JPH10275740A - Electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To absorb stripping force exerted on the connection of caps and electronic component elements with external electrodes, and eliminate incomplete connection, by forming thin buffering portions in the lower part of the U-shaped caps with the electronic component element fit between them. SOLUTION: An external electrode 2 is formed on the sides of two ceramic capacitors 1, respectively, and the ceramic capacitors 1 are bonded together using adhesive 3 composed of epoxy resin. A U-shaped cap 4 is fit onto both the sides of the assembly of the two bonded capacitor elements 1, and a thin buffering portion 5 which is recessed from both sides of the thickness, is formed in the lower part of each cap 4. In advance, cream solder is applied to the inside surface of the upper part of the buffering portions 5 so that the cream solder is brought into contact with the external electrodes 2 of the capacitor elements 1. The cream solder is dried and heated, and the external electrodes 2 are thereby connected to the caps 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to electronic components such as ceramic capacitors and varistors.

[0002]

2. Description of the Related Art Electronic components mounted on an electronic circuit board are, for example, ceramic capacitors and varistors. These electronic components include a single plate-shaped component or a component in which a plurality of plate-shaped components are stacked and used, and a metal plate is mounted on the plate-shaped side surface in order to mount them on a circuit board. There is a configuration in which a cap is fitted and a lower portion of the cap is soldered to a circuit board. FIG. 4 shows a configuration example of a conventionally used ceramic capacitor with a cap. That is, external electrodes 12 are formed on both side surfaces of the ceramic capacitor element 11, and an adhesive 13 made of epoxy resin is applied to the flat and bottom surfaces of the capacitor element 11, and two of them are bonded together in a plane. The cap 14 in which cream solder was applied on the inner surface in advance was fitted to the 11th group, and the external electrode 12 of the capacitor element 11 was connected to the cap 14 by drying and heating.

However, in such a ceramic capacitor with a cap, when the capacitor is mounted on the circuit board 15 by soldering, the cap 14 warps to the outer surface side due to expansion due to thermal expansion of the circuit board 15 itself.
A force acting to peel off the connection between the cap 14 and the cream solder of the capacitor element 11 acts, and the cap 14
There is a problem that a crack such as a crack is generated between the capacitor and the external electrode 12 of the capacitor element 11, so that the connection is incomplete and a predetermined capacitance cannot be obtained.

[0004]

As described above, in a conventional electronic component with a cap, when the electronic component is mounted on the circuit board, the thermal expansion of the circuit board causes the cap and the external electrode of the electronic component element to be in contact with each other. Cracks occur between the layers, and a predetermined capacitance cannot be obtained.

[0005] The present invention solves the above disadvantages.
By forming an expansion absorbing mechanism on the cap that fits into the electronic component element, it absorbs the peeling force applied to the connection between the cap and the external electrode of the electronic component element, eliminating incomplete connection and providing a highly reliable electronic component. It is intended to provide.

[0006]

In order to solve the above-mentioned problems, the invention according to claim 1 provides a single electronic component element,
Alternatively, in an electronic component comprising an electronic component element group in which two or more electronic component elements are bonded, and a U-shaped cap fitted to an external electrode of the electronic component element, the U-shaped cap fits the electronic component element. It is characterized in that a thin buffer portion is formed in the lower part.

In the electronic component according to the first aspect,
The warp of the U-shaped cap caused by the thermal expansion of the circuit board when the electronic component is surface-mounted on the circuit board can be absorbed by the bending of the thin buffer portion formed on the cap, so that the warpage of the cap is reduced. This has the effect of not acting on the connection between the cap and the external electrode of the electronic component element. Therefore, since the connection portion does not cause connection incompleteness due to peeling, a predetermined capacitance can be stably obtained.

The shape of these thin buffer portions may be a shape in which only one side of the thickness of the cap is depressed, or a shape in which a thin portion is formed in the center by being depressed from both surfaces.

The invention according to a second aspect is characterized in that one or two or more buffer portions in the first aspect are formed vertically.

The above-mentioned buffering portion is for absorbing the warpage of the cap due to the thermal expansion of the circuit board. Therefore, one or more upper and lower ones are provided in consideration of the degree of the warpage of the cap. It can be selected as appropriate.

[0011]

An embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the two ceramic capacitor elements 1 have external electrodes 2 formed on the side surfaces thereof, and are bonded with an adhesive 3 made of epoxy resin. The U-shaped cap 4 shown in FIG. 2 was fitted into two groups of the capacitor elements 1 bonded by this bonding from both side surfaces thereof. The cap 4 has a buffer portion 5 formed in a lower portion thereof, which is recessed from both sides of the thickness, and is made thinner. The group of capacitor elements 1 is fitted and accommodated so as to be located on the upper portion of the buffer portion 5. A cream solder is applied to the upper inner surface of the buffer section 5 in advance. Therefore, by fitting the caps 4 on both side surfaces of the group of capacitor elements 1 as described above, the cream solder applied on the upper inner surface of the buffer 5 comes into contact with the external electrodes 2 of the capacitor elements 1.

As described above, the group of capacitor elements 1 with the caps 4 fitted on both sides are dried and heated to melt the cream solder, and the external electrodes 2 are connected to the caps 4.

The ceramic capacitor thus manufactured is surface-mounted on the electronic circuit board 6 by soldering. By this mounting, even if the substrate 6 thermally expands and the cap 4 warps in the outer surface direction, the warpage is absorbed by the bending of the thin buffer portion 5 and the capacitor element 1 group connected to the upper portion of the buffer portion 5 It does not act on the connection between the external electrode 2 and the inner surface of the cap 4. Therefore, the connection of the group of capacitor elements 1 mounted on the circuit board 6 does not become incomplete, and the effect that the capacitance does not change can be obtained.

[0014]

[Example] thickness 1.5 mm x width 5.7 mm x depth 5.0
Two ceramic capacitor elements 1 were bonded to each other.
It was housed in the upper part of a thin buffer part 5 (0.07 mm in thickness) having a size of 1 mm × height 5.0 mm × depth 5.0 mm, and solder cream was applied by drying and heating the previously applied cream solder. FIG. 1 shows 500 capacitors thus manufactured.
Surface mounted on a circuit board 6 as shown in FIG.
15 min → 10 min.
Repeated 00 times. As a result, the external electrode 2 and the cap 4
There was no crack in the example in which cracks were generated between them, but 20 cracks were seen in the conventional example shown in FIG.

In the above embodiment, the buffer portion 5 has been described as having a shape in which the thickness of the cap 4 is recessed from both sides to make it thinner. However, as shown in FIG. Similar effects can be obtained.

It is also within the scope of the present invention to appropriately select the number of buffer portions, such as providing one or two or more buffer portions in consideration of the degree of warpage of the cap.

Furthermore, in the embodiment, the case where a ceramic capacitor is used as an electronic component has been described. However, a similar effect can be obtained even when one or two or more electronic component elements that are a varistor, a resistor, or a combination thereof are used. Obtainable.

[0018]

As described above, the electronic component according to the present invention has an excellent feature that does not cause cracks at the connection between the external electrode of the electronic component element and the cap. Therefore, a highly reliable electronic component having stable characteristics can be provided.

[Brief description of the drawings]

FIG. 1 is a front view showing a state where an electronic component according to the present invention is mounted on a circuit board.

FIG. 2 is a front view showing an embodiment of the cap according to the present invention.

FIG. 3 is a front view showing another embodiment of the cap according to the present invention.

FIG. 4 is a front view showing a state in which an electronic component according to a conventional example is mounted on a circuit board.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Capacitor element 2 ... External electrode 3 ... Adhesive 4 ... Cap 5 ... Buffer part

Claims (2)

[Claims] An electronic component comprising one electronic component element or an electronic component element group to which two or more electronic component elements are bonded, and a U-shaped cap fitted to an external electrode of the electronic component element, An electronic component, wherein the U-shaped cap has a thin buffer portion formed at a lower portion where the electronic component element is fitted. 2. The electronic component according to claim 1, wherein one or two or more buffer portions are formed vertically.