Manufacturing method of beryllium oxide ceramic polished substrate for thin film circuit

Abstract

The invention belongs to the technical field of electronic functional ceramic materials, and in particular relates to a method for manufacturing a beryllium oxide polished substrate for thin film circuits. The present invention comprises the following steps: A, pretreatment of beryllium oxide material, to reduce the specific surface area of ​​the powder, improve the uniformity and consistency of the mixture; B, the preparation of porcelain material and spray granulation; C, dry press preforming, and then Isostatic pressing; D, degreasing and sintering; E, substrate thinning, leveling, fine grinding; F, substrate polishing. The beryllium oxide ceramic polished substrate prepared by the present invention has the characteristics of high thermal conductivity, low porosity, cleanliness, flatness, and good surface roughness (to achieve mirror effect) on the substrate surface, and can meet the requirements of both military and civilian thin film circuits. / Devices have strong practical value for the development needs of high thermal conductivity ceramic polished substrates with high performance and high reliability.

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 closed or semi-closed pores inside polycrystalline ceramics, the surface roughness of beryllium oxide ceramics after processing is difficult to achieve a mirror effect (Ra≤0.1μm). 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 qualification 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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