JP2010245116A - Method of manufacturing piezoelectric element, and ceramic laminate with electrode - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a piezoelectric element which suppresses strain. <P>SOLUTION: The method of manufacturing the piezoelectric element 200 includes a process for preparing a first green sheet including a first metal material layer and a second metal material layer surrounding the first metal material layer, a process for preparing a second green sheet having a third metal material layer and a fourth metal material layer surrounding the third metal material layer, a process for forming a green sheet laminate by adhering the first green sheet and second green sheet, a process for forming a ceramic laminate by baking the green sheet laminate, and a process for dicing the ceramic laminate. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a piezoelectric element and a ceramic laminate with electrodes.

  As an element for performing electromechanical conversion, a piezoelectric element in which a plurality of electrodes are formed between layered piezoelectric bodies is known. As a piezoelectric body used for the piezoelectric element, a ceramic material (for example, a sintered body of a perovskite type compound) fired at a high temperature may be used for reasons such as good piezoelectricity. Such ceramic-based laminated piezoelectric elements are often manufactured using an unfired ceramic sheet called a green sheet.

  The green sheet is, for example, a sheet in a state where a slurry in which ceramic particles, a binder, and the like are dispersed is spread on a plane to remove a solvent and the like. Such a green sheet can be changed into a ceramic sheet by firing. For example, Japanese Patent Application Laid-Open No. 09-115766 discloses a part of a method of manufacturing a piezoelectric element called a multilayer ceramic electronic component by laminating and firing a plurality of green sheets called electrode-integrated green sheets and firing them. Yes.

JP 09-115766 A

  However, the shape of a green sheet on which a metal material layer (including those that become electrodes by firing) is formed may be distorted by firing. Sheet distortion may cause a decrease in performance and yield of the obtained multilayer piezoelectric element. It has been found that this phenomenon is caused by the fact that the shrinkage rate of the metal material is larger than that of the green sheet.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

One aspect of the method for manufacturing a piezoelectric element according to the present invention is as follows.
Providing a first green sheet having a first metal material layer and a second metal material layer surrounding the first metal material layer;
Preparing a second green sheet having a third metal material layer and a fourth metal material layer surrounding the third metal material layer;
Forming a green sheet laminate by bonding the first green sheet and the second green sheet;
Firing the green sheet laminate to form a ceramic laminate;
Dicing the ceramic laminate,
including.

  In this way, distortion during firing of the laminated green sheets is suppressed, and a good piezoelectric element can be manufactured.

In the method for manufacturing a piezoelectric element of the present invention,
The second metal material layer surrounds the first metal material layer in a plan view;
The fourth metal material layer may surround the third metal material layer in plan view.

In the method for manufacturing a piezoelectric element of the present invention,
The second metal material layer and the fourth metal material layer may have a mesh shape.

In the method for manufacturing a piezoelectric element of the present invention,
The second metal material layer and the fourth metal material layer may have a stripe shape.

In the method for manufacturing a piezoelectric element of the present invention,
The second metal material layer and the fourth metal material layer may be formed in a staggered pattern.

In the method for manufacturing a piezoelectric element of the present invention,
The second metal material layer and the fourth metal material layer may have a frame shape.

In the method for manufacturing a piezoelectric element of the present invention,
The second metal material layer is spaced apart from a side of the first green sheet;
The fourth metal material layer may be separated from a side of the second green sheet.

In the method for manufacturing a piezoelectric element of the present invention,
The frame-shaped side of the second metal material layer overlaps the side of the first green sheet,
The frame-shaped side of the fourth metal material layer may overlap the side of the second green sheet.

In the method for manufacturing a piezoelectric element of the present invention,
The second metal material layer and the fourth metal material layer are composed of a plurality of metal parts,
The plurality of metal parts may be separated from each other.

In the method for manufacturing a piezoelectric element of the present invention,
In the step of forming the ceramic laminate, by firing, the first green sheet is used as a first ceramic sheet, the second green sheet is used as a second ceramic sheet, and the first metal material layer is used as a first metal. The second metal material layer may be a second metal layer, the third metal material layer may be a third metal layer, and the fourth metal material layer may be a fourth metal layer.

In the method for manufacturing a piezoelectric element of the present invention,
The first metal layer is formed in a piezoelectric element forming region of the first ceramic sheet,
The third metal layer is formed in a piezoelectric element forming region of the second ceramic sheet,
The step of dicing the ceramic laminate includes: a laminate including the piezoelectric element forming region of the first ceramic sheet, the first metal layer, the piezoelectric element forming region of the second ceramic sheet, and the third metal layer. Can be done to cut out.

In the method for manufacturing a piezoelectric element of the present invention,
The second metal layer and the fourth metal layer may be formed in a region where the ceramic laminate is diced.

One aspect of the ceramic laminate with an electrode according to the present invention is:
A first ceramic sheet;
A first metal layer formed on the first ceramic sheet;
A second metal layer formed on the first ceramic sheet and surrounding the first metal layer;
A second ceramic sheet formed on the first ceramic sheet, the first metal layer and the second metal layer;
A third metal layer formed on the second ceramic sheet;
A fourth metal layer formed on the second ceramic sheet and surrounding the third metal layer;
including.

  In such a ceramic laminated body with an electrode, distortion is suppressed.

In the ceramic laminate with an electrode of the present invention,
The second metal layer surrounds the first metal layer in plan view;
The fourth metal layer may surround the third metal layer in plan view.

In the ceramic laminate with an electrode of the present invention,
The second metal material layer and the fourth metal material layer may have a mesh shape.

In the ceramic laminate with an electrode of the present invention,
The second metal material layer and the fourth metal material layer may have a stripe shape.

In the ceramic laminate with an electrode of the present invention,
The second metal material layer and the fourth metal material layer may be formed in a staggered pattern.

In the ceramic laminate with an electrode of the present invention,
The second metal layer and the fourth metal layer may have a frame shape.

In the ceramic laminate with an electrode of the present invention,
The second metal layer is spaced apart from a side of the first ceramic sheet;
The fourth metal layer may be separated from a side of the second ceramic sheet.

In the ceramic laminate with an electrode of the present invention,
The frame-shaped side of the second metal material layer is overlapped with the side of the first ceramic sheet,
The frame-shaped side of the fourth metal material layer may overlap the side of the second ceramic sheet.

In the ceramic laminate with an electrode of the present invention,
The second metal layer and the third metal layer are composed of a plurality of metal parts,
The plurality of metal parts may be separated from each other.

Sectional drawing which shows the manufacturing process of embodiment typically. Sectional drawing which shows the manufacturing process of embodiment typically. Sectional drawing which shows the manufacturing process of embodiment typically. Sectional drawing which shows the green sheet laminated body 10 of embodiment typically. The top view which shows typically the green sheet laminated body 10 of embodiment. The top view which shows typically the ceramic laminated body 110 of embodiment. Sectional drawing which shows the ceramic laminated body 110 of embodiment typically. FIG. 2 is a perspective view schematically showing the multilayer piezoelectric element 200 of the embodiment. The top view which shows typically the green sheet laminated body 20 of embodiment. The top view which shows typically the green sheet laminated body 30 of embodiment. The top view which shows typically the green sheet laminated body 40 of embodiment. The top view which shows typically the green sheet laminated body 50 of embodiment. The top view which shows typically the green sheet laminated body 60 of embodiment. The top view which shows typically the green sheet laminated body 70 of embodiment. The top view which shows typically the ceramic laminated body 170 with an electrode of embodiment. Sectional drawing which shows typically the ceramic laminated body 170 with an electrode of embodiment.

  Preferred embodiments of the present invention will be described below with reference to the drawings. In addition, the following embodiment demonstrates an example of this invention.

1. Method for Manufacturing Piezoelectric Element A method for manufacturing a piezoelectric element according to the present embodiment includes a step of preparing a first green sheet having a first metal material layer and a second metal material layer surrounding the first metal material layer, A step of preparing a second green sheet having a metal material layer and a fourth metal material layer surrounding the third metal material layer, and laminating the first green sheet and the second green sheet to form a green sheet laminate A step of forming a body, a step of forming a ceramic laminate by firing the green sheet laminate, and a step of dicing the ceramic laminate.

1.1. Step of Preparing Green Sheet FIG. 1 is a cross-sectional view schematically showing a green sheet 2 prepared in this step. The green sheet 2 has a film shape. The thickness of the green sheet 2 can be 10-30 micrometers, for example. The planar shape of the green sheet 2 is not limited. In the present embodiment, an example in which a green sheet 2 that is rectangular in plan view is used is shown.

  The green sheet 2 can have a certain plasticity. Therefore, the green sheet 2 can be plastically deformed by applying an external force. The green sheet 2 can be a ceramic sheet by being fired. A sheet made of ceramic may not have plasticity. As the green sheet 2, for example, a slurry in which a ceramic raw material is dispersed is applied to a substrate such as a film, dried, and peeled off from the film. The green sheet 2 may be prepared in a state of being formed on a substrate such as a film. When the green sheet 2 is formed on a substrate such as a film, the green sheet 2 can be easily handled in the metal layer forming step or the like.

  The material of the green sheet 2 is not particularly limited as long as it becomes a ceramic that exhibits piezoelectric characteristics when fired. For example, the green sheet 2 can be used in a state in which ceramic particles and a binder are dried and solidified. As the binder in this case, for example, a polymer material such as polystyrene, cellulose, or polyvinyl butyral (PVB) can be used. The green sheet 2 may contain other compounds such as a solvent and a surfactant.

As the ceramic particles contained in the green sheet 2, for example, particles of a perovskite oxide represented by the general formula ABO ₃ can be used. Specific examples of such particles include lead zirconate titanate (Pb (Zr, Ti) O ₃ ) (hereinafter sometimes abbreviated as “PZT” in this specification), zirconate niobate titanate. Lead oxide (Pb (Zr, Ti, Nb) O ₃ ) (hereinafter sometimes abbreviated as “PZTN” in this specification), barium titanate (BaTiO ₃ ), sodium bismuth titanate ((Bi, Na) Examples thereof include particles such as TiO ₃ ) and potassium sodium niobate ((K, Na) NbO ₃ ). Of these, it is preferable that the particles contained in the green sheet 2 are PZT and PZTN particles because the piezoelectric performance after firing is particularly good. Such ceramic particles can be sintered when the green sheet 2 is fired to form a ceramic (piezoelectric body) exhibiting piezoelectricity.

1.2. Step of Forming First Metal Material Layer and Second Metal Material Layer FIG. 2 is a cross-sectional view schematically showing a state in which the first metal material layer 4 a and the second metal material layer 6 a are formed on the green sheet 2. is there.

1.2.1. First Metal Material Layer The first metal material layer 4 a is formed on the green sheet 2. The first metal material layer 4 a becomes the first metal layer 4 that is an electrode in the piezoelectric element 200 by performing steps such as firing and dicing. The position where the first metal material layer 4 a is formed depends on the position of the piezoelectric element 200 and the arrangement of the first metal layer 4. The first metal material layer 4a is preferably formed at a position where the deformation due to firing is small (details will be described later), and is preferably provided at least avoiding the peripheral edge 2r in plan view of the green sheet 2. In this specification, the peripheral portion 2r of the green sheet 2 refers to a region along the outer periphery of the green sheet 2 when the green sheet 2 is viewed in plan, and includes a region other than the peripheral portion 2r and the peripheral portion 2r. When a line segment connecting the center point of the green sheet 2 and an arbitrary point on the outer periphery is set, it is assumed that the boundary is within a range of 0 to 50% from the outer periphery side of the line segment. The planar shape of the first metal material layer 4a is arbitrary, but is preferably a shape that takes into account deformation due to firing, dicing lines, and the like. The thickness of the 1st metal material layer 4a can be 1-2 micrometers, for example.

  The first metal material layer 4a is formed of a material that exhibits conductivity after being fired at least. The first metal material layer 4a may have conductivity before firing. Examples of the material of the first metal material layer 4a include at least one metal or alloy selected from silver, palladium, platinum, and gold. The first metal material layer 4a may have a laminated structure of a plurality of layers. Examples of the material of the first metal material layer 4a include a precursor that becomes at least one metal or alloy selected from silver, palladium, platinum, and gold by firing. Examples of such precursors include pastes and slurries of these metal powders. When the first metal material layer 4a is formed of a metal powder paste and slurry, the paste and slurry may contain a ceramic powder called co-powder. Good. The co-powder in this case is more preferably the same material as the ceramic particles contained in the green sheet 2. When the first metal material layer 4a is formed of a metal powder paste, slurry, or the like, if the co-powder is blended, the shrinkage of the size of the first metal material layer 4a may be further reduced during firing. it can. Moreover, when co-powder is mix | blended, the dimensional change of the 1st metal material layer 4a in the case of baking and the dimensional change of the green sheet 2 can be closely approached.

  When the material is a metal or an alloy, the first metal material layer 4a can be formed by a film formation method such as sputtering, vapor deposition, or CVD, and a patterning method such as photolithography. The first metal material layer 4a can be formed by a printing method such as screen printing, letterpress printing, intaglio printing, and ink jet printing when the material is a metal powder paste, slurry, or the like. Among these, according to the printing method, the 1st metal material layer 4a can be formed very simply.

1.2.2. Second Metal Material Layer The second metal material layer 6a is formed so as to surround the first metal material layer 4a in plan view (see FIG. 5). The second metal material layer 6a does not need to be continuous. Moreover, the 2nd metal material layer 6a may have a cut | interruption etc., and may surround the 1st metal material layer 4a with the some 2nd metal material layer 6a. The second metal material layer 6a becomes the second metal layer 6 by being fired. The second metal layer 6 can be a dummy electrode that does not participate in the piezoelectric element 200, for example. The planar shape of the second metal material layer 6a is arbitrary, but is preferably a shape that takes into account deformation due to firing, dicing lines, and the like. For example, the second metal material layer 6a is formed to have a frame shape. As an example of the frame shape, the second metal material layer 6a includes a first metal part 61a, a second metal part 62a connected to the first metal part 61a, and a third metal part 63a connected to the second metal part 62a. The third metal part 63a and the fourth metal part 64a connected to the first metal part 61a can be used. As an example of the frame shape, the second metal material layer 6a is further formed between the second metal part 62a and the fourth metal part 64a, and connects the first metal part 61a and the third metal part 63a. The fifth metal part 65a may be included. Further, as an example of the frame shape, a shape as shown in FIG. 14 may be used. The thickness of the 2nd metal material layer 6a can be 1-2 micrometers, for example. The thickness of the second metal material layer 6a is more preferably the same as that of the first metal material layer 4a. In this way, when the green sheets 2 are laminated, at least the thickness around the first metal material layer 4a can be made more uniform.

  The material of the second metal material layer 6a is arbitrary. The material of the second metal material layer 6a can be selected from those showing conductivity after firing. The second metal material layer 6a may have conductivity before firing. More preferably, the material of the second metal material layer 6a is the same as the material of the first metal material layer 4a. If the material of the second metal material layer 6a and the material of the first metal material layer 4a are the same, the degree of contraction of each metal material layer during firing can be made uniform, so that the deformation of the green sheet 2 is made more uniform. Can be Further, if the material of the second metal material layer 6a and the material of the first metal material layer 4a are the same, the second metal material layer 6a and the first metal material layer 4a can be formed at a time in this step.

  When the second metal material layer 4a is formed of a metal powder paste, slurry, or the like, the paste, slurry, or the like may include ceramic powder called co-powder. The co-powder in this case is more preferably the same material as the ceramic particles contained in the green sheet 2. When the second metal material layer 6a is formed of a metal powder paste, slurry, etc., if co-powder is blended, the shrinkage of the dimensions of the second metal material layer 6a may be further reduced during firing. it can. Moreover, when co-powder is mix | blended, the dimensional change of the 2nd metal material layer 6a in the case of baking and the dimensional change of the green sheet 2 can be closely approached.

  When the material is a metal, an alloy, or the like, the second metal material layer 6a can be formed by a film forming method such as sputtering, vapor deposition, or CVD, and a patterning method such as photolithography. The second metal material layer 6a can be formed by a printing method such as screen printing, letterpress printing, intaglio printing, and ink jet printing when the material is a metal powder paste, slurry, or the like. Among these, according to the printing method, the second metal material layer 6a can be formed very easily.

  The first metal material layer and the first metal are obtained through the above “1.1. Step of preparing a green sheet” and “1.2. Step of forming the first metal material layer and the second metal material layer”. A first green sheet having a second metal material layer surrounding the material layer can be prepared. Similarly, a second green sheet having a third metal material layer and a fourth metal material layer surrounding the third metal material layer can be prepared. In this case, the planar arrangement of the first and third metal material layers and the planar arrangement of the second and fourth metal material layers may be the same or different.

1.3. Step of Forming Green Sheet Laminate Green sheet laminate 10 is obtained by “1.1. Step of preparing green sheet” and “1.2. Step of forming first metal material layer and second metal material layer”. The first green sheet on which the first metal material layer and the second metal material layer are formed, and the second green sheet on which the third metal material layer and the fourth metal material layer are formed are bonded together. The

  In this step, the number, order, and arrangement of each metal material layer of each green sheet are arbitrary, and hereinafter, the green sheet in which the first metal material layer 4a and the second metal material layer 6a are simply formed will be described below. A mode of pasting 2 together will be described.

  FIG. 3 is a cross-sectional view schematically showing how the green sheets 2 are bonded together. FIG. 4 is a cross-sectional view schematically showing the green sheet laminate 10.

  In this step, the green sheet 2 is bonded, for example, as shown in FIG. The number of green sheets 2 and the order of bonding are arbitrary. Further, the surface of the green sheet 2 on which the metal material layer is formed may be the upper side or the lower side. In the example of FIG. 3, the metal material layer on the uppermost green sheet 2 is exposed on the upper surface, but the metal material layer is not further formed on the uppermost green sheet 2. The green sheets may be pasted together. The second metal material layer 6a can be used for alignment when the green sheet 2 is bonded. Further, each green sheet 2 may be formed with a mark for alignment.

  When the green sheets 2 are bonded together, the positions where the first metal material layers 4a are formed on the green sheets 2 may be different from each other. That is, the metal material layers formed on each of the plurality of green sheets 2 may have different patterns. By changing the position where the first metal material layer 4 a is formed in each green sheet 2, for example, the position and shape of the first metal layer 4 formed inside the piezoelectric element 200 can be controlled. Moreover, when bonding the green sheet 2, the position in which the 2nd metal material layer 6a in each green sheet 2 is formed may differ, but it is more preferable that it is the same. By making the position where the second metal material layer 6a is formed in each green sheet 2 the same, it is possible to further suppress the non-uniformity of the thickness of the stacked body when stacked.

  By laminating the plurality of green sheets 2, at least a part of each metal material layer is formed inside the laminate. Thereby, the green sheet laminated body 10 is formed. If necessary, as shown in FIG. 3, the green sheet laminate 10 can be press-molded by a press molding machine p. Moreover, you may press-mold for every layer as needed. In this case, the press molding can be performed by appropriately heating. If it does in this way, the space | gap inside the green sheet laminated body 10 can be reduced, for example. Since the green sheet 2 has plasticity, it can be deformed by press molding. Therefore, an integral green sheet laminate 10 in which the green sheets 2 are press-contacted as shown in FIG. 4 can be formed. The broken line shown in FIG. 4 has shown the location where the green sheet 2 was press-contacted.

  FIG. 5 is a plan view schematically showing the green sheet laminate 10 formed as described above. A cross section taken along line AA in FIG. 5 corresponds to FIG. In the example of FIG. 5, in each green sheet, three of the first metal material layers 4a form one set, and two sets of the first metal material layers 4a are respectively surrounded by the second metal material layer 6a.

1.4. Step of Forming Ceramic Laminate FIG. 6 is a plan view schematically showing the ceramic laminate 110. FIG. 7 is a cross-sectional view schematically showing the ceramic laminate 110.

  This step is performed by firing the green sheet laminate 10. Thereby, the green sheet 2 becomes a ceramic sheet, the first metal material layer 4 a becomes the first metal layer 4, and the second metal material layer 6 a becomes the second metal layer 6. Thus, a ceramic laminate 110 as shown in FIGS. 6 and 7 is formed.

  The green sheet laminate 10 is fired by heat treatment. The heat treatment is not limited as long as the heat treatment is performed at a temperature above which the green sheet 2 becomes a ceramic sheet. The heat treatment in this step may be performed in a plurality of times. For example, you may divide into temporary baking for removing the binder etc. which are contained in the green sheet 2, and main baking for sintering and crystallizing ceramic particles. When doing in this way, the temperature of temporary baking can be 300-600 degreeC, for example. The temperature of the main firing (crystallization) can be performed at 700 to 1300 ° C., for example.

  As described above, the first metal material layer 4a and the second metal material layer 6a are formed on the green sheet laminate 10. By the heat treatment in this step, the first metal material layer 4a and the second metal material layer 6a become the first metal layer 4 and the second metal layer 6, respectively. The first metal layer 4 has conductivity and can serve as an electrode for driving the piezoelectric element 200. The second metal layer 6 is formed so as to surround the first metal layer 4 and can be, for example, a dummy electrode.

  The heating in this step can be performed by various methods. Examples of the heating method that can be used in this step include heating by a hot plate, heating by RTA (Rapid Thermal Anneal), heating by electromagnetic waves such as light, and heating by an oven (furnace). When this step is performed using an oven (furnace), for example, the green sheet laminate 10 can be introduced into the oven (furnace) and heated to a predetermined temperature.

  As described above, the ceramic laminate 110 as shown in FIGS. 6 and 7 is formed. As already described, the first metal material layer 4a and the second metal material layer 6a may shrink when fired. The ceramic laminate 110 in FIG. 6 is drawn exaggerating the state of shrinkage. As shown in FIG. 7, the ceramic laminate 110 has a structure in which a plurality of first metal layers 4 are formed inside a piezoelectric ceramic. In addition, although the ceramic of the ceramic laminated body 110 is obtained by firing the pressed green sheet 2, it can be joined together by firing to be integrated.

1.5. Step of Dicing Ceramic Laminate FIG. 8 is a perspective view schematically showing a piezoelectric element 200 obtained through this step.

  In this step, the ceramic laminate 110 is diced into individual pieces. That is, this process is performed so that the laminated body (200) used as the piezoelectric element 200 is cut out. A dicing line 8 is depicted in FIGS. This step can be performed using a dicing apparatus. The width of the dicing line 8 is arbitrary. The area inside the dicing line 8 is an area where the ceramic laminate 110 is removed. As a result of the removal of the substance in the region of the dicing line 8, the separated piezoelectric element 200 as shown in FIG. 8 can be formed.

  The ceramic laminate 110 may be provided with a dicer mark for determining the dicing line 8. Such marks may be provided at the same time when the first metal material layer 4a and the second metal material layer 6a are formed on the green sheet 2, for example. Such a mark may be newly provided in the ceramic laminate 110 separately.

  The piezoelectric element 200 as shown in FIG. 8 can be manufactured as described above.

1.6. Dimensional Change in Firing In the method for manufacturing the piezoelectric element 200 of the present embodiment, in the step of firing the green sheet laminate 10 to obtain the ceramic laminate 110, each metal material layer and the green sheet are fired simultaneously. As already mentioned, the metal material layer may shrink in size while being fired to become a metal layer. Therefore, as a result, as shown in FIG. 6, the ceramic laminate 110 may be distorted.

  According to the inventor's study, each metal material layer shrinks at a temperature lower than the temperature at which the green sheet is denatured into ceramics. Therefore, the metal layer (metal material layer) shrinks first in the temperature rising process during firing. It has been found that the green sheet deforms following this contraction. Due to such a mechanism, it has been found that the ceramic around the fired metal layer is easily distorted.

  In the manufacturing method of the present embodiment, even if each metal material layer contracts during firing, the second metal material layer 6a is disposed around the first metal material layer 4a, and therefore, at least the first metal material layer. The distortion of the green sheet 2 around 4a is made uniform by the second metal material layer 6a. That is, according to the manufacturing method of the present embodiment, the second metal material layer 6a is fired in a state where the second metal material layer 6a is arranged around the first metal material layer 4a, so that the distortion of the ceramics around the first metal layer 4 is uniform. Can be

  Further, since the distortion of the green sheet 2 is likely to occur in the peripheral portion 2r, it is more preferable that the first metal material layer 4a is provided to avoid the peripheral portion 2r of the green sheet 2.

  Further, according to the inventor's study, it has been found that in the characteristics of the piezoelectric element 200, if the strain around the first metal layer 4 is uniform, the change in dimensions before and after firing is less likely to be a problem. That is, according to the manufacturing method of the present embodiment, even if each metal material layer shrinks, the ceramics around the first metal layer 4 can be shrunk so as to have a similar shape before and after firing. In addition, the performance and yield of the piezoelectric element 200 can be suppressed.

1.7. Modifications The piezoelectric element manufacturing method of the present embodiment can be variously modified. The modifications shown below are the same as the green sheet laminate 10 described above except that the aspect of the second metal material layer 6a in “1.2. Step of forming the first metal material layer and the second metal material layer” is different. It is the same. Therefore, description of members other than the second metal material layer 6a is omitted. The other steps in the modification are the same as described above.

  9 to 14 are plan views schematically showing a green sheet laminate according to a modification of the present embodiment. FIG. 15 is a plan view schematically showing an electrode-attached ceramic laminate 170 obtained by firing a green sheet laminate 70 according to a modification of the present embodiment.

  The piezoelectric element manufacturing method of the present embodiment can be modified to form the second metal material layer 6a in a mesh shape. As shown in FIG. 9, the second metal material layer 6a of the green sheet laminate 20 according to the modification has a mesh shape when seen in a plan view. The mesh shape, pitch, and width of the second metal material layer 6a are arbitrary.

  The piezoelectric element manufacturing method of the present embodiment can be modified to form the second metal material layer 6a in a stripe shape. As shown in FIG. 10, the second metal material layer 6a of the green sheet laminate 30 according to the modification has a stripe shape when seen in a plan view. The direction, pitch and width of the stripe of the second metal material layer 6a are arbitrary.

  The piezoelectric element manufacturing method of the present embodiment can be modified to form the second metal material layer 6a in a staggered pattern. As shown in FIG. 11, the second metal material layer 6 a of the green sheet laminate 40 according to the modification has a staggered pattern (checker shape) when viewed in plan. The direction, roughness, and pitch of the staggered lattice of the second metal material layer 6a are arbitrary.

  In any example of the green sheet laminate 20 to the green sheet laminate 40 described above, the second metal material layer 6a is disposed around the first metal material layer 4a. Therefore, at least the distortion of the green sheet 2 around the first metal material layer 4a can be made uniform. Further, as described above, the second metal material layer 6 a becomes the second metal layer 6 by firing and does not become the first metal layer 4 of the piezoelectric element 200. Therefore, by adopting the aspects of these modified examples, the amount of the second metal material layer 6a can be reduced, and the manufacturing cost can be reduced.

  The method for manufacturing a piezoelectric element according to the present embodiment can be modified such that the second metal material layer 6a surrounds the first metal material layer 4a and is formed entirely on the green sheet 2. As shown in FIG. 12, the second metal material layer 6a of the green sheet laminate 50 according to the modification is formed on the entire green sheet 2 excluding the periphery of the first metal material layer 4a in plan view. ing. Also in this modification, the second metal material layer 6a is disposed around the first metal material layer 4a. Therefore, at least the distortion of the green sheet 2 around the first metal material layer 4a can be made uniform. In addition, in the present modification, the entire green sheet 2 can be deformed during firing, so that the strain can be further reduced in the entire ceramic of the piezoelectric element 200.

  The piezoelectric element manufacturing method of the present embodiment can be modified to form the second metal material layer 6 a on the peripheral edge 2 r of the green sheet 2. As shown in FIG. 13, the second metal material layer 6 a of the green sheet laminate 60 according to the modification is formed on the peripheral edge 2 r of the green sheet 2 when viewed in plan. In the example shown in FIG. 13, the second metal material layer 6a surrounds the first metal material layer 4a. Further, a plurality of second metal material layers 6a are formed, and are formed so as to surround the first metal material layer 4a as a whole. Specifically, a first metal part 61a, a second metal part 62a, a third metal part 63a, and a fourth metal part 64a are formed along each side of the green sheet 2, and the first metal The part 61a, the second metal part 62a, the third metal part 63a, and the fourth metal part 64a are separated from each other. Also in this modified example, the second metal material layer 6a is disposed around the first metal material layer 4a at the peripheral edge 2r of the green sheet 2. Therefore, at least the distortion of the green sheet 2 around the first metal material layer 4a can be made uniform.

  In the method for manufacturing a piezoelectric element according to the present embodiment, the second metal material layer 6a is formed so as to surround the first metal material layer 4a and the second metal layer 6 after firing is inside the dicing line 8. Deformations can be made. The green sheet laminated body 70 concerning the modification shown in FIG. 14 becomes the ceramic laminated body 170 with an electrode shown in FIG. 15 by baking. In the ceramic laminated body with electrode 170, the second metal layer 6 is formed inside the dicing line 8. As described above, the second metal layer 6 is a result of firing the second metal material layer 6a. In the green sheet laminate 70 according to the modified example, the second metal material layer 6 a can be formed such that the second metal layer 6 after firing is inside the dicing line 8. Such a second metal material layer 6a may be arranged based on, for example, knowing in advance the degree of contraction of the second metal material layer 6a through experiments and predicting the position where the second metal layer 6 is formed. it can. Also in this modification, the second metal material layer 6a is disposed around the first metal material layer 4a. Therefore, at least the distortion of the green sheet 2 around the first metal material layer 4a can be made uniform. Further, the second metal material layer 6a becomes the second metal layer 6 by firing, and for example, the second metal layer 6 can be used as a dicer mark in the dicing process.

  The method for manufacturing a piezoelectric element according to the present embodiment can adopt at least the above-described modification. The above-described modifications can be applied to the manufacturing method of the present embodiment alone or in combination with a plurality of modifications. And the effect by each modification and the synergistic effect by a combination can be show | played.

2. FIG. 15 is a plan view schematically showing a ceramic laminate with electrode 170 which is an example of the ceramic laminate with electrode of the present embodiment. FIG. 16 is a cross-sectional view schematically showing a ceramic laminated body 170 with an electrode. A cross section taken along line BB in FIG. 15 corresponds to FIG.

  The ceramic laminate with electrode 170 of the present embodiment has a configuration in which a ceramic layer 172 and a metal layer 74 are laminated. The number of ceramic layers 172 and metal layers 174 and the order of lamination are not particularly limited. In the example of FIG. 16, the ceramic layers 172 and the metal layers 174 are alternately laminated by five layers.

  The ceramic layer 172 has a layered shape. The planar shape of the ceramic layer 172 is arbitrary. The ceramic layer 172 can be made of a ceramic having piezoelectricity. Examples of the material of the ceramic layer 172 include PZT, PZTN, barium titanate, bismuth sodium titanate, potassium sodium niobate, and the like.

  The metal layer 174 has a layered shape. The metal layer 174 does not need to be formed continuously. The metal layer 174 may be divided into a plurality of layers in the layer as in the illustrated example. When the metal layer 174 is divided in the layer, a part of ceramics of the ceramic layer 172 may be disposed in the region of the metal layer 174. The metal layer 174 includes the first metal layer 4 and the second metal layer 6. The second metal layer 6 is disposed so as to surround the first metal layer 4 in plan view. Since the first metal layer 4 is substantially the same as the first metal layer 4 described above, the description thereof is omitted. Since the second metal layer 6 is substantially the same as the second metal layer 6 described above except for the arrangement described below, the description thereof is omitted.

  The second metal layer 6 is formed inside the dicing line 8 that partitions the element region 9. The element region 9 is a region that becomes a piece when the electrode-attached ceramic laminate 170 is diced. The element region 9 is a region that becomes a piezoelectric element, for example. In the case of the electrode-attached ceramic laminate 170, the first metal layer 4 is disposed in the element region 9. The dicing line 8 can be arbitrarily arranged. The area | region inside the dicing line 8 of the ceramic laminated body 170 with an electrode will be removed by dicing.

  In the ceramic laminate with electrode 170 of the present embodiment, the second metal layer 6 surrounds the first metal layer 4. Therefore, distortion of the ceramic layer 172 in the element region 9 is suppressed. In the ceramic laminate with electrode 170 of the present embodiment, the second metal layer 6 is formed inside the dicing line 8. Therefore, for example, burrs when dicing can be suppressed. For example, the 2nd metal layer 6 can be utilized as a dicer mark in a dicing process.

  Also in the ceramic laminated body with electrode 170 of the present embodiment, the second metal layer 6 can be modified in the same manner as the second metal material layer 6a described in “1.8. Modifications”. For example, the second metal layer 6 can have a staggered shape in plan view. In this way, the amount of metal material removed by dicing can be reduced.

  The present invention is not limited to the above-described embodiments, and various modifications can be made. For example, the present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same functions, methods, and results, or configurations that have the same purposes and effects). In addition, the present invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that achieves the same effect as the configuration described in the embodiment or a configuration that can achieve the same object. Further, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

2 ... green sheet, 2r ... peripheral edge, 4 ... first metal layer, 4a ... first metal material layer,
6 ... 2nd metal layer, 6a ... 2nd metal material layer, 8 ... Dicing line,
10, 20, 30, 40, 50, 60, 70 ... green sheet laminate,
61a ... 1st metal part, 62a ... 2nd metal part, 63a ... 3rd metal part, 64a ... 4th metal part,
65a ... fifth metal part, 110, 170 ... ceramic laminate with electrode,
172 ... Ceramic layer, 174 ... Metal layer, 200 ... Piezoelectric element

Claims (21)

Providing a first green sheet having a first metal material layer and a second metal material layer surrounding the first metal material layer;
Preparing a second green sheet having a third metal material layer and a fourth metal material layer surrounding the third metal material layer;
Forming a green sheet laminate by bonding the first green sheet and the second green sheet;
Firing the green sheet laminate to form a ceramic laminate;
Dicing the ceramic laminate,
A method for manufacturing a piezoelectric element, comprising: In claim 1,
The second metal material layer surrounds the first metal material layer in a plan view;
The method for manufacturing a piezoelectric element, wherein the fourth metal material layer surrounds the third metal material layer in a plan view. In claim 1 or claim 2,
The method for manufacturing a piezoelectric element, wherein the second metal material layer and the fourth metal material layer have a mesh shape. In claim 1 or claim 2,
The method for manufacturing a piezoelectric element, wherein the second metal material layer and the fourth metal material layer have a stripe shape. In claim 1 or claim 2,
The method for manufacturing a piezoelectric element, wherein the second metal material layer and the fourth metal material layer are formed in a staggered pattern. In any one of Claims 1 thru | or 5,
The method for manufacturing a piezoelectric element, wherein the second metal material layer and the fourth metal material layer have a frame shape. In claim 6,
The second metal material layer is spaced apart from a side of the first green sheet;
The method for manufacturing a piezoelectric element, wherein the fourth metal material layer is separated from a side of the second green sheet. In claim 6,
The frame-shaped side of the second metal material layer overlaps the side of the first green sheet,
The method for manufacturing a piezoelectric element, wherein the frame-shaped side of the fourth metal material layer overlaps the side of the second green sheet. In any one of Claims 1 thru | or 8,
The second metal material layer and the fourth metal material layer are composed of a plurality of metal parts,
The method for manufacturing a piezoelectric element, wherein the plurality of metal parts are separated from each other. In any one of Claims 1 thru | or 9,
In the step of forming the ceramic laminate, by firing, the first green sheet is used as a first ceramic sheet, the second green sheet is used as a second ceramic sheet, and the first metal material layer is used as a first metal. A method of manufacturing a piezoelectric element, comprising: a layer; the second metal material layer as a second metal layer; the third metal material layer as a third metal layer; and the fourth metal material layer as a fourth metal layer. In claim 10,
The first metal layer is formed in a piezoelectric element forming region of the first ceramic sheet,
The third metal layer is formed in a piezoelectric element forming region of the second ceramic sheet,
The step of dicing the ceramic laminate includes: a laminate including the piezoelectric element forming region of the first ceramic sheet, the first metal layer, the piezoelectric element forming region of the second ceramic sheet, and the third metal layer. A method for manufacturing a piezoelectric element, which is performed so as to be cut out. In claim 10 and claim 11,
The method of manufacturing a piezoelectric element, wherein the second metal layer and the fourth metal layer are formed in a region where the ceramic laminate is diced. A first ceramic sheet;
A first metal layer formed on the first ceramic sheet;
A second metal layer formed on the first ceramic sheet and surrounding the first metal layer;
A second ceramic sheet formed on the first ceramic sheet, the first metal layer and the second metal layer;
A third metal layer formed on the second ceramic sheet;
A fourth metal layer formed on the second ceramic sheet and surrounding the third metal layer;
A ceramic laminate with an electrode. In claim 13,
The second metal layer surrounds the first metal layer in plan view;
The fourth metal layer is a ceramic laminated body with an electrode surrounding the third metal layer in a plan view. In claim 13 or claim 14,
The said 2nd metal material layer and the said 4th metal material layer are the ceramic laminated bodies with an electrode which has a mesh shape. In claim 13 or claim 14,
The second metal material layer and the fourth metal material layer are striped ceramic laminates with electrodes. In claim 13 or claim 14,
The said 2nd metal material layer and the said 4th metal material layer are ceramic laminated bodies with an electrode currently formed in the staggered lattice shape. A method according to any one of claims 13 to 17,
The second metal layer and the fourth metal layer are framed ceramic laminates with electrodes. In claim 18,
The second metal layer is spaced apart from a side of the first ceramic sheet;
The fourth metal layer is a ceramic laminate with an electrode, which is separated from a side of the second ceramic sheet. In claim 18,
The frame-shaped side of the second metal material layer is overlapped with the side of the first ceramic sheet,
The ceramic laminated body with an electrode, wherein the frame-shaped side of the fourth metal material layer and the side of the second ceramic sheet overlap. In any one of claims 18 to 20,
The second metal layer and the third metal layer are composed of a plurality of metal parts,
The plurality of metal parts are separated from each other with a ceramic laminate with electrodes.

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