JP2006190774A - Laminated ceramic electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a laminated ceramic electronic component capable of suppressing variation in electrostatic capacitance caused by the slippage of a laminate. <P>SOLUTION: Capacitor conductor patterns 3, 4 are composed of large areas 11, 21 arranged in a line in a lengthwise direction (Y direction) of a ceramic green sheet 2; narrow areas 12, 22; and small width portions 13, 23 arranged between the portions 11, 21 and the portions 12, 22 to connect the portions 11, 21 to the portions 12, 22, respectively. The area 11 is arranged on a portion of the conductor pattern 3 where the pattern 3 is connected to an external electrode, and the area 21 is arranged on a portion of the conductor pattern 4 where the pattern 4 is connected to an external electrode. The portion 12 is formed at the end of the conductor pattern 3, and the portion 22 is formed at the end of the conductor pattern 4. The portions 12, 22 are overlapped on the portions 21, 11, respectively, in a plan view in the portions 21, 11 which the portions 12, 22 oppose each other via the ceramic green sheet 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a multilayer ceramic electronic component, and more particularly to a multilayer ceramic electronic component such as a capacitor, a varistor, a thermistor, or an LC filter.

  Conventionally, a multilayer ceramic capacitor has a problem that the capacitance changes due to the displacement of the internal electrodes. That is, in the capacitor 71 having the internal electrodes 72 and 73 having the same shape as shown in the horizontal cross-sectional schematic diagram of FIG. 9, the displacement of the internal electrodes 72 and 73 in the length direction (Y direction) and the width direction (X direction). When the deviation occurs, the overlapping area of the opposed internal electrodes 72 and 73 increases and decreases, and the capacitance changes. Reference numerals 76 and 77 are external electrodes.

  Therefore, as a countermeasure, the capacitors described in FIG. 12 of Patent Document 1 and Patent Document 2 are known. As shown in FIG. 10, this capacitor 81 has internal electrodes 82 and 83 having different widths, and there is a slight displacement in the width direction (X direction) between the internal electrodes 82 and 83 during lamination. Even if it occurs, the overlapping area of the internal electrodes 82 and 83 can be kept constant, and the capacitance does not change. Reference numerals 86 and 87 are external electrodes.

However, if a positional shift in the length direction (Y direction) occurs between the internal electrodes 82 and 83, the overlapping area of the internal electrodes 82 and 83 increases and decreases, and the capacitance changes. In addition, since the tip portion of the internal electrode 82 protrudes from the opposing internal electrode 83, a large capacitance is generated between the internal electrode 82 and the external electrode 87, and a change in the capacitance due to the displacement is increased. Furthermore, when odd-numbered internal electrodes 82 and 83 having different shapes are stacked, there is a problem that the variation in capacitance increases.
Japanese Patent Laid-Open No. 6-84690 JP-A-8-273973

  SUMMARY OF THE INVENTION An object of the present invention is to provide a multilayer ceramic electronic component that can suppress variations in capacitance due to misalignment.

  In order to achieve the above object, a multilayer ceramic electronic component according to the present invention is formed by stacking a plurality of ceramic layers and internal conductors, and formed at both ends of the multilayer body and alternately connected to internal electrodes. A multilayer ceramic electronic component having a pair of external electrodes, wherein the internal electrodes are arranged between the large area part, the small area part, and the large area part and the small area part. The large area portion is arranged on the side of the internal electrode connected to the external electrode, the small area portion is formed at the tip of the internal electrode, and the large area portion is a ceramic layer in plan view. It overlaps with the small area part which opposes via.

  Examples of the multilayer ceramic electronic component include a multilayer ceramic capacitor and an LC filter.

  The large area portion and the small area portion are substantially rectangular, and the large area portion preferably has a wider electrode width and a longer electrode length than the small area portion.

  Moreover, it is preferable that a small area part has overlapped with this large area part in the large area part which opposes via a ceramic layer by planar view.

  Further, the narrow portion may be either in the case of overlapping with the narrow portion facing through the ceramic layer in a plan view or in the case of not overlapping.

  According to the present invention, since the large area portion and the small area portion overlap each other, even if the position of the internal electrode is shifted, the small area portion moves within the large area portion, and the capacitance change can be suppressed. And since the small area part is formed in the front end side of an internal electrode, the front end side of an internal electrode protrudes from the opposing internal electrode, and an electrostatic capacitance produces large between external electrodes, and the electrostatic capacitance by position shift An increase in change can also be suppressed. Furthermore, since the internal electrodes are all formed in the same shape, it is possible to suppress variation in capacitance when the internal electrodes are stacked in an odd number.

  Embodiments of a multilayer ceramic electronic component according to the present invention will be described below with reference to the accompanying drawings.

  As shown in FIG. 1, the multilayer ceramic capacitor 1 includes a ceramic green sheet 2 provided with capacitor conductor patterns 3 and 4, an outer layer ceramic green sheet 2 provided with no conductor pattern in advance, and the like.

  The ceramic green sheet 2 is obtained by dispersing a powder of magnetic material or dielectric material in a solvent to adjust a ceramic slurry, and forming this into a 30 μm thick sheet by the doctor blade method. Next, capacitor conductor patterns 3 and 4 are formed on each of the ceramic green sheets 2 by screen printing.

  The capacitor conductor patterns 3 and 4 have large area portions 11 and 21, small area portions 12 and 22, large area portions 11 and 21, which are arranged in a line in the length direction (Y direction) of the ceramic green sheet 2, respectively. The narrow area parts 13 and 23 which are arrange | positioned between the small area parts 12 and 22 and connect the large area parts 11 and 21 and the small area parts 12 and 22 and the drawer parts 14 and 24 are comprised. The large area portion 11 is disposed on the connection portion side of the capacitor conductor pattern 3 with the external electrode 32 (described later), and the large area portion 21 is disposed on the connection portion side of the capacitor conductor pattern 4 with the external electrode 33 (described later). . The small area portion 12 is formed at the tip portion of the capacitor conductor pattern 3, and the small area portion 22 is formed at the tip portion of the capacitor conductor pattern 4.

  The large area portions 11 and 21 and the small area portions 12 and 22 have a substantially rectangular shape, and the large area portions 11 and 21 have a wider electrode width (wider in the X direction) than the small area portions 12 and 22, and electrodes Long length (long in the Y direction).

  In this embodiment, the large area portions 11 and 21 have a width direction (X direction) dimension of 300 μm and a length direction (Y direction) dimension of 380 μm. The dimension in the width direction (X direction) of the small area portions 12 and 22 is 230 μm, and the dimension in the length direction (Y direction) is 310 μm. The dimensions of the narrow portions 13 and 23 in the width direction (X direction) are 120 μm, and the dimension in the length direction (Y direction) is 80 μm.

  The lead portion 14 of the capacitor conductor pattern 3 is exposed on the left side of the sheet 2. The lead portion 24 of the capacitor conductor pattern 4 is exposed on the right side of the sheet 2. In the case of the present embodiment, the width direction (X direction) of the drawer portions 14 and 24 is 200 μm, and the length direction (Y direction) is 100 μm.

  The ceramic green sheets 2 are stacked so that the capacitor conductor patterns 3 and 4 are alternately arranged. Further, after the ceramic green sheets 2 for outer layers are arranged on the upper and lower sides, the ceramic green sheets 2 are pressure-bonded to form a laminate block. The laminated body block is cut into a predetermined size and then fired integrally. Thereby, it is set as the laminated body 31 shown in FIG.

  Next, the external electrodes 32 and 33 are formed by applying and baking a conductive paste on both ends of the laminate 31. The external electrode 32 is electrically connected to the lead portion 14 of the capacitor conductor pattern 3, and the external electrode 33 is electrically connected to the lead portion 24 of the capacitor conductor pattern 4.

  In the multilayer capacitor 1 having the above configuration, as shown in FIG. 3, the large area portions 11 and 21 are overlapped with the small area portions 22 and 12 facing each other with the ceramic green sheet 2 in plan view. Specifically, each of the small area portions 12 and 22 overlaps the large area portions 21 and 11 in the large area portions 21 and 11 that are opposed to each other with the ceramic green sheet 2 in plan view. Further, the narrow portion 13 overlaps with the narrow portion 23 facing each other with the ceramic green sheet 2 in plan view. Here, the plan view refers to seeing through from the stacking direction of the ceramic green sheets 2.

  Since the large area portions 11 and 21 and the small area portions 22 and 12 overlap each other, even if the positions of the capacitor conductor patterns 3 and 4 are shifted in the width direction (X direction) as shown in FIG. Even if they are displaced in the length direction (Y direction) or in both the width direction (X direction) and the length direction (Y direction) as shown in FIG. Only the area portions 22 and 12 move, and a change in capacitance can be suppressed.

  In other words, in the structure shown in this embodiment, when the stacking deviation occurs, the facing area varies only in the narrow portions 13 and 23, and the facing area variation can be reduced. Can be suppressed.

  In addition, as a design in the case of stacking without misalignment, the narrow portion 23 facing the narrow portion 13 and the half length in the length direction (Y direction) of the narrow portions 13 and 23 are the length direction (Y It is desirable that they overlap in the direction). By designing in this way, it is possible to ensure that the variation of the facing area is limited to only the narrow portion with respect to the deviation in both directions in the length direction (Y direction).

  And since the small area parts 12 and 22 are formed in the front end side of the capacitor conductor patterns 3 and 4, the front end side of the capacitor conductor patterns 3 and 4 protrudes from the opposing capacitor conductor patterns 4 and 3, and the external electrodes 33 and It is also possible to suppress an increase in capacitance variation due to stacking deviation due to the capacitance between the first and second layers.

  Furthermore, since the capacitor conductor patterns 3 and 4 are all formed in the same shape, it is possible to suppress variation in capacitance when the capacitor conductor patterns 3 and 4 are laminated in an odd number.

  As a result, it is possible to obtain a multilayer capacitor 1 that can suppress variations in capacitance due to stacking deviation and that has small variations in capacitance.

  More specifically, a sample of the multilayer capacitor 1 was prepared and the variation rate of the capacitance was evaluated (Example 1). Here, the capacitor conductor patterns 3 and 4 have 10 layers, and the component size is 1 mm long × 0.5 mm wide × 0.5 mm thick. For comparison, in the case of the conventional multilayer capacitor 71 having the capacitor conductor patterns 72 and 73 (width of 265 μm) shown in FIG. 9 (Comparative Example 1), the capacitor conductor pattern 82 shown in FIG. In the case of the conventional multilayer capacitor 81 having a width of 300 μm and 83 (width of 230 μm) (Comparative Example 2) was also evaluated. In order to investigate the influence of capacitance variation due to stacking deviation and external electrode dimensions, a stacking deviation of 30 μm is caused in the length direction (Y direction) and width direction (X direction), and the wraparound dimension of the external electrode (folding back) The size of the part) was varied from 0.15 mm to 0.35 mm.

  As a result, the variation rate of the capacitance in Example 1 was ± 1.7%. On the other hand, the capacitance variation rate of Comparative Example 1 was ± 11.7%, and the capacitance variation rate of Comparative Example 2 was ± 3.5%. Thus, it can be seen that if the capacitor structure of Example 1 is adopted, the capacitance fluctuation can be greatly suppressed.

  Next, a trap-type multilayer LC filter 41 composed of a coil and a capacitor as shown in FIG. 7 was produced, and the variation rate of the resonance frequency was evaluated. The LC filter 41 is formed by printing the capacitor conductor patterns 3 and 4 of FIG. 3 on a ceramic green sheet whose main component is glass having a thickness of 30 μm, laminating four layers alternately, and further forming a coil conductor pattern 45 thereon. A ceramic green sheet mainly composed of glass having a thickness of 20 μm printed thereon was laminated to form a laminate block. The laminated body block was cut into a predetermined size and then fired integrally. Thereby, the laminated body 51 was obtained.

  The coil conductor pattern 45 is connected between layers through via holes formed in a ceramic green sheet to constitute a 10.5 turn coil. The coil and the capacitor are electrically connected in parallel inside the multilayer body 51. The component size was 1 mm long × 0.5 mm wide × 0.5 mm thick.

  Next, the external electrodes 52 and 53 were formed by applying and baking a conductive paste on both ends of the laminate 51. The external electrode 52 is electrically connected to the lead portion 14 of the capacitor conductor pattern 3 and is also electrically connected to one end of a coil constituted by the coil conductor pattern 45. The external electrode 53 is electrically connected to the lead portion 24 of the capacitor conductor pattern 4 and is also electrically connected to the other end of the coil constituted by the coil conductor pattern 45.

  For comparison, the shape of the coil conductor pattern 45 is the same, and the laminated LC filter (Comparative Example 3) having the capacitor conductor patterns 72 and 73 (width 265 μm) shown in FIG. A laminated LC filter (Comparative Example 4) having capacitor conductor patterns 82 (width: 300 μm) and 83 (width: 230 μm) was prepared and evaluated. In addition, in order to investigate the influence of variations in resonance frequency due to stacking deviation and external electrode dimensions, a stacking deviation of 30 μm is generated in the length direction (Y direction) and width direction (X direction), and the wraparound dimension of the external electrode (folded portion) ) Was varied from 0.15 mm to 0.35 mm.

  As a result, the variation rate of the resonance frequency in Example 2 was ± 2.4%. On the other hand, the variation rate of the resonance frequency of Comparative Example 3 was ± 9.8%, and the variation rate of the resonance frequency of Comparative Example 4 was ± 4.9%. Thus, it can be seen that if the LC filter structure of Example 2 is adopted, the resonance frequency fluctuation can be greatly suppressed.

  Further, FIG. 8 shows a multilayer capacitor 61 in which the narrow portions 13 and 23 do not overlap each other. In the case of the multilayer capacitor 61 in which the narrow portions 13 and 23 do not overlap in this way, even if a stacking shift in the width direction (X direction) occurs, the facing area of the narrow portions 13 and 23 changes almost at zero. do not do. Therefore, the multilayer capacitor 61 can suppress a change in capacitance with respect to the stacking deviation in the width direction (X direction) than the multilayer capacitor 1 (Example 1) shown in FIG.

  In addition, this invention is not limited to the said Example, It can change variously within the range of the summary.

  In particular, in the above embodiments, the multilayer capacitor and the multilayer LC filter have been described as examples. However, a multilayer varistor, a multilayer thermistor, or the like may be used.

  In the above embodiment, the width of the lead portion of the capacitor conductor pattern is narrow, but this suppresses an increase in the amount of paste applied and the lead portion becomes thick when the capacitor conductor pattern is printed on the ceramic green sheet. It is to do. Therefore, when such a problem does not occur, the size may be the same as the width of the large area portion.

  Moreover, although the said Example piles up a ceramic green sheet and forms a laminated body, it may form a laminated body by the method of repeatedly applying a conductive paste in order.

1 is an exploded perspective view showing an embodiment of a multilayer ceramic electronic component according to the present invention. The schematic diagram which shows the vertical cross section of the multilayer ceramic electronic component shown in FIG. The schematic diagram which shows the horizontal cross section of the multilayer ceramic electronic component shown in FIG. FIG. 4 is a schematic diagram showing the displacement of the internal electrode in FIG. 3. FIG. 4 is a schematic diagram showing another shift of the internal electrode in FIG. 3. FIG. 4 is a schematic diagram showing still another shift of the internal electrode of FIG. 3. The vertical cross-sectional schematic diagram which shows another Example of the multilayer ceramic electronic component which concerns on this invention. The horizontal cross-sectional schematic diagram which shows another Example of the multilayer ceramic electronic component which concerns on this invention. The horizontal cross-section schematic diagram of the conventional multilayer ceramic electronic component. The horizontal cross-section schematic diagram of another conventional multilayer ceramic electronic component.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,61 ... Multilayer capacitor 2 ... Ceramic green sheet 3, 4, 63, 64 ... Capacitor conductor pattern 11, 21 ... Large area part 12, 21 ... Small area part 13, 23 ... Narrow part 31 ... Laminate body 32, 33 ... External electrode 41 ... Laminated LC filter 45 ... Conductor pattern for coil 51 ... Laminated body 52, 53 ... External electrode

Claims (7)

In a multilayer ceramic electronic component having a laminate configured by stacking a plurality of ceramic layers and internal conductors, and a pair of external electrodes formed at both ends of the multilayer body and alternately connected to the internal electrodes,
The internal electrode is composed of a large area part, a small area part, a narrow part that is arranged between the large area part and the small area part and connects the large area part and the small area part,
The large area portion is disposed on the connection portion side of the internal electrode with the external electrode, and the small area portion is formed at a tip portion of the internal electrode,
The multilayer ceramic electronic component according to claim 1, wherein the large area portion overlaps the small area portion facing through the ceramic layer in plan view.   2. The multilayer ceramic according to claim 1, wherein the large area portion and the small area portion have a substantially rectangular shape, and the large area portion has a wider electrode width and a longer electrode length than the small area portion. Electronic components.   3. The multilayer ceramic electronic component according to claim 1, wherein the small area portion overlaps the large area portion in the large area portion opposed to the ceramic layer through the ceramic layer in a plan view. .   4. The multilayer ceramic electronic component according to claim 1, wherein the narrow portion overlaps the narrow portion facing each other through the ceramic layer in a plan view.   4. The multilayer ceramic electronic component according to claim 1, wherein the narrow portion does not overlap with the narrow portion opposed to each other through the ceramic layer in plan view.   6. The multilayer ceramic electronic component according to claim 1, wherein the multilayer ceramic electronic component is a multilayer ceramic capacitor.   The multilayer ceramic electronic component according to claim 6, wherein an inductor is provided inside the multilayer body to form an LC filter.

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