JP2004152909A - Process for producing multilayer ceramic body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a process for producing a multilayer ceramic body in which lowering of reliability due to variance in the capacitance, incomplete insulation, or the like, can be suppressed by controlling variance in the area of a conductor pattern formed on a ceramic green sheet due to deformation and variance in the effective area due to positional shift when the ceramic green sheets are laid in layers. <P>SOLUTION: After a rectangular conductor pattern 5 is formed on the surface of a ceramic green sheet 3a, a ceramic pattern 7 thicker than the conductor pattern 5 is formed in a part surrounding a region on the major surface of the ceramic green sheet 3a where the conductor pattern 5 is formed. Furthermore, another ceramic green sheet 3b is superposed on the upper surface of the ceramic green sheet 3a where the conductor pattern 5 is formed. A parent multilayer body 13 where the ceramic green sheets 3a, 3b and the conductor patterns 5 are laid alternately is formed by repeating these steps. <P>COPYRIGHT: (C)2004,JPO

Description

【００５８】
表１の結果から明らかなように、本発明である導体パターンを形成後にセラミックパターンを形成して逐次積層を行うＡ工程（試料Ｎｏ．２〜８）、およびセラミックパターンを形成後に導体パターンを形成して逐次積層を行うＢ工程（試料Ｎｏ．９〜１５）では、導体パターン形成後の変形率が０％、静電容量のばらつきが１．７％以下、高温負荷試験後のショート率も４％以下と良好な結果であった。特に、導体パターンとセラミックパターンとの厚み比を１．０５〜１．２とした試料Ｎｏ．３〜５、および、試料Ｎｏ．１０〜１２では、デラミネーションやショートが無く、静電容量のばらつきも、それぞれ１．３％以下、１．２％以下と、さらに改善できた。
【００５９】
これに対し、セラミックパターンの厚みと導体パターンの厚みとを同じとした試料Ｎｏ．１では、静電容量のばらつきが２．１％、高温負荷試験後のショート率も１６％と大きかった。
【００６０】
【発明の効果】
以上詳述したとおり、本発明によれば、セラミックグリーンシートの主面上に形成されるセラミックパターンの厚みを導体パターンよりも厚く形成することにより、積層時に、吸着ヘッドの吸着面に導体パターンを接触させずにセラミックパターンを選択的に吸着させることができることから、吸着ヘッドの吸引孔の段差による導体パターンの変形を防止でき、このため、静電容量のばらつきを低減でき、かつ絶縁不良やショートなどによる信頼性の低下をも低減できる。
【図面の簡単な説明】
【図１】本発明の、導体パターンを形成した後にセラミックパターンを形成し、逐次積層工程を行い、セラミック積層体を製造するための工程図である。
【図２】（ａ）はセラミックグリーンシート上に形成された導体パターンおよびセラミックパターンの配置を示す斜視図、（ｂ）はセラミックグリーンシート上に形成された導体パターンおよびセラミックパターンの厚み差を表わす断面模式図である。
【図３】図１のセラミック積層体の製法において、キャリアフィルムのついたセラミックグリーンシートを用い、重ね合わせ後に剥離する工程を具備する工程を示す工程図である。
【図４】本発明の、セラミックパターンを形成した後に導体パターンを形成し、逐次積層を行い、セラミック積層体を製造するための工程図である。
【図５】セラミックグリーンシート上に導体パターンのみを形成し、逐次積層を行う、従来のセラミック積層体を製造するための工程図である。
【図６】予めセラミックグリーンシート上に導体パターンおよびセラミックパターンを形成したものを、一括積層を行う、従来のセラミック積層体を製造するための工程図である。
【符号の説明】
１ 支持体
３ａ、３ｂ セラミックグリーンシート
５ 導体パターン
７ セラミックパターン
１３ 母体積層体[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing a ceramic laminate, and more particularly to a method for producing a ceramic laminate in which ceramic green sheets and conductor patterns are formed into thin layers, such as a wiring board and a multilayer ceramic capacitor.
[0002]
[Prior art]
2. Description of the Related Art In recent years, with the miniaturization and high-density mounting of electronic devices, a wiring board and a multilayer ceramic capacitor in which a conductor pattern is formed in a ceramic laminate are required to be small and thin and have high dimensional accuracy. For this reason, for example, in multilayer ceramic capacitors, ceramic green sheets and conductor patterns have been made thinner and more multilayered in order to reduce the size and increase the capacitance.
[0003]
Usually, such a laminated ceramic capacitor first forms a plurality of rectangular conductor patterns by printing a conductor paste on the surface of the ceramic green sheet, and then superposes a plurality of ceramic green sheets on which the conductor pattern is formed. Then, the base laminate is formed by laminating the base laminate, and further, the base laminate is cut at a predetermined position and fired to be manufactured.
[0004]
However, as described above, in a manufacturing method using a step of forming a conductor pattern on the surface of a ceramic green sheet or a step of laminating a plurality of ceramic green sheets on which a conductor pattern has been formed in advance, the ceramic green sheet to be used is extremely large. Due to the thinness, wrinkles are formed on the ceramic green sheet during printing or lamination, and after lamination, there is a problem that delamination is easily generated between the ceramic green sheet and the conductor pattern due to the space formed by the wrinkles. Was.
[0005]
To cope with such a problem, a device disclosed in Patent Document 1 is known. As shown in FIG. 5, according to the manufacturing method disclosed in Patent Document 1, first, a normal ceramic green sheet 53a is placed on a support body 51, and then, the surface of the ceramic green sheet 53a is An ultra-thin ceramic green sheet 53b having good adhesion and formed by adjusting the type and blending amount of the binder is overlaid. Next, a conductor paste is printed on the surface of the very thin ceramic green sheet 53b having good adhesion to form a conductor pattern 55, and then formed on the very thin ceramic green sheet 53b having good adhesion. Again, an ultra-thin ceramic green sheet 53b with good adhesion is overlaid so as to cover the conductor pattern 55 thus formed. Then, the formation of the conductor pattern 55 and the superposition of the extremely thin ceramic green sheets 53b having good adhesion are repeated to form the base laminate 63. In other words, it is described that the use of the sequential laminating step can prevent wrinkles of the ceramic green sheets 53a and 53b and delamination occurring in the base laminate 63, which are problems in the collective laminating step.
[0006]
In recent years, as the ceramic green sheets 53a and 53b are made thinner and more multilayered, measures have been taken to eliminate a step due to the thickness of the conductor pattern 55 formed on the ceramic green sheets 53a and 53b (for example, Patent Document 2).
[0007]
In the method of manufacturing a ceramic laminate disclosed in Patent Document 2, as shown in FIG. 6, a ceramic pattern 85 having the same height as a conductor pattern 83 formed on a main surface of a ceramic green sheet 81 is formed. Accordingly, it is described that a step due to the thickness of the conductor pattern 83 can be substantially eliminated, and the ceramic green sheets 81 can be laminated without being affected by the thickness of the conductor pattern 83. In the method of manufacturing such a ceramic laminate, first, a plurality of conductor patterns 83 are formed on the main surface of the ceramic green sheet 81 at predetermined intervals by printing a conductor paste. Then, a ceramic paste containing a ceramic powder is printed to form a ceramic pattern 85.
[0008]
[Patent Document 1]
Japanese Patent Publication No. 8-4045 [Patent Document 2]
JP 2000-311831 A
[Problems to be solved by the invention]
However, even when the manufacturing method disclosed in Patent Document 1 is used, when the thickness of the ceramic green sheets 53a, 53b is so small that there is no difference in thickness between the ceramic green sheets 53a, 53b and the conductor pattern 55 to be used. Again, the effect of the step due to the conductor pattern 55 appears. Therefore, when another ceramic green sheet 53b is superimposed on the conductor pattern 55 formed earlier, the conductor pattern 55 is deformed. There is a problem that the variation in the area increases and the variation in the capacitance cannot be reduced.
[0010]
In the manufacturing method disclosed in Patent Document 2, the ceramic pattern 85 is formed on the ceramic green sheet 81 along with the conductor pattern 83, but the thickness is almost the same. As shown in FIG. 6, the lamination is performed by contacting the surface on which the conductor pattern 83 and the ceramic pattern 85 are formed with the lamination head during lamination, so that the conductor pattern 83 is in the initial stage of pressurization, that is, when the pressure is low. And the ceramic pattern 85 is pressurized at the same time, and deformation by the suction head is likely to occur. For this reason, the area of the conductor pattern 83 increases, or the conductor pattern 83 extends to a region that should be insulated, and the ceramic laminate tends to have a variation in capacitance and insulation failure. was there.
[0011]
Further, as described above, this method is a method in which a plurality of ceramic green sheets 81 on which the conductor patterns 83 and the ceramic patterns 85 are formed are stacked and stacked at a time. There is a problem that the effective area is varied due to the displacement of the conductor pattern 83 that should be overlapped with a predetermined area via the green sheet 81.
[0012]
Therefore, the present invention suppresses the variation in the area due to the deformation of the conductor pattern formed on the ceramic green sheet and the variation in the effective area due to the displacement during lamination, and the reliability due to the variation in the capacitance and the insulation failure. It is an object of the present invention to provide a method for producing a ceramic laminate that can suppress a decrease.
[0013]
[Means for Solving the Problems]
The method for producing a ceramic laminate of the present invention comprises the steps of (a) placing a ceramic green sheet on a support;
(B) forming a rectangular conductor pattern on the surface of the ceramic green sheet;
(C) forming a ceramic pattern thicker than the conductor pattern on a portion of the main surface of the ceramic green sheet surrounding a region where the conductor pattern is formed; and (d) forming the ceramic pattern and the ceramic pattern. A step of superposing another ceramic green sheet on the upper surface of the formed ceramic green sheet,
(E) forming a matrix laminate in which the ceramic green sheets and the conductor patterns are alternately laminated by repeating the steps (b) to (d);
It is characterized by having.
[0014]
According to such a manufacturing method, since the ceramic pattern is formed adjacent to the conductor pattern formed on the ceramic green sheet, even when a thin ceramic green sheet is used, the ceramic green sheet can be used. The step due to the conductor pattern can be easily reduced without considering the adhesion of the ceramic pattern, and since the ceramic pattern is also provided around the conductor pattern, another ceramic green sheet is stacked on this top side In some cases, deformation of the conductor pattern due to pressure of the lamination head can be suppressed. For this reason, an increase in the area of the conductor pattern and an extension of the conductor pattern to a region that should be insulated are suppressed, so that variation in capacitance and insulation failure can be reduced.
[0015]
In addition, since the ceramic laminate of the present invention is performed by sequential lamination as described above, it is possible to reduce the displacement during lamination such as batch lamination. Also in this respect, the variation of the effective area is suppressed by stacking the conductor patterns that should originally overlap with a predetermined area via the ceramic green sheet with high accuracy, and thus the variation of the capacitance can be reduced. Further, since the lamination accuracy is high, the side margin and the end margin can be reduced, so that the ceramic laminate can be downsized. In this manner, the exposure of the conductor layer to the side surface of the ceramic laminate can be prevented, so that the short-circuit rate particularly in a high-temperature load test can be reduced.
[0016]
In the method for manufacturing a ceramic laminate, it is preferable that the relationship of 1 <t2 / t1 ≦ 1.5 is satisfied, where t1 is the thickness of the conductor pattern and t2 is the thickness of the ceramic pattern. By setting the t2 / t1 ratio in such a range, the dimensional accuracy of the conductor pattern can be improved even after pressurizing and heating during lamination, and the thickness variation of the ceramic laminate due to the excessive thickness of the ceramic pattern can be suppressed. Can be.
[0017]
In the above-described method for manufacturing a ceramic laminate, it is desirable that the ends of the conductor pattern and the ceramic pattern have inclined surfaces with respect to the main surface of the ceramic green sheet. As described above, since the end of the conductor pattern or the ceramic pattern formed on the ceramic green sheet has an inclined surface instead of a rectangular shape, the ceramic green sheet laminated thereon is steep between the conductor pattern and the ceramic pattern. Falling can be suppressed, and deformation of the ceramic laminate can be suppressed, and delamination and cracks can be prevented.
[0018]
In the method for producing a ceramic laminate, it is desirable that the relationship of t1 / t3 ≧ 0.5 is satisfied, where t1 is the thickness of the conductor pattern and t3 is the thickness of the ceramic green sheet. According to the present invention, it is possible to eliminate a step due to the conductor pattern formed on the ceramic green sheet, but in particular, the ceramic green sheet is thinned so that there is no thickness difference with the thickness of the conductor pattern as described above. It can be suitably used in such cases.
[0019]
Further, in the method for producing a ceramic laminate, it is desirable that the ceramic component in the ceramic green sheet and the ceramic component in the ceramic paste have substantially the same composition.Moreover, in the method for producing the ceramic laminate, It is desirable that the conductor pattern be an internal electrode layer of the multilayer ceramic capacitor after firing.
[0020]
Further, in the above-described method for producing a ceramic laminate, the number of layers is desirably 400 or more in terms of increasing the lamination accuracy.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
The method for manufacturing a ceramic laminate of the present invention is suitably applied to, for example, a multilayer ceramic capacitor which is one of electronic components. Therefore, a description will be given below based on a process diagram of a method of manufacturing a ceramic laminate shown in FIG.
[0022]
As shown in FIG. 1A, first, a plurality of ceramic green sheets 3a are placed on a support 1, and an electrodeless portion 4a having a predetermined thickness serving as a margin portion of the multilayer ceramic capacitor is formed. As the support 1, a material having heat resistance, such as a PET film, which is smooth and has good releasability is suitably used.
[0023]
As the ceramic green sheet 3a of the present invention, for example, a mixture of ceramic powder, an organic binder, and a solvent that dissolves the organic binder is preferably used.
[0024]
As the ceramic powder, for example, a ceramic powder mainly containing BaTiO ₃ is preferably used. Further, glass powder may be added as a known additive or sintering aid for increasing the reduction resistance.
[0025]
The thickness of the ceramic green sheet 3a is desirably 1.5 to 4 [mu] m for reasons of small size and large capacity.
[0026]
Next, as shown in FIG. 1B, a plurality of rectangular conductive patterns 5 are formed at equal intervals by printing a conductive paste on one main surface of the uppermost layer of the stacked ceramic green sheets 3a. I do.
[0027]
Here, the thickness of the conductor pattern 5 is desirably 3 μm or less, and particularly desirably 1 μm or less from the viewpoint of miniaturization and high reliability of the capacitor. Further, the relationship between the thickness of the ceramic green sheet 3a and the thickness of the conductor pattern 5 is such that the relationship of t1 / t3 ≧ 0.5 is satisfied when the thickness of the conductor pattern is t1 and the thickness of the ceramic green sheet 3a is t3. In particular, when forming a thickness difference such that the influence of the step due to the conductor pattern 5 becomes large, the manufacturing method of the present invention is particularly suitable. And it is more preferable that the t1 / t3 ratio is 0.7 or more.
[0028]
As the conductor paste used in the production method of the present invention, a paste containing metal particles, an organic solvent, and an organic binder soluble in the organic solvent is preferably used.
[0029]
As the metal particles, at least one type of metal particles selected from the group consisting of Ni, Co, and Cu is preferable. However, Ni is preferable because the firing temperature of the metal matches the firing temperature of a general insulator and the cost is low. Is desirable. In addition, as a solid content, it is preferable to use a mixture of fine ceramic powder in addition to the metal particles in order to suppress the sinterability of the conductor pattern 5.
[0030]
Furthermore, the organic binder and the organic solvent of the conductor paste can adopt the same conditions as the printing of the ceramic paste for the ceramic pattern 7 and match the volatilization rate of the organic binder from the surfaces of the ceramic green sheets 3a and 3b. For this reason, the composition is desirably the same as that of the ceramic paste. In the present invention, it is preferable that the conductor pattern 5 formed in this way be an internal electrode layer of a multilayer ceramic capacitor as one of the electronic components.
[0031]
Next, as shown in FIG. 1C, a ceramic pattern 7 is formed by printing a ceramic paste on a portion surrounding the region of the conductor pattern 5. That is, in the present invention, it is important to form the conductor pattern 5 and the ceramic pattern 7 on the ceramic green sheet 3a. That is, as shown in FIG. 2, a plurality of rectangular conductor patterns 5 are formed on the ceramic green sheet 3a at a predetermined interval L1, and a ceramic pattern 7 is formed around the conductor pattern 5.
[0032]
Here, in the manufacturing method of the present invention, the thickness t2 of the ceramic pattern 7 is set to be smaller than the thickness t1 of the conductor pattern 5 in order to reduce the step due to the conductor pattern 5 on the ceramic green sheet 3a and to suppress the pressing deformation during lamination. It is important to be thick. Furthermore, since the dimensional accuracy of the conductor pattern can be improved even after pressurizing and heating at the time of lamination, and the thickness variation of the ceramic laminate due to the excessive thickness of the ceramic pattern 7 is suppressed, the thickness of the conductor pattern 5 is reduced. Assuming that t1 is t2 and the thickness of the ceramic pattern 7 is t2, it is preferable that the relationship of 1 <t2 / t1 ≦ 1.5 is satisfied, and more preferably, 1.05 ≦ t2 / t1 ≦ 1.2.
[0033]
It is desirable that the conductor pattern 5 and the ceramic pattern 7 are in contact with each other at the peripheral portion as shown in FIG. 1. In order to reduce the gap between the two patterns 5 and 7 and prevent deformation, the ceramic pattern 7 is preferably used. More preferably, 7 overlaps the inclined surface 11 at the periphery of the conductor pattern 5.
[0034]
Here, the ceramic paste for forming the ceramic pattern 7 in the present invention contains ceramic powder, an organic solvent, and an organic binder soluble in the organic solvent.
[0035]
As the composition of the ceramic powder used for the ceramic paste, either the powder composition of the ceramic green sheet 3a or a different powder composition can be applied. However, since the firing shrinkage of the ceramic green sheet 3a and the ceramic pattern 7 are matched, It is desirable that the ceramic paste has substantially the same ceramic powder composition as the ceramic slurry forming the ceramic green sheet 3a.
[0036]
Next, as shown in FIG. 1D, on the upper surface side of the ceramic green sheet 3a on which the conductor pattern 5 and the ceramic pattern 7 are formed as described above, the conductor pattern 5 and the ceramic pattern 7 are covered. Another ceramic green sheet 3b is overlapped, and the conductor pattern 5 and the ceramic pattern 7 are brought into close contact with the ceramic green sheet 3b.
[0037]
Thereafter, the steps of FIGS. 1B to 1D are repeated so as to obtain a desired number of laminations, and finally, the layers are formed again in the step of FIG. 1A using the ceramic green sheets 3a. The non-electrode portions 4b having the same thickness are formed to form the base laminate 13.
[0038]
Note that, as described above, the present invention is a method in which, after the ceramic green sheets 3a or 3b are overlaid, the conductor pattern 5 and the ceramic pattern 7 are sequentially formed on the upper surface thereof by screen printing. In this respect, compared to the method of preparing a plurality of ceramic green sheets 3a and 3b on which the conductor patterns 5 and the ceramic patterns 7 are formed in advance and laminating them at once, displacement during lamination is less likely to be included. Since the positional accuracy of the conductor pattern 5 and the ceramic pattern 7 in FIG. 13 requires only the positional deviation of only the printing accuracy, the lamination accuracy is improved, the capacitance variation can be reduced, and the side margin and the end margin can be reduced. Can respond to the miniaturization of the ceramic laminate.
[0039]
In the method for producing a ceramic laminate of the present invention, the number of laminations is preferably 400 or more, and more preferably 500 or more, from the viewpoint of increasing the lamination accuracy.
[0040]
In the manufacturing method of the present invention, as shown in FIG. 3, the ceramic green sheets 3a and 3b may be formed by laminating a carrier film 21. Thus, the ceramic green sheets 3a having the carrier film 21 may be used. And 3b, the carrier film 21 may be peeled off after overlapping. In this case, since the ceramic green sheets 3 a and 3 b are supported by the carrier film 21, the ceramic green sheets 3 a can be applied even when the ceramic green sheets 3 a and 3 b are overlaid on the upper surface side of the conductor pattern 5 or the ceramic pattern 7 and then heated and pressed. , 3b can be suppressed from elongation and deformation. Further, in this method, since the ceramic green sheet 3b itself is not adsorbed, defects of the ceramic green sheet 3b can be prevented.
[0041]
In addition, as shown in FIGS. 4A to 4E, in the manufacturing method of the present invention, the base laminate 13 includes a portion surrounding the region where the conductor pattern 5 is formed on the main surfaces of the ceramic green sheets 3a and 3b. After the ceramic pattern 7 is formed, the conductor pattern 5 can be formed inside the ceramic pattern 7 to produce the ceramic pattern 7.
[0042]
In this case, the angle of the inclined surface around the ceramic pattern 7 is set to be smaller than that of the ceramic green sheet because the conductor pattern 5 formed after the ceramic pattern 7 can be prevented from running over at the time of printing and the spread of the pattern due to bleeding can be prevented. It is desirable that the angle is 0.5 ° or more with respect to the principal surfaces of 3a and 3b, and it is particularly desirable that the angle be 1 to 40 °. Also in this case, it is more desirable that the conductor pattern 5 overlaps the inclined surface of the peripheral portion of the ceramic pattern 7.
[0043]
(E1) of FIGS. 1 and 4 is a sectional view on the side margin side of the base laminate 13 and (e2) of FIGS. 1 and 4 is a sectional view on the end margin side. As shown in the figure, after cutting the base laminated body 13 at a dotted line portion C to form a laminated molded body, the laminated molded body is further fired under predetermined atmosphere and temperature conditions to form an external conductor. Thus, a multilayer ceramic capacitor having a ceramic layer and internal electrode layers is formed.
[0044]
Furthermore, according to this manufacturing method, the formation accuracy of the conductor pattern 5 and the ceramic pattern 7 is improved, and the variation in capacitance can be reduced. Further, even if the number of layers is increased, the formation accuracy of the conductor pattern 7 is not affected. It is possible to achieve high lamination and enlargement of the ceramic laminate.
[0045]
【Example】
A multilayer ceramic capacitor, which is one of the ceramic laminates, was manufactured as follows.
[0046]
The ceramic green sheet was prepared by adding an organic binder and an organic solvent to a ceramic powder containing BaTiO ₃ as a main component to prepare a ceramic slurry, and forming a film having a thickness of 2 μm on a carrier film using a die coater method.
[0047]
On the other hand, a part contained in the ceramic slurry was pulverized, and these ceramic powders, an organic binder for paste and an organic solvent were kneaded with three rolls to prepare a ceramic paste.
[0048]
The conductor paste was prepared by forming Ni powder having an average particle size of 0.2 μm, the organic binder and the organic solvent used in the ceramic paste into a paste in the same manner as the ceramic paste.
[0049]
Next, a plurality of the obtained ceramic green sheets are placed on a support, and a conductor pattern is printed on the main surface thereof as a step A using a screen printing apparatus. Thus, a ceramic pattern thicker than the conductor pattern was formed around the conductor pattern. Thus, a ceramic green sheet on which the ceramic pattern was applied and formed together with the conductor pattern was produced. In this case, the thickness of the conductor pattern was 1.1 μm. The angle of the inclined surface of the ceramic pattern was adjusted to 5 ° depending on the viscosity of the ceramic paste and the inclination angle of the resist.
[0050]
Next, the ceramic green sheet was again superimposed on the upper surface of the ceramic green sheet on which the ceramic pattern was applied together with the conductor pattern, and this was repeated by the number of layers shown in Table 1. Further, 10 ceramic green sheets each having no conductor pattern and no ceramic pattern formed thereon were laminated, and the first press was performed to form a base laminate.
[0051]
Next, as a step B, a ceramic pattern was printed first, and then a conductor pattern was formed around the ceramic pattern, and lamination was performed in the same manner as in the step A to produce a mother laminate. In each of the steps A and B, a method of peeling the carrier film every time the ceramic green sheets are laminated was used.
[0052]
Next, each of the matrix laminates manufactured in the steps A and B was cut into a lattice to obtain a laminate molded body. Thereafter, heating was performed at 250 ° C. in the air or 500 ° C. in a weakly reducing atmosphere to perform a de-buying treatment.
[0053]
Further, the laminated molded body after de-buying is fired at 1250 ° C. for 2 hours in a reducing atmosphere, and further re-oxidized at 900 ° C. for 4 hours in a weakly oxidizing atmosphere to obtain a ceramic laminated body. Got the body. After the firing, a Cu paste was baked at 900 ° C. on the end face of the ceramic laminate body, and further, Ni / Sn plating was performed to form external conductors alternately connected to the internal electrode layers.
[0054]
For evaluation, first, the thickness t1 of the printed conductor pattern was measured using a non-contact surface roughness meter (laser displacement meter), and the thickness ratio t2 / t1 to the thickness t2 of the ceramic pattern was determined. Observation of delamination was performed on each of the fired multilayer ceramic capacitors 100 by polishing from the end face and side face thereof, and the number of delaminations generated in the peripheral portion of the internal conductor was evaluated. The deformation rate of the conductor pattern was also measured using a laser displacement meter.
[0055]
Next, the variation in the capacitance was calculated from the measured value of the capacitance of 100 laminated ceramic capacitors after firing. In addition, the short-circuit rate after a high-temperature load test (150 ° C., a voltage twice the rated voltage was applied, and left for 1000 hours) was determined.
[0056]
On the other hand, as a comparative example, a sample in which the thickness of the ceramic pattern was the same as the thickness of the conductor pattern was prepared and evaluated.
[0057]
[Table 1]

[0058]
As is evident from the results in Table 1, step A (sample Nos. 2 to 8) in which a ceramic pattern is formed after the formation of the conductor pattern according to the present invention and successive lamination is performed, and a conductor pattern is formed after the formation of the ceramic pattern In the step B (samples Nos. 9 to 15) in which the layers are sequentially laminated, the deformation rate after the formation of the conductor pattern is 0%, the variation in the capacitance is 1.7% or less, and the short-circuit rate after the high-temperature load test is 4%. % Or less, which is a good result. In particular, in Sample No. 1 in which the thickness ratio between the conductor pattern and the ceramic pattern was 1.05 to 1.2. Sample Nos. 3 to 5 and Sample Nos. In Nos. 10 to 12, there was no delamination or short circuit, and the variation in capacitance was further improved to 1.3% or less and 1.2% or less, respectively.
[0059]
On the other hand, in Sample No. in which the thickness of the ceramic pattern and the thickness of the conductor pattern were the same. In No. 1, the variation in capacitance was 2.1%, and the short-circuit rate after the high-temperature load test was as large as 16%.
[0060]
【The invention's effect】
As described in detail above, according to the present invention, by forming the ceramic pattern formed on the main surface of the ceramic green sheet to be thicker than the conductive pattern, the conductive pattern is formed on the suction surface of the suction head during lamination. Since the ceramic pattern can be selectively sucked without contact, deformation of the conductor pattern due to the step of the suction hole of the suction head can be prevented, so that variation in capacitance can be reduced, and insulation failure and short circuit can be prevented. Therefore, a decrease in reliability due to the above-mentioned factors can be reduced.
[Brief description of the drawings]
FIG. 1 is a process diagram for manufacturing a ceramic laminate by forming a ceramic pattern after forming a conductor pattern and sequentially performing a lamination process according to the present invention.
FIG. 2A is a perspective view showing an arrangement of a conductor pattern and a ceramic pattern formed on a ceramic green sheet, and FIG. 2B shows a difference in thickness between the conductor pattern and the ceramic pattern formed on the ceramic green sheet. It is a cross section schematic diagram.
FIG. 3 is a process chart showing a step of using a ceramic green sheet provided with a carrier film in the method for producing the ceramic laminate of FIG.
FIG. 4 is a process diagram of the present invention for forming a conductor pattern after forming a ceramic pattern, sequentially performing lamination, and manufacturing a ceramic laminate.
FIG. 5 is a process diagram for manufacturing a conventional ceramic laminate in which only a conductor pattern is formed on a ceramic green sheet and successively laminated.
FIG. 6 is a process diagram for manufacturing a conventional ceramic laminate in which conductor patterns and ceramic patterns formed on ceramic green sheets in advance are collectively laminated.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Support 3a, 3b Ceramic green sheet 5 Conductive pattern 7 Ceramic pattern 13 Base laminate

Claims (7)

(A) placing a ceramic green sheet on a support;
(B) forming a rectangular conductor pattern on the surface of the ceramic green sheet;
(C) forming a ceramic pattern thicker than the conductor pattern on a portion of the main surface of the ceramic green sheet surrounding the region where the conductor pattern is formed; and (d) forming the ceramic pattern and the ceramic pattern. The steps of superposing another ceramic green sheet on the upper surface of the ceramic green sheet on which is formed and the steps (e), (b) to (d) are repeated so that the ceramic green sheet and the conductor pattern are alternately formed. A step of forming a laminated base laminate,
A method for producing a ceramic laminate, comprising: The method of claim 1, wherein a relationship of 1 <t2 / t1 ≦ 1.5 is satisfied, where t1 is the thickness of the conductor pattern and t2 is the thickness of the ceramic pattern. 3. The method for producing a ceramic laminate according to claim 1, wherein ends of the conductor pattern and the ceramic pattern have an inclined surface with respect to a main surface of the ceramic green sheet. The ceramic laminate according to any one of claims 1 to 3, wherein, when the thickness of the conductive pattern is t1 and the thickness of the ceramic green sheet is t3, a relationship of t1 / t3 ≧ 0.5 is satisfied. Recipe. The method for producing a ceramic laminate according to any one of claims 1 to 4, wherein the ceramic component contained in the ceramic green sheet and the ceramic component contained in the ceramic pattern have substantially the same composition. 6. The method for producing a ceramic laminate according to claim 1, wherein the conductor pattern becomes an internal electrode layer of the multilayer ceramic capacitor after firing. The method for producing a ceramic laminate according to any one of claims 1 to 6, wherein the number of laminates is 400 or more.

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