JPS6141224Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention aims to provide a multilayer ceramic capacitor that is easy to manufacture and has no variation in capacitance value.

A conventional multilayer ceramic capacitor consists of a plurality of porcelain sheets 10 as shown in FIG. They were stacked so that they were facing each other. In this case, the electrodes 20 applied on the porcelain sheet 10 are printed and coated exclusively by silk screen or the like, but this printing often causes misalignment or changes in the printed area due to printing unevenness. When stacking these, a predetermined electrode facing area could not be obtained, resulting in large variations in capacitance value. Furthermore, when stacking the porcelain sheets 10, it is difficult to polymerize them accurately, making it difficult to obtain a desired capacitance value. Currently, the process of stacking the porcelain sheets 10 is mostly done manually, so this misalignment is unavoidable, requiring considerable skill on the part of the workers, and requiring a lot of effort to manufacture. It had drawbacks.

The present invention was developed to eliminate the above-mentioned drawbacks, and even if there are misalignments or variations in the position and area of the electrodes, or even if there are misalignments in the stacking of porcelain sheets, the desired capacity can always be achieved. The present invention aims to provide a multilayer ceramic capacitor that provides the following properties.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a plan view of the porcelain sheet 1 provided with one electrode 2, and FIG. 3 is a plan view of the porcelain sheet 3 provided with the other electrode 4.

The porcelain sheet 1 in FIG. 2 has capacitive electrodes 2a provided at predetermined intervals from each edge.
A lead-out electrode 2b provided near one end of the porcelain sheet 1, and a connecting electrode 2c provided to connect both electrodes 2a and 2b are integrally formed.
For example, it is provided by a printing method. In this case, the connection electrode 2c is located at the center of one end of the capacitor electrode 2a and has a width that is half the width _l1 of the capacitor electrode 2a. That is, they are provided at equal lengths l ₂ and l ₂ from both sides of the capacitive electrode 2a, and have a width of 2l ₂ .

The porcelain sheet 3 in FIG. 3 has capacitive electrodes 4a provided at predetermined intervals from each edge, and a lead-out electrode 4a provided near one end of the porcelain sheet 3, similar to the one shown in the second drawing. An electrode 4b and a connecting electrode 4c provided to connect both electrodes 4a and 4b are integrally provided. In this case, the width _l3 of the capacitive electrode 4a is made larger than the width l1 of the capacitive electrode 2a of the ceramic sheet ₁ so that the capacitive electrode 2a does not protrude in the width direction when stacked. Further, the width of the connecting electrode 4c connecting the capacitor electrode 4a and the lead-out electrode 4b is the same as that of the connecting electrode 2.
It is provided with the same width as the width 2l ₂ of c. And the length h of the capacitive electrodes 2a and 4a of both porcelain sheets 1 and 3
are given equally, and are selected to have a length such that when they are properly overlapped as described later, both tips thereof are located at the center of each of the connecting electrodes 2c, 4c.

The present invention provides a porcelain sheet 1 formed in this way.
and 3, alternately, a plurality of sheets, and the lead-out electrode 2
b and 4b are stacked so that they are facing each other and fired together, and an electrode for external connection (not shown) is formed.
A multilayer capacitor is obtained by baking the

Next, the usefulness of the multilayer ceramic capacitor of the present invention will be explained in detail.

Figures 4 to 6 clearly show the positional relationship of the electrodes 2 and 4 when the porcelain sheets 1 and 3 shown in Figures 2 and 3 are overlapped, and the one shown in Figure 4 is a FIGS. 5 and 6 show a state in which the porcelain sheets 1 are properly stacked, and a state in which one of the porcelain sheets 1 is misaligned in both the width direction and the length direction, respectively.

In FIG. 4, a capacitance is obtained at a portion where both capacitance electrodes 2a, 4a and connection electrodes 2c, 4c overlap with each other, and this becomes a predetermined capacitance.
In other words, the area S where the capacitance is formed in this case is S=h ₁ l ₁ +x2l ₂ +x2l ₂ =h ₁ l ₁ +4xl ₂ . Note that h ₁ is the overlapping length of the capacitive electrodes 2a and 4a, and x is the overlapping width of the connecting electrodes 2c and 4c and the capacitive electrodes 2a and 4a, which are set equally on the left and right sides.

In Figure 5, the porcelain sheet 1 is misaligned in both the width direction (upward direction) and the length direction (leftward direction).The misalignment in the width direction is due to the fact that one capacitor electrode 4a is formed wide. , the capacitance will not change unless the other capacitor electrode 2a protrudes. On the other hand, the difference in the length direction is caused by the connection electrodes 4 that should overlap.
c and the capacitive electrode 2a no longer overlap,
The capacitance of the part _c1 decreases, but on the contrary, the capacitance of the capacitive electrode 2
The area of a facing the capacitive electrode 4a is substantially increased by the portions c ₂ and c ₂ , and the capacitance is also increased. In this case, the width 2l ₂ of the connecting electrode 4c and the length on both sides of the capacitive electrode 2a
Since the size is the same as the sum of l ₂ and l ₂ , increases and decreases in capacity cancel each other out, and the overall capacity does not change at all compared to the one shown in Figure 4. That is, in the case shown in Figure 5, if the other electrode 2 is shifted to the left by 5 mm, the area S forming the entire capacitance is S = (h ₁ + 5) l ₁ + (x - 5) 2 l ₂ +(x-5)2l ₂ = h ₁ l ₁ +5l ₁ +2xl ₂ -10l ₂ +2xl ₂ -10l ₂ , and since l ₁ = 4l ₂ , S = 4h ₁ l ₂ +20l ₂ +2xl ₂ -10l ₂ +2xl ₂ −10l ₂ = 4h ₁ l ₂ + 4xl ₂ = h ₁ l ₁ + 4xl ₂ , and it can be seen that the area is exactly the same as the one in Figure 4.

Figure 6 shows the porcelain sheet 1 shifted in the width direction (downward direction) and length direction (rightward direction);
Although this is the opposite of the one in the figure, the capacitance does not change for the same reason. In other words, the capacity of the part C ₂ that polymerizes due to misalignment increases,
This is offset by the combined capacity reduction of the portions C ₄ and C ₄ that are no longer substantially polymerized.

It goes without saying that the above description and drawings are examples for explaining the present invention, and changes may be made without departing from the spirit of the present invention, such as the shape and area of the lead-out electrode, etc. The method of derivation may be changed as necessary.

As is clear from the above explanation, in the present invention, even if misalignment occurs when applying electrodes or stacking porcelain sheets, the obtained capacity will not change at all.
A stable multilayer ceramic capacitor with a predetermined capacity can always be obtained. Furthermore, since the present invention is not affected by misalignment at all, it is not only easy to manufacture, but also has great practical effects, such as not requiring much skill on the part of the operator.

[Brief explanation of the drawing]

Figure 1 is a plan view of a ceramic sheet used in a conventional multilayer ceramic capacitor, Figures 2 and 3 are plan views showing examples of the shape of the ceramic sheet used in the multilayer ceramic capacitor of the present invention, and Figures 4 to 6. are shown in Figures 2 and 3.
Both are plan views showing a state in which the porcelain sheets shown in the figures are stacked one on top of the other. 1, 3...Porcelain sheet, 2a, 4a...Capacitive electrode, 2b, 4b...Leading electrode, 2c, 4c...Connection electrode.

Claims (1)

[Claims for Utility Model Registration] A capacitor electrode provided at a predetermined interval from the periphery, a lead-out electrode provided near one end, and a lead-out electrode provided to connect the lead-out electrode and the capacitor electrode. a plurality of porcelain sheets each having a connecting electrode formed of a plurality of porcelain sheets, the lead-out electrodes being alternately positioned facing each other, and external connection electrodes provided on the lead-out end faces of the lead-out electrodes. A ceramic capacitor, wherein the width of one of the opposing capacitive electrodes is larger than the width of the other capacitive electrode, the width of the connecting electrode is half the width of the narrower capacitive electrode, and the length of the opposing capacitive electrode is A multilayer ceramic capacitor characterized in that the capacitors are identical to each other, and their tips are located in the area of the other connecting electrode in a stacked state.