LDS-based PCB motor and micro fan thereof

Abstract

The utility model discloses a kind of PCB motor and its micro fan based on LDS, and PCB motor based on LDS includes LDS base and PCB coil board, and the surface of LDS base is equipped with the metal circuit formed by LDS technology. Reasonably replace the way of winding stator coil of traditional enameled copper wire with PCB coil board, i. e. directly printing stator coil on PCB board, can greatly reduce the volume and occupied space of stator coil, and PCB coil board is directly welded on LDS base, further simplifies structure, reduces the number of components. Integrate the overall structure of micro fan into PCB motor based on LDS, utilize the wiring flexibility of LDS base, effectively optimize overall structure layout, without occupying fluid space inside micro fan, make micro fan more compact and light. In addition, external or built-in drive circuit module structure design can also be selected, to meet different use requirements.

Description

Technical Field

[0001] This utility model relates to the field of micro fan technology, specifically to a PCB motor based on LDS 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 invention is to provide a PCB motor and its miniature fan based on LDS 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 LDS includes an LDS base and a PCB coil board. The surface of the LDS base is provided with a metal circuit formed by the LDS process. The PCB coil board includes a PCB board and a stator coil printed on the PCB board. The PCB coil board is soldered to the metal circuit of the LDS base and is electrically connected to the metal circuit.

[0012] As a preferred embodiment of this utility model, the LDS base is provided with a VIA hole for connection with the metal circuit. Since the FPC is eliminated, there is no need to make a through hole on the LDS base. The through hole required for electrical connection can be directly achieved through the VIA hole. The VIA hole can be sealed with oil or resin, which has good waterproof performance.

[0013] 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 printing, there is a total of one U terminal, one V terminal, one W terminal, and three COM terminals. 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, wired, and then soldered. With the PCB coil board, the number of solder points is reduced to six (U, V, W, and three COM). The electrical connection between the PCB coil board and the FPC is achieved via SMT, eliminating the need for wired wiring and greatly improving manufacturability.

[0014] 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.

[0015] 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.

[0016] A miniature fan includes a top cover, a fan rotor assembly, and an LDS-based PCB motor. The fan rotor assembly is rotatably mounted on an LDS base corresponding to the position of the PCB coil board. The top cover is fastened to the LDS base. The assembly is simple and makes the structure of the miniature fan more compact and thinner.

[0017] In a preferred embodiment of this invention, a central tube is provided in the middle of the LDS 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 coil board. When the PCB coil board 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 LDS base at the position corresponding to the magnet. The back iron is located inside the LDS base, which is higher than the position of the traditional LDS base bottom surface, thus shortening the distance between it and the magnet. This increases the magnetic pull force and effectively reduces the eddy current effect, thereby improving the motor efficiency.

[0019] In a preferred embodiment of this invention, the LDS base includes a base plate and a frame mounted on the base plate, with a waterproof and shock-absorbing adhesive between the base plate and the frame. This waterproof and shock-absorbing adhesive has a certain degree of elasticity, meaning the base plate and frame are in elastic contact. Since the base plate and frame are in elastic contact, and the top cover is mounted on the frame via locking lugs, installation is achieved through the frame. Therefore, when the entire unit (a portable electronic device with a fan installed) is dropped, the elastic waves generated by the drop will not be directly transmitted to the bearing system. Instead, they will be attenuated by the waterproof and shock-absorbing adhesive before being transmitted to the bearing system, thus greatly improving the drop resistance of the miniature fan. Conventional fans improve drop resistance by increasing rigidity, while this invention improves drop resistance through shock absorption; the physical principle of its shock absorption is completely different.

[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 LDS base during rotation, lowers noise, and extends service life.

[0021] In a preferred embodiment of this invention, the driving circuit module is externally mounted, or the driving circuit module is provided on the surface of the LDS base. Because using the LDS base and PCB coil board allows for convenient placement of components outside the LDS base, it not only improves the flexibility of component wiring (external wiring) but also allows for the free choice of whether or not a driving circuit module is included; the LDS base can perfectly adapt to both, greatly enhancing design flexibility.

[0022] The beneficial effects of this utility model are as follows: The utility model has a reasonable structural design, replacing the traditional method of winding stator coils with enameled copper wire with a PCB coil board, that is, directly printing the stator coils on the PCB board. This significantly reduces the volume and space occupied by the stator coils. Furthermore, the PCB coil board is directly soldered onto the LDS base, further simplifying the structure, reducing the number of components, facilitating manufacturing, and enabling the motor to adapt to thinner and lighter miniature fan designs. Integrating the LDS-based PCB motor into the overall structure of the miniature fan, utilizing the wiring flexibility of the LDS base, effectively optimizes the overall structural layout. It does not occupy the internal fluid space of the miniature fan, effectively improving the fluid performance of the miniature fan and forming a good match with the fan rotor assembly, making the miniature fan more compact and thinner. In addition, it allows for flexible selection of external or internal drive circuit module structures, with a wide range of applications to meet different usage needs.

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0024] Figure 1 This is a three-dimensional structural diagram of Embodiment 1 of this utility model. Figure 1 .

[0025] Figure 2 This is a three-dimensional structural diagram of Embodiment 1 of this utility model. Figure 2 .

[0026] Figure 3 This is a schematic diagram of the full cross-section of Embodiment 1 of this utility model.

[0027] Figure 4 This is an exploded structural diagram of Embodiment 1 of this utility model.

[0028] Figure 5 This is a schematic diagram of the PCB coil board structure in Embodiment 1 of this utility model. Figure 1 .

[0029] Figure 6 This is a schematic diagram of the PCB coil board structure in Embodiment 1 of this utility model. Figure 2 .

[0030] Figure 7 This is a three-dimensional structural diagram of Embodiment 2 of this utility model. Figure 1 .

[0031] Figure 8 This is a three-dimensional structural diagram of Embodiment 2 of this utility model. Figure 2 .

[0032] Figure 9 This is a full cross-sectional structural diagram of Embodiment 2 of this utility model. Detailed Implementation

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

[0034] The LDS base 1 has a metal circuit 11 formed by the LDS process on its surface. The metal circuit 11 includes traces, pads, metal contacts, and other structures. Additionally, the LDS base 1 may have a VIA hole for connecting to the metal circuit 11. Since the FPC is eliminated, there is no need for through-hole processing on the LDS base 1; the through-holes required for electrical connection can be directly achieved through the VIA hole. The VIA hole can be sealed with oil or resin, providing good waterproofing.

[0035] The PCB coil board 2 is soldered onto the pads of the metal circuit 11, which saves height space and reduces the number of components.

[0036] The PCB coil board 2 includes a PCB board 21 and stator coils 22 printed on the PCB board 21; specifically, the number of stator coils 22 is preferably six, which are symmetrically distributed on the PCB board 21 in a circular pattern.

[0037] The stator coil 22 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.

[0038] In this embodiment, after the pins of the six stator coils 22 are printed and connected, there is a total of one U pin, one V pin, one W pin, and three COM pins, forming a total of six solder joints. In the existing design, if six coils are needed, each coil requires two solder joints, totaling twelve solder joints. Before soldering, the six coils need to be positioned, wired, and then soldered. With the PCB coil board 2, the number of solder joints is reduced to six (U, V, W, and three COM). The electrical connection between the PCB coil board 2 and the pads of the metal circuit 11 is achieved through SMT, eliminating the need for wired wiring and greatly improving manufacturability.

[0039] In other embodiments, see Figure 6 The three COM terminals of the three stator coils 22 can be combined into one COM terminal, simplifying the wiring from the three COM terminals to one COM terminal.

[0040] The fan rotor assembly 4 is rotatably mounted on the LDS base 1, corresponding to the position of the PCB coil board 2. Specifically, a central tube 15 is provided in the middle of the LDS base 1. The fan rotor assembly 4 includes fan blades 41, a motor housing 42, a shaft core 43, and a magnet 44. The fan blades are sleeved on the motor housing 42. One end of the shaft core 43 is fixed to the center of the motor housing 42. The shaft core 43 is rotatably mounted on the central tube 15 via a bearing 45. Preferably, a wear-resistant plate 46 is provided on the bottom surface inside the central tube 15. The wear-resistant plate 46 is made of wear-resistant material, which can support the shaft core 43, reduce friction and wear on the LDS base 1 during rotation, reduce noise, and extend service life.

[0041] The magnet 44 is disposed inside the motor housing 42 and corresponds to the PCB coil board 2. When the PCB coil board 2 is energized, the generated magnetic field drives the magnet 44 and the motor housing 42 to rotate together, thereby driving the fan blades 41 to rotate and achieve the function of blowing air for heat dissipation. If only an LDS-based PCB motor needs to be manufactured, the fan blades 41 can be omitted.

[0042] Traditionally, the back iron is glued to the bottom surface of the LDS base 1. However, in this patent, the back iron 6 is embedded within the LDS base 1. That is, during injection molding, the back iron 6 is pre-positioned in the mold cavity, and the LDS base 1 is formed by injection molding, thus embedding the back iron 6 within it and aligning it with the position of the magnet 44. Because the back iron 6 is located within the LDS base 1 and is at a higher height, the distance between it and the magnet 44 is shortened, increasing the magnetic pull while effectively reducing eddy current effects and improving motor efficiency.

[0043] The top cover 3 is fastened to the LDS base 1. Specifically, the LDS base 1 includes a base plate 12 and a frame 13 disposed on the base plate 12. A waterproof and shock-absorbing adhesive 14 is provided between the base plate 12 and the frame 13. The waterproof and shock-absorbing adhesive 14 has a certain elasticity, that is, the base plate 12 and the frame 13 are in elastic contact. Since the base plate 12 and the frame 13 are in elastic contact, and the top cover 3 is set on the frame 13 by locking lugs, it is fastened to the LDS base 1. During installation, the miniature fan is installed and fixed to the portable electronic device through the mounting holes on the frame 13. When the portable electronic device is dropped, the elastic wave generated by the drop will not be directly transmitted to the bearing system, but will be attenuated by the waterproof and shock-absorbing adhesive 14 before being transmitted to the bearing system, thus providing good drop resistance.

[0044] In this embodiment, a drive circuit module 5 is provided on the surface of the LDS base 1. Specifically, the drive circuit module 5 (such as a drive IC or other drive circuit components) is set on the bottom surface of the LDS base 1, thus forming a built-in or self-contained drive circuit module structure.

[0045] Example 2, see Figure 7-9 The miniature fan provided in this embodiment has a structure that is basically the same as that in embodiment 1. The difference is that the drive circuit module is not provided on the surface of the LDS base 1. Instead, an external drive circuit module structure is used. Specifically, the drive circuit module is placed in an external position, such as on a portable electronic device. Then, the metal contacts 111 on the bottom surface of the LDS base 1 make electrical contact with the pins on the portable electronic device to achieve connection with the drive circuit module located on the portable electronic device. This simplifies the structure of the miniature fan and achieves miniaturization.

[0046] This invention rationally replaces the traditional method of winding stator coils with enameled copper wire with a PCB coil board 2. Traditional methods using multiple wound stator coils inevitably struggle to guarantee concentricity, leading to electromagnetic imbalance. The stator coils on the PCB coil board 2 are fabricated directly on the PCB board 21 using printed circuit board technology, creating multiple 2D printed coils. The high precision of the printed circuit board process significantly improves the concentricity of the individual 2D printed coils, thus significantly reducing electromagnetic imbalance. Furthermore, the use of the PCB coil board 2 allows for high dimensional accuracy. For example, a stator with a diameter of 8.5mm or an SMT stator typically has an assembly accuracy within ±0.15mm; using a PCB coil board reduces this accuracy to within ±0.05mm, greatly improving assembly precision.

[0047] Furthermore, due to the high dimensional accuracy of the PCB coil board, the distance between the magnet 44 in the fan rotor assembly 4 and the PCB coil board can be reduced, thereby enhancing the magnetic field cut by the PCB coil board and effectively improving motor efficiency. Simulation results show that using a 6-layer PCB coil board, 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 board 6-slot 8-pole motor can reach over 35%, as detailed in Table 1.

[0048] Table 1

[0049] 6 6 slots 4 poles 2.03e-5 0.199 20.3％ 6 6 slots 8 poles 2.50e-5 0.181 27.4％ 8 6 slots 8 poles 2.21e-5 0.120 36.6％

[0050] 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. A PCB motor based on LDS, comprising an LDS base, characterized in that: It also includes a PCB coil board, on the surface of the LDS base having a metal circuit formed by the LDS process, the PCB coil board including a PCB board and a stator coil printed on the PCB board; the PCB coil board is soldered to the LDS base and electrically connected to the metal circuit.

2. The PCB motor based on LDS 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 LDS 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 LDS 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 top cover and a fan rotor assembly, characterized in that: It also includes the PCB motor based on LDS as described in any one of claims 1-4, wherein the fan rotor assembly is rotatably mounted on the LDS base corresponding to the position of the PCB coil board, and the upper cover is fastened to the LDS base.

6. The miniature fan according to claim 5, characterized in that: The LDS 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 coil board.

7. The miniature fan according to claim 5, characterized in that: The LDS base has a back iron embedded in it at the position corresponding to the magnet.

8. The miniature fan according to claim 5, characterized in that: The LDS base includes a base plate and a frame on the base plate, with waterproof and shock-absorbing adhesive between the base plate and the frame.

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

10. The miniature fan according to any one of claims 5-8, characterized in that: The drive circuit module is externally mounted or the surface of the LDS base is provided with the drive circuit module.

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