JPH08181036A - Manufacture of laminated electronic component - Google Patents

Abstract

PURPOSE: To reduce a distortion and to decrease an inner electrode exposure failure in the cutting step by forming a mother laminate by pressurizing it by a press mold, then cooling it by keeping the laminate, and taking out the laminate when the temperature of the mold becomes about the ambient temperature. CONSTITUTION: When a ceramic mother laminate 6 is pressure formed, a press mold is cooled as an upper mold 5 remains set, is lowered to the ambient temperature such as, for example, 40 deg.C or lower, then the mold 5 is lifted, and the laminate 6 is taken out from the mold. Thus, the pressing distortion of the laminate 6 in the pressing step can be suppressed, and the exposure failure of an inner electrode in next cutting step can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a laminated electronic component, and more particularly to a method for press-forming a ceramic mother laminate used for producing a laminated capacitor or the like.

[0002]

2. Description of the Related Art Manufacturing of electronic parts such as multilayer capacitors
As shown in FIG. 4 (A), a plurality of ceramic green sheets 2 on which a large number of internal electrodes 1 are formed by coating are laminated, and a pressing step of forming a mother laminated body by press-contacting the laminated ceramic green sheets 2 and a mother laminated body are performed. A cutting step of cutting into individual element bodies in accordance with the arrangement of the internal electrodes 1, a step of firing the cut element bodies, and a step of forming external electrodes on the fired element bodies are sequentially performed.

The conventional pressing process is as shown in FIG.
Using a press die including a lower die 3, a frame body 4 and an upper die 5, a large number of ceramic green sheets 2 shown in FIG. 4 (A) are stacked and placed on the lower die 3. While heating, the upper die 5 is lowered to be brought into close contact with pressure to form a ceramic mother laminate 6, and the ceramic mother laminate 6 is taken out from the press die immediately after the completion of pressing. .

[0004]

By the way, when the ceramic mother laminated body 6 is immediately taken out from the press die after the pressing is completed, the ceramic mother laminated body 6 is formed due to the residual stress and elastic properties in the ceramic mother laminated body 6. A distortion phenomenon that extends in the outer peripheral direction occurs.

Along with this, the internal electrode 1 also moves and deforms toward the outer peripheral direction, but since it deforms and moves in a drum shape as shown in FIG. 4B, the position of the internal electrode 1 is changed. The large distortion reaches 100 to 200 μm, and in the next cutting step, the internal electrode 1 is applied to the cut line, and the internal electrode is exposed around the chip.

Therefore, an object of the present invention is to provide a method for manufacturing a laminated electronic component which can reduce the distortion phenomenon of the ceramic mother laminate in the pressing step and reduce defective exposure of the internal electrodes in the cutting step. To provide.

[0007]

In order to solve the above-mentioned problems, according to the present invention, after a mother laminate is formed by pressurizing with a press die, the mother laminate is kept in the press die. This is a structure in which the mother laminate is taken out of the press die and the pressing step is performed when the temperature of the press die is cooled to about room temperature.

[0008]

When the ceramic mother laminated body is formed by pressing with the press die, the press die is cooled to about room temperature with the press die set. Residual stress of the ceramic mother laminate is relaxed by shape retention and cooling with a press die,
When the ceramic mother laminate is taken out from the press die after cooling, the occurrence of press strain can be reduced, and the defective exposure of the internal electrodes in the cutting process can be reduced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.

According to the present invention, the ceramic green sheets 2 shown in FIG. 4A are laminated and pressed together to form a ceramic mother laminate, and the mother laminate is formed into individual bodies. The method of manufacturing a laminated electronic component manufactured through the cutting step of cutting, the step of firing the element body, and the step of forming external electrodes on the element body is characterized by the pressing step.

In the pressing step, as shown in FIG. 1, a pressing die including a lower die 3, a frame 4 and an upper die 5 is used, and a large number of ceramic green sheets 2 are stacked on the lower die 3. Then, the upper mold 5 is lowered in a state where it is warmed to about 40 to 80 ° C., and the ceramic green sheet 2 is pressure-adhered to form the ceramic mother laminated body 6.

When the ceramic mother laminated body 6 is pressure-formed, the press die is cooled while the upper die 5 is set,
The temperature is lowered to room temperature, for example, room temperature of 40 ° C. or lower, and then the upper die 5 is raised to take out the ceramic mother laminate 6 from the press die.

By cooling the press die, the residual stress of the ceramic mother laminated body 6 is relaxed in the press die, and the ceramic mother laminate 6 is maintained in a constant shape to lower the temperature. Therefore, the elastic property is suppressed, and the ceramic mother laminate 6 is pressed after cooling. Even if it is taken out from the mold, the occurrence of strain phenomenon that extends in the outer peripheral direction is extremely reduced. Incidentally, the press strain could be reduced to 50 μm or less.

Therefore, it is possible to reduce the occurrence of defective exposure of the internal electrodes in the cutting step of cutting the ceramic mother laminate 6 into individual bodies.

The pressing die used in the pressing step is
In the case of FIG. 1, the lower pressurizing surface of the upper mold 5 is made flat, but as shown in FIG. 3A, the upper mold 5 may be a combination of the outer frame 7 and the inner plate 8, or the lower mold surface of FIG. As described above, the concave portion 9 having a peripheral portion is provided on the lower pressing surface, and the internal electrode 1 of the mother laminated body is formed.
You may employ | adopt the structure which presses an outer peripheral part firmly rather than the part which provided.

As a cooling method after the pressing step of the press die, as shown in FIG. 1, in addition to air cooling by blowing cold air by an air blower 10 arranged below the lower die 3, as shown in FIG. 2, a Peltier element is used. The heat pump 11 used is attached to the lower surface of the lower mold 3, and the fan 12 radiates the heat of the lower mold 3, and water cooling or natural standing can be adopted.

As the laminated electronic component manufactured by press molding, a laminated ceramic capacitor, a laminated coil, a composite component and a multilayer substrate can be exemplified.

[0018]

As described above, according to the present invention, in the pressing step of pressing the ceramic green sheet to form the ceramic mother laminate, after cooling the press die to about room temperature, the ceramic mother laminate is taken out. As a result, the generation of press strain of the ceramic mother laminate in the pressing step can be suppressed, and the defective exposure of the internal electrodes in the next cutting step can be reduced.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a pressing step in the present invention.

FIG. 2 is a vertical cross-sectional view showing another example of the cooling means in the above.

FIG. 3A is a vertical sectional view showing another example of a press die,
(B) is a longitudinal sectional view showing still another example.

FIG. 4A is a plan view of a ceramic green sheet coated with internal electrodes, and FIG. 4B is a plan view showing a conventional example in which a press distortion occurs in a ceramic mother laminate.

FIG. 5 is a vertical sectional view showing a conventional pressing process.

[Explanation of symbols]

 1 Internal Electrode 2 Ceramic Green Sheet 3 Lower Mold 4 Frame 5 Upper Mold 6 Ceramic Mother Laminate 10 Fan 11 Heat Pump

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location H05K 3/46 H 6921-4E Q 6921-4E

Claims (1)

[Claims] 1. A method for manufacturing a laminated electronic component including a pressing step of laminating ceramic green sheets coated with electrodes, accommodating them in a press die, and pressurizing them in a heated state to form a mother laminate. In, in order to form the mother laminate by pressing with the press die, cool the mother laminate while it is stored in the press die, and press the mother laminate when the temperature of the press die reaches about room temperature. A method of manufacturing a laminated electronic component, comprising: taking out from a mold and performing a pressing step.