical fiber 2a is exposed so as to sandwich the emission end surface of the optical fiber 2a from both sides. The first package F is formed, for example, by mounting the aligning substrate 1 and the fixing substrate 3 in a mold, and injecting a resin material into the mold to perform resin molding.

The second package P includes a first substrate 5 and a second package 5.
It is configured to include a substrate 6, lead pins (external leads) 7, a third substrate 9, and guide pins 10. The first substrate 5 is held in the V groove of the second substrate 6, and the third substrate 9 is placed on the flat portion 6b. Grooves 9a and 9b are formed on the bottom surface of the third substrate 9 (see FIG. 4), and the ends of the lead pins 7 extending to the outside of the package P are formed between the second substrate 6 and the groove 9b. It is pinched. The first substrate 5, the second substrate 6, the lead pins 7, the third substrate 9, and the guide pins 10 are integrally held by the resin member 4 by resin molding. Resin member 4
Is not formed, the light emitted from the optical fiber 2a enters the lens portion 5a without refraction (see FIG. 1).

The specific structure of each component of the above-mentioned second package P will be described below. The first substrate 5 has a plurality of lens portions 5a formed in a line on the surface thereof. Further, the same number of light receiving portions 5b as the lens portions 5a are formed in a line in the rear surface side region where the optical axes at the time of emission of the light incident on the lens portions 5a intersect. Further, a pair of signal extracting electrodes (first electrodes) 5c are formed on both sides of each light receiving portion 5b. For the first substrate 5, for example, a semiconductor chip formed of undoped InP can be used as a material, and for the electrodes, for example, Ni can be used.
It is possible to use a structure in which B is plated with gold. When the light receiving portion 5b is formed, a method of implanting ions in the first substrate 5 to form a pn junction inside the back surface of the first substrate 5, or an epitaxial growth technique is used to form an InGaAs layer on the back surface of the first substrate 5. The method of forming a photocon type structure in which AlInAs layers are laminated can be applied. The second substrate 6 includes an inclined portion 6a and a flat portion 6b. A plurality of electrodes (second electrodes) 6c are formed at the same intervals at positions corresponding to the signal extraction electrodes 5c described above on the inclined portion 6a which is one inclined surface forming the V groove. Further, the flat portion 6b has a receiving circuit 6d formed therein,
S that protects the receiving circuit 6d and insulates between the wirings
insulating film 6e such iO _2, the insulating film formed on the 6e wiring portion 6f which is connected to the electrode 6c, lead pins 7 and directly connected electrodes extending to the outside as well as connected to an end of the wiring portion 6f (No. 3 electrodes) 6g are formed. Here, the inclined portion 6a can be formed by forming a V groove in the end portion of the second substrate 6 by dicing, for example.
By changing the depth of the groove, it is possible to easily deal with the first package body in which the height of the optical fiber 2a is different. The wiring portion 6f can be formed by using a known technique such as sputtering, plating, vapor deposition, or the like. The third substrate 9 has a groove portion 9a that encloses the chip capacitor 6h such as a chip capacitor and a chip resistor mounted on the flat portion 6b of the second substrate 6 without damaging the end portion of the lead pin 7 and the second substrate 6. A groove 9b is formed so as to sandwich the third electrode 6g in contact with the third electrode 6g (see FIG. 4).

Next, the engaging structure of the groove portion of the third substrate and the tip portion of the lead pin applicable to this embodiment will be described. In FIG. 5, the lead pin 7 is formed by the groove 9 a of the third substrate 9.
It is a longitudinal cross-sectional view showing a configuration example for sandwiching. In FIG. 5A, the rectangular area located at the end of the third substrate 9 is removed and I
The structure is shown with a V-shaped groove. The tip of the lead pin 7 is plated with gold 7a, and its surface is rough as if it had been surface treated with a file. The lead pin 7 is connected to the third electrode 6 via the bump 11 by the third substrate 9.
Although it is crimped to g, crimping is facilitated because a large number of irregularities are formed at the tip of the lead pin 7. Figure 5
The third substrate 9 shown in (b) is formed with L-shaped grooves having different depths, and the lead pin 7 having the L-shaped tip is engaged. In this case, since the engaging portion is formed in the groove portion 9a and the tip portion of the lead pin 7 is engaged with the engaging portion, the mounting state of the lead pin 7 is further stabilized.

According to this embodiment, the optical fiber 2a and the light receiving portion 5b are optically coupled by inserting the guide pin 10 into the guide hole h, so that the alignment between the components is extremely easy.

Even when the second package P is formed, the vertical alignment is achieved only by holding the first substrate 5 in the V groove of the second substrate 6, and by moving along the V groove. Horizontal alignment is achieved. Therefore,
Positioning before the package is easy, and its mounting structure is stable. Therefore, even when the mounting structure is mounted on the mold and the resin material is injected to mold the package body with resin, it is possible to prevent misalignment due to the injection pressure of the resin material.

Further, if a ball lens is used as the lens portion 5a of the first substrate 5 and the position of the lens portion 5a can be changed, vertical alignment with the optical fiber becomes possible.

Next, the flow of signals in the light receiving device according to this embodiment will be described below. The transmitted light emitted from the optical fiber 2a is received by the lens portion 5a of the first substrate 5, condensed inside the first substrate 5, and incident on the light receiving portion 5b. The incident light is converted into an electric signal by the light receiving portion 5b and sent to the signal extracting electrode 5c. Since the signal extracting electrode 5c is electrically connected to the electrode 6c formed on the inclined portion 6a of the second substrate 6, the electric signal extracted from the signal extracting electrode 5c is sent to the electrode 6c and the receiving circuit 6d. One end is sent to the lead pin 7 which extends to the outside through the electrode 6g.

The present invention is not limited to the above embodiment. In the embodiment, the structure in which the optical fiber is sandwiched between the two substrates is shown as an example, but the structure is not limited to this structure.

[0022]

Since the present invention is constructed as described above, the optical fiber and the light receiving portion can be separated from each other, and by combining these, the alignment of the parts can be realized easily and accurately. can do.

[Brief description of drawings]

FIG. 1 is a diagram showing a structure of a light receiving device using a multi-core optical fiber and a light receiving element array as one embodiment of the present invention.

FIG. 2 is an exploded perspective view showing a first substrate and a second substrate before packaging which can be used in the embodiment shown in FIG.

FIG. 3 is a side view showing a state before a package in which a first substrate that can be used in the light receiving device shown in FIG. 1 is held on an inclined surface of a second substrate.

4 is a perspective view showing a state before a package including a first substrate, a second substrate and a third substrate which can be used in the light receiving device shown in FIG. 1. FIG.

FIG. 5 is a vertical cross-sectional view showing a configuration example in which a tip portion of a lead pin is held by a groove portion of a third substrate.

[Explanation of symbols]

F ... First package body, P ... Second package body, 1 ... Alignment substrate, 2 ... Optical fiber core wire, 3 ... Fixing substrate, 4 ...
Resin member, 5 ... First substrate, 6 ... Second substrate, 7 ... Lead pin, 9 ... Third substrate, 10 ... Guide pin, 11 ... Bump.

Claims (3)

[Claims] 1. A first package body that integrally holds an optical fiber in a state where the optical fiber is positioned and an emission end face of the optical fiber is exposed to the outside, and light transmitted from the optical fiber is received. A second substrate that is connected to the first electrode and that includes a light receiving portion that outputs an electric signal and a first substrate that is connected to the light receiving portion and that takes out the electric signal and that is formed on the back surface, a V groove, and a flat portion. An electrode is formed on the slope of the V-groove, and a third electrode connected to an external lead is formed on the flat portion; and an end of the external lead is formed on the third electrode of the second substrate. A first substrate, a second substrate, and a third substrate in a state in which the first substrate is held by a V groove of the second substrate and the first electrode and the second electrode are electrically connected to each other. A second package that holds the substrate together Receiving device configured and a body. 2. The light receiving device according to claim 1, wherein a groove is formed at an end of the third substrate, and the end of the external lead is held by the groove. 3. The light receiving device according to claim 2, wherein the end portions of the external leads are metal-plated.