A brushless motor controller system and assembly method thereof

Abstract

The present invention belongs to the field of garden power tool control technology and provides a brushless motor controller system, comprising a control mainboard, a thermally conductive silicone pad, and a heat sink. The control mainboard is provided with a MOS tube, the MOS tube having a heat dissipation metal substrate and three pins. The heat dissipation metal substrate is welded to the control mainboard. The three pins of the MOS tube are connected to the control mainboard. The thermally conductive silicone pad is provided on the heat dissipation metal substrate of the MOS tube. The heat sink is provided on the thermally conductive silicone pad. Compared with the prior art, the advantage of the present invention is that the pins of the MOS tube provided in the system are directly connected to the control mainboard, and then a thermally conductive silicone pad is provided on the heat dissipation metal substrate of the MOS tube or on the top of the MOS tube. The heat sink is provided on the thermally conductive silicone pad, eliminating the need for a heat dissipation aluminum plate, resulting in a simpler structure and a smaller controller.

Description

Technical Field

[0001] The invention belongs to the technical field of garden power tool control, and in particular relates to a brushless motor controller system and an assembly method thereof. Background Art

[0002] The brushless motor controller is a DC to AC inverter, which usually requires multiple MOS tubes in TO-220 or DFN56 packages. MOS tubes are high-current power devices with large operating currents and high heat generation.

[0003] like Figure 1 As shown, the traditional controller MOS tube installation process is: the MOS tube is soldered to the PCB, and a copper strip conductor for current amplification is set on the PCB high-current loop to meet the high current requirements. The MOS tube heat dissipation method is to fix the MOS tube heat sink to the heat sink with screws. The heat sink itself and the heat sink also need to be insulated. It is necessary to add a thermally conductive insulating gasket and an insulating plastic sleeve for the screw. The gasket itself has a relatively low thermal conductivity coefficient and the thermal conductivity effect is not ideal. The insulation process during the screw installation process is very complicated and the risk of breakdown and leakage is very high. Therefore, a solution to the MOS tube heat dissipation is needed.

[0004] Currently, there are solutions to MOSFET heat dissipation. For example, Chinese patent application CN109728737A discloses a brushless motor controller system and assembly method. The system includes a heat dissipation substrate, MOSFETs, and a controller motherboard. The heat dissipation substrate is provided with signal output terminals and multiple MOSFETs. The MOSFETs have two upwardly curved pins and a heat dissipation metal substrate. The pins are inserted into the controller motherboard, which contains a high-current loop and a low-current loop. The high-current loop is connected to the two upwardly curved pins of the MOSFETs, and the heat dissipation metal substrate is connected to the signal output terminals. This solution can effectively solve the problem of excessive circuit board heat generation, but generally speaking, the structure is complex and the controller is bulky. The MOSFETs in the surface-mount package are also relatively fixed and single. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a brushless motor controller system and its assembly scheme with good heat dissipation effect, simple structure, low cost, small controller structure and adaptability to various MOS tubes in response to the current status of the existing technology.

[0006] The technical solution adopted by the present invention to solve the above technical problems is as follows: a brushless motor controller system is proposed, including a control mainboard, a thermal conductive silicone pad and a heat sink;

[0007] The control mainboard is provided with a MOS tube, which has a heat dissipation metal substrate and three pins; the heat dissipation metal substrate is welded on the control mainboard; the three pins of the MOS tube are connected to the control mainboard;

[0008] The thermally conductive silicone pad is arranged on the heat dissipation metal substrate of the MOS tube;

[0009] The heat sink is arranged on a thermally conductive silica gel pad.

[0010] Furthermore, the heat sink is an arcuate heat sink, and heat sink screw holes are provided on the heat sink.

[0011] Furthermore, there are multiple MOS tubes, and the multiple MOS tubes include a first MOS tube group and a second MOS tube group, and the first MOS tube group and the second MOS tube group are arranged opposite to each other.

[0012] Furthermore, mainboard screw holes for fixed connection with the heat sink screw holes are provided on the control mainboard between the first MOS tube group and the second MOS tube group.

[0013] Furthermore, the MOS tube is a TO-200 packaged MOS tube or a DFN56 packaged MOS tube.

[0014] Furthermore, components are provided on the control mainboard, the height of the components is the same as the height of the heat sink, and the components include chip inductors and chip electrolytic capacitors.

[0015] Furthermore, a large current loop is provided on the control mainboard, and the large current is electrically connected to the three pins of the MOS tube; a small current loop is also provided on the control mainboard, and the small current loop is directly electrically connected to the control mainboard.

[0016] A method for assembling a brushless motor controller system comprises the following steps:

[0017] The MOS tube is formed into a patch package and soldered on the control motherboard by automatic patching;

[0018] Solder the heat dissipation metal substrate of the MOS tube to the control mainboard, and connect the three pins of the MOS tube to the control mainboard;

[0019] Place the thermal conductive silicone pad on the heat dissipation metal substrate of the MOS tube;

[0020] The heat sink is fixed on the heat dissipation metal substrate provided with a thermal conductive silicone pad through the screw holes on the control mainboard.

[0021] Compared with the prior art, the present invention has at least the following beneficial effects:

[0022] (1) The pins of the MOS tube provided in the brushless motor controller system are directly connected to the control main board, and then a thermal conductive silicone pad is provided on the heat dissipation metal substrate of the MOS tube or on the top of the MOS tube, and a heat sink is provided on the thermal conductive silicone pad. There is no need to provide a heat dissipation aluminum plate, the structure is simpler, and the size of the controller is smaller.

[0023] (2) This brushless motor controller system can match two different surface-mount MOS tubes, which has a wider range of applications.

[0024] (3) In this brushless motor controller system, the heat dissipation metal substrate of the MOS tube is used as a high-current conductor to reduce heat generation and eliminate the need to install additional high-current copper bars as conductors.

[0025] (4) In this brushless motor controller system, the large current circuit and the small current circuit on the control main board are separated from each other to facilitate heat dissipation.

[0026] (5) The MOS tube in this brushless motor controller system is a surface mount package and can be automatically welded on the control motherboard, which improves the heat dissipation capacity, avoids manual welding, and saves labor costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is the MOS tube installation method in the existing brushless motor controller system;

[0028] Figure 2 This is a schematic diagram of a MOS tube formed into a TO-220 surface mount package provided by one embodiment of the present invention;

[0029] Figure 3 This is a schematic diagram of the structure of a brushless motor controller system in which a surface-mounted MOS tube is packaged in TO-220 according to one embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram of a MOS tube formed into a DFN56 surface mount package provided by one embodiment of the present invention;

[0031] Figure 5 This is a schematic diagram of the structure of a brushless motor controller system in which a surface-mounted MOS tube is packaged in DFN56 according to one embodiment of the present invention;

[0032] Figure 6 This is a flow chart of a brushless motor controller assembly method provided by one embodiment of the present invention.

[0033] Among them, 10, plastic shell, 20, control mainboard, 21, mainboard screw hole, 30, surface-mounted MOS tube, 31, heat dissipation metal substrate, 40, thermal conductive silicone pad, 50, heat sink, 51 heat dissipation screw hole. DETAILED DESCRIPTION

[0034] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

[0035] Example 1

[0036] This embodiment provides a brushless motor controller system, such as Figures 2 to 3 As shown, this embodiment provides a brushless motor controller system, which includes a control mainboard, a thermal conductive silicone pad and a heat sink; a MOS tube is provided on the control mainboard, and the MOS tube has a heat dissipation metal substrate and three pins; the heat dissipation metal substrate is welded on the control mainboard; the three pins of the MOS tube are connected to the control mainboard; the thermal conductive silicone pad is provided on the heat dissipation metal substrate of the MOS tube; and the heat sink is provided on the thermal conductive silicone pad.

[0037] like Figure 2 As shown, Figure 2 This embodiment provides a packaging method for a MOS tube, in which the TO-220 package adopts SMD chip packaging. This molding method enables the MOS tube to adopt an automatic chip placement process, that is, it can be automatically soldered on the circuit board by a chip placement machine, without the need to use a soldering iron or the like to manually solder the pins of the MOS tube, thereby improving welding efficiency and saving labor costs.

[0038] Currently, the heat dissipation metal substrate of the MOS tube is fixed to the aluminum alloy plate by screws, etc., and this process can generally only be assembled manually. However, in this embodiment, an automatic chip placement process is adopted to directly weld the heat dissipation metal substrate of the MOS tube to the control main board 20. Therefore, there is no need to manually fix the heat dissipation metal substrate 31 of the MOS tube, and there is no need to use insulating spacers for isolation, thereby ensuring that the MOS tube will not experience breakdown and leakage.

[0039] The TO-220 SMD packaged MOS transistor provided in this embodiment includes three pins: G (gate), D (drain), and S (source), all of which are bent vertically downward, with the bending direction pointing toward the heat dissipation metal substrate. These three pins are all connected to the control motherboard. The heat dissipation metal substrate 31 of the MOS transistor itself is also one of the three polarities of the MOS transistor: G (gate 13), D (drain 12), and S (source 11). The D (drain 12) itself can also serve as an electrical connection. This allows the high-current loop of the controller to be directly connected to the MOS transistor, using the MOS transistor as a high-current carrier. This eliminates the need for additional current guide copper bars on the control motherboard, saving costs. Furthermore, because the MOS transistor is welded to the aluminum substrate on the control motherboard with excellent thermal conductivity, it can effectively dissipate heat and avoid the effects of heat.

[0040] like Figure 3 As shown, this embodiment provides six MOS tubes, including a first MOS tube group and a second MOS tube group. The first MOS tube group and the second MOS tube group are arranged relative to each other. That is, the pins of the two groups of MOS tubes are placed opposite each other, and the heat dissipation metal substrates of the two groups of MOS tubes are respectively arranged outside the two groups of MOS tubes. This arrangement can evenly arrange the heat dissipation metal substrates in a row, allowing thermally conductive silicone pads to be placed on the arranged heat dissipation metal substrates, and heat sinks to be placed on the thermally conductive silicone pads, thereby achieving better heat dissipation.

[0041] The heat sink provided in this embodiment is an arched heat sink, wherein the groove position of the heat sink is used to place the MOS tube, and the raised position of the heat sink is in close contact with the silicone thermal pad to dissipate heat from the heat dissipation metal substrate of the MOS tube below the silicone thermal pad.

[0042] The mainboard screw holes and the heat dissipation screw holes provided in this embodiment are correspondingly arranged to fix the heat sink on the control mainboard. Due to the arrangement of the bow-shaped heat sink, the heat dissipation screw holes on the heat sink only need to be as follows Figure 3 The two shown save material and process costs.

[0043] The small current loop on the control motherboard includes a loop for controlling signal input and output. Similar to conventional brushless motor controllers, conventional brushless motor controllers generally have a small current loop and a large current loop, which will not be described in detail in this article.

[0044] By setting a small current loop on the control main board, the small current loop is separated from the large current loop, which facilitates heat dissipation and can avoid the impact of heat on the entire PCB board.

[0045] In this embodiment, components are arranged at the bottom of the control mainboard. The height of the components is the same as that of the heat sink. The components include chip inductors and chip electrolytic capacitors, which reduce the overall volume of the controller.

[0046] Example 2

[0047] This embodiment provides a brushless motor controller system, such as Figure 4 and Figure 5 As shown, the brushless motor controller system is as follows Figure 4 As shown, Figure 4 This embodiment provides a packaging method for a MOS tube, in which the DFN56 package adopts SMD chip packaging. This molding method enables the MOS tube to adopt an automatic chip mounting process, that is, it can be automatically soldered on the circuit board by a chip mounting machine, without the need to use a soldering iron or the like to manually solder the pins of the MOS tube, thereby improving welding efficiency and saving labor costs.

[0048] The DFN56 SMD packaged MOS tube provided in this embodiment includes a G pole (gate) that is, Figure 4 The 4 pins in the D terminal (drain) are Figure 4 Pins 5, 6, 7, and 8 in the MOSFET, as well as the S-pole (source), namely pins 123 in the figure; the large heat sink at the bottom of the DFN56 chip package MOSFET can be used as a welding surface and can also serve as the D-pole of the MOSFET, so that it can be welded on the control motherboard and electrically connected to the control motherboard. In this way, the high-current loop of the controller is directly connected to the MOSFET, and the MOSFET is used as a high-current carrier, so that there is no need to set additional guide copper bars on the control motherboard, which saves costs. In addition, since the MOSFET is welded on the aluminum substrate with very good thermal conductivity on the control motherboard, it can effectively dissipate heat and avoid the impact of heat.

[0049] like Figure 5 As shown, the number of MOS tubes provided in this embodiment is 12, and the 12 MOS tubes include a first MOS tube group and a second MOS tube group. The first MOS tube group and the second MOS tube group are arranged opposite each other, that is, the bottoms of the two MOS tube groups are soldered to the control motherboard. This arrangement can evenly arrange the MOS tubes into two rows, so that thermally conductive silicone pads can be placed on top of the arranged MOS tubes, and heat sinks can be placed on the thermally conductive silicone pads to achieve better heat dissipation.

[0050] The bottom of the heat sink provided in this embodiment is flat. In order to better fit with the thermal conductive silicone pad, corresponding screw holes are respectively provided on the heat sink and the control mainboard, and the heat sink is fixedly connected to the control mainboard through the screw holes.

[0051] On the one hand, this embodiment uses the large-area heat sink at the bottom of the MOS as a high-current conductor to reduce heat generation and eliminate the need to install additional high-current copper bars as conductors. On the other hand, the high-current loop and the small-current loop on the controller are separated from each other, which facilitates heat dissipation and solves the problem of heat generation affecting the entire circuit board. In addition, the MOS tube is formed into a surface-mount package and can be automatically welded on an aluminum substrate, thereby improving heat dissipation capacity, avoiding manual welding, and saving labor costs.

[0052] Example 3

[0053] This embodiment provides an assembly method of a brushless motor controller system, such as Figure 6 As shown, the steps include:

[0054] The MOS tube is formed into a patch package and soldered on the control motherboard by automatic patching;

[0055] Solder the heat dissipation metal substrate of the MOS tube to the control mainboard, and connect the three pins of the MOS tube to the control mainboard;

[0056] Place the thermal conductive silicone pad on the heat dissipation metal substrate of the MOS tube;

[0057] The heat sink is fixed on the heat dissipation metal substrate provided with a thermal conductive silicone pad through the screw holes on the control mainboard.

[0058] This brushless motor controller system assembly method uses the heat-dissipating metal substrate of the MOS tube as a high-current conductor, reducing heat generation and eliminating the need for additional high-current copper bars. Furthermore, a thermally conductive silicone pad is placed on the heat-dissipating metal substrate of the MOS tube or on top of the MOS tube, and a heat sink is placed on the thermally conductive silicone pad, simplifying the assembly structure.

[0059] In addition, the MOS tube in the brushless motor controller system is a patch package and can be automatically welded on the control main board, which improves the heat dissipation capacity, avoids manual welding, and saves labor costs.

[0060] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them with similar methods without departing from the scope defined by the spirit of the present invention.

Claims

1. A brushless motor controller system, characterized in that: Including control motherboard, thermal conductive silicone pad and heat sink; The control mainboard is provided with a MOS tube, which has a heat dissipation metal substrate and three pins; the heat dissipation metal substrate is welded on the control mainboard; the three pins of the MOS tube are connected to the control mainboard; The thermally conductive silicone pad is arranged on the heat dissipation metal substrate of the MOS tube; The heat sink is arranged on a thermally conductive silicone pad; The heat sink is an arched heat sink, the groove position of the heat sink is used to place the MOS tube, and the raised position of the heat sink is in contact with the thermal conductive silicone pad.

2. A brushless motor controller system according to claim 1, characterized in that: The heat sink is provided with heat sink screw holes.

3. A brushless motor controller system according to claim 2, characterized in that: There are multiple MOS tubes, and the multiple MOS tubes include a first MOS tube group and a second MOS tube group. The first MOS tube group and the second MOS tube group are arranged opposite to each other.

4. A brushless motor controller system according to claim 3, characterized in that: The control mainboard between the first MOS tube group and the second MOS tube group is provided with mainboard screw holes for fixed connection with the heat sink screw holes.

5. The brushless motor controller system according to claim 3, characterized in that: The MOS tube is a TO-200 packaged MOS tube or a DFN56 packaged MOS tube.

6. The brushless motor controller system according to claim 1, characterized in that: Components are arranged on the control mainboard. The height of the components is the same as that of the heat sink. The components include chip inductors and chip electrolytic capacitors.

7. The brushless motor controller system according to claim 1, characterized in that: The control mainboard is provided with a large current loop, which is electrically connected to the three pins of the MOS tube; the control mainboard is also provided with a small current loop, which is directly electrically connected to the control mainboard.

8. A method for assembling a brushless motor controller system, characterized in that: Including steps: The MOS tube is formed into a patch package and soldered on the control motherboard by automatic patching; Solder the heat dissipation metal substrate of the MOS tube to the control mainboard, and connect the three pins of the MOS tube to the control mainboard; Place the thermal conductive silicone pad on the heat dissipation metal substrate of the MOS tube; The heat sink is fixed on the heat dissipation metal substrate provided with a thermally conductive silicone pad through the screw holes on the control mainboard; The heat sink is an arched heat sink, the groove position of the heat sink is used to place the MOS tube, and the raised position of the heat sink is in contact with the thermal conductive silicone pad.

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