CN114361334A - Closed-loop current detection module structure and packaging method - Google Patents

Abstract

The present invention provides a closed-loop current detection module structure and a packaging method. The closed-loop current detection module packaging method includes: pre-packaging, providing a primary frame, an injection-molded connector, a secondary frame, and a detection chip, and assembling and fixing to form an injection-molded integrated frame ; The injection-molded connecting body is used to fix the primary frame and the secondary frame; the detection chip is arranged on the secondary frame; the feedback coil is assembled, a magnetic core and a feedback coil are provided, and the injection-molded integral frame is It is assembled and fixed with the magnetic core and the feedback coil; the detection chip is fixed in the air between the magnetic cores of the magnetic core. Forming and packaging, providing a packaging shell, packaging the magnetic core, the feedback coil, and the detection chip, bending the primary frame and the secondary frame, and completing the forming of shear ribs. The present invention improves the stability of the current detection module by adopting the encapsulation structure of the injection-molded integrated frame, reduces the volume of the product, and has the advantages of easy installation.

Description

A closed-loop current detection module structure and packaging method

technical field

The invention relates to the field of semiconductors, and in particular, to a closed-loop current detection module structure and a packaging method.

Background technique

In the prior art, the current domestic and foreign current detection module manufacturers all mechanically assemble the detection probe, the magnetic core, the feedback coil, the primary side and its shell into products for the closed-loop current detection module, and the mechanical structure stability of each part is poor. , easy to damage, and difficult to further reduce the size. How to improve the stability of the current detection module and reduce the size of the product has become an urgent problem to be solved.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to improve the stability of the current detection module and reduce the product volume, and to provide a closed-loop current detection module structure and a packaging method.

In order to solve the above problems, the present invention provides a closed-loop current detection module packaging method, including: pre-package, providing a primary frame, an injection-molded connector, a secondary frame, and a detection chip, and assembling and fixing them into an injection-molded integrated frame; The connecting body is used to fix the primary frame and the secondary frame and form electrical isolation; the detection chip is arranged on the secondary frame; the feedback coil is assembled, a magnetic core and a feedback coil are provided, and the injection-molded integral frame is It is assembled and fixed with the magnetic core and the feedback coil; the detection chip is fixed in the air between the magnetic cores of the magnetic core. Forming and packaging, providing a packaging shell, packaging the magnetic core, the feedback coil, and the detection chip, bending the primary frame and the secondary frame, and completing the forming of shear ribs.

The present invention also provides a closed-loop current detection module structure, comprising: an injection-molded integrated frame, including a primary frame, a secondary frame, a detection chip and an injection-molded connector, the primary frame and the secondary frame are vertically arranged, and the detection The chip is arranged on the secondary side frame; the injection molding connection body fixes the primary side frame and the secondary side frame, and electrically isolates the primary side frame and the secondary side frame; the feedback coil is wound around the feedback coil on the coil bobbin; a magnetic core, the magnetic core is bent and fixed on the feedback coil bobbin to form a magnetic core air, and the detection chip is arranged between the magnetic core air; a packaging shell, which encapsulates the magnetic core, The feedback coil and the detection chip expose the partially bent primary frame and secondary frame.

The present invention improves the stability of the current detection module by adopting the encapsulation structure of the injection-molded integrated frame, reduces the volume of the product, and has the advantages of easy installation.

Description of drawings

FIG. 1 shows a schematic diagram of the steps of the encapsulation method of the closed-loop current detection module.

FIG. 2A is a schematic bottom view of the injection-molded one-piece frame.

FIG. 2B is a schematic top view of the injection-molded one-piece frame.

FIG. 3 is a schematic top view of the assembly of the feedback coil.

FIG. 4 is a schematic diagram of the magnetic core and the feedback coil.

FIG. 5 is a schematic top view of the feedback coil assembly at another angle.

Figure 6 shows a perspective view of the molded package.

FIG. 7 is a schematic diagram of the molding package.

FIG. 8 is a schematic diagram of a plurality of the injection-molded connectors.

Detailed ways

The specific embodiments of the structure and packaging method of the closed-loop current detection module provided by the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a schematic diagram of the steps of the encapsulation method of the closed-loop current detection module. The closed-loop current detection module packaging method provided by the present invention includes: step S101, pre-package, providing a primary frame, an injection-molded connector, a secondary frame, and a detection chip, and assembling and fixing to form an injection-molded integrated frame; the injection-molded connector is used for fixing The primary side frame and the secondary side frame are electrically isolated; the detection chip is arranged on the secondary side frame; step S102, the feedback coil is assembled, a magnetic core and a feedback coil are provided, and the injection-molded one-piece frame is connected to the secondary side frame. The magnetic core and the feedback coil are assembled and fixed; the detection chip is fixed between the magnetic cores of the magnetic core; Step S103 , molding and packaging, providing a packaging shell, packaging the magnetic core, the feedback coil, and the detection chip, and bending the Describe the primary frame and the secondary frame, and complete the shear rib forming.

In a specific embodiment of the present invention, the detection chip includes a Hall sensor. In other specific embodiments of the present invention, the Hall sensor can also be replaced with an anisotropic magnetoresistance sensor, giant magnetoresistance Magnetic sensors such as resistance sensors and tunnel magnetoresistance sensors.

FIG. 2A is a schematic bottom view of the injection-molded one-piece frame; FIG. 2B is a top-view schematic diagram of the injection-molded one-piece frame. Step S101, referring to FIG. 2A and FIG. 2B, pre-package, provide a primary frame 201, an injection-molded connector 211, a secondary frame 221, and a detection chip (not shown), and assemble and fix to form an injection-molded integrated frame 20; The injection-molded connector 211 is used to fix the primary frame 201 and the secondary frame 221 and form electrical isolation; the detection chip (not shown) is disposed on the secondary frame 221 .

In a specific embodiment of the present invention, the material of the injection-molded connecting body 211 is epoxy resin; the high temperature glue is used for fixing the detection chip, and in this specific embodiment, the high temperature glue is epoxy resin.

The primary frame 201 and the secondary frame 221 are respectively provided with positioning holes 202 and 222 for positioning the primary frame 201 and the secondary frame 221 in the pre-packaging step, which will be removed by shearing ribs after the packaging is completed. In this specific embodiment, the positioning holes 202 and 222 are respectively arranged at the ends of the primary frame 201 and the secondary frame 221. After the packaging is completed, the positioning holes that are still exposed are removed by shearing ribs together with the ends. , so as to form pins on the primary frame 201 and the secondary frame 221 .

The injection-molded connector 211 has an injection-molded slot 214 for fixing the magnetic core and the injection-molded integral frame 211 subsequently. In this specific embodiment, the injection molding slot 214 is disposed on the side of the injection molding connecting body 211 away from the secondary frame.

The primary frame 201 is provided with a first fixing structure 203, the injection-molded connecting body 211 is provided with a second fixing structure (not shown), and the first fixing structure 203 cooperates with the second fixing structure to fix the The primary frame 201 and the injection-molded connector 211 . In this specific embodiment, the first fixing structure 203 is a fishbone-shaped fixing structure, and the second fixing structure includes a fishbone-shaped groove. The fishbone-shaped fixing structure cooperates with the fishbone-shaped groove to fix the primary frame 201 on the injection connecting body 211. Compared with being fixed at one point, the two sharp corners of the fishbone-shaped structure protrude. It can better prevent the primary frame 211 from vibrating.

The secondary side frame 221 is provided with bosses 223 and 224 for fixing the secondary side frame 221 and the injection-molded connecting body 211 . The width of the bosses 223 and 224 is larger than the width of the pins of the secondary frame 221 exposed to the injection-molded connector 211 , so the secondary frame 221 can be fixed on the injection-molded connector 211 to prevent the shear ribs from forming. Afterwards, the pins of the secondary frame 221 are dropped.

In a specific embodiment of the present invention, the prepackage includes a chip wire bonding package, and the feedback coil and the detection chip circuit are connected by arranging two wire bonding pads. The wire bonding pad (not shown) is set at the position 212 ; the detection chip (not shown) is set at the position 213 .

The injection-molded integrated frame 20 formed by assembling and fixing the primary frame 201 , the injection-molded connector 211 , the secondary frame 221 , and the detection chip has a stable structure and small volume, which creates a foundation for the miniaturization of the current detection module.

In a specific embodiment of the present invention, before the step of forming the integral frame by injection molding, a surface treatment step is further included, and the surface treatment step may be electroplating. The surface treatment can improve the electrical conductivity of the primary side frame 201 and the secondary side frame 221, and play a role of anti-corrosion in subsequent use.

In a specific embodiment of the present invention, as shown in FIG. 2B , the injection-molded connecting body 211 further includes a concave portion 216 , and the thickness of the concave portion 216 is smaller than that of the edge of the injection-molded connecting body 211 , which is used for connecting with subsequent In cooperation with the feedback coil bobbin, the feedback coil bobbin is fixed in the recessed portion 216 . The thickness of the thinnest part of the injection molding connector 211 is set to 0.5mm-1.0mm, and the horizontal distance between the primary frame 201 and the secondary frame 221 is greater than 0.5 mm, so that the primary frame 201 and the secondary frame 221 are separated The side frame 221 is electrically isolated. In this specific embodiment, the withstand voltage between the primary side frame and the secondary side frame is greater than 600V.

In a specific embodiment of the present invention, a plurality of the injection-molded integral frames 20 may be formed simultaneously in the pre-packaging step. Referring to FIG. 8, a plurality of the primary frames 201 are provided, and the primary frames 201 are kept end-to-end without being cut off. According to the above steps, the primary frames 201, the injection-molded connectors 211, and the secondary frames are assembled together. The frame 221 and the detection chip (not shown) are assembled and fixed to form an injection-molded integrated frame 20 in which a plurality of primary frames 201 are connected. The pre-packaging of multiple injection-molded integrated frames 20 can be completed at the same time, which is beneficial to improve production efficiency and further reduce the difficulty of positioning and assembling. The injection-molded integrated frame 20 connected with the above-mentioned multiple primary frames 201 can be separated in the step of shearing rib forming after completing the subsequent assembly of the feedback coil, molding and packaging, and become an independent package body.

FIG. 3 is a schematic top view of the assembly of the feedback coil. Step S102, referring to FIG. 3, the feedback coil is assembled, a magnetic core 301 and a feedback coil 302 are provided, and the injection-molded one-piece frame 20 is assembled and fixed with the magnetic core 301 and the feedback coil 302; a detection chip (not shown) ) is fixed between the magnetic core air 305 of the magnetic core 301 . In a specific embodiment of the present invention, high temperature glue is used to fix the magnetic core 301 , and in this specific embodiment, the high temperature glue is epoxy resin. In this specific embodiment, the magnetic core 301 is made of soft magnetic material, and the opening of the magnetic core is the magnetic core air 305 . The injection-molded connector 211 has an injection-molded slot 214, the magnetic core 301 has a magnetic-core slot 306, and the injection-molded slot 214 cooperates with the magnetic core slot 306 for positioning and fixing the magnetic core 301 and the injection-molded one. Frame 20.

In order to clearly show the assembly method of the magnetic core and the feedback coil, referring to the schematic diagram of the magnetic core and the feedback coil shown in FIG. 4 , the feedback coil 302 is wound on the feedback coil bobbin 303 . 303 has a magnetic core channel 304 ; the magnetic core 301 passes through the magnetic core channel 304 , is fixed on the feedback coil bobbin 303 and is bent to form a magnetic core air 305 . The larger the breath of the magnetic core, the weaker the anti-interference ability of the current detection device, but the larger the range; conversely, the smaller the breath of the magnetic core, the stronger the anti-interference ability of the current detection device, but the smaller the range. Therefore, an appropriate predetermined value should be selected for the magnetic core 305 . In this specific embodiment, a bending step of the magnetic core is included: a U-shaped magnetic core is provided, and after the U-shaped magnetic core is fixed on the feedback coil bobbin 303 through the magnetic core channel 304, the U-shaped magnetic core is fixed on the feedback coil bobbin 303. The two ends of the magnetic core are folded in half toward the middle, so that the end faces of the upper and lower ends face each other to form a narrow opening, and the opening is the magnetic core air 305 .

The feedback coil 302 includes a first feedback coil 302A and a second feedback coil 302B, the feedback coil bobbin 303 includes a first feedback coil bobbin 303A and a second feedback coil bobbin 303B, and the first feedback coil 302A and the second feedback coil The coil 302B is wound on the first feedback bobbin 303A and the second feedback bobbin 303B in series, and the magnetic core 301 passes through the magnetic core channels 304A and 304B of the first feedback bobbin 303A and the second feedback bobbin 303B in sequence. The first feedback coil 302A and the second feedback coil 302B are formed by winding a wire in series, that is, a circuit relationship in series; the first feedback coil 302A and the second feedback coil 302B have the same number of turns; the feedback coil 302 The more total turns of the coil of the feedback coil 302, the larger the range of the current detection device. On the contrary, the less the total number of turns of the feedback coil 302, the smaller the range of the current detection device.

FIG. 5 is a schematic top view of the feedback coil assembly from another angle, so as to more clearly show the fixed position of the feedback coil assembly magnetic core. The magnetic core slot 306 intersects with the injection slot 214 to fix the position of the magnetic core 301 . By assembling the feedback coil, the injection-molded integral frame 20 is further assembled and fixed with the magnetic core 301 and the feedback coil 302, so as to prepare a more stable current detection module.

Figure 6 shows a perspective view of the molded package. Step S103 , as shown in FIG. 6 , form packaging, provide a packaging shell 601 , encapsulate the magnetic core 301 , the feedback coil 302 , and the detection chip 306 , bend the primary frame 201 and the secondary frame 221 , and Finished rib forming. The detection chip 306 includes a stacked Hall sensor probe and a closed-loop chip to adjust the feedback coil current and detect the magnetic field strength. In other specific embodiments of the present invention, the Hall sensor can also be replaced with a magnetic sensor such as an anisotropic magnetoresistance sensor, a giant magnetoresistance sensor, and a tunnel magnetoresistance sensor.

The openings exposing the detection chip 306 shown in FIG. 6 are only used to illustrate the internal structure, and are not actual openings. In this specific embodiment, the shearing rib forming means removing the positioning holes 202 , 222 and the frame where the positioning holes 202 , 222 are located, leaving the separate primary frame 201 and the auxiliary frame outside the packaging shell 601 . Side frame 221. FIG. 7 is a schematic diagram of the molding package. The packaged package structure includes the package shell 601 , the primary side frame 201 and the secondary side frame 221 in the external visible part.

After the above steps are completed, the package structure of the present invention is obtained. Referring to FIG. 6 and FIG. 7 , the package structure includes: an injection-molded integrated frame 20 , including a primary frame 201 , a secondary frame 221 , a detection chip 306 and an injection-molded connector 211 , the primary frame 201 and the secondary frame 221 is vertically arranged, the detection chip 306 is arranged on the secondary frame 221; the injection connecting body 211 fixes the primary frame 201 and the secondary frame 221, and connects the primary frame 201 and the secondary frame 221 electrical isolation; feedback coil 302, which is wound on the feedback coil bobbin 303; magnetic core 301, which is fixed on the feedback coil bobbin 303 and bent to form a magnetic core breath 305, and all The detection chip 306 is arranged between the magnetic cores 305; the encapsulation shell 601 encapsulates the magnetic core 301, the feedback coil 302, and the detection chip 306, exposing the partially bent primary frame 201 and the secondary frame 221.

In a specific embodiment of the present invention, the primary frame 201 is provided with a first fixing structure 203, and the injection-molded connecting body 211 is provided with a second fixing structure (not shown), the first fixing structure and the The second fixing structure cooperates to fix the primary frame 201 and the injection-molded connecting body 211 . The first fixing structure is a fishbone type fixing structure, and the second fixing structure includes a fishbone type groove. The secondary side frame 221 is provided with bosses 223 and 224 for fixing the secondary side frame 221 and the injection-molded connecting body 211 . The injection-molded connector 211 has an injection-molded slot 214, the magnetic core 301 has a magnetic-core slot 306, and the injection-molded slot 214 cooperates with the magnetic core slot 306 for positioning and fixing the magnetic core 301 and the injection-molded one. Frame 20.

The feedback coil 302 is wound on the feedback coil bobbin 303, and the feedback coil bobbin 303 has a magnetic core channel 304; the magnetic core 301 passes through the magnetic core channel 304, is fixed on the feedback coil bobbin 303, and is formed by bending Core breath 305. The feedback coil 302 includes a first feedback coil 302A and a second feedback coil 302B, the feedback coil bobbin 303 includes a first feedback coil bobbin 303A and a second feedback coil bobbin 303B, and the first feedback coil 302A and the second feedback coil The coil 302B is wound on the first feedback bobbin 303A and the second feedback bobbin 303B in series, and the magnetic core 301 passes through the magnetic core channels 304A and 304B of the first feedback bobbin 303A and the second feedback bobbin 303B in sequence.

The thickness of the thinnest part of the injection-molded connector 211 is set to 0.5mm-1.0mm, and the horizontal distance between the primary frame and the secondary frame is greater than 0.5 mm, so that the primary frame 201 and the secondary frame are separated 221 electrical isolation.

The invention improves the stability of the closed-loop current detection module by forming an integral frame of injection molding, reduces the volume of the product, and is easy to install.

The above are only the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the principles of the present invention, several improvements and modifications can also be made, and these improvements and modifications should also be regarded as It is the protection scope of the present invention.

Claims (18)

1. a closed-loop current detection module packaging method, is characterized in that, comprises: Pre-packaged, providing a primary frame, an injection-molded connector, a secondary frame, and a detection chip, which are assembled and fixed to form an injection-molded integrated frame; the injection-molded connector is used to fix the primary frame and the secondary frame and form electrical isolation; The detection chip is arranged on the secondary frame; Feedback coil assembly, providing a magnetic core and feedback coil, assembling and fixing the injection-molded integral frame with the magnetic core and the feedback coil; the detection chip is fixed in the magnetic core air space of the magnetic core; Forming and packaging, providing a packaging shell, packaging the magnetic core, the feedback coil, and the detection chip, bending the primary frame and the secondary frame, and completing the forming of shear ribs. 2 . The method according to claim 1 , wherein the primary frame is provided with a first fixing structure, the injection-molded connecting body is provided with a second fixing structure, and the first fixing structure and the second fixing structure cooperate to be fixed. 3 . The primary frame and the injection-molded connector. 3. The method of claim 2, wherein the first fixing structure is a fishbone type fixing structure, and the second fixing structure comprises a fishbone type groove. 4. The method according to claim 1, wherein the secondary frame is provided with a boss for fixing the secondary frame and the injection-molded connecting body. 5 . The method according to claim 1 , wherein positioning holes are respectively provided on the primary frame and the secondary frame. 6 . 6 . The method according to claim 1 , wherein the pre-package includes chip wire bonding packaging, and the feedback coil and the chip circuit are connected by setting two wire bonding pads. 7 . 7. The method according to claim 1, wherein the thickness of the thinnest part of the injection-molded connector is set to 0.5mm-1.0mm, and the horizontal distance between the primary frame and the secondary frame is greater than 0.5 mm to electrically isolate the primary frame and the secondary frame. 8 . The method according to claim 1 , wherein the injection-molded connector has an injection-molded slot, the magnetic core has a magnetic-core slot, and the injection-molded slot is matched with the magnetic-core slot to be used for Positioning and fixing the magnetic core and the injection-molded one-piece frame. 9 . The method according to claim 1 , wherein the feedback coil is wound on a feedback coil bobbin, and the feedback coil bobbin has a magnetic core channel; the magnetic core passes through the magnetic core channel and is fixed on the The feedback coil bobbin is bent to form a magnetic core breath. 10 . The method of claim 9 , wherein the feedback coil includes a first feedback coil and a second feedback coil, the feedback coil bobbin includes a first feedback coil bobbin and a second feedback coil bobbin, and the The first feedback coil and the second feedback coil are wound on the first feedback coil bobbin and the second feedback coil bobbin in series, and the magnetic core passes through the magnetic core channels of the first feedback coil bobbin and the second feedback coil bobbin in sequence. 11. A closed-loop current detection module structure, characterized in that it comprises: The injection-molded integrated frame includes a primary frame, a secondary frame, a detection chip and an injection-molded connector, the primary frame and the secondary frame are vertically arranged, and the detection chip is arranged on the secondary frame; the injection-molded connector Fixing the primary frame and the secondary frame, and electrically isolating the primary frame and the secondary frame; a feedback coil, the feedback coil is wound on the feedback coil bobbin; a magnetic core, the magnetic core is bent and fixed on the feedback coil bobbin to form a magnetic core air, and the detection chip is arranged between the magnetic core air; an encapsulation shell, encapsulating the magnetic core, the feedback coil, and the detection chip, exposing the partially bent primary frame and the secondary frame. 12 . The closed-loop current detection module structure according to claim 11 , wherein the injection-molded connector has an injection-molding slot, the magnetic core has a magnetic-core slot, and the injection-molded slot and the magnetic core slot are the same. 13 . Cooperate to fix the magnetic core and the injection molded one-piece frame. 13. The closed-loop current detection module structure according to claim 11, wherein the feedback coil is wound on the feedback coil bobbin, and the feedback coil bobbin has a magnetic core channel; the magnetic core passes through the magnetic core channel, It is fixed on the feedback coil bobbin and bent to form a magnetic core breath. 14. The closed-loop current detection module structure according to claim 13, wherein the feedback coil comprises a first feedback coil and a second feedback coil, and the feedback coil bobbin comprises a first feedback coil bobbin and a second feedback coil a bobbin, the first feedback coil and the second feedback coil are wound on the first feedback coil bobbin and the second feedback coil bobbin in series, and the magnetic core passes through the magnetic cores of the first feedback coil bobbin and the second feedback coil bobbin in sequence aisle. 15 . The closed-loop current detection module structure according to claim 11 , wherein the primary frame is provided with a first fixing structure, the injection-molded connecting body is provided with a second fixing structure, and the first fixing structure is connected with the 15 . The second fixing structure cooperates to fix the primary frame and the injection-molded connecting body. 16 . The closed-loop current detection module structure according to claim 15 , wherein the first fixing structure is a fishbone type fixing structure, and the second fixing structure comprises a fishbone type groove. 17 . 17 . The closed-loop current detection module structure according to claim 11 , wherein the secondary frame is provided with a boss for fixing the secondary frame and the injection-molded connecting body. 18 . 18. The closed-loop current detection module structure according to claim 10, wherein the thickness of the thinnest part of the injection-molded connector is set to 0.5mm-1.0mm, and the thickness between the primary frame and the secondary frame is set to 0.5mm-1.0mm. The horizontal distance is greater than 0.5mm to electrically isolate the primary frame and the secondary frame.

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