OPTICAL TRANSMISSION MODULE AND ELECTRONIC CONTROL UNIT

Abstract

Optical transmission module comprising: - a printed circuit board (20) with a conductor pattern (22) including a ground pattern (220); - an optical connector (30) with a housing (31) and a connector part (32), wherein the housing (31) has a connector section (312) defining an opening (310a) into which an external connector (17) is fitted, wherein the connector part (32) is housed in the housing (31) and wherein the external connector (17) is optically coupled to the connector part (32); - a photoelectric conversion unit (40) located in the housing (31) behind the terminal part (32) with respect to the opening (310a), the photoelectric conversion unit (40) comprising a photoelectric conversion element (42) optically coupled to the terminal part (32) and a circuit section (41, 43) electrically connected to the photoelectric conversion element (42) and the ground pattern (220); and - a shielding element (50) having an electromagnetic shielding property and arranged to surround the connection part (32) and the photoelectric conversion unit (40), wherein - the shielding element (50) is electrically separated from the ground pattern (220), and - the printed circuit board (20) has an island (223) as the conductor pattern (22), wherein the island (223) is arranged in a top view projected in a direction perpendicular to the printed circuit board (20) at a position that overlaps the terminal section (312) and is electrically separated from the ground pattern (220).

Description

[0001] The present disclosure relates to an optical transmission module and an electronic control unit.

[0002] JP 2004-172 194 A discloses an optical transmission module. The disclosure of JP 2004-172 194 A is incorporated herein by reference as an explanation of technical elements in the present disclosure.

[0003] In the optical transmission module of JP 2004-172 194 A, a ground plane of a multilayer substrate is electrically connected to a metal housing. With such a configuration, there is a concern that components of a control circuit mounted on the multilayer substrate, and possibly an optical component, may malfunction or fail to function due to electromagnetic noise. Given the above-described or unmentioned aspects, further improvements to the optical transmission module are necessary.

[0004] The purpose of the present disclosure is to provide an optical transmission module capable of suppressing malfunction due to electromagnetic noise.

[0005] Furthermore, the purpose of the present disclosure is to provide an electronic control unit with an optical transmission module that is capable of suppressing a malfunction due to electromagnetic noise.

[0006] According to one aspect of the present disclosure, an optical transmission module comprises a printed circuit board, an optical connector, an optoelectric or photoelectric conversion unit, and a shielding element. The printed circuit board has a conductor pattern including a ground pattern. The optical connector comprises a housing and a terminal section. The housing is mounted on the printed circuit board and includes a terminal section that defines an opening into which an external connector is fitted. The terminal section, to which the external connector is optically coupled, is housed within the housing. The photoelectric conversion unit comprises a photoelectric conversion element and a circuit section. The photoelectric conversion element is optically coupled to the terminal section. The circuit section is electrically connected to the photoelectric conversion element and the ground pattern.The photoelectric conversion unit is located further inside the housing relative to the opening than the connection part. The shielding element has electromagnetic shielding properties and is arranged to surround the connection part and the photoelectric conversion unit.

[0007] The shielding element is electrically isolated from the ground pattern. The circuit pattern of the printed circuit board also includes an island that is electrically isolated from the ground pattern. The island is positioned so that, in a top view projected in a direction perpendicular to the printed circuit board, it overlaps the connection section of the enclosure.

[0008] In the optical transmission module as described above, the shielding element is electrically isolated from the ground plane of the printed circuit board. This suppresses the propagation of electromagnetic noise from the shielding element to the photoelectric conversion unit. Furthermore, the island, positioned according to the connection section of the housing, is electrically isolated from the ground plane. This further enhances the suppression of electromagnetic noise propagation. Consequently, an optical transmission module can be provided that is capable of suppressing malfunctions caused by electromagnetic noise.

[0009] According to one aspect of the present disclosure, an electronic control unit includes the optical transmission module and a control circuit that can communicate optically with an external device via the optical transmission module.

[0010] The electronic control unit incorporates the optical transmission module described above. Therefore, it is possible to suppress malfunctions caused by electromagnetic noise.

[0011] The functions, features, and advantages of the present disclosure are more clearly evident from the following detailed description with reference to the accompanying drawings, in which identical parts are labelled with the same reference numerals. The drawings show: Fig. 1 an illustration to demonstrate a schematic configuration of an electronic control unit according to a first embodiment of the present disclosure; Fig. 2 an illustration to demonstrate a perspective view, including a partial cross-section, of an optical transmission module according to the first embodiment; Fig. 3. An illustration to demonstrate a cross-sectional view along a line III-III in Fig. 2; Fig. 4. An illustration to demonstrate the positional relationship between a connecting section and an island; Fig. 5. An illustration showing a top view of an example of the optical transmission module when viewed in one direction X1. Fig. 2; Fig. 6. An illustration showing a perspective view of a printed circuit board on which clamps or supports are mounted; Fig. Figure 7 shows a top view of another example of the optical transmission module, which differs from the one in Fig. The 5 examples shown differ; Fig. 8. An illustration to demonstrate a perspective view of an external screen; Fig. 9. An illustration showing a perspective view of the outer shielding mounted on the circuit board; Fig. 10. A figure illustrating an EMF simulation result (EMF for electromagnetic field) of a reference example; Fig. 11 an illustration to demonstrate an EMF simulation result of the first embodiment; Fig. 12 a figure to illustrate a simulation result of a voltage caused by electromagnetic noise between a power supply pattern and the ground pattern on the printed circuit board; Fig. 13 a figure to illustrate a simulation result of a voltage caused by electromagnetic noise between a signal pattern and the ground pattern on the printed circuit board; Fig. 14 A figure illustrating a simulation result of a voltage caused by electromagnetic noise between a power supply pattern and the ground pattern on a circuit board of a COB module; Fig. 15 A figure illustrating a simulation result of a voltage caused by electromagnetic noise between a signal pattern and a ground pattern on a circuit board of the COB module; and Fig. 16 An illustration showing a cross-sectional view of an optical transmission module and an electronic control unit according to a second embodiment.

[0012] Several embodiments are described below with reference to the drawings. In all embodiments, corresponding elements are designated with the same reference numerals and are not described repeatedly to avoid redundancy. If some of the features of an embodiment are explained, the remaining features can be provided by the features of the other preceding embodiments. Furthermore, not only the combinations of configurations explicitly shown in the description of the respective embodiments, but also the configurations of the several embodiments can be partially combined, even if they are not explicitly shown, provided that no difficulties arise, particularly in the combination. (First embodiment)

[0013] An optical transmission module and an electronic control unit of the present embodiment are, for example, applicable to a moving body. Examples of moving bodies include vehicles, flying objects such as drones, ships, construction machinery, and agricultural machinery. An example is described below in which the optical transmission module and the electronic control unit are applied to a vehicle. It should be noted that the optical transmission module and the electronic control unit can also be used for applications other than moving bodies. <Elektronische Steuereinheit>

[0014] First, a configuration of an electronic control unit 10 is required with reference to Fig. 1 described. In Fig. Figure 1 is, for the sake of simplicity, a power supply line from a power supply circuit 13, not shown. As in Fig. As shown in Figure 1, the electronic control unit 10 (ECU) contains a connector 11 (CN), an optical transmission module 12 (OTM), a power supply circuit 13 (PWR), a control circuit 14 (CTR) and communication circuits 15 and 16 (COM1, COM2).

[0015] The electronic control unit 10 is connected to other devices mounted on the vehicle via connector 11 and optical transmission module 12. Connector 11 establishes an electrical connection between the electronic control unit 10 and these other devices. A battery 2 (BATT) is connected to connector 11 via a cable harness 1. Battery 2 is a DC power source mounted on the vehicle. The electronic control unit 10 can be supplied with electrical energy from battery 2 via cable harness 1 and connector 11. The electrical energy is supplied to the power supply circuit 13 via connector 11.

[0016] The power supply circuit 13 converts the DC voltage of battery 2 into a DC voltage of a different value. The power supply circuit 13 generates a predetermined voltage from the DC voltage of battery 2, which is required by the electronic control unit 10, and supplies the optical transmission module 12, the control circuit 14, the communication circuits 15, 16, and the like with the predetermined voltage.

[0017] An external device 4 (EX1), which is different from the battery 2, is connected to connector 11. At least one external device 4 is connected to connector 11. Several external devices 4 can be connected to connector 11. The electronic control unit 10 is communicatively connected to the external device 4. The external device 4 comprises at least one of the following: a sensor, a target device to be controlled (e.g., an actuator), and other electronic control units.

[0018] The optical transmission module 12 establishes an optical connection between the electronic control unit 10 and another device. An external device 6 (EX2) is connected to the optical transmission module 12 via a fiber optic cable 5. At least one external device 6 is connected to the optical transmission module 12. Several external devices 6 can be connected to the optical transmission module 12. The electronic control unit 10 is connected to the external device 6 to enable optical communication. The control circuit 14 is also connected to the external device 6 via the optical transmission module 12 to enable optical communication. Communication between the electronic control unit 10 and the external device 6 is faster than communication between the electronic control unit 10 and the external device 4.

[0019] The external device 6 is, for example, a peripheral monitoring sensor that monitors the periphery of a vehicle to which the external device 6 is mounted. The external device 6 comprises, as a peripheral monitoring sensor, at least one of the following devices: a peripheral monitoring camera that captures a predetermined area around the vehicle, millimeter-wave radar, sonar, and LiDAR, which captures a point cloud of feature points of a road shape or route and a structure. LiDAR stands for "Light Detection and Ranging" or "Laser Imaging Detection and Ranging".

[0020] The control circuit 14 consists primarily of a microcomputer with a processor, memory, an input / output interface, and a bus connecting these elements. The processor executes various processes by running the control program stored in memory. The control circuit 14 acquires data from at least one of the external devices 4 and 6 via the corresponding communication circuits 15 and 16 and performs processing using the acquired data. The control circuit 14 then sends the processing result to at least one of the external devices 4 and 6 via the corresponding communication circuits 15 and 16.

[0021] At least one of the communication circuits 15 or 16 has at least one transmitting function, and the other has at least one receiving function. Alternatively, each of the communication circuits 15 and 16 can have both a transmitting and a receiving function. Of the communication circuits 15 and 16, one that has only a transmitting function can be called a transmitting circuit, one that has only a receiving function can be called a receiving circuit, and one that has both transmitting and receiving functions can be called a transmit / receive circuit or a transceiver.

[0022] The electronic control unit 10 is, for example, a peripheral monitoring ECU. The external device 4 contains another electronic control unit, such as a driver assistance ECU. The external device 6 contains a peripheral monitoring sensor, such as a peripheral monitoring camera. The control circuit 14 acquires a detection signal (e.g., image data) from a peripheral monitoring sensor via the optical transmission module 12 and the communication circuit 16. The control circuit 14 analyzes and processes the acquired image data to detect the presence or absence of an obstacle in the vehicle's path, the presence or absence of a moving object around the vehicle, the position and direction of travel of the moving object, and the like.Examples of moving objects in the vicinity of the vehicle include other vehicles such as cars and light vehicles, pedestrians, and the like. The peripheral monitoring ECU sequentially transmits information about obstacles, moving objects, and the like to the external device 4 (another electronic control unit) via communication circuit 15 and connector 11.

[0023] The electronic control unit 10 is, for example, a vehicle control ECU. The external device 4 contains, as actuators, an EPS motor, an electronic throttle motor, a brake actuator, and the like. EPS stands for Electric Power Steering. The external device 4 also contains, as sensors, a vehicle speed sensor, a steering angle sensor, and the like. The external device 6 contains a peripheral monitoring sensor, such as a peripheral monitoring camera. The control circuit 14 acquires signals from the steering angle sensor, the vehicle speed sensor, and the like via connector 11 and communication circuit 15. The control circuit 14 acquires the signal from the peripheral monitoring sensor via optical transmission module 12 and communication circuit 16.The control circuit 14 performs processing using the detected detection signal and outputs a control signal to each actuator via the communication circuit 15 and the connector 11. For example, if an obstacle is detected in the path of the vehicle, the control circuit 14 controls the actuators to avoid a collision with the obstacle. <Optisches Übertragungsmodul>

[0024] The optical transmission module 12 is described below with reference to the Fig. 2 to 9 described. Fig. Figure 2 shows a perspective view of the optical transmission module 12 to illustrate its schematic configuration. Fig. Figure 2 shows some elements partially in cross-section to illustrate the internal structure of the optical transmission module 12. Fig. Figure 3 shows an illustration of a cross-sectional view along line III-III in Fig. 2. In Fig. Figure 3 also shows a simplified external connector 17 which is fitted or plugged into an optical connector 30. Fig. Figure 4 shows an illustration of the positional relationship between a connection section 312 and a connection part 32 of the optical connector 30 and an island 223 of a printed circuit board 20. Fig. Figure 4 shows the position of connection section 312 in a plan view projected in the Z direction, indicated by a dashed line. Similarly, the position of connection part 32 is shown by an alternating long and short dashed line. Fig. For the sake of simplicity, 4 ladder patterns are different from a mass pattern 220 and the island 223 have been omitted.

[0025] Fig. Figure 5 shows a top view of an example of the optical transmission module when viewed in one direction X1. Fig. 2. In Fig. For the sake of simplicity, the connection part 32 of the optical connector 30 is shown in a simplified form. To show the internal structure of an outer shield 51, the representation of the outer shield 51 is also simplified. Fig. Figure 6 shows a figure illustrating a perspective view of clamps or supports 33 mounted on the circuit board 20. Fig. In order to show the structure of the supports 33, other elements of the optical connector 30 have been omitted. Fig. Figure 7 shows an illustration of an example of the optical transmission module 12, which differs from the one in Fig. The example shown in point 5 differs. Fig. 7 are omitted to illustrate the structure of a photoelectric conversion unit 40, the connection part 32 of the optical connector 30, a partition 311 of a housing 31 and a cover of an inner shield 52. Fig. Figure 8 shows an illustration to demonstrate a perspective view of the external shielding 51. Fig. Figure 9 shows a figure illustrating a perspective view of a fixed structure of the external shielding 51. Fig. For the sake of simplicity, only supports 33 and the outer shield 51 are shown as elements located on the circuit board 20.

[0026] As in the Fig. 2 and Fig. As shown in Figure 3, the optical transmission module 12 comprises a printed circuit board 20, an optical connector 30, a photoelectric conversion unit 40, and a shielding element 50. Hereinafter, the thickness direction of the printed circuit board 20 is referred to as the Z-direction. The thickness direction of the printed circuit board 20 is a direction normal or perpendicular to a plane of the printed circuit board 20. A direction orthogonal to the Z-direction is referred to as the X-direction. A direction orthogonal to both the Z-direction and the X-direction is referred to as the Y-direction. Unless otherwise specified, a shape in a top view when viewed or projected in the Z-direction, i.e., a shape along an XY plane defined by the X and Y directions, is referred to as a planar shape. Furthermore, the top view in the Z-direction may simply be referred to as the top view.

[0027] The printed circuit board 20 has an insulating base 21 made of a resin or the like and a conductor pattern 22 arranged on the insulating base 21. The conductor pattern 22 is formed, for example, by patterning or structuring a metal foil. Other elements of the optical transmission module 12, such as the optical connector 30, the photoelectric conversion unit 40, and the shielding element 50, are arranged on a surface of the printed circuit board 20 in the Z-direction.

[0028] The conductor pattern 22 is arranged on one surface of the printed circuit board 20 in the Z-direction. The conductor pattern 22 can be arranged in several layers relative to the insulating base 21. The conductor pattern 22 can, for example, be arranged on both sides of the printed circuit board 20 or can include an inner layer pattern. In the present embodiment, the conductor pattern 22 has a four-layer arrangement with respect to the insulating base 21. A section of the conductor pattern 22 arranged on the surface of the printed circuit board 20, which differs from the interconnection sections, can be covered with a solder mask or the like. For the sake of simplicity, the solder mask is not shown in the present embodiment.

[0029] The conductor pattern 22 provides a wiring function. The conductor pattern 22 contains wiring for the electrical connection of the external device 6 and the communication circuit 16. At least one of the connector 11, the power supply circuit 13, the control circuit 14, the communication circuit 15, or the communication circuit 16 can be mounted on the printed circuit board 20. In this case, the conductor pattern 22 contains wiring for the electrical connection of the elements mounted on the printed circuit board 20.

[0030] The conductor pattern 22 includes a ground (GND) pattern 220, a power supply pattern (not shown), a signal pattern 221, and several contact points 222. The ground pattern 220 is a conductor pattern that provides a reference potential in the optical transmission module 12. The ground pattern 220 comprises a so-called solid pattern with a relatively large area. In the present embodiment, the ground pattern 220 is provided in each layer. The ground pattern 220 can be referred to as a ground line or a ground plane.

[0031] The signal pattern 221 is a conductor pattern for transmitting a signal. The signal pattern 221 can be referred to as a transmission line, a signal line, or signal wiring. The contact point 222 is a connection section to which a line terminal 44 of the photoelectric conversion unit 40 is connected. The contact point 222 can be referred to as a connection surface. The contact point 222 is provided on one surface of the printed circuit board 20. The contact point 222 comprises a power contact point (not shown), a ground contact point 222a, and a signal contact point 222b. In the present embodiment, the multiple contact points 222 are aligned in a row in the Y direction at a predetermined distance.

[0032] On one surface of the printed circuit board 20, the ground pattern 220 is arranged around the contact points 222. A groove is formed around each contact point 222 in the conductor pattern 22, so that the contact point 222 and the ground pattern 220 are electrically separated from each other. The contact point 222 is connected to a corresponding conductor pattern 22 in the inner layer, e.g., via a connecting via 23. As shown in Fig. As shown in Figure 3, for example, the signal contact point 222b is electrically connected to the signal pattern 221 of the inner layer via the through-hole 23.

[0033] The conductor pattern 22 also includes an island 223. The island 223 is electrically isolated from the rest of the conductor pattern 22. The island 223 is arranged on one surface of the printed circuit board 20. A groove 24 is formed around the island 223 in the conductor pattern 22, so that the island 223 and the ground pattern 220 are electrically isolated from each other. The groove 24 is an area from which the conductor pattern 22 has been removed, e.g., by etching.

[0034] As in the Fig. 2 and Fig. As shown in Figure 4, the island 223 of the present embodiment has a substantially rectangular shape with the X-direction as the transverse direction and the Y-direction as the longitudinal direction. One of the longitudinal sides of the island 223 is in contact with one of the sides of the printed circuit board 20, which has a substantially rectangular, flat shape, i.e., with an end 20a. The groove 24 is provided between the remaining three sides of the island 223 and the ground pattern 220. The groove 24 has a substantially U-shape in plan view.

[0035] The island 223 is arranged to overlap at least part of the connecting section 312 in a top view in the Z direction. In the present embodiment, as shown in Fig. As shown in Figure 4, the island 223 is arranged to overlap almost the entire area of ​​the connection section 312, as described below. The island 223 is arranged to overlap the main section of the connection part 32 in a plan view. The island 223 is arranged to encompass the entire connection section 312 in a plan view.

[0036] As in Fig. As shown in Figure 3, the external connector 17 is fitted or plugged into the optical connector 30 to optically couple a fiber optic cable 5 of the external connector 17 to the photoelectric conversion unit 40. The external connector 17 has a housing 170 and a ferrule 171 held in the housing 170. The ferrule 171 holds an optical fiber at one end of the fiber optic cable 5.

[0037] The optical connector 30 comprises a housing 31, a terminal section 32, and supports 33. The housing 31 is, for example, a resin-molded body. The housing 31 is attached (fixed) to the printed circuit board 20 via the supports (pegs) 33. The housing 31 has a tubular section 310 and a partition 311. Such a housing 31 can also be referred to as a head housing. On the other hand, the housing 170 of the external connector 17 can also be referred to as a plug housing.

[0038] As in Fig. As shown in Figure 5, the tubular section 310 essentially has a tubular shape with a rectangular cross-section in a plan view in the X direction. The tubular section 310 extends in the X direction when assembled. The tubular section 310 is arranged to intersect the island 223 in the X direction. An opening 310a of the tubular section 310 is located further out in the X direction than one end 20a of the printed circuit board 20. The external connector 17 is inserted into the tubular section 310 through the opening 310a. The partition 311 is provided in the X direction at the center of the tubular section 310.

[0039] The partition 311 blocks the space within the tubular section 310. As in Fig. As shown in Figure 3, the partition 311 and a section of the tubular section 310 that is closer to the opening 310a than the partition 311, i.e., the section on the front, form the connecting section 312 with the external connector 17. The connecting section 312 is shaped with irregularities for fastening. The external connector 17 is inserted into the tubular section 310 through the opening 310a. Then the housing 170 of the external connector 17 is connected to the connecting section 312.

[0040] The partition 311 and a section of the tubular section 310 on the back of the partition 311, i.e., the section on the side opposite the opening 310a, form a housing chamber 313 for the photoelectric conversion unit 40. The wall of the tubular section 310 forming the housing chamber 313 facing the circuit board 20 has a recess for electrically connecting the photoelectric conversion unit 40 to the circuit board 20.

[0041] The partition 311 is provided with a through-hole 311a. The connection part 32 extends through the through-hole 311a. Part of the connection part 32 is located in the connection section 312, and the other part is located in the housing chamber 313. The connection part 32 comprises a ferrule 320, an optical fiber 321, and a sleeve 322.

[0042] The ferrule 320 is formed, for example, using a ceramic material such as zirconium dioxide. The ferrule 320 is essentially cylindrical, and the optical fiber or waveguide 321 is held within the cylinder of the ferrule 320. The waveguide 321 is formed using a material such as resin or glass. The ferrule 320 is arranged such that the direction of extension of the cylinder, i.e., the optical axis of the waveguide 321, is essentially parallel to the X-axis.

[0043] The sleeve 322 is also formed using the same material as the ferrule 320. The sleeve 322 has a substantially cylindrical shape. The ferrule 320 is inserted into the sleeve 322 and positioned in a region extending from the rear end to the center of the cylinder. A ferrule 171 of the external connector 17 is inserted into the sleeve 322. The ferrule 171 is inserted into the sleeve 322 from an end adjacent to the opening 310a on the front side. This aligns the optical axes of the ferrule 320 and the ferrule 171. The sleeve 322 connects the ferrule 320 and the ferrule 171.

[0044] As in Fig. As shown in Figure 5, the support 33 fixes the housing 31 to the printed circuit board 20. The support 33 is a metal element. The support 33 can be formed integrally with the housing 31, for example, by insert molding. The support 33 can be attached to the housing 31 by pressing, snapping, or the like. The support 33 projects further forward towards the printed circuit board 20 than the housing 31.

[0045] Connecting the support 33 to the island 223 holds the housing 31 in a predetermined position. The support 33 can be electrically connected to the island 223. Alternatively, the support 33 can be electrically isolated from the island 223 while mechanically connected to it. For example, if a solder or conductive paste is used, the support 33 is electrically connected to the island 223. If a non-conductive adhesive is used, the support 33 is electrically isolated from the island 223 while mechanically connected to it.

[0046] In the present embodiment, the optical connector 30 has several supports 33. The supports 33 are each attached to outer surfaces of side walls of the housing 31, the side walls pointing in the Y direction. As in Fig. As shown in Figure 6, the supports 33 are connected longitudinally (in the Y direction) near opposite ends of the island 223. Each support 33 has a curved section between a fixed section attached to the housing 31 and a fixed section attached to the island 223. This gives the support 33 an essentially L-shape. The support 33 has a fixed section attached to the island 223 and an extension section extending from the fixed section in the Z direction. The support 33 has an engagement hole 330 in the extension section for attaching an external shield 51.

[0047] The photoelectric conversion unit 40 comprises a substrate 41, a photoelectric conversion element 42, a circuit chip 43, and a conductor connection 44. The substrate 41 is a printed circuit board (PCB). The substrate 41 has an insulating base 410 and a conductor pattern 411 arranged on the insulating base 410. In the case where the conductor pattern 411 is arranged in multiple layers, the conductor patterns of different layers are electrically connected via a via or the like. Although not shown in the drawings, the conductor pattern 411 includes a ground pattern, a signal pattern, a contact point, and the like. The substrate 41 is oriented such that its thickness direction is substantially parallel to the X-direction. The photoelectric conversion element 42 and the circuit chip 43 are mounted on a surface of the substrate 41.The substrate 41, the photoelectric conversion element 42 and the circuit chip 43 form a chip-on-board module (COB).

[0048] The photoelectric conversion element 42 converts a signal photoelectrically. In a case where the photoelectric conversion element 42 is a light-emitting element that converts an electrical signal into an optical signal, a surface-emitting laser, such as a VCSEL (vertical-cavity surface-emitting laser or surface-emitting diode laser), is used as the photoelectric conversion element 42. In a case where the photoelectric conversion element 42 is a light-receiving element that converts an optical signal into an electrical signal, a photodiode (PD), for example, is used as the photoelectric conversion element 42. A connection part 32, as described above, is provided for a photoelectric conversion element 42.In a case where the photoelectric conversion unit 40, for example, comprises several photoelectric conversion elements 42, the connecting parts 32 are provided accordingly for the photoelectric conversion elements 42.

[0049] The photoelectric conversion unit 40 can have either one photoelectric conversion element 42 or several photoelectric conversion elements 42. Fig. Figure 5 shows an example of a configuration in which only one terminal 32 is provided, in other words, a configuration in which only one photoelectric conversion element 42 is provided. In this case, the photoelectric conversion element 42 is either a light-emitting element or a light-receiving element. The optical axis (element center) of the photoelectric conversion element 42 coincides with the optical axis of the optical waveguide 321 held by the ferrule 320. The photoelectric conversion element 42 is optically coupled to the terminal 32.

[0050] On the other hand, Fig. Figure 7 shows an example of a configuration with two photoelectric conversion elements 42. One of the photoelectric conversion elements 42 is a light-emitting element, the other a light-receiving element. Although not shown in the drawings, the optical connector 30 has the connection part 32 for the light-emitting element and the connection part 32 for the light-receiving element. The two photoelectric conversion elements 42 are arranged in the Y direction.

[0051] The circuit chip 43 executes a predetermined process between the communication circuit 16 and the photoelectric conversion element 42. The circuit chip 43 is configured with a control circuit for the photoelectric conversion element 42, a signal amplifier circuit, and the like. For example, some of the terminals of the circuit chip 43 are connected via a bond wire to a contact point of a conductor pattern 411, and other terminals of the circuit chip 43 are connected, for example, via a bond wire to the contact point of the photoelectric conversion element 42. In the present embodiment, the substrate 41 and the circuit chip 43 constitute a single circuit unit.

[0052] The conductor connection 44 electrically connects the printed circuit board 20 and the COB module. One end of the conductor connection 44 is connected to the contact point 222 of the printed circuit board 20 via a bonding material such as solder. The other end of the conductor connection 44 is connected to the contact point of the conductor pattern 411 of the substrate 41 via a bond wire 45. The conductor connection 44 is essentially L-shaped.

[0053] The photoelectric conversion unit 40 contains several line connections 44. For example, line connection 44, acting as a ground line connection, electrically connects the ground contact point 222a and the ground pattern of the conductor pattern 411. Line connection 44, acting as a signal line connection, electrically connects the signal contact point 222b and the circuit chip 43. The signal line connection 44 can be connected to the circuit chip 43 via the contact point of the conductor pattern 411, or it can be connected to the circuit chip 43 without passing through the contact point.

[0054] The photoelectric conversion unit 40 of the present embodiment further comprises an insulating housing 46. The insulating housing 46 is, for example, a product formed or molded from resin. The insulating housing 46 is a support element that carries the substrate 41. The insulating housing 46 has a recess in a surface facing in the X direction, and the substrate 41 is attached to the bottom surface of the recess. The photoelectric conversion element 42 and the circuit chip 43 are mounted on the surface of the substrate 41 that faces the surface attached to the insulating housing 46.

[0055] The shielding element 50 has electromagnetic shielding properties and is arranged to surround the terminal 32 and the photoelectric conversion unit 40 of the optical connector 30. The shielding element 50 is electrically isolated from the ground pattern 220 of the circuit board 20. That is, the shielding element 50 is electrically isolated from the ground contact point 222a and the ground pattern of the conductor pattern 411 of the substrate 41.

[0056] The shielding element 50 of the present embodiment comprises an outer shield 51 and an inner shield 52. The outer shield 51 is arranged to surround the housing 31 of the optical connector 30. As shown in the Fig. 8 and Fig. As shown in Figure 9, the outer shield 51 has a box shape without a bottom wall on one side facing the circuit board 20. The outer shield 51 has an opening 51a in one of its side walls, extending in the Z direction. The opening 51a is located in one of the side walls of the outer shield 51 that faces in the X direction and is on the same side as the opening 310a of the housing 31. The other three side walls and one top wall of the outer shield 51 are not provided with any opening and form end walls. The top wall of the outer shield 51 faces the circuit board 20. The outer shield 51 is arranged to surround the terminal part 32 and the photoelectric conversion unit 40.

[0057] As in the Fig. 5, Fig. 7 and Fig. As shown in Figure 8, the outer shield 51 has an engagement projection 51b and a spring section 51c. The engagement projection 51b and the spring section 51c are located on the inner side of each of the side walls of the outer shield 51, with the side walls facing each other in the Y-direction. The engagement projection 51b and the spring section 51c are located near the lower end of the side wall. The engagement projection 51b engages with the engagement hole 330 of the support 33 to form a locking structure with the support 33. This locking structure positions the outer shield 51 relative to the optical connector 30. Furthermore, the outer shield 51 is secured to the optical connector 30 by the reaction force resulting from the elastic deformation of the spring section 51c.The electrical connection between the outer shielding 51 and the supports 33 is secured, as the spring sections 51c are pressed against the supports 33 on both sides in the Y direction.

[0058] The inner shield 52 is housed in the casing 31 of the optical connector 30 and is located at least between the opening 310a and the photoelectric conversion unit 40. The inner shield 52 primarily protects the photoelectric conversion unit 40 from electromagnetic waves entering the optical transmission module 12 through the opening 51a. The inner shield 52 is located in the housing chamber 313. The inner shield 52 can be electrically connected to or electrically isolated from the outer shield 51. In the present embodiment, the inner shield 52 is electrically isolated from the outer shield 51.

[0059] The inner shield 52 comprises a body section 520 and a cover 521. The body section 520 is a box-shaped cover with an opening on the side facing openings 51a and 310a, and an opening on a side facing the circuit board 20 in the Z-direction. The body section 520 is attached to the outer surface of the insulating housing 46 by adhesive or the like. The cover 521 closes the opening of the body section 520 in the X-direction. The cover 521 is attached, for example, to the end face of the insulating housing 46 surrounding the recess. The body section 520 and the cover 521 cover the photoelectric conversion unit 40 on five sides other than the side facing the circuit board 20. In other words, the body section 520 and the cover 521 form five sides of the inner shield 52.

[0060] The cover 521 has a tubular section 521a at a position corresponding to the photoelectric conversion element 42 in a top view in the X direction. The tubular section 521a extends in the X direction and is configured such that a portion of the ferrule 320 can be inserted into it. The central axis of the tubular section 521a coincides with the optical axis of the photoelectric conversion element 42. In the present embodiment, the tubular section 521a extends to a position corresponding to the through-hole 311a of the partition 311. A portion of the ferrule 320 projecting from the sleeve 322 is largely covered by the tubular section 521a.

[0061] The inner shield 52 further comprises a locking projection 522. The locking projection 522 is connected, for example, to the body section 520. The locking projection 522 extends in the Z-direction from the outer surface of the opening end in the X-direction of the body section 520. The locking projection 522 exhibits a spring-like property. In its elastically deformed state, the locking projection 522 rests against the tubular inner wall of the housing 31 and forms a locking structure with the housing 31. The inner shield 52 is attached to the housing 31 by this locking structure.

[0062] The inner shield 52 has at least one locking projection 522. As in Fig. As shown in Figure 7, the inner shield 52 can have several locking projections 522. In particular, if the photoelectric conversion unit 40 contains several photoelectric conversion elements 42, the length of the COB module is likely to increase in the Y direction. In such a case, it is therefore advantageous to have several locking projections 522 aligned in the Y direction. <Zusammenfassung der ersten Ausführungsform>

[0063] In the optical transmission module 12 and the electronic control unit 10 of the present embodiment, the shielding element 50 is electrically isolated from the ground pattern 220 of the printed circuit board 20, as described above. Since the shielding element 50 is not electrically connected to the ground pattern 220, the migration of electromagnetic noise from the shielding element 50 via the ground pattern 220 to the photoelectric conversion unit 40 can be suppressed.

[0064] Furthermore, the portion of the conductor pattern 22 at the position corresponding to the terminal section 312 of the optical connector 30 is configured as the island 223, which is electrically isolated from the ground pattern 220. As described above, if the island 223, which is a solid pattern electrically isolated from the ground pattern 220, is located directly below the terminal section 312, the effect of suppressing the propagation of the electromagnetic noise described above can be enhanced. This can suppress malfunctions of the photoelectric conversion unit 40 due to electromagnetic noise.In a case where the island 223 is designed to overlap at least part of the terminal section 312 in the Z-direction projected plan view, the malfunction of the photoelectric conversion unit 40 due to electromagnetic noise can be suppressed compared to the configuration where the ground pattern is located directly below the terminal section without the island. In a case where the island 223 is designed to overlap almost the entire area of ​​the terminal section 312, it is particularly effective at suppressing malfunctions.

[0065] The effect of island 223 is described below with reference to the Fig. 10 and Fig. 11 described. The Fig. 10 and Fig. Figure 11 shows figures of the electric field strength distribution to illustrate the results of an electromagnetic field simulation. The electromagnetic field simulation is performed using a finite element method for the analysis model of the optical transmission module, where a parallel plane wave is assumed to originate from the opening side of the optical connector, assuming a communication frequency band on the order of GHz. Fig. Figure 10 shows the result of a reference example. In the reference example, the printed circuit board is not equipped with the island as described above, and the ground pattern is also located directly below the connection section. Fig. 10. The elements which are identical or related to the elements of the present embodiment are characterized by adding “r” to the ends of the same reference numerals of the present embodiment. Fig. Figure 11 shows the result of the configuration described in the present embodiment, i.e., the configuration in which the island 223 is provided directly below the connection section 312, as shown in Fig. 4 shown.

[0066] As in the Fig. 10 and Fig. As shown in Figure 11, the electric field strength of the configuration with the island 223 is lower than that of the configuration without the island 223. Therefore, it is evident that when the island 223 is positioned directly below the terminal section 312, the influence of electromagnetic noise is reduced compared to the configuration without the island 223. By isolating the island 223 from the ground pattern 220, the noise loop current in the circuit board 20 is divided by the island 223, causing the resonant frequency of the circuit board 20 to shift towards the higher frequency and thus reducing the influence of electromagnetic noise.

[0067] Although not shown in the drawings, the simulation of electromagnetic fields is also performed for the periphery of the photoelectric conversion unit. In the reference example, where the island is not included, the electric field strength around the substrate, the photoelectric conversion element, and the circuit chip forming the COB module is high. In contrast, in the configuration where the island 223 is included, the electric field strength at the same location is low. This also demonstrates that a malfunction of the photoelectric conversion unit 40 due to electromagnetic noise can be suppressed.

[0068] As described above, the shielding element 50 is arranged such that it surrounds the connection part 32 and the photoelectric conversion unit 40, and is electrically isolated from the ground pattern 220. The shielding element 50 can, for example, be provided by only one element. The shielding element 50 can, for example, only have the outer shield 51.

[0069] The shielding element 50 of the present embodiment has the inner shielding 52 in addition to the outer shielding 51. In this case, in the configuration with the opening 51a for receiving the external connector 17, it is possible to suppress the influence of the electromagnetic noise penetrating from the opening 51a on the photoelectric conversion unit 40.

[0070] The Fig. Figures 12 to 15 show illustrations demonstrating the influence of electromagnetic noise depending on the presence or absence of an electrical connection between the outer shield 51 and the inner shield 52. Fig. 12 to 15 denotes "without conductor" the configuration in which the outer shield 51 and the inner shield 52 are electrically separated from each other, and "with conductor" denotes the configuration in which the outer shield 51 and the inner shield 52 are electrically connected to each other. Fig. Figures 12 to 15 show simulation results demonstrating tensions between different patterns due to electromagnetic noise. The simulation is performed using a finite element method for the analysis model of the optical transmission module, where a parallel plane wave is assumed to originate from the opening side of the optical connector, assuming a remote field and a communication frequency band on the order of GHz. Fig. 12 and Fig. Figure 13 shows the results of circuit board 20. Fig. Figure 12 shows the tension between the power supply pattern and the ground pattern, and Fig. Figure 13 shows the voltage between the signal pattern and the ground pattern. Fig. 14 and Fig. Figure 15 shows the results for the substrate of the COB module. Fig. Figure 14 shows the tension between the power supply pattern and the ground pattern, and Fig. Figure 15 shows the voltage between the signal pattern and the ground pattern.

[0071] Preferably, the outer shield 51 and the inner shield 52 are electrically separated from each other. Due to the electrical separation, it is less likely that noise will transfer from the outer shield 51 to the inner shield 52. Also from the in the Fig. The simulation results shown in Figures 12 to 15 demonstrate that the propagation of electromagnetic noise can be suppressed across a broad frequency band. As shown in the Fig. As shown in Figures 12 to 15, at some frequencies electromagnetic noise can be suppressed more effectively by the electrical connection of the outer shield 51 and the inner shield 52 than by the electrical separation of the outer shield 51 and the inner shield 52. Therefore, the outer shield 51 and the inner shield 52 can be electrically connected.

[0072] The outer shield 51 can be electrically connected to the island 223. According to the configuration of the present embodiment, the outer shield 51 is electrically connected to the support 33 by the reaction force of the elastic deformation of the spring element 51c. Furthermore, the support 33 is connected to the island 223 via a conductive bonding material, such as solder. Therefore, the electrical connection between the outer shield 51 and the island 223 can be realized with a simple configuration. Through this electrical connection, the island 223 can also serve as a shield for the electromagnetic wave. In addition, the propagation of electromagnetic noise can be suppressed by isolating it from the ground pattern 220.

[0073] The outer shield 51 can be electrically isolated from the island 223. In the configuration above, the outer shield 51 and the island 223 can be electrically isolated and separated by attaching the support 33 to the island 223, for example, with a non-conductive adhesive. The electrical insulation can be provided at the attachment point between the support 33 and the outer shield 51.

[0074] The example described above shows the outer shield 51 attached to the support 33. However, the attachment configuration of the outer shield 51 is not limited to this example. The outer shield 51 can be attached to the housing 31 by gluing or similar means. In this configuration as well, the outer shield 51 can be electrically isolated from the island 223. (Second embodiment)

[0075] The present embodiment is a modification of the above embodiment as a basic configuration and may include the description of the above embodiment. In the above embodiment, the shielding element 50 is not electrically connected to the metal element outside the optical transmission module 12. Alternatively, the shielding element 50 may be connected to a frame ground.

[0076] Fig. Figure 16 shows a cross-sectional view of an optical transmission module 12 and an electronic control unit 10 of the present embodiment. The electronic control unit 10 has a metal housing 18. The metal housing 18 is configured or constructed by assembling several elements 18A and 18B. Within the metal housing 18, the electronic control unit 10 contains the power supply circuit 13, the control circuit 14, the communication circuits 15 and 16, as well as at least a part of the connector 11 and at least a part of the optical transmission module 12. In the example of Fig. The entire optical transmission module 12 is housed in the metal housing 16. The metal housing 18 has openings for the connector 11 and the optical transmission module 12, respectively, to allow connections with external devices.

[0077] The metal housing 18 features a spring section, such as a finger spring, as a peripheral section of the opening for the optical transmission module 12. During assembly of the multiple elements 18A and 18B, the spring section comes into contact with the outer shield 51 of the optical transmission module 12 and deforms elastically. The electrical connection between the outer shield 51 and the metal housing 18 is ensured by the spring section pressing the outer shield 51 on both sides in the Z-direction. <Zusammenfassung der zweiten Ausführungsform>

[0078] According to the present embodiment, the outer shield 51 of the optical transmission module 12 is electrically connected to the metal housing 18 of the electronic control unit 10. This allows electromagnetic noise to be dissipated from the outer shield 51 to the metal housing 18. Consequently, it is possible to suppress malfunctions of the photoelectric conversion unit 40 caused by electromagnetic noise. The metal housing 18 corresponds to the frame ground.

[0079] The foregoing shows an example in which the metal housing 18 acts as the frame ground. However, the present embodiment is not limited to this example. At least the outer shielding 51 of the shielding element 50 can be electrically connected to a chassis ground of the vehicle. The chassis ground also acts as the frame ground. (Other embodiments)

[0080] The present disclosure, including the drawings, is not limited to the exemplary embodiments. The disclosure includes the embodiments described above and modifications based on these embodiments by a person skilled in the art. For example, the disclosure is not limited to the combinations of components and / or elements shown in the embodiments. The present disclosure can be implemented in various combinations. The disclosure may contain additional sections that may be added to the embodiments. The disclosure includes the omission of components and / or elements of the embodiments. The disclosure includes the exchange or combination of components and / or elements between one embodiment and another. The technical scope disclosed is not limited to the description of the embodiments.The various technical areas disclosed are specified by the description of the claims and should be interpreted as encompassing all modifications within the meaning and scope corresponding to or equivalent to the description of the claims.

[0081] The disclosure in the description, drawings, and the like is not limited by the description of the claims. The disclosures in the description, drawings, and the like encompass the technical ideas described in the claims and extend beyond this to a wider variety of technical ideas than those described in the claims. Therefore, various technical ideas can be derived from the disclosure in the description, drawings, and the like without being limited to the description of the claims.

[0082] When an element or layer is described as "positioned above," "connected to," "linked," or "coupled," the element or layer may be positioned directly above another element or layer, directly connected to the other element or layer, directly linked to the other element or layer, or directly coupled to the other element or layer, or there may be an intervening element or layer. Conversely, when an element or layer is described as "positioned directly above," "directly connected to," "directly linked," or "directly coupled," there is no intervening element or layer. Other terms used to describe the relationships between elements (e.g., "between" vs. "directly between" and "adjacent" vs. "adjacent") are also relevant.“Directly adjacent”) should be interpreted similarly. As used herein, the term “and / or” includes any combination and all combinations relating to one or more of the associated listed points. For example, the term A and / or B includes only A, only B, or both A and B.

[0083] The spatially relative terms "inside," "outside," "back," "below," "low," "above," "high," etc., are used here to facilitate descriptions that describe relationships between one element or feature and another. Spatially relative terms can encompass not only the orientations shown in the drawings but also other orientations of a device in use or operation. For example, if the device in the illustration is reversed, an element described as "below" or "directly below" another element or feature will be oriented "above" the other element or feature. Therefore, the term "below" can encompass both top and bottom. The device may also be oriented in the opposite direction (rotated 90 degrees or in any other direction), and the spatially relative terms used here are interpreted accordingly.

[0084] The control circuit 14 is provided by a control system with at least one computer. The control system includes at least one processor (hardware processor), which is hardware. The hardware processor can be provided by (i), (ii), or (iii) as follows. (i) The hardware processor may be a hardware logic circuit. In this case, the computer is provided by a digital circuit with an array of programmed logic units (gate circuits). The digital circuit may include a memory that stores programs and / or data. The computer may be provided by an analog circuit. The computer may be provided by a combination of a digital circuit and an analog circuit. (ii) The hardware processor can be at least one processor core that executes a program stored in at least one memory. In this case, the computer is provided by at least one memory and at least one processor core. The processor core is referred to, for example, as a CPU. The memory is also referred to as a storage medium. Memory is a non-volatile and tangible storage medium that non-temporarily stores a program and / or data that can be read by the processor. (iii) The hardware processor may be a combination of (i) and (ii) mentioned above. (i) and (ii) may be located on different chips or on a common chip.

[0085] This means that the means and / or functions provided by the control circuit 14 can be provided by pure hardware, pure software or a combination thereof.

[0086] In the example shown here, the housing 31 and the outer shield 51 have openings in the X-direction for receiving the external connector 17. However, the present disclosure is not limited to such an example. These openings can be provided on any side that differs from the side facing the printed circuit board 20, i.e., the bottom or lower side facing the printed circuit board 20. For example, the openings can be provided on the side opposite the bottom side facing the printed circuit board 20, i.e., on the upper side.

Claims

[1] Optical transmission module, comprising: - a printed circuit board (20) having a conductor pattern (22) including a ground pattern (220); - an optical connector (30) comprising a housing (31) and a terminal part (32), wherein the housing (31) has a terminal portion (312) defining an opening (310a) into which an external connector (17) is fitted, wherein the terminal part (32) is housed in the housing (31), and wherein the external connector (17) is optically coupled to the terminal part (32); - a photoelectric conversion unit (40) housed in the housing (31) behind the terminal part (32) with respect to the opening (310a), the photoelectric conversion unit (40) including a photoelectric conversion element (42) optically coupled to the terminal part (32) and a circuit section (41, 43) electrically connected to the photoelectric conversion element (42) and the ground pattern (220); and - a shielding member (50) having an electromagnetic shielding property and arranged to surround the connecting part (32) and the photoelectric conversion unit (40), wherein - the shielding element (50) is electrically separated from the ground pattern (220), and - the circuit board (20) has an island (223) as the conductor pattern (22), wherein the island (223) is arranged at a position overlapping the terminal portion (312) in a plan view projected in a direction perpendicular to the circuit board (20) and is electrically separated from the ground pattern (220). [2] The optical transmission module according to claim 1, wherein the shielding member (50) comprises an outer shield (51) arranged to surround the housing (31). [3] The optical transmission module according to claim 2, wherein the island (223) is electrically connected to the outer shield (51). [4] The optical transmission module according to claim 2, wherein the island (223) is electrically separated from the shielding member (50) having the outer shield (51). [5] The optical transmission module according to any one of claims 2 to 4, wherein the shielding member (50) comprises an inner shield (52) housed in the casing (31) and disposed at least between the opening (310a) and the photoelectric conversion unit (40). [6] The optical transmission module of claim 5, wherein the inner shield (52) is electrically separated from the outer shield. [7] Optical transmission module according to one of claims 2 to 5, wherein in the shielding element (50) at least the outer shield (51) is electrically connected to a frame ground (18). [8] Electronic control unit with: - the optical transmission module (12) according to one of claims 1 to 7; and - a control circuit (14) connected via the optical transmission module (12) in order to be able to communicate optically with an external device (6).

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