JPH0738511B2 - Ceramic electronic components - Google Patents

Description

TECHNICAL FIELD The present invention relates to a ceramic electronic component, and more particularly to a ceramic electronic component incorporating a shield electrode layer.

[Prior art]

FIG. 5 is a sectional view showing a ceramic multilayer substrate as an example of a conventional ceramic electronic component of this type. The ceramic multilayer substrate 1 includes a circuit electrode layer 3 formed in a ceramic layer 2, and the circuit electrode layer 3 is shielded by electrode layers 4 formed near the upper and lower surfaces of the ceramic layer 2. The shield electrode layer 4 is generally formed as a full-face electrode as shown in FIG.

[Problems to be Solved by the Invention]

When the shield electrode layer 4 is formed of the entire surface electrode as shown in FIG. 6, the shield electrode layer 4 divides the ceramic layer 2 into upper and lower parts, and the adhesion between the shield electrode layer 4 and the ceramic layer 2 is poor. The thermal and mechanical strength of the ceramic multilayer substrate 1 is not good. For example, when heat such as soldering for mounting an electronic component is applied to the ceramic multilayer substrate 1, since the coefficient of thermal expansion of the shield electrode layer 4 and the coefficient of thermal expansion of the ceramic layer 2 are different, It may be peeled off or destroyed with the shield electrode layer 4 as a boundary.

In order to improve the drawbacks of the entire shield electrode layer 4 shown in FIG. 6, a shield electrode layer 4'having mesh-shaped shield electrodes shown in FIG. 7 or 8 has been proposed.
However, the shield electrode layer 4'shown in FIGS. 7 and 8 partially includes continuous strip-shaped shield electrodes between both ends of the ceramic layer 2, so that the shield electrode layer 4'is improved to some extent, but it is thermally and mechanically improved. The strength is not yet sufficient.

Therefore, a main object of the present invention is to provide a ceramic electronic component in which the thermal and mechanical strength is not deteriorated even if the shield electrode layer is built in.

[Means for Solving the Problems]

The present invention provides at least a first ceramic green sheet having a circuit electrode formed thereon, two second ceramic green sheets having shield electrodes formed on both sides of the first ceramic green sheet, and a shield electrode. A third ceramic green sheet laminated on the second ceramic green sheet so as to be in direct contact with the second ceramic green sheet, wherein each ceramic green sheet is integrally fired together with the circuit electrode and the shield electrode. It is a ceramic electronic component, characterized in that the island-shaped electrodes are assembled at a predetermined space factor.

[Action]

Since the shield electrode is formed of a large number of island electrodes,
A continuous electrode portion is not formed between both ends, and when integrally fired, the second ceramic green sheet and the third ceramic green sheet (this is the first ceramic green sheet around the island electrode) And) may be integrally coupled through the gap between the island electrodes. Therefore, even if the shield electrode is interposed between the second ceramic green sheet and the third ceramic green sheet, the reduction in thermal and mechanical strength between them is minimized.

〔The invention's effect〕

According to the present invention, since the reduction in strength between the second ceramic green sheet and the third ceramic green sheet is suppressed, the problem of layer peeling does not occur.

The above-mentioned objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of the embodiments with reference to the drawings.

〔Example〕

FIG. 1 is an exploded perspective view showing an embodiment of the present invention.
Although the following embodiments will be described by taking a ceramic multilayer substrate as an example, it is pointed out in advance that the present invention is not limited thereto and can be applied to any ceramic electronic component including a shield electrode layer.

The ceramic multilayer substrate 10 of this embodiment includes eight ceramic layers 12 to 26. These ceramic layers 12 to 26 are laminated by pressure bonding ceramic green sheets formed in a size of, for example, 10 × 20 mm by a doctor blade method. , Formed by firing it. However, in the fired state, the respective ceramic layers 12 to 26 are integrated as shown in FIG. 5, but here, for convenience of illustration, the respective ceramic layers 12 to 26 are integrated.
It is shown separately for every 12 to 26.

On the upper surfaces of the ceramic layers 14 and 24, as shown in the plan view of FIG. 2, square island electrodes 28 are regularly distributed over the entire surface at regular intervals. The size of each island electrode is, for example, about 2 × 2 mm to 3 × 3 mm. The space factor of these island electrodes 28 is set to about 70%. This is because if the space factor is too large, the stress due to the thermal contraction or the difference in thermal expansion coefficient between the island electrode 28 and the ceramic layers 12 to 26 becomes large. However, the space factor is
It may be appropriately set in consideration of the strength and the required shield performance.

Then, such an island-shaped electrode 28 is formed on the ceramic green sheets forming the ceramic layers 14 and 24 by, for example, screen printing, and then integrally fired together with the ceramic green sheets.

As shown in FIG. 2, the island electrodes 28 are regularly arranged, but not at the ends of the ceramic layers 14 or 24. This is because the end of the island electrode 28 is the ceramic layer 14 or
When it is arranged so as to be exposed at the end of 24, the ceramic layer 12 laminated on the ceramic layer 14 or 24 at that part.
Alternatively, 22 is easily peeled off. Therefore,
In this embodiment, the "margin" of the ceramic layer 14 or 24 is formed around the densely arranged island electrodes 28.

On the upper surfaces of the other ceramic layers 18 and 20, circuit electrodes 30 for built-in capacitors and inductances are formed, respectively. Similar to the island-shaped electrode 28, the circuit electrode 30 is also formed on the ceramic green sheets forming the ceramic layers 18 and 20 by screen printing and integrally fired.

Although not shown in FIG. 1, the ceramic layers 12 to 26 are provided with via holes or through holes for connecting to the circuit electrodes 30, for example, if necessary.

In such a ceramic multi-layer substrate 10, the island-shaped electrodes 28 are densely arranged on the ceramic layers 14 and 24 as electrode layers by sealing, so that the ceramic layers are arranged around each island-shaped electrode 28.
14 and 24 will be exposed. As such, the exposed portions of the ceramic layers 14 and 24 can be firmly and integrally crimped to the ceramic layers 12 and 22 thereon.
"Peeling off under pressure" is unlikely to occur in the state of a green sheet, and thus a strong integral connection is possible.

When it is necessary to connect the shield electrode layer to an external earth, as shown in FIG.
It suffices to connect the spaces with a thin connection electrode 32 and connect it to the external earth. In this case, the connection electrodes 32 are randomly arranged so as not to be continuous in the horizontal direction or the vertical direction. That is, the connection position of the connection electrode 32 is selected so that the continuous portion of the island electrode 28 and the connection electrode 32 is dispersed as much as possible. If such a continuous portion becomes long, peeling is likely to occur as in the case shown in FIGS. 7 and 8.

Each island electrode may be formed as, for example, a circular island electrode 28 'as shown in FIG. 4, or may have any other shape.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of the present invention. FIG. 2 is a plan view showing the arrangement of the island electrodes of the embodiment shown in FIG. FIG. 3 is a plan view showing the arrangement of island-shaped electrodes according to another embodiment of the present invention. FIG. 4 is a plan view showing a modified example of the shape of the island electrode. FIG. 5 is a sectional view showing a conventional multilayer substrate. 6 to 8 are plan views showing the shapes of conventional island electrodes. In the figure, 10 is a ceramic multilayer substrate, 12 to 26 are ceramic layers, 28 and 28 'are island electrodes, 30 is a circuit electrode, and 32 is a connection electrode.

Claims (1)

[Claims] 1. A first ceramic green sheet having at least a circuit electrode formed thereon, and two second ceramic green sheets having shield electrodes formed on both sides of the first ceramic green sheet, respectively. A third ceramic green sheet laminated on the second ceramic green sheet so as to be in direct contact with the shield electrode, and each ceramic green sheet is integrally fired together with the circuit electrode and the shield electrode. The ceramic electronic component according to claim 1, wherein the shield electrode is formed by assembling a large number of island-shaped electrodes at a predetermined space factor.