JPH11202166A - Optical module and connection part between optical module and optical fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the degrees of freedom of an installation position and an angle. SOLUTION: This optical module 10 provided with an MT ferrule 20 is electrically connected to an electric circuit board 26 in a housing 24 with a flexible electric circuit 50 (FPC, etc.). Consequently, a ferrule coupling part is made in floating structure to solve the problem that adverse influence is exerted on the connection surface when a force perpendicular to the connection direction operates on an optical fiber 29. Here, when an elastic member 54 is charged around the optical module 10, the position of the optical module 10 becomes stable and its portability can be maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical module,
Also, the present invention relates to a connection portion between an optical module and an external optical fiber, and more particularly to a type in which the technology of an MPO optical connector is used for optical connection.

[0002]

2. Description of the Related Art In FIG. 5A, reference numeral 10 denotes an entire optical module. Reference numeral 12 denotes the package, in which a substrate 14 is mounted, and an optical element 16 (PD, LD,
LED). Reference numeral 18 denotes a lead terminal for connecting an electric circuit (circuit pattern) of the substrate 14 to the outside.

[0005] A ferrule 20 for connection is mounted on the front surface (left side in FIG. 5A) of the optical module 10. For this ferrule, for example, a known MT ferrule is processed, and the one obtained by removing the brim portion is fitted into a concave portion (not shown) of the package body opening, and attached by, for example, bonding. In the package 12, the optical fiber 22 is
Then, by a known method such as positioning of a V-groove, the optical coupling is performed by centering, and the front end is inserted and fixed in the fiber hole 200 of the MT ferrule 20. The front end of the optical fiber 22 is exposed on the front end face of the MT ferrule 20 and is polished. The MT ferrule 20 is generally used for multiple fibers and has a plurality of optical fiber holes, and a required number of optical fibers are inserted according to the number of optical elements. That is, a single-core or multi-core MT ferrule is used as needed.
202 is a mating pin hole.

FIG. 5B is a side view of FIG. 5A viewed from the left side.

Next, the connection between the optical module 10 and the external optical fiber 29 (the optical element 16 and the external optical fiber 2).
9 will be described with reference to FIG. MT above
The optical module 10 with the ferrule 20 is connected to the housing 2
4 Lead terminal 18 of optical module 10
To an electric circuit board 26 provided in the housing 24.
Electrical connection by soldering. Housing 24
At the front end (left end in FIG. 6), an optical receptacle (hereinafter, MPO receptacle 27) of an MPO optical connector (described later) is attached. Then, an optical plug (hereinafter, MPO plug) 30 formed at the tip of the optical fiber 29 is pushed into the MPO receptacle 27, and the MT ferrules 32 and 20 are connected by a connector.

Here, for convenience of explanation, an MPO optical connector (which is defined in JIS C5982 and is well known) will be briefly described.

FIG. 7 schematically shows an MPO optical connector.
The push-pull connection method will be described. FIG. 8 shows one MPO plug 30 and an optical receptacle (hereinafter, MPO plug 30).
(Receptacle) 28 is shown in somewhat more detail (in FIG. 8, on the paper, the vertical direction is widened, the horizontal direction is short,
Deformed).

The MT ferrule 32 is housed in the housing 36 so as to be movable back and forth (but not to escape forward), and with some margin in the vertical and horizontal directions (perpendicular to the paper). 34 is a guide pin. MT
The ferrule 32 is urged forward by a spring 38.
A coupling 40 is provided on the outside of the housing 36 so as to be movable back and forth, and is urged forward by a spring 42 (FIG. 8).
(A)). The coupling 40 has a projection 400 (FIG. 6).
(B)) is caught by the convex portion 360 of the housing 36 and does not escape forward.

In FIG. 6C, reference numeral 28 denotes an MPO receptacle, 44 denotes a housing, and 46 denotes an internal housing.

[0010] The MPO plug 30 is inserted into the MPO receptacle 28 and connected to the connector. As shown by a dotted line in FIG. 6A, the protrusion 362 of the housing 36 is hooked on the protrusion 460 of the inner housing 46. The inner housing 46 is pressed from the outside by the tip of the coupling 40 (push-on). Therefore, MP
The O plug 30 does not separate from the MPO receptacle 28 even when pulled backward.

To release the connector connection, the coupling 40 is pulled backward. The inner housing 46 of the MPO receptacle 28 can extend outward,
The PO plug 30 is easily detached from the MPO receptacle 28 (pull off).

Referring back to FIG. The MPO receptacle 27 in FIG. 6 may have the same structure as in FIG. 8C, but the right half may be a simple cylinder. ? ? ?

[0013]

In the case of the MPO optical connector shown in FIG. 7, the MT ferrule 32 has a floating structure in which the MT ferrule 32 slightly moves up and down, left and right within the housing 36 as described above. Therefore, even if a force in the direction perpendicular to the connection direction acts on the optical fiber 29 or the housing 24, the connection surface is not adversely affected unless an excessive force is applied.

However, in the case of FIG.
Numeral 0 is integrated with the electric circuit board 26 by the lead terminals 18 and is fixed. Therefore, the MT ferrule 20 cannot move vertically and horizontally. As a result, when a force perpendicular to the connection direction acts on the optical fiber 29, the connection surface is adversely affected, the connection loss increases, and the reflection characteristics deteriorate.

[0015]

According to the first and second aspects of the present invention, as shown in FIG. 1, one end of a flexible electric circuit 50 is electrically connected to an optical module 10 having an MT ferrule 20. The other end of the electric circuit 50 is electrically connected to the housing 24 side.

The word "flexible" is used to mean "flexible and bendable" (Kojien).

FIGS. 1B to 1D show an optical module 10 with an MT ferrule 20 in which one side of a flexible electric circuit 50 is electrically connected. This is an example of the embodiment of the first aspect of the present invention.

The flexible electric circuit 50 includes an FPC
(Flexible printed circuit board) or a flexible tape wire.

When the flexible electric circuit 50 is used, M
Since the MT ferrule 20 can move up and down and left and right in the PO receptacle 27, the MT of the connection partner MPO plug 30 which is in a floating state in the partner housing is mounted.
When connected to the ferrule 32, the connection state is maintained by the guide pin, and the two MT ferrules are integrated and float in the receptacle 27.

It should be noted that the housing 24
When the elastic member 54 is filled around the optical module 10 in the inside, the position of the optical module 10 is stabilized and the mobility can be maintained.

As the elastic member 54, sponge, rubber, spring, gel agent or the like is used.

[0022]

First Embodiment FIG. 1 will be described. Polyimide (Teflon may be used) for flexible electric circuit 50
Is used. As shown in the drawing, the conductor pattern 50 has a soldering pad at the lead terminal position, and bends therefrom to form a parallel pattern. The parallel pattern portions coat and insulate the conductive surface. A well-known gull wing (or J-lead) may be used as the lead terminal 18 for connecting the electric circuit in the optical module 10 to the conductor pattern 500 of the flexible electric circuit 50. The free end of the flexible electric circuit 50 is drawn out to the rear of the partition wall 52 and electrically connected to the electric circuit board 26 fixed to the housing 24 side.

A sponge elastic member 54 is provided around the optical module 10 by, for example, filling.

The rest is the same as the conventional case shown in FIG. 1 and 6, the MT ferrule 20 and M
Although there is a large gap between the PO receptacles 27, it is actually only a very small gap.

[0025]

Second Embodiment FIG. 2 and FIG. 3 will be described. In this case, as shown in FIG. 2A, the lead terminal 18 is not used. FIG. 3 shows the internal structure of the optical module 10. The substrate 14 to which the optical element 16 is attached is fixed to the main body 120 of the package 12. A pad is provided in an electric wiring portion of the substrate 14, and one end of a flexible electric circuit 50 made of FPC is electrically connected to the pad. The free end of the flexible electrical circuit 50 extends out of the body 120. Then lid 12
2 is attached by overmolding or bonding,
The package 12 is hermetically sealed (FIG. 3C).

The other points are the same as those in the first embodiment.

The optical module 10 with the MT ferrule 20 in this case is shown in FIGS. 2 (b) to 2 (d). (B) is a plan view, (c) is an elevation view, and (d) is a side view as viewed from the right.

As shown in FIG. 4, by using the flexible electric circuit 50, the optical module 10 and the electric circuit board 26 can be arranged at any positions. 2 (a) shows how to use in the case of FIG. 2; 2 (b) shows a case where flexible electric circuit 50 is made longer; 2 (c) shows optical module 10 with MT ferrule 20
It is a case where it is used upright.

Also, needless to say, the housing is made of plastic and the optical module is made of plastic or ceramic. Further, a positioning sleeve can be built in a region (not shown) in the receptacle where the two ferrules are connected. The positioning sleeve surrounds the tips of the ferrules and regulates the movement of the ferrule connection. As a result, both ferrules have an advantage that the amount of floating of the connection portion is limited, but the connection is easy.

Furthermore, the gist of the present invention is to float the optical module portion and connect the other end to the housing 24 side.
However, the present invention is not limited to this. For example, the optical module may be attached to a fixed body, and an electric circuit portion as well as an optical element may be formed in the optical module body.

Still further, in the above embodiment, the MPO
Although only the type has been described, it goes without saying that the present invention is applicable to other types of optical connectors.

[0032]

According to the present invention, since the optical module has an FPC,
The degree of freedom of the installation position and angle is improved. In addition, since the optical module 10 with the MT ferrule 20 moves freely in the MPO receptacle 27, external force does not reach the connection portion, and the deterioration of the connection characteristics can be prevented.

[Brief description of the drawings]

FIG. 1 relates to a first embodiment of the present invention, wherein FIG.
Explanatory drawing of the connection part between the optical module 10 with the T ferrule 20 and the external optical fiber 29, (b) is an MT ferrule 2
FIG. 2B is a plan view of the optical module 10 with 0, FIG.
(D) is a side view as viewed from the right, and (e) is a bottom view.

FIG. 2 relates to a second embodiment of the present invention, wherein FIG.
Explanatory drawing of the connection part between the optical module 10 with the T ferrule 20 and the external optical fiber 29, (b) is an MT ferrule 2
FIG. 2B is a plan view of the optical module 10 with 0, FIG.
(D) is a side view seen from the right.

FIG. 3 is an optical module 10 according to a second embodiment of the present invention.
(A) is a plan view with the lid 122 removed, (b) is an elevation view with the lid 122 separated, and (c) is a package with the lid 122 sealed. FIG.

FIG. 4 is an explanatory view of a positional relationship between the optical module with MT ferrule 20 and the electric circuit board 26 in the present invention.

FIG. 5 is an explanatory diagram of an example of the optical module 10 with the MT ferrule 20, which is common to the present invention and the prior art.

FIG. 6 is an explanatory view of a conventional example of a connection portion between the optical module 10 with the MT ferrule 20 and an external optical fiber 29.

FIG. 7 is an explanatory diagram of an MPO optical connector.

FIG. 8 is a somewhat detailed explanatory view of an MPO plug and an MPO receptacle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Optical module 12 Package 120 Main body 122 Lid 14 Substrate 16 Optical element 18 Lead terminal 20 MT ferrule 200 Fiber hole 202 Mating pin hole 22 Optical fiber 24 Housing 26 Electric circuit board 27, 28 MPO receptacle 29 Optical fiber 30 MPO plug 32 MT Ferrule 34 Guide pin 36 Housing 360,362 Convex part 38 Spring 40 Coupling 400 Convex part 42 Spring 44 Housing 46 Inner housing 460 Convex part 50 Flexible electric circuit 500 Conductor pattern 52 Partition wall 54 Elastic member

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Akio Shimomura 1440 Mutsuzaki, Sakura City, Chiba Prefecture Inside Fujikura Sakura Plant

Claims (3)

[Claims] An MT ferrule (20) is fixed to a front surface of a package (12) accommodating an optical element (16) therein, and an optical fiber (22) optically coupled to the optical element (16) in the package (12) is provided in a fiber hole of the MT ferrule (20). 2
00 is an optical module with an MT ferrule 20 having a front end exposed to the front end surface of the MT ferrule 20 and a flexible electric circuit 50 used for electrical connection to the outside. An optical module, characterized in that: 2. The optical module having the MT ferrule 20 according to claim 1 is accommodated in a housing 24 having an optical receptacle 27 attached to a front end thereof, and a light inserted into the MT ferrule 20 and the optical receptacle 28. The plug 30 and the MT ferrule 32 are connected by a connector, and the flexible electric circuit 50
Wherein the free end of the optical module is electrically connected to the housing 24 side. 3. The connection part between an optical module and an optical fiber according to claim 2, wherein an elastic member is disposed around the optical module in the housing.