CN112272445A

CN112272445A - Flexible circuit board, display panel and display device

Info

Publication number: CN112272445A
Application number: CN202011181512.4A
Authority: CN
Inventors: 俞芳
Original assignee: Kunshan New Flat Panel Display Technology Center Co Ltd
Current assignee: Kunshan New Flat Panel Display Technology Center Co Ltd
Priority date: 2020-10-29
Filing date: 2020-10-29
Publication date: 2021-01-26
Anticipated expiration: 2040-10-29
Also published as: CN112272445B

Abstract

The invention provides a flexible circuit board, a display panel and a display device, and relates to the technical field of display, wherein the flexible circuit board comprises a flexible circuit board main body and a first binding area connected with the flexible circuit board main body; the flexible circuit board is characterized in that a cover film and a solder resist ink layer connected with the cover film are arranged on the flexible circuit board main body, and the cover film is located on one side of the first binding area, and the solder resist ink layer deviates from the first binding area. According to the invention, the solder resist ink layer is utilized to separate the cover film from the first binding region, so that when the cover film is arranged on the flexible circuit board main body through the bonding glue, the bonding glue cannot overflow to the first binding region, the binding effect between the first binding region and the display panel can be improved, and the display effect of the display panel is further improved.

Description

Flexible circuit board, display panel and display device

Technical Field

The invention relates to the technical field of display, in particular to a flexible circuit board, a display panel and a display device.

Background

An OLED (Organic Light-Emitting Diode) display panel has characteristics of self-luminescence, high contrast, thin thickness, fast response speed, wide viewing angle, low power consumption, and flexible display, and is therefore widely used in display devices, such as smart watches or smart hand rings.

In order to ensure the input of the driving signal and the driving power in the display panel, a driving Circuit (IC) and a Flexible Printed Circuit (FPC) are generally bonded to the display panel. The flexible circuit board generally comprises a covering film and a flexible circuit board body and a binding area which are connected with each other, wherein the covering film is bonded on the flexible circuit board through a bonding adhesive and used for protecting copper wires or via holes on the flexible circuit board, but when the covering film is pressed on the flexible circuit board body, the bonding adhesive overflows between the covering film and the flexible circuit board and adheres to the binding area to influence the binding of the flexible circuit board, the display panel and the drive circuit and further influence the display effect of the display panel.

Disclosure of Invention

In view of the foregoing problems, embodiments of the present invention provide a flexible circuit board, a display panel, and a display device, which can prevent adhesive between a cover film and a flexible circuit board main body from overflowing to a first binding region, improve a binding effect between the first binding region and the display panel, and further improve a display effect of the display panel.

In order to achieve the above object, the embodiments of the present invention provide the following technical solutions:

a first aspect of an embodiment of the present invention provides a flexible circuit board, including: the flexible circuit board main part and with the first district of binding that the flexible circuit board main part is connected, be equipped with in the flexible circuit board main part cover the membrane and with cover the solder mask ink layer that the membrane is connected, cover the membrane and be located the solder mask ink layer deviates from on one side of the first district of binding.

The flexible circuit board as described above, wherein the projection of the cover film on the flexible circuit board main body and the projection of the solder resist ink layer on the flexible circuit board main body have an overlapping area.

The flexible circuit board as described above, wherein the length of the overlapping area is 0.3-0.4mm along the length direction of the first bonding region.

The flexible circuit board as described above, wherein the flexible circuit board includes a substrate and a patterned circuit layer disposed on the substrate.

The flexible circuit board as described above, wherein the cover film is attached to the flexible circuit board main body by an adhesive glue.

The number of the flexible circuit board main bodies is two, and the two flexible circuit board main bodies are symmetrically arranged on two sides of the first binding region.

A second aspect of embodiments of the present invention provides a display panel, which includes an array substrate and the flexible circuit board as described above; the array substrate comprises a second binding region, and the second binding region is bound with the first binding region of the flexible circuit board.

The display panel is as above, wherein the distance between the end of the second binding area facing the solder resist ink layer and the solder resist ink layer of the flexible circuit board is 0.04-0.08 mm.

The display panel as described above, wherein the display panel further includes a driver chip, the driver chip has a third bonding region, and the third bonding region is bonded on the array substrate through a flip-chip film.

A third aspect of embodiments of the present invention provides a display device including the display panel described above.

In the flexible circuit board, the display panel and the display device provided by the embodiment of the invention, the cover film and the solder resist ink layer are arranged on the flexible circuit board main body, wherein the solder resist ink layer is arranged between the cover film and the first binding area, and the cover film and the first binding area are separated by utilizing the solder resist ink layer, so that when the cover film is arranged on the flexible circuit board main body through the bonding glue, the bonding glue cannot overflow to the first binding area, the binding effect between the first binding area and the display panel can be improved, and the display effect of the display panel is further improved.

In addition to the technical problems solved by the embodiments of the present invention, the technical features constituting the technical solutions, and the advantages brought by the technical features of the technical solutions described above, other technical problems that can be solved by the flexible circuit board, the display panel, and the display device provided by the embodiments of the present invention, other technical features included in the technical solutions, and advantages brought by the technical features will be further described in detail in the detailed description.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.

Fig. 1 is a first schematic structural diagram of a flexible circuit board according to an embodiment of the present invention;

FIG. 2 is a top view of FIG. 1;

fig. 3 is a schematic structural diagram of a flexible circuit board according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a display panel according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a display panel in the related art.

Reference numerals:

10: a flexible circuit board;

11: a flexible circuit board main body;

12: a first binding region;

13: covering the film;

14: a solder resist ink layer;

15: an overlap region;

20: a second binding region.

Detailed Description

The inventors of the present disclosure found in the actual working process that: the cover film is usually bonded on the flexible circuit board by using bonding glue, the cover film is bonded on the flexible circuit board by using a pressing mode, in the pressing process, the bonding glue overflows from the space between the cover film and the flexible circuit board and overflows to the first binding area, the bonding glue can influence the flexible circuit board and the display panel or the binding of the flexible circuit board and the drive circuit, and further influences the display effect of the display panel.

In view of the above technical problems, embodiments of the present invention provide a flexible circuit board, a display panel, and a display device, in which a cover film and a solder resist ink layer are disposed on a flexible circuit board main body, the solder resist ink layer is disposed between the cover film and a first binding region, the cover film and the first binding region are separated by using the solder resist ink layer, and when the cover film is disposed on the flexible circuit board main body through a bonding adhesive, the bonding adhesive does not overflow to the first binding region, so that a binding effect between the first binding region and the display panel can be improved, and a display effect of the display panel is further improved.

In order to make the aforementioned objects, features and advantages of the embodiments of the present invention more comprehensible, embodiments of the present invention are described in detail below with reference to the accompanying drawings. It is to be understood that the described embodiments are merely a few embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1, an embodiment of the present invention provides a flexible circuit board 10, where the flexible circuit board 10 includes a flexible circuit board body 11 and a first bonding area 12 connected to the flexible circuit board body 11.

The flexible circuit board 10 may be applied to a display panel, and may also be applied to other electronic devices, and for convenience of the following description, the following embodiments are described by taking the flexible circuit board 10 as an example.

The flexible circuit board main body 11 generally includes a substrate and a patterned circuit layer disposed on the substrate, where the patterned circuit layer is used to be electrically connected to a peripheral circuit in the display panel to provide a driving signal for the display panel, so as to ensure normal display of the display panel, where the substrate may be a polyacetamide (Polyimide, PI for short), and the polyacetamide has good insulation and flexibility, so that the substrate may have a bendable characteristic.

The graphical circuit layer can be adhered to one side surface of the substrate through the adhesive, when the graphical circuit layer is prepared, the metal plate can be provided firstly, a specific pattern is formed on the metal plate by utilizing an etching mode, a circuit diagram meeting the requirement of electric connection is formed on the metal plate, in the embodiment, the metal plate can be made of a copper material, the copper material has the advantages of high conductivity and low material cost, in addition, the graphical circuit layer adopts the mode of connecting the adhesive to the substrate, the graphical circuit layer is simple and easy to realize, firm connection and low possibility of falling off.

In this embodiment, the flexible circuit board main body 11 may be implemented by bonding a Chip On Film (COF for short), that is, the flexible circuit board main body 11 is bonded to the COF first, and then the COF is bonded to the display panel.

In view of the small size of the flexible circuit board 10, if the flexible circuit board 10 is directly bonded to the display panel, on one hand, the crimping difficulty between the flexible circuit board 10 and the display panel is increased, and on the other hand, the signal writing is not facilitated, so that the problem of poor contact between the flexible circuit board 10 and the display panel exists, therefore, in the embodiment of the invention, the first bonding region 12 is arranged on one side of the flexible circuit board main body 11, and the connection between the flexible circuit board 10 and the display panel is realized by using the first bonding region 12, so that the contact area between the flexible circuit board 10 and the display panel can be increased, the crimping difficulty is reduced, the signal writing is facilitated, and the normal operation of the display panel is ensured.

Still set up on the flexible circuit board main part 11 and cover membrane 13 and hinder welding ink layer 14 with covering the connection of membrane 13, utilize to cover membrane 13 and hinder welding ink layer 14 and protect the circuit on the flexible circuit board main part 11, avoid in the flexible circuit board main part 11 that the graphical circuit layer receives to collide with, perhaps the graphical circuit layer exposes in the air by the oxidation, and then guarantees the normal work of flexible circuit board main part 11.

The cover film 13 may be made of polyimide or polyester film, and in the implementation process, a layer of adhesive is firstly coated on the side surface of the cover film 13, and then the cover film 13 is pressed on the flexible circuit board main body 11 by using a hot pressing process to protect the circuit on the flexible circuit board main body 11.

Solder resist ink is printed on the flexible circuit board body 11 to form a solder resist ink layer 14, and the solder resist ink layer 14 can protect the circuit on the flexible circuit board body 11 and also can have the functions of solder resist and solder limiting.

In the embodiment of the present invention, the cover film 13 is located on a side of the solder resist ink layer 14 away from the first binding region 12, that is, taking the orientation shown in fig. 1 as an example, the cover film 13 is located on the left side of the solder resist ink layer 14, the cover film 13 and the first binding region 12 can be separated by using the solder resist ink layer 14, when the cover film 13 is disposed on the flexible circuit board main body 11 through the adhesive, the adhesive does not overflow to the first binding region 12, the binding effect between the first binding region 12 and the display panel can be improved, and the display effect of the display panel is further improved.

In some embodiments, the projection of the cover film 13 on the flexible circuit board body 11 and the projection of the solder resist ink layer 14 on the flexible circuit board body 11 have an overlapping area 15, that is, the solder resist ink layer 14 is overlapped on the cover film 13, so that the connection strength between the cover film 13 and the solder resist ink layer 14 can be enhanced, the cover film 13 is prevented from being separated from the solder resist ink layer 14, water vapor in the outside air is prevented from eroding the patterned circuit layer, further, the patterned circuit layer is prevented from being oxidized, and the normal function of the flexible circuit board 10 is ensured.

The length of the overlapping area 15 is 0.3-0.4mm along the length direction of the first binding area 12, that is, along the X direction in fig. 2, which can both increase the connection strength between the cover film 13 and the solder resist ink layer 14 and prevent the cover film 13 and the solder resist ink layer 14 from being separated from each other.

In some embodiments, as shown in fig. 3, the number of the flexible circuit board main bodies 11 is two, the two flexible circuit board main bodies 11 are symmetrically disposed at two sides of the first binding region 12, that is, along the X direction, the first binding region 12 has a first end surface and a second end surface which are disposed oppositely, one flexible circuit board main body 11 is disposed on the first end surface, and the other flexible circuit board main body 11 is disposed on the second end surface, so that more circuits can be integrated on one flexible circuit board 10, the two flexible circuit board main bodies 11 share one first binding region 12, and on the premise that the first binding region 12 is fully utilized, the advantage of reducing the size of the flexible circuit board 10 is also provided.

A second aspect of the embodiments of the present invention provides a display panel, which includes an array substrate and the flexible circuit board 10 described in the above embodiments, wherein the array substrate has a second bonding region 20, and the second bonding region 20 is bonded to the first bonding region 12 of the flexible circuit board 10, so as to electrically connect the flexible circuit board 10 and the array substrate.

In the related art, as shown in fig. 4, generally, only the cover film 13 is used to protect the flexible circuit board 10, in an actual manufacturing process, adhesive glue needs to be coated on the cover film 13, and the cover film 13 is pressed on the flexible circuit board 11 by using a pressing device, in the above process, the adhesive glue between the cover film 13 and the flexible circuit board 10 may overflow onto the first binding region 12, in order to avoid the adhesive glue affecting an effective binding region of the first binding region 12, a distance between an end of the second binding region 20 close to the cover film 13 and the cover film 13 is usually 0.2mm to 0.5mm, so that a length of the first binding region 12 may be increased, and accordingly, on the premise that a size of the flexible circuit board 10 is certain, a length of the flexible circuit board body 11 may be shortened, and thus a design difficulty of a line on the flexible circuit board body 11 may be increased.

As shown in fig. 1 and 5, in the embodiment of the present invention, the flexible circuit board 10 is specially designed, the cover film 13 and the solder resist ink 14 are used to simultaneously protect the flexible circuit board main body 11, and the solder resist ink layer 14 is located between the first binding area 12 and the cover film 13, so that the adhesive between the cover film 13 and the flexible circuit board main body 11 is prevented from overflowing into the first binding area 12, and accordingly, the length of the first binding area 12 does not need to be increased, so that a sufficient routing space is provided for a circuit on the flexible circuit board main body 11, and the difficulty in designing the circuit on the flexible circuit board main body 11 is reduced.

In this embodiment, the array substrate may include a substrate and a TFT array layer disposed on the substrate, where the substrate serves as a carrier of the array substrate and is used to support devices disposed thereon, and the substrate may be a rigid substrate, such as a glass substrate or a plastic substrate, or a flexible substrate, such as a flexible substrate including Polyimide (PI).

The TFT array layer may include a plurality of TFTs arranged in an array and a planarization layer, and the planarization layer covers the TFT array layer.

The display panel may further include an OLED layer and an encapsulation layer, wherein the OLED layer is disposed on a side of the flat layer facing away from the substrate, wherein the OLED layer may include a cathode layer, a light emitting layer, and an anode layer, which are stacked, the cathode layer being configured to generate electrons, the anode layer being configured to generate holes, and the electrons and the holes are combined in the light emitting layer to form electron-hole pairs, i.e., excitons, which are capable of transferring energy to the organic light emitting material of the light emitting layer, so that the organic light emitting material emits light.

The packaging layer is arranged on the side, deviating from the light emitting layer, of the cathode layer, and is used for packaging the light emitting layer, so that water, oxygen and the like are prevented from entering the light emitting layer, and the working reliability of the light emitting layer is guaranteed.

The encapsulation layer can be an inorganic film, an organic film and an organic/inorganic composite film, wherein the inorganic film can be a ceramic film, such as a silicon nitride film; the organic film can be a polymer film and can be formed by superposing two or more than two polymer films; the organic/inorganic composite film may include a plurality of stacked composite films, each of which includes stacked organic thin films and inorganic thin films.

In some embodiments, as shown in fig. 5, the distance between the end of the second binding region 20 facing the solder resist ink layer 14 and the solder resist ink layer 14 is 0.04-0.08mm, for example, the distance between the end of the second binding region 20 facing the solder resist ink layer 14 and the solder resist ink layer 14 is 0.05mm, or the distance between the end of the second binding region 20 facing the solder resist ink layer 14 and the solder resist ink layer 14 is 0.06mm, compared with the related art in which the distance between the end of the second binding region 20 close to the cover film 13 and the cover film 13 is 0.2mm-0.5mm, the flexible circuit board designed in this embodiment can reduce the distance between the second binding region 20 and the cover film 13, thereby providing enough space for the circuit on the flexible circuit board body 11 and reducing the difficulty of designing the circuit on the flexible circuit board body 11.

Meanwhile, the design of the solder resist ink layer 14 can also prevent the adhesive glue between the cover film 13 and the flexible circuit board main body 11 from overflowing to the first binding area 12, so that the sensitivity between the flexible circuit board 10 and the array substrate is improved, and the normal display of the display panel is ensured.

In some embodiments, the display panel further includes a driver chip, the driver chip has a third binding region, the third binding region is bound on the array substrate through a chip on film, and the flexible circuit board is bound on the chip on film, so that a signal on the driver chip can be transmitted to the array substrate through the flexible circuit board, and normal display of the display panel is controlled.

Since the flexible circuit board is designed in this embodiment, the length difference between the first bonding area 12 and the second bonding area 20 and the length difference between the first bonding area 12 and the chip on film can be reduced, the size of the flexible circuit board 10 can be reduced, the screen occupation ratio of the non-display area in the display panel can be reduced, and the user experience can be increased.

A third aspect of embodiments of the present invention provides a display device including the display panel in any one of the above embodiments.

The display device can be a tablet computer, a smart phone, a display screen and other mobile terminals or other terminal equipment with a display panel.

In the display device provided by the embodiment of the invention, the cover film 13 and the solder resist ink layer 14 connected with the cover film 13 are arranged on the flexible circuit board main body 11, wherein the cover film 13 is positioned on one side of the solder resist ink layer 14 away from the first binding region 12, and the cover film 13 and the first binding region 12 can be separated by using the solder resist ink layer 14, so that when the cover film 13 is arranged on the flexible circuit board main body 11 through the adhesive glue, the adhesive glue cannot overflow into the first binding region 12, the binding effect between the first binding region 12 and the display panel can be improved, and the display effect of the display device can be further improved.

In addition, the above design can reduce the distance between the second binding region 20 of the display panel and the cover film 13, so as to provide a sufficient wiring space for the circuit on the flexible circuit board main body 11, reduce the design difficulty of the circuit on the flexible circuit board main body 11, reduce the size of the flexible circuit board 10, and further increase the screen occupation ratio of the display panel.

The embodiments or implementation modes in the present specification are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments may be referred to each other.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; may be mechanically coupled, may be electrically coupled or may be in communication with each other; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the description of the present specification, reference to the description of the terms "one embodiment", "some embodiments", "an illustrative embodiment", "an example", "a specific example", or "some examples", etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. The flexible circuit board is characterized by comprising a flexible circuit board main body and a first binding area connected with the flexible circuit board main body;

the flexible circuit board is characterized in that a cover film and a solder resist ink layer connected with the cover film are arranged on the flexible circuit board main body, and the cover film is located on one side, deviating from the first binding area, of the solder resist ink layer.

2. The flexible circuit board of claim 1, wherein a projection of the cover film on the flexible circuit board body has an overlapping area with a projection of the solder resist ink layer on the flexible circuit board body.

3. The flexible circuit board of claim 2, wherein the length of the overlapping area is 0.3-0.4mm along the length of the first bonding area.

4. The flexible circuit board of any one of claims 1-3, wherein the flexible circuit board comprises a substrate and a patterned wiring layer disposed on the substrate.

5. The flexible circuit board according to any one of claims 1 to 3, wherein the cover film is attached to the flexible circuit board main body by an adhesive glue.

6. The flexible circuit board according to any one of claims 1 to 3, wherein the number of the flexible circuit board main bodies is two, and the two flexible circuit board main bodies are symmetrically arranged on both sides of the first bonding region.

7. A display panel comprising an array substrate and the flexible circuit board according to any one of claims 1 to 6; the array substrate comprises a second binding region, and the second binding region is bound with the first binding region of the flexible circuit board.

8. The display panel of claim 7, wherein a distance between an end of the solder resist ink layer of the second binding area facing the flexible circuit board and the solder resist ink layer is 0.04-0.08 mm.

9. The display panel of claim 8, further comprising a driver chip having a third bonding region bonded to the array substrate via a flip-chip film.

10. A display device characterized by comprising the display panel according to any one of claims 7 to 9.