JPS59100510A - Method of producing laminated ceramic condenser - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a method for manufacturing a multilayer ceramic capacitor,
In particular, the present invention relates to a pressing method that can omit barrel polishing of capacitor chips.

[Background technology]

In general, this type of multilayer ceramic capacitor has internal electrodes B interposed alternately between a plurality of ceramic layers A, and protective layers C1C are arranged on the upper and lower surfaces of these layers, as shown in FIG. 1, for example. An electrode extension layer is formed on the exposed end of B to form D.

By the way, this capacitor has, for example, a plurality of internal electrodes B and a green sheet (ceramic layer) A laminated alternately on a protective sheet (protective layer) C, and then a protective sheet (ceramic layer) A is laminated on top of the protective sheet (protective layer) C.
It is manufactured through the following steps: laminating the laminate, integrating the laminate under pressure, cutting the laminate from a desired portion with a cutting blade to form chips, firing, and forming an electrode lead layer. In particular, in the cutting process, the laminate is cut by applying a cutting blade perpendicular to the direction in which it is laminated, so that the cut surface is approximately perpendicular.

For this reason, when forming the electrode extension layer B on the exposed end surface of the internal electrode B, even if a conductive paste containing silver, frit glass, resin, and solvent is coated on the chip end surface, the As shown in FIG. 1, the corner portion Oa is not sufficiently adhered and sometimes the corner portion Oa is exposed, which impairs the reliability of soldering to the printed board. Moreover, there is a problem in that cracks, chips, etc. occur in the corner portion Oa due to the firing process and handling of the chip, and the characteristics are significantly impaired.

Therefore, conventionally, the corner portion Oa is rounded by barrel polishing after firing the chip. According to this method, it is possible to uniformly form the electrode lead layer, prevent deterioration of characteristics due to cracks, chips, etc. at the corner portions ca, and improve reliability.

However, the chamfering operation by barrel polishing requires a long time because the hardness of the chip increases due to firing. For this reason, there is a problem in that not only mass productivity is impaired, but also the cost is adversely affected.

[Disclosure of the invention]

In view of these points, the present invention provides a method for manufacturing a multilayer ceramic capacitor that can omit the chip chamfering operation with a simple configuration and can also significantly improve work efficiency. A step of pressing a laminate in which a plurality of internal electrodes and green sheets are alternately arranged between protective sheets with a pressing body having a protrusion having a triangular cross section along the part to be cut; The laminate,
This method is characterized by including the steps of cutting into chips by cutting from the grooves corresponding to the protrusions thereof, and forming an electrode lead layer on the end surface of the chip where the internal electrodes are exposed.

According to this invention, chamfers are formed in portions corresponding to the corner portions of the chip by pressing the laminate with a pressing member having a triangular protrusion. As a result, barrel polishing after chipping can be completely omitted, and work efficiency can be significantly improved.

Moreover, the electrode extension layer can be uniformly formed on the exposed end face of the internal electrode, and the soldering properties to the printed circuit board can be ensured.

[Best mode for carrying out the invention]

An embodiment of the present invention will be described with reference to FIGS. 2 to 9.

First, as shown in FIG. 2, a protective sheet 2 made of a thick green sheet containing ceramic ink powder and a binder is placed on a base 1 and fixed. In addition, this protection sheet ) 2
- can also be formed by laminating a plurality of thin green sheets. Then, internal electrodes 3 are printed in a certain pattern on this protective sheet a. Further, a green sheet 4I having a thickness thinner than that of the protective channel 2 is placed on the internal electrode 3. Next, as shown in FIG. 3, a green sheet 41. For example, the protective sheet 2 is 20 to 30 ky
Soft press at a pressure of / m-. Then, the internal electrodes 3 are screen-printed on the green sheet 4 with a certain number of turns, and the green sheet 42 is placed on the green sheet 4. Thereafter, repeat the same operation to remove the internal electrode (3° Green Sea) 43. By laminating and integrating the protective sheets 5, a laminate 6 shown in FIG. 4 is obtained.

Note that the soft press may be omitted for each stack of green sheets and protective sheets. Next, as shown in FIG. 5, the laminate 6 is housed in a mold 9 fixed to a base 8 having a protrusion 7 with a triangular cross section on the upper surface. and,
A pressing body 11 having a protrusion 10 corresponding to the protrusion 7 of the base 8 on its lower surface is lowered in the direction of the arrow shown in the figure. Note that the protrusions 7 and 10 of the base 8 and the pressing body 11 are formed laterally along the portion of the laminate 6 to be cut. Next, as shown in FIG. 6, the laminate 6 is heated to about 50 to 100[deg.] C. and pressed with a presser 11 at a pressure of about 100-150 9/#. As a result, the protrusions 7 and 10 bite into the protective sheets 2 and 5 of the laminate 6. Therefore, when the pressing body 11 is raised, a groove 12 having a triangular cross section corresponding to the portion to be cut is formed on the upper surface of the protective sheet 5, as shown in FIG. Next, as shown in FIG. 8, the movable body 14, which has a cutting blade 13 on its lower surface corresponding to the bottom of the groove 'l2, is lowered in the direction of the arrow shown in the figure. As a result, the stacked body 6 is cut into a plurality of chips through the groove portion 12. Next, as shown in FIG.
By forming a multilayer ceramic capacitor, a multilayer ceramic capacitor can be obtained.

According to this embodiment, the chamfered portion 12a is formed in a portion corresponding to the corner portion of the chip that is cut and separated by one separation by pressing the stacked body 6 by the pressing member 11, so that the electrode lead-out layer 15.15 is almost completely cut. It can be formed to have a uniform thickness, ensure good solderability to printed boards, and eliminate the need for barrel polishing, significantly improving work efficiency.

Further, by cutting the laminate 6 while it is housed in the formwork 9, alignment of the cutting blade 13 can be omitted, and the cutting operation can be performed efficiently.

In the present invention, the laminate can also be cut while being taken out from the mold. Further, the protruding portion of the base can be omitted.

[Brief explanation of the drawing]

Figure 1 is a side sectional view of a conventional multilayer ceramic capacitor.
2. FIG. 2 to FIG. 9 are explanatory diagrams of the method of the present invention.
Figures 3 to 3 show the protective sheet and internal electrodes. Fig. 4 is a side sectional view of the laminate, Fig. 5 is a side sectional view of the laminate housed in a formwork, and Fig. 6 is a side sectional view showing the state of pressing. cross section,
FIG. 7 is a plan view after pressing, FIG. 8 is a side sectional view showing the state before cutting, and FIG. 9 is a side sectional view showing the completed state. In the figure, 2 and 5 are 4 protective sheets, 3 is an internal electrode, and 4□~4
3 is a green sheet, 6 is a laminate, 10 is a protrusion, 11
12 is a groove, 12a is a chamfered portion, and 15 is an electrode extraction layer. Carving 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 7 b Figure 6 Figure 8 Figure 9

Claims (1)

[Claims] a step of pressing a laminate formed by alternately arranging a plurality of internal electrodes and green sheets between a pair of protective sheets with a pressing body having a protrusion having a triangular cross section along a portion to be cut; Manufacturing a multilayer ceramic capacitor characterized by including the steps of: cutting this laminate into chips through grooves corresponding to the protrusions thereof; and forming an electrode lead layer on the end face of the chip where the internal electrodes are exposed. Method.