| 摘要 |
PURPOSE:To prevent generation of cracks on a chip head by a method wherein at least a polyimide resin layer is formed on the back side of the chip head in advance. CONSTITUTION:The polymerization reaction of acid dianhydride or its delivative and diamine for the purpose of obtaining the solution of polyimide precursor is performed in accordance with the conventional method which is commonly known. In general, the above-mentioned method is performed under the state wherein an organic solvent medium is present, ordinarily at the temperature of 60 deg.C or belot in the stream of nitrogen gas taking into consideration of the polymeric heat generation, and said reaction is repeated until a high degree of polymerization is obtained while maintaining the optimum temperature of 30 deg.C or below. A polyimide resin layer 8 is formed by performing a heat treatment after a polyimide precursor in the form of polar solvent solution of the nonvolatile component concentration of 10-30wt% or thereabout is applied to a chip head 1 and dried it up. Also, the heating temperature for formation of polyimide is ordinarily 100-300 deg.C or thereabout. |
