JP2009063631A - Optical transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical transmission device that can be thinned, can reduce the number of components, suppresses the leak of noise to the outside, and allows reliable high-speed optical transmission. <P>SOLUTION: The optical transmission device 1 comprises a light transmission module 100 and a light receiving module connected to the light transmission module 100 via an optical fibre 200. The light transmission module 100 comprises a light transmission unit 120, a base substrate 110 mounted with the light transmission unit 120, and a shield cover 130 for shielding the light transmitting unit 120. The shield cover 130 has an inclined surface 130b, and part thereof is formed with a reflecting surface 130c for reflecting light from a light emitting element 122 of the light transmitting unit 120 to a core of the optical fibre 200. The light receiving module is provided with a shield cover having a similar constitution. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical transmission apparatus.

  In recent years, with rapid progress of digital information processing technology, high-speed, large-capacity, high-reliability digital communication technology is required. Electric signal transmission using printed wiring boards and metal wires has limitations in data transfer speed and transmission distance due to signal quality degradation and electromagnetic noise. In order to solve this, optical communication technology has been established, and optical modules, optical transmission devices, electronic devices, and the like have been put into practical use.

As an optical transmission device, for example, a receptacle that is installed on a substrate and includes a reflecting plate on an inclined surface, and a lens is formed facing the front end surface of the optical transmission medium while interpolating the optical transmission medium And an optical plug inserted into the receptacle (see, for example, Patent Document 1).
JP 2006-139094 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide an optical transmission apparatus that can reduce the number of parts and reduce the number of components, suppress noise leakage to the outside, and perform high-speed optical transmission with high reliability.

  In order to achieve the above object, one embodiment of the present invention provides the following optical transmission device.

[1] A light emitting element having a mounting surface on the opposite side to the light output surface for outputting an optical signal, a first substrate to which the mounting surface of the light emitting element is attached, and a side opposite to the light input surface for inputting an optical signal A light receiving element having a mounting surface; a second substrate to which the mounting surface of the light receiving element is attached; an optical fiber that optically couples the light emitting element and the light receiving element; and a metal; A first surface that covers the light emitting element side of the optical fiber and has a reflection surface on the inner surface that reflects the light output from the light output surface of the light emitting element and enters the end surface of the optical fiber on the light emitting element side. And a cover made of metal, covering the light receiving element, the second substrate, and the light receiving element side of the optical fiber, and receiving the light emitted from the end face of the optical fiber on the light receiving element side element Optical transmission device and a second cover having a reflecting surface for reflecting the input surface to the inner surface.

[2] The optical transmission apparatus according to [1], wherein the reflection surfaces of the first and second covers are plane mirrors.

[3] The optical transmission device according to [1], wherein the first and second covers have a reflecting mirror as the reflecting surface.

[4] The first substrate is mounted with a drive circuit for driving the light emitting element, and the second substrate is mounted with an amplifier circuit for amplifying an output signal of the light receiving element. The optical transmission device according to [1].

[5] A first holding member that holds the light emitting element side of the optical fiber on the first substrate, and a second holding that holds the light receiving element side of the optical fiber on the second substrate. The optical transmission device according to claim 1, further comprising: a member.

[6] The optical transmission device according to [5], wherein the first and second holding members are made of silicon and have a groove for guiding the optical fiber.

  According to the optical transmission device of the first aspect, the thickness can be reduced and the number of parts can be reduced, and the leakage of noise to the outside can be suppressed to enable high-speed optical transmission with high reliability.

  According to the optical transmission device of the second aspect, a part of the inclined surface of the cover can be used as the reflecting surface.

  According to the optical transmission device of the third aspect, a part of the inclined surface of the cover can be used as the reflection surface, and incident light on the reflection surface can be condensed on the emission side.

  According to the optical transmission device of the fourth aspect, it is possible to reduce noise of the optical transmission device in which the drive circuit is provided on the same substrate as the light emitting element.

  According to the optical transmission device of the fifth aspect, it is possible to reduce noise of the optical transmission device in which the amplifier circuit is provided on the same substrate as the light receiving element.

  According to the optical transmission device of the sixth aspect, the holding member can be mass-produced.

[First Embodiment]
FIG. 1 is a perspective view showing an optical transmission apparatus according to the first embodiment of the present invention.

(Configuration of optical transmission equipment)
The optical transmission device 1 receives and processes an optical transmission module 100 that transmits an optical signal, an optical fiber 200 connected to the optical transmission module 100, and an optical signal from the optical transmission module 100 via the optical fiber 200. The optical receiver module 300 is provided.

  2 is a cross-sectional view taken along line AA of the optical transmission module shown in FIG.

  FIG. 3 is a cross-sectional view taken along line CC of the optical transmission module shown in FIG. FIG. 4 is a plan view showing the transmission unit.

(Configuration of optical transmission module)
As shown in FIG. 2, the optical transmission module 100 includes a base substrate 110, a transmission unit 120 mounted on the base substrate 110, and a first shield fixed to the base substrate 110 so as to shield the transmission unit 120. A cover (first cover) 130 and an upper holding member 132 provided inside the first shield cover 130 and formed with a V-groove 132a for holding the end of the optical fiber 200 are configured. .

  The base substrate 110 is made of glass epoxy resin or the like, has a wiring pattern for connection with the transmission unit 120 and other modules, and has a plurality of protruding pieces 130a formed at the bottom of the first shield cover 130. It has the recessed part 110a inserted.

(Configuration of transmission unit)
As shown in FIGS. 2 and 4, the transmission unit 120 includes a first substrate 121, a light emitting element 122 mounted on the first substrate 121, a lower holding member 123, semiconductor elements 124A and 124B, A plurality of solder balls 125 provided in a predetermined arrangement on the lower surface of the first substrate 121 are provided.

  The first substrate 121 includes a plurality of (in this case, three) alignment marks 121a for positioning, a wiring pattern (not shown) connected to the light emitting element 122 and the semiconductor elements 124A and 124B, the wiring pattern, It has through holes (not shown) connected to a plurality of solder balls 125, a ground pattern, and the like.

  The light emitting element 122 is, for example, a VCSEL (Vertical Cavity Surface Emitting Laser). The VCSEL has a configuration in which, for example, an active layer is sandwiched between DBR structures (Distributed Bragg Reflectors) made of a semiconductor multilayer film, and light is reflected to realize an optical resonator. The semiconductor multilayer film is usually composed of several tens of semiconductor layers, and the DBR structure is formed by changing the composition ratio of AlGaAs.

  The lower holding member 123 is cut from a silicon wafer having a thickness larger than the height of the light emitting element 122 and the semiconductor elements 124A and 124B, for example, and the lower part of one end of the optical fiber 200 is positioned (guide) on the upper surface thereof. 3 and FIG. 4 for holding, and a plurality (three in this case) of alignment marks 123b for positioning are provided.

  The V-groove 123a is formed using Si anisotropic etching. The plurality of alignment marks 123b are formed by photolithography.

  The semiconductor elements 124A and 124B are a driver IC (drive circuit) that drives the light emitting element 122, an LSI that controls the driver IC, and the like.

(Configuration of the first shield cover)
FIG. 5 is a development view of the first shield cover.

  The first shield cover 130 is made of a metal having excellent conductivity and capable of being soldered, for example, a plate material such as copper or copper alloy by laser cutting, and thereafter, the shape shown in FIGS. 1 to 3 is manufactured by welding. The first shield cover 130 has a 45 ° inclined surface 130b on one side, and the inclined surface 130b is mirror-finished on the inner surface or a mirror is attached to the inner surface as necessary. A reflecting surface (plane mirror) 130c is formed.

  The first shield cover 130 has a plurality of protruding pieces 130a on the lower edge, and these protruding pieces 130a are electrically connected to the ground pattern of the first board 121 by fitting after being mounted on the first board 121. Connected to each other and fixed with solder or the like, if necessary. Furthermore, the first shield cover 130 has an upper holding member 132 attached to the ceiling surface. The upper holding member 132 constitutes a first holding member in combination with the lower holding member 123.

  The first shield cover 130 includes the plurality of protruding pieces 130a, the inclined surface 130b, the reflective surface 130c secured on the inner surface of the inclined surface 130b, the mount surface (ceiling surface) 130d of the upper holding member 132, and the optical fiber 200. The transmission medium introduction surface 130f having the insertion port 130e, side surfaces 130g and 130h, and a plurality (three in this case) of alignment marks 130i are provided. The alignment mark 130i is formed by laser marking, for example.

(Configuration of upper holding member of optical transmission module)
FIG. 6 is a bottom view showing the upper holding member.

  As shown in FIG. 3, the upper holding member 132 is cut from the silicon wafer in the same manner as the lower holding member 123, and the lower surface thereof has a V for positioning and holding the upper portion of one end of the optical fiber 200. A groove 132a and a plurality of (here, three) alignment marks 132b for positioning are provided. The V-groove 132 a is provided at a position parallel to the V-groove 123 a of the lower holding member 123 when the upper holding member 132 is disposed to face the lower holding member 123.

  The upper holding member 132 is bonded and fixed to the mount surface 130 d of the first shield cover 130 with an adhesive 133. One end of the optical fiber 200 is bonded and fixed to the upper holding member 132 with an adhesive 134.

(Configuration of optical receiver module)
FIG. 7 is a cross-sectional view of the optical receiver module shown in FIG. 1 taken along line BB. 8 is a cross-sectional view taken along the line DD shown in FIG.

  As shown in FIG. 7, the optical receiving module 300 includes a base substrate 310, a receiving unit 320 mounted on the base substrate 310, and a second shield fixed to the base substrate 310 so as to shield the receiving unit 320. A cover (second cover) 330 and an upper holding member 332 provided inside the second shield cover 330 and formed with a V-groove 332 a for holding the end of the optical fiber 200 are configured. .

  The base substrate 310 is made of glass epoxy resin or the like, and has a wiring pattern for connection with the receiving unit 320 and the outside.

(Reception unit configuration)
As shown in FIG. 7, the receiving unit 320 includes a second substrate 321, a light receiving element 322 mounted on the second substrate 321, a lower holding member 323, semiconductor elements 324 </ b> A and 324 </ b> B, And a plurality of solder balls 325 provided in a predetermined arrangement on the lower surface of the substrate 321.

  The second substrate 321 includes a wiring pattern (not shown) connected to the light receiving element 322 and the semiconductor elements 324A and 324B, a through hole (not shown) connected to the wiring pattern and a plurality of solder balls 325, and a ground. It has a pattern.

  The light receiving element 322 is, for example, a photodiode or the like, which converts an optical signal into an electric signal and outputs it.

  The lower holding member 323 is cut out from the silicon wafer similarly to the lower holding member 123, and a V groove 323a for positioning and holding the lower portion of the other end of the optical fiber 200 is provided on the upper surface thereof. Yes.

  The semiconductor elements 324A and 324B are an amplification IC that outputs a change in current of the light receiving element 322 as a voltage change, a signal processing LSI that processes a signal from the amplification IC (amplification circuit), and the like.

(Configuration of second shield cover)
Similar to the first shield cover 130, the second shield cover 330 is made by laser-cutting a plate material such as copper, copper alloy, etc., which is excellent in conductivity and can be soldered, and then welded. 7 and FIG. 8 are manufactured. The second shield cover 330 has a 45 ° inclined surface 330b on one side, and the inclined surface 330b is mirror-finished on the inner surface as needed, or a mirror is attached to the inner surface. A reflecting surface (plane mirror) 330c is formed.

  The second shield cover 330 has a plurality of protruding pieces 330a on the lower edge, and these protruding pieces 330a are electrically connected to the ground pattern of the second substrate 321 by fitting after being mounted on the second substrate 321. And fixed with solder or the like if necessary. Furthermore, the upper shield member 332 is attached to the ceiling surface of the second shield cover 330. The upper holding member 332 forms a second holding member in combination with the lower holding member 323.

(Configuration of upper holding member of optical receiver module)
Similar to the upper holding member 132 of the optical transmission module 100, the upper holding member 332 is cut from a silicon wafer, and a V groove 332a for positioning and holding the upper portion of one end of the optical fiber 200 is formed on the lower surface of the upper holding member 332. And a plurality (three in this case) of alignment marks 332b for positioning are provided. The V-groove 332a is provided at a position parallel to the V-groove 323a of the lower holding member 323 when the upper holding member 332 is disposed to face the lower holding member 323.

  The upper holding member 332 is bonded and fixed to the mount surface 330 d of the second shield cover 330 with an adhesive 133. The other end of the optical fiber 200 is bonded and fixed to the upper holding member 132 with an adhesive 134.

(Assembly of optical transmitter module and optical receiver module)
FIG. 9 is an exploded perspective view of the optical transmission module 100, and FIG. 10 is an exploded perspective view of the optical reception module 300. The assembly of the optical transmission device 1 will be described below with reference to FIGS.

(Assembling the optical transmitter module)
First, as shown in FIG. 9, the first shield cover 130 and the transmission unit 120 of the optical transmission module 100 are individually assembled.

  The first shield cover 130 is assembled on the mount surface 130d so that the alignment mark 132b of the upper holding member 132 shown in FIG. 6 is in a predetermined position with respect to the alignment mark 130i of the mount surface 130d shown in FIG. This is done by positioning the upper holding member 132. In this state, the first holding cover 132 is completed by bonding the upper holding member 132 to the mount surface 130d with the adhesive 133. Next, as shown in FIG. 3, one end of the optical fiber 200 is positioned in the V groove 132a of the upper holding member 132, and the optical fiber 200 is bonded to the V groove 132a by the adhesive 134.

  As shown in FIG. 4, the transmission unit 120 is assembled by mounting the light emitting element 122, the semiconductor elements 124 </ b> A and 124 </ b> B, and the lower holding member 123 on the first substrate 121.

  Next, as shown in FIGS. 2 and 3, the transmission unit 120 is mounted on the base substrate 110. At this time, as shown in FIG. 4, the V groove 123 a of the lower holding member 123 is matched with the light emission center of the light emitting element 122.

  Next, as shown in FIG. 9, the first shield cover 130 to which the upper holding member 132 and one end of the optical fiber 200 are attached is positioned above the transmission unit 120, and then, as shown in FIGS. 2 and 3. In addition, the first shield cover 130 is attached to the base substrate 110 so as to cover the transmission unit 120. At this time, the protruding piece 130a of the first shield cover 130 is fitted into the recess 110a of the base substrate 110, and the protruding piece 130a is soldered to the ground pattern on the first substrate 121.

(Assembling the optical receiver module)
Next, as shown in FIG. 10, the second shield cover 330 and the receiving unit 320 of the optical receiving module 300 are assembled separately.

  As with the case of the first shield cover 130, the second shield cover 330 is assembled by positioning the upper holding member 132 on the mount surface using an alignment mark (not shown), and in this state, the upper holding member This is done by adhering 332 to the mount surface with an adhesive 133. Next, as shown in FIG. 8, one end of the optical fiber 200 is positioned in the V groove 332 a of the upper holding member 332, and the optical fiber 200 is bonded to the V groove 332 a by the adhesive 134.

  As with the transmission unit 120, the reception unit 320 is assembled by mounting the light receiving element 322, the semiconductor elements 324A and 324B, and the lower holding member 323 on the second substrate 321.

  Next, as shown in FIGS. 7 and 8, the receiving unit 320 is mounted on the base substrate 310. At this time, the V groove 123 a of the lower holding member 123 is matched with the light emission center of the light emitting element 122.

  Next, as shown in FIG. 9, the second shield cover 330 with the upper holding member 132 and one end of the optical fiber 200 attached thereto is positioned above the receiving unit 320, and then as shown in FIGS. 7 and 8. In addition, the second shield cover 330 is attached to the base substrate 310 so as to cover the receiving unit 320. At this time, the protruding piece 330a of the second shield cover 330 is fitted into the recess 310a of the base substrate 310, and the protruding piece 330a is solder-connected to the ground pattern on the second substrate 321. Thus, the optical transmission device 1 shown in FIG. 1 is completed.

(Operation of optical transmission equipment)
Next, the operation of the optical transmission device 1 will be described. When the semiconductor elements 124A and 124B shown in FIG. 2 are driven by a control means (not shown), the light emitting element 122 is excited by a drive current corresponding to the transmission signal. The light emitting element 122 emits modulated light corresponding to the transmission signal and emits light toward the reflecting surface 130 c of the first shield cover 130. The light from the light emitting element 122 is reflected in the horizontal direction by the reflecting surface 130 c and enters the core at one end of the optical fiber 200.

  The optical signal propagates through the optical fiber 200 and reaches the receiving end, enters the reflecting surface 330c shown in FIG. 7, reflects downward in FIG. 7, and enters the light receiving element 322. The light receiving element 322 converts an optical signal into an electric signal. This electrical signal is processed by the semiconductor elements 324A and 324B.

[Second Embodiment]
(Configuration of optical transmission equipment)
11A and 11B show an optical transmission apparatus according to the second embodiment of the present invention. FIG. 11A is a cross-sectional view of an optical transmission module, and FIG. 11B is a cross-sectional view of an optical reception module.

  In this embodiment, in the first embodiment, a concave mirror 140 is provided instead of the reflection surface 130c of the optical transmission module 100, and a concave mirror 340 is provided instead of the reflection surface 330c of the optical reception module 300. Other configurations are the same as those of the first embodiment.

  The concave mirror 140 has a shape capable of condensing light from the light emitting element 122 on the core of the optical fiber 200, and the concave mirror 340 has a shape capable of condensing light from the optical fiber 200 onto the light receiving element 322. Yes.

  Concave mirrors 140 and 340 are formed on inclined surfaces 130b and 330b where light emitting centers of light emitting element 122 and light receiving element 322 intersect with the core of optical fiber 200, respectively. The concave mirrors 140 and 340 desirably have a mirror finish or the like on the concave surface.

[Third Embodiment]
(Configuration of optical transmission equipment)
FIG. 12 is a perspective view showing an optical transmission apparatus according to the third embodiment of the present invention. FIG. 13 is a cross-sectional view taken along line EE of the optical transmission module shown in FIG.

  In this embodiment, an optical fiber assembly 400 including four optical fibers 201 to 204 is used in place of the optical fiber 200 in the first embodiment, and other configurations are the same as those in the first embodiment. It is the same as the form. The optical transmission module 100 and the optical reception module 300 include the number of light emitting elements 122 and light receiving elements 322 corresponding to the optical fibers 201 to 204.

  As shown in FIG. 13, the lower holding member 123 has V grooves 150A to 150D for positioning the optical fibers 201 to 204, and the upper holding member 132 is disposed to face the V grooves 150A to 150D. V-grooves 340A to 340D are provided. Although not shown, the lower holding member 323 and the upper holding member 332 of the optical receiving module 300 similarly have four V-grooves.

  In the present embodiment, the optical fiber assembly 400 is composed of four optical fibers, but may be two, three, or four or more.

[Other embodiments]
The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. For example, the combination of the components between the embodiments can be arbitrarily performed.

  For example, in each of the above embodiments, the recesses 110a and 310a may be through holes.

  In each of the above embodiments, the V grooves 123a, 150A to 150D, 332a, and 340A to 340D may be U-shaped, U-shaped, or the like.

FIG. 1 is a perspective view showing an optical transmission apparatus according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line AA of the optical transmission module shown in FIG. FIG. 3 is a cross-sectional view taken along line CC of the optical transmission module shown in FIG. FIG. 4 is a plan view showing the transmission unit. FIG. 5 is a development view of the first shield cover. FIG. 6 is a bottom view showing the upper holding member. FIG. 7 is a cross-sectional view of the optical receiver module shown in FIG. 1 taken along line BB. 8 is a cross-sectional view taken along line DD shown in FIG. FIG. 9 is an exploded perspective view of the optical transmission module. FIG. 10 is an exploded perspective view of the optical receiver module. 11A and 11B show an optical transmission apparatus according to the second embodiment of the present invention. FIG. 11A is a cross-sectional view of an optical transmission module, and FIG. 11B is a cross-sectional view of an optical reception module. FIG. 12 is a perspective view showing an optical transmission apparatus according to the third embodiment of the present invention. FIG. 13 is a cross-sectional view taken along line EE of the optical transmission module shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical transmission apparatus 100 Optical transmission module 110 Base board 110a Recess 120 Transmission unit 121 First board 121a Alignment mark 122 Light emitting element 123 First lower holding member 123a V groove 123b Alignment mark 124A, 124B Semiconductor element 125 Solder ball 130 1 shield cover 130a projecting piece 130b inclined surface 130c reflective surface 130d mount surface 130e insertion port 130f transmission medium introduction surface 130g, 130h side surface 130i alignment mark 132 upper holding member 132a V groove 132b alignment mark 133, 134 adhesive 140 concave mirror 150A- 150D V-groove 200 to 204 Optical fiber 300 Optical receiving module 310 Base substrate 310a Recess 320 Receiving unit 321 Second substrate 322 Child 323 Lower holding member 323a V groove 324A, 324B Semiconductor element 325 Solder ball 330 Shield cover 330a Protruding piece 330b Inclined surface 330c Reflecting surface 330d Mount surface 332 Upper holding member 332a V groove 332b Alignment mark 332 Upper holding member 340 Concave mirrors 340A to 340D V-groove 400 optical fiber assembly

Claims (6)

A light emitting element having a mounting surface on the side opposite to the light output surface for outputting an optical signal;
A first substrate to which the mounting surface of the light emitting element is attached;
A light receiving element having a mounting surface opposite to the light input surface for inputting an optical signal;
A second substrate to which the mounting surface of the light receiving element is attached;
An optical fiber for optically coupling the light emitting element and the light receiving element;
It is made of metal, covers the light emitting element and the light emitting element side of the optical fiber, reflects light output from the light output surface of the light emitting element, and enters the end face of the optical fiber on the light emitting element side A first cover having an inner surface with a reflecting surface;
It is made of metal and covers the light receiving element, the second substrate, and the light receiving element side of the optical fiber, and emits light emitted from an end surface of the optical fiber on the light receiving element side to the input of the light receiving element. An optical transmission device comprising: a second cover having an inner surface with a reflecting surface that reflects on the surface.   The optical transmission device according to claim 1, wherein the reflection surfaces of the first and second covers are plane mirrors.   The optical transmission device according to claim 1, wherein the reflection surfaces of the first and second covers are concave mirrors. The first substrate is mounted with a driving circuit for driving the light emitting element,
The optical transmission apparatus according to claim 1, wherein an amplification circuit that amplifies an output signal of the light receiving element is mounted on the second substrate. A first holding member for holding the light emitting element side of the optical fiber on the first substrate;
A second holding member for holding the light receiving element side of the optical fiber on the second substrate;
The optical transmission device according to claim 1, further comprising:   The optical transmission device according to claim 5, wherein the first and second holding members are made of silicon and have a groove for guiding the optical fiber.

Images