JP2002214485A - Plane optical element, plane optical element mounting body, method for producing it and optical wiring device using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plane optical element which reduces costs by improving the alignment precision of plastic optical fibers and the plane optical element without requiring the increase of the number of parts and the improvement of process controllability so as to facilitate the fixing work of the plastic optical fibers to improve productivity. SOLUTION: On the surface of the plane optical element 5, guide holes 4 for inserting and fixing the plastic optical fibers 16 for realizing optical coupling with the element 5 are formed. The guide holes 4 are formed of a thick film material 3 which has photosensitivity or electronic beam hardenability and can be hardened selectively by patterning by photolithography. The tip surfaces of the fibers 16 are worked in the shape of a lens to improve optical coupling efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[OO01]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface-type optical element capable of efficiently and optically coupling an optical fiber, and an optical package in which the surface-type optical element and the optical fiber are optically coupled at low cost. The present invention relates to an optical element and an optical package, which are also referred to as an optical interconnection module in the present specification), a manufacturing method thereof, and an optical wiring device using the same.

[OO02]

2. Description of the Related Art In recent years, optical modules for high-speed optical connection have been developed. However, there are many problems regarding the coupling between an optical element and an optical transmission medium such as an optical fiber, particularly from the viewpoint of cost reduction and high performance.

[OO03] As an optical element, a surface-type element is mainly used as a light-receiving element in terms of easiness of manufacturing and sensitivity, but when an optical fiber is optically coupled with a main surface of the surface-type element. To
Passive alignment for performing alignment without operating the light receiving element is essential for cost reduction. As a technique for that, a method of producing and assembling a fixing member is generally used. However, the mechanical accuracy of the fixing member is required, the elastic coefficient and the coefficient of thermal expansion are restricted, and the number of parts increases, so that it has been difficult to reduce the cost. In particular, when a plastic mold or the like is used for cost reduction, there is a problem that the yield of optical coupling and long-term reliability are lacking.

[0004] In a light emitting device, a vertical cavity surface emitting laser that emits light vertically from a substrate surface may be improved from the viewpoint of reducing power consumption and cost of an optical transmission module, and has been actively used. Has been studied. In the surface emitting laser,
It can be driven at a low threshold of 1 mA or less, can perform wafer-level inspection, and does not require cleavage accuracy, so cost can be reduced. The same problem as described above occurs in the optical coupling between the surface emitting laser and the optical fiber.

Therefore, a method has been proposed in which a guide hole for coupling with an optical fiber is formed with the accuracy of photolithography. For example, in Japanese Unexamined Patent Publication No. Hei 8-111559, as shown in FIG.
A structure in which a hole for fixing an optical fiber 1037 is formed on the 21 side by etching is disclosed. In FIG. 12, 1022 is a light absorbing layer, 1023 and 1027 are DBR mirrors, 1024 and 1
026 is a cladding layer, 1025 is an active layer, 1028 is a contact layer, 1032 is a SiO ₂ layer, 1033 and 1035 are electrodes, and 1036 is an antireflection film.

[O006] Japanese Patent Application Laid-Open No. 6-237016 also discloses a method of fixing an optical fiber 1210 by forming a guide hole 1209 obtained by etching a substrate on the back side of a surface emitting laser 1203 as shown in FIG. It has been disclosed. In these cases, the number of parts can be reduced and assembly is very simple, so that cost reduction can be achieved. In FIG. 13, reference numeral 1201 denotes an electronic circuit board; 1202, a light emitting chip; 1204, a transistor;
05, 1206 and 1207 are transistor electrodes, 1208 is an insulating layer, 12
11 is an adhesive.

[O007] However, in the method of making a hole in the substrate, it is difficult to control the distance between the optical fiber and the light receiving portion or the light emitting portion, and when the fiber is hit against the crystal, the crystal is damaged. There was a fear that it would. Therefore, in the invention of JP-A-6-237016, the guide hole 1209
In order to prevent the fiber from coming into contact with the crystal surface, the diameter of the tip of the guide hole is reduced (see Fig. 13), or the etching is performed with the substrate slightly left without etching completely to the epi layer. Methods such as stopping were used.

On the other hand, there has been proposed a method of mounting an optical fiber by directly fixing a member for fixing a fiber to a surface side on which a surface-type optical element is formed. For example, in JP-A-11-307869, as shown in FIG.
Disclosed are projections 2022, 2023 for fitting the fiber fixing member 2014 on the surface of 18, and a guide hole formed at a position corresponding to the light emitting portion of the surface emitting laser 2018.
In FIG. 14, reference numeral 2012 denotes a module substrate, 2016 denotes an optical fiber, 2024 denotes a fiber insertion hole, and 2026 and 2027 denote guide holes.

[OO09]

However, when a guide hole is formed by etching, the depth is usually 10
Since it is 0 μm or more, there is a problem in the controllability of the taper shape and the hole diameter, and it has been difficult to improve the yield.
Further, when the substrate is left, there is a problem of light absorption by the substrate, and there is a limit to a wavelength band that can be used.

[0010] On the other hand, in the case of using the optical fiber fixing block, the above-described problem in the production does not occur, but the cost cannot be necessarily reduced because the number of components and the processing steps are increased.

[OO11] Further, since the light emitted from the optical fiber spreads, it is important to mount the optical fiber as close as possible to the light receiving element, but it is still difficult to increase the incident efficiency to the light receiving element. Similarly, in connection with the light emitting element, it is difficult to increase the optical coupling efficiency to the optical fiber if the mismatch between the light emitting diameter and the emission angle of the light emitting element and the core diameter and the acceptance angle of the optical fiber is large. there were.

[0012] In view of such problems, an object of the present invention is to form a guide hole for fixing an optical fiber, and to increase the number of parts and the process controllability without using an optical waveguide and a planar mold. This improves the alignment accuracy of the optical element, which facilitates the work of fixing the optical fiber, improves productivity, reduces costs, and allows the distance between the planar optical element and the optical fiber to be freely adjusted. It is an object of the present invention to provide a structure which can be set and which improves the easiness and freedom of mounting. It is still another object of the present invention to provide a manufacturing method capable of mass-producing such a structure for mounting, an optical package capable of reducing cost, and an optical wiring device using the same.

[OO13] In particular, an object of the present invention is to improve the optical coupling efficiency with a light emitting or light receiving element by processing the tip of an optical fiber into a lens shape, thereby reducing the insertion loss of an optical interconnection module. Another object of the present invention is to provide a structure for reducing power consumption related to element driving, improving productivity and reducing costs.

[0014]

In the surface optical device of the present invention, a structure serving as a guide hole for inserting an optical fiber is directly formed on the surface of the surface optical device by photolithography using a thick film material. The problem is solved by making it. That is, the surface optical element capable of emitting or receiving light according to the present invention has a guide hole for inserting and fixing an optical fiber including a lens-shaped polymer so that the optical fiber can be optically coupled to the surface optical element. A thick film material (such as a thick film resist that can be polymerized) that can be selectively cured by patterning by photolithography with photosensitivity or electron beam curability on the surface of the surface type optical element. It is characterized by being formed.

The thickness of the thick film material or thick film resist is 10 μm (this is about the core of a quartz single mode fiber) to 1000 μm (this is about the core of a plastic fiber (POF) made of an acrylic material). More preferably, those having a size of about 50 μm to 500 μm are suitably used. Optical fiber size from 125μm to 1mm
Any size up to the extent is applicable. In terms of the core diameter of the optical fiber, any size from 100 μm to about 1 mm is applicable. Since the thick film material or the thick film resist is processed by a usual photolithography process, it is easy to accurately match the center position of the guide hole with the surface type optical element. Therefore, it is possible to omit a step of aligning and bonding the structures having the guide holes formed therein.

The controllability and shape control of the hole diameter are also excellent due to the characteristics of the thick film material or the thick film resist, and the process becomes simpler than the method of forming a hole by etching a substrate.

For the surface-type optical element, a surface-emitting laser, a surface-type light-receiving element, or the like is used. After mounting elements of the required chip size and number of arrays on the mounting substrate, the growth substrate is removed to form a thin film type. Thus, the mounting substrate can be used as a handling substrate. As a result, the yield of the planar optical element that can be obtained from the epi-wafer is increased, and the cost can be reduced.

Also, a plurality of the surface type optical elements are arrayed, and correspondingly, guide holes are also formed in an array, and the plurality of the surface type optical elements are only a surface type light emitting element and only a surface type light receiving element. Or, a combination of a surface light emitting element and a surface light receiving element, the surface light element is a vertical cavity surface emitting laser or a light emitting diode, a surface emitting laser is an active layer, a resonator layer, And the functional layer of only the Bragg reflection mirror layer is left, or the surface-type optical element is formed into a thin film by removing or thinning the growth substrate, or the growth substrate is left as it is. And so on.

The distance between the end face of the optical fiber and the surface type optical element can be controlled by using a thick film material or a thick film resist as two layers and controlling the distance by the thickness of the first layer.
The degree of freedom can be improved. That is, the thick-film material or the thick-film resist has a first layer in which holes smaller than the size of the optical fiber and only light can pass are formed,
A second layer is formed on the first layer and has a guide hole for fixing the optical fiber. The thickness of the first layer defines the distance between the surface type optical element and the end face of the optical fiber. I can do it.

[OO20] The shape of the optical fiber guide hole can also be freely set depending on the design of the photomask, so that the escape of the fixing adhesive can be made and the optical fiber and the guide hole can be easily fitted. (For example, the guide hole may be tapered). That is, the guide hole formed of the thick film material or the thick film resist is formed by forming only a portion corresponding to the outer shape of the optical fiber,
Along with the portion corresponding to the outer shape of the optical fiber, a groove pattern different from the outer shape is also formed, and in this case, the portion of the guide hole corresponding to the outer shape of the optical fiber and the groove pattern are continuously formed. Or be formed.

[OO21] The tip of the optical fiber is processed into a concave lens shape, and the concave portion is filled with resin. This resin is typically a resin having a higher refractive index than the optical fiber in order to improve the light focusing effect. Further, the gap between the tip of the optical fiber and the surface optical element may be filled with resin for use.

[0022] Further, in the surface-type optical element mounting body of the present invention, the above-mentioned surface-type optical element is mounted on a mounting board with electrical connection so as to be drivable, and an optical fiber is inserted into the guide hole. Is fixed.

[0023] The mounting substrate may be a mounting substrate having a heat sink function on which other optical elements or electronic elements can be integrated in a hybrid manner. A plurality of the planar optical elements are arrayed, and optical fibers can be arrayed simultaneously.
The optical fiber is composed of an optical fiber containing a polymer, that is, a plastic optical fiber (POF).

In order to further improve the efficiency of optical coupling with the element, the tip of the optical fiber is processed into a lens shape, and resin, air, or nitrogen gas is filled in the gap between the tip of the optical fiber and the surface optical element. It may be filled. This resin may be a curable resin such as an optical adhesive or a transparent resin. The tip of the optical fiber is processed into a concave lens shape, and the resin has a higher refractive index than the optical fiber, or the tip of the optical fiber is processed into a convex lens shape, and the resin has a lower refractive index than the optical fiber. Or have a rate. When the gap between the tip of the optical fiber and the planar optical element is filled with air or nitrogen gas, the tip of the optical fiber is typically processed into a convex lens shape.

[OO25] The plastic optical fiber in the present invention is
It refers to an optical fiber in which the core portion composed of a core and a clad is a polymer, or an optical fiber in which only the cladding or the core is a polymer. The periphery of the core wire may be covered with a protective layer or a polymer jacket. Further, the core portion may be a step index type (gradient index type) optical fiber or a graded index type (refractive index distribution type) optical fiber.

[OO26] The shape of the tip of the plastic optical fiber can be freely processed by pressing the tip of the plastic optical fiber against a heated mold. Alternatively, there is a method of immersing in a suitable organic solvent in which the clad or core melts, and controlling the immersion time, the pulling-up method, and the like to shape the lens into a convex lens shape or a concave lens shape. At this time, if air or nitrogen gas is filled between the light emitting or light receiving element and the end face of the optical fiber, the tip is a convex end. On the other hand, when a curable resin or the like is filled between the light-emitting or light-receiving element and the end face of the optical fiber, the surface is made convex or concave in consideration of the magnitude relationship between the refractive index of the optical fiber and the resin. In any case, the optical fiber itself can exhibit a convex lens function of condensing without mounting a separate lens after positioning.

[OO27] When using a mold, a heated convex or concave mold is pressed against the end face of a plastic optical fiber cut in a plane with a razor, etc.
A concave or convex lens is formed on the end face of the plastic optical fiber. The spherical or aspherical mold diameter is preferably equal to or larger than the core diameter of the plastic optical fiber. In the case of the concave tip structure, a curable resin having a higher refractive index than that of the plastic optical fiber is filled.
In the case of the convex structure, the gap is filled with air or nitrogen or a curable resin having a lower refractive index than that of the plastic optical fiber. As the curable resin, it is preferable to use a synthetic resin adhesive or a transparent resin which is excellent in transparency and hardly foams or shrinks and expands during curing.
For the thermosetting synthetic resin adhesive, a low-temperature curable adhesive which does not cause softening of the plastic optical fiber is preferable. For a perfluorinated polymer optical fiber and a polystyrene plastic optical fiber, the temperature is 70 ° C. The temperature is preferably 80 ° C. or less for acrylate plastic optical fibers and 125 ° C. or less for polycarbonate plastic optical fibers.

[OO28] For an optical fiber with a low refractive index of about 1.3 to 1.4, such as a perfluorinated polymer-based plastic optical fiber, if a convex lens effect is obtained by filling with a curable resin, the curability of a lower refractive index will be further reduced. It is necessary to select a resin. However, there is hardly any curable resin having such a low refractive index, and even if it is realized, the refractive index difference from the optical fiber is small, so that only a convex lens having extremely low refractive power is realized. Therefore, in the present invention, the end face of the plastic optical fiber is formed into a concave shape, and the concave structure is filled with a curable resin having a relatively high refractive index, thereby exhibiting a light-condensing action with the curable resin side as a convex lens. . Since the center of the end face of the optical fiber is dented as compared with the method in which the end face is formed as a convex lens, even when the end face is brought close to the light emitting or light receiving element, there is no contact, and the mounting of the optical fiber becomes easy.

[OO29] Further, the method for producing a surface-type optical element mounted body according to the present invention includes a step of forming a wiring pattern on a wafer-shaped mounting substrate, and sequentially mounting at least one surface-type optical element at a plurality of locations on the mounting substrate The process of mounting, the process of forming a guide hole with a thick film material on each surface type optical element, the necessary electronic devices, etc. are sequentially flip-chip mounted at the required positions, and then cut into a plurality of mounting bodies of the required size And finally, a step of inserting and fixing the optical fiber into the guide hole.

Further, the optical wiring device of the present invention is an optical wiring device mounted on a board in an electronic device via a connection lead to transmit and receive a signal between the boards by light. Electronic circuits for driving surface-type optical elements are also integrated in the element mounting body,
The optical element mounting body is surface-mounted on a pedestal for fixing a connection lead for obtaining electrical contact to constitute an optical connection module. It is mounted on an element driving electronic circuit and housed in an electrical connector. Electrical connection to the driving electronic circuit is made by connection pins for a detachable connector, and transmission and reception of signals between electronic devices are performed by light. It is characterized by the following.

As described above, the optical element mounting body in which the surface-type optical element and the optical fiber are connected by using the thick-film resist or the thick-film material is integrated with the electronic circuit, and the optical interconnection device having the transmission and reception is provided. Can be used as In that case, it can be used for optical wiring between electronic circuit boards and optical connection between electronic devices, etc.
Multi-channel large-capacity high-speed transmission at Gbps or higher can be realized at low cost.

[0032]

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

(First Embodiment) FIG. 1 is a perspective view showing a first embodiment of the present invention. Surface emitting lasers 5 arrayed in four at a pitch of 750 μm are bonded to a mounting substrate 1 via a common electrode 2. An element isolation groove of each element 5 is indicated by 8, and a portion corresponding to a light emitting point is indicated by 6. As electric wiring for driving the surface emitting laser 5, a wiring 10 for a common electrode and a wiring 9 for independent driving are formed on the mounting substrate 1. The independent electrode 25 for driving the surface emitting laser is connected to the wiring 9. In addition, driver IC12 for surface emitting laser drive
Are flip-chip mounted on the same mounting board 1.
The driver IC 12 is connected to another electronic device or the like by a wiring 13.

As an optical fiber inserted into the guide hole 4, a perfluorinated polymer plastic optical fiber 16 having a total diameter of 500 μm including a reinforcing layer is used. The POF 16 is sandwiched by a fixing jig 14 having a V-groove formed by a plastic mold and a flat jig 15 and fixed by an adhesive 17. The V groove allows the pitch and center position of the POF 16 to be aligned. The front end of the POF 16 protrudes from the surface formed by the fixing jigs 14 and 15 as shown in FIG. 1, and the protruding amount is 500 μm in the present embodiment. 4 plastic optical fibers 16
Is bonded and fixed using the fixing jigs 14 and 15, and then cut in a batch with a razor or the like, and a heated convex mold is pressed to form a spherical concave structure 18 on the end face. FIG. 2 shows an example in which a spherical concave structure 18 having a diameter smaller than the diameter of the plastic optical fiber but larger than the core diameter is formed, and a flat surface is left on the peripheral end surface.

[0035] The spherical concave structure 18 is filled with a curable resin 19 having a higher refractive index than the plastic optical fiber 16. The curable resin has a refractive index of about 1.4 to 1.7, a perfluorinated polymer optical fiber (eg, Asahi Glass, trade name Lucina) is about 1.35, and a polymethyl methacrylate optical fiber is about 1.49. The difference in refractive index is sufficient to obtain a light-condensing effect (typically, about 0.2 to 0.3). The curable resin 19 is classified into a room-temperature-curable type, a thermosetting type, and a photo-curable type. In the case of the perfluorinated polymer optical fiber, the room-temperature-curable type is used because the softening temperature is relatively low. Of course, if the curable resin has a curing temperature lower than the softening temperature of the plastic optical fiber, heat curing is possible. If the optical fiber guide hole 4 is transparent to ultraviolet light, a photo-curing type can be used. As long as the difference in refractive index is appropriate and optically stable, a non-curable resin can be used.

The POF16 used in the present embodiment has a 0.8 μm band, 1.3 μm
Fiber using perfluorinated polymer that can be transmitted in the band
(Made by Asahi Glass, trade name Lucina), but there is no limitation on materials such as those using polymetal methacrylate, polycarbonate, polystyrene, deuterated polymer, and those using UV curable resin. Further, the diameter of the guide hole 4 and the shape of the V groove of the fixing jig 14 may be designed according to the fiber diameter.

On the other hand, the guide hole 4 for the optical fiber, which is a feature of the present invention, is formed of the thick film resist 3 so that the center of each light emitting point 6 of the surface emitting laser 5 coincides with the center of the core of the optical fiber 16. Have been. FIG. 1 is a transparent perspective view for easy understanding. The thick film resist 3 is applied directly onto the mounting substrate 1 by a spin coater or the like, and is patterned by photolithography. For pattern matching, if a mark for matching with the electrode 25 formed on the surface of the surface emitting laser 5 is formed on the photomask, the center of the light emitting point 6 and the center of the guide hole 4 should be aligned with a positional accuracy of several μm or less. Can be.

In this embodiment, MicroChem
SU8-50 of the company was used. It was applied to a thickness of 200 μm by spin coating, and was prebaked at 90 ° C. on a hot plate. 3mm x 1mm outer frame size, 750μm pitch 52
Exposure was performed using an aligner while performing the above-described pattern matching using a photomask so as to have a circular pattern of 0 μm. Next, after baking after exposure at 90 ° C. again on a hot plate, the resist was developed with a developing solution. Rinse after development with isopropyl alcohol, 90 ° C in oven to completely evaporate the solvent
I went to work. As described above, since the process of the thick film resist 3 can be performed at a low temperature, the guide hole 4 can be formed without damaging the optical element 5 and the electric contact, etc., and here, SU8 was used as the thick film resist 3. However, the present invention is not limited to this.

Next, after the curable resin 19 is applied to the optical fiber guide hole 4, the plastic optical fiber 16 fixed to the fixing jig is inserted, so that the convex lens function of the end face of the optical fiber 16 is exhibited, and Optical coupling can be achieved.

[OO40] Next, FIG. 2 (A-A ′ in FIG. 4) which is a cross-sectional view of one element is shown.
A section between the surface emitting laser 5 and the POF 16 will be described using a cross section.

[O041] The details of the surface emitting laser 5 used in this embodiment will be described later. However, the structure in which the growth substrate is removed so that the process of the thick-film resist 3 is easy to perform and only the functional layer is transferred to make it thinner. And The functional layer is a one-wavelength resonator 23 including an active layer.
Is sandwiched between a p-DBR mirror 22 and an n-DBR mirror 24 made of an AlGaAs multilayer film, and has a thickness of about 7 μm.
15 air post 28 for current constriction on p-DBR mirror 22 side
It was processed into a circular shape having a diameter of μmφ, and the periphery was buried with polyimide 27 and flattened. In the vicinity of the active layer, the Al mole fraction is 0.95.
Only the above AlGaAs layer is selectively steam-oxidized in the lateral direction.
An Al _x O _y layer 29 is formed, the aperture size of the current injection region is set to about 3 μmφ, and the oscillation threshold is set to 1 mA or less.

The common electrode 20 is formed on the p-DBR mirror 22 side, and the substrate 1
AuSn solder or the like is adhered on the surface electrode pads 2. The bonding may be performed by bonding between Au. The n-side electrode 25 is formed on the surface of the surface of the n-DBR mirror 24 which is obtained by removing the GaAs substrate (not shown) so that current can be independently injected into each element. An insulating film 26 is formed on this surface,
31 and a contact hole 32 are formed so as to make contact with the wiring 9 formed on the surface of the substrate 1.
In addition, since the wiring 9 is stepped via the side wall of the surface emitting laser 5, the insulating film 26 must cover the side wall of the laser 5 and the p-side common electrode pad 2. For forming such an insulating film, for example, a photosensitive polyimide such as PIMEL manufactured by Asahi Kasei is preferably used, and the thickness is 1 μm.

As shown in FIG. 2, the plastic optical fiber 16 is fixed at a position (a wiring 9 in this example) where a flat area around the concave tip comes into contact with the element surface. Since the concave structure 18 is formed at the center of the optical fiber 16, the end face of the optical fiber does not directly hit the crystal surface of the surface emitting laser,
There is no damage to this.

[O044] On the other hand, the heat generated by the surface emitting laser is
The heat is radiated to the mounting board 1 through the pad 2. So
Therefore, the material of the mounting substrate 1 is AlN or Al
_TwoO_ThreeSi having an insulating thin film formed thereon is preferably used.

Next, with reference to FIG. 3, a description will be given of a manufacturing process of the thin film type surface emitting laser used in this embodiment. Here, for the sake of simplicity, an explanation will be given using an array of two elements.

[O046] In (a), an n-DBR mirror is placed on the n-GaAs substrate 30.
24.AlGa including active layer consisting of 3 quantum wells of GaAs / AlGaAs
The one-wavelength resonator layer 23 made of As, the P-DBR mirror 22, and the p-GaAs contact layer (not shown) are crystal-grown by a metal organic chemical vapor deposition method or the like. The air post 28 is formed by reactive etching using Cl ₂ , and the above-described selective oxidation layer 29 is formed by oxidation with water vapor. After that, an insulating film is formed from the SiN _x film 21 and flattened with the polyimide 27 to form the common electrode 20. As the common electrode 20, for example, Ti / Au can be used.

In (b), the device on the wafer prepared in (a) is cut to an appropriate size after polishing the substrate 30 to about 100 μm, and is placed on the electrode pad 2 formed on the mounting substrate 1. Au
-By Au crimping (may be assisted by ultrasonic) or A
Bond with uSn solder. At this time, electrode pad 2 is Ti / P
It consists of t / Au, and the outermost surface is Au.

[0048] In (c), the GaAs substrate 30 is etched using a mixed solution of H ₂ O ₂ and NH ₃ , and the first layer of the n-DBR mirror 24, Al, is formed.
Etching stops at As. After that, an independent electrode 25 is formed on the n-GaAs layer that has appeared after AlAs has been removed with HCl. For the independent electrode 25, for example, AuGe / Ni / Au can be used. Thereafter, annealing is performed at about 380 ° C. for contact.

In (d), the whole is coated with the polyimide 26 while forming the hole 32 for the electrode contact and the light extraction window 31 with the photosensitive polyimide. If the wiring 9 is formed by a lift-off method using Ti / Au or the like,
A thin-film surface emitting laser is mounted on the mounting substrate 1 as shown in the plan view of FIG.
5 is formed.

In the above, the manufacturing process for one chip has been described. However, a wafer-level process is actually required to improve productivity. FIG. 5 illustrates this state. From a GaAs wafer 50 on which a surface emitting laser is manufactured, a laser chip 51 of a required size (1 in the above embodiment).
(× 4 array) is cut out and bonded to a Si wafer 52 having a plurality of Al ₂ O ₃ films and electrode pads 2 formed in necessary areas 54 on the surface. At this time, the wafer 52 is
The sequential bonding is performed while aligning the required position 54 above. The laser thinning process, the wiring process, and the formation of the fiber guide hole 4 using the thick film resist 3 are collectively performed by photolithography and etching in this state.

[O051] Next, the laser driving Si-ICs 53 are sequentially bonded by flip chip honda. Finally, by dicing the chips one by one as indicated by a broken line 55, a plurality of chips can be formed at once.

[O052] In the examples up to this point, an example has been described in which the number of arrays of the surface emitting lasers 5 and the optical fibers 16 is four, but the number is of course not limited. The number may be four or more, or only one surface emitting laser and one optical fiber may be used. Further, the present invention can be applied to a surface light receiving element.

[O053] As the optical package, any of a type in which only a surface emitting laser is integrated on the transmitting side, a type in which only a surface-type light receiving element is integrated on the receiving side, or an optical package having both transmitting and receiving elements May be. Sending device,
When receiving devices are separated, one-way transmission is performed. On the other hand, when transmitting and receiving devices are housed in one module, two-way transmission is possible.

(Second Embodiment) The second embodiment of the present invention is directed to an example in which a normal surface emitting laser manufactured on a GaAs substrate is used instead of a thin film type surface emitting laser from which a GaAs substrate is removed. Get involved.
Cross-sectional structure of surface emitting laser
It is almost the same as that shown in FIG. 3 (a), except that the structure of the p-side electrode is that a window for extracting light is provided, and that the electrode is separated between elements.

FIG. 8 is a perspective view of this embodiment. Surface emitting laser 8
Increased cutout size of 4, laser 84 and IC1
The configuration is almost the same as that of FIG. 1 except that the second wiring 81 is performed by wire bonding, and the description of the same portions is omitted.

On the surface of the surface emitting laser 84 fabricated on the GaAs substrate, a p-electrode / electrical wiring and Ti / Au 82 serving as an electrode pad are formed on an insulating film. A light extraction window is formed at a position corresponding to the light emitting point 83 of the p electrode. I c
Electrode pad 80 on mounting board 1 electrically connected to 12
A wire bonding 81 is provided between the P electrode 82 and the P electrode 82. This wiring may use a flexible wiring board or the like.

[O057] Thick film resist 3 constituting fiber guide hole 4
Is formed on a surface of a GaAs substrate after a surface emitting laser and a p-electrode are formed on a GaAs substrate and then cut out into chips. Therefore, there is no process such as photolithography after the chip of the surface emitting laser 84 is mounted on the mounting substrate 1, but only surface mounting by batch reflow (heating of solder) and wiring by wire bonding.

In this embodiment, since the size of the chip cut out from the GaAs wafer is larger than in the first embodiment, the number of lasers obtained from the laser wafer, that is, the yield, is reduced, and the cost of the mounting body is increased. In addition, since driving is performed as a common cathode, the driving speed is inferior to that of the common anode type as in the first embodiment.

However, the structure according to the present embodiment is suitable for transmission of about 622 Mbps with a small number of arrays, because the number of process steps is reduced and the manufacturing cost can be reduced and the yield can be improved.

[OO60] (Third Embodiment) FIG. 6 shows a third embodiment according to the present invention.
Shown in The third embodiment of the present invention is an example in which a plastic optical fiber end face is processed into a convex shape. The plastic optical fiber 64 is a polymetal methacrylate-based optical fiber, and its end face is shaped as a convex tip 65 by heating and pressing against a concave mold. By providing a step in the optical fiber guide hole 4, the central convex portion of the optical fiber 64 is designed so as not to contact the optical element. Further, an ultraviolet-curing adhesive is used as the curable resin, the periphery is hardened, and the convex lens portion is filled with air (or an inert gas such as nitrogen) or an adhesive. When filled with an adhesive, a material having a lower refractive index than that of a plastic optical fiber is used.

[OO61] A red light emitting diode having an oscillation wavelength of 650 nm fabricated on a GaAs substrate 30 is used as a light emitting element. Referring to FIG. 9 having a similar structure (however, a surface emitting laser 84 is used in FIG. 9), and the description here is borrowed, the light emitting diode 84 fabricated on a GaAs substrate has a surface. T serving as p-electrode / electrical wiring and electrode pad on insulating film
i / Au82 is formed. A light extraction window 83 is formed at a position corresponding to the light emitting point of the p electrode. Electrode pad 80 and p-electrode on mounting substrate 1 electrically connected to IC
Wires 82 are wired by wire bonding 81. This wiring may use a flexible wiring board or the like.

[OO62] Photosensitive resin 3 constituting optical fiber guide hole 4
Is formed on the surface of a GaAs substrate after forming a light emitting diode and a p-electrode on the GaAs substrate and then cutting out the chip. Therefore, there is no process such as photolithography after mounting the light emitting diode chip 84 on the mounting substrate 1, but only surface mounting by batch reflow and wiring by wire bonding.

In this embodiment, the driving speed of the light emitting diode is lower than that of the surface emitting laser. However, in the structure of this embodiment, the number of process steps is reduced, so that the manufacturing cost can be reduced and the yield can be improved.
It is suitable for transmission with a small number of arrays and about 100 to 200 Mbps.

(Fourth Embodiment) In a fourth embodiment of the present invention, a resin is formed in a two-stage structure, and the distance between the emission surface of the surface emitting laser and the end face of the optical fiber is defined. This will be described with reference to FIG.

[OO65] 150μmφ hole smaller than core diameter of optical fiber 16
The first layer of the photosensitive resin 60 having a thickness of 100 μm is formed,
The core wire including the cladding 74 of the optical fiber 16 can be inserted
An optical fiber guide hole 63 of 300 μmφ is formed of a photosensitive resin 61 of a second layer with a thickness of 200 μm. This can be configured by repeating the same resin patterning step as in the first embodiment twice.

Here, the plastic optical fiber 16 has a core 73 and a clad 74 made of a perfluorinated polymer. After removing a protective layer (not shown) made of acrylic, the core 73 and the clad 74 are put together. Then, it is heated and pressed against a convex surface made of a minute metal hemisphere to form a concave front end portion 75. The curable resin 76 is made of a material having a higher refractive index than that of the perfluorinated polymer.
After being dropped onto the concave front end portion 75, the optical fiber is inserted into the optical fiber guide hole 63, and the space around the plastic optical fiber 16 is completely filled with the curable resin 76.

[OO67] The optical fiber guide hole structure of the two-stage structure allows the photosensitive resin layer 60 to surround the concave end portion 75 of the optical fiber.
Even when the light-emitting or light-receiving element is mounted such that the light-emitting or light-receiving element is mounted, the light-emitting or light-receiving element is not damaged. Further, the curable resin 76 inserted into the concave portion 75 at the tip of the optical fiber becomes a convex lens, and the light coupling or the light emitting or light receiving element immediately below is efficiently performed. In this method, the thickness of the first resin layer 60 can be controlled according to the focal length of the convex lens.

(Fifth Embodiment) FIG. 8 is a plan view of a pattern of a thick-film resist 70 according to a fifth embodiment of the present invention. A groove 71 is formed in addition to the guide hole 72 for mounting the fiber.

The formation of the groove 71 has the effect of shortening the development time of the thick film resist 70, the effect of alleviating the stress with the base, and the function of releasing the fixing adhesive. Further, there is an advantage that the fiber is easily fitted when inserted into the guide hole 72.

In the case of the method of forming the fiber guide hole using a thick film resist, the pattern shape can be freely designed by changing the pattern of the photomask as described above. For example, those with different fiber diameters (1 mmφ, 500 μmφ, 250 μm
) can be integrated.

(Sixth Embodiment) The sixth embodiment according to the present invention relates to a high-speed optical wiring device formed by modularizing the optical package described above.

FIG. 10 shows an optical interconnection module using a mounting body in which a surface-emitting laser or a surface-type light receiving element and a fiber are fixed by a guide hole made of a thick film resist as in the above-described embodiment. In FIG. 10 (a), 94 is 4
95 is a POF (here, the end face is drawn flat but has a concave or convex surface as in the above embodiment), 96 is a POF fixing jig, 93 is a POF
Is to cover the whole and increase the fixing strength of POF95. Further, reference numeral 92 denotes the mounting substrate 1 shown in FIG. 1, in which peripheral circuits are formed at the same time and chip resistors and capacitors are integrated. Reference numeral 90 denotes a pedestal for fixing the connection leads 91, which is bonded to the back surface of the mounting board 92 to connect the electrode pads of the mounting board 92 to the tops of the leads 91 by wire bonding. The fixation between the fiber 95 and the mounting board 92 is performed last after performing wire bonding. The connection between the connection lead 91 and the mounting board 92 may be performed by flip-chip mounting by forming a through hole in the mounting board 92.

[O073] On the other hand, FIGS. 10 (b) and 10 (c) show how the connector module and the circuit board 97 are mounted. In (b),
On the board 97, a socket 98 is fixed with a lead 102 and solder 10, and a contact is obtained with a connection lead 91 of the connector module and a leaf spring 99 of the socket 98,
Detachable. In (c), the connection leads 91 are directly soldered to the circuit board 97 (103).

[O074] By adopting such a configuration, it is possible to provide an optical wiring device in the case where high-speed signals are transmitted between boards. This is effective when the frequency exceeds 1 Gbps per channel or when electromagnetic radiation noise becomes a problem.

[075] In FIG. 10 (c), it is fixed to the circuit board 97, but the mounting board 92 and the fiber fixing jig 93 are not adhered, but can be detached at the guide hole of the thick film resist 100. Is also good. In this case, a removable mechanical mechanism may be formed by providing a nail or the like on the outer frame of the fiber fixing jig 93.
In addition, 101 is a cover.

(Seventh Embodiment) A seventh embodiment according to the present invention is a
Instead of directly mounting the optical transmitting and receiving module integrated with the optical mounting body on the motherboard as in the sixth embodiment, FIG.
As shown in (1), it is housed in an electric connector 110 so that it can be connected to and detached from an interface section of an electronic device such as a PC, a monitor, a printer, a digital camera, a digital video camera, etc. via an electric connection lead 111. The electrical connector 110 can be manufactured according to the required device standard. For example, a 26-pin MD according to the digital monitor interface standard for connecting a PC to an LCD monitor
It is also possible to use an R connector or conform to IEEE1394 or USB standards. Further, the present invention can be applied to an internal connection between a scanner unit and a photosensitive unit of a digital copier. By using the optical wiring device of the present invention for connection between these electronic devices, signal transmission of 4 to 5 channels at 1 Gbps to 2.5 Gbps per channel can be made 50 m or more. Thus,
Electric cables can be used in place of the limited high-speed video transmission. In addition, since the optical connection is used, there is no electromagnetic radiation noise generated from the transmission line, and it is possible to reduce noise measures particularly in high-speed digital transmission.

[0077]

According to the present invention, the following effects are expected. The alignment accuracy between the optical fiber and the optical element can be improved, the work of fixing the optical fiber can be facilitated, and the productivity can be improved. Further, by making the surface-type optical element thinner, it is possible to improve the ease of mounting and the degree of freedom of design when optical coupling with an optical fiber is performed without a separate lens.

[OO78] Further, optical mounting with a light-emitting or light-receiving element can be easily performed in a state where a tip lens is processed in order to increase the optical coupling efficiency of the plastic optical fiber. At this time, depending on the magnitude relationship of the refractive index between the optical fiber material and the curable or non-curable resin for filling / adhesion, the concave or convex surface at the tip can result in a convex lens effect.

[OO79] Furthermore, we reduce insertion loss with connection,
As a result, an optical interconnection module with low power consumption can be provided.

[O080] Furthermore, by providing a manufacturing method capable of mass-producing such a structure for highly efficient mounting, an optical package or an optical interconnection module capable of reducing costs and an optical module using the same. A wiring device can be realized.
Therefore, in the signal connection between boards in electronic equipment handling high-speed digital signals or between electronic equipment, it is possible to transmit signals of about 2.5 Gbps in a limited area of electrical connection, that is, about 50 Gbps or more, and large capacity video transmission Can be easily performed without any special measures against electromagnetic noise.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a surface-type optical element package according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the surface-type optical element mounted body in the first embodiment according to the present invention.

FIG. 3 is a cross-sectional view illustrating a method for manufacturing a surface optical device according to the present invention.

FIG. 4 is a plan view illustrating wiring of a surface-type optical element mounted body according to the present invention.

FIG. 5 is a perspective view illustrating a method for manufacturing a surface-type optical element mounted body according to the present invention.

FIG. 6 is a sectional view of a surface-type optical element mounted body according to a third embodiment of the present invention.

FIG. 7 is a sectional view of a surface-type optical element mounted body according to a fourth embodiment of the present invention.

FIG. 8 is a plan view of a guide hole shape according to a fourth embodiment of the present invention.

FIG. 9 is a perspective view illustrating a surface-type optical element package according to a second embodiment of the present invention.

FIG. 10 is a diagram illustrating an optical connection module according to the present invention.

FIG. 11 is a perspective view showing an optical wiring device according to the present invention.

FIG. 12 is a cross-sectional view illustrating the coupling between a first conventional planar optical device and an optical fiber.

FIG. 13 is a cross-sectional view illustrating the coupling between a second conventional planar optical device and an optical fiber.

FIG. 14 is a diagram illustrating a coupling between a third conventional planar optical device and an optical fiber.

[Explanation of symbols]

 1 ... Mounting board 2,80 ... Electrode pad 3,60,61,70,100 ... Thick film resist 4,63,72,1209 ... Fiber guide hole 5,84 ... Surface type optical element 6,31,62,83 ... Light transmission Window 8… Element separation groove 9,10,13… Electrical wiring 12,53… Si-IC 14,15,2014… Fiber fixing jig 16,64,95,1037,1210,2016… Optical fiber 17,1211… Adhesion Agents 18,75… Concave tip 19,76… Curable resin 20,25,1033,1035… Electrode 21,26,1208… Insulating film 22,24,1023,1027… DBR mirror 23… Active layer and resonator layer 27… Embedded layer 28… Air post 29… Selective oxidation Al_TwoO_ThreeLayer 30,1021… Substrate 32… Contact hole 50… Laser wafer 51… Laser chip 52… Mounting wafer 54… Mounting area 55… Dicing line for dicing 65… Convex tip 71… Groove 73… Core 74… Clad 90… Connection lead Mounting pedestals 91,111 Connection leads 92 Optical mounting bodies 93,96 Fiber fixing jig 94 Fiber array 97 Circuit board 98 Socket 99 Plate spring 101 Cover 102 Connection pins 103 Solder 110 Electrical connector 1022 … Light absorption layer 1024,1026… cladding layer 1025… active layer 1028… contact layer 1032… Si0_Two  1036… Anti-reflection film 1201… Electronic circuit board 1202… Light emitting chip 1203,2018… Surface emitting laser 1204… Transistor 1205,1206,1207… Transistor electrode 2012… Module substrate 2022,2023… Protrusion 2024… Fiber insertion hole 2026,2027… Guide hole

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Toshihiko Ouchi 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2H037 AA01 BA05 BA14 CA08 DA04 DA06 4M109 AA01 BA03 DA06 GA01 5F041 AA02 CA36 CA46 DA01 DA07 EE02 FF14 5F073 AA74 AB14 AB17 AB28 BA01 CA04 CB02 DA05 DA21 DA24 DA27 EA14 EA29 FA07 FA11

Claims (33)

[Claims] Claims: 1. A surface-type optical element capable of emitting or receiving light, for inserting and fixing an optical fiber including a lens-shaped polymer so that optical coupling with the surface-type optical element is possible. The guide hole is formed on the surface of the surface type optical element by a thick film material which has photosensitivity or electron beam curability and can be selectively cured by patterning by photolithography. Surface type optical element. 2. The planar optical device according to claim 1, wherein the thick film material is a thick film resist that can be polymerized. 3. The surface-type optical device according to claim 1, wherein the thickness of the thick film material or the thick film resist is 10 μm to 1000 μm. 4. The thick film material or the thick film resist has a first layer having a hole smaller than the size of the optical fiber and capable of transmitting only light, and is formed on the first layer to fix the optical fiber. Consisting of a second layer with guide holes for
4. The surface optical device according to claim 1, wherein the thickness of the first layer defines a distance between the surface optical device and an end face of the optical fiber. 5. The surface light according to claim 1, wherein the guide hole formed of the thick film material or the thick film resist forms only a portion corresponding to the outer shape of the optical fiber. element. 6. The guide hole formed of the thick film material or the thick film resist has a portion corresponding to the outer shape of the optical fiber and a groove pattern different from the outer shape. The planar optical device according to any one of the above. 7. The surface type optical element according to claim 6, wherein a portion of the guide hole corresponding to the outer shape of the optical fiber and a groove pattern are formed continuously. 8. The surface-type optical element according to claim 1, wherein a plurality of said surface-type optical elements are arrayed, and correspondingly, guide holes are also arrayed and formed. 9. The surface type optical device according to claim 8, wherein the plurality of surface type optical devices are only a surface type light emitting device, only a surface type light receiving device, or a combination of a surface type light emitting device and a surface type light receiving device. 10. The surface optical device according to claim 1, wherein the surface optical device is a vertical cavity surface emitting laser or a light emitting diode. 11. The surface emitting laser according to claim 1, wherein the active layer, the resonator layer,
11. The surface-type optical element according to claim 10, wherein a functional layer including only a Bragg reflection mirror layer is left. 12. The surface optical device according to claim 1, wherein the surface optical device has a thin film type by removing or thinning a growth substrate. 13. The surface optical device according to claim 1, wherein the growth substrate is left as it is. 14. The optical fiber according to claim 1, wherein a tip of the optical fiber is processed into a concave lens shape, and the concave portion is filled with a resin.
14. The surface-type optical device according to any one of items 13 to 13. 15. The surface type optical element according to claim 14, wherein the resin is a resin having a higher refractive index than the optical fiber. 16. The surface optical device according to claim 1, wherein a resin is filled in a gap between a tip of the optical fiber and the surface optical device. 17. The surface-type optical device according to claim 1, wherein the surface-type optical device is mounted on a mounting board with electrical connection so as to be drivable, and an optical fiber is inserted into the guide hole. A surface-type optical element mounted body fixed. 18. The surface-type optical element mounting body according to claim 17, wherein the mounting substrate is a mounting substrate on which another optical element or electronic element can be integrated in a hybrid manner and has a heat sink function. 19. The surface optical device package according to claim 17, wherein a plurality of the surface optical devices are arrayed, and the optical fibers are also arrayed simultaneously. 20. The surface-type optical element package according to claim 17, 18 or 19, wherein a resin is filled in a gap between a tip of the optical fiber and the surface-type optical element. 21. The surface optical element package according to claim 20, wherein the resin is a curable resin. 22. The surface-type optical element package according to claim 21, wherein the curable resin is an optical adhesive or a transparent resin. 23. The surface-type optical element mounting body according to claim 20, wherein the tip of the optical fiber is processed into a concave lens shape, and the resin is a resin having a higher refractive index than the optical fiber. 24. The surface-type optical element mounting body according to claim 20, wherein the tip of the optical fiber is processed into a convex lens shape, and the resin is a resin having a lower refractive index than the optical fiber. 25. A gap between the tip of the optical fiber and the planar optical element is filled with air or nitrogen gas.
20. The surface-type optical element package according to 7, 18 or 19. 26. The surface-type optical element package according to claim 25, wherein a tip of the optical fiber is processed into a convex lens shape. 27. The surface mold according to claim 17, wherein the tip of the optical fiber is processed by pressing the tip of the optical fiber against a heated mold having a concave lens shape or a convex lens shape. Optical element mounting body. 28. The surface light according to claim 17, wherein the tip of the optical fiber is processed by immersing the tip of the optical fiber in an organic solvent, lifting the fiber, and drying it. Element mounting body. 29. The surface-type optical element package according to claim 17, wherein the optical fiber comprises an optical fiber containing a perfluorinated polymer. 30. The surface-type optical element package according to claim 17, wherein the optical fiber is constituted by an optical fiber containing polymethyl methacrylate. 31. A method for manufacturing a surface-type optical element mounted body according to claim 17, wherein a step of forming a wiring pattern on a wafer-like mounting substrate includes the step of sequentially using at least one surface-type optical element. , The process of mounting on multiple locations on the mounting board,
Forming a guide hole with a thick film material on each surface type optical element,
After sequentially flip-chip mounting devices such as necessary electronic devices at necessary positions, cutting out a plurality of mounting bodies of a required size, and finally inserting a lens-shaped optical fiber into a guide hole and fixing the same. A method for manufacturing a surface-type optical element mounted body, comprising: 32. An optical wiring device mounted on a board in an electronic device via a connection lead and transmitting and receiving signals between the boards by light, according to claim 17, wherein Electronic circuits for driving surface-type optical elements are also integrated in the package,
An optical wiring device, wherein the optical element mounting body is mounted on a pedestal for fixing a connection lead for obtaining electrical contact, thereby forming an optical connection module. 33. The surface-type optical element mounting body according to claim 17, mounted on an electronic circuit for driving a surface-type optical element, housed in an electric connector, and mounted on the electronic circuit for driving. An optical wiring device, wherein an electrical connection is made by a connection pin for a detachable connector, and a signal between electronic devices is transmitted and received by light.