JP2638542B2 - Optical semiconductor module - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical semiconductor module containing a light receiving element for receiving output light.

[0002]

2. Description of the Related Art FIG. 7 shows the inside of a conventional optical semiconductor module. One end of an optical fiber 12 is arranged in the package 11 of the optical semiconductor module. A light receiving element 15 is fixed to a side portion of the carrier 14 arranged at the bottom of the package 11. The light receiving element 15 is arranged to face the one end of the optical fiber 12, and receives a light beam. At an end of the package 11 opposite to the side where the optical fiber 12 is arranged, two electrode pads 16 respectively connected to pins (not shown) are arranged. Carrier 14
The light receiving element 15 and the carrier 14 are bonded by a bonding wire 17, and the carrier 14 and the two electrode pads 16 are further bonded by another bonding wire 18.

FIG. 8 shows a state in which the optical semiconductor module shown in FIG. 7 is cut perpendicularly to the bottom surface of the package along the central axis at the position of the optical fiber. Also,
FIG. 9 is an enlarged view of the carrier. The carrier 14 is made of a material such as ceramic and has a rectangular parallelepiped shape, and two bonding pads 21 are arranged so as to straddle the upper surface and one side surface.

A method of mounting the optical semiconductor module having such a configuration will be described. First, the light receiving element 15 is fixed to the carrier 14 at a predetermined position using the solder 23. Next, the light receiving element 15 is bonded to the carrier 14 via the bonding pad 21. And this light receiving element 1
The carrier 14 to which 5 is attached is mounted on the package 11. Thereafter, the electrode pads 16 of the package 11 and the carrier 14 are bonded. Thus, the electrical wiring between the light receiving element 15 and the package 11 is completed.

In such a conventional optical semiconductor module, it is necessary to perform wire bonding on both poles of the light receiving element 15 in the mounting process of the light receiving element 15. Therefore, the shape of the bonding pads 21 on the carrier 14 is restricted and complicated. In the step of mounting the carrier 14 on the package 11, it was necessary to perform bonding again from the bonding pad 21 on the electrode pad 16. This complicates the production process, lowers product yield, and increases assembly costs.

Further, in such a conventional optical semiconductor module, a bonding space between the bonding pad 21 in the package 11 and the carrier 14 for fixing the bonding pad 21 and the light receiving element 15 in the package 11 is required. For this reason, the mounting space of the carrier 14 becomes large, and it has been difficult to reduce the size of the package 11. Further, in such a conventional optical semiconductor module, the number of wire bonding at the time of assembling is increased, so that the structure becomes complicated and it is difficult to improve the productivity. Further, side metallization and patterning of the carrier 14 are required, so that the cost is increased. For these reasons, it has been difficult to reduce the price of the optical semiconductor module itself.

Therefore, in Japanese Patent Application Laid-Open No. 62-124780, an optical semiconductor element is fixed to one surface of a carrier as an insulating substrate, and an electrode lead for extracting an electric signal is provided on the other surface. . These are electrically connected via via holes. In this optical semiconductor module, since the electrode leads are directly exposed to the outside from the bottom surface of the package constituting the module, it can be fixed only by soldering it on the substrate.

[0008]

SUMMARY OF THE INVENTION Japanese Patent Application Laid-Open No. 62-12 / 1987
In the proposal described in Japanese Patent No. 4780, the electrode leads are directly exposed to the outside from the bottom surface of the package constituting the module. Therefore, the signal extraction position is limited, and it is difficult to take a normal pin arrangement. Further, since the inside of the package is exposed to the outside, there is a problem that the reliability of the product is lacking.

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical semiconductor module in which a carrier is not exposed from a package, and which can be reduced in size and cost by simplifying the module mounting structure.

[0010]

According to the first aspect of the present invention, there are provided (a) a light receiving element for receiving a light beam sent from an optical fiber, and (b) a light receiving element for receiving the light beam. And a carrier in which wiring electrode pads are disposed on the opposite surface, and a carrier electrically connected between the electrode pads by a via hole, and (c) a light receiving element and the carrier are disposed at predetermined positions inside. And a package in which an electrode for external connection is arranged at a position where the wiring electrode pad of the carrier contacts in this arrangement state.

That is, according to the first aspect of the present invention, the light receiving element is arranged on one surface of the carrier, and the wiring electrode pads are arranged on the other surface. An electrode for external connection is arranged on a predetermined inner surface, and when the carrier is mounted on the package, the electrode pad for wiring and the electrode for external connection are electrically connected by contact, so that the light receiving element and the external connection are connected. Electrical connection with the electrodes. In the present invention, since the carrier is not directly connected to the external circuit, it is not necessary to expose the carrier from the package.

According to a second aspect of the present invention, two via holes according to the first aspect of the present invention are arranged so as to correspond to the two output terminals of the light receiving element. It is characterized in that one wiring electrode pad is patterned.

According to the third aspect of the present invention, the element fixing pad is disposed in one of the two via holes on the surface of the carrier according to the second aspect on which the light receiving element is fixed. One of the output terminals of the element is soldered to the pad for fixing the element, and the other output terminal is wire-bonded to the other via hole with a bonding wire.

Of course, depending on the configuration of the light receiving element, the two output terminals may be connected to the respective via holes via element fixing pads or the like without using a bonding wire.

According to the fourth aspect of the present invention, (a) a light emitting element, (b) a monitoring light receiving element for receiving a light beam output from the light emitting element, and (c) a light receiving element for receiving the light beam A wiring electrode pad is disposed on the opposite surface, and a carrier electrically connected by a via hole between the wiring electrode pad and the carrier, and (d) a light emitting element, a light receiving element, and a carrier are internally disposed. The optical semiconductor module is provided with a package which is arranged at a predetermined position and an electrode for external connection is arranged at a position where the wiring electrode pad of the carrier presses in this arrangement state.

That is, the invention according to claim 4 deals with an optical semiconductor module containing a light emitting element. The same technical idea as the first aspect of the present invention is applied to a light-receiving element for monitoring light emission for monitoring the light-emitting intensity of the light-emitting element and an electrode for external connection.

According to a fifth aspect of the present invention, the carrier according to the first or the fourth aspect of the present invention has a pattern in which a light receiving element mounting pattern is formed on one surface of one ceramic substrate and corresponds to each of these carriers. The light receiving element is mounted in each of these unit areas, and the light receiving element and the light receiving element mounting pattern in each of the unit areas are bonded with a bonding wire, and then the light receiving elements are cut and formed in each unit area. It is characterized by having. As a result, carriers can be mass-produced using existing equipment. Of course, it is natural that the carrier can be manufactured by a method other than such a method.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments.

FIG. 1 shows the inside of an optical semiconductor module according to an embodiment of the present invention. In the package 31 of the optical semiconductor module of this embodiment, one end of an optical fiber 32 is fixed by an optical fiber fixing block 33. At a position facing the one end of the optical fiber 32, a carrier 35 to which the light receiving element 34 is fixed is arranged. An electrode pad 36 is patterned between the surface of the carrier 35 opposite to the side on which the light receiving element 34 is arranged and the side surface of the package 31.

FIG. 2 shows a state in which the optical semiconductor module shown in FIG. 1 is cut at the position of the optical fiber along the central axis and perpendicular to the bottom surface of the package. Two electrode pads 36 are arranged above and below, and these are respectively connected to pins (not shown). The carrier 35 has two via holes 37 and 38. One bonding wire 39 is connected between the light receiving element 34 and the lower via hole 37.

FIG. 3 is an enlarged view of the carrier of the present embodiment. The carrier 35 is made of a material such as ceramic and has a rectangular parallelepiped shape.
An element fixing pad 41 for fixing the light receiving element 34 is arranged at a position slightly above the center of the front side opposite to the end of the device 2, and a wire bonding pad 42 is disposed at a position slightly below the front center. Have been.

On the back side of the carrier 35, in order to make electrical connection with the electrode pad 36 shown in FIG.
And wiring electrode pads 43 and 44 at positions facing each other.
Is arranged. The element fixing pad 41 and one wiring electrode pad 43, and the wire bonding pad 42 and the other wiring electrode pad 43 are electrically connected to each other by via holes 37 and 38 whose insides are metallized.

FIG. 4 is a front view of the carrier, and FIG. 5 is a side view of the carrier.

A method of mounting the optical semiconductor module having such a configuration will be described. First, the light receiving element 34 is connected to the carrier 35.
Is fixed to the element fixing pad 41 using solder. Thus, the electrode disposed on the back surface of the light receiving element 34 is electrically connected to the wiring electrode pad 43 via the via hole 37. Further, when the other electrode of the light receiving element 34 is wire-bonded to the wire bonding pad 42 using the bonding wire 39, the via hole 3
8 and is electrically connected to the wiring electrode pad 44. Thereby, the light receiving element 34 and the wiring electrode pad 4
Wiring with 3, 44 is completed.

The package 31 of the optical semiconductor module has electrode pads 36 as shown in FIGS.
Are patterned. Therefore, in advance, the light receiving element 3
The electrical wiring between the package 31 and the light receiving element 34 is completed only by mounting the carrier 35 with the wiring fixed and the carrier 35 pressed against the electrode pads 36 of the package 31. Thus, the light receiving element 3 of the optical semiconductor module
4 Simplification of the mounting process is realized.

FIG. 6 shows a main part of the manufacturing process of the carrier of the optical semiconductor module of the present embodiment. On the ceramic substrate 51, a light receiving element mounting pattern composed of an element fixing pad 41 and a wire bonding pad 42 is printed in advance in each area divided vertically and horizontally by broken lines 52 in the figure. The light receiving elements 34 are mounted on the respective areas, and bonding is performed by the bonding wires 39 shown in FIG. Thereafter, the ceramic substrate 51 is cut at the location indicated by the broken line 52, and each carrier 35 is cut.
Is produced.

As described above, the carrier 35 used in the optical semiconductor module of the present embodiment can improve mass productivity. Moreover, the manufacture of the carrier 35 having this structure is performed by using an IC.
The chip mounter and the wire bonding apparatus used in the production of the above-mentioned devices can be used as they are.

In the embodiment described above, the light receiving optical semiconductor module for receiving a light beam has been described. However, the present invention can be similarly applied to a light receiving portion for monitoring light emission monitoring of a light emitting module. As a result, the size and cost of this part can be reduced.

[0029]

As described above, claims 1 to 4 are described.
According to the invention described above, the light receiving element is arranged on one surface of the carrier, the wiring electrode pads are arranged on the other surface, the vias are electrically connected between them, and the outside is provided on the predetermined inner surface of the package. The connection electrode is arranged, and when the carrier is mounted on the package, the wiring electrode pad and the external connection electrode are electrically connected by contact, so that the electrical connection between the light receiving element and the external connection electrode is made. Connection is made. Therefore, it is not necessary to expose the carrier from the package, and the reliability of the module can be improved. Further, connection with external pins is easier than in the case where the carrier is exposed from the package.

According to the fifth aspect of the present invention, a large number of carriers can be manufactured by performing a predetermined processing on one ceramic substrate, so that the carrier is suitable for mass production, and furthermore, is suitable for ICs.
There is an advantage that a chip mounter or a wire bonding apparatus used in the manufacture of the above-described apparatus can be used as it is.

[Brief description of the drawings]

FIG. 1 is a plan view showing the inside of an optical semiconductor module according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the optical semiconductor module shown in FIG. 1 cut along a central axis of the optical semiconductor module perpendicular to a bottom surface of a package at an optical fiber.

FIG. 3 is a perspective view of a carrier used in the present embodiment.

FIG. 4 is a front view of the carrier shown in FIG. 3;

FIG. 5 is a side view of the carrier shown in FIG.

FIG. 6 is a perspective view of the ceramic substrate in a step of forming a carrier of the optical semiconductor module of the present embodiment.

FIG. 7 is a plan view showing the inside of a conventionally used optical semiconductor module.

8 is a cross-sectional view of the optical semiconductor module shown in FIG. 7 cut along a central axis of the optical semiconductor module perpendicular to the bottom surface of the package at the position of the optical fiber.

FIG. 9 is a perspective view of the carrier shown in FIG. 7;

[Explanation of symbols]

 31 package (of an optical semiconductor module) 32 optical fiber 33 optical fiber fixing block 34 light receiving element 36 electrode pad 37, 38 via hole 39 bonding wire 41 element fixing pad 42 wire bonding pad 43, 44 wiring electrode pad

Claims (5)

(57) [Claims] 1. A light-receiving element for receiving a light beam sent from an optical fiber, and the light-receiving element is arranged on a surface on the side receiving the light beam, and a wiring electrode pad is formed on the opposite surface. Place,
A carrier electrically connected between them by a via hole, and the light receiving element and the carrier are arranged at a predetermined predetermined position inside, and in this arrangement state, a position for the external connection is set at a position where the wiring electrode pad of the carrier contacts. An optical semiconductor module, comprising: a package on which electrodes are arranged. 2. The semiconductor device according to claim 2, wherein two via holes are arranged corresponding to two output terminals of the light receiving element, and two wiring electrode pads are patterned on the inner surface of the package corresponding to the via holes. The optical semiconductor module according to claim 1, wherein: 3. An element fixing pad is arranged in one of two via holes on a surface of the carrier to which the light receiving element is fixed, and one of output terminals of the light receiving element is used for fixing the element. 3. The optical semiconductor module according to claim 2, wherein the other output terminal is soldered to the pad and the other output terminal is wire-bonded to the other via hole by a bonding wire. 4. A light-emitting element, a monitor light-receiving element for receiving a light beam output from the light-emitting element, and a light-receiving element disposed on a surface on which light is received, and A wiring electrode pad is disposed, a carrier electrically connected between the wiring electrode pads by a via hole, and the light emitting element, the light receiving element, and the carrier are disposed at a predetermined predetermined position inside, and in this arrangement state, the carrier for the wiring is formed. A package in which an electrode for external connection is arranged at a position where the electrode pad contacts. 5. The carrier is formed by patterning a light receiving element mounting pattern on one surface of a single ceramic substrate for each predetermined unit area corresponding to each of the carriers, and mounting a light receiving element on each of these unit areas. 5. The optical semiconductor according to claim 1, wherein the light receiving element is formed by bonding a light receiving element and a light receiving element mounting pattern for each unit area with a bonding wire and then cutting the light receiving element for each unit area. module.