Flexible circuit board for measuring comprehensive performance of electromagnetic shielding film

Abstract

The utility model discloses a flexible circuit board for measuring comprehensive performance of an electromagnetic shielding film, which sequentially comprises a flexible circuit board, the electromagnetic shielding film and UV (ultraviolet) glue from bottom to top, the flexible circuit board sequentially comprises an FPC (flexible printed circuit) substrate layer, a copper layer and an FPC cover film from bottom to top, the copper layer is arranged on the FPC substrate layer, the FPC cover film is arranged on the copper layer, and the UV glue is arranged on the FPC cover film. The FPC cover film is provided with a grounding window and a test point window, the test point window is covered with UV glue, the UV glue abuts against the copper layer, the electromagnetic shielding film is arranged on the grounding window, and the electromagnetic shielding film abuts against the copper layer. The FPC substrate layer adopts a makeup design, the copper layer is arranged in the FPC substrate layer, the copper layer is covered by the FPC covering film, the window is arranged, the electromagnetic shielding layer and the UV glue are respectively covered, exposed copper is protected, the UV glue is separated, the exposed copper at a test point is exposed, the resistance can be measured, and the performance of the electromagnetic shielding film can be fully and comprehensively considered.

Description

Technical Field

[0001] The utility model relates to the technical field of display, in particular to a flexible circuit board for measuring the comprehensive performance of an electromagnetic shielding film. Background Art

[0002] EMI grounding resistance is an important indicator of EMI conduction performance. The shape and size of the EMI grounding window have a direct impact on the EMI conduction performance. When measuring EMI grounding resistance, it is usually necessary to measure multiple data for analysis and value selection. Generally, the EMI attached to the FPC for mobile phone display modules has different grounding window diameter specifications, and there is no better test point to measure the EMI grounding resistance. In addition, EMI's chemical corrosion resistance is also an important performance indicator. EMI's pencil hardness and friction resistance are its important physical properties.

[0003] For example, the Chinese utility model patent (CN208210425U) discloses a flexible circuit board structure, including a substrate, a metal layer, an adhesive layer, a covering film, and a silver paste structure layer. The metal layer, the adhesive layer, the covering film, and the silver paste structure layer are sequentially arranged on both sides of the substrate. The material of the metal layer is copper, and the silver paste structure layer includes silver paste and an insulating layer with a thickness of 20~45um, wherein the insulating layer is a butter layer. The silver paste structure layer added to the flexible circuit board can play the role of electromagnetic shielding and can also reduce the impact on the differential impedance value. Through the impedance test of the product, the impedance value decrease is greater than the EMI shielding film originally used.

[0004] However, when the inventor of the present invention implemented this device, he found the following defects: the EMI grounding window diameters of the FPC generally attached to the display module of mobile phones are different, and there is no good test point to measure the EMI grounding resistance. Utility Model Content

[0005] Based on this, it is necessary to provide a flexible circuit board for measuring the comprehensive performance of electromagnetic shielding film in response to the above-mentioned technical problems. The FPC soft board substrate layer adopts a patchwork design, the copper layer is arranged in the FPC soft board substrate layer, and then the copper layer is covered with FPC covering film, and then a window is set, and the electromagnetic shielding layer and UV glue are covered respectively to protect the exposed copper, separate the UV glue, and expose the exposed copper at the test point. The resistance can be measured, and the performance of the electromagnetic shielding film can be fully and comprehensively considered.

[0006] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0007] A flexible circuit board for measuring the comprehensive performance of electromagnetic shielding films.

[0008] The flexible circuit board for measuring the comprehensive performance of the electromagnetic shielding film specifically includes:

[0009] From bottom to top, it includes a flexible circuit board, an electromagnetic shielding film and UV glue. The flexible circuit board includes an FPC soft board substrate layer, a copper layer and an FPC covering film from bottom to top. The copper layer is arranged on the FPC soft board substrate layer, the FPC covering film is arranged on the copper layer, the FPC covering film is provided with a grounding window and a test point window, wherein the test point window is covered with the UV glue, the UV glue and the copper layer are in contact with each other, the electromagnetic shielding film is arranged on the grounding window, and the electromagnetic shielding film and the copper layer are in contact with each other.

[0010] As a preferred implementation of the flexible circuit board for measuring the comprehensive performance of the electromagnetic shielding film provided by the utility model, the FPC covering film is rectangular, and its size is larger than that of the copper layer.

[0011] As a preferred embodiment of the flexible circuit board for measuring the comprehensive performance of the electromagnetic shielding film provided by the utility model, the copper layer is rectangular and arranged in plural on the FPC soft board substrate layer.

[0012] As a preferred embodiment of the flexible circuit board for measuring the comprehensive performance of the electromagnetic shielding film provided by the utility model, the number of the grounding openings of the FPC covering film is two, and the shape thereof is any one of a circle, a triangle, a square, a rectangle, and a rectangle.

[0013] As a preferred embodiment of the flexible circuit board for measuring the comprehensive performance of the electromagnetic shielding film provided by the utility model, a first EMI for measuring the pencil hardness is provided at the lower end of the top surface of the FPC soft board substrate layer.

[0014] As a preferred embodiment of the flexible circuit board for measuring the comprehensive performance of the electromagnetic shielding film provided by the utility model, a second EMI for measuring the friction resistance performance is provided at the lower end of the top surface of the FPC soft board substrate layer.

[0015] As a preferred implementation of the flexible circuit board for measuring the comprehensive performance of the electromagnetic shielding film provided by the utility model, the thickness of the copper layer is 12.5um~15um.

[0016] As a preferred embodiment of the flexible circuit board for measuring the comprehensive performance of the electromagnetic shielding film provided by the utility model, the flexible circuit board is provided with a plurality of connection points for manual tearing.

[0017] As a preferred implementation of the flexible circuit board for measuring the comprehensive performance of the electromagnetic shielding film provided by the utility model, the thickness of the electromagnetic shielding film is 12um~15um.

[0018] As a preferred implementation of the flexible circuit board for measuring the comprehensive performance of the electromagnetic shielding film provided by the utility model, the electromagnetic shielding film is electrically connected to the copper layer.

[0019] Compared with the prior art, the utility model has the following beneficial effects:

[0020] The utility model provides a flexible circuit board for measuring the comprehensive performance of an electromagnetic shielding film. The FPC soft board substrate layer adopts a patchwork design, a copper layer is arranged in the FPC soft board substrate layer, and then the copper layer is covered with an FPC covering film, and then a window is provided, and the electromagnetic shielding layer and UV glue are respectively covered to protect the exposed copper, and the UV glue is separated to expose the exposed copper at the test point, so that the resistance can be measured, and the performance of the electromagnetic shielding film can be fully and comprehensively considered. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the scheme in the utility model, a brief introduction is given below to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 A schematic diagram of the structure of a flexible circuit board for measuring the comprehensive performance of an electromagnetic shielding film provided by the utility model;

[0023] Figure 2 A schematic diagram of the structure of the flexible circuit board provided by the utility model;

[0024] Figure 3 for Figure 2 Side view of.

[0025] The markings in the figure are as follows:

[0026] Flexible circuit board 1, FPC soft board substrate layer 11, copper layer 12, FPC cover film 13, grounding window 14, test point window 15; electromagnetic shielding film 2; UV glue 3; first EMI 4; second EMI 5; connection point 6. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the solution of the utility model, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the utility model.

[0028] As described in the background art, the EMI grounding window diameters of the FPC generally attached to the mobile phone display module are different, and there is no good test point to measure the EMI grounding resistance.

[0029] In order to solve this technical problem, the utility model provides a flexible circuit board 1 for measuring the comprehensive performance of an electromagnetic shielding film 2.

[0030] Specifically, please refer to Figure 1-3 The flexible circuit board 1 for measuring the comprehensive performance of the electromagnetic shielding film 2 specifically includes:

[0031] A flexible circuit board 1, an electromagnetic shielding film 2 and a UV glue 3, wherein the flexible circuit board 1 comprises, from bottom to top, an FPC soft board substrate layer 11, a copper layer 12 and an FPC covering film 13, wherein the copper layer 12 is arranged on the FPC soft board substrate layer 11, the FPC covering film 13 is arranged on the copper layer 12, the FPC covering film 13 is provided with a grounding window 14 and a test point window 15, wherein the test point window 15 is covered with the UV glue 3, the UV glue 3 and the copper layer 12 are in contact with each other, the electromagnetic shielding film 2 is arranged on the grounding window 14, and the electromagnetic shielding film 2 and the copper layer 12 are in contact with each other.

[0032] The utility model provides a flexible circuit board 1 for measuring the comprehensive performance of an electromagnetic shielding film 2. The FPC soft board substrate layer 11 adopts a patchwork design, a copper layer 12 is arranged in the FPC soft board substrate layer 11, and then the copper layer 12 is covered with an FPC covering film 13, and then a window is set, and the electromagnetic shielding layer and UV glue 3 are respectively covered to protect the exposed copper, and the UV glue 3 is separated to expose the exposed copper at the test point, so that the resistance can be measured, and the performance of the electromagnetic shielding film 2 can be fully and comprehensively considered.

[0033] In order to enable those skilled in the art to better understand the solution of the utility model, the technical solution in the embodiments of the utility model will be clearly and completely described below in conjunction with the accompanying drawings.

[0034] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features and technical solutions in the embodiments may be combined with each other.

[0035] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings. Example 1

[0036] Please refer to Figure 1-3A flexible circuit board 1 for measuring the comprehensive performance of an electromagnetic shielding film 2, which comprises, from bottom to top, a flexible circuit board 1, an electromagnetic shielding film 2 and a UV glue 3, wherein the flexible circuit board 1 comprises, from bottom to top, an FPC soft board substrate layer 11, a copper layer 12 and an FPC covering film 13, wherein the copper layer 12 is arranged on the FPC soft board substrate layer 11, the FPC covering film 13 is arranged on the copper layer 12, the FPC covering film 13 is provided with a grounding window 14 and a test point window 15, wherein the test point window 15 is covered with the UV glue 3, the UV glue 3 and the copper layer 12 are in contact with each other, the electromagnetic shielding film 2 is arranged on the grounding window 14, and the electromagnetic shielding film 2 and the copper layer 12 are in contact with each other.

[0037] Through the above structural design, the copper layer 12 is designed to be rectangular, separated one by one and open-circuited separately; the grounding window 14 of the FPC covering film 13 is circular, triangular, square, rectangular, and rectangular, and the size can be arbitrarily designed according to the test specification requirements; the FPC covering film 13 is designed to be rectangular, attached to the flexible circuit board 1, and contacts and electrically connects with the copper through the grounding window 14 of the FPC covering film 13; the test point window 15 of the FPC covering film 13 is uniformly circular to expose the copper; in order to prevent the exposed copper position of the test point from being corroded after the flexible circuit board 1 is put into high temperature, high humidity and salt spray test, it is necessary to open the window 15 at the test point to cover the UV glue 3 and solidify it for protection; the flexible circuit board 1 adopts a patchwork design, and each individual test sample is connected by a connection point 6 and can be torn off manually. For the grounding window 14 of the FPC covering film 13, the position design on the panel can be optionally circular, triangular, square, rectangular, and L-shaped from the top to the bottom, simulating the window design of the actual product; for the grounding window 14 of the FPC covering film 13, the position design on the panel can be optionally mixed arbitrarily; each test sample is made with a label to distinguish the window shape and sample number; the FPC soft board substrate layer 11 adopts a panel design, the copper layer 12 is arranged in the FPC soft board substrate layer 11, and then the copper layer 12 is covered with the FPC covering film 13, and then the grounding window 14 is arranged, and covered with an electromagnetic shielding layer and UV glue 3 respectively to protect the exposed copper, separate the UV glue 3, expose the exposed copper at the test point, and measure the resistance, which can fully and comprehensively consider the performance of the electromagnetic shielding film 2.

[0038] When in use, tear the test sample off the imposition plate.

[0039] Test the exposed copper resistance of two copper-exposed windows of a single sample and record the resistance according to the sample number.

[0040] Then apply UV glue 3 at the two copper-exposed windows, irradiate UV light, cure UV glue 3, and protect the exposed copper.

[0041] Since the samples have been separated from the plate, they can be put into reliability test separately. The general test conditions are:

[0042] Environmental testing:

[0043] Thermal shock -40~85℃ 48H;

[0044] High temperature 85℃ 240H;

[0045] High temperature and high humidity 65℃*98%RH 240H;

[0046] Low temperature -40℃ 240H;

[0047] Salt spray 5% NaCl;

[0048] Solvent resistance test: alcohol immersion, white oil immersion, acetone immersion, 7% nitric acid immersion, 10% sodium hydroxide immersion. Sample;

[0049] After the sample is granulated and soaked, the required solvent dosage is not so much. For reflow test and thermal stress test, it is especially reminded that after the sample has gone through the above experiments, the resistance value of the test point needs to be measured. At this time, you only need to apply a small amount of alcohol on the UV glue 3 to easily separate the UV glue 3, expose the exposed copper at the test point, and measure the resistance.

[0050] Specifically, the FPC cover film 13 is rectangular, and its size is larger than that of the copper layer 12 .

[0051] Through the above structural design, the FPC cover film 13 is designed to be rectangular and attached to the flexible circuit board 1. Through the window opening of the cover film, it contacts with the copper and is electrically connected.

[0052] Specifically, the copper layer 12 is rectangular and arranged in plural on the FPC soft board base material layer 11 .

[0053] Through the above structural design, the copper layer 12 is designed to be rectangular, separated one by one and open circuited respectively.

[0054] Specifically, the number of the grounding windows 14 of the FPC cover film 13 is two, and the shapes thereof are any one of circular, triangular, square, rectangular, and rectangular.

[0055] Through the above-mentioned structural design, the position design of the grounding window 14 of the covering film on the panel can be optionally circular, triangular, square, rectangular, and L-shaped from the top row to the bottom row, simulating the window design of the actual product; the test point window 15 of the covering film is uniformly circular to expose the copper.

[0056] Specifically, a first EMI4 for measuring pencil hardness is provided at the lower end of the top surface of the FPC soft board substrate layer 11 .

[0057] Specifically, a second EMI5 for measuring friction resistance is provided at the lower end of the top surface of the FPC soft board substrate layer 11 .

[0058] Through the above structural design, the end of the plate design is designed with a first EMI4 and a second EMI5 for separately measuring the pencil hardness and friction resistance of the electromagnetic shielding film 2 . Example 2

[0059] The flexible circuit board 1 for measuring the comprehensive performance of the electromagnetic shielding film 2 provided in Example 1 is further optimized. Specifically, Figure 1-3 As shown, the copper layer 12 has a thickness of 12.5 um to 15 um.

[0060] Through the above structural design, in this embodiment, the thickness of the copper layer 12 is 12.5 um. In different requirements, the thickness of the copper layer 12 can be other sizes. Example 3

[0061] The flexible circuit board 1 for measuring the comprehensive performance of the electromagnetic shielding film 2 provided in Example 1 or 2 is further optimized, such as Figure 1-3 As shown, the flexible circuit board 1 is provided with a plurality of connection points 6 for manual tearing.

[0062] Through the above structural design, the flexible circuit board 1 adopts a panel design, and each individual test sample is connected by a connection point 6 and can be torn off manually.

[0063] Specifically, the thickness of the electromagnetic shielding film 2 is 12um~15um.

[0064] Through the above structural design, in this embodiment, the thickness of the electromagnetic shielding film 2 is 12 um. In different requirements, the thickness of the copper layer 12 can be other sizes.

[0065] Specifically, the electromagnetic shielding film 2 is electrically connected to the copper layer 12 .

[0066] The use process of the flexible circuit board 1 for measuring the comprehensive performance of the electromagnetic shielding film 2 provided by the utility model is as follows:

[0067] When in use, tear the test sample off the imposition plate.

[0068] Test the exposed copper resistance of two copper-exposed windows of a single sample and record the resistance according to the sample number.

[0069] Then apply UV glue 3 at the two copper-exposed windows, irradiate UV light, cure UV glue 3, and protect the exposed copper.

[0070] Since the samples have been separated from the plate, they can be put into reliability test separately. The general test conditions are:

[0071] Environmental testing:

[0072] Thermal shock -40~85℃ 48H;

[0073] High temperature 85℃ 240H;

[0074] High temperature and high humidity 65℃*98%RH 240H;

[0075] Low temperature -40℃ 240H;

[0076] Salt spray 5% NaCl;

[0077] Solvent resistance test: alcohol immersion, white oil immersion, acetone immersion, 7% nitric acid immersion, 10% sodium hydroxide immersion. Sample;

[0078] After the sample is granulated and soaked, the required solvent dosage is not so much. For reflow test and thermal stress test, it is especially reminded that after the sample has gone through the above experiments, the resistance value of the test point needs to be measured. At this time, you only need to apply a small amount of alcohol on the UV glue 3 to easily separate the UV glue 3, expose the exposed copper at the test point, and measure the resistance.

[0079] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0080] Obviously, the embodiments described above are only some embodiments of the utility model, rather than all embodiments. The preferred embodiments of the utility model are given in the accompanying drawings, but they do not limit the patent scope of the utility model. The utility model can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the utility model more thorough and comprehensive. Although the utility model is described in detail with reference to the aforementioned embodiments, for those skilled in the art, it is still possible to modify the technical solutions recorded in the aforementioned specific implementation methods, or to replace some of the technical features therein with equivalents. Any equivalent structure made using the contents of the utility model specification and the accompanying drawings, directly or indirectly used in other related technical fields, is also within the scope of patent protection of the utility model.

Claims

1. A flexible circuit board for measuring the comprehensive performance of an electromagnetic shielding film, characterized in that: The invention relates to a flexible circuit board (1), an electromagnetic shielding film (2) and a UV glue (3) in order from bottom to top. The flexible circuit board (1) comprises, in order from bottom to top, an FPC soft board substrate layer (11), a copper layer (12) and an FPC covering film (13). The copper layer (12) is arranged on the FPC soft board substrate layer (11). The FPC covering film (13) is arranged on the copper layer (12). The FPC covering film (13) is provided with a grounding window (14) and a test point window (15). The test point window (15) is covered with the UV glue (3). The UV glue (3) and the copper layer (12) are in contact with each other. The electromagnetic shielding film (2) is arranged on the grounding window (14). The electromagnetic shielding film (2) and the copper layer (12) are in contact with each other.

2. The flexible circuit board for measuring the comprehensive performance of electromagnetic shielding film according to claim 1, characterized in that: The FPC covering film (13) is rectangular, and its size is larger than that of the copper layer (12).

3. The flexible circuit board for measuring the comprehensive performance of electromagnetic shielding film according to claim 2, characterized in that: The copper layer (12) is rectangular and arranged in plural on the FPC soft board base material layer (11).

4. The flexible circuit board for measuring the comprehensive performance of electromagnetic shielding film according to claim 1, characterized in that: The number of the grounding openings (14) of the FPC covering film (13) is two, and the shapes thereof are any one of circular, triangular, square, rectangular, and rectangular.

5. The flexible circuit board for measuring the comprehensive performance of electromagnetic shielding film according to claim 4, characterized in that: A first EMI (4) for measuring pencil hardness is provided at the lower end of the top surface of the FPC soft board substrate layer (11).

6. The flexible circuit board for measuring the comprehensive performance of electromagnetic shielding film according to claim 4 or 5, characterized in that: A second EMI (5) for measuring friction resistance is provided at the lower end of the top surface of the FPC soft board substrate layer (11).

7. The flexible circuit board for measuring the comprehensive performance of electromagnetic shielding film according to claim 6, characterized in that: The copper layer (12) has a thickness of 12.5 um to 15 um.

8. The flexible circuit board for measuring the comprehensive performance of electromagnetic shielding film according to claim 7, characterized in that: The flexible circuit board (1) is provided with a plurality of connection points (6) for manual tearing.

9. The flexible circuit board for measuring the comprehensive performance of electromagnetic shielding film according to claim 1, characterized in that: The thickness of the electromagnetic shielding film (2) is 12 um to 15 um.

10. The flexible circuit board for measuring the comprehensive performance of electromagnetic shielding film according to claim 1, characterized in that: The electromagnetic shielding film (2) is electrically connected to the copper layer (12).

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