JP2003347730A - Ceramic multilayer substrate fabricating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that defects such as warps, cracks, unsticking or the like in a substrate due to in the shrinkage in a ceramic multilayer substrate where different materials are laminated. <P>SOLUTION: The solution of the problem is achieved by means of processes as follows: preparing a main ceramic green sheet 12, ancillary ceramic green sheets 14, 15 and a restraining green sheet 13; arranging the main ceramic green seat 12 and the ancillary ceramic green sheets 14, 15 with arbitrary structure and laminating the restraining green sheets 13 so as to be arranged in upper and lower surfaces of laminated body of the main and ancillary ceramic green sheets 12, 14, 15; sintering with a higher temperature than that for sintering the main ceramic green sheet 12; and removing the restraining green sheets 13 remaining in the upper and lower surfaces. <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 method for manufacturing a ceramic multilayer substrate, and more particularly to a method for manufacturing a ceramic multilayer substrate in which a sub-material ceramic layer having a different composition is formed on a part of a main ceramic layer. It relates to a manufacturing method.

[0002]

2. Description of the Related Art Ceramic multilayer substrates are widely used as circuit boards or electronic components because inner vias can be easily formed and three-dimensional three-dimensional circuits can be formed in a small size. In particular, a multilayer substrate or electronic component using a low-temperature sintered glass-ceramic material or the like and silver or copper as a conductor has good high-frequency characteristics, and demand for a wireless module such as a mobile phone is rapidly increasing. However, on the other hand, there is a growing demand for further miniaturization, compounding, and higher functionality.

As one measure to satisfy such a new demand, a method of partially forming ceramic materials having different characteristics in a multilayer substrate has been considered. For example, it is conceivable to partially form a dielectric material having a high relative dielectric constant to incorporate a relatively large capacitor element in a small size, or to form a magnetic material to incorporate a coil element having a large inductance value. Can be

However, when different types of ceramic materials are integrally laminated and fired, the shrinkage behavior and shrinkage ratio during firing are different for each ceramic material.
There has been a problem that peeling occurs at the interface between different types of ceramic materials, and that the entire ceramic substrate is warped or undulated.

To cope with such a problem, Japanese Patent Laid-Open No. 8-339
No. 937 and Japanese Unexamined Patent Application Publication No. 11-170423 propose a ceramic multilayer substrate having a sectional structure as shown in FIG. In each of these proposals, a sub-ceramic green sheet 3 made of a material different from the main material is formed on the main ceramic green sheet 2, and a cut groove 4 is formed to a depth at which the sub-ceramic green sheet 3 is completely divided. ing. With such a configuration, the mismatch in the shrinkage behavior and shrinkage rate in the firing of different materials is limited to the range partitioned by the formed cut grooves 4, so that the amount of warpage of the fired body, the frequency of peeling, etc. Was reduced.

[0006]

However, since there is still a difference in shrinkage behavior and shrinkage ratio of different kinds of materials in the area partitioned by the cut grooves 4, there is a practical problem depending on the combination of different kinds of materials and the lamination structure. However, there has been a problem that warpage and defects such as the following occur in the ceramic substrate.

[0007] The present invention solves the above-mentioned problems, and in any heterogeneous laminated structure, warpage during firing is small,
An object of the present invention is to provide a ceramic multilayer substrate having a laminated structure of different materials, which is excellent in accuracy and reliability without cracks and peeling.

[0008]

In order to achieve the above object, the present invention has the following arrangement.

According to a first aspect of the present invention, there is provided a main ceramic green sheet composed of a ceramic material as a main material, and at least one kind composed of a ceramic material having a composition different from that of the main material as an auxiliary material. Preparing a sub-ceramic green sheet, and a restraining green sheet made of an inorganic composition material that is not substantially fired at the firing temperature of the main material and the sub-material; and A step of arranging the green sheets in an arbitrary configuration, laminating the restraining green sheets so as to be arranged on the upper and lower surfaces of the laminate of the main and sub-ceramic green sheets, and at a temperature not lower than the sintering temperature of the main ceramic material And firing at a temperature lower than the sintering temperature of the inorganic composition material constituting the restraining green sheet; Removing the inorganic composition material constituting the constraining green sheet remaining on the upper and lower surfaces of the fired substrate, which is caused by mismatching of shrinkage behavior and shrinkage rate during firing of dissimilar materials. It has the effect of reducing the amount of warpage of the substrate and suppressing defects such as cracks and peeling at the interface between different materials.

According to a second aspect of the present invention, a main ceramic green sheet composed of a ceramic material as a main material and at least one kind composed of a ceramic material having a composition different from that of the main material as an auxiliary material are provided. Preparing a sub-ceramic green sheet, and a restraining green sheet made of an inorganic composition material that is not substantially fired at the firing temperature of the main material and the sub-material; and Arranging the green sheets in an arbitrary configuration, laminating the constraining green sheets so as to be arranged on the upper and lower surfaces of the laminated body of the main and sub ceramic green sheets, and a sub-ceramic green sheet during or after the laminating step Forming a notch so as to divide at least a portion of the notch; A step of integrating the body under pressure,
A step of firing at a temperature equal to or higher than the sintering temperature of the main ceramic material and lower than the sintering temperature of the inorganic composition material constituting the restraining green sheet, and from the fired substrate obtained by the firing to the upper and lower surfaces thereof Removing the inorganic composition material constituting the remaining constraining green sheet, reducing the amount of warpage of the substrate caused by the mismatch in the shrinkage behavior and the shrinkage ratio during firing of different materials, It has an effect that defects such as cracks and peeling at the material interface can be suppressed.

The invention according to claim 3 of the present invention is characterized in that the cut is formed to include a part of the main ceramic green sheet, which is a more preferable configuration of the invention according to claim 2, This has the effect that the amount of warpage of a ceramic multilayer substrate having a dissimilar material laminated structure can be extremely reduced.

The invention according to claim 4 of the present invention is characterized in that the cut is formed to include a part of the restraining green sheet, and the invention according to claim 2 or 3 is provided. Which has an effect that the amount of warpage of a ceramic multilayer substrate having a laminated structure of different materials can be extremely reduced.

The invention according to claim 5 of the present invention is characterized in that a pressure of 100 g / cm ² or less is applied to the laminate during the firing step. This is a more preferable configuration of the described invention, and has an effect that the amount of warpage of a ceramic multilayer substrate having a dissimilar material laminated structure can be extremely reduced.

According to a sixth aspect of the present invention, the cut is formed so as to include at least one surface of a laminate composed of a main ceramic green sheet and a sub ceramic green sheet, and after the firing step, the cut is formed. And has a function of easily dividing a ceramic multi-layer substrate having a dissimilar material laminated structure into individual pieces.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for manufacturing a ceramic multilayer substrate according to the present invention will be described with reference to embodiments and drawings.

(Embodiment 1) Embodiment 1 and FIG.
The invention of claims 1 to 6 will be described with reference to FIG.

FIGS. 1 to 12 are sectional views showing a state before a firing step of a ceramic multilayer substrate according to the present invention.
In the figure, 12 is a main ceramic green sheet as a main material, 14 and 15 are sub-ceramic green sheets as sub-materials, and 13 is an inorganic composition having a sintering temperature higher than that of the main and sub-ceramic green sheets. It is a green sheet for restraint constituted.

The main ceramic green sheet 12 or the auxiliary ceramic green sheets 14 and 15 may be made of a glass ceramic composite composition obtained by mixing glass with alumina or titanium oxide, a dielectric material containing bismuth oxide as a main component, A dielectric material containing lead oxide as a main component is often used, but is not limited thereto. In addition, as a material constituting the restraining green sheet 13, alumina, magnesia, zirconia, or the like, which is a hardly sinterable inorganic material, is often used, but is not particularly limited. Add resin binder component, plasticizer, solvent, etc. to these materials,
The mixture is slurried and formed into a green sheet having an arbitrary thickness by a method such as a doctor blade method or a die coater method, but the method and thickness are not particularly limited.

The main ceramic green sheet 12 and the sub ceramic green sheets 14, 15 prepared as described above are provided.
Are arranged in an arbitrary configuration as shown in FIGS. 1 to 12,
The restraining green sheets 13 are stacked so as to sandwich the laminated body formed by the main and sub ceramic green sheets 12, 14, 15 from above and below. In this stacking step, the cuts 16 may be formed using a cutter blade or the like as shown in FIGS. When the cuts 16 are formed, the cuts 16 completely separate the sub-ceramic green sheets 14 and 15 as in the case other than FIG. 12, and the sub-ceramic green sheets 14 and 15 as shown in FIGS. May be formed only in the portion of
As shown in FIG. 7 to FIG.
May be included, and may further include the restraining green sheet 13 as shown in FIGS. or,
7 and FIGS. 10 to 12, the cuts 16 are formed in the middle of each sheet, but this case can be realized by laminating green sheets of the same material. The width of the cut 16 is not particularly limited,
There is no problem even if it is thin as when formed with a cutter blade or the like. In the case where a plurality of types of sub-ceramic green sheets 14 and 15 are formed in the laminate, as shown in FIGS. 5, 6, and 9, the cut 16 is formed in at least one type of sub-ceramic green sheet 14 or 15. Alternatively, there may be an auxiliary ceramic green sheet 15 having no cut 16 as shown in FIGS.

The laminates prepared as described above are integrated by pressing, and the ceramic green laminates 11 and 12 are integrated.
1, 31, 41 are obtained. As the pressing method, uniaxial pressing, hydrostatic pressing or the like is used, but is not particularly limited.

The ceramic green laminates 11 and 12
In 1, 31, 41, the main ceramic green sheet 12, the sub ceramic green sheets 14, 15 are sintered, and the restraining green sheet 13 is fired so as to be in an unsintered state. In this firing, since the restraining green sheet 13 does not sinter, there is almost no shrinkage due to the firing step. Therefore, the laminate of the different kinds of materials constituted by the main and sub ceramic green sheets 12, 14, 15 to be sintered is Tensile force in the plane direction from the green sheet 13,
Baking is performed while receiving a compressive force in the laminating direction. The acting force from the restraining green sheet 13 suppresses the warpage of the substrate due to the mismatch of the shrinkage behavior and the shrinkage rate during firing of the main and sub ceramic green sheets 12, 14, and 15, and cracks at the interface between different materials. Also, defects such as peeling can be suppressed. When the cuts 16 are formed in the auxiliary ceramic green sheets 14 and 15, the absolute amount of the difference in firing shrinkage behavior between the main and auxiliary ceramic green sheets 12, 14 and 15 can be reduced. Can be.

In the firing step, 100 g /
cm^TwoThe following pressure was applied to the ceramic green laminates 11 and 12.
If it is baked while acting on 1, 31, 41,
Pressure can further reduce substrate warpage
Becomes The method of action of the pressure is, for example, a sintered porous substrate.
The plates were replaced with ceramic green laminates 11, 21, 31, 41
Although there is a method of putting on, there is no particular limitation. Was
However, 100g / cm ^TwoWhen a pressure exceeding
During firing, the ceramic green laminates 11, 21, 31,
Because it may cause cracking or deformation of 41
Not preferred.

Main and sub ceramic green sheets 1
Unsintered restraining green sheets 13 remain on the upper and lower surfaces of the ceramic multi-layer substrate of a heterogeneous material laminated structure in which 2, 14, and 15 are sintered (this state is called a fired substrate). The fired substrate is removed by brushing, polishing, sand blasting, wet blasting, high-pressure water injection, ultrasonic irradiation, or the like, but the method is not particularly limited.

Through the above steps, the warpage of the laminate due to the mismatch in the shrinkage behavior and shrinkage rate of the different materials during firing is suppressed, and the heterogeneous material laminated structure in which defects such as cracks and peeling at the interface between the different materials are also suppressed. Ceramic multilayer substrate can be realized.

Also, as shown in FIGS. 8 to 11, the cuts 16 are formed by cutting the main and sub ceramic green sheets 12,1.
In the case where the laminate is formed so as to include at least one surface of the laminates 4 and 15, the cut 16 is also formed on the surface of the fired substrate.
Is formed, the ceramic multilayer substrate can be easily divided into individual pieces by applying a force along the cuts 16.

It was confirmed that the same effect could be obtained when a wiring layer was formed on the laminate of the main and sub ceramic green sheets 12, 14, and 15 using a conductive paste containing silver or copper as a main component. ing.

(Example) A ceramic multilayer substrate having a laminated structure of different materials according to the above-described embodiment was actually manufactured as follows, and the effectiveness of the present invention was confirmed as compared with a conventional method.

As a material for forming the main ceramic green sheet 12, a glass-ceramic composite oxide in which alumina and calcium borosilicate glass were mixed at a weight ratio of 50:50 was used. Sub green sheet 1
4 is made of a dielectric material containing Bi ₂ O ₃ , CaO, and Nb ₂ O ₅ as main components, and another kind of sub-ceramic green sheet 15 is made of titanium oxide and barium borosilicate glass at 40:60. Was used. Further, alumina powder having a purity of 99% was used as a material constituting the restraining green sheet 13.

Polyvinyl butyral resin as a resin binder, dibutyl phthalate as a plasticizer, butyl acetate as a solvent were added to these inorganic material powders, mixed with a ball mill, and formed into a green sheet having a thickness of 50 μm by a doctor blade method.

Each of these green sheets is 70 mm × 70
mm, and cut into a size of 40 as shown in (Table 1).
The layers were laminated under pressure at a temperature of -100 kg / cm ² .

[0031]

[Table 1]

When the cuts 16 are formed as in sample Nos. 5 to 13, the respective green sheets are stacked up to the layer where the cuts 16 are formed, and the depth is adjusted by 10 mm while using a cutter blade to adjust the depth. After forming the cuts 16 so as to form a grid of 10 mm, the green sheets of the remaining layers were further laminated thereon (for the depth of the cuts 16 for each sample, see the corresponding drawing). The notch 4 of the sample No. 1 which is a conventional example uses a dicing blade having a thickness of 200 μm.
Using a dicing machine, grooves were formed in a 10 mm × 10 mm lattice shape.

The laminate thus manufactured was heated at 80 ° C.
After pressing and integrating under the condition of −500 kg / cm ² to form ceramic green laminates 11, 21, 31, 41,
The ends were cut to a size of 60 mm × 60 mm.

The ceramic green laminates 11 and 12
The organic components such as a resin binder and a plasticizer were decomposed and removed by heat-treating 1, 31, 41 at 500 ° C. for 5 hours, and then fired at 900 ° C. for 30 minutes. Green sheet for restraint 13 remaining on the surface of the fired substrate
Was mechanically removed using a brush.

The warpage of the fired ceramic multilayer substrate is as follows:
A 5 cm square surface at the center of the substrate was measured by a laser type surface roughness meter, and determined by the difference between the maximum and minimum values. The results are shown in (Table 1).

When the restraining green sheets 13 are not laminated as in the sample numbers 0 and 1, the cuts 16 are formed.
Regardless of whether or not the substrate was warped, the amount of warpage was as large as 200 μm or more, and a part of the substrate was partially peeled off at the interface between different materials.

On the other hand, when the restraining green sheets 13 are laminated above and below the laminate as in Sample Nos. 2 to 13, the amount of warpage is 100 μm or less regardless of the arrangement of the sub-ceramic green sheets 14 and 15. And no defects such as peeling and cracks at the interface between different materials were observed at all.

In particular, when the cuts 16 were formed in the auxiliary ceramic green sheets 14 and 15 as in Sample Nos. 5 to 12, the amount of warpage of the substrate was further reduced to 70 μm or less. The formation depths of the cuts 16 are determined by the auxiliary ceramic green sheets 14 and 15 as shown in sample numbers 5 to 7.
When forming including the main ceramic green sheet 12 as in sample numbers 8 to 10,
Green sheets 13 for restraint as in sample numbers 11 and 12
The tendency that the amount of warpage was reduced in the order of the case of forming with the inclusion was observed. The cut 16 was observed, but no defects such as peeling and cracks were observed.

In addition, as shown in the sample No. 13, the cut 16 which does not divide the sub-ceramic green sheet 14 or 15
Was formed, there was no substantial difference in the amount of warpage from the case of Sample No. 2 in which the cut 16 was not formed in the same laminated structure, and the effect of forming the cut 16 was not observed. The cut 16 is preferably formed so as to divide the sub-ceramic green sheet 14 or 15.

Next, the effect of the action of the pressure on the ceramic green laminate 11 in the firing step is shown in Sample No. 2.
(FIG. 2). The results are shown in (Table 2).

[0041]

[Table 2]

Sample Nos. 14 to 18 show the results when firing was performed while applying pressure by placing various weight porous plates made of alumina on the ceramic green laminate 11.

When firing was performed while applying a pressure of 100 g / cm ² or less, the amount of warpage was clearly smaller than when no pressure was applied, and the effect was confirmed. However, as shown in sample No. 18, 150 g / c
When a large pressure exceeding m ² and 100 g / cm ² was applied, cracks occurred in the corners of the ceramic multilayer substrate, and it was found that the applied pressure was preferably 100 g / cm ² or less.

Further, for the sample Nos. 9 to 12 in which the cuts 16 were formed including the surfaces of the main or sub ceramic green sheets 12, 14, 15 after firing, a force was applied along the cuts 16 to divide the ceramic multilayer substrate. And
When the split surface was observed, no defects such as large chipping which would cause a problem in practical use were found.
It was confirmed that the ceramic multilayer substrate could be divided into individual pieces.

[0045]

As described above, according to the present invention, it is possible to obtain a ceramic multilayer substrate having a laminated structure of a heterogeneous material having a small warpage at the time of sintering, a high degree of accuracy without cracks and peeling, and an excellent reliability. It is possible to manufacture a composite, high-performance ceramic multilayer substrate and ceramic electronic component.

In addition, if a cut formed as a preferred example for achieving the above object is used, a ceramic multilayer substrate having a laminated structure of different materials can be easily divided into individual pieces, and cut by a dicing machine or the like. Compared with the construction method, processing can be performed easily in a short time, and the manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a ceramic green laminate showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a ceramic green laminate showing another example of the present invention.

FIG. 3 is a sectional view of a ceramic green laminate showing another example of the present invention.

FIG. 4 is a sectional view of a ceramic green laminate showing another example of the present invention.

FIG. 5 is a sectional view of a ceramic green laminate showing another example of the present invention.

FIG. 6 is a sectional view of a ceramic green laminate showing another example of the present invention.

FIG. 7 is a sectional view of a ceramic green laminate showing another example of the present invention.

FIG. 8 is a sectional view of a ceramic green laminate showing another example of the present invention.

FIG. 9 is a cross-sectional view of a ceramic green laminate showing another example of the present invention.

FIG. 10 is a sectional view of a ceramic green laminate showing another example of the present invention.

FIG. 11 is a sectional view of a ceramic green laminate showing another example of the present invention.

FIG. 12 is a sectional view of a ceramic green laminate showing another example of the present invention but not belonging to the invention of claim 2;

FIG. 13 is a cross-sectional view of a ceramic green laminate showing an example of the prior art.

[Explanation of symbols]

11, 21, 31, 41 Ceramic green laminate 12 before firing step Main ceramic green sheet 13 Green sheets for restraint 14, 15 Secondary ceramic green sheet 16 Cut

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Hiroshi Asano             Matsushita Electric, 1006 Kadoma, Kazuma, Osaka             Sangyo Co., Ltd. F term (reference) 5E346 AA12 CC17 CC18 EE21 GG04                       HH11

Claims (6)

[Claims] 1. A main ceramic green sheet composed of a ceramic material as a main material, at least one kind of sub ceramic green sheet composed of a ceramic material having a composition different from that of the main material as a sub material, and the main material And a step of preparing a restraining green sheet made of an inorganic composition material that is not substantially fired at the firing temperature of the auxiliary material, and arranging the main ceramic green sheet and one or more types of auxiliary ceramic green sheets in an optional configuration, A step of laminating the restraining green sheets so as to be disposed on the upper and lower surfaces of the main and sub ceramic green sheet laminates, and an inorganic composition forming the restraining green sheets at a temperature not lower than the sintering temperature of the ceramic material as the main material. Firing at a temperature lower than the sintering temperature of the material, and from the fired substrate obtained by the firing to the upper and lower surfaces thereof Removing the inorganic composition material constituting the remaining restraining green sheet. 2. A main ceramic green sheet made of a ceramic material as a main material, one or more kinds of sub ceramic green sheets made of a ceramic material having a composition different from that of the main material as an auxiliary material, and the main material And a step of preparing a restraining green sheet made of an inorganic composition material that is not substantially fired at the firing temperature of the auxiliary material, and arranging the main ceramic green sheet and one or more types of auxiliary ceramic green sheets in an optional configuration, Laminating the constraining green sheets so as to be arranged on the upper and lower surfaces of the main and sub-ceramic green sheet laminates, and cutting so as to divide at least a part of the sub-ceramic green sheets during or after the laminating step. Forming a step, and a step of pressing and integrating the laminated body having the cut formed therein, A step of firing at a temperature equal to or higher than the sintering temperature of the main ceramic material and lower than the sintering temperature of the inorganic composition material constituting the restraining green sheet, and from the fired substrate obtained by the firing to the upper and lower surfaces thereof Removing the inorganic composition material constituting the remaining restraining green sheet. 3. The method according to claim 2, wherein the cut is formed to include a part of the main ceramic green sheet. 4. The method for manufacturing a ceramic multilayer substrate according to claim 2, wherein the cut is formed to include a part of the restraining green sheet. 5. During the firing step, 100 g / cm ²
The method for manufacturing a ceramic multilayer substrate according to any one of claims 1 to 4, wherein the following pressure is applied to the laminate. 6. A cut is formed so as to include at least one surface of a laminate composed of a main ceramic green sheet and a sub-ceramic green sheet, and the substrate is divided along the cut after the firing step. 5. The method for manufacturing a ceramic multilayer substrate according to any one of 4.