National Chung Shan Institute of Science and Technology

Chia-Ting Lin

Chung-Yen Lu

Yang-Kuo Kuo

Yi-Hsiuan Yu

Jian-Long Ruan

Lea-Hwung Leu

Jlin-Fuh Yau

A method of evaluating microwave characteristics includes the steps of: (A) measuring thermal diffusion features and microwave characteristics of at least three mode samples to obtain at least three data points, wherein the mode samples include identical constituents but at different ratios thereof; (B) obtaining a mathematical relation between the data points by linear regression; (C) measuring a thermal diffusion feature of a sample under test, wherein the sample under test and the mode samples include identical constituents; and (D) substituting the thermal diffusion feature of the sample under test into the mathematical relation to evaluate a microwave characteristic of the sample under test. The method is applicable to a ceramic material to evaluate microwave characteristics of the ceramic material.

Method of evaluating microwave characteristic

The present invention relates to a method for improving adhesion between ceramic and a thick film circuit. The method is particularly directed to accelerate the formation of a ceramic-metal eutectic phase between the ceramic carrier and the metal circuit by solid-phase diffusion bonding under a positive atmosphere. A metallic conductive slurry or its oxide slurry is printed on the surface of the ceramic carrier to form a circuit pattern by a thick film screen printing. The ceramic carrier is placed in an oven with temperature controlled by a program under a positive-pressure atmosphere of an inert gas including nitrogen, hydrogen or their mixtures. An eutectic phase is formed between the ceramic carrier and the metal circuit under a high temperature eutectic condition to increase the adhesion between the ceramic carrier and the thick film circuit.

Method for improving adhesion between ceramic carrier and thick film circuit

A method of forming a pattern with high aspect ratio on a polycrystalline aluminum nitride substrate comprises the steps of (A) providing an aluminum nitride substrate and forming a barrier layer on the aluminum nitride substrate; (B) etching the barrier layer with an energy beam to form at least one recess in the barrier layer; (C) plasma etching the substrate to deepen the recess into the aluminum nitride substrate; (D) removing the barrier layer to obtain the aluminum nitride substrate having at least one pattern with high aspect ratio. The method uses the energy beam to directly form a pattern on the barrier layer, and further employs plasma etching to prepare the aluminum nitride substrate having a pattern with high aspect ratio quickly and effectively.

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Taoyuan, Taiwan

Chia-Ting Lin