Preparing method of beryllia ceramic polishing substrate for thin film circuit

Abstract

The invention belongs to the technical field of electronic function ceramic materials, and particularly relates to a preparing method of a beryllia ceramic polishing substrate for a thin film circuit.The method includes the following steps of A, preprocessing a beryllia material to reduce the specific surface area of the powder material and improve the uniformity and consistency of the mixed material; B, preparing a ceramic material and conducting spray granulation; C, conducting dry-press pre-forming and isostatic-press forming; D, conducting degreasing and burning integrated sintering; E, thinning, leveling and fine grinding the substrate; F, polishing the substrate. The beryllia ceramic polishing substrate prepared through the method has the advantages of being high in heat conductivity, low in porosity, high in surface cleanliness, levelness and surface roughness and the like, can meet the requirement of military and civil dual-purpose thin film circuits / devices for high-performance and high-reliability development of high-heat-conductivity ceramic polishing substrates and has high practical value.

Description

technical field [0001] The invention belongs to the technical field of electronic functional ceramic materials, in particular to a method for manufacturing a beryllium oxide ceramic polished substrate for thin film circuits. Background technique [0002] At present, the entire field of thin film circuits / devices is developing in the direction of miniaturization, densification, high power, and high frequency. With the continuous upgrading of micro-fabrication platforms and the continuous improvement of circuit integration, the line width of circuit wires is also decreasing, and the line width of microwave integrated circuits has been reduced to micron or even sub-micron level, which has a great impact on the circuit substrate. Higher requirements are put forward for flatness and smoothness, and the high-density integration and high power of the circuit also cause the energy scattering of the circuit to increase, which also requires the entire circuit substrate to have better ...

AI Technical Summary

Problems solved by technology

[0003] However, due to the inherent brittleness and hardness of ceramics and the problem of closed or semi-closed pores inside polycrystalline ceramics, it is difficult for the surface roughness of beryllium oxide ceramics to achieve a mirror effect (Ra≤0.1μm) after processing. Open small pits, pinholes and other defects will cause problems such as short lines, short circuits, and electrode loss in the thin film circuit during the preparation process of the thin film circuit, which will seriously affect the reliability and line width accuracy of the thin film circuit.

At the same time, because the raw materials of beryllium oxide are basically prepared by sulfuric acid method or fluorination method, there are some volatile high-temperature substances in the material. After the thin-film circuit is prepared, it will volatilize under the high-temperature working environment and form bubbling (bubbles) on the contact surface between the ceramic and the thin-film circuit. ), making the entire thin film circuit / device scrapped, seriously affecting the overall pass rate of related devices

[0004] At present, the polished surface roughness of beryllium oxide prepared according to the traditional method is about 0.08 μm. The main problems are high porosity, poor compactness, and defects such as easy scratches on the polished surface during processing. It is difficult for the substrate to meet the submicron level and below. The development requirements of thin film circuits, in order to fundamentally solve related problems, it is necessary to reduce the porosity of beryllium oxide ceramics, control the grain size of ceramics, and reduce the damage to the ceramic surface during the grinding process.

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