JP2014070004A - Heat treatment fixture - Google Patents

Abstract

The present invention provides a heat treatment jig in which a difference in the state of the upper and lower surfaces of an object to be heat treated hardly occurs.
A flat plate-like first member 1 made of a dense ceramic, a second member 2 placed on the plate-like first member 1 and having a through hole 2a in the center, and placed thereon. A plate-like third member 3 and a porous ceramic material are placed on the first member 1 in the through-hole 2a of the second member 2, and a workpiece 10 having a thickness of 100 μm or less is placed thereon. A heat treatment jig including a flat plate-like fourth member 4 to be placed, wherein the porous ceramic has air permeability and has a dense wall between the pores, and the first member 1 and the first member 4. Both the portion where the second member 2 is in contact, the portion where the second member 2 and the third member 3 are in contact, and the upper surface of the fourth member 4 are flattened, and the lower surface of the third member 3 and the fourth member 4 are flattened. The distance between the upper surface of the member 4 is larger than 100 μm and not larger than 500 μm. .
[Selection] Figure 1

Description

  The present invention relates to a heat treatment jig used in heat treatment such as firing of electronic material parts.

  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.

Among these, actuators have a very high response speed to electrical signals of the order of 10 ⁻⁶ seconds, so they are applied to XY stage positioning actuators for semiconductor manufacturing equipment, ink ejection actuators for inkjet printers, and the like. Yes.

  Piezoelectric ceramics used in such actuators use lead-containing compounds such as lead-containing ceramics such as lead zirconate titanate (hereinafter sometimes simply referred to as PZT). In recent years, bismuth layered compounds that do not contain toxic lead have been used. In such a compound, since lead and bismuth have high volatility, there is a problem that the sintered body evaporates from the molded body during firing, causing the composition to vary in composition, resulting in a non-uniform composition. In particular, the composition variation on the surface of the sintered body was large compared to the inside.

  Therefore, for firing a molded body containing a volatile substance such as lead, the composition containing the volatile substance contained in the molded body, which is the same as or similar to the molded body, is placed in a firing jig together with the molded body. It is known to suppress the evaporation of volatile substances from the composition, suppress the composition fluctuation of the molded body, particularly the composition fluctuation and structural change in the vicinity of the surface, and make the characteristics of the sintered body uniform (for example, (See Patent Document 1).

  In addition, a closed space is formed by combining dense ceramic firing jigs, a compact is placed in the closed space, a dense ceramic is placed on the compact, and the compact is made of dense ceramic. It is known to sinter and fire (see, for example, Patent Document 2).

JP-A-10-29872 JP 2007-169142 A

  However, when fired as described in Patent Document 1, since the lower surface of the molded body is in contact with the firing jig, there is a risk that the volatility of the volatile material is small and the difference between the states of the upper and lower surfaces of the sintered body is increased. When fired as described in Patent Document 2, the upper and lower surfaces of the molded body are in contact with the firing jig, and it is difficult to cause a difference in the state at the initial stage. There is a problem in that the number of times that the jig can be used is limited because the jig undergoes deformation such as warpage due to slight reaction with the molded body and thermal history, and variations in how it comes into contact with the molded body. In addition, if the firing jig placed on the molded body is thickened, the deformation can be suppressed, but since the load applied to the molded body increases, the fired product may be deformed during firing. It does not solve the problem.

  Therefore, an object of the present invention is to provide a heat treatment jig in which a difference in the state of the upper and lower surfaces of the object to be heat treated is unlikely to occur.

  The heat treatment jig of the present invention includes a flat plate-like first member, each made of a dense ceramic, and a through-hole that is placed on the first member and penetrates vertically. A second member, a flat plate-like third member placed on the second member, and a porous ceramic, placed on the first member in the through hole of the second member A flat plate-like fourth member on which an object to be heat-treated having a thickness of 100 μm or less is placed, wherein the porous ceramic has air permeability and is porous The wall is dense, the first member and the second member are in contact with each other in an annular region around the through hole, and the second member and the third member are in an annular region around the through hole. Both of the parts that contact and contact the first member and the second member, the second member and the third part Both of the portions that are in contact with each other and the upper surface of the fourth member are flattened, and the distance between the lower surface of the third member and the upper surface of the fourth member is greater than 100 μm and less than or equal to 500 μm. It is characterized by.

  According to the firing jig of the present invention, the upper surface of the object to be heat-treated has a space with a limited height of 500 μm or less, so that volatile substances can be prevented from staying and volatilization of volatile substances from continuing. On the lower surface of the object to be heat-treated, volatilization occurs to some extent from the lower surface of the object to be heat-treated through the breathable porous ceramics, and the volatilization of the volatile substance continues in the porous space. Can be suppressed, and the difference in the state of the upper and lower surfaces can be reduced.

It is the heat processing jig | tool of one Embodiment of this invention, (a) is a longitudinal cross-sectional view of the state which mounted the to-be-processed target object, (b) is a perspective view. (A), (b) is a longitudinal cross-sectional view of the state which mounted the to-be-processed target object in the heat processing jig | tool of other embodiment of this invention, respectively.

  The heat-treating member for the lead-containing compound of the present invention is used when heat-treating a heat-treated material having a thickness of 100 μm or less containing, for example, lead or bismuth, which volatilizes by heat treatment. Examples of the heat treatment include firing of the conductor applied to the substrate, aging treatment, and the like in addition to firing of the molded body. An embodiment of the firing jig of the present invention will be described with a firing jig for firing lead zirconate titanate (hereinafter referred to as PZT).

  Fig.1 (a) is a longitudinal cross-sectional view of the state which mounted the molded object 10 which is a to-be-heated material in the baking jig of this embodiment, FIG.1 (b) is a method of combining a baking jig. It is the perspective view shown so that it might understand. The firing jig includes a first member 1, a second member 2, a third member 3, and a fourth member 4.

The first member 1, the second member 2, and the third member 3 are made of dense ceramics. The dense ceramic is a ceramic having a porosity of 95% or more, preferably 98% or more. Since these are dense bodies, deformation and the like hardly occur even when firing is repeated. As the dense ceramic, a material having a low reactivity with the material of the molded body 10, particularly, a volatile substance that volatilizes by heat treatment is used. Stabilized zirconia is basically poor in reactivity and is an effective material for various molded bodies 10, and is also suitably used for molded bodies 10 containing lead and bismuth. As the stabilizer, CaO, MgO, Y ₂ O ₃ , lanthanoids and the like can be used. For lead and bismuth, cerium oxide is also a preferable dense ceramic material.

The shape of the first member 1 is a flat plate shape. The second member 2 is placed on the first member 1, and a through hole 2a penetrating vertically is opened at the center. The shape of the third member 3 is a flat plate shape, and is placed on the second member 2 so as to close the top of the through hole 2a. By combining in this way, the first member 1 and the second member 2 are in contact with each other in an annular region around the through hole 2a, and the second member 2 and the third member 3 are in an annular region around the through hole 2a. Will be in contact. Both the part where the first member 1 and the second member 2 are in contact and the part where the second member 2 and the third member 3 are in contact with each other are subjected to a flattening process such as polishing, which is more than the burned skin surface. It is made flat. Thereby, the space enclosed by the 1st member 1, the 2nd member 2, and the 3rd member 3 is made into the sealed space with almost no gas movement with the exterior. As a result, the volatile material hardly leaks out of the firing jig, so that the volatilization is difficult to continue after the density of the volatile material in the space in the firing jig is increased to some extent by firing, so the volatilization amount can be reduced. . In the flattening process, for example, the surface roughness is set to 0.5 μm or less using fine abrasive grains of 200 mesh or more.

  The first to third members 1 to 3 have a thickness of 500 μm or more, preferably 1 mm or more, so that they can be hardly deformed even when repeatedly used for firing. Also in the flattening process, it is difficult to break during processing, and processing can be performed with high accuracy.

  The shape of the 4th member 4 is flat form, and consists of porous ceramics. The fourth member 4 is placed in the through hole 2a of the second member 2 above the first member. The distance between the upper surface of the fourth member and the lower surface of the third member 3 is 500 μm or less. Thereby, the distance from the upper surface of the molded object 10 to the lower surface of the 3rd member 3 will be 500 micrometers or less. Since the space 6 between the third member 3 and the fourth member 4 is a narrow space, the volatile material volatilized from the molded body 10 is less likely to flow out to the surroundings, stays in the space 6 and is in equilibrium. The subsequent volatilization can be suppressed by reaching. The height of the space 6 is preferably as narrow as possible as long as the molded body 10 and the third member 3 do not contact each other. However, if the height of the space 5 is low, the amount of the volatile material to be filled is reduced and the outflow from the space 6 is also reduced. Note that the height of the space 6 may be considered to be the highest state (before the firing is input in the molded body) of the molded body 6 whose size changes during firing during firing.

  When the height of the space 6 varies, the volatilization amount of the volatile substance before reaching the equilibrium varies, so the variation in the distance between the third member 3 and the fourth member is the range in which the molded body 10 is placed. Is preferably 10 μm or less, particularly preferably 5 μm or less.

  The range in which the molded body 10 is placed on the upper surface of the fourth member 4 is flattened, so that the molded body 10 can be fired with a small amount of warpage or the like. In addition, since there is a certain amount of space between the upper surface of the fourth member 4 and the molded body 10 due to the unevenness, the amount of volatilization at that part increases, which causes the composition to vary depending on the location. Flattening process is necessary. In the flattening process, for example, the surface roughness is set to 0.5 μm or less using fine abrasive grains of 200 mesh or more.

  If the size of the fourth member is slightly smaller than the size of the through hole 2a, the volume of the sealed space is reduced, and volatilization of the volatile substance can be further suppressed.

  As the material of the porous ceramic, the same materials as those of the first to third members 1 to 3 can be used. As the porous ceramics, those having air permeability due to the presence of continuous pores are used. Thereby, volatilization also occurs to some extent from the lower surface of the molded body 10, and the difference from the upper surface can be reduced. If there are no continuous pores, only a small amount volatilizes to reach equilibrium, but the presence of continuous pores causes equilibrium after the volatile material has spread inside the fourth member. The difference becomes smaller. When the height of the space 6 is 500 μm or less, the difference from the upper surface can be further reduced when the porosity is 40 to 60%.

In the porous ceramic, the upper surface of the fourth member 4 can be flattened as described above because the wall between the porous portions is dense. There are various methods for producing porous ceramics, but in the state in which the aggregate is held at a limited contact point, it is easy for degranulation to occur, and in this respect also, it contacts the molded body 10. Although it is difficult to use as a firing jig, in the present embodiment, it is necessary to flatten the upper surface of the fourth member 4 and it is difficult to perform the flattening process itself after degreasing. Due to the denseness, flattening treatment can be performed, and even when used as a firing jig, the problem of degranulation hardly occurs.

  The fourth member 4 has a thickness of 500 μm or more, preferably 1 mm or more, so that it is difficult to cause deformation even when repeatedly used for firing. Also in the flattening process, it is difficult to break during processing, and processing can be performed with high accuracy. Since the 4th member 4 is porous ceramics, compared with the 1st-3rd members 1-3, it is easy to change in that respect, but the whole lower surface of the 4th member 4 touches the upper surface of the 1st member 1. Therefore, it can be used within the above-mentioned range.

  In order to increase the accuracy of the height of the space 6, in addition to the above-described parts, both the part where the first member 1 and the fourth member 4 are in contact with each other and the region facing the molded body 10 of the third member 3 are also flat. It is preferable to perform the treatment.

By using such a firing jig, a PZT sintered body having a 2.5 cm square area and a thickness of 30 μm is manufactured with a small warpage and a variation in the plane of the piezoelectric property ₃₃ of 0.1% or less. be able to.

  FIGS. 2A and 2B are embodiments of other heat treatment members of the present invention, and are longitudinal sectional views in a state where the molded body 10 is placed. Parts having little difference from the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  In the embodiment of FIG. 2A, the second member 102 has a discharge portion 102 b that protrudes above the third member 3 outside the third member 3. Another first member 1 can be placed on the discharge portion 102b, and heat treatment can be performed by stacking heat treatment jigs in multiple stages. The protrusions 102b are provided in at least three places so that the first member 1 can be supported. The protrusion 102b is preferably provided outside the entire outer periphery of the third member 3, and by doing so, it is possible to prevent the sealed space from being released due to the displacement of the third member 3 during the heat treatment.

  It is preferable that the upper surface of the protruding portion 10b and the lower surface of the upper first member 1 in contact therewith are flattened in the same manner as other portions. This part does not directly affect the heat treatment state of the molded body 10, but if it is repeatedly used in a state where the precision of this part is low, the effect of the firing jig on the top is Slightly distorted, there is a risk that the sealing performance of the sealed space will be reduced.

  In the embodiment of FIG. 2B, the first member 201 has a position on the upper surface where a plurality of second members 2 can be placed, and the third member 303 placed on the second member 2 has a position on the upper surface. By playing the role of the first member on which the four members 4 are placed, the firing jig can be used in a multi-stage stack with a small number of members.

DESCRIPTION OF SYMBOLS 1 ... 1st member 2, 102 ... 2nd member 2a, 102a ... Through-hole 102b ... Projection part 3, 303 ... 3rd member 4 ... 4th member 6 ... Space 10 ... Heat processed material (molded body)

Claims (5)

A flat plate-like first member, each made of a dense ceramic, a second member placed on the first member and having a through-hole penetrating vertically, in the center, and the second A flat plate-like third member placed on the member and porous ceramics, placed on the first member in the through hole of the second member, and has a thickness of 100 μm or less A heat treatment jig including a flat plate-like fourth member on which the object to be heat-treated is placed,
The porous ceramic has air permeability and a dense wall between pores,
The first member and the second member are in contact with each other in an annular region around the through hole, and the second member and the third member are in contact with each other in an annular region around the through hole, and the first member And both of the portions where the second member is in contact with each other, both the portions where the second member and the third member are in contact with each other, and the upper surface of the fourth member are flattened,
A heat treatment jig, wherein a distance between a lower surface of the third member and an upper surface of the fourth member is greater than 100 μm and not greater than 500 μm.   The heat treatment jig according to claim 1, wherein the variation in distance between the lower surface of the third member and the upper surface of the fourth member is 10 μm or less.   The heat treatment jig according to claim 1 or 2, wherein the porosity of the porous ceramic is 40 to 60%.   The heat treatment jig according to claim 1, wherein the dense ceramic and the porous ceramic are stabilized zirconia.   The said 2nd member is equipped with the discharge part which protruded above the said 3rd member on the outer side of the said 3rd member, The other said 1st member can be mounted on this protrusion part. 5. The heat treatment jig according to any one of 4 above.

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