A laminated chip inductor

Abstract

The application provides a laminated chip inductor, and relates to the field of electronic components. The laminated chip inductor comprises at least one stacked unit, the stacked unit comprises a first printed layer and a second printed layer, the coil structure of the first printed layer comprises a first lead hole and a second lead hole, the coil structure of the second printed layer comprises a third lead hole and a fourth lead hole, the projection of adjacent upper and lower coil structures is superposed to form a surrounding structure, the first lead hole and the third lead hole are used for connecting the first printed layer and the second printed layer, the second lead hole and the fourth lead hole are used for connecting two adjacent stacked units, at least one of two corners far away from the lead hole in the coil structure is an arc corner, and the arc corners of the first printed layer and the second printed layer are located at the same corner position in the stacking direction. By arranging the arc corner, the accumulation of electric charges at the corner when the electric charges flow through the right-angle structure is avoided, the error between the actual L value and the theoretical L value is reduced, and the Q value is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of electronic components, and particularly relates to a laminated chip inductor. BACKGROUND

[0002] The laminated chip inductor is prepared by alternately printing a plurality of layers of ferrite or ceramic slurry and conductive slurry to obtain a laminated body containing a plurality of internal electrodes, then low-temperature co-sintering to form an inductor coil with a closed magnetic circuit, and then coating an end electrode.

[0003] The inductance (L value) and the quality factor (Q value) are the most important parameters and quality indicators of the laminated chip inductor. In related technologies, the required L value is obtained by designing and controlling the number of layers of the laminated body and the screen structure of the printed internal electrodes. However, there is a certain error value between the actual obtained L value and the theoretically designed L value. The existence of the error value leads to a decrease in the inductance accuracy of the laminated chip inductor. In addition to changing the type of material used, the Q value can also be improved by designing the internal electrode. However, the process difficulty of achieving the required printing accuracy and stable printing repeatability also increases accordingly. Poor printing quality or poor reproducibility leads to a larger error value between the theoretical L value and the theoretically designed L value. SUMMARY

[0004] The main purpose of the present application is to provide a laminated chip inductor that can reduce the error between the theoretical L value and the actual L value while simultaneously meeting the demand for improving the Q value.

[0005] To achieve the above-mentioned purpose, one aspect of the present application provides a laminated chip inductor, comprising:

[0006] at least one stacking unit, the stacking unit comprising a first printing layer and a second printing layer, the first printing layer and the second printing layer each comprising a ceramic layer and a coil structure on the ceramic layer, the projections of the coil structures of adjacent upper and lower coil structures being combined in a surrounding structure, the coil structure of the first printing layer comprising a first through hole as a starting end and a second through hole as a terminating end, and the coil structure of the second printing layer comprising a third through hole as a terminating end and a fourth through hole as a starting end;

[0007] the first through hole and the third through hole are used to connect the first printing layer and the second printing layer, and the second through hole and the fourth through hole are used to connect two adjacent stacking units;

[0008] the coil structure comprises four corners, and at least one of the two corners farthest from the through hole is an arc-shaped corner;

[0009] The arc-shaped corner has a first direction circumscribed side length greater than 0 and less than or equal to half of the first direction side length of the coil structure; the arc-shaped corner has a second direction circumscribed side length greater than 0 and less than or equal to half of the second direction side length of the coil structure; the arc-shaped corner corresponds to an angle value greater than 0 and less than or equal to twice the inverse tangent of the smaller of the first direction circumscribed side length of the coil structure and the second direction circumscribed side length of the coil structure divided by the larger of the first direction circumscribed side length of the coil structure and the second direction circumscribed side length of the coil structure; the arc-shaped corner is located on a circle with a radius greater than 0.5 times the square root of the sum of the square of the second direction circumscribed side length of the coil structure of the arc-shaped corner and the square of the first direction circumscribed side length of the coil structure of the arc-shaped corner;

[0010] The arc-shaped corner of the first printed layer and the arc-shaped corner of the second printed layer are in the same corner position in the stacking direction.

[0011] In some embodiments, the parameters of the arc-shaped corner include the first direction circumscribed side length, the second direction circumscribed side length, the angle value, and the radius, and the parameters of the arc-shaped corner of the first printed layer and the parameters of the arc-shaped corner of the second printed layer are all the same.

[0012] In some embodiments, the coil structure includes a first direction first short side, a second direction short side, a first direction long side, a second direction long side, and a first direction second short side.

[0013] The first guide hole of the first printed layer is located at one end of the first direction first short side, and the second guide hole of the first printed layer is located at one end of the first direction second short side; the coil structure of the first printed layer is sequentially connected by the first guide hole, the first direction first short side, the second direction short side, the first direction long side, the second direction long side, the first direction second short side, and the second guide hole.

[0014] The third guide hole of the second printed layer is located at one end of the first direction first short side, and the fourth guide hole of the second printed layer is located at one end of the first direction second short side; the coil structure of the second printed layer is sequentially connected by the fourth guide hole, the first direction second short side, the second direction long side, the first direction long side, the second direction short side, the first direction first short side, and the third guide hole.

[0015] In some embodiments, at least one of the corners where the first direction long side connects with the second direction short side and the corners where the first direction long side connects with the second direction long side is an arc-shaped corner.

[0016] In some embodiments, when the corner where the first direction long side connects with the second direction short side is an arc-shaped corner, the second direction circumscribed edge length of the arc-shaped corner is greater than 0 and less than or equal to 0.5 times the second direction short side; the radius of the circle where the arc-shaped corner is located is less than or equal to half of the second direction short side.

[0017] In some embodiments, when the corner where the first direction long side connects with the second direction long side is an arc-shaped corner, the second direction circumscribed edge length of the arc-shaped corner is greater than 0 and less than or equal to 0.426 times the second direction long side; the radius of the circle where the arc-shaped corner is located is less than or equal to 0.426 times the second direction long side.

[0018] In some embodiments, the first direction circumscribed edge length of the arc-shaped corner is greater than or equal to 0.1 times the first direction long side and less than or equal to 0.4 times the first direction long side.

[0019] In some embodiments, when the corner where the first direction long side connects with the second direction short side is an arc-shaped corner, the second direction circumscribed edge length of the arc-shaped corner is greater than or equal to 0.065 times the second direction short side and less than or equal to 0.26 times the second direction short side; the angle value corresponding to the arc-shaped corner is greater than or equal to 28 degrees and less than or equal to 90 degrees.

[0020] In some embodiments, when the corner where the first direction long side connects with the second direction long side is an arc-shaped corner, the second direction circumscribed edge length of the arc-shaped corner is greater than or equal to 0.056 times the second direction long side and less than or equal to 0.22 times the second direction long side; the angle value corresponding to the arc-shaped corner is greater than or equal to 28 degrees and less than or equal to 90 degrees.

[0021] In some embodiments, the coil structure of the first printed layer has two arc-shaped corners; the coil structure of the second printed layer has two arc-shaped corners.

[0022] In some embodiments, the angle values of the two arc-shaped corners of the coil structure of the first printed layer are equal; the angle values of the two arc-shaped corners of the coil structure of the second printed layer are equal.

[0023] In some embodiments, the first via hole of the first printed layer and the third via hole of the second printed layer are aligned in the stacking direction; the second via hole of the first printed layer and the fourth via hole of the second printed layer are aligned in the stacking direction.

[0024] In some embodiments, the shape of the via hole on the coil structure is a tangent circle or an ellipse tangent to the edge of the first direction first short side or the first direction second short side.

[0025] In some embodiments, two corner edges of the coil structure close to the guide hole have chamfers.

[0026] In some embodiments, the laminated chip inductor further comprises an introduction layer and an exit layer, a plurality of the stacked units are arranged between the introduction layer and the exit layer, the introduction layer and the exit layer each comprise a ceramic layer and a coil structure on the ceramic layer, a starting end of the coil structure on the introduction layer is connected with the second guide hole of the coil structure of the first printed layer, and a terminal end of the coil structure on the exit layer is connected with the fourth guide hole of the coil structure of the second printed layer.

[0027] The above technical solutions of the present application have at least the following advantages or beneficial effects: by selectively designing the corners in the coil structure as arc-shaped corners, the effective area and effective length are fine-tuned, the accumulation of electric charges at the corners when the electric charges flow through the right-angle structure is avoided, and additional loss is caused, so that the size of the laminated chip inductor is moderate, and the error value between the actual L value and the theoretical L value is limited within a certain range, that is, the inductance precision is improved, and without optimizing the preparation process, on the basis of better internal electrode printing quality and reproducibility, the risk of cutting off the electrode is also reduced to meet the quality requirements of high Q value and low loss, and the Q value is improved. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is an explosion schematic diagram of a coil structure of a laminated chip inductor provided by an embodiment of the present application;

[0029] Figure 2 is a coil structure structure schematic diagram provided by an embodiment of the present application;

[0030] Figure 3 is a laminated printed sheet design pattern schematic diagram of a laminated chip inductor;

[0031] Figure 4 is another coil structure structure schematic diagram provided by an embodiment of the present application;

[0032] Figure 5 is a laminated chip inductor overall structure perspective view provided by an embodiment of the present application;

[0033] Figure 6 is a laminated chip inductor internal electrode laminated side view provided by an embodiment of the present application.

[0034] The figure legend is: the coil structure 100 of the exit layer, the coil structure 200 of the first printed layer, the coil structure 300 of the second printed layer, the coil structure 400 of the introduction layer, the stacked unit 500, the first guide hole 220, the second guide hole 210, the third guide hole 320, and the fourth guide hole 310. DETAILED DESCRIPTION

[0035] Embodiments of the present application are described below in detail with reference to the accompanying drawings, wherein the same or similar components or components having the same or similar functions are denoted by the same or similar reference numerals throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only for explanation of the present application, and should not be construed as limiting the present application.

[0036] In the description of the present application, it should be understood that the orientation description, such as the orientation or position relationship indicated by up, down, left, right, etc., is based on the orientation or position relationship shown in the drawings, and is only for the purpose of facilitating the description of the present application and simplifying the description, and does not indicate or imply that the device or component referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present application.

[0037] In the description of the present application, if there is a description of first, second, etc., it is only for the purpose of distinguishing technical features, and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the order of technical features indicated.

[0038] In the description of the present application, unless otherwise explicitly limited, the words such as arrangement, installation, connection, etc. should be broadly understood, and those skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.

[0039] In the related art, with reference to Figure 3 , Figure 3 A design pattern of a laminated printed sheet of a laminated inductor, the pattern in which the corner is a right angle shape as a basic example, the inductor comprising a laminated printed layer with a four-layer minimum laminated structure in the order of lamination from top to bottom. The minimum laminated structure in the order of lamination is respectively an introduction layer 1, a first printed layer 2, a second printed layer 3, and an outgoing layer 4, and satisfies that the first printed layer 1 and the second printed layer 2 are the minimum repeating units, the laminated printed layer is provided with a coil structure printed by conductive paste, and the coil structure can be enclosed to form a closed coil structure in the lamination direction. The corner of the coil structure of the first printed layer 1 and the second printed layer 2 of the inductor is a right angle shape, which is easy to cause the charge to accumulate at the corner when the charge flows through the right angle structure, resulting in additional loss, increasing the error between the theoretical L value and the actual L value, and also reducing the Q value, which does not meet the use scene of the inductor with high quality and high precision.

[0040] To solve the above problems, the present embodiment provides a solution, please refer to Figure 1The stacked inductor includes at least one stacking unit 500, which includes a coil structure 200 of a first printed layer and a coil structure 300 of a second printed layer (the ceramic layer is not shown in the figure). The coil structure on the printed layer is described below.

[0041] Please continue to refer to Figure 1 The coil structure 200 of the first printed layer and the coil structure 300 of the second printed layer both include a ceramic layer and a coil structure on the ceramic layer. The projections of the adjacent upper and lower coil structures overlap to form an enclosed structure. The coil structure 200 of the first printed layer ( Figure 2 ) includes a first guide hole 220 as a starting end and a second guide hole 210 as a terminating end, a coil structure 300 of the second printed layer ( Figure 4 ) includes a third guide hole 320 as a terminating end and a fourth guide hole 310 as a starting end. The first guide hole 220 and the third guide hole 320 are used to connect the first printing layer and the second printing layer, and the second guide hole 210 and the fourth guide hole 310 are used to connect two adjacent stacking units 500.

[0042] The coil structure includes four corners, and at least one of the two corners farther from the guide hole is a curved corner. Figure 2 , define the second direction side length of the coil structure as B, the first direction side length as A, the first direction circumscribed side length of the arc corner θ1 as a, and the second direction circumscribed side length as b. The first direction circumscribed side length a of the arc corner is greater than 0 and less than or equal to half of the first direction side length of the coil structure, that is, 0 <a≤0.5A,由于本实施例基于线圈结构所作的改进,避免了弧形拐角的第一方向外接边长a因超过第一方向边长A的一半,改变了原有的线圈结构,同时可以满足距离导孔较远的两个拐角中都是弧形拐角的情况,线圈结构的第一方向指的是与电感器宽度方向一致的维度,线圈结构的第二方向指的是与电感器长度方向一致的维度,线圈结构的第一方向与第二方向相互垂直。

[0043] The length b of the circumscribed side of the arc corner in the second direction is greater than 0 and is less than or equal to half of the length B of the coil structure in the second direction, i.e. 0 <b≤0.5B,同样地,避免了改变原有的线圈结构。

[0044] The angle value θ1 corresponding to the arc corner is greater than 0 and is less than or equal to 2 times the arc tangent function value of the smaller value of the first direction circumscribed side length a and the second direction circumscribed side length b divided by the larger value of the first direction circumscribed side length a and the second direction circumscribed side length b. <a≤0.5A和0<b≤0.5B的条件,可以得到弧形拐角对应的角度值θ1的取值范围,即 The angle value of the arc-shaped corner is the angle of the center angle of the circle corresponding to the arc, and the angle value is calculated according to the arc length and the radius length of the arc.

[0045] The radius of the circle where the arc-shaped corner is located is greater than 0.5 times the square root of the sum of the square of the second direction outer edge length of the arc-shaped corner and the square of the first direction outer edge length, that is, 0.5(a 2 +b 2 ) 1 / 2 The radius can make the arc corner not intersect with the extension line of A or B, keep the size of the inductor moderate, limit the error value between the actual inductance value and the theoretical inductance value within a certain range, that is, reduce the error value to improve the inductance precision, and reduce the risk of cutting the leakage electrode to meet the quality requirements of high Q value and low loss. If the radius is less than the range, the error value increases and the quality deteriorates.

[0046] The arc-shaped corner θ1 of the coil structure 200 of the first printed layer and the arc-shaped corner θ2 of the coil structure 300 of the second printed layer are in the same corner position in the stacking direction. This design is relative to the position displacement of corners of different shapes in the stacking direction, that is, according to the stacking sequence that the arc-shaped corner of the first printed layer corresponds to the right angle of the second printed layer, and the right angle of the first printed layer corresponds to the arc-shaped corner of the second printed layer. The reduction of tolerance (error between actual inductance value and theoretical inductance value) is obviously helpful. The comparison of different positions of the above corners will be further explained in the subsequent content.

[0047] In some embodiments, the coil structure 200 of the first printed layer and the coil structure 300 of the second printed layer are in an up-down enclosing structure. The side length of the coil structure can not be equal, and the corresponding two guide holes can be in the same straight line position. This embodiment is easy to distinguish the positions of different shape features of the coil structure.

[0048] It can be understood that, Figure 1 and Figure 2 The projection overlap of the adjacent up-down coil structures shown is only an example. The structure is not limited to long and short sides, and can also be the same side length. The position relationship of the two guide holes of the same coil structure can be but is not limited to the up-down position relationship and the left-right position relationship.

[0049] This embodiment realizes fine tuning of inductance by specific design of the corner of the internal electrode. On the basis of not increasing or decreasing the number of layers and without improving the printing requirements, high-precision inductance with small tolerance can still be obtained, and the high Q value and low loss quality requirements can be met at the same time.

[0050] Referring to Figure 4As shown, the second direction side length of the same defined coil structure is C, the first direction side length is A, the first direction circumscribed side length a, the second direction circumscribed side length b, the angle value θ2 and the radius r of the arc corner, the parameter range of the arc corner θ1 of the first printing layer and the parameter range of the arc corner θ2 of the second printing layer are all the same, i.e. 0 < a ≤ 0.5A, The first printing layer and the second printing layer are provided with the same arc corner, which can further reduce the tolerance.

[0051] In an example of a coil structure, please refer to Figure 2 and Figure 4 The coil structure of the first printing layer and the second printing layer includes a first direction first short side, a second direction short side, a first direction long side, a second direction long side and a first direction second short side.

[0052] The first lead hole of the first printing layer is located at one end of the first direction first short side, and the second lead hole of the first printing layer is located at one end of the first direction second short side; the coil structure of the first printing layer is sequentially connected by the first lead hole, the first direction first short side, the second direction short side, the first direction long side, the second direction long side, the first direction second short side and the second lead hole, and the width values of the coil structure are all equal, i.e. the width of each side and the width at the corner are all equal.

[0053] The third lead hole of the second printing layer is located at one end of the first direction first short side, and the fourth lead hole of the second printing layer is located at one end of the first direction second short side; the coil structure of the second printing layer is sequentially connected by the fourth lead hole, the first direction second short side, the second direction long side, the first direction long side, the second direction short side, the first direction first short side and the third lead hole, and similarly, the width of each side and the width at the corner of the coil structure are all equal.

[0054] At least one of the corners where the first direction long side and the second direction long side are connected, and the corners where the first direction long side and the second direction short side are connected is an arc corner.

[0055] In some embodiments, when the corner where the first direction long side A and the second direction long side C are connected is an arc corner, the corresponding angle value is θ2, and when the corner where the first direction long side A and the second direction short side B are connected is an arc corner, the corresponding angle value is θ1, i.e. θ1 or θ2 exists on one coil structure, or θ1 and θ2 exist at the same time.

[0056] In some embodiments, when the corner where the first direction long side A connects with the second direction short side B is an arc corner, the second direction circumscribed side length b of the arc corner is greater than 0 and less than or equal to 0.5 times the second direction short side B; the radius r of the circle where the arc corner is located is less than or equal to half of the second direction short side B; if the radius r is greater than half of the second direction short side B, the error between the actual inductance value and the theoretical inductance value of the inductor to be made will be large, and the quality factor will be reduced.

[0057] In some embodiments, when the corner where the first direction long side A connects with the second direction long side C is an arc corner, the second direction circumscribed side length b of the arc corner is greater than 0 and less than or equal to 0.426 times the second direction long side C; the radius r of the circle where the arc corner is located is less than or equal to 0.426 times the second direction long side C; if the radius r is greater than 0.426 times the second direction long side C, the error between the actual inductance value and the theoretical inductance value of the inductor to be made will be large, and the quality factor will be reduced, and the value range of the second direction circumscribed side length b on the second direction long side C is calculated according to the same arc corner parameters between the first printing layer and the second printing layer.

[0058] In some preferred embodiments, the arc corner can be set as the first direction circumscribed side length a being greater than or equal to 0.1 times the first direction long side A and less than or equal to 0.4 times the first direction long side A, i.e. 0.1A≤a≤0.4A.

[0059] In some preferred embodiments, the second direction circumscribed side length b is greater than or equal to 0.065 times the second direction short side B and less than or equal to 0.26 times the second direction short side B, i.e. 0.065B≤b≤0.26B; the angle value θ1 is greater than or equal to 28 degrees and less than or equal to 90 degrees, i.e. 28°≤θ1≤90°. With such a setting of the arc corner 0.1A≤a≤0.4A, 0.065B≤b≤0.26B and 28°≤θ1≤90°, the inductor tolerance can be reduced and the Q value can be improved.

[0060] In some preferred embodiments, the second direction circumscribed side length b is greater than or equal to 0.056 times the second direction long side C and less than or equal to 0.22 times the second direction long side C, i.e. 0.056C≤b≤0.22C; the angle value θ2 is greater than or equal to 28 degrees and less than or equal to 90 degrees, i.e. 28°≤θ2≤90°. With such a setting of the arc corner 0.1A≤a≤0.4A, 0.056C≤b≤0.22C and 28°≤θ2≤90°, the inductor tolerance can be reduced and the Q value can be improved.

[0061] In some preferred embodiments, the coil structure of the first printed layer can have two arc-shaped corners at the same time, i.e., the corners where the first direction long side and the second direction long side are connected in the coil structure of the first printed layer, and the corners where the first direction long side and the second direction short side are connected are all arc-shaped corners.

[0062] In some preferred embodiments, the coil structure of the second printed layer can have two arc-shaped corners at the same time, i.e., the corners where the first direction long side and the second direction long side are connected in the coil structure of the second printed layer, and the corners where the first direction long side and the second direction short side are connected are all arc-shaped corners.

[0063] In some embodiments, when the two arc-shaped corners θ1 and θ2 away from the via exist at the same time, the size relationship can be any one of θ1>θ2, θ1<θ2 or θ1=θ2; preferably, when θ1=θ2, the performance of the inductor can be better improved.

[0064] Referring to Figure 1 As shown in the figure, the position relationship of the vias of the first printed layer and the second printed layer is as follows: the first via 220 of the first printed layer and the third via 320 of the second printed layer are aligned in the stacking direction; the second via 210 of the first printed layer and the fourth via 310 of the second printed layer are aligned in the stacking direction.

[0065] Further, the shape of the via on the coil structure is circular, and the first via 220, the third via 320, the second via 210 and the fourth via 310 are all right circular or elliptical shapes tangent to the first direction first short side or the first direction second short side edge. By aligning the corresponding vias and setting the same via shape, the connection between the corresponding vias is facilitated.

[0066] In some preferred embodiments, the two corner edges near the via on the coil structure have a chamfer, as shown in the figure. Figure 3 As shown in the figure, the chamfer is a non-arc corner structure design that slightly rounds the 90-degree sharp part of the rectangle, which does not affect the inductance value and can prevent the accumulation of electric charge at the corner.

[0067] Referring to Figure 1 As shown in the figure, the laminated chip inductor further includes an introduction layer and an exit layer, and a plurality of the stacked units 500 are arranged between the introduction layer and the exit layer. The introduction layer and the exit layer each include a ceramic layer and a coil structure on the ceramic layer. The starting end of the coil structure 400 on the introduction layer is connected to the second via 210 of the coil structure 200 of the first printed layer, and the terminal end of the coil structure 100 on the exit layer is connected to the fourth via 310 of the coil structure 300 of the second printed layer. The internal laminated side view of the laminated chip inductor is as shown in the figure. Figure 6As shown, the connection between the lead-in layer, the stacked units and the lead-out layer forms a closed loop, forming an inductor coil with a closed magnetic circuit, and finally the coil is electroplated and packaged to obtain a complete multilayer chip inductor. Figure 5 As shown in the perspective view of the overall structure of a multilayer chip inductor.

[0068] To obtain the improvement effect of the arc-shaped corner of the first printed layer and the second printed layer on the multilayer chip inductor and the influence of the parameters of the arc-shaped corner on the performance indicators of the multilayer chip inductor, the following tests are performed. First, the various parameters and structures of the multilayer chip inductor of Example 1 are determined, and then by changing certain parameters and structures, a plurality of examples and comparative examples are obtained. Compared with Example 1, the influence of different parameters and structures on the performance indicators of the inductor is analyzed. By comparing Comparative Example 1 and Comparative Example 2 with Example 1, the influence of the arc-shaped corner and the position of the arc-shaped corner on the inductor is obtained, as follows.

[0069] The theoretical inductance value of the inductor can be calculated by formula (1).

[0070]

[0071] Wherein, μ0 is the magnetic permeability of vacuum; μ i is the relative magnetic permeability of the ceramic material; N is the effective number of turns of the inductor internal coil; A e is the effective magnetic flux area, i.e. the inductor coil area; l e is the effective magnetic path length.

[0072] The actual inductance value of the inductor can be obtained by placing the sample on the clamp of the impedance analyzer, setting the test parameters to test the frequency test spectrum from 10MHz to 3GHz, reading the actual L value at the corresponding frequency of 300MHz, and calculating the deviation of the actual L value from the theoretical L value = (actual L value - theoretical L value) / theoretical L value.

[0073] The Q value of the inductor can be detected by placing the sample on the clamp of the impedance analyzer, setting the test parameters to test the frequency test spectrum from 10MHz to 3GHz, and reading the actual Q value at the corresponding frequency of 300MHz.

[0074] First, Example 1 is determined as follows. A multilayer chip inductor is set to have 24 layers, which are sequentially stacked according to Figure 1 and the arc-shaped corner positions correspond in the stacking direction, which are lead-in layer, first printed layer, second printed layer,..., first printed layer, second printed layer, lead-out layer; the coil structure width is 45μm; A = 300μm, B = 460μm, C = 540μm.

[0075] One of the two corners away from the guide hole is shaped as an arc corner with a certain angle value, specifically: the first printing layer includes θ1, a = 0.40A = 120 μm, b = 0.26B = 120 μm, r = 0.26B = 120 μm, and θ1 = 90.00°; the second printing layer includes θ2, a = 0.40A = 120 μm, b = 0.22C = 120 μm, r = 0.22C = 120 μm, and θ2 = 90.00°.

[0076] Example 2: Different from example 1, a = 0.1A = 30 μm in the first printing layer and the second printing layer, and θ1 = θ2 = 28°.

[0077] Example 3: Different from example 1, a = 0.5A = 150 μm in the first printing layer and the second printing layer, and θ1 = θ2 = 77°.

[0078] Example 4: Different from example 1, r = 0.37B = 169 μm in the first printing layer and the second printing layer, and θ1 = θ2 = 60°.

[0079] Example 5: Different from example 1, b = 0.056C = 30 μm in the second printing layer, and θ2 = 28°.

[0080] Example 6: Different from example 1, b = 0.065B = 30 μm in the first printing layer, and θ2 = 28°; b = 0.056C = 30 μm in the second printing layer, and θ2 = 28°.

[0081] Example 7: Different from example 1, b = 0.5B = 230 μm in the first printing layer, and θ1 = 55°; b = 0.426C = 230 μm in the second printing layer, and θ2 = 55°.

[0082] Example 8: Different from example 1, b = 0.5B = 230 μm in the first printing layer, and θ1 = 60°; b = 0.056C = 30 μm in the second printing layer, and θ2 = 28°.

[0083] Example 9: Different from example 1, b = 0.5B = 230 μm in the first printing layer, and θ1 = 55°; r = 0.37B = 169 μm in the second printing layer, and θ2 = 60°.

[0084] Example 10: Different from example 1, the shape of both of the two corners away from the guide hole is shaped as an arc corner with a certain angle value, specifically: the first printing layer includes θ1 and θ2, and θ1 = θ2 = 90.00°; the second printing layer includes θ1 and θ2, and θ1 > θ2, θ1 = 90.00°, and θ2 = 60°.

[0085] Example 11: The difference from Example 1 is that the shape of the two corners away from the lead hole is set as an arc corner shape with a certain angle value, specifically: the first printing layer includes θ1 and θ2 and θ1 = θ2 = 90.00°; the second printing layer includes θ1 and θ2 and θ1 < θ2, θ1 = 60°, θ2 = 90.00°.

[0086] Example 12: The difference from Example 1 is that the shape of the two corners away from the lead hole is set as an arc corner shape with a certain angle value, specifically: the first printing layer includes θ1 and θ2 and θ1 = θ2 = 90.00°; the second printing layer includes θ1 and θ2 and θ1 = θ2 = 90.00°.

[0087] Comparative Example 1: The difference from Example 1 is that no arc corner is set, and the corners are all right angle design.

[0088] Comparative Example 2: The difference from Example 1 is that the order of the layers is in sequence according to Figure 1 the arc corner position is staggered in the stacking direction, that is, the stacking order is according to the arc corner corresponding to the right angle, and the right angle corresponding to the arc corner.

[0089] The above examples and comparative examples are calculated to obtain Table 1.

[0090] Table 1

[0091]

[0092]

[0093] Through the above theoretical inductance value calculation formula of the inductor, it is calculated that the theoretical inductance value of Examples 1-9 and Comparative Examples 1 and 2 is 120nH; the theoretical inductance value of Examples 10-12 is 100nH.

[0094] Through the comparison between Examples 1-12, it can be obtained that:

[0095] When the corner of the second direction short side and the first direction long side is an arc corner, the parameter range of the arc corner is in 0.1A≤a≤0.4A, 0.065B≤b≤0.26B, 28°≤θ1≤90°, the tolerance of the above inductor is smaller, and the Q value is higher.

[0096] Similarly, when the corner of the second direction long side and the first direction long side is an arc corner, the parameter range of the arc corner is in 0.1A≤a≤0.4A, 0.056C≤b≤0.22C, 28°≤θ2≤90°, a higher precision and higher quality stacked chip inductor can be obtained.

[0097] By comparing the first printed layer and the second printed layer of Comparative Example 1 with the first printed layer and the second printed layer of Examples 1-12, it can be seen that the arc-shaped corner design significantly improves the quality factor Q value of the inductor.

[0098] By comparing the different arc-shaped corner position designs of the first printed layer and the second printed layer of Comparative Example 2 with the first printed layer and the second printed layer of Examples 1-12 in the stacking direction, it can be seen that the same arc-shaped corner position in the stacking direction significantly reduces the tolerance of the inductor.

[0099] The above is a specific description of the preferred embodiments of the present application, but the present application is not limited to the above embodiments. Those skilled in the art can make various equivalent modifications or replacements without departing from the spirit of the present application, and these equivalent modifications or replacements are all included in the scope defined by the claims of the present application.

Claims

1. A multilayer chip inductor, characterized in that: include: At least one stacking unit, the stacking unit comprising a first printed layer and a second printed layer, the first printed layer and the second printed layer each comprising a ceramic layer and a coil structure on the ceramic layer, the projections of the adjacent upper and lower coil structures overlapping to form an enclosed structure, the coil structure of the first printed layer comprising a first guide hole as a starting end and a second guide hole as a terminating end, and the coil structure of the second printed layer comprising a third guide hole as a terminating end and a fourth guide hole as a starting end; The first guide hole and the third guide hole are used to connect the first printing layer and the second printing layer, and the second guide hole and the fourth guide hole are used to connect two adjacent stacking units; The coil structures each include four corners, and at least one of the two corners farther from the guide hole is an arc-shaped corner; The length of the circumscribed side of the coil structure in the first direction of the arc corner is greater than 0 and less than or equal to half of the length of the side of the coil structure in the first direction; the length of the circumscribed side of the coil structure in the second direction of the arc corner is greater than 0 and less than or equal to half of the length of the side of the coil structure in the second direction; the angle value corresponding to the arc corner is greater than 0 and less than or equal to the smaller value of the circumscribed side of the coil structure in the first direction and the circumscribed side of the coil structure in the second direction divided by 2 times the inverse tangent function value of the larger value of the circumscribed side of the coil structure in the first direction and the circumscribed side of the coil structure in the second direction; the radius of the circle in which the arc corner is located is greater than 0.5 times the square root of the sum of the square of the circumscribed side of the coil structure in the second direction of the arc corner and the square of the circumscribed side of the coil structure in the first direction; The arc-shaped corner of the first printing layer and the arc-shaped corner of the second printing layer are located at the same corner position in the stacking direction; The first direction of the coil structure refers to a dimension consistent with the width direction of the inductor, and the second direction of the coil structure refers to a dimension consistent with the length direction of the inductor. The first direction and the second direction are perpendicular to each other.

2. The multilayer chip inductor according to claim 1, wherein: The coil structure includes a first short side in the first direction, a short side in the second direction, a long side in the first direction, a long side in the second direction, and a second short side in the first direction; The first guide hole of the first printing layer is located at one end of the first short side in the first direction, and the second guide hole of the first printing layer is located at one end of the second short side in the first direction; The third guide hole of the second printing layer is located at one end of the first short side in the first direction, and the fourth guide hole of the second printing layer is located at one end of the second short side in the first direction.

3. The multilayer chip inductor according to claim 2, wherein: There is at least one arc-shaped corner between the corner where the long side in the first direction is connected to the short side in the second direction and the corner where the long side in the first direction is connected to the long side in the second direction; When the corner connecting the long side in the first direction and the short side in the second direction is an arc-shaped corner, the length of the circumscribed side in the second direction of the arc-shaped corner is greater than 0 and less than or equal to 0.5 times the short side in the second direction; the radius of the circle in which the arc-shaped corner is located is less than or equal to half of the short side in the second direction; When the corner connecting the long side in the first direction and the long side in the second direction is an arc-shaped corner, the circumscribed side length in the second direction of the arc-shaped corner is greater than 0 and less than or equal to 0.426 times the long side in the second direction; the radius of the circle in which the arc-shaped corner is located is less than or equal to 0.426 times the long side in the second direction.

4. The multilayer chip inductor according to claim 2, wherein: When the corner connecting the long side in the first direction and the short side in the second direction is an arc-shaped corner, the second-direction circumscribed side length of the arc-shaped corner is greater than or equal to 0.065 times the short side in the second direction and less than or equal to 0.26 times the short side in the second direction; the angle value corresponding to the arc-shaped corner is greater than or equal to 28 degrees and less than or equal to 90 degrees.

5. The multilayer chip inductor according to claim 2, wherein: When the corner connecting the long side in the first direction and the long side in the second direction is an arc-shaped corner, the circumscribed side length in the second direction of the arc-shaped corner is greater than or equal to 0.056 times the long side in the second direction and less than or equal to 0.22 times the long side in the second direction; the angle value corresponding to the arc-shaped corner is greater than or equal to 28 degrees and less than or equal to 90 degrees.

6. The multilayer chip inductor according to claim 1, wherein: The coil structure of the first printed layer has two arc-shaped corners; the coil structure of the second printed layer has two arc-shaped corners.

7. The multilayer chip inductor according to claim 6, wherein: The angle values ​​of the two arc-shaped corners of the coil structure of the first printing layer are equal; the angle values ​​of the two arc-shaped corners of the coil structure of the second printing layer are equal.

8. The multilayer chip inductor according to claim 1, wherein: The coil structure has chamfered edges at two corners close to the guide hole.

9. The multilayer chip inductor according to claim 1, wherein: The multilayer chip inductor also includes an introduction layer and a lead-out layer, and a plurality of the stacked units are arranged between the introduction layer and the lead-out layer. The introduction layer and the lead-out layer both include a ceramic layer and a coil structure on the ceramic layer. The starting end of the coil structure on the introduction layer is connected to the second guide hole of the coil structure of the first printed layer, and the ending end of the coil structure on the lead-out layer is connected to the fourth guide hole of the coil structure of the second printed layer.

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