JPS5950596A - Chip type electronic part and method of producing same - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] It is about law.

Conventionally, there are chip-shaped electronic components such as chip capacitors, chip resistors, chip inductors, LC composite chips, and RC composite chips that are used as electronic components in various electronic devices.
Generally, these chip-shaped electronic components, as schematically shown in FIG. 1 of the accompanying drawings, have an insulating substrate 1 made of ceramic or the like having a target electric circuit element such as a capacitor or an inductor inside or on its surface, and at both ends thereof. It has a structure in which external terminal electrodes 2 such as a silver layer are provided on both ends of the electric circuit element so as to be electrically connected to each other. When such a chip-shaped electronic component is used as an electronic component of an electronic device, an external terminal electrode 2 is soldered between circuit conductors 4A and 4B on a printed circuit board 3, as shown in FIG. As a result, the circuit conductors 4A and 4B are electrically connected and fixed on the printed circuit board 3. The solder applied between the external terminal electrode 2 and the circuit conductors 4A and 4B is generally in a state as shown by reference numeral 5 in FIG. It adheres over roughly equal surface areas of the circuit conductors 4A and 4B. Therefore, the larger the area of the vertical end surface of the external terminal electrode 2, the larger the area between the external terminal electrode 2 and the circuit conductor 4A.
The amount of solder adhering to 4B increases. In a structure in which external terminal electrodes are formed over the entirety of both end faces, such as in conventional chip-shaped electronic components, if the electronic component is thick, it is difficult to solder as described above when attaching it to a printed circuit board. If the amount of solder is too large, when an external deforming force such as a bending force is applied to the printed circuit board, the soldered part is likely to crack or damage the system. Problems such as poor connections often occurred.

An object of the present invention is to provide a chip-shaped electronic component that can solve these conventional problems and can be firmly attached to a printed circuit board or the like at all times.
Another object of the present invention is to provide a method for manufacturing such a chip-shaped electronic component.

The chip-shaped electronic component according to the present invention is characterized in that the upper part of the external terminal electrode is formed of an electrode material that is difficult to solder.

The method for manufacturing a chip-shaped electronic component according to the present invention includes applying a layer of a first electrode material that is difficult to solder to the entire end surface of an insulating base of a chip-shaped electronic component, and further adding It is characterized in that the external terminal electrode is formed on the end surface by applying the third electrode material, which is easy to solder, in a layered manner so as to cover the lower part.

Next, the present invention will be described in more detail with regard to embodiments of the present invention based on FIGS. 3, 4, and S of the accompanying drawings.

FIG. 3 schematically shows a chip-shaped electronic component as an embodiment of the present invention in a perspective view. The ceramic substrate 1 has external terminal electrodes 20 at both ends thereof.

The upper half 21 of the external terminal electrode 20 is made of an electrode material that is difficult to solder, and the lower half 22 is made of an electrode material that is easily soldered.

FIGS. 4(A) and 4(B) are diagrams for explaining an embodiment of the method for manufacturing a chip-shaped electronic component as shown in FIG. 3 according to the present invention.

In order to manufacture chip-shaped electronic components as shown in Figure 3,
First, as shown in the schematic cross-sectional view in FIG. 1 electrode material layer 21 is formed.

The first electrode material is preferably, for example, silver to which 15 parts of glass such as lead borosilicate glass is added. In this case, if the amount of added glass is too large, the electrical contact with the terminals of electric circuit elements such as capacitors in the ceramic substrate 1 will be poor, so the amount u of added glass is preferably 70 to 20%. be. It is preferable to use silver paste as the main component of this first electrode material in the case of a coil (inductor) chip, and in the case of a capacitor chip, it is preferable to use a palladium paste alone or with silver.

It is preferable that the main component is an alloy hardstone with . In the first electrode material, the addition of glass to the silver paste or the like has the purpose of increasing the adhesion to the end surface of the ceramic substrate 1, and the amount added may be appropriately selected from this point of view as well.

Next, as shown in the schematic cross-sectional view in FIG. 9 (81), the first
The a-th electrode material layer 22 is formed by applying the a-th electrode material, which is easy to solder, by a method such as plating so as to cover the lower half of the electrode material layer 21.

The material for the first electrode is preferably, for example, silver yeast to which 7.5% or less of glass is added.

Since the chip-shaped electronic component of the present invention has the above-described structure, when the external terminal electrodes 20 are soldered to the circuit conductors 4A and 4B of the printed circuit board 3, as shown in FIG. Since solder does not stick to the electrode material layer 21 formed of an electrode material that is difficult to solder, a very small amount of solder is used to connect the circuit conductor 4A as shown by reference number 5A.
, 4B and the external terminal electrode 20 are attached at 7./da. Such a small amount of no/da part 5A
Even if a bending force or the like is applied to the printed circuit board 3, it can stretch sufficiently in response to the bending force, so there is no risk of cracking or the like occurring in the solder part, and the connection between the circuit conductor and the external terminal electrode is eliminated. is considered to be stronger.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view showing an example of a conventional chip-shaped electronic component, FIG. 2 is a diagram showing the chip-shaped electronic component of FIG. 1 mounted on a printed circuit board, and FIG. FIG. 9 is a schematic perspective view of a chip-shaped electronic component as an example (
A) and (B) are schematic cross-sectional views for explaining one embodiment of the method for manufacturing a chip-shaped electronic component according to the present invention, and FIG. S is an example of the chip-shaped electronic component shown in FIG. is a diagram showing a fixed state. 1... Ceramic substrate, 3... Printed circuit board, 4
A, 4B...Circuit conductor, 5A...Solder part, 20.
...External terminal electrode, 21... Electrode material layer that does not easily adhere to solder, 22... Electrode material layer that easily adheres to solder. t

Claims (3)

[Claims] (1) A chip-shaped electronic component having an external terminal electrode on its end face, characterized in that the upper part of the external terminal electrode is formed of an electrode material that is difficult to solder. (2) In a method for manufacturing a chip-shaped electronic component, a first electrode material that is difficult to solder is applied in a layer over the entire end surface of an insulating base of the chip-shaped electronic component, and further
A method for manufacturing a chip-shaped electronic component, characterized in that an external terminal electrode is formed on an end surface by layering a second electrode material that is easy to solder so as to cover the lower part of the second electrode material layer. . (3) The first electrode material is made by adding glass to silver paste in an amount of 70 to 2θ, and the second electrode material is made by adding glass to silver paste in an amount of 7° or less. A method for manufacturing a chip-shaped electronic component according to claim (2).