TLVR coupling inductor with optimized insulation of primary coil and secondary coil
By using resin insulating layer and laser paint stripping technology in TLVR coupled inductors to optimize the structure of the primary secondary coil, combined with hot pressing and forming magnetic cores, the problem of insufficient insulation performance in the prior art is solved, and high voltage and high voltage resistance are achieved Coupled inductor design.
Patent Information
- Application Number
- CN202420055539.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-10
- Publication Date
- 2024-12-10
- Estimated Expiration
- 2034-01-10
AI Technical Summary
The existing TLVR coupled inductors have insufficient insulation performance between primary secondary coils, resulting in insufficient voltage withstand voltage, affecting electromagnetic compatibility and the anti-interference ability of the equipment.
The cross-shaped square conductive metal strip is used to form a wide-mouth U-shaped primary coil, and the surface is coated with resin insulating layer. Combined with laser paint peeling positioning and area control, and combined with the hot pressing forming of T-shaped and U-shaped magnetic cores, the two Close clamping and sufficient isolation of the stage coils.
It significantly improves the insulation performance between the primary secondary coils, has the ability to withstand voltage of more than 150V DC, and maintains a coupling coefficient above 0.9, improving the anti-interference ability of the inductor.
Smart Images
Figure CN222145970U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to an inductor device, in particular to a TLVR coupled inductor with optimized insulation between primary and secondary coils, belonging to the technical field of basic electronic components. Background Art
[0002] Inductors are the most commonly used components in electronic devices and are widely used in various circuits to achieve the functions of filtering, energy storage, matching, and resonance. As electronic products become increasingly miniaturized and portable, and components are assembled with high density, inductor components have developed rapidly; and in consideration of electromagnetic compatibility, the ability of electronic products to resist electromagnetic interference has become a basic design requirement, which has increased the demand and application of inductors.
[0003] The TLVR (Trans-Inductor Voltage Regulator) architecture is a newly developed VR (Voltage Regulator) power supply architecture in recent years. The biggest difference between it and the traditional DC to DCBuck (DC-DC buck) and DC (DC) architectures is that the traditional single-winding ordinary inductor is replaced with a transformer-like TLVR inductor with double windings. The ordinary inductor has only one set of windings and two pins, while the TLVR inductor has two sets of mutually coupled windings and four pins. There is a huge difference in the structural form of the two.
[0004] However, the size of such inductors is becoming increasingly smaller, and the spacing between the pins of the finished inductors is narrow. Figure 1 In the transformer inductor application shown in the figure, the application end finds that there is a potential voltage N*(Vin-Vout) between the primary coil and the secondary coil, where N is the order. Therefore, it is necessary to provide insulation isolation with a certain withstand voltage strength between the primary and secondary coils of the inductor. Summary of the invention
[0005] In view of the above-mentioned defects in the prior art, the purpose of the utility model is to provide a TLVR coupled inductor with optimized primary and secondary coil insulation, so as to effectively improve the insulation isolation between the two coils.
[0006] The technical solution for achieving the above-mentioned purpose of the utility model is a TLVR coupled inductor with optimized insulation between primary and secondary coils, comprising a primary coil, a secondary coil and a magnetic core assembly, wherein the primary coil is formed into a wide-mouth U-shaped portion based on a conductive metal strip with a square section and assembled to be compatible with the cavity of the U-shaped magnetic core in the magnetic core assembly, and the two ends of the primary coil are bent outward to form a first pin and a fourth pin, the secondary coil is formed into a narrow-mouth U-shaped portion based on a conductive metal sheet and is sleeved on the convex column of the T-shaped magnetic core in the magnetic core assembly, and the two ends of the secondary coil are bent to wrap the convex column to become a second pin and a third pin, the secondary coil is nested in the primary coil and is integrally packaged in the magnetic core assembly, the surface of the primary coil is coated with a resin insulation layer, the four pins are partially higher than the end face of the magnetic core assembly, and the laser paint stripping area of the four pins is smaller than the insulation area between the formed terminal PIN pins.
[0007] In the above-mentioned TLVR coupled inductor with optimized insulation between the primary and secondary coils, further, the outer side of the primary coil is gap-matched with the inner wall of the cavity, the gap between the primary coil and the secondary coil is gap-matched, and the symmetric center planes of the three coincide.
[0008] The TLVR coupled inductor with optimized insulation of primary and secondary coils further has the end faces filled with gaps using magnetic powder material and hot-pressed into a surface shape lower than the exposed portion of the pins.
[0009] In the above-mentioned TLVR coupled inductor with optimized insulation of primary and secondary coils, further, the terminal PIN pins of the four pins obtained by laser paint stripping are all located on the end surface of the magnetic core assembly.
[0010] The above-mentioned TLVR coupled inductor with optimized primary and secondary coil insulation, further, the terminal PIN pins obtained by laser stripping the paint of the second pin and the third pin are located at the end surface of the magnetic core assembly, and the terminal PIN pins obtained by laser stripping the paint of the first pin and the fourth pin are located at the side corner of the magnetic core assembly close to the end surface.
[0011] In the above TLVR coupled inductor with optimized insulation between primary and secondary coils, further, the height of the protruding column, the thickness of the primary coil and the thickness of the secondary coil are consistent, and the two coils are tightly clamped in the magnetic core assembly.
[0012] In the above TLVR coupled inductor with optimized insulation between primary and secondary coils, further, the protrusion is offset and positioned close to the pin, so that the pin formed by the secondary coil is partially higher than the end surface of the magnetic core assembly.
[0013] The above-mentioned TLVR coupled inductor with optimized primary and secondary coil insulation, further, the T-shaped magnetic core and the U-shaped magnetic core in the magnetic core assembly are pre-pressed bodies filled with magnetic powder material in a preset mold, and the TLVR coupled inductor is a hot-pressed body composed of two magnetic cores and two-stage coils.
[0014] Compared with the prior art, the inductor structure with optimized insulation of the primary and secondary coils of the utility model has the following advantages: by forming a resin insulation layer on the surface of the primary coil before assembly, the two-polar coils in the inductor are fully isolated, and the positioning and area control of laser paint stripping are combined to greatly improve the insulation performance between the two-polar coils, that is, the ability to withstand a voltage greater than 150V DC; at the same time, the coupling coefficient between the two-polar coils is maintained above 0.9. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 It is a schematic diagram for analyzing the potential voltage in existing transformer inductance applications.
[0016] Figure 2 It is a schematic diagram of the improved forming of the primary coil in the TLVR coupled inductor of the utility model.
[0017] Figure 3 It is a schematic diagram of the temporary assembly appearance of the primary coil in the TLVR coupled inductor of the utility model.
[0018] Figure 4 It is a schematic diagram of the temporary assembly appearance of the secondary coil in the TLVR coupled inductor of the utility model.
[0019] Figure 5 It is a schematic diagram of the overall assembly process of the TLVR coupled inductor of the utility model.
[0020] Figure 6 It is a schematic diagram of the end face of the utility model TLVR coupled inductor after laser paint stripping. DETAILED DESCRIPTION
[0021] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.
[0022] like Figures 2 to 4As shown, the TLVR coupled inductor includes a primary coil, a secondary coil 3 and a magnetic core assembly 2, wherein the primary coil is formed into a wide U-shaped portion based on a square-shaped conductive metal strip and assembled to be compatible with the cavity 21a of the U-shaped magnetic core 2a in the magnetic core assembly, and the two ends of the primary coil are bent outward to form a first pin 11 and a fourth pin 12. At the same time, the secondary coil 3 is formed into a narrow U-shaped portion based on a conductive metal sheet and is sleeved on the convex column 21b of the T-shaped magnetic core 2b in the magnetic core assembly, and the two ends of the secondary coil 3 are bent and wrapped around the convex column to become a second pin 31 and a third pin 32. The T-shaped magnetic core and the U-shaped magnetic core in the magnetic core assembly are pre-pressed bodies filled with magnetic powder materials in their respective preset molds. From the perspective of the overall assembly structure, the secondary coil 3 is nested in the primary coil and is integrally encapsulated in the magnetic core assembly 2. The above is the basic structure of the TLVR coupled inductor of this shape design in the current industry. As the main design for insulation optimization, in this embodiment, the surface of the preliminarily formed primary coil 1a is coated with a resin insulation layer to form an insulating primary coil 1b with full surface coverage and full isolation. On the other hand, the above four pins are partially higher than the end surface of the magnetic core assembly, and the laser stripping area of the four pins is smaller than the insulation area between the formed terminal PIN pins, such as Figure 5 Shown at bottom.
[0023] From the perspective of further detailed implementation, the outer side of the primary coil 1b is gap-matched with the inner wall of the cavity 21a, the gap between the primary coil 1b and the secondary coil 3 is gap-matched, and the symmetrical center planes of the three coincide; that is, the lateral assembly gaps of the three are uniform. Furthermore, the height of the protrusion 21b, the thickness of the primary coil 1b and the thickness of the secondary coil 3 molding are consistent, and the two coils are tightly clamped in the magnetic core assembly. Moreover, the protrusion 21b is offset and positioned close to the pin, so that the pin formed by the secondary coil is partially higher than the end face of the magnetic core assembly.
[0024] Usually, when the assembly is completed, large pits and pores will be formed at the end surface of the magnetic core assembly. In actual product manufacturing, the gaps at the end surface can be filled with magnetic powder and hot-pressed into a surface shape lower than the exposed part of the pin. Figure 2 , Figure 3 , Figure 4 In the preferred embodiment shown in the figure, the terminal PIN pins 12a, 32a, 31a, and 11a obtained by laser stripping of the four pins are all located on the same side of the end surface 22 of the magnetic core assembly, as shown in FIG. Figure 6 As shown in α.
[0025] In addition, in order to further isolate the terminal PIN pins formed by the primary coil and increase the creepage distance, the terminal PIN pins obtained by laser stripping the paint of the second and third pins can be located at the end surface of the magnetic core assembly, and the terminal PIN pins obtained by laser stripping the paint of the first and fourth pins can be located at the side corner of the magnetic core assembly close to the end surface, such as Figure 6 As shown in β.
[0026] Combination Figures 2 to 5 As shown, the production and assembly process of the inductor is described below to further understand the reasons for the performance improvement brought about by the above structural optimization.
[0027] First, the primary coil is a good conductor after being taken and bent, which is not conducive to the insulation isolation of the inside of the inductor package and the terminal PIN pin. Therefore, it is considered to be completely coated with silicone resin or high-temperature epoxy resin and baked for finalization. The process parameters of the baking treatment are baking at a temperature range of 150~200℃ for one hour. At the same time, the secondary coil is cut and bent to form. Since the magnetic core is assembled and packaged after separate processing, it mainly includes two parts: T-type magnetic core and U-type magnetic core. After filling the powder material with a customized mold, it is molded at a molding pressure of 8-16 tons / cm², and then baked at a temperature range of 120~200℃ for two to four hours. The structural strength of the two-part magnetic core meets the requirements of later product assembly and packaging. The powder material is a mixture of one or two or more FeSiAl / FeNi / FeSiCr / Febased amorphous / nanocrystalline.
[0028] After the prefabrication and pretreatment of the assembled parts, the primary coil is loaded into the cavity of the U-shaped magnetic core, and the secondary coil is wrapped on the convex column of the T-shaped magnetic core. The two parts are then closed together to form a block, and then hot-pressed. The semi-finished product is then sprayed to obtain the full-surface insulator A. Finally, the paint is laser stripped at each pin position to expose the metal surface of each pin with a sufficient spacing as the terminal PIN pin, and the finished product B is obtained. Of course, the finished product B can also be further electroplated.
[0029] From the above introduction and detailed description of the embodiment of the TLVR coupled inductor with optimized primary and secondary coil insulation, it can be seen that compared with the prior art, this solution has substantial characteristics and progress. Its technical effect is as follows: by forming a resin insulation layer on the surface of the primary coil before assembly, the two-stage coil in the inductor is fully isolated, and the positioning and area control of the laser paint stripping are combined to greatly improve the insulation performance between the two-stage coils, that is, the ability to withstand a voltage greater than 150VDC; at the same time, the coupling coefficient between the two-stage coils is kept higher than 0.9.
[0030] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the principles of the present application shall be included in the protection scope of the present application.
Claims
1. A TLVR coupled inductor with optimized primary and secondary coil insulation, comprising a primary coil, a secondary coil and a magnetic core assembly, wherein the primary coil is formed into a wide U-shaped portion based on a square-shaped conductive metal strip and assembled to be compatible with the cavity of the U-shaped magnetic core in the magnetic core assembly, and the two ends of the primary coil are bent outward to form a first pin and a fourth pin, the secondary coil is formed into a narrow U-shaped portion based on a conductive metal sheet and is sleeved on a convex column of a T-shaped magnetic core in the magnetic core assembly, and the two ends of the secondary coil are bent to wrap the convex column to form a second pin and a third pin, the secondary coil is nested in the primary coil and is integrally packaged in the magnetic core assembly, characterized in that: The surface of the primary coil is coated with a resin insulating layer, the four pins are partially higher than the end surface of the magnetic core assembly, and the laser paint stripping area of the four pins is smaller than the insulating area between the formed terminal PIN pins.
2. The TLVR coupled inductor with optimized primary and secondary coil insulation according to claim 1, characterized in that: The outer side of the primary coil is gap-matched with the inner wall of the cavity, the primary coil is gap-matched with the secondary coil, and the symmetric center planes of the three coincide.
3. The TLVR coupled inductor with optimized primary and secondary coil insulation according to claim 1, characterized in that: The gaps at the end surface are filled with magnetic powder material and hot-pressed to form a surface shape lower than the exposed portion of the tube pin.
4. The TLVR coupled inductor with optimized primary and secondary coil insulation according to claim 1, characterized in that: The terminal PIN pins obtained by laser paint stripping of the four pins are all located on the end surface of the magnetic core assembly.
5. The TLVR coupled inductor with optimized primary and secondary coil insulation according to claim 1, characterized in that: The terminal PIN pins obtained by laser stripping the paint of the second and third pins are located at the end surface of the magnetic core assembly, and the terminal PIN pins obtained by laser stripping the paint of the first and fourth pins are located at the side corner of the magnetic core assembly close to the end surface.
6. The TLVR coupled inductor with optimized primary and secondary coil insulation according to claim 1, characterized in that: The height of the protruding column, the thickness of the primary coil and the thickness of the secondary coil are consistent, and the two coils are tightly clamped in the magnetic core assembly.
7. The TLVR coupled inductor with optimized primary and secondary coil insulation according to claim 1, characterized in that: The protrusion is positioned close to the pin and offset so that the pin formed by the secondary coil is partially higher than the end surface of the magnetic core assembly.
8. The TLVR coupled inductor with optimized primary and secondary coil insulation according to claim 1, characterized in that: The T-shaped magnetic core and the U-shaped magnetic core in the magnetic core assembly are pre-pressed bodies filled with magnetic powder material in a preset mold, and the TLVR coupled inductor is a hot-pressed body composed of two magnetic cores and a two-stage coil.