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Thermal oxidation of blends of polystyrene and poly(vinyl methyl ether) containing a hindered phenol as antioxidant was studied at llO'C. The incorporation of the antioxidant in the miscible blend lengthens the induction period and lowers the rate of oxidation. Phase separation which preceded the end of the induction period caused the antioxidant to redistrihute itself among the different phases. This in turn controlled the induction period and the oxidation rate. The molecular weight of the PVME component in the blend remained unchanged during the induction period but decreased rapidly afterwards. Polystyrene also underwent chain scission after the end of the induction period. When low molecular weight polystyrene was blended with PVME, the films remained homogeneous throughout the oxidation reaction. This resulted in a further increase in the induction period and decrease in the rate of oxidation.

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Solders, which are the most commonly used materials in electronic packaging, have been widely used for electrical interconnections. When producing a solder joint, a layer is formed on the contact pad, followed by a reflow process conducted using infrared or thermal energy. This process requires a high‐temperature environment and long heating time. Herein, an advanced approach involving photonic soldering using intense pulsed light (IPL) energy is examined thoroughly. In particular, the relation between the bonding characteristics and pulse conditions, such as the energy, frequency, and number, for the development of ultrafast, low‐damage, and large‐area bonding technology is studied. Compared with the conventional reflow, IPL soldering requires a process time of only ≈2.5% and can improve the strength by 40%. Fracture micrographs after the die shear test indicate an interfacial fracture after conventional reflow and a mixed fracture after IPL soldering; this results in the consumption of the Cu layer after the time‐consuming reaction in the reflow and the formation of an extremely refined region in the solder joint after irradiation with IPL energy. Because of its improvement with respect to the process and bonding characteristics, IPL soldering can be a candidate for innovative interconnections in microelectronics.

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