JP3901067B2 - Optical communication module and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical communication module used for optical communication and a method for manufacturing the same.
[0002]
[Prior art]
Conventionally, in an optical communication module including an optical waveguide and an electric circuit, in order to ensure the positional accuracy of the optical waveguide and the optical component, the optical waveguide and the optical component are separated from the components and package of the electric circuit. It is formed or disposed on a substrate such as a silicon substrate on which a planar lightwave circuit (PLC) is formed (see, for example, Patent Documents 1 to 4).
[0003]
As shown in FIG. 11, the optical communication module disclosed in Patent Document 1 has an optical semiconductor element 70 disposed on a substrate 80 on which a PLC is formed, and the substrate 80 is accommodated in a package 90. Similarly, in the optical communication module disclosed in Patent Document 2, as shown in FIG. 12, a laser diode 71 as an optical semiconductor element is disposed on a substrate (silicon substrate) 80 on which a PLC is formed, and the substrate 80 Is housed in the package 90. Further, in the optical communication module disclosed in Patent Document 3, as shown in FIG. 13, optical semiconductor elements 72 to 74 are arranged on a substrate 80 on which a PLC is formed, and the substrate 80 is accommodated in a package 90. ing. Further, as shown in FIG. 14, the optical communication module disclosed in Patent Document 4 includes a laser diode 75 and photodiodes 76 and 77, which are optical semiconductor elements, arranged on a substrate 80 on which a PLC is formed. A substrate 80 is accommodated in the package 90.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 9-274121 (pages 4 to 5, FIGS. 1 to 3)
[Patent Document 2]
Japanese Patent Laid-Open No. 11-176966 (pages 4 to 5, FIGS. 1 and 2)
[Patent Document 3]
JP 2001-305364 A (page 3, FIGS. 1 and 2)
[Patent Document 4]
Japanese Unexamined Patent Publication No. 2002-94170 (pages 4 to 5, FIGS. 1 and 2)
[0005]
[Problems to be solved by the invention]
However, in each of the conventional optical communication modules described above, since the optical semiconductor element is disposed on a relatively expensive substrate 80 such as a silicon substrate and housed in a package 90 that is separate from the substrate 80, the number of components is reduced. In many cases, the number of man-hours increases during assembly for optical connection and electrical connection.
[0006]
The present invention has been made in view of the above-described reasons, and an object of the present invention is to provide an optical communication module that can reduce the number of parts and the number of man-hours during assembly as compared with the prior art, and a method for manufacturing the same.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a first aspect of the present invention provides a synthetic resin substrate that is embedded in a core portion that is optically coupled to an external optical fiber to form an optical circuit, and forms a part of the package. An optical semiconductor element provided on the surface side and optically coupled to an optical circuit, and an electric integrated circuit element cooperating with the optical semiconductor element, and the optical semiconductor element and the electric integrated circuit element are electrically connected to the substrate And a positioning part for positioning the optical semiconductor element is formed, and the core part, the optical semiconductor element, and the electric circuit pattern constitute a part of the package. Compared to the conventional case where a substrate such as a silicon substrate on which a planar lightwave circuit (PLC) is formed and an optical semiconductor element is arranged and a package are separate parts. And can reduce the number of results in low costs, also, the positioning portion for positioning the optical semiconductor element is formed on a substrate, the process required alignment during assembly is simplified. The optical semiconductor element in claim 1 is a concept including a light emitting element such as a light emitting diode and a laser diode (semiconductor laser) and a light receiving element such as a photodiode.
[0008]
  The invention of claim 1 is a lightSemiconductor elements andPowerIntegrated circuit elements andPowerA cover hermetically fixed to the substrate so as to cover the air circuit pattern, and a side surface of the substrate.PowerSince it has an external connection terminal electrically connected to the integrated circuit element, PaIntrusion of foreign matter such as dust and dirt into the package can be prevented, and the reliability of the optical communication module is improved.
[0009]
  In the invention of claim 1,The bar is the surface facing the substrateToWith integrated circuit elements, ElectricIntegrated circuit elementAnd lightSince a part of the electric circuit pattern for electrically connecting the semiconductor element is formed, it can be placed in a plane perpendicular to the thickness direction of the substrate.RuThe package can be downsized. Also, MosquitoPlaced in the barPowerIntegrated circuit elementThe lightCompared to the case where it is arranged on the substrate adjacent to the semiconductor element., ElectricIntegrated circuit elementAnd lightThe heat transmitted through the substrate to and from the semiconductor element can be reduced, and the influence of the mutual heat on the respective operation characteristics can be reduced.
[0010]
  Claim2The invention of claim1In this invention, since the cover and the substrate are concavo-convexly fitted, and the electric circuit pattern is extended on the mating surfaces of the cover and the substrate, the electric integrated circuit disposed on the cover The reliability of the electrical connection between the device and the optical semiconductor device disposed on the substrate can be improved, and the reliability can be improved by increasing the airtightness of the package.
[0011]
  Claim3The invention is claimedItem 1In the invention, since the package is constituted by the substrate and the cover, and a heat radiating plate is provided on the outer surface side of the package, heat dissipation can be improved, and deformation of the substrate due to heat generation of the respective elements. Therefore, the optical coupling portion can be prevented from being displaced, the decrease in the optical coupling efficiency can be suppressed, and the increase in the transmission loss in the optical circuit can be suppressed. Variations can be suppressed.
[0012]
  Claim4The invention is claimedItem 1In the invention, the package is constituted by the substrate and the cover, and includes a metal film that is attached to the outer surface of the package and electrically connected to the external connection terminal. Therefore, the metal film serves as a shield film. It has a function and a function as a light shielding film, so that it is possible to prevent high frequency noise due to the shielding effect and prevent malfunction of each element due to the light shielding effect.
[0013]
  Claim5The invention of claim 1 to claim 14The method of manufacturing an optical communication module according to any one of the above, wherein in forming the substrate, the core material of the core portion is formed by repeating a process of applying a photoresist on one surface side of the carrier substrate and patterning a plurality of times. A step of forming a master mold of a synthetic resin base which is formed on one surface side of the injection groove and the positioning portion and also serves as a lower cladding layer of the optical waveguide, and a mold is formed by transferring the master mold by electroplating A step of forming a base using the mold, a step of injecting the core material having a higher refractive index than the base into an injection groove in the base, and forming the core portion, A step of forming an upper clad layer made of a synthetic resin having a low refractive index and covering the core portion on the one surface side of the base; and after forming the upper clad layer, the electric circuit Characterized by comprising a step of forming a pattern, it is possible to provide an optical communication module which attained a reduction and reduction of man-hour in assembling the parts as compared with the prior art. Further, by using a mold formed by transferring the master mold by electroplating, it is possible to reduce the cost due to mass production.
[0014]
  Claim6The invention of claim5In the invention, in the step of forming the electric circuit pattern, a process of forming a conductive thin film on the one surface of the substrate, and a portion of the conductive thin film corresponding to the electric circuit pattern and a peripheral unnecessary portion Because it includes a process of irradiating the boundary region with a laser beam, a process of plating a portion corresponding to the electric circuit pattern in the conductive thin film, and a process of removing unnecessary portions of the conductive thin film. An electric circuit pattern can be accurately formed on the one surface side of the substrate having the positioning portion. In addition, the laser beam irradiation time can be shortened compared with the case where the entire unnecessary portion of the conductive thin film is irradiated with a laser beam, productivity can be improved, and the cost of the plating material can be reduced and the cost can be reduced. I can plan.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
  (Reference example)
  Of this reference exampleAs shown in FIG. 2, the optical communication module is composed of a synthetic resin substrate 10 in which a core portion 12 forming an optical circuit is embedded, and a synthetic member fixed to one surface side (upper surface side in FIG. 2) of the substrate 10. A package 1 composed of a resin cover 20 is provided, and a plurality of external connection terminals 17 (see FIG. 1) are provided on the side surface of the substrate 10. The package 1 also holds two optical fibers 2 (only one is shown in FIG. 2) that are introduced from the outside and optically coupled to the core portion 12. Here, the package 1 has two positioning grooves 14a and 14b (see FIG. 1) for positioning the end portions of the optical fibers 2 from which the coating 3 is peeled, and each positioning groove 14a on the one surface of the substrate 10. , 14b, and fixing grooves 15a, 15b (see FIG. 1) for fixing the optical fiber 2 including the coating 3 of the optical fiber 2 are formed. The fixing grooves 15a and 15b are set to be larger in depth and width than the positioning grooves 14a and 14b. The inner bottom surfaces of the fixing grooves 15a and 15b are projected from the facing surfaces of the cover 20. A holding projection 18 that holds the coating 3 of the optical fiber 2 together with the projection 28 is provided. Here, each optical fiber 2 may be bonded to the package 1 with an adhesive.
[0016]
  As shown in FIG. 1, the core unit 12 is housed in the optical fiber 2 and the receiving photodiode 32 (hereinafter referred to as a receiving photodiode) housed in the package 1 and received in the package 1. Each of the transmission laser diodes (hereinafter referred to as “transmission laser diodes”) 33 disposed apart from the transmission photodiode 32 is formed in a planar shape that is optically coupled. A multilayer filter 31 having a predetermined transmission characteristic is inserted in the middle of the core portion 12. Here, the transmission characteristic of the multilayer filter 31 is the first specified wavelength (In this reference exampleSelectively transmits an optical signal of 1.31 μm) and a second specified wavelength (In this reference exampleIs set to reflect an optical signal of 1.55 μm), and light incident on the core portion 12 from the optical fiber 2 positioned by the positioning groove 14 a formed on the one surface of the substrate 10 is a multilayer film. Guided to filter 31.
[0017]
  ButOf this reference exampleIn the optical communication module, the optical signal of the first specified wavelength incident on the core portion 12 from the optical fiber 2 positioned by the positioning groove 14a passes through the multilayer filter 31 and is guided to the receiving photodiode 32 and received. The optical signal of the second specified wavelength that has been converted into an electrical signal by the photodiode 32 and incident on the core portion 12 is reflected by the multilayer filter 31 and guided to the optical fiber 2 positioned by the positioning groove 14b. It is burned.
[0018]
  Here, the electric signal output from the receiving photodiode 32 is amplified by a first signal processing circuit including an electric integrated circuit element 35 and an electronic component 37 housed in the package 1, The signal output from the signal processing circuit can be taken out to an external device (not shown) through the external connection terminal 17. The transmission laser diode 33 oscillates by an electric signal supplied from a second signal processing circuit composed of an electric integrated circuit element 36 and an electronic component 38 housed in the package 1 and transmits an optical signal. To do. An optical signal output from the transmission laser diode 33 and incident on the core portion 12 is transmitted through the multilayer filter 31 and transmitted through the optical fiber 2 positioned in the positioning groove 14a. The second signal processing circuit is configured to convert the control signal received from the external device through the external connection terminal 17 into the electric signal and to supply the electric signal to the transmitting laser diode 33. The package 1 also houses a monitoring photodiode (hereinafter referred to as a monitoring photodiode) 34 for monitoring the output of the transmitting laser diode 33 and the like. Also,In this reference exampleEach of the receiving photodiode 32, the transmitting laser diode 33, and the monitoring photodiode 34 constitutes an optical semiconductor element, and the electric integrated circuit elements 35 and 36 cooperate with the optical semiconductor element. It is composed.
[0019]
  By the way, the substrate 10 has a housing recess 10a formed on the one surface, and a multilayer filter 31, a receiving photodiode 32, a transmitting laser diode 33, a monitoring photodiode on the inner bottom surface of the housing recess 10a. Four positioning recesses 10c, 10d, 10e, and 10f in which each of 34 is positioned are formed, and can be easily optically coupled (optically connected) to the core portion 12. That is, the multilayer filter 31 is positioned with respect to the substrate 10 and the core portion 12 by being inserted into the positioning recess 10c from above in FIG. Similarly, the receiving photodiode 32 is positioned with respect to the substrate 10 and the core portion 12 by being inserted into the positioning recess 10d from above in FIG. 2, and can be optically coupled to the core portion 12, and the transmitting laser diode 33 is 2 is inserted into the positioning recess 10e from above in FIG. 2 so that it is positioned with respect to the substrate 10 and the core portion 12 and can be optically coupled to the core portion 12. The monitoring photodiode 34 is inserted into the positioning recess 10f in the upper direction of FIG. It will be positioned with respect to the board | substrate 10 by inserting from above. In addition,In this reference exampleEach of the positioning recesses 10d to 10f constitutes a positioning portion for positioning the optical semiconductor element, but each positioning portion may be formed in a shape that can position the optical semiconductor element by at least one of the recess and the convex portion. .
[0020]
The substrate 10 is provided with the above-described electric integrated circuit elements 35 and 36 and electronic components 37 and 38 on the inner bottom surface of the housing recess 10a, and a plurality of electric circuit patterns 16 are formed. The receiving photodiode 32 and the electric integrated circuit element 35 are electrically connected via the electric circuit pattern 16, and the transmitting laser diode 33 and the electric integrated circuit element 36 are connected via another electric circuit pattern 16. Are electrically connected. The signal processing circuits and the external connection terminals 17 are also electrically connected via the electric circuit pattern 16.
[0021]
The cover 20 is hermetically fixed to the substrate 10 so as to cover the optical semiconductor elements, the electric integrated circuit elements 35 and 36, and the electric circuit pattern 16. Here, the cover 20 is formed with a recess 20 a in a portion corresponding to the storage recess 10 a of the substrate 10. Accordingly, the front end surfaces of the peripheral wall 20b of the recess 20a in the cover 20 and the peripheral wall 10b of the storage recess 10a in the substrate 10 are mating surfaces, and both mating surfaces are fixed via an adhesive (not shown). ing.
[0022]
  ButOf this reference exampleIn the optical communication module, the core portion 12, the optical semiconductor element (receiving photodiode 32, transmitting laser diode 33, monitoring photodiode 34) and electric circuit pattern 16 are arranged on the substrate 10 constituting a part of the package 1. Therefore, a substrate 80 such as a silicon substrate on which a planar lightwave circuit (PLC) is formed and an optical semiconductor element is arranged as in each of the conventional configurations shown in FIGS. 11 to 14 and the package 90 are separate parts. Compared to the case, the number of parts can be reduced and the cost can be reduced, and positioning recesses 10c for positioning the multilayer filter 31 and positioning recesses 10d to 10f for positioning the respective optical semiconductor elements are formed in the substrate 10. This simplifies the process that requires alignment during assembly. Further, even if the substrate 10 contracts or expands due to the influence of heat, the optical relative positional accuracy between the core portion 12 and each optical semiconductor element optically coupled to the core portion 12 is maintained. It is possible to suppress a decrease in optical coupling efficiency due to a temperature change caused by a change in temperature or heat generation of components in the package 1.
[0023]
Note that most of the substrate 10 excluding the core portion 12 is made of a synthetic resin having a lower refractive index than that of the core portion 12. Moreover, it is preferable to use the same synthetic resin as the substrate 10 as the material of the cover 20. By using the same synthetic resin as the substrate 10, the peripheral wall 10 b of the substrate 10 and the peripheral wall 20 b of the cover 20 are caused by temperature fluctuation. Between the front end faces of each other and foreign matter such as dust and dirt can be prevented from entering the package 1 and the reliability of the optical communication module is improved. Each optical semiconductor element is electrically connected to the electric circuit pattern 16 via a bonding wire W (see FIG. 2).
[0024]
  (Embodiment1)
  Basic configuration of optical communication module of this embodimentIs a reference example andAlmost the same, as shown in FIG., For reference exampleThe electric integrated circuit element 36 described above is disposed on the inner bottom surface of the recess 20a in the cover 20, and the transmitting laser diode 33 (see FIG. 1) is connected via the electric circuit pattern 16 formed on the inner bottom surface of the recess 20a. It is different in that it is electrically connected. Here, in the electric circuit pattern 16 formed on each of the substrate 10 and the cover 20, the electric circuit pattern 16 connected to the external connection terminal 17 is a mating surface between the substrate 10 and the cover 20 (tip surfaces of the peripheral walls 10 b and 20 b, respectively). ) (That is, the electric circuit pattern 16 is three-dimensionally wired). In additionAnd reference examplesSimilar components are denoted by the same reference numerals, and description thereof is omitted.
[0025]
Thus, in the optical communication module of the present embodiment, the electrical integrated circuit element 36 is disposed on the surface of the cover 20 facing the substrate 10, and the electrical integrated circuit element 36 and the transmitting laser diode 33 are electrically connected. Since part of the electric circuit pattern 16 to be connected is formed, the package 1 can be reduced in size in a plane orthogonal to the thickness direction of the substrate 10 (vertical direction in FIG. 3). Further, compared with the case where the electrical integrated circuit element 36 disposed on the cover 29 is disposed on the substrate 10 adjacent to the optical semiconductor element, the heat transmitted through the substrate 10 between the electrical integrated circuit element 36 and the optical semiconductor element. And the influence of the mutual heat on the respective operating characteristics can be reduced.
[0026]
Hereinafter, a basic manufacturing method of the optical communication module of the present embodiment will be described with reference to FIGS.
[0027]
First, a structure shown in FIG. 4A is obtained by forming a first resist layer 41 by applying a photoresist on one surface of a carrier substrate 40 made of a silicon substrate by spin coating or the like. In order to make the thickness of the first resist layer 41 uniform in the plane, a substrate having a smooth surface, a small surface roughness, and a small dimensional change due to heat and moisture absorption is used as the carrier substrate 40. Therefore, in this embodiment, a silicon substrate is used as the carrier substrate 40.
[0028]
Subsequently, a groove 42 is formed in a portion corresponding to a region where the core portion 12 is to be formed by lithography technology (exposure and development), and in portions corresponding to the positioning grooves 14a and 14b and the positioning recesses 10c to 10f. The first resist layer 41 is patterned and baked to form an opening that exposes the one surface of the carrier substrate 40, whereby the structure shown in FIG. 4B is obtained. In addition, as a photoresist used as the material of the first resist layer 41, a positive photoresist in which a portion exposed by ultraviolet rays or X-rays is removed during development may be employed, or a portion not exposed. It is better to use a negative type photoresist that is removed during development, and the depth varies by using a gray scale mask that can partially change the intensity of transmitted light and a laser that can control the irradiation intensity. The grooves 42 and the openings (openings formed in the portions corresponding to the positioning recesses 10c to 10f) can be easily formed.
[0029]
Next, a photoresist is applied to the entire surface of the carrier substrate 40 by spin coating to form a second resist layer 43, whereby the structure shown in FIG. 4C is obtained. Subsequently, the first resist layer 41 and the second resist layer 43 are patterned by lithographic techniques (exposure and development) so that a portion of the second resist layer 43 corresponding to the peripheral wall 10b of the substrate 10 remains. By forming the master mold 44 made of the structure shown in FIG. As the material of the second resist layer 43, as in the case of the first resist layer 41, either positive type or negative type photoresist may be adopted. Here, by making one of the first resist layer 41 and the second resist layer 43 negative type and the other positive type, the first resist layer 41 is eroded when the second resist layer 43 is developed. Can be prevented. In addition, by performing a baking process after the development of the first resist layer 41, the first resist layer 41 can be prevented from being eroded during the development of the second resist layer 43.
[0030]
After the master mold 44 is formed, a first conductive thin film (not shown) made of a metal material (for example, nickel, silver, copper, chromium, cobalt, etc.) is formed on the master mold 44 in order to perform electroforming by electroplating. The first mold 51 is formed by performing electroplating, and the structure shown in FIG. 4E is obtained. As a method for forming the first conductive thin film, for example, a sputtering method, a vapor deposition method, a chemical plating method, or the like may be adopted. However, the conductive thin film is not peeled off from the surface of the master mold 44 during electroplating. Of these film formation methods, the sputtering method is most suitable. However, at the time of film formation by sputtering, it is necessary to perform a process of activating the surface of the master mold 44 with plasma before sputtering. Moreover, as a metal material used for electroplating, for example, nickel, chromium, cobalt, copper, nickel alloy or the like may be used. In order to ensure physical properties necessary for a molding die such as surface hardness, corrosion resistance, and heat resistance. It is preferable to add a small amount of additives.
[0031]
  Subsequently, after removing the carrier substrate 40 and releasing the first mold 51 by peeling off the master mold 44, the first mold 51 is set as the upper mold as shown in FIG. The base 11 made of a synthetic resin molded product is formed by molding using the lower second mold 52 in FIG. 5A as the lower mold, and the mold 11 is released from the mold as shown in FIG. The structure shown is obtained. Here, on one surface side of the base 11 (upper surface side in FIG. 5B), For reference exampleThe positioning grooves 14a and 14b, the positioning recesses 10c to 10f (see FIG. 1), and the injection groove 10g for injecting the core material of the core portion 12 are formed. The injection groove 10g corresponds to the groove 42 in the master mold 44 described above. In this embodiment, the material of the first conductive thin film and the main component of the material used for electroplating are the same, and the first conductive thin film constitutes a part of the first mold 51. However, the material of the first conductive thin film may be different from the material used for electroplating. Further, after removing the carrier substrate 40 and the master mold 44, the first conductive thin film attached to the first mold 51 may be removed by selective etching. Further, as a method for removing the carrier substrate 40, a method of physically peeling or a method of dissolving and removing with a chemical may be employed. Further, for removing the mask mold 44, an organic solvent or a commercially available resist-specific release agent may be used. If a resist residue remains, it may be removed with an alkaline aqueous solution or plasma. The second mold 52 is formed by machining. In addition, as a method for forming the base 11, injection molding, compression molding, or the like may be performed. Here, since the base 11 also serves as the lower cladding layer of the optical waveguide, a material suitable for the cladding of the optical waveguide (for example, acrylic resin, polycarbonate resin, epoxy resin, etc.) may be used as the molding material.
[0032]
After the base 11 is released, as shown in FIG. 5C, the constituent material of the core portion 12 (hereinafter referred to as the core material) is injected into the injection groove 10g corresponding to the region where the core portion 12 is to be formed in the base 11. A synthetic resin (for example, acrylic resin, polycarbonate resin, epoxy resin, or the like) to be formed is injected using a dispenser 46 or the like to fill the injection groove 10g. Of course, a synthetic resin having a refractive index higher than that of the base 11 is used as the core material. In the present embodiment, since the dispenser 46 is used when injecting the core material into the injection groove 10g, it is possible to prevent the core material from adhering to portions other than the injection groove 10g. Further, it is desirable to insert a dummy part into the positioning recesses 10c to 10f or perform masking to prevent the core material from entering.
[0033]
Thereafter, the core material 12 injected into the injection groove 10g is cured by ultraviolet or heat to form the core 12 and the structure shown in FIG. 5D is obtained.
[0034]
Next, a substrate 10 is formed by applying a clad material so as to cover the core portion 12 and forming an upper clad layer 13 by ultraviolet curing or thermosetting, and the structure shown in FIG. 5E is obtained. In the present embodiment, the base 11, which serves also as the lower clad layer, the core part 12, and the upper clad layer 13 constitute an optical waveguide. Further, the upper clad layer 13 may be bonded as a separate part.
[0035]
After forming the above optical waveguide, a plating base layer 47 made of a second conductive thin film is formed on the one surface side of the substrate 10 to obtain the structure shown in FIG. For example, copper, nickel, silver, or the like may be used as the material of the plating base layer 47. As a film forming method of the plating base layer 47, a sputtering method, a vapor deposition method, a chemical plating method, or the like may be used. Good. Here, if the thickness of the plating base layer 47 is too thin, precipitation does not occur during the subsequent electroplating, and if it is too thick, patterning of the plating base layer 47 by the laser beam, which is the next process, becomes difficult. The thickness of the formation 47 is preferably set in the range of 0.1 μm to 10 μm.
[0036]
After the plating base layer 47 is formed on the one surface side of the substrate 10, a portion (hereinafter referred to as a circuit portion) 47 a corresponding to the electric circuit pattern 16 formed on the substrate 10 in the plating base layer 47 and the surrounding unnecessary A structure shown in FIG. 6B is formed by performing patterning for irradiating an electromagnetic wave such as a laser beam B to a boundary region with a portion (hereinafter referred to as a non-circuit portion) 47b to remove a part of the plating base layer 47. Is obtained.
[0037]
Subsequently, the structure shown in FIG. 6C is obtained by forming an electric circuit pattern 16 by applying an electric current to only the circuit portion 47a of the plating base layer 47 to perform electroplating. In addition, since a current is not passed through the non-circuit portion 47b in the plating base layer 47, the non-circuit portion 47b is not plated. Moreover, what is necessary is just to employ | adopt copper, nickel, silver etc. as a material of electroplating, for example.
[0038]
Next, the structure shown in FIG. 6D is obtained by removing the non-circuit portion 47b of the plating base layer 47 by etching using an etching solution or dry etching using plasma or the like. In addition, after completion | finish of etching, you may perform surface treatments, such as gold plating and solder plating, to the electric circuit pattern 16 as needed or according to a use.
[0039]
Thereafter, the multilayer filter 31 is mounted on the one surface side of the substrate 10 and optical semiconductor elements such as the receiving photodiode 32, the transmitting laser diode 33, and the monitoring photodiode 34 are mounted, and then wire bonding is performed. Thus, the electric circuit pattern 16 is electrically connected via the bonding wire W. After that, by mounting electrical integrated circuit elements 35, 36, electronic components 37, 38, etc. on the one surface side of the substrate 10 and electrically connecting to the electrical circuit pattern 16, the structure shown in FIG. Is obtained. Note that the order of mounting the optical semiconductor elements and the electrical components (electrical integrated circuit elements 35, 36, etc.) is not particularly limited. However, since it is necessary to position the multilayer filter 31 and the optical semiconductor element with high precision, it is necessary to perform positioning while operating each optical semiconductor element to propagate light to the core portion 12 of the optical waveguide and performing optical measurement. There is.
[0040]
Next, the optical fiber 2 is positioned by the positioning grooves 14a and 14b (see FIG. 1) of the substrate 10, and the cover 20 shown in the upper side of FIG. 7B is fixed to the substrate 10 with an adhesive (not shown). By doing so, the structure shown in FIG. 3 is obtained. Since the optical fiber 2 can be positioned with high accuracy by the positioning grooves 14a and 14b, it is not necessary to perform positioning while propagating light to the optical fiber 2, and can be mounted without adjustment.
[0041]
According to the manufacturing method described above, when the substrate 10 is formed, the process of applying the photoresist on the one surface side of the carrier substrate 40 and patterning is repeated a plurality of times, so that the core material injection groove 10g and each of the core portions 12 are formed. A step of forming a master mold 44 of a synthetic resin base 11 which is formed with positioning recesses 10c to 10f serving as positioning sections of the respective optical semiconductor elements on one surface side and also serves as a lower cladding layer of the optical waveguide; and electroplating the master mold 44 The step of forming the mold 51 by transfer, the step of forming the base 11 using the mold 51, the core material having a refractive index higher than that of the base 11 is injected into the injection groove 10g of the base 11 The step of forming the core portion 12 and the upper cladding layer 13 made of a synthetic resin having a lower refractive index than the core portion 12 and covering the core portion 12 are And forming the electric circuit pattern 16 after the upper clad layer 13 is formed, so that the number of parts and the number of man-hours for assembling can be reduced as compared with the prior art. An optical communication module capable of achieving the above can be provided. Further, by using the first mold 51 formed by transferring the above-described master mold 44 by electroplating, there is an advantage that the cost can be reduced due to mass production.
[0042]
Further, in the step of forming the electric circuit pattern 16, a process of forming a plating base layer 47 made of a conductive thin film on the one surface of the substrate 10 and a circuit portion 47 a corresponding to the electric circuit pattern 16 in the plating base layer 47. And a step of irradiating the boundary region between the non-circuit portion 47b by irradiating the laser beam B, a step of plating the portion corresponding to the circuit portion 47a, and a step of removing the non-circuit portion 47b. The electric circuit pattern 16 can be accurately formed on the one surface side of 10. Further, the irradiation time of the laser beam B can be shortened compared with the case where the entire non-circuit portion 47b of the plating base layer 47 is irradiated with the laser beam B, productivity can be improved, and the waste of the plating material can be reduced. There is an advantage that the cost can be reduced.
[0043]
  In addition, the manufacturing method demonstrated above is another embodiment.Condition and reference examplesThe present invention can also be applied to an optical communication module manufacturing method. Further, in the above-described manufacturing method, the master mold 44 is formed by repeating the process of applying the photoresist on the one surface side of the carrier substrate 40 and patterning twice, thereby forming the portions corresponding to the fixing grooves 15a and 15b. However, it is a matter of course that portions corresponding to the fixing grooves 15a and 15b can be formed in the master die 44 by appropriately designing the number of repetitions and the exposure mask.
[0044]
Incidentally, in the above-described optical communication module, as shown in FIGS. 3 and 7B, the electric circuit pattern 16 formed on the substrate 10 and the cover 20 is three-dimensionally wired and extended to the mating surface of the substrate 10 and the cover 20. The electric circuit patterns 16 are electrically connected to each other through the conductive paste 67 (see FIG. 8A) and the substrate 10 and the cover 20 are connected to each other through the adhesive 19 (see FIG. 8A). Thus, the reliability of the electrical connection between the electrical integrated circuit element disposed on the cover 20 and the optical semiconductor element disposed on the substrate 10 is improved, and the package 1 Reliability can be improved by improving airtightness.
[0045]
Further, if the concave-convex fitting structure as shown in any of FIGS. 8A, 8B, and 8C is employed, the relative positioning between the substrate 10 and the cover 20 can be facilitated, and the package can be easily mounted. The airtightness of 1 can be further improved. 8A and 8B, a recess 19 is formed on the front end surface of the peripheral wall 10b of the substrate 10, and a convex portion 29 that fits the recess 19 is provided on the front end surface of the peripheral wall 20b of the cover 20. is there. Moreover, in FIG.8 (c), the convex part 27 is protrudingly provided in the front end surface of the surrounding wall 20b in the cover 20. As shown in FIG. The peripheral wall 10b does not form the recess 19 in the portion having the external connection terminal 17 on the outer surface, and faces the portion of the peripheral wall 20b having the external connection terminal 17 on the outer surface of the peripheral wall 10b. The projecting portion 29 is not provided in the projecting portion.
[0046]
  (Embodiment2)
  The basic configuration of the optical communication module of this embodiment is an embodiment.19 and is different in that a heat radiating plate 61 is embedded on the outer surface side of the package 1 as shown in FIG. Embodiment1The same components as those in FIG.
[0047]
In the present embodiment, the heat radiating plate 61 is provided on the substrate 10 so as to be in contact with the receiving photodiode 32 and the transmitting laser diode 33. Here, as the heat radiating plate 61, a metal plate made of a metal material having a high thermal conductivity (for example, aluminum, copper, or a copper alloy), a ceramic plate made of a ceramic material having a high thermal conductivity (for example, alumina), or the like. Can be adopted.
[0048]
As a method of embedding the heat sink 61 in the substrate 10, there are a method of insert molding when the base 11 is molded, a method of bonding after processing the substrate 10 after the base 11 is molded, and the like. Further, it is also possible to adopt a method in which the external connection terminal 17 is constituted by a part of the lead frame and the other part of the lead frame is a heat sink.
[0049]
Thus, in the optical communication module of this embodiment, since the heat radiating plate 61 is provided on the outer surface side of the package 1, heat dissipation can be improved, and each element (optical semiconductor element or electric integrated circuit element 35, 36). And the deformation of the substrate 10 due to the heat generated by the electronic components 37, 38, etc. can be prevented, so that the optical coupling portion can be prevented from being displaced, the decrease in the optical coupling efficiency can be suppressed, and the optical circuit can be transmitted. The increase in loss can be suppressed, and further, the characteristic variation of each element can be suppressed.
[0050]
  (Embodiment3)
  The basic configuration of the optical coupling device of this embodiment is an embodiment.110 except that a metal film 63 that is attached to the outer surface of the package 1 and electrically connected to the external connection terminal 17 is provided as shown in FIG. Here, the metal film 63 is formed on both the substrate 10 and the cover 20. Embodiment1The same components as those in FIG.
[0051]
Thus, in the optical communication module according to the present embodiment, the metal film 63 deposited on the outer surface of the package 1 has a function as a shield film and a function as a light shield film, thereby preventing high frequency noise due to the shield effect. It is possible to prevent malfunction of each element due to the light shielding effect.
[0052]
If the metal film 63 is made of the same material as the electric circuit pattern 16, the metal film 63 can be formed simultaneously with the electric circuit pattern 16, and the transmission loss of the optical waveguide is increased without adding a new process. Can be suppressed.
[0053]
【The invention's effect】
According to the first aspect of the present invention, there is provided a substrate made of a synthetic resin, which is embedded in a core part which forms an optical circuit by being optically coupled to an external optical fiber and constitutes a part of the package, and an optical circuit provided on one surface side of the substrate. An optical semiconductor element that is optically coupled and an electric integrated circuit element that cooperates with the optical semiconductor element, and an electric circuit pattern that electrically connects the optical semiconductor element and the electric integrated circuit element is formed on the substrate. In addition, a positioning part for positioning the optical semiconductor element is formed, and the core part, the optical semiconductor element, and the electric circuit pattern are arranged on the substrate constituting a part of the package. Compared to the case where a substrate such as a silicon substrate on which a planar lightwave circuit (PLC) is formed and an optical semiconductor element is arranged and a package are separate components, the number of components can be reduced and the cost can be reduced. There are fruit, also the positioning portion for positioning the optical semiconductor element is formed on the substrate, there is an effect that process required alignment during assembly is simplified.
[0054]
  The invention of claim 1 is a lightSemiconductor elements andPowerIntegrated circuit elements andPowerA cover hermetically fixed to the substrate so as to cover the air circuit pattern, and a side surface of the substrate.PowerSince it has an external connection terminal electrically connected to the integrated circuit element, PaIntrusion of foreign matter such as dust and dirt into the package can be prevented, and the reliability of the optical communication module is improved.
[0055]
  In the invention of claim 1,The bar is the surface facing the substrateToWith integrated circuit elements, ElectricIntegrated circuit elementAnd lightSince a part of the electric circuit pattern for electrically connecting the semiconductor element is formed, it can be placed in a plane perpendicular to the thickness direction of the substrate.RuThere is an effect that the package can be downsized. Also, MosquitoPlaced in the barPowerIntegrated circuit elementThe lightCompared to the case where it is arranged on the substrate adjacent to the semiconductor element., ElectricIntegrated circuit elementAnd lightThere is an effect that the heat transmitted through the substrate to and from the semiconductor element can be reduced, and the influence of the mutual heat on the respective operation characteristics can be reduced.
[0056]
  Claim2The invention of claim1In this invention, since the cover and the substrate are concavo-convexly fitted, and the electric circuit pattern is extended on the mating surfaces of the cover and the substrate, the electric integrated circuit disposed on the cover The reliability of the electrical connection between the device and the optical semiconductor device disposed on the substrate is improved, and the reliability can be improved by increasing the airtightness of the package.
[0057]
  Claim3The invention is claimedItem 1In the invention, since the package is constituted by the substrate and the cover, and a heat radiating plate is provided on the outer surface side of the package, heat dissipation can be improved, and deformation of the substrate due to heat generation of the respective elements. Therefore, the optical coupling portion can be prevented from being displaced, the decrease in the optical coupling efficiency can be suppressed, and the increase in the transmission loss in the optical circuit can be suppressed. There is an effect that fluctuation can be suppressed.
[0058]
  Claim4The invention is claimedItem 1In the invention, the package is constituted by the substrate and the cover, and includes a metal film that is attached to the outer surface of the package and electrically connected to the external connection terminal. Therefore, the metal film serves as a shield film. It has the function and the function as a light shielding film, and there is an effect that it is possible to prevent high frequency noise due to the shielding effect and prevent malfunction of each element due to the light shielding effect.
[0059]
  Claim5The invention of claim 1 to claim 14The method of manufacturing an optical communication module according to any one of the above, wherein in forming the substrate, the core material of the core portion is formed by repeating a process of applying a photoresist on one surface side of the carrier substrate and patterning a plurality of times. A step of forming a master mold of a synthetic resin base which is formed on one surface side of the injection groove and the positioning portion and also serves as a lower cladding layer of the optical waveguide, and a mold is formed by transferring the master mold by electroplating A step of forming a base using the mold, a step of injecting the core material having a higher refractive index than the base into an injection groove in the base, and forming the core portion, A step of forming an upper clad layer made of a synthetic resin having a low refractive index and covering the core portion on the one surface side of the base; and after forming the upper clad layer, the electric circuit Because and forming a pattern, there is an effect that it is possible to provide an optical communication module which attained a reduction and reduction of man-hour in assembling the parts as compared with the prior art. In addition, there is an advantage that the cost can be reduced due to mass production by using a mold formed by transferring the master mold by electroplating.
[0060]
  Claim6The invention of claim5In the invention, in the step of forming the electric circuit pattern, a process of forming a conductive thin film on the one surface of the substrate, and a portion of the conductive thin film corresponding to the electric circuit pattern and a peripheral unnecessary portion Since it includes a process of irradiating the boundary region with a laser beam, a process of plating the part corresponding to the electric circuit pattern in the conductive thin film, and a process of removing unnecessary parts of the conductive thin film. There is an effect that an electric circuit pattern can be accurately formed on the one surface side of the substrate having the positioning portion. In addition, the laser beam irradiation time can be shortened compared with the case where the entire unnecessary portion of the conductive thin film is irradiated with a laser beam, productivity can be improved, and the cost of the plating material can be reduced and the cost can be reduced. There is an advantage that it can be planned.
[Brief description of the drawings]
[Figure 1]Reference examplesIt is a schematic perspective view of the state which showed and removed the cover.
FIG. 2 is a schematic sectional view showing the above.
FIG. 31It is a schematic sectional drawing which shows.
FIG. 4 is a cross-sectional view of main processes for explaining the manufacturing method according to the embodiment.
FIG. 5 is a main process sectional view for illustrating the manufacturing method according to the embodiment.
FIG. 6 is a sectional view of a main process for explaining the manufacturing method according to the embodiment.
FIG. 7 is a cross-sectional view of main steps for describing the manufacturing method according to the embodiment.
8A is an explanatory diagram of the main part of the above, and FIG. 8B is an explanatory diagram of another configuration example of the main part of the same.
FIG. 92It is a schematic sectional drawing which shows.
FIG. 10 is an embodiment.3It is a schematic sectional drawing which shows.
FIG. 11 is a schematic sectional view showing a conventional example.
FIG. 12 is a partially broken schematic perspective view showing another conventional example.
FIG. 13 is a schematic perspective view showing another conventional example.
FIG. 14 is a partially broken exploded perspective view showing another conventional example.
[Explanation of symbols]
  1 package
  10 Substrate
  10a Storage recess
  10c-10f Positioning recess
  10g injection groove
  11 base
  12 Core part
  13 Upper cladding layer
  14a, 14b Positioning groove
  16 Electric circuit pattern
  17 External connection terminal
  20 Cover
  31 multilayer filter
  32 photodiode (receiver photodiode)
  33 Laser diode (Transmission laser diode)
  34 Photodiode (Monitor Photodiode)
  35, 36 Electrical integrated circuit elements

Claims (6)

A synthetic resin substrate that is embedded in a core part that is optically coupled to an external optical fiber and forms an optical circuit, and an optical semiconductor element that is provided on one surface side of the substrate and is optically coupled to the optical circuit And an electric integrated circuit element cooperating with the optical semiconductor element, and an electric circuit pattern for electrically connecting the optical semiconductor element and the electric integrated circuit element is formed on the substrate, and the optical semiconductor element is positioned And a cover that is hermetically fixed to the substrate so as to cover the optical semiconductor element, the electric integrated circuit element, and the electric circuit pattern, and an electric circuit that is provided on a side surface of the substrate. And an external connection terminal connected to the substrate. The cover has an electrical integrated circuit element disposed on a surface facing the substrate, and electrically connects the electrical integrated circuit element and the optical semiconductor element. Optical communication module, wherein a part of the electric circuit pattern is formed to be. 2. The optical communication module according to claim 1 , wherein the cover and the substrate are concavo-convexly fitted, and the electric circuit pattern is extended on a mating surface of the cover and the substrate . Wherein the package substrate and the cover is configured, the optical communication module according to claim 1, characterized in that heat radiating plate is provided on the outer surface side of the package. Is the package consists of said cover and said substrate, optical communication according to claim 1, wherein is deposited on the outer surface of the package is characterized by including the external connection terminal electrically connected to the metal film module. 5. The method of manufacturing an optical communication module according to claim 1, wherein in forming the substrate, a process of applying a photoresist on one surface side of the carrier substrate and patterning is repeated a plurality of times. A step of forming a master mold of a synthetic resin base in which the groove for injecting the core material of the core section and the positioning section are formed on one surface side and also serving as a lower cladding layer of the optical waveguide; and the master mold by electroplating A step of transferring and forming a mold; a step of forming a base using the mold; and a step of injecting the core material having a higher refractive index than the base into an injection groove in the base to form the core portion A step of forming an upper clad layer made of a synthetic resin having a lower refractive index than the core portion on the one surface side of the base, and an upper clad layer Method of manufacturing an optical communication module, characterized in that after form and forming the electric circuit pattern. In the step of forming the electric circuit pattern, a laser is applied to a boundary region between a step of forming a conductive thin film on the one surface of the substrate and a portion of the conductive thin film corresponding to the electric circuit pattern and a peripheral unnecessary portion. The method includes a step of irradiating a beam, cutting a portion corresponding to the electric circuit pattern of the conductive thin film, and a step of removing unnecessary portions of the conductive thin film. Item 6. A method for manufacturing an optical communication module according to Item 5.

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