Numerical investigation on a laser based localised joining with a glass frit intermediate layer

Localised laser bonding using a glass frit intermediate layer is an ideal technology to hermetically package miniature devices without heating the function components. In this paper, we investigated from a device level packaging perspective, the influence of the laser ring diameter and width, copper boss (heat sink) diameter and misalignment of laser ring in a laser based localised bonding with glass frit intermediate layer. The conclusions are: (1) laser ring diameter and width have slight influence on the bonding process however a system with smaller laser ring diameters achieves better performance compared to that with larger ring diameters. (2) The copper boss (heat sink) diameter has significant influence on the laser power level required to achieve a particular glass frit curing temperature within the glass frit ring. Selection of an appropriate copper boss diameter is determined by the maximum allowable temperature for the temperature-sensitive devices under protection. (3) Misalignment of the laser ring has significant influence on the localised laser bonding and the recommended misalignment deviation for the laser ring should be less than 100 µm.