Anti-bubble FPC applied to electromagnetic screen
By setting up an air guide groove on the adhesive layer, the problem of large-sized FPCs being prone to bubbles during the hot pressing process is solved, and the effect of improving product quality and yield is achieved.
Patent Information
- Application Number
- CN202421468229.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-25
- Publication Date
- 2025-05-30
- Estimated Expiration
- 2034-06-25
AI Technical Summary
Large-sized FPCs are prone to bubbles during the hot pressing process, resulting in an increase in product defect rate.
An adhesive layer with an air conducting groove is used to bond the protective layer to the FPC layer to avoid the use of hot melt adhesive, and air during hot pressing is discharged through the air conducting groove.
It effectively prevents the FPC from bubbles after hot pressing, and improves the quality and yield of the product.
Smart Images
Figure CN222928566U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of flexible circuit boards, and in particular to an anti-bubble FPC applied to an electromagnetic screen. Background Art
[0002] An electromagnetic screen refers to an electromagnetic touch screen that uses electromagnetic induction technology (Electromagnetic Resonance) and can achieve precise touch and original handwriting writing, and requires an electromagnetic pen to achieve touch. In order to ensure the durability and functional reliability of the battery screen (prevent external signal interference), currently, a protective layer is usually adhered to the FPC board in the battery screen. The protective layer includes an insulating layer, a metal layer, and a shielding layer (a metal containing iron and nickel or a wave-absorbing material) arranged in sequence along the direction close to the FPC. The protective layer, the metal layer, and the shielding layer are connected to each other by a laminating machine using an adhesive.
[0003] For the adhesion between the protective layer and the FPC, since the FPC has been processed into a single product, it is impossible to use a laminating machine for rolling adhesion. Instead, a hot press is used to coat a hot melt adhesive between the FPC and the protective layer and then perform hot press adhesion.
[0004] Regarding the above related technologies, the inventor found that after the current adhesive layer is dot-coated with hot melt adhesive and then melted by hot pressing and cooled and solidified to complete the adhesion, but the FPC of the battery screen is relatively large. At this time, when dot-coating and then hot pressing, air bubbles are likely to appear inside, resulting in a decrease in the yield of the FPC. Utility Model Content
[0005] In order to solve the above technical problems, the present application provides an anti-bubble FPC applied to an electromagnetic screen, which has the advantage of reducing the occurrence of product defects caused by air bubbles in large-size FPCs.
[0006] To achieve the above object, the technical solution of the present utility model is as follows:
[0007] An anti-bubble FPC applied to an electromagnetic screen includes a protective layer, a conductor layer, and an adhesive layer for bonding the protective layer and the conductor layer;
[0008] A plurality of air guide grooves are provided on the contact surfaces of the adhesive layer with the protective layer and the conductor layer.
[0009] Implementing the above technical solution, that is, first, the protective layer is bonded and fixed to the FPC layer through the adhesive layer, without dot-coating hot melt adhesive and then adhering another layer board, so as to ensure that there is no misalignment between the protective layer and the FPC layer; the setting of the air guide grooves enables the air inside to be discharged from the air guide grooves during hot pressing, thereby preventing air bubbles from appearing inside the FPC due to its too large size after hot pressing, and thus ensuring the quality of the FPC.
[0010] As a preferred embodiment of the present application, the adhesive layer includes an adhesive base layer, and a plurality of adhesive protrusions are provided on the top surface of the adhesive base layer, and air guide grooves are formed between the plurality of adhesive protrusions.
[0011] By implementing the above technical solution, the adhesive base layer can be increased in height. After being coated on a template with protrusions and solidified and shaped, and then separated from the mold, the corresponding adhesive protrusions and air guide grooves can be formed, without the need for subsequent cutting and processing of the air guide grooves, which facilitates the processing of the adhesive layer by personnel and the depth of the air guide grooves is controllable.
[0012] As a preferred embodiment of the present application, the plurality of air guide grooves are arranged at equal intervals along the length direction of the adhesive layer.
[0013] By implementing the above technical solution, the entire FPC is evenly divided into several "units", so that the air bubbles in the "units" can be discharged, further reducing the FPC.
[0014] As a preferred embodiment of the present application, the thickness of the adhesive protrusion is 0.0001 - 5 mm.
[0015] By implementing the above technical solution, it is possible to prevent the situation where the air guide groove cannot be completely hot-pressed and closed to generate air bubbles when the adhesive protrusion is too thick during hot pressing.
[0016] As a preferred embodiment of the present application, the plurality of air guide grooves are arranged in an inclined and staggered manner.
[0017] By implementing the above technical solution, the plurality of air guide grooves form a rhombic grid, further ensuring the air exhaust effect.
[0018] As a preferred embodiment of the present application, the adhesive layer is a thermosetting adhesive layer.
[0019] By implementing the above technical solution, before hot pressing, the adhesive protection layer and the conductor are first bonded and fixed to each other by the micro-viscosity of the thermosetting adhesive layer itself. During subsequent hot pressing, the thermosetting adhesive will directly adhere and fix tightly, thus avoiding the situation where the protective layer and the FPC layer are misaligned when using conventional hot melt adhesives and the hot melt adhesive liquefies, and the situation where the liquefied hot melt adhesive overflows from the edge.
[0020] In summary, the present application includes at least one of the following beneficial technical effects:
[0021] 1. First, the protective layer is adhesively fixed on the FPC layer through an adhesive layer, without applying hot melt adhesive by dot coating and then attaching another laminate, thus ensuring that there is no misalignment between the protective layer and the FPC layer. The provision of the air guide grooves enables the internal air to be discharged from the air guide grooves during hot pressing, thereby preventing bubbles from appearing inside the FPC due to its oversize dimensions after hot pressing, and thus ensuring the quality of the FPC. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.
[0023] Figure 1 It is a schematic diagram of the overall structure of Embodiment 1 of the present application.
[0024] Figure 2 It is a schematic diagram of the structure of the protective layer of Embodiment 1 of the present application
[0025] Figure 3 It is a schematic diagram of the structure of the adhesive layer in Embodiment 1 of the present application.
[0026] Figure 4 It is a schematic diagram of the structure of the adhesive layer in Embodiment 2 of the present application.
[0027] Reference numerals: 1, protective layer; 11, insulating layer; 12, metal layer; 13, shielding layer; 2, FPC layer; 3, adhesive layer; 31, adhesive base layer; 32, adhesive protrusion; 4, air guide groove. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0028] The following will further elaborate on the present application in conjunction with the attached Figures 1-4 drawings for a more detailed description.
[0029] Embodiment 1
[0030] The embodiment of the present application discloses an anti-bubble FPC applied to an electromagnetic screen. Refer to Figure 1, the bubble-proof FPC includes a protective layer 1, an FPC layer 2, and an adhesive layer 3 for bonding the protective layer 1 and the FPC layer 2. That is, the protective layer 1 is adhesively fixed on the FPC layer 2 through the adhesive layer 3 first, without dotting hot melt adhesive and then adhering another laminate, so as to ensure that there is no misalignment between the protective layer 1 and the FPC layer 2. Among them, the adhesive layer 3 is set as a thermosetting adhesive layer. Thus, before hot pressing, the protective layer 1 and the conductor are adhesively fixed to each other first through the micro-viscosity of the thermosetting adhesive layer itself. During subsequent hot pressing, the thermosetting adhesive will directly adhere and fix tightly, thereby avoiding the occurrence of misalignment between the protective layer 1 and the FPC layer 2 when using hot melt adhesive conventionally, and the occurrence of the situation where the liquefied hot melt adhesive overflows from the edge.
[0031] The protective layer includes an insulating layer 11, a metal layer 12, and a shielding layer 13 (a metal containing iron and nickel or a wave-absorbing material) arranged in sequence along the direction close to the FPC. The protective layer, the metal layer, and the shielding layer are connected to each other through an adhesive by a laminator.
[0032] A plurality of air guide grooves 4 are provided on the contact surfaces of the adhesive layer 3 with the protective layer 1 and the FPC layer 2. That is, the setting of the air guide grooves 4 enables the internal air to be discharged from the air guide grooves 4 during hot pressing, thereby preventing bubbles from appearing inside the FPC due to its too large size after hot pressing, and thus ensuring the quality of the FPC.
[0033] The adhesive layer 3 includes an adhesive base layer 31. A plurality of spaced adhesive protrusions 32 are provided on the top surface of the adhesive base layer 31. Air guide grooves 4 are formed between the plurality of adhesive protrusions 32. Thus, by increasing the height of the adhesive base layer 31, after being coated on a template with protrusions and solidified and shaped, and then separated from the mold, the corresponding adhesive protrusions 32 and air guide grooves 4 can be formed, without subsequent cutting and processing of the air guide grooves 4, which is convenient for personnel to process the adhesive layer 3, and the depth of the air guide grooves 4 is controllable.
[0034] A plurality of air guide grooves 4 are arranged at equal intervals along the length direction of the adhesive layer 3, so that the entire FPC is evenly divided into several "units", so that the bubbles in the "units" can be discharged, further reducing the situation of bubbles generated after hot pressing due to the too large size of the FPC.
[0035] The thickness of the adhesive protrusions 32 is 0.0001 - 5 mm, to prevent the adhesive protrusions 32 from being too thick during hot pressing, resulting in the failure of the air guide grooves 4 to discharge bubbles when bubbles are generated during hot pressing closure.
[0036] The implementation principle of an anti-bubble FPC applied to an electromagnetic screen in an embodiment of the present application is as follows: First, the protective layer 1 is adhesively fixed on the FPC layer 2 through the adhesive layer 3, without dotting hot melt adhesive and then adhering another laminate, so as to ensure that there is no dislocation between the protective layer 1 and the FPC layer 2. The adhesive layer 3 is set as a thermosetting adhesive layer. Thus, before hot pressing, the protective layer 1 and the conductor are first adhesively fixed to each other through the micro-viscosity of the thermosetting adhesive layer itself. During subsequent hot pressing, the thermosetting adhesive will directly adhere and fix tightly, thereby avoiding the occurrence of dislocation between the protective layer 1 and the FPC layer 2 when using hot melt adhesive conventionally, and the occurrence of the situation where the liquefied hot melt adhesive overflows from the edge. The setting of the air guide groove 4 enables the internal air to be discharged from the air guide groove 4 during hot pressing, thereby preventing bubbles from appearing inside the FPC due to its too large size after hot pressing, and thus ensuring the quality of the FPC.
[0037] Embodiment 2
[0038] The difference between this embodiment and Embodiment 1 is that a plurality of air guide grooves 4 are arranged in an inclined and staggered manner, so that a plurality of air guide grooves 4 form a rhombic grid, thereby further ensuring the exhaust effect.
[0039] The above are all preferred embodiments of the present application. The protection scope of the present application is not limited thereby. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application should be covered within the protection scope of the present application.
Claims
1. An anti-bubble FPC used in electromagnetic screens, characterized by: It comprises a protective layer (1), an FPC layer (2), and an adhesive layer (3) for bonding the protective layer (1) and the FPC layer (2); A plurality of air guide grooves (4) are arranged on the contact surfaces between the adhesive layer (3) and the protective layer (1) and the FPC layer (2).
2. The anti-bubble FPC for electromagnetic screen according to claim 1, characterized in that: The adhesive layer (3) comprises an adhesive base layer (31), a top surface of the adhesive base layer (31) is provided with a plurality of adhesive protrusions (32), and air guide grooves (4) are formed between the plurality of adhesive protrusions (32).
3. The anti-bubble FPC for electromagnetic screen according to claim 1, characterized in that: The plurality of air guide grooves (4) are arranged at equal intervals along the length direction of the adhesive layer (3).
4. The anti-bubble FPC for electromagnetic screen according to claim 2, characterized in that: The thickness of the bonding protrusion (32) is 0.0001-5 mm.
5. The anti-bubble FPC for electromagnetic screen according to claim 1, characterized in that: The plurality of air guide grooves (4) are arranged in an inclined and staggered manner.
6. The anti-bubble FPC for electromagnetic screen according to claim 1, characterized in that: The adhesive layer (3) is a thermosetting adhesive layer.