WO2020151391A1 - Flexible circuit board and capacitive screen having same - Google Patents

Abstract

A flexible circuit board and a capacitive screen (50) having same. The flexible circuit board comprises: a base layer (22) and a conductive layer (10). The conductive layer (10) is attached to the base layer (22). The conductive layer (10) is provided with at least three conductive sheets (11) and conductive wires (12). The conductive sheets (11) are electrically connected to the conductive wires (12), respectively. The conductive sheets (11) are located on and are arranged side by side along the conductive connection side. A gap region (15) is provided between two adjacent conductive sheets (11). The width of each gap region (15) is larger than the width of each conductive sheet (11). The flexible circuit board has a small bending stress and has good flexibility, so that the accuracy and sensitivity of capacitance detection during touch recognition are improved.

Description

Flexible circuit board and capacitive screen with the flexible circuit board

This application claims the priority of the patent application filed to the State Intellectual Property Office of China on January 23, 2019, with the application number of 201920117522.8 and the invention title of "flexible circuit board and capacitive screen with the flexible circuit board".

Technical field

This application relates to the technical field of capacitive touch screens, in particular to a flexible circuit board and a capacitive screen having the flexible circuit board.

Background technique

Flexible Printed Circuit (FPC for short) has the characteristics of high wiring density, light weight, thin thickness, and good bendability, and is suitable for communication systems such as various capacitive touch screens.

The width of the gap between two adjacent conductive sheets in traditional flexible circuit boards is too narrow. Based on the market demand of large-size electronic products and the technological requirements of electronic products, when the large-size capacitive screen is bent, the structure of the flexible circuit board is Excessive bending stress increases the difficulty of processing and assembling electronic products. Due to the poor flexibility of traditional flexible circuit boards, the conductive sheet resists the bending of the flexible circuit board, which easily causes the conductive sheet to be displaced or lifted. The phenomenon of poor contact and open circuit reduces the accuracy and sensitivity of capacitance detection during touch recognition, and reduces the service life of electronic products.

Summary of the invention

The purpose of this application is to improve the defects of the prior art, and provide a flexible circuit board and a capacitive screen with the flexible circuit board. The flexible circuit board of the application has small bending stress and good flexibility. Time to improve the accuracy and sensitivity of capacitance detection.

The technical scheme is as follows:

The flexible circuit board includes: a base layer and a conductive layer, the conductive layer is attached to the base layer, the conductive layer has at least three conductive sheets and conductive wires, the conductive sheets are electrically connected to the conductive wires, and the conductive sheets are located on the conductive connection side; The sheets are arranged side by side along the conductive connection side, and there is a gap area between two adjacent conductive sheets, and the width of the gap area is greater than the width of the conductive sheet.

The width of the conductive sheet is 2 mm to 10 mm.

The width of the gap area is 2.5 mm to 20 mm.

The width of the gap region is greater than 1.5 times the width of the conductive sheet.

The conductive sheet has a first recess, and the opening width of the first recess gradually decreases from the outside to the inside.

The edge of the first gap is a circular arc segment.

There are multiple arc segments, and the multiple arc segments have at least two arc curvatures.

The maximum width of the first relief gap is 1 mm to 5 mm.

The width of the first relief is 10% to 70% of the width of the conductive sheet.

There are three arc segments, followed by the first arc segment, the second arc segment, and the third arc segment. The curvature of the first arc segment and the third arc segment are the same. The curvature is greater than the curvature of the first arc segment and the third arc segment; the first arc segment and the third arc segment are respectively located on both sides of the first recess edge, and the second arc segment is located at the Said the middle part of the first vacancy margin.

The area of the first relief is greater than one-sixth of the area of the conductive sheet.

The base layer is provided with a fourth gap, and the position of the fourth gap corresponds to the position of the first gap.

The fourth gap is flush with the first gap.

It also includes a protective layer that covers the conductive layer; the conductive layer is located on the front side of the base layer, the protective layer includes at least a front cover layer, and the front cover layer has a second gap, a second gap The gap is opposite to the conductive sheet, and at least a part of the upper surface of the conductive sheet is exposed relative to the second relief to form a first conductive surface.

The area of the second relief is greater than one third of the area of the conductive sheet.

The second vacancy has a circular arc shape.

The conductive layer is also provided on the back surface of the base layer, and the protective layer further includes a back cover layer. The back cover layer has a third relief, and the third relief is opposite to the conductive sheet on the back, and the conductive sheet At least a part of the surface area is exposed relative to the third gap to form a second conductive surface.

The exposed area of the first conductive surface of the upper surface of the conductive sheet relative to the front cover layer is larger than the exposed area of the second conductive surface of the conductive sheet relative to the back cover layer.

It also includes a gold finger. The gold finger has a substrate surface and a conductive surface. The conductive surface is electrically connected to the conductive wire. The conductive surface is in an opposite direction to the first conductive surface. The substrate surface is connected to the first conductive surface. The directions of the faces are the same.

Capacitive screen, including the screen body, the aforementioned flexible circuit board, the screen body has conductive contacts, the back of the flexible circuit board and the screen body are electrically connected through the connection layer, the conductive connection body is crimped on the conductive sheet and The first recess is electrically connected with the conductive contact.

It should be noted:

1. The aforementioned conductive sheet can be made of a metal material with good conductivity, and the conductive sheet is usually made of copper foil in actual production.

2. The aforementioned "arc curvature" refers to the approximate arc profile of the arc segment, not the arc segment formed by the splicing of fine arcs of each small segment.

3. In order to ensure the conductive effect, the first conductive surface and the second conductive surface formed on the upper and lower surfaces of the conductive sheet have good conductivity.

4. The conductive contact at least partially extends to the second and third recesses.

5. The material of the aforementioned conductive connector is metal or non-metal with certain conductivity. In practice, the conductive connector usually uses silver glue.

The advantages or principles of this application are described below:

1. The flexible circuit board, the conductive layer is attached to the base layer, the opening width of the second relief gradually decreases from the outside to the inside to the direction, so that the second relief is in a V-shaped shape, and the second relief The size of the gap is wider than the gap of the traditional slender strip. The structure of the second gap is stable, so that the conductive sheet is not easily broken with the conductive connector under the bending action of the external force on the conductive connection side, and the conductive layer is avoided. Poor contact and open circuit binding.

2. The edge of the second gap is a circular arc segment. When processing the conductive sheet of the conductive layer, only need to drill the conductive sheet by one or two cuts with a drill to process the conductive sheet and form the edge into a circular arc The second part of the segment is missing. This structure makes the processing process very simple.

3. There are three arc segments, and the three arc segments have two arc curvatures. The curvature of the second arc segment is smaller than that of the first and third arc segments to facilitate Simplify the machining process of machining arc segments. During machining, only one drill is required for the first arc and the third arc, and the second arc only needs to be drilled at the middle of the second gap. The three arc segment drills only need two drills to drill, which makes the processing easier, and at the same time reduces the defective rate in the processing and manufacturing process.

4. There is a gap area between two adjacent conductive sheets, and the width of the gap area is greater than the width of the conductive sheet, which is beneficial to increase the flexibility of the flexible circuit board, so that the flexible circuit board is not prone to poor contact and binding when bending In the case of an open circuit, the conductive sheet with a smaller width can also reduce the bending stress of the flexible circuit board, so that the conductive sheet is not easy to lift up when the flexible circuit board is bent.

5. The width of the gap area is greater than 1.5 times the width of the conductive sheet, so as to reduce the bending stress of the flexible circuit board, so that the flexible circuit board has a greater degree of bending, and can be produced and processed with longer length dimensions. Larger capacitive screen with better detection accuracy and sensitivity.

6. The area of the second gap is greater than one-sixth of the area of the conductive sheet, which is beneficial to increase the contact area of the conductive sheet and the conductive contact through the electrical connection of the conductive connector, thereby enhancing the stability of the flexible circuit board structure Sex.

7. The third relief on the front cover layer is opposite to the conductive sheet, so that the conductive connector is crimped and bound to the conductive sheet at the third relief via the first conductive surface, and passes through at least part of the upper surface of the conductive sheet. With respect to the first conductive surface formed by the exposure of the third gap, the first conductive surface bound on the conductive sheet is crimped by the conductive connector to electrically connect the conductive sheet with the conductive contact, and the conductive sheet will then receive the conductive The current signal detected by the contact is transmitted to the conductive line; the front cover layer and the back cover layer are used to cover the conductive line in the conductive layer and at least a part of the conductive sheet.

8. The area relationship between the third gap and the conductive sheet is beneficial to allow the conductive sheet to expose more of the first conductive surface through the third gap, which is beneficial to increase the crimping and binding of the conductive connector to the conductive The area of the sheet makes the conductive sheet bonded by crimping stronger and more stable.

9. The third concession in the shape of an arc in order to simplify the process flow of the product.

10. The back cover layer has a first vacancy, and a second conductive surface is formed by a partial area of the lower surface of the conductive sheet. The conductive connector is crimped and bound to the conductive sheet while making the lower surface of the conductive sheet The second conductive surface is electrically connected to the conductive contact. While the first conductive surface is conductive, the second conductive surface is electrically connected to the conductive contact. This bidirectional conductive effect can further enhance the stability of the flexible circuit board, and the back cover The first gap of the layer can expose a part of the lower surface of the conductive sheet, which is beneficial to increase the contact area between the conductive sheet and the conductive connector, so that the conductive connector can crimp the conductive sheet more stably.

11. The larger area of the first conductive surface is conductive, so that the second conductive surface avoids forming a cavity, avoiding the influence of the contact conduction, and further improving the conductive performance of the conduction.

12. The direction of the conductive surface of the gold finger is opposite to the direction of the first conductive surface, that is, the direction of the conductive surface and the conductive connecting body that is connected to the third gap is opposite.

13. The conductive contacts of the capacitive screen collect current signals from the screen. Because the conductive contacts pass through the conductive connector and are electrically connected to the first conductive surface of the flexible circuit board, and because the conductive connector makes way for the third The crimping function of the defect, the conductive connector is electrically connected to the second conductive surface at the same time, and then the current signal is transmitted to the conductive sheet through the first conductive surface and the second conductive surface, and then the current signal is transmitted to the conductive wire by the conductive sheet on.

Description of the drawings

FIG. 1 is an enlarged cross-sectional view of the flexible circuit board according to Embodiment 1 of the present application;

2 is a schematic diagram of the structure of the conductive sheet according to the first embodiment of the present application;

3 is a schematic diagram of the structure of the conductive layer according to the first embodiment of the present application;

4 is a schematic diagram of the structure of the front cover layer according to the first embodiment of the present application;

5 is a schematic diagram of the structure of the back cover layer according to the first embodiment of the present application;

6 is a schematic diagram of the structure of the conductive layer according to the first embodiment of the present application;

7 is a schematic diagram of the structure of the flexible circuit board according to the first embodiment of the present application;

8 is a schematic diagram of the structure of the conductive sheet according to the second embodiment of the present application;

Description of reference signs:

10. Conductive layer, 11, conductive sheet, 12, conductive wire, 13, first conductive surface, 14, second conductive surface, 15, gap area, 16, first gap, 161, first arc segment, 162. The second arc segment, 163, the third arc segment, 20, the front cover, 21, the second relief, 22, the base layer, 30, the back cover, 31, the third relief, 40, Gold finger, 41, substrate surface, 42, conductive surface, 50, capacitive screen, 51, screen body, 52, conductive contact, 60, conductive connector, 70, connection layer.

detailed description

The following describes the embodiments of the application in detail.

Example one:

As shown in FIGS. 1 to 7, the capacitive screen 50 includes a screen body 51 and a flexible circuit board.

The flexible circuit board includes: a base layer 22, a conductive layer 10 and a protective layer. The conductive layer 10 is attached to the base layer 22. The protective layer covers the conductive layer 10. The conductive layer 10 has dozens of conductive sheets 11 and conductive wires 12, and conductive sheets 11 are electrically connected to the conductive wires 12, the conductive sheet 11 is located on the conductive connection side; each conductive sheet 11 is arranged side by side along the conductive connection side, and there is a gap area 15 between two adjacent conductive sheets 11, the width of the gap area 15 It is larger than the width of the conductive sheet 11.

The screen body 51 has conductive contacts 52, and the back of the flexible circuit board and the screen body 51 are electrically connected through the connection layer 70. The conductive connection body 60 is crimped on the conductive sheet 11 and is connected to the first gap 16 The conductive contacts 52 are electrically connected.

There are three arc segments, and the three arc segments have two arc curvatures, which are the first arc segment 161, the second arc segment 162, the third arc segment 163, and the first arc segment 161 The curvature of the third arc segment 163 is the same, and the curvature of the second arc segment 162 is greater than that of the first arc segment 161 and the third arc segment 163; the first arc segment 161 and the third arc segment 163 are respectively Located on both sides of the edge of the first recess 16, the second arc segment 162 is located in the middle of the edge of the first recess 16; the area of the first recess 16 is larger than that of the conductive sheet 11 one-sixth of the area.

The width of the gap region 15 is greater than 1.5 times the width of the conductive sheet 11; the conductive sheet 11 has a first relief 16 whose opening width gradually changes from the outside to the inside to the direction Become smaller (in this embodiment, the edge of the first gap 16 is a circular arc segment).

The conductive layer 10 is located on the front surface of the base layer 22, and the protective layer includes a front cover layer 20. The front cover layer 20 has a second relief 21, and the second relief 21 is positioned opposite to the conductive sheet 11. A part of the upper surface of the sheet 11 is exposed relative to the second recess 21 to form a first conductive surface 13; the conductive layer 10 is also provided on the back of the base layer 22, and the protective layer further includes a back cover layer 30, The back cover layer 30 has a third relief 31, the third relief 31 is opposite to the conductive sheet 11 on the back, a part of the lower surface of the conductive sheet 11 is exposed relative to the third relief 31 to form a second conductive Surface 14; the area of the first conductive surface 13 of the upper surface of the conductive sheet 11 exposed relative to the front cover layer 20 is greater than the area of the second conductive surface 14 of the conductive sheet 11 exposed relative to the back cover layer 30; the second gap The area of 21 is greater than one-third of the area of the conductive sheet 11; the second relief 21 has an arc shape.

The base layer 22 is provided with a fourth gap, and the fourth gap is flush with the first gap 16.

It also includes a gold finger 40. The gold finger 40 has a base surface 41 and a conductive surface 42. The conductive surface 42 is electrically connected to the conductive wire 12. The conductive surface 42 is in an opposite direction to the first conductive surface 13. The direction of the base surface 41 and the first conductive surface 13 are the same.

In this embodiment, the conductive sheet 11 is copper foil, the conductive connector 60 is silver glue, and a plurality of conductive wires 12 are arranged between the protective layer and the base layer 22; the conductive sheet 11 for the conductive connection side refers to the capacitive screen 50 One side of the connection; the connection layer 70 can be adhesive, or double-sided adhesive or other adhesives.

After testing, the flexible circuit board of this embodiment has no functional abnormalities after being statically bent 50 times; the overall thickness of the flexible circuit board is less than 0.12 mm, and the material of the conductive layer 10 is rolled copper; the processing technology requirements are: chemical nickel gold, Among them, Au: 0.03um or more, Ni: 2-5um; the sample of the flexible circuit board is placed in 35±2℃, NaCl=5%, and the pH value is 6.5～7.2 in a salt spray environment for 24h. There are no rust spots and stains on the coating surface.

Specifically, in this embodiment, the maximum width of the first relief is 1.9 mm, the width of the conductive sheet is 3.0 mm, and the width of the gap area is 5.3 mm.

In this embodiment, the flexible circuit board processing method is that the method includes the following steps: depositing copper on the base layer 22 and forming a conductive layer 10 with a conductive sheet 11 and a conductive wire 12; covering the conductive layer 10 with a protective film and forming a protective layer; A circular arc is drilled on the conductive sheet 11 and a first gap 16 is formed; a large circular arc section with a small curvature and a small circular arc section with a large curvature are drilled on the conductive sheet 11 twice, and the The first handicap is missing 16.

This embodiment has the following advantages:

1. The flexible circuit board, the conductive layer 10 is attached to the base layer 22, the protective layer covers the conductive layer 10, so that the protective layer, the conductive layer 10 and the base layer 22 are crimped and bound to each other to prevent the conductive sheet 11 and the conductive wire of the conductive layer 10 12 is displaced relative to the protective layer and the base layer 22, which can increase the reliability of the flexible circuit board. The conductive sheet 11 and the conductive wire 12 are electrically connected to each other, so that the conductive sheet 11 transmits the received current signal to the conductive wire 12. When processing the conductive sheet 11 of the conductive layer 10, it is only necessary to drill the conductive sheet 11 through a drill with two cuts to process the conductive sheet 11 and form the first recess 16 with the edge of the arc segment. This process processes the conductive sheet The size of the first relief 16 of 11 is wider than that of the traditional slender strip. The structure of the first relief 16 is stable, so that the conductive sheet 11 is not easy to interact with each other under the bending action of the external force on the conductive connection side. The conductive connector 60 is broken to avoid poor contact and open bonding of the conductive layer 10, thereby enhancing the detection accuracy and sensitivity of the flexible circuit board; the screen body 51 of the capacitive screen 50 has conductive contacts 52, which are bound by crimping The conductive connector 60 fixed on the conductive sheet 11 makes the conductive connector 60 not only used for crimping and bonding, but also electrically connects the first gap 16 on the conductive sheet 11 with the conductive contact 52, When the capacitive screen 50 is bent, the connection structure between the conductive contacts 52 on the screen body 51 and the flexible circuit board greatly improves the stability of the capacitive screen 50, thereby solving the accuracy and sensitivity of the capacitive screen 50 during use. Sexual decline.

2. There are three arc segments, and the three arc segments have two arc curvatures. The curvature of the second arc segment 162 is smaller than that of the first arc segment 161 and the third arc segment 163. , In order to simplify the machining process of the arc segment. During processing, the first arc and the third arc only need to be drilled, and the second arc only needs to be drilled in the middle of the 16 edge of the first gap. With one cut, only two cuts are required to process three arc segment drills, which makes the processing easier and reduces the defective rate in the process of processing.

3. There is a gap region 15 between two adjacent conductive sheets 11, and the width of the gap region 15 is greater than the width of the conductive sheet 11, which is beneficial to increase the flexibility of the flexible circuit board and make the flexible circuit board difficult to contact when bending In the case of poor and binding open circuits, the conductive sheet 11 with a smaller width can also reduce the bending stress of the flexible circuit board, so that the conductive sheet 11 is not easy to lift up when the flexible circuit board is bent.

4. The width of the gap area 15 is greater than 1.5 times the width of the conductive sheet 11, so as to reduce the bending stress of the flexible circuit board, so that the flexible circuit board has a greater degree of bending, and can be produced and processed. Capacitive screen 50 with larger size and better detection accuracy and sensitivity.

5. The area of the first relief 16 is larger than one-sixth of the area of the conductive sheet 11, which is beneficial to increase the contact area of the conductive sheet 11 and the conductive contact 52 through the conductive connection body 60, thereby enhancing the flexibility The stability of the circuit board structure.

6. The second relief 21 on the front cover layer 20 is opposite to the conductive sheet 11, so that the conductive connector 60 is crimped and bound to the conductive sheet 11 through the first conductive surface 13 at the second relief 21, and passes At least a part of the upper surface of the conductive sheet 11 is exposed to the first conductive surface 13 formed by the second recess 21. The first conductive surface 13 bound to the conductive sheet 11 is crimped through the conductive connector 60 to make the conductive sheet 11 is electrically connected to the conductive contact 52, and the conductive sheet 11 further receives the current signal detected by the conductive contact 52 and transmits it to the conductive wire 12. The front cover layer 20 and the back cover layer 30 are used to cover the conductive layer 10 The conductive wire 12 and the conductive sheet 11 in at least part of the area.

7. The area relationship between the second relief 21 and the conductive sheet 11 is beneficial to allow the conductive sheet 11 to expose more of the first conductive surface 13 through the second relief 21, which is beneficial to increase the conductive connector 60 The crimping and binding are on the area of the conductive sheet 11, so that the crimping and binding conductive sheet 11 is stronger and more stable.

8. The arc-shaped second vacancy 21 is in order to simplify the process flow of the product.

9. The back cover layer 30 has a third gap 31, and a partial area of the lower surface of the conductive sheet 11 forms a second conductive surface 14. The conductive connector 60 is crimped and bound to the conductive sheet 11 at the same time, The second conductive surface 14 on the lower surface of the conductive sheet 11 is electrically connected to the conductive contact 52. While the first conductive surface 13 is conductive, the second conductive surface 14 is electrically connected to the conductive contact 52. This bidirectional conductive effect can be The stability of the flexible circuit board is further enhanced, and the third relief 31 of the back cover layer 30 can expose a part of the lower surface of the conductive sheet 11, which is beneficial to increase the contact area between the conductive sheet 11 and the conductive connector 60 to make the conductive sheet 11 more conductive. The connecting body 60 crimps the conductive sheet 11 more stably.

10. A larger area of the first conductive surface 13 conducts, so that the second conductive surface 14 avoids forming a cavity, avoids affecting the contact conduction, and further improves the conduction performance of the conduction.

11. The direction of the conductive surface 42 of the gold finger 40 is opposite to the direction of the first conductive surface 13, that is, the direction of the conductive surface 42 and the conductive connecting body 60 where the conductive voltage is connected to the second recess 21 is opposite; the conductive surface 42 of the gold finger 40 It is electrically connected to the conductive wire 12 to facilitate the transmission of the current signal through the conductive surface 42. The conductive surface 42 is electrically connected to the main control board. The substrate surface 41 can play a guiding role, so that the conductive surface 42 and the main The electrical connection of the control board is more stable.

12. The conductive contact 52 of the capacitive screen 50 collects current signals from the screen 51. Because the conductive contact 52 passes through the conductive connector 60 and is electrically connected to the first conductive surface 13 of the flexible circuit board, and because the conductive connector 60 With the crimping effect at the second recess 21, the conductive connector 60 is electrically connected to the second conductive surface 14 at the same time, and then the current signal is transmitted to the conductive sheet through the first conductive surface 13 and the second conductive surface 14 11, and then the conductive sheet 11 transmits the current signal to the conductive wire 12.

13. The flexible circuit board processing method in this embodiment is that when processing the conductive layer 10 of the flexible circuit board, the drilling of the drill is reduced from the traditional drilling of more than ten drills to only two drills. An arc segment and a second arc segment, and the first arc segment and the second arc segment form a first recess 16 on the conductive sheet 11. The processing technology of the first recess 16 in the conductive layer 10 Simple and further improve the production efficiency of the enterprise.

14. Traditionally drilled holes with more than ten cuts are long and slender. When the flexible circuit board of this embodiment is bent, it is prone to poor contact or open binding. However, the processing method of the capacitive screen 50 of the present invention only needs to drill two holes. The first arc segment and the second arc segment can be drilled with a knife, so that the first arc segment and the second arc segment form a first gap 16 on the conductive sheet 11. The processing method of the capacitive screen 50 It is simple and effectively reduces the process time of processing the capacitive screen 50.

Embodiment two:

As shown in FIG. 8, in this embodiment, compared with the first embodiment, the first gap 16 with the edge of a circular arc segment is one, and there is one circular arc segment.

This embodiment has the following advantages:

In this embodiment, when processing the conductive sheet 11, the drill bit only needs to drill a knife and drill a circular arc segment to complete the processing of the conductive sheet 11, and the process of processing the conductive sheet 11 is more convenient.

The above are only specific embodiments of this application, and do not limit the scope of protection of this application; any replacements and improvements made on the basis of not violating the concept of this application belong to the scope of protection of this application.

Claims (20)

1. The flexible circuit board includes: a base layer and a conductive layer, the conductive layer is attached to the base layer, the conductive layer has at least three conductive sheets and conductive wires, the conductive sheets are electrically connected with the conductive wires, and the conductive sheets are located on the conductive connection side; The conductive sheets are arranged side by side along the conductive connection side, and there is a gap area between two adjacent conductive sheets, and the width of the gap area is greater than the width of the conductive sheet.
2. The flexible circuit board of claim 1, wherein the width of the conductive sheet is 2 mm to 10 mm.
3. The flexible circuit board of claim 1, wherein the width of the gap area is 2.5 mm to 20 mm.
4. 8. The flexible circuit board of claim 1, wherein the width of the gap region is greater than 1.5 times the width of the conductive sheet.
5. 3. The flexible circuit board of claim 1, wherein the conductive sheet has a first relief, and the opening width of the first relief gradually decreases from the outside to the inside.
6. 5. The flexible circuit board of claim 5, wherein the edge of the first recess is a circular arc segment.
7. 7. The flexible circuit board according to claim 6, wherein there are multiple arc segments, and the multiple arc segments have at least two arc curvatures.
8. 5. The flexible circuit board according to claim 5, wherein the maximum width of the first recess is 1 mm to 5 mm.
9. 8. The flexible circuit board of claim 5, wherein the width of the first relief is 10% to 70% of the width of the conductive sheet.
10. The flexible circuit board according to claim 6, wherein there are three arc segments, which are a first arc segment, a second arc segment, and a third arc segment, the first arc segment, and the third arc segment. The curvatures of the arc segments are the same, the curvature of the second arc segment is greater than the curvatures of the first arc segment and the third arc segment; the first arc segment and the third arc segment are respectively located at the edge of the first gap On both sides, the second arc segment is located in the middle of the edge of the first gap.
11. 5. The flexible circuit board of claim 5, wherein a fourth recess is provided on the base layer, and the position of the fourth recess corresponds to the position of the first recess.
12. 11. The flexible circuit board of claim 11, wherein the fourth recess is flush with the first recess.
13. 8. The flexible circuit board of claim 5, wherein the area of the first recess is greater than one-sixth of the area of the conductive sheet.
14. The flexible circuit board according to any one of claims 1 to 13, further comprising a protective layer covering the conductive layer; the conductive layer is located on the front surface of the base layer, and the protective layer includes at least the front surface The cover layer, the front cover layer has a second relief, the second relief is opposite to the conductive sheet, and at least a part of the upper surface of the conductive sheet is exposed relative to the second relief to form a first conductive surface.
15. 14. The flexible circuit board of claim 14, wherein the area of the second recess is greater than one third of the area of the conductive sheet.
16. 15. The flexible circuit board of claim 14, wherein the second recess is a circular arc shape.
17. The flexible circuit board according to claim 14, wherein the conductive layer is further provided on the back of the base layer, the protective layer further comprises a back cover layer, the back cover layer has a third gap, the third gap The gap is opposite to the conductive sheet on the back, and at least a part of the lower surface of the conductive sheet is exposed relative to the third relief to form a second conductive surface.
18. 17. The flexible circuit board of claim 17, wherein the exposed area of the first conductive surface of the upper surface of the conductive sheet relative to the front cover layer is larger than the exposed area of the second conductive surface of the conductive sheet relative to the back cover layer.
19. The flexible circuit board of claim 17, further comprising a gold finger having a base surface and a conductive surface, the conductive surface is electrically connected to the conductive wire, and the conductive surface is connected to the first conductive surface. The direction is opposite, and the direction of the substrate surface and the first conductive surface are the same.
20. A capacitive screen, which includes a screen body, the flexible circuit board according to any one of the preceding claims, the screen body has conductive contacts, the back of the flexible circuit board and the screen body are electrically connected through a connection layer, and the conductive connection body is pressed It is connected to the conductive sheet and is electrically connected to the conductive contact at the first gap.

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