23. - 25. 5. 2012, Brno, Czech Republic, EU NEW SOLDERS FROM Sn-Ni-P FAMILY IN RIBBON FORM FOR ELECTRONIC COMPONENTS SOLDERING Georgiana Melcioiu, Viorel-Aurel Şerban, Cosmin Codrean, Florin Marian Cornea, Dragoş Buzdugan, Cosmin Locovei Politehnica University of Timişoara, no. 2 P-ta Victoriei, Romania georgianamelcioiu@yahoo.com, viorel.serban@rectorat.upt.ro, cosmin.codrean@mec.upt.ro, mfcornea@gmail.com, dbuzdugan@eng.upt.ro, cosmin.locovei@mec.upt.ro Abstract This paper presents the main lead-free solder alloys used to bond the electronic components and defects that occur because of the solder and their consequences. Given the preliminary research to reduce defects in electronic components is proposed a new solder alloy from Sn-Ni-Cu-P family and a technology for obtaining based on melt-spinning method. The alloy developed in ribbon form is characterized structurally by X-ray diffraction , differential thermal analysis, macroscopic and microscopic images. Keywords: whiskers, PCB, printed circuit boards, Melt-Spinning, solder, ribbons, 1. INTRODUCTION Soldering is a process of permanent joining, made from metal parts with filler material in fluid state used in the electronics industry. Through this process, we obtain solder joints that support small stresses and behave well at temperatures below 450 ºC. Soldering alloys used in electronic industry are in wire or paste form. [1]. During the soldering process, several phenomena take place some a namely: wetting, stretching, capillarity, diffusion. The requirements of soldering alloys used are:  the chemical composition must be guaranteed by the manufacturer;  the melting temperature must be lower than the base metal melting temperature;  it must have an optimal surface tension in order to ensure a good adhesion on the surface.  it must ensure a good mechanical resistance and stiffness;  it must have a clean surface, smooth, without cracks, stratification or inclusions;  the linear expansion coefficient should be approximately equal to the base metal coefficient, in order to avoid the formation of cracks or crevices ;  it must ensure a good corrosion resistance of the joint in the used environment;  it must have a low cost price. [1] In electronics are used lead or tin based alloys. The bonding of the electronic components has been achieved using Pb-based alloys. Because lead is harmful, soldering electronic components today are made with lead-free solder, based on tin.[2] Lead-free alloys that replace lead alloys used so far, must have the following basic properties: • as low as possible melting temperature; • physical properties at least as good as (fluidity, surface tension) as SnPb-based alloys, • thermal shock resistance, • a good anti-corrosive or difficult to oxidize,