JP2005136205A - Method for manufacturing laminated ceramic electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing laminated ceramic electronic components, by which pressure for press-fitting a lamination can be easily set to a suitable value and the generation of structural defects (cracks and inter-layer peelings) and defective insulation which may be generated, when the lamination is press-fitted by inappropriate pressing can be prevented. <P>SOLUTION: In a process for laminating a plurality of ceramic green sheets on which electrode patterns are formed and press-fitting the ceramic sheets, a depression rate B which is the rate of change in the thickness of the lamination, before and after pressurizing the lamination, is found out, the relation between the difference ΔA (kgf/cm<SP>2</SP>) of the pressure A and the difference ΔB (%) of the pressure reduction rate B corresponding to the ΔA is found out and the lamination is press-fitted in a pressure area, satisfying the condition ΔB/ΔA≤0.005 (%/(kgf/cm<SP>2</SP>)). In a process for press-fitting the lamination, the lamination is press-fitted in a pressure area ≥ pressure P (kgf/cm<SP>2</SP>), satisfying ΔB/ΔA≤0.005 (%/(kgf/cm<SP>2</SP>)) and ≤ (P+200) (kgf/cm<SP>2</SP>). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a multilayer ceramic electronic component, and more particularly to a method for manufacturing a multilayer ceramic electronic component such as a multilayer ceramic capacitor manufactured through a process of laminating and pressing a ceramic green sheet on which an electrode pattern is formed.

One typical multilayer ceramic electronic component is, for example, a chip-type multilayer ceramic capacitor having a structure as shown in FIG.
In this multilayer ceramic capacitor, a plurality of internal electrodes 3a and 3b are arranged inside a ceramic element 1 with a ceramic layer 2 therebetween, and one end side of the ceramic element 1 is alternately arranged on a different side of the ceramic element 1. It has a structure in which a pair of external electrodes 4 a and 4 b are provided on both end sides of the ceramic element 1 so as to be electrically connected to the internal electrodes 3 a and 3 b while being drawn out to the end faces 5 a and 5 b.

  As a method for manufacturing such a multilayer ceramic capacitor, for example, as shown in FIG. 5, after the ceramic green sheet 51a and the conductor layer 52a are laminated, the upper and lower press plates 55a and 55b are used at a predetermined pressure. A method is known in which a laminated body 53 is formed by pressure bonding, cut into a predetermined size, fired, and then an external electrode is formed at a predetermined position so as to be electrically connected to the conductor layer 52a. .

In addition, a method of forming a laminate by sealing the laminate with a film and press-bonding with hydrostatic pressure instead of the upper and lower press plates 55a and 55b is also known. In this method, for example, structural defects such as delamination are prevented by pressure bonding at a high pressure of 1000 kgf / cm ² or more (see, for example, Patent Document 1).

  However, in these methods, a laminated body is formed by pressure bonding under various pressures, and the pressure and structural defects (cracks and delamination) of the obtained product (for example, a multilayer ceramic capacitor) when the laminated body is pressure-bonded. ), It is necessary to determine the press pressure at the time of crimping after investigating the relationship between the occurrence of the pressure), and it takes a lot of time to determine the press pressure, resulting in an increase in manufacturing cost. There is.

Moreover, if the press pressure at the time of press-bonding the laminate is too high, there is a problem that the compression ratio of the ceramic green sheet becomes too high, causing an insulation failure in which the internal electrodes (conductor layers) are short-circuited.
Japanese Patent Laid-Open No. 11-40457

  The present invention solves the above-mentioned conventional problems, and can easily set the press pressure when crimping the laminate to an appropriate value, and crimps the laminate with an inappropriate pressing force. It is an object of the present invention to provide a method for manufacturing a multilayer ceramic electronic component capable of preventing the occurrence of structural defects (cracks and delamination) and insulation defects that may occur in such a case.

In order to solve the above-described problem, a method for manufacturing a multilayer ceramic electronic component of the present invention (Claim 1) includes:
A method of manufacturing a multilayer ceramic electronic component manufactured through a process of laminating and pressing a ceramic green sheet on which an electrode pattern is formed,
In the step of laminating and crimping a plurality of ceramic green sheets on which electrode patterns are formed, in each pressing pressure A, a reduction rate B, which is the rate of change in the thickness of the laminate before and after pressing,
The relationship between the difference ΔA (kgf / cm ² ) of the pressing pressure A and the difference ΔB (%) of the rolling reduction B corresponding to the ΔA is obtained,
The pressure bonding is performed in a press pressure region that satisfies the condition of ΔB / ΔA ≦ 0.005 (% / (kgf / cm ² )).

The method for manufacturing a multilayer ceramic electronic component according to claim 2 is such that ΔB / ΔA ≦ 0.005 (% / (kgf / cm) when the difference ΔA (kgf / cm ² ) of the pressing pressure A is 100 to 200. ² )) It is characterized in that the pressure bonding is performed in a press pressure region that satisfies the condition.

The method for producing a multilayer ceramic electronic component according to claim 3 comprises:
In the step of laminating a plurality of ceramic green sheets on which the electrode pattern is formed and crimping,
The above-mentioned pressure bonding is performed in a press pressure region of not less than (P + 200) (kgf / cm ² ) but not less than a pressing pressure P (kgf / cm ² ) that satisfies ΔB / ΔA = 0.005 (% / (kgf / cm ² )). It is characterized by this.

  According to a fourth aspect of the present invention, there is provided a multilayer ceramic electronic component manufacturing method that is used when a multilayer ceramic capacitor is manufactured.

The method for manufacturing a multilayer ceramic electronic component according to the present invention (Claim 1) includes a step of laminating a plurality of ceramic green sheets on which an electrode pattern is formed, and in the step of pressure bonding, While calculating the reduction rate B (%), which is the rate of change, the relationship between the difference ΔA (kgf / cm ² ) of the press pressure A and the difference ΔB (%) of the reduction rate B corresponding to the ΔA (kgf / cm ² ) Is pressed in the press pressure region that satisfies the condition of ΔB / ΔA ≦ 0.005 (% / (kgf / cm ² )). And it becomes possible to set to an appropriate value, and it is possible to prevent the occurrence of structural defects (cracks and delamination) and insulation defects that occur when the laminate is pressed with an inappropriate press pressure. Become.

That is, according to the method of the present invention, the reduction ratio B at each press pressure A is obtained, and the difference ΔA (kgf / cm ² ) of the press pressure A and the difference ΔB (%) of the reduction ratio B corresponding to the ΔA. Since the pressure is applied in the press pressure region that satisfies the condition of ΔB / ΔA ≦ 0.005 (% / (kgf / cm ² )), the pressure is applied with various press pressures as in the past. A complex process in which a laminated body is formed, and the resulting product (multilayer ceramic electronic component) is subjected to the relationship between the press pressure during crimping and the presence or absence of structural defects, and then the press pressure during crimping is determined. Since it is not necessary to perform the process, it is possible to improve the production efficiency, and it is possible to perform the crimping with an appropriate press pressure, so that a crack that occurs when the press pressure during the crimping is too low. And structural defects such as delamination, To prevent the insulation defective as occurs when less pressure is too high, it becomes possible to manufacture a highly reliable multilayer ceramic electronic component efficiently.

Further, when the difference ΔA (kgf / cm ² ) of the press pressure A is set to 100 to 200 as in the method for manufacturing a multilayer ceramic electronic component according to claim 2, ΔB / ΔA ≦ 0.005 (% / (kgf / Cm ² ) When the pressure bonding is performed in the press pressure region that satisfies the condition, it becomes possible to press the laminated body under appropriate conditions, and the present invention can be effectively realized.

Note that the difference ΔA (kgf / cm ² ) of the press pressure A is set to 100 to 200 because when ΔA is less than 100, it becomes difficult to detect ΔA and ΔB, and when ΔA exceeds 200, ΔA If the value of is appropriate, even if the requirement of ΔB / ΔA ≦ 0.005 (% / (kgf / cm ² )) is satisfied, there may be cases where the requirement is not satisfied. The result is that the effect of is impaired.

Further, as in the method of manufacturing a multilayer ceramic electronic component according to claim 3, in the step of crimping the multilayer body, a press pressure P (kgf / cm) satisfying ΔB / ΔA ≦ 0.005 (% / (kgf / cm ² )). It is possible to press the laminated body under more appropriate conditions by press-bonding in a press pressure region not less than (cm ² ) and not more than (P + 200) (kgf / cm ² ). It can be announced.

That is, the press pressure at the time of press-bonding the laminate is not less than the press pressure P (kgf / cm ² ) that satisfies ΔB / ΔA = 0.005 (% / (kgf / cm ² )), and (P + 200) (kgf / cm ² ) or less to prevent the occurrence of structural defects such as cracks and delamination when the press pressure becomes too low, and the compressibility of the ceramic green sheet when the press pressure becomes too high. It becomes possible to prevent the occurrence of insulation failure in which the internal electrodes are short-circuited due to being too high, and it becomes possible to manufacture a highly reliable multilayer ceramic electronic component more reliably.

  In addition, multilayer ceramic capacitors are becoming thinner and multilayered to meet the demands for small size and large capacity, and structural defects such as cracks and delamination can occur if the press pressure when crimping the laminate is inappropriate. In addition, the present invention is applied to the production of such a multilayer ceramic capacitor as described in claim 4 to efficiently produce a highly reliable multilayer ceramic capacitor. Is possible and is particularly meaningful.

  In the following, examples of the present invention will be shown and the features thereof will be described in more detail.

  In the first embodiment, as shown in FIG. 1, a plurality of internal electrodes 3a and 3b are disposed inside a ceramic element (ceramic electronic component element) 1 so as to face each other with a ceramic layer 2 interposed therebetween, and The one end side is alternately drawn out to the end faces 5a and 5b on different sides of the ceramic element 1, and a pair of external electrodes 4a and 4b are connected to the both end sides of the ceramic element 1 so as to be electrically connected to the internal electrodes 3a and 3b. In the case of manufacturing a multilayer ceramic capacitor having an arranged structure, a case where a laminated body in which ceramic green sheets are laminated is crimped will be described as an example.

(1) First, a ceramic powder is prepared by mixing a dielectric powder containing BaTiO ₃ as a main component, an organic binder, a dispersant and a solvent, and forming the ceramic slurry to form a plurality of ceramic green sheets. .
(2) Then, an internal electrode pattern is formed by printing on the surface of the ceramic green sheet a conductive paste for forming an internal electrode prepared by kneading Pd powder and an organic vehicle.
(3) Then, a predetermined number of ceramic green sheets on which internal electrode patterns are formed are laminated, and ceramic green sheets on which no internal electrode patterns are formed are laminated on the upper and lower sides of the ceramic green sheets. Pressure-bonded laminate) was formed.
In the press bonding process of the laminate, the press pressure A was set to 600 to 1300 (kgf / cm ² ) as shown in Table 1, and the press bonding was performed. Table 1 also shows the press pressure in units of Pa.
Then, the examined reduction rate B is the rate of change of the laminate thickness before and after pressing in the pressing pressure A, from the result, the difference between the press pressure ^{A ΔA (kgf / cm 2)} , the ΔA (kgf / cm ² ) Corresponding to the difference ΔB (%) in the rolling reduction B, that is, ΔB / ΔA (% / (kgf / cm ² )).
(4) Next, this laminated body was cut into a predetermined shape and divided into individual chips (ceramic elements), which were fired at 1300 ° C. to be porcelain.
(5) Then, a copper paste is applied as an external electrode and baked on the exposed end faces 5a and 5b of the internal electrodes 3a and 3b of the fired ceramic element 1 (FIG. 1) thus obtained. Then, the external electrodes 4a and 4b were formed, and further plated to improve solderability to obtain a multilayer ceramic capacitor as shown in FIG.

  And the incidence rate of the structural defect was investigated about the obtained multilayer ceramic capacitor. The results are shown in Table 1.

As shown in Table 1, ΔB / ΔA exceeds 0.005 (% / (kgf / cm 2)), 600~800kgf / cm 2, 800~900kgf / cm 2, in a section 900~1000kgf / cm ² is A large number of voids were contained inside the laminate, and as a result of insufficient adhesion between the internal electrode and the ceramic sheet, structural defects occurred when the press pressure A was 600 to 900 kgf / cm ² .

In contrast, ΔB / ΔA ≦ 0.005 (% / (kgf / cm 2)) press pressure 1000~1100kgf / cm ² the conditions are ^{met, 1100~1200kgf / cm 2, 1200~1300kgf /} cm 2 sections In the case where the press pressure A is 1000 to 1300 kgf / cm ² , the occurrence of structural defects was not observed. This is considered to be because the adhesion between the internal electrode and the ceramic green sheet is improved because the internal electrode is buried in the ceramic green sheet as a result of being crimped with a sufficient press pressure. .

In addition, FIG. 2 is a figure which shows the relationship between the press pressure A and the rolling reduction B at the time of crimping | bonding a laminated body. From FIG. 2, there is a displacement point X where the tendency changes greatly in the relationship between the press pressure A and the reduction ratio B. In a region where the press pressure is higher than the displacement point X, ΔB / ΔA ≦ 0.005 (% / It can be seen that the condition (kgf / cm ² )) is realized.

  As described above, according to the method of Example 1, it is possible to easily set an appropriate press pressure capable of suppressing structural defects only by examining the rolling reduction of the laminate. As in the past, press bonding with various press pressures to form a laminate, and the final product (multilayer ceramic capacitor) was examined for the relationship between the press pressure during pressing and the presence or absence of structural defects. From this, troublesome work such as determining the press pressure at the time of crimping is not required, so that production efficiency can be improved.

In Example 2, the laminated body formed by the same method as in Example 1 was subjected to pressure bonding at a press pressure of 900, 1000, 1100, 1200, 1300, 1400, 1500 kgf / cm ² shown in Table 2, The reduction ratio B and ΔB / ΔA at each press pressure A were examined, and the occurrence rate of structural defects and the occurrence rate of insulation defects were examined for the obtained samples.
The results are shown in Table 2.

In Example 2, when obtaining the value of ΔB / ΔA, the value of ΔA was set to a range of 10 (kgf / cm ² ) centered on each pressing pressure A shown in Table 2, and ΔB / The value of ΔA was determined.

Then, the relationship between the press pressure A and the reduction ratio B was plotted (see FIG. 3), and the relationship between the press pressure A and ΔB / ΔA was plotted (see FIG. 4).
As a result, as shown in FIG.
(1) Under the conditions of Example 2, the pressing pressure A at the displacement point Y that divides the region where ΔB / ΔA exceeds 0.005 and the region where ΔB / ΔA is less than 0.005 (that is, ΔB / ΔA = 0). A pressing pressure P) of .005 (% / (kgf / cm ² )) is about 1050 (kgf / cm ² );
(2) The press pressure P (1050 (kgf / cm ² )) at the point Y at which ΔB / ΔA is less than 0.005 (% / (kgf / cm ² )) corresponds to the press pressure A and the reduction ratio B in FIG. it was confirmed that substantially matches the P pressing pressure of the displacement point X where the relationship is largely changed ^{(1050 (kgf / cm 2)} ).

Taking the above-mentioned results into consideration, looking at the occurrence rate of structural defects and the occurrence rate of insulation failure in Table 2, displacement where ΔB / ΔA is less than 0.005 (% / (kgf / cm ² )). It can be seen that the occurrence of structural defects is not observed when pressure bonding is performed at a pressure equal to or higher than the pressure Y at point Y (1050 (kgf / cm ² )). However, in Table 2, the press pressure ^{P (1050 (kgf / cm 2} )) the occurrence of structural defects even when the crimped close press pressure 1000 kgf / cm ² in is not permitted.

On the other hand, insulating the failure, when pressed at a pressing pressure of up to 1300 kgf / cm ^2, although insulation failure hardly occurs, pressing pressure A is 1400 (kgf / cm ²⁾ to become the 5% sample insulation failure It can be seen that at 1500 (kgf / cm ² ), the rate of occurrence of insulation failure is as high as 20%.
From this, it is possible to prevent structural defects by satisfying the condition of ΔB / ΔA ≦ 0.005 (% / (kgf / cm ² )), but in order to suppress the occurrence of insulation failure, the press pressure I found that it was necessary not to make it too high.
That is, in Example 2, the press pressure is 1050 (kgf / cm ² ) or more, which is a press pressure P at which ΔB / ΔA = 0.005 (% / (kgf / cm ² )), and 1400 (kgf / Cm ² ).

Therefore, in order to investigate in more detail the conditions of the pressing pressure A necessary for preventing the occurrence of this insulation failure, various laminated bodies other than the laminated body used in Example 2 were prepared, and the predetermined conditions were used. Crimping was performed, and the reduction rate B and ΔB / ΔA were examined, and the structural defect occurrence rate and the insulation failure occurrence rate were examined.
As a result, pressure bonding is performed in a pressing pressure region of not less than (P + 200) (kgf / cm ² ) and not more than a pressing pressure P (kgf / cm ² ) where ΔB / ΔA = 0.005 (% / (kgf / cm ² )). As a result, it was confirmed that it was possible to prevent the occurrence of defective insulation while preventing the occurrence of structural defects.

  In the first and second embodiments, the case where a multilayer ceramic capacitor is manufactured has been described as an example. However, the present invention can be applied to the case where other various multilayer ceramic electronic components are manufactured.

  The present invention is not limited to the above embodiment in other points as well, and relates to the thickness and the number of laminated ceramic green sheets, the type of material constituting the ceramic green sheets, the thickness of the laminated body, etc. It is possible to add various applications and modifications.

According to the present invention, the optimum pressing pressure capable of suppressing structural defects such as cracks and delaminations is examined only by examining the rolling reduction B, which is the rate of change of the thickness of the laminate before and after pressing at each pressing pressure A. Insulation failure can be easily set and crimped at a pressing pressure ((P + 200) (kgf / cm ² )) within a predetermined range from the pressing pressure P determined based on the thickness change rate of the laminate. In addition, it is possible to prevent the occurrence of pressure, and for the obtained product, the press pressure at the time of crimping is determined after examining the relationship between the press pressure at the time of crimping and the presence or absence of structural defects. Since complicated processing is not required, production efficiency can be improved. Therefore, the method for manufacturing a multilayer ceramic electronic component of the present invention can be widely used when manufacturing a multilayer ceramic electronic component such as a multilayer ceramic capacitor.

It is sectional drawing which shows the structure of a multilayer ceramic capacitor. It is a figure which shows the relationship between the press pressure at the time of crimping | bonding the laminated body investigated in Example 1, and a reduction rate. It is a figure which shows the relationship between the press pressure at the time of crimping | bonding the laminated body investigated in Example 2, and a reduction rate. It is a figure which shows the relationship between the press pressure A investigated by Example 2, and (DELTA) B / (DELTA) A. It is a figure explaining the crimping | compression-bonding method of the laminated body in the manufacturing method of the conventional multilayer ceramic capacitor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ceramic element 2 Ceramic layer 3a, 3b Internal electrode 4a, 4b External electrode 5a, 5b End surface of a ceramic element

Claims (4)

A method of manufacturing a multilayer ceramic electronic component manufactured through a process of laminating and pressing a ceramic green sheet on which an electrode pattern is formed,
In the step of laminating and crimping a plurality of ceramic green sheets on which electrode patterns are formed, in each pressing pressure A, a reduction rate B, which is the rate of change in the thickness of the laminate before and after pressing,
The relationship between the difference ΔA (kgf / cm ² ) of the pressing pressure A and the difference ΔB (%) of the rolling reduction B corresponding to the ΔA is obtained,
A method for producing a multilayer ceramic electronic component, wherein the pressure bonding is performed in a press pressure region that satisfies a condition of ΔB / ΔA ≦ 0.005 (% / (kgf / cm ² )). When the difference ΔA (kgf / cm ² ) of the press pressure A is 100 to 200, the pressure bonding is performed in a press pressure region that satisfies the condition of ΔB / ΔA ≦ 0.005 (% / (kgf / cm ² )). The method for producing a monolithic ceramic electronic component according to claim 1. In the step of laminating a plurality of ceramic green sheets on which the electrode pattern is formed and crimping,
The above-mentioned pressure bonding is performed in a press pressure region of not less than (P + 200) (kgf / cm ² ) but not less than a pressing pressure P (kgf / cm ² ) that satisfies ΔB / ΔA = 0.005 (% / (kgf / cm ² )). The method for producing a multilayer ceramic electronic component according to claim 1 or 2, wherein:   4. The method for manufacturing a multilayer ceramic electronic component according to claim 1, wherein the method is used for manufacturing a multilayer ceramic capacitor.

Images