JPH06190815A - Laminate manufacturing hot press mold and manufacture of laminate therewith - Google Patents

Abstract

PURPOSE:To prevent laminate misalignment at the production of the laminate of laminated ceramic capacitor by laminatingly hot-pressing a plurality of green sheets. CONSTITUTION:The middle mold 10 and the lower mold 20 of a hot-pressing mold are made of shape memory alloy material so as to hot press green sheets 3 and green sheets 4, on each of which internal electrodes 4 are formed, under the condition being laminated to each other at normal temperature. By means of the temperature of a hot press, the shape memory alloy material acts so as to contract the interior of the mold, resulting in forcibly putting respective green sheets 3 in order.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot pressing die for producing a laminated body in a laminated ceramic capacitor, a multilayer substrate, a ceramic package and the like and a method for producing a laminated body using the same.

[0002]

2. Description of the Related Art As shown in FIGS. 2 and 3, a conventional hot press die for manufacturing a laminated body comprises a frame-shaped middle die 1 and a plate-shaped lower die 2.
It will be described based on an example in which the structure is applied to a multilayer ceramic capacitor.

This mold has a clearance C of about 100 μm for facilitating stacking with respect to the outer dimensions of the thin sheet composed of the green sheet 3 and the green sheet 3 on which the internal electrodes 4 are printed at fixed positions. It was a hot press mold with internal dimensions, and it was used to laminate and heat press to produce a laminate.

[0004]

By the way, in the above-mentioned conventional hot press mold for producing a laminated body, each green sheet to be laminated as shown in FIG. 2 in order to provide a clearance with the outer dimension of the green sheet 3. 3 moves in the mold and becomes uneven, and the internal electrodes 3 are hot-pressed in different positions in each layer, resulting in a so-called stacking shift.

In the monolithic ceramic capacitor, this misalignment not only causes a defect of small capacity, but also deteriorates the lamination accuracy and hinders the formation of multiple layers.

[0006]

A hot-press die for producing a laminate according to the present invention is a thin die in which a die material is contracted at a temperature during hot-pressing or pre-heating so that an inner die dimension is laminated. Use a shape memory alloy that has the same outer dimensions as the sheet.

Further, in using this die, a laminated body is manufactured by applying a temperature at which the inner dimension of the die becomes the same as the outer dimension of the laminated thin sheets during hot pressing.

[0008]

When the above hot press mold for producing a laminate is used,
For example, at a predetermined temperature during hot pressing, the shape of the die is changed so that the inner dimension of the die becomes the same as the outer dimension of the thin sheet, and the laminated thin sheets are aligned accordingly. As a result, the internal electrodes printed at a fixed position on the thin sheet made of, for example, a green sheet are also aligned, and it is possible to prevent stacking deviation.

Therefore, it is possible to prevent electrical initial defects such as a small capacity defect in a monolithic ceramic capacitor and insufficient insulation in other laminated bodies, and more laminating can be easily performed.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a state in which a green sheet is laminated on a hot pressing mold for producing a laminate, which is an embodiment of the present invention. In the figure, 10 is a frame-shaped middle mold made of a shape memory alloy, 20 is a plate-shaped lower mold made of the same shape memory alloy, 3 is a green sheet laminated in the mold, 4 is a green sheet 3. It is a printed internal electrode. P1 is an imitation position of the frame portion of the middle mold 10 at room temperature, that is, before applying a temperature during hot pressing, and P2 is a position of an end portion of the lower mold 20 before applying a temperature during hot pressing,
C indicates a clearance provided in the mold at room temperature.

It should be noted that the middle die 10 and the lower die 20 have P1 and P2 at a predetermined temperature of less than 100 ° C. during hot pressing.
Shape memory alloys such as Ti-Ni, Cu-Zn-Ni, and Cu-Al-Ni alloys that shrink or deform in the direction of the drawing from the position of are used.

A method of manufacturing a laminated body of a monolithic ceramic capacitor using this mold will be described below. First, in a mold concave portion formed by the middle mold 10 and the lower mold 20 at room temperature,
The green sheet 3 and the green sheet 3 on which the internal electrodes 4 are formed are laminated. At this point, the frame of the middle mold 10 and the ends of the lower mold are located at positions P1 and P2, respectively, and the clearance C is provided, so that the lamination can be easily performed as in the conventional case. After stacking a predetermined number of green sheets 3, the mold is placed in a high temperature furnace or the like and heated. Then,
The heat causes the frame portion of the middle mold 10 to shrink in the direction of the arrow shown in FIG. ,
So-called stacking deviation does not occur. Then, in this state, a weight or the like (not shown) is placed on the laminated green sheets 3 and hot pressed for a predetermined time in a pressurized state to manufacture a laminated body.

The mold made of the shape memory alloy may be operated at that temperature during hot pressing. As another embodiment, a preheating step is provided to align the green sheets 3 at that temperature, and then the green sheet 3 is aligned. You may heat-press. According to this embodiment, since the shape memory alloy material can be selected according to the preheating temperature that can be freely selected, the degree of freedom in material selection is increased.

As described above, according to the present invention, a die for hot pressing has a dimension within the die at a temperature at the time of hot pressing.
By using a shape memory alloy whose shape changes to the same external dimensions as the thin sheets to be laminated, the thin sheets laminated at the temperature during hot pressing are forcibly aligned and prevented from being misaligned. For example, it is possible to prevent electrical initial characteristic defects such as a small capacity defect of the monolithic ceramic capacitor and other insulation defects in the laminated body, and more laminating can be easily performed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a hot press die for producing a laminate of the present invention and a green sheet laminated in the die.

FIG. 2 is a cross-sectional view of a conventional hot press die for producing a laminate and a green sheet laminated in the die.

FIG. 3 is a perspective view of a conventional hot press die for producing a laminate and a green sheet laminated in the die.

[Explanation of symbols]

 3 Green sheet (thin sheet) 4 Internal electrode 10 Middle mold 20 Lower mold C Clearance

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Claims (4)

[Claims] 1. A die for laminating a plurality of thin sheets and hot-pressing them to produce a laminate, wherein a shape memory alloy that shrinks at a hot-pressing temperature or a preheating temperature is used as a die material. A hot press mold for producing a laminate, which is characterized in that 2. The shape memory alloy is Ti-Ni, Cu-Z.
It is n-Ni or Cu-Al-Ni, The hot press metal mold for laminated body manufacture of Claim 1 characterized by the above-mentioned. 3. A method for producing a laminated body, comprising laminating a plurality of thin sheets in a hot-pressing die made of a shape memory alloy material that shrinks at a hot-pressing temperature and then hot-pressing. 4. A method for producing a laminate, comprising laminating a plurality of thin sheets in a hot press mold made of a shape memory alloy material that shrinks at a preheating temperature, preheating, and then hot pressing.