First steps are taken toward a low-cost alternative to silver sintering as a highly reliable die attach technology for deep drilling applications and future power electronic modules. In this feasibility analysis, we evaluate sintering of copper particles for die attach. Particulate copper pastes are pretreated in H₂ atmosphere (50 mbar) in order to gain oxide-free particles. Subsequently, particles are sintered at a pressure of 40 N/mm² and a temperature of 350°C for 2 min. Porosity, Young's modulus as well as electrical and thermal conductivities of sintered layers are analyzed. Moreover, shear tests at ambient temperature are performed for evaluating the adhesion of monometallic as well as Cu-Au bonds according to the American military standard for chip-substrate contacts (MIL-STD-883H, method 2019.8).

Vertically aligned silicon nanowire (SiNW)‐based resonators were fabricated and utilised to detect aerosol nanoparticles (NPs) by measuring their resonant frequency shifts caused by the additional mass of trapped NPs. Inductively coupled plasma cryogenic dry etching and multiple thermal oxidations are used in the fabrication of silicon nanowire (SiNW) arrays. The SiNWs were coated with gold for contacting to the homebuilt electrostatic NP sampler to collect the flowing NPs. In order to have a dynamic resonance operation in the frequency measurement system, a piezoelectric shear actuator was mounted onto the SiNWs. Examined in a TiO ₂ aerosol sampling with a total concentration of ∼8500 NP/cm ³ , the fabricated sensor exhibited its feasibility as a nanobalance to measure aerosol NP mass at the femtogram level with a mass sensitivity of 7.1 Hz/fg and a mass resolution of 31.6 fg. The NP sampling efficiency of the developed miniaturised NP sampler was found to be three times higher than that of the commercial nanometer aerosol sampler (NAS, TSI 3089). An ultrasonic removal method was used to detach the adhered NPs and further extend the operating life of the sensor.