JPH0317206B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical field to which the invention pertains] The present invention relates to a method for manufacturing electronic components such as multilayer ceramic capacitors and multilayer chip inductors used as multilayer chip electronic components. [Prior Art] An example of this type of manufacturing method will be described with reference to FIG. 1, using a multilayer ceramic capacitor as an example. First, a slurry containing a dielectric material, an organic binder, and a plasticizer is applied to a doctor blade 1 as shown in FIG. 1a.
A film is formed on the carrier sheet 12 by 1 and dried by the dryer 13 to form a green sheet 1 with a carrier.
Create 4. Then, as shown in Figure 1b,
The green sheet 15 is peeled off from the carrier-attached green sheet 14, and is stocked in a punching case 17 by a punching device 16 into a shape that is slightly larger than a laminated mold, which will be described later. Next, an internal electrode pattern including alignment markers is printed and dried. Furthermore, the alignment marker is aligned with the reference position so that the internal electrode pattern is at the designed position, and the sheets are stacked in the punching die 18 as shown in FIG. 1c. Then, as shown in FIG. 1d, after the set number of sheets have been laminated, pressing is performed using a hot press machine 19, and the sheets are cut into a regular shape and fired. Finally, external electrodes are formed. In this case, a prescribed number of sheets with the same shape are prepared with internal electrodes printed thereon, and the internal electrode printed sheets are aligned one by one, punched out, and laminated into a mold. Moreover, the internal electrode printed sheets must be alternately oriented in order to stack them in such a way that the effective internal electrodes alternately short-circuit to the external electrodes within the capacitor. When observing the cut surface of raw chips laminated using this conventional method, it is found that the internal electrodes are misaligned by the cutting margin (approximately 1
mm), which is about 0.5mm, and the deviation is extremely variable. This becomes more noticeable as the number of laminated sheets increases. In a multilayer ceramic capacitor, this lamination misalignment is located at a location where there is a large density difference between the internal electrode portion and the cut margin (portion without internal electrodes). This will result in a significant drop in reliability. This lamination misalignment is largely due to the printing accuracy of the alignment marker and the alignment accuracy, and it is extremely difficult to improve the accuracy of both because printing blur and the like hinder the improvement. [Object of the Invention] The present invention aims to eliminate this drawback and provide a highly reliable laminated ceramic component in which the degree of lamination misalignment is reduced. [Structure of the Invention] The present invention performs a series of steps of punching a ceramic sheet, printing internal electrodes, drying, and laminating the ceramic sheet while the ceramic sheet is adsorbed to a suction pad, thereby improving printing accuracy and reducing lamination misalignment due to marker alignment. This is the method I lost. In other words, in the present invention, it is sufficient to consider two items (printing accuracy + lamination accuracy) as errors in lamination misalignment.
[Conventionally, (marker printing accuracy + marker positioning accuracy) must be taken into consideration. ] The causes of lamination misalignment can be reduced and the degree of misalignment can be made extremely small. [Example] Next, an example of the present invention will be described with reference to FIG. As a dielectric magnetic material, Pb (Nb1/2, Fe1/2)
A composite perovskite dielectric material having a composition of (W1/3)O ₃ was used. Mix this material, pre-fire,
A slurry is created from the polyvinyl butyral organic binder and solvent by wet grinding. Next, as shown in FIG. 2a, a carrier-attached green sheet 24 having a 30 μm green sheet on the carrier film 22 is prepared using a doctor blade 21. 2
3 is a dryer. This carrier-equipped green sheet 24 is obtained by peeling off the green sheet 25 in the process shown in FIG. 2b.
While punching out a shape of 100 x 120 mm using the punching device 26, it is sucked onto a suction pad 30 as a holding means.
Then, as shown in FIG. 2c, the suction pad 30
An internal electrode pattern is printed on the sheet 25' through the screen 32 by the printing machine 31 while the sheet 25' remains attracted to the sheet 25'. Next, as shown in FIG. 2d, drying is performed using a hot air dryer 33. Of course,
This step is also carried out while being adsorbed by the suction pad 30. In FIG. 2e, the sheet 25' after drying is laminated onto the punching die 28 using a suction pad 30. When a predetermined number of sheets are laminated, the heat press machine 2
Thermocompression bonding is performed in step 9. In this case, the number of internal electrode printed sheets was 61, and the internal electrode paste was a mixture of Ag powder, Pd powder, an organic binder, and a plasticizer. This laminate was cut into 12 x 16 mm pieces using a peripheral blade cutter, the binder was removed, the material was fired, an external Ag electrode was applied and baked, and the reliability of the multilayer ceramic capacitor was tested. The results are shown in Table 1. Note that a cooling pipe 34 was attached to protect the cutter of the extraction device 26 from heat. The printing machine 31 used screen printing using nylon mesh #200, and the coater used was a modified type of gravure coater.

〔Effect of the invention〕

In the conventional method, the process was a single process, not a continuous process, and the internal electrode printed sheets were stored in a stockyard, so positioning required skill.
By using the method of the present invention, productivity can be greatly improved. Furthermore, it is possible to provide a highly reliable laminated ceramic component by reducing the degree of sheet lamination misalignment.

[Brief explanation of the drawing]

1A to 1D are diagrams showing the steps of the conventional manufacturing method, and FIGS. 2A to 2F are diagrams showing the steps of the method of the present invention. In the figure, 11, 21 are doctor blades, 12,
22 is a carrier sheet, 13 and 23 are dryers, 1
4, 24 is a green sheet with carrier, 15, 2
5 is a green sheet, 16 and 26 are punching devices, 1
8 and 28 are punching molds, 19 and 29 are hot press machines, 30 is a suction pad, 31 is a printing machine, 32 is a screen, and 33 is a hot air dryer.

Claims (1)

[Claims] 1. A method for manufacturing ceramic parts in which internal electrodes are printed and laminated on ceramic green sheets, including () a step of continuously forming ceramic green sheets on a carrier film of an organic film; () After this, a step of peeling the ceramic green sheet from the carrier film and punching it into a desired size; () with the holding means holding the punched ceramic green sheet in the step (); , printing conductive internal electrodes on the back surface of the sheet through a screen; () drying the sheet while it is held in the holding means; () Thereafter, the steps () to () are repeated to stack the sheets; () The sheets stacked in the step () are bonded by thermocompression; A method for manufacturing a multilayer ceramic capacitor, characterized in that the multilayer ceramic capacitor is manufactured in the order of steps () to ().