Compound organic solderability preservatives (OSP) treating agent for lead-free printed circuit board (PCB)

Abstract

The invention discloses a compound organic solderability preservatives (OSP) treating agent for a lead-free printed circuit board (PCB). The compound OSP treating agent comprises, by weight, 0.5%-5% of 1H-Benzotriazole, 0.5%-2.5% of 2-Ethylbenzimidazole, 1%-5% of 2-heptyl-5nitrobenzimidazole, 0.2%-1.4% of 1-phenyl-5-sulfenyl tetrazole, 1%-4% of sulfanilamide thioglycoic acid, 0.1%-0.5% of copper acetate, 0.1%-0.5% of copper formate, 1%-5% of potassium iodide, 0.1%-1% of ammonia water, 4%-12% of organic acid, 1%-8% of a solubilizer, 0.1%-1% of a buffering agent, and the balance water. By means of the compound OSP treating agent, OSP which are high in adhesive force, resistant to oxidation, resistant to high temperatures, compact and transparent can be smoothly formed on the surface of a copper circuit on the PCB, a formed film is uniform and flat, heat shock resistance is good, and the treating agent is suitable for machining of single-faced and double-faced boards; a solution is stable, maintenance is easy, the operation temperature of the aqueous solution can be controlled to be 80 DEG C or lower, bending deformation of a substrate is avoided, operation cost is low, and the rate of finished products is high.

Description

technical field [0001] The invention relates to the technical field of lead-free printed circuit boards, in particular to a compound OSP treatment agent for lead-free printed circuit boards. Background technique [0002] With the development of light, thin, short, miniaturized, and multi-functional electronic products, printed circuit boards are developing in the direction of high precision, thinning, multi-layering, and small holes, especially the rapid development of SMT. , so that the continuous development of high-density thin boards for SMT (such as printed boards such as IC cards, mobile phones, notebook computers, and tuners) makes the hot air leveling process less and less suitable for the above requirements. At the same time, the Sn-Pb solder used in the hot air leveling process does not meet the environmental protection requirements. With the official implementation of the EU RoHS directive on July 1, 2006, the industry urgently needs to seek lead-free alternatives...

AI Technical Summary

Problems solved by technology

In the traditional OSP process, although the formed organic complex film can play an anti-oxidation effect, it is easy to decompose and volatilize at the welding temperature of lead-free soldering, and cannot effectively protect the copper surface, resulting in solderability of the copper surface. Deterioration of performance, poor wettability, peeling off of solder joints, failure of components