Study On The Preparation And Properties Of Al?min?m Nitride Film Subgrade Board

The new generation of AlN ceramic substrates have a thermal conductivity of230W?m.k?,dielectric loss factor of 0.0002,dielectric constant of 8.7,vol?me resistivity of>10¹⁴?.m,thermal expansion rate of 4.0-6.0,3-point bending strength of450MPa,cost of 1/4 of Al₂O₃ ceramics,and 1/5 of Be O ceramics.The performance parameters have perfectly replaced Al₂O₃ ceramic substrates and Be O ceramic substrates,which can meet the requirements of high frequency communication and heat dissipation of high power devices at the same time.Therefore,the fabrication of metallized circuits on the surface of AlN substrates has become an important research content in the design and application of HIC hybrid integrated circuits.Microstrip circuit is consists of microstrip lines and electronic components,and the main circuit board is Al₂O₃ ceramics and Be O ceramics.Due to the toxicity of Be O ceramics during processing and the serious harm to h?man body and environment,Al₂O₃ ceramics cannot be used on high power heat sinks because of its low thermal conductivity of 29 W?m.k?.In this project,AlN ceramic substrates are used as substrates,the conduction bands on the surface of the substrates are prepared by thin-film circuit technology,and passive devices such as thin-film resistance and inductance are integrated,and metallized grounding holes are processed.This effectively solves the problems of miniaturization and integration of microwave circuits.The reliability of the products is better,the manufacturing cost is lower,It will be more widely used in the market in the future.1.Briefly introduce the characteristics,application status and research trends at home and abroad of AlN ceramic substrates,and introduce the main research work of this topic,as well as the main technical indicators of products.2.Complete the circuit design and process route of AlN ceramic substrates.Three kinds of AlN baseboard circuits are designed:S-band bridge circuit,power resistance circuit and metallized hole circuit.After completion,their electrical performance parameters are tested to verify whether they meet the design requirements.Through the research on the metallization method of AlN baseboard circuit,the technological route of film is finally determined,and the AlN base surface metal layer is implanted by magnetron sputtering method.3.The key technologies of AlN baseboard circuit fabrication were studied,and the effects of punching fixture,duty cycle and scanning speed on laser processing quality were studied;the effects of different cleaning conditions and cleaning schemes on surface cleaning quality;the effects of different sputtering process conditions and parameters on film quality;the effects of Ti W anti-etching layer on wet etching line quality and the elastic modulus of UV film on scratch quality were studied.Quantitative research has completed the metallization of AlN baseboard circuit and finished products.4.Complete the All parameters of the three AlN-based circuit substrates tested.The electrical performance indexes meet the design and use requirements.