Electricity: electrical systems and devices – Electrostatic capacitors – Fixed capacitor
Reexamination Certificate
1999-06-22
2001-01-30
Kincaid, Kristine (Department: 2831)
Electricity: electrical systems and devices
Electrostatic capacitors
Fixed capacitor
C361S306100, C361S308100
Reexamination Certificate
active
06181544
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates to a ceramic electronic component. Especially, for example, it relates to the structure of a terminal part of the ceramic electronic component which includes a chip type ceramic electronic component main body such as a laminated ceramic capacitor.
2. Prior Art
For example, a case where a ceramic electronic component such as a laminated ceramic capacitor is mounted on a wiring board including aluminum which has superior heat-dissipation property is considered. Since the difference of the thermal expansion coefficient between the aluminum substrate and the ceramic electronic component is large, in a heat cycle which repeats the raise and descent of temperature, there is a problem to generate the destruction of a ceramic electronic component, etc. easily. Especially, in the case of the laminated ceramic capacitor using Pb-system ceramic dielectric having high capacitance, which is required in the power-supply marketplace, since the resistance to breakage thereof is comparatively low, it is easier to generate this problem.
In order to solve an above-mentioned problem, the ceramic electronic component
1
of the structure shown in
FIG. 4
is proposed, and offered for practical use.
The ceramic electronic component
1
shown in
FIG. 4
includes two chip type ceramic electronic component main bodies
2
for forming a laminated ceramic capacitor, for example. A terminal electrode
3
is formed on both ends of each electronic-component main body
2
. These electronic-component main bodies
2
are piled up vertically, and are mutually joined through the adhesive agent (not illustrated).
A terminal member
4
is attached in common to each terminal electrode
3
of two electronic component main bodies
2
. More specifically, the terminal member
4
includes a metal plate. The terminal member
4
is connected to each terminal electrode
3
at the base of the terminal member
4
by using solder a conductive junction material such as an electro-conductive glue. Moreover, a portion spread out from the base of the terminal member
4
is bent to the base. By that, a connecting terminal part
6
to a wiring board
5
shown with a imaginary line is provided. This connecting terminal part
6
is positioned opposing to a side surface
7
of the electronic component main body
2
positioned downwardly, said side surface
7
facing downwardly.
Such a ceramic electronic component
1
is mounted by soldering the connecting terminal part
6
of each terminal member
4
to the wiring board
5
by solder
8
.
PROBLEM TO BE SOLVED
However, the objective of attaching the terminal member
4
is to absorb stress generated by a deformation or a movement of these terminal member
4
based on expansion and contraction of the wiring board
5
by the temperature change. Also, the objective of attaching the terminal member
4
is to prevent that the electronic component main body
2
is destroyed by the heat shock. Nevertheless, the solder
8
provided for mounting may show the behavior contrary to such an objective.
Namely, not only that the solder
8
is provided on a surface facing outside of the terminal member
4
, but also that the solder
8
is provided on a surface facing inside of the terminal member
4
, that is a portion spread from the base of the terminal member
4
. The latter solder
8
may reach to the electronic component main body
2
.
Thus, as shown in
FIG. 4
, the solder
8
connects the terminal electrode
3
and the wiring board
5
directly, which prevents the terminal member
4
from deforming and moving in order to absorb the stress generated based on the expansion and contraction of the wiring board
5
by the temperature change. Therefore, the objective of providing the terminal member
4
for preventing the electronic component main body
2
from breaking by the thermal shock cannot be attained preferably.
Moreover, solder
8
provides a heat shock to the electronic component main body
2
. By this, the electronic component main body
2
may be destroyed. Or even if it does not result in the destruction of the electronic component main body
2
at that time, the stress which may bring the destruction later by the temperature change may be provided to the electronic component main body
2
.
Especially, these problems are more serious, when the electronic component main body
2
having comparatively low resistance to breakage such as the laminated ceramic capacitor using Pb ceramic dielectric is provided, or in the case where the aluminum substrate with a large thermal expansion coefficient is used as a wiring board
5
.
In order to solve the above mentioned problem, it is effective to lengthen the part spread out from the base in the terminal member
4
, and to release the connecting terminal part
6
from the side surface
7
of the electronic component main body
2
sufficiently. However, when adopting such solution means, it is necessary to control the length of the part spread out from the base of the terminal member
4
so that there is no variation. So, there is such a problem that the locating mechanism for performing the appropriate alignment between the terminal member
4
and the electronic component main body
2
, etc. may be complicated.
Consequently, the objective of this invention is to offer the ceramic electronic component which can solve the above mentioned problem.
SUMMARY OF THE INVENTION
SOLUTION TO THE PROBLEM
This invention is related to a ceramic electronic component which includes a chip-type ceramic electronic component main body which has two opposing end faces and a side surface which couples between the two end faces, wherein a terminal electrode is provided on said each end face; a terminal member including a metal plate, wherein a base of the metal plate is connected to said each terminal electrode and a portion spread out from said base is bent to said base in a direction opposing to said side surface of said ceramic electronic component main body to provide a connecting terminal part for connecting with a wiring board. In order to solve the above mentioned problem, the present invention is characterized in that a projection which projects toward said surface of said ceramic electronic component main body is provided with said connection terminal part, said projection is formed by processing said metal plate.
Preferably in this invention, the projection is formed by performing the swelling process of the metal plate.
Moreover, preferably in this invention, the base of the terminal member is bent in a U-shape. A solder affinity surface which gets accustomed to solder is formed on the surface which faces outside in the bending condition of this terminal member. And, a solder non-affinity surface which does not get accustomed to solder is formed on the surface which faces inside in the bending condition of the terminal member.
Preferably in this invention, the projection may be provided so as to contact with the side surface of the ceramic electronic component.
Further, when the terminal electrode has a side surface elongated portion which extends to a part of the side surface of the ceramic electronic component in this invention, as described above, the base of the terminal member is bent in a U-shape. And a solder affinity surface is formed on the surface facing outside in the bending condition of the terminal member, and a solder non-affinity surface is formed on the surface facing inside in the bending condition of the terminal member. In such a case, the projection may be positioned so that it projects to the side surface elongated portion of the terminal member.
Further, as described above, when the projection is positioned so as to project to the side surface elongated portion of the terminal electrode, this projection may be contacted to the side surface elongated portion.
Moreover, the ceramic electronic component based on this invention includes a plurality of ceramic electronic component main bodies. Terminal members may have the structure to be attached in common to each termi
Nakagawa Takuji
Nakamura Akira
Takagi Yoshikazu
Takahashi Masaru
Ha Nguyen
Kincaid Kristine
Murata Manufacturing Co. Ltd.
Ostrolenk Faber Gerb & Soffen, LLP
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