JPH10213723A - Photosemiconductor module and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an optical fiber from being broken and to obtain secure airtight sealing structure by forming a light input/output terminal of a ferrule which has an optical fiber inside, mounting the ferrule in a groove of a substrate, and leading its one end out of a package and joining the package and ferrule together in an airtight sealing state. SOLUTION: The photosemiconductor module is constituted by joining the substrate 10 of silicon, etc., in the package 20 and covering it with a lid 27 for airtight sealing. The substrate 10 has the groove, an electrode, and a solder pattern 12 formed and a photosemiconductor element such as a laser diode 13 is mounted on the electrode. Further, an electrode pad 24 which forms an electric input/output terminal for inside/outside electric conduction is formed at a step part on the internal surface of the packet 20, and a ferrule 25 in which the optical fiber forming the light input/output terminal is embedded is joined to one flank. Then the ferrule 25 is mounted in the groove 11 of the substrate 10 and an electrode pad 24 on the side of the package 20 and the solder pattern 12 on the electrode on the side of the substrate 10 are joined together while matched with each other.

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 used for optical communication, and more particularly to an optical semiconductor module and an optical fiber which are mounted without adjustment and hermetically sealed, and which have high mass productivity and high reliability. The present invention relates to a semiconductor module.

[0002]

2. Description of the Related Art A conventional optical semiconductor module comprises a can-type hermetically sealed optical semiconductor element, a lens system and an optical fiber fixed to a casing, and the optical axis of the optical semiconductor element and the optical fiber. For alignment, they were manufactured by positioning and aligning and welding. Also,
It has been common practice to similarly position and weld the optical semiconductor element using a butterfly type package and then hermetically seal it.

However, the above optical semiconductor module is
In the manufacturing process, it is necessary to perform alignment work while monitoring the device characteristics between the optical semiconductor device and the optical fiber.
The manufacturing process could not be simplified.

Therefore, in recent years, there has been no need for the above-mentioned alignment work for the purpose of spreading optical devices to subscriber systems.
2. Description of the Related Art An optical semiconductor module that is compact, low-cost, and excellent in mass productivity has been developed. For example, in the optical semiconductor module shown in FIG. 5, a highly accurate V-groove 41 is formed on a substrate 40 such as silicon, and an electrode or solder pattern positioned with high precision is formed on the V-groove 41. After placing the laser diode 43 as an element,
If the optical fiber 56 as an optical input / output terminal is placed and fixed in the V-groove 41, the mounting and fixing can be performed without monitoring the element characteristics (passive alignment). Thereafter, the substrate 40 and the photodiode 45 for monitoring are housed in the package 50, the optical fiber 56 is held and held by the fiber holder 59, and the lid 57 is joined with a resin to hermetically seal the optical fiber 56. Is held down by the block 58 at its outer end.

As shown in FIG. 6, a lead frame 54 serving as an electric input / output terminal is attached to a lower portion of a substrate 40 made of silicon or the like on which a laser diode 43 and an optical fiber 56 are mounted as described above. An optical semiconductor module having a structure in which the optical fiber module is hermetically sealed by molding at 60, while a receptacle 61 is provided at the outer end of the optical fiber 56 so that it can be connected to another optical connector (electronic information). Communication Society Society Conference C-204).

[0006]

However, in the optical semiconductor module shown in FIG. 5, when the optical fiber 56 is sandwiched between the package 50 and the lid 57 and fixed with an adhesive such as a resin, the optical fiber 56 has a cylindrical side surface. The workability is poor because the adhesive does not easily flow around, and the reliability of hermetic sealing around the optical fiber 56 after bonding is also poor.

On the other hand, in the resin-molded optical semiconductor module shown in FIG. 6, the end of the substrate 40 and the end of the optical fiber 56 may be damaged by the stress at the time of curing the resin 60,
There was a problem that the reliability of hermetic sealing deteriorated.

Further, in each of the optical semiconductor modules, the bare optical fiber 56 whose coating has been removed is connected to the substrate 4.
During the manufacturing process, the optical fiber 5
There was also a problem that No. 6 was easily damaged.

[0009]

Accordingly, the present invention provides a method for mounting an optical semiconductor device on an electrode formed on a substrate such as silicon.
An optical input / output terminal to the optical semiconductor element is placed in the groove of the substrate, and in an optical semiconductor module in which these are sealed with a package, the optical input / output terminal is formed of a ferrule containing an optical fiber, The ferrule is placed in the groove of the substrate and one end thereof is led out of the package, and the package and the ferrule are hermetically sealed and joined.

That is, since a ferrule containing an optical fiber is used as an optical input / output terminal and the ferrule is mounted in a groove of the substrate, breakage of the optical fiber in the manufacturing process can be prevented. In addition, one end of the ferrule is led out and hermetically sealed between the ferrule and the package, whereby a reliable hermetic sealing structure can be easily obtained.

Further, the present invention provides: B. a step of forming an electrode for mounting an optical semiconductor element on a substrate such as silicon and a groove for mounting an optical input / output terminal; B. mounting an optical semiconductor element on the electrode; An electrical input / output terminal that conducts between inside and outside of the package,
Providing an optical input / output terminal communicating between the inside and the outside; A. Step of aligning the electrodes and grooves on the substrate side with the electrical input / output terminals and the optical input / output terminals on the package side, respectively, and joining the substrate to the package. The method is characterized by a method for manufacturing an optical semiconductor module, comprising a step of hermetically sealing the substrate.

That is, by providing the optical input / output terminals on the package side in advance in the step C, it is possible to reliably hermetically seal the two. In addition, by bonding the substrate and the package, which have been manufactured in a separate step in advance, in the step D, the optical semiconductor module can be easily manufactured. At the time of this bonding, the optical input / output terminal is placed in a groove formed in the substrate in advance, so that the alignment can be automatically performed by passive alignment.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a plan view of the optical semiconductor module with the lid removed, and FIG. 1B is a cross-sectional view. In each case, units on the substrate 10 side are indicated by broken lines.

This optical semiconductor module has a package 2
A substrate 10 made of silicon or the like is bonded to the inside of the housing, and is covered with a lid 27 and hermetically sealed. The substrate 10 has a groove 11 and an electrode 1
2a and a solder pattern 12 are formed, and an optical semiconductor element such as a laser diode 13 is mounted on the electrode 12a. Further, an electrode pad 24 forming an electric input / output terminal for conducting between inside and outside is formed on a step portion 21 on the inner surface of the package 20,
A ferrule 25 in which an optical fiber 26 forming an optical input / output terminal is embedded is joined to one side surface. Then, the ferrule 25 is placed in the groove 11 of the substrate 10, and the electrode pad 24 on the package 20 side and the electrode 1 on the substrate 10 side
The solder patterns 12 on 2a are joined in a matched state.

Therefore, the external lead 2 of the electrode pad 24
An electric signal can be input to the laser diode 13 from 4a, and the light emitted from the laser diode 13 can be led out to the outside by the optical fiber 26 in the ferrule 25, and can function as an optical semiconductor module.

Hereinafter, the manufacturing process of the optical semiconductor module will be described in detail.

First, as shown in FIG.
And an electrode 12a and a solder pattern 12 thereon (Step A). The substrate 10 is made of silicon, glass, ceramics, or the like.
Form one. At this time, V-shaped grooves 11 are formed by anisotropic etching in the case of the silicon substrate 10 and by machining in the case of the glass or ceramic substrate 10.

Next, an electrode 12a is formed on the substrate 10. In the example of FIG.
The electrodes 12a at necessary positions are extended to the inside of the substrate. At this time, the position of the groove 11 is precisely adjusted to form the electrode 12a. After that, the solder pattern 12 is formed at a predetermined position on the electrode 12a.

Next, an optical semiconductor element is mounted (step B).
However, as shown in FIG. 2, a laser diode 13 as an optical semiconductor element is mounted on the electrode 12a by die bonding or wire bonding with high precision.

On the substrate 10, a monitoring photodiode 14 is mounted on another electrode 12a. That is, the emitted light from the laser diode 13
Although the light is emitted in one direction, the same light is also emitted in the opposite direction, so that the light can be monitored by the photodiode 14. A groove 15 is formed between the photodiode 14 and the laser diode 13 so that the light emitted from the laser diode 13 is reflected on the side surface of the groove 15 and enters the light receiving surface formed on the lower surface of the photodiode 14. It is.

Further, another element 16 can be mounted on another electrode 12a. As the element 16, for example, an LCR circuit such as a reactance, a capacitor, and a resistor or a thermistor is mounted.

Next, as shown in FIG. 3, a unit on the package 20 side is manufactured (step C). The package 20 is a box-shaped body made of ceramics or resin, has a step portion 21 on the inner surface, a through hole 22 on one side surface, and a through hole 2.
2 is provided with a tubular portion 23 outside. The external lead 2 is provided on the step portion 21 as an electric input / output terminal for conducting inside and outside.
There is provided an electrode pad 24 electrically connected to the electrode 4a, and a total of eight electrode pads 24 are formed at positions corresponding to the solder patterns 12 on the electrodes 12a of the substrate 10.

A ferrule 25 as an optical input / output terminal is inserted into the through hole 22, and one end of the ferrule 25 is joined to the through hole 22 in a state of being led out to the outside. This ferrule 2
Reference numeral 5 denotes a cylindrical body made of ceramics or the like, in which an optical fiber 26 is embedded in a central through hole. The ferrule 25 and the optical fiber 26 are bonded with an adhesive or the like, but in order to ensure airtight sealing, use an optical fiber 26 metallized around, and solder or the like between the ferrule 25 and the ferrule 25. Filling and joining are also possible.

The ferrule 25 and the through hole 22 of the package 20 are hermetically sealed and joined. The specific joining structure is as follows. First, when the package 20 is formed of ceramics, metallization may be applied to the inside of the through hole 22 and the outer surface of the ferrule 25, and the two may be joined by brazing or soldering. It can be completely hermetically sealed. When the package 10 is formed of resin, the package 20 can be formed very easily by molding and integrating the package around the ferrule 25.

A sleeve 27 made of ceramics, metal, or the like is attached to the outer periphery of the external lead-out portion of the ferrule 25. Although not shown, a receptacle as shown in FIG. 5 is provided around the cylindrical portion 23, and another optical connector can be detachably connected.

Next, as shown in FIG. 4, the substrate 10 is collectively joined to the package 20 face down (step D). At this time, the ferrule 25 on the package 20 side is tightly fixed to the groove 11 on the substrate 10 side, and the space between the electrode pad 24 on the package 20 side and the solder pattern 12 on the electrode 12a on the substrate 10 side is made of gold tin or the like. The board 10 and the package 20 are joined and fixed by joining with solder.
Dimensionally, the ferrule 25 is tightly fixed to the groove 11, and is manufactured so that a slight gap is formed between the electrode pad 24 and the solder pattern 12, and the gap is filled with solder and joined. preferable.

Although there is no particular need to join between the ferrule 25 and the groove 11, it is also possible to join them partially using solder or the like. For example, a part of the groove 11 of the substrate 10 is provided with a concave portion serving as a solder pool and filled with solder, and the outer periphery of the corresponding ferrule 25 is metallized, and the ferrule is filled with the solder filled in the concave portion. 25 can also be joined.

Thus, the substrate 10 and the package 2
0 face down, ferrule 25 into groove 11
In this case, the ferrule 25 and the laser diode 13 can be automatically aligned by passive alignment.

By joining the solder pattern 12 on the electrode 12a of the substrate 10 to the electrode pad 24, electric signals can be input and output to and from the laser diode 13 and other elements by the external lead 24a. at the same time,
The optical signal of the laser diode 13 can be led out to the outside by the ferrule 25, and an optical semiconductor module can be configured.

Finally, as shown in FIG. 4B, an optical semiconductor module of the present invention can be obtained by joining and covering a lid 27 at the opening of the package 20 and hermetically sealing it.

The optical semiconductor module of the present invention as described above can easily obtain a reliable hermetic sealing structure. That is, in such an optical semiconductor module, it is generally difficult to hermetically seal the periphery of the optical input / output terminal. However, in the present invention, the package 20 and the ferrule 25 are hermetically sealed in advance in step C of FIG. Because it is good to do it,
A reliable hermetic sealing structure can be easily obtained.

Further, since the ferrule 25 in which the optical fiber 26 is buried is placed in the groove 11, it is possible to prevent the optical fiber 26 from being damaged in the manufacturing process. Further, the substrate 1
Since it is only necessary to separately manufacture the unit on the 0 side and the unit on the package 20 side and join them face down,
It can be manufactured in a simple process.

In the above embodiment, an example is shown in which the laser diode 13 is used as the optical semiconductor element.
Other light emitting elements, light receiving elements such as photodiodes, or optical integrated circuits can also be used.

The number of the electrodes 12a and the electrode pads 24,
The position, shape, and the like are not limited to the above embodiment,
It goes without saying that there can be various things.

Further, as another embodiment of the present invention, although not shown, an optical fiber 26 alone may be used instead of the ferrule 25 as an optical input / output terminal. In this case, for example, an optical fiber 26 having a metallized outer peripheral surface is solder-fixed to the through hole 22 of the ceramic package 20 and hermetically sealed, and the optical fiber 26 is tightly fixed to the groove 11 by the substrate 10. Thus, the substrate 10 and the package 20 may be joined face down.

[0036]

As described above, according to the present invention, an optical semiconductor device is mounted on an electrode formed on a substrate such as silicon.
An optical input / output terminal to the optical semiconductor element is placed in the groove of the substrate, and in an optical semiconductor module in which these are sealed with a package, the optical input / output terminal is formed of a ferrule containing an optical fiber, The ferrule is placed in the groove of the substrate and one end thereof is led out of the package, and the package and the ferrule are hermetically sealed and joined to prevent breakage of the optical fiber in the manufacturing process, In addition, a reliable hermetic sealing structure can be easily obtained by hermetically sealing the space between the ferrule and the package in advance.

According to the present invention, B. a step of forming an electrode for mounting an optical semiconductor element on a substrate such as silicon and a groove for mounting an optical input / output terminal; B. mounting an optical semiconductor element on the electrode; An electrical input / output terminal that conducts between inside and outside of the package,
Providing an optical input / output terminal communicating between the inside and the outside; A. Step of aligning the electrodes and grooves on the substrate side with the electrical input / output terminals and the optical input / output terminals on the package side, respectively, and joining the substrate to the package. By manufacturing the optical semiconductor module from the step of hermetically sealing the substrate, by providing the optical input / output terminals on the package side in advance in step C, the two are reliably hermetically sealed to improve the mechanical strength. And reliability can be improved. In addition, by manufacturing the substrate and the package in separate steps and joining them in the step D, electrical connection and optical connection can be performed at the same time, so that an optical semiconductor module with excellent productivity and low cost can be manufactured. it can.

[Brief description of the drawings]

FIG. 1 shows an optical semiconductor module of the present invention,
(A) is a plan view without a lid, and (b) is a cross-sectional view taken along line XX.

FIGS. 2A and 2B show only units on the substrate side in the manufacturing process of the optical semiconductor module of the present invention, and FIG.
(B) is a sectional view taken along line YY.

3A and 3B show only a package-side unit in a manufacturing process of the optical semiconductor module of the present invention, wherein FIG. 3A is a plan view and FIG. 3B is a sectional view taken along the line ZZ.

4A and 4B show a state in which a substrate and a package are joined in a manufacturing process of the optical semiconductor module of the present invention, and FIG.
Is a plan view, and (b) is a sectional view taken along line WW.

FIG. 5 is an exploded perspective view showing a conventional optical semiconductor module.

FIG. 6 is an exploded perspective view showing a conventional optical semiconductor module.

[Explanation of symbols]

 10: Substrate 11: Groove 12: Solder pattern 12a: Electrode 13: Laser diode 14: Photodiode 15: Groove 20: Package 21: Step portion 22: Through hole 23: Cylindrical portion 24: Electrode pad 24a: External lead 25: Ferrule 26: Optical fiber 27: Sleeve

Claims (2)

[Claims] An optical semiconductor device is mounted on an electrode formed on a substrate such as silicon, and an optical input / output terminal for the optical semiconductor device is placed in a groove provided on the substrate, and these are sealed with a package. In the optical semiconductor module, the optical input / output terminal is formed of a ferrule having a built-in optical fiber, the ferrule is placed in the groove of the substrate, and one end thereof is led out of the package. An optical semiconductor module, characterized by being hermetically sealed and joined. 2. A method for manufacturing an optical semiconductor module comprising the following steps. A. B. a step of forming an electrode for mounting an optical semiconductor element on a substrate such as silicon and a groove for mounting an optical input / output terminal; B. mounting an optical semiconductor element on the electrode; An electrical input / output terminal that conducts between inside and outside of the package,
Providing an optical input / output terminal communicating between the inside and the outside; A. Step of aligning the electrodes and grooves on the substrate side with the electrical input / output terminals and the optical input / output terminals on the package side, respectively, and joining the substrate to the package. Step of hermetically sealing the substrate