Lead frame of current sensor and current sensor

Abstract

The present invention provides a lead frame of a current sensor and a current sensor, the lead frame comprising: a lead frame body having a first side and a second side that are arranged oppositely, the lead frame body comprising a U-shaped current lead and a plurality of signal processing leads, the U-shaped current lead having a protrusion protruding toward the second side to form a bending portion, the bending portion forming a mounting area for supporting a chip, the two sides of the U-shaped current lead fork and extend toward the first side, each forming a fork, the fork forming a plurality of primary input lead connection terminals on the first side; the signal processing lead respectively forms a plurality of secondary signal lead connection terminals on the second side, the signal processing lead is separated from the bending portion; a ceramic isolator is arranged on one side of the bending portion and at least covers the mounting area. The present invention can improve the ability to resist common-mode magnetic field interference, and greatly improve the insulation withstand voltage isolation effect from the primary side to the secondary side, and can be applied to higher voltage occasions.

Description

Technical Field

[0001] The present invention relates to the technical field of current sensors, and in particular to a lead frame of a current sensor and the current sensor. Background Art

[0002] Current sensors can detect both DC and AC as well as transient current peaks. Therefore, they are widely used not only in traditional power electronics, computers, and automobiles, but also in defense industries such as aerospace and shipbuilding. Monolithic Hall elements are usually based on silicon materials. This allows the amplifier and signal processing circuit to be integrated together, combining the advantages of small size, high precision, good linearity, and high reliability, and has been rapidly developed in current detection applications.

[0003] When a long wire passes current, a magnetic field proportional to the current in the wire will be generated around the wire. At this time, if the Hall element is placed in the magnetic field, the Hall element will generate an output voltage proportional to the magnitude of the magnetic field, that is, it will generate an output voltage proportional to the current in the wire.

[0004] Compared with straight copper wires, U-shaped copper wires can generate much larger magnetic fields at corners. If the U-shaped copper wire can be integrated into a single IC, it will further improve the integration, reduce the volume, enhance consistency and reliability, and ultimately reduce the difficulty of application and shorten the user's development cycle. This type of chip is defined here as a single-chip current sensor chip.

[0005] The integrated copper wire is usually separated from the Hall element and the processing circuit by insulating materials to achieve better isolation effect, so that it can be used in high-voltage occasions. In safety regulations, electronic clearance and creepage distance are usually used to measure the isolation effect. Creepage distance refers to the shortest path between two conductive parts or between conductive parts and the protective interface of the equipment measured along the insulating surface. That is, under different usage conditions, the insulating material around the conductor is polarized, causing the insulating material to be charged. Electronic clearance refers to the shortest spatial distance measured between two conductive parts or between conductive parts and the protective interface of the equipment. That is, the shortest distance that can be achieved through air while ensuring the stability and safety of electrical performance. The meaning of crawling can be regarded as the shortest distance that an ant must travel from one charged body to another charged body, which is the creepage distance. The electrical clearance is the shortest distance that an ant with wings flies. UL, CSA and VDE safety standards emphasize the safety requirements of creepage distance, which is to prevent sparks between devices or between devices and ground, thereby threatening personal safety.

[0006] Electrically, the requirement for the minimum creepage distance is related to the voltage between two conductive parts, the leakage resistance index of the insulating material, and the pollution level of the environment in which the electrical appliance is located. The minimum creepage distance is limited to prevent the creepage phenomenon between two conductors through pollutants that may appear on the surface of the insulating material. Specifically, under different usage conditions, the insulating material around the conductor is polarized, causing the insulating material to become charged. The radius of this charged area (when the conductor is circular, the charged area is annular) is the creepage distance. The size of the creepage distance is directly related to the working voltage, insulating material, etc. At the same time, it should be noted that different usage environments will also have an impact, such as air pressure, pollution, etc. The creepage distance depends on the effective value of the working voltage, and the CTI (Comparative Tracking Index) value of the insulating material has a greater impact on it.

[0007] Undoubtedly, increasing the creepage distance can increase the effective value of the working voltage, and for monolithic current sensors, it can enhance the isolation performance.

[0008] The use of current sensors can bring the following benefits: reliability and long life (non-contact working mode), large measurement range (several A to tens of KA), wide detection type (DC, current, transient peak), good dynamic performance (fast response time), wide working frequency band, strong overload capacity, good phase characteristics, and wide temperature range (-40 to 150 degrees).

[0009] Therefore, the present invention provides a lead frame for a current sensor and a current sensor. Summary of the invention

[0010] In view of the problems in the prior art, the purpose of the present invention is to provide a lead frame and a current sensor for a current sensor, which can improve the ability to resist common-mode magnetic field interference and greatly improve the insulation withstand voltage isolation effect from the primary side to the secondary side, and can be applied to higher voltage occasions.

[0011] An embodiment of the present invention provides a lead frame of a current sensor, the lead frame comprising

[0012] A lead frame body, the lead frame body having a first side and a second side that are arranged opposite to each other, the lead frame body comprising a U-shaped current lead and a plurality of signal processing leads, the U-shaped current lead having a protrusion protruding toward the second side to form at least one bent portion, the bent portion forming a mounting area for supporting a chip, two sides of the U-shaped current lead bifurcating and extending toward the first side to each form a bifurcated portion, the bifurcated portion forming a plurality of primary input lead connection terminals on the first side; the signal processing lead respectively forms a plurality of secondary signal lead connection terminals on the second side, and the signal processing lead is separated from the bent portion; and

[0013] A ceramic isolator is disposed on one side of the bent portion and at least covers the installation area.

[0014] Preferably, the middle portion of the U-shaped current lead has a protrusion protruding toward the second side direction to form the bent portion.

[0015] Preferably, at least one waist-tightening notch is respectively provided on both sides where the curved portion and the bifurcated portion meet.

[0016] Preferably, the waisted notch extends toward the central axis of the U-shaped current lead and extends into the installation area.

[0017] Preferably, the U-shaped current lead and the plurality of signal processing leads are integrally hollowed out from the lead frame.

[0018] Preferably, the ceramic separator comprises at least one ceramic sheet.

[0019] Preferably, the lead frame further includes a third side and a fourth side that are relatively arranged, and at least one of the third side and the fourth side is provided with an adjacent frame connecting end. Before the lead frame is separated from the adjacent lead frame, each lead frame is connected to the adjacent lead frame through the adjacent frame connecting end. After the lead frame is separated from the adjacent lead frame, the adjacent frame connecting end is suspended.

[0020] An embodiment of the present invention also provides a current sensor, which includes the above-mentioned lead frame, and also includes a current sensor chip. The current sensor chip is arranged on the side of the ceramic isolation member away from the bending portion. The side of the current sensor chip away from the ceramic isolation member is provided with a plurality of second wiring parts, and the second wiring parts are electrically connected to part of the signal processing leads through wires.

[0021] Preferably, a first projection pattern of the ceramic isolator on the U-shaped current lead includes a second projection pattern of the current sensor chip on the U-shaped current lead, and the ceramic isolator isolates the current sensor chip from the U-shaped current lead.

[0022] Preferably, the signal processing lead comprises:

[0023] a plurality of first leads, each of the first leads being provided with a third connection portion at an end portion facing the first side; and

[0024] A plurality of second leads, wherein the second leads are provided with a first connection portion at the end facing the first side, the first connection portion is electrically connected to the second connection portion via a wire, and the first leads and the second leads are arranged at intervals.

[0025] Preferably, the second wiring portions are respectively arranged along the edge portions on both sides of the protrusion, and the second wiring portions are respectively arranged linearly along a reference straight line, the reference straight line is parallel to the central axis of the U-shaped current lead, and at least one waisted notch is respectively provided on both sides where the bending portion and the fork portion merge, and the waisted notch extends toward the central axis of the U-shaped current lead to reach or exceed the reference straight line corresponding to the side where the waisted notch is located.

[0026] Preferably, the primary input lead connection terminal includes a current positive input terminal and a current negative output terminal, and the two ends of the wire are respectively connected to the current positive input terminal and the current negative output terminal; the secondary signal lead connection terminal includes a reference ground voltage terminal, a filter terminal, an output voltage terminal and a chip power input terminal.

[0027] The lead frame of the current sensor and the current sensor provided by the present invention have the following advantages:

[0028] The present invention realizes a single-chip Hall current sensor chip, improves integration, reduces application difficulty, and shortens customer development cycle; and, for the first time in the industry, ceramic sheets are used as insulating isolation sheet materials, the insulation withstand voltage is optimized, and the insulation withstand voltage isolation effect from the primary side to the secondary side is greatly improved, which can be applied to higher voltage occasions; for the first time in China, the insulation withstand voltage from the primary side to the secondary side of a single chip reaches more than 4800V. The present invention also reduces the on-resistance of the current copper wire, thereby increasing the current detection range; utilizes a new packaging frame design, further improving the ability to resist common-mode magnetic field interference; and enables the chip to be used in high magnetic field interference environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Other features, objectives and advantages of the present invention will become more apparent from a reading of the detailed description of non-limiting embodiments made with reference to the following accompanying drawings.

[0030] Figure 1 Schematic diagram of the structure of a lead frame of a current sensor according to an embodiment of the present invention.

[0031] Figure 2 FIG. 1 is a side view of a bent portion of several current sensors according to an embodiment of the present invention.

[0032] Figure 3 It is a schematic diagram of the connection method between lead frames of several current sensors in one embodiment of the present invention. DETAILED DESCRIPTION

[0033] The following describes the implementation methods of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in the present application. The present application can also be implemented or applied through other different specific implementation methods, and the details in the present application can also be modified or changed in various ways according to different viewpoints and application systems without departing from the spirit of the present application. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0034] The following is a detailed description of the embodiments of the present application with reference to the accompanying drawings so that those skilled in the art can easily implement the present application. The present application can be embodied in a variety of different forms and is not limited to the embodiments described herein.

[0035] In the representations of the present application, the representations with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics represented in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. Moreover, the represented specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples represented in the present application and the features of the different embodiments or examples, unless they contradict each other.

[0036] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the representation of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0037] In order to clearly describe the present application, components irrelevant to the description are omitted, and the same reference symbols are given to the same or similar components throughout the specification.

[0038] Throughout the specification, when a device is said to be "connected" to another device, this includes not only the case of "direct connection" but also the case of "indirect connection" by placing other elements therebetween. In addition, when a device is said to "include" a certain component, unless otherwise stated, it does not exclude other components, but means that other components may be included.

[0039] When a device is said to be "on" another device, it may be directly on the other device, but there may also be other devices between it. In contrast, when a device is said to be "directly" on another device, there are no other devices between it.

[0040] Although the terms first, second, etc. are used to represent various elements in some examples, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, the first interface and the second interface, etc. are represented. Moreover, as used in this article, the singular forms "one", "one" and "the" are intended to also include plural forms, unless there is an opposite indication in the context. It should be further understood that the terms "comprising" and "including" indicate the existence of features, steps, operations, elements, components, projects, kinds, and / or groups, but do not exclude the existence, occurrence or addition of one or more other features, steps, operations, elements, components, projects, kinds, and / or groups. The terms "or" and "and / or" used herein are interpreted as inclusive, or mean any one or any combination. Therefore, "A, B or C" or "A, B and / or C" means "any of the following: A; B; C; A and B; A and C; B and C; A, B and C". Only when the combination of elements, functions, steps or operations is inherently mutually exclusive in some way, will there be an exception to this definition.

[0041] The technical terms used herein are only used to refer to specific embodiments and are not intended to limit the present application. The singular form used herein also includes the plural form unless the sentence clearly indicates the contrary meaning. The meaning of "including" used in the specification is to specify specific characteristics, regions, integers, steps, operations, elements and / or components, and does not exclude the existence or addition of other characteristics, regions, integers, steps, operations, elements and / or components.

[0042] Although not defined differently, all terms, including technical and scientific terms used herein, have the same meaning as those generally understood by those skilled in the art to which this application belongs. Terms defined in commonly used dictionaries are additionally interpreted as having meanings consistent with the relevant technical literature and the contents of the current disclosure, and unless defined, shall not be overly interpreted as ideal or very formal meanings.

[0043] The technical problems to be solved by the present invention include:

[0044] (1) In motors or other automotive and industrial applications, external common-mode magnetic field interference can cause noise and affect detection accuracy.

[0045] (2) According to international regulations, current detection in 220V and 380 or higher voltage 650V appliances requires a higher insulation withstand voltage from the primary side to the secondary side of the chip

[0046] (3) Due to the trend towards high integration, the industry requires a single-chip detection solution with a high current of more than 20A.

[0047] In order to solve the technical problems in the prior art, the present invention provides a lead frame for a current sensor, the lead frame comprising: a lead frame body and a ceramic isolator. The lead frame body has a first side and a second side that are arranged opposite to each other, the lead frame body comprises a U-shaped current lead and a plurality of signal processing leads, the middle portion of the U-shaped current lead has a protrusion protruding toward the second side to form at least one bending portion, the bending portion forms a mounting area for supporting the chip, the two sides of the U-shaped current lead fork and extend toward the first side, each forming a fork, the fork forms a plurality of primary input lead connection terminals on the first side; the signal processing leads respectively form a plurality of secondary signal lead connection terminals on the second side, and the signal processing leads are separated from the bending portion. The ceramic isolator is arranged on one side of the bending portion and at least covers the mounting area.

[0048] In a preferred embodiment, in the above-mentioned device and apparatus, the middle portion of the U-shaped current lead has a protrusion protruding toward the second side direction to form a bent portion, but the present invention is not limited thereto.

[0049] In a preferred embodiment, at least one waist-constricting notch is respectively provided on both sides where the curved portion and the bifurcated portion meet, but the present invention is not limited thereto.

[0050] In a preferred embodiment, the waisted notch extends toward the center axis of the U-shaped current lead and extends into the installation area, but the present invention is not limited thereto.

[0051] In a preferred embodiment, the U-shaped current lead and the plurality of signal processing leads are integrally hollowed out from a lead frame, but the present invention is not limited thereto.

[0052] In a preferred embodiment, the ceramic separator includes at least one ceramic sheet, but is not limited thereto.

[0053] In a preferred embodiment, the lead frame further includes a third side and a fourth side that are relatively arranged, and at least one of the third side and the fourth side is provided with an adjacent frame connection end. Before the lead frame is separated from the adjacent lead frame, each lead frame is connected to the adjacent lead frame through the adjacent frame connection end, and after the lead frame is separated from the adjacent lead frame, the adjacent frame connection end is suspended, but this is not limited to this.

[0054] An embodiment of the present invention also provides a current sensor, which includes the above-mentioned lead frame. The current sensor also includes a current sensor chip. The current sensor chip is arranged on the side of the ceramic isolation component away from the bending portion. The side of the current sensor chip away from the ceramic isolation component is provided with a plurality of second wiring parts. The second wiring parts are electrically connected to some signal processing leads through wires.

[0055] In a preferred embodiment, a first projection pattern of the ceramic isolator on the U-shaped current lead includes a second projection pattern of the current sensor chip on the U-shaped current lead, and the ceramic isolator isolates the current sensor chip and the U-shaped current lead.

[0056] In a preferred embodiment, the signal processing lead comprises:

[0057] A plurality of first leads, each of the first leads being provided with a third connection portion at an end portion facing the first side; and

[0058] A plurality of second leads are provided with a first connection portion at the end of the second lead facing the first side edge, the first connection portion is electrically connected to the second connection portion through a wire, and the first lead and the second lead are arranged at intervals.

[0059] In a preferred embodiment, the second wiring portions are respectively arranged along the edge portions on both sides of the protrusion, and the second wiring portions are respectively arranged linearly along a reference straight line, the reference straight line is parallel to the central axis of the U-shaped current lead, and at least one waisted notch is respectively provided on both sides where the bending portion and the fork portion merge, and the waisted notch extends toward the central axis of the U-shaped current lead to reach or exceed the reference straight line corresponding to the side where the waisted notch is located.

[0060] In a preferred embodiment, the primary input lead connection terminal includes a current positive input terminal and a current negative output terminal, and the two ends of the wire are respectively connected to the current positive input terminal and the current negative output terminal; the secondary signal lead connection terminal includes a reference ground voltage terminal, a filter terminal, an output voltage terminal and a chip power input terminal.

[0061] When the current sensor is in use, the current being measured is connected to the primary input lead connection terminal, and the current is input into the wire. The current sensor chip is set close to the wire, that is, it is set in a magnetic field around the wire that is proportional to the current in the wire. The chip will generate an output voltage that is proportional to the magnitude of the magnetic field, that is, it will generate an output voltage that is proportional to the current in the wire. The output voltage is output from the secondary signal lead connection terminal. The output voltage accurately reflects the change in the current value of the primary wire.

[0062] The present invention not only improves the ability to resist common-mode magnetic field interference by arranging the primary input lead connection terminal and the secondary signal lead connection terminal on two opposite sides of the lead frame, but also greatly improves the insulation withstand voltage isolation effect from the primary side to the secondary side, and can be applied to higher voltage occasions. In addition, the present invention also utilizes a new packaging frame design to further improve the ability to resist common-mode magnetic field interference, and realizes a single-chip Hall current sensor chip by integrating current copper wires; widens the width of the current copper wires, so that the chip current detection capability can reach more than 100A; and for the first time in the industry, ceramic sheets 3 are used as insulating isolation sheet materials, which greatly improves the insulation withstand voltage from the primary side to the secondary side, reaching more than 4800V.

[0063] Figure 1 Schematic diagram of the structure of a lead frame of a current sensor according to an embodiment of the present invention. Figure 2 FIG. 1 is a side view of a bent portion of several current sensors in one embodiment of the present invention. Figure 1 and 2As shown, an embodiment of the present invention further provides a current sensor, the current sensor includes a lead frame and a current sensor chip 40, the lead frame includes: a lead frame body and a ceramic sheet 30. The lead frame body has a first side and a second side that are arranged opposite to each other, the lead frame body includes a U-shaped current lead 20 and a plurality of signal processing leads, the middle portion of the U-shaped current lead 20 has a protrusion protruding toward the second side to form at least one bending portion 25, the bending portion 25 forms a mounting area for supporting the chip, the two sides of the U-shaped current lead 20 fork and extend toward the first side, each forming a fork 27, the fork 27 forms a plurality of primary input lead connection terminals on the first side, and the fork 27 forks on the first side to form a plurality of primary input lead connection terminals 1, 2, 3, 4, 5, 6, 7, 8 arranged in sequence. The signal processing leads are formed into a plurality of secondary signal lead connection terminals 9, 10, 11, 12, 13, 14, 15, 16 arranged in sequence on the second side, and the signal processing leads are separated from the bending portion 25. The ceramic sheet 30 is arranged on one side of the bending portion 25 and at least covers the mounting area. The current sensor chip 40 is arranged on the side of the ceramic sheet 30 away from the bending portion 25, and a plurality of second wiring portions 24 are provided on the side of the current sensor chip 40 away from the ceramic sheet 30, and the second wiring portions 24 are electrically connected to part of the signal processing leads through the wires 21. The primary input lead connection terminals 1, 2, 3, 4, 5, 6, 7, 8 and the secondary signal lead connection terminals 9, 10, 11, 12, 13, 14, 15, 16 are respectively connected to the PAD of the current sensor chip and the frame through binding wires. In this embodiment, the first wiring part 22 corresponding to the secondary signal lead connection terminals 10, 12, 13, 15 is electrically connected to the second wiring part 24 through the wire 21, and the third wiring part 23 corresponding to the secondary signal lead connection terminals 9, 11, 14, 16 is suspended. The chip and the lead frame are encapsulated to form a new SOW16 package. The current sensor chip 40, the ceramic sheet 30, and the bending part 25 of the U-shaped current lead 20 form a sandwich structure. The ceramic sheet 30 is located between the current sensor chip 40 and the bending part 25. The super strong insulation properties of the ceramic sheet 30 are used to physically isolate the current sensor chip 40 and the bending part 25. The first projection pattern of the ceramic sheet 30 on the U-shaped current lead 20 includes the second projection pattern of the current sensor chip 40 on the U-shaped current lead 20. The ceramic sheet 30 fully isolates the current sensor chip 40 and the U-shaped current lead 20. The edge portion of the ceramic sheet 30 that extends beyond the current sensor chip 40 effectively prevents creepage. Due to the presence of the ceramic sheet 30, the ultra-high voltage of the U-shaped current lead 20 will not affect the operating voltage of the chip.

[0064] In this embodiment, at least one waisted notch 26 is provided on both sides where the bend 25 and the fork 27 meet, and the waisted notch 26 extends toward the central axis of the U-shaped current lead 20 and extends into the installation area. The structure of the waisted notch 26 can enhance the anti-interference ability of the current sensor. In addition, the second wiring portions 24 are arranged in two parallel rows along the edge portions provided on both sides of the protrusion, and the plurality of second wiring portions 24 in each row are arranged linearly along a reference straight line L, and the reference straight line L is parallel to the central axis of the U-shaped current lead 20. At least one waisted notch 26 is provided on both sides where the bend 25 and the fork 27 meet, and the waisted notch 26 extends toward the central axis of the U-shaped current lead 20 to reach or exceed the reference straight line L corresponding to the side where the waisted notch 26 is located. This structure can further enhance the anti-interference ability of the current sensor, but is not limited thereto.

[0065] In this embodiment, the lead frame provides mechanical support for the sensor chip on the one hand, and provides a signal transmission path between the sensor chip and the external circuit on the other hand. The U-shaped current conductor in the lead frame will also participate in the formation of a closed-loop current path, providing a closed-loop current path for the external current that needs to be detected. The Hall sensor on the sensor chip is located inside the U-shaped current path, forming a specific positional relationship to facilitate the calculation of the detected current value. The lead frame can be formed using a single piece of metal by existing methods such as stamping and etching (integrated hollow molding).

[0066] The lead frame also includes a third side and a fourth side that are relatively arranged, and at least one of the third side and the fourth side is provided with adjacent frame connection ends 17, 18. Before the lead frame is separated from the adjacent lead frame, each lead frame is connected to the adjacent lead frame through the adjacent frame connection ends 17, 18. After the lead frame is separated from the adjacent lead frame, the adjacent frame connection ends 17, 18 are suspended, but this is not limited to.

[0067] The primary input lead connection terminal includes a current positive input terminal and a current negative output terminal, and the two ends of the wire 21 are respectively connected to the current positive input terminal and the current negative output terminal; the secondary signal lead connection terminal includes a reference ground voltage terminal, a filter terminal, an output voltage terminal and a chip power input terminal. Among the primary input lead connection terminals, lead connection terminals 1, 2, 3, and 4 are current positive inflow terminals Ip+, lead connection terminals 5, 6, 7, and 8 are current negative outflow terminals Ip-, lead connection terminal 15 is a reference ground voltage terminal, lead connection terminal 13 is a power reference terminal Vref, lead connection terminal 12 is an output voltage terminal VOUT, and lead connection terminal 10 is a power input terminal VCC. Lead connection terminals 1 to 16 are not limited to the functions mentioned in the examples, and can also be other combinations or other functions.

[0068] When the current sensor is in use, the current to be measured flows into the lead connection terminals 1, 2, 3, 4 (Ip+) of the primary input lead connection terminal and flows out from the lead connection terminals 5, 6, 7, 8 (Ip-), that is, the current sensor chip 40 is connected to the secondary pin of the frame through the wire 21 in a magnetic field that is proportional to the current in the U-shaped current lead 20, and the current sensor chip 40 will generate an output voltage that is proportional to the magnitude of the magnetic field, that is, it will generate an output voltage that is proportional to the current in the U-shaped current lead 20, and the output voltage is output from the secondary signal lead connection terminal. Therefore, the final output voltage can accurately and real-timely reflect the change in the current value of the U-shaped current lead 20.

[0069] In order to mass produce the lead frame, two connection terminals 17 and 18 are added to connect two adjacent lead frame units and provide support. When the sensor chip is flipped on the lead frame, an insulating material is used to isolate the U-shaped current conductor from the signal processing lead on the other side. From the single lead frame unit that is finally cut, it can be seen that the connection terminals 17 and 18 will float, and the creepage distance between the U-shaped current conductor on one side and the signal processing lead depends only on the width of the package (the distance from pin 8 to pin 9), maximizing the insulation isolation effect.

[0070] The width of the U-shaped copper wire will also affect its on-resistance. Increasing the width of the copper wire can reduce the on-resistance, and under the same heat loss condition, the absolute value of the detectable current can be increased, that is, the current detection range is increased.

[0071] Figure 3 FIG. 1 is a schematic diagram of a connection method between lead frames of several current sensors in one embodiment of the present invention. Figure 3 As shown, in the actual production process, multiple current sensors are manufactured simultaneously through a lead frame motherboard. In this embodiment, the third side of the lead frame is provided with a first adjacent frame connection terminal 17, and the fourth side is provided with a second adjacent frame connection terminal 18. The adjacent frame connection terminal can also provide support for the lead frame before cutting. Each lead frame is cut according to the cutting frame 4, and an independent single lead frame can be obtained. When the current sensor chip is flipped on the lead frame, an insulating material is used to isolate the U-shaped current lead 4 from the signal processing lead on the other side. It can be seen from the lead frame finally cut that the first adjacent frame connection terminal 17 and the second adjacent frame connection terminal 18 are suspended, which will not affect the creepage distance of the current sensor. The creepage distance between the U-shaped current lead and the signal processing lead depends only on the width of the package, maximizing the insulation isolation effect.

[0072] The lead frame of the current sensor and the current sensor provided by the present invention have the following advantages:

[0073] The present invention increases the creepage distance between the primary input lead connection terminal and the secondary signal lead connection terminal to the maximum width of the lead frame, maximizes the creepage distance of the current sensor, and improves the isolation effect; through the reasonable arrangement of the lead frame, the width of the primary wire is widened, the on-resistance of the wire is reduced, thereby reducing the heat loss of the chip and widening the current measurement range; by adopting a U-shaped wire, a larger magnetic field can be generated at the corner of the wire, the integration of the sensor is improved, and the overall volume of the sensor is reduced.

[0074] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A current sensor, characterized in that: include: A lead frame body, the lead frame body having a first side and a second side that are arranged opposite to each other, the lead frame body comprising a U-shaped current lead and a plurality of signal processing leads, the middle portion of the U-shaped current lead having a protrusion protruding toward the second side to form at least one bent portion, the bent portion forming a mounting area for supporting a chip, both sides of the U-shaped current lead bifurcating and extending toward the first side to form a bifurcated portion respectively, the bifurcated portion forming a plurality of primary input lead connection terminals on the first side; the signal processing leads respectively forming a plurality of secondary signal lead connection terminals on the second side, the signal processing leads being separated from the bent portion; a ceramic spacer, the ceramic spacer being disposed on one side of the bent portion and at least covering the mounting area, and the outer edge of the bent portion protruding beyond the edge of the ceramic spacer; as well as A current sensor chip, wherein the current sensor chip is arranged on a side of the ceramic isolation component away from the bending portion, and a plurality of second wiring portions are provided on the side of the current sensor chip away from the ceramic isolation component, wherein the second wiring portions are electrically connected to part of the signal processing leads through wires, and the second wiring portions are respectively arranged on the edge portions on both sides of the protrusion, and at least one waisted notch is respectively provided on both sides where the bending portion and the fork portion meet.

2. The current sensor according to claim 1, characterized in that: The first projection pattern of the ceramic isolator on the U-shaped current lead includes the second projection pattern of the current sensor chip on the U-shaped current lead, and the ceramic isolator isolates the current sensor chip from the U-shaped current lead.

3. The current sensor according to claim 1, characterized in that: The signal processing lead comprises: a plurality of first leads, each of the first leads being provided with a third connection portion at an end portion facing the first side; and A plurality of second leads, wherein the second leads are provided with a first connection portion at the end facing the first side, the first connection portion is electrically connected to the second connection portion via a wire, and the first leads and the second leads are arranged at intervals.

4. The current sensor according to claim 1, characterized in that: The second wiring portions are respectively arranged at the edge portions on both sides of the protrusion, and the second wiring portions are respectively arranged linearly along a reference straight line, the reference straight line is parallel to the central axis of the U-shaped current lead, and the waisted notch extends toward the central axis of the U-shaped current lead to reach or exceed the reference straight line corresponding to the side where the waisted notch is located.

5. The current sensor according to claim 3, characterized in that: The primary input lead connection end includes a current positive input end and a current negative output end, and the two ends of the wire are respectively connected to the first wiring part and the second wiring part; the secondary signal lead connection end includes a reference ground voltage end, a filter end, an output voltage end and a chip power input end.

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