JP2018195655A - Method for manufacturing multilayer ceramic electronic component - Google Patents

Abstract

To provide a method for manufacturing a multilayer ceramic electronic component capable of improving reliability in mechanical strength and electric characteristic of the multilayer ceramic electronic component, by suppressing peeling between a metal powder and an organic component of an internal electrode contained in a laminate of the multilayer ceramic electronic component.SOLUTION: A method for manufacturing a multilayer ceramic electronic component comprises the steps of: preparing a plurality of ceramic green sheets; printing a conductive paste for an internal electrode on the ceramic green sheets; preparing a laminate block by laminating the plurality of ceramic green sheets; crimping the laminate block by hydrostatic pressing; and obtaining individual laminate chips by cutting the laminate block after the crimping step. In the crimping step, a pressing pressure is higher than or equal to 750 kgf and lower than or equal to 1500 kgf, a press holding time is longer than or equal to 10 seconds and shorter than or equal to 360 seconds, and a press temperature is higher than or equal to 78°C and lower than or equal to 90°C.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a method for manufacturing a multilayer ceramic electronic component.

In recent years, electronic devices such as mobile phones and portable music players have become smaller and thinner, and accordingly, substrates mounted on electronic devices and multilayer ceramic electronic components mounted on substrates have also been reduced in size and capacity. Is progressing. Along with this reduction in size and increase in capacity, in multilayer ceramic electronic components, not only the thickness of the dielectric layer (element thickness) but also the thickness of the internal electrode layer is becoming increasingly thinner, and the number of laminated layers is also increasing.
Under such circumstances, it is known to press the laminated body block in the process of manufacturing the laminated ceramic electronic component by, for example, isostatic pressing as described in Patent Document 1.

JP 61-159718 A

  However, with the progress of miniaturization and increase in capacity, it is not sufficient to simply press the laminated body block by isostatic pressing, and a gap or the like occurs between the dielectric layer and the internal electrode layer, resulting in structural defects. It sometimes occurred.

  Specifically, in an isostatic press, generally, an internal electrode paste is applied to a dielectric sheet, dried, and a plurality of them are laminated, and then a laminate block is produced by pressure bonding with an isostatic press. During the isostatic pressing, the adhesive force between the metal powder contained in the internal electrode and the resin component contained in the internal electrode is reinforced.

However, in a general hydrostatic pressure press, when the laminate block is cut and separated into individual pieces, the adhesion between the metal powder contained in the internal electrode and the resin component contained in the internal electrode may not be maintained. As a result, poor adhesion may occur.
In addition, in the firing of the singulated laminate, it is fired in a reducing atmosphere. At this time, the metal powder contained in the internal electrode is separated by sintering shrinkage of the internal electrode, so that the sintered body is sintered. There was a case where a space was generated in the internal electrode in the later laminated ceramic electronic component, and the reliability of the product in which the external electrode was formed might be lowered.

  Therefore, the main object of the present invention is to suppress the peeling between the metal powder and the organic substance of the internal electrode contained in the multilayer ceramic electronic component laminate, thereby improving the mechanical strength and electrical characteristics of the multilayer ceramic electronic component. It is an object of the present invention to provide a method for manufacturing a multilayer ceramic electronic component capable of improving the above.

In the method for manufacturing a multilayer ceramic electronic component according to the present invention, a plurality of ceramic layers and a plurality of internal electrodes are alternately stacked, and the first and second main surfaces, the first and second side surfaces, and the first And a laminated body having a second end face, a first external electrode provided on the first end face of the laminated body, and a second external electrode provided on the second end face. A step of preparing a plurality of ceramic green sheets, a step of printing a conductive paste for internal electrodes on the ceramic green sheets, a ceramic green sheet, and a ceramic green sheet printed with the conductive paste for internal electrodes Are laminated, a laminate block is prepared, a laminate block is hydrostatically pressed and crimped, and a laminate block is formed after the crimping step. And a step of obtaining individual laminate chips, the press pressure in the crimping step is not less than 750 kgf and not more than 1500 kgf, and the press holding time in the crimping step is not less than 10 seconds and not more than 360 seconds. The press temperature in the process is a method for producing a multilayer ceramic electronic component that is 78 ° C. or higher and 90 ° C. or lower.
In the method of manufacturing a multilayer ceramic electronic component according to the present invention, a metal frame formed in a frame shape provided with a space is used in the crimping step, and a multilayer block is formed in the space of the metal frame. It is preferable that the elastic body is sandwiched between the metal frame and the laminate block and is hydrostatically pressed.

According to the method for manufacturing a multilayer ceramic electronic component according to the present invention, the press holding, pressing pressure, pressing pressure, and holding time of the hydrostatic press in an appropriate range, that is, pressing pressure is 750 kgf to 1500 kgf. By managing the time at 10 to 360 seconds and the press temperature at 78 to 90 ° C., the organic matter contained in the internal electrode included in the laminate is in a state exceeding the glass transition temperature. The adhesion between the metal powder contained and the organic substance contained in the internal electrode is improved, and the metal block of the internal electrode and the organic substance of the internal electrode due to the impact of the process of cutting and stacking the laminated body block after the crimping process ( Separation of the binder) is suppressed, and the occurrence of structural defects is also suppressed in the fired laminate. Therefore, according to the method for manufacturing a multilayer ceramic electronic component according to the present invention, it is possible to provide a multilayer ceramic electronic component capable of ensuring mechanical strength and electrical characteristics for a long period of time (that is, ensuring reliability).
In addition, there may be a difference in the adhesion between the ceramic green sheets due to the step between the internal electrode pattern formed on the ceramic green sheet and the ceramic green sheet. In the method, a metal frame formed in a frame shape provided with a space is used in the crimping step, and when the laminate block is accommodated in the space of the metal frame, the metal frame and the laminate An elastic body can be sandwiched between the blocks, and pressure can be uniformly applied to the hydrostatic press and the laminate block.

  According to the present invention, the reliability of the mechanical strength and electrical characteristics of the multilayer ceramic electronic component can be improved by suppressing the peeling between the metal powder and the organic substance of the internal electrode contained in the multilayer ceramic electronic component laminate. A method of manufacturing a multilayer ceramic electronic component can be provided.

  The above-described object, other objects, features, and advantages of the present invention will become more apparent from the following description of embodiments for carrying out the invention with reference to the drawings.

It is an external appearance perspective view which shows an example of the multilayer ceramic capacitor manufactured by the manufacturing method of the multilayer ceramic electronic component concerning this invention. It is sectional drawing in the II-II line | wire of FIG. 1 which shows the multilayer ceramic capacitor manufactured by the manufacturing method of the multilayer ceramic electronic component concerning this invention. It is sectional drawing in the III-III line of FIG. 1 which shows the laminated ceramic capacitor manufactured by the manufacturing method of the laminated ceramic electronic component concerning this invention. It is a flowchart which shows the process until a ceramic green sheet is prepared. It is an external appearance perspective view of the assembly by which the laminated body block was accommodated in the metal mold | die for press. Sectional drawing in the VI-VI line of FIG. 5 which shows an assembly It is an external appearance perspective view which shows a metal frame. The state which put the assembly by which the laminated body block was accommodated in the metal mold | die for press in the bag for the isostatic pressing in a crimping | compression-bonding process is shown.

1. Multilayer Ceramic Electronic Component A multilayer ceramic capacitor will be described as a multilayer ceramic electronic component manufactured by the method for manufacturing a multilayer ceramic electronic component of the present invention. FIG. 1 is an external perspective view showing an example of a multilayer ceramic capacitor manufactured by the method for manufacturing a multilayer ceramic electronic component according to the present invention. 2 is a cross-sectional view taken along the line II-II of FIG. 1 showing a multilayer ceramic capacitor manufactured by the method for manufacturing a multilayer ceramic electronic component according to the present invention. FIG. 3 is a cross-sectional view of the multilayer ceramic electronic component according to the present invention. It is sectional drawing in the III-III line of FIG. 1 which shows the laminated ceramic capacitor manufactured by a manufacturing method.

  As shown in FIGS. 1 to 3, the multilayer ceramic capacitor 10 includes a rectangular parallelepiped multilayer body 12.

  The laminate 12 has a plurality of laminated ceramic layers 14 and a plurality of internal electrodes 16. Furthermore, the laminate 12 includes a first main surface 12a and a second main surface 12b that are opposed to the lamination direction x, and a first side surface 12c and a second side surface that are opposed to the width direction y orthogonal to the lamination direction x. 12d, and a first end surface 12e and a second end surface 12f that are opposed to a length direction z orthogonal to the stacking direction x and the width direction y. The laminated body 12 has rounded corners and ridges. In addition, a corner | angular part is a part where three adjacent surfaces of a laminated body cross, and a ridgeline part is a part where two adjacent surfaces of a laminated body intersect. Further, unevenness or the like is formed on part or all of the first main surface 12a and the second main surface 12b, the first side surface 12c and the second side surface 12d, and the first end surface 12e and the second end surface 12f. May be. Furthermore, the dimension in the length direction z of the laminate 12 is not necessarily longer than the dimension in the width direction y.

  The number of laminated ceramic layers 14 is not particularly limited, but is preferably 50 or more and 1500 or less.

  The ceramic layer 14 of the laminate 12 includes an outer layer portion 14a and an inner layer portion 14b. The outer layer portion 14a is located on the first main surface 12a side and the second main surface 12b side of the laminate 12, and is between the first main surface 12a and the inner electrode 16 closest to the first main surface 12a. And the ceramic layer 14 located between the second main surface 12b and the internal electrode 16 closest to the second main surface 12b. The region sandwiched between both outer layer portions 14a is the inner layer portion 14b. In addition, it is preferable that the thickness of the outer layer part 14a is 40 micrometers or more and 200 micrometers or less.

  Although the dimension of the laminated body 12 is not specifically limited, The dimension of the length direction z is 0.19 mm or more and 5.9 mm or less, the dimension of the width direction y is 0.08 mm or more and 5.8 mm or less, and the dimension of the lamination direction x. Is preferably 0.06 mm or more and 3.2 mm or less.

The ceramic layer 14 can be formed of a dielectric material, for example. As such a dielectric material, for example, a dielectric ceramic containing a component such as BaTiO ₃ , CaTiO ₃ , SrTiO ₃ , or CaZrO ₃ can be used. When the above-described dielectric material is included as a main component, depending on the desired characteristics of the laminated body 12, for example, a secondary material having a lower content than the main component such as an Mn compound, Fe compound, Cr compound, Co compound, or Ni compound. You may use what added the component.

When a piezoelectric ceramic is used for the multilayer body 12, the multilayer ceramic electronic component functions as a ceramic piezoelectric element. Specific examples of the piezoelectric ceramic material include, for example, a PZT (lead zirconate titanate) ceramic material.
Moreover, when a semiconductor ceramic is used for the laminated body 12, the laminated ceramic electronic component functions as a thermistor element. Specific examples of the semiconductor ceramic material include spinel ceramic materials.
When a magnetic ceramic is used for the multilayer body 12, the multilayer ceramic electronic component functions as an inductor element. When functioning as an inductor element, the internal electrode 16 is a coiled conductor. Specific examples of the magnetic ceramic material include a ferrite ceramic material.

  The thickness of the ceramic layer 14 after firing is preferably 0.4 μm or more and 15 μm or less.

  The multilayer body 12 includes, as the plurality of internal electrodes 16, for example, a plurality of first internal electrodes 16a and a plurality of second internal electrodes 16b having a substantially rectangular shape. The plurality of first internal electrodes 16 a and the plurality of second internal electrodes 16 b are embedded so as to be alternately arranged at equal intervals along the stacking direction x of the stacked body 12.

The first internal electrode 16a is positioned on one end side of the first internal electrode 16a, the first counter electrode portion 18a facing the second internal electrode 16b, and the laminated body 12 from the first counter electrode portion 18a. The first extraction electrode portion 20a up to the first end face 12e is provided. The end portion of the first extraction electrode portion 20a is drawn out to the first end surface 12e and exposed.
The second internal electrode 16b is positioned on one end side of the second counter electrode portion 18b facing the first internal electrode 16a and the second internal electrode 16b, and the laminated body 12 from the second counter electrode portion 18b. The second extraction electrode portion 20b up to the second end face 12f is provided. The end portion of the second extraction electrode portion 20b is drawn out to the second end face 12f and exposed.

  The stacked body 12 includes a first counter electrode portion 18a and a second counter electrode portion between one end in the width direction y of the first counter electrode portion 18a and the second counter electrode portion 18b and the first side surface 12c, and the first counter electrode portion 18a and the second counter electrode portion. The side part (henceforth "W gap") 22a of the laminated body 12 formed between the other end of the width direction y of 18b, and the 2nd side surface 12d is included. Further, the multilayer body 12 includes a second lead electrode of the second internal electrode 16b between the end portion of the first internal electrode 16a opposite to the first lead electrode portion 20a and the second end face 12f. It includes an end portion (hereinafter referred to as an “L gap”) 22b of the stacked body 12 formed between an end opposite to the portion 20b and the first end face 12e.

  The internal electrode 16 is appropriately made of a metal such as Ni, Cu, Ag, Pd, or Au, or an alloy containing at least one of these metals such as an Ag—Pd alloy containing one of these metals. The conductive material is contained. The resin component used for the internal electrode conductive paste for forming the internal electrode 16 is preferably ethyl cellulose or acrylic resin.

  The thickness of the internal electrode 16 is preferably 0.2 μm or more and 2.0 μm or less. The number of internal electrodes 16 is preferably 50 or more and 1500 or less.

External electrodes 24 are disposed on the first end surface 12 e side and the second end surface 12 f side of the multilayer body 12. The external electrode 24 includes a first external electrode 24a and a second external electrode 24b.
The first external electrode 24a is disposed on the surface of the first end surface 12e of the multilayer body 12, and extends from the first end surface 12e to form the first main surface 12a, the second main surface 12b, and the first side surface. 12c and second side surface 12d are formed so as to cover each part. In this case, the first external electrode 24a is electrically connected to the first extraction electrode 20a of the first internal electrode 16a. Note that the first external electrode 24 a may be formed only on the first end surface 12 e of the multilayer body 12.
The second external electrode 24b is disposed on the surface of the second end surface 12f of the multilayer body 12, and extends from the second end surface 12f to the first main surface 12a, the second main surface 12b, and the first side surface. 12c and second side surface 12d are formed so as to cover each part. In this case, the second external electrode 24b is electrically connected to the second extraction electrode 20b of the second internal electrode 16b. Note that the second external electrode 24 b may be formed only on the second end face 12 f of the multilayer body 12.

  In the stacked body 12, the first counter electrode portion 18a of the first internal electrode 16a and the second counter electrode 18b of the second internal electrode 16b are opposed to each other via the ceramic layer 14, thereby electrostatically A capacity is formed. Therefore, a capacitance can be obtained between the first external electrode 24a to which the first internal electrode 16a is connected and the second external electrode 24b to which the second internal electrode 16b is connected. The characteristics are expressed.

  The first external electrode 24a includes a first base electrode layer 26a and a first plating layer 28a disposed on the surface of the first base electrode layer 26a. Similarly, the second external electrode 24b includes a second base electrode layer 26b and a second plating layer 28b disposed on the surface of the second base electrode layer 26b.

The first base electrode layer 26a is disposed on the surface of the first end surface 12e of the multilayer body 12, and extends from the first end surface 12e to form the first main surface 12a, the second main surface 12b, and the first main surface 12e. It is formed so as to cover a part of each of the side surface 12c and the second side surface 12d.
The second base electrode layer 26b is disposed on the surface of the second end surface 12f of the multilayer body 12, and extends from the second end surface 12f to extend the first main surface 12a, the second main surface 12b, and the second main surface 12b. The first side face 12c and the second side face 12d are formed so as to cover a part thereof.
The first base electrode layer 26a may be disposed only on the surface of the first end face 12e of the multilayer body 12, and the second base electrode layer 26b may be disposed on the second end face 12f of the multilayer body 12. It may be arranged only on the surface.

Each of the first base electrode layer 26a and the second base electrode layer 26b (hereinafter also simply referred to as a base electrode layer) includes at least one selected from a baking layer, a thin film layer, and the like. The formed first base electrode layer 26a and second base electrode layer 26b will be described.
The baking layer includes glass and metal. Examples of the metal of the baking layer include at least one selected from Cu, Ni, Ag, Pd, an Ag—Pd alloy, Au, and the like. Moreover, as a glass of a baking layer, at least 1 chosen from B, Si, Ba, Mg, Al, Li etc. is included. The baking layer may be a plurality of layers. The baking layer is obtained by applying a conductive paste containing glass and metal to the laminated body 12 and baking it. The baking layer may be fired simultaneously with the ceramic layer 14 and the internal electrode 16, and the ceramic layer 14 and the internal electrode 16 are fired. After baking, it may be baked. The thickness of the thickest part of the baking layer is preferably 15 μm or more and 280 μm or less.

  Further, the thin film layer is a layer of 1 μm or less formed by a thin film forming method such as a sputtering method or a vapor deposition method and deposited with metal particles.

The first plating layer 28a is disposed so as to cover the first base electrode layer 26a. Specifically, the first plating layer 28a is disposed on the first end face 12e on the surface of the first base electrode layer 26a, and the first main surface 12a and the first main surface 12a on the surface of the first base electrode layer 26a. The second main surface 12b is preferably provided so as to reach the first side surface 12c and the second side surface 12d. The first plating layer 28a may be disposed only on the surface of the first base electrode layer 26a disposed on the first end surface 12e.
Similarly, the second plating layer 28b is disposed so as to cover the second base electrode layer 26b. Specifically, the second plating layer 28b is disposed on the second end surface 12f on the surface of the second base electrode layer 26b, and the first main surface 12a and the second main surface 12a on the surface of the second base electrode layer 26b. The second main surface 12b is preferably provided so as to reach the first side surface 12c and the second side surface 12d. The second plating layer 28b may be disposed only on the surface of the second base electrode layer 26b disposed on the second end face 12f.

Further, as the first plating layer 28a and the second plating layer 28b (hereinafter also simply referred to as a plating layer), for example, at least selected from Cu, Ni, Sn, Ag, Pd, an Ag—Pd alloy, Au, and the like. Contains one.
The plating layer may be formed of a plurality of layers. In this case, the plating layer preferably has a two-layer structure of a Ni plating layer and a Sn plating layer. By providing the Ni plating layer so as to cover the surface of the base electrode layer, it is possible to prevent the base electrode layer from being eroded by the solder used for mounting when the multilayer ceramic capacitor 10 is mounted. Further, by providing the Sn plating layer on the surface of the Ni plating layer, when the multilayer ceramic capacitor 10 is mounted, the wettability of solder used for mounting can be improved and mounting can be easily performed.

  The thickness per plating layer is preferably 4 μm or more and 12 μm or less.

The multilayer ceramic capacitor 10 including the multilayer body 12, the first external electrode 24a, and the second external electrode 24b has a dimension L in the length direction z, and the multilayer body 12, the first external electrode 24a, and the second external electrode. The dimension in the stacking direction x of the multilayer ceramic capacitor 10 including the electrode 24b is T, and the dimension in the width direction y of the multilayer ceramic capacitor 10 including the multilayer body 12, the first external electrode 24a, and the second external electrode 24b is W. Dimension.
The dimensions of the multilayer ceramic capacitor 10 are such that the L dimension in the length direction z is 0.237 mm or more and 6.45 mm or less, the W dimension in the width direction y is 0.112 mm or more and 5.9 mm or less, and the T dimension in the lamination direction x is 0.00. It is 085 mm or more and 3.4 mm or less.

2. Next, a method for manufacturing a multilayer ceramic electronic component according to the present invention will be described. Here, among the multilayer ceramic electronic components, the multilayer ceramic capacitor shown in FIG. 1 will be described as an example.

(1) Process for Preparing Ceramic Green Sheet FIG. 4 shows a flowchart of processes until a ceramic green sheet is prepared.
First, a polyvinyl butyral binder, a plasticizer, and ethanol as an organic solvent are added to a ceramic raw material, and these are wet mixed using various mills to produce a ceramic slurry (step S100). And the bubble in the produced ceramic slurry is removed by a defoaming machine (step S110). Subsequently, the ceramic slurry after defoaming is formed into a sheet shape by a lip method or the like using a sheet forming machine to obtain a ceramic green sheet (step S120). In addition, an acrylic resin etc. can also be used for the resin component.

(2) Step of printing internal electrode conductive paste on ceramic green sheet Also, an internal electrode conductive paste for forming internal electrode 16 is prepared. The conductive paste for internal electrodes includes a binder (resin component), and the resin component is preferably ethyl cellulose or acrylic resin.

  Then, for example, the internal electrode conductive paste is printed in a predetermined pattern on the surface of the ceramic green sheet, and the internal electrode pattern is formed on the ceramic green sheet. The internal electrode conductive paste can be printed by a known method such as screen printing or gravure printing.

(3) Step of Preparing Laminate Block Next, a predetermined number of outer layer ceramic green sheets on which the internal electrode pattern is not printed are laminated, and ceramic green sheets on which the internal electrode pattern is printed are sequentially laminated thereon. Further, a predetermined number of ceramic green sheets for outer layers are laminated thereon to prepare a laminate block. At this time, a plurality of ceramic green sheets on which the internal electrode patterns are printed are stacked such that the lead portions of the internal electrode patterns are staggered.

(4) Crimping process by hydrostatic pressure press In order to improve the adhesion between the ceramic green sheet and the ceramic green sheet of the laminate block after lamination and between the internal electrode pattern and the ceramic green sheet, To be implemented. When performing isostatic pressing, a pressing die 30 as shown in FIG. 5 is prepared. The pressing mold 30 includes a metal frame 32 for housing the laminate block 40, a first base plate 34a disposed so as to sandwich the laminate block 40 accommodated in the metal frame 32, and A second base plate 34b is included.

  As shown in FIG. 7, the metal frame 32 is formed in a frame shape in which a space portion 32 a having a substantially square shape in plan view for accommodating the laminated body block 40 is provided. Then, the second base plate 34 b is disposed below the metal frame 32, and the laminated body block 40 is accommodated in the space portion 32 a of the metal frame 32, and then, on the upper side of the metal frame 32. The first base plate 34a is disposed so as to cover the space 32a, and an assembly is formed as shown in FIGS. As a result, the laminate block 40 is sandwiched between the first base plate 34a and the second base plate 34b. Then, as shown in FIG. 8, this assembly is vacuum sealed in a bag 50 made of a sealable material for isostatic pressing. Thereafter, the assembly including the unfired laminated body block 40 is submerged in water, and pressure is applied to the water. Thereby, the hydrostatic pressure is applied to the laminated body block 40 and it press-bonds.

  Note that a difference in adhesion between the ceramic green sheets may occur due to a step between the internal electrode pattern formed on the ceramic green sheet and the ceramic green sheet. Therefore, an elastic body may be sandwiched between the metal frame 32 and the laminated body block 40 so that pressure is applied uniformly.

  The conditions of the isostatic pressing are preferably a press pressure of 750 kgf to 1500 kgf, a press holding time of 10 seconds to 360 seconds, and a press temperature of 78 ° C. to 90 ° C.

(5) Step of obtaining laminated body chip Thereafter, the laminated body block pressed by hydrostatic pressure is cut into a predetermined shape and dimension by a guillotine or dicing method, and a laminated body chip of a predetermined size is obtained. At this time, in order to suppress chipping generated after firing, the corners and ridges of the laminated chip may be rounded by barrel polishing or the like.

  Subsequently, the unfired laminate chip is fired to produce the laminate 12. The firing temperature is preferably 900 ° C. or higher and 1300 ° C. or lower although it depends on the material of the ceramic layer and internal electrodes.

(6) Step of forming external electrode In order to form a baking layer of external electrode 24, for example, the first lead of first internal electrode 16a exposed from first end surface 12e on the surface of laminate 12 A conductive paste for external electrodes is applied to the exposed portion of the electrode portion 20a and baked to form the first base electrode layer 26a. Similarly, in order to form the baking layer of the external electrode 24, for example, the exposed portion of the second extraction electrode portion 20b of the second internal electrode 16b exposed from the second end surface 12f of the multilayer body 12 is used. The conductive paste for external electrodes is applied and baked on to form the second base electrode layer 26b. The conductive paste for external electrodes contains Cu powder and glass frit. At this time, the baking temperature is preferably 700 ° C. or higher and 900 ° C. or lower. If necessary, one or more plating layers are formed on the surface of the baking layer, and the external electrode 24 is formed.

  As described above, the multilayer ceramic capacitor 10 shown in FIG. 1 is manufactured.

  According to the method for manufacturing a multilayer ceramic electronic component according to the present invention, the press holding, press holding time, and press temperature of the hydrostatic press in the press bonding step are in an appropriate range, that is, the press pressure is 750 kgf to 1500 kgf. By managing the time from 10 seconds to 360 seconds and the press temperature from 78 ° C. to 90 ° C., the organic matter contained in the internal electrode 16 included in the laminate 12 is in a state exceeding the glass transition temperature. The adhesion between the metal powder contained in the electrode 16 and the organic substance contained in the internal electrode 16 is improved, and the metal powder of the internal electrode 16 due to the impact or the like in the process of cutting and separating the laminate block after the crimping process Peeling of the organic substance (binder) of the internal electrode 16 is suppressed, and the occurrence of structural defects is also suppressed in the fired laminate. Therefore, according to the method for manufacturing a multilayer ceramic electronic component according to the present invention, as a multilayer ceramic electronic component capable of ensuring mechanical strength and electrical characteristics for a long period of time (that is, ensuring reliability), for example, a multilayer ceramic capacitor 10 may be provided.

  In addition, there may be a difference in the adhesion between the ceramic green sheets due to the step between the internal electrode pattern formed on the ceramic green sheet and the ceramic green sheet. According to the method, the metal frame 32 formed in a frame shape provided with the space portion 32a is used in the crimping step, and when the laminate block is accommodated in the space portion 32a of the metal frame body 32, the metal Since the elastic body is sandwiched between the frame body 32 and the laminate block and is hydrostatically pressed, pressure can be uniformly applied to the laminate block.

3. Experimental Example Next, in order to confirm the effect of the manufacturing method of the multilayer ceramic electronic component according to the present invention described above, a multilayer ceramic capacitor was manufactured based on the manufacturing method of the present invention, and the multilayer chip before sintering and sintering The presence or absence of cohesive failure inside the laminate and the life characteristics by high temperature load test were confirmed.

(1) Sample Preparation Conditions in Experimental Example First, using the above-described manufacturing method, a multilayer ceramic capacitor as a sample according to the experimental example was manufactured based on the following conditions.

In the experimental examples, the conditions for firing the laminated chip were as follows. That is, the binder (resin component) was burned by heating at 260 ° C. for 3 hours in an N ₂ atmosphere. Then, it baked at 1200 degreeC in reducing environment for 2 hours, and obtained the sintered laminated body concerning this experiment example.

The conditions for obtaining a multilayer ceramic capacitor by applying a conductive paste for external electrodes to the multilayer body were as follows. That is, a conductive paste for an external electrode containing Cu powder and glass frit is applied to both end faces of the laminate, and is baked at a temperature of 800 ° C. in an N ₂ atmosphere to be electrically connected to the internal electrode. An electrode layer was formed to obtain a multilayer ceramic capacitor according to this experimental example.

The specifications of the multilayer ceramic capacitor, which is a sample used in the experimental example, are as follows.
・ Size (design value) of multilayer ceramic capacitor: length x width x height = 3.2 mm x 1.6 mm x 1.6 mm
・ Ceramic layer material: BaTiO ₃
・ Ceramic layer thickness: 1.2 μm
・ Number of laminated ceramic layers (including outer layer part): 600 ・ Thickness of outer layer part: 120 μm
・ Material of internal electrode: Ni
-Internal electrode thickness: 0.5 μm
・ Structure of external electrode Material of base electrode layer: Baking layer containing Cu and glass Plating layer: Two-layer structure of Ni plating and Sn plating

  Further, the conditions of the hydrostatic press in the experimental example were set by changing the press pressure, the press holding time, and the press temperature, and the conditions 1 to 38 were set for the experiment. Conditions 1 to 38 of the hydrostatic press are shown in Table 1.

(2) Method of characteristic evaluation (a) Confirmation of cohesive failure in internal electrode in laminate chip before sintering 1/2 so as to be parallel to the first or second side surface in the laminate chip before sintering Sectional polishing was performed up to the 2W surface, and the state in the section was observed. In addition, when space was seen in the internal electrode, it was determined that cohesive failure was performed. Observation was performed with an optical microscope. The number of samples was 100 for each condition of the hydrostatic pressure press.

(B) Confirmation of cohesive failure in internal electrode in laminated body after sintering Cross-sectional polishing to 1/2 W surface so as to be parallel to first or second side face in laminated body after sintering, The state in the cross section was observed. Observation was performed with an optical microscope. In addition, when space was seen in the internal electrode, it was determined that cohesive failure was performed. Moreover, observation may be performed visually or with an electron microscope. The number of samples was 100 for each condition of the hydrostatic pressure press.

(C) Measurement of life characteristics by high-temperature load test A DC voltage of 50 V was applied to the obtained multilayer ceramic capacitor at 150 ° C., and the change in insulation resistance with time was observed. The time when the insulation resistance value of each multilayer ceramic capacitor was 0.1 MΩ or less was judged as a failure. The time until failure of the sample under each condition was analyzed by Weibull plot, 1% failure time (B1 Safe Life) was obtained, and pass / fail judgment was performed. Here, a sample having a time until failure of less than 0.25 hours was rejected (indicated by “x” in the table), and a sample that did not fail even after 0.25 hours passed (table) (Indicated by “◯”).

  Table 1 shows the presence / absence of cohesive failure in the laminate chip before sintering and inside the laminate after sintering, and the evaluation results of the life characteristics by the high-temperature load test with respect to conditions 1 to 38 in the experimental example.

(3) Evaluation results As shown in Table 1, conditions 3 to 5 of the hydrostatic press are that the press temperature is 78 ° C., the press pressure is 750 kgf, and the press holding time is 10 seconds or more and 360 seconds or less. In the observation results of cohesive failure, a slightly good result was obtained with respect to the condition 2 in which the press temperature and the press pressure were the same and the press holding time was 1 second. Further, in the high temperature load test, a good result was obtained. .

  The conditions 7 to 9 of the hydrostatic press are that the press temperature is 78 ° C., the press pressure is 1000 kgf, and the press holding time is 10 seconds or more and 360 seconds or less. However, a slightly good result was obtained with respect to the condition 6 in which the press holding time was 1 second under the same conditions, and furthermore, a good result was obtained in the high temperature load test.

  The conditions 11 to 13 of the hydrostatic press are that the press temperature is 78 ° C., the press pressure is 1500 kgf, and the press holding time is 10 seconds or more and 360 seconds or less. However, a good result was obtained with respect to the condition 10 in which the press holding time was 1 second under the same conditions, and a good result was obtained in the high temperature load test.

  The conditions 15 to 17 of the hydrostatic press are that the press temperature is 83 ° C., the press pressure is 750 kgf, and the press holding time is 10 seconds or more and 360 seconds or less. However, a good result was obtained with respect to the condition 14 in which the press holding time was 1 second under the same conditions, and a good result was obtained in the high temperature load test.

  The conditions 19 to 21 of the hydrostatic press are that the press temperature is 83 ° C., the press pressure is 1000 kgf, and the press holding time is 10 seconds or more and 360 seconds or less. However, a good result was obtained with respect to the condition 18 in which the press holding time was 1 second under the same conditions, and a good result was obtained in the high temperature load test.

  The conditions 23 to 25 of the hydrostatic press are that the press temperature is 83 ° C., the press pressure is 1500 kgf, and the press holding time is 10 seconds or more and 360 seconds or less. However, good results were obtained with respect to the condition 22 under the same conditions with a press holding time of 1 second, and further, good results were obtained in the high temperature load test.

  The conditions 27 to 29 of the hydrostatic press are that the press temperature is 90 ° C., the press pressure is 750 kgf, and the press holding time is 10 seconds or more and 360 seconds or less. However, a good result was obtained with respect to the condition 26 in which the press holding time was 1 second under the same conditions, and a good result was obtained in the high temperature load test.

  The conditions 31 to 33 of the hydrostatic press are that the press temperature is 90 ° C., the press pressure is 1000 kgf, and the press holding time is 10 seconds or more and 360 seconds or less. However, a good result was obtained with respect to the condition 30 in which the press holding time was 1 second under the same conditions, and a good result was obtained in the high temperature load test.

  Conditions 35 to 37 of the hydrostatic press are that the press temperature is 90 ° C., the press pressure is 1500 kgf, and the press holding time is 10 seconds or more and 360 seconds or less. However, good results were obtained with respect to the condition 34 in which the press holding time was 1 second under the same conditions, and further, good results were obtained in the high temperature load test.

  On the other hand, in condition 1, since the press temperature is 70 ° C., the press pressure is 700 kgf, and the press holding time is 1 second, relatively many cohesive failures are observed in the observation results of cohesive failure, and the results of the high temperature load test are also shown. It was bad.

  In condition 2, the press temperature is 78 ° C., the press pressure is 750 kgf, and the press holding time is 1 second. In condition 6, the press temperature is 78 ° C., the press pressure is 1000 kgf, and the press holding time is 1 second. In condition 10, the press temperature was 78 ° C., the press pressure was 1500 kgf, and the press holding time was 1 second, so the result of the high-temperature load test was poor.

  In condition 14, the press temperature is 83 ° C., the press pressure is 750 kgf, and the press holding time is 1 second. In condition 18, the press temperature is 83 ° C., the press pressure is 1000 kgf, and the press holding time is 1 second. Condition 22 was that the press temperature was 83 ° C., the press pressure was 1500 kgf, and the press holding time was 1 second.

  Condition 26 is a press temperature of 90 ° C., a press pressure of 750 kgf and a press holding time of 1 second. Condition 30 is a press temperature of 90 ° C., a press pressure of 1000 kgf and a press holding time of 1 second. In condition 34, the press temperature was 90 ° C., the press pressure was 1500 kgf, and the press holding time was 1 second.

  Further, under condition 38, the press temperature was 91 ° C., the press pressure was 1600 kgf, and the press holding time was 1 second, so the result of the high temperature load test was poor.

From the above results, according to the method for producing a multilayer ceramic electronic component according to the present invention, the conditions of the hydrostatic press in the crimping step are as follows: the press pressure is 750 kgf to 1500 kgf, the press holding time is 10 seconds to 360 seconds, By setting the press temperature in the range of 78 ° C. or higher and 90 ° C. or lower, the occurrence of fracture (cohesive fracture) in the internal electrode is suppressed in the laminated chip before sintering / the laminated body after sintering. confirmed. Therefore, according to the method for manufacturing a multilayer ceramic electronic component according to the present invention, it is possible to ensure mechanical strength and electrical characteristics for a long period of time (that is, to ensure reliability) by suppressing destruction in the internal electrode. It has been suggested that a laminated ceramic capacitor can be provided.
The effect of the present invention is that the organic matter contained in the internal electrode included in the laminate exceeds the glass transition temperature, and the adhesion between the metal powder contained in the internal electrode and the organic matter contained in the internal electrode is improved. It is considered that this is because peeling of the metal powder of the internal electrode and the organic substance (binder) of the internal electrode due to impact or the like in the process of cutting and stacking the laminated body block after the crimping process is suppressed.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation is carried out within the range of the summary.

DESCRIPTION OF SYMBOLS 10 Multilayer ceramic capacitor 12 Laminated body 12a 1st main surface 12b 2nd main surface 12c 1st side surface 12d 2nd side surface 12e 1st end surface 12f 2nd end surface 14 Ceramic layer 14a Outer layer part 14b Inner layer part 16 Inside Electrode 16a 1st internal electrode 16b 2nd internal electrode 18a 1st counter electrode part 18b 2nd counter electrode part 20a 1st extraction electrode part 20b 2nd extraction electrode part 22a Side part (W gap)
22b End (L gap)
24 external electrode 24a first external electrode 24b second external electrode 26a first base electrode layer 26b second base electrode layer 28a first plating layer 28b second plating layer 30 pressing mold 32 metal frame Body 34a First base plate 34b Second base plate 40 Laminate block 50 Bag x Stack direction y Width direction z Length direction

Claims (2)

A laminated body in which a plurality of ceramic layers and a plurality of internal electrodes are alternately laminated and having first and second main surfaces, first and second side surfaces, and first and second end surfaces;
A method for producing a multilayer ceramic electronic component, comprising: a first external electrode provided on a first end surface of the multilayer body; and a second external electrode provided on a second end surface,
Preparing a plurality of ceramic green sheets;
Printing an internal electrode conductive paste on the ceramic green sheet;
Laminating a plurality of ceramic green sheets and ceramic green sheets printed with the internal electrode conductive paste, and preparing a laminate block;
A pressure bonding step in which the laminate block is hydrostatically pressed and pressure bonded;
Cutting the laminate block after the crimping step to obtain individual laminate chips;
With
The press pressure in the crimping step is 750 kgf or more and 1500 kgf or less,
The press holding time in the crimping step is 10 seconds or more and 360 seconds or less,
The press temperature in the said crimping | compression-bonding process is a manufacturing method of a multilayer ceramic electronic component which is 78 degreeC or more and 90 degrees C or less.   In the crimping step, a metal frame formed in a frame shape provided with a space is used, and when the laminated body block is accommodated in the space of the metal frame, the metal frame and The method for manufacturing a multilayer ceramic electronic component according to claim 1, wherein an elastic body is sandwiched between the multilayer block and the hydrostatic pressing is performed.

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