Optical connector cable

Abstract

To provide an optical connector cable that can ensure electrical connection.SOLUTION: An optical connector cable comprises: a circuit board; a photoelectric conversion element provided on the circuit board; a cable including an optical fiber for propagating light input to the photoelectric conversion element or light output from the photoelectric conversion element; a lens module including a lens for optically coupling the photoelectric conversion element and the optical fiber; and a connection terminal provided on a surface of the circuit board and electrically connected to the circuit board. The connection terminal is configured to be elastically deformable.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to optical connector cables. [Background technology]

[0002] An electrical connector including a circuit board and a signal line electrically connected to the circuit board is known (see, for example, Patent Document 1). In the electrical connector described in Patent Document 1, a connection terminal configured to be elastically deformable is provided on the circuit board. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent Application Publication No. 2021 / 0143569 Summary of the Invention [Problem to be solved by the invention]

[0004] According to the connector described above, the connection terminal is configured to be elastically deformable, so that even if there is dimensional variation in the circuit board or the mating connector, the connection terminal ensures electrical connection between the circuit board and the mating connector. However, such electrical connection may also be required in optical connector cables that include a circuit board and an optical fiber.

[0005] An object of the present disclosure is to provide an optical connector cable that can ensure electrical connection. [Means for solving the problem]

[0006] The optical connector cable of the present disclosure comprises a circuit board, a photoelectric conversion element provided on the circuit board, a cable including an optical fiber that propagates light input to the photoelectric conversion element or light output from the photoelectric conversion element, a lens module including a lens that optically couples the photoelectric conversion element and the optical fiber, and a connection terminal provided on the surface of the circuit board and electrically connected to the circuit board, the connection terminal being configured to be elastically deformable. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide an optical connector cable that can ensure electrical connection. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of an optical connector cable according to one embodiment. [Figure 2] FIG. 2 is a perspective view of the internal structure of the connector shown in FIG. [Figure 3] 3 is a cross-sectional view of the connector taken along line III-III shown in FIG. 2. FIG. [Figure 4] 4 is a cross-sectional view of the connector taken along line IV-IV shown in FIG. [Figure 5] 5 is a side view of the connector shown in FIG. 1. FIG. [Figure 6] FIG. 6 is a cross-sectional view of an optical connector cable according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Description of the embodiments of the present disclosure] First, the contents of the embodiments of the present disclosure will be listed and described.

[0010] The optical connector cable of the present disclosure is [1] "an optical connector cable comprising: a circuit board; a photoelectric conversion element provided on the circuit board; a cable including an optical fiber that propagates light input to the photoelectric conversion element or light output from the photoelectric conversion element; a lens module including a lens that optically couples the photoelectric conversion element and the optical fiber; and a connection terminal provided on the surface of the circuit board and electrically connected to the circuit board, wherein the connection terminal is configured to be elastically deformable."

[0011] The optical connector cable described in [1] above includes a connection terminal provided on the surface of the circuit board. This allows the circuit board and the mating connector to be electrically connected by the connection terminal. Moreover, the connection terminal is configured to be elastically deformable. This ensures electrical connection between the circuit board and the mating connector by the connection terminal, even if there is dimensional variation in the circuit board or the mating connector. Therefore, this optical connector cable ensures electrical connection.

[0012] The optical connector cable of the present disclosure may be [2] "the optical connector cable according to the above [1], further comprising a housing that accommodates the circuit board, the photoelectric conversion element, the lens module, and the connection terminal, the housing having an opening, and a tip of the connection terminal protruding to the outside of the housing through the opening." This ensures electrical connection between the circuit board and the mating connector via the connection terminal, even if there is dimensional variation in the housing.

[0013] The optical connector cable of the present disclosure may be [3] "the optical connector cable according to the above [2], wherein the lens module includes a support surface that is parallel to the axial direction of the optical fiber and supports the optical fiber, and the housing includes a protrusion that faces the support surface via the optical fiber and presses the optical fiber against the support surface." As a result, the optical fiber is pressed against the support surface by the protrusion, thereby suppressing misalignment of the optical fiber.

[0014] The optical connector cable of the present disclosure may be [4] "the optical connector cable according to any one of [1] to [3] above, wherein the circuit board includes a first main surface and a second main surface facing the opposite side to the first main surface, and the photoelectric conversion element, the optical fiber, the lens module, and the connection terminal are located on the opposite side of the first main surface to the second main surface." This allows the optical connector cable to be made smaller.

[0015] The optical connector cable of the present disclosure may be [5] "the optical connector cable according to the above [4], further including a signal line electrically connected to the circuit board and transmitting an electrical signal input to the circuit board or an electrical signal output from the circuit board, and a ground line electrically connected to the circuit board, the signal line being located on the opposite side of the second main surface from the first main surface, and the ground line being located on the opposite side of the first main surface from the second main surface." This makes it possible to utilize both the first main surface and the second main surface of the circuit board, thereby achieving a miniaturized optical connector cable.

[0016] [Details of the embodiments of the present disclosure] Specific examples of the optical connector cable of the present disclosure will be described below with reference to the drawings. The present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims. In the description of the drawings, the same elements are given the same reference numerals, and duplicate explanations will be omitted.

[0017] Fig. 1 is a perspective view of an optical connector cable according to this embodiment. The optical connector cable 1 shown in Fig. 1 is used, for example, for transmitting and receiving optical signals between devices. The optical connector cable 1 is, for example, an active optical cable (AOC). Note that, although Fig. 1 shows one end of the optical connector cable 1, the other end of the optical connector cable 1 may also have a configuration similar to that of the one end of the optical connector cable 1.

[0018] Fig. 2 is a perspective view of the internal structure of the connector 2 shown in Fig. 1. As shown in Fig. 1 and Fig. 2, the optical connector cable 1 includes a connector 2 and a cable 3. The connector 2 has a circuit board 21, a lens module 22, a plurality of connection terminals 23, a plurality of photoelectric conversion elements 24 (see Fig. 3), and a housing 25.

[0019] The circuit board 21 is, for example, plate-shaped. Optical elements, electronic elements, and the like are provided on the circuit board 21. The circuit board 21 includes a first main surface 21a and a second main surface 21b. The second main surface 21b faces the opposite side to the first main surface 21a. The first main surface 21a and the second main surface 21b are each a flat surface that intersects with the Z-axis direction (the thickness direction of the circuit board 21). Wiring and the like are provided inside the circuit board 21.

[0020] The lens module 22 is provided on the circuit board 21. The lens module 22 is located on the opposite side of the first main surface 21a of the circuit board 21 from the second main surface 21b. The lens module 22 is disposed on the first main surface 21a. The lens module 22 is fixed to the first main surface 21a by, for example, an adhesive. The adhesive is, for example, an ultraviolet-curing adhesive. The lens module 22 is optically transparent. The material of the lens module 22 is, for example, glass or resin.

[0021] Each connection terminal 23 is provided on the surface of the circuit board 21. Each connection terminal 23 is located on the opposite side of the first main surface 21a of the circuit board 21 from the second main surface 21b. Each connection terminal 23 is arranged on the first main surface 21a. Each connection terminal 23 is located on the opposite side of the lens module 22 from the cable 3. The multiple connection terminals 23 are lined up along the X-axis direction. Each connection terminal 23 is fixed to an electrode pad 211 provided on the first main surface 21a of the circuit board 21, for example, by soldering. As a result, each connection terminal 23 is electrically connected to the circuit board 21.

[0022] The housing 25 houses the circuit board 21, the lens module 22, the connection terminals 23, and the photoelectric conversion element 24. The housing 25 has a first member 251 and a second member 252. The first member 251 is located on the opposite side of the second main surface 21b of the circuit board 21 with respect to the first main surface 21a. The second member 252 is located on the opposite side of the second main surface 21b of the circuit board 21 with respect to the first main surface 21a. The first member 251 and the second member 252 are engaged with each other while housing the circuit board 21, the lens module 22, the connection terminals 23, and the photoelectric conversion element 24.

[0023] An opening 25a is formed in the first member 251. The internal space of the housing 25 is connected to the outside of the housing 25 via the opening 25a. When viewed from the Z-axis direction, the opening 25a overlaps with the multiple connection terminals 23. When viewed from the Z-axis direction, the inner edge of the opening 25a surrounds the multiple connection terminals 23.

[0024] The cable 3 has a plurality of optical fibers 31, a plurality of signal lines 32 (see FIG. 4), a plurality of ground lines 33, a cable jacket 34, and a holding member 35. The optical fibers 31 propagate light input to the photoelectric conversion element 24 or light output from the photoelectric conversion element 24. The optical fibers 31 have, for example, a core, a clad surrounding the core, and a resin coating the clad. The optical fibers 31 are single-mode optical fibers (SMF) or multimode optical fibers (MMF). Each optical fiber 31 is located on the opposite side of the first main surface 21a of the circuit board 21 from the second main surface 21b.

[0025] The signal line 32 transmits an electrical signal input to or output from the circuit board 21. The signal line 32 and the ground line 33 each have a conductor made of a metal material (e.g., copper) and a coating that covers the conductor. The tip of the conductor is exposed from the coating.

[0026] The cable jacket 34 houses a plurality of optical fibers 31, a plurality of signal lines 32, and a plurality of ground lines 33. The tip portions of each of the optical fibers 31, each of the signal lines 32, and each of the ground lines 33 are exposed from the cable jacket 32.

[0027] The holding member 35 is inserted into the tip of the cable jacket 32 ​​in a state in which it surrounds the plurality of optical fibers 31, the plurality of signal lines 32, and the plurality of ground lines 33. The holding member 35 holds the plurality of optical fibers 31, the plurality of signal lines 32, and the plurality of ground lines 33 at the tip of the cable jacket 32.

[0028] Figure 3 is a cross-sectional view of the connector 2 taken along line III-III in Figure 2. Note that Figure 3 also shows the housing 25. As shown in Figure 3, the lens module 22 has a plate shape. The lens module 22 includes a main surface 22a, a support surface 22b, a back surface 22c, a mirror 22d, a plurality of fiber grooves 22e, a recess 22f, a recess 22g, and a plurality of lenses 22h.

[0029] The main surface 22a, the support surface 22b, and the back surface 22c each intersect with the Z-axis direction (thickness direction of the lens module 22). The main surface 22a, the support surface 22b, and the back surface 22c are each parallel to the axial direction of the optical fiber 31. The main surface 22a and the support surface 22b each face away from the circuit board 21. The main surface 22a and the support surface 22b are aligned along the Y-axis direction. When viewed from the Z-axis direction, the main surface 22a is located on the opposite side of the cable 3 with respect to the support surface 22b. The back surface 22c faces away from the main surface 22a and the support surface 22b. The back surface 22c faces the opposite side to the circuit board 21.

[0030] The mirror 22d is an inclined surface formed on the main surface 22a and recessed toward the back surface 22c. The mirror 22d is inclined along the Y-axis direction so that the farther it is from the support surface 22b, the closer it is to the back surface 22c. The mirror 22d is a flat surface parallel to the X-axis direction. The mirror 22d reflects light emitted from the optical fiber 31 or light emitted from the photoelectric conversion element 24.

[0031] Each fiber groove 22e is formed on the support surface 22b. Each fiber groove 22e extends along the Y-axis direction. When viewed from the Z-axis direction, the multiple fiber grooves 22e are aligned along the X-axis direction. When viewed from the Y-axis direction, each fiber groove 22e has, for example, a V-shape. That is, each fiber groove 22e is, for example, a V-groove. The tip portion of the optical fiber 31 is supported by the support surface 22b while being positioned in the fiber groove 22e. Each fiber groove 22e determines the position of the optical fiber 31 relative to the lens module 22 and prevents the optical fiber 31 from shifting in the X-axis direction.

[0032] The recess 22f is formed on the support surface 22b and is recessed toward the back surface 22c. When viewed from the Z-axis direction, the recess 22f is located between the plurality of fiber grooves 22e and the main surface 22a. When viewed from the Y-axis direction, both ends of the recess 22f in the X-axis direction are located outside the plurality of fiber grooves 22e. The recess 22f is connected to each of the fiber grooves 22e. The recess 22g is formed on the back surface 22c and is recessed toward the main surface 22a. When viewed from the Z-axis direction, the recess 22g is located inside the outer edge of the main surface 22a.

[0033] Each lens 22h is formed on the bottom surface of the recess 22g. Each lens 22h protrudes from the bottom surface of the recess 22g toward the opposite side to the main surface 22a. When viewed from the Z-axis direction, the multiple lenses 22h are aligned along the X-axis direction. The spacing between adjacent lenses 22h is the same as the spacing between adjacent fiber grooves 22e. The position of each lens 22h in the X-axis direction coincides with the position of each fiber groove 22e in the X-axis direction. The focal point of the lens 22h is located, for example, on the surface of the photoelectric conversion element 24 or inside the photoelectric conversion element 24. Various parameters of the lens 22h (for example, the surface shape, size, material, etc. of the lens 22h) are optimized based on the relative positions of the lens 22h and the photoelectric conversion element 24, etc.

[0034] Each photoelectric conversion element 24 is provided on the circuit board 21. Each photoelectric conversion element 24 is located on the opposite side of the first main surface 21a of the circuit board 21 from the second main surface 21b. Each photoelectric conversion element 24 protrudes from the first main surface 21a of the circuit board 21. When viewed from the Z-axis direction, the multiple photoelectric conversion elements 24 are lined up along the X-axis direction. The spacing between adjacent photoelectric conversion elements 24 is the same as the spacing between adjacent lenses 22h. The position of each photoelectric conversion element 24 in the X-axis direction coincides with the position of each lens 22h in the X-axis direction. When viewed from the Z-axis direction, each photoelectric conversion element 24 overlaps with each lens 22h. The photoelectric conversion element 24 is, for example, a light-receiving element such as a photodiode (PD) or a light-emitting element such as a vertical cavity surface emitting laser (VCSEL).

[0035] The lens 22h optically couples the photoelectric conversion element 24 and the optical fiber 31. Light emitted from the optical fiber 31 is reflected by the mirror 22d and then collected by the lens 22h. The light collected by the lens 22h is incident on the photoelectric conversion element 24. The light emitted from the photoelectric conversion element 24 is collected by the lens 22h and then reflected by the mirror 22d. The light reflected by the mirror 22d is incident on the optical fiber 31.

[0036] The first member 251 of the housing 25 includes a main body 253 and a protrusion 254. The main body 253 has, for example, a rectangular plate shape. When viewed from the Z axis direction, the outer edge of the main body 253 coincides with the outer edge of the second member 252. The protrusion 254 protrudes from the main body 253 toward the second member 252. When viewed from the Z axis direction, the protrusion 254 overlaps with the support surface 22b of the lens module.

[0037] The protrusion 254 faces the support surface 22b via the plurality of optical fibers 31. The protrusion 254 presses the plurality of optical fibers 31 against the support surface 22b. In other words, each optical fiber 31 is pressed by the protrusion 254 while being arranged in the fiber groove 22e. In this embodiment, the main body 253 and the protrusion 254 are a partial region of the first member 251 that is integrally formed from the same material. In other words, the main body 253 and the protrusion 254 are integrally formed.

[0038] 4 is a cross-sectional view of the connector 2 taken along line IV-IV in FIG. 2. The housing 25 is also shown in FIG. 4. As shown in FIG. 4, the signal line 32 is located on the second main surface 21b of the circuit board 21, opposite the first main surface 21a. The tip of the signal line 32 is disposed on the second main surface 21b. The signal line 32 is fixed to an electrode pad 212 provided on the second main surface 21b of the circuit board 21, for example, by soldering. This electrically connects the signal line 32 to the circuit board 21.

[0039] The ground line 33 is located on the opposite side of the first main surface 21a of the circuit board 21 from the second main surface 21b. The tip of the ground line 33 is disposed on the first main surface 21a. The ground line 33 is fixed to an electrode pad 213 provided on the first main surface 21a of the circuit board 21 by, for example, soldering. In this way, the ground line 33 is electrically connected to the circuit board 21.

[0040] Fig. 5 is a side view of connector 2. As shown in Fig. 5, connection terminal 23 has a thin plate shape. Connection terminal 23 electrically connects circuit board 21 and a mating connector. Connection terminal 23 includes a first portion 231, a second portion 232, a third portion 233, and a fourth portion 234.

[0041] The first portion 231, the second portion 232, the third portion 233, and the fourth portion 234 are each a partial region of the connection terminal 23 integrally formed from the same material. The first portion 231 extends along the Y-axis direction. The first portion 231 is fixed to the electrode pad 211 by solder or the like.

[0042] When viewed from the X-axis direction, the second portion 232 is located on the opposite side of the lens module 22 with respect to the first portion 231. When viewed from the X-axis direction, the second portion 232 extends in a direction inclined with respect to the Y-axis direction. When viewed from the X-axis direction, the second portion 232 extends along the Y-axis direction so that the further it is from the first portion 231, the further it is from the circuit board 21. One end of the second portion 232 on the first portion 231 side is connected to the first portion 231. When viewed from the X-axis direction, the angle between the second portion 232 and the first portion 231 is, for example, an obtuse angle.

[0043] When viewed from the X-axis direction, the third portion 233 is located on the opposite side of the second portion 232 from the circuit board 21. When viewed from the X-axis direction, the third portion 233 extends in a direction inclined with respect to the Y-axis direction. When viewed from the X-axis direction, the third portion 233 extends along the Z-axis direction so that the further away from the second portion 232 the third portion 233 is, the closer it is to the lens module 22. One end of the third portion 233 on the second portion 232 side is connected to the second portion 232. When viewed from the X-axis direction, the angle between the third portion 233 and the second portion 232 is, for example, a right angle.

[0044] When viewed from the X-axis direction, the fourth portion 234 is located closer to the lens module 22 than the third portion 233. When viewed from the X-axis direction, the fourth portion 234 extends in a direction inclined with respect to the Y-axis direction. When viewed from the X-axis direction, the fourth portion 234 extends along the Y-axis direction so that the further away from the third portion 233 the fourth portion 234 is, the closer it is to the circuit board 21. One end of the fourth portion 234 on the third portion 233 side is connected to the third portion 233. When viewed from the X-axis direction, the angle between the fourth portion 234 and the third portion 233 is, for example, an obtuse angle. The fourth portion 234 is separated from the first portion 231. That is, the fourth portion 234 is not directly connected to the first portion 231.

[0045] The connection terminal 23 is configured to be elastically deformable. The connection terminal 23 functions as a leaf spring. The connection terminal 23 is deformable so that the angles between the portions 231, 232, 233, and 234 increase or decrease. The second portion 232, the third portion 233, and the fourth portion 234 are each movable toward the circuit board 21 while the first portion 231 is fixed to the circuit board 21. The tip 23a of the connection terminal 23, where the third portion 233 and the fourth portion 234 are connected, is movable toward the circuit board 21. When the load applied to the connection terminal 23 is released, the connection terminal 23 returns from the elastically deformed state to its natural state (a state in which no internal stress is generated). The connection terminal 23 is made of a material such as phosphor bronze, beryllium copper, or a Corson alloy. The elastic modulus of the connection terminal 23 is, for example, approximately 100 GPa to 150 GPa.

[0046] When connection terminal 23 is in its natural state, tip 23a of connection terminal 23 protrudes outside housing 25 through opening 25a of housing 25. Tip 23a is located outside housing 25. When tip 23a is pressed while electrically connected to a mating connector, a state in which internal stress exists that attempts to return connection terminal 23 to its natural state is maintained. This ensures electrical connection between connection terminal 23 and the mating connector.

[0047] As described above, the optical connector cable 1 includes the connection terminals 23 provided on the surface of the circuit board 21. This allows the circuit board 21 and the mating connector to be electrically connected by the connection terminals 23. Moreover, the connection terminals 23 are configured to be elastically deformable. This ensures electrical connection between the circuit board 21 and the mating connector by the connection terminals 23, even if there is dimensional variation in the circuit board 21 or the mating connector. Therefore, the optical connector cable 1 ensures electrical connection.

[0048] Tip 23a of connection terminal 23 protrudes to the outside of housing 25 through opening 25a of housing 25. This ensures electrical connection between circuit board 21 and the mating connector via connection terminal 23, even if housing 25 varies in size.

[0049] The housing 25 includes a protrusion 254 that presses the optical fiber 31 against the support surface 22b of the lens module 22. As a result, the optical fiber 31 is pressed against the support surface 22b by the protrusion 254, and thus displacement of the optical fiber 31 is suppressed.

[0050] The lens module 22, the connection terminal 23, the photoelectric conversion element 24, and the optical fiber 31 are each located on the opposite side of the first main surface 21a of the circuit board 21 from the second main surface 21b, thereby realizing miniaturization of the optical connector cable 1.

[0051] The signal line 32 of the cable 3 is located on the opposite side of the second main surface 21b of the circuit board 21 from the first main surface 21a, and the ground line 33 of the cable 3 is located on the opposite side of the first main surface 21a from the second main surface 21b. This makes it possible to utilize both the first and second main surfaces of the circuit board, thereby realizing a compact optical connector cable 1. Furthermore, since the degree of freedom in the structure or wiring of the optical connector cable 1 is improved, compatibility with, for example, electrical connector cables is improved.

[0052] Although one embodiment of the present disclosure has been described above, the present disclosure is not limited to the above-described embodiment.

[0053] Fig. 6 is a cross-sectional view of an optical connector cable according to a modified example. As shown in Fig. 6, the protrusion 254 may be formed separately from the main body 253. The protrusion 254 and the main body 253 may each be separate members.

[0054] The cable 3 does not necessarily have to include the signal line 32 and the ground line 33. The cable 3 only needs to include at least the optical fiber 31.

[0055] Each connection terminal 23 may be located on the second main surface 21b of the circuit board 21, opposite to the first main surface 21a. Each connection terminal 23 may be electrically connected to an electrode pad provided on the second main surface 21b. In this case, the opening 25a is formed in the second member 252. [Explanation of symbols]

[0056] 1...Optical connector cable 2...Connector 3...Cable 21...Circuit board 21a...first principal surface 21b…Second main surface 22...Lens module 22a…main surface 22b…support surface 22c…Back side 22d...Mirror 22e...Fiber groove 22f...recess 22g…recess 22h...lens 23...Connection terminal 23a…Tip 24...Photoelectric conversion element 25…Case 25a…Aperture 31...Optical fiber 32...Signal line 33...Ground line 34...Cable sheath 35...Retaining member 211, 212, 213...Electrode pads 231…Part 1 232…Second part 233...Third part 234...4th part 251...First member 252...Second member 253...Main body 254...Protrusion

Claims

1. A circuit board; a photoelectric conversion element provided on the circuit board; a cable including an optical fiber that propagates light input to the photoelectric conversion element or light output from the photoelectric conversion element; a lens module including a lens that optically couples the photoelectric conversion element and the optical fiber; a connection terminal provided on a surface of the circuit board and electrically connected to the circuit board; The optical connector cable, wherein the connection terminal is configured to be elastically deformable.

2. a housing that accommodates the circuit board, the photoelectric conversion element, the lens module, and the connection terminal; An opening is formed in the housing, 2. The optical connector cable according to claim 1, wherein a tip of the connection terminal protrudes to the outside of the housing through the opening.

3. the lens module includes a support surface that is parallel to an axial direction of the optical fiber and supports the optical fiber; 3. The optical connector cable according to claim 2, wherein the housing includes a protrusion that faces the support surface across the optical fiber and presses the optical fiber against the support surface.

4. the circuit board includes a first main surface and a second main surface facing opposite to the first main surface; 4. The optical connector cable according to claim 1, wherein the photoelectric conversion element, the optical fiber, the lens module, and the connection terminal are located on the opposite side of the first main surface from the second main surface.

5. the cable further includes a signal line electrically connected to the circuit board and transmitting an electrical signal input to the circuit board or an electrical signal output from the circuit board, and a ground line electrically connected to the circuit board; the signal line is located on the opposite side of the second main surface from the first main surface, 5. The optical connector cable according to claim 4, wherein the ground wire is located on the opposite side of the first main surface from the second main surface.

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