Mechanical tests regarding low-temperature lead-free solder pastes application in automotive electronics

Taking into account the real working temperatures from different zones and daily requirement of reduction of production costs, into automotive electronics production the trend is the one towards low melting point alloys that will enable energy savings and cost reductions during the manufacturing processes. In the paper, the mechanical strength of solder joints and samples having the same transversal section as resistor 1206 case type made using Low Temperature Lead-Free (LTLF) solder pastes into VPS processes characterized by different cooling rates, were benchmarked according to temperature. The experiments were done in line with the concept of "Homologous temperatures", by measuring LTLF solder joints and alloys samples shear forces keeping the samples, respectively the surface of test boards at temperatures of up to 398K (125°C) using a dedicated auxiliary device, specially designed and manufactured to complete the multifunctional bond tester “Condor 70-3”, XYZTECH. The results of the experiments regarding references values of LTLF solder joints and alloys samples shear forces offer a data base useful in the new solder alloy creation processes and their qualification for automotive electronics domain according to RoHS 2 EU Directive.