JP2001174657A - Optical wiring layer, opto-electric wiring board and mounted board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an opto-electric wiring board capable of being mounted with high density or being miniaturized, moreover capable of easily mounting optical parts, also capable of more widening the range for selecting the optical parts by optionally assembling the optical parts to be used, and further capable of shortening the wiring with the optical parts and the electric parts. SOLUTION: In the opto-electric wiring board, the electric wiring boards are laminated on an optical wiring layer 7 having at least one optical part setting hole 3 having a light input/output part at least one side surface of which has a two-dimensional lens shape 4. A mounted board is obtained by mounting the optical parts and the electric parts on the board. Further, the electric parts may be mounted on the surface of the opposite side of the surface on which the optical parts are mounted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical wiring layer, an optical / electrical wiring board in which optical wiring and electric wiring are mixed, and a mounting board in which an optical component and an electric component are mounted on the optical / electrical wiring board.

[0002]

2. Description of the Related Art In order to make a computer capable of performing arithmetic processing faster, the clock frequency of a CPU tends to increase more and more, and a clock frequency of the order of 1 GHz has come to the present. As a result, there is a portion where a high-frequency current flows in the electric wiring made of copper on the printed circuit board in the computer, so that malfunction occurs due to generation of noise, and electromagnetic waves are generated, which adversely affects the surroundings. It will also be.

In order to solve such a problem, a part of an electric wiring made of copper on a printed circuit board is replaced with an optical fiber or an optical waveguide (hereinafter, referred to as an optical wiring), and an optical signal is used instead of an electric signal. Has been done. This is because, in the case of an optical signal, generation of noise and electromagnetic waves can be suppressed.

From the viewpoint of high-density mounting or miniaturization, it is desirable to manufacture an optical / electrical wiring board in which electric wiring and optical wiring are laminated on the same substrate. When mounting optical components such as laser light-emitting elements and light-receiving elements, it is difficult to optically match the optical axis of the optical component with the optical axis of the optical wiring. Did not.

As an improved method, there is, for example, Japanese Patent Application Laid-Open No. 8-194137. According to this method, the height from the lower surface of the optical component to the center of the active portion is made to coincide with the height from the optical component installation surface to the center of the waveguide, thereby performing height alignment. In addition, by aligning the end face of the optical component with a plane parallel to the end face of the waveguide, alignment in the optical axis direction can be performed. However, there is no physical positioning mechanism for positioning in the direction parallel to the substrate and perpendicular to the optical axis, and it is necessary to perform operations such as positioning while operating optical components, which makes the mounting time and labor difficult. There was a disadvantage that this was the case. Further, there is a disadvantage that the optical / electrical wiring board becomes very expensive.

[0006] Conventionally, the mounting method of the light emitting component and the light receiving component has been common. As a method of attaching the optical component, there are a method of attaching the optical component near the end of the optical wiring, and a method of forming a mirror inclined at approximately 45 ° on the optical wiring and bending the light substantially at a right angle to attach the optical component. Waveguide type L
Combinations of optical components have been almost limited, for example, the suitability of a D-waveguide PD and the latter is suitable for a surface-emitting LD and a planar PD.

Furthermore, conventionally, optical components and electrical components are
They were mounted side by side on the same plane. Therefore, the wiring could not be shortened, and it was difficult to operate at high speed, and the problems of unnecessary electromagnetic radiation were serious.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the state of the prior art, and is an optical / electrical wiring board capable of high-density mounting or miniaturization and capable of easily mounting optical components. The task is to provide In particular, an object is to facilitate alignment in a direction parallel to the substrate and perpendicular to the optical axis.

It is another object of the present invention to make the combination of optical components used arbitrarily widen the range of selection of optical components.

Another object is to shorten the wiring between the optical component and the electrical component.

[0011]

In order to achieve the above-mentioned object, first, according to the first aspect of the present invention, in a layered optical wiring layer having a core and a clad, at least one side surface has a two-dimensional lens shape. An optical wiring layer comprising at least one optical component installation hole having a certain optical input / output unit. According to a second aspect of the present invention, there is provided the optical wiring layer according to the first aspect, further comprising a mirror inclined by approximately 45 ° with respect to the optical wiring layer. According to a third aspect of the present invention, there is provided an optical / electrical wiring board characterized in that an electric wiring board is laminated on the optical wiring layer according to the first or second aspect. According to a fourth aspect of the present invention, there is provided a mounting substrate, wherein an optical component and an electrical component are mounted on the optical / electrical wiring substrate according to the third aspect. According to a fifth aspect of the present invention, there is provided the mounting board according to the fourth aspect, wherein an electrical component is mounted on a surface opposite to a surface on which the optical component is mounted.

[0012]

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

1. Optical Wiring Layer First, a top view and a vertical cross-sectional view of a portion of the optical wiring layer according to the present invention where light enters the optical wiring are shown in FIG.

The optical wiring layer 7 of the present invention comprises a layered cladding 2.
And an optical component installation hole 3 embedded therein. The core 1 has a higher refractive index than the cladding 2, and light mainly propagates through the core 1. That is, the core 1 and the clad 2 in the vicinity thereof become an optical wiring. The end of the core 1 reaches the side surface of the optical component installation hole 3 and is optically coupled to the internal optical component.

Laser diode (LD) as light emitting component
Component installation hole 3 for light emitting diode (LED)
Shown in A light input / output unit in the form of a two-dimensional lens (convex lens) is formed at an end of the core 1. This two-dimensional lens 4 reduces the requirement for the lateral position accuracy of the light emitting component,
The alignment of the light emitting components is facilitated. This is because, even if the light emitting components are displaced in the lateral direction, the light is always guided to the core by the light condensing action of the two-dimensional lens 4. That is, it is possible to increase the effective position accuracy in a direction parallel to the substrate and perpendicular to the optical axis, which is a problem in the related art. The two-dimensional lens 4 is very easy to manufacture. For example, it can be manufactured by dry etching using a lens-shaped mask.

The two-dimensional lens-like light input / output unit may be provided not only on one side of the optical component installation hole 3 but also on two or more sides. Also, a plurality of optical component installation holes 3 may be provided in the optical wiring. Further, it is also preferable to make the core 1 near the two-dimensional lens 4 tapered.

On the other hand, a spot size conversion LD can be used as a light emitting component.

Next, FIG. 2 shows a top view and a vertical cross-sectional view of a portion of the optical wiring layer according to the present invention where light is emitted from the optical wiring layer.

Photodiode (PD) as light receiving component
The optical component for the phototransistor receives the light reflected by the mirror 5 inclined at approximately 45 ° with respect to the optical wiring layer and emitted to the upper surface of the optical wiring. A three-dimensional lens 6 may be attached to a portion exiting the optical wiring.

The optical component installation hole 3 and the mirror 5 of the present invention can be shared by a plurality of optical components as shown in FIG.

With this structure, a combination of a waveguide type LD and a planar PD, which has been impossible in the past, has become possible. If the structure is reversed, the surface emitting LD and the waveguide type P
It goes without saying that the combination of D becomes possible.

Incidentally, the optical wiring layer in the present invention is not limited to connecting the light emitting component and the light receiving component one to one. That is, a plurality of wavelengths can be simultaneously used by connecting one light emitting component and a plurality of light receiving components by using a branch, or by multiplexing / demultiplexing using a diffraction grating or a filter.

2. Optical / Electric Wiring Board Electrical wiring is necessary to actually install and drive optical components. The optical / electrical wiring board of the present invention is basically
The optical wiring layer 7 of the present invention is laminated on an electric wiring board 8. Examples are shown in FIGS. Electric wiring board 8
May be a single layer or a multilayer substrate. As the material thereof, polyimide, glass epoxy, ceramic, or the like can be used. For lamination, a method of bonding the optical wiring layer 7 and the separately manufactured electric wiring substrate 8 is preferable. However, the optical wiring layer 7 may be formed directly on the electric wiring board 8. In the light emitting component installation hole 3, there are light emitting component installation pads 9.
Are formed. Further, in the vicinity of the mirror 5, a light receiving component installation pad 11 is formed via a via hole 10. Further, a pad 13 may be provided on a portion of the optical wiring layer other than the core 1 via the via hole 12 so that an electric component can be installed on the optical wiring layer side.

The component mounting holes 3 may be formed before bonding or after bonding. Further, the component installation hole 3 may penetrate the optical wiring layer (see FIG. 4) or may not penetrate (see FIG. 5). If it does not penetrate, the electrical connection of the optical component can be made by forming the via hole 14 in the non-penetrating part.

3. FIG. 6 shows a state in which optical components are mounted on the optical / electrical wiring board of the present invention. Light emitted from a light emitting component 15 such as an LD enters the core 1 from the side of the optical component installation hole 3 and propagates in the optical wiring.
The light is reflected by the mirror 5, changes its direction by about 90 °, emerges from above the optical wiring, and enters the light receiving component 16 such as a PD. If the light emission of the LD is modulated, the information can be detected by the PD, and high-speed signal transmission with less unnecessary electromagnetic radiation can be performed. The alignment of the light emitting component in the height direction is performed by adjusting the height from the lower surface of the light emitting component to the center of the core and the light from the optical component installation surface (the upper surface of the solder layer (not shown) formed on the optical component pad 9). This is done physically by equalizing the height to the center of the wiring layer. Positioning in the direction parallel to the substrate and perpendicular to the optical axis can be easily performed because the required accuracy is reduced by the two-dimensional lens according to the present invention.

FIG. 7 shows a state in which the electric component 17 is further mounted.
Shown in If the electrical component 17 is mounted on the surface of the optical / electrical wiring board opposite to the optical component mounting surface, the wiring between the electrical component 17 and the light emitting component 15A and the light receiving component 16A can be reduced to the thickness of the electrical wiring board, Delay in response speed can be minimized. Also, as shown in FIG. 8, a temperature stabilizing device 18 (Peltier element,
Or a heat sink).

The electric component 17 and the optical components 15A, 16
In order to shorten the distance to A, the number of layers in the vicinity of the installation part of the electric component 17 in the electric wiring board can be made smaller than that of the others.

4. Others When the light emitted from the light emitting component 15 is reflected by the side surface of the optical element installation hole and enters the light emitting component 15 again, the operation of the light emitting component 15 becomes unstable. Therefore, as shown in FIG.
This can be improved if the device is installed so as to be incident on the oblique area.

Further, positioning of the optical component in the optical axis direction,
For rough alignment in a direction parallel to the substrate and perpendicular to the optical axis, the shape of the optical component installation hole can be devised as shown in FIG. 10 to improve the positional accuracy. That is, a part of the side surface of the optical component installation hole 3 can be used as a reference surface of the optical component 15. Further, the pad 9 of the substrate can be formed at a position shifted from the electrode 15E of the optical component to the reference surface side, and the optical component can be pressed against the reference surface by the surface tension of the solder. Further, by making the corners of the optical component installation hole 3 round, the mechanical strength of the optical wiring layer 7 can be increased.

[0030]

As can be understood from the above description, the present invention has the following effects.

First, since the light input / output section is formed in a two-dimensional lens shape, the margin of the installation position of the light emitting component (or the light receiving component) is increased, and the strict alignment with the optical wiring is not required. There is. Further, optical coupling with the light receiving component increases.

Second, if a mirror is used and the structures of the light incident portion and the light emitting portion are different, a combination of a waveguide type LD and a planar PD or a combination of a surface emitting LD and a waveguide type PD becomes possible. A more optimal design can be achieved.

Third, by mounting the electrical component on the opposite side of the optical component, the length of electrical wiring of the optical component can be minimized, high-speed operation can be achieved, and unnecessary radiation of electromagnetic waves can be suppressed. it can. Further, the temperature stabilizing device can be easily installed for both the optical component and the electric component.

[0034]

[Brief description of the drawings]

FIG. 1 is a top view and a longitudinal sectional view showing an example of an optical wiring layer of the present invention.

FIG. 2 is a top view and a longitudinal sectional view showing another example of the optical wiring layer of the present invention.

FIG. 3 is a top view and a longitudinal sectional view showing another example of the optical wiring layer of the present invention.

FIG. 4 is a top view and a longitudinal sectional view showing an example of the optical / electrical wiring board of the present invention.

5A and 5B are a top view and a vertical sectional view illustrating another example of the optical / electrical wiring board of the present invention.

6A and 6B are a top view and a vertical cross-sectional view illustrating an example of a mounting board according to the present invention.

FIG. 7 is a top view and a longitudinal sectional view showing another example of the mounting board of the present invention.

FIG. 8 is a longitudinal sectional view when a temperature stabilizing device is installed on the mounting board of FIG. 7;

FIG. 9 is a top view showing an improved example of the optical wiring layer of the present invention.

FIG. 10 is a top view showing an improved example of the optical wiring layer of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Core 2 ... Cladding 3 ... Optical component installation hole 4 ... 2D lens 5 ... Mirror 6 ... 3D lens 7 ... Optical wiring layer 8 ... Electric wiring board 9 ... Light emitting component pad 10 ... Via hole 11 ... Light receiving component pad 12 ... Via hole 13 ... Pad for electric component 14 ... Via hole 15 ... Light emitting component 15A ... Light emitting component array 15E ... Light emitting component electrode 16 ... Light receiving component 16A ... Light receiving component array 17 ... Electrical component 18 ... Temperature stabilizing device

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Koji Ichikawa, Inventor, 1-5-1, Taito, Taito-ku, Tokyo Inside Toppan Printing Co., Ltd. (72) Kenta Yotsui 1-1-1, Taito, Taito-ku, Tokyo F Term in Toppan Printing Co., Ltd. (Reference) 2H047 KA04 KB08 LA09 MA07 TA01 5E346 AA60 BB01 BB20 FF45 GG40 HH21

Claims (5)

[Claims] 1. An optical wiring layer having a core and a clad, wherein at least one side has at least one optical component installation hole having an optical input / output section having a two-dimensional lens shape. Wiring layer. 2. The optical wiring layer according to claim 1, further comprising a mirror inclined by approximately 45 ° with respect to the optical wiring layer. 3. An optical / electrical wiring board, wherein an optical wiring board is laminated on the optical wiring layer according to claim 1. 4. A mounting board, wherein an optical component and an electrical component are mounted on the optical / electrical wiring board according to claim 3. 5. The mounting board according to claim 4, wherein an electric component is mounted on a surface opposite to a surface on which the optical component is mounted.