Vapor Phase Soldering (VPS), employing perfluorinated liquid, is of growing importance as a technique for mounting electronic components. The liquid mainly consisting of perfluorotripentylamine (PFTPA) has been most widely used because of some properties advantageous to VPS. It, however, had one drawback of generating poisonous thermal decomposition products such as perfluoroisobutylene (PFIB) and hydrogen fluoride (HF) at the soldering temperature, which required special safety precautions. This paper describes the analytical methods used for measuring time dependent rates of generation of PFIB and HF from the boiling sample liquids. It was found that PFTPA itself was inherently stable at the boiling temperature and that the generation of the poisonous products was attributable to some impurities probably having higher boiling points. Modified perfluorinated liquid (IL-310), manufactured by the method developed on the basis of the above findings, is practically non - toxic and can be used with safety as a VPS heat transfer medium.

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Electroless copper using sodium hypophoshite as a reducing agent was applied to copper inner-layer foil treatment process. Copper film obtained from this bath was codeposited with nickel and phosphor. Influences of pH and bath temperature dependence were small and deposited film was composed with 96wt % of copper, 3wt % of nickel, and 1wt % of phosphor. The surface morphorogy obtained from the bath containing poly acetylene glycol as a surface active agent formed from dendrite to nodulus deposition. Bond strength between this film and resin showed over 1.6kg / cm for 10 minutes of deposition. This film showed excellent chemical resistance and pink-ring phenomena were completely suppressed. Furthermore this film showed the excellent electric reliability. Copper migration did not occured. Therefore, insulating resistance was not changed.

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[in Japanese]

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