1. Field of the Invention
The present invention relates to methods for manufacturing monolithic ceramic electronic components, and more specifically to a method for manufacturing a monolithic ceramic electronic component obtained by laminating a plurality of ceramic sheets with inner conductors interposed therebetween.
2. Description of the Related Art
Recently, monolithic capacitors used in high-frequency circuits have been required to have low equivalent series inductance (ESL), and a monolithic ceramic electronic component which satisfies this requirement has been suggested in Japanese Unexamined Patent Application Publication No. 2001-185442. In this electronic component, in order to reduce ESL, through via holes and non-through via holes, which are electrically connected to inner conductors, are formed in a laminate body so that the lengths and numbers of current-conducting paths can be reduced and generated magnetic fluxes can be canceled.
The through via holes are via holes which extend between the top and bottom surfaces of the laminate body, and the non-through via holes are via holes which extend between one of the top and bottom surfaces and a position inside the laminate body.
More specifically, as shown in
This electronic component 50 is typically manufactured by a method shown in
However, in the known manufacturing method, since the thin holes 62′ are closed at the bottom, when the conductive paste is injected in the thin holes 62′ to form the non-through via holes 62, air necessarily remains at the bottom of the thin holes 62′ and it is difficult to fill the thin holes 62′ with the conductive paste to the bottom. As a result, connection failure occurs between the non-through via holes 62 and the inner conductors 55, as shown in an enlarged view at the left in
Accordingly, a manufacturing method described in Japanese Unexamined Patent Application Publication No. 2002-344140 has been suggested. This manufacturing method will be described below with reference to
However, in this manufacturing method, it is difficult to align the central axes of the separately formed through via holes 61 when the first and second laminate blocks 52 and 53 are bonded together. Accordingly, as shown in an enlarged view at the right in
In order to overcome the problems described above, preferred embodiments of the present invention provide a method for manufacturing a monolithic ceramic electronic component in which non-through via holes are connected to inner conductors with high reliability, and which does not cause connection failure in through via holes and degradation of electrical characteristics.
According to a preferred embodiment of the present invention, a method for manufacturing a monolithic ceramic electronic component including a laminate body obtained by laminating a plurality of ceramic sheets with inner conductors interposed between the ceramic sheets, the laminate body having a through via hole extending between top and bottom surfaces of the laminate body and a non-through via hole extending between one of the top and bottom surfaces of the laminate body and a position inside the laminate body, includes the steps of forming a via hole in a first laminate block in such a manner that the via hole extends through the first laminate block, laminating a ceramic sheet layer and/or a second laminate block on the first laminate block to obtain the laminate body such that the via hole is completely covered by the ceramic sheet layer and/or the second laminate block, and forming a through via hole in the laminate body obtained in the laminating step.
In the manufacturing method according to a preferred embodiment of the present invention, the via hole is formed in the first laminate block so as to extend through the first laminate block, and then the ceramic sheet layer and/or the second laminate block is/are laminated on the first laminate block such that the via hole is completely covered by the ceramic sheet layer and/or the second laminate block. Therefore, the via hole is completely filled with the conductive paste to the bottom, and the connection reliability between the non-through via hole and the inner conductor is increased.
In addition, the through via hole is preferably formed in the laminate body after the laminate body is obtained by laminating the ceramic sheet layer and/or the second laminate block on the first laminate block. In other words, the through via hole may be formed without using the method described in Japanese Unexamined Patent Application Publication No. 2002-344140. Accordingly, connection failure does not occur and required electrical characteristics (in particular, low ESL) can be maintained.
In the manufacturing method according to a preferred embodiment of the present invention, the second laminate block may include at least one of an inner conductor and a non-through via hole.
Other features, elements, steps, advantages and characteristics of the present invention will become more apparent from the following detailed description of preferred embodiments thereof with reference to the attached drawings.
Methods for manufacturing monolithic ceramic electronic components according to preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
This monolithic ceramic electronic component 10A is manufactured by the following steps. That is, first, as shown in
Next, as shown in
Next, a ceramic sheet layer 13 is laminated on the bottom surface of the first laminate block 12, as shown in
Then, as shown in
According to the first [referred embodiment, the via holes 22 are formed in the first laminate block 12 so as to extend through the first laminate block 12, and then the ceramic sheet layer 13 is laminated on the first laminate block 12. Therefore, the non-through via holes 22 are completely filled with the conductive paste to the bottom, and connection reliability between the non-through via holes 22 and the inner conductors 15 is increased.
In addition, the through via holes 21 are formed in the laminate body 11 after the laminate body 11 is obtained by laminating the ceramic sheet layer 13 and the second laminate block 14 on the first laminate block 12. Therefore, the through via holes 21 are not divided in a manner shown in
As shown in
As shown in
In this case, first, a non-through via hole 22 is formed in a first laminate block 12 having a thickness corresponding to the depth of the non-through via hole 22 so as to extend through the first laminate block 12 (see
Next, a third laminate block 14b including inner conductors 15 is laminated on the bottom surface of the second laminate block 14a to obtain a laminate body 11. Then, thin holes for through via holes 21 are formed in the laminate body 11 and are filled with conductive paste, and the through via holes 21 are obtained accordingly.
As shown in
The present invention is not limited to the methods for manufacturing the monolithic ceramic electronic components according to the above-described preferred embodiments, and various modifications are possible within the scope of the present invention.
For example, the shapes of the inner conductors included in the laminate body and the structure of the circuit formed by the inner conductors, the through via holes, and the non-through via holes may be determined arbitrarily.
While the present invention has been described with respect to preferred embodiments, it will be apparent to those skilled in the art that the disclosed invention may be modified in numerous ways and may assume many embodiments other than those specifically set out and described above. Accordingly, it is intended by the appended claims to cover all modifications of the invention which fall within the true spirit and scope of the invention.
Number | Date | Country | Kind |
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2004-167248 | Jun 2004 | JP | national |