JP4614636B2 - A firing jig for firing piezoelectric ceramics for ink jet printer heads containing Pb or Bi and having a thickness of 100 μm or less, and a piezoelectric ceramics and ink jet printer heads for ink jet printer heads containing Pb or Bi and containing Pb or Bi having a thickness of 100 μm or less Method of manufacturing piezoelectric actuator - Google Patents

Description

【００９１】
本発明の試料Ｎｏ．１〜９、１０〜１５及び１７〜４５は、圧電定数ｄ₃₁のバラツキが１０％以下であった。
【００９２】
一方、支持体の平坦度が３０μｍと大きい焼成治具を使用した本発明の範囲外の試料Ｎｏ．９は、ｄ₃₁のバラツキが１４％と大きかった。
【００９３】
また、支持板の表面粗さＲａが４μｍと大きい本発明の範囲外の試料Ｎｏ．１６は、ｄ_３１のバラツキが１５％と大きかった。
【００９４】
【発明の効果】
本発明によれば、表面が平滑で平坦な焼成治具部材によって密閉空間を形成するため、気密性の良好な密閉空間を得ることができ、その内部にＰｂまたはＢｉを含有する焼成後の厚みが１００μｍ以下となる成形体と重量体とを挿入し、特に表面が平滑で平坦な支持板と重量体とで成形体を挟みながら焼成することにより、成形体からのＰｂまたはＢｉの蒸発を顕著に抑制し、表面の組成変動を抑えることができるという知見に基づくもので、このような焼成治具を用いることにより、厚みが１００μｍ以下であっても、表面の組成変動が小さく、圧電定数のバラツキが小さく、平滑なＰｂまたはＢｉを含有するインクジェットプリンタヘッド用圧電セラミックスを得ることができる。
【００９５】
また、密閉空間の機密性が高く、密閉空間中のデッドスペースも小さくすることが可能なため、共材を使用しなくても揮発成分が蒸発するのを抑制しつつ、焼成することができる。
【００９６】
本発明によれば、ＰｂまたはＢｉを含有する、厚み１００μｍ以下の薄層のインクジェットプリンタヘッド用圧電セラミックスを作製する場合、圧電定数のバラツキを少なくすることおよび平坦度と平滑性を向上させることが可能であり、支持板に接合しても圧電体の特性劣化を抑制することができ、圧電振動層の表面組成のバラツキが抑制され、複数の圧電素子の変位バラツキを低減することができるため、インクジェットプリンタの印刷ヘッドとして好適に使用可能なアクチュエータを作製することができる。
【図面の簡単な説明】
【図１】本発明の焼成治具を用いて作成したアクチュエータを示すもので、（ａ）は概略断面図、（ｂ）は概略平面図、（ｃ）は流路部材を接合した時の概略断面図である。
【図２】本発明の焼成治具を説明するための概略断面図である。
【図３】従来の焼成治具の製造方法を説明するための概略断面図である。
【図４】実施例で用いたアクチュエータを示すもので、流路部材を接合した時の概略断面図である。
【符号の説明】
１０１・・・棚板
１０２・・・スペーサ
１０３・・・天板
１０４・・・密閉空間
１０５・・・成形体
１０６・・・主面
１０６ａ・・・棚板の主面
１０６ｂ・・・スペーサの主面
１０６ｃ・・・スペーサの主面
１０６ｄ・・・天板の主面
１０６ｅ・・・重量体の主面
１０７・・・重量体
１０８・・・内壁
１０９・・・貫通孔[0001]
BACKGROUND OF THE INVENTION
  The present invention contains Pb or BiPiezoelectric for inkjet printer headceramicTheFiring used for heat treatment such as firingHealingIngredient and containing Pb or Bi using itPiezoelectric for inkjet printer headManufacturing method of ceramics, andPiezoelectric for inkjet printer headActuator manufacturing methodRelatedTo do.
[0002]
[Prior art]
Conventionally, products using a piezoelectric ceramic include, for example, an actuator, a filter, a piezoelectric resonator (including an oscillator), an ultrasonic vibrator, an ultrasonic motor, a piezoelectric sensor, and the like.
[0003]
Among these, the actuator has a response speed of 10 to an electric signal.^-6Since it is very fast, it is applied to an XY stage positioning actuator of a semiconductor manufacturing apparatus, an ink ejection actuator of an ink jet printer, and the like.
[0004]
A piezoelectric ceramic used for such an actuator uses lead-based ceramics such as lead zirconate titanate (hereinafter sometimes simply referred to as PZT). Since lead is highly volatile, there is a problem in that it evaporates from the molded body during firing, causing a compositional variation of the sintered body, resulting in a non-uniform composition. In particular, the composition variation on the surface was large compared to the inside.
[0005]
Therefore, for firing a molded body containing a volatile component such as Pb, a composition (hereinafter referred to as a co-material) containing the volatile component contained in the molded body, which is the same as or similar to the molded body, is used together with the molded body. It has been proposed to suppress the evaporation of volatile components from the molded body, prevent composition fluctuations of the molded body, particularly composition fluctuations and structural changes near the surface, and make the characteristics uniform ( For example, Patent Document 1).
[0006]
That is, a compact is placed on a porous setter and loaded into a container, and a co-material is placed around the compact and fired. Therefore, the firing jig used in Patent Document 1 includes a container and a porous setter placed in the container in order to place the molded body.
[0007]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-29872 FIG.
[0008]
[Problems to be solved by the invention]
However, when a laminate of ceramic molded bodies with a thickness of several hundreds of μm or less is fired, the surface changes in composition compared to the inside, and it is necessary to remove the altered phase on the surface. There was a problem that was difficult.
[0009]
In addition, due to composition fluctuations during firing, the shrinkage rate varies depending on the part, so that deformation such as undulation and warpage occurs, or unevenness is locally generated, making it difficult to obtain a smooth porcelain. .
[0010]
Furthermore, due to the composition variation, there is a problem that the piezoelectric characteristics vary depending on the part of the surface, that is, there is an in-plane variation, and when this is used for an actuator for a print head of an ink jet printer, an ink ejection variation becomes large, As a result, the image quality deteriorated.
[0011]
Accordingly, an object of the present invention is to provide a firing jig that can obtain a smooth porcelain having a small surface composition variation and small characteristic variation.
[0012]
[Means for Solving the Problems]
The present invention inserts a molded body into a sealed space constituted by a flat member having a smooth surface, and in particular, forms by sandwiching the molded body between a support plate and a weight body having a smooth and flat surface. It is based on the knowledge that the evaporation of volatile components from the body can be suppressed and the composition fluctuation of the surface can be suppressed. By using such a firing jig, the composition fluctuation of the surface is small, and the characteristic variation is small. A firing jig capable of obtaining a smooth porcelain is made possible.
[0013]
  Further, according to the present invention, the contact surface of the firing jig forming the sealed space is made smooth and flat by machining or the like.spiritBy increasing the density and further reducing the dead space in the sealed space, it is possible to suppress evaporation of volatile components without using a common material.
[0014]
  That is, the thickness of the present invention containing Pb or Bi is 100 μm or less.Piezoelectric for inkjet printer headA firing jig for firing ceramics includes a support plate capable of mounting a molded body on a main surface, and a spacer having a through hole surrounding the molded body provided on the main surface of the support plate And a top plate provided on the spacer and a weight body placed on the molded body, and forming a sealed space by combining the support plate, the spacer and the top plate. The main surface of the support plate, the main surface of the spacer that contacts the main surface of the support plate, the main surface of the top plate, and the main surface of the spacer that contacts the main surface of the top plate The surface and one main surface of the weight body that contacts the ceramic molded body have a porosity of 5% or less, a surface roughness Ra of 3 μm or less, and a flatness of 20 μm or less. Is.
[0015]
  hereA main surface of the support plate, a main surface of the spacer that contacts the main surface of the support plate, a main surface of the top plate, and a main surface of the spacer that contacts the main surface of the top plate, The porosity is 5% or lessBecause, PoresTheThrough this, there is an effect of suppressing the volatile component from being scattered to the outside and further improving the hermeticity of the sintered porcelain.
[0017]
  Furthermore, it is preferable that the maximum distance between the inner wall of the through hole of the spacer and the weight body is 6 mm or less. This makes firingHealingIn the sealed space formed in the tool, the effect of suppressing evaporation of volatile components from the surface of the molded body can be further enhanced.
[0019]
  Further, one main surface of the weight body contacting the molded body has a porosity of 5% or less, a surface roughness Ra of 3 μm or less, and a flatness of 20 μm or less.BecauseSince the gap formed on the contact surface between the surface of the compact and the surface of the weight is narrow, and the evaporation from the surface of the compact is suppressed, the characteristic variation of the sintered compact obtained by firing is effective. And local unevenness, warpage, and undulation can be further suppressed.
[0020]
Furthermore, the pressure generated by the gravity of the weight body is preferably 1 to 500 Pa. Thereby, variation in the shrinkage rate of the porcelain can be suppressed, and deformation of the porcelain can be easily avoided.
[0021]
  Furthermore, the support plate and the weight are made of alumina, beryllia, zirconia, magnesia, mullite, spinel, bismuth layered compound, tungsten bronze structure compound, Pb perovskite structure compound, niobium perovskite structure compound, and tantalum perovskite structure compound. It is preferable to contain at least one of them. These materials suppress the reaction with the molded body, especially the piezoelectric material,HealingAdhesion with tools can be suppressed.
[0022]
  Furthermore, it is preferable that the support plate and the weight body are made of ceramics, and the average particle diameter of crystals constituting the ceramics is 5 to 30 μm. Thereby, the effective suppression of the deformation | transformation and breakage of the porcelain at the time of heating of heating and cooling can be expected.
  Thickness of 100 μm or less containing Pb or Bi of the present inventionPiezoelectric for inkjet printer headThe ceramic manufacturing method includes placing a spacer having a through hole on the main surface of a support plate, and after firing containing Pb or Bi in the through hole of the spacer and on the main surface of the support plate A ceramic molded body having a thickness of 100 μm or less is placed, a weight body is placed on the ceramic molded body, and Pb or Bi is fired in a state where a top plate is placed on the spacer. The thickness to contain is 100 μm or lessPiezoelectric for inkjet printer headA method for manufacturing ceramics, comprising: a main surface of the support plate; a main surface of the spacer that contacts the main surface of the support plate; a main surface of the top plate; and the main surface of the top plate The main surface of the spacer and one main surface of the heavy body that contacts the ceramic molded body have a porosity of 5% or less, a surface roughness Ra of 3 μm or less, and a flatness of 20 μm or less. The ceramic molded body is placed in a sealed space formed by the support plate, the spacer, and the top plate.
  Further, the thickness of the present invention containing Pb or Bi is 100 μm or less.For inkjet printer headA method for manufacturing a piezoelectric actuator is a piezoelectric ceramic in which a plurality of green sheets containing Pb or Bi-containing piezoelectric ceramic powder and a binder are stacked and an internal electrode is formed therein, and the thickness after firing is 100 μm or less. A step of producing a molded body, and a spacer having a through-hole is placed on the main surface of the support plate, and the piezoelectric ceramic molded body is placed on the main surface of the support plate in the through-hole of the spacer. Placing a weight body on the piezoelectric ceramic molded body, firing in a state where a top plate is placed on the spacer, and producing a piezoelectric ceramic in which an internal electrode is formed; Forming a plurality of surface electrodes on the surface of the piezoelectric ceramic, and containing Pb or Bi having a thickness of 100 μm or lessPiezoelectric for inkjet printer headA method for manufacturing an actuator, comprising: a main surface of the support plate; a main surface of the spacer that contacts the main surface of the support plate; a main surface of the top plate; and the main surface of the top plate. The main surface of the spacer and one main surface of the heavy body that contacts the piezoelectric ceramic molded body have a porosity of 5% or less, a surface roughness Ra of 3 μm or less, and a flatness of 20 μm or less. It is characterized by being.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described with reference to the drawings, taking as an example the case of using PZT as a piezoelectric ceramic.
[0024]
  The firing jig of the present invention was inserted insideContains Pb or BiceramicSusFor example, as shown in FIG. 1 (a), a support plate 101, a spacer 102, and a top plate 103 are combined to form a sealed space 104. The molded body 105 is placed in the sealed space 104 so as to come into contact with the main surface 106a of the support plate 101, the weight body 107 is placed on the molded body 105, and the firing jig is fired together with the molded body. It is for firing inside the furnace.
[0025]
Thus, the support plate 101 has the main surface 106a on which the molded body 105 is placed, and the spacer 102 is provided so as to accommodate the molded body 105 therein, that is, so as to surround the molded body 105. The top plate 103 is provided on the spacer 102.
[0026]
Therefore, as shown in FIG. 1B, the firing jig of the present invention is constituted by a jig member including a support plate 101, a spacer 102 having a through hole 109, a top plate 103, and a weight body 107. These are combined such that the weight body 107 is disposed inside the through hole 109 provided in the spacer 102.
[0027]
According to the present invention, the main surface 106 a of the support plate 101, the main surface 106 b of the spacer 102 in contact with the main surface 106 a of the support plate 101, the main surface 106 d of the top plate 103, and the main surface 106 d of the top plate 103 It is important that the main surface 106c of the spacer 102 to be in contact has a surface roughness Ra of 3 μm or less and a flatness of 20 μm or less.
[0028]
  This is, for example, combined firing when firing a molded body containing a component that easily volatilizes during firing such as Pb and Bi.HealingIf there is a large gap in the tool, the volatile component will be continuously scattered outside the jig, and as a result, a large amount of the volatile component will be scattered, resulting in a large variation in the characteristics of the sintered porcelain. Therefore, in order to suppress scattering of such volatile components from the firing jig, the contact portions between the jig members forming the gaps, that is, the contact surfaces of the support plate 101, the spacer 102, and the top plate 103 are used. It is important to control the surface state of a certain main surface 106.
[0029]
If the flatness of the main surface 106 exceeds 20 μm, a relatively large gap is likely to be formed due to surface distortion, and volatile components are likely to be scattered through the gap, resulting in variations in the characteristics of the sintered body obtained by firing the molded body. growing. In particular, when a piezoelectric ceramic having a thin layer of 5 to 100 μm is manufactured, for example, when a piezoelectric ceramic used for a print head actuator is fired, warpage and surface unevenness are likely to occur, and a flat and smooth piezoelectric ceramic is obtained. Becomes difficult.
[0030]
In order to obtain a flatter and smoother sintered body, the flatness of the main surface 106 which is a contact surface of the support plate support plate 101, the spacer 102, and the top plate 103 is preferably 15 μm or less, and more preferably 10 μm or less.
[0031]
Further, when the surface roughness Ra of the main surface 106 exceeds 3 μm, volatile components are likely to be scattered through the diffusion path formed by unevenness between the jig members, and the sintered body obtained by firing the molded body Characteristic variation increases. Therefore, it is important to set the surface roughness Ra to 3 μm in order to suppress scattering of volatile components through the diffusion path and reduce the characteristic variation of the sintered body.
[0032]
In order to effectively suppress the volatilization from the molded body by making the gap serving as the diffusion path smaller, the surface roughness Ra of the main surface 106 which is the contact surface of the support plate 101, the spacer 102 and the top plate 103. Is preferably 2.5 μm or less, more preferably 2 μm or less.
[0033]
According to the present invention, the contact surface of the firing jig, that is, the main surface 106 a of the support plate 101, the main surface 106 b of the spacer 102 that contacts the main surface 106 a of the support plate 101, and the main surface 106 d of the top plate 103 It is preferable that the surface portion of the main surface 106c of the spacer 102 contacting the main surface 106d of the top plate 103 has a porosity of 5% or less, particularly 1% or less, and further 0.5% or less.
[0034]
  By setting such a porosity, it is possible to prevent the volatile component from being scattered outside the firing jig through the pores like a porous body. In addition, by reducing the porosity as described above, it becomes possible to easily reduce the surface roughness,spiritThe density can be further increased, and as a result, the flatness, surface roughness and composition variation of the sintered body can be further improved.
[0035]
  In addition, by reducing the porosity, the main surface 106a of the support plate 101 can be crushed like a porous body conventionally used.ManyTherefore, degranulated particles adhere to the surface of the molded body 107 in contact with the main surface 106a.The, Defective productsTo beCan also be suppressed.
[0036]
In order to measure the porosity of the surface of the jig member, in order to polish the surface and evaluate the porosity of the polished surface, the minimum thickness required for polishing, for example, a thickness of several μm is actually required. This is necessary and is referred to as a surface portion in the present invention.
[0037]
The support plate 101, the spacer 102, and the top plate 103 can be used regardless of whether the whole is dense or only the surface is dense.
[0038]
For example, a dense sintered body that is dense as a whole can be regenerated at low cost by reworking the surface even if the surface is soiled or damaged by repeated use as a firing jig.
[0039]
An example of a member having a dense surface and a relatively high porosity inside is a sintered body in which sintering proceeds more easily at the surface portion than at the inside during sintering. Further, only the surface of a member having a non-dense surface, for example, a porous body can be made dense. For example, the surface of the ceramic sintered body having a surface porosity of about 2 to 8% is polished and coated with a ceramic layer, so that the main surfaces 106a and 106b of the support plate 101 and the weight body 107 are 0.1% or less. The porosity can be made as follows.
[0040]
  In particular, CVD (ConversionA thickness of several tens of μm or more, further 50 μm or more, more preferably 100 μm or more can be formed by a chemical vapor deposition method, and the surface porosity can be reduced to 1% or less by mirror polishing. Using this method, it is possible to obtain an ultra-dense and ultra-smooth surface with a porosity of 0.1% or less and a surface roughness of 100 nm or less,spiritIt is possible to obtain a sintered jig with high density. In addition, when the cost for producing the entire large support plate with a dense sintered body is high, or when it is difficult to synthesize the dense sintered body, this method reacts between the molded body and the support plate. It is especially effective when it is easy to do.
[0041]
According to the present invention, if the molded body 105 is placed on the main surface 106a of the support plate 101, there may be anything on the molded body 105, for example, a porous body may be placed. Placing the weight body 107 having the same main surface as the support plate 101 on the molded body 105 and arranging the molded body 105 so as to be sandwiched between the support plate 101 and the weight body 107 is effective for variation in composition. It is preferable in that it can be suppressed and a flatness of 20 μm or less can be easily obtained.
[0042]
When Pb and Bi having high volatility are contained, the pair of main surfaces having a large area are sandwiched between the support plate 101 having a smooth and flat surface and the weight body 105, thereby suppressing the evaporation of Pb. In-plane composition variation due to evaporation can be suppressed.
[0043]
When the molded body 105 is disposed so as to be sandwiched between the support plate 101 and the weight body 105, Pb evaporates from the side surface, but the side surface portion is used as a displacement element even if Pb composition variation occurs on the side surface portion. In the actuators that do not, the displacement characteristics are not affected, so that the compositional variation can be substantially ignored.
[0044]
The maximum distance between the inner wall 108 of the spacer 102 and the weight body 105, that is, the difference d (d = S−W) between the length S of the through hole 109 of the spacer 102 and the weight body W is 6 mm or less, particularly 4 mm. Hereinafter, it is further preferably 2 mm or less. Since the weight body 105 is disposed in the sealed space 109, the dead space (the remaining volume obtained by subtracting the volume of the molded body and the weight body 105 from the volume of the sealed space) becomes closer as the occupied space of the weight body 105 is closer to the inner wall of the spacer. Even if the volatile component evaporates, a small amount of the saturated vapor pressure is obtained even when the volatile component evaporates, and the composition variation in the porcelain can be further reduced.
[0045]
If the SW value is too small, the gap between the spacer 102 and the weight body 103 will not be too small, and the value of d (S−W) will not be difficult to separate after firing. It is preferably 0.2 mm or more, particularly 0.4 mm or more, and more preferably 0.6 mm or more.
[0046]
Furthermore, it is preferable that the shape of the through hole provided in a part of the spacer 102 and the shape of the main surface of the weight body 102 are similar. The dead space can be reduced as the shape of the main surface of the weight body 105 approaches the shape of the through hole of the spacer 102.
[0047]
  The weightTo the bodyThereforeIn addition to the compact1 to 500 Pa, particularly 10 to 300 PaPreferably there is. By applying such a pressure to the molded body, deformation of the molded body during firing can be effectively prevented without inhibiting sintering.
[0048]
The support plate used in the present invention can be made of any material as long as it can withstand the firing temperature, can be easily surface-treated, and has low reactivity with the compact powder.
[0049]
In particular, when a firing jig is used for firing a piezoelectric body, the reactivity with a molded body made of a piezoelectric ceramic powder such as PZT is low, and the characteristics of the piezoelectric body can be stabilized. Therefore, alumina, beryllia, It is preferable to contain at least one of zirconia, magnesia, mullite, spinel, bismuth layered compound, tungsten bronze structure compound, Pb perovskite structure compound, niobium perovskite structure compound and tantalum perovskite structure compound.
[0050]
Of these, zirconia and spinel, which are particularly low in reactivity, are preferred, and more than 10 mol% of Y₂O_ThreeOf these, stabilized zirconia containing at least one of CaO, MgO, and rare earths is preferable in terms of suppressing cracking of the jig, chipping deformation, and change in surface roughness in order to suppress phase transformation of zirconia. .
[0051]
Furthermore, the average particle diameter of the crystals constituting the support plate 101 is 5 to 30 μm, particularly 10 to 25 μm, in order to reduce deformation due to heating and cooling, and to prevent the occurrence of significant cracks and chips. Is preferably 15 to 20 μm.
[0052]
According to the present invention, the maximum thickness of the firing jig in which the support plate 101, the spacer 102, and the top plate 103 are assembled is preferably 15 mm or less. By setting to such a thickness, it is possible to improve the thermal uniformity, make the temperature of the molded body uniform, and more effectively suppress the characteristic variation due to firing unevenness, especially ZrO.₂It is effective when it is made of a material with low thermal conductivity such as.
[0053]
In addition, according to the present invention, in order to fire a plurality of molded bodies, for example, as shown in FIG. 2A, a plurality of support plates 111, spacers 112, and a top plate 113 are combined to form a plurality. The molded body 115 is placed on the main surface 116a of the support plate 111 and the molded body 115 is accommodated therein, that is, the spacer 112 is surrounded by the support plate 111 so as to surround the molded body 115. The top plate 113 may be provided on the spacer 112 and the spacer 112, and the molded body 115 and the weight body 117 may be disposed inside the sealed space 114.
[0054]
Thus, as shown in FIG. 2B, the firing jig of the present invention is composed of a jig member including the support plate 111, the spacer 112, the top plate 113, and the weight body 117. The weight body 117 may be disposed inside the through hole 119 of the spacer 112.
[0055]
Also, a plurality of firing jigs shown in FIGS. 1 and 2 may be stacked so that more molded bodies can be fired at once.
[0056]
Next, a method for using the firing jig of the present invention will be described by taking the firing of PZT as an example.
[0057]
First, PZT powder having a purity of 99% and an average particle diameter of 1 μm or less is prepared as a piezoelectric powder used as a raw material.
[0058]
An appropriate organic binder is added to the PZT powder and formed into a tape shape. In order to form an internal electrode at a desired portion of the tape, a conductive paste is applied, and a via hole is formed at a desired location. An electrode was formed by embedding a conductive paste in the via hole. Next, the obtained molded body is laminated. Further, it is cut into a specific shape as desired.
[0059]
In order to fire the molded body obtained by stacking, the molded body is mounted on a firing jig and placed in a firing furnace. Hereinafter, the case where the firing jig shown in FIG. 1 is used as the firing jig will be described as an example. That is, the molded body 105 is placed on the support plate 101 having a flatness of 20 μm or less and a surface roughness Ra of 3 μm or less, and the spacer 102 is placed so as to surround the molded body.
[0060]
Next, the weight body 107 is placed on the molded body 105 placed inside the through hole 109 of the spacer 102. At this time, the molded body 105 is placed so as not to be damaged so as not to be damaged. Note that the spacer 102 may be placed on the support plate 101 after the weight body 107 is placed on the compact 105 immediately after the compact 105 is placed.
[0061]
Further, the top plate 103 is placed on the spacer 102, the sealed space 104 is formed by the support plate 101, the spacer 102, and the top plate 103, and the molded body 105 and the weight body 107 are formed inside the sealed space 104. Place.
[0062]
  In this wayspiritWhat is necessary is just to insert the baking jig | tool in which the sealed space with high density | concentration was formed in a baking furnace, and to bake by desired baking temperature.
[0063]
Prior to firing, if necessary, the molded body may be degreased at a temperature of about 400 ° C. to 900 ° C.
[0064]
A surface electrode can be formed on the surface of the piezoelectric ceramic obtained by firing in this way, and the actuator can be produced by polarization. For example, as shown in FIG. 3, such an actuator is provided on a piezoelectric plate 2 made of a piezoelectric ceramic, an internal electrode 5 provided inside the piezoelectric plate 2, and a part of the main surface of the piezoelectric plate 2. The displacement element 7 is composed of the piezoelectric vibration layer 4 formed on the surface portion of the piezoelectric plate 2, the internal electrode 5, and the surface electrode 6.
[0065]
Further, for example, as shown in FIG. 3B, the surface electrodes 6 are two-dimensionally arranged at equal intervals and are independently connected to an external electronic control circuit (not shown). When a voltage is applied to the piezoelectric vibration layer 4 at a portion sandwiched between the internal electrode 5 to which the voltage is applied and the surface electrode 6 can be displaced.
[0066]
Furthermore, when applied to a print head, as shown in FIG. 3C, when the actuator 1 is joined to the flow path member 3 in which the ink flow path 3a is formed by the partition walls 3b, the displacement element 7 is displaced. As a result, the ink in the ink flow path 3 a can be ejected from the ink nozzle 8.
[0067]
If the firing jig of the present invention is used for firing, even when a thin layer actuator having a thickness of 100 μm or less as shown in FIG. 3 is manufactured, the influence of evaporation of volatile components during firing can be significantly reduced. Since the deformation of the porcelain due to shrinkage variation or the like can be reduced, the residual stress that occurs when the unevenness is corrected and fixed smoothly when fixing to the flow path member can be reduced.
[0068]
In addition, since the evaporation of volatile components from the compact can be suppressed, variations in the composition of the surface of the sintered body are suppressed, and a large number of displacement elements constituting the actuator have uniform piezoelectric characteristics. Can be reduced. In addition, by applying such an actuator to the print head of an ink jet printer, it is possible to greatly contribute to speeding up and high accuracy of the ink jet printer.
[0069]
In addition, it cannot be overemphasized that the baking jig | tool of this invention can be used for baking of not only a piezoelectric ceramic but all the powder compacts.
[0070]
【Example】
The piezoelectric ceramic was fired using the firing jig of the present invention, the actuator shown in FIG. 3 was produced, and the characteristics were evaluated. This will be specifically described below.
[0071]
First, a piezoelectric ceramic powder containing lead zirconate titanate having a purity of 99% or more was prepared as a raw material.
[0072]
The compact is made by adding butyl methacrylate as a water-based binder, ammonium polycarborate as a dispersant, isopropyl alcohol and pure water as a solvent to a piezoelectric ceramic powder mainly composed of lead zirconate titanate. After mixing, this slurry was produced in a sheet shape having a thickness of about 30 μm on a carrier film by a doctor blade method.
[0073]
Similarly, green sheets were prepared using various piezoelectric ceramic powders. Moreover, the electrically conductive paste for Ag-Pd internal electrodes was produced. The obtained conductive paste was printed on the surface of the green sheet with a thickness of 4 μm to form internal electrodes.
[0074]
Next, the green sheets on which the internal electrodes were printed were sequentially laminated so as to be sandwiched between the green sheets on which the internal electrodes were not printed, and thermoformed to obtain a molded body.
[0075]
After degreasing the molded body, as shown in FIG. 2, the molded body was placed in a sealed space so as to be sandwiched between the support plate and the weight body. Thus, the baking jig | tool which loaded the some molded object inside was arrange | positioned in the baking furnace.
[0076]
This was fired in an atmosphere of 99% oxygen or more at a firing temperature of 1000 ° C. for 2 hours to produce a piezoelectric ceramic having an internal electrode.
[0077]
The material shown in Table 1 was used for the support plate. Stabilization was measured when stabilized zirconia was used. This degree of stabilization is expressed by the proportion of cubic crystals in the entire crystal phase. Specifically, the peak intensity by X-ray diffraction (XRD) is measured, and the degree of stabilization is calculated from the following formula. .
[0078]
Stabilization degree = 100 × Vm / Vc
Where Vm and Vc are monoclinic and cubic volume fractions, respectively.
Vm = (lm (111) + lm (11-1)) / (lm (111) + lm (11-1) + lt (111) + lc (111))
Vc = lc (400) / (lc (400) + lt (400) + lt (004))
It is represented by Here, l represents the integrated intensity (peak intensity) of each reflecting surface, and the subscripts m, t, and c represent monoclinic, tetragonal, and cubic crystals, respectively.
[0079]
  The porosity of the support plate was measured by image analysis from a micrograph (200 times) of the mirror-polished surface. Flatness is measured with a device that combines a KEYENCE laser focus displacement meter and an XY stage.HealingThe tool was scanned in the long axis direction and the vertical direction, and the maximum value was evaluated. The average particle size G was mirror-polished and then etched with boiling phosphoric acid, and was obtained from the relational equation G = 1.5 × L from the average intercept length L in the SEM photograph.
[0080]
Ra of the surface of the support plate was measured by scanning an area of 100 μm × 100 μm using AFM, and was obtained from an average value of measured values at any five points in the plane.
[0081]
d = S−W is an average value in the case of the similar shape, and a maximum value in the case of the non-similar shape. Moreover, the pressure by a weight body was computed from the weight.
[0082]
  At this time,Volume V of closed space₁1326mm³, Volume V of weight body₂Is 625mm³, Volume V of molded body₃Is 75mm³It was made to become. At this time, 1.0001 ≦ V₁/ (V₂+ V₃) ≦ 4.0000 and 0.02 ≦ V₂/ V₃≦ 50 andifFurther, evaporation of volatile components from the body to be fired can be further suppressed, and variations in piezoelectric characteristics can be more effectively suppressed.V ₁ , V ₂ Is obtained by the Archimedes method and V ₃ Was determined from the outer dimensions of the molded body.
[0083]
The thickness of the obtained piezoelectric ceramic was 50 μm, and this was evaluated as follows.
[0084]
The flatness of the piezoelectric ceramic was obtained from a change in height by scanning from one end of the sample to the other end using a combination device of a KEYENCE laser focus displacement meter and an XY stage.
[0085]
The unevenness on the surface of the porcelain was calculated from the maximum value-minimum value by scanning a range of 2 mm in length and 2 mm in width by a combined device of Keyence laser focus displacement meter and XY stage.
[0086]
The Ra on the porcelain surface was also measured using AFM in the same manner as described above.
[0087]
Next, a surface electrode was formed on one side of the surface of the obtained piezoelectric ceramic. The surface electrode was formed by applying Au paste by screen printing to form 600 points per substrate. This was baked in the atmosphere of 600 to 800 ° C. to produce the actuator shown in FIGS. 3 (a) and 3 (b).
[0088]
The piezoelectric constant is d₃₁Ten points were measured by a resonance method using an impedance analyzer (Agilent Technology 4194A), and the average value was calculated. And d₃₁And calculate the difference from the average value of₃₁Displayed as a percentage as a variation.
[0089]
The displacement is measured in consideration of the use as a print head for an ink jet printer. As shown in FIG. 4, the actuator 11 produced as described above is bonded to the support plate 13 having the grooves 13 a and the partition walls 13 b, and the piezoelectric vibration layer 14. The displacement element 17 was fabricated so that the inner electrode 15 and the surface electrode 16 were sandwiched. Then, a laser beam is irradiated to the actuator from the support plate 13 side through the groove 13a by a laser Doppler displacement meter, and the displacement is measured by measuring the central portion and the peripheral portion of the actuator in contact with the groove 13a of the support plate 13. The average value was calculated. The results are shown in Table 1.
[0090]
[Table 1]

[0091]
Sample No. of the present invention. 1 to 9, 10 to 15, and 17 to 45 are piezoelectric constants d₃₁The variation was 10% or less.
[0092]
On the other hand, the sample No. out of the scope of the present invention using a baking jig having a large flatness of 30 μm of the support was used. 9 is d₃₁Variation was 14%.
[0093]
  Further, the surface roughness Ra of the support plate is 4 μm.WhenSample no. 16 is d₃₁The variation was as large as 15%.
[0094]
【The invention's effect】
  According to the present invention, since the sealed space is formed by the flat and smooth firing jig member, a sealed space with good airtightness can be obtained, and the thickness after firing containing Pb or Bi therein Inserting a molded body and a weight body having a thickness of 100 μm or less, and particularly firing by sandwiching the molded body between a smooth and flat support plate and a weight body, markedly evaporates Pb or Bi from the molded body Is based on the knowledge that the surface composition fluctuation can be suppressed, and by using such a firing jig, the surface composition fluctuation is small even when the thickness is 100 μm or less,Piezoelectric constantSmall variation and contains smooth Pb or BiPiezoelectric for inkjet printer headCeramics can be obtained.
[0095]
Further, since the confidentiality of the sealed space is high and the dead space in the sealed space can be reduced, it can be fired while suppressing evaporation of volatile components without using a common material.
[0096]
  According to the present invention, a thin layer of 100 μm or less containing Pb or BiFor inkjet printer headPiezoelectricCeramicsWhen makingReducing the variation of the piezoelectric constant andIt is possible to improve the flatness and smoothness, and even when bonded to the support plate, the deterioration of the characteristics of the piezoelectric body can be suppressed, the variation in the surface composition of the piezoelectric vibration layer is suppressed, and the plurality of piezoelectric elements Since the variation in displacement can be reduced, an actuator that can be suitably used as a print head of an ink jet printer can be manufactured.
[Brief description of the drawings]
FIGS. 1A and 1B show an actuator created using a firing jig of the present invention, where FIG. 1A is a schematic sectional view, FIG. 1B is a schematic plan view, and FIG. It is sectional drawing.
FIG. 2 is a schematic cross-sectional view for explaining a firing jig of the present invention.
FIG. 3 is a schematic cross-sectional view for explaining a conventional firing jig manufacturing method.
FIG. 4 is a schematic cross-sectional view of an actuator used in an example when a flow path member is joined.
[Explanation of symbols]
101 ... shelf board
102 ... Spacer
103 ... top plate
104 ... sealed space
105 ... Molded body
106 ... main surface
106a ... Main surface of the shelf board
106b ... Spacer main surface
106c ... Spacer main surface
106d ... Main surface of the top plate
106e ... Main surface of weight body
107 ... weight body
108 ... inner wall
109 ... through hole

Claims (7)

A support plate capable of mounting the molded body on the main surface, a spacer having a through hole surrounding the molded body provided on the main surface of the support plate, and a top plate provided on the spacer And a weight body placed on the molded body, and it is possible to form a sealed space by combining the support plate, the spacer, and the top plate, and the main surface of the support plate A main surface of the spacer contacting the main surface of the support plate, a main surface of the top plate, a main surface of the spacer contacting the main surface of the top plate, and the molded body of the weight body. One main surface that abuts has a porosity of 5% or less, a surface roughness Ra of 3 μm or less, and a flatness of 20 μm or less, and an ink jet printer having a thickness of 100 μm or less containing Pb or Bi It is firing the piezoelectric ceramic head Firing jig for. 2. The piezoelectric ceramic for an inkjet printer head according to claim 1, wherein the maximum distance between the inner wall of the through hole of the spacer and the weight body is 6 mm or less, and the thickness is 100 μm or less containing Pb or Bi. A firing jig for firing. The pressure applied to the molded body by the weight body is 1 to 500 Pa, for firing the piezoelectric ceramic for an inkjet printer head having a thickness of 100 μm or less, containing Pb or Bi according to claim 1 or 2 Firing jig. The support plate and the weight body are at least one of alumina, beryllia, zirconia, magnesia, mullite, spinel, bismuth layered compound, tungsten bronze structure compound, Pb perovskite structure compound, niobium perovskite structure compound, and tantalum perovskite structure compound. A firing jig for firing piezoelectric ceramics for an ink jet printer head containing Pb or Bi according to any one of claims 1 to 3, having a thickness of 100 µm or less. 5. The Pb or Bi according to claim 1, wherein the support plate and the weight body are made of ceramics, and an average particle diameter of crystals constituting the ceramics is 5 to 30 μm. A firing jig for firing piezoelectric ceramics for an inkjet printer head having a thickness of 100 μm or less. A spacer having a through hole is placed on the main surface of the support plate, and the thickness after firing containing Pb or Bi within the through hole of the spacer and on the main surface of the support plate is 100 μm or less. A piezoelectric ceramic molded body is placed, a weight body is placed on the piezoelectric ceramic molded body, and a top plate is placed on the spacer. The thickness of Pb or Bi containing firing is 100 μm. The following manufacturing method of piezoelectric ceramics for an ink jet printer head , wherein the main surface of the support plate, the main surface of the spacer in contact with the main surface of the support plate, the main surface of the top plate, and the top plate The main surface of the spacer that comes into contact with the main surface and the one main surface that comes into contact with the ceramic molded body of the weight body have a porosity of 5% or less and a surface roughness Ra of 3 μm or less, and Flatness of 20 μm or less Are, the ceramic molded body, the support plate, for the spacers and the top ink-jet printer head thickness 100μm following containing Pb or Bi, characterized in that it is placed in the closed space formed by the plate Manufacturing method of piezoelectric ceramics. A step of producing a piezoelectric ceramic molded body having a thickness of 100 μm or less after firing, in which a plurality of green sheets containing powder and a binder containing piezoelectric ceramic containing Pb or Bi and an internal electrode are formed inside; A spacer having a through hole is placed on the main surface of the support plate, and the piezoelectric ceramic molded body is placed on the main surface of the support plate in the through hole of the spacer. A step of producing a piezoelectric ceramic having an internal electrode formed by placing a weight body on the molded body and firing in a state where the top plate is placed on the spacer; and on the surface of the piezoelectric ceramic A method of manufacturing a piezoelectric actuator for an inkjet printer head having a thickness of 100 μm or less, comprising Pb or Bi, comprising a step of forming a plurality of surface electrodes, A main surface of the holding plate; a main surface of the spacer that contacts the main surface of the support plate; a main surface of the top plate; a main surface of the spacer that contacts the main surface of the top plate; The Pb is characterized in that the one main surface in contact with the piezoelectric ceramic molded body has a porosity of 5% or less, a surface roughness Ra of 3 μm or less, and a flatness of 20 μm or less. Or the manufacturing method of the piezoelectric actuator for inkjet printer heads of Bi containing 100 micrometers or less in thickness.

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