This paper describes the sintering properties and bondability of pressureless sintering Cu die-bonding paste for power devices operating at high temperatures. The sintered density (D_s) and thermal conductivity of pressureless sintered Cu (in H₂, 300°C) were 78% and 180 Wm^–1K^–1, respectively. In a three-point bending test, sintered Cu has a higher 0.2% yield strength than pressure sintered Ag (in air, 300°C, 10 MPa, D_s = 87%) as a comparison material. The bonding strength of sintered Cu to the adherend (Cu, Ni, Ag and Ni/Au) was 30 MPa or more. The thermal cycle tolerance of 1,000 cycles (–40°C/200°C) or more was shown in a simulated power device package which was bonded using sintered Cu and encapsulated with epoxy molding compounds.

A new patterning technology called ‘Soft Blanket Gravure' (SBG) printing has been introduced, which uses a soft and thick offset blanket (called "soft blanket"). SBG printing was developed in order to print functional ink onto curved or 3D object surfaces by employing the soft blanket. However, we found that SBG printing can receive and transfer ink more completely under various conditions where conventional gravure offset printing cannot print. In this paper, the printabilities of silver ink with SBG and conventional gravure offset printing were compared under atypical printing conditions. We found that the SBG printing technology can print uniform and thicker silver patterns successfully under various conditions, as well as relatively thin patterns using the same SBG printer configuration and printing parameters.

For smart textiles applications, textile compatible power supplies are required to ensure autonomous operation. Inspired by textile technologies, we have already developed an energy harvesting yarn where the spherical solar cell array is arranged in parallel. In this report, we show a new photovoltaic textile that weaves the energy harvesting yarn with the fabric weft, and some of its properties.