JP2917903B2 - Optical receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical receiver for converting an optical signal into an electric signal, and more particularly, to an optical receiver for optical interconnection.

[0002]

2. Description of the Related Art Optical receivers for optical interconnection are used for signal transmission between boards and the like. Signal light from a tape fiber in which a plurality of fibers are combined is received by a plurality of light receiving elements and converted into an electric signal. It has a function to convert. In general, it is composed of the same number of light receiving elements and electrical circuits as the number of fibers of the tape fiber. As the signal transmission rate between boards increases, coaxial cables, which are conventional transmission means, have been replaced by tape fibers, and their importance has been increasing in recent years.

FIG. 5 is an explanatory view showing the structure of a conventional optical receiver for optical interconnection, wherein FIG.
(B) is a top view of the array IC. In the figure, reference numeral 51 denotes a package, 52 denotes an array IC, 53 denotes a light receiving element, 54 denotes a circuit block, 55 denotes an output terminal, 56 denotes a tape fiber, 58 denotes a light receiving element substrate, and 59 denotes an input terminal.

The optical receiver is a package 51, an array IC.
52, a light receiving element substrate 58, a light receiving element 53, and a tape fiber 56. The light receiving element 53 is composed of a plurality of light receiving sections arranged at the same interval as the fiber of the tape fiber 56, and is mounted on the light receiving element substrate 58. A wiring pattern is provided on the light receiving element substrate 58 and is connected to the input terminal 59 of the array IC 52 by wire bonding or the like. The array IC 52 and the light receiving element substrate 58
The package 51 for mounting the device has a structure in which a part of the frame is cut off so that the tape fiber 56 can be inserted from the side. FIG. 5B shows the structure of a conventional array IC 52, in which an input terminal 59, a circuit block 54,
It comprises an output terminal 55. The input terminals 59 are concentrated on one side of the array IC 52, and in consideration of ease of mounting,
Other terminals are arranged on the remaining three sides. The circuit blocks 54 are arranged in parallel with each other for the number of channels. When a plurality of circuits such as the array IC 54 are integrated on the same chip, it is important to reduce crosstalk between circuit blocks. As this method, for example, Japanese Patent Application Laid-Open
The technique disclosed in the 41509 publication describes a technique in which a power supply terminal is provided independently for each circuit block to reduce crosstalk.

[0005]

In the structure of the conventional optical receiver, the input terminal 59 of the array IC 52 is connected to the array IC 52.
Must be arranged at one edge on the light receiving element substrate 58 side, and the circuit block 54 must also be arranged in parallel with it. As a characteristic of the array IC 52, sensitivity degradation due to crosstalk between circuit blocks is a problem. However, even if the power supply is separated for each circuit block as in the above-described related art, a certain circuit block cannot be used. A signal leaks from another circuit block along the substrate of the array IC 52 and crosstalk occurs. Further, with the arrangement of the conventional array IC 52, the interval between the circuit blocks 54 of the adjacent channels is narrowed, and crosstalk is more likely to occur.

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical receiver for optical interconnection with reduced crosstalk between channels and high sensitivity.

[0007]

Optical receiver of the present invention, in order to solve the problem] is an optical receiver for converting into an electric signal by receiving the light emitted from the tape fiber by the light receiving element, a plurality of light receiving elements, optical receivers in Disposed in the center of the surface of the IC mounted on the
Each light receiving element to convert optical signal to electric signal
A plurality of circuit blocks of the IC connected to the
On the side of the optical receiver IC,
One set of light receiving element and circuit block each connected
And a means for fixing the package of the optical receiver and the tape fiber so that light emitted from the tape fiber enters the light receiving element.

[0008] Further , a plurality of input terminals for crimping a light receiving element to a central portion of an IC mounted in the optical receiver are provided,
Each light receiving element may be crimped to its input terminal.

[0009] In addition, the tip of Te Pufaiba, for matching the light receiving element of the emitted light and the light receiver, and the tape fiber fixing device having a plurality of positioning pins are fixed, the optical receiver package A plurality of grooves that engage with the pins and hold the pins in an adjustable manner may be provided at the positions sandwiching the IC.

[0010]

The structure is such that the tape fiber can be fixed to the package so that the optical signal is incident on the center of the array IC. For this purpose, a circuit input terminal can be provided at the center of the array IC, and circuit blocks of adjacent channels can be alternately arranged on both sides of the input terminal. As a result, the distance between the circuit blocks can be increased, and furthermore, each of them is connected.
A groove independently surrounding a set of light receiving elements and a circuit block
Is provided, crosstalk between channels can be reduced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described in detail with reference to the drawings. 1A and 1B are explanatory diagrams showing a schematic configuration of an optical receiver according to a first embodiment of the present invention, wherein FIG. 1A is a schematic perspective view, and FIG. 1B is a schematic cross-sectional view taken along line AA of FIG. (C) shows a partial configuration of the array IC.
It is a schematic top view showing. In the figure, reference numeral 11 denotes a package, 12 denotes an array IC, 13 denotes a light receiving element, and 14a to 14a.
d is a circuit block, 15 is an output terminal, 16 is a tape fiber, 17 is a tape fiber fixing device, 18 is a hole, and 19 is a pin.

Package 1 on which array IC 12 is mounted
1 is provided with a hole 18 for fixing the tape fiber 16. The hole 18 is provided at a position where the light emitted from the tape fiber 16 hits the light receiving element 13 on the array IC 12 when the tape fiber 16 is fixed.

The tip of the tape fiber 16 is fixed by a tape fiber fixing device 17, and the light is emitted from the tape fiber 16 such that the tip of the tape fiber 16 is located below the tape fiber fixing device 17. The tape fiber fixing device 17 has a pin 1 inserted into the hole 18 of the package 11 to fix the tape fiber fixing device 17 to the package 11.
9 is added. In FIG. 1B, the pin 19 is
And the tape fiber 16 is fixed to the package 11.

As shown in FIG. 1C showing the configuration of the array IC 12, light receiving elements 13 are formed in a line at the center of the array IC 12. Circuit blocks 14a to 14d are respectively connected to the respective light receiving elements 13. here,
Adjacent channels are alternately arranged on both sides of the light receiving element, like the circuit block 14a and the circuit block 14b, and each of the circuit blocks 14a to 14d is connected to the light receiving element 13 respectively. The output terminals 15 can be arranged on all sides of the array IC, and can be arranged at any appropriate position without any limitation. This arrangement increases the distance between circuit blocks and reduces crosstalk through the substrate. FIG. 4 shows a first embodiment of the present invention.
FIG. 2 is a schematic detailed top view of the array IC according to the embodiment. Figure
Reference numeral 42 denotes an array IC, 43 denotes a light receiving element, and 44a to
44d is a circuit block, 45 is an output terminal, 49 is a train
Ji. A set of interconnected receivers of the array IC 42
Optical element 43, circuit blocks 44a to 44d and output terminal
45 are independently enclosed using groove-like trenches 49
It has a structure. With this configuration,
Mitigation is achieved. The output terminal 49 is
The structure outside the punch 49 may be used.

Next, a second embodiment of the present invention will be described with reference to the drawings. 2A and 2B are explanatory diagrams of the configuration of an array IC according to a second embodiment of the present invention, wherein FIG. 2A is a schematic top view, and FIG. 2B is a schematic side view. In the figure, reference numeral 2
2 is an array IC, 23 is a light receiving element, 24a to 24d are circuit blocks, 25 is an output terminal, and 29 is a flip chip mounting terminal. A set of interconnected arrays of ICs 22
Light receiving element 23, circuit blocks 24a to 24d and output
The terminal 25 is independently formed using a groove-shaped trench (not shown).
It has an enclosed structure.

In the center of the array IC 22, a terminal 29 for mounting the flip chip of the light receiving element 23 is provided, and the light receiving element 23 is flip chip mounted thereon. According to this embodiment, an optical receiver for optical interconnection of the present invention can be configured without forming the light receiving element 23 on the array IC 22.

Next, a third embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a schematic perspective view showing the configuration of the integrated circuit according to the third embodiment of the present invention. In the figure, reference numeral 31 denotes a package, 32 denotes an array IC, 33 denotes a light receiving element, 36 denotes a tape fiber, 37 denotes a tape fiber fixing device, 38 denotes a groove, and 39 denotes a pin.

In this embodiment, the package 31 is provided with a groove 38 which can be engaged with the pin 39 of the tape fiber fixing device 37 so as to be perpendicular to the direction of the row of the light receiving elements 33 of the array IC 32. The pins 39 of the fiber fixing device 37 are aligned with the grooves 38 so that the light receiving elements 3 of the array IC 12
It can be moved at right angles to the row of 3. if,
In the first embodiment, if the position of the hole 18 and the light receiving element 13 of the array IC 12 are shifted, the optical receiver cannot be configured. However, according to this embodiment, the position of the tape fiber fixing device 37 is shifted. The positions of the light emitted from the fiber and the light receiving element can be adjusted.

[0020]

[0021]

[0022]

An advantage of the present invention is that, in an optical receiver including an optical receiver for optical interconnection, crosstalk generated between channels can be reduced. For this reason, a receiver having good reception characteristics can be configured.

The reason is that the light emitted from the tape fiber is
This is because the signal input unit of the IC can be arranged at the center of the IC by adopting a packaging structure in which the IC is applied from above the C. By arranging the circuit blocks alternately on both sides of the signal input section, the distance between the circuit blocks is increased, and furthermore, the light receiving element of the array IC and
And circuit blocks with trenches
As a result, crosstalk via the substrate is reduced.

Also, by providing a flip-chip mounting terminal of the light receiving element in the center of the array IC and mounting the light receiving element on the flip chip, the present invention can be realized without forming the light receiving element on the array IC. Can be configured, and the manufacturing process can be simplified. If the pin receiving hole of the package is formed in a groove shape, it is easy to adjust the positions of the light emitted from the tape fiber and the light receiving element.

[0025]

According to the present invention, when an array IC was created by circuit blocks having an operation speed of 2.4 Gb / s, the distance between each circuit block was 50 μm in the conventional arrangement of array ICs. With the arrangement of the array IC of the invention, the distance between circuit blocks could be increased to 300 μm. Further, as a result of configuring the optical receiver using this array IC, the crosstalk is reduced by about 6 dB in the optical receiver of the present invention as compared with the optical receiver of the conventional configuration.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a schematic configuration of an optical receiver according to a first embodiment of the present invention. (A) is a schematic perspective view. (B) is a schematic sectional view of AA section of (a). (C) is a schematic top view showing a part of the configuration of the array IC.

FIG. 2 is an explanatory diagram of a configuration of an array IC according to a second embodiment of the present invention. (A) is a schematic top view. (B)
Is a schematic side view.

FIG. 3 is a schematic perspective view illustrating a configuration of an integrated circuit according to a third embodiment of the present invention.

FIG. 4 is a schematic detailed top view of the array IC according to the first embodiment of the present invention.

FIG. 5 is an explanatory view showing a structure of a conventional optical receiver for optical interconnection. (A) is a perspective view. (B) is a top view of the array IC.

[Explanation of symbols]

11, 31, 51 Package 12, 22, 32, 42, 52 Array IC 13, 23, 33, 43, 53 Light receiving elements 14a to 14d, 24a to 24d, 44a to 44d, 5
4 Circuit block 15, 25, 45, 55 Output terminal 16, 36, 56 Tape fiber 17, 37 Tape fiber fixing device 18 Hole 19, 39 pin 29 Flip chip mounting terminal 38 Groove 49 Trench 58 Light receiving element substrate 59 Input terminal

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ identification code FI H04B 10/135 10/14 (58) Investigated field (Int.Cl. ⁶ , DB name) H01L 31/02 G02B 6/36 G02B 6/42 H04B 10/12-10/14

Claims (3)

(57) [Claims] 1. A light receiver for converting the light emitted from the tape fiber into an electric signal received by the light receiving element, a plurality of the light receiving element, is mounted on the optical receiver in the I
C, each of which is provided at a central portion of the surface of the light receiving surface for converting an optical signal into an electric signal.
A plurality of circuit blocks of the IC connected to the element,
The light receiving elements are alternately arranged on both sides, and each is connected to the surface of the IC of the optical receiver.
Independent one set of the light receiving element and the circuit block
And a means for fixing the package of the optical receiver and the tape fiber so that light emitted from the tape fiber is incident on the light receiving element. Receiver. A plurality of input terminals for crimping the light receiving element to a center portion of the IC mounted in the optical receiver, wherein the light receiving elements are respectively crimped to the input terminals.
Optical receiver according to claim 1, characterized in that it is. 3. The tape fiber according to claim 1, further comprising a tip for aligning the outgoing light with the light receiving element of the optical receiver.
A tape fiber fixing device having a plurality of locating pins is fixedly attached, and the package of the optical receiver has
The position across the C, optical receiver according to claim 1 or 2, wherein the pin engages, wherein a plurality of grooves are provided for adjustably retaining said pin.