Flexible printed circuit (FPC) miniature heat dissipation module

Abstract

The utility model discloses an FPC miniature heat dissipation module. The FPC miniature heat dissipation module comprises a top cover, a base, a motor shell, a magnet, a stator winding, an impeller and an FPC. The stator winding is a three-phase six-slot four-pole disc type motor stator winding, a three-phase six-slot eight-pole disc type motor stator winding or a two-phase four-slot six-pole disc type motor stator winding. According to the utility model, the structural design is reasonable, the torque fluctuation and the axial force fluctuation of the motor are improved by optimizing the slot pole matching of the motor, the vibration noise of the product is further reduced, the sound quality of the product is improved, and the outburst ratio of the product can be reduced to below 4dB; and the coil in the stator winding is wound by the self-adhesive enameled wire, so that the internal space of the motor can be fully utilized, the slot space factor of the coil is increased, the turn chain number of the motor is increased, and the efficiency of the motor is further improved. In addition, the VC plate and the fins are combined to form the radiator, the radiating effect is good, and the temperature gradient of the chip is effectively improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a heat dissipation technical field, specifically relates to a FPC micro heat dissipation module. BACKGROUND

[0002] With the development of intelligent terminal such as notebook computer, tablet computer, mobile phone and other products tend to light and thin direction, the heat dissipation module for terminal product heat dissipation is also more and more thin, the sound quality requirement of micro heat dissipation module is also more and more strict. Micro fan is the main sound source in micro heat dissipation module, how to further improve the sound quality of micro fan, the fan industry has been a great challenge.

[0003] Through research, the sound quality of micro fan is related to the vibration of motor in addition to the residual unbalance of rotor. From the source of vibration, the vibration source of motor is divided into torque fluctuation and axial force fluctuation. Torque fluctuation is the main reason of motor vibration and noise. The torque fluctuation of motor and its suppression technology has been one of the research hotspots of brushless DC motor. Therefore, it is of great significance to study the method of reducing or suppressing torque fluctuation.

[0004] For micro fan, due to limited space, the current motor scheme is limited, and the current commercial micro fan motor scheme mainly includes the following:

[0005] 1. Radial flux motor. Due to limited size, 4-slot 4-pole radial motor scheme is generally used - scheme 1.

[0006] 2. Axial flux motor, also known as disc motor. Due to limited size, coreless motor structure is often used, and 4-slot 4-pole single-phase motor - scheme 2, or 3-slot 4-pole three-phase motor - scheme 3, or 4-slot 6-pole two-phase motor - scheme 4 is often used in slot and pole matching of stator and rotor.

[0007] For scheme 1, this driving mode is a typical square wave voltage driving, which has principle torque fluctuation, and it is difficult to suppress this torque fluctuation.

[0008] For scheme 2, this driving mode is still a typical square wave voltage driving, which has principle torque fluctuation, and it is difficult to start. To solve this problem, pre- eccentric positioning scheme is often used, that is, high permeability material is used to attract the position of rotor to the position easy to start. However, the introduction of high permeability material will cause additional problems. The existence of high permeability material will produce additional cogging effect, cause cogging torque pulsation, and further deteriorate torque fluctuation.

[0009] For scheme 3, the motor with the stator having an odd number of slots (or an odd number of coils) is naturally unbalanced in radial electromagnetic force, which causes additional vibration and noise.

[0010] For scheme 4, the motor can be considered as two 6-slot 6-pole single-phase disc motors connected in parallel, and for each single-phase motor, 2 coils are used to simulate the effect of 6 coils due to space limitation. In order to achieve the best torque ripple suppression effect and avoid causing unbalanced electromagnetic force, the two motors are staggered by 270 degrees of electrical angle. This scheme is the driving scheme of the commercial 4-slot 6-pole motor. In theory, this scheme has good torque ripple suppression effect, however, due to the unevenness of the magnetic field waveform, the torque ripple generated by replacing 6 coils with 2 coils is still relatively large, and the torque ripple suppression effect will be weakened to a considerable extent after two-phase superposition. In addition, the commercial 4-slot 6-pole motor has a block of insulating material outside the coil, which reduces the winding space and reduces the magnetic flux of the stator coil link, resulting in a decrease in motor efficiency.

[0011] Therefore, the above schemes are not the best scheme. Therefore, it is necessary to develop an FPC micro heat dissipation module capable of improving aerodynamic noise. Content of the utility model

[0012] In view of the above-mentioned defects, the purpose of the utility model is to provide an FPC micro heat dissipation module which has reasonable structure design, can improve aerodynamic noise and has thin thickness.

[0013] In order to achieve the above-mentioned purpose, the technical scheme provided by the utility model is:

[0014] An FPC micro heat dissipation module, which comprises a top cover, a base, a motor shell, a magnet, a stator winding, an impeller and an FPC, the FPC is arranged on the base, the stator winding is welded on the FPC, the base is provided with a middle pipe corresponding to the center position of the stator winding, the motor shell is rotationally arranged on the middle pipe, the magnet is arranged on the motor shell corresponding to the position of the stator winding, the impeller is sleeved on the motor shell, the top cover is arranged on the base, and the stator winding is a disc motor stator winding of three-phase six-slot four-pole, three-phase six-slot eight-pole or two-phase four-slot six-pole, so as to reduce the unbalanced radial magnetic pull.

[0015] As a preferred scheme of the utility model, the outer side wall of the base is provided with a plug, the interface end of the FPC is U-shaped and is sleeved outside the plug, and the interface end is provided with a gold finger, so that the installation and connection are facilitated.

[0016] As a preferred scheme of the utility model, the coil in the stator winding is wound by using self-adhesive enameled wire, so as to fully utilize the space inside the motor, increase the slot fill factor of the coil, improve the number of turns per link of the motor, and further improve the motor efficiency.

[0017] As a preferred scheme of the utility model, the coil in the stator winding is wound by using self-adhesive enameled wire, so as to fully utilize the space inside the motor, increase the slot fill factor of the coil, improve the number of turns per link of the motor, and further improve the motor efficiency.

[0018] As a preferred scheme of the utility model, the inner bottom surface of the base is provided with a rounded trapezoidal boss matched with the coil, and the FPC is provided with a trapezoidal hole through which the rounded trapezoidal boss passes, so that the rounded trapezoidal boss is clamped into the inner hole of the coil, the cooperation with the coil is good, the positioning accuracy of the coil is improved, and the assembly difficulty of the coil is reduced.

[0019] As a preferred scheme of the utility model, the FPC is provided with a circular hole through which the middle tube passes, and the cooperation is good.

[0020] As a preferred scheme of the utility model, the outer bottom surface of the base is provided with a ring groove, and the ring groove is provided with a back iron, so that the distance between the back iron and the FPC is significantly increased, and the antistatic grade is effectively improved. In addition, the back iron is changed to the outer bottom surface of the base, so that the combination part of the base and the middle tube is moved upward, the structural rigidity of the middle tube is improved, the vibration is reduced, the assembly of the back iron is also easier, and the back iron is assembled from the inside instead of the outside.

[0021] As a preferred scheme of the utility model, a radiator is arranged at the air duct position of the base, the radiator comprises a VC plate and fins arranged on the VC plate, the heat dissipation effect is good, and the temperature gradient of the chip is effectively improved.

[0022] As a preferred scheme of the utility model, a radiator is arranged at the air duct position of the base, the radiator comprises a copper plate and fins arranged on the copper plate, the copper plate is inlaid in the base, and the copper plate is provided with a through hole at the edge position.

[0023] As a preferred scheme of the utility model, the base and the middle tube are integrally connected, the connection is firm, and the structural stability is good.

[0024] As a preferred scheme of the utility model, the sidewall of the base is provided with a slot through which the interface end of the FPC extends, so as to facilitate the installation and connection.

[0025] The utility model discloses beneficial effect is: the utility model discloses reasonable structure design, through optimizing the slot pole cooperation of motor, the torque fluctuation and axial force fluctuation of motor have been improved, and then reduce the vibration noise of product, improve the sound quality of product, and the outstanding ratio of product can be reduced to 4dB below, and the coil in stator winding adopts self -adhesive enameled wire and is wound, can fully utilize the space in motor, increase the slot full rate of coil, improve the turn chain number of motor, and then improve motor efficiency.

[0026] The utility model is further described below in combination with the drawings and examples. DRAWINGS

[0027] Figure 1 It is the three-dimensional structure schematic diagram of the utility model.

[0028] Figure 2 It is the sectional structure schematic diagram of the utility model.

[0029] Figure 3 It is the exploded structure schematic diagram of the utility model.

[0030] Figure 4 It is the real object schematic diagram of stator winding in the utility model.

[0031] Figure 5 It is another structure diagram of radiator in the utility model.

[0032] Figure 6 It is another assembly drawing of radiator in the utility model.

[0033] Figure 7 It is the torque waveform diagram of comparative example 1.

[0034] Figure 8 It is the axial force waveform diagram of comparative example 1.

[0035] Figure 9 It is the radial unbalanced magnetic pull waveform diagram of comparative example 1.

[0036] Figure 10 It is the torque waveform diagram of comparative example 2.

[0037] Figure 11 It is the axial force waveform diagram of comparative example 2.

[0038] Figure 12 It is the radial unbalanced magnetic pull waveform diagram of comparative example 2.

[0039] Figure 13 It is the torque waveform diagram of three-phase six-slot eight-pole motor in the utility model.

[0040] Figure 14 is an axial force waveform diagram of the three-phase six-slot eight-pole motor in the utility model.

[0041] Figure 15 is a radial unbalanced magnetic pull waveform diagram of the three-phase six-slot eight-pole motor in the utility model. DETAILED DESCRIPTION

[0042] Embodiment, see Figures 1 to 4 The FPC micro heat dissipation module provided in the embodiment comprises a top cover 1, a base 2, a back iron 3, an impeller 4, a motor shell 5, a magnet 6, a stator winding 7, a heat sink 8 and an FPC 9.

[0043] The FPC 9 is arranged on the inner bottom surface of the base, and the stator winding 7 is welded on the FPC. In the embodiment, the stator winding 7 is preferably a three-phase six-slot four-pole disc-type motor stator winding, and in other embodiments, the stator winding 7 can also be a three-phase six-slot eight-pole or two-phase four-slot six-pole disc-type motor stator winding, so as to reduce unbalanced radial magnetic pull, improve torque fluctuation and axial force fluctuation of the motor, and further reduce vibration noise of the product and improve sound quality of the product. The coil in the stator winding 7 is preferably wound by using self-adhesive enameled wire, and the coil can be used as a separate coil unit after being formed, without the need for coating with an insulating material. In this way, the space inside the motor can be fully utilized, the slot fill factor of the coil is increased, the number of turns per link of the motor is increased, and the efficiency of the motor is further improved.

[0044] The coil in the stator winding 7 is preferably in the shape of a rounded trapezoid, so as to increase the magnetic flux of the coil turns, thereby improving the efficiency of the motor, and the efficiency of the motor can be increased by more than 30%.

[0045] Preferably, a rounded trapezoidal boss 23 matched with the coil is arranged on the inner bottom surface of the base 2, and a trapezoidal hole 91 through which the rounded trapezoidal boss 23 passes is arranged on the FPC 9. The rounded trapezoidal boss 23 is clamped into the inner hole of the coil through the trapezoidal hole 91, and the coil has good cooperation effect, the positioning accuracy of the coil is improved, and the assembly difficulty of the coil is reduced.

[0046] The base 2 is provided with a middle tube 21 corresponding to the center position of the stator winding 7, and the base 2 and the middle tube 21 are preferably in an integrated connection structure, which is firm in connection and good in structural stability. In order to avoid interference, the FPC 9 is provided with a circular hole 92 through which the middle tube 21 passes. In order to facilitate FPC wiring, the sidewall of the base is provided with a slot 24 through which the interface end of the FPC extends. The interface end of the FPC extends out of the slot 24 and is provided with a gold finger 93, which facilitates installation and connection. Specifically, a plug is provided on the outer sidewall of the base corresponding to the position of the slot 24, the interface end of the FPC extends out of the slot 24 and is U-shaped outside the plug, and then the gold finger 93 is provided on the U-shaped part, which facilitates installation and connection.

[0047] A bearing 22 is arranged in the middle tube 21, and a rotating shaft is arranged on the motor shell 5 and matched with the bearing 22, the rotating shaft is arranged in the bearing 22, the motor shell 5 is arranged on the middle tube 21 in a rotating manner, the magnet 6 is arranged on the motor shell 5 corresponding to the position of the stator winding 7, the impeller 4 is arranged on the motor shell 5, and the top cover 1 is arranged on the base 2.

[0048] An annular groove matched with the back iron 3 is arranged on the outer bottom surface of the base 2, and the back iron 3 is arranged in the annular groove, so that the distance between the back iron 3 and the FPC 9 is significantly increased, thereby effectively improving the antistatic level. In addition, the back iron 3 is changed to the outer bottom surface of the base 2, so that the combination position of the base 2 and the middle tube 21 is moved upward, the structural rigidity of the middle tube 21 is improved, vibration is reduced, and the assembly of the back iron 3 is also easier, because the fan is small in size, the back iron 3 is assembled from the inside, and it is not convenient to assemble the back iron 3 from the outside.

[0049] The heat sink 8 is arranged at the air duct position of the base 2, and the heat sink 8 comprises a VC plate 81 and fins 82 arranged on the VC plate 81. A conventional micro heat sink usually uses a common copper block as a heat absorption bottom, but due to the limited thermal conductivity coefficient of the copper block, a temperature gradient exists on the chip, which on the one hand causes the whole chip to enter the overheat protection due to local high temperature, or the chip is damaged due to the lack of temperature detection points in the local high temperature area and the lack of overheat protection. The thermal conductivity coefficient of the VC plate 81 can reach 100 times that of the copper block, which can be regarded as a thermal superconductor, so that the temperature gradient of the chip can be effectively improved.

[0050] In other embodiments, see Figure 5 and Figure 6The heat sink 8 can also include a copper plate 83 and fins 82 arranged on the copper plate 83, that is, the copper plate 83 is used to replace the VC plate 81. In production, the copper plate 83 is embedded on the base 2 by insert injection molding. In order to improve the connection strength of the copper plate 83 and the base, a through hole 831 is arranged at the edge position of the copper plate 83, so that the plastic of the base 2 is injected into the through hole 831 to form a connecting column after cooling, which can further improve the combination effect. In addition, glue can be applied to the connection between the copper plate 83 and the base 2, which can further improve the close fit and good air tightness.

[0051] Comparative Example 1: In the comparative micro heat dissipation module, a motor with four-slot six-pole and square wave driving is used, the motor efficiency is 18.3%, the torque ripple is 42.9%, and the specific torque waveform, axial force waveform and unbalanced radial magnetic pull are shown in Figure 7 、 Figure 8 and Figure 9 .

[0052] Comparative Example 2: In the comparative micro heat dissipation module, a motor with three-slot four-pole and chord wave driving is used, the motor efficiency is 21.8%, the torque ripple is 1.9%, and the specific torque waveform, axial force waveform and unbalanced radial magnetic pull are shown in Figure 10 、 Figure 11 and Figure 12 .

[0053] The utility model discloses the stator winding 7 is six-slot eight-pole, chord wave drive is illustrated by example, and the motor efficiency is 34.5% after testing, the torque ripple is 0.14%, and the specific torque waveform, axial force waveform and unbalanced radial magnetic pull are shown in Figure 13 、 Figure 14 and Figure 15 .

[0054] It can be seen that the FPC micro heat dissipation module of the utility model effectively reduces the torque fluctuation and axial force fluctuation of the motor, thereby reducing the vibration noise of the product and improving the sound quality of the product.

[0055] According to the disclosure and teaching of the above description, the skilled person in the art of the utility model can also change and modify the above embodiments. Therefore, the utility model is not limited to the specific embodiments disclosed and described above, and some modifications and changes of the utility model should fall within the protection scope of the claims of the utility model. In addition, although some specific terms are used in the specification, these terms are only for convenience of description and do not constitute any limitation on the utility model. As described in the above embodiments of the utility model, other modules and fan structures obtained by using the same or similar structures are within the protection scope of the utility model.

Claims

1. A FPC micro heat dissipation module, comprising a top cover, a base, a motor shell, a magnet, a stator winding, an impeller and an FPC, characterized in that, The FPC is arranged on the base, the stator winding is welded on the FPC, the base is provided with a middle tube corresponding to the central position of the stator winding, the motor shell is arranged on the middle tube in a rotating mode, the magnet is arranged on the motor shell corresponding to the position of the stator winding, the impeller is sleeved on the motor shell, the top cover is arranged on the base, and the stator winding is a disc motor stator winding of three-phase six-slot four-pole, three-phase six-slot eight-pole or two-phase four-slot six-pole.

2. The FPC micro heat dissipation module according to claim 1, characterized in that: The outer side wall of the base is provided with a plug, the interface end of the FPC is in a U-shaped mode and is sleeved outside the plug, and the interface end is provided with a gold finger.

3. The FPC micro heat dissipation module of claim 1, wherein: The coil in the stator winding is wound by using a self-adhesive enameled wire.

4. The FPC micro heat dissipation module of claim 2, wherein: The coil in the stator winding is in a circular-angled trapezoidal shape.

5. The FPC micro heat dissipation module of claim 4, wherein: The inner bottom surface of the base is provided with a circular-angled trapezoidal boss matched with the coil, and the FPC is provided with a trapezoidal hole through which the circular-angled trapezoidal boss passes.

6. The FPC micro heat dissipation module of claim 1, wherein: The FPC is provided with a circular hole through which the middle tube passes, and the base and the middle tube are in an integrated connection structure.

7. The FPC micro heat dissipation module of claim 1, wherein: The outer bottom surface of the base is provided with a ring groove, and the ring groove is provided with a back iron.

8. The FPC micro heat dissipation module of claim 1, wherein: A heat sink is arranged at the air duct position of the base, and the heat sink comprises a VC plate and fins arranged on the VC plate.

9. The FPC micro heat dissipation module of claim 1, wherein: A heat sink is arranged at the air duct position of the base, and the heat sink comprises a copper plate and fins arranged on the copper plate, the copper plate is inlaid in the base, and the copper plate is provided with a through hole at the edge position.

10. The FPC micro heat dissipation module of claim 1, wherein: The side wall of the base is provided with a slot through which the interface end of the FPC extends.

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