JP3193500B2 - Manufacturing method of flexible electric / optical wiring circuit module - Google Patents

Abstract

PURPOSE:To provide an electric and optical wiring circuit module capable of connecting electric and optical elements as well as electric and optical parts, that are different in height and position and located complicatedly, to each other efficiently in optical connection so that they can be mounted densely, and also provide its manufacturing method. CONSTITUTION:A core part 7, a clad layer 8, and an electric wiring 11 of an optical waveguide are formed on a polyimid film 5 to produce a flexible electric and optical wiring film. Using the film, electric and optical elements mounted on an electric and optical wiring substrate, etc., are connected to each other. Thus, because the flexible electric and optical wiring film is flexible and enables complicated wiring, electric and optical elements as well as electric and optical parts, etc., that are different in height and position and located complicatedly and densely, can be connected to each other optically and electrically.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technology for optically and electrically connecting optical elements and optical circuit components that require high-density mounting. By using flexible connecting means with wiring formed, it is possible to connect optical elements, optical circuit components or optical modules arranged in a complicated manner having different heights and positions with high optical coupling efficiency and high-density mounting. The present invention relates to optical and electrical connection technologies.

[0002]

2. Description of the Related Art Conventionally, as a method for optically and electrically connecting optical elements and optical components, optical and electrical connections are made by different methods, respectively. A method of connecting with an optical waveguide or an optical fiber formed above is generally used, and a connection using a printed wiring board, a ceramic wiring board, or the like is generally used electrically.

For example, conventional optical connection techniques include:
Optical wiring using an optical waveguide or an optical fiber as described in a literature (Ito and Ishihara, "Optical Wiring in Microelectronics", Optics, Vol. 14, No. 1, p. 51) can be mentioned. This method uses the LD as shown in FIG.
Light emitted from a light source 1 such as a (laser diode)
Light receiving element 3 formed in an array using optical fiber 2
Or a method of connecting the light source 1 and the light receiving element 3 using the optical waveguide 4 as shown in FIG.

[0004]

However, in such a conventional connection method, not only optical and electrical connections cannot be made simultaneously, but also in optical connection, connection using an optical waveguide has the same plane. It is limited only to the connection of electric and optical elements and electric and optical components mounted inside, and it is difficult to sharply bend the fiber with connection using optical fiber, so a large mounting space is required Therefore, the connection is limited to a frame or the like, and it has been difficult to efficiently connect electrical / optical elements and electrical / optical components having steps, such as in a wiring board or between wiring boards.

[0005] Under such circumstances, optical and electrical connections can be made at the same time, and the optical connection is not limited to the connection of electric / optical elements and electric / optical components mounted on the same plane. In addition, there has been an issue of realizing a technology for connecting electric / optical elements and electric / optical components having steps at high density.

The present invention has been made to solve these problems, and an object of the present invention is to provide an electric / optical element, an electric / optical component, or an electric / optical module between complicatedly arranged heights and positions. the optical coupling efficiency is to provide a method of manufacturing a flexible electric-optical wiring circuit module which can moreover be connected implemented efficiently high-density mounting can be.

[0007]

Means for Solving the Problems] To achieve the above object, a flexible electrical and optical wiring circuit module of the present invention
In the method of manufacturing, an electric wiring board or an optical wiring board is formed by using a flexible electric / optical wiring film in which a single-layer or multilayer optical waveguide and electric wiring are formed on the surface of the resin film based on a flexible resin film. to connect between the electric and optical devices or electrical and optical components mounted on the wiring board or the electrical and optical wiring board optically and electrically to the basic configuration, first, after the final treatment on a resin film
Is higher than the refractive index of the resin film.
To form a photosensitive resin layer before solidification,
Photolithography process and heat treatment for the photosensitive resin layer
Form the core layer of the optical waveguide having the desired shape through the process
Next, a thin base metal is formed on the resin film.
And then the exposure and development photo of the first photoresist
After performing the desired patterning by the process,
Forming an electrical wiring layer, and then forming the first photoresist
The electrical wires are formed by removing the strike, and then the second photo
Exposure of resist and desired pattern by photo process of development
To the ends of the electrical wiring by Au or
A pad for bonding is formed by solder plating.
Next, the base metal other than the electric wiring portion is removed,
Next, the flexible electrical and optical wiring fabricated above
Depending on the film electric wiring board or optical wiring board or
Electric or optical element or electric mounted on electric or optical wiring board
And optical and either electrically connecting the optical part, Moshiku
First, the refractive index after final treatment on the resin film is
Photosensitive with refractive index higher than that of resin film
Forming a photosensitive resin layer, and then forming a thin film on the photosensitive resin layer.
A metal film is formed, and then the photoresist is exposed and developed.
Forming a pattern of the metal film by a photolithography process,
Next, using the pattern of the metal film as a mask, the reactive gas
With the photosensitive resin layer or the photosensitive resin layer
By etching away part of the resin film
Forming a core layer of an optical waveguide having a desired shape;
Then, the photoresist and the metal film are removed to form an optical waveguide.
Fabrication, and then forming electrical wiring on the resin film
And, then, a flexible electrical and light created manufactured by the above
Electric wiring board or electric / optical wiring depending on the wiring film
Light between electrical and optical elements and electrical and optical components mounted on the substrate
And electrically and electrically connected.

[0008]

The flexible electro-optical wiring circuit module <br/> Lumpur manufacturing method of the present invention, by using an electric-optical wiring film prepared by forming an optical waveguide and electrical wiring on a film-shaped base The electrical and optical elements mounted on the electrical and optical wiring board and the like are connected. Since this electrical / optical wiring film is flexible and allows fine wiring, it can be used for optical / optical devices and electrical / optical components that are arranged in different heights and positions in a complicated manner and mounted on a substrate at high density. , Can be electrically connected.

[0009]

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

FIG. 1 to FIG. 7 are diagrams showing a material configuration of a flexible electric / optical wiring film used in an embodiment of the present invention and a manufacturing method thereof. The flexible electric / optical wiring circuit module according to the present embodiment is mounted on an electric wiring board, an optical wiring board, an electric / optical wiring board, or the like, and is connected to the optical waveguide or the electric wiring of the wiring board. -Optical components are optically and electrically connected to each other using a flexible electric / optical wiring film. As shown in FIG. 2 (f), the first configuration example of the flexible electric / optical wiring film is based on a resin film such as a polyimide film 5 having flexibility, and the surface of the resin film has a simple structure. An optical waveguide composed of a layered or multilayered core portion 7 and the like and an electric wiring 11 are formed.

First, a first example of a basic material structure and a manufacturing method of the flexible electric / optical wiring film of the first structure example will be described. 1 (a) to 1 (d) and 2 (a) to 2 (f) show them in a sectional configuration.

First, FIGS. 1 (a), (b), (c),
In (d), a polyimide film 5 is used as a resin film (a), and a liquid photosensitive polyimide 6 having a refractive index after the final treatment having a refractive index larger than that of the polyimide film 5 is provided on the polyimide film 5. (B), and through a photolithography process and a heat treatment process for the liquid photosensitive polyimide 6, a core portion (hereinafter simply referred to as a core portion in some cases) of the polyimide optical waveguide having a desired shape is formed. (C), a clad layer 8 made of another polyimide having a refractive index smaller than the refractive index of the core 7 is formed on the core 7, and a flexible optical wiring film is produced.

Next, in FIGS. 2A to 2F, FIG.
2 shows an example of a process for forming an electric wiring on the back surface of the flexible optical wiring film shown in FIG. In this process example, a base metal 9 is formed on the back surface of the flexible optical wiring film (a) manufactured in FIG.
After performing desired patterning by a photo process such as exposure and development of 0, an electric wiring 11 is formed by electrolytic plating (c), the photoresist 10 is removed (d), and another photoresist 10 is formed again. After performing a desired patterning by a photo process such as exposure, development and the like, a connection pad 12 made of gold or solder is formed on the end of the electric wiring 11 by electrolytic plating (e), and a photoresist 10 'is formed. Is removed, the underlying metal 9 other than the electric wiring 11 is removed by a selective etching method or the like utilizing a difference in film thickness (f), and a flexible electric / optical wiring film composed of both the optical waveguide and the electric wiring is formed. Can be produced.

FIGS. 3A to 3E are diagrams showing a second example of a method for producing a flexible electric / optical wiring film used in an embodiment of the present invention, in which reactive ions using a reactive gas are used. This is an example of a process for manufacturing an optical waveguide by an etching method. In this process example, another polyimide layer 13 serving as a core portion of an optical waveguide is formed on the polyimide film 5 (a), and after a predetermined heat treatment process,
A metal layer 14 is formed by electroless plating or a vacuum evaporation method (b), desired patterning is performed by a photo process such as exposure and development of the photoresist 10, and the metal layer 14 is removed by etching. (C), the polyimide layer 13 or the polyimide layer 13 is completely removed by a processing method such as a reactive ion etching method or a chemical etching method using a reactive gas in order to completely remove the polyimide layer 13. After the core 7 having a desired shape is formed by etching and removing a part of the polyimide film 5 (d), the metal mask 15 is removed, and the core 7 is placed on the core 7. By forming a clad layer 8 made of another polyimide having a refractive index smaller than the refractive index (e), a flexible optical wiring film can be produced. That. Thereafter, if electrical wiring is formed in the same manner as in FIG. 2, a flexible electrical / optical wiring film can be manufactured.

Although the structure in which the clad layer 8 is formed on the core portion 7 has been described with reference to FIGS. 1 to 3, a structure in which the clad layer is not formed and an air clad layer may be used.

FIGS. 4 (a) to 4 (e) are views showing a third example of a method for producing a flexible electric / optical wiring film used in an embodiment of the present invention. 3 shows an example of a process of forming a reflection surface at a predetermined angle in the depth direction of the core portion. In this process example, another polyimide layer 13 serving as a core portion of the optical waveguide is formed on the polyimide film 5 and after a predetermined heat treatment process (a), the metal layer is formed by electroless plating or vacuum evaporation. 14 (b), a desired patterning is performed by a photo process such as exposure and development of the photoresist 10, and the metal layer 14 is removed by etching to form a metal mask 15 (c). By removing the polyimide layer 13 in an oblique direction with respect to the depth of the core portion by a reactive ion etching method using (d), and etching the metal mask 15,
(E) A flexible optical wiring film in which the reflecting surface 17 having an oblique shape with respect to the depth of the core portion is formed can be manufactured. Thereafter, if electrical wiring is formed in the same manner as in FIG. 2, a flexible electrical / optical wiring film can be manufactured.

[0017] FIG. 5 is a perspective view showing a second configuration example of a flexible electro-optical wiring film more Ru are prepared in the Examples of the present invention. In this configuration example, regarding the configuration of the optical waveguide formed on the flexible electric / optical wiring film, the arrayed optical waveguide core 7 is formed on the polyimide film 5 by the method shown in FIG. The propagation direction of the light is changed upward at the reflection surface 17 through the core portion 7 and the outgoing light 19
Is taken out.

[0018] FIG. 6 is a top diagram illustrating a third configuration example of a more fabricated flexible electro-optical wiring film Ru to an embodiment of the present invention. This configuration example uses flexible
Regarding the configuration of the optical waveguide formed on the optical wiring film, the reflection surface 17 'is formed not in the depth direction as shown in FIGS. 4 and 5, but in the width direction of the core 7, and the reflection surface 17' is formed.
Thus, the optical path of the incident light 18 is changed on the surface of the polyimide film 5, and the emitted light 19 is extracted.

FIG. 7 is a sectional view showing a fourth configuration example of the flexible electro-optical wiring film more Ru are prepared in the Examples of the present invention. This configuration example shows a configuration example in which a multilayer optical waveguide is manufactured by basically repeating the steps shown in FIG. This configuration example relates to a configuration of an optical waveguide formed on a flexible electric / optical wiring film, in which a first layer core portion 7-1 is formed on a polyimide film 5 as a base, and a reflection surface having a predetermined angle on an end surface. After forming 17-1, the cladding layer 8-1 is formed to a height substantially equal to the height of the core portion 7-1.
The optical via 20 is formed by forming the same polyimide layer as above and performing a reactive ion etching process using a metal mask.
After forming the cladding layer 8-2 to the height of the optical via 20, the second layer core 7-2 is formed in the same manner as the first layer core 7-1, and the portion connected to the optical via 20 is formed. After the reflection surface 17-2 is formed on the end face of the cladding layer 8-
3 to form a multilayer optical waveguide. The incident light 18 passes through the lower core portion 7-1 and passes through the reflecting surface 17-.
1, the light is reflected by the reflection surface 17-2 via the optical via 20, and is extracted as the outgoing light 19 through the upper core portion 7-2. According to this configuration example, a plurality of optical waveguides can cross three-dimensionally, and complicated optical wiring can be performed.

[0020] FIG. 8 is made by an embodiment of the present invention
And is a view to a side view an example of the configuration of a module constituted by using a flexible electrical and optical wiring film. A light-emitting element 22, a driving IC 21, a light-receiving element 24, an amplifier IC 25, and the like are mounted using a flexible electric / optical wiring film 26 including a polyimide film 5 and an electric wiring 11 having a core portion 7 and a pad 12 of an optical waveguide. By connecting the two electric / optical wiring substrates 23-1 and 23-2, a flexible electric / optical wiring circuit module 27 can be manufactured. The height position of the pad 12 and the core portion 7 is controlled by controlling the thickness of the polyimide film 5 so that the pad 1
2 is connected so that light emitted from the light emitting element 22 is efficiently optically coupled to the core 7. If necessary, a configuration may be adopted in which a resin substantially equal to the refractive index of the core is used between the light emitting element or the light receiving element and the core portion, or optical coupling is performed using a lens.
In the illustrated example, the electrical / optical wiring boards 23-1 and 23-2 are used.
Are connected by an optical waveguide.
It is obvious that by forming via-connected electric wiring together with the optical waveguide, it is possible to electrically connect between the electric and optical wiring substrates.

FIG. 9 is a side view showing an example of a configuration in which the flexible electric / optical wiring circuit module manufactured as described above is mounted on a three-stage wiring board. One electric / optical wiring board 23 of one set of modules 27-1
-1 is mounted on the lower surface of the first-stage wiring board 28-1, and the other electrical / optical wiring board 23-2 is mounted on the upper surface of the second-stage wiring board 28-2. A flexible electric / optical wiring film 26-1 is provided between these substrates.
Can be connected. Further, one electric / optical wiring board 23-1 of another module 27-2 is mounted on the second-stage wiring board 28-2, and the other electric / optical wiring board 23-2 is connected to the third electric / optical wiring board 23-2. Wiring board 28-
3, these substrates can be connected to each other by using a flexible electric / optical wiring film 26-2.

In this embodiment, polyimide is used as the film material and the optical waveguide material. However, a resin such as epoxy can be used and is not limited by the resin material. Further, the substrate on which the electric / optical element or the electric / optical component is mounted may be an electric wiring substrate or an optical wiring substrate. As described above, the present invention can be variously applied according to the gist and can take various embodiments.

[0023]

As it is apparent from the foregoing description, according to the flexible electrical and optical wiring circuit module manufacturing method of the present invention, the electric-wire to form an optical waveguide and electrical wiring on a film-shaped base film However, because they are flexible and allow fine wiring, they can be placed on electrical / optical wiring boards, etc., at different heights and positions, and can be placed in a complicated manner and mounted at high density.・ Optical between optical modules with good optical coupling efficiency and mounting efficiency
Can be electrically connected.

[0024]

[Brief description of the drawings]

FIGS. 1 (a), 1 (b), 1 (c) and 1 (d) show a first example of a flexible electric / optical wiring film used in an embodiment of the present invention.
Showing a configuration example of a semiconductor device and a first manufacturing method example

FIGS. 2 (a), (b), (c), (d), (e),
(F) is a diagram showing a first configuration example and a first manufacturing method example of the flexible electric / optical wiring film.

FIGS. 3 (a), (b), (c), (d), and (e) are views showing a second example of a method for manufacturing a flexible electric / optical wiring film.

FIGS. 4 (a), (b), (c), (d), and (e) are diagrams showing a third example of a method for manufacturing a flexible electric / optical wiring film.

Perspective view showing a second configuration example of a flexible electro-optical wiring film more Ru are prepared in the Examples of the present invention; FIG

3 a top view showing a configuration example of a more fabricated flexible electro-optical wiring film Ru to the embodiment of the present invention; FIG

[7] 4 cross-sectional view showing the arrangement of a flexible electro-optical wiring film more Ru are prepared in the Examples of the present invention

[Figure 8] configuration of the flexible electrical-optical circuit module configured using a flexible electrical and optical wiring film of the
Side view of a formation example

FIG. 9 is a side view showing a configuration example in which the flexible electric / optical circuit module of the above embodiment is mounted on a wiring board.

FIGS. 10A and 10B are perspective views illustrating a conventional technique.

[Explanation of symbols]

5 Polyimide film 6 Photosensitive polyimide 7, 7-1, 7-2 Core part (core part) of optical waveguide 8, 8-1, 8-2, 8-3 Cladding layer 9 Base metal 10, 10 '... Photoresist 11 ... Electrical wiring 12 ... Pad 13 ... Polyimide layer 14 ... Metal layer 15 ... Metal mask 17, 17', 17-1, 17-2 ... Reflective surface 18 ... Incident light 19 ... Emitting light 20 ... Light Via 21 Drive IC 22 Light emitting element 23-1, 23-2 Electric / optical wiring board 24 Light receiving element 25 Amplifier IC 26, 26-1, 26-2 Flexible electric / optical wiring film 27, 27- 1, 27-2: Flexible electric / optical wiring circuit module 28-1, 28-2, 28-3: Wiring board

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kosuke Katsura 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Inventor Tsuyoshi Hayashi 1-16-1 Uchisaiwaicho, Chiyoda-ku, Tokyo Japan (56) References JP-A-61-79290 (JP, A) JP-A-61-121014 (JP, A) Polymers, Vol. 41, October, 1992, 732-735 ( 58) Fields surveyed (Int.Cl. ⁷ , DB name) G02B 6/12-6/14 H05K 1/02 JICST file (JOIS)

Claims (2)

(57) [Claims] 1. A resin film having flexibility as a base.
A single-layer or multilayer optical waveguide on the surface of the resin film
Flexible electrical and optical wiring
Electrical wiring board or optical wiring board or
Electrical / optical devices or electrical / optical devices
A method for manufacturing a flexible electric / optical wiring circuit module for optically and electrically connecting optical components, wherein a refractive index after a final treatment on a resin film is larger than a refractive index of the resin film. Form a photosensitive resin layer before solidification having a refractive index, then form a core layer of an optical waveguide having a desired shape through a photolithography process and a heat treatment process for the photosensitive resin layer, Forming a thin metal base metal on the resin film, then exposing the first photoresist, performing a desired patterning by a photo step of development, and then forming an electric wiring layer by electrolytic plating, The first photoresist is removed to form an electrical wiring, and then the second photoresist is subjected to a desired patterning by exposing and developing photo-processes to form an end of the electrical wiring. A bonding pad is formed by electrolytic plating of Au or solder, and then the base metal other than the electric wiring portion is removed. Then, the electric wiring substrate is formed by the flexible electric / optical wiring film prepared as described above. Alternatively, a method for manufacturing a flexible electric / optical wiring circuit module, comprising optically and electrically connecting optical / optical elements or electric / optical components mounted on an optical wiring substrate or an electric / optical wiring substrate. 2. A resin film having flexibility as a base.
A single-layer or multilayer optical waveguide on the surface of the resin film
Flexible electrical and optical wiring
Electrical wiring board or optical wiring board or
Electrical / optical devices or electrical / optical devices
A method for manufacturing a flexible electric / optical wiring circuit module for optically and electrically connecting optical components, wherein a refractive index after a final treatment on a resin film is larger than a refractive index of the resin film. Forming a photosensitive resin layer having a refractive index, then forming a thin metal film on the photosensitive resin layer, then exposing the photoresist, the pattern of the metal film by a photolithography process of development Then, the photosensitive resin layer or the photosensitive resin layer and a part of the resin film are etched and removed using a reactive gas using the pattern of the metal film as a mask to form a light guide having a desired shape. Forming the core layer of the waveguide, then
The photoresist and the metal film are removed to form an optical waveguide, then an electric wiring is formed on the resin film, and then the electric wiring board or the electric wiring is formed by the flexible electric / optical wiring film manufactured as described above. A method for manufacturing a flexible electric / optical wiring circuit module, comprising electrically and electrically connecting electric / optical elements and electric / optical components mounted on an optical wiring substrate.