JP2003270497A - Optical communication component and method for manufacturing stack type optical communication module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical communication component (lens for optical communication, optical bench) which is compact and can be combined with a stack type optical communication component and a method for manufacturing the compact stack type optical communication module having a three- dimensional optical path inside. <P>SOLUTION: The stack type optical communication module is manufactured by forming a cavity whose at least one end communicates with an external optical path inside substrates by stacking at least 1st and 2nd substrates in contact, expelling water from the cavity after charging plating liquid in the cavity, and filling the cavity with ultraviolet-ray setting resin and setting the resin. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical communication component used for optical communication and a method for manufacturing a laminated optical communication module.

[0002]

2. Description of the Related Art Conventionally, an optical waveguide, an LED (light emitting diode), and an L are used to realize large-capacity optical communication and optical coupling.
When optically coupling a light-emitting element such as D (laser diode) or a light-receiving element such as PD (photodiode), a light-collecting system such as a microlens is used to guide light to an optical fiber that is an optical waveguide. The lens and the incident end of the optical fiber are connected by an adhesive such as an ultraviolet curable resin (Japanese Patent Laid-Open No. 61-93419).

On the other hand, there is also a method of coupling an optical waveguide and a light emitting element or a light receiving element without using an optical system such as a lens. In the method of directly coupling the semiconductor laser and the optical fiber, the tip of the optical fiber is cut so that the center of the core of the optical fiber coincides with the center of the light emitting point of the semiconductor laser chip,
The outer shell ferrule is L to enable chip bonding.
A notch is formed in the shape of a letter, and a semiconductor laser chip is aligned with the notch so that the optical fiber and the semiconductor laser are brought into close contact with each other (Japanese Patent Laid-Open No. 63-253315). In the method of directly optically coupling the semiconductor laser chip and the optical waveguide, the active layer end face of the semiconductor laser and the optical waveguide end face are brought into contact with each other with a gap provided in the active layer end face or the optical waveguide end face interposed therebetween. , The light from the semiconductor laser chip is directly optically coupled to the optical waveguide while protecting the end surface of the active layer and the end surface of the optical waveguide (JP-A-3-3991).
3 gazette).

In any of the conventional optical coupling methods as described above, an optical distance is generated between the light emitting surface of the light emitting element and the optical waveguide in any of the methods. Since an optical system is provided, it is difficult to allow light from the light emitting element to efficiently enter the optical waveguide, and it is difficult to make the device compact.

From this point of view, a method for compactly implementing many optical processing functions has been proposed. For example, as a means for realizing transmission and reception of light between two substrates with a relatively simple structure and realizing a compact integrated optical circuit, a five-layer waveguide structure in which a plurality of substrates are three-dimensionally arranged is used. The following optical coupling device is disclosed (JP-A-61-161).
148406).

However, JP-A-61-148406
Although an example of a three-dimensional optical circuit device is shown in Japanese Patent Publication No. 6-97285, a vertical optical path is arranged on a mother substrate having a vertically standing wall structure so that the circuit substrate is as if it were a building. The horizontal optical path is installed horizontally like the floor, and the vertical optical path and the horizontal optical path are connected by a method that utilizes the difference in the refractive index from the outside air. You need a length. Therefore, the optical path cannot be sharply bent. For this reason, the horizontal circuit boards must be spaced apart from each other by a predetermined distance, so that the horizontal circuit boards cannot be laminated and adhered to each other.

On the other hand, Japanese Patent Application Laid-Open No. 54-139847 discloses an example in which a reflective layer is provided on the inner surface of an optical waveguide. However, it is provided on the inner surface of a flexible tube for a laser processing machine, and the optical path is used. Is not shown to be bent at a right angle, nor is a three-dimensional circuit disclosed. Although FIG. 1 of the publication shows that the optical path of the conventional laser processing machine is composed of a space and a reflecting mirror, it does not constitute a waveguide inside the substrate.

Further, in Japanese Patent Laid-Open No. 2-73311,
It is disclosed that after forming a copper wire in a spiral shape and plating the surface with gold, the inner copper is removed with concentrated nitric acid to form a hollow waveguide made of gold. The light tube is formed in a spiral shape rather than being bent sharply. If this light tube system is used to make a sharp bend at a right angle, it becomes difficult to secure the optical path in the tube.

In Japanese Unexamined Patent Publication No. 10-170765, a reflection film is formed on a slope of a V groove by anisotropic etching of a silicon substrate, and an optical fiber is embedded in the V groove to secure an optical path, and mounting accuracy is improved. However, in this method, the optical fibers must be arranged in a straight line, and it is not possible to form a waveguide that bends freely in a horizontal plane.

Japanese Patent Laid-Open No. 2001-133645 discloses that
It is disclosed that the upper surface, the lower surface and the side surface of the waveguide substrate are all metallized in order to shield stray light from the waveguide substrate, but metallization of the waveguide itself and sharp bending of the optical path are not disclosed. .

By the way, with the spread of the Internet,
It has become necessary to send and receive large amounts of information such as music, moving images, and computer data at high speed. For data transmission / reception using optical fibers, the transfer rate is 100 Mbp for home use.
s or more, and data can be transmitted and received at a speed of about 3 digits faster than a modem or ISDN using a telephone line which is widely used in ordinary households. Furthermore, in the backbone system, 10-40 Gbps
Has reached. In addition, in recent years, a new technology called optical multiplex communication has been introduced to enable further speeding up and capacity increase. Under such circumstances, the demand for optical communication parts is increasing more and more, and the cost reduction and the reliability improvement are the issues for parts suppliers.

A module in which at least one glass optical communication component is mounted in a groove of an optical communication component carrier (Si optical bench (SiOB)) mainly composed of silicon (Si) is a core among optical communication related components. These parts are required to have the same level of reliability as core optical communication related parts.

Up to now, when assembling a module for mounting an optical communication component, the optical communication component is mounted in the groove of SiOB and both are fixed with a plastic such as an ultraviolet curable resin. However, this method did not cause any serious problem under normal temperature and normal humidity, but there was a problem that the optical communication component floated up from the SiOB or detached from the SiOB in some cases when exposed to a high temperature and high humidity environment for a long time.

[0014]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and is an optical communication component (optical communication lens, optical component) that can be combined with a compact laminated optical communication component. Bench) and light transmitted through an optical waveguide such as an optical fiber can be efficiently incident on the optical waveguide inside the device, and this light can be transmitted to a light receiving element such as a PD. An object of the present invention is to provide a manufacturing method of a compact laminated optical communication module having a built-in three-dimensional optical path in which optical functional elements required for communication are highly integrated.

[0015]

In order to solve the above problems, the inventors of the present invention have made earnest studies, and as a result, when an electric signal is sent from a semiconductor laser to a transmission line such as a coaxial cable, the receiver receives it. The maximum transmission distance that can be achieved is a few km, but with the method of transmitting in an optical fiber and returning to an electrical signal with a photodetector, the loss of the optical fiber is small, so 100 km or more can be transmitted without a repeater. Then, the light transmitted through the optical fiber is incident on the optical waveguide provided in the substrate by using a lens or the like, and the incident light is efficiently transmitted to the light receiving element through the three-dimensionally arranged waveguide, The inventors have found that the degree of integration can be dramatically improved as compared with the case where light-emitting elements are integrated, and that the device can be made compact, and have completed the present invention.

That is, according to the present invention, in a lens for optical communication composed of first and second lens surfaces and a side surface peripheral portion, a metal film is formed only on the side surface peripheral portion. A communication lens is provided. This allows the lens to be soldered

The optical communication lens of the present invention is characterized in that a pair of lens convex surfaces is formed on both surfaces of the transparent plate. This optical communication lens is characterized in that a plurality of pairs of the lens convex surfaces are provided, and a metal film is formed on the peripheral edge portion of the plate other than the lens convex surfaces. The plate is preferably made of silicon. By forming a pair of lens surfaces on both sides, optical axis alignment becomes easy, and because a metal film is formed, soldering is possible. In particular, by using silicon with a high refractive index, the curvature of the lens can be reduced,
The aberration can be reduced and the spot size can be reduced.

Further, according to the present invention, a V groove for mounting a fiber is provided on a substrate, and a fine groove (bonding groove) intersecting with the V groove is formed on at least a part of the surface of the V groove portion. The present invention provides an optical bench characterized by the above. With this configuration, it is possible to bond by utilizing the capillary phenomenon, so that it is possible to prevent the fiber from floating and prevent the optical axis of the fiber from shifting.

Another optical bench of the present invention is characterized in that a V groove is formed on a substrate, and a metal film is formed on the surface of the V groove portion. This allows
Optical communication parts such as lenses and fibers can be soldered

The optical communication component of the present invention is characterized in that the optical waveguide end face is coated with carbon or fluorinated carbon.

Further, according to the present invention, a cavity having at least one end communicating with an external optical path is formed inside the substrate by laminating at least the first substrate and the second substrate, and the cavity is filled with a plating solution. Disclosed is a method for manufacturing a laminated optical communication module, which comprises removing moisture from a rear cavity, filling the cavity with an ultraviolet curable resin, and curing the resin by ultraviolet rays. Water may be removed by injecting an ultraviolet curable resin from one end of the cavity and pushing out water from the other end of the cavity. According to this method, the cavity having a complicated shape formed inside the substrate of the laminated optical communication module can be easily plated, and the transparent medium can be filled.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

A laminated optical communication module having a three-dimensional optical path according to the present invention has a structure in which at least a first substrate and a second substrate are directly adhered and laminated, and the first substrate is
A horizontal waveguide inside, a light bending portion provided at an end of the horizontal waveguide and having a reflecting mirror for bending the light path substantially vertically, and a first vertical portion following the light bending portion and continuing to the surface in the thickness direction. A waveguide and a cavity are formed, and the second substrate is stacked on the first substrate and faces the exposed portion of the first vertical waveguide to the substrate surface. In, a second vertical waveguide portion continuing from the surface to the inside in the thickness direction is formed by a cavity, and inside the laminated body composed of the first substrate and the second substrate, the first vertical waveguide portion is formed. A vertical optical path is formed by a cavity penetrating in the thickness direction from the inside of the substrate to the inside of the second substrate.

The laminated optical communication module of the present invention has a structure in which the first substrate and the second substrate are directly adhered and laminated, and the first substrate and the horizontal waveguide A light bending portion and a first vertical waveguide portion located at the end thereof are formed, and a second substrate is provided with a first vertical waveguide portion at a position facing a portion exposed to the substrate surface. Two vertical waveguide portions are formed. The laminated optical communication module may be composed of a first substrate and a second substrate, and has at least one other substrate outside the first substrate or the second substrate. May be Therefore, when the laminated optical communication module is composed of a laminated body of three or more substrates, one of the adjacent substrates may satisfy the above requirements.

FIGS. 1 and 9 show a substrate (or an optical bench) (1) provided with a fiber and a coupling lens and having a V-groove for mounting the fiber and the coupling lens.
1, 110), a first-stage substrate (21, 210) on which a diffraction grating and a horizontal waveguide for demultiplexing the optical signal from the coupling lens are formed, and the first-stage substrate A horizontal waveguide (32) for guiding the transmitted light, a light bent portion (34) having a reflecting mirror (33), and a vertical waveguide portion (3).
5) and the second-stage substrate (31, 310) formed with
(That is, a “first substrate”) and a vertical waveguide portion (42) for guiding the light transmitted from the first substrate, and the third stage stacked on the first substrate. Substrate (41,
410) (i.e., "second substrate"). The waveguide and the V-groove (and the diffraction grating) may be formed on the first-stage substrate, or the optical bench may be formed as a separate body and the V-groove may be formed on the optical bench, and then the waveguide is formed. Alternatively, it may be mounted on the first stage substrate.

In the present invention, at least one substrate selected from the group consisting of a silicon substrate, a plastic substrate and a glass substrate can be used as the substrate. These substrates may be used by mixing different types of substrates as long as the objects and effects of the present invention are not impaired, and the location of use is arbitrary, but the stability against heat cycle and the adhesion between the substrates may be improved. From the viewpoint, it is desirable to use the same type of substrate.

In FIGS. 1 and 9, the substrates (11, 1)
10), a V groove (not shown) and four bonding grooves (13) intersecting with the V groove are formed, and the fiber (14) and the coupling lens (15) are arranged in the V groove. ing.
Another substrate (31, 310) on the substrate (21, 210)
Is arranged, and another substrate (41, 410) is laminated on it. A wiring pattern (52) is formed on the surface of the substrate (41, 410), and in FIG.
(52) and LSI (53) are arranged at predetermined positions, and in FIG. 9, LD (54) and LSI (53) are arranged at predetermined positions. A metal plate (101) is arranged on the outer surface of the substrate (11, 110). A silicon substrate was used in the example of FIG. 1 and a plastic substrate was used in the example of FIG.

2 and 10 are schematic sectional views of the laminated optical communication module shown in FIGS. 1 and 9, respectively.

In FIG. 2, the transmitted light incident on the module is the horizontal waveguide (32) formed on the substrate (31).
Reflected by the taper portion (34) at the end of the waveguide via the optical waveguide and formed substantially perpendicular to the vertical waveguide portion (35) (“first vertical waveguide portion”) and the substrate (41). PD (5) via the waveguide (42) (“second vertical waveguide”)
Reach 1). A metal reflection film (33, 43) is formed on the wall surface of the waveguide to facilitate total reflection of light.

On the other hand, in FIG. 10, the light emitted from the LD (54) arranged on the surface of the substrate (410) has a waveguide (4) formed almost perpendicular to the substrate (410).
2) and via the vertical waveguide (35), the substrate (3
10) tapered portion (3) at the end of the horizontal waveguide
4) and is transmitted to the first-stage substrate (210) via the waveguide (32). A metal reflection film (33, 43) is formed on the wall surface of the waveguide to facilitate total reflection of light.

(First Stage Substrate) FIG. 3 is an external perspective view showing an example of a V groove and a bonding groove formed on the substrate (or optical bench). A plurality of bonding grooves (13) are formed on the substrate (11) so as to intersect the V grooves (12).
The V-groove is for fixing the fiber and the coupling lens. It suffices that at least one adhesive groove intersects with the V groove, and the adhesive groove is formed by using an adhesive or solder without interfering with the functions of the fiber and the coupling lens. It becomes possible to adhere and fix to the V groove. Conventionally, when fixing a fiber or a lens to the V groove, they are simply bonded with an ultraviolet curable resin (hereinafter abbreviated as “UV resin”) or the like, but the adhesive causes the fiber or lens to float from the V groove. There was a problem that it was fixed. However, the present invention does not have the above problem because the bonding is performed through the bonding groove that intersects the V groove. From the viewpoint of increasing the adhesive strength with respect to the V groove, the number of bonding grooves is usually 1 to 20. It is preferable to form 5 to 10 pieces.

As a method of forming the V groove, when a silicon substrate is used as the first substrate, for example, a method of patterning the silicon substrate and then performing wet etching can be mentioned. Wet etching is performed using potassium hydroxide (KOH), sodium hydroxide (NaOH), tetramethylammonium hydroxide (TMAH),
Hydrazine (EPW), HgCl ₂ , K ₂ Fe (CN)
_{6 and the} like. For example, a pit having an apex angle of about 70 ° can be formed by anisotropically etching the (100) plane of silicon with the above etching agent. When a glass substrate or a plastic substrate is used, for example, a method of forming a V groove having a desired angle by molding can be given.

Next, at least one bonding groove is formed so as to intersect the V groove. The width and depth of the groove may be appropriately determined as long as the adhesive penetrates. Examples of the method of forming the groove include a method of forming the groove by machining using dicing. Further, a flattening resist is applied to the V groove, dried, and then an inorganic film is further formed thereon by spin coating or the like (SOG: Spin On Glas
s), a photosensitive resist is further applied thereon, and patterning corresponding to the bonding groove is formed by lithography, and then SOG, the planarizing resist, silicon or glass is selectively etched using dry etching. , V
Adhesive grooves intersecting with the V-shaped grooves may be formed on the grooves as in the case of machining. Then, the resist, SOG, etc. are removed.

When a silicon substrate is used as the substrate (11), the V groove, the adhesive groove and the coupling lens fixing groove are formed as described above, and then the metal film is formed. Examples of the metal include Au, Ag, Ni, Cu and the like, and gold is preferable from the viewpoint of excellent corrosion resistance. The metal film is
The electroless plating film is preferable because it can uniformly plate every corner of the groove. By the above method, a substrate (or an optical bench) on which the fiber and the coupling lens can be fixed can be manufactured.

Next, the fiber and the coupling lens are fixed in the V groove by using a solder, an adhesive or the like. For example, molten solder or adhesive may be placed in the bonding groove, and the fiber and the coupling lens may be placed on the groove for fixing. As the adhesive, for example, an ultraviolet curable resin or the like can be mentioned, but from the viewpoint of more firmly fixing, it is desirable to bond and fix with solder.

(Optical Communication Component) The fiber or coupling lens fixed in the V groove is preferably metallized only on its side surface in order to solder and firmly adhere to the substrate. As the metallizing method, various known methods can be adopted, but it is preferable to apply the electroless plating method. The sides of the fiber and coupling lens
It is preferable to metallize before fixing in the V groove.

Here, as the fiber, any conventionally known fiber can be used as long as it is a fiber that transmits light. The optical fiber may be either a glass fiber or a plastic fiber, but a quartz glass fiber is preferable from the viewpoint of little loss of light.

The coupling lens may be any lens that can efficiently guide the light transmitted through the fiber into the module or can efficiently transmit the light transmitted through the module to the fiber, for example, glass. Made G
A RIN lens, a ball lens, a mold lens, a silicon micro lens, etc. can be used. Above all, it is preferable to use a silicon microlens array or a silicon microlens array provided with a plurality of pairs of lens convex surfaces. As these silicon microlenses (arrays), those integrally formed with the substrate on both sides of the substrate via the substrate are preferably used. The silicon microlens has a merit that it can be made compact because the focal spot diameter is small, the refractive index is high, and the focal length is short, and the aberration is small because the curvature is small. Moreover, it is easy to form a planar array, can be manufactured in a batch by dry etching, is easy to align the end faces, and is easy to align. Also, by plating the parts other than the lens part with gold (Au), spot solder welding becomes possible and AR
Since the film can be formed together with the substrate at the same time, the film can be easily attached, and by combining it with the silicon bench as used in the present invention, the expansion coefficient of the lens and the substrate can be made the same, so that the accuracy can be improved. Is further improved.

When the silicon microlens (array) is arranged on the substrate, the silicon microlens (array) is directly fixed to the substrate without forming the V-groove, for example, in the mode shown in FIGS. 18, 19 and 20. can do.
In this case, as shown in FIG. 18, first, the substrate is anisotropically etched to form a trapezoidal groove (16), and then a groove (fixing groove) (1) which is substantially perpendicular to the substrate is formed by dicing.
7) is formed. The trapezoidal groove can be formed by applying the above-described wet etching or the like. Then, as shown in the plan view of FIG. 19 and the sectional view of FIG. 20, the fiber (1) is inserted into the V-groove (12) (not visible in the figure).
4) is fixed, and fixing grooves (1) formed in the substrate (11).
The silicon microlens array (103) integrally formed on both surfaces of the substrate (102) is fixed to 7). By doing so, the microlens array can be easily fixed to the substrate, which facilitates alignment and end face alignment.

(Waveguide, Light Conversion Element) A waveguide and a diffraction grating as an example of a light conversion element are formed on the first-stage substrate. FIG. 4 and FIG. 11 are external perspective views of the first-stage substrate on which the waveguide and the diffraction grating are formed. 5 and 12 are partially enlarged views showing the waveguide and the diffraction grating. The diffraction grating (104) and the waveguide (26) are formed on the first stage substrate (21). Diffraction grating (104)
And the waveguide (26), from the viewpoint of increasing the transmission efficiency of light,
As shown in FIGS. 5 and 12, it may be formed integrally. As a method of integrally forming, for example, there is a method of applying a resist on a silicon substrate and then producing a predetermined diffraction grating pattern and a waveguide pattern by lithography. For example, if positive patterning is performed, the resist is removed from the exposed portion and silicon is exposed. Then, the silicon substrate is etched along the pattern by dry etching. The etching depth is appropriately selected.

After etching, a SiO ₂ film is formed on the silicon surface by the CVD method or thermal oxidation, and then a metal reflection film is formed by electroless plating or the like.

6 and 13 show the first-stage substrate (2
0, 210) is a sectional view taken along the line AA 'of the waveguide (26). The cross-sectional shape is not particularly limited. The waveguide is
Although it may remain hollow, it is preferable to fill the concave portion with a light-transmissive medium in order to prevent the light transmission efficiency from being lowered due to the influence of moisture in the atmosphere that enters the module.
Examples of the light transmissive medium include light transmissive resins such as acrylic resin, fluorinated polyimide resin, and fluorinated epoxy resin. Further, it may be a liquid such as a light-transmitting gel.

In the waveguide and the diffraction grating, it is desirable that a reflective film is formed on the peripheral wall surface before filling the light transmissive medium. 6 and 13 show an example in which a metal reflection film (27) is formed on the peripheral wall surface of the waveguide (26). By forming such a metal reflection film, the light is totally reflected in the waveguide, so that the light can be efficiently transmitted. As the reflective film, for example, Au, Ag, Ni, Cu
A metal film made of such a metal is used. As a method for forming the metal film, a vapor deposition method, a sputtering method, an electroless plating method and the like can be mentioned, but the electroless plating method is preferable from the viewpoint of being capable of uniformly plating the details.

Further, as shown in FIG. 7, a taper (29) is formed at the end of the waveguide (26) that guides light from the first stage substrate to the second stage substrate. FIG. 7 is an enlarged view of the terminal end portion of the waveguide (26) formed on the first-stage substrate (21). With this taper, the light transmitted through the waveguide of the first stage substrate can be efficiently launched and transmitted to the second stage substrate. From the first stage substrate to the second
Similarly, the waveguide for guiding light to the stepped substrate is also formed by etching after patterning by lithographic method. At the end of the waveguide, the light is lifted vertically with respect to the first-stage substrate, so an inclination is provided at 45 °. For example, this can be achieved by providing another member that is tapered at 45 ° at the end of the waveguide. In addition, if patterning is performed using a gray scale mask, the resist itself can be exposed and developed with a taper, and if dry etching is performed along this resist patterning, the waveguide and the tapered portion can be collectively formed by a single member. You can also

Further, the waveguide formed on the first-stage substrate has an optical bent portion as shown in FIGS. 4 and 11. Although a partially enlarged view of the bent waveguide is shown in FIG. 8, a taper (29) (that is, a “light bent portion”) is formed at a corner of 45 ° to facilitate light reflection. By bending the waveguide in this way, the planar area of the first-stage substrate can be reduced, and a more compact optical communication module can be realized.

(Second Stage Substrate) FIG. 14 is an external perspective view of the second stage substrate. Also on this substrate (31)
A waveguide (32) for optical wiring is formed. The waveguide formed on the second-stage substrate is for freely routing light in the second-stage substrate. Although FIG. 14 shows an example in which four waveguides are formed, basically the same number of waveguides as the number of waveguides formed on the first substrate may be formed. It is determined accordingly. Further, in the present embodiment, the duplexer is formed in the first stage,
It is desirable that the module itself is as small as possible. In the present embodiment, an element for converting the demultiplexed light into an electric signal, an LSI for controlling the electric circuit, etc. are on the same substrate as the optical demultiplexing circuit. Since it is not formed, the space of the entire optical communication module can be reduced.

FIG. 15 shows that the light from the first-stage substrate is emitted to the second stage.
FIG. 15 is an enlarged view of an incident portion (a portion indicated by P in FIG. 14) which is incident on the stepped substrate. As shown in FIG. 15, the light transmitted through the horizontal waveguide (26) formed on the first-stage substrate (“first substrate”) (21) is tapered (29).
The light that is reflected by and rises vertically is reflected by the vertical waveguide (2
8) (“First Vertical Waveguide”) to Vertical Waveguide (35)
In the plane of the second-stage substrate with the 45 ° taper (34) provided on the second-stage substrate (“second substrate”) (31) through (“the second vertical waveguide portion”). To the horizontal waveguide (32). The light guided in the second stage is reflected by the 45 ° taper portion (34) provided at the end of the horizontal waveguide (32) and guided to the third stage substrate.

FIG. 16 is a sectional view taken along the line BB 'of the waveguide formed on the second stage substrate, and FIG. 17 is a sectional view taken along the line CC' of the end portion of the second stage substrate. The cross-sectional shape of the waveguide formed on the second stage substrate is not particularly limited. The formed waveguide is similar to the waveguide formed on the first stage substrate,
It may be used in a hollow state or by filling the concave portion with the same light-transmissive medium as described above. Although the 45 ° taper portion is composed of a separate member in the present embodiment, it goes without saying that it may be composed of the same member.

(Third Stage Substrate) The third stage substrate is
A light receiving element such as a photodiode (PD) for converting an optical signal into an electric signal, or a light emitting diode (L
A light emitting element such as an ED) or a laser diode (LD) and an electronic component such as an LSI for control are mounted. Further, on the surface of the substrate, electric wiring is patterned by a conventionally known method, for example, a method using a lithographic method and a sputtering method (lift-off method). The electric wiring may be formed by plating. As shown in FIGS. 2 and 10, a through hole (42) is provided perpendicularly to the substrate in a portion for receiving the optical signal of the third stage, and it is vertically raised in the second stage. The light is efficiently guided to the light receiving element. The reflection film (43) is formed on the peripheral wall surface of the through hole in the same manner as the above-mentioned method.

Further, a fiber and a coupling lens as shown in FIG. 21 may be mounted on the third stage substrate.
By doing so, the optical communication module of the present invention can also be used as an optical-optical coupling element.

(1st stage, 2nd stage, 3rd stage joining)
The optical circuits (demultiplexers, waveguides, etc.) of each stage are manufactured in each substrate, and after the grooves, the diffraction grating, etc. to be the optical circuits are manufactured, the substrates of each stage are joined to form three stages. The substrates are joined, and the optical waveguide paths of the substrates can be connected three-dimensionally in space. When the substrates are joined, for example, the silicon substrates are combined together and the temperature is 1000 ° C. in a nitrogen atmosphere.
It can be joined by heat treatment in. this is,
This is because Si on the surface of the silicon substrate is chemically bonded on each surface, which is known as a so-called diffusion bonding method. The heat treatment is preferably performed at 900 to 1100 ° C. for 1 to 5 hours.

When the plastic substrates are joined, they can be joined by an ultrasonic welding method or by using an ultraviolet curable resin or the like. Similarly, in the case of joining glass substrates, they can be joined using an ultraviolet curable resin.

(Three-dimensional solid waveguide reflection film formation, medium filling) The formed substrates can be joined by the above-described method. However, from the viewpoint of suppressing light leakage as much as possible, it is effective to bond the substrates on which the waveguide, the diffraction grating, etc. are formed, and then integrally form the substrates to form the reflection film on the wall surface of the waveguide. That is, after bonding the silicon substrates, the bonded bonding substrates are immersed in various liquids for electroless plating or various liquids are forcibly injected to collectively form a metal reflection film on the waveguide wall surface and the diffraction grating wall surface. Can be formed with.

According to this method, a hollow total internal reflection type waveguide can be formed. However, if a resin having a light transmitting property is injected for each wavelength, a waveguide filled with a medium is formed. can do. For example, the cavity formed in the bonded substrate is filled with the plating solution, the water contained in the plating solution is expelled from the cavity, and then the cavity is filled with the medium. The medium may be a liquid, but the resin in the waveguide inside the substrate can also be cured by irradiating UV light from the waveguide entrance after injecting a photocurable resin such as acrylic. As a result, it is possible to prevent dust from entering, dew condensation, etc., and to manufacture a stable optical communication module.

In this embodiment, the substrate is stacked on the third stage, but it is of course applicable to an optical circuit having only one stage. It goes without saying that a configuration having four or more stages is also applicable.

After the above processing is performed, an electric wiring pattern is formed on the surface of the uppermost substrate, and electronic parts such as LSI are mounted.

(Joining of Metal Plate to Bottom Side of Lowermost Substrate) The optical demultiplexing circuit has been described above, but it can be used as a multiplexer by using a laser diode instead of a photodiode. it can. Although heat generation becomes a problem when a laser diode is mounted, in the present invention, a metal layer is laminated on the back surface of the lowermost silicon substrate so as to efficiently dissipate the heat from the silicon substrate (see FIGS. 1 and 9).
Examples of the metal forming the metal layer include Cu, Ni,
A material having good thermal conductivity such as Cr is desirable.

The silicon and the metal can be joined by the following method, for example. That is, an organic compound layer such as Teflon (registered trademark) is formed on a silicon substrate,
A silicon substrate is dry-etched on the organic compound. After dry etching for a certain period of time, an organic compound layer is formed again, and dry etching is further performed for a certain period of time.
By repeating this operation, innumerable needle-shaped silicon protrusions are formed on the surface of the silicon substrate. The height of the needle-shaped protrusion is
Although it can be controlled by the dry etching time and the number of operations, in the present invention, the needle-like protrusions having an average protrusion height of 1.2 μm were formed by etching for 3 minutes and the number of operations 10 times. The thickness of the organic compound layer may be appropriate, but in the present embodiment, it is set to 50 nm.

Here, the dry etching is performed by using a plasma etching apparatus such as reactive ion etching (RIE), and a fluorine-based gas (for example, CHF ₃ , CH ₂ F ₂ represented by C _x H _y F _z , CH ₃ F, or C _x F _y
CF ₄ , C ₂ F ₆ , C ₂ F 4, C ₃ F ₈ and C represented by
₄ F ₈ or the like) or a mixed gas of these fluorine-based gases mixed with O ₂ or the like, depending on the film quality.

In addition to the above method, similar bonding can be achieved by forming a myriad of minute recesses on the surface of the silicon substrate. In one embodiment of the present invention, a lithographic method is used to form holes with a diameter of 1 μm in a square array with a pitch of 2 μm in a resist applied to the surface of a silicon substrate, and then dry etching is performed along the holes of the silicon substrate. Innumerable recesses are formed in the. In the present invention, the depth of the depression is 0.5.
was μm. The depth, size and shape of the concave portion are not particularly limited, and silicon may be formed in a convex shape. In addition to dry etching, KOH, NaO
H, TMAH, EPW, HgCl ₂ , K ₂ Fe (CN)
Wet etching may be performed using ₆ or the like to form a depression on the surface of the silicon substrate.

After that, a metal film is formed on the surface of fine irregularities of silicon in the same manner as the above-described reflection film forming method by the electroless plating film forming method. That is, a SiO ₂ film is formed by thermal oxidation, surface treatment is performed, and then a NiP film is formed by electroless plating. In addition, N by electrolytic plating
i, Cu, etc. are formed to a thickness of 300 μm. Fine unevenness is formed on the silicon surface, and further, after thermal oxidation, by performing a surface treatment, an electroless plating film is uniformly formed on all surfaces of the fine unevenness, and further, in order to grow a metal by electrolytic plating, A very uniform metal plate can be formed. They are,
It is possible to firmly bond the silicon and the metal plate with each other by the physical bonding by the anchor effect between the fine irregularities of silicon and the chemical bonding by the surface treatment. An electrolytic plating method may be used as a plating method other than this method. In this case, although the bonding is performed only by the anchor effect, strong bonding can be obtained by appropriately selecting the height of the protrusions of silicon or the depth, pitch, shape, etc. of the depressions.

On the other hand, in the case of joining a glass plate and a metal plate, after forming an organic compound layer such as Teflon (registered trademark), the same gas as that for silicon is used, and the gas for dry etching is SF ₆ , BCl. Similar fine needle-like irregularities can be obtained by changing to a gas such as ₃ or Cl ₂ . Alternatively, a lithograph may be used to form fine holes in the resist, and then dry etching may be performed using the above gas to form the fine holes in the glass substrate. Also,
Instead of the above gas, a liquid such as hydrofluoric acid (HF) or buffered hydrofluoric acid (BHF) may be used to form the fine holes by wet etching. As described above, the plating method may be electrolytic or electroless.

The case where the optical communication module of the present invention is manufactured by using the silicon substrate has been mainly described above. However, when a waveguide, a diffraction grating or the like is manufactured by using a glass substrate, the same process is performed by lithography and etching. it can. In this case, the substrates can be joined to each other by using an ultraviolet curable (UV) adhesive or the like. The V-groove may be formed by glass molding as is conventionally done. The metal film can be easily formed on the side surfaces of the waveguide and the diffraction grating by the electroless plating method. As a method of injecting the resin, the same method as in the case of silicon can be used.

Further, it is also possible to form a resin by using a waveguide or diffraction grating made of silicon, glass or the like for each individual substrate as a mold. In the case of forming with a resin, an SiO ₂ film is first formed on at least the wall surface of the optical circuit concave portion on each substrate by a vapor phase growth method or the like, and each substrate is bonded with an ultraviolet curable (UV) resin to block. To form. After that, a metal film can be formed in the same manner as in the case of silicon or glass.

According to the above method, it is possible to combine glass and resin or glass and silicon. The glass and the resin can be bonded by an ultraviolet curable (UV) resin, and the glass and the silicon can be bonded by anodic bonding or the like.

When manufacturing the laminated optical communication module of the present invention, V-grooves, waveguides, etc. may be formed on the first-stage substrate, but the first-stage substrate on which the waveguides, etc. are formed. It is also possible to mount an optical bench having a V groove formed on it. Also,
Alternatively, a fiber having a metal film formed thereon, a coupling lens, or the like may be separately prepared and mounted in the V groove.

The metallizing method and mounting method of the optical communication component (optical bench, fiber, etc.) mountable on the laminated optical communication module of the present invention will be described below.

When the optical bench is to be metallized, the optical bench which has been subjected to a predetermined pretreatment is replaced with electroless nickel (N
i) Treatment with a plating bath and an electroless gold (Au) plating bath to form a metal film made of NiP / Au at least in the groove portion in contact with the side surface of the optical communication component. By doing so, for example, when fixing an optical fiber or the like whose side surfaces are metallized with NiP / Au to SiOB, since both surfaces are metallized with NiP / Au, both can be bonded and fixed by soldering. The solder is a metal and has a sufficiently high adhesive strength as compared with a plastic such as a UV resin. The optical bench is preferably made of silicon, but may be made of plastic or glass.

NiP / Au metallization can also be performed on the side surface of an optical communication component such as a glass fiber by the procedure described above. By mounting and soldering a glass optical communication component or the like metallized with NiP / Au on the groove portion of SiOB metallized with NiP / Au, both can be more firmly adhered and fixed.

By the way, since the optical communication component needs to allow light to pass through its end face, the metallization for soldering needs to be applied only to the side surface of the optical communication component. Therefore, first, the end surface of the optical communication component is coated with carbon or fluorinated carbon to reduce the surface energy of the end surface of the optical communication component. The coating with carbon can be performed, for example, by sputtering carbon on the end surface of the optical communication component.
The coating with fluorinated carbon may be, for example, CF ₄ , C ₂
This can be done by plasma-treating the end face of the optical communication component with a fluorine-containing gas such as F ₆ .

Next, this optical communication component is subjected to electroless Ni plating. In order to cause the electroless Ni plating reaction, it is necessary to place Pd catalyst nuclei on the surface of the optical communication component. As described above, the end surface of the optical communication component is covered with carbon or fluorinated carbon, and the surface energy is reduced. Therefore, in the step of immersing the optical communication component in the solution of the Pd catalyst nucleus, the Pd catalyst nucleus is not placed on the end surface of the optical communication component, and the Pd catalyst nucleus is attached only to the side surface. After this step, when the optical communication component is immersed in the electroless Ni plating bath, NiP is plated only on the side surface of the optical communication component. Then, when the optical communication component is immersed in the substitution type electroless Au plating bath, Au is plated only on the side surface metallized with NiP. By this series of operations, only the side surface of the optical communication component can be metallized with NiP / Au.

After this, the optical communication component is placed on the groove of SiOB metallized with NiP / Au, and both are fixed by soldering. Optical communication parts and Si by soldering
By bonding the OB, the optical communication component can be more firmly fixed on the SiOB as compared with the conventional resin bonding.

When the optical communication component is bonded and fixed to the optical bench, it may be soldered as described above.
It is also possible to bond and fix the optical communication component and the optical bench without forming a metal film. In that case, a silane coupling agent is provided on at least a side surface of the optical communication component and a groove portion of a carrier mainly composed of Si which is in contact with the optical communication component, and then both are fixed and bonded with an ultraviolet curable resin. At this time, the silane coupling agent to be used was once hydrolyzed, and then hydrolyzed to at least the side surface of the optical communication component and the groove portion of the carrier mainly composed of Si in contact with the optical communication component. After arranging the silane coupling agent, it is preferable that both are fixed and adhered with an ultraviolet curable resin.

More preferably, the silane coupling agent to be used is once hydrolyzed and then hydrolyzed on at least the side surface of the optical communication component and the groove portion of the carrier mainly composed of Si which is in contact with the optical communication component. After arranging the silane coupling agent, heat treatment is performed in the atmosphere at a temperature higher than 120 ° C., and then both are fixed and bonded with an ultraviolet curable resin. The heat treatment temperature is preferably 120 to 200 ° C, and more preferably 120 to 150 ° C.

The silane coupling agent is hydrolyzed to form a silanol group as shown in the following formula (wherein R is a substituent). _{(CH 3 O) 3 SiC 3} H 6 R + 3H 2 O = (HO) 3 SiC
₃ H ₆ R + 3CH ₃ OH (C ₂ H ₅ O) ₃ SiC ₃ H ₆ R + 3H ₂ O = (HO) ₃ Si
_{C 3 H 6 R + 3C 2} H 5 OH

The silanol groups produced form hydrogen bonds with oxygen atoms on the surface of optical communication parts (particularly, optical communication parts made of glass) and on the groove surface of the carrier mainly composed of Si. On the other hand, as the substituent represented by the above formula R, one having good compatibility with the ultraviolet curable resin is selected. By doing so, these hydrolyzed silane coupling agents are converted to S
i-based carrier and UV curable resin
Since they play an important role as an intermediary between materials in the relationship of water and oil, they can be firmly bonded.

As described above, silanol groups are present on the surface of the optical component on which the hydrolyzed silane coupling agent is arranged and the groove surface of the carrier. By heat-treating this, the dehydration condensation reaction proceeds between the silanols of the hydrolyzed silane coupling agent as shown in the formula below, and the silane coupling agent becomes stronger and the glass component surface and Si are the main constituents. It is chemically adsorbed on the groove surface of the carrier (-Si-O-Si- bond is generated). After that, if the both are adhered with an ultraviolet curable resin, the optical communication component can be more firmly fixed on the groove of the carrier having Si as a main component.

[0078] _{-SiOH + (HO) 3 SiC 3} H 6 R = -
Si-O-Si (OH) 2 C 3 H 6 R + H 2 O ( wherein, R represents a substituent.)

Here, as the silane coupling agent which can be used in the present invention, when R is a vinyl group,
For example, vinyltrimethoxysilane, vinyltriethoxysilane vinyltris (β-methoxyethoxy) silane, etc. may be mentioned. When R is an epoxy group, for example, β
-(3,4-Evoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane,
γ-glycidoxypropylmethyldiethoxysilane and the like can be mentioned. When R is a methacryloxy group, for example,
γ-methacryloxypropylmethyldimethoxysilane,
γ-methacryloxypropyltrimethoxysilane, γ-
Methacryloxypropylmethyldiethoxysilane, γ-
Methacryloxypropyltriethoxysilane and the like can be mentioned. When R is an amino group, for example, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane,
N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-
Phenyl-γ-aminopropyltrimethoxysilane and the like can be mentioned.

[0080]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples.

Example 1 A carbon film having a thickness of 10 nm was formed on the end surface of a glass optical lens having an outer diameter of 1 mm and a length of 2 mm by a sputtering method. Then, the glass optical lens was immersed in the electroless Ni plating bath. By this operation, NiP was plated only on the side surface of the glass optical lens.
Subsequently, the glass optical lens was immersed in a substitution type electroless Au plating bath to plate Au on NiP.

Anisotropic etching was applied to a (100) -plane Si wafer having a thickness of 1.5 mm to form a trapezoidal groove having a width of 1000 μm, a depth of 500 μm and a length of 5 mm. afterwards,
SiOB was immersed in an electroless Ni plating bath. By this operation, NiP was plated on the surface of SiOB. Subsequently, the SiOB is immersed in a substitution type electroless Au plating bath, and N
Au plating was performed on the iP. After this, NiP on the SiOB
/ Put a glass optical lens metallized with Au,
The two were bonded and fixed with solder.

Example 2 A side surface of a glass optical lens made in the same manner as in Example 1 except that the end surface of the glass optical lens having an outer diameter of 1 mm and a length of 2 mm was treated with CF ₄ gas plasma. Only plated. In the same manner as in Example 1, after plating the SiOB surface with NiP / Au,
An optical lens made of glass, which was metallized with NiP / Au, was placed on B, and both were adhesively fixed by soldering.

(Comparative Example 1) (100) with a thickness of 1.5 mm
Anisotropic etching with KOH was applied to the surface Si wafer to form a trapezoidal groove having a width of 1000 μm, a depth of 500 μm and a length of 5 mm. Outer diameter 1mm, length 2 on this SiOB
An optical lens made of glass having a size of 3 mm was mounted, and ultraviolet rays having a wavelength of 365 nm were irradiated, and the both were bonded with an ultraviolet curable resin.

(Evaluation) The result of measuring the adhesive strength between the SiOB obtained in Examples 1 and 2 and Comparative Example 1 and the glass optical lens on SiOB is shown in 1. The test is Si
The OB was fixed, and the bonded glass optical lens was pulled by a spring balance to determine the breaking strength. [Table 1] Sample Breaking strength (kgf / cm) Example 1 2.50 or more Example 2 1.50 or more Comparative Example 1 0.15

S obtained in Examples 1 and 2 and Comparative Example 1
A sample in which a glass optical lens was adhered and fixed to a trapezoidal groove of iOB was stored in an environment of 85 ° C. and 90% RH for 1 week.
In Examples 1 and 2, the glass optical lens was not detached, but in the sample of Comparative Example 1, the glass optical lens was detached from the trapezoidal groove of SiOB.

S obtained in Examples 1 and 2 and Comparative Example 1
A heat cycle test of 85 ° C. (2 hours) / − 40 ° C. (2 hours) was performed 10 times on a sample in which a glass optical lens was adhered and fixed to a trapezoidal groove of iOB. In Examples 1 and 2, the glass optical lens was not detached, but in the sample of Comparative Example 1, the glass optical lens was detached from the trapezoidal groove of SiOB.

Example 3 Anisotropic etching with KOH was applied to a (100) -plane Si wafer having a thickness of 1 mm,
A V groove having a width of 145 μm, a depth of 102 μm and a length of 10 mm was formed. Using wire stripper, diameter 125μ
An optical fiber core wire of m was exposed for a length of 3 cm. Γ-Glycidoxypropyltrimethoxysilane was dissolved in isopropyl alcohol, the V groove of Si and the optical fiber core wire were immersed in this solution, and then taken out from the solution and isopropyl alcohol was evaporated and dried. Next, V of Si
An optical fiber core wire was placed in the groove, an ultraviolet curable resin was applied on the optical fiber core, and ultraviolet rays having a wavelength of 365 nm were irradiated to fix the optical fiber to the V groove of Si.

(Comparative Example 2) An anisotropic etching by KOH was applied to a (100) plane Si wafer having a thickness of 1 mm,
A V groove having a width of 145 μm, a depth of 102 μm and a length of 10 mm was formed. Use wire-stripper, diameter 125μ
The m optical fiber core wire was exposed for a length of 3 cm. Then S
An optical fiber core wire was placed in the V groove of i, an ultraviolet curable resin was applied on this, and ultraviolet rays having a wavelength of 365 nm were irradiated to fix the optical fiber to the V groove of Si.

(Evaluation) Table 2 shows the results of examining the adhesive strength of the samples obtained by adhering and fixing the optical fiber in the V groove of Si obtained in Example 3 and Comparative Example 2. In the test, the V groove of Si was fixed, and the bonded optical fiber was pulled by a spring balance to determine the breaking strength.

[Table 2] Sample Breaking Strength (kgf / cm) Example 3 1.10 Comparative Example 2 0.15

As is clear from Table 2, the adhesive strength of the optical fiber is improved in Example 3 as compared with Comparative Example 2 in which the surface treatment is not performed.

The samples obtained by adhering and fixing the optical fiber in the V groove of Si obtained in Example 3 and Comparative Example 2 were heated at 85 ° C.
It preserve | saved for one week in the environment of 90% RH. In Example 3, the optical fiber was not detached, but in the sample of Comparative Example 2, the optical fiber was detached from the V groove of Si.

The samples obtained by adhering and fixing the optical fibers in the V grooves of Si obtained in Example 3 and Comparative Example 2 were subjected to 85 ° C.
(2 hours) / − 40 ° C. (2 hours) heat cycle test was performed 10 times. In Example 3, the optical fiber was not detached, but in the sample of Comparative Example 2, the optical fiber was detached from the V groove of Si.

[0095]

As described above, according to the optical communication lens of the present invention, the convex lens surfaces are integrally formed on both surfaces of the plate through the plate, so that the focal spot diameter is small and the focal length is short. A lens can be realized. Further, by plating other than the lens portion, spot solder welding can be performed, and since the AR film can be collectively formed, film attachment is easy.

Further, according to the optical bench of the present invention, since the V groove for mounting the fiber and the fine groove (bonding groove) intersecting with the V groove are formed, the floating of the fiber and the deviation of the optical axis are prevented. Can be prevented. Further, since the metal film is formed on the surface of the V groove portion, it is possible to solder an optical communication component such as a lens or a fiber without impairing the light transmittance.

Further, according to the optical communication component of the present invention, since the end face of the optical waveguide is covered with carbon or the like, the surface energy of the end face is low. Therefore, only the side surface can be plated without impairing the optical waveguide performance. Therefore, the optical communication component can be easily and firmly adhered and fixed to the optical bench by soldering or the like, and an optical communication component having excellent durability can be realized.

Further, according to the method of manufacturing a laminated optical communication module of the present invention, it is possible to easily plate a cavity having a complicated shape formed inside the substrate of the laminated optical communication module and to transmit light. It can be filled with a sexual medium. According to the optical communication component of the manufacturing method, the light transmitted by the fiber can be efficiently incident on the waveguide in the device, and the incident light can be efficiently transmitted through the waveguide formed in the device such as PD. A compact optical communication module can be realized because each substrate can be arranged three-dimensionally while being transmitted to the light receiving element. Further, by providing the metal layer on the outer surface, it is possible to efficiently dissipate the heat generated by the LD or the like and prevent the substrate from being cracked or distorted.

[Brief description of drawings]

FIG. 1 is an external perspective view showing an example of a laminated optical communication module.

FIG. 2 is a schematic sectional view of an example of a laminated optical communication module.

FIG. 3 is an external perspective view showing an example of a V groove and a bonding groove formed on the first-stage substrate.

FIG. 4 is an external perspective view of a first-stage substrate on which a waveguide and a diffraction grating are formed.

FIG. 5 is a partially enlarged view showing a waveguide and a diffraction grating of the first stage substrate.

FIG. 6 is an AA ′ of a waveguide formed on the first-stage substrate.
FIG.

FIG. 7 is an enlarged view of a terminal portion of the waveguide formed on the first-stage substrate.

FIG. 8 is an enlarged view of a bent portion of a waveguide formed on the first-stage substrate.

FIG. 9 is an external perspective view showing an example of a laminated optical communication module mounting an LD.

FIG. 10 is a schematic sectional view of an example of a laminated optical communication module mounting an LD.

FIG. 11 is an external perspective view of a first-stage substrate (plastic substrate) on which a waveguide and a diffraction grating are formed.

FIG. 12 is a partially enlarged view showing a waveguide and a diffraction grating of the first-stage substrate (plastic substrate).

FIG. 13 is a cross-sectional view taken along the line AA ′ of the waveguide formed on the second-stage substrate (plastic substrate).

FIG. 14 is an external perspective view of a second stage substrate.

FIG. 15 is an enlarged view of an incident portion that allows light from the first-stage substrate to enter the second-stage substrate.

FIG. 16 shows a waveguide B- formed on the second-stage substrate.
It is a B'sectional view.

FIG. 17 is an enlarged cross-sectional view taken along the line CC ′ of the terminal portion of the second stage substrate.

FIG. 18 is a plan view showing a V groove and a trapezoidal groove for fixing a fiber and a coupling lens.

FIG. 19 is a plan view showing an example in which a fiber and a microlens array are fixed to a substrate.

FIG. 20 is a cross-sectional view showing an example in which a fiber and a microlens array are fixed to a substrate.

FIG. 21 is an external perspective view showing a state in which a fiber and a coupling lens are mounted on a third stage substrate.

[Explanation of symbols]

11, 110 First-stage substrate or optical bench 12 V groove 13 Fine groove (bonding groove) 14 Fiber 15 Coupling lens 16 Trapezoidal groove 17 Fixing groove 21, 210 First-stage substrate (first substrate) 22 laser diode (LD) 26 horizontal waveguide 27 metal film 28 vertical waveguide 29 taper 31, 310 second stage substrate (first substrate or second substrate) 32 horizontal waveguide 33 metal film 34 taper 35 Vertical waveguides 41 and 410 Third stage substrate (second substrate) 42 Vertical waveguide 43 Metal film 51 Photodiode (PD) 52 Wiring pattern 53 LSI 101 Metal plate 102 Microlens array forming substrate 103 Silicon Microlens array 104 Diffraction grating

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tetsuhiko Sanbe             Hitachi Ma, 1-88, Torora, Ibaraki City, Osaka Prefecture             Within Kucsel Co., Ltd. (72) Inventor Akihito Sakamoto             Hitachi Ma, 1-88, Torora, Ibaraki City, Osaka Prefecture             Within Kucsel Co., Ltd. F-term (reference) 2H037 AA01 BA03 DA03 DA04 DA05                       DA06                 5F073 AB15 AB17 AB27 AB28 AB29                       BA02 EA28 EA29 FA07 FA08                       FA13 FA16 FA23 FA30                 5F088 AA01 BA11 BA15 BB01 JA03                       JA12 JA14 JA20

Claims (6)

[Claims] 1. An optical communication lens comprising first and second lens surfaces and a side surface peripheral portion, wherein a metal film is formed only on the side surface peripheral portion. 2. A lens for optical communication, comprising a pair of lens convex surfaces on both surfaces of a transparent plate. 3. An optical bench characterized in that a V groove for mounting a fiber is formed on a substrate, and a fine groove intersecting with the V groove is formed on at least a part of the surface of the V groove portion. . 4. An optical bench, wherein a V groove is formed on a substrate, and a metal film is formed on the surface of the V groove portion. 5. An optical communication component, wherein an end face of an optical waveguide is covered with carbon or fluorinated carbon. 6. A cavity having at least one end communicating with an external optical path is formed inside the substrate by laminating at least a first substrate and a second substrate, and the cavity is filled with a plating solution and then water is removed from the cavity. The method for manufacturing a laminated optical communication module, wherein the cavity is filled with an ultraviolet curable resin and the cavity is cured by ultraviolet rays.