Ultra-thin shielding film structure and circuit board structure

Abstract

The utility model discloses a kind of ultra-thin shielding film structure and circuit board structure, the ultra-thin shielding film structure includes metal seed layer and metal shielding layer, the metal seed layer is deposited on flexible substrate;The metal shielding layer is deposited on the surface of the metal seed layer.The utility model is deposited on the flexible substrate by metal seed layer, metal seed layer can be used as adhesion layer, improve the binding force between flexible substrate and metal shielding layer;Metal shielding layer is used to shield the electromagnetic signal interference of outside to circuit signal on substrate, so the ultra-thin electromagnetic shielding film obtained can significantly improve film adhesion, bending resistance and shielding effectiveness.

Description

Technical Field

[0001] This utility model relates to the field of circuit board technology, and in particular to an ultra-thin shielding film structure and a circuit board structure. Background Technology

[0002] In existing technologies, flexible printed circuit boards (FPCs) commonly employ multi-layered composite electromagnetic shielding films for surface mounting to improve electromagnetic shielding performance. This electromagnetic shielding film consists of a conductive adhesive layer (approximately 3 μm thick), a metal shielding layer (copper / aluminum, approximately 5-10 μm thick), and an organic polymer protective film (approximately 5 μm thick), forming a laminated system that is attached to the FPC surface via a lamination process. While this structure can guide electromagnetic waves through the conductivity of the metal layer, its total thickness exceeds 10 μm, leading to the following technical drawbacks:

[0003] (1) The thickness of the laminate restricts the overall thinning development of FPC, especially its insufficient adaptability to ultra-thin scenarios such as wearable devices;

[0004] (2) The difference in modulus between the rigid metal layer and the flexible substrate makes it easy for interface delamination to occur at the bending part. After 500 bends, the shielding effectiveness decreases by more than 30%.

[0005] (3) An independent protective film is required to prevent metal oxidation, which increases the material thickness and interface bonding risk;

[0006] (4) The shielding film also needs to be processed through multiple processes such as die cutting, positioning and hot pressing. The thermal curing time of the conductive adhesive in the existing structure is long (>15 seconds / piece), which affects production efficiency.

[0007] Current improvement solutions focus on thinning single materials (such as using nano-silver conductive adhesive), but are limited by material properties and cannot overcome the overall thickness bottleneck at the structural design level. Therefore, it is urgent to develop new shielding film structures that combine ultra-thin form (total thickness ≤2μm), bending resistance (>2000 cycles), and processability through interlayer structure optimization and functional integration.

[0008] The above content is only used to help understand the technical solution of this utility model and does not represent an admission that the above content is prior art. Utility Model Content

[0009] The main purpose of this invention is to provide an ultra-thin shielding film structure and a circuit board structure, which aims to solve the above-mentioned problems in the prior art.

[0010] To achieve the above objectives, this utility model provides an ultrathin shielding film structure for a flexible substrate, wherein the flexible substrate is subjected to plasma etching treatment, and the ultrathin shielding film structure comprises:

[0011] A metal seed layer, wherein the metal seed layer is deposited on the flexible substrate;

[0012] A metal shielding layer, wherein the metal shielding layer is deposited on the surface of the metal seed layer;

[0013] The total thickness of the metal seed layer and the metal shielding layer is less than 2 μm.

[0014] Preferably, in the ultrathin shielding film structure for flexible substrates, the flexible substrate is a flexible thin film or a flexible circuit board.

[0015] Preferably, in the ultrathin shielding film structure for flexible substrates, the flexible film or flexible circuit board is etched by oxygen plasma.

[0016] The metal seed layer is sputtered onto the flexible thin film or flexible circuit board;

[0017] The metal shielding layer is sputtered onto the surface of the metal seed layer.

[0018] Preferably, in the ultrathin shielding film structure for flexible substrates, the thickness of the metal seed layer is H1, where 1nm≤H1≤100nm.

[0019] Preferably, in the ultrathin shielding film structure for flexible substrates, the metal seed layer is Cr.

[0020] Preferably, in the ultrathin shielding film structure for flexible substrates, the thickness of the metal seed layer is 35 nm.

[0021] Preferably, in the ultrathin shielding film structure for flexible substrates, the thickness of the metal shielding layer is H2, where 10nm≤H2≤1000nm.

[0022] Preferably, in the ultrathin shielding film structure for flexible substrates, the metal shielding layer is Cu or Al.

[0023] Preferably, in the ultrathin shielding film structure for flexible substrates, the thickness of the metal shielding layer is 300 nm.

[0024] To achieve the above objectives, this utility model provides a circuit board structure, which includes the aforementioned ultra-thin shielding film structure.

[0025] This utility model has at least the following beneficial effects:

[0026] The ultrathin shielding film structure provided by this utility model involves depositing a metal seed layer on the flexible substrate. The metal seed layer can serve as an adhesion layer, improving the bonding force between the flexible substrate and the metal shielding layer. The metal shielding layer is used to shield external electromagnetic signals from interfering with circuit signals on the substrate. The resulting ultrathin electromagnetic shielding film can significantly improve film adhesion, bending resistance, and shielding effectiveness. The total thickness of the metal seed layer and the metal shielding layer is less than 2 μm.

[0027] Furthermore, the flexible substrate is a flexible thin film or a flexible circuit board, which is etched by oxygen plasma; the metal seed layer is sputtered on the flexible thin film or flexible circuit board; and the metal shielding layer is sputtered on the surface of the metal seed layer. Thus, the ultrathin shielding film structure is composed of an oxygen plasma-etched substrate, a high-temperature sputtered seed layer, and a metal shielding layer. The resulting shielding film is not only thinner and lighter, but also has better bending resistance and higher adhesion. At the same time, the shielding film structure is simpler, as the conductive adhesive layer of traditional shielding films is removed. Attached Figure Description

[0028] Figure 1 A schematic diagram of the ultrathin shielding film structure provided by this utility model;

[0029] Reference numerals in the drawings of this utility model:

[0030] 1-Flexible substrate, 2-Metal seed layer, 3-Metal shielding layer.

[0031] The purpose, features, and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0032] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. The present utility model will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this utility model can be combined with each other.

[0033] In this embodiment of the invention, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0034] It should be noted that the terms "first," "second," etc., in the specification, claims, and drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0035] In this embodiment of the invention, the term "multiple" refers to two or more, and other quantifiers are similar.

[0036] In this utility model, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used in relation to the direction shown in the accompanying drawings, or in relation to the vertical, perpendicular, or gravitational direction of the component itself; similarly, for ease of understanding and description, "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not used to limit this utility model.

[0037] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the various embodiments of this utility model will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details are provided in the various embodiments of this utility model to facilitate a better understanding of the invention. However, the technical solutions claimed by this utility model can be implemented even without these technical details and various variations and modifications based on the following embodiments. The division of the various embodiments below is for ease of description and should not constitute any limitation on the specific implementation of this utility model. The various embodiments can be combined with and referenced by each other without contradiction.

[0038] This invention provides an ultrathin shielding film structure for flexible substrates, such as... Figure 1 As shown, the flexible substrate 1 undergoes plasma etching. The ultrathin shielding film structure includes a metal seed layer 2 and a metal shielding layer 3. The metal seed layer 2 is deposited on the flexible substrate 1, and the metal shielding layer 3 is deposited on the surface of the metal seed layer 2. The total thickness of the metal seed layer 2 and the metal shielding layer 3 is less than 2 μm.

[0039] The ultra-thin shielding film structure provided by this utility model involves depositing a metal seed layer 2 on the flexible substrate 1. The metal seed layer 2 can serve as an adhesion layer, improving the bonding force between the flexible substrate 1 and the metal shielding layer 3. The metal shielding layer 3 is used to shield external electromagnetic signals from interfering with circuit signals on the substrate. The resulting ultra-thin electromagnetic shielding film can significantly improve film adhesion, bending resistance, and shielding effectiveness. The total thickness of the metal seed layer 2 and the metal shielding layer 3 is less than 2 μm.

[0040] In some embodiments, the flexible substrate 1 is a flexible thin film or a flexible circuit board. In other embodiments, the flexible substrate 1 may also be made of other materials, which are not specifically limited here.

[0041] The flexible substrate 1 is a flexible thin film or a flexible circuit board, which is etched by oxygen plasma. The metal seed layer 2 is sputtered on the flexible thin film or flexible circuit board. The metal shielding layer 3 is sputtered on the surface of the metal seed layer 2. Thus, the ultra-thin shielding film structure is composed of an oxygen plasma-etched substrate, a high-temperature sputtered seed layer, and a metal shielding layer 3. The resulting shielding film is not only thinner and lighter, but also has better bending resistance and higher adhesion. At the same time, the shielding film structure is simpler, as the conductive adhesive layer of traditional shielding films is removed.

[0042] The metal seed layer 2 serves an adhesive function, as well as a buffering and stress-relieving function. The metal seed layer 2 cannot be too thick, as this would affect the overall thickness; nor can it be too thin, as this would result in poor performance. In this embodiment, the thickness of the metal seed layer 2 is H1, where 1nm ≤ H1 ≤ 100nm. In some embodiments, the thickness of the metal seed layer 2 can also be 10nm, 20nm, 30nm, 35nm, 50nm, or 80nm.

[0043] In some embodiments, the metal seed layer 2 is Cr. In other embodiments, the metal seed layer 2 may be other metals.

[0044] The thickness of the metal shielding layer 3 cannot be too thick, otherwise it will be difficult to bend and will affect the overall thickness; nor can it be too thin, otherwise the shielding effect will be poor. In this embodiment, the thickness of the metal shielding layer 3 is H2, 10nm≤H2≤1000nm. In some embodiments, the thickness of the metal shielding layer 3 can also be 20nm, 50nm, 100nm, 300nm, 500nm, and 800nm.

[0045] In some embodiments, the metal shielding layer 3 is made of Cu or Al. In other embodiments, the metal shielding layer 3 may also be made of other metals, and no specific limitation is made here.

[0046] This utility model also provides a circuit board structure, which includes the aforementioned ultra-thin shielding film structure. Embodiments of the circuit board structure include the aforementioned ultra-thin shielding film structure for flexible circuit boards, and the beneficial effects of the aforementioned ultra-thin shielding film structure can be applied to this circuit board structure.

[0047] In the description of this specification, references to terms such as "this embodiment," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0048] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features of the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0049] Obviously, the embodiments described above are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, those skilled in the art can make other variations or modifications without creative effort, and all such variations or modifications should fall within the protection scope of this utility model.

Claims

1. An ultra-thin shielding film structure for a flexible substrate, characterized by, The flexible substrate undergoes plasma etching treatment, and the ultrathin shielding film structure includes: A metal seed layer, wherein the metal seed layer is deposited on the flexible substrate; A metal shielding layer, wherein the metal shielding layer is deposited on the surface of the metal seed layer; The total thickness of the metal seed layer and the metal shielding layer is less than 2 μm.

2. The ultra-thin barrier film structure for flexible substrates of claim 1, wherein, The flexible substrate is a flexible thin film or a flexible circuit board.

3. The ultrathin shielding film structure for flexible substrates as described in claim 2, characterized in that, The flexible thin film or flexible circuit board is etched by oxygen plasma. The metal seed layer is sputtered onto the flexible thin film or flexible circuit board; The metal shielding layer is sputtered onto the surface of the metal seed layer.

4. The ultra-thin barrier film structure for flexible substrates of claim 1, wherein, The thickness of the metal seed layer is H1, where 1nm ≤ H1 ≤ 100nm.

5. The ultrathin shielding film structure for flexible substrates as described in claim 4, characterized in that, The metal seed layer is Cr.

6. The ultra-thin barrier film structure for flexible substrates of claim 4, wherein, The thickness of the metal seed layer is 35 nm.

7. The ultra-thin barrier film structure for flexible substrates of claim 1, wherein, The thickness of the metal shielding layer is H2, where 10nm ≤ H2 ≤ 1000nm.

8. The ultra-thin barrier film structure for flexible substrates of claim 7, wherein, The metal shielding layer is made of Cu or Al.

9. The ultra-thin barrier film structure for flexible substrates of claim 7, wherein, The thickness of the metal shielding layer is 300 nm.

10. A wiring board structure characterized by comprising: Including the ultrathin shielding film structure as described in any one of claims 1 to 9.

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