Manufacturing method of high-performance film inductance coil

Abstract

The invention provides a manufacturing method of a high-performance film inductance coil, which comprises the following steps: S1, preparing two copper foils, processing a plurality of first coils in array arrangement on the first copper foil, and processing a plurality of second coils in array arrangement on the second copper foil; the first coil and the second coil are in axial symmetry in the first direction, the tail end of each coil exceeds half of the length of the coil in the second direction, and the second direction is perpendicular to the first direction; s2, a via hole is formed in the tail end of each first coil; s3, printing an insulating layer on the surface of each second coil; s4, the first copper foil is positioned, translated and overlaid on the second copper foil through the whole pattern, and the first coil and the second coil are in one-to-one correspondence to form a double-sided copper foil; the tail end of the second coil coincides with the via hole; s5, removing the insulating layer corresponding to the via hole, and injecting conductive metal; and S6, the conductive metal is cured, so that the surface of the second coil is conducted with the first coil, and a whole coil body is formed.

Description

Technical Field

[0001] The present invention relates to the field of inductor manufacturing, and in particular to a method for manufacturing a high-performance thin-film inductor coil. Background Art

[0002] With the rapid development of electronic technology, especially in the fields of integrated circuits (ICs), radio frequency identification (RFID), wireless communications, automotive electronics, and power electronics, the performance requirements for inductor components are increasing. As one of the key components in electronic circuits, the performance of inductors directly affects the overall efficiency and stability of the circuit. Although traditional inductor devices, such as wound inductors or ferrite inductors, can meet basic needs, their shortcomings of large size, low efficiency, and high cost are becoming increasingly prominent in high-frequency, high-density integration environments.

[0003] In this context, thin-film inductor coils have gradually become a hot topic in industry research due to their compact structure, good high-frequency performance, and easy integration. Existing thin-film inductor coil technology usually uses a precise thin-film process to alternately lay conductive layers and insulating layers on a substrate in a specific direction. Each layer undergoes a carefully designed photolithography and / or etching process to form a complex and precise conductive coil pattern. This stacked structure not only achieves the miniaturization of the inductor, but also improves the inductance and quality factor (Q value) of the inductor by optimizing the layout of multiple conductive layers.

[0004] However, despite the significant progress made in the existing thin-film inductor coil technology, there are still some urgent problems to be solved in the application scenarios that pursue higher performance requirements. Specifically, according to the magnetic circuit calculation, the existing design often has performance redundancy or waste, that is, the magnetic flux of some conductive layers or coil areas is not fully utilized, resulting in the overall inductor efficiency not being optimal. This performance waste not only limits the application of inductors in high-precision and high-efficiency circuits, but also increases material costs and production complexity. Summary of the invention

[0005] In order to solve the above problems, the purpose of the present invention is to provide a method for manufacturing a high-performance thin-film inductor coil, and also to improve the coil performance.

[0006] The present invention is achieved through the following technical solutions:

[0007] A method for manufacturing a high-performance thin-film inductor coil, comprising:

[0008] S1. Prepare two copper foils, process a plurality of first coils arranged in an array on the first copper foil, and process a plurality of second coils arranged in an array on the second copper foil; the first coils and the second coils are axially symmetrical in a first direction, and each coil end exceeds half of the length of the coil in the second direction, and the second direction is perpendicular to the first direction;

[0009] S2, opening a conducting hole at the end of each first coil;

[0010] S3, printing an insulating layer on the surface of each second coil;

[0011] S4, positioning and translating the first copper foil onto the second copper foil by whole-page pattern positioning, with the first coil corresponding to the second coil one by one to form a double-sided copper foil; the end of the second coil coincides with the conductive hole;

[0012] S5, removing the insulating layer corresponding to the via hole and injecting a conductive metal;

[0013] S6. Solidify the conductive metal to make the surface of the second coil conductive with the first coil to form a full-page coil body.

[0014] Furthermore, the method of removing insulation in S5 includes removing insulation by laser.

[0015] Furthermore, the method of curing the conductive metal in S6 includes placing the double-sided copper foil injected with the conductive metal into a reflow soldering process to solidify the conductive metal.

[0016] Furthermore, before removing the insulation corresponding to the via hole in S5, the step further includes curing the insulation layer by high temperature and pressure to combine the first copper foil with the second copper foil.

[0017] A method for manufacturing a high-performance thin-film inductor coil, comprising:

[0018] S1. Prepare two copper foils, process a plurality of first coils arranged in an array on the first copper foil, and process a plurality of second coils arranged in an array on the second copper foil; the first coil and the second coil are axially symmetrical, and the end of each coil exceeds half of its length in the direction perpendicular to the symmetry axis;

[0019] S2. Print insulation on the surface of each second coil, avoiding the end of the coil;

[0020] S3, printing a conductive metal on the end surface of the second coil;

[0021] S4, positioning and translating the first copper foil onto the second copper foil by the whole-page pattern, with the first coil corresponding to the second coil one by one, to form a double-sided copper foil;

[0022] S5. Solidify the conductive metal and the insulating layer to make the surface of the second coil conductive with the first coil, thereby forming a complete coil body.

[0023] Furthermore, the method for curing the conductive metal includes curing the conductive metal and the insulating layer by high temperature and pressure, combining the first coil and the second coil, and connecting the ends of the two coils by the conductive metal.

[0024] Furthermore, the method for processing a plurality of first coils arranged in an array and the method for processing a plurality of second coils arranged in an array include: preparing a first copper foil and a second copper foil of a first thickness, and obtaining a full-page first coil of a first thickness and a full-page second coil of a first thickness and / or a first width by etching; electroplating the first coil and the second coil to a second thickness and / or a second width; or, preparing a first copper foil and a second copper foil of a second thickness, etching from one side of the first copper foil according to the pattern of the first coil until the depth of the formed first line spacing channel reaches half of the second thickness, and then etching from the other side of the first copper foil according to the pattern of the first coil until the formed second line spacing channel is connected to the first line spacing channel; the method for processing the second coil with the second copper foil is similar.

[0025] Furthermore, the conductive metal is semi-liquid solder paste.

[0026] Furthermore, the insulating layer is semi-liquid high-temperature curing insulating glue.

[0027] Furthermore, the method further includes forming an insulating film on the surface of the full-page coil body after forming the full-page coil body.

[0028] Furthermore, a method of forming an insulating film on the surface of the entire coil body includes using a Parylene vacuum coating process or an atomic accumulation deposition process.

[0029] Compared with the prior art, the technical solution of the present invention and its beneficial effects are as follows:

[0030] The double-layer multi-turn coil manufacturing method of the present invention improves the utilization rate of the coil. Through experiments, it is known that the scheme of the present invention improves the performance of the coil in terms of direct current resistance DCR, saturation current and temperature rise current. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The copper foil with two axial symmetry provided by the embodiment of the present invention;

[0032] Figure 2 The embodiment of the present invention provides a via hole at the end of the first coil on the first copper foil;

[0033] Figure 3 An insulating layer is provided on the surface of the second coil on the second copper foil provided in an embodiment of the present invention;

[0034] Figure 4 The first copper foil provided in the embodiment of the present invention is superimposed on the second copper foil;

[0035] Figure 5 The embodiment of the present invention provides that after removing the insulating layer corresponding to the via hole, a conductive metal is injected;

[0036] Figure 6 It is a comparison chart of the performance of the coil manufactured by the present invention and the industry specifications provided by the embodiment of the present invention.

[0037] Illustration Description:

[0038] First direction - A; Second direction - B;

[0039] First coil-10; Conducting hole-11;

[0040] Second coil - 20;

[0041] Insulation - 30;

[0042] Conductive Metal-40. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0044] A method for making a high-performance thin-film inductor coil, see Figures 1 to 5 , showing the process of high-performance thin-film inductor coils. It can be understood that in order to make the diagram clearer and easier to understand, only the manufacturing process of one coil body is shown. For example, the first coil 10 in the figure shows one, and actually several first coils arranged in an array are processed on a copper foil.

[0045] The preparation method of the present invention comprises the following steps:

[0046] S1. Prepare two copper foils. The first copper foil is used to process a plurality of first coils 10 arranged in an array. The second copper foil is used to process a plurality of second coils 20 arranged in an array. The first coils 10 and the second coils 20 are axially symmetrical in the first direction A. The end of each coil exceeds half of the length B of the coil in the second direction. The second direction B is perpendicular to the first direction A. Figure 1 The first coil 10 and the second coil 20 are symmetrical with respect to the axis of direction A. The starting end of the first coil 10 is the first electrode 12, which is located on the left side of the first coil 10. The end of the first coil 10 exceeds half of its length L in the second direction B. The dotted line in the figure indicates the position of half of L. The end of the second coil 20 exceeds half of its length L1 in the second direction B.

[0047] Among them, the method for processing a plurality of first coils arranged in an array and the method for processing a plurality of second coils arranged in an array include: preparing a first copper foil and a second copper foil of a first thickness, and obtaining a full-page first coil of a first thickness and a full-page second coil of a first thickness and / or a first width by etching; electroplating the first coil and the second coil to a second thickness and / or a second width, thereby obtaining a first coil and a second coil with a higher line height and / or a wider line width, that is, the conductive cross-sectional area of ​​the first coil and the second coil is larger.

[0048] Alternatively, a first copper foil and a second copper foil of a second thickness are prepared, and etching is performed on one side of the first copper foil according to the pattern of the first coil until the depth of the formed first line spacing channel reaches half of the second thickness, and etching is performed on the other side of the first copper foil according to the pattern of the first coil until the formed second line spacing channel is connected to the first line spacing channel, so that the obtained first coil has a higher line height, and the problem of etching depth-to-width ratio is effectively avoided, and the line width of the obtained first coil is also wider, so that the conductive cross-sectional area of ​​the coil is larger. The method of processing the second coil with the second copper foil is similar.

[0049] S2, opening a conducting hole 11 at the end of each first coil 10, such as Figure 2 shown.

[0050] S3, the surface of each second coil is printed with an insulating layer, such as Figure 3 As shown, the insulating layer is formed by curing semi-liquid non-conductive glue in a high temperature environment.

[0051] S4, the first copper foil is superimposed on the second copper foil by positioning and translating the whole-page pattern, and the first coil corresponds to the second coil one by one to form a double-sided copper foil, such as Figure 4 As shown. Since the end of the first coil 10 exceeds half of its length L in the second direction B, and the end of the second coil 20 exceeds half of its length L1 in the second direction B, the end of the first coil overlaps with the end of the second coil, and the conductive hole overlaps with the end of the second coil. At this time, there is an insulating layer between the conductive hole 11 and the corresponding upper surface of the second coil.

[0052] S5. Apply a certain pressure and high temperature to the double-sided copper foil to solidify the glue, so that the first coil 10 is combined with the second coil layer 20, and the insulating layer 30 corresponding to the conductive hole 11 is removed. At this time, the upper surface of the second coil 20 is in direct contact with the outside through the insulating layer 30 and the conductive hole 11.

[0053] S6, injecting conductive metal 40, such as semi-liquid solder paste, into the conductive hole, and solidifying the liquid solder paste by reflow soldering, so that the surface of the second coil is connected to the first coil to form a full-plate coil body. Figure 5The current flows from the second electrode 22 of the second coil 20 to the end of the second coil 22, flows through the conductive metal 40 to the end of the first coil 10, flows along the pattern of the first coil 10 to the starting end of the first coil 10, that is, the first electrode 12, and then flows out.

[0054] S7. After forming the entire coil body, an insulating film is formed on the surface of the entire coil body. The method of forming the insulating film includes using parylene vacuum coating or atomic deposition process.

[0055] Of course, the entire coil body needs to go through subsequent processes such as cutting, grinding, and sealing to form a thin film inductor until the finished product is achieved.

[0056] In another embodiment, the method for making the coil comprises the following steps:

[0057] S1. Prepare two copper foils. The first copper foil is used to process a plurality of first coils 10 arranged in an array. The second copper foil is used to process a plurality of second coils 20 arranged in an array. The first coils 10 and the second coils 20 are axially symmetrical in the first direction A. The end of each coil exceeds half of the length B of the coil in the second direction. The second direction B is perpendicular to the first direction A. Figure 1 , this step is the same as the above embodiment.

[0058] S2. An insulating layer is printed on the surface of each second coil, avoiding the end surface of the second coil when printing the insulating layer. The insulating layer is formed by semi-liquid non-conductive glue solidified in a high temperature environment.

[0059] S3, printing a conductive metal on the end surface of the second coil, that is, printing a conductive metal on the surface of the second coil on which the insulating layer is not printed in S2.

[0060] S4, the first copper foil is positioned and translated onto the second copper foil through the whole-page pattern, so that the first coil corresponds to the second coil one by one, forming a double-sided copper foil. At this time, the end of the first coil is in contact with the conductive metal.

[0061] S5, solidify the conductive metal and the insulating layer, solidify the conductive metal and the insulating layer through high temperature and pressure, combine the first copper foil with the second copper foil, and make the surface of the second coil conductive with the first coil to form a full-plate coil body. The current flows from the second electrode of the second coil to the end of the second coil, flows through the conductive metal to the end of the first coil, flows along the pattern of the first coil to the starting end of the first coil, that is, the first electrode, and then flows out.

[0062] S6. After forming the entire coil body, an insulating film is formed on the surface of the entire coil body. The method of forming the insulating film includes using parylene vacuum coating or atomic deposition process.

[0063] Of course, the entire coil body needs to go through subsequent processes such as cutting, grinding, and sealing to form a thin film inductor until the finished product is achieved.

[0064] According to the magnetic circuit flow, the cross-sectional area of ​​the middle column S1, the contact area between the middle column and the upper cover or lower cover S2, the smaller the difference between S1 and S2, the higher the utilization rate. (1) According to the calculation formula of inductance L = (k*μ0*μs*N2*S) / l, the L value can be roughly calculated, where μ0 is the vacuum permeability = 4π*10 (-7) ; μs is the relative magnetic permeability of the magnetic core inside the coil, and μs=1 for an air-core coil; N2 is the square of the number of turns of the coil; S is the cross-sectional area of ​​the coil, in square meters; l is the length of the coil, in meters; the k coefficient depends on the ratio of the radius (R) to the length (l) of the coil; the calculated inductance is in Henry (H). (2) Then calculate the resistance corresponding to the inductance through: DCR=ρ×L / S; where ρ represents the resistivity of the material, L represents the length of the conductor, and S represents the cross-sectional area of ​​the conductor. (3) Then confirm through the ansys modeling and simulation software. (4) Finally, we get the following Figure 6 The parameter comparison diagram shown in the figure shows that the "H series specifications" in the first vertical direction are the specifications defined by the current industry; the data corresponding to the "improvement plan" are the test data corresponding to the present invention. It can be seen intuitively that the DC resistance DCR, saturation current and temperature rise current of the coil manufactured by the scheme of the present invention have been improved. At the same time, it can be inferred without a doubt that as the cross-sectional area S of the coil increases, the DCR decreases according to the formula. The temperature rise is related to the DCR. Through the simple industry formula: Q = I2*R*T, it can be seen that the smaller the DCR, the smaller the product heats up, that is, the larger the temperature rise current.

[0065] The smaller the magnetic circuit area of ​​the middle column and the upper and lower covers, the saturation value is obtained. Therefore, the smaller the difference between the middle column and the upper and lower covers, the greater the saturation current. It can be understood that when the double-layer multi-turn coil of the present invention is processed into a thin film inductor, the middle of each coil will be filled with magnetic material to form a middle column, and the upper and lower surfaces of each coil will also be covered with magnetic material to form an upper cover and a lower cover. Figure 5 , the area of ​​the middle column S1=π*R0 2+L0*2*R0; The contact area S2 of the upper cover or lower cover and the middle column = (π*2*R0+2*L0)*[(Hh) / 2]; wherein R0 is the radius of the semicircles on both sides of the middle column, and L0 is the length of the straight portion of the middle column; H is the thickness of the thin film inductor, h is the total thickness of the double-layer multi-turn coil of the present invention, and (Hh) / 2 is the thickness of the upper cover or lower cover. Theoretically, when S1 / S2=1, the saturation current is the largest. Therefore, during design, the design values ​​of R0, L0 and h can be adaptively adjusted according to the required height H of the final product to meet S1 / S2=1. The double-layer multi-turn coil of the present invention has symmetry between the upper and lower coils, so that when the design values ​​of R0, L0 and h theoretically meet S1 / S2=1, in fact, the difference between S1 and S2 is less than 2%, thereby greatly improving the saturation current performance of the product.

[0066] The above description shows and describes the preferred embodiments of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the invention, through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art shall not depart from the spirit and scope of the present invention, and shall be within the scope of protection of the claims attached to the present invention.

Claims

1. A method for manufacturing a high-performance thin-film inductor coil, characterized in that: include: S1. Prepare two copper foils, process a plurality of first coils arranged in an array on the first copper foil, and process a plurality of second coils arranged in an array on the second copper foil; the first coils and the second coils are axially symmetrical in a first direction, and each coil end exceeds half of the length of the coil in the second direction, and the second direction is perpendicular to the first direction; S2, opening a conducting hole at the end of each first coil; S3, printing an insulating layer on the surface of each second coil; S4, positioning and translating the first copper foil onto the second copper foil by whole-page pattern positioning, with the first coil corresponding to the second coil one by one to form a double-sided copper foil; the end of the second coil coincides with the conductive hole; S5, removing the insulating layer corresponding to the via hole and injecting a conductive metal; S6. Solidify the conductive metal to make the surface of the second coil conductive with the first coil, thereby forming a complete coil body.

2. The method for manufacturing a high-performance thin-film inductor coil according to claim 1, characterized in that: The method of removing insulation in S5 includes removing insulation using a laser.

3. The method for manufacturing a high-performance thin-film inductor coil according to claim 1, characterized in that: The method of curing the conductive metal in S6 includes placing the double-sided copper foil injected with the conductive metal into a reflow soldering process to cure the conductive metal.

4. The method for manufacturing a high-performance thin-film inductor coil according to claim 1, characterized in that: In S5, before removing the insulation corresponding to the via hole, the step further includes curing the insulation layer by high temperature and pressure to combine the first copper foil with the second copper foil.

5. A method for manufacturing a high-performance thin-film inductor coil, characterized in that: include: S1. Prepare two copper foils, process a plurality of first coils arranged in an array on the first copper foil, and process a plurality of second coils arranged in an array on the second copper foil; the first coil and the second coil are axially symmetrical, and the end of each coil exceeds half of its length in the direction perpendicular to the symmetry axis; S2. Print insulation on the surface of each second coil, avoiding the end of the coil; S3, printing a conductive metal on the end surface of the second coil; S4, positioning and translating the first copper foil onto the second copper foil by the whole-page pattern, with the first coil corresponding to the second coil one by one, to form a double-sided copper foil; S5. Solidify the conductive metal and the insulating layer to make the surface of the second coil conductive with the first coil, thereby forming a complete coil body.

6. The method for manufacturing a high-performance thin-film inductor coil according to claim 5, characterized in that: The method for curing the conductive metal includes curing the conductive metal and the insulating layer by high temperature and pressure, combining the first coil and the second coil, and connecting the ends of the two coils by the conductive metal.

7. According to the method for manufacturing a high-performance thin-film inductor coil according to claim 1 or 5, the method for processing a plurality of first coils arranged in an array and the method for processing a plurality of second coils arranged in an array include: Prepare a first copper foil of a first thickness and a second copper foil of a second thickness, and obtain a first coil of a first thickness and a second coil of a first thickness and / or a first width by etching; Plating the first coil and the second coil to a second thickness and / or a second width; Alternatively, prepare a first copper foil and a second copper foil of a second thickness, etch the first copper foil from one side according to the pattern of the first coil until the depth of the formed first line spacing channel reaches half of the second thickness, and then etch from the other side of the first copper foil according to the pattern of the first coil until the formed second line spacing channel is connected to the first line spacing channel; the method for processing the second coil with the second copper foil is the same.

8. The method for manufacturing a high-performance thin-film inductor according to claim 1 or 5, characterized in that: The conductive metal is semi-liquid solder paste.

9. The method for manufacturing a high-performance thin-film inductor coil according to claim 1 or 5, characterized in that: The insulating layer is semi-liquid high-temperature curing insulating glue.

10. The method for manufacturing a high-performance thin-film inductor according to claim 1 or 5, characterized in that: The method further includes forming an insulating film on the surface of the full-page coil body after forming the full-page coil body.

11. The method for manufacturing a high-performance thin-film inductor coil according to claim 10, characterized in that: Methods for forming an insulating film on the surface of the entire coil body include using parylene vacuum coating or atomic deposition technology.

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