JP2010052970A - Ceramic composition, ceramic green sheet, and ceramic electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To dramatically improve dielectric properties as compared with conventional properties, while controlling shrinkage behavior in sintering, and to ensure reliability. <P>SOLUTION: A ceramic composition is prepared which comprises 26-60 wt.% of a B<SB>2</SB>O<SB>3</SB>-SiO<SB>2</SB>-Al<SB>2</SB>O<SB>3</SB>-MO glass composition (wherein M denotes at least one selected from Ca, Mg, Sr and Ba, B<SB>2</SB>O<SB>3</SB>: 4-17.5 wt.%, SiO<SB>2</SB>: 28-50 wt.%, Al<SB>2</SB>O<SB>3</SB>: 0-20 wt.% and MO:36-50 wt.%), 30-65 wt.% of at least one of SrTiO<SB>3</SB>and CaTiO<SB>3</SB>, and ≤10 wt.% (including 0 wt.%) of at least one selected from Cu, Mn, Zn and Ca. The ceramic composition is sintered to produce a ceramic sintered body 2 and a compound LC component 20 including the ceramic sintered body 2 is obtained. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a ceramic composition, a ceramic green sheet, and a ceramic electronic component, and more particularly, a ceramic composition for low-temperature firing having a high dielectric constant, a ceramic green sheet using the ceramic composition, and the ceramic composition The present invention relates to a ceramic electronic component such as a ceramic multilayer substrate and a composite LC component.

  In recent years, high-frequency dielectric ceramics are widely used in, for example, dielectric resonators and MIC dielectric substrates. This type of high frequency dielectric ceramic is required to have a large relative dielectric constant εr and Q value in order to reduce the size.

  On the other hand, high-frequency dielectric ceramics have the disadvantage that when high-melting-point tungsten or molybdenum is used as the conductor material, these high-melting-point metals have a large specific resistance, so that the high-frequency characteristics of ceramic multilayer substrates are particularly limited. And it is expensive. For this reason, it is required to use a low-melting-point low-melting metal such as Ag or Cu as the conductor material.

  However, in order to obtain a ceramic sintered body by simultaneously firing the conductor material and the ceramic material, it is necessary to fire the ceramic material at a temperature lower than the melting point of these low melting point metals.

  Therefore, research on a ceramic material for low-temperature firing, which is a composite material of a ceramic component and a glass component, has been actively conducted, and practical application of a ceramic multilayer substrate using the ceramic material has been promoted.

For example, in Patent Document 1, xBaO—yTiO ₂ —zReO _3/2 (where x, y, and z represent mol%, and 8 ≦ x ≦ 18, 52.5 ≦ y ≦ 65, and 20 ≦ z ≦ 40) X + y + z = 100, and Re is a rare earth element.) 10 to 45 wt% BaO—TiO ₂ —ReO _3/2 ceramic composition and 5 to 40 wt% alumina. When, from 4 to 17.5 wt% of _B 2 _O 3, 28 to 50 wt% of _SiO 2, 0 to 20 wt% of _Al 2 _{O 3} and 36 to 50 wt% of MO (note, MO is, CaO, A borosilicate glass composition containing 40 to 65% by weight, and the BaO—TiO ₂ —ReO _{3 / 2-} based ceramic composition comprising at least one selected from MgO, SrO and BaO) And the total amount of alumina A ceramic raw material composition of 35% by weight or more has been proposed.

  In this patent document 1, by including a borosilicate glass composition, the shrinkage behavior of ceramics during firing can be suppressed, and since the glass viscosity is high, it is interdiffused with other low-temperature fired substrates. Can be suppressed. Furthermore, by including the ceramic composition, a ceramic raw material composition having a high relative dielectric constant having a relative dielectric constant εr of about 15 can be obtained.

International Publication No. 2006/046361 Pamphlet

  However, although the ceramic raw material composition of Patent Document 1 has a relatively high relative dielectric constant εr of about 15, in order to meet the demand for further miniaturization of module products and the like today, a higher dielectric constant is required. The rate εr is determined.

  However, in order to increase the relative dielectric constant εr, it is necessary to reduce the content of the glass composition and increase the content of the ceramic powder serving as the filler. On the other hand, when the content of the glass composition is lowered, the fluidity of the glass composition is lowered, so that the ceramic sintered body is easily contracted by the firing treatment. Therefore, it is necessary to increase the content of the glass composition in order to easily control the shrinkage behavior during firing. That is, it is difficult to achieve both the control of the shrinkage behavior of the ceramic sintered body during firing and the high relative dielectric constant.

  The present invention has been made in view of such circumstances, and can suppress the shrinkage behavior at the time of firing, can dramatically improve the dielectric characteristics as compared with the conventional ceramic composition, and can ensure reliability. An object is to provide a ceramic green sheet and a ceramic electronic component using the same.

The present inventor conducted intensive studies to achieve the above object, and in addition to borosilicate glass having a specific composition, SrTiO ₃ or CaTiO ₃ having a high relative dielectric constant εr was added within a predetermined range, and further a sintering aid. By including the component in a range of a predetermined amount or less, it is easy to control the shrinkage behavior of the ceramic sintered body at the time of firing, and has a favorable dielectric property with a relative dielectric constant εr of 40 or more and a Q value of 750 or more. The knowledge that a ceramic composition for low-temperature firing can be obtained was obtained.

The present invention was made based on such findings, the ceramic composition according to the present _{invention, B 2 O 3 -SiO 2 -Al} 2 O 3 -MO -based glass compositions (except, M is Ca, mg, represents at least one selected from among Sr, and _Ba, B ₂ O 3: 4~17.5 _wt%, SiO 2: 28 to 50 _{wt%, Al} 2 O 3: _0~20 wt% , MO: 36 to 50% by weight)) and 26 to 60% by weight, and at least one of SrTiO ₃ and CaTiO ₃ is contained by 30 to 65% by weight, and Cu, Mn, Zn, And the oxide containing at least 1 sort (s) selected from Ca is 10 weight% or less (however, 0 weight% is included), It is characterized by the above-mentioned.

  The ceramic green sheet according to the present invention is characterized in that the ceramic composition is formed into a sheet shape.

  Moreover, the ceramic electronic component according to the present invention is characterized by having a first ceramic layer made of a sintered body of the ceramic composition.

  The ceramic electronic component of the present invention is characterized in that the first ceramic layer and a second ceramic layer having a relative dielectric constant lower than that of the first ceramic layer are laminated.

In the ceramic electronic component of the present invention, the second ceramic layer contains 51 to 60% by weight of ceramic powder, and a B ₂ O ₃ —SiO ₂ —Al ₂ O ₃ —MO-based glass composition ( However, M represents Ca, Mg, Sr, and at least one selected from among _Ba, B ₂ O 3: 5~17.5 _wt%, SiO 2: _28~44 wt%, _Al 2 _{O 3} : 0 to 20% by weight, MO: 36 to 50% by weight.) 40 to 49% by weight of ceramic composition, and a sintered body of the ceramic composition.

  Further, the ceramic electronic component of the present invention is characterized by having a conductor pattern mainly composed of Ag or Cu.

  In the present invention, the glass composition itself is an auxiliary agent that generates a liquid phase and promotes sintering of the particles, and the oxides of Cu, Mn, Zn, and Ca wet the ceramic powder surface. This is an auxiliary agent that forms a liquid phase.

According to the above ceramic composition, the B ₂ O ₃ —SiO ₂ —Al ₂ O ₃ —MO-based glass composition blended in a predetermined ratio is contained in an amount of 26 to 60% by weight, and among SrTiO ₃ and CaTiO ₃ An oxide containing at least one of 30 to 65% by weight and containing at least one selected from Cu, Mn, Zn, and Ca is 10% by weight or less (however, 0% by weight is included). Therefore, it is possible to obtain a ceramic composition with improved dielectric properties while making it easy to control the shrinkage behavior of the ceramic sintered body during firing, and the ceramic composition capable of controlling both the shrinkage behavior and the dielectric properties. You can get things.

Specifically, a ceramic having good dielectric constant εr of 40 or more, Q value of 750 or more, insulation resistance IR of 10 ¹⁰ Ω or more, and good sinterability that can easily control shrinkage behavior during firing. A composition can be obtained.

  Therefore, it is possible to realize a ceramic green sheet and a ceramic electronic component having high quality and good dielectric properties corresponding to further downsizing of today's module products and the like.

  In the ceramic electronic component of the present invention, the first ceramic layer and the second ceramic layer having a relative dielectric constant lower than that of the first ceramic layer are laminated. By disposing a conductor for wiring on the second ceramic layer and disposing elements such as capacitors and filters on the first ceramic layer, which is a high dielectric constant layer, the ceramic substrate can be further miniaturized. It becomes possible.

  Moreover, since the ceramic composition which comprises the 1st ceramic layer and the ceramic composition which comprises the 2nd ceramic layer are similar in the component composition of a glass composition, the characteristic variation and characteristic by mutual diffusion at the time of baking Since variations and the like are unlikely to occur and the thermal expansion coefficients are also approximate, structural defects such as delamination are unlikely to occur. Furthermore, since it is not necessary for the second ceramic layer to contain an alkali metal element, it is possible to avoid a decrease in resistance characteristics due to a reaction with a resistor constituting the resistance element.

  Next, an embodiment of the present invention will be described in detail.

The ceramic composition according to the present invention includes (1) a B ₂ O ₃ —SiO ₂ —Al ₂ O ₃ —MO glass composition (borosilicate glass composition; hereinafter simply referred to as “glass composition”). (2) at least one of SrTiO ₃ and CaTiO ₃ is contained in an amount of 30 to 65% by weight, and (3) at least selected from Cu, Mn, Zn, and Ca. The oxide containing one kind (hereinafter referred to as “sintering aid component”) is prepared to be 10% by weight or less (however, 0% by weight is included).

The element M in the glass composition is at least one selected from Ca, Mg, Sr, and Ba, and the component composition thereof is B ₂ O ₃ : 4 to 17.5 wt%, SiO ₂ : 28 to 50% by weight, Al ₂ O ₃ : 0 to 20% by weight, MO: 36 to 50% by weight.

  Since the ceramic composition of the present invention has the above-described component composition, it can easily control the shrinkage behavior of the ceramic sintered body during firing, and has a high relative dielectric constant εr and Q value, and is subjected to high temperature and high humidity. However, it is possible to obtain a highly reliable ceramic composition that can withstand a long time.

Specifically, according to a method using a constraining layer, which will be described later, the sintered ceramic body after firing should ensure a dimensional accuracy of 99% or more in the XY direction with respect to the ceramic molded body before firing. And a highly reliable ceramic composition having a relative dielectric constant εr of 40 or more, a Q value of 750 or more, and an insulation resistance IR of 10 ¹⁰ Ω or more even when left for a long time under high temperature and high humidity. Can do.

  Next, the reason why the ceramic composition is blended with the above composition components will be described.

(1) Glass composition By including the glass composition described above in the ceramic composition, firing at a low temperature of 1050 ° C. or less, particularly around 900 ° C. is possible, and shrinkage behavior of the ceramic sintered body during firing However, for this purpose, the content of the glass composition should be at least 26% by weight. That is, when the content of the glass composition is decreased, although the relative dielectric constant εr is increased, the fluidity of the glass is decreased during firing, so that the ceramic sintered body is easily contracted. And in order to make this baking shrinkage as small as possible, content of a glass composition needs at least 26 weight% or more.

  On the other hand, when the content of the glass composition exceeds 60% by weight, the content of the glass composition in the ceramic composition becomes excessive, and the glass viscosity becomes too high, resulting in poor sintering. That is, when the content of the glass composition is increased, the sinterability is improved, the flowability of the glass is improved and the firing shrinkage is suppressed, but the dielectric properties such as the relative dielectric constant εr and the Q value are lowered. . Therefore, the content of the glass composition needs to be 60% by weight or less.

  Therefore, in the present embodiment, the composition components are blended so that the content of the glass composition is 26 to 60% by weight. More preferably, it is 35 to 55% by weight.

Moreover, the reason why the constituent components (B ₂ O ₃ , SiO ₂ , Al ₂ O ₃ , MO) in the glass composition are limited to the above range is as follows.

(A) B ₂ O ₃
B ₂ O ₃ is added to lower the softening temperature and promote viscous flow. When the content of B ₂ O ₃ in the glass composition is less than 4% by weight, the content is too small, For this reason, there exists a possibility that glass viscosity may become high and may cause a sintering defect. On the other hand, when the content of B ₂ O _{3 in} the glass composition exceeds 17.5% by weight, the chemical stability of the glass composition is deteriorated. As a result, when it is left for a long time under high temperature and high humidity, the insulation resistance IR May decrease and reliability may be impaired.

Therefore, in the present embodiment, the composition components are blended so that the content of B ₂ O ₃ in the glass composition is 4 to 17.5% by weight. More preferably, it is 5 to 10% by weight.

(B) SiO ₂
SiO ₂ contributes to the stability of the glass composition. However, when the content of SiO ₂ in the glass composition is less than 28% by weight, the chemical stability is deteriorated. As a result, under high temperature and high humidity. If it is left for a long time, the insulation resistance may be lowered and the reliability may be impaired. On the other hand, when the content of SiO ₂ in the glass composition exceeds 50% by weight, the content is excessive and the glass viscosity is increased, and as a result, there is a possibility of causing poor sintering.

Therefore, in the present embodiment, the composition components are blended so that the content of SiO ₂ in the glass composition is 28 to 50% by weight. More preferably, it is 38 to 48% by weight.

(C) Al ₂ O ₃
Al ₂ O ₃ is added as necessary to stabilize the glass composition, but if the content of Al ₂ O ₃ in the glass composition exceeds 20% by weight, crystallization becomes difficult and the Q value is increased. There is a risk of lowering.

Therefore, in the present embodiment, Al ₂ O ₃ may not be contained in the glass composition, but the composition components are blended so that the upper limit is 20% by weight. The content of Al ₂ O ₃ is preferably 4 to 10% by weight.

(D) MO
MO is added to lower the softening temperature and promote viscous flow like B ₂ O ₃ , but if the MO content in the glass composition is less than 36% by weight, the content is too small. For this reason, there is a possibility that the glass viscosity becomes high and sintering failure is caused. On the other hand, if the MO content in the glass composition exceeds 50% by weight, the chemical stability of the glass composition deteriorates. As a result, the insulation resistance IR decreases when left for a long time under high temperature and high humidity. There is a risk of damage.

  Therefore, in the present embodiment, the composition components are blended so that the MO content in the glass composition is 36 to 50% by weight. More preferably, it is 40 to 46% by weight.

In this manner, in the present embodiment, the overall content of the glass composition and 26 to 60 wt%, and the composition range of the constituents of the glass component _B 2 _O 3: _4~17.5 wt%, SiO ₂ : 28 to 50% by weight, Al ₂ O ₃ : 0 to 20% by weight, MO: 36 to 50% by weight, so as to obtain the desired effect in combination with other additives. .

(2) SrTiO ₃ and CaTiO ₃
SrTiO ₃ has a relative dielectric constant εr of 250, and CaTiO ₃ has a relative dielectric constant εr of 170, both of which have a high relative dielectric constant εr. Therefore, by adjusting the blending amount with the glass composition, It is possible to increase the relative dielectric constant εr while controlling the shrinkage behavior of the ceramic sintered body during firing.

However, when the total content of SrTiO ₃ and CaTiO ₃ is less than 30% by weight, the content of the glass composition increases, so that firing shrinkage can be suppressed, but a sufficiently high desired dielectric constant εr is obtained. I can't.

On the other hand, if the total content of SrTiO ₃ and CaTiO ₃ exceeds 65% by weight, the ceramic sintered body tends to shrink even if the relative dielectric constant εr is improved.

Therefore, in the present embodiment, the contents of SrTiO ₃ and CaTiO ₃ are blended so as to be 30 to 65% by weight in total, thereby achieving both the control of the shrinkage behavior and the improvement of the dielectric characteristics.

(3) Sintering aid component By containing SrTiO ₃ and CaTiO ₃ in the above-mentioned range, it is possible to sufficiently improve the relative dielectric constant εr compared to the conventional case, but it is necessary as a sintering aid component. Accordingly, the relative dielectric constant εr can be further improved by adding an oxide containing at least one selected from Cu, Mn, Zn, and Ca.

  However, if the sintering agent component exceeds 10% by weight, when left for a long time under high temperature and high humidity, the insulation resistance IR may be lowered and the reliability may be impaired.

  Therefore, in the present embodiment, the composition components are blended so that the content of the sintering aid component is 10% by weight or less (including 0% by weight). Preferably it is 1 to 6% by weight.

  Next, the ceramic green sheet of the present invention will be described.

  FIG. 1 is a perspective view of a ceramic green sheet 1 obtained using the above ceramic composition.

  The ceramic green sheet 1 can be easily manufactured as follows.

That is, B ₂ O ₃ , SiO ₂ , Al ₂ O ₃ , MO (at least one of CaO, BaO, SrO, and MgO), at least one of SrTiO ₃ and CaTiO ₃ , and necessary Depending on the case, a sintering aid component is prepared and weighed so as to obtain a predetermined component composition. Then, this weighed product is put into a ball mill together with a grinding medium such as zirconia, and mixed and pulverized for a predetermined time by wet. Next, this pulverized product is evaporated to dryness and then calcined at a predetermined temperature for about 2 hours to obtain a calcined powder (ceramic composition).

  Next, an appropriate amount of a binder, a solvent, and a plasticizer are added to the calcined powder and wet pulverized to form a slurry, which is then molded using a molding method such as a doctor blade method, thereby obtaining a predetermined thickness. A ceramic green sheet molded into a can be produced.

  And various ceramic electronic components can be obtained using this ceramic green sheet.

  FIG. 2 is a perspective view of the laminated LC component 20 showing one embodiment (first embodiment) of the ceramic electronic component.

  In the laminated LC component 20, a circuit constituting an inductance L and a capacitance C is formed inside the ceramic sintered body 2. The external electrodes 3a and 3b are formed at both ends of the ceramic sintered body 2, and the external electrodes 4a and 4b are formed at the substantially central portion. 3 is formed as an equivalent circuit LC resonance circuit.

  Next, a manufacturing method of the laminated LC component 20 will be described with reference to FIG.

  First, rectangular ceramic green sheets 5a to 5m manufactured by the above-described method are prepared.

  Next, a laser processing machine is used so that the ceramic green sheets 5c to 5k can be electrically connected to each other, and via holes 6a to 6d are formed at predetermined positions of the ceramic green sheets 5c to 5k. Next, a conductive paste mainly composed of Ag or Cu is screen-printed to form capacitor conductor patterns 7a to 7c and coil conductor patterns 8a to 8d.

  Then, after filling the via holes 6a to 6d with the conductive paste, the ceramic green sheets 5c to 5k are stacked, whereby the coil conductor patterns 8a to 8d are electrically connected in a coil shape to form a coil conductor. At the same time, the capacitor conductive patterns 7a to 7c and the ceramic green sheets 5f to 5h form a capacitance portion.

  Next, the ceramic green sheets 5a and 5b on which the conductor pattern is not formed and the ceramic green sheets 5l and 5m are sandwiched and pressed to produce a ceramic laminate.

  Next, a constraining layer containing an inorganic material that does not sinter at the sintering temperature (eg, 900 ° C.) of the ceramic laminate (eg, a ceramic green sheet (alumina green sheet having a melting point of 1500 ° C. or more as a main component) )) Is disposed on at least one main surface and fired, and then the constraining layer is removed. Thereby, the ceramic sintered body 2 is manufactured. That is, the ceramic green sheets 5a to 5m formed by forming the ceramic composition into sheets are sintered to form ceramic layers having high relative dielectric constants, respectively, and the conductor patterns for capacitors 7a to 7c and the conductor patterns for coils 8a to 8d. The via holes 6a to 6d are fired simultaneously to form internal electrodes, that is, capacitor internal electrodes and coil conductors.

  In this embodiment, since the constraining layer is disposed on at least one main surface of the ceramic laminate, the constraining layer controls the shrinkage behavior in the main surface direction (XY direction) of the ceramic laminate. As a result, it is possible to obtain the ceramic sintered body 2 with high dimensional accuracy and less warpage.

  Thereafter, the external electrodes 3a to 4b are formed by a thin film forming method such as application / baking of conductive paste, vapor deposition, plating, or sputtering. In this way, the laminated LC component 20 is manufactured.

  As described above, in the first embodiment, since the ceramic sintered body 2 is formed of the above ceramic composition, a low melting point metal mainly composed of Ag or Cu as an internal electrode material can be used. It can be produced by simultaneous firing at a low temperature. Then, it is possible to obtain the laminated LC component 20 which is controlled in the shrinkage behavior of the ceramic sintered body 2 and has a large relative dielectric constant εr and Q value and excellent dielectric properties and excellent reliability.

  FIG. 5 is a cross-sectional view of a ceramic multilayer module 30 schematically showing a second embodiment of the ceramic electronic component according to the present invention.

  In the ceramic multilayer module 30, electronic component elements 19 to 21 are arranged on the ceramic multilayer substrate 10. Examples of the electronic component elements 19 to 21 include a semiconductor device and a chip type multilayer capacitor.

  The ceramic multilayer substrate 10 includes a second ceramic layer group 12a having a relative dielectric constant εr lower than that of the first ceramic layer group 11 on both surfaces of the first ceramic layer group 11 made of a sintered body of the ceramic composition. , 12b are provided.

  The first ceramic layer group 11 is formed by laminating a plurality of ceramic layers, and internal electrodes 13 and 14 are provided between the ceramic layers, thereby forming capacitor units C1 and C2.

  Further, via holes 17 and 18 and internal wirings 15 and 16 are appropriately formed in the second ceramic layer groups 12a and 12b and the first ceramic layer group 11 as necessary.

  The electronic component elements 19 to 21 and the capacitor units C1 and C2 are electrically connected by the via holes 17 and 18 and the internal wirings 15 and 16 to form a ceramic multilayer module 30.

  In the second embodiment, the first ceramic layer group 11 is formed of the above-described ceramic composition having a high relative dielectric constant (hereinafter referred to as “first ceramic composition”), and the second The ceramic layer groups 12a and 12b are formed of a second ceramic composition having a relative dielectric constant εr lower than that of the first ceramic composition.

  The second ceramic composition has a component composition similar to that of the first ceramic composition.

Specifically, the second ceramic composition contains 51 to 60% by weight of ceramic powder, and a B ₂ O ₃ —SiO ₂ —Al ₂ O ₃ —MO glass composition (hereinafter referred to as “second glass”). Of 40 to 49% by weight.

  Here, the reason why the content of the second glass composition is 40 to 49% by weight is as follows.

  If the content of the second glass composition exceeds 49% by weight, crystallization of the glass proceeds excessively, and there is a possibility that the second ceramic layer groups 12a and 12b after firing may be distorted. On the other hand, when the content of the second glass composition is less than 40% by weight, the relative dielectric constant εr cannot be sufficiently lowered.

  Therefore, in the present embodiment, the second ceramic composition is blended so that the second glass composition is 40 to 49% by weight and the balance is made of ceramic powder.

Further, each component composition of the second glass composition is the glass composition of the first ceramic composition except that the lower limit value of B ₂ O ₃ is 5 wt% and the upper limit value of SiO ₂ is 44 wt%. Is the same.

Here, the lower limit value of B ₂ O ₃ was set to 5% by weight in order to avoid the Q value of the second ceramic layer groups 12a and 12b from being lowered, and the upper limit value of SiO ₂ was set to 44% by weight. The reason is that the sinterability may be improved too much and the relative dielectric constant εr may become too high.

As the ceramic powder, _Al 2 _{O 3} is preferred.

  Then, by forming the second ceramic layer groups 11a and 11b having a relative dielectric constant εr lower than that of the first ceramic layer group 12 in this way by using a second ceramic composition similar to the first ceramic composition. Thus, characteristic variation and characteristic variation due to mutual diffusion during firing are less likely to occur. In addition, the first ceramic composition and the second ceramic composition also have similar thermal expansion coefficients, so that structural defects such as delamination are unlikely to occur. Furthermore, since the second ceramic layer groups 11a and 11b do not need to contain an alkali metal element, for example, in the case of having a resistance element, avoiding a decrease in resistance characteristics due to a reaction with a resistor constituting the resistance element is avoided. can do.

  Then, by forming external electrodes for connection to the outside on the lower surface of the ceramic multilayer substrate, the ceramic multilayer module 30 can be easily surface-mounted on a printed circuit board or the like using the lower surface side.

  In the second embodiment, since the first and second ceramic compositions suitable for low-temperature firing are used, the internal electrodes 13, 14 and the internal wirings 15, 16 and the via holes 17, 18 are It is possible to perform simultaneous firing using a low-resistance and inexpensive low melting point metal such as Ag or Cu. That is, the capacitor units C1 and C2 can be configured using the co-fired ceramic multilayer substrate, and the module can be downsized. In addition, since the first ceramic layer group 11 uses the first ceramic composition, the ceramic multilayer module 30 has a high relative dielectric constant εr and Q value, excellent reliability, and good sinterability. Can be obtained.

  The ceramic multilayer substrate 10 is fired by disposing a constraining layer on at least one main surface of the second ceramic layer group 12a, 12b by the same method as in the first embodiment. A ceramic sintered body with controlled shrinkage behavior during firing can be easily produced.

  Further, in the capacitor units C1 and C2, since the internal electrodes 13 and 14 adjacent in the thickness direction for taking out the electrostatic capacitance are embedded in the first ceramic layer group 11, an internal electrode having a relatively small area can be used as a large static electrode. Electric capacity can be obtained, and downsizing can be promoted. That is, a conductor for wiring is arranged on the second ceramic layer group 11a which is a low dielectric constant layer, and an element such as a capacitor or a filter is arranged on the first ceramic layer group which is a high dielectric constant layer. Thus, the ceramic substrate can be further reduced in size.

  In the first and second embodiments, the laminated LC component 20 and the ceramic multilayer module 30 have been described. However, these are examples, and the present invention is not limited thereto. That is, various ceramic multilayer substrates such as multi-chip module ceramic multilayer substrates and hybrid IC ceramic multilayer substrates, or various ceramic electronic components in which electronic component elements are mounted on these ceramic multilayer substrates, as well as chip-type multilayer capacitors and chips The present invention can be applied to various chip-type multilayer electronic components such as a type multilayer dielectric antenna.

  Next, examples of the present invention will be specifically described.

[Sample preparation]
[Production of white substrate]
First, B ₂ O ₃ , SiO ₂ , Al ₂ O ₃ , CaO, BaO, SrO, and MgO were prepared as glass raw materials. And the said glass raw material was weighed so that it might become content as shown in Table 1.

Next, SrTiO ₃ was weighed so that the content of the glass composition was 45% by weight and the content of SrTiO ₃ was 55% by weight. Then, these weighed materials were put into a ball mill together with zirconia and mixed by wet for 16 hours to prepare a calcined powder (ceramic composition).

  Next, an appropriate amount of a binder, a solvent, and a plasticizer are added to the ceramic composition, and mixed and pulverized in a ball mill for 2 hours by wet mixing to form a slurry, which is then molded using a doctor blade method. Thus, ceramic green sheets of sample numbers 1 to 19 having a thickness of 25 μm were obtained.

  Next, ceramic green sheets were laminated to produce a ceramic laminate, and a constraining layer of alumina green sheets was placed on both sides of the ceramic laminate and crimped to produce a crimped body having a length of 55 mm, a width of 75 mm, and a thickness of 1 mm. .

  After this, a firing process is performed for 10 minutes at a firing temperature of 870 ° C. in an air atmosphere, then the constraining layer is removed, and a ceramic sintered body (white substrate) of sample numbers 1 to 19 having a thickness of 0.65 mm Was made.

[Production of multilayer ceramic capacitors]
First, an Ag paste containing Ag as a main component was prepared. Then, Ag paste was screen printed on the surface of the ceramic green sheet described above to form a conductor pattern. Next, the ceramic green sheets on which the conductor pattern was formed were laminated so that the electrostatic capacity could be obtained, and further sandwiched between the ceramic green sheets on which the conductor pattern was not formed to produce a ceramic laminate. And the constraining layer was arranged on both surfaces of the ceramic laminated body, and the crimping | compression-bonding body was produced.

  Next, the pressure-bonded body was subjected to a firing treatment in an air atmosphere at a firing temperature of 870 ° C. for 10 minutes. Thereafter, the constraining layer was removed, and a ceramic sintered body in which internal electrodes were embedded was produced.

Next, an Ag paste containing Ag as a main component is prepared, the Ag paste is applied to both ends of the ceramic sintered body, baked at a temperature of 800 ° C., and external electrodes are formed. A capacitor was produced. The outer dimensions of the produced multilayer ceramic capacitor were 8 mm in length, 6 mm in width, 0.5 mm in thickness, 3 effective layers, and 4 mm ² in effective electrode area.

(Sample evaluation)
About each sample (white board | substrate) of sample numbers 1-19, sinterability and the shrinkage | contraction behavior at the time of baking were evaluated.

  Specifically, for the sinterability, the red ink was dropped on the sample, and the sample in which the red ink stain occurred was judged to be poorly sintered.

  The shrinkage behavior was evaluated by calculating the shrinkage rate as follows. That is, the longitudinal and lateral lengths of the ceramic laminate before sintering and the longitudinal and lateral lengths of the sintered ceramic body after sintering are measured according to the following formulas (1) and (2). Then, the vertical direction shrinkage rate and the horizontal direction shrinkage rate were calculated, and then the shrinkage rate was calculated by Equation (3).

Longitudinal shrinkage = (longitudinal length after sintering / longitudinal length before sintering) × 100
... (1)
Lateral shrinkage = (lateral length after sintering / lateral length before sintering) × 100
... (2)
Shrinkage rate = (longitudinal shrinkage rate + lateral shrinkage rate) / 2 (3)
Further, the relative dielectric constant εr and the Q value were measured at a resonance frequency of 6 GHz. A relative dielectric constant εr of 40 or more and a Q value of 750 or more were judged as non-defective products.

Moreover, PCT (pressure cooker test) was performed and reliability was evaluated. That is, a DC voltage of 10 V was applied at a temperature of 120 ° C. and a relative humidity of 85%, and left to stand for 192 hours. Thereafter, the insulation resistance IR was measured with a resistance meter, and 10 ¹⁰ Ω or more was judged as a good product.

  Table 1 shows the component composition of the glass composition of each sample, and Table 2 shows the ceramic composition and measurement results of each sample.

  Sample No. 5 had poor sintering. This is probably because the CaO content in the glass composition was as low as 35.0% by weight and the glass viscosity was increased.

Sample No. 8 was found to have an insulation resistance IR of 10 ⁵ Ω or less after the PCT test, leading to a decrease in reliability. This is presumably because the content of CaO in the glass composition was as high as 55.0% by weight, and the chemical stability of the glass composition was deteriorated.

Sample number 9 was poorly sintered. This content of B ₂ O ₃ in the glass composition is as small as 2.0 wt%, is believed to be due to the glass viscosity becomes high.

Sample No. 12 was found to have an insulation resistance IR of 10 ⁵ Ω or less after the PCT test, leading to a decrease in reliability. This is presumably because the content of B ₂ O ₃ in the glass composition was as high as 20.0% by weight, and thus the chemical stability of the glass composition was deteriorated.

Sample No. 13 was found to have an insulation resistance IR of 10 ⁵ Ω or less after the PCT test, leading to a decrease in reliability. This is thought to be because the chemical stability of the glass composition was deteriorated because the content of CaO in the glass composition was as high as 52.0% by weight but the content of SiO ₂ was as low as 26.0% by weight. .

Sample number 16 was poorly sintered. This is presumably because the glass viscosity increased because the SiO ₂ content in the glass composition was as high as 53.0% by weight.

In Sample No. 19, the Q value decreased to 550. This is because the content of Al ₂ O ₃ in the glass composition is as large as 30.0% by weight, but although the stability of the glass is improved, it is difficult to crystallize, and this is thought to have caused a decrease in the Q value. It is.

On the other hand, sample numbers 1 to 4, 6, 7, 10, 11, 14, 15, 17, and 18 have component compositions of the glass composition within the scope of the present invention, and the glass composition in the ceramic composition. Since the content of SrTiO ₃ is 45% by weight and the content of SrTiO ₃ is 55% by weight within the scope of the present invention, the sinterability is good and the shrinkage ratio is 99% or more during firing. It was found that the shrinkage behavior of can also be suppressed. Furthermore, the dielectric constant εr is 40 or more, the Q value is 750 or more, and desired good dielectric characteristics can be obtained, and the insulation resistance IR after the PCT test is 10 ¹⁰ Ω or more to ensure reliability. I also found that I can do it.

[Sample preparation]
B ₂ O ₃ , SiO ₂ , Al ₂ O ₃ and CaO are prepared as glass raw materials, and SrTiO ₃ , CaTiO ₃ , CuO, ZnO, MnCO ₃ and CaCO ₃ are prepared as additives (fillers) other than the glass raw materials. did.

  Next, the glass raw material is weighed so that the content of the glass composition is the sample number G1 (within the scope of the present invention) in Table 1, so that the total content of the ceramic composition is Table 3. The additive material was weighed.

  Thereafter, white substrates and multilayer ceramic capacitors of Sample Nos. 21 to 39 were produced by the same method and procedure as in [Example 1].

  Table 3 shows the component compositions of sample numbers 21-39.

(Sample evaluation)
About each sample of sample numbers 21-39, sinterability was evaluated by the method similar to [Example 1], and shrinkage | contraction behavior was evaluated.

  Further, for each of the samples Nos. 21 to 39, the relative dielectric constant εr and the Q value were measured in the same manner as in [Example 1], and the PCT test was further performed to evaluate the reliability.

  These evaluation criteria are the same as those in [Example 1].

  Table 4 shows the measurement results.

Sample numbers 21 to 25 differ in the mixing ratio between the glass composition and SrTiO ₃ or CaTiO ₃ .

  Sample number 22 was poorly terminated. This is presumably because the glass composition content is as low as 25% by weight and it is difficult to fire at a low temperature of 870 ° C.

  In Sample No. 25, the relative dielectric constant εr was as low as 30.1 and the Q value was 600. This is because as the content of the glass composition increases, the sinterability improves and the fluidity of the glass also increases, so the shrinkage behavior is suppressed, but the content of the glass composition is excessive at 60% by weight. This seems to have caused a decrease in dielectric properties.

On the other hand, Sample Nos. 21, 23, and 24 have a glass composition and a blending amount of SrTiO ₃ or CaTiO ₃ within the range of the present invention, so that the sinterability is good and the shrinkage rate is 99% or more. It was found that the shrinkage behavior during firing was suppressed. In addition, the dielectric constant εr is 40 or more and the Q value is 750 or more to obtain desired good dielectric characteristics, and the insulation resistance IR after the PCT test is 10 ¹⁰ Ω or more to ensure reliability. I also found that I can do it.

Sample Nos. 26 to 37 are obtained by changing the blending ratio of SrTiO ₃ and the sintering aid component (CuO, ZnO, MnCO ₃ , and CaCO ₃ ) while keeping the content of the glass composition constant at 45% by weight. .

  As can be seen from Sample Nos. 26 to 37, as the sintering aid component increases, the relative permittivity εr improves. As shown in Sample Nos. 28, 31, 34, and 37, the sintering aid is increased. When the content of the agent component was excessive, 15% by weight, the Q value decreased. Therefore, it was found that the content of the sintering aid component needs to be 10% by weight or less.

  Sample numbers 37 and 38 are obtained by changing the content of the glass composition while maintaining constant CuO as a sintering aid component.

  As shown in Sample No. 37, by including 10% by weight of CuO as a sintering aid component, the sinterability is good even when the glass composition is reduced to 27% by weight, and the relative dielectric constant εr. It was found that can be improved to 85.5.

  However, as can be seen from Sample No. 38, even when CuO is contained at 10% by weight, if the content of the glass composition is excessively low at 20% by weight, firing at a low temperature is difficult and sintering is performed. It became defective.

From the above, the component composition of the glass composition is within the scope of the present invention, and the glass composition, SrTiO ₃ and / or CaTiO ₃ in the ceramic composition, and the sintering aid component are within the scope of the present invention. Sinterability is good, the shrinkage behavior during firing can be suppressed, the dielectric constant εr is 40 or more, the Q value is 750 or more, and good dielectric properties can be obtained. It was also found that reliability can be secured.

1 is a perspective view of a ceramic green sheet according to the present invention. 1 is a perspective view illustrating a composite LC component as an embodiment (first embodiment) of a ceramic electronic component according to the present invention. FIG. 3 is a circuit diagram showing an equivalent circuit of FIG. 2. It is a disassembled perspective view of the ceramic sintered compact for demonstrating the manufacturing method of FIG. It is sectional drawing of the multilayer module as 2nd Embodiment of the ceramic electronic component which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ceramic green sheet 2 Ceramic sintered compact 5a-5m Ceramic green sheet 7a-7c Conductor pattern 8a-8d Conductor pattern 11 1st ceramic layer group (1st ceramic layer)
12a, 12b Second ceramic layer group (second ceramic layer)
13 Internal electrode (conductor pattern)
14 Internal electrode (conductor pattern)
15 Internal wiring (conductor pattern)
16 Internal wiring (conductor pattern)

Claims (6)

B ₂ O ₃ —SiO ₂ —Al ₂ O ₃ —MO glass composition (wherein M represents at least one selected from Ca, Mg, Sr, and Ba, and B ₂ O ₃ : 4 to 17.5 _wt%, SiO 2: 28 to 50 _{wt%, Al} 2 O 3: _0~20 wt%, MO:. 36 to 50 in weight percent) together with containing 26-60 wt%,
Containing 30 to 65% by weight of at least one of SrTiO ₃ and CaTiO ₃ ;
And the ceramic composition characterized by the metal oxide containing at least 1 sort (s) selected from Cu, Mn, Zn, and Ca being 10 weight% or less (however, 0 weight% is included).   A ceramic green sheet, wherein the ceramic composition according to claim 1 is formed into a sheet shape.   A ceramic electronic component comprising a first ceramic layer made of a sintered body of the ceramic composition according to claim 1.   4. The ceramic electronic component according to claim 3, wherein the first ceramic layer and a second ceramic layer having a dielectric constant lower than that of the first ceramic layer are laminated. The second ceramic layer contains 51 to 60% by weight of Al ₂ O ₃ and a B ₂ O ₃ —SiO ₂ —Al ₂ O ₃ —MO glass composition (where M is Ca, Mg, sr, and represents at least one selected from among _Ba, B ₂ O 3: 5~17.5 _wt%, SiO 2: _{28~44 wt%, Al} 2 O 3: _0~20 wt%, MO The ceramic electronic component according to claim 4, wherein the ceramic electronic component is a sintered body of a ceramic composition containing 49 to 60 wt%.   6. The ceramic electronic component according to claim 3, wherein the ceramic electronic component has a conductor pattern mainly composed of Ag or Cu.

Images