JP2005164801A - Optical waveguide film and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that the mechanical strength of an optical waveguide film itself is reduced when forming a mirror on the way of the optical waveguide film because it is necessary to cut the film up to a core part, the problem that the mechanical strength is reduced due to reduction of thickness to a half or more because the optical waveguide film in an element mounting lower part forms a 45° mirror, and the problem that restrictions on a manufacturing process make it difficult to locally form a mirror in an arbitrary position on the optical waveguide film. <P>SOLUTION: A component mounting guide 10 for a minute mirror component having an optical path conversion function is set in a set position of a core 2 of an optical waveguide film 1 having the corer 2 buried in a clad 3, and the minute mirror component 4 is incorporated in the component mounting guide 10, and thus an optical waveguide film 1 is obtained which has such structure that light from the core is received by the mirror component 4 and is made incident on an optical function element 7 mounted by a solder bump 6, through the clad 3. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a technique for providing an optical waveguide film having a built-in optical path conversion function for connecting an optical functional element and an optical fiber.

In recent years, in the field of high-speed and large-capacity communication, research and development of optical waveguide films that connect optical functional elements and optical waveguides have been actively conducted. In particular, in an optical interconnection module that uses an optical element array in which a surface emitting laser (VCSEL) and a surface receiving photodiode (PD) are integrated in an array in a light source part and a light receiving part, respectively, Optical components for connecting between optical fibers as transmission lines are required.
As an example of an optical component for connecting the optical element array and the optical fiber, a 45 ° (degree) mirror is formed on the end face of the film on which the optical waveguide is formed, and after the 90 ° optical path is converted, the optical element array is connected. There is an optical waveguide film with a structure to As a method for forming a 45 ° mirror for 90 ° optical path conversion in this optical waveguide film, as shown in FIG. 8, it is formed by rotating and cutting a diamond blade whose tip is processed at 45 ° or 90 °. The method is generally used (see Patent Document 1). This method uses a blade having an inclination angle at the cutting edge, and forms an inclined end surface that becomes a micromirror on the optical waveguide by performing processing by applying the blade perpendicular to the optical waveguide during cutting. .

Japanese Patent Laid-Open No. 10-300961

The above-described conventional method is suitable for forming a mirror at the end of the optical waveguide film, but when forming a mirror in the middle of the film, it is necessary to cut to the core in the film. There was a problem that the mechanical strength of the device itself was lowered.
FIG. 9 shows a configuration example in which an optical functional element (PD) is flip-chip mounted with solder bumps, but the optical waveguide film under the element mounting forms a 45 ° mirror, so that the thickness is less than half, A decrease in mechanical strength occurred.

  In addition, there is a problem that it is difficult to form a mirror locally at an arbitrary position on the film due to restrictions on the manufacturing process.

  In order to solve the above-described problems, the present invention includes a 90 ° optical path conversion component in the film, thereby arranging an optical path conversion function at an arbitrary position without causing a decrease in the mechanical strength of the film itself. The biggest feature is where this is possible.

In order to solve the above-described problems of the present invention, specifically, the configuration described in the claims is adopted. That is,
A mounting guide for an optical component having an optical path conversion function is set at a setting position of the core of the optical waveguide film in which the core is embedded in the clad, and the optical component is mounted on the mounting guide. The optical waveguide film has a structure in which light from the core is received by the optical component and incident on an optical functional element mounted by solder bumps via the clad. The optical component having the optical path changing function includes at least a mirror, a lens, and a prism having a size of several tens to several hundreds of microns or less.

  According to a second aspect of the present invention, in the first aspect, the optical waveguide film having a structure in which the reflection surface of the optical component having the optical path conversion function is a single side of 45 ° and is built in the optical waveguide film.

  According to a third aspect of the present invention, in the first aspect, the reflection surface of the optical component having the optical path conversion function is formed as a plurality of 45 ° surfaces, and the light from the core is transmitted on the plurality of surfaces of the optical component. Each is received and made incident on each optical functional element, and is built in the optical waveguide film.

  According to a fourth aspect of the present invention, in the first aspect, the reflecting surface of the optical component having the optical path converting function is a concave surface and is built in the optical waveguide film.

  Further, as described in claim 5, in claim 1, at least one end face of the optical component having the optical path changing function is configured to integrate a 90 ° optical path changing prism and a minute lens, and is built in the optical waveguide film. The structure is as follows.

  As described in claim 6, in claim 1, optical input / output cores are provided in at least three directions, at least three component mounting guides are provided, and the reflection surface of the optical component is a 45 ° mirror single side. A plurality of optical parts having a reflection surface of 45 ° mirror as the reflection surface of the optical component and a 45 ° surface as the reflection surface are built in the optical waveguide film.

Moreover, as described in claim 7, a method for producing the optical waveguide film according to any one of claims 1 to 6,
Producing an optical waveguide made of a polymer material having a core layer formed on the cladding layer;
A step of forming a component mounting guide for mounting a micromirror component or the like simultaneously with the production of the core layer when forming the core layer;
A process for realizing high-precision alignment with the core by mounting an optical component having an optical path conversion function on the component mounting guide;
After mounting the optical component, a method of producing an optical waveguide film including at least a step of forming an optical waveguide film having a built-in optical path conversion function by laminating a clad thereon.

  According to the present invention, it is possible to arrange an optical component having an optical path conversion function at an arbitrary position of the optical waveguide film, and at the same time, a highly reliable optical function without reducing the strength of the optical waveguide film itself. Connection with an element can be made possible.

  Hereinafter, examples of the optical waveguide film according to the present invention will be described in detail with reference to FIGS. 1 to 7, but the present invention is not limited to these examples.

<Example 1>
An optical component having an optical path conversion function exemplified in the embodiment of the present invention is an optical component including at least a mirror, a lens, and a prism having a size of several tens of microns to several hundreds of microns or less. Called mirror parts, micro prism parts, micro lenses, etc.).

  FIG. 1 shows a first embodiment in which an optical functional element (PD) 7 is flip-chip mounted with solder bumps 6 using the optical waveguide film 1 of the present invention. In FIG. 1, the optical waveguide film 1 of the present invention has a setting guide 10 formed on a core 2 at a position where, for example, a micromirror part (45 ° mirror single side) 4 having an optical path changing function is mounted. A micromirror part 4 is mounted, a clad 3 is formed on the micromirror part 4, a light beam 14 propagating through the core 2 of the optical waveguide film 1 is taken out of the core 2, and, for example, flip chip mounting is performed using a solder bump 6 In this structure, the light is incident on the optical functional element (PD) 7. In order to guide light to the optical functional element (PD) 7, the micromirror component 4 is built in the optical waveguide film 1. That is, the light propagating through the core 2 is converted into an optical path by 90 ° at the reflecting surface 5 of the micromirror component 4 and then incident on the optical functional element (PD) 7 flip-chip mounted by the solder bump 6. . Reference numeral 14 denotes a light beam emitted from the core 2. Compared with the conventional structure shown in FIG. 9, the strength of the optical waveguide film in the lower part of the optical element mounting is not reduced, and a highly reliable optical element mounting is realized.

In FIG. 2, the manufacturing process of the optical waveguide film 1 is shown. 2A is a side view of the optical waveguide film 1, and FIG. 2B is a view as viewed from the arrow A in each side view.
First, in step (1) of FIG. 2, an optical waveguide made of a polymer material in which the core 2 is formed on the clad 3 is manufactured.
When forming the core ridge 11 in the step (2), it is important to form the component mounting guide 10 for mounting the micromirror components and the like simultaneously with the fabrication of the core ridge 11.
In the step (3), for example, by mounting a micromirror component on the component mounting guide 10, it is possible to achieve highly accurate alignment with the core ridge 11.
In step (4), after mounting the micromirror component 4 and the like, the clad 3 is laminated on the upper portion, thereby completing an optical waveguide film incorporating an optical path conversion function.

  The material constituting the optical waveguide film uses fluorinated polyimide with low propagation loss in the optical communication wavelength band (800 nm to 1600 nm), and is formed on the substrate such as silicon or quartz with high flatness by spin coating and heating process. A clad layer, a core layer, and an upper clad layer are sequentially formed, and finally peeled from the substrate to form a film. The core is processed by reactive ion etching (RIE) of oxygen using a resist patterned in a desired shape by photolithography as a mask. When the core ridge 11 is formed, a guide for mounting the micromirror component is formed at the same time. By mounting the micromirror component on this guide, the core and the reflecting surface of the microoptical component can be highly accurate. Alignment is realized. The micromirror component is manufactured by processing quartz with high precision, and the 45 ° mirror surface, which is the reflection surface, is coated with gold having high reflectivity in the optical communication wavelength band. The micromirror component can be made entirely of metal including the reflective surface. Further, the micromirror component can be manufactured using a highly heat-resistant polyimide as a material, and the same function can be realized by applying a gold coating on the reflecting surface. After the components are mounted, a clad layer is formed on the upper portion by spin coating and a heating process, thereby completing an optical waveguide film incorporating an optical path conversion function. FIG. 3 is a perspective perspective view showing the appearance of the completed optical waveguide film 1.

  In addition to the fluorinated polyimide, a highly transparent organic material such as an ultraviolet curable epoxy material or polymethyl methacrylate (PMMA) can be used as a material constituting the optical waveguide film. There are no restrictions on the material systems that make up the film. In particular, when an ultraviolet curable material is used, by selectively irradiating light when forming the core, a guide for mounting the core pattern and micromirror parts can be easily obtained compared to the case of using RIE. It can be formed.

<Example 2>
FIG. 4 shows a second embodiment of the present invention in which an optical functional element (PD) 7 is flip-chip mounted with solder bumps 6 using the optical waveguide film 1 shown in FIG. 1 of the present invention. In FIG. 4, the structure using the component which has the reflective surface 5 of 45 degrees on both surfaces for the micro mirror component 4a built in the optical waveguide film 1 is shown. In the conventional method, since mechanical strength cannot be secured, it is difficult to form mirrors close to each other. However, according to the present invention, close mirror formation can be realized without causing a decrease in strength.

<Example 3>
FIG. 5 shows a third embodiment of the present invention in which an optical functional element (PD) 7 is flip-chip mounted with solder bumps 6 using the optical waveguide film 1 of the present invention. This is a configuration in which a component having a reflective surface (concave surface) 5a on one side is used as the micromirror component 4b built in the optical waveguide film 1. In the conventional method, since it was processed with a diamond blade, it was difficult to form a reflective surface other than a flat surface. However, in the present invention, the desired reflection can be easily achieved by changing the shape of the optical component incorporated in the film. A surface can be realized.

<Example 4>
FIG. 6 shows a fourth embodiment of the present invention in which an optical functional element (PD) 7 is flip-chip mounted with solder bumps 6 using the optical waveguide film 1 of the present invention. This is a configuration using an optical component in which a microlens 9 is integrated on a microprism component 8 having a reflecting surface (45 °) 5 built in the optical waveguide film 1.

<Example 5>
FIG. 7 shows a fifth embodiment of the present invention having a structure in which light input / output is provided in three directions and the optical path is changed by 90 ° in the optical waveguide film 1 of the present invention. With the conventional method, it is impossible to realize the configuration shown in FIG. 7, but the present invention makes it possible to arrange the optical path conversion function at a desired position.

The schematic diagram which shows the structure of the optical waveguide film illustrated in Example 1 of this invention, and the connection structure of an optical function element. The figure which shows the preparation processes of the optical waveguide film illustrated in Example 1 of this invention. The perspective view which shows the external appearance of the completed optical waveguide film illustrated in Example 1 of this invention. The schematic diagram which shows the structure which carried out the flip chip mounting of the optical function element with the solder bump using the optical waveguide film illustrated in Example 2 of this invention. Sectional drawing showing the connection structure of the optical waveguide film and optical function element which were illustrated in Example 3 of this invention. Sectional drawing showing the connection structure of the optical waveguide film illustrated in Example 4 of this invention, and an optical function element. The top view showing the structure which has arrange | positioned the mirror component for optical path conversion in the arbitrary positions on the optical waveguide film illustrated in Example 5 of this invention. The schematic diagram which shows the formation method of the 45 degree mirror by the conventional dicing saw. Sectional drawing showing the connection structure of the conventional optical waveguide film and an optical function element.

Explanation of symbols

1 Optical waveguide film 2 Core 3 Cladding 4 Micro mirror component (45 ° mirror single side)
4a Micro mirror parts (45 ° mirror both sides)
4b Micro mirror parts (concave surface)
5 Reflecting surface (45 ° surface)
5a Reflective surface (concave surface)
6 Solder bump 7 Optical functional element (PD)
8 Micro prism component 9 Micro lens 10 Component mounting guide 11 Core ridge 12 Diamond blade 13 45 ° mirror surface 14 Light beam

Claims (7)

  A mounting guide for an optical component having an optical path conversion function is set at the setting position of the core of the optical waveguide film in which the core is embedded in the clad, and the optical component is built in the mounting guide, and the light from the core The optical waveguide film, wherein the optical waveguide film is received by the optical component and incident on the optical functional element mounted by the solder bump through the clad.   The optical waveguide film according to claim 1, wherein the reflection surface of the optical component having the optical path conversion function is a 45 ° single-sided surface and is incorporated in the optical waveguide film.   2. The optical component having an optical path converting function according to claim 1, wherein a plurality of reflective surfaces of 45 ° are provided, and light from the core is received by each of the plurality of surfaces of the optical component and is incident on each optical functional element. An optical waveguide film characterized in that the optical waveguide film is built in the optical waveguide film.   2. The optical waveguide film according to claim 1, wherein the reflection surface of the optical component having the optical path conversion function is a concave surface and is built in the optical waveguide film.   2. The optical waveguide film according to claim 1, wherein at least one end surface of the optical component having the optical path converting function is configured to integrate an optical path converting prism and a lens having a 90 ° angle, and is incorporated in the optical waveguide film.   2. The optical component according to claim 1, wherein optical input / output cores are provided in at least three directions, at least three of the component mounting guides are disposed, and the reflective surface of the optical component is a 45 ° mirror single side, and the reflective surface is a 45 ° mirror. An optical waveguide film characterized in that a plurality of optical components each having a double-sided surface and a plurality of optical components having a reflective surface of 45 ° are provided and incorporated in the optical waveguide film. A method for producing an optical waveguide film according to any one of claims 1 to 6,
Producing an optical waveguide made of a polymer material having a core layer formed on the cladding layer;
Forming a component mounting guide for mounting an optical component such as a mirror component simultaneously with the production of the core layer when forming the core layer;
A step of realizing highly accurate alignment with the core by mounting optical components having an optical path changing function on the component mounting guide,
A method for producing an optical waveguide film, comprising: a step of forming an optical waveguide film having a built-in optical path conversion function by laminating a clad on the optical component after mounting the optical component.

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