Novel FPC reinforcing installation structure
By welding and fixing the FPC with a laminated structure of FR4 reinforcing layer, metal connection layer and flux layer, the problems of complex and high cost of existing FPC reinforcement process are solved, and the process flow is simplified, production efficiency is improved and structural strength is enhanced.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHEJIANG YILIAN ELECTRONICS CO LTD
- Filing Date
- 2025-05-20
- Publication Date
- 2026-04-24
AI Technical Summary
The existing FPC partial reinforcement process using FR4 board adhesive bonding requires three steps: applying FR4, pressing FR4, and baking. The process is cumbersome, has low production efficiency, and high cost.
The structure consists of a laminated layer of FR4 reinforcement, a metal bonding layer, and a solder flux layer. The metal bonding layer is welded to the pad structure of the FPC, eliminating the need for traditional glue bonding and achieving direct welding fixation.
It simplifies the process, improves production efficiency, reduces costs, enhances structural strength and environmental resistance, and improves product reliability.
Smart Images
Figure CN224164933U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of flexible printed circuit board technology, specifically to a novel FPC reinforcement mounting structure. Background Technology
[0002] With the development of information electronic products, FPC (generally referring to flexible circuit boards) is a widely used type of circuit board product. In particular, it has the characteristics of being thin, flexible, rollable, low voltage, low power consumption, and low power consumption. Through embedded circuit design, it can embed a large number of compact components in a limited space. The automotive battery modules on the market use FPC busbars to replace the traditional wire harness connection method in order to achieve the purpose of collecting information such as battery module voltage and temperature.
[0003] Various components need to be soldered onto FPC boards. Due to the flexibility and bendability of FPC, the solder joints between the components and the FPC are unstable when the board is bent, making them prone to breakage and functional failure. To improve structural strength, reinforcement is applied to increase the local structural strength of the FPC product and protect the components on the FPC board. Industry-standard reinforcement primarily uses steel sheets or FR4 boards for patch reinforcement. FR4 board, as a flame-retardant reinforcing material, has higher mechanical properties, dimensional stability, impact resistance, and moisture resistance than paper-based boards. It also has excellent electrical properties, operates at higher temperatures, and its performance is less affected by the environment. The patch reinforcement process for FPC involves first soldering the components onto the FPC, and then bonding the FR4 board to the FPC with adhesive. This requires three processes: applying FR4, pressing FR4, and baking. This complex and cumbersome FR4 installation process increases the cost of FPC products and reduces their market competitiveness. Utility Model Content
[0004] Therefore, the technical problem to be solved by this utility model is to overcome the problem that the existing technology of using FR4 board glue bonding process for local reinforcement of FPC requires three processes to achieve FR4 mounting on FPC, namely, FR4 bonding, FR4 pressing and baking. The process is complicated, the production efficiency is low and the cost is increased.
[0005] To solve the above-mentioned technical problems, this utility model provides a novel FPC reinforcement mounting structure, including an FPC body and a reinforcement plate structure disposed in the reinforcement area of the FPC body. The FPC body has a pad structure in its reinforcement area, and the reinforcement plate structure includes a stacked FR4 reinforcement layer, a metal connection layer, and a solder flux layer. The reinforcement plate structure is welded and fixedly connected to the FPC body via the metal connection layer and the pad structure, so that the FR4 reinforcement layer covers the reinforcement area of the FPC body.
[0006] As a preferred embodiment, the FPC body includes a data acquisition connecting piece extending to its side, the data acquisition connecting piece having a reinforcing area for connecting the reinforcing plate structure, and a data acquisition element being disposed in the reinforcing area of the data acquisition connecting piece, the reinforcing plate structure including protective holes disposed around the data acquisition element.
[0007] As a preferred embodiment, the protective hole is filled with a sealant that covers the acquisition element.
[0008] As a preferred embodiment, the FR4 reinforcing layer is an FR4 reinforcing plate with protective holes extending through it.
[0009] As a preferred embodiment, the metal connection layer is a copper foil layer covering the bottom surface of the FR4 reinforcing plate.
[0010] As a preferred embodiment, the flux layer is a tin-plated layer covering the side of the copper foil layer facing away from the FR4 reinforcing plate.
[0011] As a preferred embodiment, the thickness of the FR4 reinforcing layer is greater than the thickness of the metal connection layer, and the thickness of the metal connection layer is greater than the thickness of the flux layer.
[0012] As a preferred embodiment, the acquisition connector includes an acquisition section with acquisition elements and pad structures, and a cantilever section extending to connect the acquisition section to the FPC body. The side of the acquisition section used to connect to the reinforcing plate structure is a reinforcing area, and the reinforcing plate structure is welded and fixed to the acquisition section.
[0013] As a preferred embodiment, the acquisition element is a temperature sensor disposed on the acquisition section, and the FPC body is provided with a temperature acquisition line extending to the acquisition section and connecting to the temperature sensor.
[0014] As a preferred embodiment, the acquisition connector has a window structure on the acquisition section that exposes the pad structure, the pad structure including at least one copper-based pad formed on the acquisition section.
[0015] Compared with the prior art, the technical solution of this utility model has the following advantages:
[0016] 1. In the novel FPC reinforcement installation structure provided by this utility model, the reinforcement plate structure adopts a laminated structure design consisting of an FR4 reinforcement layer, a metal connection layer, and a soldering flux layer. It is fixed to the FPC pads by welding through the metal connection layer, thereby realizing direct welding and fixing between the FR4 reinforcement plate and the FPC. The reinforcement increases the local structural strength of the FPC product. This installation design eliminates the multi-step process of applying glue, pressing, and baking required by traditional glue bonding. The reinforcement operation is completed in one step by welding, reducing the complexity of the process and avoiding the risks of glue aging and delamination. The metallurgical bonding characteristics of metal welding achieve a more stable mechanical connection, which is conducive to improving the durability of the reinforcement structure in harsh environments such as high temperature, high humidity, and mechanical vibration. The FR4 reinforcement plate designed with this technical solution is fixedly connected to the FPC by welding, which simplifies the process, improves production efficiency, reduces costs, enhances structural strength, has better environmental resistance and better thermal performance, and improves product reliability.
[0017] 2. In the novel FPC reinforcement mounting structure provided by this utility model, the metal connection layer is a copper foil layer covering the bottom surface of the FR4 reinforcement plate, the FPC body is preferably a copper substrate FPC, and the corresponding pad structure is a copper-based pad formed on the acquisition connection piece. The FR4 reinforcement plate is fixedly covered on the FPC at a local position by welding the copper foil layer and the copper-based pad. Since both the copper foil layer and the copper-based pad are copper, the same metal has better bonding, is easier to weld, has high welding strength, and good connection stability. This FR4 reinforcement plate replaces the traditional glue bonding process with metal welding, simplifying the process, optimizing structural performance, and reducing costs. Furthermore, the shear strength of the welded connection of this FR4 reinforcement plate is many times higher than that of the traditional adhesive connection, which can increase the local structural strength of the FPC product to protect the components on the FPC.
[0018] 3. In the novel FPC reinforcement mounting structure provided by this utility model, the flux layer is a tin-plated layer covering the copper foil layer on the side facing away from the FR4 reinforcement plate. This design has the following advantages: First, the tin-plated layer can protect the copper surface from oxidation and keep the metal surface clean, thereby ensuring the reliability of the welding; second, the tin-plated layer has a low melting point, which improves wettability and reduces the welding temperature, helping to maintain the stability of the solder joint at high temperatures, reducing the occurrence of cold solder joints or poor solder joints, and improving the welding strength; third, the tin-plated layer interacts directly with the solder during welding, promoting the formation of the welding interface, which is particularly suitable for SMT placement technology in automated production and helps to improve the yield.
[0019] 4. In the novel FPC reinforcement mounting structure provided by this utility model, the acquisition components are soldered onto the acquisition connection piece of the FPC through SMT mounting process, and the FR4 reinforcement plate is fixed onto the acquisition connection piece by metal welding. It is also compatible with SMT online mounting and soldering process, so that reinforcement and component mounting and soldering can be completed simultaneously, eliminating the glue bonding, pressing and curing and baking steps, and requiring no additional processes. This can greatly shorten the production cycle and improve production efficiency. Attached Figure Description
[0020] 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.
[0021] Figure 1 A schematic diagram of the planar structure of the novel FPC reinforcement installation structure provided for the utility model;
[0022] Figure 2 for Figure 1 The diagram shows a cross-sectional structure along line AA.
[0023] Figure 3 A three-dimensional structural schematic diagram of the novel FPC reinforcement installation structure provided for the utility model;
[0024] Figure 4 This is a partially enlarged structural diagram of the acquisition connection piece of the utility model.
[0025] Figure descriptions: 1. FPC body; 11. Temperature sampling circuit; 2. Reinforcing plate structure; 21. FR4 reinforcing layer; 22. Metal connection layer; 23. Solder flux layer; 3. Pad structure; 4. Acquisition connection piece; 41. Acquisition section; 42. Cantilever section; 5. Acquisition element; 6. Window structure; 7. Protective hole; 8. Sealing adhesive. Detailed Implementation
[0026] 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. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0027] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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 mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can also refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0028] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.
[0029] Example
[0030] This utility model provides, for example Figure 1-4 The present invention discloses a novel FPC reinforcement mounting structure, comprising an FPC body 1 and a reinforcement plate structure 2 disposed in the reinforcement area of the FPC body 1. The FPC body 1 has a pad structure 3 disposed in its reinforcement area. The reinforcement plate structure 2 comprises an FR4 reinforcement layer 21, a metal connection layer 22, and a solder flux layer 23 stacked together. The reinforcement plate structure 2 is welded and fixedly connected to the FPC body 1 through the metal connection layer 22 and the pad structure 3, so that the FR4 reinforcement layer 21 covers the reinforcement area of the FPC body 1. This technical solution adopts a reinforcement plate structure 2 with the FR4 reinforcement layer 21 as the main reinforcement body, which is welded and fixed in the designated reinforcement area of the FPC (such as around components and pads). The bonding strength is high and the durability is good, which significantly increases the thickness and rigidity of the part, thereby improving the mechanical properties and process adaptability of the FPC.
[0031] The above-described implementation method is the core technical solution of this embodiment. The reinforcing plate structure 2 adopts a laminated structure design consisting of an FR4 reinforcing layer 21, a metal connecting layer 22, and a soldering flux layer 23. It is welded and fixed to the FPC pads via the metal connecting layer 22, thus achieving direct welding and fixing between the FR4 reinforcing plate and the FPC. This reinforcement increases the local structural strength of the FPC product. This installation design eliminates the multi-step process of applying glue, pressing, and baking required for traditional adhesive bonding. The reinforcement operation is completed in one step through welding, reducing process complexity and avoiding the risks of glue aging and delamination. The metallurgical bonding characteristics of metal welding achieve a more stable mechanical connection, which is beneficial for improving the durability of the reinforcing structure in harsh environments such as high temperature, high humidity, and mechanical vibration. The FR4 reinforcing plate and FPC designed using this technical solution are fixedly connected by welding, simplifying the process, improving production efficiency, reducing costs, enhancing structural strength, and exhibiting better environmental resistance and thermal performance, thereby improving product reliability.
[0032] Further optimized settings, combined with Figure 1 , Figure 3-4 The FPC body 1 includes a data acquisition connecting piece 4 extending from its side. The data acquisition connecting piece 4 has a reinforcing area connecting to the reinforcing plate structure 2, and a data acquisition element 5 is disposed in the reinforcing area of the data acquisition connecting piece 4. The data acquisition element can be a temperature, pressure, humidity, voltage, or other cutting sensor element. The reinforcing plate structure 2 includes a protective hole 7 surrounding the data acquisition element 5, and the protective hole 7 is filled with a sealing adhesive 8 covering the data acquisition element. This structural arrangement, through the protective hole structure design of the FR4 reinforcing plate, forms a physical fence to isolate the sensitive element from external stress (such as assembly compression, drop impact), and the sealing adhesive 8 filled in the protective hole 7 can absorb and disperse impact energy, preventing stress from being directly transmitted to the solder joint of the data acquisition element, thus playing a role in stress isolation and impact resistance. At the same time, the sealing adhesive forms an airtight barrier to prevent water vapor, salt spray, and dust from entering, thereby protecting the data acquisition element.
[0033] In this embodiment, the FPC body 1 is preferably a copper-based FPC, and the corresponding pad structure 3 is a copper-based pad formed on the FPC body 1. The FR4 reinforcing layer 21 is an FR4 reinforcing plate with protective holes 7 penetrating through it. The metal connection layer 22 is a copper foil layer covering the bottom surface of the FR4 reinforcing plate. The advantage of this design is that the FR4 reinforcing plate is fixedly covered on the FPC at a local position by welding the copper foil layer to the copper-based pad. Since both the copper foil layer and the copper-based pad are copper, the same metal has better bonding properties, is easier to weld, has high welding strength, and good connection stability. This FR4 reinforcing plate replaces the traditional glue bonding process with metal welding, simplifying the process, optimizing structural performance, and reducing costs. Furthermore, the shear strength of the FR4 reinforcing plate welded together is many times higher than that of the traditional adhesive bonding, which can increase the local structural strength of the FPC product to protect the components on the FPC.
[0034] like Figure 2 As shown, the flux layer 23 is a tin-plated layer covering the side of the copper foil layer facing away from the FR4 reinforcing plate. The thickness of the FR4 reinforcing layer 21 is greater than the thickness of the metal connection layer 22, and the thickness of the metal connection layer 22 is greater than the thickness of the flux layer 23. This design has the following advantages: First, the tin plating layer can protect the copper surface from oxidation and keep the metal surface clean, thereby ensuring the reliability of the soldering; second, the tin plating layer has a low melting point, which improves wettability and lowers the soldering temperature, helping to maintain the stability of the solder joint at high temperatures, reducing the occurrence of cold solder joints or poor solder joints, and improving the soldering strength; third, the tin plating layer interacts directly with the solder during soldering, promoting the formation of the solder interface, which is particularly suitable for SMT assembly technology in automated production and helps to improve yield.
[0035] In this embodiment, as Figure 4 As shown, the acquisition connection piece 4 includes an acquisition part 41 with an acquisition element 5 and a pad structure 3, and a cantilever part 42 extending and connecting the acquisition part 41 to the FPC body 1. The reinforcing plate structure 2 is welded and fixed to the acquisition part 41, and the two are compatible in size. It can be seen that the upper side of the acquisition part 41 used to connect the reinforcing plate structure 2 is a reinforcing area. This reinforcing area can be all or part of the side of the acquisition part 41. The lower side of the acquisition part 41 is correspondingly attached to the lower reinforcing plate to improve the structural strength of the acquisition part 41. More preferably, the acquisition part... The acquisition unit 41 is provided with a window structure 6 that exposes the pad structure 3. The pad structure 3 includes two copper-based pads formed on the acquisition unit 41. The acquisition element 5 is soldered onto the acquisition connector 4 of the FPC through SMT mounting process. As can be seen from the above, the FR4 reinforcing plate is fixed to the acquisition connector by metal welding, which is also compatible with SMT online mounting process. This allows the reinforcement and component mounting to be completed simultaneously, eliminating the glue bonding, pressing curing and baking steps. No additional process is required, which can greatly shorten the production cycle and improve production efficiency.
[0036] As a preferred embodiment, such as Figure 4 As shown, the acquisition element 5 is preferably a temperature sensor disposed on the acquisition part 41. The FPC body 1 is provided with a temperature acquisition line 11 extending to the acquisition part 41 and connecting to the temperature sensor. This acquisition connection piece 4 is connected to the cell module. The temperature sensor acquires temperature information of the cell module and transmits it to the FPC to obtain the temperature information of the cell module. The FR4 reinforcing plate is soldered and attached to the acquisition part 41 of the FPC through SMT mounting process, and the temperature sensor is surrounded in the protective hole 7 of the FR4 reinforcing plate. By filling the protective hole with thermally conductive sealant, the temperature sensor can be provided with excellent thermal conductivity and sealing performance. The FR4 reinforcing plate significantly increases the thickness and rigidity of the acquisition part, avoiding component detachment or circuit breakage due to excessive bending of the FPC flexible material. In summary, the FPC reinforcement structure of this embodiment, through the combination of structural protection and functional packaging, significantly improves the environmental adaptability and structural reliability of electronic components at a limited cost, and is especially suitable for high-density, high-dynamic, and high-risk FPC application scenarios.
[0037] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.
Claims
1. A novel FPC reinforcement installation structure, comprising an FPC body (1) and a reinforcement plate structure (2) disposed at a reinforcement area of the FPC body (1), characterized in that: The FPC body (1) has a pad structure (3) in its reinforcement area. The reinforcement plate structure (2) includes a stacked FR4 reinforcement layer (21), a metal connection layer (22), and a solder flux layer (23). The reinforcement plate structure (2) and the FPC body (1) are fixedly connected by welding to the pad structure (3) through the metal connection layer (22), so that the FR4 reinforcement layer (21) covers the reinforcement area of the FPC body (1).
2. The novel FPC reinforcement installation structure according to claim 1, characterized in that: The FPC body (1) includes a data acquisition connecting piece (4) extending to its side. The data acquisition connecting piece (4) has a reinforcing area that connects to the reinforcing plate structure (2), and a data acquisition element (5) is provided in the reinforcing area of the data acquisition connecting piece (4). The reinforcing plate structure (2) includes a protective hole (7) surrounding the data acquisition element (5).
3. The novel FPC reinforcement installation structure according to claim 2, characterized in that: The protective hole (7) is filled with a sealing adhesive (8) that covers the acquisition element.
4. The novel FPC reinforcement installation structure according to any one of claims 1-3, characterized in that: The FR4 reinforcing layer (21) is an FR4 reinforcing plate with a protective hole (7) through it.
5. The novel FPC reinforcement installation structure according to claim 4, characterized in that: The metal connection layer (22) is a copper foil layer covering the bottom surface of the FR4 reinforcing plate.
6. The novel FPC reinforcement installation structure according to claim 5, characterized in that: The flux layer (23) is a tin-plated layer covering the side of the copper foil layer facing away from the FR4 reinforcing plate.
7. The novel FPC reinforcement installation structure according to claim 1, characterized in that: The thickness of the FR4 reinforcing layer (21) is greater than the thickness of the metal connection layer (22), and the thickness of the metal connection layer (22) is greater than the thickness of the solder flux layer (23).
8. The novel FPC reinforcement installation structure according to claim 2, characterized in that: The acquisition connection piece (4) includes an acquisition part (41) with an acquisition element (5) and a pad structure (3), and a cantilever part (42) extending to connect the acquisition part (41) and the FPC body (1). The reinforcing plate structure (2) is welded and fixed to the acquisition part (41).
9. The novel FPC reinforcement installation structure according to claim 8, characterized in that: The acquisition element (5) is a temperature sensor installed on the acquisition unit (41), and the FPC body (1) is provided with a temperature acquisition line (11) extending to the acquisition unit (41) and connected to the temperature sensor.
10. The novel FPC reinforcement installation structure according to claim 9, characterized in that: The acquisition unit (41) is provided with a window structure (6) that exposes the pad structure (3), the pad structure (3) including at least one copper-based pad formed on the acquisition unit (41).