JP2014172817A - Multiple structure, molded film, and method for producing multiple structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molded film which is formed by molding/solidifying slurry on the surface of a substrate, the shape stability of which is ensured and which is hardly cracked.SOLUTION: Slurry containing, at the least, ceramic raw material powder and/or metal powder, an organic binder, and a dispersion medium is prepared. The prepared slurry is applied to the surface of a substrate and molded into a film shape. The molded film shape is solidified to obtain a molded film. When the thickness of the molded film at the center of the length thereof in the predetermined direction along the surface thereof is defined as tc, and the thickness thereof at the position parted from one end of the length toward the center by 5tc in the predetermined direction is defined as te, a relationship: 1.14≤te/tc≤1.2 is satisfied.

Description

  The present invention relates to a composite structure including a base and a molded film provided on the surface of the base. The present invention also relates to the molded film. Furthermore, this invention relates to the manufacturing method of the said composite structure.

  Conventionally, a substrate and a molded film provided on the surface of the substrate by molding and solidifying a slurry containing at least ceramic raw material powder and / or metal powder, an organic binder, and a dispersion medium are provided. Composite structures are widely known (see, for example, Patent Documents 1 to 3).

Japanese Patent Laid-Open No. 06-139815 JP 2001-234106 A JP 2003-238876 A

  Usually, the molded film is prepared by preparing the slurry, forming the slurry on the surface of the substrate, and solidifying the molded film. And obtaining a solidification step.

  In general, in a film immediately after being formed on the surface of a substrate (that is, a viscoelastic body before the solidification (drying) step), due to stress derived from its own weight, the central portion of the film is at the end of the film ( Compared to the edge of the membrane) (in other words, the center of the membrane is recessed downward), and the edge of the membrane (the edge of the membrane) extends away from the center of the membrane. (See FIG. 3 described later). In the present application, this phenomenon is called “molded film sagging”.

  When the progress of the “molded film sagging” becomes remarkable, it is difficult to obtain a molded film having a desired shape after the solidification step. That is, there may be a problem that the shape stability of the molded film cannot be ensured. In addition, in the solidification process, there may be a problem that cracks occur in the molded film in relation to the above-mentioned “sag of the molded film”.

  As a result of repeated studies to cope with the above problems, the present inventor has found a technique for ensuring the shape stability of the molded film. In addition, they have also found a technique that can suppress the occurrence of cracks in the molded film in the solidification process.

  The inventor of the present invention is that when the thickness of the molding film in the predetermined direction along the surface of the substrate is tc, and the thickness at a position of 5 tc from one end in the predetermined direction toward the center is te, When the relationship of “te / tc ≦ 1.2” is established, it is determined that “shape stability is ensured”. Here, when the length from the one end to the other end facing the one end in the predetermined direction is L, the relationship of “L ≧ 30 tc and tc ≦ 0.3 mm” is established. Is preferred.

  The inventor of the present invention relates to a molded film with “stable shape stability” (that is, a film that satisfies the relationship “te / tc ≦ 1.2”), and particularly “1.14 ≦ te / tc ≦ 1. When the relationship “2” is established, it was found that cracks are hardly generated in the molded film in the solidification step (details will be described later). Here, it is preferable that the substrate is made of a ceramic having a porosity of 20% by volume or more and 60% by volume or less.

  The inventor of the present invention is to obtain a molded film (that is, a film satisfying the relationship of “1.14 ≦ te / tc ≦ 1.2”) that is “shape stability is secured and cracks are hardly generated”. The following was found as a specific method.

  That is, ρ is the density of the slurry used to form the molding film, G is the rigidity of the slurry used to form the molding film, and g is the acceleration of gravity. The value “(ρ · tc · g) / G ”, by adjusting the combination of ρ, tc, g, and G so that the relationship“ 0.015 ≦ (ρ · tc · g) /G≦0.030 ”is established, A film satisfying the relationship of “1.14 ≦ te / tc ≦ 1.2” (that is, a molded film that is “stable in shape and hardly cracks”) can be obtained. In this case, it is preferable that the relationship of 210 Pa ≦ G ≦ 302 Pa is satisfied with respect to the rigidity modulus of the slurry. Details of the above contents will be described later.

It is a perspective view of the whole composite structure manufactured by the manufacturing method concerning the embodiment of the present invention. It is a top view (top view) of the composite structure shown in FIG. FIG. 3 is a cross-sectional view corresponding to line 3-3 in FIG. 2. It is sectional drawing corresponding to FIG. 3 about the film | membrane immediately after shape | molding on the surface state of a base | substrate.

  Hereinafter, a manufacturing method of a composite structure including a molded film according to an embodiment of the present invention and a composite structure including a molded film manufactured by the manufacturing method according to an embodiment of the present invention will be described with reference to the drawings.

(Outline of the structure of the composite structure)
1 and 2 show an example of a composite structure manufactured by a manufacturing method according to an embodiment of the present invention. The composite structure shown in this example includes a flat substrate 10 and a flat molded film 20 formed on the upper surface (plane) of the substrate 10. In this example, both the base 10 and the molding film 20 have a quadrangle (more precisely, a square) in plan view. The composite structure shown in this example is fired later to finally become a product. Examples of this product include electronic circuit components and semiconductor devices. Note that the composite structure may include a curved base 10 and a curved molding film 20 formed on the upper surface (curved surface) of the base 10.

  The base 10 is made of ceramics having a porosity of 20 volume% or more and 60 volume% or less, for example. The thickness of the base 10 is 0.1 to 10 mm, and the representative length of the base 10 (in this example, the length of one side) is 10 to 200 mm. The substrate 10 may be a fired body or a molded body before firing.

  The formed film 20 is a film provided by forming and solidifying a slurry containing at least a ceramic raw material powder and / or a metal powder, an organic binder, and a dispersion medium on the upper surface of the substrate 10 (dried / solidified film). ). The ceramic raw material contained in the formed film 20 may be the same as the ceramic raw material constituting the substrate 10, but is preferably different. The porosity of the molded film 20 (film after drying / solidification) is 20 to 60% by volume. The thickness of the molded film 20 is 0.01 to 0.3 mm, and the representative length of the molded film 20 (in this example, the length L on one side (see FIG. 2)) is 1 to 30 mm.

  As shown in FIG. 3, which is a cross-sectional view corresponding to line 3-3 in FIG. 2, in the molded film 20 (film after drying and solidification), the center of the film is the end of the film (the edge of the film). In comparison, the film is distorted in the vertically downward direction (in other words, the central portion of the film is recessed in the vertically downward direction), and the end of the film (the edge of the film) extends away from the central portion of the film. That is, the above-mentioned “sag of the formed film” occurs. This “sag of the formed film” is caused by the stress derived from the weight of the film as described above.

(Outline of manufacturing method of composite structure)
Next, an outline of a method for manufacturing the molded film 20 formed on the upper surface of the substrate 10 shown in FIGS. 1 to 3 will be described.

<1> Slurry preparation process First, the slurry used when shape | molding the shaping | molding film | membrane 20 is prepared. This slurry contains at least a ceramic raw material powder and / or a metal powder, an organic binder, and a dispersion medium, and a plasticizer, a dispersion aid, and the like as necessary. The ceramic raw material powder and / or the metal powder is a main raw material powder constituting the molding film 20. The content of each component is 10 to 15% by volume of ceramic raw material powder and / or metal powder, 5 to 20% by volume of organic binder, 60 to 70% by volume of dispersion medium, and 2 to 5% by volume of plasticizer. The dispersing aid may be 2-5% by volume.

  As the ceramic raw material powder, oxide ceramics may be used, or non-oxide ceramics may be used. For example, zirconium oxide, aluminum oxide, nickel oxide, iron oxide, zinc oxide, manganese oxide, calcium oxide, tin oxide, silicon dioxide, yttrium oxide, cobalt oxide, copper oxide, lanthanum oxide, cerium oxide, chromium oxide, titanium oxide, Metal compounds for forming ceramics having a desired composition by firing such as barium titanate and strontium titanate, nitrides such as silicon nitride, titanium nitride and aluminum nitride, and carbides such as silicon carbide and titanium carbide Can be used. The particle diameter of the ceramic raw material powder is not particularly limited as long as the slurry can be prepared (that is, the powder can be stably dispersed in the dispersion medium).

  The metal powder is not particularly limited as long as it has conductivity, for example. For example, powder made of nickel, palladium, platinum, gold, silver, copper, tungsten, molybdenum, or an alloy thereof can be used. These metal powders may be used alone or in combination of two or more.

The average particle size of the ceramic raw material powder and / or metal powder is preferably 0.3 μm or more and 10 μm or less, and the specific surface area of the ceramic raw material powder and / or metal powder is 0.3 m ² / g. It is suitable that it is above and is 10 m < ² > / g or less.

  The organic binder is not particularly limited as long as it is soluble in the dispersion medium, for example. For example, butyral type such as polyvinyl butyral, acrylic type such as butyl acrylate and butyl methacrylate, cellulose type such as ethyl cellulose and methyl cellulose, urethane type resin, phenol type resin, epoxy type resin and the like can be used.

  The dispersion medium is not particularly limited as long as it dissolves an organic binder, a plasticizer, and a dispersion aid, for example. For example, alcohols (methanol, ethanol, isopropyl alcohol, butanol, 2-ethylhexanol, etc.), ethers (2-methoxyethanol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene ether, diethylene glycol monobutyl ether) Etc.), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, etc.), esters (ethyl acetate, butyl acetate, dimethyl glutarate, triacetin, ethylene glycol monomethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether) Acetate, diethylene glycol monobutyl ether acetate Over DOO, propylene glycol monomethyl ether acetate), hydrocarbons (toluene, xylene, cyclohexane, etc.), N- methyl-2-pyrrolidone, N, N- dimethylformamide, sulfolane and the like. These dispersion media may be used individually by 1 type, or may be used in combination of 2 or more types.

  As the plasticizer, for example, phthalic acid derivatives, isophthalic acid derivatives, tetrahydrophthalic acid derivatives, adipic acid derivatives, maleic acid derivatives, fumaric acid derivatives, stearic acid derivatives, oleic acid derivatives, itaconic acid derivatives, ricinol derivatives can be used. . Of these, phthalic acid derivatives are particularly preferred. Specifically, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, di- (2-ethylhexyl) phthalate, dioctyl phthalate, diisooctyl phthalate, diisobutyl phthalate, diheptyl phthalate, diphenyl phthalate and the like can be used.

  Examples of the dispersion aid include polycarboxylic acid copolymers, polycarboxylates, sorbitan fatty acid esters, polyglycerin fatty acid esters, phosphate ester copolymers, sulfonate copolymers, tertiary amines. A polyurethane polyester-based copolymer having the above can be used. In particular, polycarboxylic acid copolymers, polycarboxylates, and the like are suitable. By adding a dispersion aid, the slurry before molding can have a low viscosity and a high fluidity.

  A rheology modifier may be added to the slurry. Rheology modifiers are well known and many are already commercially available. For example, those appropriately selected from various types such as modified polyacrylic, modified urea, and polyamide based on the type of dispersion medium and the like can be used as the rheology modifier. Specific examples of rheology modifiers include “SN thickener 630”, “SN thickener 634”, “SN thickener 636”, “SN thickener 641”, and “SN thickener 4050” manufactured by San Nopco, “BYK” manufactured by BYK Chemie. -410 "," BYK-425 "," BYK-430 ", and the like can be used.

<2> Molding process (coating film forming process)
Next, using the slurry prepared as described above, as shown in FIG. 4 corresponding to FIG. 3, a film is formed on the upper surface of the substrate 10 prepared (completed) in advance. As shown in FIG. 4, the film thickness is uniform immediately after the film is formed. As a film forming method, one of known methods such as a doctor blade method and a screen printing method may be employed.

  After the film is formed, the above-described “sag of the formed film” proceeds, and as shown in FIG. 3 described above, the center of the film is distorted vertically downward compared to the end of the film (the film The center part is depressed vertically downward) and the end of the film (the edge of the film) spreads away from the center part of the film. The progress of the “sag of the formed film” ends in the course of the solidification step described later. As will be described later, the stage in which the “sag of the formed film” ends is largely dependent on the rigidity G of the slurry (described later).

<3> Solidification (Drying) Step Next, the membrane is solidified by volatilizing and removing the dispersion medium inside the membrane formed on the upper surface of the substrate 10 as described above (that is, drying the membrane). Thereby, the molding film 20 is formed (completed) on the upper surface of the substrate 10. Typically, solidification (drying) of the film is achieved by heating the film. Moreover, the solidification process is not limited to drying as follows.

  In the solidification step, a polymerization reaction may be used. That is, the slurry prepared in the slurry preparation step is a powdered forming raw material (which may contain two or more ceramic raw materials), a dispersion medium for dispersing the powder, and the forming raw material in the dispersion medium. A slurry containing a dispersion aid for uniformly dispersing, a binder precursor for generating an organic binder that is a synthetic resin by a chemical reaction, and a reaction accelerator (catalyst) for causing the chemical reaction to proceed. It may be a step of preparing. A rheology modifier may also be added to this slurry. In this case, the solidification step is a solidification drying step in which, in the primary powder molded body obtained by the molding step, the chemical reaction is advanced to solidify the slurry, and the dispersion medium is volatilized and removed from the primary powder molded body. It may be.

  In the solidification drying process, a urethane resin as an organic binder is generated by allowing the above-mentioned primary powder molded body to stand at room temperature and advancing the chemical reaction of the urethane precursor (isocyanate and polyol) as the binder precursor. And a step of solidifying (gelling) the slurry.

  The isocyanate is not particularly limited as long as it is a substance having an isocyanate group as a functional group (a polyisocyanate having a plurality of isocyanate groups can be particularly preferably used). Specifically, for example, tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), or modified products thereof can be favorably used as “isocyanate”. In addition, what has a reactive functional group other than an isocyanate group in a molecule | numerator can be favorably used as "isocyanate".

  The polyol is not particularly limited as long as it is a substance having a plurality of alcoholic hydroxyl groups as functional groups. For example, ethylene glycol (EG), polyethylene glycol (PEG), propylene glycol (PG), polypropylene glycol (PPG), polytetramethylene ether glycol (PTMG), polyhexamethylene glycol (PHMG), polyvinyl butyral (PVB), etc. It can be used favorably as “polyol”.

  In addition, a urethane precursor is not limited to the above-mentioned specific example at all. For example, other functional groups (carboxyl group, amino group, etc.) that can react with an isocyanate group may be introduced into the polyol. Alternatively, instead of or together with the polyol, a substance having the above-described carboxyl group or amino group (which may contain one alcoholic hydroxyl group) may be used. Moreover, in order to suppress the progress of the urethane reaction before molding, a blocking agent may be added to the slurry, or a blocking action may be imparted to the urethane precursor (for example, isocyanate).

  The catalyst (reaction promoter) is not particularly limited as long as it is a substance that promotes the urethane reaction. For example, triethylenediamine, hexanediamine, 6-dimethylamino-1-hexanol and the like can be used.

(Suppression of cracks in molded films with shape stability)
Hereinafter, for a molded film such as the molded film 20 (after the solidification step), the center thickness (z-axis direction) in a predetermined direction along the surface of the substrate is tc (mm), and from one end in the predetermined direction to the center. The thickness (z-axis direction) at a position of 5 tc is assumed to be te (mm). In the example shown in FIG. 3, the value tc and the value te in the cross section (3-3 cross section of FIG. 2) along the y-axis direction of the molding film 20 are shown.

  When the progress of the "molded film sagging" becomes prominent, the degree to which the center part of the film is distorted in the vertically downward direction compared to the end part of the film (in other words, the degree to which the center part of the film is recessed in the vertically downward direction) As a result, the shape stability of the molded film cannot be secured. In other words, a large value “te / tc” (> 1) means that the shape stability of the molded film is not ensured.

  Based on such knowledge, the present inventor, after the solidification step (that is, after completion of the formed film), when the relationship “te / tc ≦ 1.2” is established, “the shape stability of the formed film is ensured. It was decided that Here, when the length from the one end in the predetermined direction to the other end facing the one end in the predetermined direction is L (mm) with respect to the formed film (after the solidifying step) (see FIG. 3), “L ≧ 30 tc , And tc ≦ 0.3 mm ”is preferably established.

  With regard to such a molded film with “stable shape stability” (that is, a film that satisfies the relationship “te / tc ≦ 1.2”), depending on the preparation state of the slurry, in the solidification step (solidification drying step) In some cases, cracks were likely to occur in the molded film.

  The inventor of the present invention relates to such a molded film having “stable shape stability” (that is, a film that satisfies the relationship of “te / tc ≦ 1.2”), “1.14 ≦ te / tc ≦ 1. When the relationship of “.2” is established, it has been found that cracks are less likely to occur in the molded film in the solidification step (solidification drying step) than in the case where it is not.

Further, the density of the slurry (before the solidification process) used for forming the molded film is ρ (kg / m ³ ), and the rigidity (also called the shear modulus) of the slurry (before the solidification process) used for forming the molded film. ) Is G (Pa), the gravitational acceleration is g (m / s ² ), and attention is paid to the value “(ρ · tc · g) / G” (= dimensionless value) and the value G. The inventors have found that the value “(ρ · tc · g) / G” and the value G also have a strong correlation with the occurrence of cracks in the molded film in the solidification step (solidification drying step). In calculating the value “(ρ · tc · g) / G”, the value tc was not in “mm” (millimeter) units but in “m” (meter) units. Hereinafter, a test for confirming this will be described.

(test)
In this test, a molded film was completed on the upper surface of the substrate with 10 types of patterns (levels) using the method for manufacturing a composite structure according to the present embodiment described above. The combinations of the value “(ρ · tc · g) / G”, the value G, and the value “te / tc” in each pattern are as shown in Table 1. Ten samples (N = 10) were produced for each pattern. For each sample, the relationship “L ≧ 30 tc and tc ≦ 0.3 mm” was established.

  Specifically, the common test conditions for each pattern are as follows. In the slurry preparation step, 10 to 15% by volume of aluminum oxide raw material powder as ceramic raw material powder, 5 to 20% by volume of polyvinyl butyral as organic binder, and 60 to 70% by volume of diethylene glycol monobutyl ether acetate as a dispersion medium A mixture containing 2 to 5% by volume of dioctyl phthalate as a plasticizer and 2 to 5% by volume of a polycarboxylic acid copolymer as a dispersion aid was mixed for 14 hours by a ball mill to prepare a slurry. Next, bubbles remaining in the slurry were removed by defoaming the slurry in vacuum. In the molding process, the slurry is used to form one side of the shape in plan view (top view) on the upper surface of the flat ceramic substrate by one of known methods such as a doctor blade method and a screen printing method. Was a 15 mm square (typically a square) and a thickness of approximately 0.6 mm. The porosity of the ceramic substrate was 20% by volume or more and 60% by volume or less, and the pores in the ceramic substrate were so-called “open pores”. In the solidification step, the formed coating film was sufficiently dried at 80 ° C. for 5 hours by heating using a dryer. As a result, a molded film having a thickness tc of 0.3 mm was formed on the ceramic substrate. That is, a ceramic composite structure was obtained.

The density ρ (kg / m ³ ) of the slurry can be easily calculated by a known method from the composition of the mixture from which the slurry is based. The density ρ of the slurry is uniform throughout the formed coating film. The thickness tc and te (mm) of the molded film (after the solidification step) were measured using an Olympus laser microscope (OLS-1100).

  The rigidity G (Pa) of the slurry was measured using a viscoelastic rheometer (MCR302) manufactured by Anton Paar. As the value G shown in Table 1, a value measured under conditions where the frequency was 1 Hz and the distortion was 1% was used.

The viscosity of the slurry was also measured using the above-mentioned viscoelastic rheometer (MCR302) manufactured by Anton Paar. When the viscosity when the shear rate is 10 ⁻³ [sec ⁻¹ ] or less is “d1” and the viscosity when the shear rate is 10 ³ [sec ⁻¹ ] or more is “d2”, the value “d1 / d2” is It was 150 or more and 300 or less. That is, it can be said that this slurry has so-called “pseudoplasticity”. Here, “pseudoplasticity” refers to the property that when the shear rate is low, the viscosity becomes high, whereas when the shear rate is high, the viscosity decreases rapidly (see, for example, JP-A-10-130076). This “pseudoplasticity” is a property that is easily obtained by adding the rheology modifier described above.

  The magnitude of the rigidity G of the slurry is the “molecular weight”, “added amount” (concentration in the slurry (volume%)), and “molecular structure (straight chain, side chain)” of the organic binder contained in the slurry. And the degree of influence of the so-called “steric effect” of the organic binder can be adjusted. Specifically, when the “molecular weight” is large, the organic binder molecule becomes long and the molecules tend to be entangled (high steric effect). As a result, the rigidity G of the slurry increases. When the “addition amount” is large, many organic binders are easily entangled (the steric effect is large). As a result, the rigidity G of the slurry increases. When the “molecular structure” includes a complicated side chain structure, the organic binder tends to be entangled in a complicated manner (high steric effect). As a result, the rigidity G of the slurry increases.

  The presence or absence of cracks generated on the surface of the molded film in the solidification step was determined based on visual observation or observation using a microscope. The results are as shown in Table 1.

  As can be seen from Table 1, when the relationship of “1.14 ≦ te / tc ≦ 1.2” is established, cracks are generated in the molded film in the solidification step (solidification drying step) compared to the case where it is not. It can be difficult.

  In addition, when focusing on the value “(ρ · tc · g) / G”, ρ, tc, and so on so that the relationship “0.015 ≦ (ρ · tc · g) /G≦0.030” is satisfied. By adjusting the combination of g, a film satisfying the relationship of “1.14 ≦ te / tc ≦ 1.2” (that is, a molded film that is “stable in shape stability and hardly cracks”) It can be said that can be obtained.

  Further, when focusing on the value G, when the relationship of 210 Pa ≦ G ≦ 302 Pa is established, the film satisfying the relationship of “1.14 ≦ te / tc ≦ 1.2” (that is, “shape stability is ensured”). In addition, it is possible to obtain a “molded film” that is hardly cracked.

  Here, the value “(ρ · tc · g) / G” is added. As shown in FIG. 3, when the angle formed by the inclined surface from the top corresponding to the thickness te in the molding film 20 toward the center of the molding film 20 and the horizontal plane is θ, the strain γ at the top is “ γ = tan θ ”.

When the shear stress acting on the inside of the coating film formed by the slurry is τ, the coating film strain is γ, and the rigidity of the slurry is G, derived from the weight of the slurry that is the precursor of the molding film 20; The following equation (1) is established.
γ = τ / G (1)

Further, the shear stress τ can be expressed by the following equation (2), where ρ is the slurry density, h is the coating thickness, and g is the gravitational acceleration.
τ = ρ · h · g (2)

Substituting the relationship of the above equation (2) into the above equation (1), the following equation (3) is obtained. That is, the strain γ is proportional to ρ and h and inversely proportional to G.
γ = (ρ · h · g) / G (3)

Here, when the thickness tc in the molded film 20 shown in FIG. 3 is adopted as the value h, and the strain at the top corresponding to the thickness te in the molded film 20 shown in FIG. 3 is γ ₀ (= tan θ), The following equation (4) is obtained.
γ ₀ = (ρ · tc · g) / G (4)

As can be understood from the above equation (4), the value “(ρ · tc · g) / G” corresponds to the magnitude of the strain γ ₀ at the top corresponding to the thickness te in the molded film 20 shown in FIG. The value to be In other words, the value “(ρ · tc · g) / G”, like the value “te / tc”, can be said to be an index representing the degree of progress of the “molded film sagging” described above. In this respect, adjusting the combination of ρ, tc, g, and G so that the relationship of “0.015 ≦ (ρ · tc · g) /G≦0.030” is established results in “ 1.14 ≦ te / tc ≦ 1.2 ”(that is, to obtain a molded film that is“ stable in shape and hardly cracks ”). It can be said that the state will be adjusted.

  Hereinafter, the relationship between the rigidity G of the slurry and the occurrence of cracks in the molded film will be additionally described. In Table 1, at levels 1 and 2, the slurry has a large rigidity G. That is, the slurry is not microscopically deformed. Therefore, it is difficult to remove bubbles remaining in the slurry during the above-described defoaming treatment of the slurry, and the molding process is performed in a state where many bubbles remain in the slurry. Accordingly, many bubbles remain in the formed coating film, and the solidification step is performed in this state. As a result, in the solidification step, cracks are likely to occur due to bubbles remaining in the coating film (specifically, bubbles mixed during slurry preparation).

  On the other hand, in Table 1, at levels 7 to 10, the rigidity G of the slurry is small. That is, the slurry is easily microscopically deformed. Therefore, during the molding process and the solidification process, a phenomenon in which bubbles existing in the porous substrate move from the upper surface of the substrate to the inside of the coating film (so-called “bubble floating”) occurs. Easy to do. Therefore, the solidification step is performed in a state where many bubbles remain in the formed coating film. As a result, in the solidification step, cracks are likely to occur due to bubbles remaining in the coating film (specifically, bubbles mixed in by bubble floating).

  From the above, there exists an appropriate range of the rigidity of the slurry necessary for suppressing the occurrence of cracks in the molded film. It can be said that this appropriate range is “210 Pa ≦ G ≦ 302 Pa” described above.

  10 ... Substrate, 20 ... Molded film

Claims (18)

A substrate;
A molding film provided on the surface of the substrate by molding and solidifying a slurry containing at least ceramic raw material powder and / or metal powder, an organic binder, and a dispersion medium;
A composite structure comprising
About the molded film,
When the thickness at the center in the predetermined direction along the surface is tc and the thickness at the position of 5 tc from one end in the predetermined direction toward the center is te,
A composite structure in which a relationship of te / tc ≦ 1.2 is established. The composite structure according to claim 1,
About the molded film,
1. A composite structure in which the relationship of ≦ te / tc ≦ 1.2 is established. The composite structure according to claim 2,
When the density of the slurry used for forming the molded film is ρ, the rigidity of the slurry used for forming the molded film is G, and the gravitational acceleration is g,
A composite structure in which a relationship of 0.015 ≦ (ρ · tc · g) /G≦0.030 is established. The composite structure according to claim 3,
About the rigidity G of the slurry used for forming the molding film,
A composite structure in which a relationship of 210 Pa ≦ G ≦ 302 Pa is established. In the composite structure according to any one of claims 1 to 4,
About the molded film,
When the length from the one end to the other end facing the one end in the predetermined direction is L,
A composite structure in which a relationship of L ≧ 30 tc and tc ≦ 0.3 mm is established. In the composite structure according to any one of claims 1 to 5,
The substrate is
A composite structure composed of ceramics having a porosity of 20% by volume or more and 60% by volume or less. A molded film provided on the surface of a substrate by molding and solidifying a slurry containing at least a ceramic raw material powder and / or a metal powder, an organic binder, and a dispersion medium,
When the thickness at the center in the predetermined direction along the surface is tc and the thickness at the position of 5 tc from one end in the predetermined direction toward the center is te, the relationship of te / tc ≦ 1.2 is established. , Molding film. The molded film according to claim 7,
1.14 <= te / tc <= 1.2 Formed film | membrane in which the relationship is materialized. The molded film according to claim 8,
When the density of the slurry used for forming the molded film is ρ, the rigidity of the slurry used for forming the molded film is G, and the gravitational acceleration is g,
A molded film in which a relationship of 0.015 ≦ (ρ · tc · g) /G≦0.030 is established. In the molded film according to claim 9,
About the rigidity G of the slurry used for forming the molding film,
A molded film in which the relationship of 210 Pa ≦ G ≦ 302 Pa is established. In the molded film according to any one of claims 7 to 10,
When the length from the one end to the other end facing the one end in the predetermined direction is L,
A molded film in which the relationship of L ≧ 30 tc and tc ≦ 0.3 mm is established. In the molded film according to any one of claims 7 to 11,
The substrate provided with the molding film is
A molded film made of ceramics having a porosity of 20% by volume to 60% by volume. A composite structure comprising: a base; and a molded film provided on the surface of the base by molding and solidifying a slurry containing at least a ceramic raw material powder and / or a metal powder, an organic binder, and a dispersion medium. A manufacturing method of
Preparing a slurry containing at least ceramic raw material powder and / or metal powder, an organic binder, and a dispersion medium; and
A molding step of molding the prepared slurry into a film on the surface of the substrate;
A solidification step of obtaining the molded film by solidifying the molded film;
With
About the molded film,
When the thickness at the center in the predetermined direction along the surface is tc and the thickness at the position of 5 tc from one end in the predetermined direction toward the center is te,
A method for manufacturing a composite structure, wherein a relationship of te / tc ≦ 1.2 is established. In the manufacturing method of the composite structure according to claim 13,
About the molded film,
1.14 <te / tc <= 1.2 The manufacturing method of a composite structure in which the relationship is materialized. In the manufacturing method of the composite structure according to claim 14,
When the density of the slurry used for forming the molded film is ρ, the rigidity of the slurry used for forming the molded film is G, and the gravitational acceleration is g,
A method for manufacturing a composite structure, wherein a relationship of 0.015 ≦ (ρ · tc · g) /G≦0.030 is established. In the manufacturing method of the composite structure according to claim 15,
About the rigidity G of the slurry used for forming the molding film,
A method for manufacturing a composite structure, wherein a relationship of 210 Pa ≦ G ≦ 302 Pa is established. In the manufacturing method of the composite structure according to any one of claims 13 to 16,
About the molded film,
When the length from the one end to the other end facing the one end in the predetermined direction is L,
A method for manufacturing a composite structure, wherein a relationship of L ≧ 30 tc and tc ≦ 0.3 mm is established. In the manufacturing method of the composite structure according to any one of claims 13 to 17,
The substrate is
A method for producing a composite structure, comprising a ceramic having a porosity of 20% by volume or more and 60% by volume or less.

Images