Method for manufacturing multilayer piezoelectric textured ceramic using 2dd tgg

Abstract

The present invention relates to a method for manufacturing a multilayer piezoelectric textured ceramic. In particular, the present invention relates to a method for manufacturing a multilayer piezoelectric textured ceramic by arranging a matrix piezoelectric ceramic green sheet, and alternately laminating insertion BT(BaTiO3) template sheets and matrix piezoelectric ceramic sheets one or more times on the matrix piezoelectric ceramic green sheet in order to induce crystal orientation of the matrix ceramic, wherein the template sheet is disposed between and much thinner than the matrix ceramic sheets.

Description

Method for manufacturing layered piezoelectric textured ceramics using 2DD TGG

[0001] The present invention relates to a method for manufacturing a layered piezoelectric texture ceramic, and more particularly, to a method for manufacturing a layered piezoelectric texture ceramic using a two-dimensionally-dispered template grain growth (2DD TGG) process. Specifically, the 2DD TGG process relates to a method for manufacturing a layered piezoelectric texture ceramic by arranging a matrix piezoelectric ceramic green sheet, and alternately stacking an inserted BT (BaTiO3) template sheet and a matrix piezoelectric ceramic sheet, the insertion having a thickness much thinner than the matrix ceramic sheet arranged in the middle thereon to induce crystal orientation of the matrix ceramic, one or more times.

[0002]

[0003] In the TGG (Templated Grain Growth) process, which is generally used to manufacture crystal-oriented piezoelectric ceramics, it is difficult to manufacture by uniformly dispersing BaTiO3seed (BT seed) having a plate-like structure in the matrix piezoelectric ceramic, and therefore, mass production is even more difficult in a state where such uniformity is not guaranteed.

[0004] This is because, during the TGG process, the plate-shaped BT seeds randomly dispersed within the ceramic slurry often tilt and incline within the piezoelectric ceramic sheet manufactured through the tape casting method, which reduces the crystal orientation during the sintering process, making it difficult to expect excellent piezoelectric properties.

[0005] In addition, when manufacturing laminated piezoelectric crystal-oriented ceramics, it is difficult to uniformly distribute randomly distributed plate-shaped BT seeds in each sheet layer, and it is very difficult to control the uniform distribution and distribution so as to have directionality even within the same sheet layer.

[0006] In addition, if the template plate-shaped BT seeds are not distributed in a uniform direction within the laminated ceramic structure and tilt or collide with other particles growing from neighboring BT seeds while growing as textured particles, not only will the complete growth of the textured particles be mutually hindered, but the crystal orientation will also be lowered, which will cause deterioration of the piezoelectric properties as well as the electrical performance.

[0007]

[0008] The present invention relates to a method for manufacturing a laminated piezoelectric texture ceramic using a plate-shaped template seed such as a BT seed, by using a 2DD TGG process, to prevent tilting and dispersion of the plate-shaped template seed with non-uniform orientation, thereby ensuring good alignment, and to a method for dramatically improving piezoelectric and electrical properties by further improving the degree of crystal orientation by arranging the plate-shaped BT seeds distributed in the stacking direction to have a constant distance equal to the thickness of the matrix ceramic sheet so that grain growth due to collision of texture particles growing around the BT seed during crystal growth is not mutually interfered with.

[0009] In addition, the present invention aims to solve the problem of deterioration of piezoelectric properties due to plastic deformation and density reduction of laminated piezoelectric ceramics caused by formation of empty spaces due to volatilization of organic substances during the sintering process when using an insertion template sheet having a very thin thickness composed of a plate-shaped template seed.

[0010]

[0011] A method for manufacturing a laminated piezoelectric texture ceramic according to one embodiment of the present invention comprises the steps of: preparing a matrix piezoelectric ceramic sheet; preparing an insertion template sheet including plate-shaped BT (BaTiO3) seeds; arranging the matrix piezoelectric ceramic sheet; repeatedly stacking and arranging the insertion template sheet and the matrix piezoelectric ceramic sheets one by one on the matrix piezoelectric ceramic sheet at least once; and sintering the laminated body.

[0012] The above matrix piezoelectric ceramic sheet does not include plate-shaped BT seeds.

[0013] The thickness of the above insert template sheet is thinner than the thickness of the above matrix piezoelectric ceramic sheet.

[0014] The above matrix piezoelectric ceramic is a piezoelectric ceramic that can be manufactured into a plate-shaped sheet through a TGG (Templated Grain Growth) process.

[0015] The step of preparing the above matrix piezoelectric ceramic sheet is 0.5Pb(Ni 1 / 3 Nb 2 / 3 ) A step of preparing a slurry including a powder having a composition of O3-0.16PbZrO3-0.34PbTiO3 and a Li2CO3 powder and performing ball milling; and a step of manufacturing a piezoelectric sheet using the slurry using a tape casting process.

[0016] The step of preparing an insertion template sheet including the above-described plate-shaped BT (BaTiO3) seeds includes the steps of preparing a slurry including powders of a matrix composition and performing ball milling; adding plate-shaped BT seeds to the slurry and mixing them; and manufacturing an insertion sheet using the slurry through a tape casting process. The slurry including the powders of the above-described matrix composition includes 0.5Pb (Ni 1 / 3 Nb 2 / 3)O3-0.16PbZrO3-0.34PbTiO3 powder and slurry containing Li2CO3 powder.

[0017]

[0018] According to the present invention, by providing a method for manufacturing a laminated piezoelectric texture ceramic using a 2DD TGG process, tilting of the plate-shaped template seed mentioned above and dispersion with non-uniform orientation can be prevented.

[0019] In addition, according to the present invention, by providing a method for manufacturing a laminated piezoelectric texture ceramic using a 2DD TGG process, it is possible to prevent a deterioration in piezoelectric properties due to plastic deformation and density reduction of the piezoelectric ceramic during the firing process by manufacturing a BT insert template sheet by adding a piezoelectric ceramic matrix powder together.

[0020] In addition, according to the present invention, a thin insertion template ceramic sheet mainly composed of a mixture of plate-shaped BT seeds and matrix piezoelectric ceramic powder is manufactured, and then the thin insertion template ceramic sheet is inserted between layers of matrix piezoelectric ceramic sheets that do not include BT seeds and are thicker than the template sheet, thereby providing a piezoelectric ceramic having excellent crystal orientation through uniform alignment of BT seeds.

[0021]

[0022] FIG. 1 illustrates a flowchart of a method for manufacturing a layered piezoelectric texture ceramic using a 2DD TGG process according to one embodiment of the present invention.

[0023] Figure 2 illustrates a flowchart of a method for preparing an insert template sheet including a plate-shaped BT seed.

[0024] FIG. 3 illustrates a schematic diagram of a layered piezoelectric texture ceramic according to one embodiment of the present invention.

[0025] Figure 4 shows the appearance of the laminated piezoelectric texture ceramic of Figure 3 after sintering.

[0026] Figure 5 shows the XRD patterns of textured PNN-PZT by 2DD and 3DD TGG sintered at 1000°C for 15 hours.

[0027] Figure 6 shows FE-SEM images of textured PNN-PZT by 2DD and 3DD TGG sintered at 1000°C for 15 hours.

[0028] Figure 7 shows the piezoelectric properties of textured PNN-PZT by 2DD and 3DD TGG sintered at 1000°C for 15 hours.

[0029] Figure 8 shows a cross-sectional photograph of a layered piezoelectric crystal orientation ceramic manufactured according to the manufacturing method of the present invention (2DD TGG method).

[0030] Figure 9 shows a cross-sectional photograph of a piezoelectric crystal orientation ceramic manufactured according to a conventional manufacturing method (3DD TGG method).

[0031] Various embodiments are now described with reference to the drawings, wherein like reference numerals are used throughout the drawings to designate like elements. For purposes of explanation, various descriptions are provided herein to facilitate an understanding of the present invention. However, it will be apparent that these embodiments may be practiced without these specific descriptions. In other instances, well-known structures and devices are presented in block diagram form to facilitate the description of the embodiments.

[0032]

[0033] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. The present invention is susceptible to various modifications and variations, and thus specific embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific disclosed form, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention. Throughout the description of each drawing, similar reference numerals have been used to designate similar components.

[0034] The terminology used in this application is only used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, it should be understood that the terms "comprise" or "have" indicate the presence of a feature, step, operation, component, part, or combination thereof described in the specification, but do not preclude the possibility of the presence or addition of one or more other features, steps, operations, components, parts, or combinations thereof.

[0035] In the present invention, the insertion BT template sheet means an insertion template sheet having a very thin thickness mainly composed of a mixture of plate-shaped BT seeds and matrix piezoelectric ceramic powder.

[0036] The present invention relates to a method for improving piezoelectric and electrical properties by preventing tilting and dispersion of plate-shaped template seeds with non-uniform orientation when manufacturing a laminated piezoelectric texture ceramic using plate-shaped template seeds such as BT seeds, thereby ensuring good alignment. In addition, the present invention solves the problem of deterioration of piezoelectric properties due to plastic deformation and density reduction of piezoelectric ceramics caused by the formation of empty spaces due to volatilization of organic substances during the firing process when using an insertion template sheet composed of plate-shaped template seeds. The present invention provides a method for manufacturing a laminated piezoelectric texture ceramic having excellent crystal orientation through uniform alignment of BT seeds through a structure in which an insertion template sheet mainly composed of a mixture of plate-shaped BT seeds and matrix piezoelectric ceramic powder is manufactured and then inserted between layers of matrix piezoelectric ceramic sheets that do not include BT seeds.

[0037] In the present invention, rather than using BT seeds, an insertion template sheet including BT is inserted into the middle of a matrix piezoelectric ceramic sheet that does not include BT seeds, thereby ensuring good arrangement of BT seeds, and at the same time, by manufacturing the insertion template sheet including BT by adding matrix piezoelectric ceramic powder together, the piezoelectric properties are prevented from being deteriorated due to plastic deformation and density reduction of the piezoelectric ceramic.

[0038] FIG. 1 illustrates a flowchart of a method for manufacturing a layered piezoelectric texture ceramic using a 2DD TGG process according to one embodiment of the present invention.

[0039] As illustrated in FIG. 1, a method for manufacturing a laminated piezoelectric texture ceramic according to an embodiment of the present invention includes a step of preparing a matrix piezoelectric ceramic sheet (S 110); a step of preparing an insertion template sheet including plate-shaped BT (BaTiO3) seeds (S 120); a step of arranging the matrix piezoelectric ceramic sheet (S 130); a step of sequentially stacking the insertion template sheet on the matrix piezoelectric ceramic sheet; and a step of repeatedly stacking and arranging the matrix piezoelectric ceramic sheets one or more times (S 140); and a step of sintering the laminated body (S 150).

[0040] In step S 110, a matrix piezoelectric ceramic sheet that does not include a plate-shaped BT seed is prepared. This matrix piezoelectric ceramic sheet does not include a plate-shaped seed (e.g., a BT seed).

[0041] The matrix piezoelectric ceramic can be any piezoelectric ceramic that can be manufactured into a plate shape using the Templated Grain Growth (TGG) process. Specific examples include:

[0042] 0.68PMN-0.32PT, 0.42PMN-0.21PZ-0.37PT, 0.675PMN-0.325PT, 0.675PMN-0.325PT, 0.4PMN-0.25PZ-0.35PT + 1 mol% MnO2, 0.4PMN-0.25PZ-0.35PT , 0.6PMN-0.4PT , 0.36PIN-0.30PMN-0.34PT , 0.28PIN-0.40PMN-0.32PT, 0.36PIN-0.30PMN-0.34PT + 0.5 wt% Li2CO3, 0.69Pb(Zr 0.47 Ti 0.53 )O3-0.31Pb(Zn 0.6 Ni 0.4)NbO3, 0.76PMN-0.24PT , 0.16PYN-0.52PMN-0.32PT + 0.25 wt% CuO , 0.05PMnS-0.95[0.4PMN-0.25PZ-0.3PT], 0.675PMN-0.325PT , 21PYN-41PMN-38PT + 1.2 mol% CuO , 0.55PNN-0.15PZ-0.3PT, 0.69PZT-0.31PZNN, 25PIN-40PMN-35PT + 2 mol% MnO2, 0.025BZZ-0.375BS-0.60PT, 0.19PIN-0.445PSN-0.365PT, 1.9mol% Sm-doped 0.71PMN-29PT , 0.4PMN-0.22PZ-0.38PT, 1 mol% Sm-doped 0.71PMN-29PT , 0.24PIN-0.42PMN-0.34PT + 2 mol% MnO2, 22PYN-41PMN-37PT + 1.2 mol% CuO, 0.4PMN-0.25PZ-0.35PT, 0.24PIN- 0.42PMN-0.34PT + 2 mol% MnO2+ 0.25 wt% CuO , 0.42PNN-0.21PZ-0.37PT, 0.672PMN-0.28PT, 0.42PMN-0.25PZ-0.33PT +0.75 wt% CuO, 0.4PMN-0.22PZ-0.38PT, 0.36PNN-0.24PZ-0.40PT, 0.24PIN-0.42PMN-0.34PT + 2 mol% MnO2+ 0.25 wt% CuO , 2.5 mol% Eu-doped 0.72PMN-28PT , 0.25PIN-0.40PMN-0.35PT + 2 mol% MnO2, 0.19PIN-0.445PSN-0.365PT + 2 mol% MnO2, 0.24PIN-0.42PMN-0.34PT + 2 mol% MnO2+ 0.25 wt% CuO , 0.40BS-0.60PT + 0.125 mol% Nb, 2.5 mol% Sm-doped 0.74PMN-0.26PT , 0.27PIN-0.41PMN-0.32PT + 2 mol% MnO2, 1 mol% Sm-doped 0.70PMN-0.30PT , 0.14PMnN-0.473PZ-0.387PT + 1 mol% CuO, 0.40BS-0.60PT, 0.76PMN-0.24PT, 0.47PNN-0.228PZ-0.302PT + 1 mol% CuO, 0.36PNN-0.25PZ-0.39PT, 0.15PSN-0.55PMN-0.30PT, 0.24PNT-0.34PZ-0.42PT, (Ba. 0.85 Ca 0.15 (Zr) 0.1 Ti 0.9 )O3, 0.5Ba(Zr 0.2 Ti 0.8 )O3-0.5(Ba 0.7 Ca 0.3 TiO3, 0.55(K) 0.5 Na 0.5 NbO3-0.45(Ba) 0.85 Ca 0.15 (Ti) 0.1 Zr 0.9 (O3, (Ba 0.95 Ca 0.05 (Zr) 0.04 Ti 0.96 (O3+ 2.5 mol% CuO, 0.134) K 0.5 Bi 0.5 TiO3-0.066BaTiO3-0.8Na 0.5 Bi 0.5 TiO3, (Ba 0.95 Ca 0.05 (Ti) 0.92 Zr 0.06 Sn 0.02 (O3, 0.76(Bi)) 0.5 Na 0.5 )TiO3-0.24SrTiO3

[0043] 여기서 PMN = Pb(Mg 1 / 3 Nb 2 / 3 )O3, PNN = Pb(Ni 1 / 3 Nb 2 / 3 )O3, PZ = PbZrO3, PT = PbTiO3, PIN = Pb(In 1 / 3 Nb 1 / 2 )O3, PYN = Pb(Yb 1 / 2 Nb 1 / 2 )O3, PMnS = Pb(Mn 1 / 3 Sb2 / 3 )O3, PZNN = Pb(Zn 0.6 Ni 0.4 )NbO3, PSN = Pb(Sc 1 / 2 Nb 1 / 2 )O3, BZZ = Bi(Zn 1 / 2 Zr 1 / 2 )O3, BS = BiScO3, PNT = Pb(Ni 1 / 3 Ta 2 / 3 ) is O3.

[0044] In an embodiment of the present invention, the step of preparing a matrix piezoelectric ceramic sheet comprises: 0.5Pb(Ni 1 / 3 Nb 2 / 3 ) A step of preparing a slurry including a powder having a composition of O3-0.16PbZrO3-0.34PbTiO3 and a Li2CO3 powder and performing ball milling; and a step of manufacturing a piezoelectric sheet using the slurry using a tape casting process.

[0045] First, 0.5Pb(Ni 1 / 3 Nb 2 / 3 ) Prepare a slurry containing powder of the composition O3-0.16PbZrO3-0.34PbTiO3 and Li2CO3 powder, and perform ball milling.

[0046] In this case, the above 0.5Pb(Ni 1 / 3 Nb 2 / 3 )O3-0.16PbZrO3-0.34PbTiO3 powder is manufactured by weighing the molecular weight of PbO, NiO, Nb2O5, ZrO2, and TiO2 raw materials according to the composition formula of 0.5PNN-0.16PZ-0.34PT, and using the product manufactured by calcining at a temperature of 800 to 900°C for 3 to 5 hours. In this case, calcination is preferably performed at 850°C for 4 hours.

[0047] After adding 0.1 to 0.4 wt% of Li2CO3 powder to the powder after the above calcination is completed, ball milling is performed and drying is performed to obtain the above 0.5Pb(Ni 1 / 3 Nb 2 / 3)O3-0.16PbZrO3-0.34PbTiO3 powder and Li2CO3 powder are obtained. In this case, it is preferable to add the Li2CO3 powder in an amount of 0.2 wt% of the total mass. In this case, the ball mill is performed for 40 to 50 hours in an ethanol solvent, and the drying is performed at about 100°C to 150°C, preferably for 48 hours in an ethanol solvent, and the drying is preferably performed at about 120°C.

[0048] In addition, in step S 110, it is preferable to perform ball milling of the slurry by mixing and grinding zirconia balls together under an ethanol solvent for 4 to 24 hours.

[0049] 0.5Pb(Ni) in slurry 1 / 3 Nb 2 / 3 )O3-0.16PbZrO3-0.34PbTiO3 powder and Li2CO3 powder content is preferably 61 to 65 wt%, and most preferably 63 wt%, to obtain a piezoelectric ceramic sheet having a thickness of 15 to 25 μm, preferably about 17 μm.

[0050] In step S 120, an insertion template sheet including a plate-shaped BT seed is prepared. Fig. 2 illustrates a flowchart of a method for preparing an insertion template sheet including a plate-shaped BT seed.

[0051] As illustrated in FIG. 2, a method for preparing an insertion template sheet including plate-shaped BT seeds includes a step of preparing a slurry including powder of a matrix composition and performing ball milling (S 210); a step of adding plate-shaped BT template seeds to the slurry and mixing them (S 220); and a step of manufacturing an insertion sheet using the slurry through a tape casting process (S 230).

[0052] The slurry containing the powder of matrix composition 0.5Pb(Ni 1 / 3 Nb 2 / 3)O3-0.16PbZrO3-0.34PbTiO3 powder and a slurry containing Li2CO3 powder. 0.5Pb(Ni 1 / 3 Nb 2 / 3 )O3-0.16PbZrO3-0.34PbTiO3 powder is manufactured by weighing the molecular weight of PbO, NiO, Nb2O5, ZrO2, and TiO2 raw materials according to the composition formula of 0.5PNN-0.16PZ-0.34PT, and using the product manufactured by calcining at a temperature of 800 to 900°C for 3 to 5 hours. In this case, calcination is preferably performed at 850°C for 4 hours.

[0053] After adding 0.1 to 0.4 wt% of Li2CO3 powder to the powder after the above calcination is completed, ball milling is performed and drying is performed to obtain the above 0.5Pb(Ni 1 / 3 Nb 2 / 3 )O3-0.16PbZrO3-0.34PbTiO3 powder and Li2CO3 powder are obtained. In this case, it is preferable to add the Li2CO3 powder in an amount of 0.2 wt% of the total mass. In this case, the ball mill is performed for 40 to 50 hours in an ethanol solvent, and the drying is performed at about 80°C to 100°C, preferably for 48 hours in an ethanol solvent, and the drying is preferably performed at about 90°C.

[0054] In the above slurry, a plate-shaped template seed and 0.5Pb(Ni 1 / 3 Nb 2 / 3 ) The content of the powder having the composition of O3-0.16PbZrO3-0.34PbTiO3 and the Li2CO3 powder is 50 to 65 wt%, and preferably, an insert sheet having a thickness of 5 μm can be obtained at 60 wt%.

[0055] In the present invention, a plate-shaped BT template sheet can be used as an insert sheet, and available plate-shaped template sheets include BaTiO3, SrTiO3, and Bi4Ti3O. 12, PbTiO3, (Bi,Na)TiO3, (Bi,Na)TiO3-BT, etc., and among these, BaTiO3 seed (BT seed) was selected as having the best texture effect.

[0056] It is preferable that the thickness of the insert template sheet be thinner than the thickness of the matrix piezoelectric ceramic sheet.

[0057] In step S 130, a matrix piezoelectric ceramic sheet that does not include the plate-shaped seeds prepared in step S 110 is placed.

[0058] In step S 140, the insertion template sheet and the matrix piezoelectric ceramic sheet are sequentially stacked and placed on the matrix piezoelectric ceramic sheet placed in step S 130, and this is repeated at least once.

[0059] That is, in step S 130, a matrix piezoelectric ceramic sheet not including a plate-shaped seed is placed at the bottom, an insertion template sheet is placed thereon, and then a matrix piezoelectric ceramic sheet not including a plate-shaped seed is placed thereon again, thereby being continuously laminated one or more times. Therefore, in the laminated structure, the topmost layer becomes a matrix piezoelectric ceramic sheet not including a plate-shaped seed again. That is, the lower and upper layers each have matrix piezoelectric ceramic sheets not including a plate-shaped seed placed thereon, and an insertion template sheet including a BT seed is alternately placed with the matrix piezoelectric ceramic sheet not including a plate-shaped seed therebetween. This will be described in more detail in the following embodiments.

[0060] At step S150, the laminated laminate is sintered. Simultaneous sintering is also possible using a co-firing Ag electrode. After sintering, dry or wet polarization (air poling or wet poling) can be performed using an electric field.

[0061] The sintering step can be performed in an oxygen atmosphere at a temperature of 900 to 1025°C for 5 to 20 hours, preferably at a temperature of 975 to 1025°C for 10 to 20 hours, and most preferably at a temperature of 1000°C for 15 hours. In this case, the heating rate to reach the sintering temperature is 1°C / min. Meanwhile, when sintering is performed, co-sintering is also possible using an Ag electrode for simultaneous firing. After sintering, dry or wet polarization (air poling or wet poling) can be additionally performed using an electric field.

[0062] Ceramic properties (e.g., d) of the laminated piezoelectric texture ceramic according to one embodiment of the present invention manufactured in this manner 33 The characteristics, etc.) were measured, and these piezoelectric structures can be used as actuators, transducers, sensors, and energy harvesters.

[0063] Below, the contents of the present invention will be further explained with specific examples.

[0064]

[0065] [Example 1]

[0066] Fig. 3 is a schematic diagram of a laminated piezoelectric texture ceramic according to an embodiment of the present invention, and Fig. 4 illustrates the appearance of the laminated piezoelectric texture ceramic of Fig. 3 after sintering. Figs. 3 and 4 illustrate the appearance before and after sintering of a laminated piezoelectric texture ceramic according to an embodiment of the present invention manufactured by a 2DD TGG (Two-dimensionally-disperesed template grain growth) process. In Fig. 3, a thin PNN-PZT sheet (thin insert template sheet) having a 2DD BT template is placed between BT-free PNN-PZT green sheets (matrix piezoelectric ceramic sheets).

[0067] The matrix piezoelectric ceramic can be any piezoelectric ceramic that can be manufactured into a plate shape through the TGG (Templated Grain Growth) process, but in the examples, PNN-PZT+LC was used.

[0068]

[0069] 1) 0.5Pb(Ni 1 / 3 Nb 2 / 3 )O30.16PbZrO3-0.34PbTiO3+0.2 wt% Li2CO3 Piezoelectric Powder Synthesis

[0070] 0.5Pb(Ni 1 / 3 Nb 2 / 3 )O3-0.16PbZrO3-0.34PbTiO3(0.5PNN-0.16PZ-0.34PT) piezoelectric powder was synthesized using a general solid-state synthesis method, and the raw materials used were PbO (Kojundo Chemical, 99.99%, Japan), NiO (Kojundo Chemical, 99.9%, Japan), Nb2O5(Kojundo Chemical, 99.9%, Japan), ZrO2(Kojundo Chemical, 98%, Japan), and TiO2(Kojundo Chemical, 99.9%, Japan). First, the raw material powders were weighed according to the composition formula of 0.5PNN-0.16PZ-0.34PT and placed in a polyethylene bottle together with zirconia balls (ф= 1 mm, 3 mm, 5 mm, 10 mm), and ball milled for 24 hours, and then 90 o Drying was carried out in a C oven. The dried powder was placed in a sealed alumina crucible and 5 o 850 at a heating rate of C / min o Calcination was performed at C for 4 hours. After adding 0.2 wt% of Li2CO3 (Kojundo Chemical, 99.9%, Japan) powder to the mass of the powder after calcination, it was placed in a polyethylene bottle together with ethanol and zirconia balls (ф = 1 mm, 3 mm, 5 mm, 10 mm), and ball milled for 48 hours, and then 90 oC was dried in an oven to obtain calcined powder of 0.5PNN-0.16PZ-0.34PT+0.2 wt% Li2CO3 (PNN-PZT+LC).

[0071]

[0072] 2) 0.5Pb(Ni 1 / 3 Nb 2 / 3 )O3-0.16PbZrO3-0.34PbTiO3+0.2 wt% Li2CO3green sheet production

[0073] Ethanol (99.9%, Daejung Chemicals, Korea), toluene (99.9%, Daejung Chemicals, Korea), dibutyl phthalate (99%, Daejung Chemicals, Korea), polyvinyl butyral (BM-SZ, Sekisui, Japan), a dispersant (BYK-111, BYK-chemie GmbH, Germany), and PNN-PZT+LC calcined powder were mixed in various ratios as shown in Table 1 below and placed in a polyethylene bottle with zirconia balls (ф = 3 mm, 5 mm, 10 mm), followed by mixing and grinding for 24 hours. The slurry was sieved using a mesh cloth, and a defoaming process was performed for 10 minutes in a vacuum defoamer to remove any residual air bubbles in the slurry. The defoamed slurry was aged at 15 rpm for 2 hours. The stabilized slurry was subjected to a tape casting process with a blade gap of 60 μm and a casting speed of 1 m / min. As a result, green sheets were successfully obtained from #1 to #5, and among them, the optimal PNN-PZT+LC green sheet with a thickness of 17 μm was produced from #3. Regarding the optimal thickness, the particles grow in the crystal orientation direction from the BT plate-shaped seed upwards, downwards, and laterally during sintering centered on the inserted BT template sheet. In this case, the thickness of the matrix piezoceramic layer ultimately determines the size of the textured particles. Therefore, the growth conditions of the textured particles are determined by the sintering temperature and time, and #3 was preferable under the conditions of Example 1.

[0074]

[0075] No.(wt% ratio)PNN-PZT+LC(wt%)Ethanol(wt%)Toluene(wt%)Dibutyl phthalate(wt%)Dispersant(wt%)Polyvinyl butyral(wt%)#1 (61:39)6112.3420.291.400.294.686139#2 (62:38)6212.0219.771.370.284.566238#3 (63:37)6311.7119.251.330.284.436337#4 (64:36)6411.3918.731.290.274.326436#5 (65:35)6511.0718.211.260.264.206535

[0076] 3) Production of PNN-PZT+LC+BaTiO3micro-platelet green sheet

[0077] PNN-PZT+LC powder, ethanol (99.9%, Daejung Chemicals, Korea), toluene (99.9%, Daejung Chemicals, Korea), dibutyl phthalate (99%, Daejung Chemicals, Korea), dispersant (BYK-111, BYK-chemie GmbH, Germany), and polyvinyl butyral (BM-SZ, Sekisui, Japan) were mixed in various ratios as shown in Table 2 and placed in a polyethylene bottle with zirconia balls (ф = 3 mm, 5 mm, 10 mm). The mixture was stirred at 2000 rpm for 1 hour to prepare a slurry. The slurry was sieved through a mesh cloth, and BaTiO3 micro-platelets and a small amount of ethanol were added to the vial in the ratios shown in Table 2 below, dispersed in a sonicator for 5 minutes, and then mixed with the slurry. To remove residual air bubbles in the slurry, a degassing process was performed for 10 minutes using a vacuum deaerator, and an aging process was performed for 2 hours at 15 rpm to stabilize the slurry. The stabilized slurry was tape-casted under the conditions of a blade gap of 8 μm and a casting speed of 1 m / min, and green sheets were successfully obtained from #1 to #4, and among them, the optimal PNN-PZT+LC+BaTiO3 micro-platelet (PNN+BT) green sheet with a thickness of 5 μm was produced from #2. The thinner the BT template sheet, the better, because the BT plate-like seeds can be well arranged horizontally and contribute to the improvement of the crystal orientation.

[0078]

[0079] No.(wt% ratio)BT seed(wt%)PNN-PZT+LC(wt%)Ethanol(wt%)Toluene(wt%)Dibutyl phthalate(wt%)Dispersant(wt%)Polyvinyl butyral(wt%)#1 (65:35)6.8558.1511.0718.211.260.264.206535#2 (60:40)8.3253.6812.6520.811.440.304.806040#3 (55:45)5.8049.2014.2423.411.620.345.395545#4 (50:50)5.2744.7315.8226.021.800.375.995050

[0080] 4) Manufacturing and firing of ceramic laminates

[0081] In order to manufacture a ceramic laminate, PNN-PZT+LC green sheets and PNN+BT green sheets obtained by the tape casting process were laminated one by one at a time under the conditions of 60°C and 10 MPa, as shown in Fig. 5 (a total of 20 layers were laminated repeatedly. In this case, the gaps between the PNN+BT green sheets can be arranged to be large because there are no BT seeds in the matrix ceramic sheet, so the texture particles do not collide while growing), and a ceramic laminate having a thickness of 1.2 mm was finally manufactured. The manufactured laminate was laminated at 65 o A warm isostatic pressing (WIP) process was performed for 20 minutes under conditions of C and 25 MPa. The ceramic laminate after WIP was cut into 10 mm x 10 mm sizes using a blade cutter. 1 o 300 at a heating rate of C / min o 5 hours at C, 600 o After maintaining the ceramic laminate for 5 hours at C to burn out the remaining organic substances, the cold isostatic pressing (CIP) process was performed at a pressure of 200 MPa for 1 minute. The specimen after CIP was stored in an oxygen atmosphere for 1 o900 at a heating rate of C / min o C to 1025 o Sintering was performed for 15 hours at various sintering temperatures up to C. Ag paste was screen-printed on both sides of the sintered ceramic element and 700 o Heat treatment was performed at C for 10 minutes and 25 o The characteristics of the device were evaluated after a poling process was performed for 20 minutes in an electric field of 3 kV / mm in silicone oil of C.

[0082]

[0083] 5) Review

[0084] Figure 5 shows XRD patterns of textured PNN-PZT by 2DD and 3DD TGG sintered at 1000°C for 15 hours. 2DD TGG stands for Two-dimensionally-dispersed template grain growth and is a method used in the present invention, and 3DD TGG stands for Three-dimensionally-dispersed template grain growth and is a method used in the prior art.

[0085] Fig. 6 shows FE-SEM images of textured PNN-PZT by 2DD and 3DD TGG sintered at 1000°C for 15 hours, and Fig. 7 shows piezoelectric properties of textured PNN-PZT by 2DD and 3DD TGG sintered at 1000°C for 15 hours. The results of evaluating the properties of the devices after printing electrodes on the sintered ceramic devices and performing the poling process are shown. As shown in Fig. 7, in the case of the laminated piezoelectric textured ceramic manufactured according to the manufacturing method of the present invention (2DD TGG), the sintering temperature is 975 to 1025°C, preferably 1000°C. 33 The values ​​are and k p The value was found to be the maximum and the figure was d of 1334 pC / N 33 value and 92.4% k p I confirmed that the value appeared.

[0086] Fig. 8 shows a cross-sectional photograph of a layered piezoelectric crystal-oriented ceramic manufactured according to the manufacturing method of the present invention (2DD TGG method). Fig. 9 shows a cross-sectional photograph of a piezoelectric crystal-oriented ceramic manufactured according to a conventional manufacturing method (3DD TGG method) (using randomly dispersed BT seeds).

[0087] In the case of Fig. 8, a very high degree of texture could be observed through the appearance of horizontally arranged textured particles. In this case, it was confirmed that the plate-shaped template seeds were well arranged without tilting or non-uniform orientation. In other words, in the present invention, a textured piezoelectric crystal-oriented ceramic could be manufactured using a BT seed template sheet uniformly arranged in the horizontal direction.

[0088] Figure 9 shows a case where BT seeds were randomly added in a slurry manufacturing process according to a conventional manufacturing method. It was observed that irregularly arranged texture grains were present, and a normal texture was observed. (Figure 9 shows non-horizontally arranged BT templates.)

[0089] Table 3 below shows comparative data. As shown in Table 3, when a laminated piezoelectric texture ceramic is manufactured using a manufacturing method (2DD TGG) according to an embodiment of the present invention and a manufacturing method of the prior art (3DD TGG), the d is significantly higher than that of the manufacturing method of the prior art (randomly dispersing BT templates). 33 The values ​​are and k p You can check the value.

[0090]

[0091]

[0092] Although the present invention has been described above with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes may be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below.

Claims

1. Step of preparing a matrix piezoelectric ceramic sheet; A step of preparing an insertion template sheet including plate-shaped BT (BaTiO3) seeds; A step of placing the above matrix piezoelectric ceramic sheet; A step of sequentially stacking and arranging the insert template sheet on the matrix piezoelectric ceramic sheet; and the matrix piezoelectric ceramic sheet, repeating the process at least once; and Comprising a step of sintering the laminated body, Method for manufacturing a layered piezoelectric textured ceramic.

2. In paragraph 1, The above matrix piezoelectric ceramic sheet does not contain plate-shaped BT seeds, Method for manufacturing a layered piezoelectric textured ceramic.

3. In paragraph 1, The thickness of the above insert template sheet is thinner than the thickness of the above matrix piezoelectric ceramic sheet. Method for manufacturing a layered piezoelectric textured ceramic.

4. In paragraph 1, The above matrix piezoelectric ceramic is a piezoelectric ceramic that can be manufactured into a plate-shaped sheet through the TGG (Templated Grain Growth) process. Method for manufacturing a layered piezoelectric textured ceramic.

5. In paragraph 1, The step of preparing the above matrix piezoelectric ceramic sheet is: 0.5Pb(Ni 1 / 3 Nb 2 / 3 ) A step of preparing a slurry including powder having a composition of O3-0.16PbZrO3-0.34PbTiO3 and Li2CO3 powder and performing ball milling; and A step of manufacturing a piezoelectric sheet using the above slurry using a tape casting process, Method for manufacturing a layered piezoelectric textured ceramic.

6. In paragraph 1, The step of preparing an insertion template sheet including the above plate-shaped BT (BaTiO3) seed is as follows: A step of preparing a slurry including powder of matrix composition and performing ball milling; A step of adding plate-shaped BT seeds to the above slurry and mixing them; and A step of manufacturing an insert sheet using the above slurry through a tape casting process, Method for manufacturing a layered piezoelectric textured ceramic.

7. In paragraph 6, The slurry containing the powder of the above matrix composition contains 0.5Pb(Ni 1 / 3 Nb 2 / 3 )O3-0.16PbZrO3-0.34PbTiO3 powder and slurry containing Li2CO3 powder, Method for manufacturing a layered piezoelectric textured ceramic.

8. Manufactured according to the method for manufacturing a laminated piezoelectric texture ceramic according to any one of claims 1 to 7. Layered piezoelectric textured ceramics.

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