JP2001313438A - Photoelectron module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photoelectron module facilitating handling with a small size and having superior high speed operation. SOLUTION: The photoelectron module comprises an optical semiconductor element 10 and an optical transmitter 20 for optically coupling the element 10, which is mounted on an optically mounting board 30 disposed on the upper surface of a base 50, and a drive circuit 60 of the element 10 formed in a recess 57 which is formed on the lower surface of the base 50. The circuit 60 is connected to the element 10 via a conductor 59a which passes through the base 50.

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 in which an optical semiconductor element and an optical transmitter are optically coupled, and an electronic integrated circuit and an electronic component which are driving circuits of the optical semiconductor element are mounted on the same substrate. And an optoelectronic module for optical fiber communication.

[0002]

2. Description of the Related Art In recent years, with the spread of optical fiber communication, optical semiconductor elements, optical transmission bodies, electronic integrated circuits for driving optical semiconductor elements, and optoelectronic modules equipped with electronic components have been reduced in size and cost, and furthermore. High productivity is required.

For this reason, a structure using a mounting substrate on which a V-shaped or rectangular groove and electrodes are formed with high precision has been put to practical use for optical coupling between an optical semiconductor element and an optical transmission body such as an optical fiber or an optical waveguide.

In addition, the structure using the above mounting board allows the entire module to be reduced in size and the wiring for electric signals can be made shorter than before, so that it is also very effective in increasing the speed required for an optoelectronic module. is there.

[0005] Further, in order to reduce the productivity and cost of the optoelectronic module, instead of using a conventional hermetic sealing structure using a ceramic or metal package, a resin package is used, or a transfer mold is used. A non-hermetic structure using a resin filling method is used. Alternatively, a method of covering each element or component mounted on the base with resin is also used.

FIG. 5 shows an example of this, in which an optical mounting board 130 on which an optical semiconductor element 110 and an optical fiber 120 are mounted, an electronic integrated circuit 160 for driving the optical semiconductor element 110, and electronic components are mounted on an opto-electronic mounting board 150. It has a mounting structure in which high productivity and low cost are realized by mounting it on top and covering it with a resin 170 (Japanese Unexamined Patent Publication No.
No. 0-227953).

[0007]

In the above mounting structure, since the package used conventionally is not used,
Although it is effective for high productivity and cost reduction as an optoelectronic module, it is a structure in which an optical mounting board, an electronic integrated circuit, and electronic components are combined and integrated on a single base,
Opto-electronic modules are necessarily large. In turn,
When incorporating the optoelectronic module into an optical transmission device, a large mounting area is required, and a great deal of trouble is required for handling.

In addition, since the size of the substrate used is large, the productivity is low and the cost reduction of the optoelectronic module is naturally limited.

Further, since the optical mounting board and the electronic integrated circuit are arranged on a plane, the length of the electric signal wiring is increased, and the loss of the electric signal is increased. This loss increases as the frequency of the high-frequency signal increases, which limits or hinders the high-speed operation of the optoelectronic module. If the optical mounting substrate is made extremely small, the wiring length can be shortened, but if the clearance for mounting is included, the wiring length must be long.

Accordingly, an object of the present invention is to provide an optoelectronic module that is small, easy to handle, and excellent in high-speed operation.

[0011]

In order to solve the above problems, an optoelectronic module according to the present invention has an optical package in which an optical semiconductor element and an optical transmission body optically coupled to the optical semiconductor element are mounted on an upper surface of a base. A substrate is provided, and a drive circuit for the optical semiconductor element is mounted in a recess formed on the lower surface of the base, and the drive circuit and the optical semiconductor element are connected via a conductor penetrating the base. Consisting of

Further, a concave portion is formed on the upper surface of the base, and the optical mounting board is accommodated in the concave portion. In particular, the concave portion formed on the lower surface of the base is formed on the back surface side of the concave portion formed on the upper surface of the base, and the conductor penetrating the base is formed on the concave portion formed on both the upper surface and the lower surface of the base. It is characterized by being in communication.

In addition, a concave portion having an opening area smaller than the outer shape of the optical mounting substrate and wider than the outer shape of the optical semiconductor element is formed on the upper surface of the base, and the optical semiconductor element is accommodated in the concave portion. The optical mounting substrate is disposed in the recess with the optical semiconductor element mounting side of the optical mounting substrate facing down.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1A and 1B are diagrams schematically showing one embodiment of the optoelectronic module of the present invention, wherein FIG. 1A is a perspective view as viewed obliquely from above, and FIG. 1B is a perspective view as viewed obliquely from below. FIG. 2 is a sectional view thereof.

An optical semiconductor device 10 which is a light emitting device such as a semiconductor laser and an optical fiber 20 which is an optical transmitter are mounted on an optical mounting substrate 30 made of single crystal silicon, glass or the like. An electrode 32 (for example, a laminate of titanium, platinum, gold, or the like) for supplying power to the optical semiconductor element 10 is formed on a mounting surface 31 of the optical mounting substrate 30 in advance. The optical semiconductor element 10 is accurately positioned on the electrode 32, is also joined using solder (not shown) formed in advance on the electrode 32, and a power supply line is formed using the metal wire 40a.

On the other hand, the optical fiber 20 which is in an optically coupled state with the optical semiconductor element 10 is mounted along a groove (not shown) precisely formed on the optical mounting substrate 30 and fixed with a resin adhesive or solder. Is done. If a material capable of anisotropic etching such as silicon single crystal is used for the optical mounting substrate 30, the grooves can be formed accurately by anisotropic etching, which is convenient.

On the first main surface (upper surface) 51 of the optoelectronic mounting substrate 50 made of ceramics such as alumina as a base, a concave portion 52 having an opening area slightly larger than the outer shape of the optical mounting substrate 30 is formed. I have. On the bottom surface 53 of the concave portion 52, wiring patterns 54a and 54b corresponding to the optical mounting substrate 30 are formed.

The optical mounting substrate 3 is located at a predetermined position of the concave portion 52.
0 is mounted, and the electrode 32 and the wiring patterns 54a and 54b are connected by metal wires 40b and 40c, respectively, so that both are conductive.

The first principal surface 51 of the optoelectronic mounting substrate 50
A concave portion 57 is also formed in the second main surface (lower surface) 55 located opposite to the above. The wiring patterns 54c and 54d are also provided on the bottom surface 58 of the concave portion as a driving circuit of the optical semiconductor element mounted thereon. For example, the LSI electronic integrated circuit 60 made of single crystal silicon or gallium arsenide and the electronic component ( It is formed in accordance with the wiring pattern (not shown).
The electronic integrated circuit 60 and the electronic component are mounted at predetermined positions of the recess 57 using solder, a conductive adhesive (80), or the like. This mounting is preferable to flip-chip mounting with the circuit surface facing the bottom because the connection wires can be omitted.

A wiring pattern 54a formed on the first main surface 51 side and a wiring pattern 54 formed on the second main surface 55 side
“c” is connected by a conductive wiring 59 a which is a conductor (for example, a tungsten alloy) formed so as to penetrate the optoelectronic mounting substrate 50. Similarly, the wiring pattern 54d and the lead 56 are connected by a conductive wiring 59b, which is a conductor. Therefore, the electronic integrated circuit 6
0 and the optical semiconductor element 10 are connected as a predetermined circuit. The lead 56 may be in the form of a thin plate as shown in the drawing, or may be in the form of a pin or a ball made of solder. In any case, conduction is ensured by the metal.

Then, the optical mounting substrate 30 and the electronic integrated circuit 6
Numeral 0 is covered with, for example, epoxy resins 70a and 70b and protected from the external environment. Here, it is effective to provide a transparent resin which transmits an optical signal in advance to the optical coupling portion 21 between the optical semiconductor element 10 and the optical fiber 20 in order to obtain good optical coupling.

FIGS. 3A and 3B are views showing another embodiment of the optoelectronic module, wherein FIG. 3A is a perspective view as viewed obliquely from above, and FIG.
FIG. 3 is a perspective view seen from obliquely below. FIG. 4 is a sectional view thereof.

The mounting of the optical semiconductor element 10 and the optical fiber 20 on the optical mounting board 30 is the same as in the above embodiment. It is also effective to apply a transparent resin to the optical coupling section 21 in the same manner as described above.

On the first principal surface 51 of the optoelectronic mounting substrate 50,
A concave portion 52 having an opening area smaller than the outer shape of the optical mounting substrate 30 is formed. A wiring pattern is formed around the concave portion 52 in accordance with the electrode 32 on the optical mounting substrate.

For this wiring pattern, the optical mounting substrate 3
0 is mounted with the mounting surfaces 31 facing each other. In mounting, the electrode 32 and the wiring pattern 54a are directly joined. For this bonding, solder may be used, or a conductive adhesive may be used. Alternatively, if an annular metal pattern is formed on the outer periphery of the mounting surface 31 and the same pattern is formed on the first main surface 51, the optical coupling portion 21 can be hermetically sealed by joining using solder. It becomes possible.

As in the above embodiment, the optoelectronic mounting substrate 50 has a recess 57 corresponding to the electronic integrated circuit 60 formed on the second main surface 55 for conduction, and the electronic integrated circuit 6
0 and electronic components are mounted. Wiring pattern 54a
And 54c, and conduction between the lead 56 and the wiring pattern 54d are the same as in the above embodiment. A conductive structure from the leads 56 to the electronic integrated circuit 60 and the optical semiconductor element 10 is formed.

Then, the optical mounting substrate 30 and the electronic integrated circuit 6
Numeral 0 is covered with resins 70a and 70b and protected from the external environment.

[0029]

According to the optoelectronic module of the present invention, since the optical mounting board and the drive circuit of the optical semiconductor element are joined in a plane direction, the whole can be further reduced in size, and as a result, the optical transmission equipment can be used. The mounting area is small, and handling is simple and easy.

Further, since the distance from the optical semiconductor element mounted on the optical mounting substrate to its driving circuit and other electronic parts and further to the leads provided on the base can be extremely short, the wiring length of the electric signal can be reduced. It can be shortened and the loss of electric signal is reduced. Thereby, an excellent optoelectronic module capable of high-speed operation can be provided.

[Brief description of the drawings]

FIGS. 1A and 1B are diagrams schematically illustrating one embodiment of an optoelectronic module according to the present invention, wherein FIG. 1A is a perspective view as viewed obliquely from above, and FIG. 1B is a perspective view as viewed obliquely from below.

FIG. 2 is a cross-sectional view schematically illustrating the optoelectronic module of FIG.

FIGS. 3A and 3B are diagrams schematically illustrating another embodiment of the optoelectronic module of the present invention, wherein FIG. 3A is a perspective view as viewed obliquely from above, and FIG. 3B is a perspective view as viewed obliquely from below.

FIG. 4 is a cross-sectional view schematically illustrating the optoelectronic module of FIG.

FIG. 5 is a perspective view schematically showing a conventional optoelectronic module.

[Explanation of symbols]

 10: Optical semiconductor element 20: Optical fiber (optical transmission body) 21: Optical coupling part 30: Optical mounting substrate 31: Mounting surface 32: Electrode 40a to 40c: Metal wire 50: Optoelectronic mounting substrate (base) 51: First main component Surface (upper surface of base) 52: concave portion of first main surface 53: bottom surface of concave portion 54a to 54d: wiring pattern 55: second main surface (lower surface of base) 56: lead 57: concave portion of second main surface 58: concave portion Bottom surface 59a, 59b: conductive wiring (conductor) 60: electronic integrated circuit 70a, 70b: resin 80: solder or conductive adhesive 110: optical semiconductor element 120: optical fiber 130: optical mounting board 150: optoelectronic mounting board 160: Electronic integrated circuit 170: Resin

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 25/07 H01L 25/08 Z 25/18 H01S 5/022

Claims (4)

[Claims] 1. An optical mounting board on which an optical semiconductor element and an optical transmitter for optically coupling to the optical semiconductor element are mounted on an upper surface of a base, and the optical mounting substrate is provided in a recess formed on a lower surface of the base. An optoelectronic module comprising a drive circuit for an optical semiconductor element mounted thereon and the drive circuit and the optical semiconductor element connected via a conductor penetrating the base. 2. The optoelectronic module according to claim 1, wherein a concave portion is formed on the upper surface of the base, and the optical mounting board is accommodated in the concave portion. 3. The recess formed on the lower surface of the base is formed on the back side of the recess formed on the upper surface of the base,
3. The optoelectronic module according to claim 2, wherein the conductor penetrating the base communicates with recesses formed on both the upper and lower surfaces of the base. 4. A recess having an opening area smaller than the outer shape of the optical mounting board and wider than the outer shape of the optical semiconductor element is formed on the upper surface of the base, and the optical semiconductor element is accommodated in the recess. 2. The optoelectronic module according to claim 1, wherein the optical mounting board is disposed in the recess with the optical semiconductor element mounting side of the optical mounting board facing down. 3.