JPH0655233U - Chip-shaped electronic component - Google Patents

Abstract

(57) [Abstract] [Purpose] To enhance the bondability between the external electrode and the ceramic member and reduce the risk of environmental pollution. [Structure] A multilayer ceramic capacitor 1, which is one of chip-shaped electronic components, is mainly composed of a main body 2 and external electrodes 3a and 3b. The main body 2 is made of a dielectric material in which a plurality of internal electrodes 4a and 4b are arranged in parallel with each other with a space therebetween, and constitutes a capacitor. The internal electrodes 4a and 4b are connected to the external electrodes 3a and 3b, respectively. The external electrodes 3a and 3b are made of an electrode material containing a silver-based conductive material, glass frit, and indium. Since this electrode material contains indium, the main body 2
Highly bondable with. Further, since indium has low toxicity, it is less likely to cause environmental pollution.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a chip-shaped electronic component such as a monolithic ceramic, a chip resistor, and a multiple resistor.

[0002]

[Prior art]

 With the downsizing of electronic devices, electronic components used in the electronic devices are also downsized. For chip-shaped electronic components such as ceramic capacitors, compact and lightweight multilayer ceramic capacitors have been developed. The multilayer ceramic capacitor is, for example, a main body in which an internal electrode layer having a thickness of several μm and a ceramic dielectric layer having a thickness of several 10 μm are alternately laminated and integrated, and an internal electrode layer provided outside the main body. It is mainly composed of external electrodes connected to. The external electrode is generally formed of an electrode material containing a silver-based conductive material, glass frit, and cadmium. Here, cadmium is a component for enhancing the bondability between the external electrode and the dielectric.

[0003]

[Problems to be solved by the device]

 Since the electrode material of the conventional multilayer capacitor contains highly toxic cadmium, there is a risk of environmental pollution. This cadmium-free electrode material has a reduced bonding strength with the ceramic dielectric layer. An object of the present invention is to enhance the bondability between the external electrode and the ceramic member and reduce the risk of environmental pollution.

[0004]

[Means for Solving the Problems]

 In the chip-shaped electronic component according to the present invention, external electrodes are formed on the ends of the chip-shaped ceramic member. The external electrode is made of an electrode material containing a silver-based conductive material, glass frit, and indium.

[0005]

In the chip-shaped electronic component according to the present invention, since the electrode material forming the external electrode contains indium, the bondability with the ceramic member is high. Moreover, since the indium contained in the electrode material has low toxicity, there is little risk of environmental pollution.

[0006]

【Example】

 Referring to FIGS. 1 and 2, a multilayer ceramic capacitor that is a chip-shaped electronic component according to an embodiment of the present invention will be described. In the figure, the multilayer ceramic capacitor 1 is mainly composed of a rectangular parallelepiped main body 2 and a pair of external electrodes 3a and 3b arranged so as to face both ends of the main body 2.

The main body 2 is formed by stacking a large number of green sheets made of a magnetic material such as barium titanate and firing them to integrate them. Inside the main body 2, a large number of internal electrodes 4a and 4b are alternately arranged. The internal electrode 4a is connected to the external electrode 3a arranged on the right side end surface of the main body 2 and is insulated from the external electrode 3b arranged on the left side end surface. On the other hand, the internal electrode 4b is connected to the external electrode 3b and is insulated from the external electrode 3a. The internal electrodes 4a and 4b are arranged in parallel with each other.

The internal electrodes 4a and 4b described above are made of an electrode material containing silver-palladium as a main component. The external electrodes 3a and 3b described above are formed of an electrode material containing a silver-based conductive material, glass frit, and indium. Here, as the silver-based conductive material, silver, a powder of an alloy containing silver as a main component, or a mixture of a powder of silver and a powder of another type of conductive metal is used. Specific examples of such a silver-based conductive material include silver or a silver-palladium alloy.

The glass frit is an inorganic binder component for joining the external electrodes 3 a and 3 b to the main body 2. As the glass frit, for example, borosilicate lead glass is used. Such a glass frit is added in an amount of 0.5 to 20 parts by weight, preferably 9 to 13 parts by weight, based on 100 parts by weight of the above-mentioned silver-based conductive material. Indium contained in the electrode material is a component for enhancing the bondability between the external electrodes 3a and 3b and the internal electrodes 4a and 4b and the main body 2. The indium used here is in the form of powder, and its addition amount is set to 3 parts by weight or less, preferably 0.5 to 2 parts by weight, relative to 100 parts by weight of the above-mentioned silver-based conductive material. It

In the multilayer ceramic capacitor 1, charges are accumulated between the internal electrodes 4a and 4b to generate capacitance. Thereby, the main body 2 functions as a capacitor. The external electrodes 3a and 3b serve as input / output terminals of the capacitor formed by the main body 2. Next, a method of manufacturing the above-mentioned multilayer ceramic capacitor 1 will be described.

First, a mixture of a dielectric magnetic material such as barium titanate, an organic binder and a solvent is kneaded using a mill to prepare a slurry. Then, this slurry is formed into a green sheet having a thickness of about 15 to 30 μm. The green sheet is prepared by using, for example, a blade coater or a roll coater depending on the state of the slurry and the thickness of the green sheet.

Next, a conductive paste for forming the internal electrodes 4a and 4b is applied on the obtained green sheet. The conductive paste used here is the above electrode material to which an organic binder and a solvent have been added and which has been kneaded into a paste. The conductive paste is applied according to a predetermined internal electrode pattern so that the film thickness is about several μm.

Next, the green sheets printed with the conductive paste for the internal electrodes are laminated in a predetermined order. Then, the laminated body of green sheets is fired to form the main body 2. The temperature during baking is preferably set to a temperature at which the contraction states of both the dielectric magnetic material and the conductive paste match. The ends of the internal electrodes 4a or 4b are exposed at both ends of the body 2 obtained by firing.

Next, the external electrodes 3a and 3b are formed on both end surfaces of the obtained main body 2, that is, on the surfaces on which the internal electrodes 4a or 4b are exposed. In forming the external electrodes 3a and 3b, first, the above-mentioned conductive paste is applied to the both end faces to a thickness of about 120 to 170 μm. Here, the conductive paste can be applied by, for example, a dipping method or a transfer method. After applying the conductive paste, the solvent contained therein is volatilized to dry the conductive paste. Furthermore, when the conductive paste is fired, the external electrodes 3a and 3b are formed on the main body 2.

In the multilayer ceramic capacitor 1 thus obtained, when the external electrodes 3a and 3b are formed using a conductive material of simple silver, the nickel plating layer and the Sn-Pb solder are used. A plating layer is formed in this order. [Experimental Example] To 100 parts by weight of the silver-based conductive material, 11 parts by weight of lead borosilicate glass and indium in the proportions shown in Table 1 were added to prepare an electrode material. This electrode material was used to form the multilayer ceramic capacitor of the above-mentioned embodiment, and the external electrode thereof was subjected to a lead tensile test to check the adhesive strength with the end face portion of the main body 2, and the adhesive strength with the surface portion was determined by the bottom. Evaluation was made according to the push-and-stick test. The results are shown in Table 1.

[0016]

[Table 1]

It can be seen from Table 1 that the electrode containing indium has better adhesive strength than the electrode containing no indium. [Other Embodiments] In the above embodiments, the case where the present invention is applied to a monolithic ceramic capacitor has been described. However, a chip in which a resistor film is formed on a ceramic substrate and external electrodes are formed on the ends of the ceramic substrate. The present invention can be similarly applied to resistors and multiple resistors.

[0018]

[Effect of device]

 In the chip-shaped electronic component of the present invention, the external electrodes are formed by using an electrode material containing a silver-based conductive material, glass frit, and indium. Therefore, the external electrodes and the ceramic parts have high bondability and are environmentally friendly. Less risk of contamination.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

[Explanation of symbols]

 1 Multilayer Ceramic Capacitor 2 Main Body 3a, 3b External Electrodes 4a, 4b Internal Electrodes

Claims (1)

[Scope of utility model registration request] 1. A chip-shaped electronic component in which an external electrode is formed at an end of a chip-shaped ceramic member, wherein the external electrode is made of an electrode material containing a silver-based conductive material, glass frit, and indium. Chip-shaped electronic parts characterized by.