Rigid-flex board and electric device
By optimizing the structure and materials of the rigid-flex PCB and controlling the height difference and the thickness of the conductive material layer, the problems of insufficient sealing and mechanical strength during injection molding were solved, enabling the production and use of high-quality PCBs.
Patent Information
- Application Number
- CN202520368949.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-03
- Publication Date
- 2026-02-17
- Estimated Expiration
- 2035-03-03
AI Technical Summary
Existing rigid-flex PCBs suffer from insufficient sealing and mechanical strength due to thickness differences at the rigid-flex interface during injection molding, leading to PCB scrap and mechanical damage.
By controlling the height difference between the soft-hard interface and the hard plate within the range of 0~70μm, optimizing the thickness and structure of the conductive material layer, adopting a grid design, and using materials such as polyimide, we can ensure close contact between the injection mold and improve mechanical strength.
It improves injection molding sealing, reduces manufacturing difficulty and cost, enhances mechanical strength, and prevents damage to the PCB board during injection molding and use.
Smart Images
Figure CN223928522U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the field of circuit board especially to a rigid-flexible combined board and an electric device. BACKGROUND
[0002] The rigid-flexible combined board is a special printed circuit board (PCB), which is a composite structure combining rigid PCB and flexible PCB (FPCB for short), and can provide rigid support in other areas on the premise of keeping partial area flexible, and is suitable for application scenarios requiring bending, folding or limited space, and is widely used in electronic devices.
[0003] The thickness of the soft-hard joint of the existing rigid-flexible combined board (PCB board) is slightly thicker than that of the hard board part, and the following technical problems exist:
[0004] (1) The overall board surface is uneven, with height difference, which may not significantly affect the performance of the PCB board in the case of non-injection molding, but will cause PCB scrap problems in the injection molding process. Specifically, when the hard board part of the PCB board is injection molded, the injection mold will press down to the surface of the hard board part and the soft-hard joint to inject EMC glue or Plastic Molding Compound (PCM) into the injection molding area of the PCB board. However, the existence of height difference caused by the slightly thicker thickness of the soft-hard joint than the hard board part makes the injection mold unable to completely fit the surface of the hard board part, resulting in insufficient sealing. The injection material leaks from these gaps to the non-injection molding area of the PCB board during the injection molding process, which will pollute the PCB board and even damage its electrical performance, causing the PCB board to fail the quality test and have to be scrapped.
[0005] (2) The thickness of the soft-hard joint is slightly thicker than that of the hard board part, making the soft-hard joint the main stress point of the PCB board contacting the injection mold during injection molding. Due to small contact area and large pressure, the PCB board is easily damaged. UTILITY MODEL CONTENTS
[0006] The utility model aims to provide a rigid-flexible combined board and an electric device to alleviate the above technical problems in the prior art.
[0007] To achieve the above purpose, the utility model adopts the following technical solutions:
[0008] In a first aspect, the utility model provides a kind of rigid-flex board, including mutually combined hard board and soft board, one end of the soft board is inserted into the dielectric layer of one end of the hard board and forms the soft-hard interface of the rigid-flex board, the part of the hard board except the soft-hard interface is the hard board part of the rigid-flex board, the part of the soft board except the soft-hard interface is the soft board part of the rigid-flex board;With the thickness direction of the rigid-flex board as height direction, wherein: the height of the upper surface of the soft-hard interface is higher than or equal to the height of the upper surface of the hard board part, the height of the lower surface of the soft-hard interface is lower than or equal to the height of the lower surface of the hard board part;And, with the height difference of the upper surface of the soft-hard interface and the upper surface of the hard board part as H1, the height difference of the lower surface of the soft-hard interface and the lower surface of the hard board part as H2, then: 0≤H1≤70 μm, 0≤H2≤70 μm.
[0009] Further optionally, along the height direction, the hard board at least includes hard board upper conductive material layer, dielectric layer and hard board lower conductive material layer which are sequentially stacked from top to bottom;The soft board at least includes upper cover film, soft board upper conductive material layer, substrate layer, soft board lower conductive material layer and lower cover film which are sequentially stacked from top to bottom;With the thickness of the hard board upper conductive material layer of the hard board part as t1, the thickness of the hard board upper conductive material layer of the soft-hard interface as t2, the thickness of the hard board lower conductive material layer of the hard board part as t3, the thickness of the hard board lower conductive material layer of the soft-hard interface as t4, then: t1>t2, t1>0, t2≥0;t3>t4, t3>0, t4≥0.
[0010] In an optional embodiment of the utility model, t1=t2=0.
[0011] In another optional embodiment of the utility model, t1>0, t2>0;Wherein, in the soft-hard interface: at least one of the hard board upper conductive material layer, the soft board upper conductive material layer, the soft board lower conductive material layer and the hard board lower conductive material layer is in grid shape.In optional implementation of the optional embodiment, in the soft-hard interface: the hard board upper conductive material layer and the hard board lower conductive material layer are both in grid shape.
[0012] In the above optional embodiment and optional implementation of the utility model, further optionally, along the height direction, the hard board part and the soft-hard interface also include upper solder mask layer arranged in the uppermost layer and lower solder mask layer arranged in the lowermost layer respectively.
[0013] In the above optional embodiment and optional implementation of the utility model, further optionally, the substrate layer is polyimide layer.
[0014] In the above-described optional embodiments and their alternative implementations of this utility model, it is further optional that the conductive material layer on the rigid board, the conductive material layer on the flexible board, the conductive material layer under the flexible board, and the conductive material layer under the rigid board are all copper layers.
[0015] In the above-described optional embodiments and their alternative implementations of this utility model, the medium layer is further optionally a PP adhesive layer (Polypropylene Adhesive) or an AD adhesive layer (Anaerobic Adhesive).
[0016] In the rigid-flex plate provided in this application, the height difference between the upper surface of the rigid plate portion and the upper surface of the rigid-flex junction portion is H1, and the height difference between the lower surface of the rigid plate portion and the lower surface of the rigid-flex junction portion is H2. By controlling the height differences H1 and H2 between the surface of the rigid plate portion and the surface on the same side of the rigid-flex junction portion along the height direction to 0~70μm (including but not limited to 0μm, 30μm, or 70μm or any height value between 0μm and 70μm), the height difference of the injection molded surfaces between the rigid plate portion 110 and the rigid-flex junction portion 130 is reduced or eliminated, thereby achieving at least the following beneficial effects:
[0017] (1) By reducing or eliminating the height difference of the injection surface between the rigid plate part and the rigid-soft junction part, the contact between the injection mold and the rigid-soft board (PCB) is made closer, reducing the gap between the two and thus improving the sealing performance during injection. This not only reduces the problem of injection material leakage that may occur during injection, but also simplifies the design and manufacturing of the injection mold (no need to design the mold according to different H1 and H2), reduces the manufacturing difficulty and manufacturing cost of the rigid-soft board (PCB), and also ensures that the injection material can be uniformly filled into the rigid plate part, improving the product quality of the rigid-soft board (PCB);
[0018] (2) By reducing or eliminating the height difference of the injection surface between the rigid part and the rigid-soft junction, the transition of the rigid-soft board (PCB) in the rigid-soft junction area is made smoother, reducing the sudden change of mechanical stress. This helps to improve the mechanical strength of the rigid-soft board (PCB) in the rigid-soft junction area, prevent the area from breaking or being damaged when subjected to external pressure or vibration, and prevent the rigid-soft board (PCB) from being crushed when it is pressed by the injection mold during the injection process.
[0019] Other beneficial effects that the rigid-flex PCB provided in this embodiment can achieve can be found in the detailed description of this application.
[0020] Secondly, this utility model embodiment also provides an electrical device, which includes the rigid-flexible plate described in any of the foregoing embodiments.
[0021] Since the electrical device provided in this embodiment includes the rigid-flex PCB provided in the first aspect, the electrical device provided in this embodiment can achieve all the beneficial effects that the rigid-flex PCB provided in the first aspect can achieve. Attached Figure Description
[0022] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0023] Figure 1 This is a cross-sectional view of the overall structure of a rigid-flex plate in the prior art;
[0024] Figure 2 for Figure 1 Enlarged view of the local structure of region A in the middle;
[0025] Figure 3 for Figure 1 Enlarged view of the local structure of region C in the middle;
[0026] Figure 4 for Figure 1 Enlarged view of the local structure of region B in the middle;
[0027] Figure 5 A cross-sectional view of an optional embodiment of the rigid-flex plate provided by this utility model;
[0028] Figure 6 for Figure 5 Enlarged view of the local structure of region D in the middle;
[0029] Figure 7 A cross-sectional view of the overall structure of another optional embodiment of the rigid-flex plate provided by this utility model;
[0030] Figure 8 for Figure 7 Enlarged view of the local structure of region E in the middle.
[0031] icon:
[0032] Z-axis - height direction;
[0033] Before improvement: 100′ - Existing rigid-flex PCB; 110′ - Rigid board section; 111′ - Upper solder resist layer; 112′ - Conductive material layer on the rigid board; 113′ - Dielectric layer; 114′ - Lower conductive material layer on the rigid board; 115′ - Lower solder resist layer; 120′ - Flexible board section; 121′ - Upper cover film; 122′ - Conductive material layer on the flexible board; 123′ - Substrate layer; 124′ - Lower conductive material layer on the flexible board; 125′ - Lower cover film; 130′ - Rigid-flex interface;
[0034] Improved version: 100-Rigid-flex PCB; 110-Rigid board section; 111-Upper solder resist layer; 112-Conductive material layer on the rigid board; 113-Dielectric layer; 114-Conductive material layer on the lower part of the rigid board; 115-Lower solder resist layer; 120-Flexible board section; 121-Upper cover film; 122-Conductive material layer on the flexible board; 123-Substrate layer; 124-Conductive material layer on the lower part of the flexible board; 125-Lower cover film; 130-Rigid-flex interface. Detailed Implementation
[0035] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0036] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0037] It should be noted that similar labels and letters in the accompanying drawings indicate similar items. Therefore, once an item is defined in one accompanying drawing, it does not need to be further defined and explained in subsequent accompanying drawings.
[0038] In the description of this utility model, it should be noted that the terms "upper," "lower," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0039] Furthermore, the terms "horizontal" and "vertical" do not imply that the component must be absolutely horizontal or suspended, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.
[0040] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0041] The following detailed description, in conjunction with the accompanying drawings, outlines some embodiments of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.
[0042] Reference Figures 1 to 4 The existing rigid-flex board 100' includes a rigid board and a flexible board bonded together. Taking the thickness direction of the existing rigid-flex board 100' as the height direction Z, the rigid board includes at least a conductive material layer 112', a dielectric layer 113', and a lower conductive material layer 114' stacked from top to bottom. The flexible board includes at least an upper cover film 121', a conductive material layer 122', a substrate layer 123', a lower conductive material layer 124', and a lower cover film 125' stacked from top to bottom. One end of the flexible board is inserted into the dielectric layer 113' at one end of the rigid board to form a rigid-flex interface 130' of the rigid-flex board 100'. The portion of the rigid board other than the rigid-flex interface 130' is the rigid board portion 110' of the rigid-flex board 100', and the portion of the flexible board other than the rigid-flex interface 130' is the flexible board portion 120' of the rigid-flex board 100'.
[0043] In a typical structure of the existing rigid-flex PCB 100′, the rigid plate further includes an upper solder resist layer 111′ disposed on the uppermost layer of the rigid plate portion 110′ and the rigid-flex interface portion 130′, and a lower solder resist layer 115′ disposed on the lowermost layer of the rigid plate portion 110′ and the rigid-flex interface portion 130′. Taking this typical structure as an example, along the thickness direction (i.e., the height direction Z) of the existing rigid-flex PCB 100′, the rigid-flex interface portion 130′ of the existing rigid-flex PCB 100′ is divided into functional layers from top to bottom, forming a structure with the substrate layer 123′ as the core layer, followed by layers L2 and L1 above, and layers L3 and L4 below, that is, as shown. Figure 4 As shown, the rigid-flex interface 130′ consists of the following layers from top to bottom: L1 layer: upper solder resist layer 111′, conductive material layer 112′ on the rigid board; L2 layer: dielectric layer 113′, upper cover film 121′, conductive material layer 122′ on the flexible board; core layer: substrate layer 123′; L3 layer: lower conductive material layer 124′ on the flexible board, lower cover film 125′, dielectric layer 113′; L4 layer: lower conductive material layer 114′ on the rigid board, lower solder resist layer 115′.
[0044] In the existing rigid-flex PCB structure 100', the thickness of the rigid-flex interface 130' is slightly thicker than the rigid interface 110', which presents the following technical problems:
[0045] (1) It causes the overall board surface to be uneven, with height differences. This height difference may not have a significant impact on the performance of the PCB board in the case of non-injection molding, but it will cause PCB scrapping problems in the injection molding process. Specifically, when the rigid part of the PCB board is injection molded, the injection mold will press down to the surface of the rigid part and the soft-hard junction to inject injection molding material (EMC glue or Plastic Molding Compound, PCM) into the injection area of the PCB board. However, the height difference caused by the soft-hard junction of the PCB board being slightly thicker than the rigid part makes it impossible for the injection mold to fully fit with the surface of the rigid part, resulting in insufficient sealing. During the injection process, the injection molding material leaks from these gaps into the non-injection area of the PCB board, which will contaminate the PCB board and even damage its electrical performance, causing the PCB board to fail the quality inspection and have to be scrapped.
[0046] (2) The thickness of the soft-hard junction is slightly thicker than that of the hard plate, so that the soft-hard junction is the main stress point of the PCB board and the injection mold during injection molding. Because the contact area is small and the pressure is strong, the PCB board is easily damaged.
[0047] In contrast, the first aspect of this application provides a novel rigid-flex board 100, which includes a rigid board and a flexible board bonded together, as shown in the figure. Figures 5 to 8One end of the flexible board is inserted into the dielectric layer 113 at one end of the rigid board to form the flexible-rigid interface 130 of the rigid-flex board 100. The part of the rigid board other than the flexible-rigid interface 130 is the rigid board part 110 of the rigid-flex board 100, and the part of the flexible board other than the flexible-rigid interface 130 is the flexible board part 120 of the rigid-flex board 100.
[0048] Furthermore, taking the thickness direction of the rigid-flex plate 100 as the height direction Z, in the rigid-flex plate 100, the height of the upper surface of the rigid-flex junction 130 is equal to or higher than the height of the upper surface of the rigid plate 110, and the height of the lower surface of the rigid-flex junction 130 is equal to or lower than the height of the lower surface of the rigid plate 110; and taking the height difference between the upper surface of the rigid-flex junction 130 and the upper surface of the rigid plate 110 as H1, and the height difference between the lower surface of the rigid-flex junction 130 and the lower surface of the rigid plate 110 as H2, then 0≤H1≤70μm, 0≤H2≤70μm.
[0049] In the existing rigid-flex plate 100' structure, the height difference H1' between the upper surface of the rigid plate portion 110' and the upper surface of the rigid-flex junction portion 130', and the height difference H2' between the lower surface of the rigid plate portion 110' and the lower surface of the rigid-flex junction portion 130', are both greater than 70 μm. However, this application, through the aforementioned design, achieves the following: the height difference H1 between the upper surface of the rigid-flex junction portion 130 and the upper surface of the rigid plate portion 110 of the rigid-flex plate 100 satisfies 0 ≤ H1 ≤ 70 μm, including but not limited to H1 being 0 μm, 30 μm, or 70 μm, or any height value between 0 μm and 70 μm; and the height difference H2 between the lower surface of the rigid-flex junction portion 130 and the lower surface of the rigid plate portion 110 satisfies 0 ≤ H2 ≤ 70 μm, including but not limited to H2 being 0 μm, 30 μm, or 70 μm, or any height value between 0 μm and 70 μm. In the preferred embodiment of this application, H1 = H2 = 0.
[0050] That is, in the rigid-flex plate 100 provided in this application, the height difference between the upper surface of the rigid plate portion 110 and the upper surface of the rigid-flex interface portion 130 is H1, and the height difference between the lower surface of the rigid plate portion 110 and the lower surface of the rigid-flex interface portion 130 is H2. By controlling the height differences H1 and H2 between the surface of the rigid plate portion 110 and the surface on the same side of the rigid-flex interface portion 130 along the height direction Z to be 0~70μm (including but not limited to 0μm, 30μm, or 70μm or any height value between 0μm and 70μm), the height difference between the injection molded surfaces of the rigid plate portion 110 and the rigid-flex interface portion 130 is reduced or eliminated, thereby achieving at least the following beneficial effects:
[0051] (1) By reducing or eliminating the height difference of the injection surface between the rigid plate portion 110 and the rigid-soft junction portion 130, the contact between the injection mold and the rigid-soft junction plate 100 (PCB board) becomes tighter, reducing the generation of gaps between the two, thereby improving the sealing performance during injection. This not only reduces the problem of leakage of injection material that may occur during injection, but also simplifies the design and manufacturing of the injection mold (no need to design the mold according to different H1, H2), reduces the manufacturing difficulty and manufacturing cost of the rigid-soft junction plate 100 (PCB board), and also ensures that the injection material can be uniformly filled into the rigid plate portion 110, improving the product quality of the rigid-soft junction plate 100 (PCB board);
[0052] (2) By reducing or eliminating the height difference of the injection surface between the rigid plate portion 110 and the rigid-soft junction portion 130, the transition of the rigid-soft bond plate 100 (PCB board) in the rigid-soft junction portion 130 area is made smoother, reducing the sudden change of mechanical stress. This helps to improve the mechanical strength of the rigid-soft bond plate 100 (PCB board) in the rigid-soft junction portion 130 area, prevents the area from breaking or being damaged when subjected to external pressure or vibration, and prevents the rigid-soft bond plate 100 (PCB board) from being pressed by the injection mold during the injection process.
[0053] To achieve the above objectives, in the optional implementation of this embodiment, specifically, continue to refer to... Figures 5 to 8 In the structure of the rigid-flex board 100 provided in this embodiment, the rigid board includes at least a rigid upper conductive material layer 112, a dielectric layer 113, and a rigid lower conductive material layer 114 stacked sequentially from top to bottom; the flexible board includes at least an upper cover film 121, a flexible upper conductive material layer 122, a substrate layer 123, a flexible lower conductive material layer 124, and a lower cover film 125 stacked sequentially from top to bottom. Let the thickness of the rigid upper conductive material layer 112 of the rigid board portion 110 be t1, the thickness of the rigid upper conductive material layer 112 of the rigid-flex junction portion 130 be t2, the thickness of the rigid lower conductive material layer 114 of the rigid board portion 110 be t3, and the thickness of the rigid lower conductive material layer 114 of the rigid-flex junction portion 130 be t4. Then: t1 > t2, t1 > 0, t2 ≥ 0; t3 > t4, t3 > 0, t4 ≥ 0. Compared to the existing rigid-flex board 100', where the thickness t1' of the conductive material layer 112' on the rigid plate portion 110' is equal to the thickness t2' of the conductive material layer 112' on the rigid plate portion 130', and the thickness t3' of the conductive material layer 114' under the rigid plate portion 110' and the thickness t4' of the conductive material layer 114' under the rigid plate portion 130' are equal, the rigid-flex board 100 provided in this embodiment can further achieve at least the following beneficial effects through the above-mentioned thickness design of the conductive material layer in the rigid plate portion:
[0054] (1) The rigid-flex PCB board 100 (PCB board) is designed to allow the PCB board to be bent or folded in certain areas. Therefore, it must maintain its flexibility and bendability. If the thickness of this area is too large, the rigid-flex PCB board 130 may become rigid and lose its flexibility, thus failing to meet the design requirements. This application reduces the thickness of the conductive material layer of the rigid board in the rigid-flex PCB board 130, thereby reducing the overall thickness of this area and better maintaining the flexibility of the rigid-flex PCB board 130. This not only helps to achieve a smaller bending radius, but also reduces the stress concentration of the rigid-flex PCB board when bending or folding, preventing the area from being damaged due to excessive bending and enhancing the overall reliability of the rigid-flex PCB board 100 (PCB board).
[0055] (2) By reducing the thickness of the conductive material layer in the rigid board section at the rigid-flex junction 130, the amount of conductive material used is reduced, the material cost is lowered, and at the same time, it also helps to achieve the lightweighting of the rigid-flex board 100 (PCB board), which is suitable for weight-sensitive applications (such as aerospace, drones, wearable devices, etc.).
[0056] More specifically: refer to Figure 5 and Figure 6 In an optional embodiment of this utility model, t1=t2=0, that is, the rigid-flexible joint 130 of the rigid-flexible joint board 100 does not have a conductive material layer 112 on the rigid board and a conductive material layer 114 on the underside of the rigid board. The rigid board is treated to remove the conductive material layer at the part where it needs to cross with the flexible board to form the rigid-flexible joint 130, thereby reducing the thickness of the rigid-flexible joint 130.
[0057] Reference Figure 7 and Figure 8 In another optional embodiment of this utility model, t1 > 0, t2 > 0; wherein, in the rigid-flexible junction 130, at least one of the four conductive material layers 112 on the rigid plate, 122 on the flexible plate, 124 under the flexible plate, and 114 under the rigid plate is in a mesh shape. In an optional embodiment of this optional embodiment, both the conductive material layer 112 on the rigid plate and the conductive material layer 114 under the rigid plate in the rigid-flexible junction 130 are in a mesh shape. The mesh structure, by removing part of the material (not all of it), can achieve beneficial effects such as weight reduction, thickness reduction, improved flexibility, and dispersion of mechanical stress to prevent material damage due to stress concentration while maintaining some conductivity.
[0058] It should be noted that some embodiments of this utility model may not include the upper solder resist layer 111 and the lower solder resist layer 115. However, after removing the solder resist layer, it is necessary to ensure that the rigid-flex PCB is not affected by moisture, oxidation, or other environmental factors. Other lightweight and protective materials (such as conductive polymers or conformal coatings) can be used to replace the solder resist layer, or other protective measures can be taken. In some conventional embodiments of this utility model, based on any of the above optional embodiments and their optional implementation methods, further, along the thickness direction (i.e., the height direction Z) of the rigid-flex PCB 100, the rigid part 110 and the rigid-flex junction part 130 also include an upper solder resist layer 111 disposed on their respective uppermost layer and a lower solder resist layer 115 disposed on their respective lowermost layer.
[0059] In any of the above-described optional embodiments and their alternative implementations of this utility model, the substrate layer 123 may further be a polyimide (PI) layer. Polyimide (PI) is a flexible material because it has excellent flexibility, high temperature resistance, and electrical insulation properties. However, those skilled in the art should know that in other optional implementations, other materials, such as polyester (PET), liquid crystal polymer (LCP), polyurethane (PU), etc., may be selected as the substrate layer to meet specific design requirements or performance needs.
[0060] In any of the above-described optional embodiments and their alternative implementations of this utility model, it is further optional that the conductive material layer 112 on the rigid board, the conductive material layer 122 on the flexible board, the conductive material layer 124 under the flexible board, and the conductive material layer 114 under the rigid board are all copper layers. However, those skilled in the art should know that in other optional implementations, conductive material layers such as aluminum foil, silver foil, and gold foil can also be used. However, considering the characteristics of low cost and excellent conductivity, copper layers are currently preferred (but not limited to) as conductive material layers.
[0061] In any of the above-mentioned optional embodiments and their optional implementations of the present invention, the medium layer 113 may be a PP adhesive layer (Polypropylene Adhesive) or an AD adhesive layer (Anaerobic Adhesive). It is more preferred, but not limited to, that an AD adhesive layer is selected as the medium layer 113 to further improve the surface flatness of the soft-hard junction 130.
[0062] The second aspect of this embodiment also provides an electrical device, which includes a rigid-flex board 100 provided in any optional embodiment of the first embodiment.
[0063] Since the electrical device provided in this embodiment includes the rigid-flex board 100 described in Embodiment 1, the electrical device provided in this embodiment can achieve all the beneficial effects that the rigid-flex board 100 in Embodiment 1 can achieve. Its specific structure and the effects it can achieve can be obtained by referring to the optional or preferred implementation methods in Embodiment 1.
[0064] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to mutually. The above embodiments in this specification are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various embodiments of this utility model.
Claims
1. A rigid-flex PCB, comprising a rigid board and a flexible board bonded together, wherein one end of the flexible board is inserted into a dielectric layer (113) at one end of the rigid board to form a rigid-flex interface (130) of the rigid-flex PCB (100), the portion of the rigid board other than the rigid-flex interface (130) is the rigid board portion (110) of the rigid-flex PCB (100), and the portion of the flexible board other than the rigid-flex interface (130) is the flexible board portion (120) of the rigid-flex PCB (100); the thickness direction of the rigid-flex PCB (100) is taken as the height direction, characterized in that: The height of the upper surface of the soft-hard junction (130) is equal to or higher than the height of the upper surface of the hard plate (110), and the height of the lower surface of the soft-hard junction (130) is equal to or lower than the height of the lower surface of the hard plate (110). Furthermore, if the height difference between the upper surface of the soft-hard junction (130) and the upper surface of the hard plate (110) is H1, and the height difference between the lower surface of the soft-hard junction (130) and the lower surface of the hard plate (110) is H2, then: 0≤H1≤70μm, 0≤H2≤70μm.
2. The rigid-flex PCB according to claim 1, characterized in that: Along the height direction, the rigid board includes at least a rigid upper conductive material layer (112), a dielectric layer (113), and a rigid lower conductive material layer (114) stacked sequentially from top to bottom; the flexible board includes at least an upper cover film (121), a flexible upper conductive material layer (122), a substrate layer (123), a flexible lower conductive material layer (124), and a lower cover film (125) stacked sequentially from top to bottom; Let t1 be the thickness of the conductive material layer (112) on the rigid plate of the rigid plate part (110), t2 be the thickness of the conductive material layer (112) on the rigid plate of the soft-hard junction part (130), t3 be the thickness of the conductive material layer (114) under the rigid plate of the rigid plate part (110), and t4 be the thickness of the conductive material layer (114) under the rigid plate of the soft-hard junction part (130). Then: t1>t2, t1>0, t2≥0; t3>t4, t3>0, t4≥0.
3. The rigid-flex PCB according to claim 2, characterized in that: t1 = t2 = 0.
4. The rigid-flex PCB according to claim 2, characterized in that: t1>0, t2>0; wherein, in the hard-soft junction (130): at least one of the four conductive material layers (112) on the hard plate, the conductive material layer (122) on the soft plate, the conductive material layer (124) under the soft plate and the conductive material layer (114) under the hard plate is in a grid shape.
5. The rigid-flex PCB according to claim 4, characterized in that: In the soft-hard junction (130): the conductive material layer (112) on the hard plate and the conductive material layer (114) under the hard plate are both in a grid pattern.
6. The rigid-flex PCB according to any one of claims 2-5, characterized in that: Along the height direction, the rigid plate portion (110) and the soft-hard junction portion (130) also include an upper solder resist layer (111) on their respective uppermost layer and a lower solder resist layer (115) on their respective lowermost layer.
7. The rigid-flex PCB according to any one of claims 2-5, characterized in that: The substrate layer (123) is a polyimide layer.
8. The rigid-flex PCB according to any one of claims 2-5, characterized in that: The conductive material layer (112) on the rigid board, the conductive material layer (122) on the flexible board, the conductive material layer (124) under the flexible board, and the conductive material layer (114) under the rigid board are all copper layers.
9. The rigid-flex PCB according to any one of claims 2-5, characterized in that: The dielectric layer (113) is a PP adhesive layer or an AD adhesive layer.
10. An electrical device, characterized in that: Includes the rigid-flex plate as described in any one of claims 1-9.