JP2011197275A - Optical link module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical link module rich in mass productivity and easily miniaturized.SOLUTION: The optical link module includes an optical unit including a lead frame having a notch at one end, an optical element bonded to the primary surface of the lead frame and having an optical axis vertical to the primary surface, and a transparent resin layer having a part of the lead frame of a side opposite the one end and the optical element buried therein, a mold having a recess, and on side surface, a cylindrical ferrule guide part having a center axis matching the optical axis of the optical element of the optical unit inserted into the recess, and a reinforcing terminal extending in the recess to be brought into press contact with the notch, and protruded from the other surface of the mold where the one end becomes a side opposite the one surface.

Description

  The present invention relates to an optical link module.

  Electronic devices such as DVD components, CD components, televisions, and BS tuners often have optical terminals. An optical link in which an optical transmitter and an optical receiver are connected by an optical fiber is not affected by electromagnetic noise and does not generate electromagnetic noise. For this reason, while maintaining the quality of an image and a sound favorable, electromagnetic radiation can be suppressed and the influence of the electromagnetic noise given to other electronic devices can be reduced.

  However, the internal structures of these electronic devices are diverse, and the positions at which optical link modules such as optical transmitters and optical receivers are attached and the structures of circuit boards are different. Furthermore, in response to the demand for thinning of televisions and the like, there is an increasing demand for miniaturization of the optical link module.

  Patent Document 1 discloses an optical connector that does not require bending of leads. The optical connector includes a light emitting / receiving element, a housing, a contact having a contact lead portion, and a cover coupled to the housing. A lead extending in the axial direction of the substantially cylindrical light emitting / receiving element is connected to the contact lead portion and pressed by the cover.

JP 11-54770 A

  Provided is an optical link module that is mass-productive and easy to downsize.

  According to one aspect of the present invention, a lead frame having a notch at one end, an optical element bonded to the main surface of the lead frame and having an optical axis perpendicular to the main surface, and the one end opposite to each other An optical unit having a part of the lead frame on the side and a transparent resin layer in which the optical element is embedded, and a concave portion provided, which coincides with the optical axis of the optical element of the optical unit inserted in the concave portion A molded body having a cylindrical ferrule guide portion having a central axis on one surface side, and extending into the concave portion and pressed against the notch portion, and one end thereof is opposite to the one surface. There is provided an optical link module comprising a reinforcing terminal protruding from the other surface of the molded body.

  An optical link module which is rich in mass productivity and easy to miniaturize is provided.

FIG. 1A is a schematic perspective view of an optical link module according to this embodiment, and FIG. 1B is a schematic cross-sectional view taken along the line AA. FIG. 2A is a schematic perspective view of the light emitting device according to the present embodiment, and FIG. 2B is a schematic cross-sectional view taken along the line BB. FIG. 3A is a schematic perspective view of the optical unit, and FIG. 3B is a schematic perspective view of the opposite side. It is a model perspective view inside an optical unit. FIG. 5A is a schematic plan view of a lead frame, FIG. 5B is a schematic plan view after a molding process, and FIG. 5C is a schematic plan view showing a cut region. It is the schematic diagram which attached the optical link module concerning a comparative example to the circuit board. It is a model perspective view of the optical link module concerning the modification of this embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1A is a schematic perspective view of the optical link module according to the present embodiment viewed obliquely from above, and FIG. 1B is a schematic cross-sectional view taken along the line AA.
The optical link module 5 includes an optical unit 30, a molded body 10, and reinforcing terminals 20.

  The optical unit 30 includes a lead frame 35 having outer leads 31, 32, 33, an optical element 40 bonded to the lead frame 35 so that the optical axis 50 is perpendicular to the main surface 35 a of the lead frame 35, A transparent resin layer in which a part of the lead frame 35 not provided with the element 40 and the notch is embedded.

  The molded body 10 made of polycarbonate resin or the like is provided in a direction perpendicular to the central axis of the ferrule guide portion 11 and the cylindrical ferrule guide portion 11 provided in the opening portion 19 provided on the one surface 10a side. And the recess 12 that allows the optical unit 30 to be inserted until the optical axis 50 of the optical element 40 coincides with the central axis. In addition, it is preferable that the molded object 10 is a light-shielding material.

  The reinforcing terminal 20 can be inserted into a notch provided in the lead frame 35 so as to extend inside the recess 12. One end of the reinforcing terminal 20 protrudes from the other surface 10b opposite to the one surface 10a in a direction parallel to the central axis. The reinforcing terminal 20 may be L-shaped or the like, and may be integrally formed with resin. The diameter of the reinforcing terminal 20 can be set to 0.45 mm, for example. Moreover, if the convex part 14 which consists of resin etc. is provided and it fits with the recessed part provided in the circuit board side, it can attach to a circuit board reliably.

  In this figure, a ferrule 51 attached to an end of an optical fiber is inserted into a ferrule guide portion 11 provided inside the molded body 10. An optical connector is attached to the optical fiber, and the optical axis of the optical fiber coincides with the central axis of the ferrule guide portion 11 when the optical connector and the molded body 10 having the ferrule guide portion 11 are fitted. Thus, a module in which an optical fiber can be inserted into the cylindrical ferrule guide portion 11 can be called a receptacle type module.

  The optical link module 5 using the optical element 40 as a light receiving element functions as an optical receiver, and the optical link module 5 using the optical element 40 as a light emitting element functions as an optical transmitter. A system in which an optical receiver and an optical transmitter are connected via an optical fiber to transmit and receive an optical signal may be referred to as an optical link. If such an optical link is used, it becomes easy to mutually connect electronic devices such as a DVD component, a CD component, a television, and a BS tuner. Of course, it can also be used for data transmission between industrial devices.

  The optical axis 50 of the light receiving element is, for example, the center of the light receiving region of the light receiving photodiode. The optical axis 50 of the light emitting element is, for example, the center of the light emitting region of the LED.

  As the emission wavelength of light used for such an optical link, for example, red light near 660 nm is often used. In this case, a light emitting element having a GaAlAs light emitting layer, a light receiving element using a Si material, or the like can be used.

  The optical fiber may be APF (All Plastic Fiber), PCF (Plastic Cladding Silica Fiber), quartz fiber, or the like. In the case of the above application, since an optical signal modulated by an image and audio signal is mainly transmitted and received, a sufficient transmission band can be ensured even by using APF or PCF. In addition, the core diameter of APF and PCF is 200-980 micrometers, and the internal diameter of the ferrule guide part 11 shall be 2.5 mm.

FIG. 2A is a schematic perspective view of the light emitting device according to the present embodiment as viewed obliquely from below, and FIG. 2B is a schematic cross-sectional view taken along the line BB.
As shown in FIG. 2A, for example, three reinforcing terminals 20 protrude from the other surface 10 b of the molded body 10 in a direction parallel to the optical axis 50. The number of reinforcing terminals 20 is not limited to this. The outer leads 31, 32, 33 protrude from the transparent resin layer 29 of the optical unit 30 in a direction perpendicular to the optical axis 50. When the material of the lead frame 35 is a copper alloy, a palladium plating layer or the like is provided on the surface thereof. Further, in the recess 12, the vicinity where the reinforcing terminal 20 is provided can be a guide groove 12 a having a tapered portion.

  FIG. 3A is a schematic perspective view of one surface side, and FIG. 3B is a schematic perspective view of the other surface side. The outer leads 31, 32, 33 projecting from the transparent resin layer 29 of the optical unit 30 in the plane perpendicular to the optical axis have cutout portions 31c, 32c, 33c, respectively. In addition, arc-shaped recesses 31b, 32b, and 32b that can easily press-fit the reinforcing terminal 20 are provided in an intermediate region of the notch.

  When the optical unit 30 is inserted into the recess 12 provided in the molded body 10 in this way, the reinforcing terminals 20 integrally molded with the molded body 10 are pressed into the cutout portions 31c, 32c, and 33c, respectively. If the material of the reinforcing terminal 20 is, for example, phosphor bronze and the surface thereof is tin-plated, the electrical contact with the outer leads 31, 32, 33 having the palladium plated layer can be improved. With such a structure, the reinforcing terminal 20 and the cutout portion of the outer lead can be reliably fitted.

  The position of the optical unit 30 is determined with high accuracy in the direction along the optical axis 50 and in the plane perpendicular to the optical axis 50 by contacting the bottom surface and the lower side surface of the recess 12. In addition, the recessed part 12 may be expanded toward the outer side.

  In this figure, the outer two of the three reinforcing terminals 20 are provided outside the transparent resin layer 29 when viewed from above the recess 12, so that the optical unit 30 can be easily inserted into the recess 12. It is. Further, the intermediate reinforcing terminal 20 is on the near side of the paper surface of FIG. 1C and is outside the transparent resin layer 29. For this reason, the reinforcing terminal 20 does not prevent the optical unit 30 from being inserted. In this case, the outer lead 32 is bent at 90 degrees toward the other surface 10b in a direction parallel to the optical axis 50, and further bent so as to press-contact the reinforcing terminal 20. In this figure, the reinforcing terminal 20 and the region of the outer lead 32 having the notch 32c are bent so as to be vertical, but the bending angle is not limited to this.

  Further, as shown in FIG. 2, when the guide groove 12a is provided in the recess 12, the outer edges of the notches 31c, 32c, 33c that press-contact the reinforcing terminal 20 are further pressed by the tapered portion of the guide groove 12a. For this reason, the outer leads 31, 32, 33 and the reinforcing terminal 20 are more reliably fitted.

FIG. 4 is a schematic perspective view of the optical unit.
The optical unit 30 includes an optical element 40 and a chip capacitor 42 that are bonded on the main surface 35 a of the lead frame 35. Furthermore, integral molding is performed using a transparent resin. In the case of an optical receiver, the optical element 40 may be a light receiving IC in which a light receiving diode, a light receiving transistor, and the like are further integrated with an amplifier circuit and a control circuit. In the case of an optical transmitter, the optical element 40 is an LED (Light Emitting Diode) or an LD (Laser Diode). In addition, a drive circuit for the light emitting element may be included in the optical unit 30.

  In this figure, the outer lead 31 can be a ground (GND) terminal, the outer lead 32 can be a power supply (Vc) terminal, the outer lead 33 can be a signal terminal 33, and the like. The arrangement of the terminals is not limited to this. Since the thickness TM of the optical unit 30 can be reduced to, for example, a range of 1.5 to 3.0 mm, the distance between the other surface 10b of the molded body 10 and the front surface of the optical unit 30 (on the ferrule guide portion 11 side) is set. It is easy to shorten. In this case, if the transparent resin layer 29 covering the vicinity of the optical element 40 is molded into a convex shape, it can function as a condensing lens 29a.

5A is a schematic plan view of the lead frame, FIG. 5B is a schematic plan view after the molding process, and FIG. 5C is a schematic plan view showing a region to be cut.
The material of the lead frame 35 can be a copper-based or iron-based alloy. Further, for example, the thickness is in the range of 0.15 to 0.3 mm, and the width of the outer leads 31, 32, 33 in the protruding portion from the transparent resin layer 29 is in the range of 0.4 to 0.7 mm. be able to.

  The lead frame 35 in FIG. 5A has a die pad portion, a lead portion, a frame portion, and the like, and a large number of these are arranged. On the main surface 35a of the lead frame 35, the optical element 40 and the chip capacitor 42 are bonded using a conductive adhesive or a solder material, and wire bonding is performed. Subsequently, a transparent resin layer 29 is formed in a region to be an optical unit by a molding process (FIG. 5B). That is, the transparent resin layer 29 embeds a part of the lead frame 35 opposite to the one end and the optical element 40 in the lead frame 35 provided with the notches 31c, 32c, and 33c at one end.

  Further, the lead frame 35 is fixed to the cut mold. Subsequently, for example, the outer leads 31 and 33 are cut at predetermined positions using a die and a punch with an edge. On the other hand, at a predetermined position of the outer lead 32, cutting is performed using a die and a punch with an edge on the cutting side, bending is performed 90 degrees with a die and a punch having an R on the bending side, and a bending block or the like is further used. The outer lead 32 can be continuously bent up to 180 degrees. In this way, the optical unit 30 of FIG. 3 is completed. The process of bending the outer lead 32 having a bending angle of 90 degrees to 180 degrees may be performed separately.

  Moreover, the area | region represented with a broken line in FIG.5 (c) represents the area | region cut. Such a manufacturing method of the thin optical unit 30 is high in mass productivity, and as a result, the price of the optical link module 5 can be easily reduced.

FIG. 6A is a schematic view in which the optical link module according to the comparative example is attached to the circuit board, and FIG. 6B is a view in which the outer lead is bent and attached to the circuit board.
The optical link module 105 of the comparative example does not have a reinforcing terminal, and uses the outer lead 135 as a connection terminal with the circuit board 150. In this case, the arrangement pattern of the circuit board 150 and the distance between the circuit board 150 and the optical link module 105 differ depending on the type of electronic device and the manufacturer. Further, when the outer lead 135 and the circuit board 150 are orthogonal to each other as shown in FIG. 6A, either when the outer lead 135 is bent and made parallel to the circuit board 150 as shown in FIG. 6B. The structure of is also used.

  If the optical link module 105 having the length L100 of the outer lead 135 corresponding to such various uses can be prepared, the productivity of the assembly process of the electronic device increases. However, the number of types of optical units 130 increases and the efficiency of the manufacturing process decreases. That is, the mass productivity of the optical link module 105 decreases.

  On the other hand, it is also conceivable to perform a lead cutting process and a lead bending process for each application using the optical unit 130 having the long outer leads 135. However, a machining process using a plurality of molds is necessary. For this reason, the productivity of the assembly process of the electronic device is reduced. Furthermore, by making the outer lead 135 longer, a useless area increases, the material efficiency of the lead frame decreases, and the material cost increases.

On the other hand, in this embodiment, the optical unit 30 that can be used in common for various purposes can be efficiently mass-produced. In addition, since the length of the outer lead can be shortened, the area of the lead frame 35 can be reduced and the material efficiency can be increased. In addition, it is easy to change the length of the reinforcing terminal 20 for each application in which the mounting position, the distance from the circuit board, and the mounting structure are different. That is, the process of integrally molding the reinforcing terminal 20 with the resin or the like serving as the housing is much simpler than the manufacturing process of the optical unit 30. Furthermore, since the connection with the reinforcing terminal 20 is completed simply by inserting the optical unit 30 into the recess 12 of the molded body 10, high mass productivity is possible.
Furthermore, in a state where the optical unit 30 is inserted into the recess 12 of the molded body 10, the outer leads 31, 32, 33 are accommodated in the recess 12 and do not protrude outside the molded body 10 (FIG. 1B). ). Therefore, it can be mounted in a compact manner, and a short circuit with other surrounding electronic components or wirings can be prevented.

Next, an optical unit used for the optical link module will be described.
First, a CAN type package is used for the optical unit. The cylindrical CAN type package insulates between the lead and the metal stem using an insulating material such as glass. The diameter of the lead is often set to 0.45 mm, for example. An optical link module for connecting such a CAN-type optical element having a rod-like lead to a substrate or a housing has a large number of parts, and its manufacturing method lacks mass productivity.

  Further, when the optical element or the chip capacitor is bonded to the stem, the planar size increases. Furthermore, the position where the lead extending in the optical axis direction is connected to the external terminal needs to be separated from the stem by a predetermined distance. For this reason, the distance from the light extraction surface on the upper surface of the CAN package to the external terminal connection position needs to be 4.5 mm or more. That is, in the CAN type optical unit, it is difficult to reduce the length in the optical axis direction and the plane size perpendicular to the optical axis.

  In the present embodiment, the lead frame 35 has the outer leads 31, 32, 33 extending in a direction perpendicular to the optical axis 50, so that the length in the direction of the optical axis 50 can be easily reduced. In addition, since the lead frame 35 has a high degree of freedom in the planar pattern arrangement, the planar size can be easily reduced. For these reasons, the optical unit 30 can be downsized. In particular, the cutout portions 31c, 32c, 33c provided in the outer leads 31, 32, 33 can be pressure-contacted while sandwiching the reinforcing terminal 20 inside the recess 12 provided in the molded body 10. Further downsizing can be achieved. Further, as already described, the optical unit 30 according to the present embodiment can maintain high mass productivity.

FIG. 7 is a schematic perspective view of an optical link module according to a modification of the present embodiment.
The outer leads 31, 32, 33 are bent 180 degrees along the optical axis 50 toward the other surface 10 b of the molded body 10, and the notch portions are pressed against the reinforcing terminals 20. Further, when the tapered portion is provided in the concave portion 12, the outer edges of the outer leads 31, 32, and 33 are press-contacted by the guide groove 12a having the tapered portion, so that the connection can be made more reliably. The bending direction of the outer leads 31 and 33 may be the one surface 10a side.

  In addition, three or more notches may be provided on the main surface 35a of the lead frame 35 or a surface parallel to the main surface 35a. That is, the reinforcing terminal 20 can be press-contacted by the notch without providing a bent portion. In this case, the reinforcing terminal 20 may be provided between the transparent resin layer 29 of the optical unit 30 and the side surfaces 10 c and 10 d of the molded body 10.

  According to the present embodiment using the structure in which the reinforcing terminal 20 and the cutout portion provided in the lead frame 35 are pressed against each other, the optical link module 5 which is rich in mass productivity and can be downsized is provided. When such an optical link module is used, it becomes easy to mutually connect electronic devices such as a DVD component, a CD component, a television, and a BS tuner. In particular, electronic devices including televisions can be easily reduced in thickness and size.

  The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to these embodiments. Those skilled in the art have made various design changes with regard to the material, shape, size, arrangement, etc. of the lead frame, optical element, transparent resin layer, optical unit, molded body, recess, reinforcing terminal, etc. constituting the present invention. Even if it exists, unless it deviates from the main point of this invention, it is included in the scope of the present invention.

  5 Optical link module, 10 molded body, 11 ferrule guide portion, 12 recess, 12a guide groove, 20 reinforcing terminal, 29 transparent resin layer, 30 optical unit, 31, 32, 33 outer lead, 31c, 32c, 33c notch , 32a bent portion, 35 lead frame, 40 optical elements, 50 optical axes

Claims (5)

A lead frame having a notch at one end, an optical element bonded to the main surface of the lead frame and having an optical axis perpendicular to the main surface, a part of the lead frame opposite to the one end, and An optical unit having a transparent resin layer in which the optical element is embedded;
A molded body having a cylindrical ferrule guide portion on one side having a concave portion and having a central axis coinciding with the optical axis of the optical element of the optical unit inserted in the concave portion;
A reinforcing terminal extending from the other surface of the molded body that extends into the recess and is in pressure contact with the notch and has one end opposite to the one surface;
An optical link module comprising:   2. The optical link module according to claim 1, wherein the concave portion includes a guide groove having a tapered portion capable of press-contacting an outer edge of the notch portion of the lead frame.   The optical link module according to claim 1, wherein the lead frame has the cutout portion in the main surface or a plane parallel to the main surface.   The lead frame has a bent portion bent in a direction parallel to the optical axis, and has the notched portion in the bent portion. Optical link module.   5. The optical link module according to claim 1, wherein the cutout portion is provided outside the transparent resin layer when the concave portion is viewed from above.

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