JPH05109584A - Trimming laminated ceramic capacitor and manufacture thereof - Google Patents

Abstract

PURPOSE:To make a laminated ceramic capacitor to be trimmed. CONSTITUTION:A first one of paired first and second inner electrodes to be formed in a ceramic laminate 2 having a laminated ceramic capacitor 1 is electrically connected to a first outer electrode 40, and the second one is electrically connected to connecting electrodes 42-47. The electrodes 42-47 are respectively connected to leads 33-38 of a trimming electrode 32. A lead 39 of the electrode 32 is electrically connected to a second outer electrode 41. A position 48 to be cut by a laser is applied by a laser beam, and the lead 38 is cut. Thus, the inner electrode connected to the electrode 47 is not connected to the electrode 41, thereby reducing an electrostatic capacity of the entire capacitor 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a trimmable multilayer ceramic capacitor and a method for manufacturing the same.

[0002]

2. Description of the Related Art For example, in a high frequency circuit module such as a VCO or a tuner, it is necessary to perform an adjusting operation to absorb variations in characteristics of used components. Conventionally, such adjustment is performed by using a variable element such as a trimmer capacitor or a variable coil, or cutting a strip line with a router.

[0003]

However, in any of the above-mentioned methods for enabling adjustment, the cost is high, and when a variable element is used, the element becomes large and solder dipping is required. Since it is difficult to apply, it is difficult to automate the manufacturing of the high frequency circuit module, which is a problem.

Therefore, an object of the present invention is to provide a trimmable multilayer ceramic capacitor and a method for manufacturing the same, which can advantageously address the above-mentioned problems.

[0005]

A trimmable monolithic ceramic capacitor according to the present invention is formed by laminating a plurality of ceramic layers, and is opposed to each other by a pair of main surfaces, a pair of side surfaces and a pair of main surfaces. A ceramic laminate having an end surface is provided. Inside the ceramic laminate, first and second internal electrodes are formed so as to face each other. A first external electrode is formed on one end surface of the ceramic laminate so as to be electrically connected to the first internal electrode. A connection electrode is formed on one of the side surfaces of the ceramic laminated body so as to be electrically connected to the second internal electrode. The trimming electrode extends outside the first and second internal electrodes and along one main surface of the ceramic laminate so as to be electrically connected to the connection electrode on the one side surface. Formed in. A second external electrode is formed on the other end surface of the ceramic laminated body so as to be electrically connected to the trimming electrode.

According to the method of manufacturing a trimmable monolithic ceramic capacitor according to the present invention, in the above-mentioned trimmable monolithic ceramic capacitor, a plurality of first and second internal electrodes are provided and are alternately formed. It is applied when a plurality of connection electrodes are formed on either one side surface of the ceramic laminate so as to be electrically connected to each of the second inner electrodes. In this manufacturing method, a step of sequentially forming a conductive film to provide at least two of the plurality of connection electrodes on the one side surface, and a step of cutting the conductive film into separate connection electrodes It is characterized by having.

[0007]

In the laminated ceramic capacitor according to the present invention, if the trimming electrode is cut by applying a laser beam from the outside, for example, the second internal electrode and the second external electrode connected to the cut portion of the trimming electrode are cut off. The electrical connection with the electrode is broken. Therefore, the capacitance obtained by the entire laminated ceramic capacitor becomes small.

[0008]

Therefore, according to the present invention, it is possible to obtain a monolithic ceramic capacitor whose capacitance can be trimmed. Such a monolithic ceramic capacitor can be easily miniaturized as in a normal monolithic ceramic capacitor, and solder dipping can be applied without any problem.

Further, according to the manufacturing method of the present invention, in forming a plurality of connection electrodes for connecting each of the plurality of second internal electrodes and the trimming electrode to each other,
Since the conductive film to be provided with at least two of the plurality of connection electrodes is cut, it becomes easy to form the plurality of connection electrodes on the side surface of the ceramic laminate in a state of being close to each other. Therefore, even if the monolithic ceramic capacitor that can be trimmed in a plurality of steps is downsized, a plurality of connection electrodes can be formed without any problem.

[0010]

1 to 4 are diagrams for explaining a trimmable monolithic ceramic capacitor 1 according to an embodiment of the present invention.

As shown in FIGS. 1 and 2, the monolithic ceramic capacitor 1 includes a ceramic laminate 2. The ceramic laminate 2 is shown alone in FIG. The ceramic laminate 2 has a pair of main surfaces 3 and 4, a pair of side surfaces 5 and 6, and a pair of end surfaces 7 and 8 facing each other. The ceramic laminate 2 is obtained by laminating a plurality of ceramic layers 9 to 23 as shown in FIG.

The ceramic layers 9-23 shown in FIG. 4 preferably include a non-reducing ceramic material. This is because the insulation resistance of the reducing material is likely to deteriorate due to the laser cutting described later. By adding a binder to such a ceramic material, forming it into a sheet with a doctor blade, and then cutting it into a predetermined size, the individual ceramic layers 9 to 23 are obtained. These ceramic layers 9 to
As shown in FIG. 4, various electrodes are formed on 23 by printing, for example, except for the ceramic layers 9 and 23.

First, the ceramic layers 10, 12, 14, 1
A first internal electrode 24 is formed on each of 6, 18, and 20. The first internal electrode 24 extends to the left edge of the corresponding ceramic layer.

Further, the ceramic layers 11, 13, 15, 1
A second internal electrode 25 facing the first internal electrode 24 is formed on each of 7, 19, and 21. Of these,
Second internal electrode 25 formed on the ceramic layer 11
Is drawn out to the end edge of the ceramic layer 11 by the lead-out portion 26, and similarly, on the ceramic layer 13, the lead-out portion 2 is formed.
7, the ceramic layer 15 is pulled out by the lead-out portion 28, the ceramic layer 17 is pulled out by the lead-out portion 29, the ceramic layer 19 is pulled out by the lead-out portion 30, and the ceramic layer 21 is pulled out.
It is drawn out by the drawer 31.

A trimming electrode 32 is formed on the ceramic layer 22. The trimming electrode 32 extends to the right side edge and the two side edges of the ceramic layer 22, and preferably, the seven lead portions 33 to 33 are formed so that the trimming electrode 32 is individually led to these edge or side edges. 39 is formed. The drawer portion 33 is located at a position corresponding to the drawer portion 26. Similarly, the drawer portion 34 is located in the drawer portion 27, the drawer portion 35 is located in the drawer portion 28, the drawer portion 36 is located in the drawer portion 29, and the drawer portion 37.
Is located at the position corresponding to the drawing section 30, and the drawing section 38 is located at the position corresponding to the drawing section 31.

Such ceramic layers 9-23 are shown in FIG.
Stacked in the order shown in, compressed, then fired,
It is a sintered body. In this way, the ceramic laminate 2 shown in FIG. 3 is obtained.

In the ceramic laminate 2, the above-mentioned first internal electrode 24 is exposed on one end face 7 (not shown), and the lead-out portion 39 is exposed on the other end-face 8 and the lead-out portion 2 is formed.
6 to 28 and 33 to 35 are exposed on one side surface 5 (not shown), and the drawn-out portions 29 to 31 and 36 to 38.
Is exposed on the other side surface 6.

Next, as shown in FIGS. 1 and 2, the first outer electrode 40 is electrically connected to the first inner electrode 24 on one end face 7 of the ceramic laminate 2. Formed in. A second external electrode 41 is formed on the other end surface 8 so as to be electrically connected to the lead portion 39. Further, on one side surface 5 of the ceramic laminate 2,
Connection electrode 4 electrically connected to the lead-out portions 26 and 33
2, a connection electrode 43 electrically connected to the lead-out portions 27 and 34, and a connection electrode 44 electrically connected to the lead-out portions 28 and 35 are formed, respectively. On the other side surface 6, a connection electrode 45 electrically connected to the lead portions 29 and 36, a connection electrode 46 electrically connected to the lead portions 30 and 37, and electrically connected to the lead portions 31 and 38. The connection electrodes 47 to be connected are respectively formed.

The electrodes 40 to 47 formed on the outer surface of the ceramic laminate 2 are formed by dry plating or by applying a metal paste and baking, and may be plated if necessary.

In this way, as shown in FIGS. 1 and 2, a desired trimmable monolithic ceramic capacitor 1 is obtained. In such a monolithic ceramic capacitor 1, if a laser cut is applied toward the main surface 3, the trimming electrode 32 is cut at a desired position by penetrating the ceramic layer 23 (FIG. 4). For example, in FIG. 1, the laser cutting position 48 is shown by a broken line, and by performing such laser cutting,
The lead portion 38 of the trimming electrode 32 is cut. As a result, the connection between the second internal electrode 25 and the second external electrode 41 on the ceramic layer 21 shown in FIG. 4 is cut off, and the capacitance obtained by the entire monolithic ceramic capacitor 1 is reduced.

In this embodiment, 6 of the trimming electrodes 32 are used.
By sequentially cutting the three drawers 33 to 38, 6
Trimming in stages is possible. The number of trimming steps and the trimming ratio at each step can be changed depending on the number and area of the second internal electrodes 25 connected to the trimming electrode 32.

FIG. 5 shows the ceramic layer 22 shown in FIG.
The ceramic layer 22a used instead of is shown. The trimming electrode 32a formed on the ceramic layer 22a has a lead-out portion 49 corresponding to the three lead-out portions 33 to 35, two lead-out portions 36 and 37, as compared with the trimming electrode 32 shown in FIG. Corresponding drawer 5
0, the drawer portion 51 and the drawer portion 3 corresponding to the drawer portion 38
A pull-out portion 52 corresponding to 9 is formed. According to the monolithic ceramic capacitor obtained by using such a ceramic layer 22a, the trimming ratio can be changed by selecting the laser cutting position. That is, the trimming ratio and the pull-out portion 50 when the pull-out portion 49 is cut.
The trimming ratio in the case of cutting and the trimming ratio in the case of cutting the extraction portion 51 are 3: 2: 1, and efficient trimming can be performed according to the desired trimming ratio.

In the monolithic ceramic capacitor 1 shown in FIGS. 1 and 2, the three connecting electrodes 42 to 44 are connected.
Is formed on one side surface 5, and three connection electrodes 45 are also formed.
.About.47 were formed on the other side surface 6. These connection electrodes 42 to 44 and 45 to 47 must be formed separately from each other. However, when the size of the monolithic ceramic capacitor 1 is small,
It is not so easy to form these connection electrodes 42 to 47 in a state where they are separated from each other as described above. In view of this, the method shown in FIGS. 6 and 7 can be advantageously employed.

FIGS. 6 and 7 are for explaining one embodiment of a method of manufacturing a trimmable monolithic ceramic capacitor according to the present invention. 6 and 7, the elements corresponding to the elements shown in the above-mentioned drawings are
The same reference numerals are given, and duplicate explanations are omitted.

Referring to FIG. 6, one of the ceramic laminated bodies 2 is shown.
A first and second outer electrode 40 is provided on each of the pair of end faces.
And 41 are formed, and conductive films 53 and 54 are formed on the pair of side surfaces 5 and 6, respectively. The conductive film 53 is for providing the connection electrodes 42 to 44 shown in FIGS.
Is for providing the connection electrodes 45 to 47.

Notches 55 and 56 and 57 and 58 are formed in the conductive films 53 and 54 as shown in FIG. The formation of the cuts 55 to 58 is performed by using, for example, a laser, water, a blade or the like. By cutting the conductive film 53 by the cuts 55 and 56, the three connection electrodes 42a to 44a are provided, and by cutting the conductive film 54 by the cuts 57 and 58, the three connection electrodes 45a to 47a.
Is given. These connection electrodes 42a to 47a correspond to the above-mentioned connection electrodes 42 to 47, respectively.

As described above, according to the method shown in FIGS. 6 and 7, the plurality of connection electrodes 42a to 44a or 45a are connected.
It is easy to form the parts 47a to 47a in a small area in a state of being separated from each other while being close to each other.

In the monolithic ceramic capacitor 1a obtained in the state shown in FIG.
An overcoat made of resin, glass, or the like may be applied so as to cover 8.

Although the present invention has been described above with reference to the illustrated embodiments, various other modifications are possible within the scope of the present invention.

For example, in the embodiment shown in FIGS. 1 to 4, all the second internal electrodes 2 are used as the trimming electrodes 32.
Although 5 is connected via the connection electrodes 42 to 47, some of the second inner electrodes may be directly connected to the second outer electrode 41. Therefore, for example, in an extreme case, the number of the second internal electrode that is made to not contribute to the capacitance formation by cutting the trimming electrode 32 may be only one.

As shown in FIG. 4, the trimming electrode 32 is covered with the ceramic layer 23, but such a trimming electrode may be exposed on the outer surface of the obtained monolithic ceramic capacitor.

Further, in order to cut the trimming electrode,
In addition to laser cutting, a mechanical blade may be applied.

[Brief description of drawings]

FIG. 1 is a plan view showing a monolithic ceramic capacitor 1 according to an embodiment of the present invention.

FIG. 2 is a perspective view of the monolithic ceramic capacitor 1 shown in FIG.

FIG. 3 is a perspective view showing a single ceramic laminated body 2 included in the monolithic ceramic capacitor 1 shown in FIGS. 1 and 2.

4 is a perspective view showing a plurality of ceramic layers 9 to 23 forming the ceramic laminated body 2 shown in FIG. 3 separately from each other.

FIG. 5 is a perspective view showing a ceramic layer 22a that can be used instead of the ceramic layer 22 shown in FIG. 4 for explaining another embodiment of the present invention.

FIG. 6 is a perspective view showing a state in which the first step included in one embodiment of the method for manufacturing a laminated ceramic capacitor according to the present invention has been carried out.

FIG. 7 is a perspective view showing a state where a second step is similarly performed.

[Description of Reference Signs] 1,1a monolithic ceramic capacitor 2 ceramic laminate 3,4 main surface 5,6 side surface 7,8 end surface 9 to 23,22a ceramic layer 24 first internal electrode 25 second internal electrode 26 to 31 , 33-39, 49-52 Lead-out part 32, 32a Trimming electrode 40 First external electrode 41 Second external electrode 42-47, 42a-47a Connection electrode 48 Laser cut position 53, 54 Conductive film 55-58 Cut

Claims (2)

[Claims] 1. A pair of principal surfaces, a pair of side surfaces, and 1 which are formed by laminating a plurality of ceramic layers and face each other.
A ceramic laminate having a pair of end faces, first and second internal electrodes formed to face each other inside the ceramic laminate, and the ceramic laminate with respect to the first internal electrode On one side surface of the ceramic laminate with respect to the first external electrode and the second internal electrode, which is formed on the one end surface so as to be electrically connected to the one end surface. A connection electrode formed on the one side surface so as to be electrically connected, and extending along one main surface of the ceramic laminate outside the first and second internal electrodes, and the connection electrode A trimming electrode electrically connected to the electrode on the one side surface, and electrically connected to the trimming electrode on the other end surface of the ceramic laminate. Serial formed on the other end surface, and a second external electrode, trimmable multilayer ceramic capacitor. 2. A pair of main surfaces, a pair of side surfaces and a pair of main surfaces, which are formed by stacking a plurality of ceramic layers and are opposed to each other.
A ceramic laminate having a pair of end faces, and a plurality of first and second internal electrodes, which are alternately formed so as to face each other inside the ceramic laminate, and a plurality of the first internal electrodes. Of the first outer electrode and the plurality of second inner electrodes formed on the one end face so as to be commonly electrically connected to one end face of the ceramic laminated body. A plurality of connection electrodes formed on the one side surface so as to be electrically connected to one side surface of the ceramic laminated body for each of the plurality of connection electrodes; A trimming electrode that extends along one main surface of the ceramic laminated body on the outer side and is electrically connected to each of the plurality of connection electrodes in common on the one side surface; A method of manufacturing a trimmable monolithic ceramic capacitor, comprising: a second external electrode formed on the other end face of the ceramic laminate so as to be electrically connected to the electrode on the other end face. And a step of sequentially forming a conductive film to provide at least two of the plurality of connection electrodes on the one side surface, and a step of cutting the conductive film into separate connection electrodes. A method of manufacturing a trimmable multilayer ceramic capacitor, which comprises: