Circuit board

Abstract

The utility model provides a circuit substrate. The circuit board (10) is provided with an electric power connector (20) for inputting electric power from a power supply, a control part (40) for controlling the display of the display part by using the electric power input from the electric power connector (20) as an operation power supply, and a noise filter element (33) which is electrically connected between the electric power connector (20) and the control part (40) and is used for removing noise. The circuit board (10) has a plurality of conductor layers (L1-L4) arranged in the Z direction. The plurality of conductor layers (L1-L4) have a ground pattern. The ground pattern is located in a range including a portion of the noise filter element (33) when viewed from the Z-direction of the circuit board (10), and is formed outside a ground extraction region (43) set at a corner of the circuit board (10). According to the circuit substrate provided by the utility model, the noise can be further reduced.

Description

Technical Field

[0001] This utility model relates to a circuit board. Background Technology

[0002] Patent document 1 discloses a technique for mounting a connector and a driver on a circuit board, wherein power input to the connector is supplied to the driver via printed wiring.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent No. 7287154 Utility Model Content

[0006] The problem to be solved by utility models

[0007] In the structure of the aforementioned Patent Document 1, it is necessary to reduce the noise generated by the circuit board.

[0008] This invention was made in view of the above circumstances, and its purpose is to provide a circuit board that can further reduce noise.

[0009] Methods for solving problems

[0010] To achieve the above objectives, the circuit board of this utility model includes: a connector for receiving power from a battery mounted in a vehicle; a control unit for controlling the display of a display device using the power received from the connector as an operating power source; and a noise filter element electrically connected between the connector and the control unit to reduce noise. The circuit board comprises:

[0011] Multiple conductor layers are arranged along the thickness direction of the circuit substrate.

[0012] One or more of the plurality of conductor layers have a grounding pattern.

[0013] The grounding pattern is located in the area containing at least a portion of the noise filter element when viewed from the thickness direction of the circuit board, and is formed outside the grounding extraction area set at the corner of the circuit board.

[0014] Utility Model Effect

[0015] According to this invention, noise can be further reduced. Attached Figure Description

[0016] Figure 1 This is a block diagram of an in-vehicle display device according to one embodiment of the present invention.

[0017] Figure 2 This is a schematic diagram illustrating the layer structure of a circuit board according to one embodiment of the present invention.

[0018] Figure 3 This is a schematic top view of the circuit board according to one embodiment of the present invention.

[0019] Figure 4 This is a top view showing a portion of the conductor layer (L4) of a circuit board according to one embodiment of the present invention.

[0020] Figure 5 This is a top view showing a portion of the conductor layer (L3) of a circuit board according to one embodiment of the present invention.

[0021] Figure 6 This is a top view showing a portion of the conductor layer (L2) of a circuit board according to one embodiment of the present invention.

[0022] Figure 7 This is a top view showing a portion of the conductor layer (L1) of a circuit board according to one embodiment of the present invention.

[0023] Figure 8 It is magnification Figure 4 A diagram composed of a portion of the image.

[0024] Symbol Explanation

[0025] 1: Vehicle-mounted display device;

[0026] 3: Display section;

[0027] 4: Control board unit;

[0028] 5: Power supply;

[0029] 10: Circuit board;

[0030] 10a, 10b: Mounting surfaces;

[0031] 20: Electrical connector;

[0032] 20i: Power supply terminal section;

[0033] 20o: Grounding terminal section;

[0034] 25: Signal connector;

[0035] 31, 32: Noise filters;

[0036] 31i, 32i: Input terminals;

[0037] 31o, 32o: Output terminals;

[0038] 33: Noise filter components;

[0039] 35: Package;

[0040] 38: Components;

[0041] 40: Control Department;

[0042] 40i: Power terminal;

[0043] 40o: Ground terminal;

[0044] 41a, 41b: Through holes;

[0045] 41c, 41d, 42c, 42d: Solder;

[0046] 41g, 42g: Low potential pattern;

[0047] 41h, 42h: High potential patterns;

[0048] 43: Grounding extraction area;

[0049] 44: Not within the installation range;

[0050] 45: Grounding pattern;

[0051] 46: Control signal pattern;

[0052] A1, A2: Wiring;

[0053] D1, D2: Distance;

[0054] L1~L4: Conductor layers;

[0055] GND: Ground;

[0056] If: Information signal. Detailed Implementation

[0057] The following description, with reference to the accompanying drawings, illustrates an embodiment of the in-vehicle display device with a circuit board.

[0058] like Figure 1 As shown, the vehicle display device 1 has a display unit 3 and a control board unit 4.

[0059] The display unit 3 displays vehicle information under the control of the control board unit 4. The display unit 3 may be, for example, a liquid crystal display panel, an organic EL (Electro-Luminescence) display, or an analog instrument.

[0060] In addition, the vehicle display device 1 can be a head-up display device, and the display unit 3 can emit the display light of the head-up display device.

[0061] The control board unit 4 receives power from the power source 5, which is the vehicle battery, and controls the display unit 3.

[0062] The control board unit 4 includes a circuit board 10, a power connector 20, a signal connector 25, a noise filter element 33, and a control unit 40.

[0063] Connectors 20 and 25 (i.e., power connector 20 and signal connector 25), noise filter element 33, and control unit 40 are mounted on the circuit board 10.

[0064] The power connector 20, noise filters 31 and 32, and control unit 40 are electrically connected by wiring A1 and A2 formed by the wiring pattern of the circuit board 10 to form a circuit.

[0065] The power connector 20 has: a power terminal portion 20i, which receives power from the power source 5; and a ground terminal portion 20o, which is connected to ground GND.

[0066] Noise filter 31 is provided on wiring A1 between power supply terminal section 20i and control section 40. Noise filter 32 is provided on wiring A2 between ground terminal section 20o and control section 40.

[0067] Noise filters 31 and 32 are common-mode filters or inductors. Noise filters 31 and 32 reduce the noise generated by wiring A1 and A2. Specifically, noise filters 31 and 32 prevent noise generated by the control unit 40 from passing through to the power supply 5 side. Noise generated from the circuit board 10 is reduced by noise filters 31 and 32.

[0068] Noise filters 31 and 32 can be known noise reduction units other than common-mode filters or inductors.

[0069] The signal connector 25 receives an information signal If from the vehicle ECU (Electronic Control Unit) and outputs the input information signal If to the control unit 40.

[0070] The control unit 40 is a microcontroller that receives power from the power supply 5 and controls the display unit 3 to display information based on the input information signal If. The control unit 40 has a power supply terminal 40i and a ground terminal 40o.

[0071] The power terminal 40i is electrically connected to the power terminal section 20i of the power connector 20 via wiring A1, and current passing through the noise filter 31 is input from the power terminal section 20i.

[0072] The grounding terminal 40o is electrically connected to the grounding terminal 20o of the power connector 20 via wiring A2, and outputs current through the noise filter 31 to the grounding terminal 20o.

[0073] The current from the power supply 5 flows in the following order: power supply terminal 20i → noise filter 31 → control unit 40 → noise filter 32 → ground terminal 20o → ground GND outside the circuit board 10.

[0074] The circuit board 10 is a printed circuit board, formed into a rectangular plate shape, or more precisely, a rectangular plate shape with rounded corners. In the following description, the length direction of the circuit board 10 is defined as the X direction, the width direction of the circuit board 10 is defined as the Y direction, and the thickness direction of the circuit board 10 is defined as the Z direction.

[0075] like Figure 2 As shown, the circuit board 10 has mounting surfaces 10a and 10b formed on both sides in the Z direction. A control unit 40 and a noise filter element 33 are mounted on mounting surface 10a. Connectors 20 and 25 are mounted on mounting surface 10b.

[0076] like Figure 3 As shown, the circuit board 10 has four sides S1 to S4 when viewed from the Z direction.

[0077] Edges S1 and S4 extend along the Y direction and are parallel to each other. Edges S2 and S3 extend along the X direction and are parallel to each other.

[0078] When viewed from the Z direction, the power connector 20 is located above or near edge S1, and near edge S2, that is, near the corner formed by edges S1 and S2. "Near edge S2" means that it is closer to edge S2 than the center position of edge S1 in the Y direction.

[0079] like Figure 7 As shown, the signal connector 25 is adjacent to the power connector 20 in the Y direction and is located further away from the edge S2 than the power connector 20.

[0080] like Figure 4 As shown, the noise filter element 33 is located at the periphery of the corner formed by edges S1 and S2 (across the outline of the grounding extraction area 43, which will be described later), and the control unit 40 is located closer to the center of the circuit board 10 than the noise filter element 33. The position of the noise filter element 33 will be described in detail later.

[0081] Next, the layer structure of the circuit board 10 will be described.

[0082] like Figure 2As shown, the circuit board 10 has multiple conductor layers L1 to L4 overlapping along the Z direction. The multiple conductor layers L1 to L4 are stacked in the Z direction in the order of conductor layer L1→L2→L3→L4. An insulating layer is formed between each conductor layer L1 to L4, and the wiring patterns of each conductor layer L1 to L4 are connected by vias or through holes.

[0083] like Figure 4 As shown, a control unit 40 and a noise filter element 33 are mounted on the mounting surface 10a (the side of conductor layer L4 opposite to conductor layer L3) of conductor layer L4. Figure 7 As shown, connectors 20 and 25 are mounted on the mounting surface 10b of conductor layer L1 (the side of conductor layer L1 opposite to conductor layer L2). Furthermore, connectors 20 and 25 can be mounted on the same surface as noise filter element 33.

[0084] like Figures 4-7 As shown, each conductor layer L1 to L4 has a grounding pattern 45. The grounding pattern 45 is used for electrical grounding and is formed to form a current loop (e.g., wiring A2) for the electrical circuit formed by the circuit board 10. The grounding pattern 45 is also called full-area grounding and is continuously formed in the area excluding signal wiring, solder sections, and through holes.

[0085] In each conductor layer L1 to L4, a grounding pattern 45 is formed in the area other than the grounding extraction area 43, but no grounding pattern 45 is formed in the grounding extraction area 43. In other words, in each conductor layer L1 to L4, the grounding pattern 45 is formed by opening up the grounding extraction area 43.

[0086] The grounding extraction region 43 is formed in overlapping areas along the Z direction. The grounding extraction region 43 is defined in the area that includes a portion of the noise filter 31 in the Z direction. The grounding extraction region 43 is formed as a rectangle at the corner formed by sides S1 and S2, specifically, as a rectangle that is longer in the Y direction.

[0087] On the circuit board 10, a non-mounted area 44 for unmounted components 38 is formed. The non-mounted area 44 is located at the corner formed by sides S1 and S2. The non-mounted area 44 is located within the grounding pull-out area 43 and is rectangular, more precisely, a rectangle that is longer in the Y direction.

[0088] like Figure 3As shown, multiple components 38, other than the noise filter element 33, are mounted in an area outside the non-mounting area 44 of the circuit board 10. Components 38 include diodes, capacitors, resistors, transistors, integrated circuits, etc. Wiring patterns (not shown) are formed at the locations where components 38 are mounted on the circuit board 10. Therefore, no wiring patterns are formed in the non-mounting area 44. Furthermore, the wiring patterns not formed in the non-mounting area 44 refer to wiring patterns directly connected to components 38. Conductive patterns, described later, connecting the noise filter element 33 to the connector 20, can be formed in the non-mounting area 44. In addition, these conductive patterns include so-called power lines, as well as wiring at the same potential (branch wiring or inspection solder joints, vias).

[0089] In addition to noise filter element 33, other noise filter elements that reduce the noise of the conductive pattern can be installed in the non-installation area 44. Common-mode filters or known noise reduction units such as inductors and ceramic capacitors can be used as other noise filter elements.

[0090] like Figure 4 As shown, conductor layer L4 has a ground pattern 45 including a low potential pattern 42g, high potential patterns 41h and 42h, a low potential pattern 41g and a control signal pattern 46 as conductive patterns.

[0091] The control signal pattern 46 is formed between the signal connector 25 and the control unit 40. The control signal pattern 46 is surrounded by a grounding pattern 45 with gaps.

[0092] The high-potential pattern 41h and the low-potential pattern 41g are formed within the grounding pull-out region 43 of the conductor layer L4 and are conductive to the power connector 20. The high-potential pattern 41h and the low-potential pattern 41g are located on the side of the grounding pull-out region 43 away from the edge S2 in the Y direction and in the center of the grounding pull-out region 43 in the X direction.

[0093] The low-potential pattern 41g is approximately L-shaped, and the high-potential pattern 41h is formed intermittently at the inner corner of the low-potential pattern 41g. On the side of the high-potential pattern 41h and the low-potential pattern 41g away from edge S2, through holes 41a and 41b, communicating with the power connector 20, are formed. Through hole 41a communicates with the power terminal portion 20i of the power connector 20 (see reference). Figure 1 The through hole 41b becomes conductive and connects to the grounding terminal 20o of the power connector 20 (see reference). Figure 1 It becomes in the on state.

[0094] like Figure 8As shown, solder 41c and 41d are formed on the high-potential pattern 41h and the low-potential pattern 41g, respectively. Viewed from the Z-direction, solder 41c and 41d are rectangular shapes, longer in the X-direction. Solder 41c of the high-potential pattern 41h is fixed with the input terminal 31i of the noise filter element 33 (described later) connected to the high-potential pattern 41h. Solder 41c is located in the Y-direction at a position closer to the edge S3 than the center position within the high-potential pattern 41h; in this example, it is located at the end of the high-potential pattern 41h on the edge S3 side in the Y-direction. Therefore, compared to a structure where the solder is formed at the center position within the high-potential pattern 41h in the Y-direction, the high-potential pattern 41h can be formed at a position away from the ground pattern 45. This ensures the distance between the high-potential pattern 41h and the ground pattern 45 in the Y-direction.

[0095] Solder 41c is located in the X direction within the high-potential pattern 41h, on the side of the high-potential pattern 42h. Figure 8 The left end.

[0096] The solder 41d of the low-potential pattern 41g is fixed in a state where the output terminal 32o of the noise filter element 33 (described later) is connected to the low-potential pattern 41g. The solder 41d is located in the Y direction closer to the high-potential pattern 41h than the central position within the low-potential pattern 41g. In this example, it is located at the end of the high-potential pattern 41h side within the low-potential pattern 41g in the Y direction.

[0097] Solder 41d is located in the X direction within the low potential pattern 41g, on the side of the low potential pattern 42g. Figure 8 The left end.

[0098] The high-potential pattern 41h and low-potential pattern 41g of conductor layer L4 are formed at least a distance D1 away from other conductive patterns (e.g., ground pattern 45, high-potential pattern 42h, low-potential pattern 42g, and control signal pattern 46). The distance D1 is set to suppress the transmission of noise and other interference between the high-potential pattern 41h and low-potential pattern 41g and the other conductive patterns.

[0099] The distance D1 is set to be greater than the shortest distance D2 between the control signal pattern 46 and the surrounding ground pattern 45.

[0100] The distance D1 is preferably set to 2mm or more. The upper limit of the distance D1 can be any value, but it can be set to, for example, 5mm to 15mm.

[0101] The high-potential pattern 42h and the low-potential pattern 42g are formed outside the grounding extraction area 43 of the conductor layer L4.

[0102] The high-potential pattern 42h is located at least a distance D1 away from the high-potential pattern 41h in the X direction. The high-potential pattern 42h is roughly rectangular in shape and longer in the X direction. The three sides of the high-potential pattern 42h, excluding the side on the grounding extraction area 43 side, are surrounded by a grounding pattern 45 containing the low-potential pattern 42g. The high-potential pattern 42h is connected to the control unit 40 via the wiring patterns of the other conductor layers L1 to L3 (not shown).

[0103] Solder 42c is formed on the high-potential pattern 42h. The solder 42c of the high-potential pattern 42h is fixed in a state in which the output terminal 31o of the noise filter element 33 (described later) is connected to the high-potential pattern 42h.

[0104] Solder 42c is located in the Y direction at a position closer to the edge S3 than the center position within the high-potential pattern 42h. In this example, it is located at the end of the high-potential pattern 42h on the edge S3 side within the Y direction. As a result, the high-potential pattern 42h can be formed at a position away from the ground pattern 45, ensuring the distance between the high-potential pattern 42h and the ground pattern 45 in the Y direction.

[0105] Solder 42c is located in the X direction within the high-potential pattern 42h, on the side of the high-potential pattern 41h. Figure 8 The right end of (the end of).

[0106] The low-potential pattern 42g is formed as part of the grounding pattern 45 and is located at least a distance D1 away from the low-potential pattern 41g in the X direction. The low-potential pattern 42g is connected to the control unit 40 via the grounding pattern 45.

[0107] The low-potential pattern 42g is located near the high-potential pattern 42h in the Y direction with a gap. The low-potential pattern 42g is located on the S2 side closer to the high-potential pattern 42h.

[0108] Solder 42d is formed on the low-potential pattern 42g. The solder 42d of the low-potential pattern 42g is fixed in a state in which the input terminal 32i of the noise filter element 33 (described later) is turned on with the low-potential pattern 42g.

[0109] Solder 42d is located in the Y direction closer to the high-potential pattern 42h than the center position within the low-potential pattern 42g. In this example, it is located at the end of the high-potential pattern 42h side within the low-potential pattern 42g in the Y direction. Solder 42d is located in the X direction within the low-potential pattern 42g, on the side of the low-potential pattern 41g. Figure 8 The right end of (the end of).

[0110] Solder 42c and 42d, when viewed from the Z direction, appear as rectangles that are longer in the X direction.

[0111] like Figure 8 As shown, the noise filter element 33 includes noise filters 31 and 32, a cubic package 35 housing the noise filters 31 and 32, input terminals 31i and 32i, and output terminals 31o and 32o. The input terminals 31i and 32i and the output terminals 31o and 32o are formed as legs extending from the bottom of the package 35. The input terminals 31i and 31o are located at both ends of the noise filter 31 and are arranged along the X direction. The input terminals 32i and 32o are located at both ends of the noise filter 32 and are arranged along the X direction.

[0112] Input terminal 31i is fixed to the high-potential pattern 41h in a conductive state via solder 41c. Input terminal 32i is fixed to the low-potential pattern 42g in a conductive state via solder 42d. Output terminal 31o is fixed to the high-potential pattern 42h in a conductive state via solder 42c. Output terminal 32o is fixed to the low-potential pattern 41g in a conductive state via solder 41d.

[0113] Next, the current path on the circuit board 10 will be explained.

[0114] The current from the power terminal 20i of the power connector 20 flows in the following order: high potential pattern 41h → input terminal 31i → noise filter 31 → output terminal 31o → high potential pattern 42h → wiring pattern (not shown) → control unit 40 → grounding pattern 45 (low potential pattern 42g) → input terminal 32i → noise filter 32 → output terminal 32o → low potential pattern 41g → grounding terminal 20o.

[0115] (Effect)

[0116] Based on the described embodiment, the following effects are achieved.

[0117] (1) A power connector 20, which is an example of a connector, receives power from a battery (power source 5) mounted in a vehicle; a control unit 40, which uses the power received from the power connector 20 as an operating power source to control the display of the display unit 3; and a noise filter element 33, which is electrically connected between the power connector 20 and the control unit 40 and is used to remove noise, are mounted on the circuit board 10. The circuit board 10 has a plurality of conductor layers L1 to L4 arranged along the thickness direction (Z direction) of the circuit board 10. Each of the plurality of conductor layers L1 to L4 has a grounding pattern 45. The grounding pattern 45 is formed in a region including a portion of the noise filter element 33 when viewed from the Z direction of the circuit board 10, and is formed outside the grounding extraction region 43 set at the corner of the circuit board 10.

[0118] According to this structure, the grounding pattern 45 is not formed in the grounding extraction region 43. Therefore, the conductors (grounding pattern 45) around the noise filter element 33 can be reduced, and the noise reduction effect achieved by the noise filter element 33 can be improved.

[0119] In particular, by setting the ground extraction region 43 at the corner of the circuit board 10, two of the four directions around the noise filter element 33 (in Figure 3 In the two directions (from the noise filter element 33 toward side S1 and from the noise filter element 33 toward side S2), there is no conductor, which can improve the noise reduction effect achieved by the noise filter element 33.

[0120] (2) The circuit board 10 is polygonal with rounded corners. The circuit board 10 has mounting surfaces 10a and 10b for mounting a plurality of components 38 that are different from the noise filter components 33. The power connector 20 is disposed on or near one of the first sides of the polygon, namely side S1, and near side S2, which is an example of the second side and side S3, which is an example of the third side. The plurality of components 38 are disposed outside the non-mounting range 44 between the power connector 20 and side S2 in the mounting surfaces 10a and 10b.

[0121] According to this structure, multiple elements 38 are not disposed in the non-mounting area 44. Accordingly, no wiring pattern as a conductor is formed in the non-mounting area 44, and unnecessary lengthening of the wiring can be suppressed. As a result, the noise reduction effect achieved by the noise filter element 33 can be improved.

[0122] Furthermore, this utility model is not limited to the above-described embodiments and drawings. Modifications (including the deletion of constituent elements) can be appropriately implemented without altering the spirit of this utility model. An example of a modification is described below.

[0123] (Modified Example)

[0124] In the above embodiment, a control unit 40 that controls the display unit 3 is used as the load mounted on the circuit board 10, but the object controlled by the control unit 40 can be anything other than the display unit 3. Alternatively, a load other than the control unit 40 can be mounted on the circuit board 10.

[0125] In the above embodiment, either noise filter 31 or 32 can be omitted; for example, noise filter 32 can be omitted. In this case, the input terminal 32i, output terminal 32o, and solder 41d and 42d of the noise filter element 33 are omitted, and they are continuously connected in a low-potential pattern 41g and 42g. In this modified example, since the grounding pattern 45 is not formed in the grounding extraction region 43 of the conductor layers L1 to L3 excluding the conductor layer L4, the effect described above (1) can be achieved.

[0126] In the above embodiment, the non-installation range 44 is set within the grounding extraction area 43, but it is not limited thereto. The grounding extraction area 43 and the non-installation range 44 can be set within the same range, and the grounding extraction area 43 can also be set within the non-installation range 44.

[0127] In the above embodiment, the grounding extraction region 43, viewed from the Z direction, is set within a range that includes a portion of the noise filter element 33, but is not limited thereto; it can be set within the entire range that includes the noise filter element 33.

[0128] In the above embodiment, any one of the multiple conductor layers L1 to L4 can be a layer without the grounding pattern 45.

[0129] In the above embodiments, the circuit board 10 has mounting surfaces 10a and 10b on both sides, but it may have a mounting surface on only one side.

[0130] In the above embodiments, the circuit board 10 is a polygonal shape with rounded corners, but it can be a polygon without rounded corners.

[0131] In the above embodiments, the circuit board 10 is in the shape of a quadrilateral plate, but it can be in other polygonal plate shapes.

[0132] The positions of the solders 41c, 41d, 42c, and 42d within the patterns 41h, 42h, 41g, and 42g in the above embodiments can be appropriately changed. For example, the solders 41c, 41d, 42c, and 42d can be positioned approximately at the center of the Y direction within each pattern 41h, 42h, 41g, and 42g.

[0133] In the above embodiments, the vehicle display device 1 may not be mounted on the vehicle.

Claims

1. A circuit board comprising: a connector for receiving power from a battery mounted in a vehicle; a control unit for controlling the display of a display device using the power received from the connector as an operating power source; and a noise filter element electrically connected between the connector and the control unit for reducing noise, characterized in that, The circuit board has multiple conductor layers arranged along the thickness direction of the circuit board. One or more of the plurality of conductor layers have a grounding pattern. The grounding pattern is located in the area containing at least a portion of the noise filter element when viewed from the thickness direction of the circuit board, and is formed outside the grounding extraction area set at the corner of the circuit board.

2. The circuit board according to claim 1, characterized in that, The circuit board is polygonal, or a polygonal shape with rounded corners. The circuit board has a mounting surface on which multiple components, different from the noise filter components, are mounted. The connector is located on or near the first side of the polygon, and is disposed near the second side of the second and third sides adjacent to the first side. The plurality of components are disposed outside the non-mounting range between the connector and the second side in the mounting surface.

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