JP2013169689A - Method of manufacturing ceramic substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a ceramic substrate that can reduce a deviation from a design value.SOLUTION: Projections and recesses are formed on one or both of a surface PS1 of a first mold 22A and a surface IS2 of a second mold 23A, a green sheet region PTY is arranged between the surface PS1 of the first mold 22A and the surface IS2 of the second mold 23A which are opposed to each other, and is fired after pressing the arranged green sheet region PTY while one or both of the first mold 22A and second mold 23A are vibrated.

Description

  The present invention relates to a technique for manufacturing a ceramic substrate.

  Conventionally, a method has been proposed in which a green sheet is placed between a pair of template plates, and the mold plate is pressed to form irregularities corresponding to the irregularities formed on one surface of the template plate, followed by firing. (See Patent Document 1).

JP-A-1-234209

  However, in the green sheet in which irregularities are formed by pressing the template, the density of the lower part of the concave part tends to be larger than the density of the peripheral part of the lower part of the concave part.

  When such a green sheet is fired, there is a difference between the amount of contraction at the lower part of the recess and the amount of contraction at the peripheral part of the lower part, and the lower part is distorted. For this reason, the subject that the ceramic substrate greatly separated from the design value of the size and shape in a crevice was produced.

  Therefore, an object of the present invention is to provide a method of manufacturing a ceramic substrate that can reduce a gap from a design value.

  In order to solve such a problem, the method for manufacturing a ceramic substrate according to the present invention is such that the surface of the first mold is opposed to each other by forming irregularities on one or both of the first mold surface and the second mold surface. And an arrangement step of arranging a green sheet part to be pressed between the surface of the second mold and one of the first mold and the second mold with respect to the green sheet part or It comprises a pressing step of pressing while vibrating both, and a baking step of baking the green sheet portion that has undergone the pressing step.

  In this method of manufacturing a ceramic substrate, since the mold vibrates at the time of pressing, the ceramic particles in the lower part of the concave part transferred to the green sheet are dispersed in the peripheral part of the concave part, and the lower part in the concave part and the peripheral part thereof And the difference in density becomes smaller. Therefore, when the green sheet is fired, the difference in shrinkage between the lower part of the recess and the peripheral part thereof is smaller than when the mold is not vibrated during pressing, and the amount of distortion in the lower part of the recess is reduced. . In this way, the distance from the design value can be reduced.

  In addition, the unevenness is formed on the surface of the first mold and is not formed on the surface of the second mold. In the pressing step, the second mold is vibrated, It is preferable to press the green sheet part.

  When a mold is pressed on a green sheet, generally, the weight and hardness of the mold tend to be large in order to increase the wear resistance of the mold surface on which irregularities are formed. For this reason, when the metal mold | die which has an uneven surface is vibrated, the vibration efficiency with respect to a green sheet will fall, and, as a result, the dispersion efficiency of a ceramic particle will also fall. In this regard, when the second mold having no irregularities is vibrated, the selection range of the constituent materials in the second mold is increased by the amount that the wear resistance does not need to be increased. For this reason, the weight or hardness of a 2nd metal mold | die can be made small, and the vibration efficiency with respect to a green sheet can be improved. As a result, irregularities can be transferred to the green sheet without lowering the dispersion efficiency of the ceramic particles.

  In the pressing step, it is preferable that the first mold is set to a temperature lower than that of the second mold.

  When the mold is vibrated at the time of pressing, heat caused by the vibration is locally generated in the concave portion transferred to the green sheet, and the temperature rises from the other portion to cause foaming or cracking in the concave portion. There is a tendency. In this regard, when the temperature of the first mold is lower than the temperature of the second mold, the heat generated in the concave portion of the green sheet due to the vibration of the second mold is caused by the first mold having the uneven surface. Can be cooled. Therefore, while the ceramic particles in the lower part of the concave part transferred to the green sheet are dispersed in the peripheral part by the vibration of the second mold, the temperature rise in the concave part due to the vibration can be suppressed.

  In the pressing step, the green sheet is preferably vibrated in a pressing direction.

  In this case, since the vibration is transmitted to the green sheet in the thickness direction, the unevenness transferred to the green sheet is more in the surface direction of the green sheet than when the vibration is transmitted to a direction other than the thickness direction of the green sheet portion. Can be suppressed. Therefore, the unevenness transferred to the green sheet can be further reduced from the design value.

  Moreover, it is preferable that vibration is stopped when one of the first mold and the second mold in the pressed state is separated from the green sheet portion.

  In this case, the unevenness transferred to the green sheet spreads in the surface direction of the green sheet as compared with the case where the mold is continuously vibrated even when the pressed mold is separated from the green sheet portion. Can be suppressed. Therefore, the unevenness transferred to the green sheet can be further reduced from the design value.

  As described above, according to the present invention, there is provided a method for manufacturing a ceramic substrate that can reduce a gap from a design value.

It is sectional drawing which shows schematically the press apparatus which concerns on embodiment of this invention. It is a flowchart which shows the manufacturing method of the ceramic substrate which concerns on embodiment of this invention. It is a figure which shows the mode of an arrangement | positioning process from the viewpoint similar to FIG. It is a figure which shows the mode of a press process from the viewpoint similar to FIG. It is an image figure which shows the mode of dispersion | distribution of a ceramic particle.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view schematically showing a press apparatus according to an embodiment of the present invention. As shown in FIG. 1, the press apparatus 1 which concerns on this embodiment is provided with the conveyance part 10 and the press part 20 as main components.

  The transport unit 10 is a unit that transports the green sheet in a predetermined amount unit in the feed direction SD. The green sheet is a paste-like sheet containing ceramic powder as a raw material and a binder for the ceramic powder.

  The transport unit 10 in the present embodiment is, for example, a rail-type conveyor that transports a green sheet in a predetermined amount unit in the feed direction SD with both ends sandwiched in the longitudinal direction of the green sheet. The transport unit 10 is appropriately provided with a positioning mechanism for positioning the green sheet at a predetermined position.

  The press unit 20 includes an elevator 21, first molds 22 </ b> A and 22 </ b> B, second molds 23 </ b> A and 23 </ b> B, and an ultrasonic transducer 24.

  The elevator 21 is arranged on one side with the conveyance road surface RS in the conveyance unit 10 as a boundary, and is an apparatus that can move in both directions D1 and D2 away from the conveyance road surface RS.

  The first mold 22A and the first mold 22B are attached to the elevator 21 as separate bodies independent of each other. The first mold 22A has a surface (hereinafter referred to as a press surface) PS1 to be pressed on the green sheet, and the first mold 22B has a press surface PS2. These press surfaces PS1 and PS2 are directly opposed to the transport road surface RS in the transport unit 10, and the press surface PS1 is disposed on the front side in the feed direction SD with respect to the press surface PS2.

  Unevenness of a predetermined pattern is formed on such press surfaces PS1 and PS2. In the case of the present embodiment, the press surface PS1 of the first mold 22A is provided with a concave / convex pattern for transferring depressions on one surface of the green sheet, for example, and the press surface PS2 of the first mold 22B is formed on, for example, a green sheet A concavo-convex pattern for obtaining a through hole or a through groove for cutting out the outer frame is formed.

  The second mold 23A and the second mold 23B are the bases of the green sheets and are arranged as separate bodies independent of each other. The second mold 23A has a surface (hereinafter referred to as a mounting surface) IS1 that is in contact with one surface of the green sheet, and the second mold 23B has a mounting surface IS2.

  These placement surfaces IS1 and IS2 are arranged on the opposite side to the side where the press surfaces PS1 and PS2 are arranged with the conveyance road surface RS in the conveyance unit 10 as a boundary, and are directly opposed to the press surfaces PS1 and PS2. The mounting surfaces IS1 and IS2 are not formed with the uneven pattern formed on the press surface PS1 or PS2, and the mounting surfaces IS1 and IS2 are flat.

  The ultrasonic transducer | vibrator 24 is a vibration source which gives an ultrasonic vibration with respect to the 2nd metal mold | die 23A, for example, is attached to the surface of the 2nd metal mold | die 23A. In the case of the present embodiment, the vibration applied from the ultrasonic transducer 24 is in a direction (pressing direction) orthogonal to the placement surface IS1 of the second mold 23A.

  The green sheet is pressed using such a press device 1.

  FIG. 2 is a flowchart showing a method for manufacturing a ceramic substrate according to an embodiment of the present invention. As shown in FIG. 2, the method for manufacturing a ceramic substrate according to the present embodiment includes an arrangement process P1, a pressing process P2, and a firing process P3 as main processes.

<Arrangement process>
This arrangement | positioning process P1 is a process of arrange | positioning the green sheet site | part used as press object between press surface PS1 of 22 A of 1st metal mold | die, and mounting surface IS1 of 2nd metal mold | die 23B.

  Specifically, the green sheet is conveyed by a predetermined amount in the feed direction SD, and the green sheet portion PTY to be pressed is placed on the placement surface IS1 of the second mold 23A as shown in FIG.

  If there is a green sheet portion PTX that has already been placed on the placement surface IS1 immediately before placing the green sheet portion PTY on the placement surface IS1 of the second mold 23A, the green sheet portion PTX is It mounts on mounting surface IS2 in the 2nd metal mold | die 23B of a back | latter stage.

<Pressing process>
In this pressing step P2, the second mold 23A is vibrated with respect to the green sheet portion disposed between the press surface PS1 of the first mold 22A and the mounting surface IS1 of the second mold 23B. This is a step of pressing the press surface PS1 of the first mold 22A.

  Specifically, as the first stage, the ultrasonic transducer 24 is driven, and the second mold 23 </ b> A is vibrated by the ultrasonic waves oscillated from the ultrasonic transducer 24.

  As a second stage, as shown in FIG. 4, the elevator 21 is moved from the pre-press position to the press position, and the first is relative to the green sheet portion PTY placed on the placement surface IS1 of the second mold 23A. The press surface PS1 of the mold 22A is pressed with a predetermined pressing amount. At this time, the temperature of the first mold 22A or the second mold 23A is adjusted by the cooling mechanism so that the first mold 22A has a lower temperature than the second mold 23A.

  When the green sheet part PTX is placed on the placement surface IS2 of the second mold 23B, the press surface PS2 of the first mold 22B is simultaneously placed on the green sheet part PTX simultaneously with the pressing of the first mold 22A. Is pressed with a predetermined pressing amount. In this case, the green sheet portion PTX is cut from the green sheet body.

  As shown in FIG. 3, the pre-press position includes the press surface PS1 of the first mold 22A and the press surface PS2 of the first mold 22B, and the green sheet portion PTY facing the press surfaces PS1 and PS2. A position where one surface of the PTX is in a non-contact state.

  As a third stage, when a predetermined period has elapsed from the time when the elevator 21 moves to the press position, the driving of the ultrasonic vibrator 24 is stopped, and as shown in FIG. Return to position.

  In this way, the uneven pattern of the press surface PS1 is transferred to the green sheet portion PTY. Thereafter, the green sheet portion PTY is placed on the placement surface IS2 of the second mold 23B at the subsequent stage by the transport unit 10, and the press surface PS2 of the first mold 22B facing the second mold 23B. It is cut by a press and conveyed to a subsequent baking furnace.

<Baking process>
This firing step P3 is a step of firing the green sheet portion that has undergone the pressing step P2.

  Specifically, for example, the arrangement process P1 and the pressing process P2 described above are circulated, and the green sheet part sequentially cut in the pressing process P2 is conveyed to a firing furnace by a conveying mechanism, and the green sheet part is fired. Is done. As a result, a green sheet portion is obtained as a ceramic substrate.

  As described above, in the manufacturing method according to the present embodiment, as shown in FIG. 4, the green sheet portion PTY disposed between the press surface PS1 of the first mold 22A and the mounting surface IS1 of the second mold 23A is disposed. The first mold 22A is pressed while vibrating the second mold 23A.

  For this reason, as shown in FIG. 5, the ceramic particles in the lower part of the concave part CP transferred to the green sheet part PTY are dispersed in the peripheral part of the concave part CP, and the density of the lower part and the peripheral part of the concave part CP is reduced. The difference becomes smaller.

  Accordingly, when the green sheet portion PTY is fired, the difference in shrinkage between the lower portion of the concave portion CP and the peripheral portion thereof becomes smaller than when the second mold 23A is not vibrated at the time of pressing, and the lower portion of the concave portion. The amount of distortion is reduced. In this way, the distance from the design value can be reduced.

  By the way, when the first mold 22A is pressed to the green sheet portion PTY, generally, the weight and hardness of the first mold 22A tend to be large in order to improve the wear resistance of the press surface PS1 of the first mold 22A. . For this reason, when the first mold 22A is vibrated, the vibration efficiency with respect to the green sheet portion PTY is lowered, and as a result, the dispersion efficiency of the ceramic particles is also lowered.

  In this regard, in the case of the present embodiment, as shown in FIG. 4, the second mold 23A having the placement surface IS1 with no unevenness is set as a vibration target and placed on the placement surface IS1. The press surface PS1 of the first mold 22A on which irregularities are formed is pressed against the green sheet portion PTY.

  That is, since the second mold 23A having no irregularities is the object of vibration, the wear resistance of the second mold 23A is higher than that when the first mold 22A having irregularities is the object of vibration. The selection range of the constituent material is expanded by the amount that does not need to be increased. Therefore, one or both of the weight and hardness of the second mold 23A is made smaller than that of the first mold 22A so that the second mold 23A is made of aluminum or the like, and vibration with respect to the green sheet portion PTY is performed. Efficiency can be increased.

  As a result, irregularities can be transferred to the green sheet portion PTY without reducing the dispersion efficiency of the ceramic particles.

  In the case of the present embodiment, in the pressing step P2, the first mold 22A is set to a temperature lower than the temperature of the second mold 23A.

  When the second mold 23A is vibrated at the time of pressing the first mold 22A, heat caused by the vibration is locally generated in the concave portion CP transferred to the green sheet portion PTY. There is a tendency that the temperature rises from the part and foaming or cracking occurs.

  In this regard, when the first mold 22A is set to a temperature lower than that of the second mold 23A, the heat generated in the concave portion CP of the green sheet portion PTY due to the vibration of the second mold 23A is transferred to the green sheet portion PTY. Can be cooled by the first mold 22A on which the concavo-convex pattern is formed. Accordingly, while the ceramic particles in the lower portion of the concave portion CP transferred to the green sheet portion PTY are dispersed in the peripheral portion of the concave portion CP by the vibration of the second mold 23A, the temperature rise in the concave portion CP due to the vibration. Can be suppressed.

  In the case of the present embodiment, in the pressing step P2, the second mold 23A is vibrated in a direction orthogonal to the placement surface IS1 of the second mold 23A.

  For this reason, vibration is transmitted in the thickness direction to the green sheet portion PTY placed on the placement surface IS1 of the second mold 23A. Therefore, as compared with the case where vibration is transmitted in a direction other than the thickness direction of the green sheet portion PTY, it is possible to suppress the unevenness transferred to the green sheet portion PTY from spreading in the surface direction of the green sheet. As a result, it is possible to further reduce the unevenness transferred to the green sheet portion PTY from being separated from the design value.

  In the case of the present embodiment, the vibration is stopped when the first mold 22A in the pressed state moves away from the green sheet portion PTY.

  Therefore, when the first mold 22A in the pressed state is separated from the green sheet part PTY, the unevenness transferred to the green sheet part PTY is more uneven than when the second mold 23A is continuously vibrated. Spreading in the surface direction of the PTY can be suppressed. Therefore, it is possible to further reduce the unevenness transferred to the green sheet portion PTY from being separated from the design value.

  The embodiment has been described above as an example, but the present invention is not limited to the embodiment.

  For example, in the above-described embodiment, the green sheet GT is the moving object in order to place the green sheet portion PTY between the first mold 22A and the second mold 23A. However, the first mold 22A or the second mold 23A may be a movement target, and the first mold 22A or the second mold 23A and the green sheet GT may be a movement target. In short, the green sheet part PTY may be disposed between the first mold 22A and the second mold 23A.

  In the above embodiment, the first mold 22A having the press surface PS1 on which the first pattern is formed and the first mold 22B having the press surface PS2 on which the second pattern is formed are independent from each other. It was attached to the elevator 21 as a separate body. However, the first mold having the press surface PS1 and the first mold having the press surface PS2 may be integrally attached to the elevator 21. Further, the first mold 22B having the press surface PS2 is omitted, and the first mold having the press surface on which both the second pattern and the first pattern are formed is attached to the elevator 21. Also good. Moreover, the first mold 22A and the first mold 22B may be attached to different elevators.

  In the above embodiment, the second mold 23A and the second mold 23B are separated from each other, but may be integrated. However, from the viewpoint of increasing the vibration efficiency for the green sheet placed on the second mold 23A, it is preferable that the second mold 23A and the second mold 23B are separate from each other. Note that the second mold 23A and the second mold 23B may be omitted.

  In the above embodiment, the first mold 22A and the second mold 23A, and the first mold 22B and the second mold 23B are arranged in order along the feed direction SD of the green sheet. A first mold and a second mold may be further arranged at the subsequent stage of the first mold 22B and the second mold 23B.

  Moreover, in the said embodiment, although one surface of the 2nd metal mold | die 23A was made into the flat surface by which an unevenness | corrugation is not formed, the unevenness | corrugation may be formed in the said one surface. Note that the uneven pattern to be formed on one surface of the second mold 23A may be the same as or different from the press surface PS1 of the first mold 22A.

  Moreover, in the said embodiment, although the 2nd metal mold | die 22 was fixed, you may move as a press object.

  Moreover, in the said embodiment, although the drive timing of the ultrasonic transducer | vibrator 24 was made before press surface PS1 (PS2) contacted one surface of the green sheet site | part PTY (PTX), press surface PS1 (PS2) on the said one surface. It may be after the contact.

  In the above embodiment, the first mold 22A is a non-vibration target, and the second mold 23A is a vibration target. However, the first mold 22A may be a vibration target, the second mold 23A may be a non-vibration target, and the first mold 22A and the second mold 23A may be a vibration target. However, from the viewpoint of suppressing the unevenness transferred to the green sheet portion PTY from spreading in the surface direction of the green sheet, it is preferable that the mold having the surface on which the unevenness pattern for transferring the depression is formed be a non-vibration target. .

  Moreover, in the said embodiment, the several green sheet site | part was cut | disconnected from the one green sheet GT. However, one green sheet GT may be divided and a green sheet portion may be cut from each of the divided green sheets.

  The method for manufacturing a ceramic substrate according to the present invention has applicability in various industries that handle ceramic substrates.

DESCRIPTION OF SYMBOLS 1 ... Press apparatus 10 ... Conveyance part 20 ... Press part 21 ... Elevator 22A, 22B ... 1st metal mold PS1, PS2 ... Press surface 23A, 23B ... 2nd metal Type IS1, IS2 ... Placing surface 24 ... Ultrasonic transducer PTX, PTY ... Green sheet part CP ... Recess P1 ... Placement process P2 ... Pressing process P3 ... Baking process

Claims (5)

An object to be pressed is formed between the surface of the first mold and the surface of the second mold that are unevenly formed on one or both of the surface of the first mold and the surface of the second mold and face each other. An arrangement step of arranging a green sheet portion,
A pressing step of pressing the green sheet portion while vibrating one or both of the first mold and the second mold;
And a firing step for firing the green sheet portion that has undergone the pressing step. The unevenness is formed on the surface of the first mold and is not formed on the surface of the second mold.
2. The method of manufacturing a ceramic substrate according to claim 1, wherein in the pressing step, the green sheet portion is pressed while the second mold is vibrated. 3. The method of manufacturing a ceramic substrate according to claim 2, wherein in the pressing step, the first mold is set to a temperature lower than the temperature of the second mold. 2. The method of manufacturing a ceramic substrate according to claim 1, wherein in the pressing step, the green substrate portion is vibrated in a pressing direction. 2. The ceramic substrate according to claim 1, wherein in the pressing step, vibration is stopped when one of the first mold and the second mold in a pressed state is separated from the green sheet portion. Manufacturing method.

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