An inductor

Abstract

The utility model discloses an inductance belongs to inductance technical field, including porcelain core framework and a copper wire, a copper wire is wound on porcelain core framework in axial, and the coil winding of winding on porcelain core framework at least includes two interval arrangement's coil winding, and each section coil winding adopts the way of lap winding, and the outgoing end of copper wire is connected to the electrode arranged on porcelain core framework.

Description

Technical Field

[0001] This utility model relates to an inductor and belongs to the field of inductor technology. Background Technology

[0002] With the development of electronic technology, customers have increasingly higher requirements for inductor components. For example, some customers require inductors to have both high inductance and high self-resonant frequency in their designs. Traditional wire-wound ceramic inductors cannot meet these high self-resonant frequency requirements. Figure 1 The inductor shown is an example. Traditional methods to improve self-tuning include sparse winding or replacing the material with one of lower dielectric constant. However, for high inductance, such as inductors above the μH level, the size of the ceramic core pillars limits the ability to further improve self-tuning through sparse winding; replacing the material with one of lower dielectric constant only increases the cost. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide an inductor and its manufacturing method, which can improve the self-resonant frequency of the inductor.

[0004] In order to solve the above-mentioned technical problems of this utility model, the technical solution adopted by this utility model is as follows: an inductor, including a ceramic core skeleton and a copper wire, the copper wire being axially wound on the ceramic core skeleton, the coil winding wound on the ceramic core skeleton including at least two coil windings arranged at intervals, each coil winding adopting a stacked winding method, and the lead end of the copper wire being connected to the electrodes arranged on the ceramic core skeleton.

[0005] Furthermore, the copper wire described above consists of a conductor and an outer insulating layer, wherein the outer insulating layer is made of modified polyesterimide.

[0006] Furthermore, the aforementioned ceramic core framework is a ceramic body.

[0007] Furthermore, the aforementioned ceramic core skeleton includes two side pillars and a central pillar fixedly connected between the two side pillars.

[0008] Furthermore, the aforementioned electrode is an Ag / Ag-Pt-Ni-Sn electrode, which is disposed on the top of the side post.

[0009] The beneficial effects of this utility model are as follows: Compared with the prior art, this utility model divides the original flat-wound inductor into multiple segments and layers for winding. Due to the reduction of distributed capacitance after segmentation, the segmented and stacked inductor has a higher self-resonant frequency than the traditional flat-wound inductor. Under the premise of satisfying the inductance, the segmented and stacked inductor improves the self-resonant frequency. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of an existing copper wire wound inductor structure; Figure 2This is a schematic diagram of the inductor structure in Example 1. Detailed Implementation

[0011] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0012] Example 1: As Figure 2 As shown, an inductor is an I-shaped chip inductor. Its specific structure includes a ceramic core frame 1 and a copper wire 2. The copper wire 2 is axially wound on the ceramic core frame 1. The coil winding 3 wound on the ceramic core frame 1 includes at least two spaced coil windings. Each coil winding 3 is wound in a lap-wound manner, dividing the original flat winding into multiple segments. The lead-out end of the copper wire 2 is connected to the electrode 4 arranged on the ceramic core frame 1. After the coil winding 3 is wound, the ceramic core frame 1 is installed in a shell 5 with a top opening and encapsulated with potting compound. The electrode 4 remains on the opening side of the shell 5. Due to the reduction of distributed capacitance after segmentation, the segmented lap-wound inductor has a higher self-resonant frequency than the traditional flat-wound inductor.

[0013] The copper wire 2 consists of a conductor and an outer insulating layer. The outer insulating layer is made of modified polyesterimide and has a circular cross-section. Copper serves as the conductor, and the outer insulating layer is used for insulation between adjacent coils. The ceramic core frame 1 is a ceramic body, mainly composed of alumina. The ceramic core frame 1 includes two side posts and a central post fixedly connected between the two side posts. The electrode 4 is an Ag / Ag-Pt-Ni-Sn electrode, which is disposed on the top of the side posts.

[0014] Example 2: A method for manufacturing an inductor, the method comprising the following steps: First, during the electroplating of the ceramic core skeleton, Ag / Ag-Pt, Ni, and Sn layers are used for electroplating, with the thicknesses of each layer being Ag / Ag-Pt: 10-35μm, Ni: 6-20μm, and Sn: 9±3μm, respectively. Secondly, the winding machine clamps one end of the ceramic core skeleton and starts winding with a copper wire. After winding the first section of the coil winding with a preset number of turns, a gap is left between the coil winding and the bent coil winding. The copper wire is pulled to the starting position of the next section through the winding program to continue winding. This process is repeated to complete the multi-layer stacking of multiple coil windings. Finally, the insulating film of the copper wire on the electrode is destroyed by thermo-pressure welding, and the tin melts naturally at high temperature and combines with the copper wire, thus fixing the copper wire to the electrode.

[0015] By using a segmented, overlapping winding structure, the self-harmonicity can be increased by nearly double compared to flat winding. From the self-harmonicity formula (1): SRF=1 / (2*π*√(L*C_p)) (1) With a fixed inductance L, the magnitude of the self-resonant frequency is entirely determined by the distributed capacitance Cp; the smaller Cp is, the larger the SRF is.

[0016] The distributed capacitance Cp mainly consists of inter-turn capacitance and inter-layer capacitance. For inter-turn capacitance, due to the increase in physical distance d after segmentation, according to the parallel plate capacitance formula (2): C=ε*S / (4*π*k*d) (2) The capacitance C is inversely proportional to the distance d, therefore the capacitance decreases. Furthermore, and most importantly, the coils with the highest and lowest potentials are physically separated. Two turns of coil that were originally close together in the flat winding with a huge potential difference are now placed in different segments, separated by a gap. Now, the maximum potential difference between any two turns of coil is limited to the potential difference within a segment, rather than the total voltage difference of the entire coil. For example, if divided into 4 segments, the maximum potential difference within a segment is only 1 / 4 of the total voltage. This sharp decrease in potential difference directly leads to a significant reduction in the energy stored in the capacitor and the equivalent capacitance. E = 1 / 2 * C * V 2 The effect of interlayer capacitance is relatively small because the potential difference after segmentation is very small, so its contribution to capacitance is also very small.

[0017] Specific example: The non-magnetic inductor design uses a 3.9μH inductance, with a U-shaped ceramic core measuring 2.43mm in length, 2mm in width, and 1.8mm in height. The center column measures 1.43mm in length and 2mm in width, using 0.05mm diameter enameled copper wire divided into 6 segments. Each segment has 2 / 3 / 5, 1 / 3 / 5, 1 / 2 / 4, 1 / 2 / 4, 1 / 2 / 4, and 1 / 2 / 4 turns respectively, with a 0.02~0.03mm gap between each segment. Testing showed that this example achieves a self-resonant frequency of 110MHz, while a conventionally wound inductor with the same number of turns and dimensions only achieves a self-resonant frequency of 60MHz. This invention increases the self-resonant frequency by 180%.

[0018] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. An inductor, characterized in that, It includes a ceramic core skeleton and a copper wire. The copper wire is axially wound on the ceramic core skeleton. The coil winding wound on the ceramic core skeleton includes at least two coil windings arranged at intervals. Each coil winding adopts a stacked winding method. The lead end of the copper wire is connected to the electrode arranged on the ceramic core skeleton.

2. An inductor according to claim 1, characterized in that, The copper wire consists of a conductor and an outer insulating layer, the outer insulating layer being made of modified polyesterimide.

3. An inductor according to claim 1, characterized in that, The ceramic core skeleton is a ceramic body.

4. An inductor according to claim 1, characterized in that, The ceramic core skeleton includes two side columns and a central column fixedly connected between the two side columns.

5. An inductor according to claim 4, characterized in that, The electrode is an Ag / Ag-Pt-Ni-Sn electrode, which is disposed on the top of the side post.

Images