JP5136142B2 - Optical substrate manufacturing method - Google Patents

Description

The present invention relates to a method of manufacturing an optical board having electric wiring and optical interconnection.

  Conventionally, electrical wiring has been mainly used in electronic devices. However, in order to meet the demand for higher performance of information processing apparatuses, high-frequency transmission has become necessary in recent years, and transmission using optical wiring is also being studied as means for transmitting high-frequency signals. One method for easily incorporating transmission by optical wiring is to use an optical substrate. An optical substrate is a component that can be easily mounted on an electronic substrate, which includes an optical wiring, an element that converts light into electricity, a power supply unit for controlling the element, a control unit for the element, and the like. What is important in transmission by optical substrates is to reduce optical loss, to easily install optical wiring into conventional electronic substrates, and to manufacture optical substrates used for optical wiring integration at low cost. It can be done. Various studies are currently being conducted on such optical substrates.

  Light propagates in the atmosphere with a divergence angle. For this reason, if the propagation distance in the atmosphere is long, the light spreads larger than the size of the light receiving portion, and thus the light propagation loss increases. In order to reduce such light loss, it is necessary to arrange the components as close as possible. As a means for solving this problem, a method of using a resin material (matching oil or the like) having the same refractive index as a connecting portion is generally known.

  Conventionally used electronic boards have been devised in various ways to reduce electrical transmission loss. In addition, most of the conventionally used elements are designed on the assumption that they operate by electricity. Therefore, the technology of the electronic substrate and the electronic element can be effectively utilized by simply incorporating the optical substrate into the conventional electronic substrate.

  As an optical module used in combination with an electronic substrate, a light emitting / receiving element, an optical wiring (optical waveguide, optical fiber, etc.), and an electrical wiring are used to convert an electrical signal into an optical signal and from an optical signal into an electrical signal. Have already been published. As an example, a structure in which a clad portion and a core portion are formed on a substrate and a light emitting / receiving element is further provided on the clad layer can be cited (Patent Document 1). As another example, there is one that uses a groove so that an optical fiber is not laterally displaced (Patent Document 2).

  As a problem of the above example, it can be considered that it is very difficult to form wiring inside the substrate. In addition, since no wiring layer is provided on the substrate, it is difficult to reduce the transmission loss by high-frequency transmission by installing a control IC or the like near the light emitting / receiving element on the same optical substrate. Further, in the case of a shape in which an optical wiring (clad, core, etc.) or a light emitting / receiving element is embedded in the substrate, it takes much time and time to form the substrate. The problem is that it cannot be easily removed.

  On the other hand, there is an example in which through holes and recesses are formed in the substrate, the light emitting and receiving elements are embedded, and optical wiring is arranged in the recesses. In this example, the alignment is simply performed by forming a recess in which the substrate is disposed. Moreover, it has the structure which can be electrically connected also to a lower electronic substrate by connector connection (patent document 3).

  The problem with this example is that it is necessary to use silicon or glass as the material of the substrate and to form a groove shape of a through hole or a recess, so that it is very difficult and costly to produce the substrate. It is done. Moreover, there exists a possibility that the thickness of the whole base material may become thicker than necessary.

JP 2000-47044 A JP 2007-156378 A JP 2006-11210 A

  The present invention has been made in consideration of the above-described problems of the prior art, and an object of the present invention is to be able to optically accurately and easily align the light emitting / receiving element and the optical wiring. It is another object of the present invention to provide a simple and inexpensive method for manufacturing an optical substrate.

In order to solve the above-mentioned problem in the present invention, an invention relating to claim 1 is directed to an insulating resin layer in which electrical wiring is arranged on one surface, and a light emitting / receiving element in which a light emitting / receiving portion is arranged toward the insulating resin layer. The optical wiring is disposed in the groove part from which the insulating resin layer of the optical substrate made of the optical wiring disposed at a position optically connected to the light receiving and emitting element is removed, and has an electrical wiring of the insulating resin layer In the optical substrate in which the surface on the side and the surface on the light receiving and emitting part side of the optical wiring are in the same plane,
Processing the insulating resin layer on the metal layer to form a groove,
A process of attaching the insulating resin surface to the supporting base material so as to face each other;
Processing the metal layer to remove the metal layer in the groove, and to form an electrical wiring and a light receiving and emitting element connection portion;
Placing optical wiring in the groove of the insulating resin layer;
A method for manufacturing an optical substrate, comprising: a step of mounting a light receiving / emitting surface of a light receiving / emitting element on both of an insulating resin layer and an optical wiring with a light receiving / emitting portion of the optical wiring facing.

According to a second aspect of the present invention, there is provided an insulating resin layer in which electric wiring is arranged on one surface, a light emitting / receiving element arranged with the light emitting / receiving portion facing the insulating resin layer side, and a position optically connected to the light emitting / receiving element. The optical wiring is arranged in the groove part from which the part of the insulating resin layer of the optical substrate formed of the optical wiring is removed, the surface of the insulating resin layer on the side having the electric wiring, and the light receiving and emitting part of the optical wiring In an optical substrate whose side surface is in the same plane,
Processing the insulating resin layer on the metal layer to form a groove,
A process of attaching the insulating resin surface to the supporting base material so as to face each other;
Processing the metal layer to remove the metal layer in the groove, and to form an electrical wiring and a light receiving and emitting element connection portion;
Placing optical wiring in the groove of the insulating resin layer;
Mounting the light emitting / receiving surface of the light emitting / receiving element on both of the insulating resin layer and the optical wiring with the light emitting / receiving portion of the optical wiring facing;
A method for manufacturing an optical substrate, characterized in that it comprises a step of removing the supporting substrate.

According to a third aspect of the present invention, there is provided an insulating resin layer in which electrical wiring is arranged on one surface, a light emitting / receiving element arranged with the light emitting / receiving section facing the insulating resin layer, and a position optically connected to the light receiving / emitting element. The optical wiring is arranged in the groove part from which the part of the insulating resin layer of the optical substrate formed of the optical wiring is removed, the surface of the insulating resin layer on the side having the electric wiring, and the light receiving and emitting part of the optical wiring In an optical substrate whose side surface is in the same plane,
Processing the insulating resin layer on the metal layer to form a groove,
A process of attaching the insulating resin surface to the supporting base material so as to face each other;
Processing the metal layer to remove the metal layer in the groove, and to form an electrical wiring and a light receiving and emitting element connection portion;
Placing optical wiring in the groove of the insulating resin layer;
Directing the light emitting / receiving surface of the light emitting / receiving element toward the light emitting / receiving portion of the optical wiring, mounting on both the insulating resin layer and the optical wiring, and covering at least a part of the optical substrate with a mold resin;
A method for manufacturing an optical substrate, characterized in that it comprises a step of removing the supporting substrate.

According to a fourth aspect of the present invention, there is provided an insulating resin layer in which electrical wiring is disposed on one surface, a light emitting / receiving element in which the light emitting / receiving portion is disposed toward the insulating resin layer, and a position that is optically connected to the light receiving / emitting element. The optical wiring is arranged in the groove part from which the part of the insulating resin layer of the optical substrate formed of the optical wiring is removed, the surface of the insulating resin layer on the side having the electric wiring, and the light receiving and emitting part of the optical wiring In an optical substrate whose side surface is in the same plane,
A step of processing the insulating resin layer on the metal layer to form a groove portion, a step of bonding the insulating resin surface to the support base material,
Processing the metal layer to remove the metal layer in the groove, and to form an electrical wiring and a light receiving and emitting element connection portion;
Placing a dummy film in the groove of the insulating resin layer;
The step of mounting the light emitting / receiving surface of the light emitting / receiving element on both the insulating resin layer and the dummy film, facing the dummy film side,
Covering at least the dummy film of the support substrate with a mold resin;
Removing the support substrate;
Removing the dummy film;
A method for manufacturing an optical substrate, characterized in that it comprises the step of arranging the optical wiring in the groove of the insulating resin layer.

The present invention has the following effects.
1stly, in this invention, arrangement | positioning is taken so that the surface of the side which has the electrical wiring of an insulating resin layer and the surface of the light-receiving / emitting part side of an optical wiring may become the same plane. Thus, the light emitting / receiving element can be mounted in parallel on a plane composed of the optical wiring and the insulating resin layer. In addition, when the thickness of the insulating resin layer and the optical wiring is the same (FIG. 1A), since the lower surface of the optical substrate has a flat structure, the optical substrate is mounted on the flat electronic substrate. Can be easily performed. In addition, since this optical substrate has a structure in which the optical wiring and the light emitting / receiving element are close to each other, there is an effect of reducing the optical loss of the connection portion.

  Secondly, by forming a groove along the shape of the optical waveguide in the insulating resin, there is an advantage that the position where the optical wiring is arranged is determined, and the optical positioning of the optical waveguide and the light emitting / receiving element is easy. With this structure, the optical wiring can be positioned at low cost.

  Third, when a photosensitive resin is used for the insulating resin layer, a groove along the shape of the optical waveguide can be formed by patterning the photosensitive resin by photolithography. In this case, the groove of the insulating resin layer for alignment can be easily formed at low cost. Also, by forming this insulating resin layer, the optical wiring can be positioned and arranged with high accuracy.

  Fourth, by filling the resin between the optical wiring and the light receiving / emitting element, the light receiving / emitting element can be stably disposed on the optical wiring. In addition, in the case of filling a resin that is transparent and has the same refractive index as that of the cladding layer of the optical wiring, an effect of reducing the connection loss between the optical wiring and the refractive index can be provided.

  Fifth, when the thickness of the insulating resin layer is the same as the thickness of the optical wiring, the bottom surface of the optical substrate has a flat structure by manufacturing the optical substrate on the support base material. In this case, it is possible to easily mount the lower surface of the optical substrate on the flat electronic substrate.

<Optical substrate>
1A and 1B are sectional views of the optical substrate in the present invention, and FIG. 1C is a plan view thereof. The optical substrate of the present invention has a light emitting / receiving element on an insulating resin substrate, and the light receiving / emitting element is mounted on both the optical wiring and the insulating resin. The light incident / exit portion of the optical wiring is optically aligned with the light emitting / receiving portion of the light emitting / receiving element.

  The insulating resin 11 is patterned at the portion where the optical wiring is disposed and the portion where the optical substrate is vertically connected. Arbitrary organic materials and inorganic materials can be used for the insulating resin layer. Specifically, an acrylic resin, a silicone material, a silicon wafer, a metal material, a glass material, a laminated plate material, or the like can be used, and it is particularly desirable that the photosensitive resin is used. This is because, as will be described later, by performing patterning using photosensitivity, the optical wiring placement site can be easily removed, and the optical wiring can be mounted with high positional accuracy. As an example of the photosensitive resin, a photosensitive polyimide resin, a photosensitive acrylic resin, a photosensitive epoxy resin, or a photosensitive epoxy acrylate resin obtained by polymerizing these can be used.

Regarding the arrangement position of the insulating resin layer and the optical wiring, it is necessary that the surface of the insulating resin layer on the side having the electric wiring is arranged on the same plane as the surface of the optical wiring on the side of the light receiving and emitting part. As a first method for satisfying this, there is a method using an insulating resin and an optical wiring having the same film thickness as shown in FIG. In this case, for example, when the thickness of the optical wiring is 100 μm, the thickness of the insulating resin layer is set to 100 μm.
As the second method, there is a method using an optical wiring having a thickness different from that of the insulating resin, as shown in FIG. In this case, the thickness of the optical wiring may be thicker or thinner than the insulating resin layer.

  As the optical wiring, a general optical wiring or optical waveguide composed of a core and a clad covering the outer periphery of the core can be used. An optical fiber or the like can also be used, and the number of grooves in which the optical wiring is arranged is not limited to one. The thing of the structure which collected many optical wiring is also included. Examples of the material include polymeric materials such as carbonate-based, epoxy-based, acrylic-based, imide-based, urethane-based, norbornene-based materials, and inorganic materials such as quartz. Further, the transmission mode can be configured as a single mode, a multimode, a single multi mixed wiring, or the like.

  The optical path conversion is performed by a mirror structure or mirror parts. The optical substrate shown in FIG. 1 uses a mirror structure. In this case, light is converted by 90 ° light path by cutting the end of the wiring at 45 °. In addition to such a structure, a metal layer can be formed on the mirror surface, or components for optical path conversion can be placed separately from the optical wiring.

  In order to optically connect the light emitting / receiving element to the optical wiring, the light receiving / emitting element is disposed with the light emitting / receiving surface facing the insulating resin layer side. Further, the light emitting / receiving element is installed on both the optical wiring and the insulating resin layer, and at least a part of the light receiving / emitting surface is installed at a position optically connected to the optical wiring. As the light emitting / receiving element, a single channel or a plurality of channels of optical elements can be used. Specifically, an edge-emitting LD (laser diode), a surface-emitting LD, a surface-emitting PD (photodiode), or the like can be used. The electrode can be used both on the same surface as the light receiving and emitting surface of the device and on the opposite surface. The light emitting / receiving element can be mounted by wire bonding by manufacturing a back electrode as shown in FIG. 1, or by flip chip mounting by solder bumps.

  In addition, if necessary, an IC chip such as a control IC for the light emitting / receiving element can be mounted on the optical substrate. The control chip can be mounted by wire bonding, flip chip, or the like.

  By arranging elements such as the control IC of the light emitting / receiving element on the insulating resin layer on the electric wiring arrangement side, optical wiring can be used in the vicinity of the IC chip, and the photoelectrically converted electric signal is transmitted inside the substrate. Since it can be connected to the IC without passing through, it is possible to suppress the loss of the high-frequency signal due to the electrical wiring.

  If necessary, a transparent resin can be filled between the light emitting / receiving surface of the light emitting / receiving element and the input / output surface of the optical wiring. As the filling resin, a generally used polymer material can be used. Specifically, an epoxy material, an acrylic material, an imide material, a urethane material, a silicone material, an organic material mixed with an inorganic filler, or the like can be used, but is not limited thereto. Further, in order to eliminate the difference in refractive index at the interface, a material having the same refractive index as that of the cladding material can be used as the filling resin. In this case, optical loss at the connection portion between the optical wiring and the light emitting / receiving element can be suppressed. In addition, an optical substrate with high environmental reliability can be obtained by improving the strength of the connection site.

  The optical substrate of the present invention is effective for electronic devices or optical components that involve a large amount of information input / output. As specific examples of mounting an optical substrate, it is conceivable to use various computers including a notebook computer and a large business computer, a home game machine, a recording / reproducing machine, a television, a router, and the like. These applications are effective because signals can be efficiently transmitted and received without receiving noise. Specific examples of optical components on which optical substrates are mounted include optical interconnections (optical electrical wiring boards), optical connectors, optical connectors, optical couplers, optical couplers, optical splitters, and optical components such as optical transceivers. The same effect can be expected by installing.

<Optical substrate manufacturing method>
Next, the manufacturing method of the optical board | substrate of this invention is demonstrated. In the following description, a case where a photosensitive resin is used for the insulating resin layer will be described.

  First, the film which bonded the insulating resin layer 8 and the copper foil layer 7 is used (FIG. 2 (a)). The insulating resin layer is patterned by photolithography to remove the portion where the optical wiring is installed and the upper and lower conductive portions (FIG. 2B). As the photosensitive resin used for the insulating resin layer, a photosensitive polyimide resin, a photosensitive acrylic resin, a photosensitive epoxy resin, a photosensitive epoxy acrylate resin obtained by polymerizing these, or the like can be used. As the photolithography process, exposure using a mask pattern and subsequent development process are performed.

  Next, the insulating resin surface is bonded to the support substrate 10 (FIG. 2C). A general laminating method can be used for bonding. As the support substrate, generally used organic materials, inorganic materials, and the like can be used. Specifically, a carbonate material, an epoxy material, an acrylic material, an imide material, a urethane material, a silicone material, an organic material mixed with an inorganic filler, and the like can be used. However, the material is not limited thereto. Further, an ultraviolet peelable pressure-sensitive adhesive layer can be provided on the support substrate.

  In the present invention, the arrangement position of the insulating resin layer and the optical wiring requires that the surface of the insulating resin layer on the side having the electric wiring is arranged on the same plane as the surface of the optical wiring on the light emitting / receiving portion side. However, when the thickness of the insulating resin layer is the same as that of the optical wiring (FIG. 1A), the upper and lower surfaces of the insulating resin layer are flush with the upper and lower surfaces of the optical wiring. A flat shape may be used. On the other hand, when the thickness of the insulating resin is different from the thickness of the optical wiring (FIG. 1B), the supporting base material needs to be shaped in consideration of the thickness of the optical wiring.

  In any of the above cases, the surface of the insulating resin layer on the side having the electric wiring is flush with the surface of the optical wiring on the side of the light emitting / receiving section. For this reason, the light emitting / receiving element can be arranged in a substantially horizontal state on both the optical wiring and the insulating resin layer. Further, in this structure, the distance between the light receiving and emitting portions between the optical wiring and the light receiving and emitting elements is reduced, so that it is considered that the optical connection accuracy is also improved.

  The insulating resin layer is held and fixed by using the support base material. For this reason, even when the thickness of the insulating resin layer is thin, the optical substrate can be stably mounted. Further, when the thickness of the insulating resin layer is the same as the thickness of the optical wiring, the lower surface of the optical substrate can be easily flattened by performing the optical substrate manufacturing process on the supporting base material.

  Next, the copper foil is patterned to form a wiring pattern and a mounting pad (FIG. 2D). This metal processing method can be used as a copper foil patterning method. Specifically, a resist pattern is formed in accordance with the wiring pattern and the mounting pad pattern, and the wiring pattern is formed by etching. Moreover, you may perform nickel, gold plating, and soldering resist printing as needed.

  Further, as described above, a control chip of the light emitting / receiving element may be mounted as necessary. In this case, a control chip of a light emitting / receiving element and other elements can be mounted on the patterned copper foil. The control chip can be mounted by wire bonding, flip chip mounting, connector mounting, or the like.

  Next, patterning is performed, and the optical wiring is mounted on the optical wiring installation site on the insulating resin layer from which unnecessary portions have been removed (FIG. 2E). At this time, since the optical wiring is aligned by the groove pattern of the insulating resin layer, the arrangement is easy.

  Next, the light emitting / receiving element is mounted so as to be directly bonded to the input / output surface of the optical wiring (FIG. 2F). The light emitting / receiving element and the electric wiring can be mounted by a method of forming a back electrode on the light emitting / receiving element and performing wire bonding, or a method of forming a through electrode. At this time, a resin may be filled in the gap between the light emitting / receiving element and the optical wiring as required (FIG. 2G). By filling the resin, it is possible to reduce the optical loss at the connection portion between the light emitting / receiving element and the optical wiring.

  If necessary, the entire substrate or an arbitrary place can be molded with a molding resin. In the case of performing molding, the supporting base material can be finally peeled to obtain the optical substrate of the present invention (FIG. 2 (h)). In addition, when an ultraviolet peeling type pressure-sensitive adhesive layer is provided on the supporting substrate, the supporting substrate can be peeled off by irradiation with ultraviolet rays.

  In the case of molding, a dummy film 13 can be used instead of the optical wiring at the time of molding (FIG. 3 (f)). In this case, a dummy film having the same film thickness and size as the optical wiring is installed instead of the optical wiring, and the supporting base material is covered with the mold resin. Alternatively, when the film thickness of the optical wiring and the film thickness of the insulating resin layer are different as shown in FIG. 1B, a flat support substrate can be formed by using a dummy film that matches the film thickness of the optical wiring. By using it easily, the surface of the optical wiring (on the side of the light emitting / receiving portion) and the surface of the insulating resin layer can be made flush.

  As the material of the dummy film, carbonate material, epoxy material, acrylic material, imide material, urethane material, silicone material, organic material mixed with inorganic filler, and the like can be used, but are not limited thereto. Since the dummy film is subjected to a heating process at the time of molding, it is desirable to use a film that can withstand the heating process. Further, by providing a heat-resistant adhesive layer on the upper and lower surfaces of the dummy film, it is possible to prevent penetration of the mold resin.

  When the optical substrate is molded, it is desirable to fill a transparent resin having the same refractive index as that of the cladding layer between the light emitting / receiving element and the dummy film. This is because, as described above, the mold resin can be prevented from entering the connecting portion between the light emitting / receiving element and the optical wiring, and the optical loss at the connecting portion between the light receiving / emitting element and the optical wiring can be reduced. Similarly, when a dummy film is used, a transparent resin may be filled between the light emitting / receiving element and the dummy film.

  Next, an arbitrary place of the optical substrate is molded, and the supporting base material and the dummy film are peeled off (FIG. 3 (i)). By covering the supporting base material with the mold resin, a portion where the dummy film is peeled off is formed as an optical wiring installation portion. When an ultraviolet curable pressure-sensitive adhesive layer is provided on the support substrate, the support substrate can be peeled off by ultraviolet irradiation as described above.

  Through the above steps, an electric circuit package on which parts other than the optical wiring are mounted is manufactured. The electric circuit package can be formed in a substantially rectangular shape in plan view. Therefore, if an insulating substrate made of a material that can be applied to a known roll-to-roll manufacturing apparatus is selected, a large number of electric circuit packages can be manufactured. That is, it is possible to manufacture the optical substrate with high productivity by manufacturing the electrical circuit package excluding the optical wiring portion as a previous stage.

  Finally, the optical substrate of the present invention can be manufactured by fitting and joining the optical wirings to the locations where the dummy film is removed (FIG. 3 (j)). In this manufacturing method, the arrangement part of the optical wiring becomes a groove-shaped opening by the pattern of the insulating resin layer and the mold resin, so that the connection between the optical wiring and the light emitting / receiving element, the connection between the optical wirings is easy, Can be mounted with high accuracy. Further, in this method, since the molding is performed before the optical wiring is mounted, the optical waveguide can be prevented from being damaged due to the high-temperature process of forming the mold.

  Examples of the present invention will be described below, but the present invention is not construed as being limited thereto. In the following description, the optical waveguide of the optical substrate is described as one layer, but it is not always necessary to have one layer. In the following embodiments, the optical waveguide is described as multimode, but it is not necessarily required to be multimode.

<Example 1>
First, as a photosensitive insulating material, 52 parts by weight of bisphenol A type epoxy acrylate (Lipoxy VR-90: Showa High Polymer) and 15 parts by weight of phthalic anhydride are stirred in a propylene glycol monomethyl ether acetate solvent at 110 ° C. for 30 minutes for alkali development. Type photosensitive insulating resin varnish raw material was prepared. Furthermore, 50 parts by weight of the alkali-developable photosensitive insulating resin varnish raw material, 17 parts by weight of an alicyclic epoxy compound (EHPE3150: Daicel Chemical), 30 parts by weight of a photocurable epoxy resin (Cyclomer M100: Daicel Chemical), Propylene glycol monomethyl ether acetate solvent was added to 3 parts by weight of a photoinitiator (LucirinTPO: BASF) and dispersed in a continuous horizontal sand mill for about 3 hours to prepare an alkali development type photosensitive insulating resin varnish.

  Next, the alkali-developable photosensitive insulating resin varnish is applied on a copper foil with a slit coater, dried at 70 ° C. for 20 minutes, and a semi-cured state of about 50 μm thickness so as to have the same film thickness as the optical waveguide film. The photosensitive insulating resin layer 8 was formed to produce a photosensitive insulating resin with one side copper foil (FIG. 2A).

Next, a photomask was brought into close contact with the photosensitive insulating resin layer 8, and was exposed to an ultrahigh pressure mercury lamp at 500 mJ / cm ² and cured with ultraviolet rays. Thereafter, development with about 5% organic amine alkali aqueous solution, washing with water, and sufficient drying in a 90 ° C. oven were performed to obtain a patterned insulating resin layer 8 (FIG. 2B).

  Next, the insulating resin layer 8 was laminated on the support base material 10 (PET: manufactured by Toyo Ink) (FIG. 2C).

  Next, an etching resist pattern was formed on the copper foil 7, and the copper foil was etched to obtain a patterned copper foil 7 (FIG. 2D).

Next, the optical waveguide film 1 (multimode epoxy optical waveguide film: manufactured by NTT-AT) was placed on the support substrate from which the insulating resin was removed by patterning (FIG. 2 (e)). The installation position alignment performed abutment alignment using the outer shape of the insulating resin layer 8.

  A control chip 6 (VCSEL (surface emitting diode) driver chip: manufactured by HELX AG) was mounted on the copper foil 7, and electrical connection was performed by wire bonding (FIG. 2 (f)).

Next, the light emitting element 2 (4ch VCSEL: made by ULM) is mounted on the copper foil 7 and the optical waveguide film 1 using the refractive index matching material 9 (epoxy adhesive: manufactured by NTT-AT), and wire bonding is performed. (Fig. 2 (f)). At this time, alignment was performed so that the light input position of the optical waveguide film 1 and the light output position of the light emitting element 2 were matched, and the periphery of the refractive index matching material 9 was cured by UV exposure of 500 mJ / cm ² .

  Next, the entire surface of the insulating resin layer and a part of the optical wiring were covered with a mold resin (FIG. 2G).

  Next, the support substrate 10 was peeled off to produce an optical substrate (FIG. 2 (h)).

  As a result of the optical characteristic evaluation, a stable light output of 0.9 to 1.1 mW could be confirmed in each channel.

<Example 2>
First, in the same manner as in Example 1, an alkali development type photosensitive insulating resin varnish was prepared.

  Next, the photosensitive insulating resin 8 with a one-sided copper foil was manufactured similarly to Example 1 (FIG. 3 (a)).

Next, a photomask was brought into close contact with the photosensitive insulating resin layer 8, and was exposed to ultraviolet light at 500 mJ / cm ² with an ultra-high pressure mercury lamp, and was cured with ultraviolet rays. Thereafter, development with about 5% organic amine alkali aqueous solution, washing with water, and sufficient drying in a 90 ° C. oven were performed to obtain a patterned insulating resin layer 8 (FIG. 3B).

  Next, the insulating resin layer 8 was laminated on the support base material 10 (PET: manufactured by Toyo Ink) (FIG. 3C).

  Next, an etching resist pattern was formed on the copper foil 7, and the copper foil was etched to obtain a patterned copper foil 7 (FIG. 3D).

  Next, a solder resist 11 was applied on the patterned copper foil 7 (FIG. 3E). Subsequently, a gold plating 12 was applied to the control chip placement site.

  Next, an optical waveguide dummy film 13 (polyimide film: made by DuPont) having the same film thickness (50 μm) as the insulating resin layer was placed on the support substrate from which the insulating resin was removed by patterning (FIG. 3F). . The installation position alignment performed abutment alignment using the outer shape of the insulating resin layer 8.

  Next, a control chip 6 (VCSEL driver chip: manufactured by HELIX AG) was mounted on the copper foil 7 (FIG. 3G). At this time, solder bumps 14 were used for electrical connection of the control chip.

Next, the light emitting element 2 (4ch VCSEL: made by ULM) is mounted on the copper foil 7 and the optical waveguide dummy film 13 using the refractive index matching material 9 (epoxy adhesive: manufactured by NTT-AT), and the wire Electrical connection was made by bonding (FIG. 3G). At this time, alignment was performed so that the light input position of the optical waveguide film 1 and the light output position of the light emitting element 2 were matched, and the periphery of the refractive index matching material 9 was cured by UV exposure of 500 mJ / cm ² .

  Next, the whole was molded with the mold resin 5 (FIG. 3H).

  Next, the support base material 10 and the optical waveguide dummy film 14 were peeled off (FIG. 3 (i)).

  Next, the optical waveguide film 1 (multimode epoxy optical waveguide film: manufactured by NTT-AT) was installed at the place where the optical waveguide dummy film was peeled off (FIG. 3 (j)). The installation position alignment performed abutment alignment using the outer shape of the insulating resin layer 8.

  As a result of the optical characteristic evaluation, a stable light output of 0.9 to 1.1 mW could be confirmed in each channel.

It is explanatory drawing of the optical board | substrate of this invention (a; sectional drawing, b: sectional drawing, c: top view). It is explanatory drawing of the manufacturing method of the optical board | substrate of this invention. It is explanatory drawing of the manufacturing method of the optical board | substrate of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical waveguide film 2 Light receiving / emitting element (VCSEL)
3 Wire bonding 4 Back electrode 5 Mold resin 6 Control IC
7 Copper foil layer 8 Insulating resin layer 9 Refractive index matching material (transparent resin)
DESCRIPTION OF SYMBOLS 10 Support base material 11 Solder resist 12 Gold plating layer 13 Dummy film 14 Solder bump

Claims (4)

From the insulating resin layer in which the electrical wiring is arranged on one surface, the light emitting / receiving element arranged with the light emitting / receiving portion facing the insulating resin layer side, and the optical wiring arranged in a position optically connected to the light emitting / receiving element The optical wiring is disposed in the groove portion from which a part of the insulating resin layer of the optical substrate is removed, and the surface of the insulating resin layer on the side having the electric wiring and the surface of the optical wiring on the side of the light receiving and emitting part are in the same plane. In an optical substrate,
Processing the insulating resin layer on the metal layer to form a groove,
A process of attaching the insulating resin surface to the supporting base material so as to face each other;
Processing the metal layer to remove the metal layer in the groove, and to form an electrical wiring and a light receiving and emitting element connection portion;
Placing optical wiring in the groove of the insulating resin layer;
A method of manufacturing an optical substrate comprising: a step of mounting the light receiving / emitting surface of the light emitting / receiving element on both the insulating resin layer and the optical wiring with the light receiving / emitting surface of the optical wiring facing. From the insulating resin layer in which the electrical wiring is arranged on one surface, the light emitting / receiving element arranged with the light emitting / receiving portion facing the insulating resin layer side, and the optical wiring arranged in a position optically connected to the light emitting / receiving element The optical wiring is disposed in the groove portion from which a part of the insulating resin layer of the optical substrate is removed, and the surface of the insulating resin layer on the side having the electric wiring and the surface of the optical wiring on the side of the light receiving and emitting part are in the same plane. In an optical substrate,
Processing the insulating resin layer on the metal layer to form a groove,
A process of attaching the insulating resin surface to the supporting base material so as to face each other;
Processing the metal layer to remove the metal layer in the groove, and to form an electrical wiring and a light receiving and emitting element connection portion;
Placing optical wiring in the groove of the insulating resin layer;
Mounting the light emitting / receiving surface of the light emitting / receiving element on both of the insulating resin layer and the optical wiring with the light emitting / receiving portion of the optical wiring facing;
The method of manufacturing an optical substrate, characterized in that it comprises a step of removing the supporting substrate. From the insulating resin layer in which the electrical wiring is arranged on one surface, the light emitting / receiving element arranged with the light emitting / receiving portion facing the insulating resin layer side, and the optical wiring arranged in a position optically connected to the light emitting / receiving element The optical wiring is disposed in the groove portion from which a part of the insulating resin layer of the optical substrate is removed, and the surface of the insulating resin layer on the side having the electric wiring and the surface of the optical wiring on the side of the light receiving and emitting part are in the same plane. In an optical substrate,
Processing the insulating resin layer on the metal layer to form a groove,
A process of attaching the insulating resin surface to the supporting base material so as to face each other;
Processing the metal layer to remove the metal layer in the groove, and to form an electrical wiring and a light receiving and emitting element connection portion;
Placing optical wiring in the groove of the insulating resin layer;
Directing the light emitting / receiving surface of the light emitting / receiving element toward the light emitting / receiving portion of the optical wiring, mounting on both the insulating resin layer and the optical wiring, and covering at least a part of the optical substrate with a mold resin;
The method of manufacturing an optical substrate, characterized in that it comprises a step of removing the supporting substrate. From the insulating resin layer in which the electrical wiring is arranged on one surface, the light emitting / receiving element arranged with the light emitting / receiving portion facing the insulating resin layer side, and the optical wiring arranged in a position optically connected to the light emitting / receiving element The optical wiring is disposed in the groove portion from which a part of the insulating resin layer of the optical substrate is removed, and the surface of the insulating resin layer on the side having the electric wiring and the surface of the optical wiring on the side of the light receiving and emitting part are in the same plane. In an optical substrate,
A step of processing the insulating resin layer on the metal layer to form a groove portion, a step of bonding the insulating resin surface to the support base material,
Processing the metal layer to remove the metal layer in the groove, and to form an electrical wiring and a light receiving and emitting element connection portion;
Placing a dummy film in the groove of the insulating resin layer;
The step of mounting the light emitting / receiving surface of the light emitting / receiving element on both the insulating resin layer and the dummy film, facing the dummy film side,
Covering at least the dummy film of the support substrate with a mold resin;
Removing the support substrate;
Removing the dummy film;
The method of manufacturing an optical substrate, characterized in that it comprises the step of arranging the optical wiring in the groove of the insulating resin layer.