Effect of Coloured Pigment on Intermetallic Compound Growth of Sn-3.0Ag-0.5Cu Solder Joint

The colouration of solder paste opens up a space for technology requirements for the identification, marking, standardization, testing and evaluation processes of the solder inconnection. Two types of colour pigments, green (G) and glow in the dark (GD) are used to study the effect of coloured solder on stability of solder joint Sn-3.0Ag-0.5Cu (SAC 305). Colourless solder paste is used as a control sample to compare the results of the study. The isothermal aging test is used to observe the growth of intermetallic compound (IMC). GD colour pigment with a percentage of 5% has shown growth stability with the lowest changes of IMC growth, 5.6 mu m for coloured solder joint as compared to other higher colour pigment percentage with higher changes of IMC growth up to 9 mu m after subjected to isothermal aging at 150 degrees C for 1000 h. However, IMC growth stability with the use of coloured solder paste is lesser than the colourless solder paste. Therefore, the addition of colour pigments should be considered on the stability of the microstructure and the growth of the IMC layer so that it will not affect the solder joint quality and reliability.