JPH116941A - Surface packaging type optical module and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify steps and to decrease the man-hours of manufacture by disposing plural pieces of Au/Sn bumps for positioning and a straight bump right under a waveguide between an optical semiconductor element and an Si-V-groove substrate to connect and fix the element and the substrate and mounting an optical fiber at the V-groove of the Si-V-groove substrate. SOLUTION: The Au/Sn bumps 4 and the straight bump 5 right under the waveguide connect and fix an LD-chip 1 and the Si-V-groove substrate 6 to each other. Au/Sn solder is completely fused, by which the Au/Sn bumps 4 and the straight bump 5 right under the waveguide are liquefied at above the m. p. thereof. As the temp. falls to the m. p. or below, the Au/Sn bumps 4 and the straight bump 5 right under the waveguide turn to solid. At this time, the connection and fixation are achieved by the Au/Sn bumps 4 and straight bump 5 right under the waveguide which are connecting materials with the Si-V-groove substrate 6 and the LD-chip 1. Next, the connection and fixation are completed by mounting the optical fiber 8 in the V-groove 7 of the Si-V- groove substrate 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical transmitter having an electric signal / optical signal conversion function and an optical receiver having an optical signal / electric signal conversion function used separately or integrally for use in an optical data transmission apparatus. The present invention relates to an optical coupling structure of an optical semiconductor element in an optical transceiver module.

[0002]

2. Description of the Related Art Conventionally, techniques in such a field include:
For example, there is one disclosed in the document name: 95 IEICE Autumn University SC-1-12 “Development of Surface Mount Optical Module”, pp. 331-332. FIG. 8 is a configuration diagram of such a conventional surface mount type optical module. FIG. 8 (a) is a perspective view showing the entire surface mount type optical module, and FIG. 8 (b) is FIG.
8A is a cross-sectional view taken along line AA, FIG. 8C is a plan view of the Si substrate of the surface-mounted optical module, and FIG. 8D is a plane of the optical semiconductor element mounting surface of the surface-mounted optical module. Figure,
FIG. 8E is a plan view showing a recognition mark on the optical semiconductor element mounting surface.

In these figures, 101 is an optical semiconductor device, 102 is a silicon substrate (hereinafter referred to as Si substrate),
103 is a V groove, 104 is solder, 105a is a recognition mark on the Si substrate side, 105b is a recognition mark on the optical semiconductor element side, 1
Reference numeral 06a denotes a Si substrate side electrode pattern, and 106b denotes an optical semiconductor element side electrode pattern. The optical semiconductor element 101 is mounted on the Si substrate 102 by a visual method, with respect to the Si substrate-side recognition mark 105a shown in the plan view of the Si substrate in FIG. The optical semiconductor element 101 is mounted on the Si substrate 102 by detecting and positioning the optical semiconductor element side recognition mark 105b provided on the Si substrate 102 by infrared rays.
The solder substrate side electrode pattern 106a provided on the Si substrate 102 shown in FIG. 6C and the optical semiconductor element side electrode pattern 106b provided on the optical semiconductor element mounting surface in FIG.
04 is connected.

An optical fiber 107 is connected and fixed to the V-shaped groove 103, so that optical coupling between the optical semiconductor element 101 and the optical fiber 107 is achieved.

[0005]

However, the above-mentioned conventional surface mount type optical module has the following problems. (1) The positioning adjustment at the time of mounting the optical semiconductor element is necessary, which complicates the process, and requires a lot of man-hours to manufacture.
Costs rise.

(2) Since it is difficult to recognize a recognition mark for positioning, accurate positioning is difficult. SUMMARY OF THE INVENTION An object of the present invention is to provide a surface mount type optical module which eliminates the above-mentioned problems, omits optical axis adjustment by the self-alignment effect, and at the same time can efficiently secure current, and a method of manufacturing the same. And

[0007]

In order to achieve the above object, the present invention provides: [1] In a surface mount type optical module, a plurality of positioning Au / Sn bumps and a straight bump directly under a waveguide are provided in an optical semiconductor device. And an Si-V-groove substrate for connection and fixing, and an optical fiber is mounted in the V-groove of the Si-V-groove substrate.

[2] In a surface mount type optical module,
A plurality of Au / Sn bumps for positioning and a comb-shaped bump just below the waveguide are provided between the optical semiconductor element and the Si-V groove substrate;
In addition to the connection and fixing, an optical fiber is mounted in the V-groove of the Si-V-groove substrate. [3] In the method for manufacturing a surface mount optical module, a plurality of Au / Sn bumps for positioning and a straight bump directly below the waveguide are provided between the optical semiconductor element and the Si-V groove substrate,
In addition to the connection and fixing, an optical fiber is mounted in the V-groove of the Si-V-groove substrate, and the optical axis adjustment is omitted by the self-alignment effect, and at the same time, an efficient current is secured.

[4] In the method of manufacturing the surface mount type optical module, a plurality of Au / Sn bumps for positioning and a comb-like bump just below the waveguide are provided between the optical semiconductor element and the Si-V groove substrate and connected and fixed. At the same time, an optical fiber is mounted in the V-groove of the Si-V-groove substrate, and the optical axis adjustment is omitted by the self-alignment effect, and at the same time, an efficient current is secured.

[5] In the method for manufacturing a surface-mounted optical module according to the above [3] or [4], the optical semiconductor element and the Si-V groove substrate are thermocompression-bonded using Au / Sn bumps as a connecting material. This thermocompression bonding is temporary fixing, and connection fixing is A
The u / Sn bump is completely melted to fix the connection. [6] The method for manufacturing a surface-mounted optical module according to [3] or [4], wherein the Au / Sn bump is melted in an atmosphere having a reducing action to melt the Au / Sn bump and the Si-V groove substrate. Are connected and fixed using Au / Sn bumps as connecting members.

[0011]

Embodiments of the present invention will be described below in detail. In the following embodiments, a surface-mounted optical module will be described using an edge light emitting device (hereinafter, an LD-chip) as an optical semiconductor device. FIG. 1 is a perspective view showing a surface-mounted optical module (optical coupling structure of an optical semiconductor element) showing a first embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes an LD-chip (edge light emitting element), 2 denotes a waveguide serving as an optical resonator.
It is formed in the chip 1. Reference numeral 3 denotes a light emitting unit,
It is located at the end face of the waveguide 2 of the chip 1; 4 is Au / Sn
The bumps contribute to positioning and fixing (details will be described later). Reference numeral 5 denotes a straight bump directly below the waveguide, and LD-
It is located directly below the waveguide 2 so that current flows efficiently to the lower surface of the LD-chip 1 by power supply from the upper surface of the chip 1.

Reference numeral 6 denotes a Si-V groove substrate,
It is a base for connecting and fixing the chip 1. Reference numeral 7 denotes a V groove, which is formed in the Si-V groove substrate 6. An optical fiber 8 is positioned and fixed in the V-groove 7 of the Si-V-groove substrate 6. Light is emitted from the light emitting section 3 of the LD-chip 1, and the beam enters the optical fiber 8. Thereby, optical coupling is achieved between the LD-chip 1 and the optical fiber 8.

Here, the Au / Sn bump 4 and the straight bump 5 directly below the waveguide are made of, for example, Au / Sn. These bumps 4 and 5 are LD-chip 1 and Si-V
The groove substrates 6 are connected and fixed. Such a bump is formed by providing bump forming electrodes on the LD-chip 1 and the Si-V groove substrate 6. FIG. 2 shows the first embodiment of the present invention.
FIG. 3 is a plan view showing an electrode structure formed on an LD-chip showing an embodiment, and FIG. 3 is a perspective view showing a state in which bumps are formed on a Si-V groove substrate showing a first embodiment of the present invention.

As shown in FIG. 2, on the back surface of the LD-chip 1, bump electrodes 11 are formed at four corners and a straight electrode 12 is formed at the center. On the other hand, as shown in FIG.
Au / Sn bumps 4 and straight bumps 5 directly below the waveguide corresponding to the straight electrodes 12 are formed on the Si-V groove substrate 6 at four locations corresponding to the bump electrodes 11. The Au / Sn bump 4 has a hemispherical shape which is advantageous for positioning and fixing the LD-chip 1. Further, the straight bump 5 directly below the waveguide is of a semi-cylindrical shape, so that an efficient current flow can be secured.

The method for supplying the Au / Sn solder is Au
There are various methods, such as a method of directly supplying / Sn solder pieces and a method of supplying by soldering, and the method is not limited. FIG.
FIG. 4 is a manufacturing process diagram of the surface-mounted optical module showing the first embodiment of the present invention. (1) First, as shown in FIG. 4A, a Si-V groove substrate 6 on which bumps 4 and 5 are formed is prepared.

(2) Then, as shown in FIG.
An LD having electrodes 11 and 12 (see FIG. 2) on the back surface on bumps 4 and 5 of Si-V groove substrate 6 and having waveguide 2
Align chip 1; The mounting accuracy at this time is the mounting accuracy of a general flip chip bonder (± 5 to 10 μm).
m order). Further, in this embodiment, the weight is 20
The Si-V groove substrate 6 and the LD-chip 1 are temporarily fixed by using Au / Sn bumps 4 and straight bumps 5 immediately below the waveguides.

(3) Next, as shown in FIG.
The connection and fixing of the LD-chip 1 are completed by reflow. Here, the temporarily fixed product is reflowed at a temperature (for example, 350 ° C.) at which the Au / Sn solder is completely melted. The atmosphere during reflow is hydrogen, nitrogen,
Any gas such as a mixed gas may be used, but in the embodiment, hydrogen which can be expected to have a reducing action is used. By completely melting the Au / Sn solder, the Au / Sn bump 4 and the straight bump 5 immediately below the waveguide are liquefied at or above their melting point (280 ° C. in this case). As the melting point becomes lower than the melting point, the Au / Sn bump 4 and the straight bump 5 immediately below the waveguide become solid.

At this time, connection and fixation between the Si-V groove substrate 6 and the LD-chip 1 are achieved by the Au / Sn bumps 4 and the straight bumps 5 immediately below the waveguide, which are connection materials. The connection accuracy is on the order of ± 2 μm, which is higher than the mounting accuracy.
This is due to the self-alignment effect peculiar to the bump connection. The self-alignment effect is a self-alignment effect caused by the surface tension of the bump itself during the melting and solidification of the bump.

(4) Next, as shown in FIG.
The optical fiber 8 is mounted on the V-groove 7 of the i-V-groove substrate 6 to complete the connection and fixation. Here, the optical fiber 8 is fixed by applying it to the V-groove 7, and a UV adhesive is used as a connection material in this embodiment. In general, the V-groove is formed using a thin-film forming technique, and therefore has a formation accuracy on the order of sub-μm. Also, the outer shape accuracy of the optical fiber 8 is on the order of ± 1 μm. Therefore, if the connection accuracy of the LD-chip 1 and the connection accuracy of the optical fiber 8 as shown in FIG.

Next, a second embodiment of the present invention will be described. FIG. 5 is a perspective view of a surface mount optical module according to a second embodiment of the present invention. In this embodiment, instead of the straight bumps 5 directly under the waveguide of the first embodiment, comb-like bumps 9 directly under the waveguide are used. Otherwise, the configuration is the same as that of the first embodiment, and the same portions are denoted by the same reference numerals and description thereof is omitted.

In this embodiment, Au / Sn is used as the Au / Sn bump 4 and the comb-like bump 9 just below the waveguide. These bumps are LD-chip 1 and Si-V
The groove substrates 6 are connected and fixed. Such a bump is formed by providing bump forming electrodes on the LD-chip 1 and the Si-V groove substrate 6. FIG. 6 is a plan view showing an electrode structure formed on an LD-chip according to a second embodiment of the present invention, and FIG. 7 is a state in which bumps are formed on a Si-V groove substrate according to the second embodiment of the present invention. FIG.

As shown in FIG. 6, on the back surface of the LD-chip 1, bump electrodes 11 are formed at four corners and a comb-shaped electrode 21 is formed at the center. On the other hand, as shown in FIG. 7, Au / Sn bumps 4 at four locations corresponding to the bump electrodes 11 and a comb-like bump just below the waveguide corresponding to the comb-like electrodes 21 are formed on the Si-V groove substrate 6 as shown in FIG. 9 are formed. Here, the Au / Sn bumps 4 have a hemispherical shape that is advantageous for positioning and fixing the LD-chip 1, and the comb-like bumps 9 directly below the waveguide are for ensuring an efficient current flow.

The method of supplying the Au / Sn solder is Au
There are various methods, such as a method of directly supplying / Sn solder pieces and a method of supplying by soldering, and the method is not limited. Further, the manufacturing method of this embodiment is the same as that of the first embodiment, and the description thereof is omitted. In the above embodiment, the LD-chip is described. However, the same effect can be obtained with a light receiving element.

Further, the present invention is not limited to the above-described embodiment, and various modifications can be made based on the gist of the present invention, and these are not excluded from the scope of the present invention.

[0026]

As described above, according to the present invention, the following effects can be obtained. (A) By adjusting the positioning when mounting the optical semiconductor element,
The process is simplified, and the number of man-hours for the production can be reduced, and the cost can be reduced.

(B) By providing the Au / Sn bump for positioning and the straight bump directly below the waveguide between the LD-chip and the Si-V groove substrate and connecting and fixing the same, the above-mentioned effect (A) can be obtained. Thus, efficient current can be secured. (C) Positioning Au / Sn bumps and comb-shaped bumps directly under the waveguide are provided between the LD-chip and the Si-V groove substrate,
By fixing the connection, the effect of the above (A) can be obtained, and at the same time, efficient current can be secured.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a surface mount optical module according to a first embodiment of the present invention.

FIG. 2 is a plan view showing an electrode structure formed on an LD-chip according to the first embodiment of the present invention.

FIG. 3 is a perspective view showing a state in which bumps are formed on the Si-V groove substrate according to the first embodiment of the present invention.

FIG. 4 is a manufacturing process diagram of the surface mount optical module showing the first embodiment of the present invention.

FIG. 5 is a perspective view of a surface mount optical module according to a second embodiment of the present invention.

FIG. 6 is a plan view showing an electrode structure formed on an LD-chip according to a second embodiment of the present invention.

FIG. 7 is a perspective view showing a state in which bumps are formed on a Si-V groove substrate according to a second embodiment of the present invention.

FIG. 8 is a configuration diagram of a conventional surface mount type optical module.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 LD-chip (edge light-emitting element) 2 Waveguide (optical resonator) 3 Light-emitting part 4 Au / Sn bump 5 Straight bump just under a waveguide 6 Si-V groove substrate 7 V groove 8 Optical fiber 9 Comb under a waveguide Bump 11 Bump electrode 12 Straight electrode 21 Comb-shaped electrode

Claims (6)

[Claims] A plurality of Au / Sn bumps for positioning and a straight bump directly below a waveguide are connected to an optical semiconductor element and Si-V.
It is provided between the grooved substrates and connected and fixed.
A surface mount type optical module in which an optical fiber is mounted in a V-groove of a groove substrate. 2. A plurality of positioning Au / Sn bumps and a comb-like bump just below a waveguide are provided between an optical semiconductor element and a Si-V groove substrate, and are connected and fixed, and V-grooves of the Si-V groove substrate are provided. A surface-mount type optical module with an optical fiber attached to it. 3. A plurality of Au / Sn bumps for positioning and a straight bump directly below a waveguide are connected to an optical semiconductor element and Si-V.
It is provided between the grooved substrates and connected and fixed.
A method for manufacturing a surface mount type optical module, comprising mounting an optical fiber in a V-groove of a groove substrate, omitting optical axis adjustment by a self-alignment effect, and simultaneously ensuring efficient current. 4. A plurality of positioning Au / Sn bumps and a comb-like bump just below the waveguide are provided between the optical semiconductor element and the Si-V groove substrate, and are connected and fixed, and the V groove of the Si-V groove substrate is provided. A method of manufacturing a surface-mount type optical module, wherein an optical fiber is mounted on the optical module, the optical axis adjustment is omitted by a self-alignment effect, and an efficient current is secured at the same time. 5. The method for manufacturing a surface-mounted optical module according to claim 3, wherein the optical semiconductor element and the Si-
A surface-mounted optical device characterized in that a V-groove substrate is thermocompression-bonded using Au / Sn bumps as a connecting material, and the thermocompression bonding is temporarily fixed, and the connection and fixing is performed by completely melting the Au / Sn bumps and fixing the connection. Module manufacturing method. 6. The method for manufacturing a surface-mount type optical module according to claim 3, wherein the step of melting the Au / Sn bump is performed in an atmosphere having a reducing action, so that the optical semiconductor element and the Si-V groove substrate are separated. A method for manufacturing a surface-mount type optical module, wherein an Au / Sn bump is connected and fixed as a connection material.