JP2005306672A - Method for manufacturing laminated ceramic board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a laminated ceramic board, in which the bend in a thickness direction and the distortions in an external form direction are reduced and the laminated ceramic board having excellent shape and dimensional accuracy is obtained and the method is simple and simplicity of operation is excellent. <P>SOLUTION: At the time of baking a sheet laminate body formed by laminating a plurality of sheets of ceramic green sheets, the gap between a pressing plate arranged above the sheet laminate body and the sheet laminate body is previously opened and the baking of the sheet laminate body is started firstly in the load-free state so that the abutting area of the sheet laminate body and the pressing plate exists at the point of the time of reaching the end of the baking. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a multilayer ceramic substrate, and more particularly to a method for manufacturing a multilayer ceramic substrate formed by stacking and firing a plurality of plate-shaped ceramic green sheets.

  In order to reduce the size of an electronic device, it is effective to reduce the size of an electronic component used in the electronic device and use a substrate having a laminated structure as a circuit substrate for mounting the electronic component. For this reason, multilayer ceramic substrates having various additional structures have been proposed.

  In general, a multilayer ceramic substrate includes a multilayer integrated body composed of a plurality of laminated ceramic sheets. Inside the multilayer integrated body, for example, a number of ceramic sheets extending along a predetermined interface between ceramic sheets. The internal conductor film and some via-hole conductors extending so as to penetrate the predetermined ceramic sheet in the thickness direction are formed. Further, an outer conductor film is also formed on the upper and lower outermost plane portions of the laminated integrated product.

  Such an internal conductor film, via-hole conductor, and external conductor film are configured so as to interconnect circuit elements formed in, for example, a multilayer ceramic substrate, or in a via-hole conductor, penetrate the substrate. It is comprised so that the conduction | electrical_connection between the upper and lower plane parts of a laminated integrated object may be ensured.

  When firing a multilayer ceramic substrate having such an internal conductor film or via-hole conductor, the effects of non-uniformity in the way heat is transferred to the green sheet multilayer ceramic substrate during firing and the temperature distribution that occurs inside the firing furnace Due to the impact, shrinkage of internal electrodes, etc. during the firing process, the influence of the layout of the internal electrodes, etc., during the firing process, warpage in the thickness direction, and distortion of the outer shape, which is usually rectangular, etc. Occur. Since such warpage and distortion directly affect the required dimensional accuracy of the substrate, it is desirable to suppress their generation as much as possible.

  Further, in the information / communication field, transmission information has a high capacity and high frequency for high speed processing, and there is a strong demand for the use of a substrate having excellent electrical characteristics that can be used in the GHz range. Therefore, it is desired that a ceramic substrate such as a low-temperature fired ceramic (hereinafter referred to as LTCC) substrate be a circuit substrate such as a high-frequency substrate. However, a ceramic substrate such as an LTCC substrate is likely to be distorted and warped as compared with a normal ceramic substrate fired at about 1500 ° C. due to the addition of a glass component. Conventionally, in order to suppress the occurrence of distortion and warping, the substrate material is appropriately changed, the inner conductor pattern area in the substrate thickness direction is made as symmetric as possible in terms of electrical characteristics, and conductors with different firing shrinkage rates In order to maintain the required electrical characteristics, the substrate area is not selected, the electrode area is not adjusted symmetrically in the thickness direction of the substrate, and different firing shrinkage ratios are obtained. There has been a demand for a method for suppressing the occurrence of distortion and warpage without combining conductors.

  As conventional techniques for suppressing the occurrence of such warpage and distortion, there are techniques described in Japanese Patent Application Laid-Open Nos. 6-329476 and 2002-290041.

  In JP-A-6-329476, in order to obtain a ceramic substrate with less warpage, unsintered sheets that are not fired at a firing temperature are arranged above and below a laminate of ceramic green sheets to be fired, and these are placed on a setter. It has been proposed that a laminated body of ceramic green sheets is fired in a state where a hard porous body is placed on the upper surface of the uppermost unsintered sheet and a load is applied.

  However, in the above proposal, since the firing is performed in a state where the load is always applied in the thickness direction, the warpage in the thickness direction can be reduced, but the contraction in the outer direction of the width and length of the substrate is hindered. There is a problem that distortion, which is a deformation of the outer shape, easily occurs.

  Also, from the start of sintering until full-scale shrinkage begins, the resin content in the green sheet is not sufficiently scattered (excluded), and the remaining carbon components are generated by subsequent firing in a high temperature range. In addition, there is a risk of occurrence of cracks in the substrate due to swelling or the like.

  In addition, there arises a disadvantage that steps such as installation of an unsintered sheet in a preparation stage before sintering and an operation for removing an equivalent of the unsintered sheet performed after firing become complicated.

  On the other hand, in Japanese Patent Laid-Open No. 2002-290041, a green laminated structure composed of a dielectric and a conductor is used in order to obtain a multilayer ceramic substrate having excellent shape and dimensional accuracy by reducing warpage in the thickness direction and distortion in the external direction. In the firing of a ceramic substrate, it has been proposed that firing is first started with a load applied to the green multilayer ceramic substrate, and then firing is performed while removing the load during the firing process.

  However, even in this proposal, there is a possibility that a load is still applied to the substrate when the substrate continues to contract, and the contraction in the outer direction of the width and length of the substrate may be hindered and distortion may occur. is there.

  In addition, since firing is started with a load applied to the green multilayer ceramic substrate, the resin in the green sheet is sufficiently scattered (excluded) from the start of sintering until full-scale shrinkage begins. However, there is a possibility that the remaining carbon component may be generated or the substrate may be cracked due to swelling or the like due to subsequent firing in a high temperature region.

  In addition, since firing is started with a load applied to the green multilayer ceramic substrate, there is a need for a spread powder, etc., such as the spread of such spread powder and the removal operation of the spread powder performed after firing. Is also inconvenient.

JP-A-6-329476 JP 2002-290041 A

  The present invention was devised based on such actual conditions, and its purpose is to reduce the warpage in the thickness direction and the distortion in the outer direction, and to obtain a multilayer ceramic substrate having excellent shape and dimensional accuracy. Needless to say, an object of the present invention is to provide a method for manufacturing a multilayer ceramic substrate which is a simple method and excellent in the ease of operation.

  In order to solve such problems, the method for producing a multilayer ceramic substrate according to the present invention is such that, when a sheet laminate formed by laminating a plurality of ceramic green sheets is fired, the sheet laminate is first obtained. Leave a gap between the pressure plate and the sheet laminate, and start firing the sheet laminate in a load-free state until the end of firing. It is comprised so that a contact part with a board may exist.

  Further, as a preferred embodiment of the present invention, the press plate has a peripheral edge held by a spacer to make a gap with the sheet laminate, and the spacer is composed of a heat-shrinkable member that shrinks by firing. Is done.

  Moreover, as a preferable aspect of the present invention, the heat shrinkable member constituting the spacer is configured to include a ceramic green sheet in a part thereof.

  Moreover, as a preferable aspect of the present invention, the heat shrinkable member constituting the spacer is made of a ceramic green sheet material.

  Moreover, as a preferable aspect of the present invention, the heat shrinkable member constituting the spacer is composed of the same material as the ceramic green sheet constituting the sheet laminate.

  As a preferred embodiment of the present invention, the pressing plate is composed of a porous plate.

  Moreover, as a preferable aspect of the present invention, the floor plate laid under the sheet laminate is composed of a porous plate.

  Moreover, as a preferable aspect of the present invention, the temperature at the time when the sheet laminate and the pressing plate abut is changed by changing the height setting of the spacer.

  Also, as a preferred embodiment of the present invention, the weight of the pressing plate placed on the spacer is changed, or the number of the pressing plates placed on the spacer is changed, thereby changing the contraction speed of the spacer, and the sheet laminate The temperature at the time when the object and the pressing plate abut is changed.

  Further, as a preferred embodiment of the present invention, the shrinkage rate of the spacer is changed by changing the cross-sectional area of the spacer and the number of the spacers used, and the temperature at the time when the sheet laminate and the pressing plate abut is changed. It is configured to be allowed to.

  Further, in the method for manufacturing a multilayer ceramic substrate of the present invention, there is a contact portion between the sheet laminate and the pressing plate until the end of firing, and the maximum amount of warpage is defined at the contact portion. The load of the pressing plate on the sheet laminate is set so that the maximum amount of warpage falls within the required range of dimensional accuracy.

  In the method for manufacturing a multilayer ceramic substrate of the present invention, when firing a sheet laminate formed by laminating a plurality of ceramic green sheets, a load from above is first applied to the sheet laminate. The firing is started in a load-free state, the temperature is gradually raised, and thereafter, a load from above is applied to the sheet laminate body until reaching a high-temperature holding unit that maintains a constant high temperature.

  As a preferred embodiment of the present invention, when the temperature at the high temperature holding portion in the firing temperature profile is Tp, the temperature band in which the load from the top is applied to the sheet laminate is (0.9 to 1.0). ) It is configured to be Tp.

  The method for producing a multilayer ceramic substrate according to the present invention includes a pressing plate and a sheet that are first disposed above a sheet laminate when firing a sheet laminate formed by laminating a plurality of ceramic green sheets. Leave a gap with the laminate, start firing in a load-free state for the sheet laminate, and there is a contact part between the sheet laminate and the pressure plate until the end of firing. As a matter of course, it is possible to obtain a multilayer ceramic substrate having excellent shape and dimensional accuracy by reducing warpage in the thickness direction and distortion in the outer direction, and by a simple method and simple operation. Also excellent.

  Hereinafter, the best mode for carrying out the method for manufacturing a multilayer ceramic substrate of the present invention will be described in detail with reference to FIGS.

  FIG. 1 is a schematic cross-sectional view (including an apparatus configuration) showing a state before starting firing when manufacturing a multilayer ceramic substrate, and FIG. 2 is a schematic cross-sectional view showing a state after completion of firing when manufacturing a multilayer ceramic substrate ( Device configuration). FIG. 3 is a plan view showing an arrangement example of spacers arranged around the multilayer ceramic substrate, and corresponds to a view taken along the line AA of FIG. FIG. 4 is a schematic perspective view schematically showing an example of the configuration of the multilayer ceramic substrate, and FIG. 5 is a cross-sectional view of the multilayer ceramic substrate shown in FIG.

  A multilayer ceramic substrate 10 illustrated in FIGS. 4 and 5 is obtained by laminating a predetermined number of ceramic green sheets made of, for example, a dielectric 11 mainly composed of a glass component, and firing it at a high temperature to obtain a predetermined dielectric characteristic. It is what I did. A conductor 15 made of, for example, an Ag (silver) electrode is disposed at a predetermined position of a predetermined ceramic green sheet as shown in the figure. These conductors 15 are usually fired simultaneously with the firing of the ceramic green sheet.

  The method for producing the multilayer ceramic substrate 10 of the present invention is characterized by a firing method when firing a sheet laminate 10a formed by laminating a plurality of ceramic green sheets.

  That is, in the method for manufacturing a multilayer ceramic substrate of the present invention, as shown in FIG. 1, first, the gap (gap g) between the pressing plate 51 and the sheet laminate 10a disposed above the sheet laminate 10a is formed. Leave the sheet laminated body 10a to start firing in a load-free state, and act so that the contact portion between the sheet laminated body 10a and the pressing plate 51 exists until the end of firing. It becomes. Hereinafter, each step will be described in detail.

[ Ceramic green sheet preparation process and lamination process ]
First, a plurality of ceramic green sheets serving as the base material of the multilayer ceramic substrate are prepared. Ceramic green sheets, for _{example, SiO 2, B 2 O 3} , Al 2 O 3, MgO, CaO, SrO, La 2 O 3, TiO 2, Bi 2 O 3, Nd 2 O 5, BaO, Nd 2 O 5 , Sb ₂ O ₃ , ZnO and other ceramic materials are mixed with a binder (eg, polyvinyl butyral, acrylic resin), a solvent (eg, toluene, xylene, butanol, etc.), a plasticizer, etc., and mixed thoroughly. A slurry is prepared, and the slurry is cast (coated) on a carrier film such as a PET film by a doctor blade method or the like to form a tape. Usually, this tape molded product is cut into a predetermined size.

  The thickness of such a ceramic green sheet is usually 65 to 245 μm.

  In such a ceramic green sheet, a conductor made of a through-hole conductor, an internal conductor film, or the like is appropriately disposed according to design specifications. These conductors can be formed by, for example, screen-printing a conductive paste after appropriately performing a pre-processing as necessary.

  Next, the sheet laminate 10a is formed by laminating the plurality of ceramic green sheets.

[Pressurization process]
Before placing the sheet laminate of the present invention on a setter, an operation for pressurizing the sheet laminate is usually performed. The operating conditions are, for example, a temperature of 35 to 80 ° C., a pressure of 50 to 100 MPa, and a pressing time of about 5 to 10 minutes.

[Step of setting sheet laminate to setter device (before firing)]
The sheet laminate 10a laminated in this way is set in a setter device as shown in FIG. That is, the setter device has two upper and lower setter plates 51 and 55. For convenience of explanation, the lower setter plate 55 is referred to as a setter placement plate 55 for placing the sheet laminate 10a, and the setter plate 51 located on the upper side is referred to as a setter pressing plate 51.

  These setter plates 51 and 55 are usually composed of a porous (a porosity of about 20 to 50%) alumina sintered body.

  The sheet laminate 10a is placed on the setter placement plate 55 located below the setter device. In the present invention, it is sufficient to place the sheet laminate 10a directly on the setter mounting plate 55, but it is also possible to lay unfired powder proposed in the prior art.

As shown in the embodiment of FIG. 1, spacers 7 are arranged around the sheet laminate 10a to be fired (a plan view of an example of the arrangement is shown in FIG. 3). That is, the initial height h _S0 of the spacer 7 installed on the setter mounting plate 55 is set to be higher than the initial thickness t _G0 of the sheet laminate 10a before firing.

  Therefore, a gap of about 30 to 80 μm is left between the pressing plate 51 (setter pressing plate 51) disposed above the sheet laminate 10a and the upper surface of the sheet laminate 10a (initial gap g Formation). This state is a state before the firing is started (FIG. 1).

  The spacer 7 used in the present invention is composed of a heat shrinkable member that shrinks by a firing operation. This is to achieve the effect of the present invention.

The heat-shrinkable member constituting the spacer 7 is preferably formed by interposing a ceramic green sheet in a part of the spacer 7, a member appropriately selected from general ceramic green sheet materials, or a sheet laminate 10a. It is good to make using the same material as the ceramic green sheet. As a more preferable specific example, a thin sheet (for example, composed of a material having SiO ₂ , B ₂ O ₃ , Al ₂ O ₃ , MgO, CaO, SrO, etc.) is stacked on the sheet laminate 10a. A piece obtained by cutting out a small piece from the pressed substrate as the spacer 7 is used. In this case, the thin sheet portion forms an initial gap g at the start of firing. In addition, by using the same material as the sheet laminate 10a as the spacer material in this way, the economical burden of blending a new spacer material is eliminated, and shrinkage characteristics without load are also obtained. Since (shrinkage behavior) is substantially the same, there is a merit that a design that exhibits the operation of the present invention is relatively easy to perform.

[Baking process of sheet laminate]
Next, the temperature in the firing furnace is raised and firing of the sheet laminate 10a in the state shown in FIG. 1 is started. The temperature operation conditions over time in the firing step are usually (1) a temperature raising section as a first stage in which the temperature is gradually raised from room temperature, and (2) second temperature that maintains a constant high temperature after the temperature rises. It has a high temperature holding section as a stage and (3) a temperature lowering section as a third stage for gradually lowering the held high temperature.

From the start of such a firing step, the sheet laminate 10a and the spacer 7 made of a heat shrink member both start to gradually shrink from a certain temperature, and the initial height h _S0 of the spacer 7 and the sheet laminate 10a The value of the initial thickness t _G0 becomes smaller and smaller. In particular, since the spacer 7 is loaded by the pressing plate 51 (setter pressing plate), the actual contraction speed of the spacer 7 increases rapidly at a certain temperature, and the gap (initial gap) that existed before firing is increased. As shown in FIG. 2, g) is lost or reduced after firing, and as a result, when the series of firing steps is completed, the contact portion between the sheet laminate 10a and the pressing plate 51 is not present. It is configured to exist. Usually, since slight warpage cannot be completely avoided, firing is completed with the pressing plate 51 (setter pressing plate) partially in contact with the sheet laminate 10a.

  In particular, contact between the four corners of the sheet laminate and the pressing plate 51 (setter pressing plate) is often confirmed by warping of the four corners of the sheet laminate 10a.

  That is, it can be said that there is a contact portion between the sheet laminate 10a and the pressing plate 51 until the end of firing, and the maximum amount of warpage is defined at the position of the contact portion. Therefore, for example, the load of the pressing plate 51 on the sheet laminate 10a may be set so that the maximum amount of warpage falls within the required range of dimensional accuracy.

  By the way, in order to further consider the shrinkage process in the present invention, each of the sheet laminate 10a and the spacer 7 made of the heat shrinkable member is either before or after entering the high temperature holding portion as the second stage of firing. The contraction is considered complete. Therefore, in the present invention, at the time when the contraction of the sheet laminate 10a is completed, the contact portion between the sheet laminate 10a and the pressing plate 51 already exists, and finally the firing can be confirmed visually. The contact part of the sheet | seat laminated body 10a and the press plate 51 exists until now.

  In the present invention, the temperature range in which a load is applied to the sheet laminate 10a is (0.9 to 1.0) Tp, more preferably, where Tp is the temperature at the high temperature holding portion in the firing temperature profile, (0.95 to 1.0) Tp, more preferably (0.98 to 1.0) Tp. The temperature Tp in the high temperature holding part is 850 to 930 ° C., and the holding time is 5 minutes to 10 hours.

  Such a suitable temperature range for initiating contact was confirmed by the following method. That is, the inventors measured the dimensional variation rate (%) due to firing for each of the sheet laminate 10a and the spacer 7 (the load of the setter pressing plate is loaded) in advance, and then the temperature. The graph is created by plotting the dimensional variation rate (%) with respect to the sheet, and using this graph, the optimum temperature range for pressing the sheet laminate 10a with the pressing plate 51 (setter pressing plate) (temperature at which both start contact) As a result of an experiment for confirming where this is, an experimental result capable of reducing a good warpage and distortion in the range of (0.9 to 1.0) Tp was obtained.

  In addition, as a method of adjusting the temperature at which both the sheet laminate 10a and the pressing plate 51 (setter pressing plate) start contact, for example, (1) changing the initial height setting of the spacer 7 ( (Synonymous with changing the gap before firing (initial gap g)), (2) changing the weight of the pressing plate 51 placed on the spacer (the number of the pressing plates 51 may be changed), (3) Examples of the method include changing the cross-sectional area and the number used.

  In any case, for the sheet laminate 10a and the spacer 7 (particularly in a state where a load is applied), the dimensional variation rate (%) due to firing is measured for each temperature, and the dimensional variation rate (%) with respect to the temperature. ) Is a very effective work for carrying out the present invention.

Hereinafter, the present invention will be described in more detail with reference to specific examples.
(Example 1)
[ Ceramic green sheet preparation process and lamination process ]
First, 10 ceramic green sheets serving as the base material of the multilayer ceramic substrate were prepared. The ceramic green sheet was blended with ceramic components so that the composition after firing would be the following composition.

Material composition : Al ₂ O ₃ : 44.53 wt%
・ SiO ₂ -B ₂ O ₃ -SrO-MgO-CaO glass: 55.47wt%

  That is, a binder (acrylic resin), a solvent (toluene, alcohol), and a plasticizer (butylphthalyl butyl glycolate) are blended with such a ceramic material, and a slurry is prepared by sufficiently stirring and mixing. Was cast (coated) on a carrier film made of PET film by a doctor blade method to form a tape. The coating thickness was 125 μm.

Then, the tape molding was cut into a size of 118 mm × 106 mm.
A conductor made of a through-hole conductor and an internal conductor film was arranged on such a ceramic green sheet by screen printing a conductive paste as shown in FIG.

A sheet laminate was formed by laminating the 10 ceramic green sheets prepared in this way. Then, as a result of pressurizing the sheet laminate with a pressure of 70 MPa, the initial thickness t _G0 of the sheet laminate was 1000 μm.

[Step of setting sheet laminate to setter device (before firing)]
The sheet laminate thus laminated was set in a setter device as shown in FIG. That is, a sheet laminate is placed on a setter placement plate (alumina sintered body with a porosity of about 40%), while a setter pressing plate (alumina with a porosity of about 40%) located above. The sintered body was held by a spacer so as not to hit the sheet laminate.

The setter pressing plate had a size of 130 mm × 120 mm, and its weight was 40 g. Further, as shown in FIG. 3, the spacers are arranged at 8 locations, and one size thereof is 5 mm × 5 mm, and the initial height h _S0 is 1052 μm (initial gap = 52 μm).

In addition, the spacer material was prepared using a material substantially the same as the ceramic green sheet constituting the sheet laminate. That is, a thin sheet (made of a material containing SiO ₂ , B ₂ O ₃ , Al ₂ O ₃ , MgO, CaO, and SrO, the thickness of which is 65 μm) is stacked on the sheet laminate, and the substrate is pressed as a spacer. What cut out the small piece was used. The thin sheet portion forms an initial gap at the start of firing.

  In addition, in advance, for each of the spacer to which the load from the setter pressing plate is applied and the sheet laminate to be fired, data on the firing furnace set temperature and thickness variation (%) as shown in FIG. I asked for it. In addition, based on this data, in the vicinity of 900 ° C. (corresponding to the temperature near the high temperature holding portion in the firing temperature profile) without inhibiting the shrinkage in the X and Y directions (strain in the external direction) of the sheet laminate. The process in which the sheet laminate and the spacer actually contracted was determined so that the setter pressing plate could start to contact the sheet laminate and have a warp correction effect (see FIG. 7).

[Baking process of sheet laminate]
The temperature in the firing furnace was raised and the sheet laminate was fired in an air atmosphere. In the firing temperature profile, the temperature rising rate at the temperature rising portion was 300 ° C./hr, the temperature Tp at the high temperature holding portion was 900 ° C., and the holding time was 10 minutes. The temperature lowering rate in the temperature lowering section was 600 ° C./hr.
It was confirmed that there was a contact portion between the sheet laminate and the setter pressing plate at the time when such a series of firing steps was completed. With respect to the multilayer ceramic substrate that had been fired, (1) the amount of warpage of the fired substrate and (2) distortion in the outer direction of the fired substrate were measured in the following manner.

(1) About the multilayer ceramic substrate in which the amount of warpage of the fired substrate has been completed, as shown in FIG. 8, each of the three lines in the X direction and the Y direction (line portions (x1, x2, y1, y2 near the four sides) and approximately The amount of warpage, which is the displacement in the thickness direction (from the back to the front of the paper or the front side) along the center line portion (x3, y3)), is determined using a surface shape measuring device (manufactured by Kosaka Laboratory Co., Ltd.). It was. The total number of laminated ceramic substrates used for the measurement was five.

  For comparison, the same measurement was performed on a comparative sample in which the sheet laminate was simply placed on a setter mounting plate and fired without using the correction method of the present invention.

(2) For the multilayer ceramic substrate that has been subjected to strain firing in the external direction of the fired substrate, as shown in FIG. 9, 13 lines (x1,..., X13) in the X direction and 12 lines in the Y direction as shown in FIG. The lengths of (y1,..., Y12) were each measured using a projector device (manufactured by Nikon Corporation). Thereafter, based on these values, the maximum deviation amounts ΔXmax and ΔYmax from both ends were respectively obtained as shown in the figure, and used as linearity values. The smaller the linearity value, the smaller the maximum deviation amounts ΔXmax and ΔYmax, and the smaller the distortion in the outer direction of the fired substrate. The total number of laminated ceramic substrates used for the measurement was five.

  For comparison, the same measurement was performed on a comparative sample in which the sheet laminate was simply placed on a setter mounting plate and fired without using the correction method of the present invention.

  The measurement results regarding the warpage amount of the fired substrate and the distortion in the outer direction of the fired substrate are shown in Table 1 and Table 2, respectively.

  As shown in Table 1, the average warpage amount (average value) of the multilayer ceramic substrate corrected by the method of the present invention is 32 μm or less in both the X direction and the Y direction, and those of the comparative sample (without correction) It can be seen that the effect of reducing warpage is manifested in comparison with.

  The manufacturing method (correcting method) of the present invention is a disadvantageous condition from the viewpoint of suppressing the occurrence of distortion because the contact portion between the sheet laminate and the setter pressing plate is present. It can be said. Nevertheless, as shown in Table 2, it can be said that the linearity of the multilayer ceramic substrate in the present invention is the same level as that of the comparative sample (without correction), and the manufacturing method of the present invention. It can be seen that (correction method) does not promote the generation of distortion.

  Even when the spacer material is changed to a green sheet composition different from that of the ceramic green sheet constituting the sheet laminate, the same excellent effects as those of the present invention shown in Tables 1 and 2 can be exhibited. It could be confirmed.

  The method for producing a multilayer ceramic substrate of the present invention is widely applicable to the ceramic electronic component industry.

It is a schematic sectional drawing (including an apparatus configuration) showing a state before starting firing when manufacturing a multilayer ceramic substrate. It is a schematic sectional drawing (an apparatus structure is included) which shows the state after completion of baking when manufacturing a multilayer ceramic substrate. It is a top view which shows the example of arrangement | positioning of the spacer arrange | positioned around a multilayer ceramic substrate, and is equivalent to the AA arrow line view of FIG. It is the schematic perspective view which showed typically an example of the structure of the laminated ceramic substrate. FIG. 5 is a cross-sectional view of the multilayer ceramic substrate shown in FIG. 4. It is a graph which shows an example of the data of a baking furnace preset temperature and thickness fluctuation | variation (%). It is a graph which shows an example of the process in which a sheet laminated body and a spacer actually shrink. It is a schematic plan view for demonstrating the method to measure the curvature amount of a baking board | substrate about the laminated ceramic board | substrate which baking completed. It is a schematic plan view for demonstrating the method to measure the distortion | strain of the external direction of a baking board | substrate about the laminated ceramic board | substrate which completed baking.

Explanation of symbols

DESCRIPTION OF SYMBOLS 7 ... Spacer 10 ... Multilayer ceramic substrate 10a ... Sheet laminated body 15 ... Conductor 51 ... Setter pressing board 55 ... Setter mounting board g ... Initial gap

Claims (13)

When firing a sheet laminate formed by laminating a plurality of ceramic green sheets,
First, leave a gap between the pressure plate placed above the sheet laminate and the sheet laminate, start firing the sheet laminate in a load-free state, and until the end of firing A method for producing a laminated ceramic substrate, wherein a contact portion between a sheet laminate and a pressing plate is present.   2. The press plate according to claim 1, wherein a height of the pressing plate is held by a spacer in order to leave a gap with the sheet laminate, and the spacer is formed of a heat shrink member that shrinks by firing. A method for producing a multilayer ceramic substrate.   The method for producing a multilayer ceramic substrate according to claim 2, wherein the heat shrinkable member constituting the spacer includes a ceramic green sheet in a part thereof.   The method for manufacturing a multilayer ceramic substrate according to claim 2, wherein the heat shrinkable member constituting the spacer is made of a ceramic green sheet material.   The method for producing a multilayer ceramic substrate according to claim 2, wherein the heat shrinkable member constituting the spacer is made of the same material as the ceramic green sheet constituting the sheet laminate.   The method for manufacturing a multilayer ceramic substrate according to claim 1, wherein the pressing plate is formed of a porous plate.   The method for manufacturing a multilayer ceramic substrate according to any one of claims 1 to 6, wherein a base plate laid under the sheet laminate is composed of a porous plate.   The multilayer ceramic substrate according to any one of claims 2 to 7, wherein a temperature at the time when the sheet laminate and the pressing plate abut is changed by changing a height setting of the spacer. Manufacturing method.   When the weight of the pressing plate placed on the spacer is changed or the number of the pressing plates placed on the spacer is changed to change the contraction speed of the spacer so that the sheet laminate and the pressing plate come into contact with each other The method for producing a multilayer ceramic substrate according to any one of claims 1 to 7, wherein the temperature at the substrate is changed.   2. The temperature at the time when the sheet laminate and the pressing plate come into contact is changed by changing the contraction speed of the spacer by changing the cross-sectional area of the spacer and the number of spacers used. The manufacturing method of the multilayer ceramic substrate in any one of thru | or 7.   There is a contact portion between the sheet laminate and the pressure plate until the end of firing, and the maximum warpage amount is defined at the contact portion, and the maximum warpage amount is required for dimensional accuracy. The method for producing a multilayer ceramic substrate according to any one of claims 1 to 10, wherein a load of the pressing plate on the sheet laminate is set so as to fall within a range. When firing a sheet laminate formed by laminating a plurality of ceramic green sheets,
First, start the firing in a load-free state without applying a load from the top to the sheet laminate, gradually increase the temperature, and then reach the high temperature holding part that maintains a constant high temperature A method for producing a multilayer ceramic substrate, wherein a load is applied to an object from above.   The temperature range in which a load from above is applied to the sheet laminate is (0.9 to 1.0) Tp, where Tp is the temperature at the high temperature holding portion in the firing temperature profile. Manufacturing method of multilayer ceramic substrate.

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