Patent ID: 6524644
Filing Date: 2003-02-25
Classification: B23K,C23C,C23F,H05K

Abstract:
A method for imparting corrosion protection by means of an organic solderability preservative solution to an electronic component in preparation for soldering, which component has copper circuitry and gold circuitry, the method comprising the following steps in sequence:a) contacting the component with a pre-treatment solution which imparts the copper circuitry over the gold circuitry with selectivity for the organic solderability preservative, the pretreatment solution comprising a benzamidazole compound having the formula: â€ƒwherein R1, R2, R3 and R4 are independently selected from the group consisting of hydrogen atoms, substituted or unsubstituted alkyl groups of 1-10 carbon atoms, substituted or unsubstituted aryl groups, halogen atoms, alkoxy groups of 1 to 10 carbon atoms, alkyl amino groups of 1 to 10 carbon atoms, cyano groups, nitro groups, and mixtures thereof; b) contacting the component with the organic solderability preservative solution to selectively deposit organic solderability preservative on the copper circuitry while substantially excluding deposition of organic solderability preservative on the gold circuitry, thereby avoiding staining of the gold circuitry and deterioration of conductivity of the gold circuitry by the organic solderability preservative.