JPH05235553A - Ceramic multilayer electronic component - Google Patents

Abstract

PURPOSE:To wire in a high density and to reduce in size by electrically connecting a viahole connector only by a conductor to be filled in the viahole without intermediary of an extended part. CONSTITUTION:A retaining plate 35 is moved down in a direction 38, and ceramic green sheets 28 are pressed toward a cover 33. A piston 32 is lifted in a direction 39, and conductor paste 30 in a cylinder 31 is press-fitted in a viahole 24 through a hole 34 of the cover 33. The sheets 28 remain as they are or are separated one by one, and the paste 30 is dried. Viahole connectors 26 do not have extended parts, and are electrically connected only by a conductor 25 to be filled in the viahole 24 on a boundary of a ceramic layer 22 between the connectors 26. High density wiring and a reduction in size which are disturbed by the presence of the extended part are performed. Further, formation of a protrusion on a surface of a ceramic laminate due to accumulation of the thicknesses of the extended parts can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic multilayer electronic component provided with a via hole connecting portion composed of a via hole and a conductor filled therein. Ceramic multilayer electronic components to which the present invention is directed include ceramic multilayer circuit boards, hybrid ICs having a ceramic multilayer structure, and L having the same ceramic multilayer structure.
There are C composite parts.

[0002]

2. Description of the Related Art For example, in a ceramic multilayer circuit board, attention is paid to a via hole connection portion provided therein, which has a form as shown in FIG. 5 or FIG. That is, the conductor 3 does not stay in the via hole 4 but forms the overhanging portion 5 in either the via hole connecting portion 1 shown in FIG. 5 or the via hole connecting portion 2 shown in FIG. These projecting portions 5 extend on the interface of the ceramic layer (not shown).

Such an overhanging portion 5 serves to increase the contact area between the conductors 3 at the interface of the ceramic layer and improve the reliability of electrical conduction, and the advantage thereof is not always required. Although it cannot be denied, in the step of filling the via hole 4 with the paste to be the conductor 3, the overhanging portion 5 is formed regardless of whether or not it is preferred.

FIG. 7 and FIG. 8 each show a method of filling the via hole 4 with a paste to be the conductor 3.

In the method shown in FIG. 7, screen printing by the screen 6 is used. The ceramic green sheet 7 provided with the via holes 4 is placed on the suction stage 9 via the breathable sheet 8. Vacuum suction is applied to the suction stage 9 as shown by an arrow 10, and a negative pressure is applied to each of the via holes 4 via the breathable sheet 8 by the vacuum suction. A pattern 11 is formed on the screen 6 at a position corresponding to the via hole 4. These patterns 11 have a diameter 12 which is slightly larger than the diameter of the via hole 4. Conductor paste 13
Are filled in the via holes 4 by being judged by the squeegee 14 on the screen 6.

The breathable sheet 8 described above is, for example,
Suction stage 9 composed of paper and other filter materials
It also has a function of preventing the conductor paste 13 from being soiled, and when it becomes soiled, it is replaced with a new one.
If the breathable sheet 8 is mechanically weak,
A member that supports the lower surface of the breathable sheet 8 may be provided on the suction stage 9 side.

On the other hand, the method shown in FIG. 8 is different from the method shown in FIG. 7 in that instead of the breathable sheet 8, the via hole 4 is used.
The feature is that the suction stage 16 provided with the suction holes 15 corresponding to the position is used. 8, the elements corresponding to the elements shown in FIG. 7 are designated by the same reference numerals, and the screen 6 and the elements related thereto are not shown. In the method shown in FIG. 8, the conductor paste 13 is screen-printed in a state in which a negative pressure is applied to each of the via holes 4 through the suction holes 15 of the suction stage 16, whereby the inside of the via holes 4 is printed. The conductor paste 13 is filled. In addition, in order to prevent the suction stage 16 from being contaminated by the conductive paste 13, the suction hole 15
Has a diameter larger than that of the via hole 4.

As described above, when the conductive paste 13 is filled in the via hole 4, according to the method shown in FIG.
8, the overhanging portion 5 is formed only on one surface of the ceramic green sheet 7, and on the other hand, according to the method shown in FIG. 8, the overhanging portion 5 is formed on the ceramic green sheet 7 as shown in FIG. Are formed on both sides of the.

[0009]

[Problems to be Solved by the Invention] The via hole 4 described above.
In the case of filling the conductor paste 13 into the conductive paste 13, the pattern 11 and the via hole 4 must be properly aligned using the screen 6. Considering this, and the fact that there are many places that must be aligned in this way, and the distortion of the screen 6 itself,
As described above, the diameter 12 of the pattern 11 must be designed larger than the diameter of the via hole 4. For example,
If the diameter of the pattern 11 is equal to or smaller than the diameter of the via hole 4, as shown in FIG. 11, when the pattern 11 and the via hole 4 are misaligned with each other, the conductive paste 13 is 100 % May not be filled. Therefore, it is practically impossible to make the diameter of the pattern 11 equal to or smaller than the diameter of the via hole 4.

Generally, the diameter of the pattern 11 is the via hole 4
The diameter is about 100 to 200 μm. Also,
In such a ceramic multilayer circuit board, the diameter of the via hole 4 may be designed to be about 100 μm in order to increase the density. In such a case, the diameter of the overhanging portion 5 becomes about 2 to 3 times the diameter of the via hole 4, resulting in a large waste of space. Further, the wiring pattern also needs a certain gap in order to avoid contact with the via-hole connecting portion 1 or 2, and the presence of the overhanging portion 5 adversely affects miniaturization and high density of the ceramic multilayer circuit board. Has become.

Further, as shown in FIG. 12, when the thickness of the overhanging portion 5 formed in the via hole connecting portion 17 is accumulated, the ceramic laminated body 18 composed of a plurality of ceramic layers is formed.
The convex portion 19 may appear on the surface of the. Such a convex portion 19 has a larger number of overhanging portions 5, that is,
The longer the series length of the via hole connecting portion 17, the more conspicuous it appears. The presence of the convex portion 19 indicates that the ceramic laminated body 18 is present.
This causes a problem that, for example, the resistance paste cannot be printed properly on the surface of, or the circuit component cannot be mounted properly.

In the case of the method shown in FIG. 8, as shown in the leftmost conductor paste 13,
Through holes 20 may be formed in the conductor paste 13. In such a case, the conductive paste 13 may be dried thereafter, the ceramic green sheets 7 may be stacked and thermocompressed, and the conductive paste 13 may shrink or deform during firing, which may lead to conduction failure in the via hole connection portion. ..

Therefore, it is an object of the present invention to provide a ceramic multilayer electronic component which can solve the above-mentioned problems.

[0014]

According to the present invention, there is provided a ceramic laminated body including a plurality of ceramic layers, and a plurality of the ceramic layers are provided with via holes and via hole connecting conductors filled therein. In order to solve the above-mentioned technical problem, the via-hole connecting part is a ceramic between the via-hole connecting parts. The layer interface is characterized in that it includes a portion electrically connected only by the conductor filled in the via hole.

[0015]

According to the present invention, since the via hole connecting portion is electrically connected only by the conductor filled in the via hole without passing through the overhanging portion, all the problems caused by the presence of the overhanging portion are solved. be able to.

[0016]

As described above, according to the present invention, in the ceramic multi-layer electronic component, wiring can be performed at a high density, and the size can be reduced.

Further, it is possible to prevent the convex portion from being formed on the surface of the ceramic laminate by accumulating the thickness of the overhang portion. Therefore, when printing a resistance paste or mounting a circuit component on the surface of the ceramic laminate, proper printing or mounting is not hindered.

After the via hole is filled with the conductor,
A wiring pattern for forming an inductor, a capacitor, etc. is printed on a specific ceramic layer, but according to the present invention, since the overhanging portion is not formed around the via hole, there is no unevenness due to the overhanging portion, and therefore, Printing can be performed with high accuracy. This is particularly advantageous when fine line printing has to be performed.

When the overhanging portion is formed as in the conventional case, the wiring pattern may be printed so as to overlap the overhanging portion. In this case, the thickness of the conductor layer becomes thicker particularly in the overhang portion, and shrinkage during firing of the ceramic laminated body may cause delamination and warpage of the ceramic laminated body. According to this, these problems can be solved and the quality of the ceramic laminate can be improved.

[0020]

EXAMPLE A ceramic multilayer circuit board will be described below as an example of the present invention.

FIG. 1 is a sectional view showing a ceramic multilayer circuit board 21 according to this embodiment. The ceramic multilayer circuit board 21 includes a ceramic laminated body 23 including a plurality of ceramic layers 22. A via hole connecting portion 26 including a via hole 24 and a conductor 25 filling the inside thereof is provided in a plurality of these ceramic layers 23 so as to penetrate through the plurality of ceramic layers 22. Further, some wiring patterns 27 are formed with conductors 25 along the interface of the ceramic layer 22 and the surface of the ceramic multilayer circuit board 21.

In this embodiment, FIG. 5 or FIG.
As is clear from the comparison with the via-hole connecting portions 1 or 2 shown in FIG. It is characterized in that they are electrically connected only by the conductors 25 filled in. Since the via hole connection portion 26 is formed in this manner,
When filling the paste that becomes the conductor 25,
Specifically, one of the following three methods is adopted.

FIG. 2 shows the first method. The plurality of ceramic green sheets 28 provided with the via holes 24 are stacked. Beer hall 2
For example, a drill, a punch or the like is used for forming 4. After the via holes 24 are individually formed in each of the ceramic green sheets 28, the plurality of ceramic green sheets 2 are aligned while the via holes 24 are aligned with each other.
8 may be stacked, or a series of via holes 24 may be formed at once after stacking a plurality of ceramic green sheets 28. Further, the plurality of ceramic green sheets 28 may be replaced with a single ceramic green sheet having a relatively large thickness.

The plurality of ceramic green sheets 28 described above are placed on the paste supply device 29. The paste supply device 29 is for press-fitting the conductor paste 30 into the via hole 24, and includes a cylinder 31, a piston 32.
And a lid 33. The lid 33 is provided with a hole 34 at a position corresponding to the position of the via hole 24. The diameter of the hole 34 is set to be larger than the diameter of the via hole 24 in order to allow a certain amount of misalignment between the via hole 24 and the hole 34.
Is larger than the diameter of.

A pressing plate 35 is arranged above the paste supply device 29. An elastic body 36 made of, for example, rubber or the like is provided on the lower surface of the pressing plate 35 in order to absorb irregularities. In addition, the elastic body 36 and the ceramic green sheet 2
The breathable sheet 37 is disposed between the sheet 8 and the sheet 8. The breathable sheet 37 is made of, for example, paper or other filter material, and has a function of preventing the elastic body 36 from being soiled by the conductor paste 30. Breathable sheet 37
Will be replaced with a new one when it becomes dirty.

In filling the via holes 24 with the conductor paste 30, first, the holding plate 35 descends as shown by an arrow 38, and the ceramic green sheet 28 is covered with the lid 3.
It is pressed toward 3. Then, the piston 32 rises as shown by the arrow 39, and the conductor paste 30 in the cylinder 31 passes through the hole 34 of the lid 33 and passes through the via hole 2.
It is press-fitted in 4. Next, the ceramic green sheets 28 are left as they are or separated one by one, and the conductor paste 30 is dried.

Since the protruding portion is formed by the conductive paste 30 on the lower surface of the lowermost ceramic green sheet 28, the ceramic green sheet 2 is usually formed.
8 is not used. Therefore, this bottom ceramic green sheet 28 need not be a ceramic green sheet and may be replaced with other sheet materials.

The ceramic green sheet 28 is
Usually, it is formed by applying a ceramic slurry on a suitable carrier film with a doctor blade or the like. Therefore, the ceramic green sheet 28
However, the via hole 24 is formed in the state of being lined with such a carrier film, and then, as shown in FIG.
You may implement the process as shown in FIG.

FIG. 3 shows the second method. Here, the ceramic green sheet 28 is the breathable sheet 4.
It is placed on the suction stage 41 through 0. Further, a sheet-shaped mask 42 is arranged on the upper surface of the ceramic green sheet 28. The mask 42 is provided with holes 43 at positions corresponding to the via holes 24 provided in the ceramic green sheet 28. The diameter of these holes 43 is the same as the diameter of the via hole 24. In addition, it is preferable that the via hole 24 and the hole 43 be formed in a state where the ceramic green sheet 28 and the mask 42 are overlapped with each other.
Are simultaneously formed by drilling, punching, etc.

Vacuum suction is applied to the suction stage 41 as indicated by an arrow 44, whereby a negative pressure is exerted in the via hole 24 and the hole 43 through the breathable sheet 40. In this state, the conductor paste 30 is supplied onto the mask 42 and is separated by the squeegee 45 to fill the via holes 24 and the holes 43 with the conductor paste 30.

The breathable sheet 40 is made of substantially the same material as the breathable sheet 8 (FIG. 7) or the breathable sheet 38 (FIG. 2) described above, and performs substantially the same function.

Next, the conductor paste 30 filled as described above is dried as it is or after the ceramic green sheet 28 is separated from the mask 42, and is then stacked.

In the above method, the mask 42 is used.
May be a carrier film that serves as a backing means when the ceramic green sheet 28 is molded.

FIG. 4 shows the third method. The method shown in FIG. 4 uses the same elements as those shown in FIG. Therefore, these common elements are denoted by the same reference numerals, and duplicate description will be omitted.

The method shown in FIG. 4 is characterized by using the screen 46. The screen 46 is the mask 4
It is arranged above 2. The diameter of the pattern provided on the screen 46 is the same as that of the via hole 24 and the hole 43.
Is set larger than the diameter of.

In this method, a negative pressure is applied to the via holes 24 and the holes 43 by the suction stage 41, and the conductor paste 30 separated by the squeegee 45 is used.
But via holes 24 and holes 4 through the screen 46
3 is filled. At this time, the overhanging portion 4 is formed on the mask 42.
7 is formed, the mask 42 is removed, and the ceramic green sheet 28 does not have such an overhang portion.

Although the present invention has been described above with reference to a ceramic multilayer circuit board, the present invention is broadly applicable to hybrid ICs and LC composite parts as long as it has a ceramic multilayer structure and a via hole connecting portion. It can be applied to ceramic multilayer electronic components.

[Brief description of drawings]

FIG. 1 is a sectional view showing a ceramic multilayer circuit board 21 according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a first method for filling the conductive paste 30 in the via holes 24.

FIG. 3 is a cross-sectional view showing a second method for filling the via hole 24 with a conductor paste 30.

FIG. 4 is a cross-sectional view showing a third method for filling via hole 24 with conductive paste 30.

FIG. 5 is a cross-sectional view showing a form of a conventional via hole connecting portion 1.

FIG. 6 is a cross-sectional view showing a form of a via hole connecting portion 2 as another conventional example.

FIG. 7 is a cross-sectional view showing a first conventional method for filling the via hole 4 with a conductor paste 13.

FIG. 8 is a cross-sectional view showing a second conventional method for filling via hole 4 with conductive paste 13.

9 is a cross-sectional view showing an applied state of the conductor paste 13 obtained by the method shown in FIG.

10 is a cross-sectional view showing an applied state of the conductor paste 13 obtained by the method shown in FIG.

FIG. 11 is a cross-sectional view for explaining a problem encountered when the diameter of the pattern 11 provided on the screen 6 is the same as the diameter of the via hole 4.

FIG. 12 is an overhang portion 5 formed in the via hole connecting portion 17.
FIG. 9 is a cross-sectional view of the ceramic laminate 18 for explaining the problem caused as a result of the accumulation of the thickness of the ceramic laminate.

[Explanation of symbols]

 21 ceramic multilayer circuit board 22 ceramic layer 23 ceramic laminated body 24 via hole 25 conductor 26 via hole connecting portion 28 ceramic green sheet 30 conductor paste

Continuation of front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location // H01G 4/40 321 9174-5E

Claims (1)

[Claims] 1. A ceramic laminated body including a plurality of ceramic layers, wherein a plurality of the ceramic layers has a via hole connecting portion made of a via hole and a conductor filled therein, extending over the plurality of ceramic layers. In the ceramic multilayer electronic component provided so as to penetrate, the via-hole connecting portions are electrically connected only by the conductor filled in the via-holes on the interface of the ceramic layer between the via-hole connecting portions. A ceramic multilayer electronic component comprising a portion.