JP2009244702A - Optical communication module, method for manufacturing optical communication module, plastic optical fiber module, optical signal transmission method using plastic optical fiber module, electronic apparatus, and method for manufacturing electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical communication module, etc. wherein a sealing property of a connection part of a plastic optical fiber is improved, an end face is protected, and miniaturization is readily attained. <P>SOLUTION: The optical communication module 1 includes a first lead frame 3 having a pad portion 5; a second lead frame 9 having a bonding portion 11; an optical element 7 set on the pad portion 5; a first molding 15 including the optical element 7; a second molding 17 including the first molding 15; and a plastic optical fiber 19. In the module 1, the first lead frame 9 has a side face 3c, the pad portion 5 is formed on the side face 3c, a guide hole 17a is formed on the second molding 17 so as to face the optical element 7, and in a state that the plastic optical fiber 19 is led into the guide hole 17a, a gap between the second molding 17 and the plastic optical fiber 19 is filled with a cured object of adhesive 21. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical communication module and a plastic optical fiber module used for short-distance optical signal transmission, particularly in portable electronic devices such as mobile phones, PDAs, mobile personal computers, video cameras, digital still cameras, and game machines, and flat-screen televisions. The present invention relates to a plastic optical fiber module and an electronic apparatus that can be suitably used for optical signal transmission in a part that is semi-permanently fixed in an electronic apparatus that can move an installation place when a projector or the like is used. In particular, it is suitably used for transmitting an optical signal between an upper unit and a lower unit through the hinge part in a portable electronic device comprising two units having a hinge part for opening and closing, such as a mobile phone or a mobile computer. The present invention relates to a plastic optical fiber module. Furthermore, the present invention relates to an optical communication module manufacturing method, an optical signal transmission method using a plastic optical fiber module, and an electronic device manufacturing method.

  Plastic optical fibers are more flexible than silica-based optical fibers, and have a large aperture and a high numerical aperture. It is used in fields such as signal transmission and sensors.

  Conventionally, a plastic optical fiber and an optical transmission circuit / optical reception circuit are connected with an optical connector for fitting a plug terminated with a plastic optical fiber and a receptacle equipped with the optical transmission circuit / optical reception circuit. .

  In recent years, plastic optical fibers have been tried to be used for signal connection between parts that involve opening and closing operations and rotating operations of portable electronic devices, and can be suitably used for optical signal transmission in parts that require repeated bending. Has been proposed (see, for example, Patent Document 1).

As such a plastic optical fiber module for portable electronic devices, if an optical connector is used to connect a conventional plastic optical fiber and an optical transmission circuit / optical reception circuit, the plastic optical module cannot be reduced in size, and portable electronic Since it is difficult to reduce the size of the device, a small optical module that does not use an optical connector has been proposed (see Patent Document 2).
Japanese Patent Laid-Open No. 2007-249111 Japanese Patent Laid-Open No. 2007-94200

  However, the optical module described in Patent Document 2 is not completely sealed because it simply fits the projections and recesses of the projections and grooves, and the end face of the plastic optical fiber or the optical system due to intrusion of dust or moisture. Performance could be degraded.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems. An optical communication module and an optical communication module in which a connection portion of a plastic optical fiber is well sealed, an end surface of the plastic optical fiber is protected, and the size can be easily reduced. It is an object of the present invention to provide a manufacturing method, a plastic optical fiber module including an optical communication module, an optical signal transmission method using the plastic optical fiber module, an electronic device, and a manufacturing method of the electronic device.

  As a result of intensive studies in order to solve the above problems, the present inventors have completed the present invention.

  The present invention includes a first lead frame having a pad portion, a second lead frame having a bonding portion, an optical element placed on the pad portion, a first molded body including the optical element, An optical communication module comprising a second molded body including the molded body and a plastic optical fiber, wherein the first lead frame has a plate portion extending in a band shape, and the plate portion is a pair of It has a plate surface and a side surface narrower than the plate surface, the pad portion is provided on the side surface of the plate portion, the optical element is connected to the bonding portion by a bonding wire, and the first molded body is transparent A first resin, a pad part and a part of the first lead frame, a bonding part and a part of the second lead frame, and an optical element, wherein the second molded body is at least in the visible light region. so The first molded body is made of a transparent second resin, and the second molded body has a guide hole formed in a portion facing the optical element, and a plastic optical fiber is introduced into the guide hole. The gap between the second molded body and the plastic optical fiber is filled with a cured product of an adhesive.

  According to the present invention, the optical element is included in the first molded body made of the transparent first resin, the guide hole is formed in the second molded body including the first molded body, and the guide hole is formed. Since the plastic optical fiber is introduced into the plastic optical fiber, the gap between the second molded body and the plastic optical fiber is filled and fixed with an adhesive, so that the sealing of the plastic optical fiber connection is good and the end face of the plastic optical fiber is good. Is configured to be protected. Furthermore, the pad portion on which the optical element is installed is provided on the side surface, not on the plate surface of the first lead frame. Accordingly, the plastic optical fiber can be extended toward the side of the first lead frame with its end face facing the optical element, so that it is easy to make it compact and easy to downsize. .

  Further, it is preferable that the pad portion has a flat portion standing along the side surface and extending in a direction intersecting the plate surface, and a bent portion connecting the side surface and the flat portion.

  Further, the first lead frame is formed by bending a base material molded into a predetermined shape to form a plate portion and a pad portion. The thickness of the first lead frame is 50 to 350 μm, and the flat portion of the pad portion The height is preferably 30 μm or more and 600 μm or less.

  Furthermore, it is preferable that the width of the flat portion of the pad portion is equal to or greater than the height of the flat portion of the pad portion.

  Further, the plastic optical fiber surrounds the sheath layer with a core of 7 or more and 10,000 or less made of a transparent core resin, at least one sheath layer surrounding the core and made of a transparent sheath resin having a refractive index lower than that of the core resin. It is preferable that a multi-core plastic optical fiber having a cross-sectional shape constituted by a sea layer made of a sea resin and a coating layer surrounding the multi-core plastic optical fiber are provided.

  Furthermore, a photo-curing adhesive can be used as the adhesive, and in particular, the photo-curing adhesive is preferably an ultraviolet-curing adhesive.

  Further, the optical element may be a light emitting element, and the light emitting element is preferably a surface emitting laser having a light wavelength of 400 nm or more and 1700 nm or less.

  Furthermore, the optical element may be a light receiving element, and the light receiving element is preferably a photodiode having a sensitivity peak in a wavelength range of 400 nm to 1700 nm.

  According to the present invention, in the above-described method for manufacturing an optical communication module, a step of mounting an optical element on a pad portion of a lead frame having a pad portion and a bonding portion, and the bonding portion and the optical element are connected by a bonding wire. A step of molding a first molded body so as to include a part of a lead frame having a pad portion and a bonding portion, and an optical element; and a lead frame having a first lead frame having a pad portion. A step of cutting into a second lead frame having a bonding portion, a step of molding a second molded body including a first molded body and having a guide hole in a portion facing the optical element, and a guide hole And a step of introducing a plastic optical fiber into the guide hole and a step of curing the adhesive. .

  According to another aspect of the present invention, there is provided a plastic optical fiber module including an optical communication module having an optical element made of the light emitting element and an optical communication module having an optical element made of the light receiving element. The plastic optical fiber is a common plastic optical fiber.

  According to another aspect of the present invention, there is provided an optical signal transmission method characterized in that signal transmission is performed using the plastic optical fiber module described above in an electronic device.

  In addition, an electronic device according to the present invention includes a first housing, a second housing, and an electronic device having a hinge portion that connects the first housing, and the first housing includes an optical element including a light receiving element. An optical communication module having an optical element composed of a light emitting element, a hinge portion having a hole, and a plastic optical fiber of each optical communication module This is a common plastic optical fiber, and one plastic optical fiber is characterized by passing through a hole in the hinge portion.

  Further, the present invention is a method of manufacturing an electronic device having a first housing, a second housing, and a hinge portion for connecting them, a first lead frame having a first pad portion, A second lead frame having a first bonding portion; a first optical element disposed on the first pad; a first molded body including the first optical element; and a first molded body A first optical communication module including a plastic optical fiber, wherein the first lead frame has a first plate portion extending in a strip shape, The plate portion has a pair of plate surfaces and a side surface narrower than the plate surface, the first pad portion is provided on the side surface of the first plate portion, and the first optical element is the first optical element. The first molded body is connected to the first bonding part by a bonding wire of Made of a transparent first resin, including a first pad part and a part of the first lead frame, a first bonding part and a part of the second lead frame, and a first optical element, The second molded body includes a first molded body made of a second resin which is opaque at least in the visible light range, and the second molded body includes a first portion in a portion facing the first optical element. Introducing and bonding one end of the plastic optical fiber to the first guide hole of the first optical communication module in which the guide hole is formed; passing the other end of the plastic optical fiber through the hole of the hinge portion; A third lead frame having a second pad portion; a fourth lead frame having a second bonding portion; a second optical element disposed on the second pad portion; and a second optical element. Including a third molded body and a third molded body A second optical communication module comprising a fourth molded body and a plastic optical fiber, wherein the third lead frame has a second plate portion extending in a band shape, and the second plate portion is , Having a pair of plate surfaces and a side surface narrower than the plate surface, the second pad portion is provided on the side surface of the second plate portion, and the second optical element is a second bonding wire Connected to the second bonding portion, the third molded body is made of a transparent third resin, a part of the second pad portion and the third lead frame, the second bonding portion and the fourth bonding portion. A part of the lead frame and the second optical element are included, and the fourth molded body includes a third molded body made of a fourth resin which is opaque at least in the visible light region. The second guide hole is formed in the part facing the second optical element. Introducing and bonding the other end of the plastic optical fiber into the second guide hole of the second optical communication module, attaching the first optical communication module to the first housing, Attaching the optical communication module to the second housing.

  According to the present invention, the sealing portion of the connecting portion of the plastic optical fiber is good, the end face of the plastic optical fiber is protected, and the size can be easily reduced.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated in detail, referring an accompanying drawing. In the drawings, the same elements are denoted by the same reference numerals if possible. In addition, the dimensional ratios in the components in the drawings and between the components are arbitrary for easy viewing of the drawings.

  FIG. 1 is a schematic cross-sectional view of the optical communication module according to the present embodiment, and FIG. 2 is a schematic cross-sectional view of the optical communication module taken along line II-II in FIG. The optical communication module 1 of this embodiment includes a first lead frame 3, a second lead frame 9, an optical element 7, a first molded body 15, a second molded body 17, and a plastic optical fiber 19. Yes.

  The first lead frame 3 is made of a plate-like member, and has a plate portion 3a extending in a strip shape and a pad portion 5 standing on the plate portion 3a. The plate portion 3a has a pair of plate surfaces 3b and a side surface 3c that is narrower than the plate surface 3b. The plate portion 3 a and the pad portion 5 are integrally connected, and a part of the side surface 3 c of the plate portion 3 a becomes a virtual cross section on the base side of the pad portion 5. Accordingly, the pad portion 5 is provided on the side surface 3c (virtual cross section) of the plate portion 3a. An optical element 7 is installed on the pad portion 5.

  FIG. 3 is a perspective view of a part of the first lead frame and the pad portion. The pad part 5 stands up along the side surface 3c. Moreover, the pad part 5 has the flat part 5a extended in the direction which cross | intersects the plate surface 3b, and the bending part 5b which connects the side surface 3c and the flat part 5a. The pad portion 5 can be formed by, for example, bending a part of the first lead frame 3 that is a base material by approximately 90 degrees. After bending a part of the first lead frame 3, a part of the bent part 5b may be shaved to form a wider flat part 5a. On the flat portion 5a, the optical element 7 is mounted with a conductive adhesive such as silver paste.

  The thickness 3t of the first lead frame 3 is preferably 50 μm or more and 350 μm or less. This is because when the thickness 3t is 50 μm or more, it is possible to avoid a deterioration in yield at the time of wire bonding, which will be described later, and when it is 350 μm or less, the height of the package can be suppressed to 1 mm or less. This is because 1 can be suitably applied to a portable electronic device. Further, the height 5ah of the flat portion 5a is preferably 30 μm or more and 600 μm or less. This is because when the height 5ah is 30 μm or more, the planar size of the optical element 7 is about 30 μm square at a minimum, so that the optical element 7 having a small size can be easily installed on the pad portion 5, and is 600 μm or less. This is because the height of the package can be suppressed to 1 mm or less. From the viewpoint of miniaturization, the width 5aw of the flat portion 5a is preferably equal to or greater than the height 5ah of the flat portion 5a. The bending angle of the bending part 5b is preferably approximately 90 degrees. Moreover, it is preferable that the curvature radius R of the outer peripheral part of the bending part 5b is 0.1 micrometer or more and 300 micrometers or less. Such an aspect of the first lead frame 3 and the pad portion 5 is preferable when the length of one side of the bottom surface of the optical element 7 is larger than the thickness 3t of the first lead frame 3.

  The optical element 7 is, for example, a light emitting element or a light receiving element. When the optical element 7 is a light emitting element, the optical communication module 1 is a light emitting module. For example, a semiconductor laser or LED can be used as the light emitting element. In particular, when the optical communication module 1 is used in a portable electronic device that requires low power consumption, the light emitting element is preferably a surface emitting laser having an emission wavelength of 400 nm to 1700 nm. When the optical element 7 is a light receiving element, the optical communication module 1 is a light receiving module. As the light receiving element, for example, a photodiode can be used. The light receiving element needs to be sensitive to the emission wavelength of the light emitting element. For example, when the light emitting element is a surface emitting laser having an emission wavelength of 400 nm to 1700 nm, it is preferable to use a photodiode having a sensitivity peak in the wavelength range of 400 nm to 1700 nm as the light receiving element.

  The second lead frame 9 is a plate-like member and has a bonding portion 11 on its side surface. The bonding part 11 can be formed, for example, by bending a part of the second lead frame 9 approximately 90 degrees. Alternatively, the side surface of the second lead frame 9 may be used as the bonding portion 11. The bonding part 11 and the optical element 7 are electrically connected by a bonding wire 13 made of a metal such as gold. From the viewpoint of facilitating manufacturing, the bonding part 11 is preferably provided on a surface substantially parallel to the pad part 5.

  As a material constituting the first lead frame 3, the second lead frame 9, and the pad portion 5, for example, a metal material such as an iron nickel alloy, aluminum, or copper can be used. In addition to these, iron-nickel alloy plated with various metals, aluminum, copper, or the like can also be used. In particular, copper is preferable because it has high conductivity and is also suitable for precision pressing. The first lead frame 3 and the second lead frame 9 are obtained by etching the plate made of the metal material described above after protecting it with a precision mold according to a predetermined method or protecting it with a pattern mask made of a photoresist. Can be manufactured. Thus, since the first lead frame 3 and the second lead frame 9 are conductive members, if a voltage is applied between the first lead frame 3 and the second lead frame 9, the optical element 7 can be operated.

  FIG. 4 shows a modification of the first lead frame. In this embodiment, the side surface 3c of the first lead frame 3 forms a pad portion. The optical element 7 is mounted on the side surface 3c with a conductive adhesive such as silver paste. In this case, the width and height of the pad portion are equal to the width and height of the side surface 3c, respectively. Such an aspect of the first lead frame 3 is preferable when the length of one side of the bottom surface of the optical element 7 is smaller than the thickness of the first lead frame 3.

  In the method for manufacturing an optical communication module according to the present embodiment, the first lead frame 3 and the second lead frame 9 have a portion that becomes the first lead frame 3 and a portion that becomes the second lead frame 9 as tie bars. The pad portion 5 and / or the bonding portion 11 is formed by bending a part of the first lead frame 3 and / or the second lead frame 9 approximately 90 degrees as necessary. The optical element 7 is mounted on the pad part 5 and connected to the bonding part 11 by the bonding wire 13 so that the pad part 5, the bonding part 11 and the optical element 7 are included, and The first lead 15 is formed by molding the first molded body 15 with a transparent first resin so as not to include the tie bar portion, and cutting the tie bar portion. It is preferable to divide the frame 3 and the second lead frame 9.

  The first molded body 15 is molded so as to include a part of the pad part 5 and the first lead frame 3, a part of the bonding part 11 and the second lead frame 9. The first resin constituting the first molded body 15 needs to be transparent at least at the wavelength of light emitted or received by the optical element 7, and preferably has heat resistance. As the first resin, an epoxy resin, polybutylene terephthalate resin, ABS resin, polycarbonate resin, liquid crystal polymer resin, or the like can be suitably used. Among them, the epoxy resin has already been used as a sealant for most packages of semiconductors, and a transparent epoxy resin can be suitably used as the first resin of the optical communication module 1.

  The second molded body 17 is molded so as to include the first molded body 15 and to have a guide hole 17 a at a portion facing the optical element 7 through the first molded body 17. A plastic optical fiber 19 is introduced into the guide hole 17a. A gap between the second molded body 17 and the plastic optical fiber 19 is filled with a curing agent of an adhesive 21, and the plastic optical fiber 19 is connected to the second molded body 17. In this way, the plastic optical fiber 19 and the optical element 7 are fixed so as to face each other. When the optical element 7 is a light emitting element, light emitted from the light emitting element enters the plastic optical fiber 19, and when the optical element 7 is a light receiving element, the light emitted from the plastic optical fiber 19 enters the light receiving element.

  The second resin constituting the second molded body 17 is an opaque resin at least in the visible light region, and preferably has heat resistance. A resin made opaque by adding a colorant such as carbon black to the transparent resin can also be used as the second resin. As the second resin, epoxy resin, polybutylene terephthalate resin, ABS resin, polycarbonate resin, liquid crystal polymer resin, and the like are preferable. Among these, polybutylene terephthalate resin and liquid crystal polymer resin have stable dimensions when molded, and can be suitably used.

  When connecting the plastic optical fiber 19 to the second molded body 17, the plastic optical fiber 19 may be introduced into the guide hole 17 a after filling the guide hole 17 a with the adhesive 21. The adhesive 21 may be filled into the guide hole 17a after being introduced into the guide hole 17a. Further, the amount of the adhesive 21 used at this time is preferably such that the adhesive 21 protrudes a small amount when the plastic optical fiber 19 is fully introduced into the guide hole 17a to be introduced.

  The adhesive 21 is preferably a light curable adhesive, and more preferably an ultraviolet curable adhesive. When using a photo-curing adhesive, after the step of filling the adhesive 21, the photo-curing adhesive is irradiated with light to cure the photo-curing adhesive. Therefore, the adhesive 21 is more preferably an anaerobic ultraviolet light curable adhesive that naturally cures when the surface is cured by light irradiation. Further, the adhesive 21 is preferably an adhesive having a low viscosity because it is difficult for bubbles to enter.

  The plastic optical fiber 19 is more flexible than the silica-based optical fiber and can be suitably used in the optical communication module 1 of the present embodiment because it is easy to treat and connect to the end face. In particular, in the optical communication module 1, it is preferable to use a plastic optical fiber having a cross-sectional shape as shown in FIG. A plastic optical fiber 19 shown in FIG. 5 includes a multi-core plastic optical fiber 38 and a covering layer 36 surrounding the multi-core plastic optical fiber 38. The multi-core plastic optical fiber 38 includes a plurality of cores 33 made of transparent core resin, at least one sheath layer 34 surrounding each core 33 and made of a transparent sheath resin having a lower refractive index than the core resin, And a sea layer 35 made of sea resin surrounding the sheath layer 34. The number of the cores 33 is preferably 7 or more and 10,000 or less. Such a plastic optical fiber 19 can be suitably used in the optical communication module 1 because of its repeated flexibility.

  The core resin is made of polymethyl methacrylate resin, the sheath resin is made of a copolymer of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride having a Shore D hardness of 25 to 55, and the sea resin is made of vinylidene fluoride and tetrafluoro. It preferably consists of a copolymer with ethylene. The core resin is made of a polymethyl methacrylate resin, the sheath resin is made of a copolymer of vinylidene fluoride and tetrafluoroethylene, and the sea resin is made of tetrafluoroethylene, hexafluoropropylene having a Shore D hardness of 25 or more and 55 or less. It is also preferable to consist of a copolymer with vinylidene fluoride. The covering layer 36 is preferably made of nylon 12. The outer diameter of the multi-core plastic optical fiber 38 is preferably 0.25 mm or more and 0.55 mm or less. Moreover, in order to reduce the optical loss accompanying the error of the attachment position of the optical element 7 to the pad part 5, it is preferable that the fiber numerical aperture of the plastic optical fiber 19 is high, and it is 0.4 or more and 0.7 or less. Is preferred.

  When the plastic optical fiber 19 is used for signal transmission, it is important to efficiently couple light between the plastic optical fiber 19 and the optical element 7. Therefore, when a surface emitting laser is used as the optical element 7, the first molded body 15 present at the boundary between the surface emitting laser and the plastic optical fiber 19 is molded into a convex shape and emitted from the surface emitting laser by the convex lens action. It is preferable that the laser light is condensed and incident on the plastic optical fiber 19. When a photodiode is used as the optical element 7, the first molded body 15 existing at the boundary between the plastic optical fiber 19 and the photodiode is molded into a convex shape, and laser light emitted from the plastic optical fiber 19 is emitted. It is preferable that the light is condensed and incident on the photodiode.

  The optical communication module 1 as described above includes the optical element 7 in the first molded body 15 made of a transparent first resin, and guides the second molded body 17 including the first molded body 15. Since the hole 17a is formed, and the plastic optical fiber 19 is introduced into the guide hole 17a, the gap between the second molded body 17 and the plastic optical fiber 19 is filled and fixed with the adhesive 21, so that the plastic optical fiber The connection part 19 has a good sealing property, and the end face of the plastic optical fiber 19 is protected. Furthermore, the pad portion 5 on which the optical element 7 is installed is provided not on the plate surface 3 b of the first lead frame 3 but on the side surface 3 c. Accordingly, the plastic optical fiber 19 can be extended toward the side of the first lead frame 3 with its end face facing the optical element 7, so that it is easy to make the plastic optical fiber 19 compact. It becomes easy.

  FIG. 6 shows a schematic diagram of a portable electronic device including the plastic optical fiber module according to this embodiment.

  A portable electronic device 100 as an electronic device includes a first housing 51, a second housing 57, and a hinge portion 53 that connects the first housing 51 and the second housing 57.

  The first casing 51 has an optical communication module 1a. The optical communication module 1a has the same configuration as the optical communication module 1 shown in FIG. 1, but includes a light receiving element 7a such as a photodiode as an optical element. The second casing 57 includes the optical communication module 1b. The optical communication module 1b has the same configuration as the optical communication module 1 shown in FIG. 1, but includes a light emitting element 7b such as a surface emitting laser as an optical element. The optical communication module 1a and the optical communication module 1b have one common plastic optical fiber 19. The plastic optical fiber 19 passes through the hole 53 h of the hinge portion 53. The optical communication module 1a and the optical communication module 1b constitute a plastic optical fiber module 50.

  The plastic optical fiber module 50 can be suitably used in the portable electronic device 100 or in an electronic device that can move an installation place at the time of use. Examples of the portable electronic device 100 include a mobile phone, a PDA, a mobile personal computer, a video camera, a digital still camera, a game machine mobile phone, a notebook computer, and a portable game machine. In addition to the portable electronic device 100, the electronic device may be a movable electronic device such as a flat-screen TV or a projector. The plastic optical fiber module 50 can be used for optical signal transmission through a portion that repeatedly bends such as the hinge portion 53 in the portable electronic device 100 and the movable electronic device. When transmitting an electrical signal in such an application, it is necessary to cover the periphery of the wire with a shield to prevent noise. However, when transmitting an optical signal with the plastic optical fiber module 50 of the present embodiment, a high-speed signal is required. Even so, shielding is unnecessary.

  In particular, in the portable electronic device 100 including the liquid crystal portion as the first housing 51, the keyboard portion as the second housing 57, and the hinge portion 53 that connects them, the first housing 51 is an optical communication module. 1a, the second casing 57 has an optical communication module 1b, the hinge portion 53 has a hole 53h, and the optical communication module 1a and the optical communication module 1b have one common plastic optical fiber 19. It can be suitably used for the portable electronic device 100 connected by.

  The portable electronic device 100 includes a step of introducing one end of the plastic optical fiber 19 into one guide hole 17a of the optical communication modules 1a and 1b and bonding the plastic optical fiber 19 with the adhesive 21, and the other end of the plastic optical fiber 19 has the hinge portion 53. A step of passing through the hole 53h, a step of introducing the other end of the plastic optical fiber 19 into the other guide hole 17a of the optical communication modules 1a and 1b and bonding them with the adhesive 21, and a second of the other of the optical communication modules 1a and 1b. It can be suitably manufactured by the process of mounting in the casing 57 and the process of mounting one of the optical communication modules 1 a and 1 b in the first casing 51. It goes without saying that the optical communication modules 1a and 1b can be similarly implemented even if the mounting order to the plastic optical fiber 19 and the mounting order to the first casing 51 or the second casing 57 are reversed. Absent. By adopting such a manufacturing method, in addition to the above effects, the inner diameter and outer diameter of the hole 53h of the hinge portion 53 can be reduced, and a thin portable electronic device 100 can be obtained. The hole 53h of the hinge part 53 can also be used as a hole through which an electric line passes as a power line or a signal line.

(Production of the first optical communication module)
A part of a lead frame made of copper having a thickness of 150 μm is bent at a bending angle of 90 degrees and a curvature radius of 150 μm so that a flat portion has a height of 350 μm and a width of 600 μm (first pad portion). A lead frame was prepared. A surface emitting laser (first optical element) having an emission wavelength of 850 nm is mounted on the pad portion, and a bonding portion (first bonding portion) of the surface emitting laser and the lead frame is made of a gold bonding wire (first Connection wire).

  Next, primary molding was performed with a transparent epoxy resin so that a part of the lead frame including the surface emitting laser and the pad portion and the bonding portion was covered, thereby producing a first molded body (see FIG. 1). Next, the tie bar portion of the lead frame was cut and divided into a first lead frame having a pad portion and a second lead frame having a bonding portion. Next, a liquid crystal polymer that becomes opaque at least in the visible light region is covered with a guide hole (first guide hole) having a diameter of 0.61 mm for covering the first molded body and introducing a plastic optical fiber. Next, a second molded body was produced by molding. The mold dimensions (package dimensions) of the second molded body excluding the guide hole that is the introduction portion of the plastic optical fiber were 3 mm in length, 3 mm in width, and 1 mm in height.

  Next, an anaerobic ultraviolet curable adhesive is filled in the guide hole, and one end of a multicore plastic optical fiber (multicore plastic optical fiber (product name: SMCN-400P-6) manufactured by Asahi Kasei Electronics Co., Ltd.) is cut into 20 cm. The first optical communication module was manufactured by introducing into the holes and irradiating the adhesive with ultraviolet rays to cure.

(Production of second optical communication module and plastic optical fiber module)
A part of a copper lead frame having a thickness of 150 μm is bent at a bending angle of 90 degrees and a curvature radius of 150 μm, and a pad portion (second pad portion) having a flat portion height of 350 μm and a width of 600 μm is formed. A lead frame was prepared. A silicon photodiode (second optical element) having sensitivity at a wavelength of 850 nm is mounted on the pad portion, and a bonding portion (second bonding portion) of the photodiode and the lead frame is made of a gold bonding wire (first Connected by two bonding wires).

  Next, primary molding was performed with a transparent epoxy resin so that a part of the lead frame including the photodiode and the pad portion and the bonding portion was covered, thereby producing a third molded body (see FIG. 1). Next, the tie bar of the lead frame was cut and divided into a third lead frame having a pad portion and a fourth lead frame having a bonding portion. Next, a liquid crystal polymer that becomes opaque at least in the visible light region is covered with a guide hole (second guide hole) having a diameter of 0.61 mm for covering the third molded body and introducing a plastic optical fiber. Next, a fourth molded body was produced by molding. The mold dimensions (package dimensions) of the fourth molded body excluding the introduction portion of the plastic optical fiber were 3 mm in length, 3 mm in width, and 1 mm in height.

  Next, anaerobic ultraviolet curing adhesive is filled in the guide hole (second guide hole), and the other end of the multi-core plastic optical fiber of the first optical communication module is introduced into the guide hole, and the adhesive The second optical communication module was manufactured by irradiating with UV rays and cured to produce a plastic optical fiber module.

(Evaluation of plastic optical fiber module)
After this plastic optical fiber module was allowed to stand at room temperature for 24 hours, optical power and tensile strength were measured. When the injection current of the surface emitting laser was 6.9 mA, the photocurrent of the silicon photodiode was 0.31 mA. When this plastic optical fiber module was left in a constant temperature and humidity chamber at 85 ° C. and 85% humidity for 1000 hours and measured under the same conditions, the photocurrent of the silicon photodiode was 0.30 mA and was stable for a long time.

  Next, after another plastic optical fiber module manufactured by the same manufacturing method was left at room temperature for 24 hours, the second molded body was gripped and a tensile test was performed at a tensile speed of 100 mm / min. The breaking strength was 18 Newton. Met.

  Next, another plastic optical fiber module manufactured by the same method is left in a constant temperature and humidity chamber with a temperature of 85 degrees and a humidity of 85% for 1000 hours, and then the second molded body is held and a tensile test is performed at a pulling speed of 100 mm / min. As a result, the breaking strength was 19 Newtons, which was stable for a long time.

  The present invention relates to an optical signal in a portable electronic device such as a mobile phone, a PDA, a mobile personal computer, a video camera, a digital still camera, or a game machine, or in an electronic device that can move an installation place when using a flat-screen TV, a projector, It can be suitably used for transmission.

It is a schematic diagram of the cross section of the optical communication module which concerns on embodiment. It is a schematic diagram of the cross section of the optical communication module along the II-II line | wire in FIG. It is a perspective view of a part of 1st lead frame and a pad part. It is a figure which shows the modification of a 1st lead frame. It is sectional drawing of a plastic optical fiber. It is a schematic diagram of a portable electronic device provided with a plastic optical fiber module.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1a, 1b ... Optical communication module, 3 ... 1st lead frame, 3a ... Plate part, 3b ... Plate surface, 3c ... Side surface, 5 ... Pad part, 5a ... Flat part, 7 ... Optical element, 9 ... Second lead frame, 11 ... Bonding part, 13 ... Bonding wire, 15 ... First molded body, 17 ... -2nd molded object, 17a ... guide hole, 19 ... plastic optical fiber, 21 ... adhesive agent, 50 ... plastic optical fiber module, 100 ... portable electronic device.

Claims (16)

A first lead frame having a pad portion; a second lead frame having a bonding portion; an optical element disposed on the pad portion; a first molded body including the optical element; An optical communication module comprising a second molded body including a molded body and a plastic optical fiber,
The first lead frame has a plate portion extending in a strip shape, and the plate portion has a pair of plate surfaces and a side surface narrower than the plate surface,
The pad portion is provided on the side surface of the plate portion,
The optical element is connected to the bonding portion by a bonding wire,
The first molded body is made of a transparent first resin, the pad portion and a part of the first lead frame, the bonding portion and a part of the second lead frame, and the optical element. Contains
The second molded body is composed of a second resin that is opaque at least in the visible light region, and includes the first molded body,
In the second molded body, a guide hole is formed in a portion facing the optical element, and the second molded body, the plastic optical fiber, and the plastic optical fiber are introduced into the guide hole. An optical communication module characterized in that the gap is filled with a cured adhesive.   The pad portion has a flat portion standing along the side surface and extending in a direction intersecting the plate surface, and a bent portion connecting the side surface and the flat portion. The optical communication module according to claim 1. The first lead frame is formed by bending the base material formed into a predetermined shape to form the plate portion and the pad portion,
The thickness of the first lead frame is 50 to 350 μm,
The optical communication module according to claim 2, wherein a height of the flat portion of the pad portion is not less than 30 μm and not more than 600 μm.   4. The optical communication module according to claim 2, wherein a width of the flat portion of the pad portion is equal to or greater than a height of the flat portion of the pad portion. The plastic optical fiber includes a core of 7 to 10,000 made of a transparent core resin, at least one sheath layer surrounding the core and made of a transparent sheath resin having a refractive index lower than that of the core resin, and the sheath layer A multi-core plastic optical fiber having a cross-sectional shape composed of a sea layer made of sea resin surrounding
The optical communication module according to claim 1, further comprising: a coating layer surrounding the multi-core plastic optical fiber.   The optical communication module according to claim 1, wherein the adhesive is a photo-curing adhesive.   The optical communication module according to claim 6, wherein the photocurable adhesive is an ultraviolet curable adhesive.   The optical communication module according to claim 1, wherein the optical element is a light emitting element.   The optical communication module according to claim 8, wherein the light emitting element is a surface emitting laser having a light wavelength of 400 nm or more and 1700 nm or less.   The optical communication module according to claim 1, wherein the optical element is a light receiving element.   The optical communication module according to claim 10, wherein the light receiving element is a photodiode having a sensitivity peak in a wavelength range of 400 nm to 1700 nm. In the manufacturing method of the optical communication module according to any one of claims 1 to 11,
Mounting an optical element on the pad portion of the lead frame having a pad portion and a bonding portion;
Connecting the bonding part and the optical element with a bonding wire;
Molding a first molded body so as to include a part of a lead frame having the pad portion and the bonding portion, and the optical element;
Cutting the lead frame into a first lead frame having the pad portion and a second lead frame having the bonding portion;
Molding a second molded body including the first molded body and having a guide hole in a portion facing the optical element;
Filling the guide hole with an adhesive;
Introducing the plastic optical fiber into the guide hole;
Curing the adhesive, and a method of manufacturing an optical communication module. A plastic optical fiber module comprising the optical communication module according to claim 8 or claim 9 and the optical communication module according to claim 10 or claim 11,
The plastic optical fiber module of each of the optical communication modules is a common plastic optical fiber. An optical signal transmission method for performing signal transmission using the plastic optical fiber module according to claim 13 in an electronic device. In the electronic device having the first housing, the second housing, and the hinge portion connecting them,
The optical communication module according to claim 10 or claim 11 is mounted on the first casing.
The optical communication module according to claim 8 or claim 9 is mounted on the second casing,
The hinge portion has a hole;
The plastic optical fiber of each optical communication module is a common plastic optical fiber,
One said plastic optical fiber has passed the hole of the said hinge part, The electronic device characterized by the above-mentioned. A method of manufacturing an electronic device having a first housing, a second housing, and a hinge portion connecting them,
A first lead frame having a first pad portion; a second lead frame having a first bonding portion; a first optical element disposed on the first pad portion; and the first light. A first optical communication module comprising a first molded body including an element, a second molded body including the first molded body, and a plastic optical fiber, wherein the first lead frame Has a first plate portion extending in a band shape, and the first plate portion has a pair of plate surfaces and a side surface narrower than the plate surface, and the first pad portion. Is provided on the side surface of the first plate portion, the first optical element is connected to the first bonding portion by a first bonding wire, and the first molded body is a transparent first Made of resin, the first pad portion and the first Including a part of the lead frame, a part of the first bonding part and the second lead frame, and the first optical element, wherein the second molded body is opaque at least in the visible light region. The first light comprising the first molded body made of a second resin, the first molded hole having a first guide hole formed in a portion facing the first optical element. Introducing and bonding one end of the plastic optical fiber into the first guide hole of the communication module;
Passing the other end of the plastic optical fiber through a hole of the hinge portion;
A third lead frame having a second pad portion; a fourth lead frame having a second bonding portion; a second optical element disposed on the second pad portion; and the second light. A second optical communication module comprising a third molded body including an element, a fourth molded body including the third molded body, and the plastic optical fiber, wherein the third lead The frame has a second plate portion extending in a band shape, and the second plate portion has a pair of plate surfaces and a side surface narrower than the plate surface, and the second pad portion. Is provided on the side surface of the second plate portion, the second optical element is connected to the second bonding portion by a second bonding wire, and the third molded body is a transparent third The second pad portion and the front A part of the third lead frame, a part of the second bonding part and the fourth lead frame, and the second optical element are included, and the fourth molded body is at least in the visible light region. The second molded body is made of an opaque fourth resin, includes the third molded body, and the fourth molded body has a second guide hole formed in a portion facing the second optical element. Introducing and bonding the other end of the plastic optical fiber to the second guide hole of the optical communication module;
Attaching the first optical communication module to the first housing;
Attaching the second optical communication module to the second housing;
The method of manufacturing an electronic device according to claim 15, comprising:

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