Laminated inductor and manufacturing method thereof
By compensating the line width widening of the wound conductor of the laminated inductor during the printing process, the problem of degradation of the pass rate caused by poor printing in the prior art is solved, and the effect of improving the yield of the winding conductor and the resistance value of the coil conductor is achieved.
Patent Information
- Application Number
- CN202411983566.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2025-04-08
AI Technical Summary
During the printing process, existing stacked inductors are prone to poor conditions such as conductor pattern line width being too narrow and circuit breaking, resulting in a decrease in the pass rate.
By widening the line width of the winding conductor perpendicular to the printing processing direction, the line width of the winding conductor in the width direction of the laminated body is greater than or smaller than the line width of the winding conductor in the length direction of the laminated body, ensuring that the resistance value of the coil conductor after printing is not too high.
The yield of the winding conductor is improved, the resistance value of the coil conductor is not too high, and the pass rate of the stacked inductor is improved.
Smart Images
Figure CN119786190A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of inductors, and in particular to a stacked inductor and a manufacturing method thereof. Background Art
[0002] Inductors are a common electronic component that mainly plays the role of filtering, oscillating, delaying, trapping, screening signals, filtering noise, stabilizing current, and suppressing electromagnetic interference in circuits. According to different structures, inductors can be divided into wound inductors, thin film inductors, laminated inductors, etc. Among them, laminated inductors are characterized by miniaturization and thinness, and are widely used in small circuits. At present, laminated inductors use screen printing to print conductor paste on the insulating layer to form a wound conductor. However, due to the small line width of the wound conductor, it is easy to have undesirable conditions such as too narrow line width of the conductor pattern and open circuit during printing. In addition, during printing, the defective rate of the part of the wound conductor perpendicular to the printing direction will be significantly higher than that of the part parallel to the printing direction, which will cause the coil resistance to be high and the qualified rate of the laminated inductor to decrease. Summary of the invention
[0003] An object of the present invention is to provide a laminated inductor, which improves the yield of a wound conductor and the qualified rate of the laminated inductor.
[0004] In order to achieve the above object, the present invention provides a stacked inductor, comprising:
[0005] A stacked body, comprising a plurality of insulating layers stacked and arranged along a height direction of the stacked body;
[0006] A coil conductor is provided in the stack, the coil conductor includes a plurality of groups of connected winding conductors and through conductors, the winding conductor is provided on the surface of the insulating layer, the through conductor penetrates the insulating layer, the winding conductor located at the uppermost end of the stack is connected to the first lead end, and the winding conductor located at the lowermost end of the stack is connected to the second lead end;
[0007] Two groups of external electrodes are installed at two ends of the stacked body along the length direction of the stacked body, and the two groups of external electrodes are electrically connected to the first lead-out end and the second lead-out end respectively;
[0008] Among them, the line width of the wound conductor along the width direction of the stack is greater than the line width of the wound conductor along the length direction of the stack, or the line width of the wound conductor along the width direction of the stack is smaller than the line width of the wound conductor along the length direction of the stack.
[0009] In some embodiments, the coiled conductor is in the shape of a polygon, a circle, an ellipse, or a quadrilateral.
[0010] In some embodiments, the line width of the wound conductor along the length direction of the stacked body is denoted as Dy, and 30 μm≤Dy≤100 μm is satisfied.
[0011] In some embodiments, the line width of the wound conductor along the width direction of the stack is denoted as Dx, and the difference between the line width and Dy is d=|Dx-Dy|, then 0.03≤d / Dy≤0.2 is satisfied.
[0012] In another aspect, the present invention provides a method for manufacturing a stacked inductor, comprising:
[0013] providing an insulating layer, and forming a through hole in the insulating layer;
[0014] Printing a conductive paste on the surface of the insulating layer to form a winding conductor, and filling the conductive paste in the through hole to form a through conductor, so that the winding conductor is connected to the through conductor, wherein the line width of the winding conductor along the width direction of the laminate is not equal to the line width of the winding conductor along the length direction of the laminate;
[0015] Arranging a plurality of the insulating layers in layers to form a green body of a laminate;
[0016] The laminated inductor is obtained by subjecting the green body of the laminate to debinding, sintering and external electrode manufacturing.
[0017] In some embodiments, when the width direction of the stack is perpendicular to the printing direction, the line width of the coiled conductor along the width direction of the stack is greater than the line width of the coiled conductor along the length direction of the stack.
[0018] In some embodiments, when the length direction of the stack is perpendicular to the printing process direction, the line width of the coiled conductor along the length direction of the stack is greater than the line width of the coiled conductor along the width direction of the stack.
[0019] In some embodiments, the thixotropy index of the conductive paste is 2-3.
[0020] In some embodiments, the thixotropy index of the conductive paste is 3-5.
[0021] The present invention provides a stacked inductor and a manufacturing method thereof, which has the following beneficial effects compared with the prior art:
[0022] The present invention can avoid undesirable situations such as too narrow line width and circuit breakage of the conductor pattern after printing by widening the line width of the winding conductor perpendicular to the printing processing direction, thereby improving the yield of the winding conductor printing, ensuring that the resistance value of the coil conductor is not too high, and improving the qualified rate of the laminated inductor. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 A three-dimensional schematic diagram of a stacked inductor provided in some embodiments of the present invention.
[0024] Figure 2 for Figure 1 Schematic diagram of the cross-sectional structure along position A.
[0025] Figure 3 for Figure 1 Schematic diagram of the cross-sectional structure at position B along the middle.
[0026] Figure 4 for Figure 1 Schematic diagram of the cross-sectional structure along position C.
[0027] Figure 5 A schematic diagram of a structure in which a wound conductor of a stacked inductor is in a trapezoidal shape is provided in some embodiments of the present invention.
[0028] Figure 6 A schematic diagram of a structure in which a wound conductor of a stacked inductor is in a curved quadrilateral shape is provided in some embodiments of the present invention.
[0029] Figure 7 A schematic diagram of a stacked inductor with a wound conductor in a rectangular shape is provided in some embodiments of the present invention.
[0030] Figure 8 A schematic flow chart of a method for manufacturing a stacked inductor provided for some other embodiments of the present invention.
[0031] In the figure: 1, laminated body; 11, insulating layer; 2, coil conductor; 21, wound conductor; 22, through conductor; 23, first lead terminal; 24, second lead terminal; 3, external electrode; x, width direction of the laminated body; y, length direction of the laminated body; z, height direction of the laminated body. DETAILED DESCRIPTION
[0032] The technical solutions 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, rather than all the embodiments.
[0033] It should be understood that, in the description of the present application, the terms "upper", "lower", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. The terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated, that is, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In addition, unless otherwise specified, "multiple" means two or more.
[0034] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.
[0035] like Figure 1-7 As shown, the stacked inductor provided by some embodiments of the present invention includes a stacked body 1, a coil conductor 2 and two sets of external electrodes 3. When working, the two sets of external electrodes 3 are connected to the circuit, and after power is turned on, the coil conductor 2 converts electrical energy into magnetic energy for storage. When the stacked inductor is in a state where no current flows through, it will try to block the flow of current when the circuit is connected; conversely, when the stacked inductor is in a state where current flows through, it will try to maintain the current unchanged when the circuit is disconnected.
[0036] The laminate 1 includes a plurality of insulating layers 11 stacked in a height direction z of the laminate. The insulating layers 11 protect the coil conductor 2 and can increase the inductance value. In addition, the laminate 1 is formed by combining the plurality of insulating layers 11 in a stacked arrangement, so that the volume and weight of the laminated inductor are small, which is convenient for integration and installation, and also has a good heat dissipation effect.
[0037] The coil conductor 2 is arranged in the laminate 1, and the coil conductor 2 includes a plurality of groups of connected winding conductors 21 and through conductors 22. The winding conductor 21 is arranged on the surface of the insulating layer 11, and the through conductor 22 penetrates the insulating layer 11. The two ends of the coil conductor 2 are correspondingly provided with a first lead-out end 23 and a second lead-out end 24. Specifically, the coil conductor 2 is wound around the height direction of the laminate 1 to form a coil, and the winding conductor 21 located at the uppermost end of the laminate 1 is connected to the first lead-out end 23, and the winding conductor 21 located at the lowermost end of the laminate 1 is connected to the second lead-out end 24.
[0038] Two sets of external electrodes 3 are installed at the two ends of the stack body 1 along the length direction y of the stack body, and the two sets of external electrodes 3 are respectively electrically connected to the first lead end 23 and the second lead end 24. The two sets of external electrodes 3 can be connected to the two ends of the coil conductor 2 to ensure normal power supply.
[0039] like Figure 2-4 As shown, in some embodiments, the width direction x of the stack 1 is taken as a direction perpendicular to the printing process, and the line width of the winding conductor 21 along the width direction x of the stack 1 is made greater than the line width of the winding conductor 21 along the length direction y of the stack 1.
[0040] like Figure 7 As shown, in other embodiments, the length direction y of the stack 1 is used as the direction perpendicular to the printing process, and the line width of the winding conductor 21 along the width direction x of the stack 1 is made smaller than the line width of the winding conductor 21 along the length direction y of the stack 1. The purpose is to ensure that the line width of the winding conductor 21 along the direction perpendicular to the printing process is wide enough to facilitate processing and manufacturing.
[0041] Based on the above structural setting, the yield rate of printing the wound conductor 21 can be improved, the resistance value of the coil conductor 2 is ensured not to be too high, and the qualified rate of the laminated inductor is improved.
[0042] In some embodiments, the winding conductor 21 is in the shape of a polygon, a circle, an ellipse, or a curved quadrilateral. The specific shape is selected according to actual design requirements.
[0043] In some embodiments, the line width of the wound conductor 21 along the length direction y of the laminate 1 is denoted as Dy, and 30 μm≤Dy≤100 μm is satisfied.
[0044] In some embodiments, the line width of the winding conductor 21 along the width direction x of the laminate 1 is denoted as Dx, and the difference between the line width and Dy is d=|Dx-Dy|, then 0.03≤d / Dy≤0.2 is satisfied.
[0045] like Figure 8 As shown, some other embodiments of the present invention provide a method for manufacturing a stacked inductor, comprising the following steps:
[0046] S1. providing an insulating layer and forming a through hole on the insulating layer;
[0047] S2, printing a conductive paste on the surface of the insulating layer to form a winding conductor, and filling a conductive paste in the through hole to form a through conductor, so that the winding conductor is connected to the through conductor, when the width direction x of the laminate 1 is perpendicular to the printing direction, the line width of the winding conductor 21 along the width direction x of the laminate 1 is greater than the line width of the winding conductor 21 along the length direction y of the laminate 1; when the length direction y of the laminate 1 is perpendicular to the printing direction, the line width of the winding conductor 21 along the length direction y of the laminate 1 is greater than the line width of the winding conductor 21 along the width direction x of the laminate 1;
[0048] S3, forming a green body of a laminate by stacking a plurality of insulating layers;
[0049] S4. The green body of the laminate is subjected to binder removal, sintering and external electrode manufacturing to obtain a laminated inductor.
[0050] In some embodiments, the insulating layer is obtained by preparing an insulating layer film by a tape casting method.
[0051] In some embodiments, the thixotropy index of the conductive paste is 2-3, and the value of d / Dy is 0.03-0.1.
[0052] In some embodiments, the thixotropy index of the conductive paste is 3-5, and the value of d / Dy is 0.1-0.2.
[0053] The size of the above-mentioned difference d can be adjusted according to the thixotropy index of the slurry. When the thixotropy of the slurry is large, the viscosity is recovered faster after printing, and the actual printed line width is narrower. It is necessary to increase the difference d of the designed line width to ensure that the actual line width meets the requirements.
[0054] In some embodiments, the outer electrode is manufactured through a sintering process.
[0055] In some embodiments, the conductive paste includes, by weight, 60 parts of silver powder, 12 parts of ethyl cellulose, 20 parts of pine alcohol, and 3 parts of thixotropic agent polyamide wax.
[0056] In order to verify the relationship between the qualified rate of the laminated inductor and the specific value of the line width of the winding conductor, the specific values of different line widths of the winding conductors of Examples 1-7 are provided, and other parameters are the same. The difference d and the value of d / Dy are calculated, as shown in Table 1 below:
[0057] Table 1
[0058] Serial number Dy / μm Dx / μm d / μm d / Dy Example 1 45 50 5 0.111 Example 2 45 52 7 0.156 Example 3 45 54 9 0.2 Example 4 30 33 3 0.1 Example 5 70 80.5 10.5 0.15 Example 6 100 120 20 0.2 Example 7 45 55 10 0.222
[0059] In addition, Examples 8-13 are provided, which differ from Example 1 only in that the thixotropic index of the conductive paste is changed by changing the amount of the thixotropic agent added in the conductive paste, or the difference d is also adjusted accordingly, as shown in Table 2:
[0060] Table 2
[0061] Serial number Thixotropic agent parts / parts Thixotropy index d / μm d / Dy Example 1 3 3.6 5 0.111 Example 8 5 5.0 5 0.111 Example 9 2 2.8 4 0.089 Example 10 1 2.1 1.5 0.033 Embodiment 11 1 2.1 1 0.022 Example 12 1 2.1 5 0.111 Embodiment 13 5 5.0 3 0.067
[0062] And, provide examples 14-16, examples 14 and 15 and example 1 (see Figures 2 to 4 ) is only different in that: Figure 5 As shown, the wound conductor of Example 14 is trapezoidal; Figure 6 As shown, the winding conductor of Example 15 is a curved quadrilateral. The difference between Example 16 and Example 1 is that the printing direction of Example 16 is different from that of Example 1. Figure 7 As shown, the line width of the wound conductor along the width direction of the laminate is smaller than the line width of the wound conductor along the length direction of the laminate.
[0063] A comparative example 1 is also provided, which differs from the embodiment 1 in that Dx and Dy of the comparative example 1 are both equal to 45 μm, and no widening compensation is performed.
[0064] Examples 1-16 and Comparative Example 1 were evaluated by the following method:
[0065] Appearance inspection: Observe the printed coil conductor through an optical microscope, and divide the number of products with short-side defects, missing printing, ink soaking, etc. by the total production volume to obtain the coil appearance defect rate.
[0066] Conductive test: The multilayer inductor is tested by power-on, and the resistivity of the product is measured by a resistivity meter. Products with poor printing on the short side have high resistivity or even short circuits. The defective products are divided by the total production volume to obtain the coil conductivity defect rate.
[0067] Inductance L value and quality factor Q value: obtained by testing the multilayer inductor at a frequency of 100MHz using an impedance analyzer.
[0068] Specific performance parameters are shown in Table 3 below:
[0069] Table 3
[0070]
[0071]
[0072] By analyzing the data in Table 3, it can be seen that in Examples 1-16, by widening the portion of the winding conductor perpendicular to the printing direction to compensate, printing defects can be reduced and the product qualification rate can be improved. Comparative Example 1 does not perform widening compensation, and its defect rate is relatively high.
[0073] By comparing Example 7 with Examples 1-3, and by comparing Examples 10-12, it can be seen that when the ratio of the widening compensation size d to the line width Dy is 0.03-0.2, the technical effect of the present solution can be better achieved. The d / Dy value of Example 7 is too large, and as a result, the L value and Q value are lower than those of Examples 1-3. The d / Dy value of Example 11 is too small, and its effect of alleviating poor printing is not as good as that of Examples 10 and 12.
[0074] By comparing Example 1 with Examples 8-13, it can be seen that adjusting the value of d / Dy according to the thixotropy of the conductive paste can better achieve the technical effect of the present solution. The paste of Example 12 has a smaller thixotropy and a larger d / Dy, and its L value and Q value are lower than those of Example 1 and Example 8; the paste of Example 13 has a larger thixotropy and a smaller d / Dy, and its defective rate is higher than that of Example 8.
[0075] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.
Claims
1. A stacked inductor, characterized in that: include: A stacked body, comprising a plurality of insulating layers stacked and arranged along a height direction of the stacked body; A coil conductor is provided in the stack, the coil conductor includes a plurality of groups of connected winding conductors and through conductors, the winding conductor is provided on the surface of the insulating layer, the through conductor penetrates the insulating layer, the winding conductor located at the uppermost end of the stack is connected to the first lead end, and the winding conductor located at the lowermost end of the stack is connected to the second lead end; Two groups of external electrodes are installed at two ends of the stacked body along the length direction of the stacked body, and the two groups of external electrodes are electrically connected to the first lead-out end and the second lead-out end respectively; Among them, the line width of the wound conductor along the width direction of the stack is greater than the line width of the wound conductor along the length direction of the stack, or the line width of the wound conductor along the width direction of the stack is smaller than the line width of the wound conductor along the length direction of the stack.
2. The laminated inductor according to claim 1, wherein: The coiled conductor is in the shape of a polygon, a circle, an ellipse, or a quadrilateral with curved edges.
3. The laminated inductor according to claim 1, wherein: The line width of the wound conductor along the length direction of the laminate is denoted as Dy, and 30 μm ≤ Dy ≤ 100 μm is satisfied.
4. The laminated inductor according to claim 3, wherein: The line width of the wound conductor along the width direction of the stacked body is denoted as Dx, and the difference between it and Dy is d=|Dx-Dy|, which satisfies 0.03≤d / Dy≤0.
2.
5. A method for manufacturing a laminated inductor according to any one of claims 1 to 4, characterized in that: include: providing an insulating layer, and forming a through hole in the insulating layer; Printing a conductive paste on the surface of the insulating layer to form a winding conductor, and filling the conductive paste in the through hole to form a through conductor, so that the winding conductor is connected to the through conductor; wherein the line width of the winding conductor along the width direction of the laminate is not equal to the line width of the winding conductor along the length direction of the laminate; Arranging a plurality of the insulating layers in layers to form a green body of a laminate; The laminated inductor is obtained by subjecting the green body of the laminate to debinding, sintering and external electrode manufacturing.
6. The method for manufacturing a laminated inductor according to claim 5, wherein: When the width direction of the laminate is perpendicular to the direction of printing, the line width of the coiled conductor along the width direction of the laminate is made larger than the line width of the coiled conductor along the length direction of the laminate.
7. The method for manufacturing a laminated inductor according to claim 5, wherein: When the length direction of the laminate is perpendicular to the direction of printing, the line width of the coiled conductor along the length direction of the laminate is made larger than the line width of the coiled conductor along the width direction of the laminate.
8. The method for manufacturing a laminated inductor according to claim 5, wherein: The thixotropy index of the conductive paste is 2-3, and the value of d / Dy is 0.03-0.
1.
9. The method for manufacturing a laminated inductor according to claim 5, wherein: The thixotropy index of the conductive paste is 3-5, and the value of d / Dy is 0.1-0.2.