JPH0797537B2 - Method for manufacturing monolithic ceramic capacitor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a laminated ceramic capacitor, and more particularly to a cutting and positioning method for cutting a laminated body having internal electrodes formed into chips.

[0002]

2. Description of the Related Art As shown in FIG. 6, a manufacturing process of a monolithic ceramic capacitor comprises laminating a plurality of ceramic green sheets 3 each having an internal electrode 4 applied thereon, and further arranging a ceramic green sheet having no internal electrode applied from above and below. After sandwiched by several sheets, pressure pressing is performed to form a laminated body 2. Next, the laminate is cut vertically and horizontally according to the position of the internal electrode 4, and a rectangular raw chip 8 as shown in FIG. 5 is cut out.
The cut raw chip 8 is baked, and then external electrodes are applied to both end surfaces to complete.

A conventional cutting positioning method used for cutting a laminated body is disclosed in Japanese Patent Laid-Open No. 64-73709. When the green sheet 3 is pressure-pressed to form the laminated body 2, for example, a hydrostatic pressure is used to uniformly apply pressure from around the laminated body 2 in the liquid to press-bond the green sheet 3. At this time, since the internal electrodes 4 are formed by coating on the internal green sheet 3, the green sheet 3
When a plurality of the internal electrodes 4 are laminated, there is a difference in the total laminated thickness between the portion with the internal electrodes 4 and the portion without the internal electrodes 4 by the total thickness of the internal electrodes 4. When hydrostatic pressure is applied to the laminated body 2, the surface of the portion without the internal electrodes 4 is recessed by (electrode thickness × the number of electrode forming green sheets) × 1/2, and as shown in FIG. A step 5 is formed at the boundary between the portion with and without the electrode 4.
Is formed. The step 5 on the surface is optically detected using an image sensor or the like, and the cutting position is determined based on this.
Raw chips had been cut out.

[0004]

In the conventional positioning method, the thickness of the internal electrode applied to the green sheet is 1 to 1.
In the case of a laminated ceramic capacitor having a laminated number of about 2 μm (10 or less), there is a problem that the step 5 cannot be detected because the step 5 does not appear on the surface even when the isostatic pressing is performed. Further, in the case of manufacturing a very small monolithic ceramic capacitor, the margin portion 7 of the raw chip after cutting in FIG. 5 becomes extremely narrow, the step 5 portion cannot be read accurately, and it shifts from the predetermined cutting position 6. Since it is cut at a different position, the margin portion 7 becomes smaller than a predetermined width, resulting in insulation failure or the like.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for manufacturing a monolithic ceramic capacitor which solves the above-mentioned conventional drawbacks.

According to the present invention, a plurality of green sheets to which internal electrodes are applied are laminated, and further, a plurality of ceramic green sheets to which internal electrodes are not applied are sandwiched from above and below to be pressed and pressed. The internal electrode of the body is electrically detected, the cutting position is determined based on this, and the laminated body is cut at this cutting position to cut out the raw chip.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS.
Will be described with reference to.

First, the internal electrode 4 is formed on the surface in a predetermined pattern.
A predetermined number of the coated ceramic green sheets 3 are stacked, and the ceramic green sheets (predetermined number) on which the internal electrodes 4 are not applied are sandwiched from above and below, and pressed to form a laminated body 2. Next, as shown in FIG. 1, the eddy current sensor 1 moves vertically and horizontally on the laminated body 2 to detect the position of the internal electrode 4 by the voltage difference. For example, as shown in FIG. 2, when the sensor on the laminated body moves from left to right, it is about 3.5 (V) at a portion where the internal electrode 4 is present and about 4.0 (at a portion without the internal electrode 4 (between the electrodes)). V) is shown. Here, the voltage around the detection position d and f is about 3.75 (V)
Is a partition voltage, and the detection position d exceeds 3.75 (V) when the detection position moves from c → d → e → f,
A position intermediate to the detection position f obtained by dividing 3.75 (V) is set as a cutting position. In the vertical direction, the cutting position is similarly detected and the cutting is performed.

As described above, the position of the internal electrode 4 is detected by the eddy current type sensor, the cutting 6 is determined based on the detected position, and the laminate is cut along the cutting position 6 with a blade. The raw chip 8 as shown in FIG. 5 is cut out. The raw chip 8 thus cut out is baked, and then external electrodes are applied to both end faces to complete the process.

In the above description, the eddy current type sensor is taken as an example of the electric detection means, but other than that, a capacitance type sensor or an ultrasonic type sensor may be adopted.

[0011]

As described above, according to the present invention, the position of the internal electrode 4 of the laminated body 2 is electrically detected and the cutting position 6 is determined based on this, so that the step 5 does not appear on the surface. Since the margin portion 7 is narrow such as the laminated body 2 and the small capacitor, there is no problem that the cutting position 6 cannot be accurately detected even if the step 5 portion is also narrow, and it is possible to cut even the small margin portion 7 having the narrow margin portion 7. . Further, it has a great effect that the defective rate due to cutting is reduced.

[Brief description of drawings]

FIG. 1 is a schematic diagram of the present invention.

FIG. 2 is a relationship diagram between the internal electrode position shown in FIG. 1 and the output voltage of the sensor.

FIG. 3 (a) is a cross-sectional view of a laminate (without step), (b).
Is a cross-sectional view of the laminated body (with steps).

FIG. 4 is an enlarged view of a cut portion of the laminated body.

FIG. 5 is a perspective view of a monolithic ceramic capacitor and a raw chip.

FIG. 6 is a schematic diagram showing a configuration of a laminated body.

[Explanation of symbols]

 1 sensor (eddy current type) 2 laminated body 3 green sheet 4 internal electrode 5 step 6 cutting position 7 margin 8 raw chip

Claims (4)

[Claims] 1. A laminated body in which a plurality of ceramic green sheets coated with internal electrodes are laminated, and further pressed from above and below by the number of the ceramic green sheets not coated with internal electrodes, the inside of said laminated body being pressed. A method for manufacturing a monolithic ceramic capacitor, which comprises electrically detecting an electrode, determining a cutting position based on this, cutting the laminated body, and cutting out a raw chip. 2. The method for manufacturing a laminated ceramic capacitor according to claim 1, wherein the electrical detection method is an eddy current sensor. 3. The method of manufacturing a monolithic ceramic capacitor according to claim 1, wherein the electrical detection method is a capacitance type sensor. 4. The method of manufacturing a ceramic capacitor according to claim 1, wherein the electrical detection method is an ultrasonic sensor.