Optical communication module

Abstract

To provide an optical communication module with which it is possible to reduce the size and heighten the performance of circuit boards.SOLUTION: An optical transmission module 10A comprises a wiring board 20, a light-emitting element 30, and a bias tee unit 35 that is constituted having an inductor 33 and a capacitor 34. The light-emitting element 30 and the bias tee unit 35 are arranged on a first plane 20a of the wiring board 20, and a signal line 22 extending along a prescribed extension direction and ground patterns 24a, 24b are formed on the first plane 20a of the wiring board 20. A section of the ground pattern 24a and the light-emitting element 30 are arranged at one extension end of the signal line 22 adjoining in the extension direction, with the anode of the light-emitting element 30 connected by wire to the signal line 22. The cathode of the light-emitting element 30 is connected by wire to the ground pattern 24a so that the angle formed with respect to the extension direction of the signal line 22 is 90 degrees or greater in a plan view.SELECTED DRAWING: Figure 1

Description

[[Technical Field]]

[0001] The present invention relates to an optical communication module. [[Background Art]]

[0002] Conventionally, technologies relating to an optical communication module mounted with an optical element (a light-emitting element or a light-receiving element) are known (see Patent Document 1). This optical communication module has a structure in which the optical element is disposed on a substrate, and wiring on the substrate is used as paths for signals and electric power.

[0003] An optical transmission module for high-frequency signal transmission generally includes a light-emitting element, and a bias tee unit configured to include an inductor and a capacitor. On the other hand, an optical reception module generally includes a light-receiving element, a bias tee unit configured to include an inductor and a capacitor, and an amplifier. In the case of using a structure in which a light-emitting / receiving element is disposed on a substrate and wiring on the substrate is used as paths for signals and electric power, the light-emitting / receiving element is connected by wire bonding to a ground portion or a signal line located at a position distant from the light-emitting / receiving element. [[Prior Art Documents]] [[Patent Documents]]

[0004] [[Patent Document 1]] Japanese Patent Application Laid-Open No. 2006-4971 [[Summary of the Invention]] [[Problem to be Solved by the Invention]]

[0005] Generally, on a substrate, it is necessary to form a ground portion for wire connection with the optical element between the optical element and a signal line, which limits the degree of freedom in routing wiring near the optical element. In addition, the wire connecting the optical element to the ground portion or the signal line becomes longer, and further, the distance between the optical element and an amplifier or the like increases.

[0006] This invention has been made in view of the problems of the prior art. The object of this invention is to provide an optical communication module that can be miniaturized and improved in performance by eliminating the ground section between the optical element and the signal line, which is used to connect the optical element to the wire. [Means for solving the problem]

[0007] An optical communication module according to an aspect of the present invention comprises a wiring board, an optical element, and a bias tee portion comprising an inductor and a capacitor, wherein the optical element and the bias tee portion are arranged on the same plane of the wiring board, and a signal line and a ground portion are formed on the same plane of the wiring board, extending at least along a predetermined extending direction, a part of the ground portion and the optical element are arranged adjacent to one end of the signal line in the extending direction, one of the anode and cathode of the optical element is wire-connected to the signal line, and the other of the anode and cathode of the optical element is wire-connected to a part of the ground portion such that the angle it makes with respect to the extending direction of the signal line is 90 degrees or more in a plan view. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an optical communication module that can achieve miniaturization and high performance of the substrate by eliminating the ground section between the optical element and the signal line, which is used for connecting the optical element to the wire. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram showing the top view of an example of an optical communication module according to the first embodiment. [Figure 2A] This is a schematic diagram showing the top view of an example of an optical communication module according to the second embodiment. [Figure 2B] This is a cross-sectional view taken along line AA in Figure 2A. [Figure 3] This is a schematic diagram showing the top view of an example of an optical communication module according to the third embodiment. [Figure 4A]This is a schematic diagram showing the top view of an example of an optical communication module according to the fourth embodiment. [Figure 4B] Figure 4A is a cross-sectional view taken along line BB. [Figure 5] This is a schematic diagram showing the top view of an example of an optical communication module according to the fifth embodiment. [Figure 6] This is a schematic diagram showing the top view of an example of an optical communication module according to the sixth embodiment. [Figure 7] This is a schematic diagram showing the top view of an example of an optical communication module according to the seventh embodiment. [Figure 8A] This is a schematic diagram showing an example of a state in which the lens is fixed in the optical communication module according to the eighth embodiment. [Figure 8B] Figure 8A is a cross-sectional view taken along the line C1-C1. [Figure 8C] Figure 8A is a cross-sectional view taken along the line C2-C2. [Modes for carrying out the invention]

[0010] The optical communication module according to this embodiment will be described in detail below with reference to the drawings. Note that the dimensional ratios in the drawings are exaggerated for illustrative purposes and may differ from the actual ratios.

[0011] [First Embodiment] Figure 1 is a schematic diagram showing the top surface of the optical transmission module 10A according to the first embodiment.

[0012] The optical transmission module 10A comprises a wiring board 20, a light-emitting element 30, and a bias tee section 35 comprising an inductor 33 and a capacitor 34. In this optical transmission module 10A, the light-emitting element 30 and the bias tee section 35 are arranged on the first surface 20a (top surface) of the wiring board 20. In addition, in the optical transmission module 10A, signal lines 22, 23 and ground patterns 24a, 24b made of conductors are formed on the first surface 20a of the wiring board 20.

[0013] A plurality of through holes 26 are formed in the wiring board 20. These through holes 26 may connect the ground patterns 24a and 24b on the first surface 20a of the wiring board 20 to ground patterns (not shown) in other layers. The positions and the number of through holes illustrated herein are only an example, and may be changed as appropriate.

[0014] The signal lines include a first signal line 22 extending in a predetermined direction from a first end 22a to a second end 22b. The signal lines also include a second signal line 23 extending from the second end 22b of the first signal line 22, and extending from a first end 23a to a second end 23b in a direction orthogonal to the first signal line 22.

[0015] A capacitor 34 is connected to the middle of the first signal line 22, and an inductor 33 is connected to a wiring extending from the second signal line 23.

[0016] In the optical transmission module 10A, a part of the ground pattern 24a and a light emitting element 30 are arranged adjacent to the second end 22b of the first signal line 22 in the extending direction of the first signal line 22. The light emitting element 30 is mounted on the part of the ground pattern 24a adjacent to the second end 22b of the first signal line 22 in the extending direction of the first signal line 22.

[0017] An anode (positive electrode) of the light emitting element 30 is connected to the second end 22b of the first signal line 22 via a wire 40. On the other hand, a cathode (negative electrode) of the light emitting element 30 is connected to the ground pattern 24a via a wire 41 in a direction substantially orthogonal to the extending direction of the first signal line 22.

[0018] In the optical transmission module 10A, the angle between the wire 41 extending from the cathode of the light-emitting element 30 and the first signal line 22 is set to be between 90 degrees and 100 degrees in a plan view. That is, the angle between the wire 41 extending from the cathode of the light-emitting element 30 and the first signal line 22 is within the range of 90 to 100 degrees in a plan view.

[0019] Next, we will explain the effects and benefits of the optical transmission module 10A.

[0020] The optical transmission module 10A according to the first embodiment comprises a wiring board 20, an optical element (light-emitting element 30), and a bias tee section 35 comprising an inductor 33 and a capacitor 34. The optical element (light-emitting element 30) and the bias tee section 35 are arranged on the same surface (first surface 20a) of the wiring board 20. A first signal line 22 extending at least along a predetermined extending direction and a ground section (ground patterns 24a, 24b) are formed on the same surface (first surface 20a) of the wiring board 20. A part of the ground section (ground pattern 24a) and the optical element (light-emitting element 30) are arranged adjacent to one end (second end 22b) of the first signal line 22 in the extending direction of the first signal line 22. The anode of the optical element (light-emitting element 30) is wire-connected to the first signal line 22. The cathode of the optical element (light-emitting element 30) is wired to a portion of the ground section (ground pattern 24a) such that the angle it makes with respect to the extending direction of the first signal line 22 is 90 degrees or more in a plan view.

[0021] The cathode of the light-emitting element 30 is connected to the ground pattern 24a via a wire 41 in a direction approximately perpendicular to the extending direction of the first signal line 22, eliminating the need to form a ground between the light-emitting element 30 and the first signal line 22. This allows the distance D between the light-emitting element 30 and the first signal line 22 to be shortened, enabling miniaturization of the wiring board 20 and improving the flexibility of wiring around the light-emitting element 30. Furthermore, the wire 41 connecting the light-emitting element 30 to the first signal line 22 can be shortened, improving the frequency response characteristics. For example, shortening the length of the wire 41 at a frequency of 28 GHz can result in a gain improvement of about 1 dB.

[0022] Furthermore, in the optical transmission module 10A according to the first embodiment, the aforementioned angle is within the range of 90 to 100 degrees in a plan view.

[0023] In other words, the angle formed by the wire 41 extending from the cathode of the light-emitting element 30 and the first signal line 22 does not necessarily have to be 90 degrees (orthogonal), and may be an angle slightly larger than 90 degrees, up to about 100 degrees.

[0024] [Second Embodiment] Figure 2A is a schematic diagram showing the top surface of the optical transmission module 10B according to the second embodiment, and Figure 2B is a cross-sectional view including a section passing through the pad 27 of the optical transmission module 10B.

[0025] The optical transmission module 10B comprises a wiring board 20, a light-emitting element 30, and a bias tee section 35 comprising an inductor 33 and a capacitor 34. In this optical transmission module 10B, the light-emitting element 30 and the bias tee section 35 are arranged on the first surface 20a (top surface) of the wiring board 20. In addition, in the optical transmission module 10B, signal lines 22, 23, ground patterns 24b, 24c made of conductors, and pads 27 made of conductors are formed on the first surface 20a of the wiring board 20.

[0026] On the second surface 20b (bottom surface) of the wiring board 20, the ground pattern 25 and the substrate 21 are stacked. Figure 2B illustrates an example in which the optical transmission module 10B has four layers of ground patterns, but it is not limited to this; the optical transmission module 10B only needs to have at least two layers of ground patterns.

[0027] Multiple through-holes 26 are formed in the wiring board 20. These through-holes 26 connect the ground patterns 24b, 24c and pads 27 on the first surface 20a of the wiring board 20 to the ground patterns 25 of other layers. The positions and number of through-holes shown are examples and may be changed as appropriate.

[0028] The signal line includes a first signal line 22 extending in a predetermined direction from a first end 22a to a second end 22b. The signal line also includes a second signal line 23 extending from the second end 22b of the first signal line 22 and extending in a direction perpendicular to the first signal line 22 from a first end 23a to a second end 23b.

[0029] Capacitor 34 is connected in the middle of the first signal line 22, and inductor 33 is connected to wiring extending from the second signal line 23.

[0030] In the optical transmission module 10B, the pad 27 and the light-emitting element 30 are arranged adjacent to the second end 22b of the first signal line 22 in the direction of extension of the first signal line 22. The light-emitting element 30 is mounted on the pad 27 adjacent to the second end 22b of the first signal line 22 in the direction of extension of the first signal line 22.

[0031] The anode (positive terminal) of the light-emitting element 30 is connected to the second end 22b of the first signal line 22 via wire 40. On the other hand, the cathode (negative terminal) of the light-emitting element 30 is connected to the pad 27 via wire 41 in a direction substantially perpendicular to the extending direction of the first signal line 22.

[0032] In the optical transmission module 10B, the angle between the wire 41 extending from the cathode of the light-emitting element 30 and the first signal line 22 is set to be between 90 degrees and 100 degrees in a plan view. That is, the angle between the wire 41 extending from the cathode of the light-emitting element 30 and the first signal line 22 is within the range of 90 to 100 degrees in a plan view.

[0033] Next, we will explain the effects of the optical transmission module 10B.

[0034] The optical transmission module 10B according to the second embodiment comprises a wiring board 20, an optical element (light-emitting element 30), and a bias tee section 35 comprising an inductor 33 and a capacitor 34. The optical element (light-emitting element 30) and the bias tee section 35 are arranged on the same surface (first surface 20a) of the wiring board 20. A first signal line 22 extending at least along a predetermined extending direction and a ground section (ground patterns 24b, 24c, pads 27) are formed on the same surface (first surface 20a) of the wiring board 20. A part of the ground section (pads 27) and the optical element (light-emitting element 30) are arranged adjacent to one end (second end 22b) of the first signal line 22 in the extending direction of the first signal line 22. The anode of the optical element (light-emitting element 30) is wire-connected to the first signal line 22. The cathode of the optical element (light-emitting element 30) is wired to a portion of the ground portion (pad 27) such that the angle it makes with respect to the extending direction of the first signal line 22 is 90 degrees or more in a plan view.

[0035] Since the cathode of the light-emitting element 30 is connected to the pad 27 via a wire 41 in a direction substantially perpendicular to the extending direction of the first signal line 22, the formation of a ground section between the light-emitting element 30 and the first signal line 22 becomes unnecessary. Therefore, the distance D between the light-emitting element 30 and the first signal line 22 can be shortened, making it possible to miniaturize the wiring board 20 and improve the flexibility of wiring around the light-emitting element 30. In addition, the wire 41 connecting the light-emitting element 30 to the first signal line 22 can be shortened, improving the frequency response characteristics. For example, shortening the length of the wire 41 at a frequency of 28 GHz can result in a gain improvement of about 1 dB.

[0036] Furthermore, in the optical transmission module 10B according to the second embodiment, the aforementioned angle is within the range of 90 to 100 degrees in a plan view.

[0037] In other words, the angle formed by the wire 41 extending from the cathode of the light-emitting element 30 and the first signal line 22 does not necessarily have to be 90 degrees (orthogonal), and may be an angle slightly larger than 90 degrees, up to about 100 degrees.

[0038] [Third Embodiment] Figure 3 is a schematic diagram showing the top surface of the optical receiving module 11A according to the third embodiment.

[0039] The optical receiving module 11A comprises a wiring board 20, a light-receiving element 31, a bias tee section 35 comprising an inductor 33 and a capacitor 34, and an amplifier 36. In this optical receiving module 11C, the light-receiving element 31, the bias tee section 35, and the amplifier 36 are arranged on the first surface 20a (top surface) of the wiring board 20. In addition, in the optical receiving module 11A, signal lines 22, 23 and ground patterns 24b, 24d, 24e made of conductors are formed on the first surface 20a of the wiring board 20.

[0040] Multiple through-holes 26 are formed in the wiring board 20. These through-holes 26 may connect the ground patterns 24b, 24d, and 24e on the first surface 20a of the wiring board 20 to the ground patterns (not shown) of other layers. The positions and number of through-holes shown are examples and may be changed as appropriate.

[0041] The signal line includes a first signal line 22 extending in a predetermined direction from a first end 22a to a second end 22b. The signal line also includes a second signal line 23 extending from the second end 22b of the first signal line 22 and extending in a direction perpendicular to the first signal line 22 from a first end 23a to a second end 23b.

[0042] Capacitor 34 is connected in the middle of the first signal line 22, and inductor 33 is connected to the wiring extending from the second signal line 23. Capacitor 34 may also be built into the amplifier 36.

[0043] The amplifier 36 has amplifier wiring 37. This amplifier 36 is connected to the first signal line 22 and ground patterns 24b, 24d, and 24e in order to amplify the amplitude of the signals flowing through the signal lines 22 and 23.

[0044] In the optical receiving module 11A, a portion of the ground pattern 24d and the photodetector 31 are arranged adjacent to the second end 22b of the first signal line 22 in the direction of extension of the first signal line 22. The photodetector 31 rests on a portion of the ground pattern 24d adjacent to the second end 22b of the first signal line 22 in the direction of extension of the first signal line 22.

[0045] The cathode (negative pole) of the light-receiving element 31 is connected to the second end 22b of the first signal line 22 via wire 40. On the other hand, the anode (positive pole) of the light-emitting element 30 is connected to the pad 27 via wire 41 in a direction substantially perpendicular to the extending direction of the first signal line 22.

[0046] In the optical receiving module 11A, the angle between the wire 41 extending from the anode of the photodetector 31 and the first signal line 22 is set to be between 90 degrees and 100 degrees in a plan view. That is, the angle between the wire 41 extending from the anode of the light-emitting element 30 and the first signal line 22 is within the range of 90 to 100 degrees in a plan view.

[0047] Next, we will explain the effects of the optical receiving module 11A.

[0048] The optical receiving module 11A according to the third embodiment comprises a wiring board 20, an optical element (photodetector 31), and a bias tee section 35 comprising an inductor 33 and a capacitor 34. The optical element (photodetector 31) and the bias tee section 35 are arranged on the same surface (first surface 20a) of the wiring board 20. A first signal line 22 extending at least along a predetermined extending direction and a ground section (ground patterns 24b, 24d, 24e) are formed on the same surface (first surface 20a) of the wiring board 20. A part of the ground section (ground pattern 24d) and the optical element (photodetector 31) are arranged adjacent to one end (second end 22b) of the first signal line 22 in the extending direction of the first signal line 22. The cathode of the optical element (photodetector 31) is wire-connected to the first signal line 22. The anode of the optical element (photodetector 31) is wired to a portion of the ground section (pad 27) such that the angle it makes with respect to the extending direction of the first signal line 22 is 90 degrees or more in a plan view.

[0049] The anode of the photodetector 31 is connected to the ground pattern 24d via a wire 41 in a direction approximately perpendicular to the extending direction of the first signal line 22, eliminating the need to form a ground between the photodetector 31 and the first signal line 22. This allows the distance D between the photodetector 31 and the first signal line 22 to be shortened, enabling miniaturization of the wiring board 20 and improving the flexibility of wiring around the photodetector 31. Furthermore, the wire 41 connecting the photodetector 31 to the first signal line 22 can be shortened, improving the frequency response characteristics. For example, shortening the length of the wire 41 at a frequency of 28 GHz can result in a gain improvement of about 1 dB.

[0050] Furthermore, in the optical transmission module 10A according to the third embodiment, the aforementioned angle is within the range of 90 to 100 degrees in a plan view.

[0051] In other words, the angle formed by the wire 41 extending from the anode of the photodetector 31 and the first signal line 22 does not necessarily have to be 90 degrees (orthogonal), and may be an angle slightly larger than 90 degrees, up to about 100 degrees.

[0052] Furthermore, an impedance mismatch between the light-receiving element 31 and the amplifier 36 can cause a resonance phenomenon due to reflected waves, which can affect the frequency response characteristics. This is influenced by the distance between the light-receiving element 31 and the amplifier 36. According to this embodiment, the distance between the light-receiving element 31 and the amplifier 36 can be easily adjusted, making it possible to eliminate the aforementioned resonance phenomenon.

[0053] [Fourth Embodiment] Figure 4A is a schematic diagram showing the top surface of the optical receiving module 11B according to the fourth embodiment, and Figure 4B is a cross-sectional view including a section passing through the pad 27 of the optical receiving module 11B.

[0054] The optical receiving module 11B comprises a wiring board 20, a light-receiving element 31, a bias tee section 35 comprising an inductor 33 and a capacitor 34, and an amplifier 36. In this optical receiving module 11D, the light-emitting element 30, the bias tee section 35, and the amplifier 36 are arranged on the first surface 20a (top surface) of the wiring board 20. In the optical receiving module 11B, signal lines 22, 23, ground patterns 24b, 24d, 24e made of conductors, and pads 27 made of conductors are formed on the first surface 20a of the wiring board 20.

[0055] On the second surface 20b (bottom surface) of the wiring board 20, the ground pattern 25 and the substrate 21 are stacked. Figure 4B illustrates an example in which the optical receiving module 11B has four layers of ground patterns, but it is not limited to this, and the optical receiving module 11B only needs to have at least two layers of ground patterns.

[0056] Multiple through-holes 26 are formed in the wiring board 20. These through-holes 26 connect the ground patterns 24b, 24d, 24e and pads 27 on the first surface 20a of the wiring board 20 to the ground patterns 25 of other layers. The positions and number of through-holes shown are examples and may be changed as appropriate.

[0057] The signal line includes a first signal line 22 extending in a predetermined direction from a first end 22a to a second end 22b. The signal line also includes a second signal line 23 extending from the second end 22b of the first signal line 22 and extending in a direction perpendicular to the first signal line 22 from a first end 23a to a second end 23b.

[0058] Capacitor 34 is connected in the middle of the first signal line 22, and inductor 33 is connected to the wiring extending from the second signal line 23. Capacitor 34 may also be built into the amplifier 36.

[0059] The amplifier 36 has amplifier wiring 37. This amplifier 36 is connected to the first signal line 22 and ground patterns 24b, 24d, and 24e in order to amplify the amplitude of the signals flowing through the signal lines 22 and 23.

[0060] In the optical receiving module 11B, the pad 27 and the photodetector 31 are arranged adjacent to the second end 22b of the first signal line 22 in the direction of extension of the first signal line 22. The photodetector 31 is mounted on the pad 27 adjacent to the second end 22b of the first signal line 22 in the direction of extension of the first signal line 22.

[0061] The cathode (negative pole) of the light-receiving element 31 is connected to the second end 22b of the first signal line 22 via wire 40. On the other hand, the anode (positive pole) of the light-emitting element 30 is connected to the pad 27 via wire 41 in a direction substantially perpendicular to the extending direction of the first signal line 22.

[0062] In the optical receiving module 11B, the angle between the wire 41 extending from the anode of the photodetector 31 and the first signal line 22 is set to be between 90 degrees and 100 degrees in a plan view. That is, the angle between the wire 41 extending from the anode of the photodetector 31 and the first signal line 22 is within the range of 90 to 100 degrees in a plan view.

[0063] Next, we will explain the effects of the optical receiving module 11B.

[0064] The optical receiving module 11B according to the fourth embodiment comprises a wiring board 20, an optical element (photodetector 31), and a bias tee section 35 comprising an inductor 33 and a capacitor 34. The optical element (photodetector 31) and the bias tee section 35 are arranged on the same surface (first surface 20a) of the wiring board 20. A first signal line 22 extending at least along a predetermined extending direction and a ground section (ground patterns 24b, 24d, 24e, pads 27) are formed on the same surface (first surface 20a) of the wiring board 20. A part of the ground section (pads 27) and the optical element (photodetector 31) are arranged adjacent to one end (second end 22b) of the first signal line 22 in the extending direction of the first signal line 22. The cathode of the optical element (photodetector 31) is wire-connected to the first signal line 22. The anode of the optical element (photodetector 31) is wired to a portion of the ground section (pad 27) such that the angle it makes with respect to the extending direction of the first signal line 22 is 90 degrees or more in a plan view.

[0065] Since the anode of the light-emitting element 30 is connected to the pad 27 via a wire 41 in a direction substantially perpendicular to the extending direction of the first signal line 22, the formation of a ground between the photodetector 31 and the first signal line 22 becomes unnecessary. Therefore, the distance D between the photodetector 31 and the first signal line 22 can be shortened, making it possible to miniaturize the wiring board 20 and improve the flexibility of wiring around the photodetector 31. In addition, the wire 41 connecting the photodetector 31 to the first signal line 22 can be shortened, improving the frequency response characteristics. For example, shortening the length of the wire 41 at a frequency of 28 GHz can result in a gain improvement of about 1 dB.

[0066] Furthermore, in the optical receiving module 11B according to the fourth embodiment, the aforementioned angle is within the range of 90 to 100 degrees in a plan view.

[0067] In other words, the angle formed by the wire 41 extending from the anode of the photodetector 31 and the first signal line 22 does not necessarily have to be 90 degrees (orthogonal), and may be an angle slightly larger than 90 degrees, up to about 100 degrees.

[0068] Furthermore, an impedance mismatch between the light-receiving element 31 and the amplifier 36 can cause a resonance phenomenon due to reflected waves, which can affect the frequency response characteristics. This is influenced by the distance between the light-receiving element 31 and the amplifier 36. According to this embodiment, the distance between the light-receiving element 31 and the amplifier 36 can be easily adjusted, making it possible to eliminate the aforementioned resonance phenomenon.

[0069] [Fifth Embodiment] Figure 5 is a schematic diagram showing the top view of an example of an optical transmission module 10C according to the fifth embodiment. Components that are substantially the same as those in the optical communication module (optical transmission module or optical reception module) described above are denoted by the same reference numerals, and their descriptions are omitted.

[0070] As shown in Figure 5, the through-hole 26 of the pad 27 may be located on the opposite side from the signal lines 22 and 23.

[0071] [Sixth Embodiment] Figure 6 is a schematic diagram showing the top view of an example of an optical transmission module 10D according to the sixth embodiment. Components that are substantially the same as those in the optical communication module (optical transmission module or optical reception module) described above are denoted by the same reference numerals, and their descriptions are omitted.

[0072] As shown in Figure 6, the optical transmission module 10D may have the inductor 33 formed by a pattern rather than a chip.

[0073] [Seventh Embodiment] Figure 7 is a schematic diagram showing the top view of an example of an optical receiving module 11C according to the seventh embodiment. Components that are substantially the same as those in the optical communication module (optical transmitting module or optical receiving module) described above are denoted by the same reference numerals, and their descriptions are omitted.

[0074] The capacitor 34 and amplifier 36, etc., do not need to be placed on the same wiring board 20 as the light-receiving element 31 (or light-emitting element 30). As shown in the optical receiving module 11C in Figure 7, a separate wiring board 20 may be provided, and the capacitor 34 and amplifier 36, etc., may be placed on this separate wiring board 20. In this case, adjacent wiring boards 20, 20 may be connected by a connector 42.

[0075] [Eighth Embodiment] Figure 8A is a schematic diagram showing an example of a state in which the lens-equipped mirror 50 is fixed in the optical transmission module 10E according to the eighth embodiment. Figures 8B and 8C are cross-sectional views of the optical transmission module 10E, each including a cross-section passing through the lens-equipped mirror 50. Components that are substantially the same as those in the optical communication module (optical transmission module or optical reception module) described above are denoted by the same reference numerals, and their descriptions are omitted.

[0076] The optical transmission module 10E includes a mirror with a lens 50, an optical fiber 51, and a connector 52 connecting the mirror with a lens 50 and the optical fiber 51. When fixing the mirror with a lens 50, which optically couples with the light-emitting element 30 (or light-receiving element 31), to the wiring board 20 with adhesive, it may be fixed to the first surface 20a around the pad 27 on the wiring board 20 via an adhesive layer 53.

[0077] By fixing the mirror with lens 50 to the substrate surface (first surface 20a) of the wiring board 20, which has superior adhesion compared to the wiring on the wiring board 20, the mirror with lens 50 can be fixed more firmly. In addition, the pad 27 on which the light-emitting element 30 (or light-receiving element 31) is mounted can be made smaller, making it easier to secure the adhesive surface between the mirror with lens 50 and the substrate surface (first surface 20a) of the wiring board 20. Furthermore, by providing the pad 27 separately from the ground pattern, the symmetry of the adhesive portion between the mirror with lens 50 and the wiring board 20 can be ensured, making it easier to align the mirror with lens 50 when mounting it.

[0078] Although this embodiment has been described above, this embodiment is not limited to these, and various modifications are possible within the scope of the gist of this embodiment. [Explanation of symbols]

[0079] 10A, 10B, 10C, 10D, 10E Optical Transmitter Modules 11A, 11B, 11C Optical Receiver Module 20 Wiring boards 20a Page 1 22 Signal Lines 22b 2nd end 24a Ground Pattern 24b Ground Pattern 24c Ground Pattern 24d Ground Pattern 24e Ground Pattern 27 pads 30 light-emitting elements 31. Photodetector 33 Inductors 34 Capacitors 35 Bias Tee Section 40 wires 41 wires

Claims

[Claim 1] It comprises a wiring board, an optical element, and a bias tee section composed of an inductor and a capacitor, The optical element and the bias tee portion are arranged on the same plane of the wiring board. At least a signal line extending along a predetermined direction of extension and a ground portion are formed on the same surface of the wiring board. A portion of the ground portion and the optical element are arranged adjacent to one end of the signal line in the extending direction in the extending direction, One of the anodes and cathodes of the optical element is wired to the signal line. The anode and cathode of the optical element are wired to the portion of the ground such that one of the two angles it makes with respect to the extending direction of the signal line is within the range of 90 to 100 degrees in a plan view. Optical communication module.

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