JP2007254281A - Method for manufacturing sintered compact, sintered compact, member for sintering, method for manufacturing ceramic multilayered substrate, and ceramic multilayered substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sintered compact having high dimensional accuracy by suppressing the warping of the sintered compact and reducing the variation in firing shrinkage. <P>SOLUTION: The sintered compact is manufactured by firing an object 5 to be fired. Ceramic composition objects 2A, 2B which contain binders and are not sintered at a temperature at which the object 5 to be fired is sintered are arranged to cover a part of the surface the object to be fired, sheet-like bodies 6A, 6B composed of materials stable at the sintering temperature of the object 5 to be fired are installed on the ceramic composition objects 2A, 2B. The object 5 to be fired is then fired. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing a sintered body and a method for producing a ceramic multilayer substrate.

  In a high-frequency circuit wireless device such as a mobile phone, a multilayer dielectric filter is used as a high-frequency circuit filter, for example, as a top filter, a transmission interstage filter, a local filter, a reception interstage filter, or the like. Such a dielectric multilayer filter is disclosed, for example, in JP-A-5-243810.

Multilayer dielectric filters are screen-printed with a paste for a built-in electrode in a predetermined pattern on a predetermined number of green sheets, and a plurality of green sheets are stacked and cut to form a substrate before firing. For example, the built-in electrode was manufactured by baking at 600-1100 degreeC. Then, after the substrate is barrel-polished, a surface layer electrode is formed by applying a metal paste for a surface layer electrode to a predetermined region of the surface of the substrate and baking it on the surface of the substrate. This surface electrode acts as a terminal for the built-in electrode. A representative example of a multilayer dielectric filter of the type using such a metal paste is disclosed in Japanese Patent Laid-Open No. 6-120603.

  However, when a large number of multilayer dielectric filters are fired, the sintered body may be warped. In addition, the firing shrinkage rate of the sintered body varies, and the dimensional accuracy of the sintered body tends to decrease.

An object of the present invention is to provide a sintered body with high dimensional accuracy by suppressing warpage of the sintered body, reducing variation in the shrinkage of firing, and producing a sintered body such as a ceramic multilayer substrate. is there.

Another object of the present invention is to suppress warpage of a substrate, reduce variation in firing shrinkage, and improve dimensional accuracy in a ceramic multilayer substrate such as a multilayer dielectric filter.

The invention according to the first aspect is a method for producing a sintered body by firing a fired body,
A ceramic composition object that contains a binder and does not sinter at a temperature at which the sintered body sinters is disposed so as to cover a part of the surface of the sintered object, and the sintered object is placed on the ceramic composition object. A plate-like body made of a material that is stable at the sintering temperature is set, and then the body to be fired is fired.

The present invention also relates to a sintered body obtained by the above method. Moreover, this invention concerns on the member for sintering for using for the said method.

Hereinafter, the present invention will be invented with reference to the schematic views of FIGS.
FIG. 1A shows a sintering member used in the firing process, and FIG. 1B shows the body 1 to be fired. The following description will focus on the process for manufacturing the ceramic multilayer substrate.

In this example, the sintering member 1 is a ceramic molded plate 5. A built-in electrode paste 4 is formed inside the ceramic forming plate 5, and surface layer electrode pastes 2 </ b> A and 2 </ b> B are formed on the main surfaces 5 a and 5 b of the forming plate 5, respectively. Next, the ceramic composition object 3A is provided on the main surface 5a, and the ceramic composition object 3B is provided on the main surface 5b, thereby obtaining the sintering member 1 of FIG.

Next, as shown in FIG. 2, the sintering member 1 is sandwiched between a pair of plate-like bodies 6A and 6B. Here, the plate-like body 6A is in close contact with or in contact with the ceramic composition object 3A, and the plate-like body 6B is in close contact with or in contact with the ceramic composition object 3B. A gap 10 is generated between the main surfaces 5a and 5b of the plate-like body 5 and the plate-like bodies 6A and 6B. In this state, the sintering member 1 is placed in the furnace 7 as shown in FIG. 3, and the heater 8 generates heat and fires.

In the present invention, the ceramic composition objects 3A and 3B that contain a binder and that do not sinter at a temperature at which the fired body sinters are adhered or contacted so as to cover part of the surface of the fired body 1 Then, the plate-like bodies 6A and 6B are placed thereon, and the fired body 1 is fired. As a result, as a result of the ceramic composition objects 3A and 3B being in close contact with or in contact with the plate-like bodies 6A and 6B thereon, the ceramic composition object acts as a kind of spacer, and between the surface of the body to be fired and the plate-like body. A gap 10 is generated. And if sintering of a to-be-fired body advances in this state, a to-be-fired body will carry out baking shrinkage gradually. At this time, the ceramic composition objects 3A and 3B are in close contact with or in contact with the plate-like bodies 6A and 6B, but are not sintered, and thus do not lose some fluidity.

In this state, a load is applied from the plate-like body to the body to be fired 1 to suppress warping of the plate-like body. However, warping of the fired body increases when the fired body shrinks in size in the firing process in a state where the plate-like body restrains deformation of the fired body 1. However, in the present invention, the ceramic composition objects 6 </ b> A and 6 </ b> B act as a kind of ceramic bearing and do not suppress dimensional shrinkage accompanying firing of the sintering member 1. As a result, it is possible to prevent warping during firing of the body to be fired 5 and improve its dimensional accuracy.

The invention according to the second aspect is a method for producing a ceramic multilayer substrate comprising a ceramic sintered body having a built-in electrode,
When a heat conduction control plate is installed on each of the main surface and the other main surface side of the ceramic molded plate, and the ceramic molded plate is sintered, a sintered body is obtained. The ratio (Ta / Tb) between the conductivity Ta and the thermal conductivity Tb of the sintered body is 0.01 or more and 50 or less.

The present invention also relates to a ceramic multilayer substrate obtained by the above method.

Hereinafter, the invention according to the second aspect will be further described with reference to the schematic diagrams of FIGS. 4 to 6. As shown in FIG. 4, the ceramic multilayer substrate to be fired 10 is fired in a state of being sandwiched between a pair of heat conduction control plates 15A and 15B to obtain a ceramic multilayer substrate. Here, the ceramic multilayer substrate is fired while being sandwiched between a pair of heat conduction control plates, and the relationship between the heat conductivity Ta of the heat conduction control plate and the heat conductivity Tb of the sintered body is set to a constant ratio. Found that is important.

That is, by installing the heat conduction control plates 15A and 15B, the heat from the heater in the furnace is not directly applied to the ceramic multilayer substrate, but is once irradiated to the surface 15b of the heat conduction control plates 15A and 15B. become. Here, in the vicinity of the surface 15b of the heat conduction control plates 15A and 15B, temperature unevenness occurs due to convection and radiation distribution in the furnace. 16 is a relatively high temperature region, and 17 is a relatively low temperature region. If the thermal conductivity of the heat conduction control plate is low, temperature unevenness hardly occurs at the interface between the surface 5a of the molded plate 5 and the heat conduction control plate 15a, and in this respect, the temperature distribution during firing of the molded plate 5 becomes smaller. Should be able to suppress warpage. However, in reality, the warpage was increased in spite of the fact that the load was applied with the molded plate 5 sandwiched between the heat conduction control plates.

The reason is considered as follows. That is, when the thermal conductivity of the heat conduction control plate is low, as shown in FIG. 5, a part of the heat near the surface 15b of the heat conduction control plate is caused by convection as indicated by the arrow A. Conducted to the inner surface 15a side, a hot spot 16A is generated. This hot spot is considered to affect the shrinkage of the molded plate during firing and cause warping.

In particular, in the case of a ceramic multilayer substrate, the difference in thermal expansion and firing shrinkage between the ceramic molded body 5 and the electrode 4 is large, so that the substrate is liable to be warped. Easy to receive.

On the other hand, when the thermal conductivity Ta of the heat conduction control plate is too high, as shown in FIG. 6, the hot spots on the respective surfaces 15a of the heat conduction control plates 15A and 15B retain almost the same planar pattern. However, it tends to be transferred to the hot spot 18 on the inner surface 15a. As a result, it is considered that the internal deviation of the firing shrinkage increases in the sintering process of the molded plate 5 and causes warping.

On the other hand, according to the invention according to the second aspect, as shown in FIG. 4, since the heat conduction control plate has a reasonably low heat conductivity, the surfaces of the heat conduction control plates 15A and 15B. The hot spot 16 on 15b is difficult to be transferred to the inner surface 15a. Moreover, since the heat conduction control plate has a reasonably high thermal conductivity, hot spots due to convection from the side surface of each heat conduction control plate are less likely to occur, and also from this point, the internal deviation of the firing shrinkage of the molded plate Is less likely to be warped.

In the present invention, the ratio (Ta / Tb) between the thermal conductivity Ta of the thermal conduction control plate and the thermal conductivity Tb of the sintered body is set to 0.01 or more and 50 or less. Ta / Tb is more preferably 45 or less. Alternatively, Ta / Tb is more preferably 0.05 or more.

In the invention according to the first aspect, the body to be fired is not particularly limited, but may be a green sheet laminate, a degreased body thereof, a powder molded body, or a degreased body thereof. In this invention, a clearance gap can be provided between a to-be-fired body main surface and a plate-shaped object. Thereby, the organic substance can be efficiently degreased from the main surface of the body to be fired. Thereby, the whole to-be-fired body can be shrunk uniformly especially in a degreasing process. That is, in the degreasing process, the molded body and the ceramic composition object are in close contact with or in contact with only the organic components contained in the molded body and the ceramic composition object, respectively, and in the sintering process, the ceramic composition object on the surface of the molded body is constrained. You can move freely without This further improves the dimensional accuracy of the sintered body.

The kind of sintered body is not particularly limited, and may be a composite material including ceramics, semiconductors, and ceramics. Examples of ceramics include oxide-based ceramics such as oxides of rare earth elements such as alumina, zirconia, partially stabilized zirconia, titania, silica, magnesia, ferrite, cordierite, and yttria; barium titanate, strontium titanate, titanate Examples include complex oxides such as lead zirconate, rare earth element manganite, rare earth element chromite; nitride ceramics such as aluminum nitride, silicon nitride, and sialon; carbide ceramics such as silicon carbide, boron carbide, and tungsten carbide. . As the semiconductor, Si, MoSi ₂ , WSi ₂ , NbSi ₂ , TaSi ₂ , Nb ₅ Si ₂ , and Ti ₅ Si ₃ can be displayed.
Examples of the composite material include alumina / partially stabilized zirconia and Si / SiC.

Particularly preferably, the sintered body is a porcelain containing a ceramic component and a glass component. In this case, the following composition type porcelain is preferable.
_{BaO-Nd 2 O 3 -Bi 2} O 3 -TiO 2 - glass components _BaO-TiO 2 -ZnO- glass components _{BaO-SiO 2 -Al 2 O 3} -B 2 O 3 -ZnO system - glass component BaO-SiO _{2 -Al 2 O 3 -B 2 O 3} -ZnO-Bi 2 O 3 system - glass component _{BaO-TiO 2 -ZnO-SiO 2} -B 2 O 3
BaO—TiO ₂ —Bi ₂ O ₃ —Nd ₂ O ₃ —ZnO—SiO ₂ —B ₂ O ₃ system + glass component BaO—TiO ₂ —Bi ₂ O ₃ —La ₂ O ₃ —Sm ₂ O ₃ —ZnO— SiO ₂ —B ₂ O ₃ system + glass component MgO—CaO—TiO ₂ —ZnO—Al ₂ O ₃ —SiO ₂ —B ₂ O ₃ —glass component

Although a glass component is not specifically limited, The glass of the following composition systems is preferable.
B ₂ O ₃ -SiO ₂ , ZnO-B ₂ O ₃ -SiO ₂ , Bi ₂ O ₃ -B ₂ O ₃ -SiO ₂ , Bi ₂ O ₃ -ZnO-B ₂ O ₃ -SiO ₂

The porcelain may contain an oxide or a metal component other than the above components. Examples of such oxides and metal components include MgO, CaO, SrO ₂ , Y ₂ O ₃ , V ₂ O ₃ , MnO, Mn ₂ O ₃ , CoO, NiO, Nd ₂ O ₃ , Sm ₂ O ₃ , La ₂ O ₃ , Ag, Cu, Ni, Pd.

The above-mentioned porcelain is often a wiring board used at a high frequency (0.5 GHz or more), and since a circuit such as LCR is formed, the dimensional accuracy directly affects the characteristics, so the dimensional accuracy is important. . Moreover, the ceramic composition as described above is sensitive to temperature in firing shrinkage, warps when fired as it is, and dimensional accuracy is particularly likely to vary.

The firing temperature of the sintered body of the present invention is not particularly limited. When the sintered body is the porcelain, the firing temperature is preferably 1000 ° C. or less.

Next, the ceramic composition object will be described.
The ceramic composition object must contain a binder and not be sintered at a temperature at which the fired body is sintered. This is for preventing the ceramic composition object from adhering to the plate-like body in the firing step. From this viewpoint, the difference between the sintering start temperature of the ceramic composition object and the firing temperature of the sintered body of the present invention is preferably 50 ° C. or higher.

Although the binder which comprises a ceramic composition object is not specifically limited, The following can be illustrated.
Organic binder: for example, ethyl cellulose, PVB, acrylic resin, PVA

Ceramics constituting the ceramic composition body include ceramics such as oxide ceramics such as oxides of rare earth elements such as alumina, zirconia, titania, silica, magnesia, ferrite, cordierite, yttria, etc .; barium titanate, titanium Composite oxides such as strontium oxide, lead zirconate titanate, rare earth manganite, rare earth element chromite; nitride ceramics such as aluminum nitride, silicon nitride, sialon; carbides such as silicon carbide, boron carbide, tungsten carbide Examples thereof include ceramics.

Particularly preferably, the ceramic composition body is a material that does not sinter up to 1000 ° C. Preferably, the ceramic composition object expands smoothly and continuously without having an inflection point of thermal expansion up to the firing temperature of the body to be fired. Thereby, it is possible to prevent unnecessary stress from being applied to the object to be fired when the temperature is increased. Examples of such materials include alumina, zirconia, mullite, cordierite, steatite, magnesia, silica glass, silicon nitride, aluminum nitride, and silicon carbide.

A plate-like body made of a material that is stable at the sintering temperature of the body to be fired is placed on the ceramic composition object. Being stable at the sintering temperature of the body to be fired means that there is substantially no dimensional shrinkage due to sintering and does not chemically react with the ceramic composition object. As such a material, the above-described ceramics can be exemplified.

Preferably, the to-be-fired body contains a green sheet, and particularly preferably, the to-be-fired body is composed of a laminate of green sheets. In this case, the built-in electrode can be easily formed in the body to be fired.

In a preferred embodiment, the body to be fired is provided with an unsintered electrode layer, and in this case, the effect of the invention according to the first aspect is particularly great. This is because if the electrode is included on the surface and / or inside of the body to be fired, the heat conduction becomes complicated and the temperature distribution inside the body during firing tends to be non-uniform. Great effect.

In particular, the effect of the present invention is great when an unsintered electrode layer is present on the surface of the body to be fired. This is because when the plate-like body is placed on the surface of the body to be fired and sintered, the unsintered electrode layer is sintered in close contact with the plate-like body. It becomes difficult to peel off from the body. Moreover, as a result of the unsintered electrode layer being bonded to the plate-like body, the dimensional shrinkage of the fired body is constrained by the plate-like body that does not shrink in the sintering process, resulting in an increase in warpage of the sintered body. . According to the first aspect of the invention, since direct contact between the unsintered electrode layer and the plate-like body can be prevented, warpage due to such restraint of the body to be fired can be prevented.

In the invention according to the first aspect, the ceramic composition object is disposed so as to cover a part of the surface of the body to be fired. At this time, the planar form of the ceramic composition object on the surface of the body to be fired is not particularly limited, but it is preferable that a predetermined pattern is repeated on the surface. As such a form, an arbitrary planar repetitive pattern can be used in addition to the lattice shape and island shape as shown below.

In a preferred embodiment, the body to be fired has a pair of main surfaces, and the ceramic composition object covers 0.5% or more and 60% or less of the total area of at least one main surface of the body to be fired. ing. If this is less than 0.5%, the load is concentrated on a partial region of the surface of the body to be fired, and the firing shrinkage rate of the body to be fired changes in that region, so that the warpage of the sintered body tends to increase. is there. From this viewpoint, the covering area is more preferably 1.0% or more. On the other hand, when the covering area is larger than 60%, scattering of a material from the body to be fired, such as a binder, is suppressed, so that the firing shrinkage rate is reduced and warpage tends to increase. From this viewpoint, the covering area is preferably 60% or less, and more preferably 50% or less.

In a preferred embodiment, the ceramic composition object forms band-like protrusions, and the band-like protrusions form a lattice. In this case, various surface layer electrodes can be formed in each lattice, which is suitable for mass production of a large number of electronic devices.

FIG. 7A shows a sintering member 1A according to this embodiment, and FIG. 7B is a cross-sectional view of the sintering member 1A. The to-be-fired body 5 of the main sintering member 1A has a flat plate shape. Band-shaped protrusions 13a and 13b are formed on one main surface 5a and the other main surface 5b of the to-be-fired body 5, respectively, and the band-shaped protrusions intersect to form ceramic composition objects 13A and 13B having a lattice pattern 13A. It is composed. An unsintered electrode layer 2A is formed in each lattice. In addition, although an unsintered electrode layer can be formed also inside the to-be-fired body 5, illustration was abbreviate | omitted in FIG.

In a preferred embodiment, the width W of the band-shaped protrusion is 0.03 to 2 mm, and the height is 0.01 to 0.25 mm.

If the width W of the band-shaped protrusion is smaller than 0.03 mm, it becomes difficult to stabilize the shape of the ceramic composition object, and a molding defect of the ceramic composition object occurs. As a result, there is a bias in the manner in which the load is applied from the plate-like body to the ceramic composition object, the firing shrinkage of the body to be fired changes, and the warp of the sintered body tends to increase. From this point of view, it is more preferable that the width W of the belt-like protrusion is 0.05 mm or more.

If the width W of the band-shaped protrusion is larger than 2.0 mm, the body to be fired becomes insufficiently degreased, the firing shrinkage rate decreases, and the warp of the sintered body tends to increase. From this point of view, it is preferable that the width W of the belt-like protrusion is 1.5 mm or less.

In a preferred embodiment, the ceramic composition object is an island-like body formed in a state of being separated from each other on the surface of the body to be fired. Here, the island-like body means a protrusion provided in a separated form when seen in a plan view, and there is no particular limitation on the form and size of each protrusion.

Fig.8 (a) shows the member 1B for sintering which concerns on this embodiment, FIG.8 (b) is sectional drawing of the member 1B for sintering. The to-be-fired body 5 of the main sintering member 1B has a flat plate shape. A large number of island-shaped bodies 23A and 23B are formed on one main surface 5a and the other main surface 5b of the body 5 to be fired, respectively, and each island-shaped body 23A and 23B is planar on each main surface. As shown in FIG.

In this embodiment, it is preferred that each island-shaped portion 23A, the area of 23B which is 0.0025 mm ² to 4 mm ^2. If the area of each island-shaped body is smaller than 0.0025 mm ² , it is difficult to form a ceramic composition object, the form and dimensions of each island-shaped body become unstable, the firing shrinkage of the body to be fired changes, and the sintered body There is a tendency for warpage to increase. From this viewpoint, it is preferable that the area of each island-shaped body is 0.0049 mm ² or more.

Moreover, when the area of each island-shaped body exceeds 4 mm < ² >, the scattering removal of materials, such as a binder, from right under an island-shaped body is suppressed at the time of sintering, and the unevenness | contraction of baking shrinkage tends to arise.

Moreover, it is preferable that the height (d in FIG.7 (b) and FIG.8 (b)) of a ceramic composition object is 0.01-0.25 mm. If this is smaller than 0.01 mm, scattering and removal of the material from the surface of the body to be fired will be insufficient, and the firing shrinkage rate will be small. This is particularly a problem when degreasing is performed from the fired body. Moreover, when the electrode is formed in the surface layer part of the ceramic molded body, for example, when it is formed by a screen printing method, the height of the electrode is often about 0.01 mm. For this reason, when the height of the ceramic composition object is less than 0.01 mm, the surface layer electrode comes into contact with the plate-like body, and the surface layer electrode is damaged.

Further, if the height d of the ceramic composition object exceeds 0.25 mm, it becomes difficult to make the shape of the ceramic composition object uniform, and unevenness is particularly likely to occur in the height. As a result, there is a bias in how the load is applied to the body to be fired, and the fired body tends to be distorted and warped.

In the invention according to the second aspect, examples of the ceramic sintered body include those described above. Further, the material of the heat conduction control plate is not particularly limited as long as it matches the limitation of the thermal conductivity in the invention according to the second aspect among the materials of the plate-like body. Moreover, when using a ceramic composition object, it is preferable that the specific structure is as above-mentioned.

Further, from the viewpoint of preventing temperature unevenness on the surface of the heat conduction control plate from being transmitted to the body to be fired, the thickness of the heat conduction control plate is preferably 0.2 mm or more. Moreover, in the invention which concerns on a 1st aspect, it is preferable that a plate-shaped object is a heat conduction control board in the invention which concerns on a 2nd aspect.

The electronic component that is the subject of the present invention is not particularly limited, and examples thereof include a laminated dielectric filter, a multilayer wiring board, a dielectric antenna, a dielectric coupler, a dielectric composite module, and a dielectric / magnetic composite module.

The process itself for producing the porcelain is known per se. Preferably, the raw materials of each component are mixed at a predetermined ratio to obtain a mixed powder, the mixed powder is calcined at 900 to 1300 ° C., and the calcined body is pulverized to obtain a ceramic powder. And preferably, a ceramic sheet and a glass powder made of SiO ₂ , B ₂ O ₃ and ZnO are used to produce a green sheet, the green sheets are laminated, and the fired body 5 is manufactured. Next, according to the present invention, the fired body is degreased and fired.

The metal electrode that can be used in the ceramic multilayer substrate is not limited, but a silver electrode, a copper electrode, a nickel electrode, a palladium electrode or an electrode made of an alloy thereof is preferable, an electrode made of silver or a silver alloy is more preferable, and a silver electrode is particularly preferable. .

[Embodiment of Invention According to First Aspect]
(Manufacture of ceramic powder)
Each powder of barium carbonate, alumina, silicon oxide, zinc oxide, and bismuth oxide is weighed so as to have a predetermined composition and wet mixed. This mixed powder is calcined at 900 ° C. to 1000 ° C. to obtain a calcined body. The calcined powder was pulverized to a predetermined particle size with a ball mill, and the powder was dried to obtain a ceramic powder.

(Manufacture of glass powder)
Each powder of zinc oxide, boron oxide and silicon oxide is weighed and dry-mixed, the mixed powder is melted in a platinum crucible, and the melt is dropped into water to rapidly cool to obtain a massive glass. This glass is wet pulverized to obtain a low-melting glass powder.

(Manufacture of ceramic molded body 5)
Polyvinyl alcohol binder, DOP as a plasticizer, toluene and isopropyl alcohol as a plasticizer are added to the ceramic powder (50% particle size of about 0.5 μm) of the composition system of BaO—Al ₂ O ₃ —SiO ₂ —ZnO—Bi ₂ O ₃ After mixing and defoaming, green sheets were formed with a doctor blade. The thickness of the green sheet is 100 μm. On the green sheet, an electrode paste containing Ag was printed to form unsintered electrode layers 4, 2A, 2B. Twenty green sheets were laminated to obtain a plate-shaped molded body 5 having a total thickness of about 200 μm, a length of about 100 mm, and a width of 100 mm. The thickness of the surface electrode is about 10 μm.

(Forming ceramic composition objects)
100% alumina powder with 50% particle size of about 2 μm
5 parts by weight of ethylcellulose as an organic binder was added to parts by weight to obtain a paste. This was printed on the main surfaces 5a and 5b of the ceramic molded body 5 by screen printing. The specifications of the plate making used for screen printing are mesh: # 200, emulsion: 30 μm. Since the maximum thickness of the layer that can be formed by printing once is about 40 to 50 μm, the layer having a height higher than that was repeatedly printed to increase the thickness. However, the shape is stable until printing is repeated 5 times, but beyond that, the shape becomes unstable.

(Plate-like body 6A, 6B)
A porous alumina plate having a thickness of 2 mm × 100 mm × 100 mm and a weight of about 50 g was used.

(Baking process)
A belt furnace with a maximum temperature of 920 ° C and an air atmosphere, with a heat schedule of 15 hours. Degreasing prior to the firing is not performed.

(Evaluation)
(Firing shrinkage)
After firing, the firing shrinkage of the obtained substrate was determined by measuring the distance between the electrodes on the surface with an image processing apparatus.
(Warpage of substrate) Measured with a surface roughness meter.
(Scratches of electrode on substrate surface) Observation with a stereomicroscope.

(Experiment Nos. 1-37)
Experiments with numbers shown in Tables 1, 2, 3, and 4 were performed. However, the form of the ceramic composition object was a lattice shape as shown in FIG. And the width W, height d, and area ratio of the strip | belt-shaped protrusion which comprises a grating | lattice were changed as shown in Tables 1-4. The results are shown in each table.

In Experiment Nos. 1 to 11 shown in Table 1, the area ratio of the ceramic composition object (band-like protrusion) to the main surface was variously changed. As a result, by setting the area ratio to 0.5% or more and 60% or less, the firing shrinkage rate was almost the target value, and the warpage of the substrate after firing could be reduced. Further, no scratches on the surface electrode were observed.

In Experiment Nos. 12 to 21 shown in Table 2, the widths of the band-shaped protrusions were variously changed. As a result, it was confirmed that by setting the width of the band-shaped protrusions to 0.03 to 2 mm, the firing shrinkage rate could be a target value, and the warpage of the substrate after firing could be suppressed. Further, no scratches on the surface electrode were observed.

In the experiment numbers 22 to 30 shown in Table 3, the height d of the band-shaped protrusions was variously changed. As a result, it was confirmed that by setting the height of the band-shaped projections to 0.01 to 0.25 mm, the firing shrinkage rate can be set as a target value, and the warpage of the substrate after firing can be suppressed.

In the experiment numbers 31-37 shown in Table 4, the area ratio of the ceramic composition object was variously changed. As a result, in the absence of the ceramic composition object, the firing shrinkage ratio deviated from the target value, the warpage of the substrate after firing was large, and the surface electrode was damaged. Results consistent with the above were also obtained in experiment numbers 32-37.

(Experiment numbers 38-65)
Experiments with numbers shown in Tables 5, 6, and 7 were performed. However, the shape of the ceramic composition object was an island shape as shown in FIG. And the area ratio with respect to the main surface of the area of each island-like body, the height, and the whole ceramic composition object was changed as shown in Tables 5-7. The results are shown in each table.

In the experiment numbers 38 to 48 shown in Table 5, the area ratio of the ceramic composition object was variously changed. As a result, by setting the area ratio to 0.5 to 60%, the firing shrinkage rate could be the target value, and the warpage of the substrate after firing could be suppressed. Further, no scratch was observed on the surface electrode.

In the experiment numbers 49-56 shown in Table 6, the area of each island was changed variously. As a result, by a 0.0025 mm ² to 4 mm ² area, can the firing shrinkage ratio and the target value, could suppress warpage of the substrate after firing. Further, no scratch was observed on the surface electrode.

In the experiment numbers 57 to 65 shown in Table 7, the height d of each island-shaped body was variously changed. As a result, by setting d to 0.01 to 0.25 mm, the firing shrinkage rate could be the target value, and the warpage of the substrate after firing could be suppressed. Further, no scratch was observed on the surface electrode.
As described above, according to the present invention, when manufacturing a sintered body such as a ceramic multilayer substrate, the warpage of the sintered body is suppressed, the variation in the firing shrinkage rate is reduced, and the sintering with high dimensional accuracy is performed. The body can be provided.

[Embodiment of Invention of Second Aspect]
(Manufacture of ceramic powder)
Each powder of barium carbonate, alumina, silicon oxide, zinc oxide, and bismuth oxide is weighed so as to have a predetermined composition and wet mixed. This mixed powder is calcined at 9000 to 1000 ° C. to obtain a calcined body. The calcined powder was pulverized to a predetermined particle size with a ball mill, and the powder was dried to obtain a ceramic powder.

(Manufacture of glass powder)
Each powder of zinc oxide, boron oxide and silicon oxide is weighed and dry-mixed, the mixed powder is melted in a platinum crucible, and the melt is dropped into water to rapidly cool to obtain a massive glass. This glass is wet pulverized to obtain a low-melting glass powder.

(Manufacture of ceramic molded body 5)
Polyvinyl alcohol binder, DOP as a plasticizer, toluene and isopropyl alcohol as a plasticizer are added to the ceramic powder (50% particle size of about 0.5 μm) of the composition system of BaO—Al ₂ O ₃ —SiO ₂ —ZnO—Bi ₂ O ₃ After mixing and defoaming, green sheets were formed on a doctor blade. The thickness of the green sheet is 120 μm. An electrode paste containing Ag was printed on this green sheet to form unsintered electrode layers 4, 2A, 2B. Twenty green sheets were laminated and molded using CIP to obtain a flat molded body 5 having a total thickness of about 2400 μm, a length of about 100 mm, and a width of 100 mm. The thickness of the surface electrode is about 10 μm.

Next, the obtained ceramic molded plate 5 was sandwiched between a pair of heat conduction control plates 15A and 15B as shown in FIG. 4, and fired in a belt furnace having a maximum temperature of 920 ° C. and an air atmosphere. The heat schedule is 15 hours. Degreasing prior to the firing is not performed.

Here, the material of the heat conduction control plate was changed as shown in Table 8. The dimensions of the heat conduction control plate are 150 mm long, 150 mm wide, and 1.0 mm thick. Table 8 shows the thermal conductivity (25 ° C.) after firing of the molded body 5 and the thermal conductivity (25 ° C.) of the material of the heat conduction control plate. The resulting sintered body was measured for warpage and firing shrinkage, and the results are shown in Table 8.

As can be seen from this result, by setting the thermal conductivity Ta of the thermal conduction control plate / the thermal conductivity Tb of the sintered body within the range of the present invention, the temperature difference on the back surface of the molded body during firing can be reduced. Moreover, the curvature of a sintered compact can be suppressed and the firing shrinkage rate of a molded object can be made into a target value.

Next, in the same manner as described above, the material of the ceramic molded plate 5 and the material of the heat conduction control plate were changed as shown in Tables 9 to 13, and the same measurement as above was performed.

As can be seen from these results, by setting the thermal conductivity Ta of the thermal conduction control plate / the thermal conductivity Tb of the sintered body within the range of the present invention, the temperature difference on the back surface of the molded body during firing is reduced. In addition, warping of the sintered body can be suppressed, and the firing shrinkage rate of the molded body can be set to the target value.

As described above, according to the present invention, in a ceramic multilayer substrate, warpage of the substrate can be suppressed, variation in the firing shrinkage rate can be reduced, and dimensional accuracy can be improved.

(A) is sectional drawing which shows typically the member 1 for sintering used for baking by this invention, (b) is a cross section which shows the to-be-fired body 5 provided with surface layer electrode 2A, 2B typically. FIG. The state which pinched | interposed the assembly 1 of Fig.1 (a) with a pair of plate-shaped object is shown typically. The state which accommodated the member 1 for sintering in the furnace is shown typically. The temperature unevenness when the ceramic molded plate 5 is sandwiched and fired between the pair of heat conduction control plates 15A and 15B is shown. The temperature unevenness when the ceramic molded plate 5 is sandwiched and fired between the pair of heat conduction control plates 15A and 15B is shown, and the case where the heat conductivity of the heat conduction control plate is low is shown. The temperature unevenness when the ceramic molded plate 5 is sandwiched and fired between the pair of heat conduction control plates 15A and 15B is shown, and the case where the heat conductivity of the heat conduction control plate is high is shown. (A) is a perspective view which shows typically the state which formed the lattice-shaped ceramic composition object 13A, 13B in the main surface of the ceramic forming board 5, (b) is a ceramic forming board and ceramic composition of (a). It is sectional drawing of an object. (A) is a perspective view which shows typically the state which formed the island-shaped ceramic composition object 23A, 23B in the main surface of the ceramic shaping | molding board 5, (b) is a ceramic shaping | molding board and ceramic composition of (a). It is sectional drawing of an object.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1A, 1B Sintering member 2A, 2B Surface electrode 3A, 3B Ceramic composition object 4 Built-in electrode 5 To-be-fired body (ceramic shaping | molding board) 6A, 6B Plate-shaped body 8 Heater 10 Crevice 13A, 13B Lattice-shaped ceramic composition object 13a, 13b Band-shaped protrusion 16 Hot spot on the surface of the heat conduction control plate 18 Hot spot on the inner surface of the heat conduction control plate 23A, 23B Island-shaped body W Width of the band-shaped protrusion d height

Claims (32)

A method for producing a sintered body by firing a body to be fired,
A ceramic composition object containing a binder and not sintered at a temperature at which the fired body sinters is disposed so as to cover a part of the surface of the fired body, and the ceramic composition object is placed on the ceramic composition object. A method for producing a sintered body, comprising: installing a plate-like body made of a material stable at a sintering temperature of the body to be fired, and then firing the body to be fired. The method according to claim 1, wherein the sintered body is a ceramic. The method according to claim 1, wherein the fired body includes a built-in electrode. The method according to claim 1, wherein an unsintered electrode layer is formed on a surface of the object to be fired. The method according to claim 4, wherein a gap is provided between the green electrode layer and the plate-like body. 6. A method according to any one of the preceding claims, characterized in that the ceramic composition body contains a ceramic powder that does not sinter at 1000C. The fired body has a pair of main surfaces, and the ceramic composition object covers 0.5% or more and 60% or less of the total area of at least one main surface of the fired body. 7. A method according to any one of claims 1 to 6, characterized in that 8. A method according to any one of the preceding claims, characterized in that the ceramic composition object has a height of 0.01 to 0.25 mm. 9. A method according to any one of the preceding claims, characterized in that the ceramic composition object forms band-like protrusions, and the band-like protrusions form a lattice. The method according to claim 9, wherein the width of the band-shaped protrusion is 0.03 to 2 mm. The method according to any one of claims 1 to 8, wherein the ceramic composition object is an island formed on the surface in a state of being separated from each other. It characterized in that the area of each island-shaped portions is 0.0025 mm ² to 4 mm ^2, The method of claim 11. The said to-be-fired body has a pair of main surface, and the said ceramic composition object is formed in each main surface, respectively, The Claim 1 characterized by the above-mentioned. Method. The sintered bodies are BaO—Nd ₂ O ₃ —Bi ₂ O ₃ —TiO ₂ —glass based porcelain, BaO—TiO ₂ —ZnO—glass based porcelain and BaO—Al ₂ O ₃ —SiO ₂ —ZnO—Bi _2. The method according to claim 1, wherein the method is one or more ceramics selected from the group consisting of O ₃ -glass-based ceramics. A sintered body obtained by the method according to any one of claims 1 to 14. The sintered body according to claim 15, which is a ceramic multilayer substrate. A sintering member including a body to be fired for use in a firing process,
A ceramic composition object that contains a body to be fired and a binder and that does not sinter at a temperature at which the body to be fired sinters, and the ceramic composition body covers a part of the surface of the body to be fired It is arranged so that it may do. The member for sintering characterized by the above-mentioned. The sintering member according to claim 17, wherein the body to be fired is a body to be fired for ceramics. The sintering member according to claim 17 or 18, wherein the fired body includes a built-in electrode. The sintering member according to any one of claims 17 to 19, wherein an unsintered electrode layer is formed on a surface of the body to be fired. 21. The sintering member according to any one of claims 17 to 20, wherein the ceramic composition body contains ceramic powder that is not sintered at 1000C. The fired body has a pair of main surfaces, and the ceramic composition object covers 0.5% or more and 60% or less of the total area of at least one main surface of the fired body. The sintering member according to any one of claims 17 to 21, characterized in that it is characterized in that The member for sintering according to any one of claims 18 to 22, wherein a height of the ceramic composition object is 0.01 to 0.25 mm. 24. The sintering member according to any one of claims 17 to 23, wherein the ceramic composition object forms a band-shaped protrusion, and the band-shaped protrusion forms a lattice. 25. The member for sintering according to claim 24, wherein a width of the band-shaped protrusion is 0.03 to 2 mm. The member for sintering according to any one of claims 17 to 23, wherein the ceramic composition object is an island-like body formed on the surface in a state of being separated from each other. The area of each island-shaped portion is characterized in that it is a 0.0025 mm ² to 4 mm ^2, sintered member according to claim 26, wherein. The fired bodies are BaO—Nd ₂ O ₃ —Bi ₂ O ₃ —TiO ₂ —glass based porcelain, BaO—TiO ₂ —ZnO—glass based porcelain, and BaO—Al ₂ O ₃ —SiO ₂ —ZnO—Bi _2. O 3 _-, characterized in that an object to be fired for one or more porcelain selected from the group consisting of glass-based ceramics, sintered member according to any one of claims 17 to 27. A method for producing a ceramic multilayer substrate comprising a ceramic sintered body having a built-in electrode,
When obtaining the sintered body by installing a heat conduction control plate on one main surface and the other main surface of the ceramic forming plate and sintering the ceramic forming plate, the heat conduction control plate A method for producing a ceramic multilayer substrate, wherein a ratio (Ta / Tb) of the thermal conductivity Ta of the sintered body and the thermal conductivity Tb of the sintered body is 0.01 or more and 50 or less. A ceramic composition object containing a binder and not sintered at a temperature at which the ceramic molded plate sinters is disposed so as to cover a part of the one main surface of the ceramic molded plate. 30. The method according to claim 29, characterized in that the heat conduction control plate is installed on an object. The sintered bodies are BaO—Nd ₂ O ₃ —Bi ₂ O ₃ —TiO ₂ —glass based porcelain, BaO—TiO ₂ —ZnO—glass based porcelain and BaO—Al ₂ O ₃ —SiO ₂ —ZnO—Bi _2. O 3 _-, characterized in that one or more ceramic selected from the group consisting of glass-based ceramics, claim 29 or 30 a method according. 32. A ceramic multilayer substrate obtained by the method according to any one of claims 29 to 31.

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