無電解ニッケル合金めっき皮膜のハンダ付け性について

抄録

The solderability properties of electroless nickel-phosphorous alloy and nickel-tin-phosphorous alloy films deposited by sodium hypophosphite as a reducing agent were studied using quantitative contact angle and spread factor measurements with reference to the effect of the phosphorous and tin contents of alloy films. Two kinds of solder balls, 60/40 (tin/lead), containing 2% resin and dropped enough flux, 1mm in diameter were used for solderability test at 210°C. It was found that nickel-phosphorous alloy films containing about 7% phosphorous provided best solderability properties of nickel-phosphorous films. With regard to the particle size, good solderability was obtained as the particle size decreased and thus the deposit was amorphous. It was also found that nickel-tin-phosphorous alloy films provided better solderabilities with increasing tin content of the alloy films.