JP2003004962A - Electro-optic hybrid substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electro-optic hybrid substrate having a light transmission medium adequately arranged in relation with electric wiring layers. SOLUTION: This electro-optic hybrid substrate has the plural electric wiring layers 11 to 14 for transmitting electric signals and the light transmission medium 15 arranged in the position between the electric wiring layers 11 and 12. The electric wiring layers 11 and 14 are respectively arranged on the front surface and the rear surface of the electric insulating sections 16. The electric wiring layers 12 and 13 and the light transmission medium 15 are embedded into the electric insulating sections 16. Electric elements 17 and optical elements 18 are arranged on the electric wiring layer 11. The light transmission medium 15 is arranged within the electric insulating sections 16 in such a manner that the medium can be optically coupled to the optical elements 18. Between the electric wiring layers 11 to 14 are provided with vias 19 for electrically connecting the layers to each other. The vias 19 are arranged in the positions apart from the light transmission medium 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electro-optical hybrid board in which an optical transmission medium optically coupled with an optical element on an electric wiring layer is provided on an electric circuit board.

[0002]

2. Description of the Related Art With the recent improvement in semiconductor process technology, the performance of semiconductor devices has dramatically improved. However, in an electric circuit that connects these semiconductor elements, the operation speed is limited by a signal delay caused by capacitance between wirings or wiring resistance, or electromagnetic noise (EMI: Electromagnetic
The issue of "Interference" is becoming ignorable. Therefore, attention has been paid to in-board optical interconnection, in which semiconductor elements are connected by optical wiring. This technique proposes an electro-optical hybrid board including a medium having an optical wiring function on a conventional printed board on which electric wiring is performed.

For example, Japanese Patent Laid-Open No. 2000-147270 discloses a printed wiring board having an optical wiring function. This technique is intended to embed an optical fiber or an optical waveguide in an insulating layer of a printed wiring board so that electrical / optical wiring can be made compact and easy. Further, Japanese Patent Laid-Open No. 2001-7463 discloses an opto-electric hybrid board and a method for manufacturing the same. In this technique, the electric insulating layer and the optical waveguide portion are made of the same material, and the optical waveguide portion and the electric wiring portion are three-dimensionally mounted and the cost is reduced. However, the optical fiber and the optical waveguide are basically technologies for one-to-one communication, and as the number of signal lines to be transmitted increases, the routing of wiring and the manufacturing process become more difficult.

Under such circumstances, a low-cost and highly expandable optical interconnection is proposed, for example, in "Electronics", October 2000, pages 49-53, "New Concept Optical Sheet Bus Technology". Has been done. According to this technique, for example, a low-cost plate-shaped light guide path (optical transmission medium) made of resin is provided, and a reflection / diffusion optical system is provided inside to transmit light output from one point to multiple points. A broadcast type optical transmission medium can be obtained. By using this plate-shaped optical transmission medium and the diffusion optical system, simultaneous communication from one element to a plurality of elements and bus wiring by light can be easily realized. Therefore, it is conceivable to apply such a plate-shaped optical transmission medium to a printed circuit board for electrical wiring to form an electro-optical hybrid board.

[0005]

However, in a mixed electric and optical board, it is necessary to provide an interlayer via (contact) for electrically connecting a plurality of electric wiring layers. If a via is provided in a flat optical transmission medium that spreads in a planar shape on the electro-optical hybrid board, there is a problem that the progress of light is hindered.

Therefore, it is an object of the present invention to provide an electro-optical hybrid board having an optical transmission medium that is preferably arranged in relation to an electric wiring layer.

[0007]

SUMMARY OF THE INVENTION The above-described object is to provide at least two electric wiring layers for transmitting electric signals, and optical transmission which is arranged between the electric wiring layers and is optically coupled to an optical element on the electric wiring layers. This is achieved by an electro-optical hybrid board that includes a medium and a via that electrically connects the electrical wiring layers at a position apart from the optical transmission medium. Here, the optical transmission medium has a plurality of light entrance / exit portions at one end and a light reflection portion at the other end, or at least one light incident portion at one end and at least one light at the other end. It may have an emitting portion. Further, at least the light incident portion may have a light diffusing means, and the light reflecting portion may have a light diffusing means.

Further, the electro-optical hybrid board according to the present invention includes a plurality of electric wiring layers laminated via an electric insulation portion, and electric elements and optical elements arranged in the uppermost electric wiring layer.
And a broadcast type optical transmission medium disposed in the electrical insulation portion so as to be optically coupled to the optical element. Here, the electric element may be arranged closer to the edge than the position of the optical element in the uppermost electric wiring layer. With this configuration, it is possible to obtain an electro-optical hybrid board having an optical transmission medium that is preferably arranged in relation to the electric wiring layer.

[0009]

1 is a plan view showing an embodiment of an electro-optical hybrid board according to the present invention, and FIG. 2 is a sectional view taken along the line AB of FIG. The electro-optical hybrid board 10 of the present embodiment includes a plurality of electric wiring layers 11 to 14 for transmitting electric signals, and an optical transmission medium 15 arranged between the electric wiring layers 11 and 12. The electrical wiring layers 11 and 14 are electrically insulating portions 16 respectively.
The electric wiring layers 12 and 13 and the optical transmission medium 15 are embedded in the electric insulating portion 16, respectively.

On the electric wiring layer 11, transistors and I
Electrical element 17 such as C or capacitor or resistor, and optical element 1 such as laser diode or photodiode
8 are arranged. The optical transmission medium 15 is the optical element 1
8 is arranged in the electrical insulation part 16 so as to be optically connectable with it. A specific example of the optical transmission medium 15 will be described later. Further, vias 19 are provided between the electrical wiring layers 11 to 14 to electrically connect the layers. The via 19 is the optical transmission medium 15
It is located in a position away from.

An electric wirable area is defined on the electro-optical hybrid board 10, and the interlayer via 19 is provided within the area.
This electrically wirable area is an area excluding the area where the optical transmission medium 15 exists when the electro-optical hybrid board 10 is viewed in plan in FIG. By doing so, the optical transmission medium 1
Since there is no via in the optical transmission medium 5 that prevents the progress of light, the optical signal is uniformly diffused and propagated in the optical transmission medium 15.

3A and 3B are views showing an example of a flat optical transmission medium used in the present invention. FIG. 3A is a perspective view and FIG. 3B is a side view. In the figure, the core 34 of the optical transmission medium 31
It is desirable to use a transparent medium, and it is desirable that a clad 35 having a smaller refractive index than the transparent medium of the core portion is arranged on the upper and lower surfaces and the left and right side surfaces of the core 34. As the material of the translucent medium, for example, a plastic material such as polymethylmethacrylate, polycarbonate, amorphous polyolefin, or inorganic glass can be used.

The optical signal incident on the optical transmission medium 31 travels inside a core 34 molded in a flat plate shape. Optical transmission medium 31
The light-reflecting portion 33 on one end surface has a role of reflecting an optical signal. Therefore, the light reflecting portion 33 polishes the surface. In addition to this light reflecting means, a light diffusing means can be further provided. The end surface facing the reflection surface is shown in FIG.
As shown in (a), it is processed into a step shape, and the light incident / exiting portion 32 is provided therein. Further, as shown in FIG. 3B, the end face is processed into a 45 ° face 37 with respect to the upper and lower faces of the flat plate and polished so that light is easily reflected. Depending on the case, you may vapor-deposit a metal film etc. on this end surface.

The light entrance / exit section 32 is preferably subjected to processing such as mirror-polishing so that there is no loss when entering / exiting the light, and a light diffusing means may be provided. By doing so, the optical signal 36 input from the light input / output unit 32 is reflected by the 45-degree surface 37, propagates in the core 34, is reflected by the reflecting surface 33 at the other end surface, and is again reflected by the 45-degree surface 37. The light is reflected and emitted from the light incident / emitting portion 32. At this time, the light diffuses widely and returns, so that it is possible to take out the same optical signal not only from the light incident / emitting portion to which the light signal 36 is input, but also from other light incident / emitting portions. That is, a broadcast type optical transmission medium is configured, and signals can be exchanged between arbitrary light input / output units 32.

4A and 4B are views showing another example of the optical transmission medium used in the present invention. FIG. 4A is a perspective view and FIG. 4B is a side view. In this example, as shown in the figure, the optical transmission medium 41, the light emitting elements 42 and 42 ′ arranged at the ends thereof, the light receiving elements 43 and 43 ′ arranged at the opposite ends thereof, and the optical transmission medium 41 are shown. 45 ° bevels 4 formed at both ends of the
4, 44 'and light emitting elements 42, 42' of the optical transmission medium 41
And a diffusing optical system 45 provided on the surface opposite to.

In this example, the optical signal emitted from the light emitting element 42 enters the optical transmission medium 41. At this time, the optical signal is diffused by the diffusion optical system 45. This diffused light is 4
The light is reflected by the 5 ° inclined surface 44, travels to the side of the light receiving element 43 located at the opposite end, and the 45 ° inclined surface 4 at that end.
It is reflected again at 4 ', so that the optical signal is received by the light receiving element 4
Light is received at 3. In this example, the provision of the diffusion optical system 45 enables broadcast transmission.

In the present invention, for example, such an optical transmission medium of the broadcast type can be arranged in the electrical insulation portion to form an electro-optical hybrid board. As shown in FIGS. 1 and 2, the electro-optical hybrid board 10 includes an electric insulation section 16 as shown in FIG.
It has a plurality of electric wiring layers 11 to 14 which are laminated with each other, and the electric element 17 and the optical element 18 are arranged in the uppermost electric wiring layer 11. The optical transmission medium 15 is arranged in the electrical insulating portion 16 so as to be optically coupled with the optical element 18. As a result, the electro-optical hybrid board including the optical transmission medium 15 can be manufactured compactly. In this case, the electric element 17 is preferably arranged closer to the edge than the position of the optical element 18 of the uppermost electric wiring layer 11. As a result, the optical element 18 can be arranged at a relatively central portion of the electric wiring layer 11, and as a result, the area of the flat optical transmission medium 15 embedded in the electric insulating portion 16 can be easily secured. .

As described above, according to the present invention, when a flat or sheet-shaped optical transmission medium is used, if there is an obstacle that blocks the progress of light within a certain area, the uniformity of propagation is impaired. However, by limiting the region where the via is provided between the electrical wiring layers that may penetrate through the sheet, uniform diffuse transmission of light is possible. Further, by devising the positional relationship between the optical element and the optical transmission medium, the structure of the electro-optical hybrid board can be simplified and its fabrication becomes easy. As a result, especially when the number of signal lines to be transmitted is large, it is possible to realize a lower cost electro-optical hybrid board as compared with the conventional optical fiber or optical waveguide.

[0019]

According to the present invention, it is possible to obtain an electro-optical hybrid board having an optical transmission medium that is preferably arranged in relation to an electric wiring layer.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of an electro-optical hybrid board according to the present invention.

2 is a cross-sectional view taken along the line AB of the electro-optical hybrid board shown in FIG.

3A and 3B are views showing an example of a flat optical transmission medium used in the present invention, FIG. 3A is a perspective view, and FIG. 3B is a side view.

FIG. 4 is a diagram showing another example of the optical transmission medium used in the present invention, in which (a) is a perspective view and (b) is a side view.

[Explanation of symbols]

10 Electro-optical mixed board 11-14 Electric wiring layer 15 Optical transmission media 16 Electrical insulation 17 Electric element 18 Optical element 19 beer 31 Optical Transmission Medium 32 Light entry / exit section 33 Light reflection part 34 core 35 clad 36 Optical signal 37 45 degree surface

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Ken Uemura             430 Green, Sakai, Nakai-cho, Ashigaragami-gun, Kanagawa Prefecture             Inside of Fuji Xerox Co., Ltd. (72) Inventor Hidenori Yamada             430 Green, Sakai, Nakai-cho, Ashigaragami-gun, Kanagawa Prefecture             Inside of Fuji Xerox Co., Ltd. (72) Inventor Junji Okada             430 Green, Sakai, Nakai-cho, Ashigaragami-gun, Kanagawa Prefecture             Inside of Fuji Xerox Co., Ltd. (72) Inventor Shinya Kyozuka             430 Green, Sakai, Nakai-cho, Ashigaragami-gun, Kanagawa Prefecture             Inside of Fuji Xerox Co., Ltd. (72) Inventor Kazuhiro Sakai             430 Green, Sakai, Nakai-cho, Ashigaragami-gun, Kanagawa Prefecture             Inside of Fuji Xerox Co., Ltd. (72) Inventor Tsutomu Hamada             430 Green, Sakai, Nakai-cho, Ashigaragami-gun, Kanagawa Prefecture             Inside of Fuji Xerox Co., Ltd. (72) Inventor Nori Takanashi             430 Green, Sakai, Nakai-cho, Ashigaragami-gun, Kanagawa Prefecture             Inside of Fuji Xerox Co., Ltd. (72) Inventor Masaaki Miura             430 Green, Sakai, Nakai-cho, Ashigaragami-gun, Kanagawa Prefecture             Inside of Fuji Xerox Co., Ltd. (72) Inventor Takehiro Niitsu             430 Green, Sakai, Nakai-cho, Ashigaragami-gun, Kanagawa Prefecture             Inside of Fuji Xerox Co., Ltd. (72) Inventor Tomao Baba             430 Green, Sakai, Nakai-cho, Ashigaragami-gun, Kanagawa Prefecture             Inside of Fuji Xerox Co., Ltd. (72) Inventor Shoji Hisada             430 Green, Sakai, Nakai-cho, Ashigaragami-gun, Kanagawa Prefecture             Inside of Fuji Xerox Co., Ltd. (72) Inventor Kenichi Kobayashi             430 Green, Sakai, Nakai-cho, Ashigaragami-gun, Kanagawa Prefecture             Inside of Fuji Xerox Co., Ltd. (72) Inventor Akira Toshima             430 Green, Sakai, Nakai-cho, Ashigaragami-gun, Kanagawa Prefecture             Inside of Fuji Xerox Co., Ltd. F term (reference) 2H037 AA01 BA02 BA11 CA39 DA03                 2H047 KA03 KB08 KB09 MA07 QA05                       RA08 TA05 TA47                 5E338 AA03 BB75 CC10 CD40                 5E346 AA12 AA15 AA32 AA43 AA51                       BB20 FF45 HH01 HH21

Claims (7)

[Claims] 1. At least two electric wiring layers for transmitting electric signals, an optical transmission medium disposed between the electric wiring layers and optically coupled to an optical element on the electric wiring layer, and from the optical transmission medium. An electro-optical hybrid board comprising: a via that electrically connects the electrical wiring layers at separate positions. 2. The electro-optical hybrid board according to claim 1, wherein the optical transmission medium has a plurality of light input / output sections at one end and a light reflection section at the other end. 3. The optical transmission medium has at least one end at one end.
2. The electro-optical hybrid board according to claim 1, wherein the electro-optical hybrid board has one light incident portion and at least one light emitting portion at the other end. 4. The electro-optical hybrid board according to claim 2, wherein at least the light incident part has a light diffusing means. 5. The electro-optical hybrid board according to claim 2, wherein the light reflecting portion has a light diffusing unit. 6. A plurality of electric wiring layers laminated via an electric insulation part, an electric element and an optical element arranged in the uppermost electric wiring layer, and the electric element which is optically connectable with the optical element. An electro-optical hybrid board comprising: a broadcast type optical transmission medium arranged in an insulating portion. 7. The electro-optical hybrid board according to claim 6, wherein the electric element is arranged closer to the edge of the uppermost electric wiring layer than the position of the optical element.