100M vehicle-mounted Ethernet chip common mode inductor and production process

Abstract

The 100M vehicle-mounted Ethernet chip type common-mode inductor comprises a middle column, a magnetic chip, a first enameled wire and a second enameled wire, a first flange and a second flange are vertically welded to the two ends of the middle column respectively, and the middle column, the first flange and the second flange form an H-shaped magnetic core framework. The middle column and the first flange and the second flange which are vertically welded at the two ends form the H-shaped magnetic core framework, a stable magnetic conduction path is provided for the inductor, and it is ensured that a magnetic field is intensively distributed in a middle column area; a pad electrode a and a pad electrode b of the first flange and a pad electrode c and a pad electrode d of the second flange adopt a non-protruding design that the pad electrode a and the pad electrode b are flush with the bottoms of the flanges, compared with a traditional protruding electrode, the electrodes can be prevented from being damaged by stress during installation, and the stability of 100M vehicle-mounted Ethernet signal transmission is ensured; the first varnished wire and the second varnished wire respectively form a first winding and a second winding on two sides of the center post, and a crossing section between the two windings realizes primary and secondary crossing commutation.

Description

Technical Field

[0001] This invention relates to the field of common mode inductor technology, specifically to a 100M automotive Ethernet chip common mode inductor and its manufacturing process. Background Technology

[0002] As automotive electronics technology rapidly iterates towards intelligence and connectivity, the in-vehicle network architecture is upgrading from traditional bus to high-bandwidth Ethernet. Among them, 100M automotive Ethernet, with its advantages of low cost, stable transmission speed, and simplified wiring, has become the core carrier for data interaction between in-vehicle infotainment systems, advanced driver assistance sensors (such as cameras and radar), and body control systems. The stability and anti-interference capability of its signal transmission directly determine the operational reliability of the entire vehicle's electronic systems.

[0003] Currently, most traditional common-mode inductors employ a "U-shaped + I-shaped" combined magnetic core or an integrated rectangular frame structure. However, these structures suffer from uneven air gap distribution and dispersed magnetic fields in the magnetic permeability path. On one hand, the low coupling efficiency between the side and central magnetic pillars of the U-shaped core leads to a decrease in effective permeability, making it prone to magnetic saturation during 100MHz high-frequency signal transmission. This results in increased differential-mode signal attenuation, failing to meet signal integrity requirements at 100Mbps. On the other hand, insufficient fit at the core joints of the integrated frame can generate additional magnetic leakage, increasing the fluctuation range of the common-mode rejection ratio and potentially causing electromagnetic interference to surrounding automotive chips.

[0004] Furthermore, traditional common-mode inductors often employ parallel double-wire winding or segmented forward winding structures, neglecting phase matching between the primary and secondary windings. In the parallel double-wire winding structure, the distance between the two enameled wires is fixed and there is no commutation design. At 100MHz high frequencies, the increased inter-wire parasitic capacitance leads to increased differential-mode signal loss and fluctuations in transmission rate. While the segmented forward winding structure can reduce parasitic capacitance, the magnetic field directions of the two winding segments are aligned, failing to achieve effective phase compensation. The common-mode rejection ratio attenuates significantly at high frequencies, making it difficult to suppress common-mode interference generated by vehicle motors, high-voltage wiring harnesses, etc., which can easily lead to bit errors in Ethernet signals.

[0005] Therefore, we propose a 100M automotive Ethernet chip common-mode inductor that can solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a 100M vehicle-mounted Ethernet chip common-mode inductor and its manufacturing process, which solves the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a 100M automotive Ethernet chip common-mode inductor, comprising a central column, a magnetic chip, a first enameled wire, and a second enameled wire. The two ends of the central column are vertically welded with a first flange and a second flange, respectively. The central column, the first flange, and the second flange form an H-core skeleton. The first flange is provided with pad electrodes a and b, and the second flange is provided with pad electrodes c and d. Pad electrodes a, b, c, and d are all flush with the bottom of their respective flanges. The first and second enameled wires form a first winding section and a second winding section on both sides of the central column, respectively. A cross section for primary-secondary cross-commutation is provided between the first and second winding sections.

[0008] In a preferred embodiment of the present invention, the spacing between the first enameled wire and the second enameled wire of the crossing segment is in the range of 0.15-0.20 mm.

[0009] In a preferred embodiment of the present invention, the first tail of the first enameled wire and the second tail of the second enameled wire are respectively welded to the pad electrode c and the pad electrode d.

[0010] In a preferred embodiment of the present invention, a first adhesive is applied to the top center of the first stop edge, and a second adhesive is applied to the top center of the second stop edge. The magnetic chip is bonded to the first stop edge and the second stop edge by the first adhesive and the second adhesive.

[0011] In a preferred embodiment of the present invention, the length and width dimensions of the magnetic chip are the same as those of the H-core skeleton, and the thickness of the magnetic chip is in the range of 0.6-1.2 mm.

[0012] The present invention also provides a manufacturing process for the aforementioned 100M automotive Ethernet chip common-mode inductor, comprising the following steps:

[0013] S1. The pad electrodes a and b at the bottom of the first stop and the pad electrodes c and d at the bottom of the second stop are all treated with electroplating silver. The electroplating layers are Ag bottom layer, Ni middle layer and Sn surface layer from the inside to the outside. The minimum thickness of the Ag bottom layer is 6μm, the minimum thickness of the Ni middle layer is 2μm and the minimum thickness of the Sn surface layer is 3μm.

[0014] S2. Hang the first enameled wire and the second enameled wire on the pad electrode a and pad electrode b of the first stop of the H magnetic core frame, respectively, and fix them by spot welding.

[0015] S3. Using a double-wire winding method, the first enameled wire and the second enameled wire are wound counterclockwise along the central column, with the second enameled wire at the bottom layer and the first enameled wire at the top layer, thus completing the first section of winding.

[0016] S4. Control the two wire feeding pins to rotate 180° and wind one turn, so that the first enameled wire and the second enameled wire form an intersection segment and are separated by a gap of 0.15-0.20mm, so as to realize the phase reversal between the bottom layer and the top layer;

[0017] S5. Continue to wind the wire counterclockwise along the central column using a double-wire winding method. At this time, the first enameled wire is located at the bottom layer and the second enameled wire is located at the top layer. After completing the second section of winding, control the wire feeding guide to rotate -180° back to the original position.

[0018] S6. Hang the end of the first enameled wire on the pad electrode c of the second side and the end of the second enameled wire on the pad electrode d of the second side. Fix them by spot welding. Then, apply corresponding adhesive at the midpoint between the top of the first and second sides to assemble the magnetic chip onto the H magnetic core frame. Fix it by drying.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] In this invention, the central column and the first and second vertically welded end plates form an H-core skeleton, providing a stable magnetic conduction path for the inductor and ensuring a concentrated magnetic field distribution in the central column area. The pad electrodes a and b of the first end plate and the pad electrodes c and d of the second end plate adopt a non-protruding design that is flush with the bottom of the end plate. Compared with traditional protruding electrodes, this avoids electrode damage during installation and ensures the stability of 100M vehicle Ethernet signal transmission. The first and second enameled wires form the first and second winding sections on both sides of the central column, respectively. The cross section between the two winding sections realizes primary and secondary cross-commutation. By adjusting the winding phase of the enameled wire, a low impedance is presented for the useful vehicle Ethernet signal, meeting the high-efficiency transmission requirements of differential mode signals at 100M speed. Attached Figure Description

[0021] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0022] Figure 1 This is a schematic diagram of the structure of a 100M vehicle-mounted Ethernet chip common-mode inductor according to the present invention;

[0023] Figure 2 This is a schematic diagram of the magnetic chip installation of a 100M vehicle-mounted Ethernet chip common-mode inductor according to the present invention;

[0024] Figure 3 This is a front view of a 100M vehicle-mounted Ethernet chip common-mode inductor according to the present invention;

[0025] Figure 4This is a circuit diagram of a 100M vehicle-mounted Ethernet chip common-mode inductor according to the present invention;

[0026] Figure 5 This is a circuit diagram of the winding internal circuit of a 100M vehicle-mounted Ethernet chip common-mode inductor according to the present invention.

[0027] Figure 6 This is a performance diagram of a 100M vehicle-mounted Ethernet chip common-mode inductor according to the present invention;

[0028] Figure 7 This is a schematic diagram of the terminal silver plating of a 100M vehicle-mounted Ethernet chip common-mode inductor according to the present invention.

[0029] In the diagram: 1. First guard edge; 2. Second guard edge; 3. Center post; 4. Pad electrode a; 5. Pad electrode b; 6. Pad electrode c; 7. Pad electrode d; 8. First enameled wire; 9. Second enameled wire; 10. First wire tail; 11. Second wire tail; 12. First adhesive; 13. Second adhesive; 14. Magnetic chip; 15. First winding segment; 16. Cross segment; 17. Second winding segment. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0031] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0032] Please see Figures 1-7This invention provides a technical solution: a 100M vehicle-mounted Ethernet chip common-mode inductor, including a central column 3, a magnetic chip 14, a first enameled wire 8, and a second enameled wire 9. The two ends of the central column 3 are vertically welded with a first baffle 1 and a second baffle 2, respectively. The central column 3, the first baffle 1, and the second baffle 2 form an H-core skeleton. The first baffle 1 is provided with a pad electrode a4 and a pad electrode b5, and the second baffle 2 is provided with a pad electrode c6 and a pad electrode d7. The pad electrodes a4, b5, c6, and d7 are all flush with the bottom of the corresponding baffle. The first enameled wire 8 and the second enameled wire 9 form a first winding 15 and a second winding 17 on both sides of the central column 3, respectively. A cross section 16 for primary and secondary cross-commutation is provided between the first winding 15 and the second winding 17.

[0033] In this invention, the central column 3, together with the first and second vertically welded end plates 1 and 2, forms an H-core skeleton, providing a stable magnetic path for the inductor and ensuring that the magnetic field is concentrated in the central column 3 region. The pad electrodes a4 and b5 of the first end plate 1 and the pad electrodes c6 and d7 of the second end plate 2 adopt a non-protruding design that is flush with the bottom of the end plate. Compared with traditional protruding electrodes, this avoids damage to the electrodes during installation and ensures the stability of 100M vehicle Ethernet signal transmission. The first enameled wire 8 and the second enameled wire 9 form the first winding 15 and the second winding 17 on both sides of the central column 3, respectively. The cross section 16 between the two winding sections realizes the primary and secondary cross-commutation. By adjusting the winding phase of the enameled wire, the useful signal of the vehicle Ethernet is presented with low impedance, meeting the high-efficiency transmission requirements of differential mode signals at 100M speed.

[0034] In an optional embodiment, the spacing between the first enameled wire 8 and the second enameled wire 9 of the cross segment 16 ranges from 0.15 to 0.20 mm.

[0035] It should be noted that the spacing between the two enameled wires is limited to 0.15-0.20mm. This spacing can prevent the insulation layer from being damaged by friction due to the two wires being too close, and at the same time prevent the magnetic coupling from weakening due to the spacing being too far.

[0036] In an optional embodiment, the first tail 10 of the first enameled wire 8 and the second tail 11 of the second enameled wire 9 are respectively welded to the pad electrode c6 and the pad electrode d7.

[0037] It should be noted that by fixing the wire tail with electric welding, a tight connection between the wire tail and the electrode can be achieved. Compared with the traditional winding method, this can reduce the contact resistance of the first wire tail 10 and the second wire tail 11, and also prevent the first wire tail 10 and the second wire tail 11 from becoming loose and causing signal transmission interruption.

[0038] In an optional embodiment, a first adhesive 12 is applied to the top center of the first edge 1, and a second adhesive 13 is applied to the top center of the second edge 2. The magnetic chip 14 is bonded to the first edge 1 and the second edge 2 by the first adhesive 12 and the second adhesive 13.

[0039] It should be noted that the first adhesive 12 and the second adhesive 13 can accurately fix the magnetic chip 14 to the top of the frame, ensuring the fit between the magnetic chip 14 and the frame.

[0040] In an optional embodiment, the length and width dimensions of the magnetic chip 14 are the same as those of the H-core skeleton, and the thickness of the magnetic chip 14 ranges from 0.6 to 1.2 mm.

[0041] It should be noted that the magnetic chip 14 can completely cover the top of the frame, so that the first side 1, the second side 2 and the central column 3 form a complete closed magnetic circuit; the thickness of the magnetic chip 14 is in the range of 0.6-1.2mm, which can meet the magnetic flux required for 100M signal transmission, and can avoid the overall volume of the inductor from increasing due to excessive thickness.

[0042] In an optional embodiment, a manufacturing process for a 100M automotive Ethernet chip common-mode inductor includes the following steps:

[0043] S1, pad electrodes a4 and b5 at the bottom of the first guard edge 1, and pad electrodes c6 and d7 at the bottom of the second guard edge 2 are all treated with electroplating silver. The electroplating layers are Ag bottom layer, Ni middle layer and Sn surface layer from the inside to the outside. The minimum thickness of the Ag bottom layer is 6μm, the minimum thickness of the Ni middle layer is 2μm and the minimum thickness of the Sn surface layer is 3μm. The Ag underlayer possesses excellent conductivity, reducing the resistance of the electrode itself and minimizing signal transmission losses, thus meeting the high transmission rate requirements of 100M automotive Ethernet. The Ni middle layer effectively prevents metal diffusion between the Ag underlayer and the Sn surface layer. The Sn surface layer exhibits good solder wettability and excellent environmental corrosion resistance, extending the inductor's lifespan in the complex automotive environment. The minimum Ag underlayer thickness of 6μm prevents excessively thin Ag layers from causing localized resistance increases and affecting signal transmission efficiency. The minimum Ni middle layer thickness of 2μm blocks the diffusion path between Ag and Sn. The minimum Sn surface layer thickness of 3μm ensures sufficient molten material in the Sn layer during soldering.

[0044] S2. The first enameled wire 8 and the second enameled wire 9 are respectively hung on the pad electrode a4 and the pad electrode b5 of the first sidewall 1 of the H magnetic core frame, and fixed by spot welding.

[0045] S3. Using a double-wire winding method, the first enameled wire 8 and the second enameled wire 9 are wound counterclockwise along the central column 3, with the second enameled wire 9 located at the bottom layer and the first enameled wire 8 located at the surface layer, thus completing the first section of winding 15.

[0046] S4. Control the two wire feeding pins to rotate 180° and wind one turn, so that the first enameled wire 8 and the second enameled wire 9 form an intersection segment 16 and are separated by a gap of 0.15-0.20mm, so as to realize the phase reversal between the bottom layer and the top layer.

[0047] S5. Continue to wind the wire counterclockwise along the central column 3 using the double-wire winding method. At this time, the first enameled wire 8 is located at the bottom layer and the second enameled wire 9 is located at the surface layer. After completing the second section of winding 17, control the wire feeding guide to rotate -180° back to the original position.

[0048] S6. Hang the end of the first enameled wire 8 on the pad electrode c6 of the second side 2, and hang the end of the second enameled wire 9 on the pad electrode d7 of the second side 2. Fix them by spot welding. Then, apply corresponding adhesive at the midpoint between the top of the first side 1 and the second side 2, and assemble the magnetic chip 14 onto the H magnetic core frame. Fix it by drying.

[0049] In an optional embodiment, when the two wires are wound in parallel in steps S3 and S5, the tightness of the windings must be kept consistent to avoid poor product consistency due to uneven winding tension, which would affect the transmission performance of the inductor.

[0050] It should be noted that the tightness of the double-wire winding in steps S3 and S5 is consistent, which can ensure that the winding density of each turn of enameled wire on the central post 3 is the same.

[0051] In an optional embodiment, the amount of adhesive applied in step S6 needs to be controlled to avoid applying too much or too little adhesive, which could affect the fixing effect and normal use of the magnetic chip 14 and the H magnetic core skeleton.

[0052] It should be noted that when there is too much adhesive, the excess adhesive may overflow into the central column 3 area. Since the adhesive layer is a non-magnetic material, if it overflows into the central column 3, it will increase the air gap of the magnetic circuit and reduce the magnetic permeability.

[0053] When the amount of adhesive is too small, the adhesive cannot completely cover the contact area between the top of the retaining edge and the magnetic chip 14, resulting in the magnetic chip 14 not being firmly fixed and easily loosening under vehicle vibration environment.

[0054] In an optional embodiment, the drying temperature and drying time of the first adhesive 12 and the second adhesive 13 in step S5 ensure that the adhesives are fully cured, so that the magnetic chip 14 is tightly attached to the H magnetic core skeleton, thereby improving the overall structural strength of the product.

[0055] It should be noted that if the drying temperature is too low or the drying time is too short, the adhesive will not be fully cured and the adhesive layer will not be strong enough; if the drying temperature is too high or the drying time is too long, the adhesive may age and deteriorate, losing its stickiness.

[0056] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0057] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A 100M vehicle-mounted Ethernet chip common-mode inductor, comprising a center column (3), a magnetic chip (14), a first enameled wire (8), and a second enameled wire (9), characterized in that: The two ends of the central column (3) are vertically welded with a first sidewall (1) and a second sidewall (2). The central column (3), the first sidewall (1) and the second sidewall (2) form an H-core skeleton. The first sidewall (1) is provided with a pad electrode a (4) and a pad electrode b (5). The second sidewall (2) is provided with a pad electrode c (6) and a pad electrode d (7). The pad electrodes a (4), b (5), c (6) and d (7) are all flush with the bottom of the corresponding sidewall. The first enameled wire (8) and the second enameled wire (9) form a first winding (15) and a second winding (17) on both sides of the central column (3). A cross section (16) for primary and secondary cross-commutation is provided between the first winding (15) and the second winding (17).

2. The 100M vehicle-mounted Ethernet chip common-mode inductor according to claim 1, characterized in that: The spacing between the first enameled wire (8) and the second enameled wire (9) of the intersection segment (16) is 0.15-0.20 mm.

3. A 100M vehicle-mounted Ethernet chip common-mode inductor according to claim 2, characterized in that: The first wire tail (10) of the first enameled wire (8) and the second wire tail (11) of the second enameled wire (9) are respectively welded to the pad electrode c (6) and the pad electrode d (7).

4. A 100M vehicle-mounted Ethernet chip common-mode inductor according to claim 3, characterized in that: The top center of the first edge (1) is coated with a first adhesive (12), and the top center of the second edge (2) is coated with a second adhesive (13). The magnetic chip (14) is bonded to the first edge (1) and the second edge (2) by the first adhesive (12) and the second adhesive (13).

5. A 100M vehicle-mounted Ethernet chip common-mode inductor according to claim 4, characterized in that: The length and width dimensions of the magnetic chip (14) are the same as those of the H magnetic core skeleton, and the thickness of the magnetic chip (14) ranges from 0.6 to 1.2 mm.

6. A manufacturing process for a 100M vehicle-mounted Ethernet chip common-mode inductor according to any one of claims 1-6, characterized in that, Includes the following steps: S1, the pad electrodes a (4), b (5) at the bottom of the first side (1) and the pad electrodes c (6) and d (7) at the bottom of the second side (2) are all treated with silver plating. The plating layers are Ag bottom layer, Ni middle layer and Sn surface layer from the inside to the outside. The minimum thickness of the Ag bottom layer is 6μm, the minimum thickness of the Ni middle layer is 2μm and the minimum thickness of the Sn surface layer is 3μm. S2. The first enameled wire (8) and the second enameled wire (9) are respectively hung on the pad electrode a (4) and the pad electrode b (5) of the first stop (1) of the H magnetic core frame, and fixed by spot welding. S3. Using a double-wire winding method, the first enameled wire (8) and the second enameled wire (9) are wound counterclockwise along the central column (3), with the second enameled wire (9) located at the bottom layer and the first enameled wire (8) located at the surface layer, thus completing the first section of winding (15). S4. Control the two wire feeding guides to rotate 180° and wrap around once, so that the first enameled wire (8) and the second enameled wire (9) form an intersection (16) and are separated by a gap of 0.15-0.20mm, so as to realize the phase change between the bottom layer and the top layer; S5. Continue to wind the wire counterclockwise along the central column (3) in a double-wire winding manner. At this time, the first enameled wire (8) is located at the bottom layer and the second enameled wire (9) is located at the surface layer. After completing the second section of winding (17), control the wire feeding guide to rotate -180° back to the original position. S6. Hang the end of the first enameled wire (8) on the pad electrode c (6) of the second side (2), and hang the end of the second enameled wire (9) on the pad electrode d (7) of the second side (2). Fix them by spot welding. Then, apply the corresponding adhesive at the midpoint between the top of the first side (1) and the second side (2) to assemble the magnetic chip (14) onto the H magnetic core frame. Fix it by drying.

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