耐高温有机保焊剂的研究

Study on high-temperature-resistant organic solderability preservative

以苯并咪唑和糖类聚合物PS为成膜物质,甲酸–醋酸为主要溶剂,制备了水性有机保焊剂(OSP)。研究了影响OSP稳定性以及OSP处理后印制线路板(PCB)抗氧化性的主要因素,获得了优化的OSP配方为:苯并咪唑1.5%,PS 0.45%,甲酸–醋酸7.5%,Cu SO4·5H2O 0.4%,水余量;p H 4.3。该OSP可在室温稳定贮存30 d以上。PCB于45°C下在其中浸渍处理1 min后,在室温下的抗氧化时间可达15 d,在300°C高温下能抵抗10 s的热冲击3次,满足高温无铅焊接的要求。

A water-based OSP （organic solderability preservative） was prepared with benzimidazole and carbohydrate polymer PS as film-forming materials and formic acid-acetic acid as main solvents. The main factors affecting the stability of OSP solution and anti-oxidization of OSP-treated PCB （printed circuit board） were studied. The optimal OSP formulation （pH = 4.3） was obtained as follows： benzimidazole 1.5%, PS 0.45%, formic acid-acetic acid 7.5%, CuSO4·5H2O 0.4%, and water as balance. The OSP solution prepared therewith can be stably stored for at least 30 days at room temperature. The PCB treated by immersion in the OSP at 45 ℃ for 1 min has an anti-oxidation time of 15 days at room temperature, and can endure a 10-second thermal shock at 300 ℃ for three times, meeting the requirements of high temperature lead-free welding.