Electronic substrate

Abstract

The electronic substrate comprises: a substrate having an upper surface grounding portion on the upper surface; at least one first connection plate formed on the upper surface and connected to the first signal line; at least one second connection plate formed on the upper surface and connected to the second signal line; at least one third connection plate arranged on a portion of the upper surface between the first connection plate and the second connection plate and connected to the upper surface grounding portion; and at least one fourth connection plate arranged on a portion of the upper surface on the opposite side of the first connection plate and the third connection plate and connected to the upper surface grounding portion.

Description

Technical Field

[0001] The present invention relates to electronic substrates. Background Art

[0002] Patent document 1 discloses a camera, which includes: a circuit board that converts light passing through a lens into an electrical signal; a connector that has an outer skin conductor and connects the circuit board to an external cable; a shielded conductor that is arranged outside the circuit board; and an insulating housing that accommodates the circuit board and the shielded conductor. The connector of the camera includes an inner connector mounted on the circuit board, an intermediate connector connected to the inner connector and to the shielded conductor, and an outer connector that connects the external cable to the intermediate connector, the shielded conductor is supported by the outer skin conductor of the intermediate connector, the support structure of the outer skin conductor supporting the shielded conductor has rotational symmetry with respect to the entire periphery of the outer skin conductor, the shielded conductor has a form that wraps around the circuit board starting from the boundary between the outer skin conductor of the intermediate connector and the shielded conductor, and the insulating housing is connected to the intermediate connector to be supported.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-75715 Summary of the invention

[0006] The present disclosure has been made in view of the above-mentioned conventional situation, and an object of the present disclosure is to provide an electronic substrate capable of suppressing the influence of noise.

[0007] The present disclosure provides an electronic substrate, which comprises: a substrate having an upper surface grounding portion on the upper surface; at least one first connection plate, which is formed on the upper surface and connected to the first signal line; at least one second connection plate, which is formed on the upper surface and connected to the second signal line; at least one third connection plate, which is arranged on a portion of the upper surface located between the at least one first connection plate and the at least one second connection plate and connected to the upper surface grounding portion; and at least one fourth connection plate, which is arranged on a portion of the upper surface on the opposite side of the at least one first connection plate and the at least one third connection plate and connected to the upper surface grounding portion.

[0008] According to the present disclosure, the influence of noise can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a diagram showing an example of a system configuration using a camera having the electronic substrate according to the first embodiment.

[0010] Figure 2 This is a plan view of an example of the electronic substrate according to the first embodiment.

[0011] Figure 3 Yes means Figure 2 Schematic diagram of section 3-3.

[0012] Figure 4A It is a plan view showing an example of a magnetic field loop generation state of an electronic substrate of a comparative example.

[0013] Figure 4B Yes means Figure 4A Schematic diagram of section 4B-4B.

[0014] Figure 5 This is a diagram for explaining the operation of showing an example of a magnetic field loop generation condition of the electronic substrate according to the first embodiment in a top view.

[0015] Figure 6 This is a diagram for explaining the operation of showing an example of the correlation between the magnetic field attenuation amount and the distance of each of two magnetic field loops. DETAILED DESCRIPTION

[0016] (The reason for obtaining the contents of Implementation Method 1)

[0017] Patent document 1 discloses a camera in which a shielded conductor has a form that wraps around a circuit substrate, and a support structure in which an outer skin conductor of an intermediate connector supports the shielded conductor has rotational symmetry with respect to the entire periphery of the outer skin conductor. As a result, the existing camera can stabilize the potential and effectively shield electromagnetic waves radiated from peripheral devices toward the circuit substrate, thereby achieving noise resistance. In addition, the existing camera can also effectively shield electromagnetic waves radiated from the circuit substrate toward the peripheral devices. However, in the structure of the circuit substrate of the existing camera, when a plurality of cables connected between different systems are connected to the circuit substrate in close proximity to each other, interference may occur between the cables, and the influence of noise cannot be suppressed.

[0018] Therefore, in the following first embodiment, an example of an electronic substrate that can suppress the influence of noise when a plurality of cables are used will be described.

[0019] Hereinafter, with appropriate reference to the drawings, an embodiment in which the structure and function of the camera substrate of the present disclosure are specifically disclosed will be described in detail. However, an overly detailed description may be omitted. For example, a detailed description of a well-known matter or a repeated description of a substantially identical structure may be omitted. This is to avoid the following description from becoming unnecessarily lengthy so that it is easy for a person skilled in the art to understand. In addition, the drawings and the following description are provided to enable a person skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0020] Figure 1 This is a diagram showing a configuration example of a system using the camera 11 having the electronic substrate 13 according to the first embodiment. Figure 2 1 is a top view of the electronic substrate 13. The camera 11 of the first embodiment is, for example, a vehicle-mounted camera. In addition, the electronic substrate 13 of the first embodiment is described as an electronic substrate provided in the camera 11, but it is self-evident that the application is not limited to the camera. In addition, the electronic substrate 13 may not be a substrate provided in the camera 11. For example, the electronic substrate 13 may be a substrate provided in a converter for separating images, sounds, control signals, etc.

[0021] The camera 11 is configured to have at least a lens (not shown) and an image sensor (not shown). The image sensor is, for example, a solid-state imaging element such as a CCD (Charged-Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor), which converts an optical image formed on an imaging surface into an electrical signal. The camera 11 is used, for example, as one of the sensing technologies for realizing automatic driving of a vehicle, and can be connected to the first control device 15 and to the second control device 17 for communication. The camera 11 sends an image signal including the captured image to the first control device 15. In addition, the camera 11 generates a control signal and sends the generated control signal to the second control device 17. In addition, for example, the image signal is a signal having a frequency of several MHz or more (high-speed signal), and the control signal is a signal having a frequency of several hundred kHz or less (low-speed signal), and the image signal is a signal having a higher speed than the control signal.

[0022] Furthermore, the transmission method of the image signal including the captured image of the camera 11 may be an analog video signal output method or a high-speed serial digital signal output method capable of stably outputting high-definition image information.

[0023] The first control device 15 receives a video signal of an image captured by the camera 11 and performs output control of the video signal. The first control device 15 is, for example, a car-mounted navigation system or the like.

[0024] The second control device 17 performs control based on the control signal received from the camera 11. The second control device 17 is, for example, a central control device of the vehicle.

[0025] The electronic substrate 13 of the first embodiment (see Figure 2 ) A vehicle-mounted camera 11 sends an image signal to a first control device 15 and sends a control signal to a second control device 17.

[0026] The electronic substrate 13 includes a substrate 19 , a first land 21 , a second land 23 , a third land 25 , and a fourth land 27 .

[0027] The electronic board 13 is integrally connected to the camera 11. The electronic board 13 receives an electrical signal converted by, for example, an image sensor on the side opposite to a camera lens (not shown) (ie, the back side of the camera 11).

[0028] The image sensor (not shown) is provided with a plurality of terminal portions (not shown) such as bumps on the side opposite to the imaging surface. The electronic substrate 13 is provided with a plurality of terminal portions for connecting the camera 11 and a plurality of cables (not shown). Furthermore, the plurality of terminal portions are connected to the plurality of cables respectively using solder or the like.

[0029] The electronic substrate 13 is a multi-layer substrate. In addition, the electronic substrate 13 is not limited to a multi-layer substrate, and may be any of a single-sided substrate, a double-sided substrate, a build-up substrate, a rigid substrate, and a flexible substrate.

[0030] In the electronic substrate 13, a plurality of first lands 21, second lands 23, third lands 25, and fourth lands 27 are formed on the upper surface 29 of the substrate 19. In the first embodiment, the surface on the side opposite to the lens (not shown) of the camera 11 on which the plurality of lands are formed is referred to as the upper surface 29 of the substrate 19.

[0031] A grounding portion 31 is formed on the upper surface 29 of the substrate 19. The plurality of connection pads formed on the upper surface 29 of the substrate 19 are connected to terminal portions of an image sensor (not shown) or the like through through holes, vias, or printed circuit patterns. In addition, when the substrate 19 is a rigid substrate, for example, a glass epoxy substrate or the like can be used, but the present invention is not limited thereto.

[0032] In addition, the substrate 19 is formed in a rectangular shape, but is not limited to this. For example, the substrate 19 may be formed in a rectangular shape with four corners rounded.

[0033] The grounding portion 31 is formed of a copper foil or the like which covers the upper surface 29 and has a substantially similar shape to that of the substrate 19. The grounding portion 31 may be provided in a linear shape along the shapes of the plurality of lands, for example.

[0034] The plurality of first connection pads 21 are respectively formed on the upper surface 29 of the substrate 19. The plurality of first connection pads 21 are arranged in a direction along the long side of the substrate 19 and are formed to be insulated from the ground portion 31. The first connection pads 21 are formed, for example, in a rectangular shape with the long side along the short side of the substrate 19. In addition, the shape of each of the plurality of first connection pads 21 is not limited thereto. Furthermore, the number of the plurality of first connection pads 21 is not limited to Figure 2 The number shown may be 1 or more than 3.

[0035] The second connection pad 23 is formed on the upper surface 29 of the substrate 19. The second connection pad 23 is arranged along the long side of the substrate 19 with the first connection pad 21 on the left side of the plurality of first connection pads 21, and is formed to be insulated from the ground portion 31. The second connection pad 23 is formed in a rectangular shape with the long side along the short side of the substrate 19. In addition, the shape of the second connection pad 23 is not limited to this. Furthermore, the number of the second connection pads 23 is not limited to Figure 2 The number shown may also be multiple.

[0036] The third land 25 is formed on the upper surface 29 of the substrate 19. The third land 25 is arranged between the plurality of first lands 21 and the second land 23, and is formed to be connected to the ground portion 31. The third land 25 of the first embodiment is formed into a substantially cross shape by cutting off the four corners formed in the rectangular shape in an L-shape, and the midpoints of the four sides are connected to the ground portion 31. Thus, when the third land 25 is joined to the wiring conductor using solder or the like, the diffusion of heat caused by heat conduction can be suppressed, thereby facilitating soldering.

[0037] The fourth land 27 is formed on the upper surface 29 of the substrate 19. The fourth land 27 is arranged on the side opposite to the third land 25 across the plurality of first lands 21, and is formed to be connected to the ground portion 31. The fourth land 27 is formed into a substantially cross shape with the midpoints of the four sides connected to the ground portion 31 by cutting off the four corners of the rectangular shape in an L-shape, similarly to the third land 25. Thus, when the fourth land 27 is joined to the wiring conductor using solder or the like, it is possible to suppress the diffusion of heat caused by heat conduction, thereby facilitating soldering.

[0038] In the electronic substrate 13, a plurality of first connection pads 21, second connection pads 23, third connection pads 25 and fourth connection pads 27 are arranged in a row on the upper surface 29 of the substrate 19. Figure 2 One end side of the substrate 19 shown ( Figure 2 left end side) toward the other end side ( Figure 2The second connection pad 23, the third connection pad 25, the plurality of first connection pads 21, and the fourth connection pad 27 are arranged in the order of the second connection pad 23, the third connection pad 25, the plurality of first connection pads 21, and the fourth connection pad 27. The plurality of first connection pads 21 are arranged adjacent to each other for differential purposes. Therefore, in the electronic substrate 13, the five connection pads consisting of the second connection pad 23, the third connection pad 25, the plurality of first connection pads 21, and the fourth connection pad 27 are arranged along the long side of the substrate 19. In addition, the number and area of ​​the connection pads are not limited to Figure 2 Example shown.

[0039] In addition, for the electronic substrate 13 of embodiment 1, in order to obtain the effect of reducing the influence of noise, the following structure is preferred: the number of the third connection pads 25 and the fourth connection pads 27 is the same, and the third connection pads 25 and the fourth connection pads 27 are configured to be symmetrical to each other, but it is not limited to this. For example, the number and area of ​​the third connection pads 25 and the fourth connection pads 27 may be different. Specifically, the area of ​​the third connection pad 25 may be smaller than the area of ​​the fourth connection pad 27, or larger than the area of ​​the fourth connection pad 27. In addition, the third connection pad 25 and the fourth connection pad 27 may be multiple. Specifically, two third connection pads 25 may be formed, and one fourth connection pad 27 may be formed. In this case, the third connection pad 25 and the fourth connection pad 27 are in contact with the line passing through one third connection pad 25 and one fourth connection pad 27 (i.e. Figure 2 In other words, when a plurality of third connection pads 25 and fourth connection pads 27 are provided, the plurality of third connection pads 25 and fourth connection pads 27 are arranged in a direction along the short side of the substrate 19.

[0040] In the electronic substrate 13, the first land 21 is arranged in an area that is 80% of the distance between the centers of the third land 25 and the fourth land 27 (see Figure 6 ). In addition, the electronic substrate 13 is formed so that the area of ​​the third connection land 25 is smaller than the area of ​​the fourth connection land 27 .

[0041] Figure 3 Yes means Figure 2 3 - 3 is a schematic diagram of a cross section of an example of the electronic substrate 13 shown.

[0042] The first signal lines 33 are connected to the plurality of first connection pads 21 of the electronic substrate 13, respectively. The plurality of first connection pads 21 and the plurality of first signal lines 33 are connected, for example, by solder or the like. The second signal line 35 is connected to the second connection pad 23. The second connection pad 23 and the second signal line 35 are connected, for example, by solder or the like. The third connection pad 25 and the fourth connection pad 27 are connected to the same shield conductor 37. The shield conductor 37 is composed of a box-shaped conductor with at least a lower portion opened.

[0043] The shield conductor 37 of the first embodiment is formed in a cylindrical shape so as to cover the plurality of first lands 21 and the plurality of first signal lines 33 . Figure 2 The shield conductor 37 at the cross-sectional position 3-3 in FIG. 1 is connected between the third land 25 and the fourth land 27 by solder or the like. That is, the shield conductor 37 is connected to the ground portion 31 via the third land 25 and the fourth land 27, and becomes equal to the potential of the ground portion 31. Thus, the first land 21 and the first signal line 33 are electromagnetically shielded by the shield conductor 37. The connection portions of the third land 25 and the fourth land 27 and the shield conductor 37, which are connected by solder or the like, become the contact points 39 described later. In addition, usually, the entire periphery of the shield conductor 37 is not connected to the ground portion 31, that is, the shield conductor 37 and the ground portion 31 are connected at multiple locations, and multiple gaps are generated at the locations where they are not connected.

[0044] In the electronic substrate 13, for the plurality of first connection pads 21 and second connection pads 23, gaps 41 are provided between their respective peripheries and the grounding portion 31 to avoid connection with the grounding portion 31, the third connection pad 25, and the fourth connection pad 27. In addition to the insulating gaps 43 for avoiding the connection between adjacent connection pads or the grounding portion, the plurality of gaps 41 also include gaps 45 of a predetermined distance. The insulating gaps 43 are usually formed to be about 0.1 mm. The gaps 45 for making it easy to generate the magnetic field loop described later are set to a predetermined distance, for example, about 0.2 mm to 0.4 mm. In addition, it is preferred that the plurality of gaps 41 are respectively set to 0.3 mm to 0.5 mm, but it is not limited thereto. For example, when the electronic substrate 13 of the first embodiment is large enough, the plurality of gaps 41 can be respectively set to be larger than 0.5 mm.

[0045] In addition, the plurality of gaps 45 may be uneven at each side of the plurality of first lands 21, second lands 23, third lands 25, and fourth lands 27. As described above, the plurality of gaps 45 only need to be set to 0.3 mm to 0.5 mm for each of the plurality of gaps 41 including the insulating gap 43. That is, the manufacturing worker of the substrate 19 of the first embodiment only needs to arrange (connect) each land so that each of the plurality of gaps 41 including the gaps 45 and the insulating gap 43 is 0.3 mm to 0.5 mm, which can make the arrangement (connection) work of each land more efficient.

[0046] The substrate 19 of the electronic substrate 13 has a grounding portion 31 covering the lower surface 47 on the side opposite to the upper surface 29. The grounding portion 31 is provided with a plurality of grounding portion removal portions 49 corresponding to the positions of the plurality of first connection lands 21 and the positions of the second connection lands 23. Thus, the electronic substrate 13 can avoid connection (contact) between the plurality of first connection lands 21 and the second connection lands 23 and the grounding portion 31 by the plurality of grounding portion removal portions 49.

[0047] Figure 4A 1 is a top view showing an example of a magnetic field loop generated by an electronic substrate 51 of a comparative example. Figure 4B Yes means Figure 4A Schematic diagram of section 4B-4B.

[0048] exist Figure 4A In the electronic substrate 51 of the comparative example shown, the image transmission pin (not shown) of the camera 11 that outputs a high-speed signal is connected to the plurality of first connection pads 21, for example, through a conductive hole that penetrates the electronic substrate 51. In addition, in the electronic substrate 51, a control signal pin (not shown) that sends a low-speed signal is connected to the second connection pad 23. The plurality of first connection pads 21 of the comparative example are respectively connected to the plurality of first signal lines 33 on the upper surface 29 of the substrate 19. In addition, Figure 5 The second land 23 of the comparative example shown is connected to the second signal line 35 on the upper surface 29 of the substrate 19 .

[0049] In the electronic substrate 51 of the comparative example, noise of the image signal in the high-speed signal generated from the plurality of first signal lines 33 is transmitted to the second signal line 35. As a result, the second signal line 35 acts as an antenna, generating radiation noise. The second signal line 35 acts as an antenna when receiving external radio waves, and the generated radiation noise is transmitted to the image signals of each of the plurality of first signal lines 33, causing image disturbance.

[0050] In addition, in the electronic substrate 51 of the comparative example, the connection target system of the plurality of first signal lines 33 (image transmission cables) connected to the plurality of first connection pads 21 is different from the connection target system of the second signal line 35 (vehicle control cable) connected to the second connection pad 23, so the same shielding conductor 37 cannot be used to cover the plurality of first connection pads 21 and second connection pads 23 with different connection targets. Furthermore, generally, image signals are signals that communicate at high speed, and there are concerns about the influence of noise. Therefore, as described above, a shielding conductor that shields noise needs to be provided. In addition, control signals are signals that communicate at low speed, and generally the influence of noise is small, so shielding is not necessarily required (i.e., not necessary).

[0051] Therefore, as in the electronic substrate 51 of the comparative example, when a plurality of connection pads on the same substrate are connected to different systems and one of them contains a high-speed communication image signal, noise radiation from the image signal or disturbance of the image signal caused by external radio waves may occur.

[0052] However, in the electronic substrate 51 of the comparative example, only one contact 39 is provided to conduct (connect) the shield conductor 37 and the third land 25. At this time, the common mode current is generated around the contact 39 connecting the ground portion 31 and the shield conductor 37. Figure 4A The one magnetic field loop 55 shown. Therefore, in the electronic substrate 51 of the comparative example, since the noise caused by the magnetic field loop 55 is transmitted to the image transmission cable (plurality of first signal lines 33), it is difficult to suppress the influence of the noise.

[0053] Figure 5 This is an operation explanatory diagram showing an example of a state in which a magnetic field loop 55 of the electronic substrate 13 according to the first embodiment is generated in a plan view.

[0054] In the electronic substrate 13 of the first embodiment, a third connection pad 25 connected to the ground portion 31 is arranged between the plurality of first connection pads 21 and the second connection pads 23 , and a fourth connection pad 27 connected to the ground portion 31 is arranged on the side opposite to the third connection pad 25 across the first connection pad 21 . Figure 5 The third connection pad 25 and the fourth connection pad 27 shown are arranged symmetrically with the first connection pad 21 interposed therebetween. That is, in the electronic substrate 13 of the first embodiment, the ground portion 31 and the contact point 39 of the shield conductor 37 are arranged symmetrically with the first connection pad 21 interposed therebetween. Thus, a magnetic field loop 55 rotating in the same direction is generated in the electronic substrate 13 with each of the two contact points 39 as the center, and the two contact points 39 connect the third connection pad 25 arranged on the left side of the plurality of first connection pads 21 and the fourth connection pad 27 arranged on the right side to the shield conductor 37, respectively.

[0055] In addition, the configuration of the third connection plate 25 and the fourth connection plate 27 is not limited to the above-mentioned bilateral symmetry. The third connection plate 25 and the fourth connection plate 27 can be configured so that the magnetic field loops generated by each other are offset. For example, the third connection plate 25 and the fourth connection plate 27 can be relative to each other. Figure 2 The middle points of the plurality of first lands 21 are arranged line-symmetrically about a line orthogonal to the 3-3 section line. The third lands 25 and the fourth lands 27 may also be arranged line-symmetrically about the 3-3 section line.

[0056] The two magnetic field loops 55 become magnetic fields in opposite directions to each other in the portion where the plurality of first connection pads 21 are arranged (i.e., inside the shield conductor 37) and cancel each other out. That is, in the electronic substrate 13, by generating two magnetic field loops 55, the magnetic field loops 55 generated by the common mode current in the portion where the plurality of first connection pads 21 are arranged (i.e., inside the shield conductor 37) can be canceled out.

[0057] Thus, the electronic substrate 13 of the first embodiment can reduce the noise generated from the second signal line 35 to the plurality of first signal lines 33. In addition, the electronic substrate 13 can suppress the influence of noise even when the circuit substrate cannot be covered with the same shield conductor 37 or when only a part of the wiring can be covered incompletely with the shield conductor 37. As a result, the electronic substrate 13 can improve the low noise / noise resistance performance.

[0058] In addition, in the electronic substrate 13 of embodiment 1, even if the connection targets of multiple connection pads on the same substrate are different in system and one of them contains a high-speed communication image signal, noise radiation from the image signal can be suppressed and disturbance of the image signal caused by external radio waves can be suppressed.

[0059] Figure 6 It is an operation explanatory diagram showing an example of the correlation between the magnetic field attenuation amount and the distance of each of the two magnetic field loops 55 .

[0060] The electronic substrate 13 is arranged such that the plurality of first connection pads 21 are located in an area that is 80% of the distance D between the centers of the third connection pad 25 and the fourth connection pad 27 (i.e. Figure 6 The position of the midpoint (0.8D) / 2 of the area 0.8D coincides with the position of the midpoint D / 2 of the center-to-center distance D.

[0061] Here, when a current flows through a wiring of a finite length, the magnetic field intensity H at a point P separated from the wiring by a distance R becomes H=(cosθ1+cosθ2) / 4πR, and is inversely proportional to the distance R. Therefore, the magnetic field intensity H is maximum at the midpoint D / 2 of each first connection pad 21, and decreases as it moves away from the center position toward the third connection pad 25 or the fourth connection pad 27.

[0062] Two magnetic field loops 55 are generated with the third connection plate 25 and the fourth connection plate 27 as the center (see Figure 5 ) have the same magnetic field strength at the center of each first connection plate 21, and the magnetic fields are in opposite directions and cancel each other out. Figure 6 As shown, with respect to the magnetic field strength H of each of the third land 25 and the fourth land 27, at the midpoint D / 2 of the center-to-center distance D, the magnetic field loops 55 of both have opposite directions and equal strengths.

[0063] By arranging the electronic substrate 13 so that the plurality of first lands 21 are respectively located in the region of 80% of the distance D between the centers of the third land 25 and the fourth land 27 (i.e. Figure 6 In other words, the electronic substrate 13 is configured as follows: the plurality of first connection pads 21 are respectively arranged at positions Figure 6 Within the region 0.8D shown, the effectiveness of the noise reduction effect of each of the two magnetic field loops 55 is ensured.

[0064] As described above, the electronic substrate 13 of embodiment 1 comprises: a substrate 19 having a grounding portion 31; a first connection pad 21 formed on the upper surface 29 of the substrate 19 and connected to the first signal line 33; a second connection pad 23 formed on the upper surface 29 and connected to the second signal line 35; a third connection pad 25 arranged on a portion of the upper surface 29 located between the first connection pad 21 and the second connection pad 23 and connected to the grounding portion 31; and a fourth connection pad 27 arranged on a portion of the upper surface 29 on the opposite side of the third connection pad 25 across the first connection pad 21 and connected to the grounding portion 31.

[0065] Thus, in the electronic substrate 13 of the first embodiment, the substrate 19 has a grounding portion 31. The grounding portion 31 is provided, for example, to cover the upper surface 29 of the substrate 19. On the upper surface 29 of the substrate 19, four types of connection pads are arranged in a row. The four types of connection pads are arranged in the order of the second connection pad 23, the third connection pad 25, the first connection pad 21, and the fourth connection pad 27 from one end side of the substrate 19 toward the other end side. In the first embodiment, two first connection pads 21 are provided. Therefore, five connection pads are arranged.

[0066] Among them, a first signal line 33 such as a video transmission cable is connected to the first connection land 21. A second signal line 35 such as a vehicle control cable is connected to the second connection land 23.

[0067] The first connection pad 21 and the second connection pad 23 are insulated from the grounding portion 31. The insulation between the grounding portion 31 and the connection pads can be achieved by cutting off the grounding portion 31 covering the upper surface 29 of the substrate 19 at the position of each connection pad to separate it from the outer periphery of the connection pad. In this case, the gap 41 formed between the periphery of the connection pad and the grounding portion 31 includes an insulating gap 43.

[0068] On the other hand, the third land 25 and the fourth land 27 arranged on both sides via the two first signal lines 33 are connected to the ground portion 31. The connection between the land and the ground portion 31 can be achieved by leaving a portion of the outer periphery of each land connected to the ground portion 31.

[0069] Therefore, in the electronic substrate 13 of embodiment 1, even if the connection targets of the plurality of connection pads on the same substrate are different in system and one of them contains a high-speed communication image signal, noise radiation from the image signal can be suppressed and disturbance of the image signal caused by external radio waves can be suppressed.

[0070] In the electronic substrate 13 of the first embodiment, the first land is disposed within a region that is 80% of the center-to-center distance between the third land and the fourth land. Thus, the electronic substrate 13 of the first embodiment is configured to ensure the effectiveness of the noise reduction effect of each of the two magnetic field loops 55.

[0071] In addition, in the electronic substrate 13 of the first embodiment, the first connection land 21 and the second connection land 23 are formed to have a gap 41 between their respective peripheries and the grounding portion 31. The gap 41 includes an insulating gap 43 and a void 45. The insulating gap 43 is provided to prevent a short circuit between the connection land and the grounding portion 31, and is generally formed to be about 0.1 mm. The void 45 is different from the insulating gap 43, and is provided to facilitate the generation of a magnetic field loop 55, and is set to be about 0.2 mm to 0.4 mm. That is, in the electronic substrate 13, a gap 41 of about 0.3 mm to 0.5 mm is set between the periphery of the first connection land 21 and the periphery of the second connection land 23, respectively, and the grounding portion 31. As a result, in the electronic substrate 13, the magnetic field loop 55 is easily generated (in other words, the magnetic field loop 55 is not easily combined with the grounding portion 31), and the noise reduction effect is easily obtained. In addition, it is needless to say that the insulating gap 43 and the void 45 are not limited to the above-mentioned values.

[0072] In addition, in the electronic substrate 13 of the first embodiment, the substrate 19 has a grounding portion 31 covering the lower surface 47 on the lower surface 47 opposite to the upper surface 29. The portion of the grounding portion 31 on the lower surface 47 corresponding to the first connection land 21 and the second connection land 23 is removed. Thus, in the electronic substrate 13, the magnetic field loop 55 is not easily combined with the grounding portion 31 even on the lower surface 47 of the substrate 19. As a result, the magnetic field loop 55 is easily generated, and the noise reduction effect is more easily obtained.

[0073] In addition, the substrate 19 is formed with a relatively thin thickness. In the case of the substrate 19 with a relatively thin thickness, for example, the second signal line 35 connected to the second connection pad 23 and the grounding portion 31 provided on the lower surface 47 directly below the second signal line 35 are combined to cause a diffusion phenomenon of noise. In the electronic substrate 13, the grounding portion 31 on the lower surface 47 is removed at a position corresponding to the first connection pad 21 and the second connection pad 23, thereby suppressing the diffusion of noise caused by the grounding portion 31 provided on the lower surface 47.

[0074] In addition, in the electronic substrate 13 of the first embodiment, a gap 41 is provided between the outer periphery of the first connection pad 21 and the outer periphery of the second connection pad 23 and the grounding portion 31. The gap 41 includes an insulating gap 43 for avoiding bonding, and a gap 45 of a predetermined distance. The insulating gap 43 is usually formed to be about 0.1 mm. The gap 45 for making it easy to generate the magnetic field loop 55 is a predetermined distance, for example, set to about 0.2 mm to 0.4 mm. The gap 45 only needs to ensure that it is the predetermined distance, and does not need to be formed particularly evenly. As a result, the electronic substrate 13 can relax the processing accuracy when forming the connection pads.

[0075] In the electronic substrate 13 , at least one of the first land 21 , the second land 23 , the third land 25 , and the fourth land 27 is present in plural numbers.

[0076] In addition, in the electronic substrate 13 of the first embodiment, any one of the first connection pad 21, the second connection pad 23, the third connection pad 25, and the fourth connection pad 27 is provided in plural. For example, for the first connection pad 21 to which the image transmission cable, i.e., the first signal line 33, is connected, by providing the first connection pad 21, for example, in two, balanced transmission using two image signals with a phase difference of 180° can be performed. Thus, the electronic substrate 13 can reduce radiation and is not easily affected by external noise by performing balanced transmission.

[0077] In the electronic substrate 13 , the third lands 25 and the fourth lands 27 arranged in plurality are arranged side by side in a direction intersecting a line passing through one third land 25 and one fourth land 27 .

[0078] In addition, the electronic substrate 13 of the first embodiment is provided with a plurality of third connection pads 25 and a plurality of fourth connection pads 27. In this case, the plurality of third connection pads 25 and the plurality of fourth connection pads 27 are arranged in a direction intersecting with a line passing through one third connection pad 25 and one fourth connection pad 27. That is, the plurality of third connection pads 25 and the plurality of fourth connection pads 27 are arranged so as not to be arranged in a straight line. For example, in the case where two third connection pads 25 and two fourth connection pads 27 are arranged, the third connection pads 25 are arranged at a pair of adjacent corners of a quadrilateral, respectively, and the fourth connection pads 27 are arranged at another pair of adjacent corners, respectively. Thus, in the electronic substrate 13, compared with the case where there are one third connection pad 25 and one fourth connection pad 27, the effect of eliminating the magnetic field loop can be increased, and the noise reduction effect can be further obtained.

[0079] In the electronic substrate 13 of the first embodiment, the third land 25 is disposed between the first land 21 and the second land 23. Thus, when the third land 25 is formed with an area smaller than that of the fourth land 27, it is not easy to interfere with other components or lands (e.g., the first land 21 or the second land 23).

[0080] Various embodiments have been described above with reference to the accompanying drawings, but it goes without saying that the present disclosure is not limited to the above examples. It is obvious that those skilled in the art can think of various changes, modifications, replacements, additions, deletions, and equivalents within the scope of the claims, and it can be understood that the above examples also belong to the protection scope of the present disclosure. In addition, the constituent elements of the various embodiments described above can be arbitrarily combined within the scope of the subject matter of the invention.

[0081] Industrial Applicability

[0082] The present disclosure is useful as an electronic substrate that suppresses the influence of noise.

[0083] Description of Reference Numerals

[0084] 13. Electronic substrate; 19. Substrate; 21. 1st connection pad; 23. 2nd connection pad; 25. 3rd connection pad; 27. 4th connection pad; 29. ​​Upper surface; 31. Grounding portion; 33. 1st signal line; 35. 2nd signal line; 41. Gap; 43. Insulating gap; 45. Space; 47. Lower surface; 49. Grounding portion removed; D. Center-to-center distance.

Claims

1. An electronic substrate, wherein: The electronic substrate comprises: a substrate having an upper surface grounding portion on an upper surface; at least one first connection pad formed on the upper surface and connected to the first signal line; at least one second connection pad formed on the upper surface and connected to the second signal line; at least one third connection pad, which is disposed on a portion of the upper surface between the at least one first connection pad and the at least one second connection pad and is connected to the upper surface ground portion; at least one fourth connection pad, which is disposed on a portion of the upper surface opposite to the at least one third connection pad across the at least one first connection pad and connected to the upper surface ground portion; and a shield conductor connected to the upper surface ground portion via the at least one third connection pad and the at least one fourth connection pad, and covering the at least one first connection pad and the first signal line to electromagnetically shield the at least one first connection pad and the first signal line, The shield conductor is connected to the at least one third connection pad at the first contact point. The shield conductor is connected to the at least one fourth connection pad at the second connection point. The at least one third connection disk and the at least one fourth connection disk are configured so that a first magnetic field loop generated around the first contact point and a second magnetic field loop generated around the second contact point and rotating in the same direction as the first magnetic field loop cancel each other out.

2. The electronic substrate according to claim 1, wherein: The at least one third land and the at least one fourth land are disposed bilaterally symmetrically with the at least one first land interposed therebetween.

3. The electronic substrate according to claim 1, wherein: The shield conductor is formed in a cylindrical shape so as to cover the at least one first connection land and a part of the first signal line.

4. The electronic substrate according to claim 1, wherein: The at least one first land is disposed in a region that is 80% of a distance between the centers of the at least one third land and the at least one fourth land.

5. The electronic substrate according to any one of claims 1 to 4, wherein The gap provided between the outer periphery of each of the at least one first connection land and the at least one second connection land and the upper surface ground portion includes a space of a predetermined distance.

6. The electronic substrate according to any one of claims 1 to 4, wherein The substrate has a lower surface grounding portion covering the lower surface on a lower surface opposite to the upper surface. The lower surface ground portion does not exist at a position corresponding to the at least one first connection land and the at least one second connection land.

7. The electronic substrate according to claim 5, wherein: The gaps are not equal.

8. The electronic substrate according to any one of claims 1 to 4, wherein At least one of the at least one first connection pad, the at least one second connection pad, the at least one third connection pad, and the at least one fourth connection pad is plural.

9. The electronic substrate according to claim 8, wherein: The plurality of third lands or the plurality of fourth lands are arranged side by side in a direction intersecting a line passing through one of the plurality of third lands and one of the plurality of fourth lands.

10. The electronic substrate according to any one of claims 1 to 4, wherein The area of ​​the at least one third connection land is smaller than the area of ​​the at least one fourth connection land.

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