JP4744268B2 - Optical module - Google Patents

Description

  The present invention forms an optical module used in a photoelectric conversion unit corresponding to a light receiving device for receiving light transmitted through an optical fiber used for optical communication or transmitting light to the optical fiber, and the optical module. It is related to the mounting method.

  In recent years, optical communication has been promoted to households, as represented by FTTH (Fiber to the Home). Therefore, improvement in characteristics, miniaturization, and cost reduction of optical communication components are required. It has been. However, the downsizing of the photoelectric conversion device to which the optical fiber is connected is delayed, and the cause is that the photoelectric conversion device and the optical component are attached to the metal package or the metal holder, so that they are optically coupled by optical coupling in space. It was because it was assembled by adjusting. In such an optical module, a TO-CAN type in which a laser diode or a photodiode which is a photoelectric conversion element (hereinafter referred to as an optical element) is coupled to an optical fiber with a lens is widely used. This TO-CAN type optical module is sealed with a metal cap with a lens after mounting optical elements on a package or carrier. Thereafter, when attaching a ferrule or receptacle holding an optical fiber, the peak of optical coupling was read, and resistance welding or laser welding was performed to mechanically join the package and the receptacle.

  On the other hand, as an optical module aiming at miniaturization, there is an optical module manufactured using a device that does not mount a conventional lens (see, for example, Patent Documents 1 and 2).

  The optical module disclosed in Patent Document 1 uses a ferrule and directly optically couples an optical fiber and an optical element without using a lens. As shown in FIG. 5, the optical module includes a ferrule 52 in which a module optical fiber 53 is embedded above a substrate 50 with a flexible cable 54 on which a lateral light receiving element 51 (referred to as an optical element) is mounted. The end face of the ferrule 52 in a state where the optical element and the optical fiber are directly optically coupled by the active alignment method with the optical axis of the ferrule being arranged substantially perpendicular to the ferrule end face. The substrate 50 was fixed with resin.

In the optical module 60 shown in Patent Document 2, as shown in FIG. 6, an optical fiber 62 is inserted into the ferrule 61, and the core 62a of the optical fiber 62 near the rear end of the ferrule 61 is axially moved. Axis crossing along the direction intersecting the axial direction of the optical fiber 62 and the axial exposed surface 61a parallel to the axial direction of the optical fiber 62 near the rear end of the ferrule 61 in the state exposed to the outside along An exposed surface 61 b is formed, and a photodiode 64, which is an optical element, is disposed on the axially parallel exposed surface 61 a of the ferrule 61.
JP 2004-341370 A JP 2004-191794 A

  However, although the optical module disclosed in Patent Document 1 is configured so that the optical fiber and the optical element (surface light emitting element) are close to each other, the optical fiber and the optical element are optically coupled without a lens. Therefore, the coupling loss of light between the optical fiber and the optical element has increased. Further, since the surface light emitting / receiving element has a smaller light output and inferior light receiving / emitting characteristics than the side light emitting / receiving optical element, for example, when transmitting light at a relatively long distance using this optical module, There is a possibility that the problem of insufficient light output and sensitivity may occur. Here, when a side-receiving / emitting optical element (optical element) is applied to this optical module, the substrate on which the optical element is mounted needs to be supported by a support member such as a cylindrical sleeve, so the number of parts is reduced. As the number of the optical fibers and the optical elements increases, it is difficult to position the optical fibers and the optical elements relative to each other and efficiently optically couple them.

  The optical module disclosed in Patent Document 2 has been positioned so that the optical fiber 62 and the photodiode 64 are on the same axis on the ferrule 61 having a stepped portion. Needed to process the ferrule 61 with high accuracy. However, such processing of the ferrule 61 is technically very difficult because it is necessary to suppress variations in the micron unit of the ferrule 61 to be small. In addition, when forming an electrode in the notched portion of the ferrule 61, thin film processing by plating or vapor deposition or thick film processing by printing or the like was used, but a stepped portion is generated in the notched portion. For this reason, it is difficult to attach a photomask or a printing mesh to the stepped portion, and this makes it impossible to accurately form electrodes.

  In addition, when a receptacle or the like can be removed from the package or cap on which the photoelectric conversion element is mounted, it is necessary to mount each member with high accuracy. However, when mounting the optical fiber in the ferrule, since it is usually performed with resin, the mounting temperature has to be relatively low, for example, 100 ° C. or less. As a result, at the time of mounting, it is necessary to use an expensive welding device such as a laser device in order to locally increase the temperature, and thus there is a restriction on the manufacturing process.

Wherein in the optical module according to an embodiment of the present invention, an optical fiber having a graded index fiber portion, an optical element having a light receiving portion or the light emitting portion is optical fiber optically coupled, as before Symbol Fiber It is interposed between the optical element so that the peak of optical coupling between the graded index fiber part and the light receiving part or light emitting part of the optical element is maximized, and is cured so as to maintain the state. A transparent resin, and the transparent resin is applied to one end of the optical fiber and a light receiving portion or a light emitting portion of the optical element, and the transparent resin is a UV curable resin.

  The optical fiber may further include a coreless fiber portion at least at one end or both ends of the graded index fiber portion.

  Moreover, it is preferable that the optical fiber is held inside a cylindrical body, and a protruding portion having a flat portion substantially parallel to the optical axis direction of the optical fiber may be formed at one end of the cylindrical body. .

  In the present invention, it is preferable that the optical element is mounted on a substrate, the substrate is placed on the planar portion, and the lower surface portion of the substrate and the planar portion of the protruding portion are joined.

  In the present invention, a terminal for supplying power to the optical element may be further provided on the substrate.

  The optical element may be covered with a resin that is integrally bonded to one end of the cylindrical body.

  Moreover, it is preferable that the other end of the cylindrical body is held by a holder into which a plug for optically coupling with the optical fiber is inserted.

  Further, it is preferable that the optical element is a side incident type light receiving element or a side emission type light emitting element.

In the optical module according to one aspect of the present invention , a graded index fiber portion is provided in the optical fiber, and between the optical fiber and the optical element, between the graded index fiber portion and the light receiving portion or the light emitting portion of the optical element. with a peak of the optical coupling is interposed so as to maximize, and a transparent resin cured to maintain its state. As a result, since the optical fiber and the optical element are optically coupled without using a large lens as in the prior art, the optical module can be reduced in size while maintaining high light coupling efficiency between the optical fiber and the optical element. . In the optical module according to one aspect of the present invention, the transparent resin is interposed so that the peak of optical coupling between the graded index fiber portion and the light receiving portion or the light emitting portion of the optical element is maximized, and the state Since the distance and angle of the optical coupling can be finely adjusted by curing so as to maintain the above, workability in assembling the optical module can be improved. Furthermore, in the optical module according to one embodiment of the present invention, since the light receiving portion or the light emitting portion of the one end portion and the light element of the optical fiber, transparency resin is deposited, between the optical fiber and the optical element It suppresses the formation of space formed, implemented and good optical coupling small because it can reduce the amount of transparency resins for optical adjustment can be realized. As a result, efficiently performed through the light transfer GaToru bright resin between the optical fiber and the optical element, it can be miniaturized. Furthermore, in the optical module according to one aspect of the present invention, the transparent resin is a UV curable resin. Thereby, the position of the optical element can be stabilized, so that the coupling loss of light can be reduced.

  Further, if the optical fiber includes a coreless fiber part at least at one end of the graded index fiber part, for example, a position located between the optical element and the graded index fiber part, the optical fiber is coupled to the optical element. Since the distance (working distance) of the optical fiber can be adjusted by the coreless fiber, the space on the optical path is suppressed, and the boundary surface of the space in contact with the optical component or the optical fiber, that is, the refractive index is abrupt. Therefore, it is possible to reduce the boundary surface that changes, so that it is possible to suppress light reflection loss. Further, with such a configuration, since the amount of the transparent resin used for optical adjustment can be reduced, the resin that depends on the temperature difference at the same time as reducing the loss of light generated slightly when passing through the resin is reduced. It is possible to suppress physical fluctuations due to the thermal expansion.

  Still further, if the optical fiber includes a coreless fiber part at both ends of the graded index fiber part, as described above, the distance (working distance) of the optical fiber optically coupled to the optical element is adjusted. can do. On the other hand, for example, when an optical fiber in which a single mode fiber part is connected to one end of the graded index fiber part via a coreless fiber part is used, a single mode fiber in which light from an optical element (light emitting element) is optically coupled. Since the working distance with the core can be adjusted by the coreless fiber section, light can be efficiently incident on the single mode fiber section.

  Furthermore, if the optical fiber is held inside a cylinder, for example, a ferrule, light loss due to bending or breakage of the optical fiber can be suppressed, and operability is improved when assembling an optical module. To do. Further, if a protruding portion having a flat portion substantially parallel to the optical axis direction of the optical fiber is formed at one end of the cylindrical body, mounting of an optical element or the like is facilitated. Furthermore, when the optical element is mounted on the substrate, the substrate is placed on the planar portion, and the lower surface portion of the substrate and the planar portion of the protruding portion are joined, the optical element and the optical fiber After angle alignment, the substrate can be supported, the optical element and the optical fiber can be optically coupled with reduced light loss, and the positional deviation of the optical coupling portion after mounting is reduced. .

  Furthermore, if a terminal for supplying power to the optical element is further provided on the substrate, it can be easily connected to a connector or the like, and the active alignment operation at the time of mounting the optical element is simplified.

  Still further, if a resin in which the optical element is integrally bonded to one end of the cylindrical body, for example, a resin having high moisture resistance is used, the optical element is made of resin even when used in a high temperature and high humidity environment. By protecting, a highly reliable optical module can be provided. For example, if a colored resin having a light shielding function is used, even if other light (optical noise) enters the optical element from the outside of the optical module, the optical noise can be blocked by the resin. The reliability of the optical module is improved.

  Furthermore, the other end of the cylindrical body is held by a holder into which a plug for optically coupling with the optical fiber is inserted, so that the optical fiber of the plug and the inside of the cylindrical body are held. The optical fiber is easily optically connected.

  Here, the MFD (mode field diameter) of the side incident type light receiving element and the side emission type light emitting element is smaller than that of the surface receiving type light emitting element. However, in the present invention, since an optical fiber having a graded index fiber portion having a lens function is used, a side-incidence type that has relatively long transmission characteristics compared to a surface-emitting type element. An optical module on which a light receiving element or a side emission type light emitting element is mounted can be provided.

  The optical module according to the present invention will be described below with reference to FIGS.

  FIG. 1 shows an optical module 100 according to a first embodiment of the present invention, in which (a) is a plan view and (b) and (c) are sectional views. The optical module 100 includes an optical fiber 1 (single mode fiber portion 1a, graded index fiber portion 1b, and coreless fiber portion 1c) that holds a cylindrical body (hereinafter referred to as a ferrule 2) and light emission corresponding to an optical element. Corresponding to a terminal that can be connected to the electrode pattern 7, the via-hole conductor 8, and an external electronic circuit on a substrate (hereinafter referred to as a carrier 6) on which the element 3, the light-receiving element 4, and the chip component 5 are mounted. The photoelectric conversion device 101 including the terminal pins 9 to be configured, the transparent resin 10 that adheres the ferrule 2 and the substrate 6, and the encapsulation resin 11 that covers the optical element mounted on the substrate 6.

  For the optical fiber 1, an optical fiber such as a single mode fiber portion 1a, a graded index fiber portion 1b, a coreless fiber portion 1c, or the like is used.

  A single mode fiber portion 1a used for a part of the optical fiber 1 is an optical fiber suitable for long-distance optical communication, and is an optical fiber having a mode field diameter of about 10 μm and a cladding diameter of about 125 μm. It is composed of glass.

  The graded index fiber portion 1b used for a part of the optical fiber 1 is an optical fiber having an axially symmetric refractive index distribution that gradually decreases from the central axis to the outer periphery of the optical fiber. Used for transmission. This refractive index distribution decreases toward the outer periphery of the optical fiber depending on the distance from the central axis of the optical fiber, that is, the value of the square of the optical fiber radius. Further, since the refractive index distribution of the graded index fiber portion 1b has the same lens effect as the GRIN lens, if the graded index fiber portion 1b having an appropriate refractive index distribution is used with an appropriate length, the coupling efficiency is increased. An optical system can be constructed well.

  Here, since a normal GRIN lens is generally larger than the diameter of the optical fiber, a special jig is required for attachment to the optical fiber. However, the graded index fiber portion 1b as in the present invention has an outer diameter equivalent to, for example, the single mode fiber portion 1a and can be easily connected by fusion.

  The coreless fiber part 1c used for a part of the optical fiber 1 is connected to one end or both ends of the graded index fiber part 1b by, for example, fusion. The coreless fiber portion 1c is an optical fiber having a function of securing (adjusting) a working distance in which the optical element and the optical fiber 1 are optically coupled efficiently. The coreless fiber portion 1c is a glass body having a uniform refractive index, and is made of, for example, a quartz glass body having n = 1.46 or so. The length of the coreless fiber portion 1c is set to a length that ensures a working distance in which the optical element is optically coupled to the single mode fiber efficiently.

  Here, as shown in FIG. 1B, when the coreless fiber portion 1c is fusion-bonded to one end located on the optical element side of the graded index fiber portion 1b, for example, the graded index fiber portion is previously provided. 1b and the coreless fiber part 1c are prepared by fusion splicing, and the length of the coreless fiber 1c may be adjusted according to the length of the graded index fiber part 1b. At this time, the coreless fiber part 1c is It can also be used as a margin. In addition, as shown in FIG. 1C, when the coreless fiber portion 1c ′ is interposed between the single mode fiber portion 1a and the graded index fiber portion 1b, the length of the graded index fiber and the mounting position thereof are taken into consideration. In addition, the length is set so as to secure a working distance in which the optical element and the optical fiber 1 are optically coupled efficiently.

  The ferrule 2 has a function of holding the optical fiber 1 inside (through hole), and can suppress external force acting on the optical fiber. Moreover, the ferrule 2 is comprised, for example from ceramics, such as an alumina and a zirconia, or glass. Further, if the ferrule 2 is made of ceramics, it can be produced by firing a molded body formed into a cylindrical shape by extrusion molding or the like, and performing polishing or the like.

  The light emitting element 3 is an active device for converting an electrical signal such as communication data into light and transmitting the light from the light emitting unit 3a to a transmission medium such as an optical fiber, and is composed of a compound semiconductor such as GaAs or InP. Yes. Since the optical element 3 in the optical module of the present invention can be applied to both light reception and light emission, FIG. 1 shows a case where the optical element 3 is a light emitting element. It may be an element. Furthermore, the light-emitting element 3 can be applied regardless of the side light emission or the surface light-emitting element, and the light receiving element can similarly take this form.

  The light receiving element 4 is an active device having a function of receiving and monitoring light emitted from the light emitting portion 3a of the light emitting element 3 and converting the received light into an electrical signal, and is a compound semiconductor such as GaAs or InP. It is composed of Then, this electric signal is transmitted to the control circuit of the light emitting element 3 through an electrode or the like, and the light quantity of the light emitting element 3 is controlled by feedback from the control circuit.

  The chip component 5 includes, for example, a driver IC made of a Si semiconductor mounted in the vicinity of the light emitting element 3 and a Si semiconductor mounted in the vicinity of the light receiving element 4 in addition to a capacitor, a resistor, and an inductance chip component. The preamplifier IC is used, and is mounted on the electrode pattern by a method such as wire bonding, flip chip, or brazing. The chip component is electrically connected to the optical element through the electrode pattern 7.

  The carrier 6 serving as a substrate is for mounting the light-emitting element 3, the light-receiving element 4, the chip component 5, and the like corresponding to the optical element, and can be obtained by adding a predetermined glass component to ceramics such as alumina or ceramics. It may be a ceramic substrate made of a ceramic material made of LTCC (low temperature fired ceramic) or a resin substrate made of a resin material.

  The via-hole conductor 8 is electrically connected to the electrode pattern 7 and is also electrically connected to a power supply / signal supply or signal extraction terminal pin 9 that controls connection to an external electronic circuit. The terminal pin 9 only needs to be capable of transferring electricity to and from an external electronic circuit. For example, the terminal pin 9 is made of an alloy of Fe and Ni, a metal ball, a bump made of solder or the like, or a resin in which a conductor is embedded. A flat cable or the like may be used.

  The transparent resin 10 is a resin that allows light transmission, and has a function of adjusting the distance between the optical fiber 1 and the light emitting element 3 and optimizing the optical coupling between the optical fiber 1 and the light emitting element 3. .

  The transparent resin 10 only needs to be a resin that allows light transmission. For example, a UV curable resin (for example, an epoxy resin) that is cured by irradiation with ultraviolet rays, a thermosetting resin (for example, an acrylic resin) that is cured by heat, Further, a thermoplastic resin (for example, polycarbonate resin) that is softened by heat and then cured by cooling can be used. In particular, if the transparent resin 10 is a UV curable resin or a resin that can be cured at the initial stage by UV irradiation, the optical fiber 1 and the light emitting element 3 are aligned through the transparent resin 10 without applying heat during optical adjustment. And can be optically coupled. This is because when the transparent resin 10 is cured by heat at the time of optical adjustment, the mounted optical element moves slightly when the transparent resin 10 is cured, or when the optical fiber 1 is held inside the ferrule 2. This is because if the heat resistance of the adhesive used is low, the optical fiber 1 may be misaligned, resulting in a large light coupling loss. The adjustment of the optical coupling by the transparent resin 10 means that the light emitted from the optical element 3 (light emitting element) or the optical fiber 1 is transmitted through the graded index fiber portion 1b to the optical fiber 1 or optical element 3 (light emitting element). Is to adjust the distance and angle so that the beam waist has a peak of optical coupling when incident on the beam.

  Below, the manufacturing method of the optical module 100 is demonstrated.

  First, the single-mode fiber part 1a, the graded index fiber part 1b, and the coreless fiber part 1c are fused and connected by heat to obtain the optical fiber 1.

  Next, as shown in FIG. 1B, at one end of a cylindrical body made of ceramics or the like, there is a flat portion substantially parallel to the axial direction of the through hole into which the optical fiber 1 is inserted (the optical axis direction of the optical fiber). The ferrule 2 is produced by forming the protruding portion. In addition, this protrusion part can be cut | disconnected and formed with the sawtooth etc. which the diamond material which cuts a semiconductor is distribute | arranged on the surface, for example. Thereafter, the optical fiber 1 is inserted so that the coreless fiber portion 1c is positioned on the protruding portion side, and is bonded to the inside of the ferrule 2 by an adhesive such as epoxy resin applied in the through hole. The optical fiber 1 is held. In the form of the ferrule 2 shown in FIG. 1B, a protruding portion having a flat portion substantially parallel to the optical axis direction of the optical fiber is provided so that the photoelectric conversion device can be easily mounted and gripped after optical adjustment. This form is merely an example, and the shape of the ferrule 2 is not particularly limited as long as it is a cylindrical body that can hold the optical fiber 1 inside.

  Next, the manufacturing method of the photoelectric conversion apparatus 101 which comprises an optical module is demonstrated.

  First, for example, a multilayer ceramic molded body is filled with a via hole conductor 8 or an electrode pattern 7 with a paste such as tungsten or molybdenum, printed, and then simultaneously fired with a ceramic material to obtain a carrier 6. Next, after plating the upper surface of the via-hole conductor 8 with Ni or the like, the terminal pin 9 is attached to the plated layer with a brazing material. Finally, after the electrode pattern 7 is subjected to Ni plating, Au plating, or the like, a light emitting element, a light receiving element, a chip component, an IC, and the like are mounted by wire bonding or bumps. Note that the material, size, and terminal pin take-out direction of the carrier 6 are selected so as to be easily gripped by a mounting apparatus or jig during optical preparation, and the form of the carrier 6 shown in FIG. 1 is merely an example. .

Next, the joining of the ferrule 2 that holds the optical fiber 1 inside and the photoelectric conversion device 101 will be described. First, the end surface of the ferrule 2 on which the protruding portion is formed and the UV portion made of epoxy resin or the like on the flat portion of the protruding portion. A cured resin (transparent resin 10) is applied. In addition, in order to suppress reflection of light, the end surface of the ferrule 2 may be subjected to an oblique polishing process or a non-reflective coating.

  Next, in a state where the transparent resin 10 is not cured, the light emitting element 3 is operated by supplying power to the terminal pins 9 of the photoelectric conversion device 101 through a socket (not shown) or the like, and the flat portion of the protruding portion of the ferrule 2 is operated. The photoelectric conversion device 101 is placed. Then, light from the light emitting portion 3a of the ferrule 2 and the light emitting element 3 enters the optical fiber 1, and the end face of the ferrule 2 (one end portion of the optical fiber 1) and the photoelectric conversion device 101 so that the peak of optical coupling is maximized. After positioning the interval of the light emitting part 3a of the light emitting element 3 by adjusting the thickness of the transparent resin 10, the adhesion angle, and the like, the transparent resin 10 is irradiated with ultraviolet light and cured, so that the end surface (light One end of the fiber 1) and the photoelectric conversion device 101 (the light emitting portion 3a of the light emitting element 3) are attached to the transparent resin 10. Finally, in order to protect the light emitting element 3, the light receiving element 4, the chip component 5, and the like, the optical module 100 is obtained by coating with an encapsulation resin 11 such as a thermosetting resin.

  Next, the operation of the optical module 100 will be described.

  An electrical signal or power supplied from an external circuit board (not shown) is fed from the terminal pin 9, and the electrical signal is transmitted to the optical element 3 (light emitting element) via the via-hole conductor 8 and the electrode pattern 7. The optical element 3 converts it into an optical signal.

  The optical signal (light) passes through the transparent resin 10 and enters the graded index fiber portion 1b via the coreless fiber portion 1c. The light incident on the graded index fiber portion 1b is focused on an appropriate beam by the lens function of the graded index fiber portion 1b, and then incident on the single mode fiber 1a. Such an optical module 100 is used as an optical module for optical transmission.

  When the optical element 3 is a light receiving element, the light transmitted from the single mode fiber portion 1a becomes an optical signal emitted from the end of the optical fiber and enters the graded index fiber portion 1b. The light incident on the graded index fiber portion 1b is focused to an appropriate beam by the lens function of the graded index fiber portion, and is incident on the light receiving element through the coreless fiber 1c and the transparent resin 10. The light receiving element converts the incident optical signal into an electric signal. Thereafter, the electrical signal passes through the electrode pattern 7 and the via-hole conductor 8 and is transmitted to an external circuit board (not shown) connected via the terminal pin 9. Such an optical module 100 is used as an optical module for receiving light.

  And according to the optical module of this invention, the graded index fiber part 1b is provided in the optical fiber 1, and the graded index fiber part 1c and the light-receiving part or light emission part of an optical element are provided between the optical fiber 1 and the optical element. A transparent resin for adjusting the optical coupling is interposed. As a result, in the optical module of the present invention, the optical fiber 1 and the optical element are optically coupled without using a conventional large lens, so that the light coupling efficiency between the optical fiber 1 and the optical element is maintained. However, the optical module can be miniaturized. Furthermore, in the optical module of the present invention, since the optical coupling can be finely adjusted with the transparent resin 10, workability in assembling the optical module can be improved. Such an optical module of the present invention is mounted as an active component such as a communication device for a station or a subscriber that is small and inexpensive and requires mass productivity, such as FTTH, and is used for voice signals such as telephones, mails, faxes, etc. It is used in a communication module that transmits and receives data signals such as video signals for television and movies, etc., to optical signals.

  FIG. 2 is a cross-sectional view showing an optical module 200 according to the second embodiment of the present invention. 2 to 4, the same members as those in FIG. 1 are denoted by the same reference numerals and description thereof is omitted.

  The optical module 200 is a so-called optical receptacle type optical module including the optical module 100, the holder 21, the sleeve 22, and the shell 25 used in the first embodiment of the present invention.

  The holder 21 has a through hole, and is a member for holding one end of the ferrule 2 of the optical module 100 on the inner surface of the through hole, and is made of a metal such as stainless steel.

  The sleeve 22 is a cylindrical body having a through hole, and the ferrule 2 is inserted from the opening at one end of the through hole, while the plug 23 for holding the optical fiber 24 is inserted from the opening at the other end. It is a member. The sleeve 22 has a function of promoting optical coupling by bringing the optical fiber 1 held inside the ferrule 2 inside the through-hole into contact with the optical fiber 24 held inside the plug 23. The sleeve 22 is made of, for example, metal, ceramics such as zirconia, or resin.

  The material and shape of the plug 23 may be the same as those of the ferrule 2. Furthermore, if each end face where the plug 23 and the ferrule 2 abut each other is PC-polished, the optical coupling can be further improved.

  The shell 25 has an opening for guiding the plug and is a member for protecting a part of the sleeve 22 and is made of, for example, a metal such as stainless steel, ceramics, or resin.

  In such an optical receptacle type optical module 200, optical coupling between an external optical component, for example, the plug 23 and the optical module 100 can be easily realized via the sleeve 22.

  Next, a method for manufacturing the optical module 200 will be described.

  First, according to the manufacturing method of the optical module 100, the ferrule 2 holding the optical fiber 1 and the photoelectric conversion device 101 are manufactured.

  Next, one end of the ferrule 2 is press-fitted into the through hole of the holder 21 manufactured by cutting or the like, and the ferrule 2 is held in the holder 21. Next, a cylindrical sleeve 22 made of ceramics such as zirconia is inserted into the other end of the ferrule 2 and fixed. Further, a cylindrical shell 25 made of resin or the like is disposed so that a part of the sleeve 22 is accommodated, and the shell 25 is fixed to the holder 21 by press-fitting or bonding, whereby the optical receptacle portion 20 is manufactured. The

  Finally, the optical module 200 is obtained by curing the transparent resin 10 using the same method as in the first embodiment of the present invention and bonding and fixing the ferrule 2 and the photoelectric conversion device 101 with high accuracy.

  FIG. 3 is a cross-sectional view showing an optical module 300 according to the third embodiment of the present invention.

  The optical module 300 has the same basic configuration as the optical module 100, but differs in that there is no protrusion at one end of the ferrule 2. The photoelectric conversion element 101 is covered with the resin 31, and the ferrule is covered with the resin 31. 2 is integrally joined.

  Specifically, instead of the encapsulation resin 11 used in the optical module 100, a part of the ferrule 2 is covered, and a transfer mold is made of the resin 31 so that the ferrule 2 and the photoelectric conversion device 101 are integrated. It is a form to do.

  In the optical module 300, the process of forming the protruding portion on the ferrule 2 can be omitted. Therefore, the end surface joined to the photoelectric conversion element 101 of the ferrule 2 may be a plane as shown in FIG.

  The resin 31 is made of a low expansion coefficient resin such as an epoxy resin in order to reduce the displacement of the optical component due to temperature changes. In addition, the resin 31 may be mixed with 30 to 60% by weight of a filler made of silica or the like in the resin in order to improve moisture resistance. Further, the volume of the resin 31 is 5 to 30% by weight of the filler to be added. 0.1 to 2.0 ml / g pores may be formed.

  The resin 31 may be a colored resin having a light shielding property such as a black resin that blocks light from the outside incident on the optical module.

  Next, a method for manufacturing the optical module 300 will be described.

  First, the optical module 100 is manufactured according to the manufacturing method of the optical module 100. In the optical module 100, no protrusion is formed on the ferrule 2.

  Next, the optical module 100 manufactured as described above is attached to an injection mold, and an epoxy resin, for example, is used as the resin 31, and the resin 31 is set in a tablet shape and applied to a resin supply portion. The optical module 300 is obtained by placing the melted resin into a mold and cooling and curing.

  FIG. 4 is a sectional view showing an optical module 400 according to the fourth embodiment of the present invention.

  The optical module 400 is an optical receptacle type optical module using the optical module 300. Even with this optical module 400, the same effect as the optical module 200 can be obtained. The optical module 400 can be manufactured by using the manufacturing method of the optical module 200 and the optical module 300.

  The above is merely a few examples of the embodiment according to the present invention, and various modifications may be made to the above-described embodiment without departing from the technical idea or principle of the present invention.

The optical module of this invention is shown, (a) is a top view, (b), (c) is sectional drawing. It is sectional drawing which shows optical module 2nd embodiment of this invention. It is sectional drawing which shows optical module 3rd embodiment of this invention. It is sectional drawing which shows optical module 4th embodiment of this invention. It is a perspective view which shows the conventional optical module. It is a perspective view which shows the conventional optical module.

Explanation of symbols

1, 24, 53, 62 ... optical fiber 1a ... single mode fiber part 1b ... graded index fiber part 1c, 1c '... coreless fiber part 2, 52, 61 ... ferrule (cylinder body)
3, 4, 51, 64... Optical element (light emitting element, light receiving element, laser diode photodiode)
3a: Light emitting part, light receiving part 5: Chip component 6: Carrier (substrate)
7 ... Electrode pattern 8 ... Via hole conductor 9 ... Terminal pin 10 ... Transparent resin 11 ... Encapsulation resin 20 ... Optical receptacle 21 ... Holder 22 ... Sleeve 23 ... Plug 25 ... Shell 31 ... Resin 54 ... Flat cable 100, 200, 300, 400, 500, 600 ... Optical module 101 ... Photoelectric conversion device

Claims (10)

An optical fiber having a graded index fiber portion;
An optical element having a light receiving part or a light emitting part optically coupled to the optical fiber ;
The optical fiber and the optical element are interposed so that the peak of optical coupling between the graded index fiber part and the light receiving part or light emitting part of the optical element is maximized, and the state is maintained. comprising a transparent resin cured to a,
The transparent resin is attached to one end of the optical fiber and the light receiving part or the light emitting part of the optical element,
An optical module, wherein the transparent resin is a UV curable resin.   The optical module according to claim 1, wherein the optical fiber further includes a coreless fiber portion at at least one end of the graded index fiber portion.   The optical module according to claim 2, wherein the optical fiber further includes a coreless fiber portion at both ends of the graded index fiber portion.   The optical module according to claim 1, wherein the optical fiber is held inside a cylindrical body.   The optical module according to claim 4, wherein a projecting portion having a flat portion substantially parallel to the optical axis direction of the optical fiber is formed at one end of the cylindrical body.   6. The light according to claim 5, wherein the optical element is mounted on a substrate, the substrate is placed on the planar portion, and a lower surface portion of the substrate and a planar portion of the protruding portion are joined. module.   The optical module according to claim 6, further comprising a terminal for supplying power to the optical element on the substrate.   The optical module according to claim 4, wherein the optical element is covered with a resin that is integrally bonded to one end of the cylindrical body.   The optical module according to any one of claims 4 to 8, wherein the other end of the cylindrical body is held by a holder into which a plug for optically coupling with the optical fiber is inserted.   The optical module according to claim 1, wherein the optical element is a side-incident light receiving element or a side-emitting light emitting element.

Images