JPH0795630B2 - Composite monolithic ceramic parts - Google Patents

Description

TECHNICAL FIELD The present invention relates to a composite laminated ceramic component.

[Prior Art] Conventionally, for an electronic circuit using a large-capacity capacitor, a chip-type capacitor is mounted on a substrate made of alumina or the like to achieve high integration.

That is, a hybrid integrated circuit is formed by forming a wiring pattern of resistors, electrodes and conductors on an insulating substrate such as ceramics by a printing method and mounting a chip type capacitor and a semiconductor integrated circuit on the same surface. Was being made. In addition, recently, development of a composite ceramic component in which a dielectric material forming a capacitor is sandwiched between insulators has been advanced, and its application to a hybrid integrated circuit or the like is being performed.

Further, in recent years, with the rapid technological progress of electronics, various electronic parts are shifting to miniaturization, and in terms of cost reduction, miniaturization of parts has become an essential condition.

However, in conventional composite parts such as hybrid integrated circuits,
To some extent, it is possible to print resistors, electrodes, and wiring patterns with higher density on a limited insulating substrate such as ceramics, and to mount chip capacitors, semiconductor integrated circuits, etc. in a higher degree of integration. There is.

For example, when a high-density wiring pattern is formed, the quality is lowered or the cost is soared. In the highly integrated design, there are problems such as a mounting space problem due to an increase in the number of mounting parts and a shape restriction. It became a problem.

Therefore, in order to achieve high density and high integration, a composite laminated ceramic component having a structure in which resistors and capacitors are housed and laminated in an insulating substrate is being developed.

FIG. 2 is a cross-sectional view of a substrate before laminated formation showing an example of this composite laminated ceramic component.

In this example, two of the three dielectric layers 1 having a predetermined dielectric constant are provided with the electrode layers 3 forming the electrodes of the capacitor, and these are laminated to form a capacitor. One of the outermost layers of the insulator layer 2 is provided with a pad electrode 6 for an external circuit on the outer surface, and the lead conductor 4 and the connection pattern wiring 5 provided on the insulator layer 2 together with other components, wiring, etc. The external pad electrode 6 and the electrode layer 3 are connected to each other when the insulating layer 2 and the dielectric layer 1 are laminated and pressure-bonded. These dielectric materials and insulating materials have different properties from each other, and among them, a two-component composition of aluminum oxide and lead borosilicate glass is usually used as the insulating material.

[Problems to be Solved by the Invention] In the above-described conventional composite laminated ceramic component, the laminated dielectric layers 1 and insulating layers 2 are made of dielectric materials having different properties from each other, and are made of an insulating material. Therefore, due to a slight difference in shrinkage ratio or a large difference in thermal expansion coefficient between the materials, a phenomenon such as peeling or cracking is likely to occur at the interface between the insulating layer 2 and the dielectric layer 1 and stability of quality is improved. And there is a drawback that it hinders reliability.

It is an object of the present invention to provide a composite multilayer ceramic component that prevents peeling and cracks from occurring at the interface between an insulating layer and a dielectric layer and that has improved quality stability and reliability.

[Means for Solving the Problems] The present invention provides an insulator layer, a dielectric layer provided with an internal electrode forming a capacitor, and a conductor for guiding the capacitor of the dielectric layer to the uppermost part of the insulator layer. In a composite multilayer ceramic component including a conductor wiring layer, the insulating material forming the insulating layer contains a three-component composition of aluminum oxide, magnesium oxide and lead borosilicate glass as a main component, and a dielectric layer is formed. The composite laminate characterized in that the dielectric material contains a compound of perovskite structure containing lead as a main component, and the difference in thermal expansion coefficient between the insulating material and the dielectric material is within 2.0 × 10 ⁻⁶ / ° C. It is a ceramic part.

In conventional composite monolithic ceramic parts, insulator materials and dielectric materials are used that have different thermal characteristics (coefficient of thermal expansion), and this difference is a factor that causes cracking after sintering. Was becoming.

In the present invention, the above-mentioned materials are used as the insulating material and the dielectric material, and the thermal expansion coefficient difference between the insulating material forming the insulating layer and the dielectric material forming the dielectric layer is 2 × 10 5.
^By controlling the temperature within ^-6 / ℃, the difference in the coefficient of thermal expansion between both layers is reduced, and the occurrence of cracks is prevented.

The proportion of each component constituting the insulating material is such that aluminum oxide is 20% by weight or less, magnesium oxide is 15 to 40% by weight,
It is preferable that the lead borosilicate glass has a composition range of 52 to 75% by weight.

When the content of aluminum oxide exceeds 20% by weight and the content of magnesium oxide exceeds 40% by weight, sintering is not performed at 1000 ° C. or lower, and the coefficient of thermal expansion decreases when the content of magnesium oxide is less than 15% by weight. Further, in the case of lead borosilicate glass, when the content is out of the above range, the glass stability cannot be obtained, and foaming and outflow of glass components easily occur.

Regarding the shrinkage difference between the insulating material and the dielectric material after sintering, the subtle difference in shrinkage does not become a problem due to the matching of the thermal expansion coefficients described above. It is possible to make it appropriate by controlling the composition ratio of the body.

[Embodiment] Next, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a cross-sectional view of a substrate before lamination molding showing one embodiment of the present invention. The main component of the substrate cross-sectional view of FIG. 1 is the second
Since it is similar to that in the figure, description of the same components will be omitted. This example is different from the conventional composite laminated ceramic part shown in FIG. 2 in that the insulator material forming the insulator layer 2 is a two-component composition of aluminum oxide and lead borosilicate glass in the past. On the other hand, in this example, the insulating material was a three-component composition of aluminum oxide, magnesium oxide, and lead borosilicate glass, and the difference in the coefficient of thermal expansion from the dielectric material was controlled within 2 × 10 ⁻⁶ / ° C. Especially.

Next, the manufacturing method of this embodiment will be described.

In order to obtain the ceramic green sheets of the dielectric layer and the insulating layer, first, the powder raw materials are weighed and mixed or pulverized by a ball mill or the like. Next, the mixed powder raw material is calcined using an electric furnace or the like to prepare a pre-calcined powder material. The pre-calcined powder material obtained by calcination is mixed with an organic solvent and an organic binder to obtain a slurry. This slurry is formed into a green sheet on a polyethylene film using a casting device such as a doctor blade method to obtain a ceramic green sheet.

According to the above method, an insulating ceramic green sheet,
Dielectric ceramic green sheets are produced and cut into predetermined shapes to produce individual ceramic green sheet pieces.

The dielectric material used here is a compound having a perovskite structure containing lead, and the dielectric constant of this dielectric material is
Depending on the composition ratio of the constituent elements, it is almost 500-200
It can be controlled in the range of 00. Therefore, it is extremely advantageous for forming a large capacity capacitor.

As the insulating material used here, a composite material of alumina, magnesia, lead borosilicate glass,
Materials such as cordierite-based ceramics and calcillite-based ceramics can be adapted by controlling the coefficient of thermal expansion, and the dielectric constant of these insulator materials is about 5-10.

On the other hand, as the metal body, one having a composition containing at least one of Au, Ag, Pb, Pt, Cu, Ni and the like is used.

Next, Ag-Pd paste is used for the dielectric ceramic green sheet pieces, the electrode layer 3 of the capacitor is printed, and a through hole is made in each ceramic green sheet piece that requires a through hole. Fill the Pd paste to form the conductor 4. Similarly, an outer pad electrode 6 is formed on a ceramic green sheet piece which is the outermost insulator layer 2, and a conductor wiring layer 5 connecting the conductor 4 and the outer pad electrode 6 is the insulator green layer 2. Form into pieces.

Next, they are laminated so as to have a structure as shown in FIG. The press-pressed green laminated ceramic body is cut into a predetermined shape with a knife blade or the like, and then binder removal processing is performed at a temperature of about 500 ° C. Then, by sintering at a temperature of about 850 to 1000 ° C, a composite laminated ceramic component with a built-in capacitor can be obtained.

Table 1 shows the difference in the coefficient of thermal expansion between the insulating material and the dielectric material and the occurrence of cracks in the component when a composite multilayer ceramic component is manufactured by using the respective component amounts described in the same table as the material composition of the insulating layer. It indicates the presence or absence.

As can be seen from the table, in the composite laminated ceramic component of the present invention, the difference in the coefficient of thermal expansion between the insulating layer and the dielectric layer is controlled, and the stress due to thermal stress is controlled to prevent the occurrence of cracks. .

[Effects of the Invention] As described above, in the composite laminated ceramic component of the present invention, the difference in the coefficient of thermal expansion between the two layers is controlled by using a predetermined material as the material of the insulating layer and the dielectric layer.
Since stress due to thermal stress is controlled, cracks do not occur, and delamination due to subtle contraction differences between dissimilar materials can also be suppressed, making it possible to improve quality stability and reliability. Have.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a substrate before lamination molding showing an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a substrate before lamination molding showing an example of a conventional composite laminated ceramic component. 1 ... Dielectric layer, 2 ... Insulator layer, 3 ... Capacitor electrode layer, 4 ... Conductor, 5 ... Conductor wiring layer, 6 ... External pad electrode

Claims (1)

[Claims] 1. A composite comprising an insulating layer, a dielectric layer provided with an internal electrode forming a capacitor, a conductor for guiding the capacitor of the dielectric layer to the uppermost part of the insulating layer, and a conductor wiring layer. In the laminated ceramic component, the insulating material forming the insulating layer contains a three-component composition of aluminum oxide, magnesium oxide and lead borosilicate glass as a main component,
And the dielectric material forming the dielectric layer is composed mainly of a compound having a perovskite structure containing lead, and the thermal expansion coefficient difference between the insulating material and the dielectric material is within 2.0 × 10 ^-6 / ° C. Composite multilayer ceramic parts characterized by: