JP2858609B2 - Manufacturing method of multilayer ceramic electronic component - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a multilayer ceramic electronic component such as a multilayer chip inductor.

[0002]

2. Description of the Related Art Heretofore, as one method of manufacturing a laminated ceramic electronic component, there has been known a sheet method in which an internal conductor pattern is printed on ceramic green sheets and a laminate is obtained by laminating these sheets. . As an example of a method of manufacturing a multilayer ceramic electronic component using such a conventional sheet method, a method of manufacturing a multilayer ceramic inductor will be described below.

First, a through hole is formed at a predetermined position in a ceramic green sheet. Next, a coil conductor pattern (inner conductor pattern), which is formed into a helical coil by laminating and connecting through holes, is printed on one main surface of the sheet in which the through holes are formed, using a conductive paste.

Next, sheets having the through holes and the coil conductor patterns formed thereon are laminated in a predetermined configuration, and ceramic green sheets (dummy sheets) having no through holes and the coil conductor patterns laminated above and below the sheets. . Next, the obtained laminate is pressed and fired, and an external electrode is formed on the end face from which the coil end is led out.

[0005]

However, according to the above-mentioned conventional method for manufacturing a multilayer ceramic electronic component, the displacement of the laminate generated during the pressing of the laminate is large (FIG. 4), so that the internal conductor is exposed or obtained. In addition, there is a problem that the characteristic variation of the electronic component is increased.
This is the portion where the internal conductor pattern is formed in the laminate,
This is because, due to the difference in the thickness in the laminating direction from the portion where the internal conductor pattern is not formed (the thickness of the internal conductor pattern and the thickness of the sheet are substantially the same), the pressure distribution in the laminate varies.

That is, in the pressing of the laminated body, first, the uppermost sheet constituting the laminated body is pressed by the pressing plate of the descending pressing machine, and the pressed uppermost sheet is lowered by one. This is performed by sequentially pressing the lower layer sheets, such as pressing the sheet of the first layer, and pressing the sheet of the next layer to press the sheet of the next lower layer. , Of the sheets constituting these laminates,
When the sheet on which the internal conductor pattern is formed is pressurized, the pressure is locally concentrated due to the difference in the thickness of the sheet in the laminating direction between the portion where the internal conductor pattern is formed and the portion where the internal conductor pattern is not formed. ), The sheet is stretched or deformed.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art and to provide a method of manufacturing a laminated ceramic electronic component in which lamination displacement during bonding of a laminate is extremely small.

[0008]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventor has found that ceramic green sheets on which an internal conductor pattern is printed are pre-pressed one by one by a flat plate press, and then laminated and stacked. It has been found that the above-mentioned problems can be solved by pressure bonding, and the present invention has been achieved.

That is, the present invention is a method for manufacturing a multilayer ceramic electronic component in which a ceramic green sheet on which an internal conductor pattern is printed is laminated, pressed, fired and then an external electrode is formed, wherein the internal conductor pattern is printed. After pre-pressing the ceramic green sheets one by one in the laminating direction, that is, one by one in the laminating direction
An object of the present invention is to provide a method for manufacturing a multilayer ceramic electronic component, which comprises smoothing by pressing, laminating and pressing.

[0010]

According to the method for manufacturing a laminated ceramic electronic component of the present invention, ceramic green sheets on which internal conductor patterns are printed are pre-pressed one by one in the laminating direction by a flat plate press, and then laminated and pressed.

The pre-press in the method of the present invention is to press a ceramic green sheet on which an internal conductor pattern is printed by a flat plate in a laminating direction. By applying pressure in the laminating direction, the internal conductor pattern that has protruded to the same height as the sheet thickness on the sheet surface sinks into the sheet, and the entire sheet including the internal conductor pattern is smoothed.

By forming the laminate with the pre-pressed and smoothed sheet, the pressure concentrated on the internal conductor pattern forming portion of the sheet when the laminate is pressed is dispersed. (The pressure distribution in the laminate becomes uniform). Therefore, elongation and deformation of the sheet are prevented, and lamination displacement is significantly reduced.

Hereinafter, the present invention will be described in more detail by way of examples. However, the scope of the present invention is not limited by the following examples.

[0014]

Embodiment 1 As one embodiment of the method of the present invention, a method for manufacturing a multilayer ceramic inductor will be described below.

First, Ni-Zn ferrite powder and a binder containing polyvinyl butyral as a main component are mixed,
The obtained slurry was formed into a sheet by a doctor blade method. Next, through holes 5 are formed at predetermined positions in the obtained ceramic green sheet 1,
These sheets were mixed with Ag powder and ethylcellulose as a binder (using α-terpineol and butyl carbitol acetate as a solvent), and formed into a paste to form a coil conductor pattern 2 having a shape as shown in FIG. Was printed (FIG. 1A).

Next, the sheets 1 on which the coil conductor patterns 2 are printed are placed one by one on a rubber plate 4 in a press machine, and pressed (pre-pressed) by a metal plate 3 from above (FIG. 1). (B)) Sheet 1 including coil conductor pattern 2
Was smoothed (FIG. 1 (c)). Next, the pre-pressed sheet 1 and the dummy sheet are laminated in the mode shown in FIG. 2 (FIG. 1 (d)) and thermocompression-bonded (FIG. 1).
(E)) A molded body in which the spiral coil 7 is embedded inside the ferrite substrate 6 was obtained.

Next, the compact obtained as described above was cut into a chip size (1.6 × 0.8 mm), debindered, and fired (FIG. 3). After firing, a conductive paste for an external electrode was applied to the end face of the obtained inductor body from which the coil ends were led out, and baked to form an external electrode, thereby obtaining a multilayer chip inductor.

The overlap displacement (lamination displacement) of the internal electrodes in the multilayer chip inductor manufactured as described above is as follows.
The average was about 70 μm.

[0019]

Example 2 A laminated chip inductor was manufactured in the same manner as in Example 1 except that a rubber plate in a press machine on which the sheet was placed was used as a metal plate when pre-pressing a sheet on which a coil conductor pattern was printed. However, the overlap displacement (lamination displacement) of the internal electrodes in the obtained multilayer chip inductor was about 50 μm on average.

[0020]

[Comparative Example] A multilayer chip inductor was manufactured in the same manner as in Example 1 except that the pre-pressing step of the sheet on which the coil conductor pattern was printed was omitted. Lamination displacement) was about 120 μm on average.

[0021]

According to the development of the method of the present invention, the overlapping displacement (lamination displacement) of the internal conductors generated when the laminate is crimped is significantly reduced, so that the exposure of the internal conductors is prevented, and the characteristics of electronic components such as inductance are varied. Has become smaller.
Therefore, by manufacturing a multilayer ceramic electronic component according to the method of the present invention, the yield is dramatically improved.

[Brief description of the drawings]

FIG. 1 shows a pre-pressing process and a laminating / stacking process during the production of a multilayer ceramic inductor according to an embodiment of the present invention.
It is explanatory drawing of a crimping process, (a) is sectional drawing which shows the sheet | seat in which the coil conductor pattern was printed, (b) is (a).
Side cross-sectional view showing the state when pre-pressing the sheet between the rubber plate and the metal plate in the press machine,
(C) is a side cross-sectional view showing a smoothed sheet after pre-pressing, (d) is a side cross-sectional view showing a state when the sheets of (c) are stacked, and (e) is a lamination of (d). It is a sectional side view which shows the aspect at the time of crimping a body.

FIG. 2 is an exploded perspective view of a laminate obtained in a manufacturing process of the multilayer ceramic inductor according to one embodiment of the present invention.

FIG. 3 is a side sectional view of a multilayer chip inductor element body obtained in a manufacturing process of a multilayer ceramic inductor according to an embodiment of the present invention, which is cut in a laminating direction.

FIG. 4 is a side sectional view of a multilayer chip inductor body manufactured by a conventional method, which is cut in a stacking direction.

[Explanation of symbols]

 1 Ceramic green sheet 2 Coil conductor pattern 3 Metal plate 4 Rubber plate 5 Through hole 6 Ferrite base 7 Coil

Claims (1)

(57) [Claims] 1. A method of manufacturing a laminated ceramic electronic component, comprising forming an external electrode after laminating, pressing and firing a ceramic green sheet on which an internal conductor pattern is printed, wherein the ceramic green sheet is printed with the internal conductor pattern. By pressing the sheets one by one in the laminating direction
A method for manufacturing a multilayer ceramic electronic component, comprising laminating and pressing after smoothing .