JPH01241810A - Composite laminated ceramic structure - Google Patents

Abstract

PURPOSE:To obtain a composite laminated ceramic structure of high quality generating no delamination crack by arranging mixture layers of an insulator and a dielectric between an insulating layer and a dielectric layer in order to ease up thermal stress generated at the time of sintering and cooling. CONSTITUTION:The mixture layers 11-13 placed between the insulating layers 2 and the dielectric layers 1 are the mixture of insulating composition and dielectric composition. The weight ratio of an insulator to a dielectric is 80:20 in the mixture layer I 11, 50:50 in the mixture layer II 12 and 20:80 in the mixture layer III 13. Raw material powder is mixed with an organic solvent and an organic inverter to make slurry and a green sheet on a polyethylene film. A ceramic green sheet of the insulator, a green sheet of the dielectric and a green sheet of the mixture of an insulating material and a dielectric material are respectively made for being cut in a prescribed shape respectively so that the respective ceramic green sheet pieces are made. Next, after being laminated and put into a press metal mold, thermal fixing press is performed and a raw laminate is cut in a prescribed shape followed by debinder treatment and sintering so as to obtain a composite lamination ceramic structure.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a composite laminated ceramic horizontal body made of a composite of different materials, and particularly to a composite made of a uniform composite of ceramic materials having different sintering shrinkage properties or thermal expansion properties. The present invention relates to a laminated ceramic structure.

[Conventional technology]

Conventionally, capacitors have been formed by forming an electronic circuit on a substrate made of ceramic or the like provided with a wiring layer, disposed between wiring conductors, and soldered. However, in this method, one chip type or disk type capacitor must be installed.

On the other hand, in recent years, attempts have been made to form electronic circuits including capacitors and the like inside substrates using high frit technology.

That is, a dielectric layer and an internal electrode for a capacitor are alternately formed on a ceramic substrate made of alumina or the like by a screen printing method, and then an insulating layer J34 which becomes the surface of the substrate is formed thereon and fired to form a capacitor. There is. However, in this case, there is a drawback that the number of steps for printing each pattern increases, resulting in poor workability. In addition, the dielectric constant of the dielectric material is small, and as printing layers are repeated, the flatness of the printed area becomes extremely poor, making it difficult to increase the number of layers, making it difficult to form capacitors with large capacitance. was impossible.

As described above, in conventional composite components such as hybrid integrated circuits, there is a limit to mounting elements at high density on a limited number of insulating substrates such as ceramics.

Therefore, in order to achieve higher density and higher integration, new composite laminated ceramic structures are being developed that have a laminated structure in which resistors and capacitors are housed within an insulating substrate.

An example of this composite laminated ceramic structure is shown in FIG.

In this example, a capacitor electrode layer 3 is formed on a dielectric layer 1 having a predetermined dielectric constant, and a capacitor is realized by laminating these layers, and one of the outermost insulating layers 2 has an external circuit on its outer surface. An external pad electrode 6 for connection is provided, and an intermediate insulating layer 2 is provided between the external pad electrode 6 and the electrode layer 3 of the capacitor.
These insulator layers 2. It has a structure in which dielectric layers 1 are stacked and connected. It goes without saying that the dielectric material and insulator material forming the dielectric layer 1 and the insulator layer 2 have different properties.

[Problem to be solved by the invention]

The conventional composite laminated ceramic structure described above includes laminated dielectric layers 1. Since the insulator layer 2 is formed of dielectric materials and insulator materials that have different properties, the insulator layer 2 Phenomena such as peeling and cracking tend to occur at the interface between the dielectric layer 1 and the dielectric layer 1, which has the drawback of impairing quality stability and reliability.

In addition, during the cooling process after sintering and during heat treatment such as soldering, there were drawbacks such as the occurrence of cracks due to the different thermal expansion coefficients of the respective materials.

An object of the present invention is to provide a composite laminated ceramic structure that can prevent peeling and cracking at the interface between an insulator layer and a dielectric layer, and improve quality stability and reliability. It is in.

[Means to solve the problem]

The present invention provides a composite laminated ceramic structure made of a ceramic insulating material and a dielectric material, in which the dielectric material contains lead, and a layer formed of the ceramic insulating material and a layer formed of the dielectric material. A layer made of a mixture of the ceramic insulating material and the dielectric material is formed between the layers, and the mixture ratio is such that the amount of the dielectric material increases in stages when viewed from the layer made of the ceramic insulating material. It is formed from a mixed layer of at least two types so that

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view of an embodiment of the present invention before lamination molding.

In the first embodiment, the insulating layer 2 shown in FIG. 1 contains 40 to 60 wt% of aluminum oxide and 1 to 40 wt% of lead oxide.
%, silicon oxide 2-40wt% 1M boron oxide 1-3
0 wt%, 0.05 to 25 w of group ■ element oxide
t%, oxides of group ■ elements (excluding carbon, silicon, and lead) from 0.01%], Ow t%, total 100 w
An inorganic powder that can be sintered at about 900° C. and has a composition of 1.5 t % was used. Further, the dielectric layer 1 has P b (M
n I/3. N b 2/3) o, o+ (M g I
/2・W I/2) 0.645 T i 0-3450
A composite perovskite-based high dielectric material powder having a composition of No. 3 and which can be sintered at about 900° C. was used.

On the other hand, the mixed layer 11 to be sandwiched between the insulating layer 2 and the dielectric layer 1
No. 13 is a mixture of the insulating composition and dielectric composition shown above. Specifically, the mixed layer Ill has a weight ratio of insulator to dielectric of 80:20. The mixed layer 1112 has a ratio of 50:50. Mixed layer (13) had a ratio of 20:80.

Next, the manufacturing method of this example will be explained. Generally, to obtain a ceramic clean sheet, raw material powder is mixed with an organic solvent and an organic binder to obtain a slurry. This slurry is used to form a green sheet on a polyethylene film using a casting method. The thickness of the green sheet is 6-50 to 100 μm.

Ceramic clean sheet of insulator using the above method,
A dielectric clean sheet and a clean sheet of a mixture of insulating paulownia material and dielectric material are each produced and cut into a predetermined shape to produce each ceramic clean sheet piece. The dielectric material used here has a dielectric constant of about 1500~
It is in the range of about 3000, which is advantageous for forming a large capacitance capacitor.

Next, they are laminated so as to have the structure shown in FIG. 1, put into a press mold, and subjected to thermocompression pressing.

After cutting the press-bonded green laminate into a predetermined shape, deintering treatment is performed at a temperature of around 500'C, and
A composite laminated ceramic structure was obtained by sintering at a temperature of about 1000°C to 100°C.

The second example is a mixture of the three types shown in the first example!
11, 12. Instead of 13, the weight ratio of insulator to dielectric is 95 to 5, 80 to 20.60 to 40, 4.0
Five types of mixed layers were used: 60:20:80. The manufacturing method of these clean sheets was the same as that of the first example, or the thickness of each clean sheet was unified to 50 μm. These five types of clean sheets are sandwiched between the insulating layer 2 and the dielectric layer 1. At this time, the mixed layer is arranged so that the dielectric material increases in stages when viewed from the insulating layer 2. There is.

In the case of this structure, a 500°C deintering step and an 8
Even when processed at a sintering temperature of 50° C. to 900° C., no delamination or cracks occurred, and a highly reliable composite laminated ceramic structure was obtained. The dielectric material formed inside has a dielectric constant of 2500, making it possible to realize a large capacitance capacitor. On the other hand, the insulator layer exhibits a dielectric constant of 75, and is expected to sufficiently speed up the formation of signal wiring.

In the third embodiment, in place of the insulating layer 2 used in the first embodiment (1y), a layer made of a mixture of 95 weight percent insulator and 5 weight percent dielectric was used.

In this case, the dielectric constant of the insulating layer was a relatively small value of 0, which was sufficient for signal wiring. Naturally, there was no delamination or cracking, and a high-quality structure was obtained.

〔Effect of the invention〕

As explained above, the present invention provides a method for disposing a mixture layer of an insulator and a dielectric between the insulator layer and the dielectric layer in order to alleviate the thermal stress generated during sintering and cooling. It is possible to obtain a high quality composite laminated ceramic structure without lamination cracks.

[Brief Description of the Drawings] Figure 1 is a cross-sectional view of an embodiment of the present invention before lamination molding;
FIG. 2 is a cross-sectional view of an example of a conventional composite laminated ceramic structure before lamination molding. 1. Dielectric layer, 2. Insulator layer, 3. Electrode layer of capacitor, 4. Output conductor, 5. Connection pattern wiring, 6. External pad electrode, 11 to 13. Mixed layer. Agent Patent Attorney Otoichi Uchihara 9≧ No. j Figure 1 Dielectric 4 layers 2, Lee rtA and \ζ Ireton eimuff 1 Mixed @ T 12, Mixed layer ■ 1.3 Mixed @ Buttocho

Claims (1)

[Claims] In a composite laminated ceramic structure made of a ceramic insulating material and a dielectric material, the dielectric material contains lead, and the layer between the layer formed of the ceramic insulating material and the layer formed of the dielectric material is A layer made of a mixture of a ceramic insulating material and the dielectric material is formed, and the mixing ratio is at least such that the amount of the dielectric material increases in stages from the layer made of the ceramic insulating material. A composite laminated ceramic structure characterized by being formed from two types of mixed layers.