FPC-based PCB motor and micro fan thereof

Abstract

This invention discloses a PCB motor based on an FPC and its micro fan. The FPC-based PCB motor includes an FPC flexible board and a PCB coil board. Multiple stator coils are printed on the PCB coil board to form a PCB stator winding. This invention replaces the traditional method of winding stator coils with enameled copper wire with directly printing the stator coils on the PCB coil board, and connecting and fixing them using the FPC flexible board. It cleverly utilizes the high integration of the PCB coil board and the flexibility and bendability of the FPC flexible board, allowing for better layout and installation of the motor within a limited space. Compared with traditional motor solutions, it significantly reduces the volume and space occupied by the stator coils, making it more suitable for thin and light fan designs. At the same time, it simplifies the assembly process, improves production efficiency, and reduces costs. The FPC-based PCB motor can be better integrated into the overall structure of the micro fan, making the micro fan more compact and thinner.

Description

Technical Field

[0001] This utility model relates to the field of micro fan technology, specifically to an FPC-based PCB motor and its micro fan. Background Technology

[0002] As smart devices such as laptops, tablets, and mobile phones become increasingly thinner and lighter, the fans used for cooling these devices are also becoming thinner and thinner, posing a significant challenge to the fan industry.

[0003] Due to space constraints, the motor solutions currently available for micro fans are relatively limited. The main motor solutions for commercially available micro fans are as follows:

[0004] 1. Radial flux motor. Due to space constraints, a 4-slot, 4-pole radial motor solution is generally used – Solution 1.

[0005] 2. Axial flux motor, also called a disc motor. Due to space constraints, it often adopts a coreless motor structure. In terms of the slot and pole configuration of the stator and rotor, a 4-slot 4-pole single-phase motor is often used - Scheme 2;

[0006] Alternatively, a 3-slot 4-pole three-phase motor - Option 3;

[0007] Alternatively, a 4-slot, 6-pole, two-phase motor - Option 4.

[0008] While the above-mentioned motors can meet certain usage requirements, their stator coils are all made of enameled copper wire and consist of multiple coils, which not only takes up a lot of space but also makes the assembly process relatively complex. As portable electronic devices become smaller and smaller, the potential for miniaturization of the above motor architectures is also decreasing. Therefore, none of the above solutions are the optimal options. Utility Model Content

[0009] To address the aforementioned shortcomings, the purpose of this utility model is to provide an FPC-based PCB motor and its miniature fan that has a reasonable structural design and occupies little space.

[0010] To achieve the above objectives, the technical solution provided by this utility model is as follows:

[0011] A PCB motor based on FPC includes a PCB coil board and an FPC flexible board. Multiple stator coils are printed on the PCB coil board to form a PCB stator winding. The PCB coil board is soldered to the FPC flexible board and electrically connected to the metal circuit on the FPC flexible board.

[0012] In a preferred embodiment of this invention, the number of stator coils is six. After the terminals of the six stator coils are connected via printed circuitry, there is a total of one U terminal, one V terminal, one W terminal, and three COM terminals, with the three COM terminals connected in parallel. This significantly reduces the number of components and improves manufacturability. The existing design requires six coils, each with two solder points, totaling twelve solder points. Before soldering, the six coils need to be positioned, wire-organized, and then soldered. With the PCB stator winding, the number of solder points is reduced to six (U, V, W, and three COM). The electrical connection between the PCB stator winding and the FPC is achieved via SMT, eliminating the need for wire-organization and greatly improving manufacturability.

[0013] As a preferred embodiment of this utility model, the number of stator coils is six. After the terminals of the six stator coils are printed and connected, there is a total of one U terminal, one V terminal, one W terminal and one COM terminal. The three COM terminals of the three stator coils are directly combined into one, which makes the wiring more convenient.

[0014] As a preferred embodiment of this utility model, the stator coil includes several layers of stacked 2D printed coils, and the 2D printed coils of each layer are electrically connected through interlayer vias, eliminating the wiring process and simplifying the production process.

[0015] A miniature fan includes a base, a top cover, a fan rotor assembly, and an FPC-based PCB motor. The FPC flexible board is disposed inside the base, and the fan rotor assembly is rotatably disposed on the base corresponding to the position of the PCB stator winding. The top cover is fastened to the base. The assembly is simple and makes the structure of the miniature fan more compact and thinner.

[0016] In a preferred embodiment of this invention, the FPC flexible board is fixed inside the base using adhesive or glue. This method is simple to operate and ensures stable installation of the FPC flexible board within the base. Compared to traditional mechanical fixing methods, it avoids the additional space occupation and structural complexity caused by screws and other fasteners, further simplifying the assembly process of the micro fan and improving production efficiency and product yield.

[0017] In a preferred embodiment of this invention, a central tube is provided in the middle of the base. The fan rotor assembly includes fan blades, a motor housing, a shaft, and a magnet. The fan blades are sleeved on the motor housing, and one end of the shaft is fixed to the center of the motor housing. The shaft is rotatably mounted on the central tube via a bearing. The magnet is disposed inside the motor housing and corresponds to the PCB stator winding. When the PCB stator winding is energized, the generated magnetic field drives the magnet and the motor housing to rotate together, thereby driving the fan blades to rotate and achieve the function of blowing air for heat dissipation.

[0018] As a preferred embodiment of this utility model, a back iron is embedded in the base corresponding to the position of the magnet. The back iron is located inside the base, which is higher than the traditional position on the bottom surface of the base, thus shortening the distance between it and the magnet. This increases the magnetic pull and effectively reduces the eddy current effect, thereby improving the motor efficiency.

[0019] As a preferred embodiment of this utility model, a waterproof sealant is provided between the top cover and the base, which has a good sealing effect and can prevent external moisture, dust and other foreign objects from entering the interior of the miniature fan, thus protecting the normal operation of the motor and other electronic components.

[0020] In a preferred embodiment of this invention, a wear-resistant plate is provided on the bottom surface inside the central tube. The wear-resistant plate is made of wear-resistant material, which supports the shaft core, reduces friction and wear on the base during rotation, lowers noise, and extends service life.

[0021] The beneficial effects of this utility model are as follows: The structure of this utility model is rationally designed, replacing the traditional method of winding stator coils with enameled copper wire with directly printing the stator coils on a PCB coil board, and connecting and fixing them using an FPC flexible board. This structure cleverly utilizes the high integration of the PCB coil board and the flexibility and bendability of the FPC flexible board, allowing for better layout and installation of the motor within a limited space. Compared with traditional motor solutions, it significantly reduces the volume and space occupied by the stator coils, enabling the motor to adapt to thinner and lighter miniature fan designs. Simultaneously, it simplifies the assembly process, improves production efficiency and reliability, and reduces costs. Integrating the FPC-based PCB motor into the overall structure of the miniature fan, utilizing the flexibility and bendability of the FPC flexible board, allows it to better adapt to the limited space within the base and forms a good fit with the fan rotor assembly, effectively optimizing the overall structural layout and making the miniature fan more compact and thinner.

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0023] Figure 1 This is a three-dimensional sectional view of Embodiment 1 of the present invention. Figure 1 .

[0024] Figure 2 This is a frontal sectional view of Embodiment 1 of this utility model.

[0025] Figure 3 This is an exploded structural diagram of Embodiment 1 of this utility model.

[0026] Figure 4 This is a schematic diagram of the stator coil structure in Embodiment 1 of this utility model. Figure 1 .

[0027] Figure 5 This is a schematic diagram of the FPC flexible circuit board in Embodiment 1 of this utility model. Figure 1 .

[0028] Figure 6 This is a schematic diagram of the PCB stator winding structure in Embodiment 1 of this utility model. Figure 1 .

[0029] Figure 7 This is a schematic diagram of the stator coil structure in Embodiment 1 of this utility model. Figure 2 .

[0030] Figure 8 This is a schematic diagram of the FPC flexible circuit board in Embodiment 1 of this utility model. Figure 2 .

[0031] Figure 9 This is a schematic diagram of the PCB stator winding structure in Embodiment 1 of this utility model. Figure 2 .

[0032] Figure 10 This is a frontal sectional view of Embodiment 2 of this utility model. Detailed Implementation

[0033] Example 1, see Figures 1 to 6 This embodiment provides a miniature fan, which includes a base 1, a top cover 2, a fan rotor assembly 3, an FPC flexible board 4, and a PCB coil board 5.

[0034] The PCB coil board 5 has multiple stator coils printed on it to form a PCB stator winding 6. Specifically, there are six stator coils, which are symmetrically distributed in a circle on the PCB coil board 5.

[0035] In this embodiment, see Figure 4 , Figure 5 and Figure 6 The stator coils consist of six coils. After being printed and connected, the six stator coils have one U terminal, one V terminal, one W terminal, and one COM terminal. The three COM terminals of the three stator coils are directly combined into one, making wiring easier. Each stator coil comprises several layers of stacked 2D printed coils, preferably six or eight layers. The 2D printed coils in each layer are electrically connected through interlayer vias, eliminating the need for wiring and simplifying the manufacturing process. The four solder points (U, V, W, and one COM) on the PCB coil board 5 are soldered onto the FPC flexible board 4 using SMT technology, resulting in a strong bond, good structural stability, and eliminating the need for wire management.

[0036] In other embodiments, see Figure 7 , Figure 8 and Figure 9 After the six stator coils are printed and connected, they form a total of one U terminal, one V terminal, one W terminal, and three COM terminals, creating six solder joints. These six solder joints (U, V, W, and three COM terminals) on the PCB coil board 5 are soldered onto the FPC flexible board 4 using SMT technology, resulting in a strong bond, good structural stability, and no need for wire management. The three COM terminals are connected in parallel via the FPC's metal traces.

[0037] The FPC flexible board 4 is disposed within the base 1. Preferably, the FPC flexible board 4 is directly glued and fixed within the base 1 using adhesive or glue. Compared to traditional mechanical fixing methods, this avoids the additional space occupation and structural complexity caused by screws and other fasteners, and is also simple to operate.

[0038] The FPC flexible board 4 has metal circuits with solder pads. The PCB coil board 5 is soldered to the solder pads of the FPC flexible board 4, achieving electrical connection between the PCB coil board 5 and the metal circuits on the FPC flexible board. The fan rotor assembly 3 is rotatably mounted on the base 1 corresponding to the position of the PCB stator winding 6, and the upper cover 2 is fastened to the base 1. Preferably, a waterproof sealant 7 is provided between the upper cover 2 and the base 1 to improve the sealing effect and prevent external moisture, dust, and other foreign objects from entering the interior of the miniature fan.

[0039] The base 1 has a central tube 11 located in the middle. The fan rotor assembly 3 includes fan blades 31, a motor housing 32, a shaft core 33, and a magnet 34. The fan blades are sleeved on the motor housing 32. One end of the shaft core 33 is fixed to the center of the motor housing 32. The shaft core 33 is rotatably mounted on the central tube 11 via a bearing. The magnet 34 is located inside the motor housing 32 and corresponds to the PCB stator winding 6. When the PCB stator winding 6 is energized, the generated magnetic field drives the magnet 34 and the motor housing 32 to rotate together, thereby driving the fan blades 31 to rotate and achieve the function of blowing air for heat dissipation. If only an FPC-based PCB motor needs to be manufactured, the fan blades 31 can be omitted.

[0040] Traditionally, the back iron is glued to the bottom surface of the base 1. However, in this patent, the back iron 8 is embedded in the base 1. That is, during injection molding, the back iron 8 is pre-positioned in the mold cavity, and the base 1 is formed by injection molding, thus embedding the back iron 8 within it and aligning it with the position of the magnet 34. Because the back iron 8 is located within the base 1 and is at a higher height, the distance between it and the magnet 34 is shortened, increasing the magnetic pull while effectively reducing eddy current effects and improving motor efficiency.

[0041] Example 2, see Figure 10The miniature fan provided in this embodiment has a structure that is basically the same as that in embodiment 1. The difference is that a wear-resistant plate 9 is provided on the bottom surface inside the central tube 11, which can support the shaft core 33, reduce the friction and wear of the shaft core 33 on the base 1 during rotation, and also reduce noise and make the operation more stable.

[0042] This invention replaces the traditional method of winding stator coils with enameled copper wire by directly printing the stator coils on the PCB coil board 5, and connecting and fixing them using the FPC flexible board 4. This structure cleverly utilizes the high integration of the PCB coil board 5 and the flexibility and bendability of the FPC flexible board 4, allowing for better layout and installation of the motor within a limited space. Compared with traditional motor solutions, it significantly reduces the volume and space occupied by the stator coils, enabling the motor to adapt to thinner and lighter miniature fan designs. Simultaneously, it simplifies the assembly process, improves production efficiency and reliability, and reduces costs. Integrating the FPC-based PCB motor into the overall structure of the miniature fan, utilizing the flexibility and bendability of the FPC flexible board 4, allows it to better adapt to the limited space within the base 1 and forms a good fit with the fan rotor assembly 3, effectively optimizing the overall structural layout and making the miniature fan more compact and thinner.

[0043] Meanwhile, the traditional combination of multiple winding stator coils inevitably makes it difficult to guarantee concentricity, which will inevitably lead to an imbalance of electromagnetic forces. However, the multiple 2D printed coils of the PCB stator winding 6 adopt printed circuit board technology, which can significantly improve the concentricity of each 2D printed coil and significantly reduce the imbalance of electromagnetic forces.

[0044] Furthermore, due to the use of PCB stator winding 6, the manufacturing process characteristics of this winding determine its dimensional accuracy, which can reach a high level. Taking a coil stator or SMT stator with a diameter of 8.5mm as an example, its stator assembly accuracy is approximately within ±0.15mm. However, with the use of PCB stator winding 6, the accuracy can reach within ±0.05mm, greatly improving the assembly accuracy.

[0045] Furthermore, due to the high dimensional accuracy of the PCB stator winding 6, the distance between the magnet 34 in the fan rotor assembly 3 and the PCB stator winding 6 can be reduced, thereby enhancing the magnetic field cut by the PCB stator winding 6 and effectively improving motor efficiency. Simulation results show that using a 6-layer PCB stator winding 6, the efficiency of a 6-slot 4-pole motor can reach over 20%, the efficiency of a 6-slot 8-pole motor can reach around 30%, and the efficiency of an 8-layer PCB-6-slot 8-pole motor can reach over 35%, as detailed in Table 1.

[0046] Table 1

[0047] 6 6 slots 4 poles 2.01e-5 0.200 20.0％ 6 6 slots 8 poles 2.48e-5 0.182 27.1％ 8 6 slots 8 poles 2.19e-5 0.121 36.0％

[0048] Based on the disclosure and teachings of the above specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, this utility model is not limited to the specific embodiments disclosed and described above, and some modifications and changes to this utility model should also fall within the protection scope of the claims of this utility model. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on this utility model. As described in the above embodiments of this utility model, other motors or fans obtained using the same or similar structures are all within the protection scope of this utility model.

Claims

1. An FPC-based PCB motor comprising a PCB coil plate, characterized in that: It also includes an FPC flexible board, on which multiple stator coils are printed to form a PCB stator winding. The PCB coil board is soldered to the FPC flexible board and electrically connected to the metal circuit on the FPC flexible board.

2. The PCB motor based on FPC according to claim 1, characterized in that: The number of stator coils is six. After the terminals of the six stator coils are printed and connected, there is a total of one U terminal, one V terminal, one W terminal and three COM terminals.

3. The PCB motor based on FPC according to claim 1, characterized in that: The number of stator coils is six. After the terminals of the six stator coils are printed and connected, there is a total of one U terminal, one V terminal, one W terminal and one COM terminal.

4. The PCB motor based on FPC according to claim 1, characterized in that: The stator coil comprises several layers of stacked 2D printed coils, and the 2D printed coils of each layer are electrically connected through interlayer vias.

5. A miniature fan, comprising a base, a top cover, and a fan rotor assembly, characterized in that: It also includes the FPC-based PCB motor according to any one of claims 1-4, wherein the FPC flexible board is disposed in the base, the fan rotor assembly is rotatably disposed on the base corresponding to the position of the PCB stator winding, and the upper cover is fastened to the base.

6. The miniature fan according to claim 5, characterized in that: The FPC flexible board is fixed inside the base by adhesive or bonding agent.

7. The miniature fan according to claim 5, characterized in that: The base has a central tube in the middle position. The fan rotor assembly includes fan blades, motor housing, shaft core and magnet. The fan blades are sleeved on the motor housing. One end of the shaft core is fixed at the center position of the motor housing. The shaft core is rotatably mounted on the central tube through a bearing. The magnet is set inside the motor housing and corresponds to the PCB stator winding.

8. The miniature fan according to claim 5, characterized in that: A back iron is embedded in the base at the position corresponding to the magnet.

9. The miniature fan according to claim 5, characterized in that: Waterproof sealant is provided between the top cover and the base.

10. The miniature fan according to any one of claims 5-9, characterized in that: Wear-resistant plates are provided on the bottom surface inside the middle tube.

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