Multilayer FPC and display screen

Abstract

The utility model discloses a multi-layer FPC and a display screen. The multi-layer FPC comprises a lower-layer FPC and an upper-layer FPC which can be adjacently arranged in a laminated mode. Wherein at least one first golden finger is arranged on the upper surface of the end part of the lower-layer FPC; second golden fingers in one-to-one correspondence with the first golden fingers are respectively arranged on the upper surface and the lower surface of the corresponding end part of the upper-layer FPC; the two second golden fingers which are in one-to-one correspondence to the upper surface and the lower surface of the upper-layer FPC are electrically connected; in a working state, the lower layer FPC and the upper layer FPC are laminated, bonded and fixed; wherein the first golden finger is electrically connected with the second golden finger on the lower surface of the upper-layer FPC through the ACF. According to the multi-layer FPC, the applicability of the multi-layer FPC can be effectively improved, and the application flexibility is high. And the FPC layer is unitized, so that the cost loss caused by FPC defective products can be reduced.

Description

Technical Field

[0001] The present application relates to the technical field of flexible circuit boards, and particularly to a multi-layer FPC and a display screen. Background Art

[0002] Due to reasons such as the miniaturization of the volume of electronic devices and the convenience of user installation, the routing space of FPC (Flexible Printed Circuit) is getting smaller and smaller. When the area cannot be increased, it is necessary to increase the number of FPC layers to achieve routing.

[0003] In the existing multi-layer FPCs, several layers of copper foils and substrates are usually overlapped and bonded together to form several integrally formed FPC layers. Such multi-layer FPCs are customized products that cannot be adjusted according to user needs, rather than conventional products, resulting in low applicability and poor flexibility in application. Summary of the Invention

[0004] In order to solve at least one problem existing in the prior art, the purpose of the present application is to provide a multi-layer FPC and a display screen, which can effectively improve the applicability of the multi-layer FPC, have strong flexibility in application, and help reduce the cost loss caused by defective FPCs.

[0005] To achieve the above purpose, a multi-layer FPC provided by the present application includes at least two independent single-layer FPCs, namely a lower-layer FPC and an upper-layer FPC that can be adjacently stacked; wherein,

[0006] On the upper surface of the end of the lower-layer FPC, at least one first gold finger is provided;

[0007] On the upper surface and the lower surface of the corresponding end of the upper-layer FPC, second gold fingers corresponding to the first gold fingers one by one are respectively provided; and, an electrical connection is formed between two second gold fingers corresponding to each other on the upper surface and the lower surface of the upper-layer FPC.

[0008] In the working state, the lower-layer FPC and the upper-layer FPC are stacked and bonded and fixed; wherein, the first gold finger and the second gold finger on the lower surface of the upper-layer FPC are electrically connected through ACF.

[0009] Optionally, the upper-layer FPC is a top-layer FPC; a conventional gold finger arranged in parallel with the first gold finger is further provided on the upper surface of the top-layer FPC.

[0010] Optionally, each layer of the multi-layer FPC includes a lower insulating layer, a lower conductive layer, a base insulating layer, an upper conductive layer, and an upper insulating layer that are sequentially stacked.

[0011] Further optionally, a first opening is provided in the upper insulating layer of the bottom FPC of the multi-layer FPC to form a first internal gold finger;

[0012] For the upper layer FPC adjacent to the bottom FPC, a second opening is provided in its lower insulating layer to form a second internal gold finger corresponding to the first internal gold finger one by one;

[0013] In the working state, the first internal gold finger and the second internal gold finger are arranged in alignment and are electrically connected through ACF.

[0014] Optionally, a first opening is provided in the upper insulating layer of the middle layer FPC of the multi-layer FPC to form a first internal gold finger;

[0015] For the upper layer FPC adjacent to the middle layer FPC, a second opening is provided in its lower insulating layer to form a second internal gold finger corresponding to the first internal gold finger one by one;

[0016] In the working state, the first internal gold finger and the second internal gold finger are arranged in alignment and are electrically connected through ACF.

[0017] Further optionally, the number of the first internal gold fingers is multiple.

[0018] Optionally, the lower layer FPC is bonded to the lower insulating layer of the adjacent upper layer FPC through the upper insulating layer.

[0019] Optionally, through holes are provided in the upper layer FPC, and the through holes are arranged close to the corresponding second gold fingers; a conductive layer is provided on the periphery of the through holes, and the conductive layer electrically connects two second gold fingers corresponding to the upper surface and the lower surface of the upper layer FPC.

[0020] Optionally, the number of the first gold fingers is multiple.

[0021] To achieve the above object, the present application also provides a display screen, including the multi-layer FPC as described above.

[0022] A multi-layer FPC and a display screen of the present application are designed as at least two independent single-layer FPCs. A first gold finger is provided on the upper surface of the end of the lower layer FPC, and second gold fingers that are electrically connected up and down in a one-to-one correspondence are provided on the upper and lower surfaces of the corresponding end of the upper layer FPC. When in use, the lower layer FPC and the upper layer FPC are laminated and bonded and fixed, so that the first gold finger and the second gold finger on the lower surface of the upper layer FPC are electrically connected through ACF, thereby forming a multi-layer FPC, and realizing the arrangement of traces by increasing the number of FPC layers. Thus, the applicability of the multi-layer FPC can be effectively improved, and the application flexibility is strong. The FPC layer is unitized, which also helps to reduce the cost loss caused by defective FPCs.

[0023] Other features and advantages of the present application will be set forth in the following description, and in part will be obvious from the description, or may be learned by practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings are provided to further understand the present application, and constitute a part of the description, and together with the embodiments of the present application, are used to explain the present application, and do not constitute a limitation to the present application. In the drawings:

[0025] Figure 1 is a top view of a multi-layer FPC according to an embodiment of the present application;

[0026] Figure 2 is Figure 1 a front structural schematic diagram of the lower-layer FPC of the multi-layer FPC in ;

[0027] Figure 3 is Figure 1 a front structural schematic diagram of the upper-layer FPC of the multi-layer FPC in ;

[0028] Figure 4 is Figure 1 a back structural schematic diagram of the upper-layer FPC of the multi-layer FPC in ;

[0029] Figure 5 is Figure 1 an A-A' sectional view of the multi-layer FPC in.

[0030] Among them, specifically include the following reference numerals:

[0031] Multi-layer FPC 100;

[0032] Lower-layer FPC 20; First gold finger 21; First opening 22; First internal gold finger 23;

[0033] Upper-layer FPC 30; Second gold finger 31; Conventional gold finger 32; Second opening 33; Second internal gold finger 34; Through hole 35;

[0034] ACF 40;

[0035] Lower insulating layer 51; Lower conductive layer 52; Base insulating layer 53; Upper conductive layer 54; Upper insulating layer 55. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] Embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although some embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. On the contrary, these embodiments are provided to more thoroughly and completely understand the present application. It should be understood that the drawings and embodiments of the present application are only for exemplary purposes and are not used to limit the protection scope of the present application.

[0037] As used herein, the term "comprising" and its variations are open-ended, that is, "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". The relevant definitions of other terms will be given in the following description.

[0038] Next, embodiments of the present application will be described in detail with reference to the accompanying drawings.

[0039] As Figures 1-5 shown, the multi-layer FPC 100 includes at least two independent single-layer FPCs, namely, the lower-layer FPC 20 and the upper-layer FPC 30 that can be stacked adjacent to each other.

[0040] Among them, on the upper surface of the end of the lower-layer FPC 20, at least one first gold finger 21 is provided. On the upper surface and the lower surface of the corresponding end of the upper-layer FPC 30, second gold fingers 31 corresponding to the first gold fingers 21 one by one are respectively provided; and, an electrical connection is formed between the two second gold fingers 31 corresponding to each other on the upper surface and the lower surface of the upper-layer FPC 30.

[0041] In the working state, the lower-layer FPC 20 and the upper-layer FPC 30 are stacked and bonded and fixed. Among them, the number of the first gold fingers 21 is the same as that of the second gold fingers 31 on the lower surface of the upper-layer FPC 30, and they are electrically connected through the ACF 40. In a specific example, the lower-layer FPC 20 can also be bonded to the lower insulating layer 51 of the adjacent upper-layer FPC 30 through the upper insulating layer 55.

[0042] It should be noted that the above-mentioned lower-layer FPC 20 can be the bottom-layer FPC in the multi-layer FPC 100 or the middle-layer FPC in the multi-layer FPC 100. The above-mentioned upper-layer FPC can be the top-layer FPC in the multi-layer FPC 100 or the middle-layer FPC in the multi-layer FPC 100.

[0043] It should also be noted that ACF (Anisotropic Conductive Film) is a material that can achieve electrical connection in a short time. Its characteristic is that it conducts electricity in the longitudinal stress direction, while having high impedance characteristics in the transverse plane. Thus, the circuit between the first gold finger and the corresponding second gold finger is conducted, while short circuits between adjacent gold fingers are avoided.

[0044] As an example, the above-mentioned upper FPC 30 is the top FPC, that is, this multi-layer FPC 100 is a double-layer FPC. The upper surface of the top FPC is also provided with conventional gold fingers 32 arranged in parallel with the first gold fingers 21.

[0045] As another example, the above-mentioned upper FPC 30 is an intermediate layer FPC, that is, other upper FPCs are stacked above this intermediate layer FPC.

[0046] It can be understood that the above-mentioned ACF electrical connection gold finger structure can be provided at one end of the multi-layer FPC, or can be provided at both ends of the multi-layer FPC. The present application does not make specific restrictions on this.

[0047] According to the multi-layer FPC 100 of the embodiment of the present application, it is designed as at least two independent single-layer FPCs, and a first gold finger 21 is provided on the upper surface of the end of the lower FPC 20, and second gold fingers 31 that are electrically connected up and down in a one-to-one correspondence are provided on the upper and lower surfaces of the corresponding end of the upper FPC 30.

[0048] When in use, by laminating and bonding the lower FPC 20 and the upper FPC 30, the first gold finger 21 and the second gold finger 31 on the lower surface of the upper FPC 30 are electrically connected through the ACF 40, thereby forming the multi-layer FPC 100 and realizing the arrangement of traces by increasing the number of FPC layers. Thus, the applicability of the multi-layer FPC can be effectively improved, and the application flexibility is strong. The unitization of the FPC layer also helps to reduce the cost loss caused by defective FPCs.

[0049] In the embodiment of the present application, as Figure 5 shown, each layer of the multi-layer FPC 100 may include a lower insulating layer 51, a lower conductive layer 52, a base insulating layer 53, an upper conductive layer 54, and an upper insulating layer 55 that are sequentially stacked. In a specific example, the material of the above-mentioned insulating layer is PI (Polyimide) or PET (Polyethylene terephthalate); the above-mentioned conductive layer is copper foil.

[0050] Optionally, the upper insulating layer 55 of the bottom FPC of the multi-layer FPC 100 is provided with a first opening 22 to expose the first internal gold finger 23. For the upper FPC adjacent to the bottom FPC, its lower insulating layer 51 is provided with a second opening 33 to expose the second internal gold finger 34 corresponding to the first internal gold finger 23 one by one. In the working state, the first internal gold finger 23 and the second internal gold finger 34 are arranged in alignment and are electrically connected through the ACF 40.

[0051] Optionally, the upper insulating layer 55 of the middle FPC of the multi-layer FPC 100 is provided with a first opening 22 to expose the first internal gold finger 23. For the upper FPC adjacent to the middle FPC, its lower insulating layer 51 is provided with a second opening 33 to expose the second internal gold finger 34 corresponding to the first internal gold finger 23 one by one. In the working state, the first internal gold finger 23 and the second internal gold finger 34 are arranged in alignment and are electrically connected through the ACF 40.

[0052] That is to say, the multi-layer FPC 100 can not only achieve electrical connection of the gold fingers in the end region, but also can achieve partial electrical connection of the gold fingers in the internal region according to specific requirements. In a specific example, the number of the first internal gold finger 23 and the second internal gold finger 34 between adjacent two layers of FPCs is the same and the number is multiple.

[0053] Optionally, through holes 35 are formed in the upper FPC 30, each second gold finger 31 on the upper surface corresponds to one through hole 35, and the through hole 35 is arranged close to the corresponding second gold finger 31. The conductive layer penetrates through the through hole 35 and covers the periphery of the through hole 35. The conductive layer electrically connects two second gold fingers 31 corresponding to the upper surface and the lower surface of the upper FPC 30, so that the upper and lower second gold fingers 31 are electrically connected.

[0054] This application also provides a display screen, including the multi-layer FPC in the above embodiment.

[0055] It should be noted that the concepts such as "first" and "second" mentioned in this application are only used to distinguish different structures, and are not used to limit the order of functions performed by these structures, or the interdependent relationship or relative importance.

[0056] In the description of this application, it should be noted that the relationship between structures should be understood in a broad sense. For example, the connection can be a fixed connection or a detachable connection; the orientation or positional relationship indicated by terms such as "upper", "lower", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to this application.

[0057] It should be noted that in the drawings, for clarity, the dimensions of layers, regions, components, and their relative dimensions may be exaggerated. Throughout the drawings, the same or similar reference numerals denote the same or similar components or components having the same or similar functions.

[0058] Those of ordinary skill in the art can understand that the above are only preferred embodiments of the present application and are not used to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A multi-layer FPC, characterized in that: It includes a lower layer FPC and an upper layer FPC which can be stacked adjacently; wherein, At least one first gold finger is provided on the upper surface of the end of the lower layer FPC; On the upper surface and the lower surface of the corresponding end of the upper layer FPC, second gold fingers corresponding to the first gold fingers are respectively provided; and an electrical connection is formed between the two second gold fingers corresponding to the upper surface and the lower surface of the upper layer FPC; In the working state, the lower layer FPC is bonded and fixed to the upper layer FPC; wherein the first gold finger is electrically connected to the second gold finger on the lower surface of the upper layer FPC via ACF.

2. The multilayer FPC according to claim 1, characterized in that: The upper layer FPC is a top layer FPC; the upper surface of the top layer FPC is also provided with a conventional gold finger arranged in parallel with the first gold finger.

3. The multilayer FPC according to claim 1, characterized in that: Each layer of the multi-layer FPC includes a lower insulating layer, a lower conductive layer, a base insulating layer, an upper conductive layer and an upper insulating layer which are stacked in sequence.

4. The multilayer FPC according to claim 3, characterized in that: The upper insulating layer of the bottom FPC of the multi-layer FPC is provided with a first opening to form a first internal gold finger; The upper layer FPC adjacent to the bottom layer FPC has a lower insulating layer with a second opening, forming a second internal gold finger corresponding to the first internal gold finger one by one; In a working state, the first internal gold finger and the second internal gold finger are arranged in alignment and are electrically connected through the ACF.

5. The multilayer FPC according to claim 3, characterized in that: The upper insulating layer of the middle layer FPC of the multi-layer FPC is provided with a first opening to form a first internal gold finger; The upper layer FPC adjacent to the middle layer FPC has a lower insulating layer with a second opening to form a second internal gold finger corresponding to the first internal gold finger one by one; In a working state, the first internal gold finger and the second internal gold finger are arranged in alignment and are electrically connected through the ACF.

6. The multilayer FPC according to claim 4 or 5, characterized in that: The number of the first internal golden fingers is multiple.

7. The multilayer FPC according to claim 3, characterized in that: The lower layer FPC is bonded to the lower insulating layer of the adjacent upper layer FPC through the upper insulating layer.

8. The multilayer FPC according to claim 1, characterized in that: The upper FPC is provided with a through hole, which is arranged close to the corresponding second gold finger; the through hole is covered with a conductive layer, which electrically connects the two second gold fingers corresponding to the upper and lower surfaces of the upper FPC.

9. The multilayer FPC according to claim 1, characterized in that: The number of the first golden fingers is multiple.

10. A display screen, characterized in that: include: The multilayer FPC as claimed in any one of claims 1 to 9.

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