Flexible printed circuit (FPC) easy to bend and display module

Abstract

The utility model discloses a flexible printed circuit (FPC) easy to bend. The FPC easy to bend comprises an FPC body. The FPC body comprises a copper foil, a base material layer, a copper layer and a PI layer. The PI layer, the copper layer, the base material layer, the copper layer and the PI layer are sequentially stacked, the copper foil is arranged on one face of the binding area of the FPC body, the copper foil on the bending area has stress when being bent, and therefore at least one round hole is formed in the copper foil of the bending line on the FPC body, the stress of the copper foil can be reduced, and the binding area of the FPC is made to be softer and easier to bend. The hardness of the PI layer is high, and the bending gap is arranged on the PI layer far away from the copper foil, so that the FPC is softer and is easy to bend. The bending notch is formed in the opposite surface of the binding area, and bending-resistant green oil is arranged on the bending notch. The bending-resistant green oil not only enhances the bending-resistant performance of the FPC in the binding area of the FPC so that the FPC is not easy to break, but also has an insulating property so as to avoid short circuit. In addition, the utility model further discloses a display module.

Description

Technical Field

[0001] The utility model relates to the field of FPC, in particular to an easily bendable FPC and a display module. Background Art

[0002] The FPC on the main screen is an essential component of the display module. During module assembly, it must be bent and aligned to attach to the backlight's metal frame. However, the FPC's bend is not flexible enough, resulting in high stress and prone to damage and breakage. Therefore, an FPC with excellent bendability is urgently needed. Utility Model Content

[0003] The purpose of the present invention is to overcome the deficiencies in the prior art and provide an easily bendable FPC and a display module.

[0004] The purpose of this utility model is achieved through the following technical solutions:

[0005] A flexible printed circuit board (FPC) that is easily bent comprises: an FPC body, the FPC body comprising a copper foil, a substrate layer, a copper layer, and a PI layer, wherein the PI layer, the copper layer, the substrate layer, the copper layer, and the PI layer are stacked in sequence; a copper foil is provided on one side of a binding area of ​​the FPC body, at least one circular hole is provided in the copper foil, a bending notch is provided on the PI layer away from the copper foil, the bending notch is provided on a side opposite to the binding area, and a bending-resistant green oil is provided on the bending notch.

[0006] In one embodiment, the number of the circular holes is three, and the circular holes are arranged in a straight line along the bending line of the FPC body in the binding area.

[0007] In one embodiment, the diameter of the circular hole is 1.5um-2.5um.

[0008] In one embodiment, a component area is provided on the FPC body, and an EMI film is provided on the component area.

[0009] In one embodiment, the thickness of the copper foil is 0.03 mm.

[0010] In one embodiment, a copper leakage area is provided on the FPC body.

[0011] In one embodiment, a connector is provided on the FPC body.

[0012] In one embodiment, the FPC body is provided with a steel sheet on the back side of the connector.

[0013] In one embodiment, the model of the bending-resistant green oil is Guanpin L45LG20H43A.

[0014] A display module includes the above-mentioned easily bendable FPC.

[0015] Compared with the prior art, the present invention has at least the following advantages:

[0016] The easy-to-bend FPC of the present invention is achieved by setting up an FPC body. The FPC body includes a copper foil, a substrate layer, a copper layer and a PI layer. The PI layer, the copper layer, the substrate layer, the copper layer and the PI layer are stacked in sequence. Copper foil is provided on one side of the binding area of ​​the FPC body, and the copper foil in the bending area will have stress when bent. Therefore, at least one circular hole is provided on the copper foil of the bending line on the FPC body to reduce the stress of the copper foil, making the binding area of ​​the FPC softer and easier to bend. Since the hardness of the PI layer is relatively high, a bending notch is provided on the PI layer away from the copper foil, making the FPC softer and easier to bend. The bending notch is provided on the opposite side of the binding area, and anti-bending green oil is provided on the bending notch. The anti-bending green oil not only enhances the bending resistance of the FPC in the binding area of ​​the FPC, making the FPC not easy to break, but also has insulating properties to avoid short circuits. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following briefly introduces the drawings required for use in the embodiments.

[0018] Figure 1 Schematic diagram of the stacking structure of the easily bendable FPC in one embodiment of the present invention;

[0019] Figure 2 Schematic diagram of the partial structure of an easily bendable FPC in one embodiment of the present invention;

[0020] Figure 3 It is a structural diagram of a display module in one embodiment of the present invention.

[0021] Reference numerals:

[0022] FPC body 10 , PI layer 11 , copper layer 12 , substrate layer 13 , round hole 14 , bending-resistant green paint 15 , copper leakage area 16 , copper foil 17 , connector 20 , and display module 30 . DETAILED DESCRIPTION

[0023] In order to facilitate understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings.

[0024] This application proposes a flexible FPC, please refer to Figure 1 and Figure 2, comprising: an FPC body 10. The FPC body 10 includes a copper foil 17, a base material layer 13, a copper layer 12, and a PI layer 11. The PI layer 11, copper layer 12, base material layer 13, copper layer 12, and PI layer 11 are stacked in sequence. Copper foil 17 is provided on one side of the binding area of ​​the FPC body 10. Bend stress is generated by bending the copper foil 17 in the bending area. Therefore, at least one circular hole 14 is provided in the copper foil 17 at the bend line of the FPC body 10 to reduce the stress on the copper foil 17, making the binding area of ​​the FPC more flexible and bendable. Due to the high hardness of the PI layer 11, bending notches are provided in the PI layer 11 away from the copper foil 17, making the FPC more flexible and bendable. The bending notches are provided on the opposite side of the binding area, and anti-bending green oil 15 is applied to the bending notches. The anti-bending green oil 15 not only enhances the bending resistance of the FPC in the binding area, making it less prone to breakage, but also provides insulation properties to prevent short circuits. Preferably, the thickness of the copper foil 17 is 0.03 mm.

[0025] It should be noted that the bend-resistant green oil 15 is a special ink. Its main function is to improve the physical stability of the circuit board, prevent the physical disconnection of the conductor circuit, reduce the copper pollution of the soldering tank, and prevent insulation deterioration and corrosion caused by external environmental factors such as dust and moisture. In addition, the bend-resistant green oil 15 can also prevent short circuits caused by bridging during the welding process. After high-temperature baking, the printed ink will not warp or discolor, which can meet the insulation and protection functions of the copper surface covering ink, reduce the total thickness of the product, and ensure that the rebound force of the FPC is small, which is convenient for module assembly and easy to promote and apply. Among them, the model of the bend-resistant green oil 15 used in this application is Guanpin L45LG20H43A.

[0026] In one embodiment, please refer again to Figure 2 There are three circular holes 14, arranged in a straight line along the bend line of the FPC body 10 in the binding area. These three circular holes 14 effectively reduce the bending stress on the copper foil 17 without affecting the binding and conductive properties of the FPC. Preferably, the diameter of the circular holes 14 is 1.5 μm to 2.5 μm.

[0027] Furthermore, the FPC body 10 is provided with a component area, and an EMI film is provided on the component area. The EMI film is used to shield electromagnetic interference. When electronic products are interfered with by electromagnetic radiation, the image will become blurred. The EMI film is provided on the component area to prevent the electronic components in the component area from being interfered with by external electromagnetic interference and thus improve the reliability of the product.

[0028] In one embodiment, a copper leakage area 16 is provided on the FPC body 10 . The copper leakage area 16 is an extension of the copper layer 12 and is exposed to the outside to dissipate heat from the FPC body 10 .

[0029] Furthermore, the FPC body 10 is provided with a connector 20, which is snapped onto a test fixture during factory inspection, improving electrical connection efficiency and reducing errors in connecting wires. Furthermore, the FPC body 10 is provided with a steel plate on the back of the connector 20 to support the connector 20 and prevent the FPC body 10 from bending or breaking at this point due to the weight of the connector 20, which could affect alignment and fit.

[0030] It should be noted that the circular hole is set in the non-routing area of ​​the FPC body or opened on the GND routing line.

[0031] See also Figure 3 The present application also proposes a display module 30, comprising the above-mentioned easily bendable FPC.

[0032] The above-described embodiments merely represent several implementation methods of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that a person of ordinary skill in the art would be able to make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present utility model patent shall be determined by the appended claims.

Claims

1. A bendable FPC, characterized in that: include: The FPC body includes a copper foil, a substrate layer, a copper layer and a PI layer, wherein the PI layer, the copper layer, the substrate layer, the copper layer and the PI layer are stacked in sequence, a copper foil is provided on one side of the binding area of ​​the FPC body, at least one circular hole is provided on the copper foil, a bending notch is provided on the PI layer away from the copper foil, the bending notch is provided on the opposite side of the binding area, and a bending-resistant green oil is provided on the bending notch.

2. The easily bendable FPC according to claim 1, characterized in that: The number of the circular holes is three, and the circular holes are arranged in a straight line along the bending line of the FPC body in the binding area.

3. The easily bendable FPC according to claim 1, characterized in that: The diameter of the circular hole is 1.5um-2.5um.

4. The easily bendable FPC according to claim 1, characterized in that: A component area is provided on the FPC body, and an EMI film is provided on the component area.

5. The easily bendable FPC according to claim 1, characterized in that: The thickness of the copper foil is 0.03 mm.

6. The easily bendable FPC according to claim 1, characterized in that: A copper leakage area is provided on the FPC body.

7. The easily bendable FPC according to claim 1, characterized in that: The FPC body is provided with a connector.

8. The easily bendable FPC according to claim 7, characterized in that: The FPC body is provided with a steel sheet on the back side of the connector.

9. The easily bendable FPC according to claim 1, wherein: The model of the bending-resistant green oil is Guanpin L45LG20H43A.

10. A display module, characterized in that: The flexible FPC comprises the flexible FPC according to any one of claims 1 to 9.

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