Light-transmitting structure applied to FPC (Flexible Printed Circuit) board

Abstract

The utility model relates to the technical field of FPC boards, in particular to a light-transmitting structure applied to an FPC board, which comprises a first protective layer, an FPC board layer and a second protective layer, the FPC board layer is provided with a silk-screen layer and a circuit connecting layer, the silk-screen layer is connected to the circuit connecting layer, the circuit connecting layer is connected to the first protective layer, the second protective layer is connected to the silk-screen layer relative to the first protective layer, and the first protective layer is connected to the FPC board layer. The silk-screen layer is used for silk-screen lines, and the line connecting layer, the first protective layer and the second protective layer are light-transmitting layers, so that the structure of the silk-screen layer can be observed through the first protective layer or the second protective layer. According to the scheme, the structural design of the multiple light-transmitting layers is adopted, and the effects of optimizing the product structural design, improving the overall light transmittance of the FPC board and improving the customer satisfaction degree are achieved.

Description

Technical Field

[0001] The utility model belongs to the technical field of FPC boards, and particularly relates to a light-transmitting structure applied to FPC boards. Background Art

[0002] FPC boards (flexible printed circuit boards), with their characteristics of being thin, flexible, and bendable, play a key role in modern electronic product design. They are widely used in portable devices such as smartphones, tablets, laptops, medical devices, automotive electronics, wearable technologies, display technologies, aerospace, military and defense equipment, industrial automation, photographic equipment, printers, household appliances, and flexible batteries, etc.

[0003] With the progress of display technologies such as OLED and LCD, as well as the pursuit of aesthetics, design freedom, and interactive design, the market demand for transparent FPC boards that can seamlessly cooperate with these technologies is continuously increasing, especially for the increasing demand for flexible and transparent electronic devices. The overall light transmittance of existing FPC boards cannot meet customer requirements; secondly, the production of the multi-layer structure of traditional FPC boards usually uses glue for connection, which easily leads to adhesive failure in high-temperature environments, insufficient flexibility in the design thickness and shape of FPC boards, low production efficiency, and inconsistent bonding quality of products. Therefore, the utility model proposes a new solution for the above technical problems. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a light-transmitting structure applied to FPC boards. By adopting the structural design of multiple light-transmitting layers, the effects of optimizing the product structure design, improving the overall light transmittance of FPC boards, and enhancing customer satisfaction are achieved.

[0005] Based on this, the utility model provides a light-transmitting structure applied to FPC boards, including:

[0006] The first protective layer;

[0007] The FPC board layer, the FPC board layer is provided with a silk-screen layer and a circuit connection layer. The silk-screen layer is connected to the circuit connection layer, and the circuit connection layer is connected to the first protective layer;

[0008] The second protective layer, the second protective layer is connected to the silk-screen layer relative to the first protective layer. The silk-screen layer is used for silk-screening circuits, and the circuit connection layer, the first protective layer, and the second protective layer are light-transmitting layers, so that the structure of the silk-screen layer can be observed through the first protective layer or the second protective layer.

[0009] For a light-transmitting structure applied to FPC boards as described above, the circuit connection layer is a transparent PI layer or a PET layer.

[0010] A light-transmitting structure applied to an FPC board as described above, wherein the screen printing layer is a conductive silver paste layer.

[0011] A light-transmitting structure applied to an FPC board as described above, wherein the thickness range of the screen printing layer is 3 - 50 μm.

[0012] A light-transmitting structure applied to an FPC board as described above, wherein the first protective layer and the circuit connection layer are fixedly connected by high temperature.

[0013] A light-transmitting structure applied to an FPC board as described above, wherein the thickness of the first protective layer is 4 - 100 μm.

[0014] A light-transmitting structure applied to an FPC board as described above, wherein the second protective layer is connected to the screen printing layer by hot pressing.

[0015] A light-transmitting structure applied to an FPC board as described above, wherein the thickness of the second protective layer is 12.5 - 50 μm.

[0016] A light-transmitting structure applied to an FPC board as described above, wherein the first protective layer is a transparent PI layer or a PET layer.

[0017] A light-transmitting structure applied to an FPC board as described above, wherein the second protective layer is a transparent PI layer or a PET layer.

[0018] Implementing the embodiments of the present utility model has the following beneficial effects:

[0019] 1. This solution adopts a structural design of multiple light-transmitting layers. The FPC board layer is provided with a screen printing layer and a circuit connection layer. The screen printing layer is fixedly connected to the circuit connection layer for screen printing circuits. The first protective layer and the second protective layer are respectively connected to the circuit connection layer and the screen printing layer, and the circuit connection layer, the first protective layer, and the second protective layer are light-transmitting layers. The light-transmitting layer design of the circuit connection layer enables the circuits after screen printing to be observed from either the first protective layer or the second protective layer, greatly improving the overall light transmittance of the FPC board layer after connection, achieving the effects of optimizing the product structure design, improving the overall light transmittance of the FPC board, and enhancing customer satisfaction. Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0021] Figure 1 It is a schematic structural diagram of the present utility model;

[0022] In the figure: 1 - First protective layer; 2 - FPC board layer; 3 - Second protective layer. Specific embodiments

[0023] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0024] As Figure 1 shown, an embodiment of the present invention provides a light-transmitting structure applied to an FPC board, including:

[0025] First protective layer 1;

[0026] FPC board layer 2, the FPC board layer 2 is provided with a silk screen layer and a circuit connection layer, the silk screen layer is connected to the circuit connection layer, and the circuit connection layer is connected to the first protective layer 1;

[0027] Second protective layer 3, the second protective layer 3 is connected to the silk screen layer relative to the first protective layer 1, the silk screen layer is used for silk-screening circuits, and the circuit connection layer, the first protective layer 1, and the second protective layer 3 are light-transmitting layers, so that the structure of the silk screen layer can be observed through the first protective layer 1 or the second protective layer 3.

[0028] Specifically, the circuit connection layer is a transparent PI layer or a PET layer to enhance light transmittance and durability and is suitable for use in various environments; the circuit connection layer is provided with a microporous structure to enhance its heat dissipation performance and air permeability to improve the stability of the FPC board layer 2 in high-temperature or high-humidity environments.

[0029] Furthermore, the silk screen layer is a conductive silver paste layer, the conductive silver paste layer includes nano silver particles to improve its conductivity and wear resistance and is suitable for high-precision circuit applications; and the conductive silver paste layer is formed by precision screen printing technology to ensure the thickness uniformity of the silver paste layer and the stability of the circuit to be suitable for high-density circuit designs; conductive polymer materials can also be incorporated into the conductive silver paste layer to enhance its flexibility and adhesion to be suitable for FPC board designs with complex shapes; the surface of the conductive silver paste layer is also subjected to an antioxidant treatment to prevent the oxidation of silver and improve its long-term conductivity and corrosion resistance.

[0030] Furthermore, the thickness range of the screen printing layer is 3 - 50 μm, and the thickness of the silver paste layer is positively correlated with its electrical conductivity and antioxidant performance to optimize the electrical performance according to different application scenarios. When the thickness of the screen printing layer is 3 - 10 μm, it is a single-layer structure, suitable for low-current signal transmission. When the thickness of the screen printing layer is 10 - 50 μm, it is a multi-layer structure, suitable for high-current or high-power applications.

[0031] Furthermore, the first protective layer 1 and the circuit connection layer are fixedly connected by high-temperature and ultraviolet curing technologies. Among them, ultraviolet curing can improve the connection speed and accuracy to be applicable to the design of precision circuits. The curing temperature and time of the first protective layer 1 and the circuit connection layer can be precisely controlled according to the material characteristics of the first protective layer 1 and the circuit connection layer. Preferably, it is cured at 130°C - 200°C for 30 - 90 minutes to optimize the curing effect and enhance the connection strength between the layers. The first protective layer 1 can also be connected to the circuit connection layer by vacuum environment curing to reduce the formation of bubbles and voids and improve the connection strength.

[0032] Furthermore, the thickness of the first protective layer 1 is 4 - 100 μm. When the thickness is 4 - 20 μm, it is a single-layer structure, suitable for applications with high requirements for thinness, lightness, and flexibility. When the thickness of the first protective layer 1 is 20 - 100 μm, it is a multi-layer composite structure to enhance its mechanical strength and environmental resistance. The first protective layer 1 can also adopt a nano-material enhanced composite structure to improve its tear resistance and impact resistance, suitable for high-stress areas that require additional protection. The first protective layer 1 is also provided with microstructures within its thickness range to enhance the heat dissipation performance of the first protective layer 1 or increase the surface friction to meet specific application requirements.

[0033] Furthermore, the second protective layer 3 is connected to the screen printing layer by hot pressing, and the hot pressing temperature, pressure, and time can be precisely controlled according to the material characteristics of the second protective layer 3 and the screen printing layer. Preferably, the temperature is 160°C - 190°C, the pressure is 80 - 110 kg, and hot pressing is performed for 80 - 110 seconds to optimize the hot pressing effect. Then, the second protective layer 3 and the screen printing layer after hot pressing are cured. Preferably, it is cured at a temperature of 160°C for 30 - 90 minutes to optimize the curing effect and enhance the connection strength between the layers. The hot pressing and curing processes of the first protective layer 1 can also be carried out in a vacuum environment to reduce bubble formation and improve the uniformity and reliability of the connection.

[0034] Furthermore, the thickness of the second protective layer 3 is 12.5 - 50 μm, and the thickness is controlled by a precision coating process to ensure the optimal state of thickness uniformity and adhesion performance during the thermocompression bonding process; the thickness of the thinner area of the second protective layer 3 is 12.5 - 25 μm to enhance flexibility and transparency; the thickness of the thicker area is 25 - 50 μm to improve mechanical strength and wear resistance; a microporous structure is also provided in the thicker area of the second protective layer 3 to improve heat dissipation performance and breathability, suitable for high-temperature or high-humidity environments.

[0035] Further, the first protective layer 1 is a transparent PI layer or a PET layer. A reflective coating can be applied to the surface of the first protective layer 1, and the reflective coating can reduce light reflection to enhance its applicability in optical devices; nano-coating treatment can also be performed on the surfaces of the first protective layer 1 and the second protective layer 3 to improve their stain resistance, water resistance, and wear resistance, suitable for applications in harsh environments; heat-conducting fillers are also added to the first protective layer 1 to enhance the heat dissipation performance of the first protective layer 1 and the second protective layer 3, suitable for applications in high-power electronic devices.

[0036] Furthermore, the second protective layer 3 is a transparent PI layer or a PET layer. A reflective coating can be applied to the surface of the second protective layer 3, and the reflective coating can reduce light reflection to enhance its applicability in optical devices; nano-coating treatment can also be performed on the surface of the second protective layer 3 to improve its stain resistance, water resistance, and wear resistance, suitable for applications in harsh environments; heat-conducting fillers are also added to the second protective layer 3 to enhance the heat dissipation performance of the first protective layer 1 and the second protective layer 3, suitable for applications in high-power electronic devices; the second protective layer 3 is preferably a transparent PI or PET cover film, which is convenient for quickly attaching it to the screen printing layer to improve production efficiency.

[0037] In the present utility model, the first protective layer 1, the circuit connection layer, and the second protective layer 3 are connected by thermocompression and curing. Compared with traditional glue treatment, thermocompression and curing treatment can be completed in a shorter time without waiting for the glue to cure and spending a large amount of labor costs, and it is easier to integrate into an automated production line to improve production efficiency; on the one hand, thermocompression and curing treatment can control the temperature and pressure to improve the thickness uniformity of the connection area. This uniform adhesion performance reduces the formation of bubbles and voids, improving the overall quality, reliability, and light transmittance of the FPC board; on the other hand, traditional glue connection may release harmful substances during the curing process, affecting the environment and the health of operators, while thermocompression and curing treatment generally does not release volatile organic compounds (VOCs), and has better environmental protection.

[0038] It should be understood that in the present utility model, terms such as "first" and "second" are used to describe various information, but such information should not be limited to these terms, and these terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of the present utility model, "first" information may also be referred to as "second" information, and similarly, "second" information may also be referred to as "first" information. In addition, the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model 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 should not be construed as a limitation to the present utility model.

[0039] The above is the preferred embodiment of the present utility model. It should be pointed out that for those of ordinary skill in the art of this technology, without departing from the principle of the present utility model, several improvements and deformations can still be made, and these improvements and deformations are also regarded as the protection scope of the present utility model.

Claims

1. A light-transmitting structure applied to an FPC board, characterized in that: include: A first protective layer (1); An FPC board layer (2), the FPC board layer (2) being provided with a silk screen layer and a circuit connection layer, the silk screen layer being connected to the circuit connection layer, and the circuit connection layer being connected to the first protective layer (1); A second protective layer (3), the second protective layer (3) being connected to the silk-screen layer relative to the first protective layer (1), the silk-screen layer being used for silk-screening circuits, and the circuit connection layer, the first protective layer (1) and the second protective layer (3) being light-transmitting layers, so that the structure of the silk-screen layer can be observed through the first protective layer (1) or the second protective layer (3).

2. The light-transmitting structure applied to an FPC board according to claim 1, characterized in that: The circuit connection layer is a transparent PI layer or a PET layer.

3. The light-transmitting structure applied to an FPC board according to claim 2, characterized in that: The silk-screen layer is a conductive silver paste layer.

4. The light-transmitting structure applied to an FPC board according to claim 3, characterized in that: The thickness of the silk-screen layer ranges from 3 to 50 μm.

5. The light-transmitting structure applied to an FPC board according to claim 1, characterized in that: The first protective layer (1) and the line connection layer are fixedly connected by high temperature.

6. The light-transmitting structure applied to an FPC board according to claim 1, characterized in that: The thickness of the first protective layer (1) is 4-100 μm.

7. The light-transmitting structure applied to an FPC board according to claim 3, characterized in that: The second protective layer (3) is connected to the silk-screen layer by heat pressing.

8. The light-transmitting structure applied to an FPC board according to claim 7, characterized in that: The thickness of the second protective layer (3) is 12.5-50 μm.

9. The light-transmitting structure applied to an FPC board according to claim 8, characterized in that: The first protective layer (1) is a transparent PI layer or a PET layer.

10. The light-transmitting structure applied to an FPC board according to claim 9, characterized in that: The second protective layer (3) is a transparent PI layer or a PET layer.

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