JP3424680B2 - Optical fiber module - 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 fiber module used in a device for exchanging data between devices.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 17 (JP-A-3-218).
An optical fiber module as described in Japanese Patent No. 134) has been known. FIG. 17 is a plan view showing a conventional optical fiber module, which has a width of 76 mm.
mm (75 mm), a LD (laser diode) module 1 for transmitting an optical signal, a PD (photodiode) module 2 for receiving an optical signal, a semiconductor IC 4 for converting an optical signal into an electric signal, and a circuit board 3 having a length of 75 mm. 5. A connector 6 for exchanging electric signals with a mother board (not shown) was mounted.

FIG. 18 is a main sectional view showing a lower frame of a conventional optical fiber module (described in Japanese Patent Laid-Open No. 3-218134), in which a spacer 8 and a J clip 9 formed on the lower frame 7b are used to form a mother board ( The conventional optical fiber module is fixed (not particularly shown).

FIG. 19 is a main sectional view showing the holding of a circuit board of a conventional optical fiber module. The circuit board 3 is inserted into the rear portion of the lower frame 7b and then the upper frame 7a.
The circuit board 3 was held by the lower frame 7b.

[0005]

However, the prior art has the following problems.

1) In order to exchange electrical signals with parallel data, even if it is an 8-bit parallel signal, if other signals are included, there are as many as 50 signal lines, a large connector shape, and serial / parallel conversion. Therefore, a semiconductor IC is also required, and the device itself has to be large. The size of the device itself not only goes against the rapid downsizing trend of host computers in recent years, but also greatly limits the degree of freedom in designing the motherboard of a system maker.

2) The conventional optical fiber module and the mother board are fixed to each other by using the J-clip 9 which is a resin leg extending from the lower frame 7b as shown in FIG. 18 and has an opening for fixing the mother board. A large hole was required for the part, which greatly limited the degree of freedom in designing the motherboard of the system maker. Further, since the structure is such that a load of force due to the attachment / detachment of the optical fiber is applied to the J clip 9 and the lead (not shown) of the connector 6, the resin J clip 9 is broken or the lead has an electrical connection failure. Etc. have occurred, and the reliability of the optical fiber module has been reduced.

Further, in order to avoid the stress applied to the leads of the LD module 1 and the PD module 2, it is necessary to improve the accuracy of parts of each part and manage the parts (such as acceptance inspection of parts), resulting in a low cost of the optical fiber module. Making it difficult.

3) In the conventional optical fiber module, the connector 6 is fixed to the circuit board 3 by soldering, and then the signal line of the connector 6 is directly soldered to the mother board. It restricted the cost reduction of the module.

4) In the method of holding the circuit board 3 shown in FIG. 19, warpage is generated on the circuit board 3 and the reliability of the circuit board 3 is significantly lowered. Further, the holding method shown in FIG. 19 requires a sufficient length of the circuit board 3 and a sufficient length L of holding the circuit board, which limits the miniaturization of the optical fiber module.

5) Most of the circuit board 3 is exposed, and when the operator handles the conventional optical fiber module or when the user mounts the conventional optical fiber module on the motherboard, the conventional optical fiber module is used. The module was easily damaged by static electricity.
This is a cause of an expensive optical fiber module which is poor in reliability.

6) Due to long-term storage or the like, dust or the like is mixed in the LD module and the PD module into which the optical fiber fits, causing a bite between the optical fiber and the module, resulting in remarkable reliability of the optical fiber module. Had lowered.

SUMMARY OF THE INVENTION Therefore, the present invention solves the above-mentioned conventional problems, and an object thereof is to provide an optical fiber module which is compact, has a high degree of freedom in designing a mother board, and is low in cost and highly reliable.

[0014]

An optical fiber module of the present invention is a connector connected to a motherboard of a host computer and an LD (laser diode) serial data transmitted from the motherboard for converting an LD electric signal. Semiconductor IC and LD electric signal LD
LD module for converting optical signals for PD, and P for converting optical signals for PD (photodiode) to electrical signals for PD
A D module, a semiconductor IC for PD that converts an electrical signal for PD into serial data for PD, a circuit board including a connector, a semiconductor IC for LD, and a semiconductor IC for PD, and L
An LD shield plate that electrically shields the D module, a PD shield plate that electrically shields the PD module, a first frame that holds the circuit board, the LD module, and the PD module, a circuit board, and the LD module. An optical fiber module having a PD module and a second frame for holding the PD module, wherein the connector is a surface mount type, and the LD module and the lead of the PD module are coupled at the connector side on the circuit board.
It has an LD variable resistor for adjusting the drive current of the module,
The D variable resistor is provided on the side opposite to the connector side on the circuit board, and has the PD variable resistor for signal detection of the PD module, and the PD variable resistor is provided on the opposite side to the connector side on the circuit board. Semiconductor IC for signal processing
Is 3 or less, the width is 17 mm or more and 25.4 mm or less, the length is 30 mm or more and 50 mm or less, and the external shape is, and the width is 19 mm or more and 25.4 mm or less,
Length is 45 mm or more and 65 mm or less, height is 9 mm or more 2
The first frame has an outer shape of 5.4 mm or less, a second frame has a claw for coupling an optical signal, and the first frame has a protrusion for protecting the claw. ,
The second frame is made of a resin material, and the first frame and the second frame have holding means for holding the circuit board. The holding means is a snap-fit mechanism, and the first frame and the second frame. The frame holds the front end of the circuit board, the first frame has an arm, and the step provided on the arm is used to hold at least one rear part of the circuit board, and the optical signal data transfer rate Is 200 megabits / second or more.

Thus, paying attention to the space between the expansion slots of the host computer, two semiconductor ICs and a surface mount type connector are used, and the fixing to the motherboard is carried out by tapping screws. Compact fiber optic module (width 2
5.4 mm, length 50.8 mm, height 11.5 mm).

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In all the drawings in this embodiment, the same parts are allotted with the same reference numerals.

FIG. 1 is a block diagram of an optical fiber module showing a first embodiment of the present invention. In FIG. 1, a circuit board (hereinafter referred to as a PCB) 30 uses an LD (laser diode) driver 33, which is a semiconductor IC, to transfer an electric signal (serial data) sent through a PCB connector 32 to an LD element in an LD module 50. (Not shown: see FIG. 8 described later) is driven to transfer data as an optical signal to an optical fiber (ferrule: not shown) inserted in the LD module opening 52. On the other hand, the PD (photodiode) module 40 receives an optical signal from an optical fiber (not shown) inserted in the PD module opening 42, and the optical signal is a PD element (not shown in particular: to be described later). 8)) and is converted into a voltage by the trans-impedance amplifier section 35a of the amplifier 35 which is a semiconductor IC. Further, the optical signal converted into a voltage is converted from an analog signal into a digital signal by the waveform shaping circuit section 35b and transferred to the mother board as serial data via the PCB connector 32. Since the optical fiber module of the present invention exchanges electric signals as serial data, the PCB connector 32 requires only about 22 signal lines, and not only the size of the PCB connector 32 itself becomes very compact, but also the PCB connector 32 is very compact.
The 30 is also compact and realizes high-speed data transfer with high reliability of 130 MB / s (megabits / second) or more. Although the amplifier 35 is a single semiconductor IC in the first embodiment of the present invention, a transformer impedance
Even if the amplifier section 35a and the waveform shaping circuit section 35b are each configured as two semiconductor ICs, the effect of the present invention is not lost.

Next, the compact design of the PCB 30 will be described with reference to FIG. In general, the expansion slots for inserting the motherboard into the host computer are often designed at 25.4 mm intervals, and the expansion slots can be mounted on the motherboard horizontally or vertically with respect to the intervals of 25.4 mm. It is necessary to design and realize a simple optical fiber module. Ie PCB
It is desirable that the width direction of 30 is designed to be 25.4 mm or less.

The shape of the PCB connector 32 is 22
When the pin pitch (2 columns and 11 rows) is 1.27 mm, the width direction is about 14 mm and the length direction is 2.5 mm, and the housing portion and the lead portion (not particularly shown)
The external dimensions of the PCB connector 32 including the width is 17m in the width direction.
m, 5 mm in the length direction. Semiconductor IC (33 and 3
The outer dimensions of 5) are 7 mm in the width direction and 10 mm in the length direction (10 mm in the width direction and 7 mm in the length direction may be used).
Considering the external dimensions of the PCB connector 32 and the semiconductor IC, component mounting on the PCB 30 and the PCB 3
Considering the wiring pattern of 0, it is desirable that the external dimensions of the PCB 30 are 19 mm or more in width and 30 mm or more in length. Even if the number of semiconductor ICs used for signal processing is increased to 3, the length direction of the PCB 30 is 50 mm.
It can be designed as follows. That is, the external dimensions of the PCB 30 are 17 mm to 25.4 mm in width and 30 mm in length.
It would be desirable to design from mm to 50 mm. In the first embodiment of the present invention, the PCB 30 has a width of 2
A highly reliable PCB 30 is realized by adopting 2.5 mm, a length of 32 mm (longest part) and a thickness of 1.6 mm with high mechanical strength. Furthermore, the PCB connector 32 uses a surface mounting type, and only two semiconductor ICs for signal processing are used.
A PCB 30 having a small shape is realized. However, the first embodiment of the present invention does not limit the substrate thickness of the PCB 30.

FIG. 2 is a perspective view of an optical fiber module showing a second embodiment of the present invention. A compact design of the optical fiber module will be described with reference to FIG.

The PCB 30 is held by the upper frame 10 and the lower frame 20, and these assemblies form an optical fiber module. The PCB 30 is an LD element (see FIG. 8).
LD driver 33, which is a semiconductor IC for driving (see), a variable resistor 34 for adjusting drive current of an LD element (not shown), and a mother board (not shown). PCB connector 32 and the like. Further, an upper frame thin portion 17 for keeping the average thickness of the upper frame 10 constant is provided in the upper frame 10.

As described above in the compact design of the PCB 30 in the first embodiment of FIG. 1, there are two expansion slots for inserting the motherboard into the host computer.
It is often designed with 5.4 mm spacing, and it is necessary to design and realize an optical fiber module that can be mounted horizontally or vertically on the motherboard with respect to this expansion slot spacing of 25.4 mm. About 25.
Dimensions of 4 mm or less would be desirable. Where PC
The design dimension of B30 is from 17 mm to 25.4 mm in width and from 30 mm to 50 mm in length. Focusing on the width direction, the frame of the optical fiber module is provided in order to avoid deviation in a direction perpendicular to the width direction of the PCB 30. Is PCB
It is desirable that the width be larger than 30. For example, if the width of the frame is larger than the width of the PCB 30 by 2 mm or more, P
It is possible to provide the frame with a step for preventing the shift of the CB 30. Therefore, it is more desirable to design the width dimension of the optical fiber module to be about 19 mm to 25.4 mm in consideration of the width dimension of the PCB 30.

Next, in the longitudinal direction, the PCB 30 is 3
The length of the LD module 50 is about 1 mm from 0 mm to 50 mm.
Considering that it is about 5 mm, 45 mm to 10
It will be about 0 mm. That is, it is desirable that the lengthwise dimension of the optical fiber module is designed to be about 45 mm to 100 mm.

Further, although the height direction has been described above, it is desirable that it is 25.4 mm or less in consideration of vertical installation and horizontal installation to install the optical fiber module of the present invention between the expansion slots of the host computer. Further, considering the case where the optical fiber module of the present invention is doubly stacked and mounted on a mother board, 12.7 mm or less is a more desirable dimension. Also, considering the reverse insertion prevention mechanism of an optical fiber plug (not shown) that fits into the optical fiber module, the receiving of the optical fiber plug, the strength of the frame, etc., the height of the optical fiber module is 9 mm or more. It is more desirable to design in.
Therefore, the height direction of the optical fiber module is 9 mm
It is desirable that the distance is about 25.4 mm.

Under the above conditions, however, the optical fiber module of the present invention shown in FIG. 2 realizes a microminiature module having a width of 25.4 mm, a length of 50.8 mm and a height of 11.5 mm. It goes without saying that by incorporating the necessary and sufficient functions as an optical fiber module in a compact external dimension, the degree of freedom in the system manufacturer's motherboard design can be dramatically expanded.

3 and 4 are exploded perspective views of an optical fiber module showing a third embodiment of the present invention. 3 and 4, a laser diode module 50 (hereinafter referred to as an LD module) that emits an optical signal and a photodiode module 40 (hereinafter referred to as a PD module) that receives an optical signal are included in a circuit board 30 (hereinafter referred to as a PCB) of the module. The PCB 30 has a PD shield plate 41 and an LD shield plate 51 for avoiding electromagnetic noise or electrostatic noise. Further, the PCB 30 has a PCB connector 32 for achieving electrical connection with the mother board 60, an LD driver 33 which is a semiconductor IC for driving the LD module 50, and a variable resistor 34 for adjusting the drive current of the LD module 50. Alternatively, a variable resistor 34 or the like for adjusting the detection level of the received signal from the PD module 40 is also added. Here, in order to effectively utilize the mounting surface of the PCB 30, a surface mounting type is used for the PCB connector 32,
A variable resistor 34 is mounted on the back surface of the PCB connector 32. By using the surface-mounting type PCB connector 32 in the optical fiber module of the present invention, the manual soldering process of the connector, which is conventionally performed, becomes unnecessary, and the low-cost optical fiber module by automatic mounting can be realized. Further, not only the variable resistor 34 but also the chip resistor, the capacitor,
Alternatively, a circuit component such as a semiconductor IC may be mounted, and a compact PCB 30 can be realized.

Further, by disposing the variable resistor 34 on the upper surface of the PCB 30, the adjustment process at the time of assembling the optical fiber module is facilitated. That is, the PC of PCB30
Since the B connector 32 is attached to a jig substrate for adjusting and assembling the optical fiber module, it is better to mount the variable resistor 34 on the upper surface of the PCB 30 than to arrange the variable resistor 34 on the PCB connector 32 side. The efficiency of the operator's adjustment work increases. As a result, the efficiency of the adjustment work is improved to realize a low-cost optical fiber module.

PD lead 47 and LD lead 57 are PCB
A relatively wide land (not shown) is provided on the PCB connector 32 side in order to improve the assemblability into the unit 30. On the other hand, the mother board 60 also has a mother connector 62 corresponding to the PCB 30.

PD module 40, LD module 50
The mounted PCB 30 such as
And the recesses 22 of the lower frame 20 are temporarily fixed by a snap-fit mechanism, and the assembly of the upper frame 10, the PCB 30, the lower frame 20 and the like forms an optical fiber module. The PD module 40 and the LD module 50 on the PCB 30 have a PD shield plate 41 which also serves as a leaf spring material,
It is fixed to the upper frame 10 and the lower frame 20 via the LD shield plate 51. Also, the PD shield plate 4
1. The LD shield plate 51 is fixed to the PCB 30 with solder or the like, and the lower frame 20 covers the shield plates 41 and 51.
The shield plate 41 and the LD shield plate 51 have very high mechanical stability. Since the shield plates 41 and 51 are electrically insulated from the mother board 60 by the lower frame 20, there is no short circuit or leak with the mounted components on the mother board 60, and a highly reliable optical fiber module is realized.

The lower frame 20 is also provided with a claw 23 for coupling an optical signal with another optical fiber module, and the claw 23 and an optical fiber plug (not shown) are fitted together. .

The temporarily fixed optical fiber module is a PC
After the B connector 32 and the mother connector 62 are fitted to each other, after the coarse positioning is performed on the motherboard 60,
It is completely fixed on the mother board 60 with three tapping screws 70. Tapping screw 70 is motherboard 6
After passing through the mother opening 61, the lower frame opening 21, and the PCB opening 32, which are provided on the upper side, the optical fiber module is completely fixed on the mother board 60 by screwing in the upper frame opening 11. .

Generally, the deterioration of the component positioning accuracy of the mother connector 62 and the PCB connector 32 is caused by the PD module 4
0, each lead of the LD module 50 (PD lead 47,
A load is applied to the LD lead 57). That is, the leads of the PD module 40 and the LD module 50 are fixed on the PCB 30 by soldering or the like.
Since the CB connector 32 is also fixed on the PCB 30 by soldering or the like, the component positioning accuracy of the mother connector 62 with respect to the mother opening 61 and the component positioning accuracy of the PCB connector 32 with respect to the PCB opening 31 must be improved. The error is PD module 4
0, each lead of the LD module 50 or the land (not shown) of the PCB 30 becomes a load. More specifically, when the optical fiber module is incorporated into the mother board 60, if the mother connector 62 is mounted separately from the mother opening 61, tensile stress is applied to the lands of the PD lead 47, the LD lead 57 and the PCB 30. On the contrary, when the mother connector 62 approaches the mother opening 61 and the components are mounted, the PD lead 47, LD
A compressive stress is applied to the lead 57 and the land of the PCB 30. These stresses significantly reduce the reliability of the optical fiber module. Conversely, these tensile stresses,
Alternatively, in order to avoid the compressive stress, it is necessary to improve the positioning accuracy of the connector parts, but this will increase the cost of the optical fiber module. PCB
It goes without saying that the connector 32 also has the same adverse effect.

However, in the third embodiment of the present invention, the mother opening 61, the lower frame opening 21, and the PCB opening 31 have holes with a diameter of 3.2 mm, and the upper frame opening 11 has a hole with a diameter of 2.2 mm. The tapping screw 70 (diameter about 2.6 mm) is provided to fix the optical fiber module.
By adopting, it is possible to reduce the component positioning accuracy of the mother connector 62 with respect to the mother opening 61 and the component positioning accuracy of the PCB connector 32 with respect to the PCB opening 31, and the PD module 40 and the LD module, which have been problems in the past, have become possible. 50 leads (47 and 57)
Alternatively, the load of tensile stress or compressive stress on the land of the PCB 30 is eliminated so that a highly reliable optical fiber module can be realized. Further, since the mounting and positioning accuracy of the parts can be drastically reduced as compared with the conventional case, not only the parts management of the PCB connector 32 assembly of the PCB 30 becomes easy, but also the parts such as the PCB 30 and the PCB connector 32 themselves. Since the accuracy of can be reduced, a very inexpensive optical fiber module can be realized.

Here, the upper frame opening 1 described above is used.
1, the numerical values of the lower frame opening 21 and the like are examples,
The present invention does not limit these numerical values. It should be additionally noted that the effects of the present invention are not lost even with numbers other than these limited numbers as long as the configuration of the third embodiment of the present invention is used.

As described above, by making the optical fiber module compact, compact, and having the minimum necessary functions, the system maker can design a very flexible motherboard. That is, since the optical fiber module of the present invention is compact, it occupies a small area on the mother board, and only three small holes are required for fixing the optical fiber module. Can be realized.

Not only that, but the arrangement of the three openings (the upper frame opening 11, the lower frame opening 21, the mother opening 61, etc.) forms an isosceles triangle,
The stress load due to the attachment / detachment of the optical fiber plug is ideally distributed to realize a highly reliable optical fiber module.

FIG. 5 is a main sectional view of an optical fiber module showing a fourth embodiment of the present invention. In FIG. 5, P
The optical fiber module including the CB 30, the upper frame 10 and the lower frame 20 penetrates the mother opening 61, the lower frame opening 21 together with the mother board 60, and is fixed by the tapping screw 70 at the upper frame opening 11. The electrical connection between the optical fiber module and the mother board 60 is performed by the PCB connector 32 and the mother connector 62.
Through.

The upper frame opening 11 and the lower frame opening 21 can also be used as reference holes for the component receiving inspection of the upper frame 10 and the lower frame 20, respectively. Each of the three upper frame openings 11 and the lower frame openings 21 has a draft taper set to 0 degrees at the time of molding, so that each opening (the upper frame opening 11 and the lower frame opening 21 does not increase in cost). ) Hole accuracy can be kept high. Since the hole accuracy of the opening can be maintained at a high level, it is possible to easily inspect the part by creating a part receiving inspection jig corresponding to this opening. That is, the upper frame opening 11 and the lower frame opening 21 can be used not only as holes for fixing the optical fiber module to the mother board 60 but also as holes for inspecting parts.

Further, the optical fiber module of the present invention has a structure in which the load on the optical fiber module due to the attachment / detachment of the optical fiber plug is received by the three tapping screws 70. More specifically, the JIS standard for optical fiber modules by attaching and detaching optical fiber plugs is 90N.
(Newton), the diameter of the tapping screw 70 is 1.3 mm in order to satisfy this standard in the optical fiber module of the present invention (using three tapping screws 70).
The above is desirable. Further, considering the safety in design, it is more desirable that the diameter of the tapping screw 70 is 2 mm or more. However, in the optical fiber module of the present invention, the tapping screw 70 has a diameter of 2.6.
By adopting mm, a highly reliable optical fiber module with a safety factor of 3 or more is realized.

In the fourth embodiment of the present invention, the tapping screw 70 is used for fixing to the mother board 60, but an insert nut or the like (not shown) is attached to the upper frame opening 11 to make it a normal small screw. Screw (key screw with cross hole,
The effect of the present invention is not lost even if a small screw with a thread is used as a substitute for the tapping screw 70.

By adopting the configuration of the optical fiber module shown in the fourth embodiment of FIG. 5, not only is there a problem such as the breakage of the resin frame, which has been a problem in the prior art, but also an electrical connection failure of the leads. It is clear that there will be nothing.

FIG. 6 is a main sectional view of an optical fiber module showing a fifth embodiment of the present invention. As described in the third embodiment of FIG. 3 above, the PCB 30 is temporarily fixed to the upper frame 10 and the lower frame 20 by the snap-fit mechanism, but in FIG. 6, the elastic deformation of the arm 14 of the upper frame 10 is performed. It is also used to lightly press the rear part of the PCB 30. More specifically, the arm 14
On the contact surface between the upper frame opening 11 and the PCB 30, a step (illustrated in an emphasized manner) of about 0.2 mm is provided in the upper frame opening 11. By adopting such a configuration, the handling of the optical fiber module in the temporarily fixed state of the optical fiber module becomes good. That is, not only the front part of the PCB 30 is held by the snap-fit mechanism, but also the rear part of the PCB 30 is held by the arm 14 of the upper frame 20,
A more stable optical fiber module assembly can be realized, and not only the optical fiber module can be easily attached to the mother board 60, but also the optical fiber module itself can be easily handled.

Further, the conventional PCB is a frame PCB.
However, in the fifth embodiment of the present invention, the front end of the PCB 30 and the central part of the PCB 30 are slightly more than the front end of the PCB 30 and the front end of the PCB. The configuration is such that the PCB 30 is held at the rear part, and the warpage problem of the PCB 30 is solved. Furthermore, the structure of this embodiment does not require a special stroke (length) for the PCB or the upper and lower frames, which has been conventionally required, and easily downsizes the optical fiber module.

FIG. 7 is a perspective view of a lower frame of an optical fiber module showing a sixth embodiment of the present invention.
The lower frame 20 described in 1. is described in more detail.

The upper frame 10 and the lower frame 20 of the sixth embodiment of the present invention are made of PBT (polybutylene terephthalate) and have a glass mixing ratio of 10% to 30%, and have excellent durability. In particular, the durability of the claw 23 of the lower frame 20 for attaching and detaching the optical fiber plug is improved. In addition, the claw 23 of the lower frame 20
In order to reduce the force applied to the upper frame 10, the upper frame protrusion 16 (not shown; see FIG. 5) that abuts the lower frame protrusion 26 at the base of the claw 23.
(Not shown: see FIG. 5). The lower frame 20, which has a large load due to the attachment / detachment of the optical fiber plug, is provided with a lower plate 25, ribs 24, etc. in order to improve the rigidity of the entire lower frame 20.

Although PBT was used as the frame material in the sixth embodiment of the present invention, this does not limit the material of the frame of the optical fiber module of the present invention.
Other resin materials and the like may be used.

FIG. 8 is a main plan view of an optical fiber module showing a seventh embodiment of the present invention, and a plan view of a lower frame 20, a PCB 30, an LD module 50, a PD module 40 and the like for more detailed explanation. And a part is a sectional view. Generally, in the optical fiber module, the distance between the PD module 40 and the LD module 50 is 12.
The mainstream is set to 7 mm, and the diameters of the PD element 45 and the LD element 55 are around 5 mm. These P
In order to protect the D element 45 and the LD element 55 and to mechanically couple with the optical fiber, the PD module 40
The LD module 50 needs to be designed to have a diameter of about 6 mm to 8 mm. Therefore, the design limit is about 4.7 mm to 6.7 mm for the diameter of the lower frame opening 22. Here, the average thickness of the lower frame 20 is 1.
Assuming 5 mm, the diameter of the lower frame opening 22 is 1.
It is about 7 mm to 3.7 mm.

The optical fiber plug is mechanically attached / detached using the claw 23 of the lower frame 20.
The upper frame opening 21 is provided near the claw 23 that receives the most load.
The optical fiber module of the present invention has. In addition, the diameter of the upper frame opening 21 is about 3 mm, and the average thickness of the lower frame 20 is 1.5 mm. Since the optical fiber module of the present invention is extremely downsized as compared with the conventional optical fiber module, it is highly possible to provide an opening for fixing the optical fiber module in the central portion of the lower frame 20 and near the claw 23. It is very effective in achieving a reliable optical fiber module. In the seventh embodiment of the present invention, the lower frame opening 21 is provided at a position approximately 2.5 mm from the lower frame protrusion 26 that is most subjected to the stress applied to the claw 23, so that the diameter is 3 mm and the average wall thickness is 1.5 mm. The high-rigidity lower frame 20 is realized, and thus the highly reliable optical fiber module is realized.

FIG. 9 is a main sectional view of an optical fiber module showing an eighth embodiment of the present invention, and shows an assembly of only an upper frame 10 and a lower frame 20 as a sectional view for ease of explanation. . The upper frame 10 is provided with an upper frame thin portion 17 to prevent sink marks caused by uneven thickness of the upper frame 10. More specifically, the upper shield fitting portion 1 that fits with the PD shield plate 41
7a and the upper module fitting portion 17b fitted to the LD module are prevented from being deteriorated in accuracy of parts due to sink marks or the like.
Similarly for the lower frame 20, the lower shield fitting portion 27
The lower frame thin portion 27 is provided in order to prevent the deformation of the a and the lower module fitting portion 27b due to sink marks or the like. In the eighth embodiment of the present invention, by providing these thin wall portions, both the upper frame 10 and the lower frame 20 have an average wall thickness of 1.5 mm, and a highly reliable upper and lower frame is realized.

FIG. 10 is a sectional view of an optical fiber module showing a ninth embodiment of the present invention. The difference from the above-mentioned fourth embodiment of FIG. 5 is that the tapping screw 70 is not used,
The pin 71 is fixed to the lower frame 20 by integral molding (or press fitting) or the like, and the nut 72 fixes the optical fiber module to the mother board 60. Upper frame 1
The upper frame opening 11 of 0 is set larger than the diameter of the pin 71, and the upper part of the pin 71 is located above the joint surface between the upper frame 10 and the lower frame 20 so that the upper frame 10 and the PCB 30 can be roughly positioned. It is jumping to the top.
In addition, the pin 71 extends to the bottom of the motherboard 60,
It also enables rough positioning of the optical fiber module as a guide pin for automatic assembly. Further, the rib 24 is extended to the mother board 60 side in order to further improve the rigidity of the optical fiber module.

Even with the configuration shown in FIG. 10, the PD modules 40, L described above with reference to FIG. 5 are obtained.
Not only can the load on each lead of the D module 50 or the land of the PCB 30 be completely eliminated, but also the positioning accuracy of the components such as the connector and the precision of the components themselves can be reduced. Module can be realized. Further, the pin 71 integrally formed with the lower frame 20 can be used as a reference position for the component receiving inspection of the lower frame 20. In addition, the LD shown in FIG.
It is also possible to integrally form the shield plate 51, the PD shield plate 41, and the like on the lower frame 20 together with the pins 71, thereby further reducing the cost of the optical fiber module.

Of course, the effect of the present invention will not be lost even if the fourth embodiment shown in FIG. 5 and the ninth embodiment shown in FIG. 10 are used together.

Although the nine pins 71 (or the tapping screw 70) are used in the ninth embodiment of the present invention, the nail 2 which is most stressed by the attachment / detachment of the optical fiber plug.
Even if the pin 71 (or the tapping screw 70) is adopted only in the opening near 3 and the resin protrusion extending from the lower frame is used in the opening near the other arm 14, the effect of the present invention is lost. I will not be told.

FIG. 11 is a perspective view of an optical fiber module showing a tenth embodiment of the present invention. The optical fiber module (an assembly of the upper frame 10, the lower frame 20 and the PCB 30) is provided with a cover for preventing electrostatic breakdown. 18 is added. Cover 1 after assembling and adjusting with optical fiber module
By mounting 8, the component mounting portion of the PCB 30 is almost covered with the upper and lower frames (10 and 20) and the cover 18, and electrostatic damage due to handling of the optical fiber module, which was a conventional problem, is eliminated. It becomes possible to do.

The material of the cover 18 is not particularly limited by the presence or absence of conductivity. That is, whether it is a metal material or a resin material, there is no limitation in terms of the electrostatic breakdown resistance of the PCB 30 as the material of the cover 18. More specifically, in this embodiment, the same PBT as that of the upper frame is used as the material of the cover 18, but there is no electrostatic breakdown of the PCB 30 at the time of handling the optical fiber module, which has been a conventional problem.

Further, from the viewpoint of the electrostatic breakdown resistance of the PCB 30 and the electromagnetic shield of the PD module 40, the same effect is obtained when the iron alloy is used as the material of the cover 18. Further, as the material of the cover 18, not only iron alloy but also iron, aluminum, aluminum alloy,
It is also noted that the same effect was obtained even when copper, copper alloy, or the like was used. It should be noted that the method of fixing the cover 18 to the optical fiber module is not limited to the fitting method using the arm 14, the snap fitting, the adhesion, or the like.

Next, the upper surface of the upper frame 10 of the optical fiber module of the present invention is flat and the lower frame 2
0 has also been designed with a flat bottom plate to improve rigidity, and is an identification label 90 that indicates the manufacturing site of the optical fiber module, or a certification label that indicates that the laser safety standard has been met. It is possible to easily attach 91 or the like.

A step portion (not shown) of about 0.3 mm is formed on the flat portion (not shown) of the upper frame 10 and the flat portion (not shown) of the lower frame 20. Is provided to facilitate the work of attaching the identification label 90 and the certification label 91.

Of course, in order to further reduce the cost of the optical fiber module of the present invention, these labels may be not only affixed but may be stamped on each frame.

FIG. 12 is a plan view of an optical fiber module showing an eleventh embodiment of the present invention. The difference from the tenth embodiment of FIG. 11 is that the upper frame 10 is integrally formed with a cover portion 18a. It is a point. Further, as a difference, the cover opening portion 19 is provided in the cover portion 18a, and the variable resistance on the PCB 30 can be adjusted even after the optical fiber module is assembled. By molding the cover portion 18a integrally or simultaneously at the time of molding the upper frame 10 in this manner, it is possible to realize a more reliable and less expensive optical fiber module. It should be noted that the effect of the present invention is not lost even if the cover opening 19 shown in the eleventh embodiment of the present invention is applied to the previously described tenth embodiment of FIG. deep.

FIG. 13 is an exploded perspective view of an optical fiber module showing a twelfth embodiment of the present invention. When the optical fiber module is fixed to the mother PCB 60, the auxiliary plate 7 is used.
3 is used. The auxiliary plate 73 is provided with a fixing portion 74, and the fixing portion 74 is rotated about 90 degrees to assist in fixing the optical fiber module.
Although the tapping screw 70 or the pin 71 shown in the fourth embodiment (see FIG. 5) or the ninth embodiment (see FIG. 10) is sufficient for fixing the optical fiber module, By using this auxiliary plate 73, a more reliable optical fiber module can be provided. Furthermore, by using a metal material as the material of the auxiliary plate 73, the auxiliary plate 73 has a protection effect against external electromagnetic noise with respect to the PD module 40 and a shielding effect against external electromagnetic noise emitted from the LD module 50. . More specifically, in the twelfth embodiment of the present invention, the iron alloy is used as the material of the auxiliary plate 73, but the same effect can be obtained by using iron, aluminum, aluminum alloy, copper, copper alloy or the like. Please note that. In addition, in the twelfth embodiment of the present invention, the fixing assistance is provided to the mother board 60 from the upper portion of the optical fiber module. It should be noted that the effect is not lost.

FIG. 14 is a perspective view of an optical fiber module showing a thirteenth embodiment of the present invention. The LD module 5 is used when the optical fiber module is not in operation (storage, transportation, etc.).
0, or a module cap 80 for preventing dust mixed in the PD module is added to the optical fiber module (assembly of the upper frame 10, the lower frame 20, the PCB 30, etc.).

Next, FIG. 15 is used to explain the module cap 80 in more detail. FIG. 15 is a plan view of an optical fiber module showing a thirteenth embodiment of the present invention, and in order to explain the module cap 80 in detail, the LD module 50 is shown in a sectional view.
In FIG. 15, the PD element 45 is fixed to the PD module 40 by adhesion (or welding) or the like.
5 is fixed to the LD module 50 by welding (or bonding), and the PD module 40 and the LD module 5
0 is temporarily physically fixed to the lower frame 20, and electrically P
It is connected to the PCB 30 via the D lead 47 and the LD lead 57. The module cap 80 is configured so as not to contact the claws 23 of the lower frame 20, and is provided with a cap protrusion 85 for holding the module cap 80 in the optical fiber module, so that the module cap 80 can be easily attached and detached by the handler 87. I also have. When the module cap 80 is attached to the optical fiber module, the cap end surface 82 does not contact the ferrule contact surface 56 of the LD module 50, and the module cap 80
The module contact surface 84 of the above contacts the LD module end surface 53 of the LD module 50 to prevent dust from entering the LD module opening 52. Further, the diameter of the cap potch 83 is designed to be sufficiently smaller than the diameter of the LD module opening 52, so that the module cap 80 can be easily attached and detached without generating dust and the like.

FIG. 16 is a perspective view of an optical fiber module showing a thirteenth embodiment of the present invention, showing a module cap 80 in a more understandable manner. The elastic portion 86 from the module contact surface 84 to the cap end surface 82, which prevents the entry of dust into the LD module 50 and the PD module 40, is elastically deformed via the cap protrusion 85.
A module cap 80 is retained on the fiber optic module. The module cap 80 has a cap opening 81 for component acceptance inspection, and relatively soft polyethylene is selected as the material of the module cap 80, but the material is not particularly limited as long as it is a resin material. .

[0065]

As described above, according to the present invention, the optical fiber module has a width of 25.4 mm and a length of 50.8 m.
m and height is 11.5 mm, and it has a minimum required function. 1) Since the electric signals are exchanged by serial data, the number of signal lines is as small as 22 and the connector shape is also small. Semiconductor IC for serial / parallel conversion
Not only is it unnecessary, it is possible not only to cope with the rapid downsizing trend of host computers in recent years, but also to greatly expand the degree of freedom in designing motherboards by system manufacturers.

2) The fixing of the optical fiber module of the present invention and the motherboard is accomplished by using tapping screws which penetrate each opening, so that three small holes for the motherboard opening are sufficient, and the motherboard design of the system maker is sufficient. The degree of freedom has been dramatically expanded. further,
Since all the load of force due to the attachment / detachment of the optical fiber is applied to the tapping screw, there is no electrical connection failure of the lead, and a highly reliable optical fiber module is realized.

Further, by adopting a constitution in which the variations in the parts are absorbed by the three openings, the stress applied to the leads of each module is eliminated, the accuracy of the parts is improved, and the parts are managed (parts acceptance inspection, etc.). ) Is unnecessary, and an inexpensive fiber optic module is easily realized.

3) In the optical fiber module of the present invention, P
By adopting the surface mounting type as the CB connector, the manual work such as directly attaching the signal line to the mother board by soldering has been eliminated, and the cost of the optical fiber module has been reduced.

4) A holding method is used in which the front part of the circuit board holds the circuit board by a snap-fitting mechanism of the upper frame and the lower frame, and the rear part of the circuit board holds the circuit board with a weak elastic force. By using it, no warp is generated on the circuit board, and the reliability of the circuit board is significantly improved. Further, the sufficient length of circuit board holding L which was conventionally required is not required, and a compact optical fiber module is realized.

5) The circuit board is covered by the upper and lower frames, covers, etc., which facilitates the handling of the operator who assembles or inspects, improves the efficiency of assembling or inspecting the optical fiber module, and is inexpensive. In addition to the realization of a new optical fiber module, there is no electrostatic damage to the circuit board, resulting in a highly reliable fiber module.

6) A simple shape and an inexpensive module cap are added to prevent dust from entering during long-term storage and to prevent biting between the optical fiber and the module. Has significantly improved the reliability of.

As described above, the practical effects of the present invention are extremely large.

[Brief description of drawings]

FIG. 1 is a block diagram of an optical fiber module showing a first embodiment of the present invention.

FIG. 2 is a perspective view of an optical fiber module showing a second embodiment of the present invention.

FIG. 3 is an exploded perspective view of an optical fiber module showing a third embodiment of the present invention.

FIG. 4 is an exploded perspective view of an optical fiber module showing a third embodiment of the present invention.

FIG. 5 is a main sectional view of an optical fiber module showing a fourth embodiment of the present invention.

FIG. 6 is a main sectional view of an optical fiber module showing a fifth embodiment of the present invention.

FIG. 7 is a perspective view of a lower frame of an optical fiber module showing a sixth embodiment of the present invention.

FIG. 8 is a main sectional view of an optical fiber module showing a seventh embodiment of the present invention.

FIG. 9 is a sectional view of an optical fiber module showing an eighth embodiment of the present invention.

FIG. 10 is a sectional view of an optical fiber module showing a ninth embodiment of the present invention.

FIG. 11 is a perspective view of an optical fiber module showing a tenth embodiment of the present invention.

FIG. 12 is a plan view of an optical fiber module showing an eleventh embodiment of the present invention.

FIG. 13 is an exploded perspective view of an optical fiber module showing a twelfth embodiment of the present invention.

FIG. 14 is a perspective view of an optical fiber module showing a thirteenth embodiment of the present invention.

FIG. 15 is a plan view of an optical fiber module showing a thirteenth embodiment of the present invention.

FIG. 16 is a perspective view of a module cap of an optical fiber module showing a 13th embodiment of the present invention.

FIG. 17 is a plan view showing a conventional optical fiber module.

FIG. 18 is a main sectional view showing a lower frame of a conventional optical fiber module.

FIG. 19 is a main sectional view showing holding of a circuit board of a conventional optical fiber module.

[Explanation of symbols]

1 LD Module 2 PD Module 3 PCB (Circuit Board) 4 Semiconductor IC 5 Semiconductor IC 6 Connector 7a Upper Frame 7b Lower Frame 8 Spacer 9 J Clip L Circuit Board Holding Length 10 Upper Frame 11 Upper Frame Opening 12 Convex 14 Arm 16 Upper frame protrusion 17 Upper frame thin portion 17a Upper shield fitting portion 17b Upper module fitting portion 18 Cover 18a Cover portion 19 Cover opening 20 Lower frame 21 Lower frame opening 22 Recess 23 Claw 24 Rib 25 Lower plate 26 Lower frame projection Part 27 Lower frame Thin part 27a Lower shield fitting part 27b Lower module fitting part 30 PCB (Circuit board) 31 PCB opening 32 PCB connector 33 LD driver 34 Variable resistance 35 Amplifier 35a Transformer impedance amplifier part 36b Waveform shaping circuit part 0 PD module (photodiode module) 41 PD shield plate 42 PD module opening 45 PD element 47 PD lead 50 LD module (laser diode module) 51 LD shield plate 52 LD module opening 53 LD module end surface 55 LD element 56 Ferrule contact surface 57 LD lead 60 Motherboard 61 Mother opening 62 Mother connector 70 Tapping screw 71 Pin 72 Nut 73 Auxiliary plate 74 Fixed portion 80 Module cap 81 Cap opening 82 Cap end surface 83 Cap potch 84 Module contact surface 90 Identification Label 91 Certification Label

─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-5-215943 (JP, A) JP-A-5-52802 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G02B 6/42 G02B 6/36 H01S 5/022 H01L 31/02

Claims (4)

(57) [Claims] 1. A connector connected to a motherboard of a computer, an LD electric signal conversion means for converting LD (laser diode) serial data transmitted from the motherboard into an LD electric signal, and the LD electric signal. LD module for converting the optical signal into an LD optical signal, and P
A PD module for converting an optical signal for D (photodiode) into an electric signal for PD, and a PD electric signal for the PD
Electrical signal converting means for converting into serial data for use, a circuit board comprising the connector, the electrical signal converting means for LD and the electrical signal converting means for PD, the circuit board, the LD module and the PD module A first frame for holding and a second frame,
An electrical signal is exchanged via the connector, and the electrical signal is an optical fiber module that is serial data, which has elasticity in one of the first and second frames and engages with a plug. A claw is provided, a first protrusion that protrudes in a direction perpendicular to the claw is provided at the root of the claw on one of the frames, and a first projection that protrudes toward the root of the claw is provided on the other frame . Rush
An optical fiber module comprising a second protrusion that abuts against a starting portion . 2. The optical fiber module according to claim 1, wherein the first and second frames and the claw are made of a resin material. 3. The optical fiber module according to claim 1, wherein a notation portion such as a safety notation or a manufacturing notation indicating a manufacturing place or the like is provided in each of the first frame and the second frame. 4. A module cap which is composed of the first and second frames and which is inserted into the opening and the exit of the light along the direction in which the light beam goes in and out. Fiber optic module.