A flexible circuit board with low cost and excellent plasticity
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JIANGMEN NEW MATERIALS TECHNOLOGY CO LTD
- Filing Date
- 2025-09-11
- Publication Date
- 2026-08-07
AI Technical Summary
目前市面上的存在如下问题：目前的柔性电路板，一般采用PI膜材质来制作，其成本较高，可塑性较差，散热性能也较差；
[0007]Compared with the prior art, the beneficial effects of this utility model are as follows: This utility model provides a low-cost and highly flexible circuit board with excellent plasticity. Through the layered combination of a solder resist ink layer, a circuit layer, a double-layer PET layer, and a support and heat dissipation layer, it achieves a balance between low cost and excellent plasticity. The circuit layer and the two PET layers provide conductivity and flexible support, the support and heat dissipation layer enhances the strength and heat dissipation performance of the circuit board, and the second PET layer provides outer protection. The layers are thermo-pressed and bonded together, which not only reduces the complexity of the production process and material costs, but also ensures the stability and durability of the overall structure. Using PET + aluminum foil + PET instead of PI film better controls expansion and contraction, and also reduces costs.
Smart Images
Figure CN224610991U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of flexible circuit board technology, and specifically to a low-cost flexible circuit board with excellent plasticity. Background Technology
[0002] Flexible circuit boards are circuit boards made with flexible insulating substrates as the base. They are characterized by being bendable, foldable, lightweight, and thin, and can be freely wired in three-dimensional space, thereby saving installation space and improving assembly flexibility. The following problems exist in the current market: Current flexible circuit boards are generally made of PI film material, which has high cost, poor plasticity, and poor heat dissipation performance; The technical problem to be solved by this utility model is to provide a flexible circuit board with low cost and excellent plasticity. Utility Model Content
[0003] The technical problem this invention addresses is: to provide a low-cost flexible circuit board with excellent plasticity; by combining a solder resist ink layer, a circuit layer, a double-layer PET layer, and a supporting heat dissipation layer, a balance between low cost and excellent plasticity is achieved. The circuit layer and the two PET layers provide conductivity and flexible support, the supporting heat dissipation layer enhances the strength and heat dissipation performance of the circuit board, and the second PET layer provides outer protection. The layers are thermo-pressed together, reducing manufacturing complexity and material costs while ensuring the stability and durability of the overall structure. Using PET + aluminum foil + PET instead of PI film better controls expansion and contraction, and also reduces costs.
[0004] A low-cost flexible circuit board with excellent plasticity comprises, from top to bottom: a solder resist ink layer, a circuit layer, a first PET layer, a support and heat dissipation layer, and a second PET layer that provides protection; and the circuit layer, the first PET layer, the support and heat dissipation layer, and the second PET layer are integrally formed by hot pressing.
[0005] Preferably, the thickness of the solder resist ink layer is 15um; the thickness of the circuit layer is 30um or 50um; the thickness of the first PET layer is 38um; the thickness of the support and heat dissipation layer is 20um to 35um; and the thickness of the second PET layer is 12um.
[0006] Preferably, the material of the circuit layer is pure aluminum; the material of the heat dissipation support layer is pure aluminum; and the materials of the first PET layer and the second PET layer are PET.
[0007] Compared with the prior art, the beneficial effects of this utility model are as follows: This utility model provides a low-cost and highly flexible circuit board with excellent plasticity. Through the layered combination of a solder resist ink layer, a circuit layer, a double-layer PET layer, and a support and heat dissipation layer, it achieves a balance between low cost and excellent plasticity. The circuit layer and the two PET layers provide conductivity and flexible support, the support and heat dissipation layer enhances the strength and heat dissipation performance of the circuit board, and the second PET layer provides outer protection. The layers are thermo-pressed and bonded together, which not only reduces the complexity of the production process and material costs, but also ensures the stability and durability of the overall structure. Using PET + aluminum foil + PET instead of PI film better controls expansion and contraction, and also reduces costs.
[0008] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description
[0009] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0010] Figure 1 This is a schematic diagram of the layered structure of this utility model.
[0011] In the diagram: 1. Solder resist ink layer; 2. Circuit layer; 3. First PET layer; 4. Support and heat dissipation layer; 5. Second PET layer. Detailed Implementation
[0012] The technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this utility model, and 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.
[0013] It should be noted that the terms "first," "second," etc., used in this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this disclosure described herein can be implemented in orders other than those illustrated or described herein. The implementation methods described in the following exemplary embodiments do not represent all implementation methods consistent with this disclosure.
[0014] Please see Figure 1In this embodiment of the utility model, a low-cost flexible circuit board with excellent plasticity includes, from top to bottom: a solder resist ink layer 1, a circuit layer 2, a first PET layer 3, a support and heat dissipation layer 4, and a second PET layer 5 that provides protection; and the circuit layer 2, the first PET layer 3, the support and heat dissipation layer 4, and the second PET layer 5 are integrally formed by hot pressing.
[0015] Specifically, the flexible circuit board's structural design achieves a balance between low cost and excellent plasticity through a layered combination of solder resist ink layer 1, circuit layer 2, double-layer PET layer, and supporting heat dissipation layer 4. The circuit layer 2 and the two PET layers provide conductivity and flexible support, the supporting heat dissipation layer 4 enhances the circuit board's strength and heat dissipation performance, and the second PET layer 5 provides outer protection. The layers are thermo-pressed together, reducing manufacturing complexity and material costs while ensuring overall structural stability and durability. This flexible circuit board is primarily used in diffuse reflection LED light circuit boards, high-power LED light circuit boards, linear LED light circuit boards, and advertising LED light circuit boards.
[0016] Furthermore, the thickness of the solder resist ink layer 1 is 15um; the thickness of the circuit layer 2 is 30um or 50um; the thickness of the first PET layer 3 is 38um; the thickness of the support and heat dissipation layer 4 is 20um to 35um; and the thickness of the second PET layer 5 is 12um.
[0017] Specifically, the flexible circuit board achieves a balance between structure and performance in its thickness design: a 15μm solder resist ink layer 1 ensures insulation and protection of the circuitry; a 30μm or 50μm circuit layer 2 provides stable conductivity and can be selected in different thicknesses to meet current carrying requirements according to the application scenario; a 38μm first PET layer 3 gives the circuit board good flexibility and support; a 20 to 35μm support and heat dissipation layer 4 improves mechanical strength and heat dissipation performance without significantly increasing thickness; a 12μm second PET layer 5 serves as an outer protective layer, playing a role in scratch resistance, moisture protection, and overall encapsulation, thereby achieving comprehensive optimization of electrical performance, mechanical performance, and reliability under low-cost conditions; when the circuitry is dense, a thinner 20μm support layer is selected; when the circuitry is sparse, a 30μm-35μm support layer is selected; the circuit design is adjusted according to the final product application. If the thickness is too thick, it will cause unnecessary waste, and if it is too thin, it will affect the shaping and molding effect.
[0018] Furthermore, the material of the circuit layer 2 is pure aluminum; the material of the heat dissipation support layer 4 is pure aluminum; and the materials of the first PET layer 3 and the second PET layer 5 are PET.
[0019] Specifically, the flexible circuit board is designed with specific material selection in mind: both the circuit layer 2 and the supporting heat dissipation layer 4 are made of pure aluminum, which not only ensures good conductivity and heat dissipation but also reduces material costs; while the first PET layer 3 and the second PET layer 5 are both made of PET material, which utilizes its excellent flexibility, heat resistance and insulation to ensure the board can be bent and plastic while playing a role in electrical isolation and mechanical protection, thereby achieving a balance between lightweight, low cost and optimized overall performance.
[0020] Furthermore, the forming of flexible circuit boards includes the following steps: S1: The 30um circuit layer 2 is laminated with the 38um first PET layer 3, and the first laminated layer is obtained after curing. S2: The 20um support heat dissipation layer 4 and the 12um second PET layer 5 are laminated together and cured to obtain the second laminated layer; S3: The first composite layer of S1 and the second composite layer of S2 are laminated together and cured to form a flexible circuit board composite material; S4: The flexible circuit board composite material in S3 is printed, etched, and de-inked to become aluminum etched circuits. S5: Silk screen solder mask is applied to the aluminum etched circuit surface of S4, and LED beads and resistors are soldered onto the surface-treated pads.
[0021] Specifically, S1: First, a circuit layer with a thickness of 30um or 50um is laminated and cured with a first PET layer of 38um. This step ensures a tight bond between the conductive layer and the substrate PET, providing both conductivity and flexibility and initial mechanical strength to the circuit board. S2: Then, the 20um to 35um support heat dissipation layer is laminated with the 12um second PET layer and cured to give the heat dissipation layer a flexible protective shell, which prevents the metal heat dissipation layer from being easily oxidized or damaged during use, while improving the overall strength and heat dissipation performance. S3: The first composite layer obtained from S1 and S2 is further laminated and cured with the second composite layer to form a complete multilayer flexible circuit board composite structure. In this process, the unity of conductivity, heat dissipation, protection and flexibility is achieved. S4: Print, etch, and remove ink from the composite material to form fine aluminum etched lines. This step is a key process to realize the circuit function and ensure the accuracy and reliability of the electrical connection. S5: Finally, screen-print solder mask on the etched circuit surface to ensure electrical insulation and protection. At the same time, reserve solderable areas at the pads to facilitate the mounting of electronic components such as LEDs and resistors, thus completing the functionalization of the circuit board.
[0022] In S1 and S2, the PET layer is independently laminated with the circuit layer and the supporting heat dissipation layer, which has several key advantages: 1. Improve composite quality and bonding strength: When laminated alone, the PET layer can be more evenly adhered to the surface of the circuit layer or heat dissipation layer, avoiding bubbles, wrinkles or uneven delamination that may occur when multiple layers are laminated at one time, thereby improving the overall structural stability of the composite material. 2. Facilitates process control and curing: When each group of materials is cured separately, the temperature and pressure can be optimized according to the characteristics of the circuit layer and PET, and the characteristics of the heat dissipation layer and PET, to ensure the best bonding strength and flexibility of each composite layer and reduce stress concentration during subsequent multi-layer lamination. 3. Reduce material damage and warping: Multi-layer one-time lamination is prone to uneven thermal stress or metal layer warping. Separate lamination allows each group of materials to stabilize and form during the curing process before secondary lamination, reducing the risk of warping, cracking or breakage. 4. Flexibility and maintainability: The two sets of semi-finished materials formed after independent lamination can be inspected for quality separately, which makes it easy to find and remove defective boards, reduce scrap rate, and facilitate the adjustment and optimization of subsequent processes.
[0023] In addition, the present invention uses PET+aluminum foil+PET instead of traditional PI film, which has several key advantages: 1. Although PI film (polyimide) is resistant to high temperature, its coefficient of thermal expansion is relatively large and its directionality is obvious. It is prone to dimensional expansion and contraction during etching, hot pressing, welding and other processes, which affects the accuracy of the circuit. PET has a relatively low coefficient of thermal expansion. When aluminum foil is added in the middle of the PET layer, its coefficient of thermal expansion is even lower and more stable, forming a "metal-plastic symmetrical sandwich" structure, which can effectively suppress the overall dimensional expansion and contraction and improve dimensional stability. 2. Single-layer PI is prone to overall expansion and contraction when heated; while the sandwich structure of PET + aluminum foil + PET has a two-way restraint effect. PET provides flexibility, and aluminum foil acts as a "skeleton" for stability, making the material less prone to deformation under thermal and mechanical stress and maintaining circuit accuracy. 3. PI film is a high-performance engineering plastic with outstanding high-temperature resistance, but it is expensive, usually 3 to 5 times more expensive than PET. PET material is widely available and low in cost, while aluminum foil is also relatively cheap. Therefore, the overall cost of the PET+aluminum foil+PET combination is significantly lower than that of using PI film alone.
[0024] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention.
Claims
1. A low-cost flexible circuit board with excellent plasticity, characterized in that, From top to bottom, it includes: solder resist ink layer (1), circuit layer (2), first PET layer (3), support and heat dissipation layer (4), and second PET layer (5) which plays a protective role; and the circuit layer (2), first PET layer (3), support and heat dissipation layer (4), and second PET layer (5) are formed into an integral structure by hot pressing.
2. The flexible circuit board with low cost and excellent plasticity as described in claim 1, characterized in that, The thickness of the solder resist ink layer (1) is 15um; the thickness of the circuit layer (2) is 30um or 50um; the thickness of the first PET layer (3) is 38um; the thickness of the support heat dissipation layer (4) is 20um to 35um; and the thickness of the second PET layer (5) is 12um.
3. The flexible circuit board with low cost and excellent plasticity as described in claim 1, characterized in that, The material of the circuit layer (2) is pure aluminum; the material of the heat dissipation support layer (4) is pure aluminum; and the materials of the first PET layer (3) and the second PET layer (5) are PET.