JPH0722222B2 - Method for dividing ceramic laminate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to division of a ceramic laminated plate for dividing a large-area ceramic laminated plate in which a plurality of ceramic laminated bodies are collectively formed into individual ceramic laminated bodies. Regarding the method.

[Prior Art] Ceramic laminates used in the electronics industry include, for example, monolithic ceramic capacitors and laminated composite elements. These ceramic laminates are in line with the trend of light, thin, short and small electronic components. Miniaturization is advanced and high dimensional accuracy is required.

In the conventional method for manufacturing a ceramic laminate, a conductive paste is printed on an unfired ceramic sheet by screen printing or the like to form a plurality of conductors, a plurality of internal electrodes, and the like. A predetermined number of these sheets are stacked and pressure-bonded to form a ceramic laminated plate. When this ceramic laminated plate is divided into individual ceramic composite elements, ceramic laminated capacitors, or the like, the laminated plate is first fixed to a support base with an adhesive such as an adhesive tape or paraffin.
Generally, an adhesive tape is used, and an adhesive tape having an appropriate strength is selected in consideration of the adhesive strength of the adhesive tape and the peelability after cutting.

The means for dividing the laminated body is roughly classified into the following two ways.

The first method is a method in which a thin rectangular blade having a length equal to or longer than the length of the side in the cutting direction of the laminated plate is vertically arranged at a predetermined position, and the blade tip is pressed against the laminated plate to push it down. is there. This is a method of repeatedly cutting by sequentially moving the positions of the blades and similarly pressing, and it is effective in cutting a relatively thin laminated plate. However, if the laminated board becomes a little thicker, the blade escapes when cutting, and it is not possible to cut perpendicularly to the board surface, the cut surface of the cut laminated body is inclined, and the laminated body becomes a trapezoidal shape. Has the disadvantage that it becomes worse. Therefore, the first method can be used only when the laminated body has a thickness that does not make a trapezoid, that is, when the laminated body is thin.

The second method is similar to the first method, in which the laminated plate fixed to the support base is brought into contact with the laminated plate while rotating the rotary blade made of a rotatable disc having a blade formed on the peripheral edge. Then, the circular plate is vertically moved by a depth corresponding to the thickness of the laminated plate to divide the laminated plate.

According to this method, unlike the first method, the cut surface is perpendicular to the plate surface without being restricted by the thickness of the laminated plate. It is possible to cut with high precision, and the second method is widely used these days as a method of dividing most ceramic laminated plates.

[Problems to be Solved by the Invention] However, in the above-mentioned second method, when the ceramic laminate is miniaturized, the floor area of each ceramic laminate becomes small, and the adhesive force to the support is small. Because,
When the ceramic laminated plate is cut by a rotating blade, the divided individual ceramic laminated bodies are scattered or misaligned, which causes a problem that the shape or the dimension is broken.

[Means for Solving the Problems] As a means for solving the above problems, a method for dividing a ceramic laminated plate as described below has been developed. That is, in a method of dividing an unfired ceramic laminated plate in which a plurality of unfired ceramic sheets containing a ceramic raw material powder and a binder are laminated and pressure-bonded into a plurality of small laminated bodies, At least one end sheet of the plate is constituted by a ceramic sheet using a binder different from the binder contained in the ceramic sheet constituting the main body of the ceramic laminated plate, or a ceramic sheet having a different binder content, and the ceramic laminated plate Is fixed on a support base with the end sheet facing down, a kerf is formed from the ceramic laminate plate main sheet side to a depth reaching a part of the end sheet, and this laminate plate is then removed from the support base. Peel and heat treatment to remove binder, then divide into individual small laminates by barreling It is a division method of a ceramic laminate which is characterized and.

[Operation] According to the present invention, since the sheet forming the end layer of the ceramic laminate is fixed on the support base as it is without being fragmented by cutting, the adhesive force is large,
The individual laminated bodies do not scatter when the kerfs are formed in the ceramic laminated plate.

The sheet constituting the end layer of the ceramic laminated plate contains a binder different from the binder in the ceramic sheet constituting the main body of the laminated plate, or a binder having a content different from that. That is, the binder in the terminal sheet is a binder whose composition is more likely to be decomposed or scattered by heating than the binder in the ceramic sheet constituting the main body of the ceramic laminated plate, or the content thereof is relatively significant. Because of the small amount, the binder is more likely to scatter than the binder in the sheet which is the main component of the ceramic laminated plate upon heating, or the amount thereof remaining in the ceramic sheet after heating is very small. Therefore the laminate is
It can be easily divided by the subsequent barrel treatment. This is because the ceramic sheet of the terminal constitution layer is more likely to collapse than the main sheet because of the above reason.

Example 1 A derivative ceramic raw material powder containing barium titanate as a main component and a binder solution containing an acrylic resin as a main component were prepared.

First, 1,000 g of the above-mentioned derivative ceramic raw material powder and resin content 98
A dielectric ceramic slurry was prepared by mixing with 1,000 g of a binder solution containing g. Next, the slurry was coated by a reverse coater on a polyethylene terephthalate film (hereinafter referred to as PET) to a thickness of 30 μm, and 1
After drying at a temperature of 00 ° C., it was peeled from PET to form a 120 mm square ceramic green sheet, which was used as the first ceramic green sheet constituting the main body of the ceramic laminate.

Next, 1,000 g of the derivative ceramic raw material powder and 60 parts of resin content
A dielectric ceramic slurry was prepared by mixing with 1,000 g of a binder solution containing g. The slurry was applied on PET with a reverse coater to a thickness of 80 μm, dried at a temperature of 100 ° C., and then peeled off from PET to form a 120 mm square ceramic.
A green sheet was formed and used as a second ceramic green sheet which constitutes a part of the ceramic laminated plate.

A first green sheet on which a plurality of internal electrodes are screen-printed using a conductive paste containing Ni as a main component on the first ceramic green sheet, and 60 sheets of this are stacked, and the internal electrodes are not printed on the upper and lower sides thereof. A stack 1 is made by stacking 5 sheets each, and a second green sheet (sheet with a reduced binder ratio) 2 is further stacked on one end face and pressure-bonded to form an unfired ceramic laminate (Fig. 1). reference).

Next, a cutting support table (cutting table 3 in FIG. 1) having a through hole (suction hole 4 in FIG. 1) and capable of holding an article thereon by suction through the through hole is provided. The laminated plate (1 + 2) on the surface of the second green sheet (first
The sheet 2) side in the figure is placed downward, and suction is applied from the through hole 4 to fix and hold the laminated plate on the support base.

While rotating the rotary blade in that state, from the main sheet side of the laminated plate toward the support, until the tip of the rotary blade reaches a depth of about 1/3 of the thickness of the second green sheet. The rotary blade was moved vertically to form a kerf leaving about 2/3 of the thickness of the second green sheet (Fig. 1 (a)).
FIG. 3B is a partially enlarged view of FIG. This operation was sequentially repeated with a predetermined kerf spacing. After repeating a predetermined number of times, the support base was rotated by 90 degrees, and the cutting operation was repeated in the same manner to form a plurality of kerfs at center line intervals capable of forming a grid pattern of 4.0 mm × 2.1 mm.

This was heated to 250 ° C., held for 3 hours, subjected to binder removal processing, and further subjected to rotary barrel processing. Barreled monolithic ceramic capacitors were divided into individual sizes.

Fifty randomly selected monolithic ceramic capacitors thus obtained were measured in size with a micrometer, and their average value () and standard deviation (3σ) are shown in Table 1. .

Since the present invention is an invention of a method for dividing a monolithic ceramic capacitor, not an invention of a manufacturing method, the description of the firing step after barrel processing is omitted. The same applies to the following examples and comparative examples.

[Example 2] Table 1 shows the results obtained in the same manner as in Example 1 except that the resin amount of the binder solution of the second ceramic green sheet was changed to 60 g instead of 60 g in Example 1. It was shown to.

[Example 3] Table 1 shows the results obtained in the same manner as in Example 1 except that the resin amount of the binder solution of the second ceramic green sheet was changed to 60 g instead of 60 g in Example 1. It was shown to.

[Example 4] Table 1 shows the results obtained in the same manner as in Example 1 except that the resin amount of the binder solution of the second ceramic green sheet was changed to 60 g instead of 60 g in Example 1. It was shown to.

[Example 5] In Example 1, the binder solution of the second ceramic green sheet was replaced with a binder solution containing an acrylic resin as a main component instead of a binder solution containing a low-molecular methacrylic resin as a main component. The results obtained in the same manner as in Example 1 except for the above are shown in Table 1.

[Comparative Example 1] In Example 1, the laminated body 1 from which the second ceramic green sheet 2 was removed was used, and this was fixed to the cut table 3 with the adhesive film 2 '(Fig. 2 (a)). The results obtained in the same manner as in Example 1 are shown in Table 1 except for the above. An enlarged view of the lower end of the kerf in this case is shown in FIG. 2 (b).

As shown in the above examples, even if processed at the same temperature,
The amount of binder remaining in the second ceramic sheet is
It can be seen that the predicted effect can be obtained when the amount of the binder remaining in the first ceramic sheet is smaller than that of the first ceramic sheet.

[Effect of the Invention] According to the present invention, even if the ceramic laminate is downsized and the floor area of each ceramic laminate is reduced, the lower surface of the laminate remains as one piece and is not subdivided. The adhesive strength does not decrease, and when the ceramic laminated plate is cut with a rotating blade, the ceramic laminated body does not scatter or shift in position, and it is possible to divide the ceramic laminated body with good shape and dimension accuracy. Therefore, the present invention greatly contributes to improvement of dimensional accuracy and productivity.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a state in which a kerf is formed in a ceramic laminated plate by the method of the present invention, (a) is a side view,
(B) is an enlarged view of the lower end of the kerf shown in (a). FIG. 2 is an explanatory view showing a state in which a kerf is formed in a ceramic laminated plate by a conventional method, (a) is a side view,
(B) is an enlarged view of the lower end of the kerf shown in (a). Explanation of symbols 1 …… Layered body with a sheet having a normal binder ratio 1 ′ …… Layered body 2 …… Sheet with a reduced binder ratio 2 ′ …… Adhesive film 3 …… Cut base 4 …… Suction hole 5 …… Kerf

Claims (1)

[Claims] 1. A plurality of sheets having a plurality of conductors, a plurality of internal electrodes and the like formed by printing a conductive paste by screen printing on an unfired ceramic sheet containing a ceramic raw material powder and a binder. , A method of stacking a plurality of unfired ceramic sheets on which conductors and internal electrodes are not formed above and below these laminated sheets and pressing and integrating the unfired ceramic laminated plates into a plurality of small laminates, As a sheet to be arranged at one end of the ceramic laminated plate, the binder in the sheet has such a composition that it is more easily decomposed or scattered by heating than the binder in the first ceramic green sheet constituting the main body of the ceramic laminated plate. Or to use a second ceramic green sheet of the same kind of binder but low content The second ceramic green sheet is pressure-bonded and integrated so that the second ceramic green sheet is more likely to collapse than the first ceramic green sheet in the binder removal treatment in the subsequent step, and the obtained ceramic laminated plate is bonded to the terminal end. The arranged second ceramic green sheet is fixed on a support, and a kerf having a depth that reaches a part of the second ceramic green sheet but does not cut the second ceramic green sheet is formed in a predetermined direction. A predetermined number of sheets are formed for each, and then the laminated plate is removed together with the uncut second ceramic green sheet from the support, heat-treated to remove the binder, and then barrel-processed to obtain individual laminates each having a predetermined size. A method for dividing a ceramic laminated plate, characterized by dividing into ceramic pieces.