JP2003347731A - Stacked ceramic electronic part and method for its manufacturing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a multilayer ceramic substrate having conductive films and via hole conductors which prevent contraction caused in baking and thus ensure high reliability in connection. <P>SOLUTION: The multilayer ceramic substrate 11 is obtained by; forming on a support 16 a metal foil 17 which is integrally provided with sheets 18 that serve as the conductive films 14, and bumps 19 that serve as the via hole conductors 15; transferring the metal foil 17 to a ceramic green sheet 20 from the support 16 so that the bumps 19 are thrusted thicknesswise into the ceramic green sheet 20; stacking a plurality of such ceramic green sheets 20; and baking the resulting green stacked body 23. <P>COPYRIGHT: (C)2004,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer ceramic electronic component and a method for manufacturing the same.
The present invention relates to an improvement in a method of forming a conductor film and a via-hole conductor provided in a multilayer ceramic electronic component.

[0002]

2. Description of the Related Art A multilayer ceramic electronic component is an interesting multilayer ceramic electronic component for the present invention. 2. Description of the Related Art In recent years, there has been an increasing demand for miniaturization in order to enable high-speed propagation to a multilayer ceramic substrate on which a semiconductor element such as an IC or an LSI, which is becoming higher in frequency and higher in density, is mounted.

Therefore, the ceramic layer provided on the multilayer ceramic substrate is required to be made of a material having a lower dielectric constant. On the other hand, a wiring layer such as a conductor film provided on the multilayer ceramic substrate or a via-hole conductor is required. In some cases, it is required to be made of a material having a lower electric resistance. As a material constituting the ceramic layer giving a lower dielectric constant, for example, BaO-Al ₂
For example, 1000, such as O ₃ —SiO ₂ mixed ceramics
Attention has been focused on low-temperature sintered ceramics that can be sintered at a temperature of not more than ℃. For example, attention has been paid to copper or silver.

As described above, a multilayer ceramic substrate having a ceramic layer formed of a low-temperature sintered ceramic is generally manufactured as follows.

First, a slurry obtained by mixing a low-temperature sintered ceramic raw material powder, an organic binder, and an organic solvent is
The sheet is formed into a sheet shape by a sheet forming method such as a doctor blade method to produce a ceramic green sheet. Next, a through-hole for a via-hole conductor is punched into the ceramic green sheet, and the through-hole is filled with a conductive paste containing a copper metallized composition or a silver metallized composition. A conductive film is formed by a screen printing method or the like using the same conductive paste. Next, a heating step for removing the binder is performed on the green laminate obtained by laminating a plurality of ceramic green sheets and pressing in the laminating direction, and then a firing step.

However, according to the above-described method for manufacturing a multilayer ceramic substrate, a wiring conductor such as a conductor film or a via-hole conductor is formed of a sintered body of a conductive paste. That is, the conductive paste contains not only the metal powder but also a resin, a solvent and other additives, the solvent is volatilized in the drying step, and the resin and the additive are thermally decomposed or decomposed in the firing step. The wiring conductor is formed by sublimation and sintering of the metal powder and part of the additive. As a result, voids and grain boundaries are unavoidable inside the wiring conductor, and there is a limit to the reduction in the resistance of the wiring conductor, and it is not always necessary to form a high-frequency circuit that requires a further reduction in resistance. Not suitable.

Further, there is a limit in improving the printing accuracy of a conductive paste for forming a conductive film. Therefore, for example, it is difficult to form fine wiring having a wiring width of less than 100 μm with a good yield. . Therefore, there is a limit to satisfy the demand for further miniaturization of the multilayer ceramic substrate and further higher density of the wiring.

Accordingly, a multilayer ceramic substrate using a metal foil made of copper or the like as a conductor film has been proposed. By forming the wiring conductor from a metal foil, the metal foil is dense, so that the resistance of the wiring conductor can be reduced.Also, regarding the surface roughness of the wiring conductor, when this is formed using a conductive paste Can provide a smoother surface as compared with, so the loss in high frequency applications is small, and
By using photolithography technology, fine patterning is possible and linearity can be improved, so that an advantage that loss in high frequency applications is small can be expected.

[0009]

However, although the above-mentioned advantages are provided by forming the conductor film of the wiring conductor from a metal foil, the conductive paste is applied to the via-hole conductor. Since this is obtained by sintering, the above-described problem remains.

Further, as described below, a problem is also encountered in that the connection failure between the via-hole conductor and the conductor film is likely to occur due to shrinkage of the conductive paste.

FIGS. 6 and 7 are sectional views showing a ceramic layer 1 provided on a multilayer ceramic substrate. 6 and 7 show the via-hole conductor 2 and the conductor film 3 connected thereto.

The via-hole conductor 2 is made of a sintered body of a conductive paste, while the conductor film 3 is made of a metal foil. Due to the materials constituting the via-hole conductor 2 and the conductor film 3 and the process for forming them, the structure of the connection portion between the via-hole conductor 2 and the conductor film 3 is as shown in FIG. In this case, the conductor film 3 is formed so as to cover the end surface of the conductor film 3, or the via hole conductor 2 is formed so as to penetrate the conductor film 3 as shown in FIG.

Since the via-hole conductor 2 of the via-hole conductor 2 and the conductor film 3 is formed from a conductive paste, the solvent or resin contained therein may be thermally decomposed or dried during drying or firing. Always shrinks due to volatilization. As a result, in any of the structures of FIGS.
A connection failure may occur between the via-hole conductor 2 and the conductor film 3.

Since the conductive film 3 made of a metal foil does not substantially shrink in the firing step, for example, in order to match the shrinkage behavior of the conductive film 3 and the ceramic layer 1, for example,
An inorganic material for shrinkage suppression, which does not sinter at the sintering temperature of the ceramic material powder contained in the ceramic green sheet, is placed above and below a green laminate including a plurality of laminated ceramic green sheets including the ceramic green sheet to be the ceramic layer 1. A method of applying a so-called non-shrinkage process in which firing is performed in a state in which an outer constraining layer containing a material powder is arranged has also been proposed.

According to the non-shrinkage process, the shrinkage behavior in the plane direction of the ceramic layer 1 can be made substantially coincident with the shrinkage behavior in the plane direction of the conductor film 3 made of metal foil. It is completely powerless to match the shrinkage behavior with the via-hole conductor 2 which is formed and therefore always shrinks during firing.

Such a problem is not limited to a multilayer ceramic substrate, but a multilayer ceramic electronic component including a multilayer body composed of a plurality of laminated ceramic layers and a wiring conductor such as a conductor film and a via-hole conductor. This is true for any multilayer ceramic electronic component.

An object of the present invention is to provide a multilayer ceramic electronic component and a method for manufacturing the same, which can solve the above-described problems.

[0018]

SUMMARY OF THE INVENTION According to the present invention, there is provided a laminate comprising a plurality of laminated ceramic layers, a conductor film formed on the ceramic layer, and a specific ceramic layer connected to the conductor film. And a via-hole conductor provided so as to penetrate in the thickness direction, which is firstly directed to a multilayer ceramic electronic component, and is characterized by having the following configuration in order to solve the above-described technical problem. I have.

That is, in the multilayer ceramic electronic component according to the present invention, the conductor film and the via-hole conductor are integrally formed of a metal foil, and the metal foil provides the sheet-like portion providing the conductor film and the via-hole conductor. And a bump portion formed so as to swell from a part of the sheet-like portion.

The above-mentioned metal foil preferably contains at least one of copper and silver.

According to another aspect of the present invention, there is provided a laminate comprising a plurality of laminated ceramic layers, a conductor film formed on the ceramic layer, and penetrating a specific ceramic layer in the thickness direction while being connected to the conductor film. And a via-hole conductor provided to perform the method described above.

The method of manufacturing a multilayer ceramic electronic component according to the present invention is characterized in that the following steps are performed in order to solve the above-mentioned technical problem.

First, a metal foil integrally provided with a sheet-shaped portion providing a conductor film and a bump portion formed so as to rise from a part of the sheet-shaped portion so as to provide a via-hole conductor is formed on a support. Then, a metal foil forming step is performed.

On the other hand, a ceramic green sheet preparing step of preparing a ceramic green sheet to be a ceramic layer is performed.

Next, a transfer step of transferring the metal foil from the support to the ceramic green sheet is performed so that the bump portions of the metal foil are made to protrude in the thickness direction of the ceramic green sheet.

In addition, a laminating step of laminating a plurality of ceramic green sheets is performed.

In addition, a firing step of firing a green laminate composed of a plurality of stacked ceramic green sheets is performed.

In the method for manufacturing a multilayer ceramic electronic component according to the present invention, there are several embodiments regarding the metal foil forming step described above.

In the first embodiment, a metal foil having a thickness at least corresponding to the height of a bump portion is attached to a support, and the metal foil is etched by using a photolithography technique to thereby form a metal foil. A step of giving a shape of a sheet portion and a bump portion to the foil is performed.

In the second embodiment, a step of sequentially forming a sheet portion and a bump portion on a support by an additive plating method using a photolithography technique is performed.

In the third embodiment, a step of forming a metal film to be a sheet-shaped portion on a support, a step of patterning the metal film by etching, and a step of forming a metal film on the metal film by using a photolithography technique. And forming a bump portion by an additive plating method.

In the method for manufacturing a multilayer ceramic electronic component according to the present invention, there are several embodiments regarding the laminating step as follows.

In the first embodiment, the laminating step is performed such that the ceramic green sheets after the transfer step are laminated.

In the above embodiment, the ceramic green sheet is prepared in a state of being lined with a carrier film to cover the softness of the ceramic green sheet, and the transfer step is performed on the ceramic green sheet lined with the carrier film. In the laminating step, the carrier film is preferably peeled after laminating the ceramic green sheets.

In the second embodiment, the laminating step is performed so as to laminate the ceramic green sheets before performing the transferring step, and the transferring step is performed on the ceramic green sheets after completing the laminating step. Is done.

The bump portion of the metal foil is preferably tapered.

In the transfer step, if the bump portion of the metal foil is formed so as to penetrate into the ceramic green sheet to form a through hole in the ceramic green sheet, the ceramic green sheet has a through hole for a via hole conductor. There is no need to provide holes in advance.

In the method for manufacturing a multilayer ceramic electronic component according to the present invention, a non-shrinkage process may be applied.

When the non-shrinkage process is applied, for example, an interlayer constraining layer containing a shrinkage-suppressing inorganic material powder that does not sinter at the sintering temperature of the ceramic material powder contained in the ceramic green sheet forms a raw laminate. A step of forming an interlayer constraining layer on a specific ceramic green sheet so as to be located along an interface between the plurality of ceramic green sheets is performed.

In place of or in addition to the above-described embodiment, the outer material containing the second inorganic material powder for shrinkage suppression which does not sinter at the sintering temperature of the ceramic material powder contained in the ceramic green sheet. The constraining layer may be arranged so as to sandwich the green laminate in the laminating direction, and the outer constraining layer may be removed after the firing step.

The present invention is also directed to a multilayer ceramic electronic component obtained by the above-described manufacturing method.

[0042]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following, in describing embodiments of the present invention, a multilayer ceramic substrate as an example of a multilayer ceramic electronic component will be described.

FIG. 1 is a view for explaining a first embodiment of the present invention, in which several typical steps included in a method for manufacturing a multilayer ceramic substrate are sequentially shown in sectional views.

FIG. 1 (7) shows a multilayer ceramic substrate 11 obtained through the steps shown in FIGS. 1 (1) to 1 (6). The multilayer ceramic substrate 11 includes a multilayer body 13 including a plurality of stacked ceramic layers 12 and a multilayer body 13 formed on the ceramic layer 12.
A number of conductor films 14 located on the outer surface of the substrate and / or along a particular interface between the ceramic layers 12;
Several via-hole conductors 15 are provided so as to penetrate the specific ceramic layer 12 in the thickness direction while being connected to the conductor film 14.

The illustrated multilayer ceramic substrate 11
Is simplified to avoid complication of the drawings. In an actual multilayer ceramic substrate, a substrate in which a larger number of ceramic layers are laminated, a substrate constituting a passive element such as a capacitor and / or an inductor by a conductor film and a via-hole conductor, and a cavity are formed. There are things. Also, in FIG. 1 (7), illustration of active elements such as semiconductor IC chips and passive elements such as chip capacitors mounted on the multilayer ceramic substrate 11 or in the cavity is omitted.

In order to manufacture such a multilayer ceramic substrate 11, first, as shown in FIG.
Is prepared, and a metal foil 17 is attached on the support 16. As the support 16, for example, an organic film made of a polyethylene resin, a polyester resin, a polycarbonate resin, or the like, or a metal film made of aluminum, stainless steel, or the like is used. The metal foil 17 is made of, for example, copper, a copper alloy, silver, or a silver alloy.

Although not shown, a commercially available adhesive made of, for example, a polyacrylic resin or a polyisobutylene-based resin is applied to the support 16 for attaching the metal foil 17 on the support 16 or For example, an adhesive organic mixture or the like obtained by mixing terpineol, butyl carbitol, butyl carbitol acetate, or an alcohol with ethyl cellulose, acrylic resin, polyvinyl butyral, methacrylic resin, or epoxy resin, and the like is applied. The metal foil 17 is laminated on the agent or the adhesive organic mixture.

Next, the metal foil 17 is etched while using the photolithography technique, as shown in FIG.
As shown in (2), the metal foil 17 is given the shape of a sheet-like portion 18 and a bump portion 19 rising from a part of the sheet-like portion 18. The sheet-like portion 18
This is for providing the conductor film 14 shown in FIG. 1 (7), and the bump portion 19 is for providing the via hole conductor 15.

More specifically, a photosensitive film is adhered to the surface of the metal foil 17 shown in FIG. 1 (1), and this is masked by a glass master on which a desired exposure pattern is formed. After the development, the photosensitive film is developed so as to give a desired pattern.

Next, by using the photosensitive film patterned as described above as a resist, the metal foil 17 is etched to form the bump portions 19 first. Here, when the metal foil 17 is made of copper, for example, a solution of ammonium peroxodisulfate or ferric chloride is used as an etchant. When the metal foil 17 is made of silver, for example, nitric acid or the like is used as an etchant. Used as

Next, the same method as described above is repeated to give a desired pattern on the sheet-like portion 18.

As described above, the metal foil 17 integrally including the sheet-like portion 18 and the bump portion 19 is provided on the support 1.
6 are formed. As apparent from the above-described method, the metal foil 17 attached to the support 16 in FIG. 1A has a thickness corresponding to at least the height of the bump portion 19.

The above-mentioned sheet-like portion 18 corresponds to FIG.
As shown on the left side of the figure, there are those that extend wider than the diameter of the bump portion 19, and those shown on the right side have only the same planar dimensions as the diameter of the bump portion 19.

On the other hand, as shown in FIG. 1C, a ceramic green sheet 20 to be the ceramic layer 12 is prepared. The ceramic green sheet 20 preferably contains a low-temperature sintered ceramic material in order to enable simultaneous firing with the metal foil 17 containing copper or silver in a firing step described later.

The ceramic green sheet 20 is made of, for example, a mixture of powders of barium oxide, silicon oxide, alumina, calcium oxide and boron oxide, a binder of polyvinyl butyral and a plasticizer of di-n-butyl phthalate. A slurry obtained by mixing a solvent consisting of toluene and isopropylene alcohol is formed into a sheet by a doctor blade method or the like,
This can be obtained by drying.

As the low-temperature sintered ceramic material contained in the ceramic green sheet 20, as described in the above example,
In addition to the glass that is produced at the time of firing, a composition that can be sintered at a lower temperature by adding a sintering aid such as glass or copper oxide or magnesium oxide in advance may be used. The ceramic green sheet 20
As for the binder, plasticizer and solvent contained in the above, those other than the above examples may be used.

Next, as shown in FIG. 1 (3), the metal foil 17 held by the support 16 is pressed against the ceramic green sheet 20 as shown by an arrow 21. As shown in (4), the bump portion 19 of the metal foil 17 is
0 in the thickness direction. And FIG.
As shown in (5), when the support 16 is peeled from the metal foil 17, the metal foil 17
Transferred to 0 side.

More specifically, the structure shown in FIG. 1 (4) was compressed from 1 to 60 MPa in a pressure range of 1 to 100 MPa using a pressure plate heated to a temperature range of 70 to 150 ° C.
By pressing for 2 seconds, the metal foil 17 is
To the ceramic green sheet 20.

In this case, if one or both surfaces of the metal foil 17 are roughened to such an extent that the high-frequency characteristics do not become a problem, the above-mentioned transferability is further improved by the anchor effect, and the adhesion to the ceramic green sheet 20 is improved. Is more improved. Further, a resin adhesive which is burned off in the firing step may be applied to the surface of the metal foil 7 in advance. This can further enhance the adhesion between the metal foil 17 and the ceramic green sheet 20 to which the metal foil 17 has been transferred.

In the above embodiment, the metal foil 17
The bump portion 19 of the ceramic green sheet 20
The through holes are formed in the ceramic green sheet 20 as shown by the broken lines in FIG. 1 (3).

As shown in FIG.
It is preferably tapered. By making the bump portion 19 tapered, the ceramic green sheet 2 of its own can be formed.
This is because it is easy to form a through hole in the ceramic green sheet 20 due to the entry into 0. Further, even when the through-hole 22 is provided in the ceramic green sheet 20 in advance, if the bump 19 is tapered, the bump 19 can be smoothly inserted into the through-hole 22.

As described above, in order to form the tapered bump portion 19, if the etching is applied as in this embodiment, the etching may be stopped before the etching is completely completed. Good. In general, the etching is less likely to be etched toward the end portion, and is more difficult to be etched on the lower side than on the upper side, so that the bump portion 19 can have a tapered shape.

Next, as shown in FIG.
A plurality of ceramic green sheets 20 including a plurality of ceramic green sheets 20 holding 7 are laminated and then pressed in the laminating direction at a temperature of 80 ° C. and a pressure of 150 MPa, for example, to obtain a raw laminate 23. Can be

Next, the green laminate 23 is baked in a reducing atmosphere, for example, at a temperature of 900 ° C. for one hour through a binder removal process, whereby the green laminate 23 shown in FIG.
2 is obtained.

In the multilayer ceramic substrate 11, the ceramic layer 12 is derived from the ceramic green sheet 20, and the conductor film 14 is formed on the sheet-like portion 1 of the metal foil 17.
8, and the via-hole conductor 15 is derived from the bump portion 19 of the metal foil 17. afterwards,
If necessary, the conductor film 14 exposed on the surface of the laminate 13
Is subjected to Ni / Au plating, Ni / Sn plating and / or Ni / solder plating.

According to this embodiment, since the sheet portion 18 for providing the conductor film 14 and the bump portion 19 for providing the via hole 15 are integrally formed from the metal foil 17, the sheet portion 18 and the bump portion 19 are formed integrally. Since the shrinkage behavior during the firing process is substantially the same, a connection failure does not occur between the conductor film 14 and the via-hole conductor 15.

As a modification of the first embodiment described with reference to FIG. 1, an embodiment in which a non-shrink process as described below is applied is also possible.

Referring to FIG. 1 (6), the firing step is performed with the outer constraining layer 24 disposed so as to sandwich the raw laminate 23 in the laminating direction. Outer restraint layer 24
Is to add a suitable binder and a solvent to the shrinkage-suppressing inorganic material powder that does not sinter at the sintering temperature of the ceramic material powder contained in the ceramic green sheet 20, and form a slurry obtained by mixing into a sheet. Is obtained by

As described above, the ceramic material powder contained in the ceramic green sheet 20 is, for example, 10%.
In the case of a low-temperature sintered ceramic material powder that can be sintered at a temperature of 00 ° C. or less, examples of the inorganic material powder for suppressing shrinkage included in the outer constraining layer 24 include alumina, mullite, aluminum nitride, zirconia, and anorthite. , Forsterite and cordierite powders are advantageously used.

The shrinkage-suppressing inorganic material powder contained in the outer constraining layer 24 does not substantially sinter in the firing step, so that the outer constraining layer 24 does not substantially shrink. Therefore, the shrinkage suppressing action of the outer constraining layer 24 is exerted on the raw laminate 23, and the raw laminate 2
In No. 3, shrinkage occurs in the thickness direction, but shrinkage hardly occurs in the main surface direction of the ceramic green sheet 20.

As a result, the dimensional accuracy of the laminated body 13 after sintering shown in FIG.
In addition, high density wiring provided by the via hole conductor 15 can be achieved with high reliability. In addition, the shrinkage behavior of the ceramic green sheet 20 in the main surface direction during the firing process can be substantially matched with the shrinkage behavior of each of the sheet portion 18 and the bump portion 19 of the metal foil 17. Therefore, in the obtained multilayer ceramic substrate 11, peeling between the ceramic layer 12 and the conductor film 13 can be suppressed.

After the firing step, outer constraining layer 24 is removed by, for example, sandblasting.

FIG. 2 is for explaining a second embodiment of the present invention, and is particularly for explaining another embodiment relating to a metal foil forming step. In FIG.
Elements corresponding to the elements shown in FIG. 1 are denoted by the same reference numerals, and redundant description will be omitted.

In this embodiment, first, as shown in FIG. 2A, a support 16 is prepared. While using the photolithography technique on this support 16, FIG.
As shown in FIG. 2, first, a sheet-like portion 18 is formed by an additive plating method, and then, as shown in FIG. 2C, a bump portion 19 is formed by a similar method.

As described above, when the bump portion 19 is formed by the additive plating method, the deposition speed is usually high at a position away from the resist, so that the bump portion 19 is tapered almost naturally. it can. However, in order to more reliably form the tapered bump portion 19, first, a resist having a wide opening pattern is formed and a plating film is deposited, and then a resist having a smaller opening pattern is formed and plating is performed. It is preferable to apply a two-stage deposition, such as depositing a film.

In this manner, the metal foil 17 integrally including the sheet-like portion 18 and the bump portion 19 is placed on the support 1.
After completing the metal foil forming step of forming on 6, the steps shown in FIGS. 1 (3) to (7) are performed as in the case of the first embodiment, and the intended multilayer ceramic substrate 11 is obtained. be able to.

As still another modification of the metal foil forming step, a metal film to be the sheet-like portion 18 is formed on the support 16 and the metal film is patterned by etching. 2), a bump portion 19 is formed on the patterned metal film, that is, the sheet portion 18 by using a photolithography technique, as shown in FIG. It may be formed by a plating method.

FIG. 3 is a view for explaining a third embodiment of the present invention, and particularly shows a modified example relating to a ceramic green sheet preparing step, a transferring step and a laminating step. 3, elements corresponding to the elements shown in FIG. 1 are denoted by the same reference numerals, and overlapping description will be omitted.

The step shown in FIG. 3A corresponds to the step shown in FIG. In this embodiment, FIG.
As shown in (1), the ceramic green sheet 20
Is used while being backed by a carrier film 25. This prevents the soft ceramic green sheet 20 from being undesirably deformed or damaged in the steps up to the laminating step.

As described above, the ceramic green sheet 20 is obtained by forming the ceramic slurry into a sheet by a doctor blade method or the like. This sheet forming step is usually performed on the carrier film 25. This is performed so that the ceramic green sheet 20 is formed. Therefore, the formed ceramic green sheet 20 may be supplied to the step shown in FIG. 3A without peeling from the carrier film 25.

As shown in FIG. 3A, the metal foil 1 held on the support 16 is directed to the ceramic green sheet 20 lined with the carrier film 25.
7 are arranged, and the metal foil 17 is pressed toward the ceramic green sheet as indicated by an arrow 21. As a result, as shown in FIG. 3B, the bump portions 19 of the metal foil 17 protrude in the thickness direction of the ceramic green sheet 20. Next, as shown in FIG. 3C, the support 16 is removed, and as a result, the metal foil 17 is transferred from the support 16 to the ceramic green sheet 20. At this stage, the ceramic green sheet 20 is also backed by the carrier film 25.

Next, as shown in FIG. 3 (4), the ceramic green sheets 20 are laminated with the carrier film 25 facing upward, and are pressed toward the previously laminated ceramic green sheets 20, and thereafter, In, the carrier film 25 is peeled from the ceramic green sheet 20.

In this way, the green laminate 23 is obtained, and thereafter, the same steps as those in the first embodiment are performed, and the intended multilayer ceramic substrate 11 is obtained.

FIG. 4 is for explaining the fourth embodiment of the present invention, and particularly shows a modification relating to the transfer step and the laminating step. In FIG. 4, elements corresponding to the elements shown in FIG. 1 or FIG. 3 are denoted by the same reference numerals, and redundant description will be omitted.

Referring to FIG. 4A, ceramic green sheet 2 lined with carrier film 25
0 are stacked on the previously laminated ceramic green sheet 20 with the carrier film 25 facing up and then pressed down, after which the carrier film 25 is peeled off. At this stage, the metal foil 17 is not provided on the ceramic green sheet 20 that has just been laminated.

Next, as shown in FIG. 4B, toward the ceramic green sheet 20 just laminated,
The metal foil 17 formed on the support 16 is pressed as shown by an arrow 21, and as a result, as shown in FIG. Rushed into. Thereafter, the support 16 is removed, and as a result, the metal foil 17 is removed from the support 1.
6 to a ceramic green sheet 20.

In this way, the green laminate 23 shown in FIG. 1 (6) is obtained. Thereafter, the same steps as those in the first embodiment are performed, and the intended multilayer ceramic substrate 1 is formed.
1 is obtained.

FIG. 5 is for explaining the fifth embodiment of the present invention, and particularly for explaining a modification of the non-shrinkage process. In FIG. 5, elements corresponding to the elements shown in FIG. 1 are denoted by the same reference numerals, and redundant description will be omitted.

The step shown in FIG. 5 corresponds to the step shown in FIG. As shown in FIG. 5, an interlayer constraining layer 26 containing a shrinkage-suppressing inorganic material powder that does not sinter at the sintering temperature of the ceramic material powder contained in the ceramic green sheet 20 is formed on the ceramic green sheet 20.

In this embodiment, the ceramic green sheet 20 on which the interlayer constraining layer 26 is formed is shown in FIG.
Steps corresponding to the steps (3) to (7) are performed. Therefore, the raw laminate 23 shown in FIG.
In FIG. 1, the interlayer constraining layer 26 is located along the interface between the ceramic green sheets 20. In the laminated body 13 after sintering shown in FIG.
An interlayer constraining layer 26 is located along the interface between the two.

As described above, when the ceramic material powder contained in the ceramic green sheet 20 can be sintered at a temperature of 1000 ° C. or less, the interlayer constraining layer 26 is made of, for example, alumina, mullite, aluminum nitride, glass ceramic, It contains at least one of zirconia, anorthite, forsterite and cordierite powder as a main component, contains 15 to 60% by volume of a borosilicate glass powder having a softening point of 780 ° C and a particle size of 1.5 μm, and further contains polyvinyl butyral. A slurry obtained by mixing a binder made of di-n-butylphthalate and a plasticizer made of di-n-butyl phthalate with a solvent made of toluene and isopropylene alcohol is applied on the ceramic green sheet 20.

The inorganic material powder for suppressing shrinkage, such as alumina powder, contained in the interlayer constrained layer 26 does not substantially sinter in the firing step. Does not occur. Therefore,
The shrinkage-suppressing action of the interlayer constraining layer 26 is exerted on the ceramic green sheet 20, and the shrinkage of the ceramic green sheet 20 in the main surface direction in the firing step is suppressed. As a result, the dimensional accuracy of the laminated body 13 after sintering can be increased, and high density wiring can be achieved with high reliability. Further, in the firing step, the shrinkage behavior of the ceramic green sheet 20 and the shrinkage behavior of the metal foil 17 can be substantially matched, and the laminated body 13 after sintering can be obtained.
In this case, the problem of peeling of the ceramic layer 12 or the like can be suppressed.

The interlayer constraining layer 26 has the above-described composition, and as a result of the firing step, is densified and solidified. Therefore, it is not removed after the firing step, and the multilayer ceramic substrate 11 as a product is not removed. Will be left.

Such a non-shrink process by the interlayer constraining layer 26 may be used together with the non-shrink process by the outer constraining layer 24 shown by the imaginary line in FIG.

The non-shrink process by the interlayer constraining layer 26 can be applied to the third and fourth embodiments described with reference to FIGS. 3 and 4, respectively.

If the interlayer constraining layer 26 is formed over the entire surface of the ceramic green sheet 20 as shown in FIG. 5, there is no problem of alignment accuracy. You may make it form only in the area | region corresponding to the area | region where the shape part 18 was formed.

Further, the interlayer constraining layer 26 is
It is not necessary to be located along all the interfaces between the plurality of ceramic green sheets 20 in the above, and it may be located along only a specific interface.

In the state shown in FIG. 5, the interlayer constraining layer 26 is formed on the side of the ceramic green sheet 20 where the bump portion 19 of the metal foil 17 enters, but it is upside down. That is, the interlayer constraining layer 26 may be formed on the lower surface side of the ceramic green sheet 20.

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

For example, in the above-described embodiment, the metal foil 17 is mainly composed of copper or silver. However, the metal foil 17 is mainly composed of nickel, palladium, tungsten, gold, platinum or the like. You may.

In the illustrated embodiment, the metal foil 17
The bump portion 19 provided in the above has a height that penetrates one ceramic green sheet 20, but may have a height that penetrates two or more ceramic green sheets.

In the above-described embodiment, for example, L
Although the present invention is directed to a multilayer ceramic substrate 11 used for a C filter, a multi-chip module, a chip scale package, and the like, the present invention is directed to a laminate including a plurality of laminated ceramic layers, Other multilayer ceramics such as a multilayer capacitor and a multilayer inductor as long as they include a conductive film to be formed and a via-hole conductor provided so as to penetrate a specific ceramic layer in the thickness direction while being connected to the conductive film. It can also be applied to electronic components.

[0103]

As described above, according to the present invention, since the conductor film and the via-hole conductor are integrally formed of the metal foil having the sheet-like portion and the bump portion, the conductor film and the via-hole conductor are formed in the drying and shrinking steps, for example. There is no difference in the shrinkage behavior between the film and the via-hole conductor, and therefore no connection failure occurs between the conductor film and the via-hole conductor.

Further, since the metal foil is not made of a sintered body of a conductive paste but made of a dense metal body, an increase in electric resistance due to the presence of voids and grain boundaries in the conductor is avoided. Therefore, it is advantageous for lowering the resistance of the wiring conductor, and can be particularly suitable for forming a high-frequency circuit requiring low resistance.

In the method for manufacturing a multilayer ceramic electronic component according to the present invention, the step of forming a bump portion serving as a via-hole conductor on a metal foil does not increase even if the number of bump portions increases, and one support A plurality of bump portions can be simultaneously formed on the metal foil on the body. In the step of transferring the metal foil from the support to the ceramic green sheet, a plurality of bump portions formed on the metal foil can simultaneously protrude in the thickness direction of the ceramic green sheet. From such a thing,
By providing a through hole in a ceramic green sheet and filling it with a conductive paste as in the related art, higher productivity can be realized as compared with the case where a via hole conductor is formed.

Further, in order to provide a via-hole conductor, a through-hole is provided in a ceramic green sheet as in a conventional case,
If the method of filling the conductive paste there is adopted, insufficient filling of the conductive paste may occur due to air or foreign matter mixed in, and therefore, a connection failure may occur. Is relatively difficult to detect at a stage before lamination of the ceramic green sheets. On the other hand, according to the present invention, since the metal foil having the bump portion to be the via-hole conductor is exposed from the ceramic green sheet before lamination, the connection failure can be easily performed by, for example, metal detection or continuity inspection. , And as a result, the yield is improved.

Further, since the conductive film and the via-hole conductor are made of metal foil, it is possible to measure a certain degree of electrical characteristics even before firing. Therefore, when it is determined that the electric characteristics are defective, it can be selected at a stage before firing, and it is possible to avoid performing an unnecessary firing process. In the case of a multilayer ceramic substrate, it is possible to avoid mounting expensive components such as an IC on a multilayer ceramic substrate having poor electrical characteristics.

In some cases, the conductive film and / or the via-hole conductor appearing on the outer surface of the multilayer ceramic electronic component are subjected to wet plating. In the case of being composed of a sintered body of the above, the plating solution may permeate and deteriorate the characteristics of the multilayer ceramic electronic component or reduce the reliability. Since the film and via-hole conductor are made of dense metal foil,
Such a problem as the penetration of the plating solution can be avoided.

The sheet portion for the conductor film provided by the metal foil and the bump portion for the via hole conductor are formed by using, for example, a photolithography technique.
Since it can be finely formed with high accuracy, it is possible to sufficiently meet the demand for further miniaturization of the multilayer ceramic electronic component and further higher density of the wiring.

In the transfer step included in the method for manufacturing a laminated ceramic electronic component according to the present invention, the bump portion of the metal foil forms a through-hole in the ceramic green sheet by entering the ceramic green sheet by itself. This eliminates the need for a step of providing a through hole in the ceramic green sheet in advance, and can reduce the number of steps.

Further, when the bump portion of the metal foil is tapered, the protrusion of the bump portion into the ceramic green sheet can be more smoothly performed.

In the method of manufacturing a multilayer ceramic electronic component according to the present invention, a so-called non-shrinkage process in which a firing step is performed in a state where an interlayer constraining layer and an outer constraining layer are arranged on a green laminate is applied. In addition, the dimensional accuracy of the laminated body after sintering can be increased, and the density of the wiring provided by the conductor film and the via-hole conductor can be increased with high reliability. In addition, the shrinkage behavior of the ceramic green sheet in the main surface direction during the firing process can be substantially matched with the shrinkage behavior of each of the metal foil sheet portion and the bump portion. Therefore, in the obtained multilayer ceramic electronic component, peeling between the ceramic layer and the conductive film can be suppressed.

[Brief description of the drawings]

FIG. 1 is a sectional view sequentially showing several typical steps included in a method for manufacturing a multilayer ceramic substrate 11 according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing characteristic steps included in a second embodiment of the present invention.

FIG. 3 is a cross-sectional view showing characteristic steps included in a third embodiment of the present invention.

FIG. 4 is a cross-sectional view showing characteristic steps included in a fourth embodiment of the present invention.

FIG. 5 is a sectional view showing a characteristic step included in a fifth embodiment of the present invention.

FIG. 6 is a cross-sectional view for illustrating a problem to be solved by the present invention and showing one ceramic layer 1 provided on a conventional multilayer ceramic substrate.

7 is a cross-sectional view similar to FIG. 6, for explaining a problem to be solved by the present invention, and showing another form of ceramic layer 1 provided in a conventional multilayer ceramic substrate.

[Explanation of symbols]

11 Multilayer ceramic substrate 12 ceramic layer 13 laminate 14 Conductive film 15 Via hole conductor 16 Support 17 Metal foil 18 Sheet-shaped part 19 Bump part 20 ceramic green sheets 23 Raw laminate 24 Outer restraint layer 25 Carrier film 26 interlayer constrained layer

   ────────────────────────────────────────────────── ─── Continuation of front page    F term (reference) 5E346 AA12 AA15 AA32 AA35 AA38                       AA43 BB01 BB11 CC18 CC32                       CC39 DD02 DD12 DD33 EE24                       FF24 FF35 FF36 GG08 GG09                       HH07 HH11

Claims (14)

[Claims] 1. A laminate comprising a plurality of laminated ceramic layers, a conductor film formed on the ceramic layer, and a specific ceramic layer penetrating in a thickness direction while being connected to the conductor film. And a via-hole conductor provided as described above, wherein the conductive film and the via-hole conductor are integrally formed of a metal foil, and the metal foil is a sheet-shaped portion that provides the conductive film. And a bump portion formed so as to rise from a part of the sheet-shaped portion so as to provide the via-hole conductor. 2. The multilayer ceramic electronic component according to claim 1, wherein said metal foil contains at least one of copper and silver. 3. A laminate comprising a plurality of laminated ceramic layers, a conductor film formed on the ceramic layer, and penetrating a specific ceramic layer in the thickness direction while being connected to the conductor film. And a via-hole conductor provided as described above, comprising: a sheet-shaped portion providing the conductive film and a part of the sheet-shaped portion provided to provide the via-hole conductor. Forming a metal foil integrally provided with the formed bump portion on a support, a metal foil forming step; preparing a ceramic green sheet to be the ceramic layer; a ceramic green sheet preparing step; The gold is placed in such a manner that the bump portion of the foil protrudes in the thickness direction of the ceramic green sheet. Transferring a metal foil from the support to the ceramic green sheet; transferring the plurality of ceramic green sheets; and stacking the plurality of ceramic green sheets; and a raw laminate including the stacked plurality of ceramic green sheets. And a firing step of firing the multilayer ceramic electronic component. 4. The step of forming a metal foil includes the steps of: attaching a metal foil having a thickness corresponding to at least the height of the bump portion on the support; and etching the metal foil using a photolithography technique. 4. A method of manufacturing a multilayer ceramic electronic component according to claim 3, further comprising: giving a shape of the sheet-like portion and the bump portion to the metal foil. 5. The metal foil forming step includes a step of sequentially forming the sheet-shaped portion and the bump portion on the support by using an additive plating method while using a photolithography technique. Of manufacturing a multilayer ceramic electronic component. 6. The metal foil forming step includes: forming a metal film to be the sheet portion on the support; patterning the metal film by etching; and using a photolithography technique. Forming the bump portion on the metal film by an additive plating method. The method of manufacturing a multilayer ceramic electronic component according to claim 3, further comprising: 7. The method of manufacturing a multilayer ceramic electronic component according to claim 3, wherein said laminating step is performed so as to laminate said ceramic green sheets after said transfer step. . 8. The ceramic green sheet preparing step includes a step of preparing the ceramic green sheet in a state where the ceramic green sheet is lined with a carrier film, and the transfer step includes a step of preparing the ceramic green sheet lined with the carrier film. The laminating step includes a step of peeling the carrier film after laminating the ceramic green sheets,
A method for manufacturing a multilayer ceramic electronic component according to claim 7. 9. The stacking step is performed so as to stack the ceramic green sheets before performing the transfer step, and the transfer step is performed on the ceramic green sheets after the stacking step is completed. The method for producing a multilayer ceramic electronic component according to claim 3, wherein the method is performed. 10. The method for manufacturing a multilayer ceramic electronic component according to claim 3, wherein said bump portion of said metal foil is tapered. 11. The ceramic green sheet according to claim 3, wherein, in the transferring step, the bump portion of the metal foil forms a through hole in the ceramic green sheet by intruding itself into the ceramic green sheet. A manufacturing method of the multilayer ceramic electronic component according to the above. 12. A first material that does not sinter at the sintering temperature of the ceramic material powder contained in the ceramic green sheet.
The interlayer constraining layer containing the shrinkage-suppressing inorganic material powder is located along an interface between the plurality of ceramic green sheets constituting the green laminate, so that the interlayer confining layer is formed on a specific ceramic green sheet. The method for manufacturing a multilayer ceramic electronic component according to claim 3, further comprising a step of forming a constraining layer. 13. A second material that does not sinter at the sintering temperature of the ceramic material powder contained in the ceramic green sheet.
Further comprising a step of arranging the outer constraining layer containing the inorganic material powder for suppressing shrinkage in such a manner as to sandwich the green laminate in the laminating direction. The method for manufacturing a multilayer ceramic electronic component according to claim 3, further comprising: 14. A multilayer ceramic electronic component obtained by the manufacturing method according to claim 3. Description: