Ultra-thin NFC structure and display module

Abstract

The utility model provides an ultra-thin NFC (near field communication) structure and a display module. The ultra-thin NFC structure comprises a ferrite layer, an FPC (flexible printed circuit) and a back double-sided adhesive which are sequentially stacked, the ferrite layer comprises a protective film, a ferrite body and a ferrite double-sided adhesive which are stacked in sequence; the FPC comprises an upper copper plating layer, an upper base copper layer, an upper AD adhesive layer, a base material and a lower AD adhesive layer which are stacked in sequence. The upper copper plating layer and the upper base copper layer form an FPC coil; the thickness of the ferrite layer is 94 to 100 microns; the thickness of the FPC ranges from 63 micrometers to 109 micrometers. On the premise that functions and cost are not affected, the problem that the thickness of an existing NFC structure cannot meet the light and thin design requirement of a product is solved.

Description

Technical Field

[0001] This utility model relates to the field of display technology, and in particular to an ultra-thin NFC structure and display module. Background Technology

[0002] The thickness of the NFC (Near Field Communication) chip itself, as well as the protective materials used in the packaging process, all contribute to the overall thickness of the NFC structure. Thinner tag-type NFC modules are around 0.2–0.7 mm thick, while highly integrated embedded NFC modules can reach 0.8–1 mm or even thicker. Currently, the NFC structure in display modules consists of ferrite and FPC. The front and back of the FPC have protective and adhesive layers to safeguard the coil circuitry. These protective layers typically consist of a PI (polyimide) film and an adhesive layer. These protective layers increase the overall thickness of the NFC structure.

[0003] Modern wearable electronic products are increasingly integrating various functions, and in order to achieve a thinner and more comfortable fit, they are pursuing the ultimate in thickness. Therefore, the existing NFC structure cannot meet the requirements for product thinning. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides an ultra-thin NFC structure and display module, aiming to solve the problem that the thickness of existing NFC structures cannot meet the requirements of lightweight product design without affecting functionality and cost.

[0005] The technical solution adopted in this utility model is as follows:

[0006] This invention provides an ultra-thin NFC structure, comprising a ferrite layer, an FPC, and a double-sided adhesive backing stacked sequentially.

[0007] The ferrite layer comprises a protective film, a ferrite body, and a ferrite double-sided adhesive layer stacked sequentially.

[0008] The FPC comprises an upper copper plating layer, an upper base copper layer, an upper AD adhesive layer, a substrate, and a lower AD adhesive layer stacked sequentially; the upper copper plating layer and the upper base copper layer constitute the FPC coil;

[0009] The thickness of the ferrite layer is 94–100 micrometers;

[0010] The thickness of the FPC is 63–109 micrometers.

[0011] The further technical solution is as follows:

[0012] The thickness of the upper copper plating layer is 10 micrometers, and the thickness of the upper base copper layer is 18 micrometers;

[0013] The thickness of the upper AD adhesive layer is 13 micrometers;

[0014] The thickness of the substrate is 12 micrometers;

[0015] The thickness of the lower AD adhesive layer is 13 micrometers.

[0016] The thicknesses of the protective film, the ferrite body, and the double-sided ferrite adhesive are 10 micrometers, 80 micrometers, and 10 micrometers, respectively.

[0017] An ink layer is also provided between the ferrite layer and the FPC.

[0018] The ink layer is photosensitive green oil or photosensitive yellow oil, and the thickness of the ink layer is 15 micrometers.

[0019] The FPC also includes a lower base copper layer and a lower copper plating layer stacked sequentially between the lower AD adhesive layer and the back double-sided adhesive layer, the lower base copper layer and the lower copper plating layer forming a gold-plated jumper area.

[0020] The thickness of the lower base copper layer is 18 micrometers; the thickness of the lower copper plating layer is 10 micrometers.

[0021] The surface of the lower AD adhesive layer that is bonded to the back side is marked with silkscreen.

[0022] The NFC structure has a through-hole for alignment and connection with the main screen FPC.

[0023] This utility model also provides a display module, including the ultra-thin NFC structure described above.

[0024] The beneficial effects of this utility model are as follows:

[0025] This invention achieves a reduction in the overall thickness of the NFC chip by optimizing the stacking structure of the FPC. This, in turn, reduces the stacking thickness of the display module, making the entire electronic product thinner and lighter. Alternatively, it frees up space for other components such as the battery, resulting in longer battery life.

[0026] This invention is applicable to FPCs with single-layer or double-layer traces, providing copper trace protection through an ink layer. Alternatively, when the FPC manufacturing process and ferrite layer manufacturing process are carried out and bonded in the same location, the ink layer can be eliminated directly, achieving further thinning.

[0027] This invention provides a gold-plated jumper area for FPCs with double-layer wiring. The gold plating of the jumpers prevents oxidation, allowing for direct double-sided adhesive to be applied to the back of the FPC. This solves the problem that the thickness of existing NFC structures cannot meet the requirements for thinner and lighter product designs without affecting functionality or cost.

[0028] Other features and advantages of this invention will be set forth in the following description or may be learned by practicing this invention. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the stacked structure of the ultra-thin NFC structure in Embodiment 1 of this utility model.

[0030] Figure 2 This is a front view of the ultra-thin NFC structure of Embodiment 1 of this utility model.

[0031] Figure 3 This is a schematic diagram of the stacked structure of the ultra-thin NFC structure in Embodiment 2 of this utility model.

[0032] Figure 4 This is a front view of the back of the ultra-thin NFC structure according to Embodiment 2 of this utility model.

[0033] In the diagram: 1. Ferrite layer; 2. FPC; 3. Positioning hole; 4. Double-sided adhesive backing; 5. Release paper; 6. Silkscreen marking; 7. Solder pad; 101. Protective film; 102. Ferrite body; 103. Ferrite double-sided adhesive; 201. FPC coil; 202. Upper AD adhesive layer; 203. Substrate; 204. Lower AD adhesive layer; 205. Ink layer; 206. Gold-plated jumper area; 2011. Upper copper plating layer; 2012. Upper base copper layer; 2061. Lower copper plating layer; 2062. Lower base copper layer. Detailed Implementation

[0034] The specific embodiments of this utility model are described below with reference to the accompanying drawings.

[0035] Example 1

[0036] See Figure 1 and Figure 2 The ultra-thin NFC structure of this embodiment includes a ferrite layer 1, an FPC 2 and a double-sided adhesive backing 4 stacked sequentially.

[0037] The ferrite layer 1 includes a protective film 101, a ferrite body 102, and a ferrite double-sided adhesive 103 stacked sequentially.

[0038] FPC2 includes an upper copper plating layer 2011, an upper base copper layer 2012, an upper AD adhesive layer 202, a substrate 203, and a lower AD adhesive layer 204 stacked sequentially; the upper copper plating layer 2011 and the upper base copper layer 2012 constitute the FPC coil 201.

[0039] The thickness of ferrite layer 1 is 94–100 micrometers; the thickness of FPC2 is 63–109 micrometers.

[0040] in:

[0041] The protective film 101 can be made of PET material to prevent dirt and scratches on the surface of the ferrite body 102. It can be removed after the NFC structure is assembled onto the display module.

[0042] The ferrite body 102 is made of high-temperature sintered ferrite material, which can reduce the absorption of signal magnetic field by metal materials and increase magnetic field strength, thereby effectively increasing the sensing distance, which helps NFC to realize card reading function and enhance reading distance and sensitivity.

[0043] Ferrite double-sided adhesive 103 is located on the upper copper plating layer 2011 and is used to bond and connect ferrite layer 1 and FPC 2.

[0044] The upper copper layer 2011 is for the upper and lower layers to conduct through vias and to increase the copper thickness. A layer of copper is plated on the surface of the upper base copper layer 2012 by electroplating.

[0045] The upper base copper layer 2012 is the FPC trace layer, which constitutes the main body of the FPC coil 201;

[0046] The upper AD adhesive layer 202 is used to bond the substrate 203 and the upper copper layer 2012;

[0047] Substrate 203, typically made of polyimide (PI) or polyester film (PET), is the basic material that makes up the FPC;

[0048] The lower AD adhesive layer 204 is used to bond the substrate 203 and the double-sided adhesive 4 on the back side;

[0049] Double-sided adhesive on the back 4 is used to attach the NFC structure to the back of the display.

[0050] Specifically, the AD adhesive layer uses AD adhesive (AD Sealant), a material commonly used in chip packaging.

[0051] See Figure 4 Release paper 5 is provided on the double-sided adhesive backing 4. The release paper 5 is removed when the NFC structure is assembled onto the display module.

[0052] In this embodiment of the ultra-thin NFC structure, compared to conventional FPCs which have cover films on both the front and back, the cover film on the front FPC coil and the cover film on the back AD adhesive are removed.

[0053] After removing the cover film on the front FPC coil, the FPC and ferrite processes are manufactured and bonded in the same location, ensuring that the removal of the cover film does not affect product quality. After removing the cover film on the back AD adhesive, double-sided adhesive is used on the back to achieve both protection and bonding.

[0054] When the FPC process and the ferrite layer process cannot be produced and pasted in the same place, an ink layer 205 is set between the ferrite layer 1 and the FPC 2 to ensure the product quality during intermediate transportation and circulation.

[0055] The ink layer 205 is specifically photosensitive green oil or photosensitive yellow oil, which is directly printed onto the upper copper plating layer 2011 of the FPC coil 201 during manufacturing.

[0056] Preferably, the stacking thickness of the ultra-thin NFC structure (non-jump area of ​​FPC single-layer trace) based on the most conventional 1 / 2OZ double-layer adhesive substrate in this embodiment is as follows:

[0057] Protective film 101 thickness: 10 micrometers;

[0058] Ferrite body 102 thickness: 80 micrometers;

[0059] Ferrite double-sided adhesive 103 thickness: 10 micrometers;

[0060] The thickness of the top copper plating layer in 2011 was 10 micrometers.

[0061] The thickness of the top copper layer in 2012 was 18 micrometers.

[0062] The thickness of the top AD adhesive layer 202 is 13 micrometers.

[0063] Substrate 203 thickness: 12 micrometers;

[0064] The thickness of the lower AD adhesive layer 204 is 13 micrometers.

[0065] Double-sided adhesive on the back, thickness: 15 microns;

[0066] The total thickness is 181 micrometers.

[0067] With other functional film layer thicknesses remaining the same as in this embodiment, the stacking thickness of a conventional NFC structure (non-jump area of ​​FPC single-layer trace) is 236 micrometers, where the thickness of the front and back cover films is 12.5 micrometers (PI film) + 15 micrometers (adhesive layer). However, the ultra-thin NFC structure in this embodiment, by removing the front and back cover films, reduces the thickness to 181 micrometers.

[0068] The thickness of the ink layer 205 is preferably 15 micrometers. That is, for the ultra-thin NFC structure with ink layer 205, its thickness is 196 micrometers, which is still much smaller than the thickness of the traditional structure.

[0069] See Figure 2 As a specific implementation, the NFC structure in this embodiment also has a through positioning hole 3, which is used for alignment and connection with the main screen FPC. The lead end of the FPC coil 201 is provided with a solder pad 7 for electrical connection with the main screen FPC.

[0070] Example 2

[0071] See Figure 3 and Figure 4 The ultra-thin NFC structure of this embodiment differs from that of Embodiment 1 in that: FPC2 further includes a lower base copper layer 2062 and a lower copper plating layer 2061 stacked sequentially between the lower AD adhesive layer 204 and the back double-sided adhesive 4, and the lower base copper layer 2062 and the lower copper plating layer 2061 constitute a gold-plated jumper area 206.

[0072] The gold-plated jumper area 206 is treated with gold to prevent oxidation, so there is no need to put a cover film (i.e. the cover film on the back AD adhesive as described in Example 1) on the jumper surface of the gold-plated jumper area 206, and there is no need to brush ink, it can be directly pasted on the back double adhesive 4.

[0073] In a specific embodiment, the thickness of the lower base copper layer 2062 is 18 micrometers, and the thickness of the lower copper plating layer 2061 is 10 micrometers. Compared with Example 1, the total thickness has increased by 28 micrometers, but it is still less than the thickness of the conventional structure.

[0074] In one specific embodiment, the surface of the lower AD adhesive layer 204 that is bonded to the back double-sided adhesive 4 is provided with a silkscreen mark 6. This mark is used to indicate the product model or information.

[0075] In summary, by removing the front and back cover films from a conventional NFC FPC, applying green oil to the front coil surface and then attaching a ferrite layer, and plating gold nickel at the jumper positions on the back to prevent oxidation, and then directly attaching the back double-sided adhesive, the ultra-thin NFC structure of this embodiment is obtained.

[0076] Example 3

[0077] This embodiment provides a display module, including the ultra-thin NFC structure described in Embodiment 1 or Embodiment 2.

[0078] The display module can be used in wearable electronic products such as smartwatches. Because the overall thickness of NFC is reduced, the stacking thickness of the display module can be decreased, making the entire electronic product thinner and lighter. Alternatively, space can be allocated to other components such as batteries, resulting in longer battery life.

[0079] It will be understood by those skilled in the art that the above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model 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 make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An ultra-thin NFC structure, characterized in that, It includes a ferrite layer (1), an FPC (2), and a double-sided adhesive backing (4) stacked sequentially; The ferrite layer (1) includes a protective film (101), a ferrite body (102), and a ferrite double-sided adhesive (103) stacked sequentially. The FPC (2) includes an upper copper plating layer (2011), an upper base copper layer (2012), an upper AD adhesive layer (202), a substrate (203), and a lower AD adhesive layer (204) stacked sequentially; the upper copper plating layer (2011) and the upper base copper layer (2012) constitute the FPC coil (201); The thickness of the ferrite layer (1) is 94-100 micrometers; The thickness of the FPC(2) is 63 to 109 micrometers.

2. The ultra-thin NFC structure according to claim 1, characterized in that, The thickness of the upper copper plating layer (2011) is 10 micrometers, and the thickness of the upper base copper layer (2012) is 18 micrometers; The thickness of the upper AD adhesive layer (202) is 13 micrometers; The substrate (203) has a thickness of 12 micrometers; The thickness of the lower AD adhesive layer (204) is 13 micrometers.

3. The ultra-thin NFC structure according to claim 1, characterized in that, The thicknesses of the protective film (101), the ferrite body (102), and the ferrite double-sided adhesive (103) are 10 micrometers, 80 micrometers, and 10 micrometers, respectively.

4. The ultra-thin NFC structure according to claim 1, characterized in that, An ink layer (205) is also provided between the ferrite layer (1) and the FPC (2).

5. The ultra-thin NFC structure according to claim 4, characterized in that, The ink layer (205) is photosensitive green oil or photosensitive yellow oil, and the thickness of the ink layer (205) is 15 micrometers.

6. The ultra-thin NFC structure according to claim 1, characterized in that, The FPC (2) further includes a lower base copper layer (2062) and a lower copper plating layer (2061) stacked sequentially between the lower AD adhesive layer (204) and the back double-sided adhesive (4), wherein the lower base copper layer (2062) and the lower copper plating layer (2061) constitute a gold-plated jumper area (206).

7. The ultra-thin NFC structure according to claim 6, characterized in that, The thickness of the lower base copper layer (2062) is 18 micrometers; the thickness of the lower copper plating layer (2061) is 10 micrometers.

8. The ultra-thin NFC structure according to claim 1, characterized in that, The lower AD adhesive layer (204) has a silkscreen mark (6) on the side surface that is bonded to the back double-sided adhesive (4).

9. The ultra-thin NFC structure according to claim 1, characterized in that, The NFC structure has a through positioning hole (3) for alignment and connection with the main screen fpc.

10. A display module, characterized in that, Includes the ultra-thin NFC structure as described in any one of claims 1 to 9.

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