Circuit board and manufacturing method thereof

Abstract

The invention provides a circuit board and a manufacturing method thereof, the circuit board is provided with a first area, a connection area and a second area which are mutually connected, the first area and the second area are oppositely arranged, the circuit board comprises a capacitor layer and a coil layer, and the capacitor layer comprises a first capacitor sheet located in the first area and a second capacitor sheet located in the second area; the coil layer comprises a first coil located in the first area and a second coil located in the second area, the first end of the first coil is electrically connected with the third end of the second coil through a conductive circuit, the second end of the first coil and the fourth end of the second coil extend to the connecting area and form two output ends, the first coil is used for generating first magnetic force, and the second coil is used for generating second magnetic force. The second coil is used for generating second magnetic force opposite to the first magnetic force in direction, so that the distance between the first area and the second area is variable, and the capacitance between the first capacitor piece and the second capacitor piece is changed. The circuit board provided by the invention is internally provided with the fine tuning capacitor structure, and the fine tuning capacitor structure is small in occupied space, simple in structure and low in cost.

Description

Technical Field

[0001] The present application relates to the technical field of printed circuit boards, and in particular to a circuit board and a method for manufacturing the same. Background Art

[0002] The main characteristic of capacitors is to block direct current and pass alternating current. They are often used for inter-electrode coupling, filtering, decoupling, bypassing and signal tuning. Among them, adjustable capacitors are also called fine-tuning capacitors (or micro-variable capacitors, variable capacitors, etc.). They are capacitors whose capacitance can be continuously adjusted and changed within a certain range. Fine-tuning capacitors are generally widely used as tuning, compensation capacitors / correction capacitors in various tuning and oscillation circuits of radios (such as radios, televisions) or NFC / RFID card readers and other equipment.

[0003] However, existing fine-tuning capacitors have the problems of occupying a large space, requiring soldering, requiring a predetermined position to be reserved in the PCB, and being costly. Summary of the invention

[0004] In view of this, in order to solve at least one of the above problems, it is necessary for the present application to provide a circuit board containing a fine-tuning capacitor.

[0005] In addition, the present application also needs to provide a method for manufacturing the above-mentioned circuit board.

[0006] An embodiment of the present application provides a circuit board, the circuit board having a first area, a connection area, and a second area connected to each other, the first area and the second area are located at two ends of the connection area and are arranged opposite to each other, the circuit board comprises a capacitor layer and a coil layer stacked with the capacitor layer, the capacitor layer comprises a first capacitor sheet located in the first area and a second capacitor sheet located in the second area, the first capacitor sheet has a first conductive portion extending to the connection area and used for electrical lead-out, and the second capacitor sheet has a second conductive portion extending to the connection area and used for electrical lead-out; the coil layer comprises a first coil located in the first area and a second coil located in the second area, the first coil comprises a first end and a second end, the second coil comprises a third end and a fourth end, the first end is electrically connected to the third end through a conductive line, the second end and the fourth end extend to the connection area and form two output ends, wherein the first coil is used to generate a first magnetic force, the second coil is used to generate a second magnetic force, the first magnetic force is opposite to the direction of the second magnetic force, so that the distance between the first area and the second area is variable, so as to change the capacitance between the first capacitor sheet and the second capacitor sheet.

[0007] In some possible embodiments, a first bending line is provided at a connection between the first zone and the connecting zone, a second bending line is provided at a connection between the second zone and the connecting zone, the first zone can be bent around the first bending line toward or away from the connecting zone, and the second zone can be bent around the second bending line toward or away from the connecting zone.

[0008] In some possible embodiments, the first region, the connection region, and the second region form a U-shape, and the capacitor layer is located at the innermost layer of the U-shape.

[0009] In some possible embodiments, a first elastic sheet is disposed on the surface of the first bending line, and a second elastic sheet is disposed on the surface of the second bending line.

[0010] In some possible embodiments, the circuit board further includes a conducting layer located between the capacitor layer and the coil layer, and the conductive circuit is located in the conducting layer.

[0011] In some possible embodiments, the conductive circuit includes a third coil located in the first area, a fourth coil located in the second area, and a connecting portion located in the connecting area, two ends of the connecting portion are respectively connected to one end of the third coil and one end of the fourth coil, an end of the third coil away from the connecting portion is electrically connected to the first end, an end of the fourth coil away from the connecting portion is electrically connected to the third end, and the current directions of the third coil and the fourth coil are the same.

[0012] In some possible embodiments, the conductive circuit is located in the capacitor layer and is electrically isolated from the first capacitor sheet and the second capacitor sheet.

[0013] The present application also provides a method for manufacturing a circuit board, the method comprising:

[0014] A circuit substrate is provided, wherein the circuit substrate has a first area, a connection area, and a second area connected to each other, wherein the first area and the second area are located at two ends of the connection area and are arranged opposite to each other, and the circuit substrate includes a substrate layer, and a first metal layer and a second metal layer arranged on two opposite surfaces of the substrate layer;

[0015] Patterning the first metal layer to form a capacitor layer, the capacitor layer comprising a first capacitor plate located in the first area and a second capacitor plate located in the second area, the first capacitor plate having a first conductive portion extending to the connection area and used for electrical lead-out, and the second capacitor plate having a second conductive portion extending to the connection area and used for electrical lead-out; and

[0016] The second metal layer is patterned to form a coil layer, the coil layer includes a first coil located in the first area and a second coil located in the second area, the first coil includes a first end and a second end, the second coil includes a third end and a fourth end, the first end is electrically connected to the third end through a conductive line, the second end and the fourth end extend to the connection area and form two output ends, wherein the current directions in the first coil and the second coil are opposite, thereby obtaining the circuit board.

[0017] In some possible embodiments, the method for manufacturing the circuit substrate includes:

[0018] Providing a first substrate, the first substrate having the first area, the connection area and the second area, the first substrate comprising a first base layer, the first metal layer located on a surface of the first base layer, and a third metal layer located on a surface of the first base layer away from the first metal layer;

[0019] The third metal layer is patterned to form a conductive layer, the conductive circuit is located in the conductive layer, the conductive circuit includes a third coil located in the first area, a fourth coil located in the second area, and a connecting portion located in the connecting area, two ends of the connecting portion are respectively connected to one end of the third coil and one end of the fourth coil, the ends of the third coil and the fourth coil away from the connecting portion are both electrically connected to the first metal layer, and the current directions of the third coil and the fourth coil are the same; and

[0020] A first insulating layer is formed on the surface of the conductive layer, and a second base layer and the second metal layer are formed on the surface of the first insulating layer. The second metal layer is located on a surface of the second base layer away from the first insulating layer.

[0021] In some possible embodiments, in the step of patterning the first metal layer to form a capacitor layer, the manufacturing method further includes:

[0022] The first metal layer is patterned to form the conductive circuit, and the conductive circuit is electrically isolated from the first capacitor plate and the second capacitor plate.

[0023] In some possible embodiments, after the step of patterning the second metal layer to form a coil layer, the manufacturing method further includes:

[0024] A first bending line is formed at the connection between the first area and the connecting area, and a second bending line is formed at the connection between the second area and the connecting area. The first area can be bent around the first bending line toward or away from the connecting area, and the second area can be bent around the second bending line toward or away from the connecting area.

[0025] In some possible embodiments, after forming the first bending line and the second bending line, the manufacturing method further includes:

[0026] A first elastic sheet is disposed on the surface of the first bending line, and a second elastic sheet is disposed on the surface of the second bending line.

[0027] Compared with the prior art, the embodiment of the present application designs a capacitor layer and a coil layer in the circuit board. By changing the relative distance between the first coil and the second coil, the capacitance value between the first capacitor sheet and the second capacitor sheet can be changed, thereby forming a fine-tuning capacitor structure in the circuit board. The fine-tuning capacitor structure is small in size and is directly formed in the circuit board without the need for welding steps. The overall circuit board structure is simple and the cost is low. Moreover, the circuit board with the fine-tuning capacitor structure can be used as an independent capacitor circuit board or as a part of the circuit board. The structural design is flexible and adaptable. In addition, by setting the first spring sheet and the second spring sheet, the rigidity of the flexural zone can be enhanced and the risk of breakage in the flexural zone can be reduced, thereby improving the reliability of the circuit board. Rigid shaping can be achieved after bending to ensure that the relative distance between the first zone and the second zone is fixed after shaping, thereby improving the stability of the capacitance value. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of the structure of a circuit board in a flattened state provided by an embodiment of the present application.

[0029] Figure 2 for Figure 1 Schematic diagram of the structure of the circuit board in the bent state.

[0030] Figure 3 For along Figure 1 Cross-sectional view of section III-III.

[0031] Figure 4 for Figure 1 Schematic diagram of the structure of the separation state of each layer in the circuit board.

[0032] Figure 5 A schematic structural diagram of the separation state of each layer in a circuit board provided in another embodiment of the present application.

[0033] Figure 6 A schematic structural diagram of the separation state of each layer in a circuit board provided in yet another embodiment of the present application.

[0034] Figure 7 This is a structural schematic diagram of the operation of a fine-tuning capacitor structure in a circuit board in one embodiment of the present application.

[0035] Figure 8 for Figure 7 Schematic diagram of the first and second zones in a calm state.

[0036] Fig. 9 for Figure 7 Schematic diagram of the first zone and the second zone in the deformed state.

[0037] Fig.10 A manufacturing flow chart of a circuit board provided in accordance with an embodiment of the present application.

[0038] Figures 11 to 16 A schematic structural diagram of a circuit board manufacturing process provided in one embodiment of the present application.

[0039] Main component symbols

[0040] Circuit board 100

[0041] Capacitor layer 1

[0042] The first capacitor 11

[0043] The second capacitor 12

[0044] The first conductive portion 13

[0045] The second conductive portion 14

[0046] Coil layer 2

[0047] First coil 21

[0048] Second coil 22

[0049] First End 23

[0050] Second end 24

[0051] The third end 25

[0052] Fourth End 26

[0053] Conductive layer 3

[0054] Conductive circuit 31

[0055] The third coil 32

[0056] Fourth coil 33

[0057] Connecting part 34

[0058] First bending line 4

[0059] Second bending line 5

[0060] First Shrapnel 6

[0061] Second shrapnel 7

[0062] First Base 81

[0063] Insulation layer 82

[0064] Second Base 83

[0065] Protective layer 9

[0066] Circuit board 10

[0067] Substrate layer 20

[0068] The first metal layer 30

[0069] The second metal layer 40

[0070] First substrate 50

[0071] The third metal layer 60

[0072] Zone 1A

[0073] Zone 2B

[0074] Connection area C

[0075] The following specific implementation methods will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0076] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0077] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. When an element is considered to be "set on" another element, it may be directly set on the other element or there may be a central element at the same time.

[0078] See also Figures 1 to 3The embodiment of the present application provides a circuit board 100, wherein the circuit board 100 has a first area A, a connection area C, and a second area B connected to each other, wherein the first area A and the second area B are located at two ends of the connection area C and are arranged opposite to each other. The circuit board 100 includes a capacitor layer 1 and a coil layer 2 stacked with the capacitor layer 1. The capacitor layer 1 includes a first capacitor sheet 11 located in the first area A and a second capacitor sheet 12 located in the second area B, wherein the first capacitor sheet 11 has a first conductive portion 13 extending to the connection area C and used for electrical lead-out, and the second capacitor sheet 12 has a second conductive portion 14 extending to the connection area C and used for electrical lead-out. The coil layer 2 includes a first coil 21 located in the first area A and a second coil 22 located in the second area B, the first coil 21 includes a first end 23 and a second end 24, the second coil 22 includes a third end 25 and a fourth end 26, the first end 23 is electrically connected to the third end 25 through a conductive line 31, the second end 24 and the fourth end 26 extend to the connection area C and form two output ends, specifically, the two output ends can be used to connect the positive and negative poles of an external power supply. The first coil 21 is used to generate a first magnetic force, and the second coil 22 is used to generate a second magnetic force, the first magnetic force is opposite to the second magnetic force, so that the distance between the first area A and the second area B is variable, so as to change the capacitance between the first capacitor sheet 11 and the second capacitor sheet 12. Specifically, by setting the winding directions of the first coil 21 and the second coil 22 to be opposite, the current directions in the first coil 21 and the second coil 22 can be opposite, so that the first magnetic force generated by the first coil 21 and the second magnetic force generated by the second coil 22 are opposite in direction. Under the action of the first magnetic force and the second magnetic force in opposite directions, the first area A and the second area B can be bent in directions away from each other, thereby increasing the distance between the first area A and the second area B, or the first area A and the second area B can be bent in directions close to each other, thereby decreasing the distance between the first area A and the second area B.

[0079] In some embodiments, a first bending line 4 is provided at the connection between the first zone A and the connection zone C, a second bending line 5 is provided at the connection between the second zone B and the connection zone C, the first zone A can be bent around the first bending line 4 toward or away from the second zone B, and the second zone B can be bent around the second bending line 5 toward or away from the first zone A.

[0080] In some embodiments, the first area A, the connection area C and the second area B form a U-shape, and the capacitor layer 1 is located at the innermost layer of the U-shape. By setting the capacitor layer 1 in the innermost layer (the surface where the first area A and the second area B are close to each other is the inner surface), the impact on the capacitance can be reduced and the change of the capacitance value can be made more precise.

[0081] In some embodiments, a first spring sheet 6 is provided on the surface of the first bending line 4, and a second spring sheet 7 is provided on the surface of the second bending line 5. By providing the first spring sheet 6 and the second spring sheet 7 in the flexure zone, it is possible to ensure that the flexure zone where the first bending line 4 and the second bending line are located has flexibility, thereby enhancing the rigidity of the flexure zone, reducing the risk of breaking in the flexure zone, and improving the reliability of the circuit board 100. Specifically, the first spring sheet 6 and the second spring sheet 7 can both be copper sheets, which can be rigidly shaped after bending, ensuring that the relative distance between the first area A and the second area B is fixed after shaping, so as to improve the stability of the capacitance value.

[0082] In some embodiments, Figure 4 As shown, the circuit board 100 also includes a conducting layer 3 located between the capacitor layer 1 and the coil layer 2, and the conductive circuit 31 is located in the conducting layer 3. Specifically, the conductive circuit 31 includes a third coil 32 located in the first area A, a fourth coil 33 located in the second area B, and a connecting portion 34 located in the connecting area C, and the two ends of the connecting portion 34 are respectively connected to one end of the third coil 32 and one end of the fourth coil 33, and the end of the third coil 32 away from the connecting portion 34 is electrically connected to the first end 23, and the end of the fourth coil 33 away from the connecting portion 34 is electrically connected to the third end 25. And the current directions of the third coil 32 and the fourth coil 33 are the same. Specifically, the winding directions of the third coil 32 and the fourth coil 33 can be set to be the same, so that the current directions in the third coil 32 and the fourth coil 33 can be the same.

[0083] In some embodiments, a first base layer 81, an insulating layer 82 and a second base layer 83 are further provided between the capacitor layer 1 and the coil layer 2, wherein the coil layer 2 is located on a surface of the first base layer 81, the conductive layer 3 is located on the surface of the first base layer 81 away from the coil layer 2, the insulating layer 82 is located on the surface of the conductive layer 3 and extends to the line gap of the conductive layer 3, the second base layer 83 is located on the surface of the insulating layer 82, and the capacitor layer 1 is located on the surface of the second base layer 83 away from the insulating layer 82.

[0084] In other embodiments, Figure 5 As shown, the circuit board 100 further includes a conducting layer 3 located between the capacitor layer 1 and the coil layer 2, and the conductive circuit 31 is located in the conducting layer 3. Specifically, the conductive circuit 31 may be a wire having two connection ends, which is used to electrically connect the first end 23 of the first coil 21 and the third end 25 of the second coil 22. By adding the conducting layer 3, the electrical conduction between the first coil 21 and the second coil 22 can be easily achieved.

[0085] In other embodiments, Figure 6As shown, the conductive circuit 31 is located in the capacitor layer 1 and is electrically isolated from the first capacitor sheet 11 and the second capacitor sheet 12. That is, the conductive circuit 31 and the capacitor layer 1 are made in the same layer, so that the circuit board 100 forms a two-layer structure, which is conducive to fully utilizing the space in the circuit board 100 and reducing the thickness of the circuit board 100. In this embodiment, there is no need for an insulating layer 82 and a second base layer 83. The capacitor layer 1 and the coil layer 2 are isolated by the first base layer 81 to form a double-layer structure design, wherein a conductive hole is formed through the first base layer 81 to achieve electrical conduction between the conductive circuit 31 and the first coil 21 and the second coil 22.

[0086] It is understandable that other circuit layers (not shown) can be formed in the circuit board 100, and the capacitor layer 1 and the coil layer 2 are directly electrically connected to other circuit layers to form an integrated circuit board with multiple functions. It is understandable that the circuit board 100 can also be just a capacitor circuit board, and the first conductive part 13 and the second conductive part 14 can be used to form an external solder pad, directly soldering an external connector or other circuit board.

[0087] like Figures 7 to 9 As shown, the first bending line 4 can form a bending zone at the connection between the first area A and the connection area C, and the second bending line 5 can also form a bending zone at the connection between the second area B and the connection area C, so that the first area A and the second area B can be bent relative to the connection area C, thereby changing the relative distance between the first area A and the second area B. Specifically, the bending of the first area A and the second area B relative to the connection area C is achieved by the first coil 21 and the second coil 22. In the flat state, as shown in FIG. Figure 8 As shown, the first area A and the second area B are arranged substantially perpendicular to the connecting area C. At this time, the distance between the first area A and the second area B is indicated as h1, and the capacitance between the first capacitor sheet 11 and the second capacitor sheet 12 is indicated as C1. Since the winding directions of the first coil 21 and the second coil 22 are opposite, after power is turned on, the first magnetic force generated by the first coil 21 and the second magnetic force generated by the second coil 22 are opposite in direction, as shown in FIG. Fig. 9 As shown, under the action of the first magnetic force and the second magnetic force, the first area A and the second area B can be bent in a direction away from each other, so that the distance between the first area A and the second area B increases, forming a deformed state, thereby changing the distance between the first capacitor plate 11 and the second capacitor plate 12, increasing the distance from h1 to h2, and then changing the capacitance value between the first capacitor plate 11 and the second capacitor plate 12, changing the capacitance value C1 to C2. When the current value decreases to 0, under the action of the first spring 6 and the second spring 7, the first area A and the second area B will return to Figure 8 Therefore, the distance between the first area A and the second area B can be controlled by controlling the magnitude of the current in the first coil 21 and the second coil 22, thereby adjusting the magnitude of the capacitance value to form a fine-tuning capacitor structure.

[0088] See also Fig.10 The present application also provides a method for manufacturing the circuit board 100, the method comprising the following steps:

[0089] Step S1, such as Figures 11 to 14 As shown, a circuit substrate 10 is provided, wherein the circuit substrate 10 has a first area A, a connection area C, and a second area B that are connected to each other, wherein the first area A and the second area B are located at two ends of the connection area C and are arranged opposite to each other, and the circuit substrate 10 includes a substrate layer 20, and a first metal layer 30 and a second metal layer 40 arranged on two opposite surfaces of the substrate layer 20.

[0090] Step S2, such as Fig.15 As shown, please refer to Figure 4 , patterning the first metal layer 30 to form a capacitor layer 1, the capacitor layer 1 includes a first capacitor plate 11 located in the first area A and a second capacitor plate 12 located in the second area B, the first capacitor plate 11 has a first conductive portion 13 extending to the connection area C and used for electrical lead-out, and the second capacitor plate 12 has a second conductive portion 14 extending to the connection area C and used for electrical lead-out.

[0091] Step S3, such as Fig.15 As shown, please refer to Figure 4 , patterning the second metal layer 40 to form a coil layer 2, the coil layer 2 includes a first coil 21 located in the first area A and a second coil 22 located in the second area B, the first coil 21 includes a first end 23 and a second end 24, the second coil 22 includes a third end 25 and a fourth end 26, the first end 23 is electrically connected to the third end 25 through a conductive line 31, the second end 24 and the fourth end 26 extend to the connection area C and form two output ends, wherein the current directions in the first coil 21 and the second coil 22 are opposite, to obtain the circuit board 100.

[0092] In some embodiments, in step S1, the method for manufacturing the circuit substrate 10 includes:

[0093] Step S11, as Fig.11 As shown, a first substrate 50 is provided, wherein the first substrate 50 has the first area A, the connection area C and the second area B, and the first substrate 50 includes a first base layer 81, the first metal layer 30 located on a surface of the first base layer 81, and a third metal layer 60 located on a surface of the first base layer 81 away from the first metal layer 30.

[0094] Step S12, as Fig.12 and Fig.13 As shown, please refer to Figure 4 , patterning the third metal layer 60 to form a conducting layer 3, the conductive circuit 31 is located in the conducting layer 3, the conductive circuit 31 includes a third coil 32 located in the first area A, a fourth coil 33 located in the second area B, and a connecting portion 34 located in the connecting area C, the two ends of the connecting portion 34 are respectively connected to one end of the third coil 32 and one end of the fourth coil 33, the ends of the third coil 32 and the fourth coil 33 away from the connecting portion C are both electrically connected to the first metal layer 40, the current directions of the third coil 32 and the fourth coil 33 are the same, that is, the winding directions of the third coil 32 and the fourth coil 33 are the same. It can be understood that in other embodiments, reference is made to Figure 5 The conductive line 31 in the conductive layer 3 may also be a metal wire, with both ends being conductively connected to the first metal layer 40 .

[0095] Step S13, as Fig.14 As shown, an insulating layer 82 is formed on the surface of the conductive layer 3, and a second base layer 83 and a second metal layer 40 are formed on the surface of the insulating layer 82, and the second metal layer 40 is located on the surface of the second base layer 83 away from the insulating layer 82. Specifically, the second base layer 83 and the second metal layer 40 can be formed on the surface of the insulating layer 82 by lamination.

[0096] In other embodiments, in step S2, Figure 6 , while patterning the first metal layer 40 to form the capacitor layer 1, the step further includes:

[0097] The first metal layer 40 is patterned to form the conductive circuit 31, the conductive circuit 31 is electrically isolated from the first capacitor sheet 11 and the second capacitor sheet 12, and both ends of the conductive circuit 31 are electrically connected to the second metal layer 50. The conductive circuit 31 can be prepared while the capacitor layer 1 is prepared, and the two are arranged in the same layer, which simplifies the preparation process and reduces the cost.

[0098] In some embodiments, Fig.16 The method further comprises the following steps after step S3:

[0099] A first bending line 4 is formed at the connection between the first area A and the connecting area C, and a second bending line 5 is formed at the connection between the second area B and the connecting area C. The first area A can be bent around the first bending line 4 toward or away from the second area B, and the second area B can be bent around the second bending line 5 toward or away from the first area A.

[0100] Specifically, the first bending line 4 and the second bending line 5 are formed by forming at least one row of through holes arranged in a straight line, and the through holes can be formed by laser drilling or mechanical drilling. Moreover, the aperture of the through hole needs to be controlled within a small range, which can ensure the bending property while not reducing the strength and reliability of the circuit board 100. In addition, it is necessary to avoid drilling holes on the line when drilling.

[0101] Specifically, before forming the first bending line 4 and the second bending line 5, a CVL-protective layer 9 can also be attached to the surface of the capacitor layer 1 and the coil layer 2 respectively. The through holes of the first bending line 4 and the second bending line 5 penetrate the protective layer 9. And, subsequently, the first spring sheet 6 and the second spring sheet 7 are attached to the surface of the protective layer 9, specifically, the first spring sheet 6 and the second spring sheet 7 are combined on the surface of the protective layer 9 close to the coil layer 2 to reduce the impact on the capacitor layer 1.

[0102] In some embodiments, Figure 3 As shown, after forming the first bending line 4 and the second bending line 5, the manufacturing method further comprises the steps of:

[0103] A first elastic sheet 6 is disposed on the surface of the first bending line 4 , and a second elastic sheet 7 is disposed on the surface of the second bending line 5 .

[0104] It can be understood that the capacitor layer 1, the coil layer 2 and the conductive layer 3 can be prepared by an additive method or a subtractive method.

[0105] The embodiment of the present application designs a capacitor layer 1 and a coil layer 2 in the circuit board 100. By changing the relative distance between the first coil 21 and the second coil 22, the change of the capacitance value between the first capacitor sheet 11 and the second capacitor sheet 12 can be achieved, so that a fine-tuning capacitor structure is formed in the circuit board 100. The fine-tuning capacitor structure is small in size and is directly formed in the circuit board 100. There is no need for a welding step. The overall circuit board 100 has a simple structure and low cost. Moreover, the circuit board 100 with a fine-tuning capacitor structure can be used as an independent capacitor circuit board or as a part of a circuit board. The structural design is flexible and adaptable. In addition, by setting the first spring sheet 6 and the second spring sheet 7, the rigidity of the flexing zone can be enhanced, the risk of breaking the flexing zone can be reduced, and the reliability of the circuit board 100 can be improved, and rigid shaping can be achieved after bending to ensure that the relative distance between the first area A and the second area B is fixed after shaping to improve the stability of the capacitance value.

[0106] The above description is only an optimized specific implementation of the present application, but it cannot be limited to this implementation in actual application.

Claims

1. A circuit board, characterized in that: The circuit board has a first area, a connection area, and a second area connected to each other, the first area and the second area are located at two ends of the connection area and are arranged opposite to each other, and the circuit board includes: a capacitor layer, the capacitor layer comprising a first capacitor sheet located in the first area and a second capacitor sheet located in the second area, the first capacitor sheet having a first conductive portion extending to the connection area and used for electrical lead-out, and the second capacitor sheet having a second conductive portion extending to the connection area and used for electrical lead-out; and a coil layer stacked with the capacitor layer, the coil layer comprising a first coil located in the first area and a second coil located in the second area, the first coil comprising a first end and a second end, the second coil comprising a third end and a fourth end, the first end being electrically connected to the third end via a conductive line, the second end and the fourth end extending to the connection area and forming two output ends, The first coil is used to generate a first magnetic force, and the second coil is used to generate a second magnetic force. The first magnetic force is opposite to the second magnetic force in direction, so that the distance between the first area and the second area is variable to change the capacitance between the first capacitor plate and the second capacitor plate.

2. The circuit board according to claim 1, characterized in that The connection between the first zone and the connecting zone has a first bending line, and the connection between the second zone and the connecting zone has a second bending line. The first zone can be bent toward or away from the connecting zone around the first bending line, and the second zone can be bent toward or away from the connecting zone around the second bending line.

3. The circuit board according to claim 2, characterized in that: The first region, the connection region and the second region form a U-shape, and the capacitor layer is located at the innermost layer of the U-shape.

4. The circuit board according to claim 3, characterized in that: A first spring sheet is disposed on the surface of the first bending line, and a second spring sheet is disposed on the surface of the second bending line.

5. The circuit board according to claim 1, wherein: The circuit board also includes a conducting layer located between the capacitor layer and the coil layer, and the conductive circuit is located in the conducting layer.

6. The circuit board according to claim 5, characterized in that: The conductive circuit includes a third coil located in the first area, a fourth coil located in the second area, and a connecting portion located in the connecting area, two ends of the connecting portion are respectively connected to one end of the third coil and one end of the fourth coil, one end of the third coil away from the connecting portion is electrically connected to the first end, one end of the fourth coil away from the connecting portion is electrically connected to the third end, and the current directions of the third coil and the fourth coil are the same.

7. The circuit board according to claim 1, characterized in that: The conductive circuit is located in the capacitor layer and is electrically isolated from the first capacitor sheet and the second capacitor sheet.

8. A method for manufacturing a circuit board, characterized in that: include: A circuit substrate is provided, wherein the circuit substrate has a first area, a connection area, and a second area connected to each other, wherein the first area and the second area are located at two ends of the connection area and are arranged opposite to each other, and the circuit substrate includes a substrate layer, and a first metal layer and a second metal layer arranged on two opposite surfaces of the substrate layer; Patterning the first metal layer to form a capacitor layer, the capacitor layer comprising a first capacitor sheet located in the first area and a second capacitor sheet located in the second area, the first capacitor sheet having a first conductive portion extending to the connection area and used for electrical lead-out, and the second capacitor sheet having a second conductive portion extending to the connection area and used for electrical lead-out; as well as The second metal layer is patterned to form a coil layer, the coil layer includes a first coil located in the first area and a second coil located in the second area, the first coil includes a first end and a second end, the second coil includes a third end and a fourth end, the first end is electrically connected to the third end through a conductive line, the second end and the fourth end extend to the connection area and form two output ends, wherein the current directions in the first coil and the second coil are opposite, thereby obtaining the circuit board.

9. The method for manufacturing a circuit board according to claim 8, wherein: The manufacturing method of the circuit substrate comprises: Providing a first substrate, the first substrate having the first area, the connection area and the second area, the first substrate comprising a first base layer, the first metal layer located on a surface of the first base layer, and a third metal layer located on a surface of the first base layer away from the first metal layer; The third metal layer is patterned to form a conductive layer, the conductive circuit is located in the conductive layer, the conductive circuit includes a third coil located in the first area, a fourth coil located in the second area, and a connecting portion located in the connecting area, two ends of the connecting portion are respectively connected to one end of the third coil and one end of the fourth coil, the ends of the third coil and the fourth coil away from the connecting portion are both electrically connected to the first metal layer, and the current directions of the third coil and the fourth coil are the same; and A first insulating layer is formed on the surface of the conductive layer, and a second base layer and the second metal layer are formed on the surface of the first insulating layer. The second metal layer is located on a surface of the second base layer away from the first insulating layer.

10. The method for manufacturing a circuit board according to claim 8, wherein: In the step of patterning the first metal layer to form a capacitor layer, the manufacturing method further comprises: The first metal layer is patterned to form the conductive circuit, and the conductive circuit is electrically isolated from the first capacitor plate and the second capacitor plate.

11. The method for manufacturing a circuit board according to claim 8, wherein: After the step of patterning the second metal layer to form a coil layer, the manufacturing method further includes: A first bending line is formed at the connection between the first area and the connecting area, and a second bending line is formed at the connection between the second area and the connecting area. The first area can be bent around the first bending line toward or away from the connecting area, and the second area can be bent around the second bending line toward or away from the connecting area.

12. The method for manufacturing a circuit board according to claim 11, wherein: After forming the first bending line and the second bending line, the manufacturing method further includes: A first elastic sheet is disposed on the surface of the first bending line, and a second elastic sheet is disposed on the surface of the second bending line.

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