KR100276265B1 - A device and method for manufactoring the piezo electric elements - Google Patents

Abstract

The present invention relates to an apparatus and method for manufacturing a filter or a piezoelectric plate for a vibrator using vibration of a piezoelectric plate having a piezoelectric characteristic. The technical gist of the present invention is a separate auxiliary electrode layer 51 for performing a polarization process on the wafer 50. And the fixing bar 33 of the fixing jig 30 for the dummy wafer 50 ′ in which a plurality of wafers 50 are directly stacked without forming a wax layer 52 for stacking the wafers 50 in the polarization process. The first and second fixing pieces of which the surface roughness (V) of the contact surfaces 32a and 34a are processed to 0.5-1.5 μm as a spring 35 having a tensile force F of 3-5 kg / cm 2, 32) (34) and settle in the insulating oil (11), and then apply the high voltage to the wafer 50 'as the power control 50 to perform the polarization process, thereby to filter and the piezoelectric plate for the vibrator It is characterized in that the manufacturing.

Accordingly, the manufacturing process of the piezoelectric plate is extremely shortened, and thus the piezoelectric plate productivity and polarization workability are further improved, and the electrical characteristics of the piezoelectric plate are further improved despite the simplified polarization process.

Description

Piezoelectric Plate Manufacturing Apparatus and Method

The present invention relates to a piezoelectric component such as a piezoelectric filter (FILTER) or a resonator that is used as a frequency band or a reference signal source by using thickness vibration or longitudinal vibration energy generated between electrodes formed on both sides of a piezoelectric plate. The present invention relates to a polarization apparatus and a method essential for exhibiting piezoelectric properties in a substrate manufacturing process, and more particularly, to eliminate the need for forming a separate auxiliary electrode layer and wax layer for a wafer polarization process, drying, and removing the auxiliary electrode layer and wax layer after the polarization process. Due to the extremely short manufacturing process of the piezoelectric plate, the polarization workability is improved, as well as the manufacturing cost is reduced by the simplified polarization process, the piezoelectric properties of the piezoelectric plate are improved, and thus the electrical characteristics of the piezoelectric plate are further improved. Improved piezoelectric component manufacturing productivity improves piezoelectric component reliability It will be one on the piezoelectric substrate manufacturing apparatus and a method to make.

In general, when a mechanical force is applied to a piezoelectric body, a voltage is generated, and when a signal is applied, a vibration is generated. A specific frequency band is selected using the latter vibration, or a piezoelectric component is used as a reference signal source of an electronic component. In general, piezoelectric plates used in piezoelectric parts use ceramics of BaTiO ₃ series or PZT series, and ceramic filters and electronic devices that select video and audio signals (frequency) of all current communication media devices by specific bands. It is classified as a ceramic oscillator used as a reference signal source.

On the other hand, the manufacturing process of the piezoelectric component briefly, as shown in Figure 1, after printing the auxiliary electrode layer 152 for the polarization process on the wafer 150 provided by processing the piezoelectric block 150a, which is a ceramic 1A and 2B, a high voltage is applied to the wafer 150 to perform a polarization process (FIG. 1C), and after the deposition of a metal film on the wafer 150 through the polarization process, the auxiliary electrode layer 152 is removed. When the filter and the vibrator piezoelectric plates 160 and 160 'are manufactured by removing all of them, the input / output electrodes 153a and 153' and the ground electrode 153b are formed on the piezoelectric plates 160 and 160 ', respectively. After (FIG. 1D) (FIG. 1D '), the last step is the coating and curing (FIG. 1E) (FIG. 1E') of the resin coatings 154 and 154 'which are wax coating and protective layers.

In this case, as shown in FIG. 1C, the reason for performing the polarization process on the wafer 150 is to form a random spontaneous polarization structure of the initial wafer l50a in a uniform arrangement through the polarization process. The piezoelectric properties of the piezoelectric substrates 100 and 100 ′ are essential in the manufacturing process of the piezoelectric plates 160 and 160 ′ for the piezoelectric parts 100 and 100 ′.

In addition, in order to shorten the polarization process of the wafer in the manufacture of the piezoelectric plate, the polarization positive is applied in a state in which a plurality of wafers 150 are stacked in a dummy type 150 'instead of one wafer 150. In the polarization process of the dummy piezoelectric body 150 ′, as shown in FIG. 2, when the auxiliary electrode layer 152 for the polarization process is formed on both sides of the processed wafer 150, a plurality of wafers are formed. After completion of the polarization process by coating and curing the wax layer 151 between the layers 150, the auxiliary electrode layer 152 and the wax layer 151 are removed to manufacture piezoelectric plates 160 and 160 ′.

In the conventional piezoelectric plate manufacturing method related to such a technique, as shown in FIG. 3, the power supply 121 is operated to insulate the filling in the water tank 110 as the heat generator 120 in the polarization water tank 110. After the temperature of the silicon oil 111 is maintained at 100 ° -150 ° C., the first fixing plate 132 at the center of the fixing jig 120 connected to the external power control 140 and the case 131 on both sides thereof. The wafer 150 or the dummy wafer 150 'is fixed between the spring 135 and the second fixing plate 134 of the fixed bar 133 that is stacked and stacked, and then precipitated in the silicon oil 111. The polarization process is performed by applying a high voltage of 10-40 mA / cm to the wafer 150 '.

At this time, the reason why the wafer 150 'is settled in the silicon oil 111 filled in the water tank 110 is that the wafer 150' is cracked due to the glow discharge even when a voltage of 5 mA / cm is applied in the air. This is because it is easily destroyed, and thus the temperature of the silicon oil 111 is typically maintained at a temperature of 100 °-150 ℃, and thus maintaining the temperature of the silicon oil 111 above a certain temperature, the wafer during the polarization process This is to facilitate the electron movement of the 150 and to arrange the spontaneous polarization structure of the wafer 150 constantly.

However, in the conventional piezoelectric plate manufacturing method as described above, as illustrated in FIGS. 1 to 3, the wax layer 151 coated and cured in order to stack the wafer 150 in a dummy shape 150 ′ is formed. As the gap between the wafer 150 and the auxiliary electrode layer 152 flows between the surface of the wafer 150 and the auxiliary electrode layer 152, a high voltage of 10-40 mA / cm is applied during the polarization process of the wafer 150. Then, a leakage current is generated between the surface of the wafer 150 and the auxiliary electrode layer 152, so that cracks are easily generated in the wafer 150. In particular, even if the destruction of the wafer 150 does not occur, the wax layer 151 The piezoelectric component 100 (100 ') manufactured by the polarization process because the polarization structure of the wafer 150 is not uniform due to the phenomenon that an electric field passes between the wax layers 151 without passing through the wafer 150 during the polarization process. Of the piezoelectric plates 160 and 160 'for the There was a point.

In addition, as shown in FIG. 2, during the polarization process for manufacturing the piezoelectric plate, the auxiliary electrode layers 152 are formed on both sides of the wafer 150, and after the polarization process is performed through curing and drying operations, the auxiliary electrode layers 152 are formed. At the same time, the wax layer 151 for the dummy wafer 150 'is also applied, cured, and dried, and after the polarization process, a separate wax layer 151 is removed to perform the piezoelectric plate. As the manufacturing process is very complicated, productivity and workability are extremely reduced, as well as the solvent used to remove the auxiliary electrode layer and the wax layer is extremely harmful to the human body, and there are various problems such as environmental problems caused by the solvent.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. The object of the present invention is to provide the surface roughness (V) of the first and second fixing pieces of the fixing jig for oil impregnation of the wafer for the polarization process in the manufacturing of piezoelectric plates. By fixing the wafer as a spring having a precision of 0.5-1.5 탆 and the first and second fixing pieces have a tensile force of 3-5 kg / ㎠, forming a separate auxiliary electrode layer and wax layer during the manufacturing process of the piezoelectric plate, drying, and An object of the present invention is to provide a piezoelectric plate manufacturing apparatus which minimizes the piezoelectric plate manufacturing process by eliminating the need for removal.

In addition, another object of the present invention, there is no need for the cumbersome and harmful work of forming and removing the auxiliary electrode layer and wax layer for the polarization process during the piezoelectric plate manufacturing process is further shortened and smoother, as well as manufactured piezoelectric plate It is to provide a piezoelectric plate manufacturing method in which the electrical properties of the piezoelectric component is improved, and the manufacturing cost of the piezoelectric component is improved.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram for explaining a manufacturing procedure of a general piezoelectric component.

Figure 2 is a schematic diagram showing a dummy wafer in a conventional wafer polarization process.

Figure 3 is an overall configuration diagram showing a conventional piezoelectric plate manufacturing apparatus.

Figure 4 is an overall configuration diagram showing a piezoelectric plate manufacturing apparatus according to the present invention.

Fig. 5 is a schematic diagram showing a dummy wafer in which a plurality of wafers are directly stacked in the piezoelectric engine manufacturing method of the present invention.

Figure 6 is a main part of the piezoelectric plate manufacturing apparatus of the present invention, showing the fixing jig of the polarizer.

Figure 7 is a schematic diagram showing the sequence of the present invention piezoelectric plate manufacturing method.

Figure 8 (a) and (b) is a schematic diagram for explaining the conventional manufacturing process of the piezoelectric plate according to the present invention.

9A to 9C are graphs showing selectivity, frequency bandwidth, and frequency characteristics of the piezoelectric plate according to the present invention, respectively.

* Explanation of symbols for main parts of the drawings

1: polarizer 10: water tank

20: heater 30: fixing jig

31: case 32, 34: first and second fixing pieces

32a, 34a: fixing piece contact surface 35: spring

40: power supply control 50: wafer

50 ': dummy wafer 60: piezoelectric plate

As a technical means for achieving the above object, the present invention provides a polarization tank filled with oil therein, a heater provided in the bottom of the tank, and a fixing jig to fix the wafer in the oil, A piezoelectric plate manufacturing apparatus including a power control connected to the fixing jig and installed outside the tank, the first fixing piece being rolled in the inner center of the case, and both wafer contact surfaces are processed as a constant surface roughness (V); A plurality of fixing bars are rolled through the case, springs are formed so as to have a predetermined tensile force (F) between the case and the tip outside the fixing bar, and the wafer with the first fixing piece at the end of the fixing bar. The fixing surface is installed to be fixed, and the contact surface in contact with the wafer includes a fixing jig having a second fixing piece which is processed as a constant surface roughness (V). It characterized by providing a manufacturing piezoelectric organs environments devices.

The method may further include forming a wafer by processing a ceramic block, forming, curing, and drying auxiliary electrode layers on both sides of the wafer, and applying, curing, and drying a wax layer between the wafers to convert the plurality of wafers into dummy wafers. Providing a piezoelectric characteristic by applying a high voltage to the dummy wafer to perform polarization affinity, and removing the auxiliary electrode layer and the wax layer of the wafer through the polarization process. A method of manufacturing a dummy wafer by directly filling a plurality of wafers prepared by processing a ceramic block with a plurality of wafers without forming a separate auxiliary electrode layer and a wax layer, and a heat generator provided with insulating oil filled in the tank bottom And maintaining the temperature at 100-150 ℃ as a solid soup in the fixed bar of the fixed jig As a result, the dummy wafer is fixed with a tensile force (F) of 3-5 kg / cm 2 between the first and second fixing pieces of the fixing jig having the surface roughness (V) of the contact surface processed to 0.5-1.5 탆 and settle in the oil. And a high voltage of 10-40 mA / cm < 2 > is applied to the first and second fixing pieces connected to the anode (+) and the cathode (-) as a power control installed outside the tank to polarize the piezoelectric properties on the wafer. It characterized by providing a piezoelectric plate manufacturing method comprising the step of performing a process, and the step of washing the oil and pure water through the polarization process.

Hereinafter, the present invention will be described in detail based on the immersed drawings.

Figure 4 is an overall configuration diagram showing a piezoelectric plate manufacturing apparatus according to the present invention, Figure 5 is a schematic diagram showing a dummy wafer in which a plurality of wafers are directly stacked in the piezoelectric plate manufacturing method of the present invention, Figure 6 The present invention is a principal part showing a fixing jig of a polarizing device according to the inventor of the piezoelectric plate manufacturing apparatus, and FIG. 7 is a schematic schematic diagram showing the procedure of the piezoelectric plate manufacturing method of the present invention.

Polarization tank 10 filled with oil 11 therein, a heat generator 20 installed at the inner bottom of the tank 10, and a fixing jig for fixing the wafer 50 in the oil 11 to settle. 30 and a piezoelectric polarization device 1 including a power control block 40 which is connected to the fixing jig 30 and the connection cable 41 and installed outside the water tank 10 is provided.

In addition, the fixing jig 30 is rolled in the inner center of the case 31, both the piezoelectric contact surface (32a, 32b) is the first fixing piece 32 is processed as a constant surface roughness (V), A fixing bar 33 penetrating through the case 31 and having a spring 35 having a predetermined tensile force F between the case 31 and the tip, and a first fixing piece at an end of the fixing bar 33; The contact surface 34a which is provided to fix the 32 and the wafer 50 to the fixed contact with the wafer 50 is provided with a second fixing piece 34 which is processed as a constant surface roughness V. As shown in FIG.

Meanwhile, the dummy wafer 50 'is provided as a dummy type wafer 50' in which a plurality of ceramic wafers 50 are directly stacked, and the first fixing piece 32 and the second fixing piece 50 are provided. The surface roughness (V) of each contact surface 32a, 34a of the piece 34 is formed in 0.5-1.5 micrometers, and the spring 35 carried in the said fixing bar 33 is 3-5 kg / cm <2>. It consists of a configuration to have a tensile force (F) of.

Hereinafter, the embodiment of the present invention will be described in detail.

EXAMPLE

As shown in FIG. 7, one large ceramic block 50a is processed to prepare a plurality of wafers 50. In this case, the ceramic block 50a is mainly made of ceramic, such as BaTiO ₃ or PZT series. The piezoelectric component, which is a piezoelectric filter or a vibrator, uses the thickness torsional vibration or the thickness vibration mode of the piezoelectric ceramic, and thus the ceramic block 50a is formed as a wafer 50 through a precise polishing process.

At this time, the ceramic block 50a is first polished with alumina (# 800), and then secondarily polished with Green Carbide (# 2500-3500) to maintain surface roughness of 2.5 to 4.5 μmm. The reason why the surface roughness of the ceramic block 50a is important is to apply uniform film formation by grinding to a thickness according to a frequency band.

In addition, the surface of the ceramic block (50a) is polished by removing the slurry (Slurry) attached to the surface by an ultrasonic cleaner and cut into a size of 20-50mm x 20-50mm, after preparing a plurality of wafers (50) again Dry to a temperature of 100-200 ° C.

Next, as shown in FIGS. 4 to 7, an essential polarization process is performed during the manufacturing process of the piezoelectric plate 60. Such a polarization positive is a high temperature polarization method in which a high voltage is applied to the piezoelectric characteristics of the wafer 50. The polarization method is performed in such a way that the spontaneous polarization structure of the wafer 50 is random and exhibits a uniform and uniform polarization structure, that is, piezoelectric characteristics.

First, the insulating silicon oil 11 is filled in the water tank 10, and the power supply 21 of the heater 20 installed under the water tank 10 is operated to operate the temperature of the silicon oil 11. Is maintained at 100-150 ° C in order to more smoothly perform the polarization process of the wafer 50.

In addition, in order to insert the wafer 50 into the silicon oil 11, a fixed jig 30 is used, and a plurality of the dried wafers 50 are directly directly used to rapidly proceed the polarization process of the wafer 50. It piles up and provides the dummy wafer 50 '.

In particular, as shown in Figs. 2 and 5, the conventional dummy wafer 150 'is provided in a dummy form by applying and curing the wax layer 151 between the plurality of wafers 150. In this case, a plurality of wafers 50 are directly stacked and provided as dummy wafers 50 'without the need for such separate wax layer application and curing, and at the same time, the auxiliary electrode layer 152 required for the conventional wafer polarization process is formed. It also eliminates the need for hardening and drying, which will be explained in detail below.

On the other hand, after pulling the fixing bar 33 of the fixing jig 30 to the rear, the first and second fixing pieces 32, 34 by the tension force (F) of the spring (35) in the fixed bar 33 The wafer 50 or the dummy wafer 50 'is fixed in between, and the spring 35 pushes the second fixing piece 34 toward the center of the first fixing piece 32 as a tension spring. To secure 50, it is configured to have a tensile force F of 3-5 kg / cm 2, and the preferred tensile force F of the spring 35 is 4 kg / cm 2.

That is, it is the tensile force of the spring 35 that fixes the dummy wafer 50 'between the first and second fixing pieces 32, 34, so that the tensile force of the spring 35 is greater than 3 kg / cm &lt; 2 &gt; If small, minute spacing is generated between the stacked wafers 50 fixed between the first and second fixing pieces 32 and 34, which is caused by the leakage current due to the high voltage applied during the polarization process. 50 ') is destroyed, on the contrary, if the tensile force F of the spring 35 is greater than 5 kg / cm 2, it is unreasonable to the wafer 50 to be fixed between the first and second fixing pieces 32 and 34. The force is applied to the wafer 50 is easily broken by the crack generated in the wafer 50.

In addition, the surface roughness of the wafer contact surfaces 32a and 34a of the first and second fixing pieces 32 and 34 is very important, which performs the polishing of the surface of the wafer 50a very precisely over two times. Since the surface roughness of the wafer 50 is maintained extremely precisely, if the surface roughness of the contact surfaces 32a and 34a fixed between the first and second fixing pieces 32 and 34 is accurate, the fixed wafer 50 This is because the overall adhesiveness of the) is improved, and as will be described in more detail below, this has a significant effect on the shortening of the polarization process and the electrical characteristics of the piezoelectric substrate 60.

That is, as shown in FIGS. 2, 3, and 8 (a), in the manufacturing process of the conventional piezoelectric substrates 160 and 160 ', the auxiliary electrode layer 52 for polarization is formed on both sides of the wafer 150. In order to form, cure and dry, a total of 200 minutes (3 hours 20 minutes) of working time is required, and at the same time, a separate wafer for the dummy wafer 150 'is not shown in FIG. The wax layer 151 needs to be coated and cured, and at the same time, in order to manufacture the piezoelectric plates 160 and 160 ′ through the polarization process, the auxiliary electrode layer 152 and the wax layer 151 are removed after the polarization process. An additional time of about 60 minutes is required, and the use of an electrode removal solvent that is harmful to the human body is required.

On the contrary, as shown in Figs. 7 and 8 (b), in the present invention, an appropriate tensile force (F) between the first and second fixing pieces (32) and (34) having an intimate surface roughness (V) is achieved. By performing the polarization process by fixing the dummy wafer 50 ', the overall adhesion of the wafer 50 is improved, thus eliminating the need for forming, curing and drying the auxiliary electrode layer and the wax layer. 60 'process is extremely short and there is no need for the use of harmful solvents.

Next, after the dummy wafer 50 'is fixed to the fixing jig 30 and precipitated in the oil 11 maintained at a constant temperature, the operator attaches a cable (1) to the first and second fixing pieces 32 and 34. When the power control 40 outside the water tank 10 connected as 41 is operated, a negative electrode (-) is connected to the first fixing piece 32 as a positive electrode (+) to the second fixing piece 34, and the wafer is connected. A high voltage of 10 -14 mA / cm is applied to the 50, which is about 30 minutes. Accordingly, the wafer 50 is polarized to exhibit piezoelectric characteristics in which the spontaneous polarization structure is uniformly arranged. It is made of ').

In particular, the wafer 50 or the directly stacked dummy wafer 50 'is fixed with an appropriate tensile force F between the first and second fixing pieces 32 and 34 having a precise surface roughness V, so that high voltage is applied. By being applied, the piezoelectric bodies 60 and 60 'manufactured according to the present invention have improved electrical characteristics as described above, without the electric field pass phenomenon during the polarization process by the conventional wax layer.

9A to 9C are graphs showing the selectivity, the frequency bandwidth and the frequency characteristics of the piezoelectric plate according to the present invention, respectively. First, as shown in FIG. The selectivity (Qm, Qulity Factor) of (160) (60) can be seen that the selectivity (Qm) is uniform according to the voltage applied in the case of the present invention, as shown in Figure 9 (b), As for the bandwidth (◁ F), it can be seen that the present invention has a higher bandwidth than the conventional one when voltage is applied. As shown in Fig. 9C, in the oscillation frequency characteristic (F) of the piezoelectric plate, It can be seen that even when the applied voltage is increased as compared with the conventional case, it shows a more uniform frequency band, and accordingly, in the present invention without forming a separate auxiliary electrode layer, the piezoelectric component plate 60 for piezoelectric parts having better electrical characteristics is provided. (60 ') can be manufactured.

Subsequently, as shown in FIG. 7, the piezoelectric plates 60 and 60 'manufactured by performing the polarization process on the wafer 50 are cleaned with oil to remove the oil 11 adhering to the surface. Then, after drying for about 1 hour between approximately 100-200 ° C, the piezoelectric component main electrode layers (input and output electrodes and lead patterns of the piezoelectric component) 52a, 52b, 52 'on the piezoelectric substrates 60, 60'. After the evaporation process, the resin layers 53 and 53 'are coated, cured, and coated to perform the manufacturing process of the piezoelectric component, which is the filter 70 or the vibrator 701.

As described above, according to the piezoelectric plate manufacturing apparatus and method of the present invention, a separate auxiliary electrode layer and wax layer for the wafer polarization process and a wax layer are formed and dried, and the auxiliary electrode layer and the wax layer removed after the polarization process are not necessary. This extremely shortening not only improves the polarization workability, but also reduces the manufacturing cost through a simplified polarization process, and also improves the piezoelectric properties of the piezoelectric plate, thereby further improving the electrical properties of the piezoelectric plate. There is an excellent effect that the product reliability of the component is improved.

Claims (7)

(Correction) The polarization tank 10 in which the oil 11 is filled inside, the heater 20 installed in the inner bottom of the tank 10, and the wafer 50 in the oil 11 are fixed to settle. In the piezoelectric plate manufacturing apparatus (1) comprising a fixing jig 30 and a power control 40 connected to the fixing jig 30 and installed outside the water tank 10, the inner center of the case 31 The first fixing piece 32 which is rolled up on both sides and the wafer contact surface 32a is processed as a constant surface roughness V, and a plurality of fixing bars 33 are rolled through the case 31 and fixed. The wafer 35 together with the first fixing piece 32 at the end of the fixed bar 33 and the spring 35 which is piled up so as to have a constant tensile force F between the case 31 and the tip of the outside of the bar 33. The fixing jig 3 provided with the second fixing piece 34 which is installed to fix the 50 and the contact surface 34a in contact with the wafer 50 is processed as a constant surface roughness V. Piezoelectric plate manufacturing apparatus characterized in that it comprises a 0). (Correction) The piezoelectric plate manufacturing apparatus according to claim 1, wherein the wafer (50 ') has a dummy shape in which a plurality of ceramic wafers (50) are directly stacked. The surface roughness (V) of each of the contact surfaces 32a and 34a of the first fixing piece 32 and the second fixing piece 34 of the fixing jig 30 is 0.5 to 1.5 탆. Piezoelectric plate manufacturing apparatus characterized in that configured. The piezoelectric plate manufacturing apparatus according to claim 1, wherein the tensile force (F) of the spring (35) that is installed in the fixing bar (33) is composed of 3-5 kg / cm 2. (Correction) processing the ceramic block 50a to provide a wafer 50, forming, curing and drying auxiliary electrode layers on both sides of the wafer 50, and a wax layer between the wafers 50. Applying, curing and drying to prepare the plurality of wafers 50 as a dummy wafer 50 ', and applying a high voltage to the dummy wafer 50' to perform a polarization process to exhibit piezoelectric characteristics. And, in the piezoelectric plate manufacturing method comprising the step of removing the auxiliary electrode layer and the wax layer of the wafer 50 through the polarization process, a plurality of wafers 50 provided by processing the ceramic block (50a) separate auxiliary electrode layer and Directly stacking a plurality of wafers 50 to form a dummy wafer 50 'without forming a wax layer, and placing the insulating silicone oil 11 filled in the tank 10 on the bottom of the tank 10. 100-150 ° C. silver as the heater 20 And a fixing jig processed by the surface roughness V of the contact surfaces 32a and 34a to 0.5-1.5 μm as a spring 35 mounted on the fixing bar 33 of the fixing jig 30. Fixing the dummy wafer 50 'with a tensile force F of 3-5 kg / cm &lt; 2 &gt; between the first and second fixing pieces 32 and 34 of 30) to precipitate in the oil 11; A high voltage of 10-40 kg / cm is applied to the first and second fixing pieces 32 and 34 connected to the positive electrode and the negative electrode as a power control 50 installed outside the water tank 10. And performing polarization affinity to exhibit piezoelectric properties on the wafer (50), and treating the wafer (50) through oil and pure water through the polarization process. The first and second fixing pieces 32 and 34 of the fixing jig 30 for fixing the dummy wafer 50 'have contact surfaces 32a and 34a with a surface roughness (V) of 1 μm. Piezoelectric plate manufacturing method characterized in that it is configured to have. The method of manufacturing a piezoelectric plate according to claim 5, wherein the tensile force (F) of the spring (35) which is installed on the fixing bar (33) is composed of 4 kg / cm 2.