WO2026066469A1 - Hall current sensor and preparation method therefor - Google Patents

Abstract

A Hall current sensor and a preparation method therefor, which relate to the technical field of sensors. The method comprises: preparing a substrate (1), wherein the substrate (1) has a first region (11) and a second region (12), 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), wherein the frame (2) comprises a current-carrying pin frame (21) formed in the first region (11) and a signal pin (22) formed in the second region (12); providing, at one end of the signal pin (22), a Hall chip (3) that is electrically connected to the signal pin (22); providing a magnetic concentrator (4) on the current-carrying pin frame (21), such that the magnetic concentrator (4) covers the Hall chip (3); and performing injection molding processing on the region of the magnetic concentrator (4) in the frame (2), so as to encapsulate the magnetic concentrator (4), the Hall chip (3), a portion of the current-carrying pin frame (21) and a portion of the signal pin (22). The substrate (1) having different thicknesses is used, and the frame (2) comprising the current-carrying pin frame (21) and the signal pin (22) is formed in a single cutting operation, thereby meeting the production requirements of one-shot injection molding of high-current Hall sensors, improving the accuracy of the relative position between the current-carrying pin frame (21) and the Hall chip (3), and saving on the costs.

Description

Hall current sensor and its fabrication method

Cross-references to related applications

This application claims priority to Chinese Patent Application No. 2024113587898, filed on September 27, 2024, entitled "Hall Current Sensor and Method for Fabrication Thereof", the entire contents of which are incorporated herein by reference.

Technical Field

This application relates to the field of sensor technology, specifically to a Hall current sensor and its fabrication method.

Background Technology

Currently, integrated Hall current sensors on the market include small current sensors and large current sensors. Among them, large current sensors are more widely used. Their working principle is as follows: when current flows through the current-carrying pin frame, a magnetic field is generated around it. The magnetic concentrator set on the current-carrying pin frame concentrates the magnetic field. Finally, the Hall chip embedded in the middle of the magnetic concentrator detects the magnitude of the magnetic field strength. Then, the signal pin outputs a signal to achieve the purpose of detecting the magnitude of the current in the current-carrying pin frame.

The manufacturing method of high current sensors is usually as follows: First, the current-carrying pin frame is processed, then the magnetic concentrator is manually or automatically fitted in, then the packaged Hall chip and signal pins are assembled and installed in the magnetic concentrator, and finally the current-carrying pin frame, magnetic concentrator and Hall chip are wrapped together.

However, in this manufacturing process, the first injection molding is performed when assembling the Hall chip and signal pins, and the second injection molding is performed when covering the current-carrying pin frame, magnetic concentrator, and Hall chip. That is, there are two injection molding processes in the production process, which makes the manufacturing cycle long, the process steps cumbersome, and requires the investment of two sets of injection molds, resulting in high mold costs. In addition, during the process of installing the Hall chip and signal pins into the magnetic concentrator, the relative position of the current-carrying pin frame and the Hall chip is prone to large errors, causing the Hall sensing element inside the Hall chip to deviate from the position of the current-carrying pin frame, thus affecting the product performance.

Application content

In view of this, this application provides a Hall current sensor and its fabrication method to solve the problem that existing high-current Hall sensors have two injection molding processes and the relative positions of the current-carrying pin frame and the Hall chip are prone to deviation, which in turn affects production efficiency and product performance.

In a first aspect, this application provides a method for fabricating a Hall current sensor, comprising:

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

A frame is formed by cutting a substrate, the frame including a current-carrying pin frame formed in a first region and signal pins formed in a second region;

A Hall chip is placed at one end of the signal pin, and the Hall chip is electrically connected to the signal pin.

Place the magnetic concentrator on the current-carrying pin frame so that the magnetic concentrator covers the Hall chip;

The area containing the magnetic concentrator within the frame is injection molded to encapsulate the magnetic concentrator, Hall effect chip, part of the current-carrying pin frame, and part of the signal pins.

Beneficial effects: The method for fabricating the Hall current sensor of this application uses substrates with different thicknesses and forms a frame including the current-carrying pin frame and the signal pin in one step by cutting and molding. This satisfies the different material thickness requirements of the current-carrying pin frame and the signal pin, thereby meeting the production requirements of high-current Hall sensors by one-step injection molding. Moreover, compared with the installation of specially made manual jigs, the one-step molding of the frame can also position the relative positions of the current-carrying pin frame and the signal pin, which helps to improve the accuracy of the relative positions of the current-carrying pin frame and the Hall chip, improve product consistency, and the Hall chip does not need to be precisely installed onto 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.

In one alternative embodiment, the preparation of the substrate includes:

A first initial substrate is provided, wherein the thickness of the first initial substrate is uniform throughout;

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.

Beneficial effects: By selecting a first initial substrate with a thickness greater than or equal to the thickness of the current-carrying pin frame, such as copper with good thermal ductility, the first initial substrate is hot-rolled to obtain a substrate with alternating thick and thin layers. Then, a thicker current-carrying pin frame and a thinner signal pin can be formed in one step by mechanical stamping. The preparation is simple and convenient, which is conducive to mass production.

In one alternative embodiment, the preparation of the substrate includes:

Provide a second initial substrate;

One end of the second initial substrate is bent.

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

Beneficial effects: By selecting a second initial substrate with the same thickness as the thinner signal pins, and utilizing the plasticity of copper, one end is bent and stacked onto the original second initial substrate. The thickened stacked area forms the first region to shape the current-carrying pin frame, while the original single-layer copper area forms the second region to shape the signal pins. Using thinner copper of the same thickness eliminates the need for additional processing of the copper itself; bending and stacking create substrates of varying thicknesses. Furthermore, the thickened stacked portion has lower current resistance and less heat generation, further contributing to reduced power consumption.

In one alternative embodiment, bending one end of the second initial substrate includes:

The first bend is performed at one end of the second initial substrate;

The first bend is then folded a second time, and the second bend folds the first bend in half.

Beneficial effects: The second initial substrate is bent twice. The thicker first region consists of three layers of the second initial substrate, of which the two bent layers are of equal size. The thinner second region consists of a single layer of the second initial substrate. The two bending processes form a substrate with two different thicknesses. The process is simple and easy to operate.

In one alternative embodiment, stacking and fixing the bent portion to the second initial substrate includes: stacking and fixing the bent portion to the second initial substrate together by riveting or welding.

Beneficial effects: Laser welding can be used to form stable substrate structures with different thicknesses through multi-point fixing.

In one alternative implementation, the magnetic concentrator has an opening, and the current-carrying pin frame is U-shaped; mounting the magnetic concentrator on the current-carrying pin frame such that the magnetic concentrator covers the Hall chip includes:

A glue dot is placed at one end of the current-carrying pin frame near the Hall chip;

Place the magnetic concentrator inside the U-shaped current-carrying pin frame, with the opening of the magnetic concentrator facing the side where the glue dot is located.

The magnetic concentrator is moved from the current-carrying pin frame side toward the signal pin side to at least place the Hall chip within the opening of the magnetic concentrator;

Secure the magnetic concentrator to the current-carrying pin frame at the glue dot.

Beneficial effects: Using equipment with dispensing, suction and vertical advance functions, the magnetic concentrator is precisely pushed and fixed onto the current-carrying pin frame through automated assembly. The installation is stable and fast, which helps to improve production efficiency and reduce costs in mass production.

In one alternative implementation, the height L of the opening of the magnetic concentrator is greater than the thickness H of the current-carrying pin frame, and the difference between the height L and the thickness H ranges from 0.1 mm to 0.2 mm.

Beneficial effects: Setting the opening height of the magnetic concentrator to have a gap of 0.1mm to 0.2mm between it and the thickness of the current-carrying pin frame facilitates the installation of the magnetic concentrator without causing excessive shaking. It also ensures that the magnetic concentrator has sufficient redundancy during installation and will not touch the bonding wires of the Hall chip, thereby improving the accuracy of the magnetic concentrator installation and thus enhancing the consistency of product performance.

In one alternative implementation, the frame further includes a connection portion that connects the current-carrying pin frame and the signal pin to limit the relative position of the current-carrying pin frame and the signal pin.

Beneficial effects: The connection part is set in the first and second regions to connect the current-carrying pin frame and the signal pin, which effectively avoids relative displacement between the current-carrying pin frame and the signal pin, thereby ensuring the accurate installation of the Hall chip and the magnetic concentrator.

In one alternative embodiment, in the cutting substrate, a plurality of current-carrying pin frames are formed in a first region, and a corresponding plurality of signal pins are formed in a second region;

After injection molding the area where the magnetic concentrator is located within the frame, the process also includes:

The connecting part of the frame is cut to obtain multiple individual Hall current sensor units. Each Hall current sensor unit includes a current-carrying pin frame, a magnetic concentrator, a Hall chip, a signal pin, and a plastic package structure.

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

Secondly, this application also provides a Hall current sensor, fabricated using the aforementioned method, comprising: a current-carrying pin frame, a signal pin, a Hall chip, a magnetic concentrator, and a plastic encapsulation structure. The signal pin is spaced apart from the current-carrying pin frame, and the thickness of the signal pin is less than the thickness of the current-carrying pin frame. The Hall chip is disposed at one end of the signal pin near the current-carrying pin frame and spaced apart from the current-carrying pin frame, and is electrically connected to the signal pin. The magnetic concentrator is disposed at one end of the current-carrying pin frame near the signal pin and at least covers the Hall chip. The plastic encapsulation structure is disposed at the location 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.

Beneficial effects: The Hall current sensor of this application has current-carrying pin frames and signal pins of different thicknesses that are cut and formed in one step. The relative position between the current-carrying pin frames and signal pins 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, and improving product consistency. At the same time, the plastic encapsulation structure completes the packaging in one injection molding, which is simple to manufacture and helps to save costs.

Attached Figure Description

To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

Figure 1 is a schematic flowchart of the fabrication method of the Hall current sensor according to an embodiment of this application;

Figure 2 is a top view of a substrate according to an embodiment of this application;

Figure 3 is a front view schematic diagram of the first initial substrate according to an embodiment of this application;

Figure 4 is a side view of a substrate according to an embodiment of this application;

Figure 5 is a front view schematic diagram of the second initial substrate according to an embodiment of this application;

Figure 6 is a schematic diagram of bending the second initial substrate according to an embodiment of this application;

Figure 7 is a front view schematic diagram of a substrate in another form according to an embodiment of this application;

Figure 8 is a top view of the framework of an embodiment of this application;

Figure 9 is a top view of the current-carrying pin frame and signal pins according to an embodiment of this application;

Figure 10 is a side view of a magnetic concentrator according to an embodiment of this application;

Figure 11 is a top view of a magnetic concentrator according to an embodiment of this application;

Figure 12 is a front view schematic diagram of the magnetic concentrator according to an embodiment of this application;

Figure 13 is a side view of a magnetic concentrator sleeved on a current-carrying pin frame according to an embodiment of this application.

Figure 14 is a top view of a magnetic concentrator sleeved on a current-carrying pin frame according to an embodiment of this application;

Figure 15 is a top view of an embodiment of this application after adhesive dots are set on the current-carrying pin frame;

Figure 16 is a top view of an embodiment of this application showing the magnetic concentrator placed in the U-shaped space of the current-carrying pin frame;

Figure 17 is a top view of an embodiment of this application, showing the magnetic concentrator being pushed onto the current-carrying pin frame;

Figure 18 is a side view of the area where the magnetic concentrator is located after plastic sealing according to an embodiment of this application.

Figure 19 is a top view of the area where the magnetic concentrator is located after plastic sealing according to an embodiment of this application;

Figure 20 is a side view of an embodiment of this application after bending the current-carrying pin frame and the signal pin;

Figure 21 is a top view of an embodiment of this application after the current-carrying pin frame and signal pin are bent.

Explanation of reference numerals in the attached figures:
10 - First initial substrate; 100 - Second initial substrate;
1. Substrate; 11. First region; 12. Second region;
2. Frame; 21. Current-carrying pin frame; 22. Signal pin; 23. Connector;
3. Hall effect chip; 31. Chip body; 32. Bonding wire;
4. Magnetic concentrator; 41. Opening; 42. Inclined surface;
5. Plastic-encapsulated structure;
6. Adhesive dots.

Detailed Implementation

The present application will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the present application and not intended to limit it. It should also be noted that, for ease of description, only the parts relevant to the present application are shown in the drawings, not all structures. In the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily obscuring the concepts of the present application. The accompanying drawings show various structural schematic diagrams according to embodiments of the present application. These drawings are not drawn to scale, and some details are enlarged for clarity and may be omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions/layers with different shapes, sizes, and relative positions as needed. In the context of this application, 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. Additionally, if one layer/component is "above" another layer/component in one orientation, then when the orientation is reversed, that layer/component can be "below" that other layer/component.

In related technologies, for high-current Hall effect sensors manufactured in a single injection molding process, a thicker material is typically needed for the current-carrying lead frame to maximize the detection current while minimizing heat generation. However, using a thicker frame limits the manufacturability of the gaps between materials (the spacing between the material segments in the frame, similar to the spacing between signal pins) (generally requiring a gap greater than twice the thickness of the copper material), and thicker materials are also unsuitable for the signal pins. Conversely, using a thinner material for the current-carrying lead frame limits the maximum current it can withstand. This creates an irreconcilable conflict between product manufacturability and measurement range. Of course, low-current Hall effect sensors do not require a thicker current-carrying lead frame, thus avoiding this problem.

To address this contradiction in high-current Hall current sensors, this embodiment provides a method for fabricating a Hall current sensor. Referring to Figures 1 to 21, the fabrication method includes the following steps:

S101, Prepare substrate 1. Substrate 1 has a first region 11 and a second region 12. The thickness of substrate 1 corresponding to the first region 11 is greater than the thickness of substrate 1 corresponding to the second region 12.

Referring to Figure 2, the substrate 1 in this embodiment is a material of varying thickness, specifically copper, which has excellent electrical conductivity. A high-conductivity heat-resistant copper alloy (KFC) can be selected. In the longitudinal direction of Figure 2, that is, in the width direction of the substrate 1, there are regions with alternating thicknesses. 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.

S102, the substrate 1 is cut to form a frame 2, the frame 2 including a current-carrying pin frame 21 formed in a first region 11 and a signal pin 22 formed in a second region 12.

For example, a thick and thin substrate 1 is formed into a frame 2 with integrated thickness using a punching die, as shown in FIG8. The thicker first region 11 is punched into a current-carrying pin frame 21, and the thinner second region 12 is punched into a signal pin 22.

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

Referring to Figure 9, a Hall chip 3 is mounted at the end of signal pin 22 near the current-carrying pin frame 21, establishing an electrical connection between the Hall chip 3 and the current-carrying pin frame 21, facilitating the output of signals from the Hall chip 3 through signal pin 22. The Hall chip 3 is a magnetic field sensor based on the Hall effect, capable of converting magnetic field information into electrical signals. The Hall chip 3 typically includes a magnetic field system, a Hall element, and a signal processing circuit integrated into the chip body 31, as well as bonding wires 32 configured to output electrical signals. The magnetic field system converts 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's output signal into a signal suitable for the application. In this embodiment, the Hall chip 3 is an integrated circuit (IC) chip exhibiting the Hall effect.

S104, the magnetic concentrator 4 is placed on the current-carrying pin frame 21, so that the magnetic concentrator 4 covers the Hall chip 3.

Referring to Figures 10 to 14, a magnetic concentrator 4 is fitted onto the current-carrying pin frame 21 so that when current flows through the current-carrying pin frame 21, a magnetic field is generated around the current-carrying pin frame 21. The magnetic concentrator 4 concentrates this magnetic field, and then the magnitude of the magnetic field strength is detected by the covered Hall chip 3, thereby obtaining the magnitude of the current passing through the current-carrying pin frame 21. Finally, the signal is output through the signal pin 22 to realize the detection of the magnitude of the current passing through the current-carrying pin frame 21.

S105, injection molding is performed on the area where the magnetic concentrator 4 is located within the frame 2 to encapsulate the magnetic concentrator 4, Hall chip 3, part of the current-carrying pin frame 21, and part of the signal pin 22.

Referring to Figures 18 and 19, the area where the magnetic concentrator 4 is located is encapsulated. The main functional parts of the Hall current sensor can be encapsulated in one injection molding process, achieving efficient leakage protection and ensuring the normal operation of the Hall current sensor.

The method for fabricating the Hall current sensor in this embodiment uses a substrate 1 with different thicknesses. A frame 2, including a current-carrying pin frame 21 and a signal pin 22, is formed by cutting and molding in one step. This satisfies the different material thickness requirements of the current-carrying pin frame 21 and the signal pin 22, thereby meeting the production requirements of a high-current Hall sensor through one-step injection molding. Moreover, compared with the installation of a specially made manual jig, the one-step molding of the frame 2 can also position the relative positions of the current-carrying pin frame 21 and the signal pin 22, which helps to improve the accuracy of the relative positions 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 precisely installed onto the current-carrying pin frame 21, that is, no additional customized Hall chip 3 assembly equipment is required, which helps to save costs and simplify the process.

As an optional implementation, step S101 of preparing the substrate 1 includes:

S1011a, a first initial substrate 10 is provided, the first initial substrate 10 having a uniform thickness throughout;

S1012a, the first initial substrate 10 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 10.

That is, a first initial substrate 10 with a thickness greater than or equal to the thickness of the current-carrying pin frame 21, such as copper, is selected. Taking advantage of its good thermal ductility, the first initial substrate 10 is hot-rolled to obtain a substrate 1 with alternating thick and thin layers as shown in Figure 3. Then, it is mechanically stamped once to form a thicker current-carrying pin frame 21 and a thinner signal pin 22. The preparation is simple and convenient, which is conducive to mass production.

As an optional implementation, as shown in Figures 5 to 7, step S101 of preparing the substrate 1 may also include:

S1011b, providing a second initial substrate 100;

S1012b, one end of the second initial substrate 100 is bent;

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

That is, a second initial substrate 100 with the same thickness as the thinner signal pin 22 is selected. Taking advantage of the plasticity of copper, it is bent at one end and stacked and fixed on the original second initial substrate 100. The stacked and 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 a thinner copper material of the same thickness, no additional processing is required on the copper material itself. After bending and stacking, a substrate 1 of different thicknesses can be formed. Moreover, the stacked and thickened part has low current resistance and low heat generation, which helps to further reduce power consumption.

In one embodiment, referring to FIG6, step S1012b of bending one end of the second initial substrate 100 includes:

The first bend is performed at one end of the second initial substrate 100;

The first bend is then folded a second time, and the second bend folds the first bend in half.

This means that the second initial substrate 100 is bent twice. The thicker first region 11 consists of three layers of the second initial substrate 100, of which the two bent layers are of equal size. The arrows in Figure 6 indicate the direction of the force applied during the stamping and bending. Specifically, the single-layer second initial substrate 100 is made of copper plate with a thickness of 0.5 mm. After two bends, substrates 1 with two thicknesses of 1.5 mm and 0.5 mm are formed.

In one embodiment, referring to FIG7, the step S1013b of stacking and fixing the bent portion with the second initial substrate 100 includes: stacking and fixing the bent portion with the second initial substrate 100 together by riveting or welding. The welding can be laser welding to ultimately form a thicker first region 11 and a thinner second region 12. The arrows in FIG7 indicate the direction of riveting or laser spot welding.

Referring to Figures 10 to 17, the magnetic concentrator 4 in this embodiment has an opening 41, and the current-carrying pin frame 21 is U-shaped. Step S104 above, which mounts the magnetic concentrator 4 onto the current-carrying pin frame 21, allows the magnetic concentrator 4 to cover the Hall chip 3. This assembly can be automated using equipment with dispensing, pick-up, and longitudinal advance functions, including the following steps:

S1041, glue dots 6 are set at one end of the current-carrying pin frame 21 near the Hall chip 3.

As shown in Figure 15, the U-shaped current-carrying pin frame 21 includes vertical input and output terminals on both sides, and a horizontal detection terminal in the middle. In this embodiment, the detection terminal in the middle is suitable for setting the magnetic concentrator 4 to detect the current. Therefore, adhesive is applied to the middle detection terminal to form adhesive dots 6, which facilitates the fixation of the magnetic concentrator 4.

S1042, place the magnetic concentrator 4 inside the U-shaped current-carrying pin frame 21, with the opening 41 of the magnetic concentrator 4 facing the side where the glue point 6 is located.

As shown in Figure 16, the magnetic concentrator 4 is placed in the blank area between the input and output ends of the current-carrying pin frame 21 by mechanical suction, and the opening 41 of the magnetic concentrator 4 is aligned with the detection end, so as to push the opening 41 of the magnetic concentrator 4 into the detection end and avoid bumping and damage.

S1043, the magnetic concentrator 4 is moved from the side of the current-carrying pin frame 21 toward the side of the signal pin 22 so as to place the Hall chip 3 at least within the opening 41 of the magnetic concentrator 4.

As shown in Figure 17, the magnetic concentrator 4 is pushed into the current-carrying pin frame 21 by the longitudinal thrust structure along the direction indicated by the arrow, 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.

S1044, fix the magnetic concentrator 4 to the current-carrying pin frame 21 at glue point 6.

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, the magnetic concentrator 4 needs to be moved downwards to make contact with the adhesive dot 6. Then, the adhesive dot 6 is cured by means such as ultraviolet curing or thermal curing to enhance the stability of the magnetic concentrator 4 and the current-carrying pin frame 21. This also ensures that the magnetic concentrator 4 has sufficient redundancy and will not touch the bonding wire 32 of the Hall chip 3, thus ensuring smooth signal output.

The above-mentioned automated assembly method precisely fixes the magnetic concentrator 4 onto the current-carrying pin frame 21, which helps to mass production, thereby improving production efficiency and reducing costs.

Referring to Figures 10 and 13, 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 pin frame 21, and the difference between the height L and the thickness H ranges from 0.1 mm to 0.2 mm.

The height of the opening 41 of the magnetic concentrator 4 is close to the thickness of the thicker current-carrying pin frame 21 in the frame 2. In this embodiment, a spacing of 0.1mm to 0.2mm is provided to facilitate the installation of the magnetic concentrator 4 without causing significant shaking, thereby improving the installation accuracy of the magnetic concentrator 4 and enhancing product performance consistency. If the spacing is less than 0.1mm, the magnetic concentrator 4 will be difficult to fit into the current-carrying pin frame 21; if the spacing is greater than 0.2mm, it is easy to cause a problem of not being able to fit tightly, resulting in up-and-down shaking.

In addition, referring to Figures 10 and 11, the outer wall of the opening 41 of the magnetic concentrator 4 is also formed with a bevel 42, which facilitates the advancement and assembly of the magnetic concentrator 4, while avoiding damage to other structures by sharp right-angle structures.

Referring to Figure 8, the frame 2 also includes a connecting portion 23 that connects 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.

It is understood that when the current-carrying pin frame 21 and signal pin 22 are formed by processing the frame 2 through the substrate 1, no electrical connection is required between the two in the final product. In this embodiment, a linear connecting portion 23 is provided in both the first region 11 and the second region 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 installation, the connecting portion 23 can be removed by cutting to ensure the relative isolation between the current-carrying pin frame 21 and the signal pin 22.

In one embodiment, in 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 step S105 of injection molding the region where the magnetic concentrator 4 is located within the frame 2, the method further includes:

S106, the connecting part 23 of the frame 2 is cut to obtain multiple individual Hall current sensor units. Each Hall current sensor unit includes a current-carrying pin frame 21, a magnetic concentrator 4, a Hall chip 3, a signal pin 22, and a plastic encapsulation structure 5.

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

Specifically, the injection-molded frame 2 is then cut using a rib-cutting and forming equipment, that is, cut and removed from the connection part 23. Then, the input and output ends of the current-carrying pin frame 21 and the free end of the signal pin 22 in each Hall current sensor unit are bent. Referring to Figures 20 and 21, a single Hall current sensor product is obtained.

This embodiment also provides a Hall current sensor, which is fabricated using the above-described method for preparing a Hall current sensor. The sensor includes: a current-carrying pin frame 21, a signal pin 22, a Hall chip 3, a magnetic concentrator 4, and a plastic encapsulation 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 disposed at one end of the signal pin 22 near the current-carrying pin frame 21 and spaced apart from the current-carrying pin frame 21; the Hall chip 3 is electrically connected to the signal pin 22. The magnetic concentrator 4 is disposed at one end of the current-carrying pin frame 21 near the signal pin 22, and the magnetic concentrator 4 at least covers the Hall chip 3. The plastic encapsulation structure 5 is disposed 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 pin 22.

In this embodiment, the Hall current sensor has current-carrying pin frame 21 and signal pin 22 of different thicknesses, which are formed by cutting in one step. 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, and improving product consistency. At the same time, the plastic encapsulation structure 5 completes the encapsulation in one injection molding, which is simple to manufacture and helps to save costs.

The above description does not provide detailed explanations of the technical aspects of each layer's patterning, etching, etc. However, those skilled in the art should understand that various technical means can be used to form layers and regions of the desired shape. Furthermore, to form the same structure, those skilled in the art can also design methods that are not entirely identical to those described above. Additionally, although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination.

Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and all such modifications and variations fall within the scope defined by the appended claims.

Claims (10)

A method for fabricating a Hall current sensor, characterized by comprising: Prepare a substrate (1) having 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); The substrate (1) is cut to form a frame (2), the frame (2) including a current-carrying pin frame (21) formed in the first region (11) and a signal pin (22) formed in the second region (12); A Hall chip (3) is provided at one end of the signal pin (22), and the Hall chip (3) is electrically connected to the signal pin (22); The magnetic concentrator (4) is placed on the current-carrying pin frame (21) so that the magnetic concentrator (4) covers the Hall chip (3); The area containing the magnetic concentrator (4) within the frame (2) is injection molded 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). The method for fabricating a Hall current sensor according to claim 1, characterized in that the substrate (1) comprises: A first initial substrate (10) is provided, wherein the thickness of the first initial substrate (10) is uniform throughout; The first initial substrate (10) 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 (10). The method for fabricating a Hall current sensor according to claim 1, characterized in that the substrate (1) comprises: Provide a second initial substrate (100); One end of the second initial substrate (100) is bent; The bent portion is stacked and fixed with the second initial substrate (100) to form a first region (11) in the stacked area, and the remaining area is a second region (12). The thickness of the second region (12) corresponding to the substrate (1) is equal to the thickness of the second initial substrate (100). The method for fabricating a Hall current sensor according to claim 3, characterized in that the bending process at one end of the second initial substrate (100) includes: A first bend is made at one end of the second initial substrate (100); The first bend is then folded a second time, and the second bend folds the first bend in half. The method for preparing a Hall current sensor according to claim 4 is characterized in that the step of stacking and fixing the bent portion with the second initial substrate (100) includes: stacking and fixing the bent portion with the second initial substrate (100) together by riveting or welding. The method for fabricating a Hall current sensor according to claim 1 is characterized in that the magnetic concentrator (4) has an opening (41), and the current-carrying pin frame (21) is U-shaped; the step of mounting the magnetic concentrator (4) on the current-carrying pin frame (21) so that the magnetic concentrator (4) covers the Hall chip (3) includes: A glue dot (6) is provided at one end of the current-carrying pin frame (21) near the Hall chip (3); The magnetic concentrator (4) is placed inside the U-shaped current-carrying pin frame (21), with the opening (41) of the magnetic concentrator (4) facing the side where the glue dot (6) is located. The magnetic concentrator (4) is moved from the side of the current-carrying pin frame (21) toward the side of the signal pin (22) to at least place the Hall chip (3) within the opening (41) of the magnetic concentrator (4); The magnetic concentrator (4) is fixed to the current-carrying pin frame (21) at the glue point (6). According to the method for preparing the Hall current sensor according to claim 6, the height L of the opening (41) of the magnetic concentrator (4) is greater than the thickness H of the current-carrying pin 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. The method for fabricating a Hall current sensor according to any one of claims 1-7, characterized in that the frame (2) further comprises: A connection portion (23) connects 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). The method for fabricating a Hall current sensor according to claim 8 is 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 plurality of corresponding signal pins (22) are formed in the second region (12); After injection molding the area where the magnetic concentrator (4) is located within the frame (2), the process further includes: Cut the connecting part (23) of the frame (2) to obtain multiple individual Hall current sensor units. Each Hall current sensor unit includes a current-carrying pin frame (21), a magnetic concentrator (4), a Hall chip (3), a signal pin (22), and a plastic encapsulation structure (5). In the Hall current sensor unit, the end of the current-carrying pin frame (21) away from the magnetic concentrator (4) is bent, and the end of the signal pin (22) away from the magnetic concentrator (4) is bent. A Hall current sensor, fabricated using the method for preparing a Hall current sensor according to any one of claims 1-9, is characterized by comprising: Current-carrying pin frame (21); The signal pin (22) is spaced apart from the current-carrying pin frame (21); the thickness of the signal pin (22) is less than the thickness of the current-carrying pin frame (21); A Hall chip (3) is disposed at one end of the signal pin (22) near the current-carrying pin frame (21) and 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 disposed at one end of the current-carrying pin frame (21) near the signal pin (22), and the magnetic concentrator (4) at least covers the Hall chip (3); A plastic encapsulation structure (5) is disposed 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).