JP2014127581A - Multilayer ceramic electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayer ceramic electronic component in which desired component characteristics can be maintained well, even if a component-specific conductor part incorporated in the component body is formed by using a thin film formation method, and a plurality of strip connections are formed at the end of the conductor part.SOLUTION: A multilayer ceramic capacitor 10 has a plurality of strip connections 12a at the end of an internal electrode 12, formed by using a thin film formation method, substantially in parallel and integrally via a strip gap 12b. End of each strip connection 12a is connected with an external electrode 14. The strip connection 12a has a width in the range of 3-80 μm, the width of the strip connection 12a and the width of strip gap 12b satisfy a condition; the width W12a of the strip connection 12a≥the width W12b of the strip gap 12b.

Description

  The present invention relates to a multilayer ceramic electronic component including a multilayer ceramic capacitor, a multilayer ceramic inductor, and the like, in particular, a multilayer ceramic electronic in which a component-specific conductor portion incorporated in a component body is formed by using a thin film forming method. Regarding parts.

  A component-specific conductor portion (for example, a plurality of internal electrodes of a multilayer ceramic capacitor or a coil of a multilayer ceramic inductor) formed by using a thin film formation method (for example, a sputtering method or a vapor deposition method) is built in the component body. In general, a multilayer ceramic electronic component (for example, a multilayer ceramic capacitor or a multilayer ceramic inductor) having a structure in which an external electrode provided on a component body is connected to an end of the conductor is generally (1) a large number of conductors. A step of producing a plurality of laminated green sheets including a green sheet in which patterns (divided into conductor portions) are provided in a predetermined arrangement; (2) a plurality of conductors by appropriately stacking and laminating the laminated green sheets. A step of producing a laminated sheet including a pattern; (3) a conductor obtained by cutting the laminated sheet so that the conductor pattern is divided; Manufactured through a step of manufacturing a multilayer chip including (4) a step of baking the multilayer chip to manufacture a fired chip, and (5) a step of manufacturing an external electrode on the fired chip so as to be connected to the end of the conductor portion. (See Patent Documents 1 and 2 below).

  By the way, since the conductor pattern included in the laminated sheet prepared in the step (2) is already hard, the cutting load in the step (3) is a thick film forming technique (paste is printed and dried). Compared with the case of forming the object by using a method in which the product is baked in a step corresponding to the step (4)). In order to reduce the cutting load, as shown in FIG. 2 of the following Patent Document 2, the shape of the cut portion of the conductor pattern formed in the step (1) has a plurality of strip-like portions arranged substantially in parallel. The width of the plurality of strip-shaped portions may be narrowed as a shape, but when the width of the strip-shaped portions is narrowed (in other words, the gap between the strip-shaped portions is widened), the component characteristics of the laminated ceramic electronic component after manufacture, In particular, it has been confirmed by experiments that the frequency characteristics fluctuate.

Japanese Patent Application Laid-Open No. 01-042809 JP 09-31232 A

  An object of the present invention is to provide a component-specific conductor portion built in the component main body by using a thin film forming method, and a plurality of strip-shaped connection portions are formed at the end portions of the conductor portion. It is an object of the present invention to provide a multilayer ceramic electronic component that can maintain good component characteristics at the initial stage.

  In order to achieve the above-mentioned object, the present invention has a component-specific conductor formed by using a thin film forming method built in the component body, and an external electrode provided on the component body is connected to the end of the conductor portion. In the multilayer ceramic electronic component having the above-described structure, the conductor portion has a plurality of strip-like connection portions at the end portions thereof substantially in parallel with the strip-like gap and integrally, and the end of each strip-like connection portion is provided. It is connected to the external electrode, and the width of the band-shaped connecting portion is in the range of 3 to 80 μm, and the width of the band-shaped connecting portion and the width of the band-shaped gap are the width of the band-shaped connecting portion ≧ the width of the band-shaped gap. The condition is satisfied.

  According to the present invention, even when a conductor portion unique to a component built in the component body is formed by using a thin film forming method and a plurality of strip-like connection portions are formed at the end portion of the conductor portion. It is possible to provide a monolithic ceramic electronic component capable of maintaining good component characteristics at the initial stage.

  The above object and other objects, structural features, and operational effects of the present invention will become apparent from the following description and the accompanying drawings.

1A is a side view of a multilayer ceramic capacitor to which the present invention is applied, FIG. 1B is a cross-sectional view taken along line BB in FIG. 1A, and FIG. It is a longitudinal cross-sectional view which follows the CC line of B). 2 (A) to 2 (I) are diagrams illustrating a method of manufacturing the multilayer ceramic capacitor shown in FIG. FIG. 3 is a diagram showing the specifications of the strip-shaped connecting portions and the strip-shaped gaps of Samples 1 to 20 and the evaluation results thereof. FIG. 2B is a view corresponding to FIG. 1B showing a structural modification of the multilayer ceramic capacitor shown in FIG. 1.

  1A to 1C show a multilayer ceramic capacitor (hereinafter simply referred to as a capacitor) to which the present invention is applied.

  This capacitor 10 has a substantially rectangular parallelepiped shape having a reference dimension relationship of length> width = height or length> width> height, and a pair is provided at both ends in the longitudinal direction of the substantially rectangular parallelepiped component body 11. The external electrode 14 is provided. Incidentally, the length of the capacitor 10 refers to the horizontal dimension in FIGS. 1A and 1C, the width refers to the vertical dimension in FIG. 1B, and the height refers to FIG. And the dimension of the up-down direction in FIG.1 (C) is pointed out.

  The component main body 11 incorporates a plurality (20 in the figure) of internal electrodes 12 which are conductor portions peculiar to the components so as to face each other substantially in parallel in the height direction. In addition, each internal electrode 12 is covered with a dielectric portion 13 at the periphery (except for the end of each band-like connection portion 12a, which will be described later connected to the external electrode 14), and the internal electrodes 12 face each other substantially in parallel in the height direction. The dielectric portions 13 are present in layers between each of the gaps. Each internal electrode 12 is formed by using a thin film forming method such as a sputtering method or a vapor deposition method, and the material thereof is a metal such as nickel or silver. The dielectric portion 13 is formed by using a thick film forming method (a method of stacking sheets obtained by applying slurry and drying and firing the stacked sheets), and the material thereof is ceramic, for example, barium titanate. Strontium titanate, calcium titanate, magnesium titanate, calcium zirconate, calcium zirconate titanate, barium zirconate or titanium oxide.

  As can be seen from FIG. 1 (B) and FIG. 1 (C), odd-numbered internal electrodes 12 from the top are provided with a plurality of (six in the drawing) strip-like connection portions 12a having a predetermined width W12a at the left end portions. They are provided in parallel and integrally with each other via a belt-like gap 12b of W12b, and the end of each belt-like connecting portion 12a is connected to the left external electrode 14. The even-numbered internal electrodes 12 from the top also have a plurality (six in the figure) of strip-shaped connecting portions 12a having a predetermined width W12a at the right end portions thereof in parallel with the strip-shaped gaps 12b having a predetermined width W12b, and They are integrally formed, and the ends of the respective strip-like connecting portions 12a are connected to the right external electrode.

  As will be apparent from the following description, the width W12a of each strip-like connecting portion 12a of each internal electrode 12 is preferably in the range of 3 to 80 μm regardless of the width W12 of each internal electrode 12. In addition, the relationship between the width W12a of each strip-like connection portion 12a of each internal electrode 12 and the width W12b of each strip-like gap preferably satisfies the condition of the width W12a of the strip-like connection portion 12a ≧ the width W12b of the strip-like gap. .

  Each external electrode 14 has a two-layer structure of a base layer (no reference) closely attached to both ends in the length direction of the component body 11 and a surface layer formed on the surface of the base layer, or a base layer and a surface layer. It has a multilayer structure having one or more intermediate layers between them. The underlayer is made of, for example, nickel or silver, the surface layer is made of, for example, tin, palladium, gold, or zinc, and the intermediate layer is made of, for example, platinum, palladium, gold, copper, or nickel.

  2A to 2I show a method of manufacturing the capacitor 10 shown in FIG.

  When the capacitor 10 shown in FIG. 1 is manufactured, first, a base made of a plastic such as polyethylene terephthalate or a metal such as stainless steel is formed by using a thin film forming method such as sputtering, vapor deposition, electrolytic plating, or electroless plating. A transfer sheet TS is produced by forming a large number of conductor patterns CP in a predetermined arrangement (for example, a matrix arrangement or a staggered arrangement) with a predetermined thickness made of a metal material constituting the internal electrode 12 on one surface of a sheet (no reference). (See FIG. 2A). As can be seen from FIG. 2A, each conductor pattern CP formed on the transfer sheet TS has two strip-shaped connection portions 12a formed by the internal electrodes 12 (including the strip-shaped connection portions 12a) shown in FIG. It has a shape that is connected through.

  Further, a slurry containing ceramic material powder constituting the dielectric portion 13 is prepared, and the slurry is applied to one surface of a base sheet (not shown) made of plastic such as polyethylene terephthalate using a die coater or the like. The first green sheet S1 is manufactured by coating with a width and drying (see FIG. 2B).

  Next, the surface on which the respective conductor patterns CP of the transfer sheet TS are formed is superposed on one surface of the first green sheet S1 and thermocompression bonded, and then the base sheet of the transfer sheet TS is peeled off to form a plurality of conductor patterns CP. The transferred second green sheet S2 is manufactured, and a third green sheet S3 in which the transfer positions of the second green sheet S2 and each conductor pattern CP are shifted in the left-right direction is manufactured (FIGS. 2C and 2). (See (D)).

  Next, using a suction head having a punching blade and a heater or the like, the portion punched from the first green sheet S1 (not including the base sheet) is stacked on the upper surface of the stacking table (not shown) until a predetermined number is reached and heat is applied. The parts punched from the second green sheet S2 (not including the base sheet) and the parts punched from the third green sheet S3 (not including the base sheet) are alternately formed on the upper surface thereof, and each has a predetermined number. They are stacked and thermocompression bonded until they reach, and the top punched parts (not including the base sheet) are stacked and thermocompression bonded until reaching a predetermined number, and this is used with a hot isostatic press or the like. Finally, the laminated sheet LS is manufactured by thermocompression bonding (see FIGS. 2E and 2F).

  Next, using a dicing machine, a press cutting machine, or the like, the laminated sheet LS is cut into a lattice shape (see the thick line in the figure) to produce a laminated chip LC (see FIG. 2G). As can be seen from FIG. 2 (G), each conductor pattern CP in the laminated sheet LS is divided by cutting substantially the center of the portion where the two strip-like connecting portions 12a are connected.

  Next, a large number of laminated chips LC are put into a firing furnace, and firing (including binder removal processing and firing processing) is performed in an atmosphere and a temperature profile according to the ceramic material included in the first green sheet S1. A fired chip (corresponding to the component main body 11) BC is manufactured (see FIG. 2H).

  Next, using a roller applicator or the like, the external electrode paste (including the powder of the material constituting the base layer) is applied to both ends in the longitudinal direction of the fired chip BC, and the metal material contained in the external electrode paste is applied. Baking is performed in an appropriate atmosphere and temperature profile to form a base layer, and subsequently forming a surface layer on the surface of the base layer, or one or more intermediate layers and a surface layer in order by an electrolytic plating method, A pair of external electrodes 14 is manufactured (see FIG. 2I).

  Here, the specifications of the strip conductor portions 12a and the strip gaps 12b of the samples 1 to 20 prepared for verifying the effect obtained by the capacitor 10 shown in FIG. 1, the evaluation methods and the evaluation results thereof are cited with reference to FIG. To explain.

  Each sample 1-20 is a 1005 size capacitor having the same structure as the capacitor 10 shown in FIG. 1. The internal electrodes 12 are made of nickel, the total number is 200, and each width W12 is approximately 370 μm, long. The thickness (including the strip-shaped connection portion 12a) is approximately 800 μm, the thickness (including the strip-shaped connection portion 12a) is approximately 1 μm, and the length L12a of each strip-shaped connection portion 12a is approximately 140 μm. The dielectric portion 13 is made of barium titanate, and the thickness of the layered portion of the dielectric portion 13 existing between the internal electrodes 12 is approximately 1.2 μm. Each external electrode 14 has a two-layer structure composed of a silver base layer and a tin surface layer, and the length of the portion of the component main body 11 that wraps around the left and right surfaces and the top and bottom surfaces is approximately 200 μm. .

  Each sample 1-20 is manufactured according to the said manufacturing method (refer FIG. 2 (A)-FIG. 2 (I)), Comprising: Each internal electrode 12 is formed by sputtering method. The “width W12a (μm) of the strip-shaped connecting portion 12a”, “width W12b (μm) of the strip-shaped gap 12b”, and “number of strip-shaped connecting portions 12a” in the samples 1 to 20 are as shown in FIG.

  The “number of strip-shaped connecting portions 12a” of Samples 4, 7, 10, 13, 16, and 19 shown in FIG. 3 are “width W12a (μm) of strip-shaped connecting portion 12a” and “width W12b of strip-shaped gap 12b (μm)”. According to the numerical value described in “)”, the width W12 is the maximum number that can be accommodated at the end of the internal electrode 12 having a width of about 370 μm. In addition, the “number of strip connections 12a” of Samples 1 to 3 is the same as Sample 4 for comparison, and the “number of strip connections 12a” of Samples 5 and 6 is the same as Sample 7 for comparison. Samples 8 and 9 have the same “number of strip connections 12a” as sample 10 for comparison, and samples 11 and 12 have the same “number of strip connections 12a” as sample 13 for comparison. 14 and 15 have the same “number of strip connections 12a” as sample 16 for comparison, and samples 17, 18 and 20 have the same “number of strip connections 12a” as sample 19 for comparison. .

  The “resonance frequency fluctuation rate (%)” in FIG. 3 is a percentage of the deviation between the resonance frequency obtained in the design stage of each sample 1 to 20 and the average value of the actual resonance frequency of each of 30 samples 1 to 20. It is represented by. Incidentally, the actual resonant frequency of each sample 1-20 is each self-resonant point, and was measured with an impedance analyzer (4294A manufactured by Agilent Technologies).

  In addition, the “morphological abnormality rate (%) at the end of the belt-like connecting portion 12a” in FIG. 3 is obtained by manufacturing each sample 1 to 20 in accordance with the above manufacturing method (see FIGS. 2A to 2I). In the middle, 100 laminated chips LC produced in the laminated chip producing process (see FIG. 2G) are each taken out, and cracks or chips are formed at the end of the strip-like connecting portion 12a (pointing to the cut surface and its vicinity). Whether or not there is a morphological abnormality such as the occurrence of burrs is observed with an optical microscope, and the number n confirmed as having a morphological abnormality is expressed as a percentage (n / 100).

  As can be seen from FIG. 3, among samples 2 to 19, a change in resonance frequency of −1% is confirmed in samples 4, 7, 10, 16 and 19, and a band shape of 1% in samples 17, 18 and 19 is observed. Although an abnormality in the shape of the end of the connecting portion 12a was confirmed, the frequency variation rate is very small. Therefore, if the width W12a of the strip-shaped connecting portion 12a is in the range of 3 to 80 μm, the width W12b of the strip-shaped gap 12b is concerned. Therefore, it can be said that the desired frequency characteristics can be maintained satisfactorily.

  Further, as can be seen from FIG. 3, if the slight resonance frequency fluctuation is confirmed among the samples 2 to 19, and the samples 4, 7, 10, 16, and 19 are excluded, the width W12a of the strip-like connecting portion 12a is 3 Even within the range of ˜80 μm, it can be said that the desired frequency characteristics can be maintained better if the condition of the width W12a of the band-shaped connecting portion 12a ≧ the width W12b of the band-shaped gap is satisfied.

  In each of Samples 2 to 19 shown in FIG. 3, the thickness of the internal electrode 12 (including the strip-shaped connecting portion 12a) is approximately 1 μm. However, when the thickness of the internal electrode 12 is less than 1 μm, Even when the internal electrode 12 is made of a metal other than nickel, even if it is thicker than 1 μm, the width W12a of the band-shaped connecting portion 12a is in the range of 3 to 80 μm, and the width W12a of the band-shaped connecting portion 12a ≧ each band-shaped The same effect as described above can be obtained if the condition of the gap width W12b is satisfied.

  FIG. 4 shows a structural modification of the capacitor 10 shown in FIG.

  This capacitor 10 ′ is different from the capacitor 10 shown in FIG. 1 in that the width between the internal electrode 12 and the plurality of strip-shaped connection portions 12b is narrower than the width W12 of the internal electrode 12, and the plurality of strip-shaped connections. The leading portion 12c has a width greater than the entire width of the portion 12b. In this capacitor 10 ', although the length L12a of the strip-shaped connecting portion 12b is shortened by providing the lead-out portion 12c, the width W12a of the strip-shaped connecting portion 12a is in the range of 3 to 80 μm, and the strip-shaped connecting portion If the condition of width W12a of 12a ≧ width W12b of each band gap is satisfied, even if the thickness of the internal electrode 12 is thinner than 1 μm or thicker than 1 μm, in addition, the internal electrode 12 is other than nickel Even when made of metal, the same effect as described above can be obtained.

  As described above, the embodiment in which the present invention is applied to the multilayer ceramic capacitor has been described. However, the present invention is applied to multilayer ceramic electronic components other than the multilayer ceramic capacitor, for example, a multilayer ceramic inductor having a built-in coil as a conductor portion unique to the component. When applied, in detail, even when a plurality of strip-shaped connection portions are provided substantially in parallel and integrally with the end portions of the coil via the strip-shaped gap, the width of the strip-shaped connection portions is in the range of 3 to 80 μm, As long as the condition of the width of the band-shaped connecting portion ≧ the width of the band-shaped gap is satisfied, the same effect as described above can be obtained.

  DESCRIPTION OF SYMBOLS 10, 10 '... Multilayer ceramic capacitor, 11 ... Component main body, 12 ... Internal electrode, 12a ... Band-shaped connection part, 12b ... Band-shaped gap | interval, 13 ... Dielectric part, 14 ... External electrode.

Claims (2)

In a multilayer ceramic electronic component having a structure in which a component-specific conductor formed using a thin film forming method is built in a component main body, and an external electrode provided on the component main body is connected to an end of the conductor portion ,
The conductor portion has a plurality of strip-like connection portions at its end portions substantially in parallel with the strip-like gap, and integrally, and the end of each strip-like connection portion is connected to the external electrode,
The width of the band-shaped connecting portion is in the range of 3 to 80 μm, and the width of the band-shaped connecting portion and the width of the band-shaped gap satisfy the condition of the width of the band-shaped connecting portion ≧ the width of the band-shaped gap.
A multilayer ceramic electronic component characterized by that. The conductor portion is formed using a sputtering method, a vapor deposition method, an electrolytic plating method or an electroless plating method.
The multilayer ceramic electronic component according to claim 1, wherein:

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