TW200900371A - Method for manufacturing piezoelectric ceramic - Google Patents

Abstract

The invention relates to a manufacturing method of piezoceramics (piezoelectrics layer 2) which manufactures piezoceramics by sintering piezoelectric material contained TiO2 raw material, ZrO2 raw material and PbO raw material as main components. The method is charactered in that content range of P2O5 mixed into piezoelectric material is from 40ppm to 350ppm, the P2O5 in form of being contained to TiO2 raw material and ZrO2 raw material is mixed into piezoelectric material. When piezoelectric material used in piezoceramics contains P, the P in form of P2O5 through TiO2 raw material and ZrO2 raw material is mixed with amount of above-mentioned range, piezoelectric strain property can be increased remarkably.

Description

200900371 IX. Description of the Invention: [Technical Field] The present invention relates to a method of manufacturing a pressure electromagnetic device. [Prior Art]

C Previously, (iv) components were used in, for example, phono, sensor, paste = various uses. Then, as a repetitive electric component, a single-plate dust electric appliance and a laminated type electric component are known. The single-electrode element has a structure in which a tantalum layer formed of a repeating electromagnetic device is formed between a pair of electrode layers. The laminated piezoelectric element has a structure in which a piezoelectric layer and an internal electrode are alternately laminated. In the laminated piezoelectric element, the two end faces of the lamination direction of the element body are covered by a protective layer formed of a plurality of piezoelectric layers. A material of a magical electromagnetic device used in such a piezoelectric element is disclosed in Japanese Laid-Open Patent Publication No. Hei 5-24917. SUMMARY OF THE INVENTION In recent years, it has been desired to further improve the piezoelectric strain characteristics of the piezoelectric layer of the above-mentioned electromagnetic device. Then, the inventors of the present invention conducted intensive studies, and as a result, newly discovered techniques capable of remarkably improving the piezoelectric strain characteristics. That is, the object of the present invention is to provide a method of manufacturing a pressure electromagnetic device which can improve piezoelectric strain characteristics. The singer found that the piezoelectric material used in the pressure electromagnetic device contains Ρ2Ρ5, so that the Ρ2〇5 is injected into the piezoelectric material from the Ti〇2 raw material and Zr02 in a specific range. In the case of materials, the piezoelectric strain characteristics can be remarkably improved to complete the present invention. In other words, the method for producing a pressure electromagnetic device according to the present invention is to produce a piezoelectric material by firing a piezoelectric material containing TiO 2 129184.doc 200900371 material, Zr 〇 2 raw material, and Pb 〇 raw material as main components, and Ti〇 The P2〇5 system of the raw material and the Zr〇2 raw material is mixed into the piezoelectric material in a content range of 40 ppm or more and 350 ppm or less. The local Mingk is used to improve the piezoelectric electromagnetic properties of piezoelectric strainers. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the best mode for carrying out the invention will be described in detail with reference to the accompanying drawings.

state. In addition, the same elements or the same elements are denoted by the same reference numerals, and the description is omitted when the description is repeated. Referring to Fig. 1, a piezoelectric element manufactured by the manufacturing method according to the embodiment of the present invention is described. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing a piezoelectric device of an embodiment of the present invention. The piezoelectric element 1 shown in Fig. is a single-plate piezoelectric element having a piezoelectric layer 2 of a piezoelectric actuator and a __ counter electrode layer disposed so as to sandwich the piezoelectric layer. When a voltage is applied between the electrodes 3A and 3B, an electric field is generated in the piezoelectric layer 2 sandwiched by the electrode 3B, and the piezoelectric element is displaced (stretching operation). The piezoelectric layer 2 is mainly composed of a piezoelectric material of PZT糸 piezoelectric ceramic, and the piezoelectric material of the piezoelectric layer 2 contains phosphorus. The phosphonium is present in the piezoelectric material in the form of an atom, an oxide or a compound of the b metal contained in the piezoelectric layer 2. It is relatively dispersed in the electric layer 2. The electrode layer 3a is a conductive layer mainly composed of a metal. As a package 129184.doc 200900371 metal contained in the metal layers 3A, 3B, for example, Ag, Au, Cu, Ni,

Pd or an alloy of such metals (for example, an Ag-Pd alloy) or the like. Next, the manufacturing procedure of the above piezoelectric element will be described with reference to Fig. 2 . Fig. 2 is a flow chart showing a method of manufacturing a piezoelectric element according to an embodiment of the present invention. When the piezoelectric element 1 is manufactured, the starting material is first prepared (step su). This starting material contains a PZT-based piezoelectric material as a main component. As the piezoelectric material, powder materials such as PbO, Ti〇2, Zr〇2, Zn0, and her can be listed. Each of the raw materials is weighed so that the powdery raw materials reach a specific composition ratio.

Next, the above plurality of starting materials are subjected to wet mixing for about 24 hours by using a stabilized zirconia ball as a medium ball mill (step S12). Then, the mixed raw materials are dried (step si3). Next, the mixed raw material is subjected to heat treatment at a temperature of, for example, about 850 ° C for about 2 hours to carry out preliminary calcination (step S14). Thereby obtaining the main content

A raw material composition of a composite oxide oxide material of a titanium ore structure having a Pb, Zr, and Ti element. After the raw material composition is subjected to wet pulverization by a ball mill (step (1))' is dried (step S16)', a powder (piezoelectric powder) of the raw material composition is obtained. Then, a binder such as a polyvinyl alcohol is added to the pressure electromagnetic powder to be granulated (step s), and formed into a gusset shape by press molding or the like (step s 18). Thereby, 3ft p A ^ ) is passed down to become the piezoelectric body of the piezoelectric device. After the obtained piezoelectric green sheet is placed on a stable oxidizing errone or the like, it is heated in an atmosphere to remove a binder or the like contained in the piezoelectric green sheet (step S19: Remove the binder). 129184.doc 200900371 Then, the piezoelectric green sheet is heated for about 2 hours at a temperature of, for example, 1050 to 1200 ° C in a closed rice bowl to perform a baking treatment (main baking) (step S20) ). Finally, the silver paste is fired on both faces of the obtained fired body to form electrode layers 3A and 3B (step S21). Thereby, the piezoelectric element j of FIG. 1 is obtained, and the piezoelectric element 1 is composed of a piezoelectric layer 2 which is fired as a piezoelectric actuator, and an electrode layer 3A which is fired on both faces of the piezoelectric layer 2. 38. The inventors have found that, as described above, in order to add P to the piezoelectric material, when P2〇5 is mixed from the Ti〇2 raw material and the Zr〇2 raw material into the piezoelectric material, it is added directly to the piezoelectric material. In comparison with the case of p, a pressure electromagnetic device having excellent piezoelectric strain characteristics (d3 1) can be obtained. Here, the content of the Ti〇2 powder raw material in the piezoelectric material and the content of the lanthanum element of the 21> 〇2 powder raw material are converted into the content of P2〇5, and the content is adjusted to 40 ppm or more according to the molar standard. In the range of 35 〇ppm or less, the phosphorus element in which the content is mixed in the piezoelectric material "If the content of the phosphorus element is less than 40 ppm, the sintering of the piezoelectric material by firing is insufficient, and the piezoelectric layer 2 is present. The density is low and it is difficult to obtain a sufficient displacement. On the other hand, if the content of phosphorus exceeds 35 〇 ppm, the value of the piezoelectric strain constant (d31) will be lower than the practical level. Further, after the electrode layer 3A and the galvanic steel β (for example, a paste containing an Ag-Pd alloy) are applied onto the piezoelectric green sheet without using the above method, the removal of the binder is performed (step Sl9) and the main firing (step M0), which can also be obtained with the map! The piezoelectric element is the same component. In this case, although the metal contained in the electrode paste layer is easily diffused in the piezoelectric green sheet during the main firing, the phosphorous element which is easily reacted with the metal is dispersed in the piezoelectric green sheet. Therefore, the metal spreads evenly in the piezoelectric green sheets. As a result, the piezoelectric green sheet (piezoelectric layer 2) which is sintered is more uniformly shrunk than the case where the piezoelectric green sheet does not contain phosphorus. As a result, the piezoelectric layer 2 has a shape with a small strain, and the strain of the piezoelectric element 1 as a whole is also small. [Embodiment 1] Hereinafter, the present invention will be described in more detail by way of examples.

(Example) First, the powder (starting material) of the raw material composition of the piezoelectric material was obtained by performing steps S11 to S16 shown in Fig. 2 . Ti02 and Zr〇2 containing P2〇5, and Pb〇, Zn〇, and Nb2〇5 are contained in the starting material. Then, the starting materials were weighed and mixed to obtain Pbo.wlXZninNb2/3) after firing.压Ti〇 44zr〇 46]〇3 is composed of a pressure electromagnetic device. Next, as shown in step S17, the powder of the raw material composition of the piezoelectric material is granulated by adding a polyvinyl alcohol-based binder, and then the press forming shown in step S18 is performed under conditions of about 196 MPa. A piezoelectric body piece having a gusset shape having a side length of about 20 mm and a thickness of 15 mm was obtained. Subsequent processing As shown in step S19, the piezoelectric green sheet is subjected to binder removal. As shown in step S20, the piezoelectric green sheet is placed in a sealed container of magnesium oxide (MgO). Thereby, a gusset shape was obtained. Finally, the obtained electromagnetic pressure was obtained by heating at 11 50 ° C for 2 hours. The pressure electromagnetic device is processed to have a height of 129184.doc -10·200900371^匪, and a silver burn-in electrode is formed on both sides thereof, thereby obtaining a veneer having the same piezoelectric element as shown in FIG. Piezoelectric element 侔 /, ^ 111111 x 3 mm). Further, in the above-mentioned (4), the single-plate piezoelectric element was subjected to polarization treatment (processing conditions: 3 kV/mm, 15 minutes).

压电 The piezoelectric strain constant of the single-plate piezoelectric element obtained in the above manner is measured. The measurement method is: according to the electrostatic capacitance, resonance frequency, and anti-resonance frequency measured by the impedance analyzer, #出出Piezoelectric strain constant X' was observed by a scanning electron microscope, and the average particle diameter of the electro-magnetic particles was used as a circular approximation diameter, and the image processing software (Mac View) was used for measurement. In the same manner as the above-described embodiment, the steps su to si6 shown in Fig. 2 are carried out to obtain a powder of the raw material composition of the piezoelectric material. The starting material contains D, 〇2, Zr〇2, Pb〇. , Zn〇, 仙2〇5, in which (4) reagent is added. Then 'the starting material added with Ρ2〇5 is weighed and mixed to obtain pb〇99 after firing [[Zn is warfare ^ Next, as shown in step S17, a powder of a raw material composition of the piezoelectric material is added to a powder of a 7 7 ρ β Α ethylene-based yeast to be granulated, and then granulated. Reporting under the condition of 96 MPa _ The press forming shown in step S18 A piezoelectric green sheet having a gusset shape having a side length of about 20 mm and a choice of r, and a size of 5 mm is obtained. ', and then, as shown in step S19, the piezoelectric green sheet is removed and bonded. The treatment of the agent, as shown in the boat c, 7 township S20, put the piezoelectric green sheet into the close contact of magnesium oxide (Mg〇). In the middle, heat at 1150 ° C for 2 hours to carry out the main treatment. Burning 129184.doc 200900371. Obtaining a slab-shaped pressure electromagnetic device. Finally, the obtained pressure electromagnetic device is processed to have a height of 1 〇mm, and then a silver burnt electrode is formed on both sides thereof. Thus, a single-plate piezoelectric element (12 mm x 3 mm) identical to that of the piezoelectric element shown in the figure is produced. Further, the single-plate piezoelectric element is polarized (processed in a 120 ° C stone oil) Conditions: 3 kV/mm, 15 minutes) The piezoelectric strain constant of the single-plate piezoelectric element obtained by the above method was measured in the same manner as in the example, and was observed by a scanning electron microscope (inspection of the electromagnetic device) The cross section is obtained by using an image processing software (Mac View) using the average particle diameter of the piezoelectric particles as a circular approximate diameter. The piezoelectric strain constants measured by the above examples and comparative examples are shown in the following Tables 1 and 3, wherein the horizontal axis of the graph in Fig. 3 indicates P2 in the piezoelectric material. The content of 5 (ppm), and the vertical axis represents the piezoelectric strain constant (pC/N). [Table 1] Example P2O5 Content (ppm) 40 150 250 350 450 d31 Characteristics (pC/N) 225 220 210 200 170 Comparative Example P2O5 content (Ppm) - 150 250 350 450 d31 Characteristics (pC/N) - 210 190 170 145 Based on these measurement results (tables in Table 1 and Figure 3), it is known that Ρζ〇5 is added directly to the piezoelectric material. Compared to the comparison example, make! >2〇5 The value of the piezoelectric strain constant of the example in which the powder raw material and the Zr〇2 powder raw material are mixed into the piezoelectric material becomes high. Further, the content of the Ti〇2 powder raw material in the piezoelectric material and the phosphorus element of the Zr〇2 powder raw material are converted into the content of cerium, and when the content is 350 ppm or less, according to the 129184.doc -12·200900371 ear standard The piezoelectric strain constant reaches a practically sufficient value (above 200 pC/Ν). On the other hand, if p2〇5 exceeds 350 ppm, the piezoelectric strain constant is lower than 200 Pc/N. Therefore, it is preferable that the ?2〇5 is not more than 350卩卩111 from the Τι〇2 raw material and the Zr〇2 raw material mixed into the piezoelectric material. Further, the microscope photographs of the examples and comparative examples are shown in Fig. 4 . After measuring the average particle diameter of the piezoelectric particles based on the 4 photographs, the horizontal axis of the graph of FIG. 5 and the graph of FIG. 5 is shown to be p2〇5 containing 1 (PPm) of the piezoelectric material, and the vertical axis represents the piezoelectric particles. Average particle size (μπι). Ο Based on the results of these measurements (photograph of Fig. 4 and the graph of Fig. 5), it can be seen that when the same concentration is 5 in the electrical material, and the ice is added to the piezoelectric material 2Ρ5 (Comparative Example) In contrast, in the case where the Ti 2 powder raw material and the ΖΓ〇 2 powder raw material are mixed into the piezoelectric material (Example), the obtained pressure electromagnetic device is composed of piezoelectric particles having a large average particle diameter. ', I7 is an average particle diameter of the comparative example when the specific P2〇5 content range (10) is more than m and 35 〇 ppm is compared with an arbitrary amount. As described above, the average particle diameter of the embodiment is larger than that of the comparative example. Therefore, the pressure electromagnetic device of the embodiment can achieve higher sintering. The present invention is not limited to the above embodiment, and various modifications can be made. Example: A two-plate piezoelectric element is used as an example to describe a piezoelectric element, but a laminated element type piezoelectric element can also be applied. BRIEF DESCRIPTION OF THE DRAWINGS A perspective view of a piezoelectric element according to an embodiment of the present invention is shown. 129l84.doc 200900371 Fig. 2 is a flow chart showing a method of manufacturing the piezoelectric element shown in Fig. 1. Fig. 3 is a graph showing the measurement results of the examples of the present invention. Fig. 4 is a photomicrograph showing the measurement results of the examples of the present invention. Fig. 5 is a graph showing the measurement results of the examples of the present invention. [Description of main component symbols] 1 Piezoelectric element 2 Piezoelectric layer 3A, 3B Electrode layer S11~S21 Step 129184.doc -14-

Claims (1)

200900371 X. Patent application scope: 1. A method for manufacturing a pressure electromagnetic device, which is a piezoelectric material obtained by firing a piezoelectric material containing Ti〇2 raw material, Zr〇2 raw material and PbO raw material as a main component, thereby producing a pressure electromagnetic device. The TiO2 raw material and the P205 contained in the Zr02 raw material are mixed into the piezoelectric material in a content of 40 ppm or more and 550 ppm or less. J 129184.doc