Hall current sensor and preparation method thereof

Abstract

The present invention relates to the field of sensor technology, and discloses a Hall current sensor and a preparation method thereof. The method comprises: preparing a substrate, the substrate having a first region and a second region, the thickness of the substrate corresponding to the first region being greater than the thickness of the substrate corresponding to the second region; cutting the substrate to form a frame, the frame comprising a current-carrying pin frame formed in the first region and a signal pin formed in the second region; a Hall chip electrically connected to the signal pin is arranged at one end of the signal pin; a magnetic concentrator is arranged on the current-carrying pin frame, and the magnetic concentrator covers the Hall chip; the magnetic concentrator region in the frame is injection molded to encapsulate the magnetic concentrator, the Hall chip, part of the current-carrying pin frame and part of the signal pin. By using substrates with different thicknesses, a frame including a current-carrying pin frame and a signal pin is formed by cutting at one time, so as to meet the production requirements of one-time injection molding of a large current Hall sensor, improve the accuracy of the relative position of the current-carrying pin frame and the Hall chip, and save costs.

Description

Technical Field

[0001] The present invention relates to the technical field of sensors, and in particular to a Hall current sensor and a preparation method thereof. Background Art

[0002] Currently, the integrated Hall current sensors on the market include small current sensors and large current sensors, among which large current sensors are more widely used. Its working principle is: when current passes through the current-carrying pin frame, a magnetic field will be generated around it, and the magnetic concentrator mounted on the current-carrying pin frame will gather the magnetic field. Finally, the Hall chip embedded in the middle of the magnetic concentrator is used to detect the strength of the magnetic field. After that, the signal pin outputs a signal to achieve the purpose of detecting the current size in the current-carrying pin frame.

[0003] The manufacturing method of high current sensors is usually: first process the current-carrying pin frame, then manually or automatically insert the magnetic concentrator, then assemble the packaged Hall chip and signal pins and install them in the magnetic concentrator, and finally wrap the current-carrying pin frame, magnetic concentrator and Hall chip together.

[0004] However, during the manufacturing process, the first injection molding is performed when assembling the Hall chip and the signal pin, and the second injection molding is performed when encapsulating the current-carrying pin frame, the magnetic concentrator and the Hall chip; that is, there are two injection molding processes in the production process, the manufacturing cycle is long, the process steps are complicated, and two sets of injection molds are required, and the mold cost is relatively high; in addition, during the installation of the Hall chip and the signal pin on the magnetic concentrator, the relative position of the current-carrying pin frame and the Hall chip is prone to large errors, causing the Hall sensitive element inside the Hall chip to deviate from the position of the current-carrying pin frame, thereby affecting product performance. Summary of the invention

[0005] In view of this, the present invention provides a Hall current sensor and a preparation method thereof to solve the problem that the existing large current Hall sensor has two injection molding processes and the relative position of the current-carrying pin frame and the Hall chip is prone to deviation, thereby affecting production efficiency and product performance.

[0006] In a first aspect, the present invention provides a method for preparing a Hall current sensor, comprising:

[0007] Prepare a substrate, the substrate having a first region and a second region, the thickness of the substrate corresponding to the first region is greater than the thickness of the substrate corresponding to the second region;

[0008] Cutting the substrate to form a frame, the frame including a current-carrying pin frame formed in a first area, and a signal pin formed in a second area;

[0009] A Hall chip is arranged at one end of the signal pin, and the Hall chip is electrically connected to the signal pin;

[0010] The magnetic concentrator is arranged on the current-carrying lead frame so that the magnetic concentrator covers the Hall chip;

[0011] The area where the magnetic concentrator is located in the frame is injection molded to encapsulate the magnetic concentrator, the Hall chip, part of the current-carrying lead frame and part of the signal pins.

[0012] Beneficial effect: The preparation method of the Hall current sensor of the present invention adopts a substrate with different thicknesses, and forms a frame including a current-carrying pin frame and a signal pin through one-time cutting, so as to meet the different requirements of the current-carrying pin frame and the signal pin on the material thickness, thereby meeting the production requirements of one-time injection molding of a large current Hall sensor. Moreover, compared with the installation of a special manual jig, the one-time molding of the frame can also locate the relative position of the current-carrying pin frame and the signal pin, which helps to improve the accuracy of the relative position of the current-carrying pin frame and the Hall chip, and improve product consistency. The Hall chip does not need to be accurately installed on the current-carrying pin frame, that is, no additional customized Hall chip assembly equipment is required, which helps to save costs and simplify the process.

[0013] In an optional embodiment, preparing a substrate comprises:

[0014] Providing a first initial substrate, wherein the first initial substrate has a uniform thickness at all locations;

[0015] The first initial substrate is hot-rolled to form a first region and a second region, wherein the thickness of the substrate corresponding to the first region is less than or equal to the thickness of the first initial substrate.

[0016] Beneficial effect: A first initial substrate having a thickness greater than or equal to that of a current-carrying lead frame, such as a copper material having good thermal ductility, is selected. A thick and thin substrate is obtained by hot-rolling the first initial substrate, and then a thicker current-carrying lead frame and a thinner signal pin are formed at one time by mechanical stamping. The preparation is simple and convenient, and is conducive to mass production.

[0017] In an optional embodiment, preparing a substrate comprises:

[0018] providing a second initial substrate;

[0019] Performing a bending process on one end of the second initial substrate;

[0020] The bent portion is stacked and fixed with the second initial substrate to form a first area in the stacked area, and the remaining area is a second area. The thickness of the substrate corresponding to the second area is equal to the thickness of the second initial substrate.

[0021] Beneficial effect: A second initial substrate with the same thickness as the thinner signal pin is selected, and the plasticity of the copper material is used to bend it at one end and stack it on the original second initial substrate. The stacked thickened area forms the first area to form the current-carrying pin frame, and the area of ​​the original single-layer copper material is the second area to form the signal pin. When using thinner copper materials of the same thickness, there is no need to perform additional process treatment on the copper material itself. After bending and stacking, substrates of different thicknesses can be formed. In addition, the stacked thickened part has a small current internal resistance and heat generation, which helps to further reduce power consumption.

[0022] In an optional embodiment, the bending process at one end of the second initial substrate includes:

[0023] Performing a first bend at one end of the second initial substrate;

[0024] The first bent part is bent a second time, and the second bend folds the first bent part in half.

[0025] Beneficial effect: The second initial substrate is bent twice, the thicker first area is composed of three layers of the second initial substrate, wherein the two bent layers are equal in size, and the thinner second area is composed of a single layer of the second initial substrate. After two bendings, a substrate with two thicknesses is formed, and the process is simple and easy to operate.

[0026] In an optional implementation, stacking and fixing the bent portion and the second initial substrate includes: stacking and fixing the bent portion and the second initial substrate together by riveting or welding.

[0027] Beneficial effect: Laser welding can be used for welding, and a stable substrate structure with different thicknesses can be formed by multi-point fixing.

[0028] In an optional embodiment, the magnetic concentrator has an opening, and the current-carrying pin frame is U-shaped; installing the magnetic concentrator on the current-carrying pin frame so that the magnetic concentrator covers the Hall chip includes:

[0029] Set a glue point on one end of the current-carrying lead frame close to the Hall chip;

[0030] Place the magnetic concentrator in the U-shaped current-carrying lead frame, with the opening of the magnetic concentrator facing the side where the glue point is located;

[0031] Pushing the magnetic concentrator to move from the current-carrying pin frame side toward the signal pin side, so as to place at least the Hall chip in the opening of the magnetic concentrator;

[0032] Secure the magnetic concentrator to the current carrying leadframe at the glue point.

[0033] Beneficial effects: By using equipment with dispensing, suction and longitudinal pushing functions, the magnetic concentrator is accurately pushed and fixed on the current-carrying lead frame through automated assembly. The installation is stable and fast, which is conducive to mass production, thereby improving production efficiency and reducing costs.

[0034] In an optional implementation, a height L of the opening of the magnetic concentrator is greater than a thickness H of the current-carrying lead frame, and a difference between the height L and the thickness H ranges from 0.1 mm to 0.2 mm.

[0035] Beneficial effect: The opening height of the magnetic concentrator is set to have a spacing of 0.1mm~0.2mm from the thickness of the current-carrying pin frame, which facilitates the installation of the magnetic concentrator without causing large shaking. It can also ensure that during the installation process, the magnetic concentrator has sufficient redundancy and will not touch the welding wire of the Hall chip, thereby improving the accuracy of the magnetic concentrator installation and thus improving the consistency of product performance.

[0036] In an optional implementation, the frame further includes: a connecting portion connecting the current-carrying pin frame and the signal pin to limit the relative position of the current-carrying pin frame and the signal pin.

[0037] Beneficial effect: A connection portion is provided in the first area and the second area to connect the current-carrying pin frame and the signal pin, thereby effectively avoiding relative displacement between the current-carrying pin frame and the signal pin, thereby ensuring accurate installation of the Hall chip and the magnetic concentrator.

[0038] In an optional embodiment, in cutting the substrate, a plurality of current-carrying lead frames are formed in the first region, and a corresponding plurality of signal pins are formed in the second region;

[0039] After the area of ​​the frame where the magnetic concentrator is located is injection molded, it also includes:

[0040] Cutting the connecting part of the frame to obtain a plurality of separate Hall current sensor units, each Hall current sensor unit comprising a current-carrying pin frame, a magnetic concentrator, a Hall chip, a signal pin and a plastic packaging structure;

[0041] In the Hall current sensor unit, an end of the current-carrying pin frame away from the magnetic concentrator is bent, and an end of the signal pin away from the magnetic concentrator is bent.

[0042] In a second aspect, the present invention also provides a Hall current sensor, which is manufactured by the above-mentioned preparation method of the Hall current sensor, and includes: a current-carrying pin frame, a signal pin, a Hall chip, a magnetic concentrator and a plastic packaging structure, wherein the signal pin and the current-carrying pin frame are spaced apart, and the thickness of the signal pin is less than the thickness of the current-carrying pin frame; the Hall chip is arranged at one end of the signal pin close to the current-carrying pin frame, and is spaced apart from the current-carrying pin frame, and the Hall chip is electrically connected to the signal pin; the magnetic concentrator is arranged at one end of the current-carrying pin frame close to the signal pin, and the magnetic concentrator at least covers the Hall chip; the plastic packaging structure is arranged at the position of the magnetic concentrator to encapsulate the magnetic concentrator, the Hall chip, part of the current-carrying pin frame and part of the signal pin.

[0043] Beneficial effects: The Hall current sensor of the present invention has current-carrying pin frames and signal pins of different thicknesses that are formed by one-time cutting, and the relative position between the current-carrying pin frame and the signal pin is stable, thereby ensuring the accuracy of the relative position between the Hall chip installed at one end of the signal pin and the current-carrying pin frame, as well as the stability and accuracy of the magnetic concentrator installation, thereby improving product consistency; at the same time, the plastic packaging structure is packaged by one-time injection molding, which is simple to prepare and helps save costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0045] Figure 1 is a schematic flow chart of a method for preparing a Hall current sensor according to an embodiment of the present invention;

[0046] Figure 2 is a schematic top view of a substrate in a form of an embodiment of the present invention;

[0047] Figure 3 is a schematic side view of a substrate in one form of an embodiment of the present invention;

[0048] Figure 4 is a front view schematic diagram of an initial second substrate according to an embodiment of the present invention;

[0049] Figure 5 is a schematic diagram of an embodiment of the present invention when the initial second substrate is bent;

[0050] Figure 6 is a front view schematic diagram of another form of a substrate according to an embodiment of the present invention;

[0051] Figure 7is a schematic top view of a frame of an embodiment of the present invention;

[0052] Figure 8 is a top view schematic diagram of a current-carrying pin frame and a signal pin according to an embodiment of the present invention;

[0053] Fig. 9 is a side view schematic diagram of a magnetic concentrator according to an embodiment of the present invention;

[0054] Fig.10 is a schematic top view of a magnetic concentrator according to an embodiment of the present invention;

[0055] Fig.11 is a front view schematic diagram of a magnetic concentrator according to an embodiment of the present invention;

[0056] Fig.12 It is a side view schematic diagram of a magnetic concentrator according to an embodiment of the present invention being sleeved on a current-carrying lead frame;

[0057] Fig.13 is a top view schematic diagram of a magnetic concentrator according to an embodiment of the present invention being sleeved on a current-carrying lead frame;

[0058] Fig.14 is a top view schematic diagram of an embodiment of the present invention after setting glue dots on a current-carrying lead frame;

[0059] Fig.15 is a top view schematic diagram of an embodiment of the present invention after a magnetic concentrator is placed in a U-shaped space of a current-carrying lead frame;

[0060] Fig.16 It is a top view schematic diagram of a push magnetic concentrator according to an embodiment of the present invention to be sleeved on a current-carrying lead frame;

[0061] Fig.17 is a side view schematic diagram of the embodiment of the present invention after the area where the magnetic concentrator is located is plastic-sealed;

[0062] Fig.18 is a schematic top view of the area where the magnetic concentrator is located after plastic sealing processing according to an embodiment of the present invention;

[0063] Fig.19 is a side view schematic diagram of a current-carrying pin frame and a signal pin after being bent according to an embodiment of the present invention;

[0064] Fig. 20 It is a top view schematic diagram of the embodiment of the present invention after the current-carrying pin frame and the signal pin are bent.

[0065] Description of reference numerals:

[0066] 100. a second initial substrate;

[0067] 1. substrate; 11. first region; 12. second region;

[0068] 2. frame; 21. current-carrying pin frame; 22. signal pin; 23. connection part;

[0069] 3. Hall chip; 31. Chip body; 32. Bonding wire;

[0070] 4. magnetic concentrator; 41. opening; 42. inclined surface;

[0071] 5. Plastic sealing structure;

[0072] 6. Glue dots. DETAILED DESCRIPTION

[0073] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only some structures related to the present invention are shown in the accompanying drawings, rather than all structures. In the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention. Various structural schematic diagrams according to embodiments of the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified for the purpose of clear expression, and some details may be omitted. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships between them are only exemplary, and may be deviated due to manufacturing tolerances or technical limitations in practice, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs. In the context of the present invention, when a layer / element is referred to as being "on" another layer / element, the layer / element may be directly on the other layer / element, or there may be an intermediate layer / element between them. In addition, if one layer / element is "on" another layer / element in one orientation, then when the orientation is reversed, the layer / element may be "below" the other layer / element.

[0074] In the related art, for a large current Hall sensor that is injection molded in one step, in order to maximize the detection current and reduce the heating problem, thicker materials are usually required to make the current-carrying pin frame. However, if thicker materials are used to make the frame, the gap between the materials (the partition distance in the middle after the material is made into a frame, similar to the spacing between signal pins) will be limited due to processability (generally the gap is required to be greater than one times the thickness of the copper material), and the signal pins are not suitable for thicker materials; if thinner materials are used to make the current-carrying pin frame, the maximum current that the current-carrying pin frame can withstand will be limited, which leads to an irreconcilable contradiction between the processability and measurement range of the product. Of course, small current Hall sensors do not require thicker current-carrying pin frames, which means that there is no such problem.

[0075] In order to solve this contradiction of the large current Hall current sensor, this embodiment provides a method for preparing a Hall current sensor, referring to Figures 1 to 20 , the preparation method comprises the following steps:

[0076] S101 , preparing a substrate 1 , wherein the substrate 1 has a first region 11 and a second region 12 , and a thickness of the substrate 1 corresponding to the first region 11 is greater than a thickness of the substrate 1 corresponding to the second region 12 .

[0077] refer to Figure 2 The substrate 1 of this embodiment is made of materials of different thicknesses, and copper can be used specifically, which has excellent electrical conductivity, and a high-conductivity heat-resistant copper alloy (KFC) is preferred. Figure 2 The longitudinal direction, that is, the width direction of the substrate 1, has thick and thin regions, the thicker region is the first region 11, and the thinner region is the second region 12. The same substrate 1 has different thicknesses, which facilitates the manufacture of structures with different thickness requirements.

[0078] S102 , cutting the substrate 1 to form a frame 2 , wherein the frame 2 includes a current-carrying pin frame 21 formed in the first area 11 and a signal pin 22 formed in the second area 12 .

[0079] For example, a substrate 1 with alternating thicknesses is formed into a frame 2 with integrated thicknesses by using a punching die, such as Figure 7 The correspondingly thicker first region 11 is punched into a current-carrying lead frame 21 , and the thinner second region 12 is punched into a signal lead 22 .

[0080] S103 , a Hall chip 3 is disposed at one end of the signal pin 22 , and the Hall chip 3 is electrically connected to the signal pin 22 .

[0081] refer to Figure 8 , install the Hall chip 3 at one end of the signal pin 22 close to the current-carrying pin frame 21, realize the electrical connection between the Hall chip 3 and the current-carrying pin frame 21, and facilitate the Hall chip 3 to export the signal through the signal pin 22. The Hall chip 3 is a magnetic field sensor made according to the Hall effect, which can convert magnetic field information into electrical signals; the Hall chip 3 usually includes a magnetic field system, a Hall element and a signal processing circuit integrated in the chip body 31, and a bonding wire 32 for outputting electrical signals. The magnetic field system can convert the input signal into a magnetic field signal, the Hall element converts the magnetic field signal into an electrical signal, and the signal processing circuit converts the Hall element output signal into a signal that meets the application. It can be understood that the Hall chip 3 of this embodiment is an integrated circuit (IC) chip with a Hall effect.

[0082] S104 , disposing the magnetic concentrator 4 on the current-carrying lead frame 21 , so that the magnetic concentrator 4 covers the Hall chip 3 .

[0083] refer to Figures 9 to 13The magnetic concentrator 4 is sleeved on the current-carrying pin frame 21, so that when current passes through the current-carrying pin frame 21, a magnetic field is generated around the current-carrying pin frame 21. The magnetic concentrator 4 gathers the magnetic field, and then detects the magnitude of the magnetic field strength through the covered Hall chip 3, thereby obtaining the magnitude of the current passing through the current-carrying pin frame 21, and finally outputs it through the signal pin 22, thereby realizing the detection of the magnitude of the current passing through the current-carrying pin frame 21.

[0084] S105 , performing injection molding on the area where the magnetic concentrator 4 is located in the frame 2 to encapsulate the magnetic concentrator 4 , the Hall chip 3 , part of the current-carrying pin frame 21 and part of the signal pins 22 .

[0085] refer to Fig.17 and Fig.18 The area where the magnetic concentrator 4 is located is plastic-sealed, and the main functional parts of the Hall current sensor can be encapsulated by one injection molding, thereby achieving efficient leakage protection and ensuring the normal operation of the Hall current sensor.

[0086] The preparation method of the Hall current sensor of the present embodiment adopts a substrate 1 with different thicknesses, and forms a frame 2 including a current-carrying pin frame 21 and a signal pin 22 by cutting at one time, so as to meet the different requirements of the current-carrying pin frame 21 and the signal pin 22 for material thickness, thereby meeting the production requirements of one-time injection molding of a large current Hall sensor. Moreover, compared with the installation of a special manual jig, the one-time molding of the frame 2 can also locate the relative position of the current-carrying pin frame 21 and the signal pin 22, which helps to improve the accuracy of the relative position of the current-carrying pin frame 21 and the Hall chip 3, and improve product consistency. The Hall chip 3 does not need to be accurately installed on the current-carrying pin frame 21, that is, there is no need to customize the Hall chip 3 assembly equipment, which helps to save costs and simplify the process.

[0087] As an optional embodiment, the step S101 of preparing the substrate 1 includes:

[0088] S1011a, providing a first initial substrate, wherein the first initial substrate has a uniform thickness at all locations;

[0089] S1012a, hot rolling the first initial substrate to form a first region 11 and a second region 12, wherein the thickness of the first region 11 corresponding to the substrate 1 is less than or equal to the thickness of the first initial substrate.

[0090] That is, a first initial substrate having a thickness greater than or equal to that of the current-carrying lead frame 21 is selected, such as copper, and its good thermal ductility is utilized to obtain the first initial substrate by hot rolling. Figure 3 The thick and thin substrate 1 shown is then mechanically stamped once to form a thicker current-carrying lead frame 21 and a thinner signal lead 22 . The preparation is simple and convenient, and is conducive to mass production.

[0091] As another optional implementation, Figures 4 to 6 As shown, the step S101 of preparing the substrate 1 may also include:

[0092] S1011b, providing a second initial substrate 100;

[0093] S1012b, performing a bending process on one end of the second initial substrate 100;

[0094] S1013b, stack and fix the bent portion with the second initial substrate 100 to form a first region 11 in the stacked area, and the remaining area is the second region 12. The thickness of the substrate 1 corresponding to the second region 12 is equal to the thickness of the second initial substrate 100.

[0095] That is, a second initial substrate 100 having the same thickness as the thinner signal pin 22 is selected, and the plasticity of the copper material is utilized to bend it at one end and stack it and fix it on the original second initial substrate 100, and the stacked thickened area forms the first area 11 to form the current-carrying pin frame 21, and the area of ​​the original single-layer copper material is the second area 12 to form the signal pin 22. By using the thinner copper material of the same thickness, there is no need to perform additional process treatment on the copper material itself, and after bending and stacking, a substrate 1 of different thicknesses can be formed, and the stacked thickened part has a small internal resistance of current and a small heat generation, which helps to further reduce power consumption.

[0096] In one embodiment, reference Figure 5 Step S1012b of performing a bending process on one end of the second initial substrate 100 includes:

[0097] Performing a first bend at one end of the second initial substrate 100;

[0098] The first bent part is bent a second time, and the second bend folds the first bent part in half.

[0099] That is, the second initial substrate 100 is bent twice, and the thicker first region 11 is composed of three layers of the second initial substrate 100, wherein the two bent layers are equal in size. Figure 5 The direction indicated by the middle arrow is the direction of the force applied during the stamping and bending. Specifically, the single-layer second initial substrate 100 is a copper plate with a thickness of 0.5 mm, and after being bent twice, a substrate 1 with two thicknesses of 1.5 mm and 0.5 mm is formed.

[0100] In one embodiment, reference Figure 6In step S1013b, stacking and fixing the bent portion and the second initial substrate 100 includes: stacking and fixing the bent portion and the second initial substrate 100 together by riveting or welding, and laser welding can be used for welding to finally form a thicker first region 11 and a thinner second region 12. Figure 6 The arrow in the middle shows the direction of riveting or laser spot welding.

[0101] refer to Figures 9 to 16 In this embodiment, the magnetic concentrator 4 has an opening 41, and the current-carrying lead frame 21 is U-shaped; the above-mentioned step S104 installs the magnetic concentrator 4 on the current-carrying lead frame 21 so that the magnetic concentrator 4 covers the Hall chip 3, which can be automatically assembled by a device with dispensing, suction and longitudinal pushing functions, including the following steps:

[0102] S1041 , a glue point 6 is provided on one end of the current-carrying lead frame 21 close to the Hall chip 3 .

[0103] like Fig.14 As shown, the U-shaped current-carrying lead frame 21 includes vertical input and output terminals at both sides, and a horizontal detection terminal in the middle. In this embodiment, the detection terminal in the middle is suitable for setting a magnetic concentrator 4 to detect current, so glue is applied to the detection terminal in the middle to form a glue point 6, which is convenient for fixing the magnetic concentrator 4.

[0104] S1042 , placing the magnetic concentrator 4 in the U-shaped current-carrying lead frame 21 , with the opening 41 of the magnetic concentrator 4 facing the side where the glue point 6 is located.

[0105] like Fig.15 As shown, the magnetic concentrator 4 is placed in the blank area between the input end and the output end of the current-carrying lead frame 21 by mechanical suction, and the opening 41 of the magnetic concentrator 4 is opposite to the detection end, so as to facilitate pushing the opening 41 of the magnetic concentrator 4 relative to the detection end to avoid collision and damage.

[0106] S1043 , pushing the magnetic concentrator 4 to move from the current-carrying pin frame 21 side toward the signal pin 22 side, so as to at least place the Hall chip 3 in the opening 41 of the magnetic concentrator 4 .

[0107] like Fig.16 As shown, along the direction indicated by the arrow, the magnetic concentrator 4 is pushed into the current-carrying pin frame 21 using the longitudinal thrust structure, so that the magnetic concentrator 4 covers the detection end of the current-carrying pin frame 21 and the Hall chip 3, so that the magnetic field signal enhanced by the magnetic concentrator 4 can be fully transmitted to the Hall chip 3 and converted into an electrical signal output.

[0108] S1044, fix the magnetic concentrator 4 on the current-carrying lead frame 21 at the glue point 6.

[0109] In order to facilitate the smooth advancement of the magnetic concentrator 4, the opening 41 of the magnetic concentrator 4 is usually set to be slightly larger than the thickness of the current-carrying pin frame 21. Therefore, it is necessary to move the magnetic concentrator 4 downward to make it contact with the glue point 6, and then cure the glue point 6 by methods such as UV curing or thermal curing to enhance the stability of the magnetic concentrator 4 and the current-carrying pin frame 21. It can also ensure that the magnetic concentrator 4 has sufficient redundancy and will not touch the welding wire 32 of the Hall chip 3, thereby ensuring smooth signal output.

[0110] The magnetic concentrator 4 is accurately fixed on the current-carrying lead frame 21 by the above-mentioned automated assembly method, which is conducive to mass production, thereby improving production efficiency and reducing costs.

[0111] refer to Fig. 9 and Fig.12 In this embodiment, the height L of the opening 41 of the magnetic concentrator 4 is greater than the thickness H of the current-carrying lead frame 21 , and the difference between the height L and the thickness H is in the range of 0.1 mm to 0.2 mm.

[0112] The height dimension of the opening 41 of the magnetic concentrator 4 is close to the thickness of the thicker current-carrying lead frame 21 in the frame 2. In this embodiment, a spacing of 0.1 mm to 0.2 mm is set to facilitate the installation of the magnetic concentrator 4 without causing large shaking, thereby improving the accuracy of the installation of the magnetic concentrator 4 and improving the consistency of product performance. If the spacing is less than 0.1 mm, it is difficult for the magnetic concentrator 4 to be inserted into the current-carrying lead frame 21; if the spacing is greater than 0.2 mm, it is easy to cause the problem of loose insertion, resulting in up and down shaking.

[0113] In addition, reference Fig. 9 and Fig.10 The outer wall surface of the opening 41 of the magnetic concentrator 4 is also formed with an inclined surface 42, which facilitates the advancement and assembly of the magnetic concentrator 4 and avoids damage to other structures caused by the sharp right-angle structure.

[0114] refer to Figure 7 The frame 2 also includes a connecting portion 23 connecting the current-carrying pin frame 21 and the signal pin 22 to limit the relative position of the current-carrying pin frame 21 and the signal pin 22.

[0115] It can be known that when the current-carrying pin frame 21 and the signal pin 22 are formed by processing the frame 2 through the substrate 1, there is no need for electrical connection between the two in the final product. In this embodiment, a linear structure connecting portion 23 is set in both the first area 11 and the second area 12 to connect the current-carrying pin frame 21 and the signal pin 22, effectively avoiding relative displacement between the current-carrying pin frame 21 and the signal pin 22, thereby ensuring the accurate installation of the Hall chip 3 and the magnetic concentrator 4. After the installation is completed, the connecting portion 23 can be removed by cutting to ensure the relative isolation of the current-carrying pin frame 21 and the signal pin 22.

[0116] In one embodiment, in the step S102 of cutting the substrate 1, a plurality of current-carrying pin frames 21 are formed in the first region 11, and a plurality of corresponding signal pins 22 are formed in the second region 12; then after the step S105 of performing injection molding on the region where the magnetic concentrator 4 is located in the frame 2, the method further includes:

[0117] S106, cutting the connection portion 23 of the frame 2 to obtain a plurality of separate Hall current sensor units, each of which includes a current-carrying pin frame 21, a magnetic concentrator 4, a Hall chip 3, a signal pin 22 and a plastic packaging structure 5;

[0118] S107 , in each Hall current sensor unit, bend the end of the current-carrying pin frame 21 away from the magnetic concentrator 4 , and bend the end of the signal pin 22 away from the magnetic concentrator 4 .

[0119] Specifically, the frame 2 after injection molding is cut by a cutting molding device, that is, the connection portion 23 is cut and removed, and then the input end and the output end of the current-carrying pin frame 21 and the free end of the signal pin 22 of each Hall current sensor unit are bent, referring to Fig.19 and Fig. 20 , and obtain a single Hall current sensor product.

[0120] The present embodiment also provides a Hall current sensor, which is manufactured by the above-mentioned preparation method of the Hall current sensor, and includes: a current-carrying pin frame 21, a signal pin 22, a Hall chip 3, a magnetic concentrator 4 and a plastic packaging structure 5; the signal pin 22 is spaced apart from the current-carrying pin frame 21, and the thickness of the signal pin 22 is less than the thickness of the current-carrying pin frame 21; the Hall chip 3 is arranged at one end of the signal pin 22 close to the current-carrying pin frame 21, and is spaced apart from the current-carrying pin frame 21, and the Hall chip 3 is electrically connected to the signal pin 22; the magnetic concentrator 4 is arranged at one end of the current-carrying pin frame 21 close to the signal pin 22, and the magnetic concentrator 4 at least covers the Hall chip 3; the plastic packaging structure 5 is arranged at the position of the magnetic concentrator 4 to encapsulate the magnetic concentrator 4, the Hall chip 3, part of the current-carrying pin frame 21 and part of the signal pin 22.

[0121] The Hall current sensor of this embodiment has a current-carrying pin frame 21 and a signal pin 22 of different thicknesses that are formed by one-time cutting. The relative position between the current-carrying pin frame 21 and the signal pin 22 is stable, thereby ensuring the accuracy of the relative position between the Hall chip 3 installed at one end of the signal pin 22 and the current-carrying pin frame 21, as well as the stability and accuracy of the installation of the magnetic concentrator 4, thereby improving product consistency; at the same time, the plastic packaging structure 5 is packaged by one-time injection molding, which is simple to prepare and helps save costs.

[0122] In the above description, the technical details of the patterning and etching of each layer are not described in detail. However, those skilled in the art should understand that various technical means can be used to form layers, regions, etc. of desired shapes. In addition, in order to form the same structure, those skilled in the art can also design methods that are not completely the same as the methods described above. In addition, although the various embodiments are described above separately, this does not mean that the measures in the various embodiments cannot be used in combination to advantage.

[0123] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A method for preparing a Hall current sensor, characterized in that: include: Preparing a substrate (1), wherein the substrate (1) has a first region (11) and a second region (12), wherein the thickness of the substrate (1) corresponding to the first region (11) is greater than the thickness of the substrate (1) corresponding to the second region (12); Cutting the substrate (1) to form a frame (2), the frame (2) comprising a current-carrying pin frame (21) formed in the first area (11), and a signal pin (22) formed in the second area (12); A Hall chip (3) is arranged at one end of the signal pin (22), and the Hall chip (3) is electrically connected to the signal pin (22); Arranging a magnetic concentrator (4) on the current-carrying lead frame (21) so that the magnetic concentrator (4) covers the Hall chip (3); The region within the frame (2) where the magnetic concentrator (4) is located is subjected to injection molding to encapsulate the magnetic concentrator (4), the Hall chip (3), part of the current-carrying pin frame (21), and part of the signal pins (22).

2. The method for preparing a Hall current sensor according to claim 1, characterized in that: The method of preparing the substrate (1) comprises: Providing a first initial substrate, wherein the first initial substrate has a uniform thickness at all locations; The first initial substrate is hot-rolled to form a first region (11) and a second region (12), wherein the thickness of the first region (11) corresponding to the substrate (1) is less than or equal to the thickness of the first initial substrate.

3. The method for preparing a Hall current sensor according to claim 1, characterized in that: The method of preparing the substrate (1) comprises: Providing a second initial substrate (100); Performing a bending process on one end of the second initial substrate (100); The bent portion is stacked and fixed with the second initial substrate (100) to form a first area (11) in the stacked area, and the remaining area is a second area (12), and the thickness of the substrate (1) corresponding to the second area (12) is equal to the thickness of the second initial substrate (100).

4. The method for preparing a Hall current sensor according to claim 3, characterized in that: The bending process at one end of the second initial substrate (100) comprises: Performing a first bend at one end of the second initial substrate (100); The first bent part is bent a second time, and the second bend folds the first bent part in half.

5. The method for preparing a Hall current sensor according to claim 4, characterized in that: The stacking and fixing the bent portion and the second initial base material (100) comprises: stacking and fixing the bent portion and the second initial base material (100) together by riveting or welding.

6. The method for preparing a Hall current sensor according to claim 1, characterized in that: The magnetic concentrator (4) has an opening (41), and the current-carrying pin frame (21) is U-shaped; the step of installing the magnetic concentrator (4) on the current-carrying pin frame (21) so that the magnetic concentrator (4) covers the Hall chip (3) comprises: A glue point (6) is provided at one end of the current-carrying lead frame (21) close to the Hall chip (3); The magnetic concentrator (4) is placed in the U-shaped current-carrying lead frame (21), with the opening (41) of the magnetic concentrator (4) facing the side where the glue point (6) is located; Pushing the magnetic concentrator (4) to move from the current-carrying pin frame (21) side toward the signal pin (22) side, so as to at least place the Hall chip (3) in the opening (41) of the magnetic concentrator (4); The magnetic concentrator (4) is fixed on the current-carrying lead frame (21) at the glue point (6).

7. The method for preparing a Hall current sensor according to claim 6, characterized in that: The height L of the opening (41) of the magnetic concentrator (4) is greater than the thickness H of the current-carrying lead frame (21), and the difference between the height L and the thickness H is in the range of 0.1 mm to 0.2 mm.

8. The method for preparing a Hall current sensor according to any one of claims 1 to 7, characterized in that: The framework (2) also includes: A connecting portion (23) connecting the current-carrying pin frame (21) and the signal pin (22) to limit the relative position of the current-carrying pin frame (21) and the signal pin (22).

9. The method for preparing a Hall current sensor according to claim 8, characterized in that: In the cutting of the substrate (1), a plurality of current-carrying pin frames (21) are formed in the first region (11), and a corresponding plurality of signal pins (22) are formed in the second region (12); After the region in the frame (2) where the magnetic concentrator (4) is located is subjected to injection molding, the method further comprises: Cutting the connecting portion (23) of the frame (2) to obtain a plurality of separate Hall current sensor units, wherein any of the Hall current sensor units comprises a current-carrying pin frame (21), a magnetic concentrator (4), a Hall chip (3), a signal pin (22) and a plastic packaging structure (5); In the Hall current sensor unit, one end of the current-carrying pin frame (21) away from the magnetic concentrator (4) is bent, and one end of the signal pin (22) away from the magnetic concentrator (4) is bent.

10. A Hall current sensor, manufactured by the method for manufacturing a Hall current sensor according to any one of claims 1 to 9, characterized in that: include: a current carrying lead frame (21); A signal pin (22) is arranged at a distance from the current-carrying pin frame (21); the thickness of the signal pin (22) is smaller than the thickness of the current-carrying pin frame (21); A Hall chip (3) is arranged at one end of the signal pin (22) close to the current-carrying pin frame (21) and is spaced apart from the current-carrying pin frame (21); the Hall chip (3) is electrically connected to the signal pin (22); A magnetic concentrator (4) is arranged at one end of the current-carrying pin frame (21) close to the signal pin (22), and the magnetic concentrator (4) at least covers the Hall chip (3); A plastic packaging structure (5) is arranged at the location of the magnetic concentrator (4) to encapsulate the magnetic concentrator (4), the Hall chip (3), part of the current-carrying pin frame (21), and part of the signal pins (22).

Images