JP2011233837A - Optical transceiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical transceiver which has an increased heat dissipation performance of an optical module.SOLUTION: An optical transceiver for optical communication has at least two optical modules. Each of the optical modules, which serves as a heating element, is surface mounted on a flexible substrate. A first heat dissipation member is placed between the optical modules, with the flexible substrate in between the first dissipation member and each optical module.

Description

  The present invention relates to an optical transceiver used for optical communication.

  In recent years, many communication devices and devices including the communication devices have been reduced in size and density. As a result, optical transceivers built into communication devices, particularly optical communication devices that transmit and receive optical signals, are also required to be smaller and more dense, and two optical transceivers must be installed in the space of one conventional optical transceiver. Is required.

  For example, the Compact SFP (Small Form Factor Pluggable), which is the industry standard specification for small pluggable optical transceivers, has two single-fiber bidirectional optical transceivers in a housing with dimensions defined by the same industry standard specification, SFP. It is required to be installed.

  A configuration example of an optical transceiver capable of realizing the Compact SFP is described in Patent Document 1, for example. Patent Document 1 shows a configuration in which two optical modules are mounted on one or two rigid boards corresponding to two optical transceivers.

JP 2010-067652 A

  A configuration in which two optical transceivers are mounted in one casing such as the Compact SFP is effective for downsizing the optical communication apparatus. However, this configuration has higher heat dissipation than the optical transceiver conforming to the SFP because the ambient temperature environment during the operation of the optical transceiver does not change even though the mounting density is twice that of the optical transceiver conforming to the SFP. Performance is required.

  Patent Document 1 shows a configuration in which an optical module is surface-mounted on a rigid substrate as described above. In such a configuration, heat generated in the optical module is transferred to the upper surface of the optical module (a surface not connected to the rigid substrate). ) Can only dissipate heat, and there is a problem that sufficient heat dissipation performance cannot be obtained.

  The present invention has been made to solve the problems of the background art as described above, and an object thereof is to provide an optical transceiver in which the heat dissipation performance of the optical module is further improved.

In order to achieve the above object, an optical transceiver of the present invention includes at least two optical modules serving as heating elements,
Two flexible substrates on which the optical module is surface-mounted;
A first heat dissipating member disposed between the optical modules with the flexible substrate interposed therebetween;
Have

  According to the present invention, the heat dissipation performance of the optical module can be further improved.

It is a perspective view which shows one structural example of the optical transceiver of this invention. It is a perspective view which shows the assembly example of the optical module and flexible substrate which were shown in FIG. It is a perspective view which shows an example of the pad for thermal radiation with which the optical module and flexible substrate shown in FIG. 1 are provided.

  Next, the present invention will be described with reference to the drawings.

  In the optical transceiver of this embodiment, the optical module, which is a heating element, is surface-mounted on a thin flexible substrate instead of a rigid substrate. And a heat radiating member is arrange | positioned between optical modules on both sides of a flexible substrate. In this way, heat can be radiated not only from the top surface but also from the back surface of the optical module, and the heat radiation performance is improved.

  Patent Document 1 described above shows a configuration using a flexible rigid substrate in which a rigid substrate on which an optical module is mounted and a rigid substrate on which an electric circuit is mounted are integrally connected by a flexible substrate. Therefore, when a defect is detected in one of the two optical modules in the product test after assembly, the entire optical transceiver including the other optical module that is a non-defective product is determined to be defective and discarded. As a result, the yield in the manufacturing process of the optical transceiver decreases, and the manufacturing cost of the optical transceiver increases. Therefore, in the optical transceiver of the present embodiment, a flexible board on which an optical module is mounted does not use a rigid board (printed board) on which an electric circuit is mounted. In the present embodiment, the flexible substrate is connected to a rigid substrate on which an electric circuit is mounted after mounting the optical module. The flexible board on which the optical module is mounted and the rigid board on which the electric circuit is mounted can be connected by soldering, but in this embodiment, they are connected via an electric connector. In this way, replacement of the optical module is facilitated.

  FIG. 1 is a perspective view showing a configuration example of the optical transceiver of the present invention, and FIG. 2 is a perspective view showing an assembly example of the optical module and the flexible substrate shown in FIG.

  As shown in FIG. 1, the optical transceiver 10 of this embodiment includes optical modules 1a and 1b, flexible substrates 2a and 2b, a printed circuit board 4, heat radiation members 6a, 6b and 6c, a housing 7, an upper cover 8, and a lower cover. 9.

  The printed circuit board 4 is a flexible rigid board in which, for example, two rigid boards are connected by a flexible board, and an IC 5 is mounted on each rigid board. The IC 5 is an electric circuit that performs a required process on a transmission / reception signal (electric signal) that realizes the function as the optical transceiver 10. On the rigid substrate, an electric circuit for executing a required process may be formed, and the type of the element is not limited to IC5. For example, an electric circuit that executes a required process may include a processor such as a CPU or DSP, or may include individual elements such as a transistor, a diode, a resistor, a capacitor, and a coil.

  Electrical connectors 3a and 3b are mounted on the rigid boards of the printed circuit board 4. The IC 5 mounted on the rigid board and the optical modules 1a and 1b mounted on the flexible boards 2a and 2b are connected to the electrical connector 3a, Connected via 3b.

  The optical modules 1a and 1b convert an electrical signal output from the IC 5 on the printed circuit board 4 into an optical signal and output it to an optical fiber or the like, and convert an optical signal received from the optical fiber or the like into an electrical signal for printing. Output to the IC 5 on the substrate 4.

  The optical module 1a is surface-mounted on the flexible substrate 2a, and the optical module 1b is surface-mounted on the flexible substrate 2b. A heat dissipating member 6a (second heat dissipating member) is installed on the upper surface of the optical module 1a not connected to the flexible substrate 2a, and a heat dissipating member 6b (second heat dissipating member) on the upper surface of the optical module 1b not connected to the flexible substrate 2b. Is installed. The heat dissipation member 6a may be bonded and fixed on the optical module 1a, and the heat dissipation member 6b may be bonded and fixed on the optical module 1b. Although FIG. 1 shows a configuration example in which one optical module is mounted on one flexible substrate, the number of optical modules mounted on the flexible substrate is not limited to one, and a plurality of optical modules is mounted. Modules may be mounted.

  The flexible substrates 2a and 2b are arranged so that the back surfaces on which the optical modules 1a and 1b are not mounted face each other, and a heat radiation member 6c (first heat radiation member) is inserted between the back surfaces. That is, the heat radiation member 6c is disposed between the optical modules 1a and 1b with the flexible substrates 2a and 2b interposed therebetween. As the heat radiating member 6c, a well-known heat radiating sheet may be used, or a metal member may be used. Further, when the housing 7, the upper cover 8, or the lower cover 9 is formed of a member having a low thermal resistance, for example, a metal member, the heat radiating member 6 c has a shape or size that contacts the housing 7, the upper cover 8, or the lower cover 9. It may be. In that case, the heat generated in the optical modules 1a and 1b is radiated from the heat radiating member 6c to the external space through the housing 7, the upper cover 8 or the lower cover 9, so that the heat radiation performance of the optical modules 1a and 1b is further improved. To do.

  As shown in FIG. 2, the flexible substrate 2 (2a, 2b) includes a mounting portion on which the optical module 1 (1a, 1b) is mounted, and a surface extended from the mounting portion (hereinafter referred to as an extension portion). An edge connector 2c is formed at the end of the extension. The edge connector portion 2c is formed by exposing the surface of the internal wiring of the flexible substrate 2, for example. The internal wiring is exposed on both sides of the flexible substrate 2 respectively.

  The flexible boards 2a and 2b are bent at the boundary between the mounting part and the extension part so that the edge connector part 2c can be inserted into the electrical connector 3 (3a and 3b) mounted on each rigid board of the printed board 4. Yes. The flexible substrate 2 is formed with a thickness of, for example, about 0.3 mm so that the thermal resistance is small.

  As shown in FIG. 3, the optical module 1 (1a, 1b) has a leadless structure including electrode pads for soldering, and the light of the pad forming surface of the optical module 1 and the flexible substrate 2 (2a, 2b). Heat radiation pads 11 are provided on the mounting surface of the module 1 (hereinafter referred to as module mounting surface), and the heat radiation pads 11 are connected to each other when the optical module 1 is mounted on the flexible substrate 2. These heat radiation pads 11 may be used as a ground potential. Further, the heat radiation pad 11 may be formed on the back surface of the flexible substrate 2 where the optical module 1 is not mounted.

  As described above, the optical transceiver described in Patent Document 1 has a configuration in which an optical module is surface-mounted on a rigid substrate, and heat generated by the optical module is transferred to the upper surface of the optical module (a surface that does not contact the rigid substrate). ) Can only dissipate heat.

  On the other hand, in the optical transceiver 10 of this embodiment, the optical modules 1a and 1b are surface-mounted on the thin flexible boards 2a and 2b, and heat is radiated between the optical modules 1a and 1b with the flexible boards 2a and 2b interposed therebetween. Since the member 6c is disposed, heat generated in the optical modules 1a and 1b can be dissipated from the upper and back surfaces of the optical modules 1a and 1b, respectively. Therefore, the heat dissipation performance of the optical modules 1a and 1b is improved.

  Further, by providing heat dissipation pads 11 on the pad forming surface of the optical module 1 and the module mounting surface of the flexible substrate 2 and connecting them when the optical module 1 is mounted, the heat generated in the optical module 1 is dissipated. It can be efficiently conducted to 6c. Therefore, the heat dissipation performance of the optical module 1 is further improved. Furthermore, if the heat dissipation pad 11 is formed on the back surface of the flexible substrate 2 where the optical module 1 is not mounted, the heat generated in the optical module 1 can be more efficiently conducted to the heat dissipation member 6c. In that case, the heat dissipation performance of the optical module 1 is further improved.

  Moreover, in the optical transceiver 10 of this embodiment, since the IC 5 mounted on the printed board 4 and the optical module 1 mounted on the flexible board 2 are connected via the electrical connector 3, the product test of the optical transceiver 10 is performed. Even if the optical module 1 is determined to be defective sometimes, the optical module 1 determined to be defective can be easily replaced. Therefore, the yield at the time of manufacturing the optical transceiver 10 is improved.

  Further, the edge connector portions 2c are provided on both surfaces of the end portion of the flexible substrate 2, and the flexible substrate 2 is arranged so as to be bent at the boundary between the mounting portion and the extension portion as shown in FIG. Two flexible substrates 2a and 2b can be made common. Therefore, it is not necessary to prepare two types of flexible boards 2a and 2b for the optical modules 1a and 1b. Further, even if it is determined that one of the optical modules 1a or 1b is defective during the product test of the optical transceiver 10, it can be replaced with the optical module 1 mounted on the flexible substrate 2 having the same shape.

  Accordingly, a decrease in yield during the manufacture of the optical transceiver 10 is suppressed, and the number of parts of the optical transceiver 10 is reduced, so that the manufacturing cost of the optical transceiver 10 can be reduced.

1, 1a, 1b Optical module 2, 2a, 2b Flexible substrate 3, 3a, 3b Electrical connector 4 Printed circuit board 5 IC
6a, 6b, 6c Heat radiation member 7 Housing 8 Upper cover 9 Lower cover 10 Optical transceiver 11 Heat radiation pad

Claims (6)

At least two optical modules serving as heating elements;
Two flexible substrates on which the optical module is surface-mounted;
A first heat dissipating member disposed between the optical modules with the flexible substrate interposed therebetween;
Having optical transceiver.   The heat radiation pad provided on each of the optical module and the one surface of the flexible substrate on which the optical module is mounted, which are connected to each other when the optical module is mounted on the flexible substrate. Optical transceiver. The heat dissipating pad is
The optical transceiver according to claim 2, wherein the optical transceiver is formed on the other surface of the flexible substrate in contact with the first heat dissipation member.   4. The optical transceiver according to claim 1, further comprising a second heat dissipating member installed on an upper surface of the optical module that is not connected to the flexible substrate. 5. It further includes a printed circuit board on which required electrical circuits are mounted,
The optical transceiver according to claim 1, wherein the flexible substrate is connected to the printed circuit board after the optical module is mounted. An electrical connector mounted on the printed circuit board;
The optical transceiver according to claim 5, wherein the electrical circuit and the optical module are connected via the electrical connector.

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