JPH04164306A - Terminal electrode formation method of electronic part - Google Patents

Abstract

PURPOSE:To enhance the productivity by a method wherein multiple electronic parts coated with a conductive paint through the intermediary of boron nitride(BN) base ceramic powder are closely juxtaposed to be baked in a baking furnace. CONSTITUTION:Cordierite or alumina-made jig 7 is prepared for a baking jig 7 while a laminated ceramic capacitors 8 coated with a conductive paint for terminal electrodes are closely juxtaposed on the surface of this jig 7 not to be overlapped with one another. Next, the laminated ceramic capacitors 8 juxtaposed on the jig 7 are sprayed with BN base ceramic powder. Next, the jig 7 sprayed with the BN base ceramic powder is fed to a conveyor belt baking furnace at the temperature of 550-650 deg.C. Next, within the jig 7 finishing the baking step, the BN base ceramic powder and the laminated ceramic capacitors 8 are separated from one another using a mesh. During this separating step, no residual laminated layer ceramic capacitors 8 left on the mesh due to the mutual adherence of the terminal electrodes to one another are observed at all.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming terminal electrodes for electronic components, and more particularly to a method for forming terminal electrodes in multilayer ceramic capacitors and the like by firing conductive paint.

[Second] Long mouth technique - A multilayer ceramic capacitor having a general structure as shown in FIG. 2 is manufactured as follows.

First, after kneading the finely divided ceramic powder and an organic binder, a green sort is produced by the doctor blade method. Next, this raw sheet is cut into a desired area, and internal electrodes are applied to one side of the sheet by screen printing and dried to prepare a raw sort. Next, the desired number of raw sheets with internal electrodes printed on them are stacked by sandwiching them from above and below with a protective layer made of raw sheets without electrodes printed on them to form a laminate, which is heat-pressed and then cut into individual pieces. to form individual raw chips. These individual pieces of raw chips are fired and are shown in Figure 2 (
A baked chip 1 shown in a) is produced.

Then, a conductive paint containing silver as a main component and a small amount of glass flint is applied to both ends to form terminal electrodes 2, 2. Finally, it is baked to produce a chip type multilayer ceramic capacitor 3.

Furthermore, if desired, the chip type multilayer ceramic capacitor 3 may be provided with lead wires 4, 4 as shown in FIG. 2(b).
Solder and finally mold with resin 5,
A multilayer ceramic capacitor 6 with leads is produced.

8f' - By the way, in the above conventional baking of the terminal electrodes 2, 2, a large number of baked chips 1, 1 with conductive paint applied to both ends
... are placed on a jig or the like and fired all at once, but since the conductive paint to be baked contains a small amount of glass frit, the baking takes place at a temperature of 400°C. The glass frit y) melts in the above), and the molten glass frit comes out on the surface of the terminal electrodes 2, 2.
If the chips are baked in a state where they are in contact with each other, the glass frit exposed on the surface causes the chips to stick to each other at the terminal electrodes 2.2. Therefore, in this case, the chips must be scattered in a sparse state during baking, resulting in poor productivity.

In addition, after baking, sprinkle powder to prevent the terminal electrodes 2, 2 from sticking together, and apply ceramic such as alumina or zirconia to the part where the terminal electrodes 2, 2←center→are in contact.

Ru. However, the glass frit on the surface of the terminal electrodes 2, 2 reacts with the ceramic powder such as alumina, zirconia, etc., and the alumina and zirconia powder adheres to the surface of the terminal electrodes 2, 2, resulting in poor solderability of the terminal electrodes 2, 2. This has a negative effect on the appearance, and even when the surfaces of the terminal electrodes 2, 2 are plated, the parts to which the alumina and zirconia powders are attached are not plated.

--This invention discloses that when baking a conductive paint, a large number of electronic components coated with a conductive paint are sometimes baked in a dense array with a boron nitride (hereinafter referred to as BN) based gelaminok powder interposed therebetween. It is characterized by

The BN-based ceramic powder described above sometimes prevents the terminal electrodes from contacting each other when the terminal electrodes are baked, and the baking can prevent the terminal electrodes from sticking together afterward. Further, since the BN ceramic powder does not react with the metal or glass frit that constitutes the conductive paint, the BN ceramic powder does not adhere to the terminal electrode after the terminal electrode is baked.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

Figure 1 shows a jig 7 (setter; made of cordierite, alumina) used for baking, and a laminated ceramic capacitor 8 coated with conductive paint for terminal electrodes arranged densely thereon.
FIG. 1 is a plan view of FIG.

The method for burning the terminal electrodes of a multilayer ceramic capacitor according to the present invention is as follows.

First, a jig 7 made of cordierite or alumina is prepared as a jig used for baking, and the multilayer ceramic capacitors 8 coated with conductive paint for terminal electrodes are placed on the top surface of this jig 7 tightly so as not to overlap each other. Arrange. Next, B.N.
ceramic powder (e.g. DENKABORON NITRIDE H)
TD Denki Kagaku Kogyo Co., Ltd.) is sprayed onto the laminated ceramic capacitor 8 arranged on the jig 7. Since the above-mentioned BN ceramic powder has a particle size of about 1Oθμ− to 300μ■, when it is sprinkled, it can be uniformly sprinkled on the jig 7 without being scattered around.

Next, the jig 7 on which the BN ceramic is sprinkled is placed in a conveyor belt firing furnace and fired at a temperature of 550°C to 650°C for about 1 hour. After baking, the jig 7 is separated into a BN ceramic powder and a multilayer ceramic capacitor 8 using a mesh. During this separation, the multilayer ceramic capacitor 8 remaining on the mesh was not observed due to the terminal electrodes sticking together. Since some BN-based ceramic powder adheres to the surface of the separated multilayer ceramic capacitor 8, ultrasonic cleaning is performed to remove this.

As a result of this ultrasonic cleaning, no residual BN ceramic powder was found on the terminal electrode, and the terminal electrode was plated and
, No plating adhesion due to adhesion of BN-based ceramic powder was observed.

Although the above embodiments have been described with respect to the formation of terminal electrodes of a multilayer ceramic capacitor, the present invention can be applied to the formation of terminal electrodes of any other electronic component such as a capacitor, a resistor, a semiconductor element, or the like.

As explained above, in this invention, the terminal electrodes of laminated ceramics and capacitors are sometimes baked by using BN ceramic powder, and the baking is arranged closely on the jig.
Productivity will be approximately doubled. In addition, since the BN-based ceramic powder does not adhere to the terminal electrode after baking, there is no adverse effect on quality.

[Brief explanation of the drawing]

FIG. 1 is a plan view of chip-type multilayer ceramic capacitors arranged closely on a jig to explain a method for baking terminal electrodes of a multilayer ceramic capacitor according to an embodiment of the present invention. It is a partially enlarged plan view. Fig. 2 is a diagram showing an outline of a multilayer ceramic capacitor, Fig. 2(a) is a cross-sectional view of a chimp type multilayer ceramic capacitor, and Fig. 2(b) is a multilayer ceramic capacitor with leads. shows a front view. Figure 1112(b)

Claims (1)

[Claims] When terminal electrodes are formed by baking conductive paint on the electronic component body, a large number of electronic components coated with conductive paint are densely arranged with boron nitride ceramic powder interposed therebetween. A method for forming terminal electrodes of electronic components, characterized by baking.