阅读说明：本技术 一种一体化芯片式电流传感器及其制造方法 (Integrated chip type current sensor and manufacturing method thereof ) 是由 朱文琴 侯晓伟 张文江 关克 马华超 吴如兆 于 2020-11-23 设计创作，主要内容包括：本申请公开了一种一体化芯片式电流传感器及其制造方法,涉及电流传感器技术领域,该一体化芯片式电流传感器包括钣金引线框导体装置与铁芯；所述钣金引线框导体装置粘接有磁感应探头,并设置有包裹所述磁感应探头的塑封体；所述铁芯呈U状并形成有U型槽,所述塑封体插接在所述铁芯的U型槽内；所述塑封体的外侧设置有包裹所述铁芯的壳体。本申请具有将霍尔ASIC芯片、铁芯和母排进行一体化注塑,极大减小传感器的重量尺寸并有效提高了抗振动和抗热冲击能力；与此同时,霍尔ASIC芯片组装用引线框架和母排一体化设置,间距精确,实现提高原边与次边的隔离电压的目的,具有简化设计难度、加工简单、适用于自动化生产以及提高批量化制造工艺水平的效果。(The application discloses an integrated chip type current sensor and a manufacturing method thereof, relating to the technical field of current sensors, wherein the integrated chip type current sensor comprises a metal plate lead frame conductor device and an iron core; the metal plate lead frame conductor device is bonded with a magnetic induction probe and is provided with a plastic package body wrapping the magnetic induction probe; the iron core is U-shaped and is provided with a U-shaped groove, and the plastic package body is inserted in the U-shaped groove of the iron core; and a shell for wrapping the iron core is arranged on the outer side of the plastic package body. The Hall ASIC chip, the iron core and the busbar are subjected to integrated injection molding, so that the weight and the size of the sensor are greatly reduced, and the vibration resistance and the thermal shock resistance are effectively improved; meanwhile, the lead frame and the busbar for assembling the Hall ASIC chip are integrally arranged, the distance is accurate, the purpose of improving the isolation voltage of the primary side and the secondary side is achieved, and the Hall ASIC chip has the effects of simplifying the design difficulty, being simple to process and being suitable for automatic production and improving the level of a batch manufacturing process.)

1. An integrated chip-type current sensor, characterized in that: comprises a sheet metal lead frame conductor device (3) and an iron core (2); the metal plate lead frame conductor device (3) is adhered with a magnetic induction probe (6) and is provided with a plastic package body (7) wrapping the magnetic induction probe (6); the iron core (2) is U-shaped and is provided with a U-shaped groove, and the plastic package body (7) is inserted into the U-shaped groove of the iron core (2); and a shell (1) wrapping the iron core (2) is arranged on the outer side of the plastic package body (7).

2. The integrated chip-type current sensor according to claim 1, wherein: the metal plate lead frame conductor device (3) comprises a busbar (4) and a lead frame (5) with a plurality of pins, a gap is formed between the busbar (4) and the lead frame (5), and the magnetic induction probe (6) is adhered to the lead frame (5); the plastic package body (7) is connected and fixed with the busbar (4) and the lead frame (5).

3. The integrated chip-type current sensor according to claim 2, wherein: the magnetic induction probe (6) is adhered to the middle part of the upper side of the lead frame (5).

4. The integrated chip-type current sensor according to claim 1, wherein: the plastic package body (7) is provided with two bilaterally symmetrical positioning ribs (71), and the corresponding end of the iron core (2) is inserted between the two symmetrical positioning ribs (71).

5. The integrated chip-type current sensor according to claim 1, wherein: the magnetic induction probe (6) is provided with an integrated Hall ASIC chip, and the Hall ASIC chip comprises a Hall element and an interface signal processing circuit which are integrated by adopting a CMOS process.

6. The integrated chip-type current sensor according to claim 5, wherein: the interface signal processing circuit is used for acquiring the output corresponding to different current values of each temperature point, operating an internal calibration program to compensate zero point, gain, temperature drift and nonlinearity of the current sensor, and storing a calibration coefficient in an EEPROM.

7. A method for manufacturing an integrated chip type current sensor is characterized by comprising the following steps:

step 1, fixing a busbar (4) and a lead frame (5) according to a preset gap, and forming a sheet metal lead frame conductor device (3);

step 2, bonding a magnetic induction probe (6) to the upper central part of a lead frame (5) of the sheet metal lead frame conductor device (3);

step 3, performing primary injection molding operation on the sheet metal lead frame conductor device (3) bonded with the magnetic induction probe (6) through a thermosetting material, and cooling the thermosetting material to form a plastic package body (7), so that the plastic package body (7) wraps the magnetic induction probe (6) while connecting and fixing the busbar (4) and the lead frame (5) to form a primary injection molding blank;

step 4, inserting the primary injection molding blank into a U-shaped groove of the U-shaped iron core (2) to enable the plastic package body (7) to be located in the middle of the iron core (2) to obtain a combined structure body;

and 5, carrying out secondary injection molding operation on the combined structural body through the thermosetting material or the thermoplastic material, and cooling the thermosetting material or the thermoplastic material to form a shell (1) wrapping the plastic package body (7) and the iron core (2) so as to obtain the finished product current sensor.

8. The method of claim 7, wherein the integrated chip-type current sensor comprises: in the step 2, the magnetic induction probe (6) is manufactured by integrating a Hall element and an interface signal processing circuit by adopting a CMOS process.

9. The method of claim 8, wherein the integrated chip-type current sensor comprises: the interface signal processing circuit is used for acquiring the output corresponding to different current values of each temperature point, operating an internal calibration program to compensate zero point, gain, temperature drift and nonlinearity of the current sensor, and storing a calibration coefficient in an EEPROM.

10. The method of claim 7, wherein the integrated chip-type current sensor comprises: in the step 3, two positioning fillets (71) which are symmetrical left and right are formed on one side of the plastic package body (7), and the two positioning fillets (71) are matched with one end of the iron core (2).

Technical Field

The application relates to the technical field of current sensors, in particular to an integrated chip type current sensor and a manufacturing method thereof.

Background

In a power grid in the field of power systems, particularly in a high-voltage direct-current transmission system, a power grid structure in hybrid operation of alternating current and direct current generates large interference on the power grid, the quality of power transmission is directly influenced, and if earth direct current is not processed and isolated, direct current magnetic biasing can be formed, and the direct current magnetic biasing can seriously influence a transformer. Therefore, it is necessary to filter out the dc component in the ac/dc hybrid case, and a current sensor for detecting the dc component in the ac current case is used as a dc detection device to detect each set of transformer.

Chinese patent with publication number CN201285410Y discloses a current sensor, which comprises a shell, an iron core arranged in the shell, and a circuit board connected with a hall element, wherein a cable connected with an internal circuit board is led out from the shell, and the current sensor is characterized in that: the casing is formed by last casing, lower casing equipment to go up and be formed with the through-hole that supplies to survey female the passing of electric current mother between casing and the lower casing, be equipped with first iron core in the last casing with the circuit board, and first iron core with circuit board looks electricity links, be equipped with the second iron core corresponding with first iron core in the lower casing.

However, each part of the current sensor needs to be separately machined, and it is difficult to achieve the requirement of high precision in installation, which affects the performance of the current sensor and the manufacturing and using cost, and needs to be improved.

Disclosure of Invention

In view of the above, a first objective of the present application is to provide an integrated chip-type current sensor to achieve the purposes of improving product performance and effectively reducing manufacturing and using costs. The specific scheme is as follows:

an integrated chip type current sensor comprises a metal plate lead frame conductor device and an iron core; the metal plate lead frame conductor device is bonded with a magnetic induction probe and is provided with a plastic package body wrapping the magnetic induction probe; the iron core is U-shaped and is provided with a U-shaped groove, and the plastic package body is inserted in the U-shaped groove of the iron core; and a shell for wrapping the iron core is arranged on the outer side of the plastic package body.

Preferably: the metal plate lead frame conductor device comprises a bus bar and a lead frame with a plurality of pins, a gap is formed between the bus bar and the lead frame, and the magnetic induction probe is adhered to the lead frame; the plastic package body is connected with and fixes the busbar and the lead frame.

Preferably: the magnetic induction probe is adhered to the middle part of the upper side of the lead frame.

Preferably: the plastic package body is provided with two bilaterally symmetrical positioning ridge bars, and the corresponding end of the iron core is inserted between the two symmetrical positioning ridge bars.

Preferably: the magnetic induction probe is provided with an integrated Hall ASIC chip, and the Hall ASIC chip comprises a Hall element and an interface signal processing circuit which are integrated by adopting a CMOS (complementary metal oxide semiconductor) process.

Preferably: the interface signal processing circuit is used for acquiring the output corresponding to different current values of each temperature point, operating an internal calibration program to compensate zero point, gain, temperature drift and nonlinearity of the current sensor, and storing a calibration coefficient in an EEPROM.

A second object of the present application is to provide a method for manufacturing an integrated chip-type current sensor, comprising the steps of:

step 1, fixing a busbar and a lead frame according to a preset gap, and forming a metal plate lead frame conductor device;

step 2, bonding the magnetic induction probe to the upper central part of the lead frame of the metal plate lead frame conductor device;

step 3, performing primary injection molding operation on the metal plate lead frame conductor device bonded with the magnetic induction probe through a thermosetting material, and cooling the thermosetting material to form a plastic package body, so that the plastic package body wraps the magnetic induction probe while connecting and fixing the busbar and the lead frame to form a primary injection molding blank;

step 4, inserting the primary injection molding blank into a U-shaped groove of a U-shaped iron core to enable the plastic package body to be located in the middle of the iron core, and obtaining a combined structural body;

and 5, performing secondary injection molding operation on the combined structural body through the thermosetting material or the thermoplastic material, and cooling the thermosetting material or the thermoplastic material to form a shell for wrapping the plastic package body and the iron core so as to obtain the finished product current sensor.

Preferably: in step 2, the magnetic induction probe is manufactured by integrating a hall element and an interface signal processing circuit by adopting a CMOS process.

Preferably: the interface signal processing circuit is used for acquiring the output corresponding to different current values of each temperature point, operating an internal calibration program to compensate zero point, gain, temperature drift and nonlinearity of the current sensor, and storing a calibration coefficient in an EEPROM.

Preferably: in step 3, two positioning fillets which are symmetrical left and right are formed on one side of the plastic package body, and the two positioning fillets are matched with one end of the iron core.

According to the above scheme, the present application provides an integrated chip-type current sensor and a manufacturing method thereof, and the integrated chip-type current sensor has the following beneficial effects: the integrated Hall ASIC chip and CMOS process are adopted, the Hall element and the rear end signal processing circuit are integrated in one chip, the output corresponding to different current values of each temperature point is acquired through debugging software, an internal calibration program is operated to compensate the zero point, the gain, the temperature drift and the nonlinearity of the sensor, and the calibration coefficient of the chip is stored in the EEPROM; the Hall ASIC chip, the iron core and the busbar are subjected to integrated injection molding, so that the weight and the size of the sensor are greatly reduced, and the vibration resistance and the thermal shock resistance are effectively improved; meanwhile, the lead frame and the busbar for assembling the Hall ASIC chip are integrally arranged, the distance is accurate, the purpose of improving the isolation voltage of the primary side and the secondary side is achieved, and the Hall ASIC chip has the effects of simplifying the design difficulty, being simple to process and being suitable for automatic production and improving the level of a batch manufacturing process.

The manufacturing method of the integrated chip type current sensor has the following beneficial effects: through the secondary injection molding process, at first encapsulate the electromagnetic induction probe to form the structure of installation magnetic core, make female arranging and lead frame mould plastics for the first time and become the shaping fixed, when avoiding the magnetic induction probe to expose, reduce the operation degree of difficulty and the cost of moulding plastics for the second time, realize promoting product property ability and effectively reduce the effect of making and use cost.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, it is obvious that the drawings in the following description are only embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a schematic structural diagram of an integrated chip-type current sensor disclosed in the present application;

FIG. 2 is a schematic diagram of a partial cross-sectional structure of an integrated chip current sensor as disclosed herein;

fig. 3 is a schematic view of a combined structure of a sheet metal lead frame conductor device and a magnetic induction probe disclosed in the present application;

FIG. 4 is a schematic diagram of the integrated chip-type current sensor with the housing removed according to the present disclosure;

fig. 5 is a schematic cross-sectional structural view of the integrated chip-type current sensor with the housing removed according to the present disclosure.

Description of reference numerals: 1. a housing; 2. an iron core; 3. a sheet metal lead frame conductor means; 4. a busbar; 5. a lead frame; 6. a magnetic induction probe; 7. molding the body; 71. and (5) positioning the fillet.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

As shown in fig. 1, 2 and 3, an integrated chip-type current sensor includes a sheet metal lead frame conductor device 3 and an iron core 2. The metal plate lead frame conductor device 3 is bonded with a magnetic induction probe 6 and is provided with a plastic package body 7 wrapping the magnetic induction probe 6. The sheet metal lead frame conductor device 3 comprises a busbar 4 and a lead frame 5 with a plurality of pins. Meanwhile, a gap is formed between the busbar 4 and the lead frame 5, and the magnetic induction probe 6 is bonded on the lead frame 5, so that the plastic package body 7 plays a role of connecting and fixing the busbar 4 and the lead frame 5, further, when the plastic package body 7 realizes the integrated molding of the magnetic induction probe 6, the lead frame 5 and the busbar 4, the size of the gap between the busbar 4 and the lead frame 5 is accurately controlled, the isolation voltage of the primary side and the secondary side is ensured, the processing and production process is effectively simplified, and the device is suitable for automatic production. Correspondingly, the magnetic induction probe 6 is protected by the plastic package body 7, so that the purpose of avoiding the influence of the exposure of the magnetic induction probe 6 in the air on the subsequent processing is achieved.

It should be mentioned that the core 2 is U-shaped and formed with a U-shaped slot. The plastic package body 7 is inserted in the U-shaped groove of the iron core 2. And a shell 1 for wrapping the iron core 2 is arranged on the outer side of the plastic package body 7. The shell 1 plays a role in protecting the iron core 2, realizes the effect of integrally molding the secondary inductive probe, the iron core 2 and the busbar 4, and effectively improves the vibration resistance and the thermal shock resistance while greatly reducing the weight and the size of the current sensor.

As shown in fig. 4 and 5, the magnetic induction probe 6 is bonded to the upper middle portion of the lead frame 5. And two positioning ridge bars 71 which are symmetrical left and right are arranged on the plastic package body 7. The corresponding one end of iron core 2 is pegged graft between two symmetrical location fillets 71 for two location fillets 71 are spacing to the installation of iron core 2 is fixed, further reduce the degree of difficulty of manufacturing.

It should be noted that the magnetic induction probe 6 is provided with an integrally integrated hall ASIC chip. The Hall ASIC chip comprises a Hall element and an interface signal processing circuit which are integrated by adopting a CMOS process. The interface signal processing circuit is used for acquiring the output corresponding to different current values of each temperature point, operating an internal calibration program to compensate the zero point, the gain, the temperature drift and the nonlinearity of the current sensor, and storing a calibration coefficient in an EEPROM.

The application also provides a manufacturing method of the integrated chip type current sensor, which comprises the following steps:

step 1, fixing a busbar 4 and a lead frame 5 according to a preset gap, and forming a sheet metal lead frame conductor device 3;

step 2, adopting a CMOS process, and integrating a Hall element and an interface signal processing circuit to manufacture a magnetic induction probe 6; and the magnetic induction probe 6 is adhered to the central part of the upper side of the lead frame 5 of the metal plate lead frame conductor device 3;

step 3, performing primary injection molding operation on the sheet metal lead frame conductor device 3 bonded with the magnetic induction probe 6 through a thermosetting material, and cooling the thermosetting material to form a plastic package body 7, so that the plastic package body 7 wraps the magnetic induction probe 6 while connecting the fixed busbar 4 and the lead frame 5 to form a primary injection molding blank;

step 4, inserting the primary injection molding blank into a U-shaped groove of the U-shaped iron core 2 to enable the plastic package body 7 to be located in the middle of the iron core 2, and obtaining a combined structure body;

and 5, performing secondary injection molding operation on the combined structure through the thermosetting material or the thermoplastic material, and cooling the thermosetting material or the thermoplastic material to form the shell 1 wrapping the plastic package body 7 and the iron core 2 to obtain the finished product current sensor.

It should be noted that the interface signal processing circuit is configured to collect outputs corresponding to different current values at each temperature point, run an internal calibration program to compensate for a zero point, a gain, a temperature drift, and nonlinearity of the current sensor, and store a calibration coefficient in the EEPROM. Meanwhile, two positioning fillets 71 which are symmetrical left and right are formed on one side of the plastic package body 7, and the two positioning fillets 71 are matched with one end of the iron core 2.

In summary, the integrated chip-type current sensor of the present application integrates the hall element and the rear-end signal processing circuit in one chip by adopting the integrated hall ASIC chip and CMOS process, collects the outputs corresponding to different current values at each temperature point by debugging software, runs an internal calibration program to compensate the zero point, gain, temperature drift and nonlinearity of the sensor, and the calibration coefficient of the chip is stored in the EEPROM; the Hall ASIC chip, the iron core 2 and the bus bar 4 are integrally injected, so that the weight and the size of the sensor are greatly reduced, and the vibration resistance and the thermal shock resistance are effectively improved; meanwhile, the lead frame 5 and the busbar 4 for assembling the Hall ASIC chip are integrally arranged, the distance is accurate, the purpose of improving the isolation voltage of the primary side and the secondary side is achieved, and the Hall ASIC chip assembly device has the effects of simplifying design difficulty, being simple to process, being suitable for automatic production and improving the level of a batch manufacturing process.

Correspondingly, according to the manufacturing method of the integrated chip type current sensor, the electromagnetic induction probe 6 is firstly packaged through a secondary injection molding process, a structure for installing the magnetic core is formed, the busbar 4 and the lead frame 5 are molded and fixed in the primary injection molding, the operation difficulty and the cost of the secondary injection molding are reduced while the exposure of the magnetic induction probe 6 is avoided, and the effects of improving the product performance and effectively reducing the manufacturing and using costs are achieved.

References in this application to "first," "second," "third," "fourth," etc., if any, are intended to distinguish between similar elements and not necessarily to describe a particular order or sequence. It will be appreciated that the data so used may be interchanged under appropriate circumstances such that the embodiments described herein may be practiced otherwise than as specifically illustrated or described herein. Furthermore, the terms "comprises" and "comprising," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, or apparatus.

It should be noted that the descriptions in this application referring to "first", "second", etc. are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present application.

The principle and the implementation of the present application are explained herein by applying specific examples, and the above description of the embodiments is only used to help understand the method and the core idea of the present application; meanwhile, for a person skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.