Die-bonding for a nitride light-emitting diode (LED) by sintering of micrometer size Ag particles in air at 200°C was investigated. Micrometer size Ag particles absorb oxygen remarkably well at 200°C and above, and on sintering, they form a porous layer. The activating temperature of the sintering is in good agreement with the oxygen adsorption temperature. Sintering does not progress in the absence of oxygen. A reduction of thermal resistance and an improvement of reliability are achieved by the sintered layer as a die attach to a surface-mount-type LED. This mounting method is useful in the die bonding of electronic components, and is an alternative technique to high-temperature lead soldering.