The physical properties and structural stability of the Quad Flat No-Leads (QFN) package with different gamma radiation doses have been investigated. The packages were irradiated with Co-60 gamma radiation with varying doses of 5 Gy, 50 Gy, 500 Gy, 5 kGy and 50 kGy with operating dose of 2.54 kGylh at room temperature. The infinite focus microscope (IFM) was used to measure the dimensional change and slantinglwarpage behaviour, while the 3D CT Scan X-ray machine was used to determine the occurrence of deflection on a wire in package due to exposure. It is believed that radiation effect on ceramic filler in the epoxy mold compound (EMC) plays an important role to induce the defects and resulted in swelling of the package. The slantinglwarpage behaviour is believed to be caused by the swelling behaviour of ceramic filler and further induced structural stability. The induced stress on the EMC structural after the dimensional change and slantinglwarpage failure leads to the occurrence of wire sweep. The finding suggests that defect production in swelled ceramic filler leads to the occurrence of dimensional and structure instability.
Tin-lead (SnPb) alloys are widely used in microelectronic packaging industry. It serves as a connector that provide the conductive path needed to achieve the connection from one circuit element to another circuit element. In this research, the effect of gamma irradiation on the micromechanical behaviour of tin-lead (SnPb) solder alloy has been investigated using the nano-indentation testing. Gamma radiation with a Cobalt-60 source were exposed to SnPb solders with different doses from 5 Gy to 500 Gy. In this study, the nano-indentation technique was used to understand the evolution of micromechanical properties (hardness and reduced modulus) of SnPb solder joints subjected to gamma irradiation. The results showed that the hardness of the SnPb alloys was enhanced with increasing of gamma radiation. The hardness was greatest at dose of 500 Gy of sample, 25.6 MPa and had the lowest value at un-irradiated sample. However, the reduced modulus was decreased by increasing the irradiation of gamma due to the intrinsic properties and the atomic bonding of the material.