JP5230903B2 - Setter for firing - Google Patents

Description

  The present invention relates to a setter for firing that is used when an object such as a ceramic-based electronic material component is placed and fired.

The prior art will be described by taking the firing of piezoelectric ceramics as an example. Piezoelectric ceramics using PZT (PbZrTiO3) or the like as a raw material are formed as follows. That is, the raw material powder is molded to form an object made of an unfired ceramic molded body. This unfired object is placed on the placement surface of the firing setter. And the piezoelectric ceramic is manufactured by inserting the flat plate-shaped baking setter which mounted the target object into a baking furnace, and heating and holding for a predetermined time at baking temperature (for example, 800-1400 degreeC). . The firing setter described above is formed of a fired ceramic body having a mounting surface on which an object is placed.

  In the setter for baking, it is requested | required to raise the baking precision of a target object further. Here, in order to satisfactorily burn the object, it is preferable that the temperature distribution on the mounting surface on which the object is placed be as uniform as possible. However, in the firing setter having a flat plate shape, there is a high possibility that a temperature difference occurs between the outer edge region of the firing setter that is easy to touch air and the central region that is difficult to touch air except the surface. Furthermore, it is not preferable that the setter for firing warps during firing of the object.

  The present invention has been made in view of the above circumstances, and is advantageous for reducing the temperature difference between the outer edge region and the central region, and is a novel firing setter having high warping suppression and high deformation resistance. It is in the subject to provide.

(1) A firing setter according to the aspect 1 is a firing setter for placing and firing an object to be fired, and a lattice structure using a ceramic as a base material and including a lattice wall body that forms a plurality of parallel holes. The upper end surface of the lattice wall body forms a mounting portion on which an object is placed , and the direction in which the parallel holes extend and the upper end surface are inclined . The object may be oxide-based, nitride-based, or carbide-based. The lattice structure is a structure in which a large number of hole openings are gathered. Since it is a lattice structure, it has a large number of parallel holes (substantially parallel holes). Therefore, the outer edge region and the central region of the setter for firing come into contact with air. This is advantageous in reducing the temperature difference between the outer edge region and the central region of the firing setter.

Moreover, the lattice wall body which has a lattice structure is strengthened. Therefore, compared with the case where the setter for baking is flat plate shape, the deformation resistance with respect to curvature etc. is high. The cross-sectional shape of the parallel holes is not particularly limited, and examples thereof include a quadrangular shape, a triangular shape, a hexagonal shape, a circular shape, and an elliptical shape. The upper end surface of the lattice wall forms a placement portion on which the object is placed, and the direction in which the parallel holes extend and the upper end surface are inclined. By tilting, the upper end surface of the mounting portion can be widened, and the adjustment of the area of the upper end surface area becomes easy.

(2) In the method for manufacturing a setter for firing according to aspect 2 , a plurality of parallel holes are formed by preparing a ceramic-based material having fluidity and extruding the material into a die having a large number of holes. an extrusion forming an extruded continuous body with a grid wall, cut to form the and an inclined direction against the extruded continuous body along its length in the longitudinal direction and cut at predetermined intervals a plurality of grating structures And a firing step of firing the lattice structure.

A plurality of lattice structures can be taken out from one extruded continuous body, which is advantageous for cost reduction. Furthermore, since the extruded continuous body is unfired or semi-fired, it is easy to form an unfired or semi-fired lattice structure by cutting the extruded continuous body into a round shape with a cutting element such as a wire. Furthermore, the upper end surface of the lattice structure forms a placement portion on which the object is placed, and the direction in which the parallel holes extend and the upper end surface are inclined. By tilting, the upper end surface of the mounting portion can be widened, and the adjustment of the area of the upper end surface area becomes easy.

(3) A method for manufacturing a setter for firing according to aspect 3 includes a preparation step of preparing a ceramic-based material having fluidity, and a plurality of parallel holes are formed by extruding the material into a die having a large number of holes. an extrusion forming an extruded continuous body with a grid wall, a firing step of firing the extruded continuous body, a calcined extruded continuous body at a predetermined interval in the inclination direction and the length direction for its length And cutting to form a plurality of lattice structures. A plurality of lattice structures can be taken out from one extruded continuous body, which is advantageous for cost reduction. Furthermore, the upper end surface of the lattice structure forms a placement portion on which the object is placed, and the direction in which the parallel holes extend and the upper end surface are inclined. By tilting, the upper end surface of the mounting portion can be widened, and the adjustment of the area of the upper end surface area becomes easy.

( Embodiment 1 as the basis ) Embodiment 1 as the basis of the present invention will be described in detail with reference to FIGS. The setter 1 for firing is intended to be fired by placing an object W to be fired, and is formed of a lattice structure 2 having ceramic as a base material. The lattice structure 2 includes a lattice wall body 25 having a lattice structure that forms a plurality of parallel holes 22, and a frame body 29 that functions as an outer frame that holds the lattice wall body 25. The lattice wall body 25 and the parallel holes 22 are substantially parallel to the center line P of the lattice structure 2. The cross-sectional shape of the parallel hole 22 is a square shape. The cross-sectional shape of the parallel hole 22 may be triangular or circular.

The upper end surface 27u of the lattice wall 25 forms a placement portion 27 that faces the bottom portion of the object W and can place the bottom portion. The upper end surface 27u is preferably a flat surface, but is not limited thereto. The base material of the firing setter 1 may be oxide, nitride, or carbide, but is generally based on at least one of zirconia, alumina, magnesia, mullite, silicon carbide, and silicon nitride. It can be a material. As the zirconia, stabilized zirconia formed of cubic zirconia or partially stabilized zirconia in which cubic crystals and tetragonal crystals are mixed can be used. When the setter 1 for firing is based on cubic zirconia, the cubic zirconia is chemically very stable. Therefore, when firing the unfired or semi-fired object W, the object W And the setter 1 for firing can be extremely reduced. For this reason, the setter 1 for baking can suppress the reaction with the target object W over a long period of time, and can be used stably. In the case of zirconia, a predetermined amount (for example, 1 to 13 mol%, 2 to 10 mol%) of at least one of Y ₂ O ₃ , CaO, MgO, and rare earth elements (for example, La, Ce, Nd, etc.) is included as a stabilizer. It is preferably formed of stabilized zirconia (FSZ) or partially stabilized zirconia (PSZ). PSZ has higher strength and higher toughness than FSZ. The reactivity of the FSZ with the object W is suppressed more than the PSZ. When the height of the lattice structure 2 is H and the diameter of the lattice structure 2 is D, any of H = D, H≈D, H <D, and H> D may be used. However, in the embodiment shown in FIG. 1, H <D, particularly H <1/3 · D, and the lattice structure 2 is flattened. If the lattice structure 2 is flattened, the material cost of the lattice structure 2 is reduced. In addition, the lattice wall body 25 has a lattice structure having a reinforcing rib effect and is reinforced, and thus has high strength and high rigidity while reducing the material cost. Furthermore, it is advantageous to reduce the wall thickness of the lattice wall body 25.

  In use, as shown in FIG. 2, an unfired or semi-fired object W (for example, piezoelectric ceramic) is placed on the placement portion 27 of the upper end surface 27 u of the lattice wall body 25. The lattice structure 2 on which the object W is placed is placed in a firing furnace (not shown), and the object W is heated to a degreasing temperature region and degreased. Next, the object W is fired by heating it to a firing temperature region of the degreased object W at a predetermined temperature (for example, 1250 to 1350 ° C., particularly 1300 ° C.) for a predetermined time (for example, 90 to 150 minutes, particularly 120 minutes). To do. The firing temperature and firing time are not limited to these.

  Even after firing the lattice structure 2, the lattice structure 2 has a plurality of parallel holes 22. Therefore, the contact area between the object W and the lattice structure 2 is reduced. Therefore, the degreasing property from the object W is ensured, and the degreasing property is improved. Furthermore, when the unfired object W is fired, the chemical reaction (diffusion) between the object W and the lattice structure 2 is suppressed. Therefore, it is advantageous for maintaining the high quality of the object W after firing. Furthermore, since the lattice structure 2 has a plurality of parallel holes 22, the material volume is reduced and the material cost is reduced as compared with the bulk body.

  As can be understood from FIG. 1, the inside of the parallel hole 22 is air. Accordingly, the outer edge region 1r of the firing setter 1 is also easily exposed to air, and the central region 1m is also exposed to air. For this reason, the temperature difference which generate | occur | produces in the outer edge area | region 1r and center area | region 1m of the setter for baking is reduced. For this reason, the baking precision of the target object W can be improved. Furthermore, even when the object W is placed on the lattice structure 2 and fired many times, the lattice wall 25 has a reinforcing property. For this reason, the warp deformability of the lattice structure 2 is suppressed, and the durability of the lattice structure 2 is improved.

  When the number of times of use increases and the mounting portion 27, which is the upper end surface of the lattice wall body 25, wears out, the mounting portion 27 can be polished or cut to regenerate the new mounting portion 27. Since the lattice structure 2 has a height H, it is possible to increase the number of reproductions of the mounting portion 27, which is advantageous for cost reduction. Thus, when the new mounting portion 27 is regenerated, the lattice structure 2 has a plurality of parallel holes 22, so that only the lattice wall body 25 of the lattice structure 2 needs to be polished or cut. 22 itself is a space and is not polished or cut. Therefore, the polishing area itself and the cutting area itself of the lattice structure 2 can be reduced, which is advantageous in reducing polishing resistance and cutting resistance.

  Moreover, as shown in FIG. 3, you may use the auxiliary tool 4 which mounts the bottom part of the lattice structure 2. As shown in FIG. The lattice structure 2 is mounted on the base 8 functioning as a floor surface via the auxiliary tool 4. A bottom portion 22 b which is a bottom surface of the lattice structure 2 is located above the base 8 with the auxiliary tool 4 interposed therebetween. The auxiliary tool 4 forms a space 40 below the bottom 2 b of the lattice structure 2 and opens the bottom 22 b of the parallel hole 22 to the space 40. Thereby, the communication property that the bottom 22b of the parallel hole 22 communicates with the outside air is enhanced. Therefore, when the object W is fired, even if gas is generated from the object W, the bottom portion 22b of the parallel hole 22 is lifted from the base surface 8c of the base 8, so that the gas is latticed through the space 40. It can be discharged to the outside of the body 2 well.

  Furthermore, since the lattice structure 2 in which the parallel holes 22 and the lattice wall body 25 are alternately repeated is adopted as the setter 1, compared to when the bottom surface of the object W is placed on a flat plate-shaped setter and fired, The bottom surface of the object W can touch the air in the same manner as the top and side surfaces of the object W. Therefore, firing unevenness of the object W is further reduced.

  In manufacturing the lattice structure 2, as shown in FIG. 5, a ceramic-based material 7 having fluidity and a die 6 are prepared. As shown in FIG. 5, the die 6 includes a large number of supply holes 6a, a large number of slit holes 6c communicating with the supply holes 6a so as to have an opening area smaller than that of the supply holes 6a, a supply hole 6a, And a guide surface 6d formed between the slit hole 6c. As shown in FIG. 5, the raw material 7 is continuously extruded to the die 6 in the direction of the arrow XA. As a result, the raw material 7 is allowed to permeate through the supply holes 6a and the slit holes 6c, and the unfired extruded continuous body 2A (see FIG. 4) including the lattice wall bodies 25 having a lattice shape is continuously extruded.

  Next, the unfired extruded continuous body 2A is cut into a ring shape by a cutting element such as a wire in the length direction, thereby forming an unfired (including semi-fired) lattice structure 2 having a reduced length. Next, the unfired lattice structure 2 is heated and held in a firing temperature region for a predetermined time to be fired, thereby forming the fired lattice structure 2. Since a plurality of lattice structures 2 can be taken out from a single extruded continuous body 2A having a long length, it is advantageous for cost reduction.

  In manufacturing, a form in which a plurality of holes are formed by punching is also conceivable. In this case, defects such as burr generated at the time of punching may grow as cracks when the firing of the object W is repeated a plurality of times. In this respect, according to this embodiment, since the parallel holes 22 are formed by extrusion molding, it is possible to suppress the occurrence of defects such as burr generated at the time of punching, which is advantageous for suppressing the growth of cracks. is there. In addition, since the wall surface of the parallel hole 22 is shape | molded by extrusion molding, it becomes a smooth surface easily.

  Depending on the composition of the stabilizer content and the like, zirconia may undergo phase transformation with volume change as the temperature rises. A phase transformation accompanied by a volume change tends to generate cracks. Even in such a case, since the lattice structure 2 has the plurality of parallel holes 22, the volume change can be relaxed, which is advantageous in suppressing cracks.

  By the way, when the wall of the lattice structure 2 constituting the setter 1 is formed of zirconia, the following advantages can be expected. That is, the zirconia component may be included in the object W. When the object W is fired in the furnace, the zirconia component generally has a low thermal conductivity, and therefore a certain amount of time is required for the firing treatment. In this regard, if the setter 1 and the object W both have a zirconia component, the setter 1 and the object W are heated and / or cooled in the same manner. Expected to decrease.

  In addition, when the lattice structure 2 of the setter 1 has a parallel hole assembly structure, compared with the temperature distribution when the setter has a flat plate shape, the repeating structure of the parallel holes 22 and the wall thickness of the lattice wall 25 is Therefore, the temperature distribution of the portion where the lattice structure 2 of the setter 1 receives the object W can be within a smaller range, which is advantageous in stabilizing the firing quality of the object W. In addition, since zirconia is generally stronger than other ceramics such as alumina, the wall thickness of the lattice wall body 25 of the lattice structure 2 constituting the setter 1 made of zirconia is reduced, Even if the number of holes of the parallel holes 22 is increased, there is an advantage that the durability as the setter 1 to which heat is repeatedly applied is not easily lowered.

( Basic Form 2) FIG. 6 shows a basic form 2 of the present invention. 1 to 3 apply mutatis mutandis. According to this embodiment , a ceramic-based material 7B having fluidity is prepared. The raw material 7B includes a material 70 that can be burned off. Examples of the material 70 that can be burned out include papers, pulps, woods, yarns, resins obtained by cutting into fine sizes, carbon powders such as graphite powder and carbon black. The resins may be thermoplastic or thermosetting. As shown in FIG. 6, the raw material 7 </ b> B is continuously extruded to the die 6. Thereby, the unfired extruded continuous body 2A is continuously extruded. The green extruded continuous body 2A includes a material 70 that can be burned off. Next, the extruded extruded continuous body 2A is cut into a predetermined length to form an unfired lattice structure. Next, the unfired lattice structure is fired while being held in the firing temperature region for a predetermined time and for a predetermined time to form a fired lattice structure. In this case, the burnable substance 70 is burned off during firing. Therefore, a large number of pores that are continuous pores are formed in the lattice structure 2. Therefore, the lattice structure after firing becomes porous. Accordingly, when the object W is fired, even if gas is generated from the object W, the gas can be discharged from the pores of the lattice structure.

( Basic Form 3) FIGS. 7 and 8 show a basic form 3 according to the present invention. According to this embodiment , as shown in FIG. 7, the porous body 100 in the form of parallel holes having a large number of continuous pores 100x is formed. The porous body 100 is made of a material that can be burned out (for example, paper having a high porosity, foams such as polystyrene foam, and an aggregate in which a large number of particles are bonded with a resin binder). Then, the porous parallel-hole aggregate porous body 100 is impregnated with a slurry material 7C having fluidity containing a large number of fine ceramic powder particles. The number of impregnations can be multiple. Thereafter, the parallel-hole assembly carrier 100 is dried and then heated and held in a baking temperature region for a predetermined time. In this case, the parallel hole aggregate porous body 100 formed with a material that can be burned down is burned down to form a lattice structure 2C (see FIG. 8). The fired lattice structure 2C is porous. Therefore, when firing the target object W on the lattice structure 2C, the gas can be efficiently discharged from the pores 2x of the lattice structure 2C even when the amount of gas generated from the object W is large. it can.

FIG. 9 shows an embodiment according to the present invention . According to this embodiment, as shown by an arrow in FIG. 9, the unfired extruded continuous body 2A is cut by a cutting element such as a wire in the length direction thereof. Thus, a plurality of unfired lattice structures 2 having a reduced length are formed. In this case, the cutting direction is inclined at an angle θ (θ = obtuse angle) with respect to the axis P3 of the extruded continuous body 2A. By adjusting the inclination angle θ, the cross-sectional shape of the parallel hole 22 can be tuned (adjusted). Even when the cross-sectional shape of the parallel hole 22 is a perfect circle when cutting in a direction perpendicular to the axis P3, the cross-sectional shape of the parallel hole 22 can be tuned to an elliptical shape by adjusting the inclination angle θ. Even when the cross-sectional shape of the parallel hole 22 is square when cutting in a direction perpendicular to the axis P3, the cross-sectional shape of the parallel hole 22 can be tuned to a rhombus by adjusting the inclination angle θ.

  (Others) The planar shape of the frame 28 of the lattice structure 2 is circular. However, the planar shape is not limited to this, and the planar shape may be rectangular, hexagonal or octagonal. In addition, the present invention is not limited to the embodiment described above and shown in the drawings, and can be implemented with appropriate modifications without departing from the scope of the invention. The following technical idea can also be grasped from the above description.

It is a perspective view which shows the baking setter which concerns on the form 1 used as the foundation . It is a side view which shows the state which has mounted the target object on the baking setter. It is a side view which shows the state which has mounted the target object on the baking setter installed in the auxiliary jig. It is a perspective view which shows the extrusion continuum extruded. It is a perspective view which shows the principal part of the state which is extrusion-molding the extrusion continuum. It is a perspective view which shows the principal part of the state which concerns on the form 2 used as the foundation, and is extruding the extrusion continuous body. It is a perspective view which shows the parallel hole assembly porous body which concerns on another form . It is a perspective view which shows the baking setter which concerns on another form . It is a side view which shows the manufacture process of the baking setter which concerns on embodiment .

In the figure, 22 is a parallel hole, 25 is a lattice wall body, 2 is a lattice structure, W is an object, 27 is a placing portion, and 4 is an auxiliary tool.

Claims (6)

In a firing setter for placing and firing an object to be fired, the firing setter is formed of a ceramic-based lattice structure including a lattice wall body that forms a plurality of parallel holes. A firing setter characterized in that the end surface forms a mounting portion on which the object is placed , and the direction in which the parallel holes extend and the upper end surface are inclined .   The setter for firing according to claim 1, wherein the ceramic is any one of zirconia, silicon carbide, mullite, alumina, magnesia, and silicon nitride.   3. The firing setter according to claim 1, wherein an auxiliary tool for placing the lattice structure is provided, and the auxiliary tool opens the bottom of the parallel hole.   The setter for firing according to any one of claims 1 to 3, wherein the lattice wall body has a large number of pores that can be continuous pores. A preparation step of preparing a ceramic-based raw material having fluidity, an extrusion step of forming an extruded continuous body including a lattice wall body that forms a plurality of parallel holes by extruding the raw material into a die having a large number of holes; comprising a cutting step of forming the extruded continuous body is an inclined direction and longitudinal direction for its length is cut at predetermined intervals a plurality of grating structures, and a firing step of firing the grid structure Manufacturing method of setter for baking. A preparation step of preparing a ceramic-based raw material having fluidity, an extrusion step of forming an extruded continuous body including a lattice wall body that forms a plurality of parallel holes by extruding the raw material into a die having a large number of holes; a firing step of firing the extrusion continuum, the calcined extrusion continuum an inclined direction against its length and longitudinal cut to a predetermined distance and a cutting step of forming a plurality of grid structures The manufacturing method of the setter for baking containing.

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