This paper deals with behavior of lead-free solder joint applied in 3D electronic packaging structure. There are plenty of factors which influences reliability and life-time of solder compound connection. Type of substrates, selection of materials and process arrangement are the main areas to investigate. The content consists from three main parts. The first deals with introduction of designed test pattern, material, and process arrangement and applied testing methods. Second part continues with ANSYS software simulation of solder interconnections during thermo-mechanical stress tests and third part is aimed to experimental evaluation of results in the comparison to simulated results.