JPH10117024A - Manufacture of ceramic diaphragm structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make small undulation of diaphragm structure after the baking by causing the temperature and contraction rate during the sintering process of a ceramic green base material and ceramic green sheet to satisfy a specific formula and then setting the average sintering temperature difference of the base material expressed by the formula to be larger than 0. SOLUTION: A ceramic green base material and a ceramic green sheet satisfy the formulae I to III (wherein S (base material) and S (sheet) express respectively the contraction rate (%) of the base material and sheet, while T70 (base material) and T70 (sheet) respectively indicate the temperature ( deg.C) during the sintering process of the base material and sheet) and sets the average sintering temperature difference of the ceramic green base material expressed by the formula IV (where N indicates the number of layers forming the base material and T70 (base material)n indicates the sintering temperature of the nth layer from the lowest layer among the layers forming the base material when the side where the sheet is stacked in the integrated stacked layer substrate is placed in the upper side) to the value larger than 0.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for manufacturing a ceramic diaphragm structure used as a constituent member of various sensors, piezoelectric / electrostrictive actuators, and the like.

[0002]

2. Description of the Related Art What is a ceramic diaphragm structure?
This is a structure in which a thin diaphragm plate having flexibility is attached to a base having at least one window portion so as to cover the window portion to form a diaphragm. Such a ceramic diaphragm structure is used for various sensors by configuring the diaphragm portion to detect a bending displacement received from an object to be measured by an appropriate detecting means, and the diaphragm portion has a piezoelectric / electrostrictive element. By applying pressure to a pressurized chamber formed therein, the piezoelectric / electrostrictive actuator is used as a component of a piezoelectric / electrostrictive actuator.

[0003] The ceramic diaphragm structure is formed by integrally attaching a thin ceramic green sheet (hereinafter, referred to as a green sheet) to a ceramic green substrate (hereinafter, referred to as a green substrate) and then performing firing. After being manufactured and fired, the green substrate becomes a substrate and the green sheet becomes a diaphragm plate. However, in recent years, in order to prevent cracks and dents from occurring in the diaphragm during the firing process, the diaphragm 1 has a convex shape in a direction opposite to the window 8 provided in the base 2 as shown in FIG. A ceramic diaphragm structure 3 formed so as to be used is used. By making the diaphragm portion 1 convex as described above, the natural resonance frequency can be increased as compared with the case where the diaphragm portion 1 has a flat shape. Further, it has been recognized that the diaphragm portion 1 has excellent mechanical strength, and has advantages such as not hindering sintering of various films formed on the surface thereof.

When a ceramic diaphragm structure having such a convex diaphragm portion is manufactured, the following formula (A) is used for a green substrate and a green sheet.
(B) and (c); (b) S (substrate) −S (sheet) ≧ −0.08 ｛T
₇₀ (substrate) -T ₇₀ (sheet)} - 1 (b) 0 ≦ T ₇₀ (substrate) -T ₇₀ (sheet) ≦ 300 (c) S (substrate) -S (sheet) ≦ 20 (where, S ( Substrate) and S (sheet) represent the shrinkage (%) of the green substrate and the green sheet, respectively.
T ₇₀ (substrate) and T ₇₀ (sheet) represent the sintering temperature of the green substrate and green sheet, respectively. 2), that is, a material in a range shown by oblique lines in FIG. 2, so that a crack or the like does not occur in the diaphragm portion, and the green sheet is provided in the direction opposite to the window portion provided on the base during firing. Japanese Patent Application Laid-Open No. 8-51238 discloses that the projection can be made to project in a convex shape. That is, by providing a predetermined difference between the shrinkage ratio and the sintering temperature between the green base and the green sheet, a convex-shaped thin portion can be formed.

The shrinkage rate (%) refers to the shrinkage rate (%) of the length in the plane direction when the green substrate and the green sheet are fired independently at the same temperature as when they are fired integrally. And the shrinkage ratio of the length in the plane direction is represented by {(length before firing−length after firing) / length before firing} × 100 (%), where the plane direction is the thickness direction. Instead, it indicates a predetermined direction on the surface on which the green substrate or green sheet is formed. The sintering temperature is defined as the shrinkage rate, S (base) and S (sheet) of 70 during the firing process.
% And is a measure of the sintering rate.

[0006]

However, the method disclosed in Japanese Patent Application Laid-Open No. 8-51238 discloses that the shrinkage ratio and the sintering temperature of the green substrate are uniform from the vicinity of the green sheet to the remote part. Assumed,
In this method, there is a problem that the undulation of the diaphragm structure 3 is increased, and the entire ceramic substrate 15 including the diaphragm structure is warped. Here, as shown in FIGS. 5 and 7, a ceramic diaphragm structure 3 is constituted by the base 2 and the diaphragm portion 1, and a plurality of the ceramic diaphragm structures 3 are collected to constitute a ceramic substrate 15. I have.

[0007] It is difficult to sufficiently correct the above-mentioned warpage or undulation even if a load is loaded and refiring is performed. If the correction load is increased, the diaphragm portion 1 and the base 2 are damaged. In addition, if warpage or undulation is left, the dimensional accuracy of the diaphragm structure 3 is reduced, so that the accuracy in printing a pattern on the diaphragm plate is reduced or the film thickness is varied. In this case, when the variation in the detection accuracy is used for a piezoelectric / electrostrictive actuator, the displacement amount is reduced or varied.

[0008] Accordingly, the present invention provides a process for firing,
The diaphragm portion can be formed so as to have a convex shape in a direction opposite to the window portion provided in the base, and the undulation after firing of the diaphragm structure and / or the warpage after firing of the ceramic substrate including the same are advantageous. It is an object of the present invention to provide a method for manufacturing a ceramic diaphragm structure that can be reduced in size.

[0009]

That is, according to the present invention, a green substrate having one or more windows and comprising one or more layers is provided on a green substrate comprising one or more layers. The ceramic diaphragm is formed such that the green sheet is laminated so as to cover the window portion to form an integral laminate, and then fired, so that the diaphragm portion has a convex shape in a direction opposite to the window portion. A method for manufacturing a structure, wherein the green substrate and the green sheet are formed by the following formulas (A), (B) and (C); (A) S (substrate) -S (sheet) ≧ −0.08 ｛ T
₇₀ (substrate) -T ₇₀ (sheet)} - 1 (b) 0 ≦ T ₇₀ (substrate) -T ₇₀ (sheet) ≦ 300 (c) S (substrate) -S (sheet) ≦ 20 (wherein, S (Substrate) and S (sheet) represent the shrinkage (%) of the green substrate and green sheet, respectively.
T ₇₀ (substrate) and T ₇₀ (sheet) represent the sintering temperature (° C.) of the green substrate and the green sheet, respectively. Satisfies the following formula (d);

[0010]

(Equation 5)

(Wherein, N represents the number of layers constituting the green substrate, and T ₇₀ (substrate) _n represents the layer constituting the green substrate when the side on which the green sheets are laminated is the upper side in the above-mentioned integrated laminate) Among them, the sintering temperature (° C.) of the n-th layer from the lowermost layer is represented, and t _n and t _{n + 1} are respectively measured from the lower surface and the upper surface of the n-th layer after firing the integrated laminate. (The distance to the neutral line of the substrate is indicated by a minus sign for a surface located below the neutral line, and a + sign is given for a surface located above the neutral line.)
The manufacturing method of the ceramic diaphragm structure whose average sintering temperature difference of the green base represented by these is larger than 0 is provided.

According to the present invention, a thin green sheet having one or more layers is provided on a green substrate having one or more windows and having one or more layers. A method for manufacturing a ceramic diaphragm structure in which the diaphragm is formed so as to be convex toward the opposite direction to the window by firing after laminating so as to cover the window to form an integrated laminate, followed by firing. The green substrate and the green sheet are represented by the following formula (A):
(B) and (c); (b) S (substrate) −S (sheet) ≧ −0.08 ｛T
₇₀ (substrate) -T ₇₀ (sheet)} - 1 (b) 0 ≦ T ₇₀ (substrate) -T ₇₀ (sheet) ≦ 300 (c) S (substrate) -S (sheet) ≦ 20 (wherein, S (Substrate) and S (sheet) represent the shrinkage (%) of the green substrate and green sheet, respectively.
T ₇₀ (substrate) and T ₇₀ (sheet) represent the sintering temperature (° C.) of the green substrate and the green sheet, respectively. ), And the following formula (e);

[0013]

(Equation 6)

(Wherein, N represents the number of layers constituting the green substrate, and S (substrate) _n represents the number of layers constituting the green substrate when the side on which the green sheets are laminated in the integrated laminate is faced up. among them, contraction of the n th layer from the bottom layer represents (%), t _n and t _{n + 1,} respectively, a neutral substrate from the lower surface and the upper surface of the n-th layer after firing the integral laminate The distance to the line is indicated by a minus sign for a surface located below the neutral line and a + sign for a surface located above the neutral line.) The present invention provides a method for producing a ceramic diaphragm structure having a difference in average shrinkage of a green substrate larger than 0.

In the method for manufacturing a ceramic diaphragm structure, the following formula (f):

[0016]

(Equation 7)

[0017] (wherein, M is among the layers constituting the substrate in the after firing the integral laminate, represents the number of layers located below the neutral line, A _n is firing the integral laminate Of the layers constituting the substrate after the above, represents the thickness of the n-th layer from the bottom layer, while the M-th layer from the bottom layer represents the thickness from the lower surface of the layer to the neutral line,
T ₇₀ (substrate) _n represents the above-mentioned meaning, and A represents the distance from the lower surface of the lowermost layer of the substrate to the neutral line after firing the above-mentioned integrated laminate. ), The sintering temperature (° C.) of the green substrate below the neutral line of the substrate is expressed by the following formula (G);

[0018]

(Equation 8)

(In the formula, L represents the number of layers constituting the green sheet, and T ₇₀ (sheet) _n represents the layer constituting the green sheet when the side on which the green sheet is laminated faces upward in the integrated laminate. represents sintering developing temperature of the n-th layer from the bottom layer (℃) of, B _n is definitive after firing the integrated laminate, the layers constituting the diaphragm plate, the bottom layer of the n-th layer Represents the thickness, and B represents the thickness of the diaphragm plate).

The green sheet has an average particle size of 0.1.
It is preferable to use a material which is partially stabilized zirconia, fully stabilized zirconia or alumina, or a mixture thereof, or a material which becomes these materials after firing.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the following formulas (a), (b) and (c); (a) S (substrate) -S (sheet) ≧ −0.08 ｛T
₇₀ (substrate) -T ₇₀ (sheet)} - 1 (b) 0 ≦ T ₇₀ (substrate) -T ₇₀ (sheet) ≦ 300 (c) S (substrate) -S (sheet) ≦ 20 (symbols in the formula Means the above-mentioned meaning.) A ceramic diaphragm structure is manufactured using a green substrate and a green sheet having a shrinkage ratio and a sintering temperature that satisfy the following conditions.

[0022]

(Equation 9)

The average sintering temperature difference represented by the formula is greater than 0, or the following formula (e);

[0024]

(Equation 10)

A substrate having a difference in average shrinkage ratio larger than 0 is used.

In the formula (D), N represents the number of layers constituting the green substrate. Further, T ₇₀ (substrate) _n is the n-th layer from the lowest layer among the layers constituting the green substrate when the side on which the green sheets are laminated in the monolithic laminate is faced up as shown in FIG. The sintering temperature (° C.) is represented by t _n and t _{n + 1} , respectively, and the neutral line 5 is the distance from the lower surface and the upper surface of the n-th layer after firing of the integrated laminate to the neutral line of the substrate. The surface located below is indicated by a minus sign, and the surface located above the neutral line 5 is indicated by a plus sign. Here, the neutral line 5 refers to a line connecting the midpoints of the distance from the lower surface of the lowermost layer 4 to the upper surface of the Nth layer 6 after firing the integrated laminate. In the formula (E), S (substrate) _n represents the shrinkage rate (%) of the n-th layer from the bottom layer when the side on which the green sheets are laminated is the top in the integrated laminate.

In the formula (A), S (substrate) is represented by the following formula (H):

[0028]

[Equation 11]

(Wherein N and S (substrate) _n represent the above-mentioned meanings, C _n represents the thickness of the n-th layer from the bottom layer after firing the integrated laminate, and C represents the thickness of the integrated laminate. T represents the thickness of the substrate after firing.)
₇₀ (substrate):

[0030]

(Equation 12)

(Wherein, N, T ₇₀ (substrate) _n , C _n and C represent the above-mentioned meanings). When the green sheet is composed of a plurality of layers, S (sheet) and T ₇₀ (sheet) are calculated in the same manner.

Therefore, according to the method of the present invention, the influence of the temperature during the sintering of the green substrate and the shrinkage rate on the green sheet is adjusted in consideration of the change due to the distance from the green sheet, that is, The green base is composed of a plurality of layers having different sintering temperatures and shrinkage rates, and by adjusting those values, the diaphragm part becomes convex toward the opposite direction to the window provided in the base body, and the diaphragm structure is formed. The undulation after firing of the body and / or the warping after firing of the ceramic substrate containing the same can be advantageously reduced.

Specifically, for example, in the fired material substrate 7 shown in FIG. 4, the average sintering temperature difference and the average shrinkage ratio difference are:
It is calculated as follows by the equations (d) and (e), respectively.

[0034]

(Equation 13)

[0035]

[Equation 14]

In the formula, T _{1 to} T ₆ and S _{1 to} S ₆ are
Each represents the sintering temperature and shrinkage ratio of the n-th layer.
All the other layers have a thickness of 100 μm after firing, except that the fifth layer has a thickness of 200 μm after firing.

When bonding the layers constituting the green substrate, an adhesive layer may be provided between the layers. In such a case, the above calculation is performed by treating the adhesive layer as the substrate layer. The sintering temperature of the green substrate below the neutral line is preferably higher than the sintering temperature of the green sheet, since the formation stability of the convex shape is improved.

In the present invention, the sintering temperature (° C.) of the green substrate below the neutral line after firing is higher than the sintering temperature (° C.) of the green sheet. It is preferable from the viewpoint of improving the formation stability.

Here, the sintering temperature (° C.) of the green base in the lower part from the neutral line of the base after firing is represented by the following formula (f):

[0040]

(Equation 15)

[0041] (wherein, M is among the layers constituting the substrate in the after firing the integrated laminate, represents the number of layers positioned below a neutral line, A _n is definitive after firing the integral laminate Of the layers constituting the base, the thickness of the n-th layer from the bottom layer is represented, and the thickness of the M-th layer from the bottom layer is the thickness from the lower surface of the layer to the neutral line, and T ₇₀ (base) _n is A represents the above-mentioned meaning, and A represents the distance from the lower surface of the lowermost layer of the substrate to the neutral line after firing the integrated laminate.) The sintering temperature (° C.) of the green sheet is represented by the following formula: (G);

[0042]

(Equation 16)

(In the formula, L represents the number of layers constituting the green sheet, and T ₇₀ (sheet) _n represents the layer constituting the green sheet when the side on which the green sheet is laminated in the integrated laminate is faced up. Represents the sintering temperature (° C.) of the n-th layer from the bottom layer, and B _n is the thickness of the n-th layer from the bottom layer among the layers constituting the diaphragm plate after firing the integrated laminate. And B represents the thickness of the diaphragm plate.)

In the present invention, the ceramic diaphragm structure is manufactured using a green substrate and a green sheet satisfying the above-mentioned conditions. Specifically, for example, it is manufactured as follows.

First, a green substrate and a green sheet are formed. These include mullite, beryllia, spinel, titania, aluminum nitride, silicon nitride, stabilized zirconia, partially stabilized zirconia, alumina, or a mixed material thereof. Alternatively, a material that becomes the above-described material after firing may be used.

In particular, as the material of the green sheet, it is preferable to use partially stabilized zirconia, fully stabilized zirconia or alumina, or a mixture thereof, or a material which becomes these materials after firing.
More preferably, the present inventors have disclosed in
By adding a compound such as yttrium oxide disclosed in JP-A-09912, etc., the crystal phase is partially stabilized as a tetragonal crystal or a mixed crystal composed of two or more of cubic, tetragonal and monoclinic crystals. A material containing zirconia as a main component is used.

As the material of the green substrate, it is preferable to use the same material as the green sheet from the viewpoint of integrally forming the green substrate and the green sheet. In addition, ceramic materials such as glass ceramics and cordierite are used. May be used.

The green sheet may be in the form of a powder having an average particle diameter of 0.05 to 1.0 μm, such as partially stabilized zirconia, fully stabilized zirconia, alumina or any of these, in view of the mechanical strength of the diaphragm. It is preferable to use a material containing a mixture as a main component or a material which becomes such a material after firing.

Also, the thickness of the diaphragm plate of the ceramic diaphragm structure is preferably 30 μm or less, more preferably 3 to 20 μm. In addition, the denseness is preferably 90% or more in terms of relative density (bulk density / theoretical density) from the viewpoint of strength, Young's modulus, and the like, more preferably 95% or more, and 98% or more. Is more preferable.

On the other hand, the thickness of the substrate is not particularly limited.
It is appropriately determined according to the purpose of use of the diaphragm structure. However, in order to further enhance the effects of the present invention, it is preferable that the total thickness of the substrate is 50 μm or more.

The green substrate and the green sheet are prepared by mixing a slurry or paste prepared by blending the above materials with an appropriate binder, a plasticizer, a dispersant, a sintering aid, an organic solvent and the like, by a doctor blade method, a calendar method, and the like. , Printing method, a component obtained by molding by a conventionally known method such as a reverse roll coater method, if necessary, cutting, cutting, punching and the like after processing, by laminating, by forming a predetermined shape and It is obtained by making it a predetermined thickness.

Next, an integrated laminate is prepared by overlapping the green substrate and the green sheet. The green sheet is laminated on the green substrate so as to cover the window of the green substrate, and is formed into an integrated laminate by thermocompression bonding or the like.

Finally, the laminate is fired,
A ceramic diaphragm structure is obtained in which the diaphragm protrudes in a convex shape in the direction opposite to the window provided in the base.
The firing temperature is preferably from 1200 to 1700 ° C, more preferably from 1300 to 1600 ° C.

[0054]

EXAMPLES Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

(Example 1) By using the manufacturing method of the present invention, the base is composed of two layers so as to satisfy the above-mentioned formulas (a), (b) and (c) and to satisfy the formula (d). A ceramic diaphragm structure was manufactured. 6. 100 parts by weight of partially stabilized zirconia powder (containing 0.1 to 0.5% of alumina) having an average particle diameter in a range of 0.4 to 1.0 μm, and polyvinyl butyral resin as a binder.
6 parts by weight, 3.8 parts by weight of dioctyl phthalate as a plasticizer, and 1: a mixture of toluene and 2-propanol as a solvent.
1 (volume ratio) of the mixture was 80 parts by weight and, if necessary, a sorbitan fatty acid ester of 0 to 2.0 was added as a dispersant.
The parts by weight were mixed in a ball mill for 5 to 50 hours to prepare a slurry. This slurry was defoamed, and the viscosity was adjusted so as to be 2000 cps for the green sheet and 20,000 cps for the green substrate.

The above slurry was formed into a predetermined shape by a doctor blade method to obtain each layer constituting a green substrate. Green sheets were formed by a reverse roll coater method.

The shrinkage rate decreases as the mixing time in the ball mill increases and as the amount of the dispersant added increases.
The sintering temperature, the longer the mixing time in the ball mill,
Also, the higher the alumina content, the lower the powder particle size becomes smaller, but by controlling these factors,
The shrinkage of the green substrate was adjusted to 20.76%, and the shrinkage of the green sheet was adjusted to 21.50%.

Further, the first layer of the green substrate (the n-th layer from the bottom when the ceramic diaphragm structure is arranged so that the diaphragm plate is on the top) is referred to as the n-th layer. ) At 1310 ° C
Then, the sintering temperature of the second layer of the green substrate is set to 1330 ° C.
Then, the sintering temperature of the green sheet was adjusted to 1272 ° C.

By superposing the above layers, 2
A green substrate composed of layers is manufactured, and the green sheets are further laminated and heat-pressed at 100 ° C. and 200 kg / cm ² for 1 minute to form an integrated laminate at 1500 ° C.
By firing for 3 hours, three windows 8 shown in FIG.
A ceramic substrate on which four diaphragm structures 3 each having the above-mentioned structure were disposed was manufactured. Each window portion 8, that is, the diaphragm portion 1
Is a rectangular shape of 0.5 × 0.7 mm, and the interval between the windows 8 is 0.3 m along the side of 0.5 mm.
m. The first layer 9 of the base 2 was provided with a hole 10 having a diameter of 0.2 mm communicating with each window 8. The base 2 had a thickness of 100 μm for both the first layer 9 and the second layer 11, and the diaphragm plate 12 had a thickness of 10 μm.

With respect to the above-mentioned diaphragm structure, whether or not the diaphragm portion had a convex shape, and the magnitude of the undulation after firing of the diaphragm structure and / or the degree of warpage after firing of the ceramic substrate including the same were evaluated. Table 1 shows the results. Table 1 shows the formulas (d), (e),
(H), (d) and (f), the average sintering temperature difference and average shrinkage difference of the green substrate calculated respectively, and the sintering temperature (T ₇₀ (substrate)) and shrinkage ratio of the entire green substrate (S (substrate)) and the sintering temperature at the lower side of the neutral line of the green substrate are also shown. In calculating these values, the sintering temperature (T ₇₀ (substrate) _n ) and shrinkage ratio (S (substrate) _n ) of each layer of the green substrate were determined to be 10 × 10 mm composed of the sheets constituting each layer. The value measured independently using the measurement sample of No. was used. These values are also shown in Table 1.

(Examples 2 to 8) In the same manner as in Example 1 except that the sintering temperature and the shrinkage rate of each layer constituting the green substrate were set to values different from those in Example 1, the above-mentioned formula (I) was used. ), (B) and (c), and the formula (d)
Alternatively, a ceramic substrate which satisfies at least one of (e) and in which four ceramic diaphragm structures each having a two-layer base were arranged was manufactured. However, Examples 4 and 8
In the above, the sintering temperature and shrinkage rate of the green sheet were 1262 ° C. and 21.38%, respectively.

With respect to the above-mentioned diaphragm structure, whether or not the diaphragm portion had a convex shape and the magnitude of the undulation after firing of the diaphragm structure and / or the degree of warpage after firing of the ceramic substrate including the same were evaluated. Table 1 shows the results. Table 1 also shows calculated values such as the sintering temperature and shrinkage rate of each layer constituting the green base and the average sintering temperature difference of the green base calculated based on the above formula.

[0063]

[Table 1]

(Comparative Examples 1 to 6)
(B) and (c) or formulas (b) and (c) are satisfied,
A ceramic diaphragm structure not satisfying any of the formulas (d) and (e) or the formulas (a), (d) and (e) was manufactured. Except that the sintering temperature and shrinkage rate of each layer constituting the green base were set to values different from those in Example 1, the point that the base was composed of two layers, the manufacturing method, and the like were the same as in Example 1.
Is the same as The sintering temperature and shrinkage rate of the green sheet were each 127 degrees in the same manner as in Example 1.
2 ° C. and 21.50%.

With respect to the above-mentioned diaphragm structure, whether or not the diaphragm portion had a convex shape, and the magnitude of the undulation after firing of the diaphragm structure and / or the degree of warpage after firing of the ceramic substrate including the same were evaluated. Table 2 shows the results. Table 2 also shows calculated values such as the sintering temperature and shrinkage rate of each layer constituting the green base and the average sintering temperature difference of the green base calculated based on the above equation.

[0066]

[Table 2]

(Embodiment 9) Using the manufacturing method of the present invention, the above formulas (a), (b) and (c) should be satisfied, and at the same time both formulas (d) and (e) should be satisfied. A ceramic diaphragm structure having five substrates was manufactured.

100 parts by weight of alumina powder having an average particle diameter in the range of 0.2 to 0.8 μm, 11 parts by weight of polyvinyl butyral resin as a binder, 5.5 parts by weight of dioctyl phthalate as a plasticizer, solvent 110 parts by weight of a 1: 1 (volume ratio) mixture of toluene and 2-propanol, and if necessary, 0 to 3.0 parts by weight of a sorbitan fatty acid ester as a dispersant, for 5 to 50 hours by a ball mill By mixing, a slurry was prepared. This slurry is defoamed, and for green sheets, 2000 c
20,000 cp for green substrate
The viscosity was adjusted so as to be s, and each layer constituting the green substrate and the green sheet were formed in the same manner as in Example 1.

By controlling the same factors as in Example 1, the shrinkage ratio of the green sheet was adjusted to 21.40%, and the sintering temperature was adjusted to 1270 ° C. On the other hand, the shrinkage ratio of the green substrate is 20.50%, 20.63% in order from the first layer.
%, 20.59%, 20.38% and 20.79%
The sintering temperature is set to 1310 ° C. and 1340 in order from the first layer.
° C, 1330 ° C, 1360 ° C and 1330 ° C.

After the above-described layers are superimposed to form a green substrate composed of five layers, green sheets are further superimposed and subjected to a heat and pressure treatment at 100 ° C. and 200 kg / cm ² for 1 minute to form an integrated laminate. By firing for 3 hours, a diaphragm structure 3 having three windows 8 shown in FIG. 6 was manufactured. Each of the windows 8, that is, the shape of the diaphragm 1 was a rectangular shape of 0.8 × 1.2 mm, and the interval between the windows 8 was 0.5 mm along the 0.8 mm side. Further, the fourth layer and the second layer of the base 2 had the same shape as the fifth layer, and the first layer and the third layer were provided with holes 10 having a diameter of 0.2 mm communicating with the respective window portions 8. Substrate 2
Has a thickness of 200 μm for the first layer, 250 μm for the second layer,
The third layer was 100 μm, the fourth layer was 50 μm, and the fifth layer was 100 μm. Further, the thickness of the diaphragm plate 12 was set to 20 μm.

With respect to the above-mentioned diaphragm structure, whether or not the diaphragm portion had a convex shape and the magnitude of the undulation after firing of the diaphragm structure and / or the degree of warpage after firing of the ceramic substrate including the same were evaluated. Table 3 shows the results. Table 3 shows the average sintering temperature difference and the average shrinkage difference of the green substrate calculated based on the above equation, the sintering temperature and the shrinkage ratio of the entire green substrate, and the value of the green substrate below the neutral line. The sintering temperature is also shown.

Example 10 In the same manner as in Example 9, except that the sintering temperature and the shrinkage rate of each layer constituting the green base were set to values different from those in Example 9, the above-mentioned formula (A) was used. While satisfying (b) and (c), the formula (d)
And a ceramic diaphragm structure having five layers of the substrate was manufactured. The green sheet sintering temperature and shrinkage were 1260 ° C. and 21.30%, respectively.
And

With respect to the above-mentioned diaphragm structure, it was evaluated whether or not the diaphragm portion had a convex shape, and the undulation after firing of the diaphragm structure and / or the degree of warpage after firing of the ceramic substrate including the same. Table 3 shows the results. Table 3 also shows calculated values such as the sintering temperature and shrinkage rate of each layer constituting the green base and the average sintering temperature difference of the green base calculated based on the above formula.

Comparative Example 7 A ceramic diaphragm structure that satisfies the above-mentioned formulas (a), (b) and (c) but does not satisfy any of the formulas (d) and (e) was manufactured.
Except that the sintering temperature and the shrinkage rate of each layer constituting the green base were set to values different from those of the ninth embodiment, the base was composed of five layers, and the manufacturing method was the same as that of the ninth embodiment. The sintering temperature and shrinkage rate of the slurry used for manufacturing the green sheet were also set to 1270 ° C. and 21.40%, respectively, as in Example 9.

With respect to the above-mentioned diaphragm structure, it was evaluated whether or not the diaphragm portion had a convex shape, and the degree of the undulation after firing of the diaphragm structure and / or the degree of warpage after firing of the ceramic substrate including the same. Table 3 shows the results. Table 3 also shows calculated values such as the sintering temperature and shrinkage rate of each layer constituting the green base and the average sintering temperature difference of the green base calculated based on the above formula.

[0076]

[Table 3]

In the examples, the diaphragm portions were all convex, and the degree of undulation after firing of the diaphragm structure and / or the degree of warpage generated after firing of the ceramic substrate containing the same was small, but in the comparative example, In some cases, the diaphragm portion did not have a convex shape. Even in the case of the convex portion, the degree of undulation after firing of the diaphragm structure and / or the degree of warpage generated after firing of the ceramic substrate containing the same was large.

[0078]

In the manufacturing method of the present invention, the sintering temperature and the shrinkage rate of the green substrate and the green sheet are controlled so as to satisfy a predetermined formula. Can be adjusted in consideration of the change of the influence of the green sheet on the distance from the green sheet, and as a result, the diaphragm portion has a convex shape in the direction opposite to the window provided on the base, and the diaphragm structure After firing and / or warpage after firing of a ceramic substrate containing the same can be advantageously reduced. Therefore, when the diaphragm structure is used for the sensor, variation in detection accuracy can be prevented,
When used for a piezoelectric / electrostrictive actuator, it is possible to prevent a decrease or variation in the amount of displacement.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of a ceramic diaphragm structure having a convex diaphragm portion.

FIG. 2 is a graph showing a range of values that a shrinkage ratio and a sintering temperature of a green substrate and a green sheet should take in order to make a diaphragm portion convex.

FIG. 3 is a cross-sectional view showing another example of a ceramic diaphragm structure having a convex diaphragm portion.

FIG. 4 is a partial cross-sectional view showing one example of a ceramic base body after firing an integrated laminate composed of a plurality of layers.

FIG. 5 is a cross-sectional view showing still another example of a ceramic diaphragm structure having a convex diaphragm portion.

FIG. 6 is a cross-sectional view showing still another example of a ceramic diaphragm structure having a convex diaphragm portion.

FIG. 7 is a perspective view showing an example of a ceramic substrate having a plurality of ceramic diaphragm structures.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Diaphragm part, 2 ... Substrate, 3 ... Ceramic diaphragm structure, 4 ... Lowermost layer, 5 ... Neutral line, 6 ... Nth layer from the lowermost layer, 7 ... Green substrate, 8 ... Window part, 9 ... First Layer, 10: hole, 11: second layer, 12: diaphragm plate.

──────────────────────────────────────────────────の Continued on front page (51) Int.Cl. ⁶ Identification code FI H01L 41/08 C

Claims (4)

[Claims] 1. A thin ceramic green sheet comprising one or more layers and a ceramic green substrate comprising one or more layers having one or more windows and covering said windows. A method of manufacturing a ceramic diaphragm structure in which the diaphragm is formed so as to have a convex shape in a direction opposite to the window by firing after firing to form an integral laminate. The ceramic green substrate and the ceramic green sheet are represented by the following formulas (a), (b), and (c); (a) S (substrate) −S (sheet) ≧ −0.08 ｛T
₇₀ (substrate) -T ₇₀ (sheet)} - 1 (b) 0 ≦ T ₇₀ (substrate) -T ₇₀ (sheet) ≦ 300 (c) S (substrate) -S (sheet) ≦ 20 (wherein, S (Substrate) and S (sheet) represent the shrinkage (%) of the ceramic green substrate and the ceramic green sheet, respectively, and T ₇₀ (substrate) and T ₇₀ (sheet) represent the ceramic green substrate and the ceramic, respectively. (Representing the sintering temperature (° C.) of the green sheet)) and the following formula (d); (Wherein, N represents the number of layers constituting the ceramic green substrate, and T ₇₀ (substrate) _n represents, when the ceramic green sheet laminated side of the integrated laminate is faced up,
Among the layers constituting the ceramic green substrate, the sintering temperature (° C.) of the n-th layer from the lowermost layer is represented by t _n and t _{n
n + 1} is the distance between the lower surface and the upper surface of the n-th layer after firing of the integrated laminate to the neutral line of the base, and the symbol-for the surface located below the neutral line. The surface located above the neutral line is indicated by a value with a plus sign. The method of manufacturing a ceramic diaphragm structure, wherein the average sintering temperature difference of the ceramic green substrate represented by the formula (1) is larger than 0. 2. A ceramic green substrate having one or more layers and having one or more layers, a thin ceramic green sheet comprising one or more layers, and a cover covering the windows. A method of manufacturing a ceramic diaphragm structure in which the diaphragm is formed so as to have a convex shape in a direction opposite to the window by firing after firing to form an integral laminate. The ceramic green substrate and the ceramic green sheet are represented by the following formulas (a), (b), and (c); (a) S (substrate) −S (sheet) ≧ −0.08 ｛T
₇₀ (substrate) -T ₇₀ (sheet)} - 1 (b) 0 ≦ T ₇₀ (substrate) -T ₇₀ (sheet) ≦ 300 (c) S (substrate) -S (sheet) ≦ 20 (wherein, S (Substrate) and S (sheet) represent the shrinkage (%) of the ceramic green substrate and the ceramic green sheet, respectively, and T ₇₀ (substrate) and T ₇₀ (sheet) represent the ceramic green substrate and the ceramic, respectively. (Representing the sintering temperature (° C.) of the green sheet)) and the following formula (e): (In the formula, N represents the number of layers constituting the ceramic green substrate, and S (substrate) _n constitutes the ceramic green substrate when the side on which the ceramic green sheets are laminated in the integrated laminate faces upward. of the layers, contraction rate of the n th layer from the bottom layer represents (%), t _n and t _{n + 1,} respectively, the substrate from the lower surface and the upper surface of the n-th layer after firing the integral laminate The distance to the neutral line is indicated by a minus sign for a surface located below the neutral line, and a value indicated by a + symbol for a surface located above the neutral line.) A method for producing a ceramic diaphragm structure, wherein the average shrinkage difference of the ceramic green substrate represented is larger than 0. 3. The following formula (f): (Wherein, M is among the layers constituting the substrate in the after firing the integral laminate, represents the number of layers located below the neutral line, A _n is the in after firing the integral laminate Of the layers constituting the base, the thickness of the n-th layer from the bottom layer is represented. For the M-th layer from the bottom layer, the thickness from the lower surface of the layer to the neutral line is represented by T ₇₀ (base) _n Represents the above-mentioned meaning, and A represents the distance from the lower surface of the lowermost layer of the substrate to the neutral line after firing the integrated laminate.) The sintering temperature (° C.) of is calculated by the following formula (g); (Where L represents the number of layers constituting the ceramic green sheet, and T ₇₀ (sheet) _n represents the number of layers constituting the ceramic green sheet when the side on which the ceramic green sheet is laminated faces upward in the integrated laminate. It represents sintering developing temperature of the n-th layer from the bottom layer (℃) among the layers, B _n
Represents the thickness of the n-th layer from the bottom layer among the layers constituting the diaphragm plate after firing the integrated laminate, and B represents the thickness of the diaphragm plate. 3. The method for producing a ceramic diaphragm structure according to claim 1, wherein the temperature is higher than the sintering temperature (° C.) of the ceramic green sheet represented by (1). 4. A partially stabilized zirconia, wherein the ceramic green sheet has an average particle size of 0.05 to 1.0 μm,
The method for producing a ceramic diaphragm structure according to claim 1, 2 or 3, comprising a completely stabilized zirconia or alumina, a mixture thereof, or a material which becomes these materials after firing.