JPS6248369B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a laminated ceramic capacitor in which a plurality of ceramic pieces each having an electrode layer formed on one side are laminated.

In general, a multilayer ceramic capacitor is manufactured by forming an electrode layer 2 on the top surface of a thin rectangular ceramic piece 1 by a printing method, as shown in FIGS. It has a structure in which a capacitor element 3 is formed by integrating them by hot pressing, and external electrodes 4 and 5 are further formed on both end surfaces of the capacitor element 3. The electrode layer 2 on the ceramic piece 1 is formed in a shape that is exposed on one end surface of the ceramic piece 1, and the plurality of ceramic pieces 1 are stacked with the exposed end surfaces of the electrode layers 2 facing oppositely. be done. Then, the end faces of the electrode layer 2 are exposed layer by layer on both end faces of the capacitor element 3, and the external electrodes 4 and 5 collectively electrically connect these end faces.

Incidentally, conventionally, a plurality of capacitor elements of such a multilayer ceramic capacitor are manufactured at once in the following steps. First, a long tape-shaped thin ceramic sheet 6' as shown in FIG. 3 is prepared and sequentially cut into predetermined lengths. The ceramic sheet 6' is prepared, for example, by applying a slurry mixture of ceramic powder, a binder, and a solvent onto a film in the form of a thin film using a doctor blade method, and then drying the film by heating. Next, the ceramic sheets 6 cut to a fixed size are sequentially fed into a printing machine, and a plurality of electrode layers 7 are printed on the ceramic sheets 6 in a row and column pattern, as shown in FIG. The electrode layers 7 lined up side by side to form a row have the same pattern in each row a ₁ , a _{2 .} . . , for example, the first, second, and third electrode layers 7b ₁ from the left in FIG. , 7b ₂ and 7b ₃ . The first electrode layer 7b ₁ has the same width as the electrode layer ₂ in the capacitor _shown in FIG. The electrode layers 7b ₁ , 7b ₂ , and 7b ₃ are arranged at regular intervals. Next, a plurality of ceramic sheets 6 that have undergone the cutting and printing processes are stacked in sequence, and at this time, the orientation of the ceramic sheets 6 is reversed 180 degrees for each layer as shown in Figures 5 and 6. . Also, during this lamination, the upper ceramic sheet 6 is placed on the electrode layer 7 of the lower ceramic sheet 6.
The electrode layers 7 are aligned so that they do not protrude in the width direction and are partially intersected at a constant ratio in the length direction. Then, the plurality of laminated ceramic sheets 6, 6, . . . are heat-pressed in the lamination direction to integrate them, and then cut at the arrow lines in FIG. 6 to separate them into individual capacitor elements.

In this way, conventionally, mass production has been attempted using ceramic sheet 6, but ceramic sheet 6 is
It is difficult to handle because it is extremely thin, measuring 10 μm in size, and the printing process is complicated because it has to be cut to a certain size and then transported to a printing machine and positioned one by one for printing. The biggest drawback of this conventional manufacturing method is that the printed ceramic sheets 6 must be alternately reversed by 180 degrees and stacked. In other words, the extremely thin ceramic sheet 6 remains flat.
Reversing it 180° required a high degree of skill. Furthermore, although it is easy to position the ceramic sheets 6 sent out from the printing machine in the same direction, reversing the orientation will cause a large positional shift, so it is necessary to align the ceramic sheets 6 on the lower ceramic sheet 6 and position them accurately. It was very difficult to place and the workability was poor. In addition, since it is difficult to align the ceramic sheets 6, the electrode layers 7, 7 of the upper and lower ceramic sheets 6, 6 may be greatly misaligned.
The rate of occurrence of defects such as a decrease in capacitor element capacity and shorts between electrode layers has increased, and improvements have been desired.

The present invention meets these demands, and includes a step of printing an electrode layer on a long tape-shaped ceramic sheet, a step of cutting the printed ceramic sheet into predetermined dimensions, and a step of cutting the cut ceramic sheet into the same size. A method of manufacturing a laminated ceramic capacitor is provided, which includes the steps of laminating the laminated ceramic sheets in their orientation and subdividing the laminated ceramic sheets into capacitor elements. Hereinafter, the present invention will be sequentially explained for each step with reference to the drawings.

In the present invention, as shown in FIG. 7, a capacitor element is manufactured through a printing process 8 - cutting process 9 - laminating process 10 - cutting process 11. First, in the printing process 8, a long tape-shaped ceramic sheet 12 created in the same manner as before is intermittently fed in the longitudinal direction, and is sequentially printed on the top surface of the ceramic sheet 12 from the tip side at a certain fixed position of the printing machine. This is a step of printing the electrode layer 13. What is important in this printing process is to print the electrode layer 13 in the following pattern, which is different from the conventional one. For example, as shown in FIG. 8, if the horizontal rows of the electrode layer 13 from the tip of the ceramic sheet 12 are m ₁ , m _{2 .} . . , each odd-numbered row
For example, three first to third lines lined up in m ₁ , m ₃ , m ₅ ...
Electrode layer m ₁ -1, m ₁ -2, m ₁ -3, m ₃ -1, m ₃
-2, m ₃ -3... are all printed in the same pattern. In other words, the first electrode layer m _{1 -1} , m _{3 -1} ... at the left end of each odd-numbered column m ₁ , m ₃ , m 5 ...
It has the same width and slightly larger length as the electrode layer 2 in the figure, and has a second electrode layer m ₁ -2, m ₃ -2... and a third electrode layer.
Electrode layers m ₁ -3, m ₃ -3... are electrode layers 2 in Fig. 1.
They have the same width and twice the length, and they are lined up at regular intervals. On the other hand, each even-numbered column m ₂ ,
m ₄ , m ₆ . . . are different patterns obtained by inverting the odd-numbered patterns by 180 degrees, and are respectively three first to third electrode layers m ₂ -1, m ₂ -2, m ₂ -3, m ₄ -1 , m ₄ ―
2, m ₄ -3... are lined up. Printing of the electrode layer 13 in such a pattern is carried out one row at a time in synchronization with the feeding of the ceramic sheet 12, or sequentially for even numbered rows at a time. Also, at the same time as printing this electrode layer 13, each row m ₁ , m ₂ . . . on the ceramic sheet 12 is printed.
Positioning marks 14 are printed on both end sides.

The ceramic sheet 12 that has completed the printing process is then cut into predetermined lengths at the next predetermined position. The feature of this cutting process is that the ceramic sheet 12 is cut into a certain number of odd rows including an odd number of rows m ₁ , m ₂ , m _{3 .} . . of the electrode layer 13. midway between column m ₃ and the fourth column m ₄ ,
The middle of the 6th column m ₆ and the 7th column m ₇ is sequentially cut. Now, if the cut ceramic sheets of a certain size are numbered 12-1, 12-3, etc. in the order of cutting, as shown in FIG _. ，
The electrode layer 13 of m ₂ and m ₃ is printed, and the second cut and separated ceramic sheet 12-2 has a row of electrode layers 13.
Electrode layers 13 of m ₄ , m ₅ , and m ₆ are printed. In other words, if the second ceramic sheet 12-2 is stacked on top of the first ceramic sheet 12-1 without changing its direction, the odd-numbered rows m ₁ and m ₃ of the ceramic sheet 12-1 will be stacked as shown in FIG. The even numbered rows m ₄ and m ₆ of the ceramic sheet 12-2 intersect, and the even numbered row m ₂ of the ceramic sheet 12-1 intersects with the odd numbered row m ₅ of the ceramic sheet 12-2.

Therefore, in the next stacking step 10, the ceramic sheets 12-1, 12-2, . For example, as shown in FIG. 11, this lamination work uses a lifting platform 16 that moves up and down between guide walls 15, 15 facing each other across the width of the ceramic sheet 12, and raises and lowers the lifting platform 16 while lowering the platform 16 at a fixed pitch. The ceramic sheets 12-1, 12-2, etc. cut and separated may be sequentially supplied and stacked. At this time, alignment of the ceramic sheets 12-1, 12-2, . . . can be conveniently and accurately performed using the positioning marks 14. In this way, the laminate 17 in which _the ceramic sheets 12-1, _12-2 , _{. . .}
―……, m ₂ ― m ₅ ― m ₈ ― m ₁₁ ―……, m ₃ ― m ₆ ― m ₉
―m ₁₂ ―……, they face each other in an intertwined state. Then, after a predetermined number of layers, for example, an odd-numbered x-th ceramic sheet 12-x, is completed, a protective sheet (not shown), for example, is further layered. Then, this laminate 17 is taken out from the lifting table 16, hot-pressed in the stacking direction, and sent to the next cutting step 11. In the cutting step 11, the laminated body 17 is finely divided into individual capacitor elements by cutting at the arrow points in FIG.

The printed pattern of the electrode layer 13 in the above printing process can be modified in various ways, and the modified row is shown in the 13th row.
This will be explained with a diagram. This means that each odd column n ₁ , n ₃ , n ₅
. . . an electrode layer n ₁ -1, n 1 -2, n ₁ -3, n _{3 -1} , n ₃ - with the same width and twice the length as electrode layer 2 in Fig. 1.
2. Arrange n ₃ -3.... On the other hand, each even-numbered column
n ₂ , n ₄ , n ₆ . . . have electrode layers n ₂ -1, n ₂ -4, n ₄ having the same width as the electrode layer 2 and slightly larger length at both ends.
-1, n ₄ -4..., with an electrode layer n ₂ -2, n ₂ -3, n ₄ - having the same width as electrode layer 2 and twice the length in the center.
2. Arrange n ₄ -3.... This odd number sequence n ₁ , n ₃ , n ₅
. . . and the even-numbered columns n ₂ , n ₄ , n ₆ . . . are set so that they partially intersect when stacked. In this case as well, the ceramic sheets 12 are cut into odd-numbered rows and stacked without changing the orientation. Further, in this case, the ceramic sheet laminate 17' is cut at the arrow locations in FIG.

As explained above, according to the present invention, since the ceramic sheet is cut after printing the electrode layer,
Ceramic sheet positioning during printing becomes easier, allowing faster and more accurate printing. In addition, since the cut and separated ceramic sheets can be stacked in the same direction, work efficiency can be greatly improved compared to the conventional manufacturing method in which the ceramic sheets are turned 180 degrees for each sheet. There is less worry about misalignment during printing, and the rate of non-defective products can be improved.

[Brief explanation of the drawing]

FIGS. 1 and 2 are a partial cross-sectional perspective view and a side sectional view of a general multilayer ceramic capacitor, and FIGS. 3 to 6 are for explaining each step of a conventional method for manufacturing a multilayer ceramic capacitor. , FIG. 3 and FIG. 4 are plan views of the ceramic sheet, FIG. 5 is an exploded side view of the ceramic sheet laminate, FIG. 6 is a plan view of the ceramic sheet laminate, and FIG. 7 is a diagram of the manufacturing method according to the present invention. A schematic side view explaining the entire process, FIG. 8 is a plan view of the ceramic sheet in the printing process shown in FIG. 7, FIG. 9 is an exploded perspective view of the ceramic sheet laminate in the lamination process shown in FIG. 7, and FIG. 10 is a plan view of the ceramic sheet after lamination in Figure 9;
Fig. 1 is a perspective view showing a specific example of the apparatus for the lamination process shown in Fig. 7, Fig. 12 is a plan view of the ceramic sheet laminate shown in Fig. 7, and Fig. 13 is a modification of the printing pattern in the printing process according to the present invention. FIG. 14 is a plan view of a ceramic sheet showing an example, and FIG. 14 is a plan view of a laminate made of the ceramic sheets of FIG. 13. 8... Printing process, 9... Cutting process, 10... Lamination process, 11... Cutting process, 12,12-1,1
2-2... Ceramic sheet, 13, m ₁ -1,
m ₂ -1... n ₁ -1, n ₂ -1... electrode layer, 17,
17'... Ceramic sheet laminate.

Claims (1)

[Claims] 1. The patterns of odd-numbered columns and even-numbered columns arranged vertically on a long tape-shaped ceramic sheet with the long direction being vertical and the short direction being horizontal, are different from each other,
In addition, there is a process of printing electrode layers with the same pattern for odd or even numbered rows, and a process of printing a certain length of the ceramic sheet in the horizontal direction between the odd numbered rows and even numbered rows of the vertical electrode layers. A process of sequentially cutting the electrode layers so that the number of rows is a constant odd number, a process of aligning the cut ceramic sheets in the same direction and stacking them, and pressurizing the stacked ceramic sheet stack. 1. A method for manufacturing a multilayer ceramic capacitor, comprising the steps of integrating and cutting and separating into individual capacitor elements.