JPH0766076A - Manufacture of laminated chip component and laminated chip component - Google Patents

Abstract

PURPOSE:To prevent generation of breaking, cracks and delamination so as to improve reliability by previously bevelling the corner parts of a laminated chip in the shape of C or R before a cut-out process. CONSTITUTION:Through-holes 3 whose sections are rhombic or in the shape having curvature on the sides of a rhomb are stamped out from green sheets 1 and 2 having the points of intersection of the cut-out arranged lines 5 of the laminated chips. Later, these are laminated inside a laminated metal mold and subjected to thermocompression bonding so as to obtain a laminate having the through-holes 3 in the positions corresponding to the points of intersection of the arranged cut-out lines 5 of the laminated chips. The obtained laminates are cut off by a dicing saw along the lines shown by the arranged cut-out lines so as to obtain individual laminated chips having R-parts on four corners in the thickness direction. Later, debindering and sintering are followed by bevelling treatment inside a barrel device having alumina beads as a medium.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated chip part used in a circuit of electronic equipment and a method for manufacturing the same.

[0002]

2. Description of the Related Art Multilayer chip parts, represented by monolithic ceramic capacitors, monolithic ceramic inductors, multi-layer varistors, etc., are being promoted in miniaturization and densification of shapes and structures, and demands for reliability are strict. It has become to. These laminated chip parts are printed with a predetermined electrode layer or conductor pattern on a standard ceramic green sheet, and then laminated in a laminated die with high accuracy and thermocompression bonded to the electrode layer or conductor pattern inside. A green sheet laminating method is generally used to obtain a laminated body containing. The laminated body obtained by this is cut along a predetermined position with a dicing saw or a pressing device, a plurality of laminated chips are cut out and sintered, and then the laminated chip sintered body is subjected to a barrel device or the like. Is used to chamfer the edge portion of the chip to obtain a laminated chip as shown in FIG. After that, external electrodes are formed and finished as a laminated chip component.

In this case, the following matters can be mentioned as factors relating to the reliability of the laminated chip.

1. Occurrence of delamination when forming a laminated body.

In recent years, the more compact and high-density laminated chip parts are promoted, the more the number of laminated ceramic green sheets tends to increase. In laminated ceramic capacitors and the like, the green sheets including a protective sheet are It is not uncommon for the number of layers to be 100 to 200. However, a problem occurs when the laminated body is formed. That is, when the green sheets are stacked in the stacking mold, if an air layer is spread between the green sheets, the adhesion between the green sheets will be incomplete inside the obtained stacked body, which may cause delamination. It is important that air is smoothly removed when stacking the green sheets, but in the stacking of one sheet by the conventional method, the larger the size, the more difficult it is to remove air.

2. Delamination occurs near the cut surface of the laminate.

When cutting out a laminated chip from the laminated body, it is necessary to minimize distortion at the cut surface. When the strain applied to the cut surface of the laminate is large, it causes delamination near the cut surface. As a cutting blade,
There is a dicing saw blade or a single-blade blade, but it is important to minimize the contact area between the cutting blade and the cut surface of the laminate in order to alleviate the strain, and it is even more effective if there is an escape area for the cutting chips. There is. In the conventional laminated body, strain is relaxed by setting cutting conditions such as cutting speed reduction, but there is a limit in work efficiency.

3. Decrease in reliability due to internal defects such as chipping, cracks, and delamination due to impact during chamfering of the laminated chip sintered body.

Barrel polishing is usually used in the chamfering treatment of the sintered body, but the impact during barrel polishing is small,
And it is necessary to keep it in a short time. Particularly, in the case of a rectangular laminated chip, the impact on the ridge portion is strong, and chipping, cracking, and delamination are likely to occur from that portion.

[0010]

As described above, according to the conventional manufacturing method, 1) the step of producing a laminated body, 2) the step of cutting out individual laminated body chips from the laminated body, and further 3) the sintering. Including the problem that delamination inside the laminate, delamination on the surface of the laminate chip or chipping, cracking, and expansion of delamination of the laminate chip are likely to occur at the stage of chamfering the laminated chip However, there is a problem that the reliability is deteriorated due to these. Specifically, the deterioration of reliability means deterioration of insulation resistance of a product or a short circuit phenomenon.

[0011]

In order to solve the above-mentioned problems, when a laminated body is formed and a predetermined laminated chip is cut out, the corners of the ridge line in the thickness direction of the laminated chip have a C or R shape. It is characterized in that a green sheet to be laminated is punched at a corresponding portion in advance so as to have a chamfered shape. Alternatively, a screen pattern may be used that has a chamfered shape.

[0012]

The laminated chip cut out from the laminated body by laminating the green sheets having the corners formed on the ridgeline portion in the thickness direction of the laminated chip is punched in advance by the conventional method. For example, the same shape as that of the corner portion that should be formed on the ridgeline portion in the thickness direction is already obtained by chamfering into the C or R shape. According to this method, even when a large number of green sheets are stacked in a stacking mold, delamination due to the entrainment of air between the green sheets can be eliminated. Furthermore, when cutting the laminated chip from the laminated body, the cutting blade passes through the punched hole portion, so that the hole serves as an escape area for the cutting powder, and the contact area between the cutting blade and the laminated body can be reduced. Therefore, the amount of strain applied at the time of cutting can be minimized, and the occurrence of delamination can be prevented.
Even if the final finishing treatment of chamfering is performed after sintering, since the ridge line portion in the thickness direction of the laminated chip is chamfered in a C or R shape in advance, the barrel for chamfering is performed. Since the processing time can be greatly shortened and the impact given to the sintered body can be relaxed, the occurrence of chipping, cracking and delamination can be prevented.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a schematic view showing the structure of a laminated body for obtaining a plurality of laminated ceramic capacitor chips, wherein reference symbol a is a protective film layer on which an internal electrode layer is not printed,
Reference numeral b represents an internal electrode layer made of a green sheet on which the internal electrode pattern 4 is printed. The green sheets 1 and 2 forming a and b are made of ceramic powder and PVB.
The slurry mixed with as a binder was formed into a thickness of 20 μm by the doctor blade method, and then the size was 100 × 13.
The green sheet 2 was punched out to a thickness of 0 mm, and the green sheet 2 was formed by regularly repeating the internal electrode pattern 4 in a plane by Ag.
/ Pd paste is used for printing. As shown in FIG. 3, the green sheets 1 and 2 have punched out through-holes 3 having a rhombic section or a rhombic section with a curvature centered on the intersection of the planned cutting lines 5 (shown by dotted lines) of the laminated chip. After processing, the product is stacked in a laminated die and thermocompression bonded under the conditions of a temperature of 80 ° C. and a pressure of 200 Kg / cm ² to obtain a laminated body having a through hole 3 at a position corresponding to the intersection of the planned cutting lines 5 of the laminated chip. Is obtained. By cutting the obtained laminated body with a dicing saw along the line indicated by the planned cutting line 5, individual laminated chips having R portions indicated by reference symbol R at four corners in the thickness direction as shown in FIG. Is obtained. After that, debinding and 900 ° C
After the sintering was performed, the outer shape of the laminated chip was rounded by a chamfering treatment in a barrel device using alumina beads as a medium for a short time of several minutes.
5.0mm x size by applying and baking g paste
A multilayer ceramic capacitor having a size of 2.0 mm × 1.7 mm, 150 internal electrode layers and a capacity of 10 μF was obtained.

In this example, delamination inherent in the laminated chip sintered body was non-destructively probed using an ultrasonic flaw detector having an image processing device. In addition, the degree of occurrence of chipping on the appearance was examined with a certain standard. Further, a pressure cooker test (PCT) was performed to examine the short-circuit occurrence rate due to the insulation resistance deterioration in the reliability acceleration test. These results are summarized in Table 1 in comparison with the conventional method.

[0016]

[Table 1]

As shown in Table 1, according to the present invention, it was confirmed that the delamination occurrence rate, the chipping occurrence rate, and the short-circuit occurrence rate have remarkable effects.

[0018]

EFFECTS OF THE INVENTION According to the present invention, it has been confirmed that the delamination that occurs in a laminated chip can be eliminated and that chipping that occurs in the process can be prevented, and the reliability of laminated chip components can be improved. I was able to do it.

[Brief description of drawings]

FIG. 1 is an external perspective view showing a laminated chip of the present invention.

FIG. 2 is an external perspective view showing the structure of the laminate of the present invention.

FIG. 3 is a plan view showing an example of forming a through hole in a dummy sheet and an electrode sheet.

FIG. 4 is an external perspective view showing a conventional laminated chip.

[Explanation of symbols]

 a protective film layer b internal electrode layer 1 dummy sheet having a through hole 2 electrode sheet having a through hole 3 through hole 4 internal electrode pattern 5 (multilayer chip) planned cutting line R (cut into a C or R shape) R Department

Claims (2)

[Claims] 1. A method of manufacturing a laminated chip component, wherein a laminated chip having a predetermined shape is cut out from a laminated body including internal electrode layers and fired to obtain individual laminated chip components. C or R in advance
A method of manufacturing a laminated chip component, characterized in that the shape is chamfered. 2. A laminated chip component obtained by cutting a laminated chip having a predetermined shape from a laminated body including an internal electrode layer and firing the laminated chip, which has a C or R shape in advance before a corner of the laminated chip is cut out. A laminated chip part characterized by being chamfered.