Photoelectric module

Abstract

This photoelectronic module is provided with a main wiring board (101), an optical circuit chip (102), an electronic circuit chip (103), an electronic component (104), an optical fiber (105), an auxiliary wiring board (121), and a housing (106). The auxiliary wiring board (121) is connected on the main wiring board (101) inside the housing (106), and the optical circuit chip (102) and the electronic circuit chip (103) are mounted on the auxiliary wiring board (121).

Description

Optical / Electrical Module

[0001] The present invention relates to an opto-electrical module.

[0002] In recent years, the scope of application of optical communication modules and devices has expanded beyond long-distance communications to include links between data centers, mobile phone base stations, and edge routers, resulting in increasing demand for improved performance. To improve the performance of optical communication modules and devices, it is necessary to closely arrange electrical ICs that process electrical signals, such as digital signal processors (DSPs), drivers, and transimpedance amplifiers (TIAs), with optical circuit chips in order to improve high-frequency characteristics. This has led to active discussions about co-packaged optics (CPO) modules (Non-Patent Documents 1 and 2). To miniaturize CPOs, it is necessary to ensure the quality of the optical fibers and optical connections within the modules.

[0003] As a conventional technology, there is a CPO that includes an electrical IC that combines a digital signal processing circuit chip (XSR, TRX, CDR in Fig. 4), a driver, and a transimpedance amplifier, and a silicon photonics chip (Si-Photonic IC in Fig. 4), as shown in Non-Patent Document 1. This CPO includes multiple silicon photonics chips, as shown in Fig. 6(a) and Fig. 7 in Non-Patent Document 1, and optical fibers for optical input / output are required for each of these silicon photonics chips.

[0004] 6A and 6B, a typical optoelectronic module having optical transmission and reception functions will be described. The optoelectronic module includes a wiring substrate 301, an optical circuit chip 302, an electronic circuit chip 303, electronic components 304, an optical fiber 305, and a housing 306. The optical circuit chip 302, the electronic circuit chip 303, and the electronic components 304 are mounted on the wiring substrate 301. A portion of the optical circuit chip 302 protrudes outside the wiring substrate 301 in a plan view.

[0005] The optical circuit chip 302 includes an optical transmitter configured with an optical modulator, an optical waveguide, a splitter, an optical attenuator, etc., and an optical receiver configured with a photodiode, an optical waveguide, an optical attenuator, etc. A signal from the electronic circuit chip 303 is input to the optical transmitter via the wiring board 301, and the optical circuit chip 302 includes a terminal 307 for outputting a received signal from the optical receiver to the TIA of the electronic circuit chip 303.

[0006] A traveling-wave electrode Mach-Zehnder modulator (MZM) is often used for the optical transmitter of the optical circuit chip 302. In conventional technology, it is mounted face-down by flip-chip mounting, and the transmission signal input terminal group, reception signal output terminal group, and MZM electrodes of the optical circuit chip 302 are arranged on the bottom surface of the optical circuit chip 302 (the surface facing the wiring substrate 301).

[0007] The electronic circuit chip 303 includes a digital signal processing circuit (DSP), a driver circuit (DRV), and a transimpedance amplifier circuit (TIA). Although these may be implemented as individual chips, this example shows them integrated into the electronic circuit chip 303. The DRV amplifies the transmission signal output from the digital signal processing circuit, and the TIA amplifies the reception signal output from the optical circuit, and each has the function of connecting to the digital signal processing circuit.

[0008] The electronic circuit chip 303 generally has a plurality of terminals 308 for outputting transmission signals and inputting reception signals on the line side (i.e., the side that outputs signals to the optical transmitter and the side that receives signals from the optical receiver). For example, a digital signal processing circuit chip based on the 400GBASE-DR4 standard has eight transmission signal output terminals (4 lanes x positive / negative) and reception signal input terminals.

[0009] The electronic components 304 are a group of components necessary for driving the optical circuit chip 302 and the electronic circuit chip 303, and may be capacitors, inductors, resistors, etc. The electronic components 304 may also be a control microcomputer, an AD converter, a DA converter, an electric switch, etc.

[0010] The wiring board 301 is a build-up board using a resin as a base material, and can have a multilayer wiring structure of about 10 layers. Intra-board wiring 309 is formed in each layer of the wiring board 301 and between layers, and input and output of electrical signals to and from the outside is performed via input and output electrical terminals 310.

[0011] The housing 306 is fixed to the wiring substrate 301 while surrounding the optical circuit chip 302 and the electronic circuit chip 303, and prevents dust from adhering to each chip. The housing 306 also fixes the optical fiber take-out section 312, which will be described later. The housing 306 can be made of, for example, aluminum, stainless steel, copper, or the like.

[0012] The optical fiber 305 is connected to the optical circuit chip 302 for optical input / output. The optical fiber 305 can be arranged in an array of multiple optical fibers. In the case of 400GBASE-DR4, a minimum of eight optical fibers 305 are required: four for transmission and four for reception. Furthermore, if continuous light for optical transmission is supplied from an external source, at least one additional optical fiber is added to these. For ease of handling, the optical fibers 305 arranged in an array of multiple optical fibers are usually fixed to each other with adhesive or a coating using a method called taping or ribbonizing. The optical fiber can be made of silica glass, plastic, or the like.

[0013] The optical fiber 305 is fixed to one end of the optical circuit chip 302 by a fixing part 311. In order to connect the optical fiber 305 to an optical waveguide formed in a position close to the bottom surface of the optical circuit chip 302, the fixing part 311 protrudes below the bottom surface of the optical circuit chip 302. Therefore, to prevent interference (contact) between the bottom of the fixing part 311 and the wiring board 301, the end of the optical circuit chip 302 to which the fixing part 311 is fixed protrudes outside the wiring board 301 in a plan view.

[0014] The fixing component 311 is made of glass, a material different from that of the optical fiber 305, and serves to increase the connection strength between the optical fiber 305 and the optical circuit chip 302. The optical fiber 305 is optically connected to the outside of the housing 306 via an optical fiber outlet 312 installed in the housing 306. The optical fiber outlet 312 is made of a resin molded part called a boot, which has a through hole for passing the optical fiber 305 through.

[0015] The optical fiber 305 and the fixing part 311 are connected using an optically transparent adhesive to the center of the end face of the optical circuit chip 302. The optical fiber 305 extends horizontally in the optical axis direction to the outside of the housing 306 (module).

[0016] In order to achieve double the transmission capacity of 400GBASE-DR4, a plurality of optical circuit chips 302a and 302b and a plurality of electronic circuit chips 303a and 303b are mounted on a wiring substrate 301 as shown in FIG.

[0017] R. Mahajan et al., "Co-Packaged Photonics For High Performance Computing: Status, Challenges And Opportunities", Journal of Lightwave Technology, vol. 40, no. 2, pp. 379-392, 2022. R. Stone et al., "Co-packaged Optics for Data Center Switching", European Conference on Optical Communications, 20446618, 2020.

[0018] Incidentally, miniaturization of the module is an important technical issue, and in order to further miniaturize the module (housing 306), it is important to reduce the size of the housing 306 to a size close to that of the wiring board 301. For this reason, it is required to further narrow the gap between the optical fiber extraction part 312 and the fixing part 311 fixed to the optical circuit chip 302 mounted protruding outside the wiring board 301.

[0019] In this manner, in a configuration requiring a short distance between the optical circuit chip 302 and the optical fiber take-out portion 312, the optical fiber 305 between the fixing part 311 and the optical fiber take-out portion 312 may be bent significantly due to buckling. In the optical fiber 305 where such a large bend has occurred, there are portions where the bending radius is small, and as is well known, in such portions, optical loss within the optical fiber 305 increases. Furthermore, in portions where the bending radius is small, the optical fiber 305 may break.

[0020] The bending state of the optical fiber 305 described above is determined by the distance in the optical axis direction (bending length) between each end of the fixing part 311 and the optical fiber output part 312, and the distance in the height direction of the housing 306 as viewed from the mounting surface of the wiring board 301 (bending height). If the bending radius R of the bent part, determined by the bending length and bending height, becomes smaller than the radius that can guarantee the quality of the optical fiber 305, characteristic degradation such as increased loss and increased polarization extinction ratio occurs due to leakage of propagating light from the core of the optical fiber 305 or microcracks caused by bending. Furthermore, if mechanical loads or environmental loads such as stress concentration or vibration shock are applied, the optical fiber 305 may break, causing it to lose its function as an optoelectronic module.

[0021] 7, in order to fit a socket or the like used to mount an optoelectronic module without causing misalignment, a structure such as a constriction 341 may be provided on the exterior of the housing 306'. In such cases, in order to accommodate multiple chips within the housing 306', the fixing parts 311a and 311b are connected to the optical circuit chips 302a and 302b at positions offset to the inside of the chips rather than at the center of their end faces. For this reason, the optical fibers 305a and 305b are bent in the optical axis direction in a plan view to reach the optical fiber extracting portions 312a and 312b.

[0022] As described above, when multiple optical circuit chips are arranged, they buckle and bend relative to the optical axis in a planar view, which adds the element of bend width to the bend length and bend height, further increasing the risk of increased loss and breakage. Furthermore, because the arrayed optical fibers 305 a, 305 b are tape-shaped or ribbonized, it is not easy to bend them in the width direction. Forcing the optical fibers to bend not only increases the risk of optical fiber breakage, but also places excessive stress on the connections between the optical circuit chips 302 a, 302 b and the optical fibers 305 a, 305 b, potentially resulting in increased connection loss and adhesive detachment.

[0023] As described above, the conventional technology has had the problem that the optical fiber between the optical circuit chip and the optical fiber extraction section in the module is prone to deterioration in characteristics and breakage.

[0024] The present invention has been made to solve the above problems, and aims to suppress deterioration of the characteristics and breakage of the optical fiber between the optical circuit chip and the optical fiber extraction section in the module.

[0025] The optoelectronic module of the present invention comprises a housing, a main wiring board accommodated in the housing, a sub-wiring board connected on top of the main wiring board inside the housing, an optical circuit chip mounted on the sub-wiring board inside the housing, an optical fiber optically connected to an optical input / output terminal on a side end face of the optical circuit chip, a fixing part for fixing the optical fiber to the optical input / output terminal, and an optical fiber extraction part fixed to the side of the housing opposite the optical input / output terminal for extracting the optical fiber to the outside of the housing, and the optical circuit chip is mounted on the sub-wiring board with the optical input / output terminal side protruding beyond the sub-wiring board.

[0026] As described above, according to the present invention, an optical circuit chip is mounted on a sub-wiring board connected to a main wiring board, thereby suppressing deterioration of the characteristics and breakage of the optical fiber between the optical circuit chip and the optical fiber extraction section in the module.

[0027] FIG. 1A is a plan view showing the internal configuration of an opto-electric module according to a first embodiment of the present invention. FIG. 1B is a cross-sectional view showing the configuration of an opto-electric module according to the first embodiment of the present invention. FIG. 2 is a plan view showing the internal configuration of an opto-electric module according to a second embodiment of the present invention. FIG. 3 is a cross-sectional view showing the configuration of an opto-electric module according to a third embodiment of the present invention. FIG. 4A is a plan view showing the internal configuration of an opto-electric module according to a fourth embodiment of the present invention. FIG. 4B is a cross-sectional view showing the configuration of an opto-electric module according to the fourth embodiment of the present invention. FIG. 4C is a cross-sectional view showing another configuration of an opto-electric module according to the fourth embodiment of the present invention. FIG. 5A is a plan view showing the internal configuration of an opto-electric module according to a fifth embodiment of the present invention. FIG. 5B is a cross-sectional view showing the configuration of an opto-electric module according to the fifth embodiment of the present invention. FIG. 6A is a plan view showing the internal configuration of a conventional opto-electric module. FIG. 6B is a cross-sectional view showing the configuration of a conventional opto-electric module. FIG. 7 is a plan view showing the internal configuration of a conventional opto-electric module.

[0028] Hereinafter, an opto-electric module according to an embodiment of the present invention will be described.

[0029] First Embodiment First, an opto-electric module according to a first embodiment of the present invention will be described with reference to Figures 1A and 1B. Figure 1A shows the inside of the module, and Figure 1B shows a cross section taken along line xx' in Figure 1A.

[0030] This opto-electric module includes a main wiring board 101, an optical circuit chip 102, an electronic circuit chip 103, electronic components 104, an optical fiber 105, a sub-wiring board 121, and a housing 106. This opto-electric module is, for example, a pigtail-type module. Although not shown, an optical connector such as an MPO (Multi-Fiber Push On) connector is connected to the tip of the optical fiber 105 outside the housing 106. This opto-electric module complies with, for example, the 400GBASE-DR4 standard, and the optical fibers 105 can be configured with eight optical fibers, four for transmission and four for reception, and at least one additional optical fiber can be added to supply continuous light for optical transmission from the outside.

[0031] The sub-wiring substrate 121 is connected to the top of the main wiring substrate 101 inside the housing 106. The optical circuit chip 102 and the electronic circuit chip 103 are mounted on the sub-wiring substrate 121. Electronic components 104 can also be mounted on the sub-wiring substrate 121. The optical circuit chip 102 is mounted on the sub-wiring substrate 121 with the optical input / output terminal 131 side protruding from the sub-wiring substrate 121.

[0032] The main wiring board 101 is a build-up board based on resin, and can have a multilayer wiring structure of about 1 mm thick and about 10 layers. Internal wiring 109 is formed on each layer of the main wiring board 101 and between layers, and electrical signals are input and output from and to the outside via input and output electrical terminals 110. The internal wiring 109 can be, for example, copper wiring. The input and output electrical terminals 110 can be, for example, electrodes for a land grid array (LGA), a ball grid array (BGA), or other structures.

[0033] Substrate-to-substrate terminals 122 are formed on the top of the main wiring board 101, realizing electrical connection with the sub-wiring board 121. The sub-wiring board 121 is generally called an interposer. The sub-wiring board 121 can have a thickness of about 0.5 mm and a multi-layer wiring structure of about eight layers. The substrate-to-substrate terminals 122 can be made of BGA, copper pillars (CuP), solder, etc.

[0034] The optical circuit chip 102 has an optical circuit made up of an optical waveguide with a silicon core, and has a thickness of, for example, about 1 mm. The optical circuit chip 102 can also be made of a quartz-based material or a compound semiconductor such as InP. The optical circuit chip 302 is flip-chip (FC) mounted on the sub-wiring substrate 121 by optical circuit terminals 107 and electrically connected thereto.

[0035] The optical circuit chip 102 can include, for example, an optical transmitter including an optical modulator, an optical waveguide, a splitter, an optical attenuator, etc., and an optical receiver including a photodiode, an optical waveguide, an optical attenuator, etc. A signal from the electronic circuit chip 103 is input to the optical transmitter via at least the sub-wiring substrate 121, and a received signal from the optical receiver is output to the TIA of the electronic circuit chip 103.

[0036] A traveling-wave electrode Mach-Zehnder modulator (MZM) is often used for the optical transmitter of the optical circuit chip 102. The transmission signal input terminal group, reception signal output terminal group, and MZM electrodes (optical circuit terminals 107) of the optical circuit chip 102, which is mounted face-down on the sub-wiring substrate 121 by flip-chip mounting, are arranged on the lower surface of the optical circuit chip 102 (the surface facing the sub-wiring substrate 121).

[0037] The electronic circuit chip 103 includes a digital signal processing circuit (DSP), a driver circuit (DRV), and a transimpedance amplifier circuit (TIA). Although these may be implemented as individual chips, this example shows them integrated into the electronic circuit chip 103. The DRV amplifies the transmission signal output from the digital signal processing circuit, and the TIA amplifies the reception signal output from the optical circuit, and each has the function of connecting to the digital signal processing circuit.

[0038] The electronic circuit chip 103 generally has a plurality of electronic circuit terminals 108 for outputting transmission signals and inputting reception signals on the line side (i.e., the side that outputs signals to the optical transmitter and the side that receives signals from the optical receiver). For example, a digital signal processing circuit chip based on the 400GBASE-DR4 standard has eight transmission signal output terminals (4 lanes x positive / negative) and reception signal input terminals.

[0039] The electronic components 104 are a group of components necessary for driving the optical circuit chip 102 and the electronic circuit chip 103, and may be capacitors, inductors, resistors, etc. The electronic components 104 may also be a control microcomputer, an AD converter, a DA converter, an electric switch, etc. In the first embodiment, the electronic components 104 are mainly mounted (implemented) on the main wiring substrate 101 or the sub-wiring substrate 121 on the optical input / output terminal 131 side of the optical circuit chip 102.

[0040] The housing 106 is fixed to the main wiring board 101, surrounding the optical circuit chip 102 and the electronic circuit chip 103, and prevents dust from adhering to each chip. The housing 106 also fixes the optical fiber take-out section 112, which will be described later. The housing 106 can be made of, for example, aluminum, stainless steel, copper, or the like.

[0041] The optical fibers 105 are connected to the optical circuit chip 102 for optical input and output. The optical fibers 105 can be arranged in an array of multiple fibers. In the case of 400GBASE-DR4, a minimum of eight optical fibers 105 are required: four for transmission and four for reception. Furthermore, if continuous light for optical transmission is supplied from an external source, at least one additional optical fiber is added to these. For ease of handling, the optical fibers 105 arranged in an array of multiple fibers are usually fixed to each other with adhesive or a coating using a method called taping or ribbonizing.

[0042] The optical fiber 105 is fixed to one end of the optical circuit chip 102 by a fixing part 111. To connect the optical fiber 105 to an optical waveguide formed in a position close to the bottom surface of the optical circuit chip 102, the fixing part 111 protrudes downward from the bottom surface of the optical circuit chip 102. To prevent interference (contact) between the bottom of the fixing part 111 protruding downward and the sub-wiring board 121, the optical input / output terminal 131 of the optical circuit chip 102 to which the fixing part 111 is fixed protrudes outside the sub-wiring board 121 in a plan view. However, because the optical circuit chip 102 is mounted on the sub-wiring board 121, there is no interference between the bottom of the fixing part 111 and the main wiring board 101, even in a configuration in which the optical circuit chip 102 is disposed in the center of the main wiring board 101, for example.

[0043] The fixing component 111 is made of glass, a material different from that of the optical fiber 105, and serves to increase the connection strength between the optical fiber 105 and the optical circuit chip 102. The optical fiber 105 is optically connected to the outside of the housing 106 via an optical fiber outlet 112 installed in the housing 106. The optical fiber outlet 112 is generally called a boot, and can be a resin molded component having a through hole for passing the optical fiber 105 through.

[0044] The optical fiber 105 and the fixing part 111 are connected to the center of the end face of the optical circuit chip 102 using an optically transparent adhesive. The optical fiber 105 extends horizontally in the optical axis direction to the outside of the housing 106 (module).

[0045] According to this embodiment, the optical circuit chip 102 is mounted on the sub-wiring substrate 121, so the lower end of the fixing component 111 can be positioned away from the surface of the main wiring substrate 101. This allows for greater flexibility in the placement of the optical circuit chip 102 on the main wiring substrate 101. Therefore, the distance between the optical input / output terminal 131 of the optical circuit chip 102 and the optical fiber output portion 112 can be increased without hindering the miniaturization of the housing 106. As a result, the optical fiber 105 between the fixing component 111 and the optical fiber output portion 112 can be increased in length, thereby preventing the optical fiber 105 from bending significantly due to buckling. In this embodiment, the bend radius R of the bent portion, determined by the bend length and bend height, is 15 mm or more, which is the minimum recommended bend radius for optical fibers. This allows the insertion loss of the optical fiber to be less than 0.1 dB, and also significantly reduces the probability of fiber breakage due to bending.

[0046] [Embodiment 2] Next, an opto-electric module according to embodiment 2 of the present invention will be described with reference to Fig. 2. Fig. 2 shows the inside of the module. This opto-electric module includes a main wiring board 101, an optical circuit chip 102, an electronic circuit chip 103, electronic components 104, an optical fiber 105, a sub-wiring board 121, and a housing 106. These components are configured in the same manner as in embodiment 1 described above.

[0047] In the second embodiment, a first optical connector 113 is used as the optical fiber extraction section. The optical fiber 105 is optically connected to the outside of the housing 106 via the first optical connector 113 installed (fixed) in the housing 106. One end of the optical fiber 105 is connected to the optical input / output terminal 131 of the optical circuit chip 102, and the other end is fixed to the first optical connector 113. In addition, the first optical connector 113 is connectable to a second optical connector 114. By connecting the first optical connector 113 and the second optical connector 114, the optical fiber 105 is optically connected to an external optical fiber 115.

[0048] The first optical connector 113 may be, for example, a receptacle, and the second optical connector 114 may be, for example, a plug. The first optical connector 113 and the second optical connector 114 may be, for example, MT (Mechanically Transferable) ferrules. Furthermore, the first optical connector 113, which is an MT ferrule, may be provided with a guide pin 116, and the second optical connector 114, which is an MT ferrule, may be provided with a guide pin guide hole 117. The first optical connector 113 and the second optical connector 114 are connected by inserting the guide pin 116 into the guide pin guide hole 117. This connection enables accurate alignment of the optical fiber 105 and the external optical fiber 115. Furthermore, the optical connector is not limited to an MT ferrule, and an LC connector may also be used.

[0049] As described above, when the first optical connector 113 is a receptacle, the optical fiber 105 is generally fixed more firmly than when it is a boot, etc. Even in such a case, as in the first embodiment described above, the optical fiber 105 between the fixing part 111 and the first optical connector 113 can be made longer, and the optical fiber 105 can be prevented from bending significantly due to buckling.

[0050] Furthermore, the first optical connector 113 serving as the optical fiber take-out unit can be made movable in the optical axis direction. For example, by providing a movable rail on the side of the housing 106 and on the first optical connector 113, the first optical connector 113 can be made movable relative to the first optical connector 113. After the other end of the optical fiber 105 is connected and fixed to the first optical connector 113, the first optical connector 113 is moved to an appropriate position. Thereafter, the first optical connector 113 is fixed to the housing 106 using an adhesive or the like. The same can be done with the optical fiber take-out unit 112 in the first embodiment described above.

[0051] When assembling this type of module, variations in the length of the optical fiber occur due to processing accuracy. For example, the optical fiber length has a median value of 30 mm, with a dimensional error of ±1 mm. In this case, if the optical fiber take-out section is completely fixed to the housing, the dimensional error may prevent sufficient buckling length and buckling height from being ensured. In contrast, by moving the optical fiber take-out section after connecting the optical fiber, the optical fiber can be fixed while ensuring a quality-friendly length.

[0052] Third Embodiment Next, an opto-electric module according to a third embodiment of the present invention will be described with reference to Fig. 3. This opto-electric module includes a main wiring substrate 101, an optical circuit chip 102, an electronic circuit chip 103, electronic components 104, an optical fiber 105, a fixing component 111, a sub-wiring substrate 121, a housing 106, and an optical fiber outlet 112. These components are configured in the same manner as in the first embodiment described above.

[0053] The third embodiment further includes a reinforcing component 118 that reinforces the fixing component 111 provided on the protruding portion of the optical circuit chip 102. The reinforcing component 118 can be attached and fixed to the back surface of the optical circuit chip 102 and the side surface of the fixing component 111. For example, if the protruding length of the optical circuit chip 102 from the sub-wiring substrate 121 is 1.5 mm, a reinforcing component 118 with a length of 1 mm in the protruding direction can be used.

[0054] By using the reinforcing component 118, the optical waveguide of the optical circuit chip 102 and the optical fiber 105 are more firmly fixed together, which increases the resistance to stress caused by buckling and further improves the quality.

[0055] [Fourth Embodiment] Next, an opto-electric module according to a fourth embodiment of the present invention will be described with reference to Figures 4A and 4B. Figure 4A shows the interior of the module, and Figure 4B shows a cross section taken along line xx' in Figure 4A. This opto-electric module includes a main wiring board 101, an optical circuit chip 102, an electronic circuit chip 103, electronic components 104, an optical fiber 105, a fixing component 111, a sub-wiring board 121, a housing 106, and a first optical connector 113. These components are configured in the same manner as in the second embodiment described above.

[0056] In the fourth embodiment, a daughter board 123 is further provided which is connected onto the main wiring board 101. The daughter board 123 is disposed inside the housing 106 between the first optical connector 113, which is an optical fiber extraction portion, and the sub-wiring board 121. For example, electronic components 104 are mounted on the daughter board 123. The daughter board 123 can be mounted with the first optical connector 113 side protruding beyond the main wiring board 101.

[0057] Daughter board 123 can be connected to main wiring board 101 by a well-known inter-board connector. Daughter board 123 can also be connected to main wiring board 101 by an electrical cable made of a flexible printed circuit board. Daughter board 123 can be positioned above optical fiber 105 between fixed part 111 and first optical connector 113 (optical fiber extraction portion) as viewed from main wiring board 101.

[0058] As described above, by using the sub-wiring board 121, it is possible to increase the length of the optical fiber 105 between the fixing part 111 and the first optical connector 113. This increases the space between the fixing part 111, on which the optical fiber 105 is installed, and the optical fiber extraction portion, making it easier to install the daughter board 123.

[0059] 4C , the daughter board 123 can be inserted between the main wiring board 101 and the fixed component 111. If the thickness of the sub-wiring board 121 is 0.5 mm, the length from the optical axis center of the optical fiber 105 to the bottom end of the fixed component 111 is 0.3 mm, and the daughter board 123 is inserted below the fixed component 111, the height clearance can be approximately 0.05 mm. In this way, by appropriately setting the thickness of the sub-wiring board 121, the space between the main wiring board 101, the optical fiber 105, and the fixed component 111 can be further increased, and the daughter board 123 can be inserted below the fixed component 111, thereby increasing the area of ​​the daughter board 123, for example.

[0060] [Fifth Embodiment] Next, an opto-electric module according to a fifth embodiment of the present invention will be described with reference to Figures 5A and 5B. Figure 5A shows the interior of the module, and Figure 5B shows a cross section taken along line xx' in Figure 5A. The opto-electric module according to the fifth embodiment is configured to include multiple pairs of optical circuit chips and optical fiber extraction sections. In this way, by using multiple optical circuit chips, it is possible to ensure a transmission capacity that is twice that of 400GBASE-DR4.

[0061] In the fifth embodiment, a plurality of optical circuit chips 102 a, 102 b and a plurality of electronic circuit chips 103 a, 103 b are mounted on a sub-wiring substrate 121. Optical fibers 105 a, 105 a are connected and fixed to the optical circuit chips 102 a, 102 b by fixing parts 111 a, 111 b.

[0062] As in the second embodiment, the other ends of the optical fibers 105 a and 105 a are connected and fixed to the first optical connectors 113 a and 113 b, respectively. The first optical connectors 113 a and 113 b are connectable to the second optical connectors 114 a and 114 b.

[0063] In this example, a constriction 141 is provided on the exterior of the housing 106′. The constriction 141 is used to fit a socket or the like used to mount an optoelectronic module without causing misalignment. Even if the housing 106′ has the constriction 141 protruding toward the interior, the optical circuit chip 102a and the optical circuit chip 102b can be installed at positions away from the first optical connector 113a and the first optical connector 113b. This allows the fixing parts 111a and 111b to be connected to the centers of the optical input / output ends of the optical circuit chip 102a and the optical circuit chip 302b. Therefore, the optical fibers 105a and 105b can reach the first optical connector 113a and the first optical connector 113b without bending them in the optical axis direction in a plan view. As a result, according to the fifth embodiment, it is possible to prevent an increase in loss or risk of breakage of the optical fiber due to buckling and bending in the optical axis direction in a plan view.

[0064] The configurations of the above-described embodiments can be combined with each other. For example, a daughter board can be applied to the opto-electric module described using embodiment 1. Furthermore, a reinforcing component can be used in the opto-electric modules described using embodiments 4 and 5.

[0065] As described above, according to the present invention, an optical circuit chip is mounted on a sub-wiring board connected to a main wiring board, thereby making it possible to suppress deterioration in the characteristics of the optical fiber between the optical circuit chip and the optical fiber extraction section in the module, breakage, etc. When there is a limit to the length specification of the module in order to further reduce its size, the length of the optical fiber is inevitably shortened, which has been a problem in that the quality of the module deteriorates due to buckling of the optical fiber, but this problem can be solved by the present invention.

[0066] Some or all of the above-described embodiments may also be described as, but are not limited to, the following supplementary notes.

[0067] [Supplementary Note 1] An opto-electric module comprising: a housing; a main wiring board accommodated in the housing; a sub-wiring board connected onto the main wiring board inside the housing; an optical circuit chip mounted on the sub-wiring board inside the housing; an optical fiber optically connected to an optical input / output terminal on a side end face of the optical circuit chip; a fixing part for fixing the optical fiber to the optical input / output terminal; and an optical fiber extraction part fixed to a side of the housing facing the optical input / output terminal and for extracting the optical fiber to the outside of the housing, wherein the optical circuit chip is mounted on the sub-wiring board with the optical input / output terminal side protruding beyond the sub-wiring board.

[0068] [Supplementary Note 2] The opto-electric module according to Supplementary Note 1, wherein the optical fiber outlet includes a receptacle.

[0069] [Supplementary Note 3] The opto-electric module according to Supplementary Note 1 or 2, wherein the optical fiber take-out portion is movable in the optical axis direction.

[0070] [Supplementary Note 4] The opto-electric module according to any one of Supplementary Notes 1 to 3, further comprising a reinforcing component that reinforces the fixing component provided on the protruding portion of the optical circuit chip.

[0071] [Appendix 5] The opto-electric module according to any one of appendices 1 to 4, further comprising a daughter board connected on the main wiring board between the optical fiber take-out portion and the sub-wiring board inside the housing.

[0072] [Supplementary Note 6] The opto-electric module according to any one of Supplementary Notes 1 to 5, comprising a plurality of pairs of the optical circuit chip and the optical fiber take-out portion.

[0073] It should be noted that the present invention is not limited to the embodiments described above, and it is clear that many modifications and combinations can be made by a person having ordinary knowledge in the art within the technical concept of the present invention.

[0074] 101...main wiring board, 102...optical circuit chip, 103...electronic circuit chip, 104...electronic component, 105...optical fiber, 106...casing, 107...optical circuit terminal, 108...electronic circuit terminal, 109...internal wiring, 110...input / output electrical terminal, 111...fixed component, 112...optical fiber extraction section, 121...subsidiary wiring board, 122...substrate-substrate terminal, 131...optical input / output terminal.

Claims

1. An opto-electrical module comprising: a housing; a main wiring board contained in the housing; a sub-wiring board connected onto the main wiring board inside the housing; an optical circuit chip mounted on the sub-wiring board inside the housing; an optical fiber optically connected to an optical input / output terminal on a side end face of the optical circuit chip; a fixing part for fixing the optical fiber to the optical input / output terminal; and an optical fiber extraction part fixed to a side of the housing facing the optical input / output terminal for extracting the optical fiber to the outside of the housing, wherein the optical circuit chip is mounted on the sub-wiring board with the optical input / output terminal side protruding beyond the sub-wiring board.

2. An opto-electrical module according to claim 1, wherein said optical fiber outlet comprises a receptacle.

3. An opto-electric module according to claim 1, wherein the optical fiber outlet is movable in the optical axis direction.

4. An opto-electrical module according to claim 1, further comprising a reinforcing part for reinforcing said fixing part provided on the protruding portion of said optical circuit chip.

5. An opto-electrical module according to claim 1, further comprising a daughter board connected on said main wiring board between said optical fiber outlet and said sub-wiring board inside said housing.

6. An opto-electrical module according to any one of claims 1 to 5, comprising a plurality of pairs of the optical circuit chip and the optical fiber extraction section.

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