JPH08194137A - Electro-optical hybrid module and its production - Google Patents

Abstract

PURPOSE: To obtain an optical coupling structure with which the easy optical axis alignment in a height direction is assured and to improve the radiation characteristic of a mounted end face type optical element by specifying the structure of a mixed electrical and optical module. CONSTITUTION: High-density electric wiring is realized by using a mixed electrical and optical hybrid wiring board 10 formed by laminating and integrating polymer optical waveguides 14 on multilayered copper polyimide wiring layers 11'. The distance between the front surface of a solder layer 13" formed on an optical element installation region 13 and the optical axis of the optical waveguides 14 is set equal to the distance from the base of the end face type optical element 12 to the center 12' in the active part. As a result, the optical axis of the optical waveguides 14 in the height direction and the optical axis of the end face type optical element 12 are aligned simply by bringing the base of the end face type optical element 12 into contact with the front surface of the solder layer 13". Further, the rear surface of the metallic conductor layer 13' on the optical element installation region 13 and the multilayered ceramic substrate 11 are connected by columnar conductors 18 to lower the thermal resistance of the layers between the rear surface of the metallic conductor layer 13' and the multilayered ceramic substrate 11, by which the radiation characteristic of the end face type optical element 12 mounted in the optical element installation region 13 is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a module for use in an optical communication device and the like, and to an electro-optical hybrid module in which an optical waveguide and an end-face type optical element are optically coupled to each other, and a method of manufacturing the same.

[0002]

2. Description of the Related Art An optical coupling structure between an optical waveguide and an end-face type optical element of a conventional electro-optical hybrid module will be described for a general light-emitting element as an end-face type optical element.

16 and 17 show an example of such an electro-optical hybrid module, and FIG. 16 is a perspective view,
FIG. 17 is a sectional view taken along line xx 'in FIG. In the figure, 41 is a Si substrate, 42 is an end face type optical element, 42 'is the center of the light emitting portion of the end face type optical element 42, 43 is an optical element installation region,
43 'is a conductor layer formed on the optical element mounting region 43,
43 ″ is a solder layer formed on the conductor layer 43 ′, 44 is an optical waveguide, 45 is an upper optical waveguide clad, 46 is an optical waveguide core, and 47 is a lower optical waveguide clad.

Optical waveguide of a conventional electro-optical hybrid module-
In the end-face type optical coupling structure between optical elements, the optical waveguide core 4 is used.
The distance between the optical axis of 6 and the upper surface of the solder layer 43 '' is
It is manufactured so as to have a distance equal to the distance between the bottom surface of the end facet type optical element 42 in contact with 3 ″ and the center 42 ′ of the light emitting portion of the optical element. That is, the lower optical waveguide clad layer 47, the optical waveguide core layer 46, and the upper optical waveguide clad layer 45, which are made of silica glass, are formed on the Si substrate 41.
After being formed by a high temperature treatment of 500 ° C., an etching mask for forming an optical waveguide is formed on the upper surface of the upper optical waveguide clad layer 45 and reactive ion etching is performed to form an optical waveguide 44 and an installation region 43 of the end surface type optical element 42. To form. In this example, the surface of the optical element installation region 43 is made of Si.
It is flush with the upper surface of the substrate 41. In the above description,
The reference numerals of the respective layers of the optical waveguide 44 before and after patterning are the same for convenience of illustration. Next, a metal conductor (for example, Au / Ni / C) is formed on the optical element installation region 43.
r) is vapor-deposited to form a conductor layer 43 ', and a thin film solder layer (for example, Au / Sn eutectic solder) 43''is formed thereon. After that, the end face type optical element 42 is set on the solder layer 43 ″ in the optical element setting area 43 by using a positioning device (not shown). That is, the optical element installation area 4
3, the optical axis of the end facet type optical element 42 and the optical axis of the optical waveguide 44 in the plane parallel to the surface of the end facet type optical element 42 are aligned.
Contact the bottom surface of the solder layer 43 ″ with the solder layer 4 ″.
By heating and melting 3 ″, the end-face type optical element 42
Through the conductor layer 43 'and the solder layer 43''
Fix on top. Thereby, the optical coupling structure is completed.

In this method, since Si forming the substrate 41 has a smaller etching rate in the reactive ion etching than the silica glass forming the optical waveguide 44, the upper surface of the Si substrate 41 serves as an etching stop layer. The optical element installation region 43 can be deeply machined with high precision. Therefore, adjustment of the optical axis in the height direction of the end-faced optical element 42 with respect to the optical waveguide 44 is performed only by bringing the end-faced optical element 42 into contact with the upper surface of the solder layer 43 ″ formed on the surface of the optical element installation region 43. It has the advantage that it can be performed and the alignment becomes easy.

18 and 19 show an optical coupling structure between an optical waveguide and an end face type optical element of another conventional electro-optical hybrid module, FIG. 18 is a perspective view, and FIG. A cross-sectional view along the line xx 'is shown. 50 in the figure
Is a conventional electro-optical mixed wiring board, 51 is a multilayer ceramic substrate, 51 'is a copper polyimide multilayer wiring layer, 52 is an end face type optical element, 52' is the center of the light emitting portion of the end face type optical element 52, and 53 is an optical element installation region , 53 ', a conductor layer formed on the optical element mounting region 53, 53 ", a solder layer formed on the conductor layer 53', 54, a polymer optical waveguide, 55, a polymer upper optical waveguide cladding, 56, a polymer. The optical waveguide core and 57 are polymer lower optical waveguide claddings.

The optical coupling structure between the optical waveguide and the end face type optical element of the above conventional electro-optical hybrid module is realized as follows. That is, the copper polyimide multilayer wiring layer 51 '
After the polymer lower optical waveguide clad layer 57, the polymer optical waveguide core layer 56, and the polymer upper optical waveguide clad layer 55 are formed thereon by heat treatment at 400 ° C. or lower, the polymer optical waveguide is formed on the upper surface of the polymer upper optical waveguide clad layer 55. An etching mask for formation is formed, and reactive ion etching is performed on the upper surface of the polymer upper optical waveguide clad layer 55 to form the polymer optical waveguide 54 and the installation region 53 of the end surface type optical element 52. In the above description, the reference numerals of the layers of the optical waveguide 54 before and after patterning are the same for convenience of illustration. A metal conductor (for example, Au / Ni / C) is previously formed in the copper polyimide multilayer wiring layer 51 '.
u) is formed. Therefore, by the reactive ion etching, the conductor layer 53 'made of the metal conductor appears on the surface. After forming a thin film solder layer (for example, Au / Sn eutectic solder) 53 ″ on the conductor layer 53 ′, the solder layer 53 ′ on the optical element mounting region 53 is formed by using a positioning device (not shown). The end facet type optical element 52 is installed on the above. That is, the optical axis of the end surface type optical element 52 and the optical axis of the optical waveguide 54 are aligned in a plane parallel to the optical element installation region 53, the bottom surface of the end surface type optical element 52 is brought into contact with the solder layer 53 ″, and soldering is performed. The end facet type optical element 52 is fixed by heating and melting the layer 53 ″. This completes the optical coupling structure.

In this method, since the optical waveguide is laminated and integrated with the copper-polyimide multilayer wiring layer which is a high-density electrical wiring,
There is an advantage that it can be electrically or optically connected to a large number of LSIs and optical elements on the electro-optical mixed wiring board.

[0009]

However, as shown in FIG.
In the conventional electro-optical hybrid module described with reference to FIG. 17 and FIG. 17, since a high temperature treatment of 1500 ° C. is required to form the optical waveguide 44, the optical waveguide cannot be laminated and integrated on the copper polyimide multilayer wiring layer. However, there is a problem that it is difficult to form high-density electrical wiring necessary for electrical connection with a large number of LSIs and optical elements. Further, since the optical element installation area 43 is formed on the Si substrate, there is also a problem that high-density electrical wiring cannot be formed in and under the optical element installation area.

Further, in another electro-optical hybrid module using the other conventional electro-optical hybrid wiring board described with reference to FIGS. 18 and 19, the reactive ion etching conditions are controlled with high accuracy over the entire substrate surface. Therefore, if the etching is performed so that the polymer does not remain on the metal conductor on the optical element installation region 53, the copper polyimide multilayer wiring layer 51 ′ in the portion where the polymer optical waveguide 54 is not laminated is over-etched. As a result, there is a possibility that the electric wiring or the conductor pad on the multilayer wiring layer 51 'or the multilayer wiring layer 51' will be eroded. When the metal conductor layer 53 'formed on the optical element installation region 53 is over-etched, the conductor thickness is reduced, and the bottom surface of the end face type optical element 52 is formed on the conductor layer 53' by the solder layer 53 ". It becomes difficult to adjust the optical axis in the height direction of the end facet type optical element 52 with the polymer optical waveguide 54 by simply contacting the end surface type optical element 52 with a metal conductor layer 53 ′ and a solder which are sequentially formed on the optical element installation region 53. There is a problem in that the adhesive strength with the layer 53 ″ becomes weak and it becomes difficult to fix the end facet type optical element 52. Further, since the end-face type optical element 52 is mounted on the copper-polyimide multilayer wiring layer 51 'having poor thermal conductivity, there is a problem that the heat dissipation is poor and the optical signal characteristics are deteriorated.

[0011]

In order to solve the above-mentioned problems, the electro-optical hybrid module according to claim 1 of the present invention comprises an insulating layer and a first conductor layer which are multi-layered on a substrate. An electro-optical hybrid wiring board in which a multilayer wiring layer is formed, and an optical waveguide formed by sandwiching an optical waveguide core with an upper and a lower optical waveguide clad having a lower refractive index than the optical waveguide core is formed on the multilayer wiring layer. And an end-face type optical element optically coupled to the optical waveguide of the electric-optical hybrid wiring board, wherein the electrical-optical hybrid module is provided in front of an end portion of the optical waveguide on the substrate with respect to a light propagation direction. An optical element installation region having vertical sidewalls is formed, and a second conductor layer is formed on the surface of the optical element installation region parallel to the plane of the optical waveguide, and on the second conductor layer. Has a solder layer formed in parallel with the second conductor layer. Further, the distance from the surface of the solder layer to the optical axis of the optical waveguide core is set equal to the distance from the back surface of the end facet type optical element in contact with the solder layer to the center of the active portion of the end facet type optical element, The end facet type optical element is fixed to the solder layer on the electro-optical hybrid wiring board at a position where the optical axis passing through the center of the active portion of the end facet type optical element coincides with the optical axis of the optical waveguide core. , Is characterized.

An electro-optical hybrid module according to a second aspect of the present invention is the electro-optical hybrid module according to the first aspect, wherein the back surface of the second conductor of the electro-optical hybrid wiring board is connected to the substrate by a columnar conductor. It is characterized by being

According to a third aspect of the present invention, there is provided a method of manufacturing an electro-optical hybrid module, wherein an electric wiring layer is formed by laminating an insulating layer and a first conductor layer on a substrate. An electro-optical hybrid wiring board in which an optical waveguide having an optical waveguide core sandwiched by upper and lower optical waveguide clads sandwiching the optical waveguide core is laminated on a multilayer electric wiring layer, and the electro-optical hybrid wiring board A method of manufacturing an electro-optical hybrid module having an end facet type optical element optically coupled to the optical waveguide of, wherein the insulator layer is made of a polymer, and the multi-layer wiring layer is formed of the insulator layer. A second conductor layer made of metal is formed parallel to the upper surface, and the second conductor layer is formed on the second conductor layer.
Forming a first metal layer, which is made of a material different from that of the second conductor and has a smaller reactive ion etching rate than that of the optical waveguide material, in parallel with the conductor layer having the same dimension or more,
At a position on the upper surface of the multilayer wiring layer which is parallel to the first metal layer without covering the first metal layer and where the lower optical waveguide clad is not stacked, the reactive ion etching rate is smaller than that of the optical waveguide material. Forming a second metal layer,
A lower optical waveguide clad layer made of a polymer to be the lower optical waveguide clad, an optical waveguide core layer made of a polymer to be the optical waveguide core, and an upper surface of the insulating layer on the side where the second metal layer is formed, An upper optical waveguide clad layer made of a polymer to be the upper optical waveguide clad,
The distance between the optical axis center of the optical waveguide core and the surface of the solder layer formed on the second conductor layer is parallel to the upper surface of the multilayer wiring layer, and the end surface mounted on the solder layer. Of the first optical waveguide clad layer on the upper surface of the upper optical waveguide clad layer such that the distance from the contact surface of the solder layer of the optical device to the center of the active portion of the end face type optical device is the same.
Forming a third metal layer having a smaller reactive ion etching rate than the optical waveguide material in parallel without covering the second metal layer and reacting vertically to the upper surface of the upper optical waveguide clad layer. And the third ion
Of the upper optical waveguide clad layer where the metal layer is not formed, the optical waveguide core layer, the lower optical waveguide clad layer, and the multilayer wiring layer where the second and third metal layers are not formed. The step of simultaneously forming the optical waveguide and the installation area of the optical element, the step of removing the first, second and third metal layers, and the step of forming the second conductor on the installation area of the optical element. And a step of forming the solder layer in parallel with the second conductor.

A method for manufacturing an electro-optical hybrid module according to a fourth aspect of the present invention is the method for manufacturing the electro-optical hybrid module according to the third aspect, wherein the side surface on the active portion side of the end facet type optical element is the optical waveguide end portion. The light passing through the optical axis of the optical waveguide and the center of the active portion of the end face type optical element, which is in contact with the side wall of the optical element installation area on the side parallel to the side surface, and is projected on a plane parallel to the surface of the optical element installation area. Aligning the axes, the bottom surface of the end surface type optical element is brought into contact with the surface of the solder layer in parallel to heat the solder layer and the end surface type optical element, and the solder layer is melted to generate the electric light. The end face type optical element is fixed to a mixed wiring board.

[0015]

According to the electro-optical hybrid module of the present invention having the above structure, the density of electric wiring can be increased by applying the copper-polyimide multilayer wiring layer. Moreover, the copper-polyimide multilayer wiring layer of the portion where the metal conductor layer and the optical waveguide formed on the surface of the optical element installation region for mounting the end face type optical element are not laminated,
Since it is covered with a metal mask whose etching rate for reactive ion etching is lower than that of the polymer optical waveguide material, it is not eroded even by reactive ion etching.
Therefore, it is possible to prevent damage to the copper-polyimide multilayer wiring layer in the portion where the metal conductor layer and the optical waveguide formed on the optical element installation area are not damaged, and moreover, the bottom surface of the end-face type optical element is soldered on the optical element installation area. It is possible to realize an optical coupling structure in which the optical axis alignment in the height direction can be easily performed only by bringing the layers into contact with each other. Furthermore, since the back surface of the metal conductor layer formed on the optical element installation area and the multilayer ceramic substrate are connected by the columnar conductor, the thermal resistance of the layer between the optical element installation area and the multilayer ceramic substrate is reduced, and mounting is performed. It is possible to improve the heat dissipation characteristics of the end face type optical element.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(Embodiment 1) FIGS. 1 and 2 show an optical coupling structure between an optical waveguide and an end surface type optical element of a first embodiment of an electro-optical hybrid module of the present invention. 1 is a perspective view, and FIG. 2 is a sectional view taken along the line xx ′ of FIG. 10 in the figure
Is an electro-optical mixed wiring board, 11 is a multilayer ceramic substrate, 1
1'is a copper polyimide multilayer wiring layer, 12 is an end-face type optical element,
Reference numeral 12 'is the center of the light emitting portion of the optical element 12, 13 is a groove-shaped optical element installation region for mounting the end-face type optical element 12, and 13' is a (second) conductor layer formed on the optical element installation region 13. 1
3 ″ is a solder layer formed on the conductor layer 13 ′, 1
3 '''is a side wall of the optical element mounting region 13, 14 is a polymer optical waveguide, 15 is a polymer upper optical waveguide cladding, 16
Is a polymer optical waveguide core, and 17 is a polymer lower optical waveguide clad.

In the end face type optical element 12, for example, a 5-channel InGaAsP-based FP having a thickness of 90 μm and a light emitting portion center 12 ′ of which is 5 μm from the surface.
Laser array (pitch between channels is, for example, 400μ
m) is used. The polymer optical waveguide 14 aligned with the same channel pitch as the optical element 12 is made of a polymer (for example, fluorinated polyimide) having a high affinity with the copper-polyimide multilayer wiring layer 11 'and a high light transmittance. The polymer optical waveguide core 16 has, for example, a thickness width of 50 μm,
Upper and lower polymer optical waveguide claddings 15, 17
Is, for example, 40 μm thick and 50 μm wide. A solder layer 13 ″ (for example, Au / Sn) having a thickness of, for example, 5 μm formed on the conductor layer 13 ′ (for example, Au / Ni / Cu).
The upper surface of the eutectic solder) is set 20 μm from the upper surface of the copper-polyimide multilayer wiring layer 11 ′ in parallel with the upper surface.
In addition, the polymer optical waveguide 14 on the optical element installation region 13 side
A line connecting the ends between the channels in parallel with the upper surface of the copper-polyimide multilayer wiring layer 11 ′ (in the direction orthogonal to the drawing) is parallel to the side wall 13 ′ ″ of the optical element installation region 13, and The ″ ″ stands upright on the upper surface of the solder layer 13 ″. Here, the side surface of the end facet type optical element 12 on the light emitting portion side is set parallel to the side wall 13 ″ ″. The line connecting the end portions between the channels of the polymer optical waveguide 14 in parallel with the upper surface of the copper-polyimide multilayer wiring layer 11 '(the direction orthogonal to the drawing) is the same as the side wall 13''' of the optical element installation region 13. It does not have to be in the plane. The surface connecting the ends of the polymer optical waveguides 14 between the channels is the side wall 1 of the optical element mounting region 13.
It does not have to be parallel to 3 ", especially the polymer optical waveguide 1
4 does not generate resonance between the end portion 4 and the side surface 12 ″ of the end facet type optical element 12 on the light emitting surface side, the polymer optical waveguide 1
The surface connecting the ends of the four channels is the optical element installation region 13
Slightly (eg 8-9 °) to the side wall 13 '' of
It is good to lean.

The distance (= 85 μm) between the bottom surface of the end face type optical element 12 and the center 12 'of the light emitting portion of the optical element is the solder layer 1
Since the distance from the upper surface of 3 ″ to the center of the polymer optical waveguide core 16 is equal, the bottom surface of the end facet type optical element 12 is simply brought into contact with the upper surface of the solder layer 13 ″ so that the height of the polymer optical waveguide 14 is increased. And the optical axis of the end surface type optical element 12 can be matched.

In the present embodiment, the case where the light emitting element is used as the end face type optical element 12 has been described, but the optical element to be used is a light receiving element such as a waveguide type light receiving element or an optical switch.
C may also be used.

(Embodiment 2) FIGS. 3 and 4 show an optical coupling structure between an optical waveguide and an end face type optical element according to a second embodiment of the electro-optical hybrid module of the present invention. 3 is a perspective view, and FIG. 4 is a sectional view taken along the line xx ′ of FIG. In the figure, the same elements as those in FIGS. 1 and 2 are designated by the same reference numerals to simplify the description. The difference between the structure shown in FIG. 1 and FIG. 2 and the structure shown in FIG. 3 and FIG.
Is connected to the multilayer ceramic substrate 11 via a columnar conductor 18 having a diameter of 100 μm and made of copper having a high thermal conductivity. This columnar conductor 1
By providing 8 so as to penetrate through the multilayer wiring layer 11 ′,
The thermal resistance of the copper polyimide multilayer wiring layer 11 'on the back surface of the conductor layer 13' is reduced, and the heat dissipation of the end face type optical element 12 fixed to the solder layer 13 '' can be improved.

(Embodiment 3) FIGS. 5 to 12 show an example of a method for manufacturing an electro-optical hybrid module according to the present invention. In the figure, reference numeral 20 denotes an electric / optical hybrid wiring board of the present invention (see FIG.
2) and 21 are multilayer ceramic substrates, 21 'is a copper-polyimide multilayer wiring layer, 23 is a groove-shaped optical element installation area, and 23' is a (second) conductor layer formed on the optical element installation area 23,
23 ″ is a solder layer formed on the conductor layer 23 ′,
3 ″ ″ is a wall surface of the optical element installation region 23, 24 is a polymer optical waveguide, 25 ′ is a polymer upper optical waveguide clad layer, 2
6'is a polymer optical waveguide core layer, 27 'is a polymer lower optical waveguide clad layer, 28 is a columnar conductor, 29 is a first metal layer formed on the conductor layer 23' in the copper-polyimide multilayer wiring layer 21 ', 29 Reference numeral ′ is a second metal layer formed on the surface of the copper-polyimide multilayer wiring layer 21 ′, and reference numeral 29 ″ is a third metal layer formed on the polymer upper optical waveguide clad layer 25 ′.

First, for example, a photosensitive polyimide layer is formed on a multilayer ceramic substrate 21 made of alumina by spin coating and curing, and a copper wiring (first conductor layer) is formed thereon by electrolytic and electroless plating. Then, this is repeated to form a copper polyimide multilayer wiring layer 21 '. The copper wirings between the layers are connected by vias made of copper formed by electrolytic and electroless plating. A second conductor layer 23 'made of, for example, Au / Ni / Cu is provided parallel to the upper surface at a position 25 μm from the upper surface of the copper-polyimide multilayer wiring layer 21', and a second conductor layer made of Ti, for example, is formed on the conductor layer 23 '. The first metal layer 29 is formed by electrolytic and electroless plating or vapor deposition, for example, about 4000 Å. Also,
A columnar conductor 28 made of copper is formed between the back surface of the second conductor layer 23 'and the multilayer ceramic substrate 21 by electrolytic and electroless plating (FIGS. 5 and 6).

Next, on the surface of the copper-polyimide multilayer wiring layer 21 ', a second metal layer 29' made of, for example, Ti is formed on a portion of the portion where the polymer optical waveguide 24 is not laminated and which does not cover the first metal layer 29. Is formed by vapor deposition to, for example, about 40,000Å (FIGS. 7 and 8).

Next, on the surface of the copper-polyimide multilayer wiring layer 21 ', a polymer lower optical waveguide clad layer 27' made of fluorinated polyimide and having a thickness of 40 .mu.m, a polymer optical waveguide core layer 26 'having a thickness of 50 .mu.m, and a thickness of 40 .mu.m. The polymer upper optical waveguide clad layer 25 ′ is spin-coated, cured and sequentially laminated, and then the polymer upper optical waveguide clad layer 25 ′.
A third metal layer 29 ″ made of, for example, Ti is formed by vapor deposition, for example, on the order of 4000 Å, only on the surface of the surface where the polymer optical waveguide 24 is formed (FIGS. 9 and 1).
0).

Next, using the third metal layer 29 ″ as a mask, reactive ion etching is performed until the first metal layer 29 is exposed from the surface of the polymer upper optical waveguide cladding layer 25 ′, and the polymer optical waveguide is etched. 24 and optical element installation area 2
3 is formed at the same time. Further, after removing the first, second and third metal layers 29, 29 ', 29''with hydrofluoric acid or the like, a thin film solder layer 23' made of, for example, Au / Sn eutectic solder is formed on the conductor layer 23 '. Is formed to a thickness of, for example, 5 μm by vapor deposition to complete the electro-optical hybrid wiring board 20 of the present invention (FIGS. 11 and 12). A line connecting the end portions between the channels of the polymer optical waveguide 24 in parallel with the upper surface of the copper-polyimide multilayer wiring layer 21 '(in the direction orthogonal to the drawing) is the same as the side wall 23 "' of the optical element installation region 23. It does not have to be in the plane. Further, the surface connecting the end portions between the channels of the polymer optical waveguide 24 does not have to be parallel to the side wall 23 ″ ′ of the optical element installation region 23. In particular, the end portion of the polymer optical waveguide 24 and the end surface type optical element. In order not to generate resonance with the side surface on the light emitting surface side, the surface connecting the ends of the channels of the polymer optical waveguide 24 to the side wall 23 ″ ′ of the optical element installation region 23 is slightly ( It may be inclined, for example, 8 to 9 °. Further, as the first, second and third metal layers 29, 29 ′ and 29 ″, a metal of Ti or less (such as Al) may be used.

(Embodiment 4) FIGS. 13 to 15 show an embodiment showing an example of a method of mounting an end face type optical element in an electro-optical hybrid module of the present invention. In the figure, 30 is an electro-optical mixed wiring board of the present invention, 31 is a multilayer ceramic substrate, 3
1'is a copper polyimide multilayer wiring layer, 32 is an end face type optical element,
32 'is a stripe of the end face type optical element 32, 32' is a side surface of the end face type optical element 32 on the light emitting surface side, 33 is an optical element mounting region, 33 'is a side wall of the optical element mounting region 33, and 33''is a solder layer. , 34 are polymer optical waveguides, and 38 is a columnar conductor.

As described with reference to FIGS. 1 and 2, the distance between the bottom surface of the end surface type optical element 32 and the center of the light emitting portion of the optical element is determined by the distance from the upper surface of the solder layer 33 '' to the light of the polymer optical waveguide 34. Equal to the distance to the axis. Further, a line connecting the end portions between the channels of the polymer optical waveguide 34 on the optical element installation area 33 side in parallel with the upper surface of the copper-polyimide multilayer wiring layer 31 ′ is parallel to the side wall 33 ′ of the optical element installation area 33. And the side wall 3
3'is perpendicular to the upper surface of the solder layer 33 ''. The line connecting the ends of the polymer optical waveguide 34 between the channels in parallel with the upper surface of the copper-polyimide multilayer wiring layer 31 ′ may not be in the same plane as the side wall 33 ′ of the optical element installation region 33. The surface connecting the ends of the polymer optical waveguides 34 between the channels need not be parallel to the side wall 33 'of the optical installation region 33. In particular, the end of the polymer optical waveguides 34 and the end surface type optical element 3 may be formed.
In order not to generate resonance with the side surface 32 ″ of the second light emitting surface, the surface connecting the ends of the channels of the polymer optical waveguide 34 to the side wall 33 ′ of the optical element installation region 33 is slightly different. It may be inclined (for example, 8 to 9 °).

First, the stripe 3 of the end surface type optical element 32
The light emitting surface side surface 32 'of the optical element 32 is adjusted so that the center of the longitudinal direction of 2'is aligned with the center of the width of the polymer optical waveguide 34, for example, by using a positioning device (not shown). ′ Is pressed parallel to the side wall 33 ′ of the optical element installation region 33 (FIG. 13). Next, the bottom surface of the end-face type optical element 32 is pressed against the top surface of the solder layer 33 '''(FIG. 14).
Finally, the solder layer 33 ″ is melted by heating and the end face type optical element 32 is fixed, so that the end face type optical element 3 is fixed.
2 is mounted on the electro-optical hybrid wiring board 30 (FIG. 15). As the electro-optical hybrid module thus configured, the case where the surface connecting the ends of the channels of the polymer optical waveguide 34 is parallel to the side wall 33 ′ of the optical element installation region 33 is manufactured. The optical axis position deviation in the vertical direction is 1 μm or less, and the positional deviation in the in-plane direction perpendicular to it is 2 μm
In the following, the end face type optical element 32 can be mounted on the electro-optical hybrid wiring board 30, and the optical coupling loss between the optical coupling structures is 8 to 9 dB.
(Λ = 1.3 μm) was obtained.

In this embodiment, the case where the light emitting element is used as the end face type optical element 32 has been described, but the optical element to be used is the optical I such as the waveguide type light receiving element or the optical switch.
C may also be used.

[0031]

As described above, the present invention realizes high-density electrical wiring by using an electro-optical hybrid wiring board in which a polymer optical waveguide is laminated and integrated in a copper-polyimide multilayer wiring layer, and at the same time, on the optical element installation area. The distance between the surface of the solder layer formed on the optical axis of the optical waveguide and the distance between the bottom surface of the end facet type optical element and the center of the active portion, and on the metal conductor layer for forming the solder layer, and On the copper polyimide multilayer wiring layer where the polymer optical waveguide is not laminated, the etching rate for reactive ion etching is smaller than that of the polymer optical waveguide material, and reactive ion etching is performed by providing a metal mask with an etching stop layer effect. As a result, corrosion of the metal conductor layer and the copper-polyimide multilayer wiring layer on the optical element installation area was prevented. As a result, the distance between the surface of the solder layer formed on the optical element installation region and the optical axis of the optical waveguide does not change due to reactive ion etching. The optical axis of the optical waveguide in the height direction and the optical axis of the end facet type optical element can be aligned simply by bringing the bottom surfaces into contact with each other. Furthermore, since the back surface of the metal conductor layer on the optical element installation area and the multilayer ceramic substrate were connected by columnar conductors, the thermal resistance of the layer between the back surface of the metal conductor layer and the multilayer ceramic substrate was reduced. It is possible to improve the heat dissipation characteristics of the end-face type optical element mounted on.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of an electro-optical hybrid module according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line xx ′ of FIG.

FIG. 3 is a perspective view of a main part of an electro-optical hybrid module according to a second embodiment of the present invention.

4 is a cross-sectional view taken along the line xx ′ of FIG.

FIG. 5 is a perspective view for explaining the third embodiment of the present invention, and is a perspective view showing a step of the method for manufacturing the electro-optical hybrid module of the present invention.

FIG. 6 is a cross-sectional view of the structure shown in FIG. 5 for explaining the third embodiment of the present invention and showing steps of the method for manufacturing the electro-optical hybrid module of the present invention.

FIG. 7 is a perspective view for explaining the third embodiment of the present invention, and is a perspective view showing a step of the method for manufacturing the electro-optical hybrid module of the present invention.

FIG. 8 is a cross-sectional view of the structure shown in FIG. 7, showing the steps of the method for manufacturing the electro-optical hybrid module of the present invention, for explaining the third embodiment of the present invention.

FIG. 9 is a perspective view for explaining the third embodiment of the present invention, and is a perspective view showing a step of the method for manufacturing the electro-optical hybrid module of the present invention.

FIG. 10 is a cross-sectional view of the structure shown in FIG. 9 showing the steps of the method for manufacturing the electro-optical hybrid module of the present invention for explaining the third embodiment of the present invention.

FIG. 11 is a perspective view for explaining the third embodiment of the present invention and is a perspective view showing steps of the method for manufacturing the electro-optical hybrid module of the present invention.

FIG. 12 is a cross-sectional view of the structure shown in FIG. 11, showing the steps of the method for manufacturing the electro-optical hybrid module of the present invention, for explaining the third embodiment of the present invention.

FIG. 13 is a cross-sectional view for explaining the fourth embodiment of the present invention, which is a sectional view showing a step of mounting an end facet optical element in the method for manufacturing an electro-optical hybrid module of the present invention.

FIG. 14 is a perspective view for explaining the fourth embodiment of the present invention, and is a perspective view showing a step of mounting an end facet optical element in the method of manufacturing an electro-optical hybrid module of the present invention.

FIG. 15 is a perspective view for explaining the fourth embodiment of the present invention, and is a perspective view showing a step of mounting an end facet optical element in the method of manufacturing an electro-optical hybrid module of the present invention.

FIG. 16 is a perspective view of a main part of a conventional electro-optical module.

FIG. 17 is a cross-sectional view taken along the line xx ′ of FIG.

FIG. 18 is a perspective view of a main part of another conventional electro-optical module.

19 is a cross-sectional view taken along the line xx ′ of FIG.

[Explanation of symbols]

10, 20, 30 Electro-optical mixed wiring board 11 of the present invention 11, 21, 31, 51 Multilayer ceramic substrate 11 ', 21', 31 ', 51' Copper polyimide multilayer wiring layer 12, 32, 42, 52 End face type optical element 12 ', 42', 52 'Center of light emitting part of end face type optical element 13, 23, 33, 43, 53 Optical element installation area 13', 23 ', 33', 43 ', 53' Formed on optical element installation area (Second) conductor layers 13 ″, 23 ″, 33 ″, 43 ″, 53 ″
Solder layer 13 ″ ″, 23 ″ ″, 33 ′ Side wall of optical device mounting area 14, 24, 34, 54 Polymer optical waveguide 15, 55 Polymer upper optical waveguide cladding 16, 56 Polymer optical waveguide core 17, 57 Polymer lower portion Optical waveguide clad 18, 28, 38 Columnar conductor 25 'Polymer upper optical waveguide clad layer 26' Polymer optical waveguide core layer 27 'Polymer lower optical waveguide clad layer 29 Copper conductor formed on conductor layer 23' in multilayer wiring layer First metal layer 29 'Second layer formed on the surface of copper polyimide multilayer wiring layer
Metal layer 29 ″ of the third metal layer formed on the polymer upper optical waveguide clad 32 ′ Stripe of the end face type optical element 32 ″ Side surface of the end face type optical element on the light emitting surface 44 Quartz glass optical waveguide 41 Si substrate 45 Silica-based upper optical waveguide clad 46 Silica-based optical waveguide core 47 Silica-based lower optical waveguide clad 50 Conventional electro-optical hybrid wiring board

Claims (4)

[Claims] 1. A multi-layer wiring layer formed by laminating an insulating layer and a first conductor layer is formed on a substrate, and an optical waveguide core is bent on the multi-layer wiring layer more than the optical waveguide core. An electro-optical hybrid wiring board in which optical waveguides sandwiching low-upper and lower optical waveguide clads are laminated; and an end face type optical element optically coupled to the optical waveguides of the electro-optical hybrid wiring board In the electro-optical hybrid module, an optical element installation area having a side wall perpendicular to the light propagation direction is formed in front of the optical waveguide end portion on the substrate, and the optical element installation area has a surface on which the optical element installation area is formed. A second conductor layer is formed in parallel with the plane of the optical waveguide, and a solder layer is formed on the second conductor layer in parallel with the second conductor layer. The distance to the optical axis of the optical waveguide core is The optical axis is set to be equal to the distance from the back surface in contact with the solder layer to the center of the active portion of the end facet type optical element, and the optical axis passing through the center of the active portion of the end facet type optical element matches the optical axis of the optical waveguide core. The electro-optical hybrid module, wherein the end-face type optical element is fixed to the solder layer on the electro-optical hybrid wiring board at a position. 2. The electro-optical hybrid module according to claim 1, wherein a rear surface of the second conductor of the electro-optical hybrid wiring board is connected to the substrate by a columnar conductor. 3. An electric wiring layer formed by laminating an insulating layer and a first conductor layer is formed on a substrate, and an optical waveguide core is bent on the multilayer electric wiring layer more than the optical waveguide core. An electro-optical hybrid wiring board in which optical waveguides sandwiching low and high optical waveguide clads are stacked; and an end-face type optical element optically coupled to the optical waveguides of the electro-optical hybrid wiring board A method of manufacturing an electro-optical hybrid module, wherein the insulator layer is made of a polymer, and a second conductor layer made of metal is formed in parallel with an upper surface of the multilayer wiring layer made of the insulator layer. A first metal layer made of a material different from that of the second conductor and having a smaller reactive ion etching rate than that of the optical waveguide material is provided on the second conductor layer in parallel with the second conductor layer in the same dimension or more. The step of forming and the upper surface of the multilayer wiring layer Forming a second metal layer having a smaller reactive ion etching rate than the optical waveguide material at a position not covering the first metal layer and in parallel and not stacking the lower optical waveguide clad; A lower optical waveguide clad layer made of a polymer to be the lower optical waveguide clad, an optical waveguide core layer made of a polymer to be the optical waveguide core, and an upper surface of the insulating layer on the side where the second metal layer is formed, An upper optical waveguide clad layer made of a polymer to be the upper optical waveguide clad,
The distance between the optical axis center of the optical waveguide core and the surface of the solder layer formed on the second conductor layer is parallel to the upper surface of the multilayer wiring layer, and the end surface mounted on the solder layer. Of the first optical element, the second optical element, and the second optical element on the upper surface of the upper optical waveguide clad layer so that the distance from the solder layer contact surface of the optical element to the center of the active portion of the end surface optical element becomes equal.
Forming a third metal layer having a smaller reactive ion etching rate than that of the optical waveguide material in parallel without covering the metal layer of the above, and the reactive ion perpendicular to the upper surface of the upper optical waveguide clad layer. Etching is performed, and the upper optical waveguide clad layer, the optical waveguide core layer, the lower optical waveguide clad layer, and the second and third metal layers on which the third metal layer is not formed are not formed. Etching the multilayer wiring layer to simultaneously form the optical waveguide and the optical element installation region; removing the first, second, and third metal layers; and the optical device installation region. And a step of forming the solder layer in parallel with the second conductor on the upper second conductor, the manufacturing method of the electro-optical hybrid module. 4. A surface parallel to the side surface of the end face type optical element on the side of the active portion, which is in parallel contact with the side wall of the optical element installation area on the end side of the optical waveguide, and which is parallel to the surface of the optical element installation area. The optical axis of the optical waveguide projected onto the optical axis and the optical axis passing through the active portion center of the end face type optical element are aligned, and the bottom surface of the end face type optical element is brought into contact with the surface of the solder layer in parallel to the solder layer. 4. The electro-optical hybrid module according to claim 3, wherein the electro-optical hybrid module is fixed to the electro-optical hybrid wiring board by heating the edge optical device and melting the solder layer. Production method.