TLVR inductor used on vertical power supply module
By optimizing the core and coil structure of TLVR inductors, efficient integration and reduced space occupation in high-density PCBs are achieved, improving the coupling performance and withstand voltage performance between coils, making them suitable for scenarios such as artificial intelligence, data centers, and autonomous driving.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-14
- Publication Date
- 2026-03-10
AI Technical Summary
In high-density PCBs, the structural design of TLVR inductors suffers from low coupling efficiency between the two-stage coils and large component space requirements, making it difficult to achieve efficient integration within a limited space.
It adopts a combination of irregular magnetic cores and plate magnetic cores, a special structural design for primary and secondary coils, and forms a stable pre-assembled body through thermo-press packaging, adding insulation treatment and electrode pads, and optimizing the assembly structure of magnetic cores and coils.
It improves the space utilization of TLVR inductors in high-density PCBs, reduces the interference of components to the surrounding environment, enhances the coupling performance and withstand voltage performance between coils, achieves a coupling coefficient of 0.94, reduces mutual interference, and is suitable for scenarios such as artificial intelligence, data centers, and autonomous driving.
Smart Images
Figure CN223986482U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to an inductor device especially to a TLVR inductor for vertical power module belongs to basic electronic component technical field. BACKGROUND
[0002] Inductance is the most common electronic device, is widely used in various circuits, can achieve the function of filtering, energy storage, matching, resonance. In the electronic product is small, portable, component high density assembly, inductance component can develop rapidly, and in the electromagnetic compatibility, the anti-electromagnetic interference ability of electronic product becomes the basic design requirement, thus increase the inductance demand and application.
[0003] TLVR (Trans-Inductor Voltage Regulator, conduction inductor voltage regulator) architecture is a rising VR (Voltage Regulator, voltage inverter) power supply architecture, it is the biggest difference with traditional DC to DC Buck (DC to DC Buck), DC (direct current) architecture is that the traditional single winding ordinary inductance is improved to have two winding similar to transformer TLVR inductor, ordinary inductance only has a winding to match two pins, and TLVR inductor has two sets of mutually coupled windings to match four pins, both in structure form there is great difference.
[0004] At present, the TLVR inductor in the industry is designed, in addition to the coupling efficiency between two coils as the main target pursuit, the number of components and the occupied space in high-density PCB are also the focus of attention. Therefore, the multi-group integration and coupling coefficient optimization of TLVR inductor in limited space become a technical blank that needs to be filled in the industry. SUMMARY
[0005] The utility model aims at providing a TLVR inductor for vertical power module, and is committed to improving the performance of inductor device and optimizing the occupied space of components in high-density PCB.
[0006] The technical solution of this utility model to achieve the above-mentioned objective is: a TLVR inductor for a vertical power module, which is formed by combining a primary and secondary composite irregular magnetic core, a chip magnetic core, a primary coil, and a secondary coil. The main body of the irregular magnetic core is formed into a cube and assembled in pairs in mirror image. One side of any irregular magnetic core in each pair is flat, and the other side has a meandering groove. The other side of the irregular magnetic core is divided by the groove into a secondary bump located at the corner and a semi-enclosed primary bump. The secondary coil wraps around the secondary bump. The primary coil is bent and shaped in accordance with the groove and its surface is insulated. A first pre-assembled body is formed between the secondary coil and the primary bump. The chip magnetic core is sandwiched by the first pre-assembled body and a mirror image of the second pre-assembled body and hot-pressed into a whole. The surface of the package has a number of electrode pads corresponding to each coil.
[0007] Furthermore, the depth of the slots in the irregularly shaped magnetic core is uniform and the same as the width of the two-stage coils.
[0008] Furthermore, the two ends of the groove in the irregular magnetic core are provided with stepped portions that correspond to the positioning and engagement of the primary coil.
[0009] Furthermore, both the irregularly shaped magnetic core and the sheet magnetic core are cold-pressed bodies made of powder material based on a customized mold.
[0010] Furthermore, the primary coil is an embedded accessory formed by cutting and continuously bending a flat copper strip, and the surface of the primary coil is coated with an epoxy resin insulating layer. The secondary coil is formed by continuously bending and partially wrapping the middle section of the primary coil. One end of the primary coil is partially bent so that the outward surface is flush with the top surface of the irregular magnetic core, and the other end is partially bent so that the outward surface is flush with the bottom surface of the irregular magnetic core.
[0011] Furthermore, the secondary coil is a wrapping accessory made of flat enameled wire cut and bent into a C-shape, and the outward surface of one side of the secondary coil is flush with the side wall of the irregular magnetic core, and the outward surface of the top side of the secondary coil is flush with the top surface of the irregular magnetic core.
[0012] Furthermore, four electrode pads for the secondary coil are provided on the top surface of the package, and two electrode pads for the primary coil are provided on the top and bottom surfaces of the package, respectively. Additionally, a stripping process is performed to increase the insulation distance between the two coils.
[0013] Compared with existing technologies, the advantages of this inductor are as follows: By optimizing the core structure and the pre-formed shape of the coils, the assembly structure is improved. On the one hand, the two-stage coils can be stably pre-assembled with the irregularly shaped core. Furthermore, the use of a chip core to isolate the two sets of mirror-image pre-assembled products through thermoforming helps reduce the space occupied by the inductor in high-density PCBs and its interference with the surrounding environment. On the other hand, each set of coils and the two-stage coils within each set are reliably isolated, improving the withstand voltage between the two-stage coils and the device performance. This results in a coupling coefficient greater than 0.94 for a single TLVR and a mutual coupling coefficient less than 0.1 between two TLVRs. This further improves the circuit's operating environment and promotes the development of hardware performance in applications such as AI servers / data centers / autonomous driving, and smart city transportation. Attached Figure Description
[0014] Figure 1 This is a close-up structural diagram of the irregularly shaped magnetic core in a preferred embodiment of the inductor of this utility model.
[0015] Figure 2 This is a close-up structural diagram of the chip magnetic core in a preferred embodiment of the inductor of this utility model.
[0016] Figure 3 This is a close-up structural diagram of the primary coil in a preferred embodiment of the inductor of this utility model.
[0017] Figure 4 This is a close-up structural schematic diagram of the secondary coil in a preferred embodiment of the inductor of this utility model.
[0018] Figure 5 This is a schematic diagram showing the evolution of the external shape of the inductor according to a preferred embodiment of this utility model. Detailed Implementation
[0019] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.
[0020] This invention proposes a TLVR inductor for use in vertical power modules, aiming to improve the performance of inductor devices and optimize the space occupied by components in high-density PCBs. Figures 1 to 5 As shown, the basic structure of this inductor is assembled from a pre-formed irregular magnetic core 1, a chip magnetic core 2, a primary coil 4, and a secondary coil 3, and obtained through a series of manufacturing processes including thermoforming, painting, partial paint stripping, and electroplating. An overview of each functional component is provided below. Figure 1The main body of the irregularly shaped magnetic core 1 shown is formed into a cube and assembled in pairs of mirror images. One side surface 11 of each irregularly shaped magnetic core in each pair is flat, while the other side surface has a meandering groove 14. The other side surface of the irregularly shaped magnetic core is divided by the groove 14 into a secondary bump 12 located at the corner and a semi-enclosed primary bump 13. The outer side of the primary bump 13 is the sidewall and part of the bottom wall of the irregularly shaped magnetic core, while the inner side faces the groove. Only a small part of the surface of the secondary bump borrows the top wall of the irregularly shaped magnetic core, while most of the surface faces the groove or is used for non-closed wrapping of the secondary coil 3. The primary coil 4 is bent and shaped according to the groove and has an insulated surface. It is assembled one-to-one between the secondary coil 3 and the primary bump 13 to form a first pre-assembled body IA. The first pre-assembled body IA and the mirror image of the second pre-assembled body IB encapsulate the clip-on magnetic core 2 and heat-press it into a whole. As the basis for connecting the inductor to the PCB, several electrode pads are also required on the surface of the package corresponding to each coil. The specific distribution shape will be detailed later.
[0021] For the design considerations of integrating two sets into one and mass production, the aforementioned irregularly shaped magnetic cores, plate magnetic cores, and two-stage coils can all be prefabricated and reused in batches. Based on the overview of this technical solution and the illustrations of preferred embodiments, the detailed features of each functional component of this inductor also include: Figure 3 The primary coil shown is an insert component formed by cutting and continuously bending a flat copper strip, and the surface of the primary coil is coated with an epoxy resin insulating layer to achieve isolation towards the secondary coil. The middle section 41 of the primary coil is continuously bent and partially wraps around the secondary coil 4. The upper end of the primary coil 4 is partially bent so that the outward surface 42 is flush with the top surface of the irregular magnetic core, and the other end is bent downward to partially wrap around the primary bump 13 so that its outward surface 43 is flush with the side wall of the irregular magnetic core, and then partially bent so that its outward surface 44 is flush with the bottom surface of the irregular magnetic core. Figure 4 The secondary coil 3 shown is a wrapping accessory made of flat enameled wire cut and bent into a C-shape. The middle section 31 of the secondary coil is also linearly horizontal, the two side sections 32 are bent and flipped up, and the tail section 33 is bent at the top to form an opening. In the actual pre-assembly state, the secondary coil is bent and shaped according to the dimensions of each side of the secondary protrusion and then directly fitted and positioned on it; in the finished state, the outward surface of one side of the secondary coil is flush with the side wall of the irregular magnetic core, and the outward surface of the top side of the secondary coil is flush with the top surface of the irregular magnetic core.
[0022] The depth of the grooves in the irregularly shaped magnetic core is uniform in all directions, and the width is the same as that of the primary and secondary coils, so that there is no outward protrusion on the mating surface of the pre-mounted body facing the plate magnetic core, allowing the two to fit tightly together. Furthermore, as... Figure 1 As shown, the two ends of the receiving groove are provided with stepped parts that correspond to the positioning and engagement of the primary coil, which not only provides the positioning accuracy and anti-dislodgement of the primary coil, but also leaves sufficient area for the primary coil forming electrode pad.
[0023] The aforementioned preferred embodiments of the irregularly shaped magnetic cores (mirror-image pairs) and plate magnetic cores are both assemblies prefabricated based on powder materials and customized molds, specifically using a cold pressing molding process. The powder material used for the magnetic core can be one or more mixtures of Fe-based / FeSiCr / FeSiAl / FeNi / FeSi / amorphous / nanocrystalline materials, with one of epoxy resin, silicone resin, or acrylic resin added and stirred evenly before being injected into a customized mold conforming to the device's shape, and the molding pressure range is 6-12 Tons / cm².
[0024] This invention aims to optimize the high coupling performance of dual-unit integrated TLVR inductors in vertical power module applications. Based on the aforementioned primary coil surface coating, flush-fitting of the two-stage magnetic cores, and thermoforming encapsulation, the insulation gap between the two-stage magnetic cores is close to zero, which is beneficial for improving the coupling performance of a single TLVR (coupling coefficient greater than 0.94). Furthermore, the two-stage coils have partial enamel stripping and electroplating to form electrode pads on both sides of the package surface, and enamel stripping treatment is performed near the two-stage coils to increase the insulation distance (e.g., ...). Figure 5 As shown in the lower left corner, leave sufficient gaps for paint peeling (81).
[0025] like Figure 5 As shown in the diagram, the complete manufacturing process of this inductor is as follows: First, a shaped magnetic core 1, a chip magnetic core 2, a primary coil 4, and a secondary coil 3 are prefabricated in the required proportions. Then, the secondary coil is fitted onto the secondary bump of the shaped magnetic core, and the primary coil is inserted and positioned in the groove to form the first pre-assembled body IA. Simultaneously, a second pre-assembled body IB, which is a mirror image of the first pre-assembled body, is fabricated. Then, a pair of pre-assembled bodies are used to sandwich the chip magnetic core and are assembled with flush edges to form a complete assembly 5. The complete assembly is then transferred into a pre-fabricated thermoforming mold, and all gaps are filled with one or more mixtures of Fe-based / FeSiCr / FeNi / FeSiAl / amorphous or nanocrystalline materials. The mixture is then held at a molding temperature range of 100-200℃ and a molding pressure of 4-12 Tons / cm² for 30-180 seconds to obtain a thermo-pressed encapsulated body 6. After the thermo-pressed encapsulated body is cooled, it is then painted to cover the entire surface with an insulating varnish film 7. Then, partial varnish stripping is performed to form exposed but unconnected conductor contacts at both ends of the primary and secondary coils. Finally, the varnish-stripped body 8 is electroplated to form several electrode pads 91 distributed on the top and bottom surfaces of the TLVR inductor, resulting in the finished product 9 to be inspected. These processes are then sequentially subjected to external inspection, testing, quality inspection, packaging, and shipment.
[0026] In summary, the preferred embodiment of the TLVR inductor for vertical power modules described above demonstrates that, compared to existing technologies, its technical advantages are as follows: By optimizing the core structure and the prefabricated shape of the coils, the assembly structure is improved. On the one hand, this allows for stable pre-assembly of the two-stage coils with the irregularly shaped core. Furthermore, the use of a chip core to isolate the two sets of mirror-image pre-assembled products through thermoforming helps reduce the space occupied by the inductor in high-density PCBs and minimizes interference to the surrounding environment. On the other hand, reliable isolation is achieved between each set of coils and between each set of two-stage coils, improving the withstand voltage between the two-stage coils and the device performance. This results in a coupling coefficient greater than 0.94 for a single TLVR and a mutual coupling coefficient less than 0.1 between two TLVRs (as determined by Ansys Maxwell simulation). This further improves the circuit's operating environment and promotes the development of hardware performance in application scenarios such as AI servers / data centers / autonomous driving and smart city transportation.
[0027] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the principles of this application should be included within the protection scope of this application.
Claims
1. A TLVR inductor for use on a vertical power module, characterized by: The inductor is combined by a primary-secondary composite special-shaped magnetic core, a chip magnetic core, a primary coil and a secondary coil, the main body of the special-shaped magnetic core is shaped as a square block and is assembled in pairs of mirror images, the side surface of any one of the special-shaped magnetic cores in each pair is flat, and the other side surface is provided with a winding groove extending in a zigzag manner, the other side surface of the special-shaped magnetic core is divided by the winding groove into a secondary protrusion located at a corner and a primary protrusion in a half-enclosing shape, the secondary coil is wrapped around the secondary protrusion, and the primary coil is bent and shaped in correspondence with the winding groove and is subjected to surface insulation treatment, and a first pre-assembled body is formed by assembling the primary coil between the secondary coil and the primary protrusion, the chip magnetic core is clamped by the first pre-assembled body and a mirror image second pre-assembled body and is heat-pressed and packaged into an integrated body, and the surface of the packaged body is provided with a plurality of electrode pads corresponding to each coil.
2. The TLVR inductor for use on a vertical power module of claim 1, wherein: The depth of the winding groove in the special-shaped magnetic core is uniform and is the same as the width of the two-stage coil.
3. The TLVR inductor for use on a vertical power module of claim 1, wherein: The two ends of the winding groove in the special-shaped magnetic core are provided with step portions corresponding to the primary coil and positioned and clamped therein.
4. The TLVR inductor for use on a vertical power module of claim 1, 2 or 3, wherein: The special-shaped magnetic core and the chip magnetic core are both cold-pressed shaped bodies based on a customized mold from a powder material.
5. The TLVR inductor for use on a vertical power module of claim 1, wherein: The primary coil is a kind of embedded fitting cut from a flat copper strip and continuously bent and shaped, and the surface of the primary coil is sprayed with an epoxy resin insulation layer, the middle section of the primary coil is continuously bent and partially wrapped to form the secondary coil, and one end of the primary coil is partially bent so that the outward surface is flush with the top surface of the special-shaped magnetic core, and the other end of the primary coil is partially bent so that the outward surface is flush with the bottom surface of the special-shaped magnetic core.
6. The TLVR inductor for use on a vertical power module of claim 1, wherein: The secondary coil is a kind of wrapped fitting cut from a flat enameled wire and bent into a C shape, and the outward surface of one side of the secondary coil is flush with the side wall of the special-shaped magnetic core, and the outward surface of the top side of the secondary coil is flush with the top surface of the special-shaped magnetic core.
7. The TLVR inductor for use on a vertical power module of claim 1, wherein: Four electrode pads of the secondary coil are arranged on the top surface of the packaged body, and each two electrode pads of the primary coil are arranged on the top surface and the bottom surface of the packaged body, respectively, and a paint stripping treatment is performed to increase the insulation distance near the two-stage coil. In the packaged body,