The copper layer of ceramic substrate coated copper was pre-oxidized by means of controlling oxidation method.The effects of per-oxidation temperature and oxygen partial pressure on the phase and thickness of copper oxide were studied.The phase of copper oxide film was measured by Raman spectroscopy.The absorbance of copper oxide film was tested by ultraviolet-visible spectrophotometer.The relationship between the absorbance and thickness of copper oxide was determined.The results indicate that Cu_2O is for...