Studies On Roll-bounded Cu/Mo/Cu Cladding Sheets

The heat of integrated circuit has raised severely along with its larger scale, so an urgent demand of materials with high thermal conductivity and low thermal expansion coefficient, which matches to those of integrated circuit materials, has been launched. This thesis works at producing process of a large demanded electronic package composite material — Cu/Mo/Cu cladding sheets. The technique of adding reagent coat is put forward for improving composition condition, because of the oversized mill load caused by large t reduction in first rolling pass. The principal works in the thesis are as follows:Aluminum based alloy are used as the reagent coat based on the property of basal material. Cu/Mo/Cu cladding sheets was produced by cold roll-bonding. Bonding effect and mechanical properties of cladding sheets have been analyzed by means of SEM, OM et al. Meanwhile, some main influencing factors, such as surface preparation, first reduction, annealing temperature and further processing, are studied and some optimum process conditions are obtained. The results show that surface preparation before bonding has an important effect on the combined strength of Cu/Mo/Cu cladding sheets. The rougher the surface is, the higher the strength is. The combined strength of the cladding sheets treated by burnishing method had the highest values, and the normal chemical method treated ones had the lowest values. The deformation rate is also an important effect of the combined strength. The bigger the rate is, the higher the strength is. The cladding sheets would have optimal properties if they were rolled at room temperature with a 50% first reduction, in the help of reagent coat. The annealing temperature had an important effect on the properties of the cladding sheets. When annealing temperature is below 500℃, increasing the temperature would enlarge the enlarge the diffusion depth and improve the combined strength. The cladding sheets annealed at 500℃ and held 60min had the best all round properties. During further processing of Cu/Mo/Cu cladding sheets, a series of small deformations and a final annealing could also improve the mechanical properties obviously.