CN214851965U - Circuit board and electronic equipment - Google Patents

Abstract

A circuit board and electronic equipment relate to but are not limited to the technical field of circuit boards, and the circuit board comprises a first circuit board, wherein the first circuit board comprises a first substrate and a first circuit layer arranged on a first side surface of the first substrate, and the first circuit layer comprises a first grounding circuit; the circuit board further comprises a first protective layer and a first electromagnetic interference shielding layer which are sequentially stacked on one side of the first circuit layer, which is far away from the first substrate; the first protection layer is provided with a first opening, at least one part of the first grounding circuit is exposed out of the first opening, a first conductive material is filled in the first opening, the height difference between the surface of the first conductive material and the surface of the first protection layer, which is far away from the first substrate, is 0-2 micrometers, and the first conductive material connects the first electromagnetic interference shielding layer with the first grounding circuit. The utility model discloses circuit board can prevent that the circuit board from windowing in the part and causing local perk, unevenness's problem behind the exposure circuit layer.

Description

Circuit board and electronic equipment

Technical Field

The embodiment of the utility model provides a but not limited to circuit board technical field, concretely relates to circuit board and electronic equipment.

Background

At present, electronic products are used more and more widely in life, and circuit boards are important parts of the electronic products. In some technologies, in order to achieve grounding, electromagnetic shielding, and the like of a circuit board, a covering layer covering a circuit layer needs to be windowed to expose a grounding circuit of the circuit layer so as to be connected with an electromagnetic interference shielding film or a conductive layer, but problems such as local tilting and unevenness of the circuit board may be caused.

SUMMERY OF THE UTILITY MODEL

An embodiment of the utility model provides a circuit board and electronic equipment can prevent that the circuit board from windowing locally and causing local perk, unevenness's problem behind the exposure circuit layer.

The embodiment of the utility model provides a circuit board, including first circuit board, first circuit board includes first base plate and locates the first circuit layer on the first side of first base plate, first circuit layer includes first ground circuit; the circuit board further comprises a first protective layer and a first electromagnetic interference shielding layer which are sequentially stacked on one side of the first circuit layer, which is far away from the first substrate; the first protection layer is provided with a first opening, at least one part of the first grounding circuit is exposed out of the first opening, a first conductive material is filled in the first opening, the height difference between the surface of the first conductive material and the surface of the first protection layer, which is far away from the first substrate, is 0-2 micrometers, and the first electromagnetic interference shielding layer is connected with the first grounding circuit through the first conductive material.

Optionally, the first circuit board further includes a second circuit layer disposed on the second side of the first substrate, where the second circuit layer includes a second ground circuit;

the circuit board further comprises a first insulating layer, a second electromagnetic interference shielding layer and a conducting layer which are sequentially stacked on one side, far away from the first substrate, of the second circuit layer;

the first insulating layer and the second electromagnetic interference shielding layer are provided with second openings, at least one part of the second grounding circuit is exposed out of the second openings, a second conductive material is filled in the second openings, the height difference between the surface of the second conductive material and the surface, far away from the first substrate, of the second electromagnetic interference shielding layer is 0-2 micrometers, and the conductive layer is connected with the second grounding circuit through the second conductive material.

Optionally, the second conductive material is a metal material; or/and the conducting layer is made of conducting adhesive.

Optionally, the first conductive material is a metal material.

Optionally, the first protective layer includes a first cover layer and a first adhesive layer, and the first adhesive layer is located between the first cover layer and the first circuit layer.

Optionally, the circuit board includes a main body portion and a bendable portion located on a first side of the main body portion, the main body portion includes a plurality of circuit boards stacked, each circuit board includes a substrate and at least one circuit layer disposed on the substrate, the plurality of circuit boards includes the first circuit board, and the first circuit board extends to the bendable portion;

the first protection layer, the first electromagnetic interference shielding layer and the first opening are all located at the bendable portion.

Optionally, the main body portion and the bendable portion each include the first insulating layer, the second electromagnetic interference shielding layer, and the conductive layer, and the second opening is located in the main body portion.

Optionally, the circuit board further comprises a binding portion located at a second side of the main body portion opposite to the first side;

the plurality of circuit boards include the second circuit board, the second base plate and at least one circuit layer of second circuit board extend to binding portion, the extension of second circuit board extremely the circuit layer of binding portion is equipped with naked binding pin, it is connected to bind the pin configuration to bind with external circuit.

Optionally, the binding portion includes a third circuit layer and a second protective layer sequentially stacked on the first side surface of the second substrate, the binding pin is disposed at an end of the third circuit layer away from the main body portion, and the second protective layer exposes the binding pin; the binding portion further includes a third protective layer disposed on the second side of the second substrate.

Optionally, the second protective layer comprises a second cover layer and a second adhesive layer, the second adhesive layer being located between the second cover layer and the third circuit layer; or/and the third protective layer comprises a third covering layer and a third adhesive layer, and the third adhesive layer is positioned between the third covering layer and the second substrate.

Optionally, the plurality of circuit boards further include a third circuit board, the first circuit board, the second circuit board and the third circuit board are sequentially stacked, two adjacent circuit boards are bonded through a bonding layer, and the first side face of the first substrate faces the second circuit board.

Optionally, the second circuit board in the main body portion includes a third circuit layer and a fourth circuit layer respectively disposed on two sides of the second substrate, and the third circuit board includes a third substrate, and a fifth circuit layer and a sixth circuit layer respectively disposed on two sides of the third substrate;

the main part is still including overlapping in proper order and locating keeping away from of third circuit board second insulating layer and the third electromagnetic interference shielding layer of second circuit board one side, the third electromagnetic interference shielding layer with first electromagnetic interference shielding layer body coupling.

The embodiment of the utility model provides a still provide an electronic equipment, including arbitrary embodiment the circuit board.

The utility model discloses circuit board, fill first conducting material through the first opening at first protective layer, and the difference in height on the surface of first conducting material and the surface of keeping away from first base plate of first protective layer is 0 micron to 2 microns, and thus, on the one hand, first conducting material fills up the segment difference of the first opening part of first protective layer, first protective layer surfacing has been guaranteed, and circuit board thickness does not increase, follow-up back on first electromagnetic interference shielding layer is attached to first protective layer, first electromagnetic interference shielding layer surface is level and smooth equally, and thus, can not produce bubble or stranded gas between the two when attaching double sticky tape or other tie coat on first electromagnetic interference shielding layer, thereby when the circuit board passes through double sticky tape or other tie coats and attaches to flexible OLED screen back, can not make the film seal bad. On the other hand, the first conductive material fills up the step difference at the first opening of the first protective layer, and then after the first electromagnetic interference shielding layer is attached to the first protective layer, the stress balance of the circuit board (for example, when the circuit board is a flexible circuit board) at the first opening can be achieved, and the circuit board is prevented from tilting. In addition, the first conductive material connects the first emi shielding layer and the first ground line, and thus the shielding function of the first emi shielding layer can be achieved.

Drawings

The accompanying drawings are included to provide a further understanding of the technical solutions of the present invention, and are incorporated in and constitute a part of this specification, together with the embodiments of the present invention for explaining the technical solutions of the present invention, and do not constitute a limitation on the technical solutions of the present invention.

FIG. 1a is a schematic cross-sectional view of a circuit board of some techniques;

FIG. 1b is a schematic structural view of the circuit board of FIG. 1a after a double-sided tape is attached;

FIG. 2 is a schematic cross-sectional view of a circuit board in accordance with some exemplary embodiments;

FIG. 3 is a schematic diagram of a plan view of a circuit board in accordance with further exemplary embodiments;

FIG. 4 is a schematic cross-sectional view taken along line A-A of FIG. 3;

the reference signs are:

10. the circuit board comprises a substrate, 11, a circuit layer, 12, a protective layer, 13 and an electromagnetic interference shielding layer;

001. a double-sided tape, 01, a first double-sided adhesive, 02 and a second double-sided adhesive;

21. the connector comprises a main body part, a main body part 22, a bendable part, a main body part 23, a binding part 211, a component area 212, a connector 221 and a grounding area;

31. a first circuit board 311, a first substrate 312, a first circuit layer 313, a second circuit layer,

32. a second wiring board 321, a second substrate 322, a third wiring layer 323, a fourth wiring layer,

33. a third wiring board 331, a third substrate 332, a fifth wiring layer 333, a sixth wiring layer,

41. a first adhesive layer, 42, a second adhesive layer,

51. a first insulating layer, 52, a second insulating layer,

61. a first EMI shielding layer, 62, a second EMI shielding layer, 63, a third EMI shielding layer,

71. a first protective layer 711, a first adhesive layer 712, a first cover layer,

72. a second protective layer, 721, a second adhesive layer, 722, a second cover layer,

73. a third protective layer, 731, a third adhesive layer, 732, a third cover layer,

81. a conductive layer is formed on the substrate,

91. a first conductive material, 92, a second conductive material.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments with reference to the accompanying drawings. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention.

In some technologies, as shown in fig. 1a, fig. 1a is a schematic cross-sectional structure diagram of some circuit boards, where the circuit board needs to have high electromagnetic shielding and signal interference resistance capabilities, an electromagnetic interference shielding film (abbreviated as EMI film) 13 is attached to a surface of the circuit board, and a window is opened on a cover film (abbreviated as CVL)12 of the circuit board, so that the EMI film 13 is connected to a ground line of a circuit layer (the circuit layer is disposed on a substrate 10) 11, thereby implementing an electromagnetic shielding function of the EMI film 13. In this grounding method, a local step (height difference) is formed at the grounding position of the EMI film 13 because the cover film 12 is windowed. On the one hand, as shown in fig. 1a, since the shielding requirement of the current consumer electronic product on the circuit board is higher, the number of the grounding points of the EMI film 13 on the circuit board is large, the area is small, the surface of the circuit board is uneven, and the step difference cannot be filled from the outer surface of the EMI film 13. In this case, as shown in fig. 1b, fig. 1b is a schematic structural diagram of the circuit board of fig. 1a after the double-sided tape is attached, when the double-sided tape 001 with a relatively thin thickness or other adhesive layers are attached to the surface of the circuit board (i.e., the outer surface of the EMI film 13), due to the uneven surface of the circuit board, air bubbles and trapped air are formed between the double-sided tape 001 and the EMI film 13 at a position M corresponding to the opening of the cover film 12, so that when the circuit board is attached to the back surface of the flexible Organic Light Emitting Diode (OLED) panel through the double-sided tape 001, the trapped air and air bubbles may cause local position material deformation, resulting in poor film printing; on the other hand, because there is a step difference in the windowing area of the cover film 12, after the EMI film 13 is attached, the circuit board in the windowing area (for example, when the circuit board is a flexible circuit board) may be tilted due to the pulling of stress, which affects the assembly of the module.

The embodiment of the utility model provides a circuit board, including first circuit board, first circuit board includes first base plate and locates the first circuit layer on the first side of first base plate, first circuit layer includes first ground circuit; the circuit board further comprises a first protective layer and a first electromagnetic interference shielding layer which are sequentially stacked on one side of the first circuit layer, which is far away from the first substrate; the first protection layer is provided with a first opening, at least one part of the first grounding circuit is exposed out of the first opening, a first conductive material is filled in the first opening, the height difference between the surface of the first conductive material and the surface of the first protection layer, which is far away from the first substrate, is 0-2 micrometers, and the first electromagnetic interference shielding layer is connected with the first grounding circuit through the first conductive material.

The utility model discloses circuit board, fill first conducting material through the first opening at first protective layer, and the difference in height on the surface of first conducting material and the surface of keeping away from first base plate of first protective layer is 0 micron to 2 microns, and thus, on the one hand, first conducting material fills up the segment difference of the first opening part of first protective layer, first protective layer surfacing has been guaranteed, and circuit board thickness does not increase, follow-up back on first electromagnetic interference shielding layer is attached to first protective layer, first electromagnetic interference shielding layer surface is level and smooth equally, and thus, can not produce bubble or stranded gas between the two when attaching double sticky tape or other tie coat on first electromagnetic interference shielding layer, thereby when the circuit board passes through double sticky tape or other tie coats and attaches to flexible OLED screen back, can not make the film seal bad. On the other hand, the first conductive material fills up the step difference at the first opening of the first protective layer, and then after the first electromagnetic interference shielding layer is attached to the first protective layer, the stress balance of the circuit board (for example, when the circuit board is a flexible circuit board) at the first opening can be achieved, and the circuit board is prevented from tilting. In addition, the first conductive material connects the first emi shielding layer and the first ground line, and thus the shielding function of the first emi shielding layer can be achieved.

The utility model discloses circuit board, the difference in height on the surface of first conducting material's surface and the surface of keeping away from first base plate of first protective layer is 0 micron to 2 microns, promptly, first conducting material's surface and the surface of keeping away from first base plate of first protective layer can the parallel and level, perhaps, first conducting material's surface is higher than or is less than the surface of keeping away from first base plate of first protective layer 0 micron to 2 microns.

The embodiment of the utility model provides a circuit board can be flexible circuit board (FPC), Printed Circuit Board (PCB) or soft or hard combination circuit board (RFPC), the utility model provides a type to the circuit board is not injectd.

The utility model discloses the circuit board can be single face circuit board, double-sided circuit board or multilayer circuit board, and the number of piles on circuit layer can be one deck or multilayer, the embodiment of the utility model provides a not injecing to this.

In some exemplary embodiments, as shown in fig. 2, fig. 2 is a schematic cross-sectional structure diagram of a circuit board of some exemplary embodiments. The circuit board comprises a first circuit board 31, the first circuit board 31 comprises a first substrate 311 and a first circuit layer 312 arranged on a first side of the first substrate 311, and the first circuit layer 312 comprises a first grounding circuit; the circuit board further comprises a first protective layer 71 and a first electromagnetic interference shielding layer 61 which are sequentially stacked on one side of the first circuit layer 312 far away from the first substrate 311; the first protection layer 71 is provided with a first opening, the first opening exposes at least a part of the first ground line, the first opening is filled with a first conductive material 91, a height difference between a surface of the first conductive material 91 and a surface of the first protection layer 71 away from the first substrate 311 is 0 to 2 micrometers (in the example of fig. 2, the height difference is 0 micrometer, that is, a surface of the first conductive material 91 is flush with a surface of the first protection layer 71 away from the first substrate 311), and the first conductive material 91 connects the first electromagnetic interference shielding layer 61 and the first ground line.

In this embodiment, the first circuit board 31 may further include a second circuit layer 313 disposed on the second side surface of the first substrate 311, where the second circuit layer 313 includes a second ground circuit; the circuit board may further include a second protective layer 72 and a second electromagnetic interference shielding layer 62 sequentially stacked on a side of the second circuit layer 313 away from the first substrate 311; the second protection layer 72 is provided with a second opening, the second opening exposes at least a part of the second ground line, a second conductive material 92 is filled in the second opening, a height difference between a surface of the second conductive material 92 and a surface of the second protection layer 72 far from the first substrate 311 is 0 to 2 micrometers, and the second conductive material 92 connects the second electromagnetic interference shielding layer 62 and the second ground line.

In an example of this embodiment, as shown in fig. 2, the first protection layer 71 may be provided with one or more first openings, and the shape of the first openings may be rectangular, circular, polygonal, irregular, and the like, and the number and the shape of the first openings are not limited in this embodiment. In one example of this embodiment, the material of the first substrate 311 may be Polyimide (PI), polyetheretherketone (peek), or dacron. The material of the first and second circuit layers 312 and 313 may be copper. In one example of this embodiment, the first conductive material 91 may be a metal material, such as any one or more of gold, silver, and copper. The first conductive material 91 may be filled in the first opening through a plating process or a coating process, for example, metal copper may be filled in the first opening through a plating process, or a silver paste may be dotted in the first opening through a coating process and cured, so that a height difference between a surface of the first conductive material 91 and a surface of the first protection layer 71 away from the first substrate 311 is ensured to be 0 to 2 micrometers. The second conductive material 92 may be formed of the same material and in the same manner as the first conductive material 91.

In an example of this embodiment, the first electromagnetic interference shielding layer 61 may be a first electromagnetic interference shielding film, and the first electromagnetic interference shielding film may include a protective film, a shielding functional layer and a conductive adhesive layer sequentially stacked on one side surface of the protective film. The first electromagnetic interference shielding film can be attached to the first protective layer 71 through a hot pressing process and is in contact with the first conductive material 91, and the shielding functional layer is connected with the first conductive material 91 through a conductive adhesive layer, so that the shielding functional layer is connected with the first grounding circuit.

In an example of this embodiment, as shown in fig. 2, the first protection layer 71 may include a first cover layer 712 and a first adhesive layer 711, where the first adhesive layer 711 is located between the first cover layer 712 and the first circuit layer 312, and the first cover layer 712 is adhered to the first circuit layer 312 by the first adhesive layer 711. In one example of the present embodiment, the process of forming the first protective layer 71 may include: a first cover film having the first opening is attached to the surface of the first circuit layer 312, the first cover film includes a first cover layer 712 and a first adhesive layer 711 disposed on one side of the first cover layer 712, the first cover film can be thermally pressed on the first circuit layer 312 by using a thermal pressing process (a lamination process), and the first adhesive layer 711 is melted and adheres the first cover layer 712 to the first circuit layer 312 during the thermal pressing process. After the first protection layer 71 is formed, the first opening is filled with a first conductive material 91 to fill the step difference of the first protection layer 71 at the first opening, and then a first EMI shielding layer (the first EMI shielding layer may be an EMI film) 61 is attached on the first protection layer 71 and the first conductive material 91.

In an example of this embodiment, the second protection layer 72 may include a second cover layer 722 and a second adhesive layer 721, and the second adhesive layer 721 is located between the second cover layer 722 and the third circuit layer 322. The second protective layer 72 and the second electromagnetic interference shield layer 62 may be disposed in the same manner as the first protective layer 71 and the first electromagnetic interference shield layer 61.

The utility model discloses circuit board, fill first conducting material 91 through the first opening at first protective layer 71, and the difference in height of the surface of first conducting material 91 and the surface of first protective layer 71 of keeping away from first base plate 311 is 0 micron to 2 microns, and thus, first conducting material 91 fills up the section difference of the first opening part of first protective layer 71, first protective layer 71 surfacing has been guaranteed, and circuit board thickness does not increase, attach in first electromagnetic interference shielding layer 61 back on first protective layer 71, first electromagnetic interference shielding layer 61 surfacing equally, and the same is said, after second electromagnetic interference shielding layer 62 attaches on second protective layer 72, second electromagnetic interference shielding layer 62 surfacing equally levelly and smoothly. Therefore, after the first double-sided adhesive 01 is attached to the first electromagnetic interference shielding layer 61 and the second double-sided adhesive 02 is attached to the second electromagnetic interference shielding layer 62, no air bubble or air trapping is generated between the first double-sided adhesive 01 and the first electromagnetic interference shielding layer 61 and between the second double-sided adhesive 02 and the second electromagnetic interference shielding layer 62, and therefore when the circuit board is attached to the back of the flexible OLED screen through the double-sided adhesive tape or other bonding layers, poor film printing cannot be caused. In addition, the first conductive material 91 fills up the step difference at the first opening of the first protection layer 71, and subsequently after the first electromagnetic interference shielding layer 61 is attached to the first protection layer 71, the stress balance of the circuit board (for example, when the circuit board is a flexible circuit board) at the first opening can be realized, so as to prevent the circuit board from tilting at the first opening.

In other exemplary embodiments, as shown in fig. 3, fig. 3 is a schematic plan view of a circuit board according to other exemplary embodiments. The circuit board may be a rigid-flex board, and may include a main body portion 21, a bendable portion 22 located at a first side of the main body portion 21, and a binding portion 23 located at a second side of the main body portion 21 opposite to the first side. The main body 21 may include a plurality of circuit layers, a surface of the main body 21 may be provided with a component area 211, and the component area 211 may include components such as a chip, a capacitor, and a resistor. The main body portion 21 may be provided with a connector 212, and the connector 212 may be connected to an external circuit. The bendable part 22 may be bent, the bendable part 22 may be provided with a grounding region 221, at least a part of the grounding line of the circuit board may be exposed from the film layer covering the grounding region 221, and the exposed at least a part of the grounding line may be connected to the electromagnetic interference shielding layer of the circuit board, so as to achieve the electromagnetic shielding function of the electromagnetic interference shielding layer. The binding part 23 is used for realizing binding connection between the circuit board and an external circuit. In some examples, when the circuit board is applied to the display device, the circuit board may be bound and connected to the display panel through the binding part 23, and the circuit board may be connected to a main board of the display device through the connector 212. One or more openings may also be provided in the circuit board to avoid components or structures of the display device.

In some exemplary embodiments, as shown in fig. 4, fig. 4 is a schematic cross-sectional view taken at a-a of fig. 3. The circuit board of the present embodiment includes a first circuit board 31, where the first circuit board 31 includes a first substrate 311 and a first circuit layer 312 disposed on a first side of the first substrate 311, and the first circuit layer 312 includes a first ground circuit; the circuit board further comprises a first protective layer 71 and a first electromagnetic interference shielding layer 61 which are sequentially stacked on one side of the first circuit layer 312 far away from the first substrate 311; the first protection layer 71 is provided with a first opening, the first opening exposes at least a part of the first ground line, the first opening is filled with a first conductive material 91, a height difference between a surface of the first conductive material 91 and a surface of the first protection layer 71 away from the first substrate 311 is 0 to 2 micrometers (in the example of fig. 4, the height difference is 0 micrometer, that is, a surface of the first conductive material 91 is flush with a surface of the first protection layer 71 away from the first substrate 311), and the first conductive material 91 connects the first electromagnetic interference shielding layer 61 and the first ground line.

In the circuit board of this embodiment, the first opening of the first protection layer 71 is filled with the first conductive material 91, and the height difference between the surface of the first conductive material 91 and the surface of the first protection layer 71, which is far away from the first substrate 311, is 0 to 2 micrometers, so that the first conductive material 91 fills the step difference at the first opening of the first protection layer 71, thereby ensuring that the surface of the first protection layer 71 is smooth, and the thickness of the circuit board is not increased, and after the first electromagnetic interference shielding layer 61 is attached to the first protection layer 71, it can be ensured that the surface of the first electromagnetic interference shielding layer 61 is also smooth. In addition, the first conductive material 91 fills up the step difference at the first opening of the first protection layer 71, and then after the first electromagnetic interference shielding layer (in some examples, an EMI film) 61 is attached to the first protection layer 71, the stress balance of the circuit board (for example, when the circuit board at the first opening is a flexible circuit board) at the first opening can be realized, so as to prevent the circuit board from tilting at the first opening.

In one example of this embodiment, the first conductive material 91 may be a metal material, such as any one or more of gold, silver, and copper. The first conductive material 91 may be filled in the first opening through a plating process or a coating process, for example, metal copper may be filled in the first opening through a plating process, or a silver paste may be dotted in the first opening through a coating process and cured. The first conductive material 91 is formed in the first opening by adopting an electroplating process or a coating process, so that the filling requirements of different step differences of different circuit boards can be met, the height difference between the surface of the first conductive material 91 and the surface, far away from the first substrate 311, of the first protection layer 71 can be ensured to be 0-2 micrometers under the filling requirements of different step differences, and the first electromagnetic interference shielding layer 61 and the first grounding circuit can be reliably connected.

In an example of the present embodiment, the first protection layer 71 may be provided with one or more first openings, and the shape of the first openings may be rectangular, circular, polygonal, irregular, and the like. In some examples, the region where the first opening is located is the ground region 221 in fig. 3.

In an example of this embodiment, the first electromagnetic interference shielding layer 61 may be a first electromagnetic interference shielding film, and the first electromagnetic interference shielding film may include a protective film, a shielding functional layer and a conductive adhesive layer sequentially stacked on one side surface of the protective film. The first electromagnetic interference shielding film can be attached to the first protective layer 71 through a hot pressing process and is in contact with the first conductive material 91, and the shielding functional layer is connected with the first conductive material 91 through a conductive adhesive layer, so that the shielding functional layer is connected with the first grounding circuit.

In an example of this embodiment, the first protection layer 71 may include a first cover layer 712 and a first adhesive layer 711, where the first adhesive layer 711 is located between the first cover layer 712 and the first circuit layer 312, and the first cover layer 712 is adhered to the first circuit layer 312 by the first adhesive layer 711. The material of the first cover layer 712 may be polyimide, and the material of the first adhesive layer 711 may be epoxy resin or acryl. Illustratively, the process of forming the first protective layer 71 may include: a first cover film having a first opening is attached to the surface of the first circuit layer 312, the first cover film includes a first cover layer 712 and a first adhesive layer 711 disposed on one side of the first cover layer 712, the first cover film can be thermally pressed on the first circuit layer 312 by using a thermal pressing process, and the first adhesive layer 711 is melted and adheres the first cover layer 712 to the first circuit layer 312 during the thermal pressing process. After the first protection layer 71 is formed, the first opening is filled with the first conductive material 91 to fill the step difference of the first protection layer 71 at the first opening, and then the first emi shielding layer 61 is attached to the first protection layer 71 and the first conductive material 91.

In an example of this embodiment, the thickness of the first substrate 311 may be 10 to 15 micrometers, such as 12.5 micrometers; the thickness of the first circuit layer 312 may be 10 microns to 15 microns, such as 12 microns; the first protection layer 71 includes a first covering layer 712 and a first adhesive layer 711, the thickness of the first protection layer 71 may be 25 micrometers to 35 micrometers, for example, the thickness of the first covering layer 712 is 12.5 micrometers, the thickness of the first adhesive layer 711 is 20 micrometers, that is, the thickness of the first protection layer 71 is 32.5 micrometers, and then the thickness of the first conductive material 91 is 30.5 micrometers to 34.5 micrometers, for example, 32.5 micrometers; the thickness of the first emi shielding layer 61 may be 10 microns to 20 microns, such as 16 microns.

In some exemplary embodiments, as shown in fig. 4, the first circuit board 31 may further include a second circuit layer 313 disposed on the second side of the first substrate 311, the second circuit layer 313 including a second ground circuit; the circuit board further comprises a first insulating layer 51, a second electromagnetic interference shielding layer 62 and a conducting layer 81 which are sequentially stacked on one side of the second circuit layer 313 far away from the first substrate 311; the first insulating layer 51 and the second electromagnetic interference shielding layer 62 are provided with a second opening (the second opening penetrates through the first insulating layer 51 and the second electromagnetic interference shielding layer 62), the second opening exposes at least a part of the second ground line, a second conductive material 92 is filled in the second opening, a height difference between a surface of the second conductive material 92 and a surface of the second electromagnetic interference shielding layer 62 far away from the first substrate 311 is 0 micrometer to 2 micrometer (in the example of fig. 4, the height difference is 0 micrometer, that is, a surface of the second conductive material 92 is flush with a surface of the second electromagnetic interference shielding layer 62 far away from the first substrate 311), and the second conductive material 92 connects the conductive layer 81 and the second ground line.

In one example of this embodiment, the second conductive material 92 may be a metal material, such as any one or more of gold, silver, and copper. The second conductive material 92 may be filled in the second opening through a plating process or a coating process, for example, metal copper may be filled in the second opening through a plating process, or a silver paste may be dotted in the second opening through a coating process and cured. The second conductive material 92 is formed in the second opening by an electroplating process or a coating process, so that the requirements of different circuit boards for filling different level differences can be met, and the height difference between the surface of the second conductive material 92 and the surface, far away from the first substrate 311, of the second electromagnetic interference shielding layer 62 can be ensured to be 0-2 micrometers under the conditions of the requirements of different level differences for filling, so that the conductive layer 81 can be reliably connected with a second grounding circuit, and the grounding of the conductive layer 81 is realized.

In one example of the present embodiment, the material of the first insulating layer 51 may be insulating ink, such as PSR ink. The material of the second emi shielding layer 62 may be a metal material, such as silver, and the second emi shielding layer 62 may be formed by an electroplating process. The material of the conductive layer 81 may be conductive adhesive. In other examples, the first insulating layer 51 may be a cover film having the second opening, the cover film including an insulating film and an adhesive layer provided on one side of the insulating film, the cover film being bonded to the second wiring layer 313 by the adhesive layer.

In some exemplary embodiments, as shown in fig. 3 and 4, the circuit board may include a main body portion 21 and a bendable portion 22 located at a first side of the main body portion 21, the main body portion 21 may include a plurality of circuit boards stacked, each of the circuit boards includes a substrate and at least one circuit layer disposed on the substrate, the plurality of circuit boards includes the first circuit board 31, and the first circuit board 31 extends to the bendable portion 22; the first protection layer 71, the first emi shielding layer 61, and the first opening are all located in the bendable portion 22.

In one example of the present embodiment, the first substrate 311, the first circuit layer 312, and the second circuit layer 313 of the first circuit board 31 may all extend to the bendable part 22, that is, the main body part 21 and the bendable part 22 all include the first circuit board 31. In an example of this embodiment, the main body portion 21 and the bendable portion 22 may each include the first insulating layer 51, the second electromagnetic interference shielding layer 62, and the conductive layer 81. The second opening may be located in the main body portion 21 or the bendable portion 22. The number of layers of the circuit layer of the bendable portion 22 is less than that of the main body portion 21, and the number of layers of the circuit layer of the bendable portion 22 is less to facilitate bending.

In one example of the present embodiment, the thickness of the second circuit layer 313 may be 15 to 25 micrometers, such as 21 micrometers; the thickness of the first insulating layer 51 may be 20 to 30 microns, such as 25 microns; the thickness of the second EMI shielding layer 62 may be 10 microns to 20 microns, such as 16 microns; the total thickness of the first insulating layer 51 and the second electromagnetic interference shielding layer 62 is, for example, 41 micrometers, and the thickness of the second conductive material 92 is 39 micrometers to 43 micrometers, for example, 41 micrometers; the thickness of the conductive layer 81 may be different between the main body portion 21 and the bendable portion 22, for example, the thickness of the conductive layer 81 of the main body portion 21 may be 100 micrometers to 200 micrometers, such as 150 micrometers, and the thickness of the conductive layer 81 of the bendable portion 22 may be 20 micrometers to 40 micrometers, such as 30 micrometers.

In some exemplary embodiments, as shown in fig. 4, the circuit board may further include a binding portion 23 located at a second side of the main body portion 21 opposite to the first side; the plurality of circuit boards include a second circuit board 32, the second substrate 321 and at least one circuit layer of the second circuit board 32 extend to the binding portion 23, and the circuit layer of the second circuit board 32 extending to the binding portion 23 is provided with a bare binding pin (a position indicated by reference numeral 322 in fig. 4) configured to be bound and connected with an external circuit.

In an example of this embodiment, the binding portion 23 may include a third circuit layer 322 (the third circuit layer 322 is one circuit layer of the second circuit board 32) and a second protective layer 72 sequentially stacked on the first side surface of the second substrate 321, one end of the third circuit layer 322, which is far away from the main body portion 21, is provided with the binding pin, and the second protective layer 72 exposes the binding pin; the binding part 23 may further include a third protective layer 73 provided on the second side of the second substrate 321.

In an example of this embodiment, the second protection layer 72 may include a second cover layer 722 and a second adhesive layer 721, and the second adhesive layer 721 is located between the second cover layer 722 and the third circuit layer 322. The third protective layer 73 can include a third cover layer 732 and a third adhesive layer 731, wherein the third adhesive layer 731 is disposed between the third cover layer 732 and the second substrate 321. The second cover layer 722 and the third cover layer 732 may be made of polyimide. The material of the second adhesive layer 721 and the third adhesive layer 731 may be epoxy resin or acryl. For example, the forming process of the second protective layer 72 and the third protective layer 73 may be the same, and taking the forming process of the second protective layer 72 as an example, a second cover film having a third opening is attached on the surface of the third circuit layer 322, the second cover film includes a second cover layer 722 and a second adhesive layer 721 disposed on one side of the second cover layer 722, the second cover film may be thermally bonded on the third circuit layer 322 by using a thermal compression process, the second adhesive layer 721 is melted and bonds the second cover layer 722 on the third circuit layer 322 during the thermal compression process, and the third opening exposes the bonding pins of the third circuit layer 322.

In one example of the present embodiment, the thickness of the second substrate 321 may be 10 micrometers to 30 micrometers, such as 20 micrometers; the thickness of the third circuit layer 322 may be 10 microns to 20 microns, such as 16 microns; the second protective layer 72 includes a second cover layer 722 and a second adhesive layer 721, the thickness of the second protective layer 72 may be 25 micrometers to 35 micrometers, for example, the thickness of the second cover layer 722 is 12.5 micrometers, and the thickness of the second adhesive layer 721 is 20 micrometers; the third protective layer 73 includes a third covering layer 732 and a third adhesive layer 731, and the thickness of the third protective layer 73 may be 25 micrometers to 35 micrometers, for example, the thickness of the third covering layer 732 is 12.5 micrometers, and the thickness of the third adhesive layer 731 is 20 micrometers.

In some exemplary embodiments, as shown in fig. 4, the plurality of circuit boards may further include a third circuit board 33, the first circuit board 31, the second circuit board 32, and the third circuit board 33 may be sequentially stacked, adjacent two circuit boards are bonded by an adhesive layer, and the first side of the first substrate 311 on which the first circuit layer 312 is disposed toward the second circuit board 32. The side of the second substrate 321 on which the third circuit layer 322 is provided may be disposed toward the first wiring board 31. In the main body 21, the first circuit board 31 and the second circuit board 32 may be bonded to each other by a first adhesive layer 41, and the third circuit board 33 and the second circuit board 32 may be bonded to each other by a second adhesive layer 42.

In one example of this embodiment, the second circuit board 32 in the main body 21 may include a third circuit layer 322 and a fourth circuit layer 323 respectively disposed on two sides of the second substrate 321, the third circuit layer 322 may be located on a first side of the second substrate 321 facing the first circuit board 31, and the fourth circuit layer 323 may be located on a second side of the second substrate 321 facing the third circuit board 33. The first circuit layer 312 of the first circuit board 31 is located on a first side of the first substrate 311 facing the second circuit board 32, and the second circuit layer 313 of the first circuit board 31 is located on a second side of the first substrate 311 facing away from the second circuit board 32. The third circuit board 33 includes a third substrate 331, and a fifth circuit layer 332 and a sixth circuit layer 333 respectively disposed on two sides of the third substrate 331, where the fifth circuit layer 332 may be located on a first side of the third substrate 331 facing the second circuit board 32, and the sixth circuit layer 333 may be located on a second side of the third substrate 331 facing away from the second circuit board 32. In this example, the first adhesive layer 41 may be adhered between the first circuit layer 312 of the first circuit board 31 and the third circuit layer 322 of the second circuit board 32, and the second adhesive layer 42 may be adhered between the fourth circuit layer 323 of the second circuit board 32 and the fifth circuit layer 332 of the third circuit board 33. The number of layers of the circuit layer of the main body portion 21 of the circuit board of this example is six, and each of the three circuit boards includes one substrate and two circuit layers respectively provided on both side surfaces of the substrate. In other examples, the number of layers of the circuit layer of the main body 21 may be designed as needed, for example, three, four, and the like. The substrate of each of the three circuit boards may be made of polyimide, polyetheretherketone or dacron, and the material of each circuit layer may be copper. In some examples, the forming of each wiring board may include: providing a base material, wherein the base material comprises an insulating base plate and copper layers (a glue layer or no glue layer can be arranged between the insulating base plate and the copper layers) covered on two surfaces of the insulating base plate, and if the thickness of the copper layer of the base material cannot reach the thickness of a required circuit layer, the copper layer with a certain thickness can be electroplated on the copper layer of the base material; and carrying out procedures of exposure, development, etching and the like on the copper layers on the two surfaces to form a required circuit layer.

In an example of this embodiment, the main body 21 may further include a second insulating layer 52 and a third electromagnetic interference shielding layer 63 stacked in this order on the third circuit board 33 on the side away from the second circuit board 32. The second insulating layer 52 may be disposed on the sixth wiring layer 333 of the third wiring board 33, and the material of the second insulating layer 52 may be insulating ink, such as PSR ink. In other examples, the second insulating layer 52 may be a cover film including an insulating film and an adhesive layer provided on one side of the insulating film, and the cover film is laminated on the sixth wiring layer 333 by the adhesive layer. The third emi shielding layer 63 and the first emi shielding layer 61 may be integrally connected, for example, the third emi shielding layer 63 and the first emi shielding layer 61 are the same emi shielding film attached to the main body 21 and the foldable portion 22, or the third emi shielding layer 63 and the first emi shielding layer 61 are made of the same metal material and may be formed on the main body 21 and the foldable portion 22 through the same electroplating process. As shown in fig. 4, a certain height difference exists between the main body portion 21 and the bendable portion 22 on the surface of the circuit board close to the third circuit board 33, the portion of the main body portion 21 protruding out of the bendable portion 22 includes a plurality of circuit layers of the second circuit board 32 and the third circuit board 33, the end surfaces of the plurality of circuit layers close to the bendable portion 22 are exposed as seen in fig. 4, but in the actual circuit board manufacturing process, in the process of forming the insulating layer on the surface of the circuit layer and in the process of bonding the adjacent circuit boards by using the bonding layer, the materials for forming the insulating layer and the bonding layer partially overflow the edge of the circuit board so as to cover the end surfaces of the plurality of circuit layers close to the bendable parts 22, in this way, the third emi shielding layer 63 and the first emi shielding layer 61 formed later do not contact the end surfaces of the plurality of circuit layers near the bendable portion 22.

In one example of this embodiment, the thickness of the fourth circuit layer 323 may be 10 to 20 micrometers, such as 16 micrometers; the thickness of the third substrate 331 may be 10 to 15 microns, such as 12.5 microns; the thickness of the fifth wiring layer 332 may be 10 microns to 20 microns, such as 12 microns; the thickness of the sixth wiring layer 333 may be 15 micrometers to 25 micrometers, such as 21 micrometers; the thickness of the second insulating layer 52 may be 20 to 30 microns, such as 25 microns; the thickness of the third emi shielding layer 63 may be 10 to 20 microns, such as 16 microns; the thickness of the first adhesive layer 41 may be 30 to 50 micrometers, such as 40 micrometers; the thickness of the second adhesive layer 42 may be 30 to 50 microns, such as 40 microns.

The utility model discloses circuit board can be applicable to multiple display module assembly (for example OLED display module assembly, LCD display module assembly etc.). The circuit board may include a display circuit and may further include a touch circuit, and the display circuit and the touch circuit may be disposed on different circuit layers. The circuit board is bound with the display panel of the display module through the binding part 23, and the bendable part 22 of the circuit board can be bent to the back of the display panel and fixed on the back of the display panel.

The embodiment of the utility model provides a still provide an electronic equipment, including arbitrary embodiment the circuit board. The electronic device may be a display device, such as a product or a component with a display function, for example, a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame, a navigator, and the like. In some examples, the electronic device may be a touch display device.

In the description of the embodiments of the present invention, it should be noted that the terms "upper", "lower", "left", "right", "top", "inner", "outer", "axial", "four corners" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are only for the convenience of describing the embodiments of the present invention, and do not indicate or imply that the structures indicated have specific orientations, are constructed and operated in specific orientations, and thus, are not to be construed as limitations of the present invention.

In the description of the embodiments of the present invention, unless otherwise explicitly specified or limited, the terms "connected," "fixedly connected," "mounted," and "assembled" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; the terms "mounted," "connected," and "fixedly connected" may be directly connected or indirectly connected through intervening elements, or may be connected through the interconnection between two elements. The specific meaning of the above terms in the embodiments of the present invention can be understood in specific cases by those skilled in the art.

Claims (13)

1. A circuit board, characterized by: the circuit board comprises a first circuit board, wherein the first circuit board comprises a first substrate and a first circuit layer arranged on a first side surface of the first substrate, and the first circuit layer comprises a first grounding circuit;

the circuit board further comprises a first protective layer and a first electromagnetic interference shielding layer which are sequentially stacked on one side of the first circuit layer, which is far away from the first substrate;

the first protection layer is provided with a first opening, at least one part of the first grounding circuit is exposed out of the first opening, a first conductive material is filled in the first opening, the height difference between the surface of the first conductive material and the surface of the first protection layer, which is far away from the first substrate, is 0-2 micrometers, and the first electromagnetic interference shielding layer is connected with the first grounding circuit through the first conductive material.

2. The circuit board of claim 1, wherein: the first circuit board further comprises a second circuit layer arranged on the second side surface of the first substrate, and the second circuit layer comprises a second grounding circuit;

the circuit board further comprises a first insulating layer, a second electromagnetic interference shielding layer and a conducting layer which are sequentially stacked on one side, far away from the first substrate, of the second circuit layer;

the first insulating layer and the second electromagnetic interference shielding layer are provided with second openings, at least one part of the second grounding circuit is exposed out of the second openings, a second conductive material is filled in the second openings, the height difference between the surface of the second conductive material and the surface, far away from the first substrate, of the second electromagnetic interference shielding layer is 0-2 micrometers, and the conductive layer is connected with the second grounding circuit through the second conductive material.

3. The circuit board of claim 2, wherein: the second conductive material is a metal material; or/and the conducting layer is made of conducting adhesive.

4. The circuit board of claim 1, wherein: the first conductive material is a metal material.

5. The circuit board of claim 1, wherein: first protective layer includes first overburden and first viscose layer, first viscose layer is located first overburden with between the first circuit layer.

6. The circuit board of claim 2, wherein: the circuit board comprises a main body part and a bendable part positioned on the first side of the main body part, the main body part comprises a plurality of circuit boards which are stacked, each circuit board comprises a substrate and at least one circuit layer arranged on the substrate, the plurality of circuit boards comprise the first circuit board, and the first circuit board extends to the bendable part;

the first protection layer, the first electromagnetic interference shielding layer and the first opening are all located at the bendable portion.

7. The circuit board of claim 6, wherein: the main body portion and the bendable portion include the first insulating layer, the second electromagnetic interference shielding layer and the conductive layer, and the second opening is located in the main body portion.

8. The circuit board of claim 6, wherein: the circuit board further includes a binding portion located at a second side of the main body portion opposite to the first side;

the plurality of circuit boards include the second circuit board, the second base plate and at least one circuit layer of second circuit board extend to binding portion, the extension of second circuit board extremely the circuit layer of binding portion is equipped with naked binding pin, it is connected to bind the pin configuration to bind with external circuit.

9. The circuit board of claim 8, wherein: the binding part comprises a third circuit layer and a second protective layer which are sequentially stacked on the first side surface of the second substrate, the binding pin is arranged at one end, far away from the main body part, of the third circuit layer, and the second protective layer exposes the binding pin; the binding portion further includes a third protective layer disposed on the second side of the second substrate.

10. The circuit board of claim 9, wherein: the second protective layer comprises a second covering layer and a second adhesive layer, and the second adhesive layer is positioned between the second covering layer and the third circuit layer; or/and the third protective layer comprises a third covering layer and a third adhesive layer, and the third adhesive layer is positioned between the third covering layer and the second substrate.

11. The circuit board of claim 8, wherein: the plurality of circuit boards further comprise a third circuit board, the first circuit board, the second circuit board and the third circuit board are sequentially stacked and arranged, two adjacent circuit boards are bonded through a bonding layer, and the first side face of the first substrate faces the second circuit board.

12. The circuit board of claim 11, wherein: the second circuit board in the main body part comprises a third circuit layer and a fourth circuit layer which are respectively arranged on two side surfaces of the second substrate, and the third circuit board comprises a third substrate, a fifth circuit layer and a sixth circuit layer which are respectively arranged on two side surfaces of the third substrate;

the main part is still including overlapping in proper order and locating keeping away from of third circuit board second insulating layer and the third electromagnetic interference shielding layer of second circuit board one side, the third electromagnetic interference shielding layer with first electromagnetic interference shielding layer body coupling.

13. An electronic device, characterized in that: comprising a circuit board according to any of claims 1-12.

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