JPH10275738A - 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 an blank area between the mounting faces of the U-shaped caps and the underside of the electronic component element. 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 blank area 6 is formed between the underside of the capacitor element 1 assembly and the mounting faces 5 of the caps 4. In advance, cream solder is applied to the inside surface of the upper part of the caps 4 for housing the capacitor element 1 assembly 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 a side surface of the plate in order to mount them on a circuit board. There is a configuration in which a cap is fitted and the lower surface 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 for peeling acts on the connection between the cap 14 and the cream solder of the capacitor element 11, 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,
Or, 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 mounting surface of the U-shaped cap and the electronic component It is characterized by having a blank portion between the device and the lower surface of the device.

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 is caused by the bending of the blank portion provided between the mounting surface of the cap and the lower surface of the electronic component element. Since it can be absorbed, there is an effect that the warpage of the cap does not act on the connection between the cap and the external electrode of the electronic component element. Therefore, since the connection incompleteness due to the peeling of the connection portion does not occur,
A predetermined capacitance can be stably obtained.

According to a second aspect of the present invention, in the first aspect of the present invention, the blank portion has the same size as the width of the cap or is formed narrower than the width of the cap. .

In the electronic component according to the second aspect, the size and shape of the blank portion for absorbing the warp of the U-shaped cap caused by the thermal expansion of the circuit board are the same as the width of the cap, or Because it is narrower than the width of the cap,
When the thickness of the cap is set to be thin, the warpage of the cap can be absorbed by the bending of the cap itself even if the width is the same as the width of the cap. be able to. The absorption of the warpage of the cap is to absorb the warpage of the cap due to the thermal expansion of the circuit board by the bending of the blank portion provided on the cap itself. Therefore, when the thickness is set so that the cap bends, the dimension of the blank portion may be the same as the width of the cap, and when the thickness of the cap is thick, the width is set so as to cause the bending by reducing the width. Is what you do.

[0010]

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 to both side surfaces of the two capacitor element groups bonded by this bonding. In this fitting, since the upper part of the cap 4 is fitted, a space portion 6 is formed between the lower surface of the group of capacitor elements 1 and the mounting surface 5 of the cap 4.

Then, cream solder is applied in advance to the upper inner surface of the cap 4 for accommodating one group of capacitor elements. Therefore, by fitting the caps 4 on both side surfaces of the group of capacitor elements 1 as described above, the cream solder applied to the upper inner surface thereof comes into contact with the external electrodes 2 of the capacitor elements 1.

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

The ceramic capacitor thus manufactured is surface-mounted on the electronic circuit board 7 by soldering. By this mounting, even if the substrate 7 thermally expands and the cap 4 warps in the outer surface direction, the warpage is absorbed by the bending of the blank portion 6 and the external electrodes 2 of the group of capacitor elements 1 connected to the top of the cap 4 And does not act on the connection between the cap 4 and the inner surface of the cap 4. Therefore, the connection of the group of capacitor elements 1 mounted on the circuit board 7 does not become incomplete,
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.
(1 mm × height 6.0 mm × width 5.0 mm), the cream solder previously applied to the upper inner surface of the cap 4 was dried and heated, and soldered. At this time, a blank portion 6 is formed between the lower surface of the group of capacitor elements 1 and the mounting surface 5 of the cap 4.

The capacitor 500 manufactured as described above
The test pieces were surface-mounted on a circuit board 7 as shown in FIG. As a result, there was no crack between the external electrode 2 and the cap 4 in the embodiment, but 20 cracks were found in the conventional example shown in FIG.

In the above-described embodiment, the configuration in which the blank portion 6 is simply provided on the mounting surface 5 of the cap 4 has been described. However, when the material thickness of the cap 4 is large, the width of the blank portion 6 is set to be narrow. Thus, the same effect can be obtained even if bending occurs. As shown in FIG. 3, the width of the blank 6 may be reduced to a semicircular blank 8 on both sides, or may be reduced to a semi-polygon or rectangle.

Further, in the embodiment, the case where two ceramic capacitors are connected as the electronic components has been described. However, when one or two or more electronic component elements which are a varistor, a resistor, or a combination thereof are used. However, a similar effect can be obtained.

[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 perspective 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 ... Cap mounting surface 6 ... Blank part 7 ... Electronic circuit board 8 ... Semicircular blank part

Claims (2)

[Claims] An electronic component comprising one electronic component element or 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. An electronic component having a blank portion between a mounting surface of the U-shaped cap and a lower surface of the electronic component element. 2. The electronic component according to claim 1, wherein the blank portion is formed to have the same size as the width of the cap or smaller than the width of the cap.