H-IX.4 12:00 OPTIMIZATION OF MICROVIA-TECHNOLOGY USING AN EXCIMER LASER FOR
APPLICATION IN MICROELECTRONICS
Boniface Manirambona, Johan De Baets, Alfons Vervaet, University of Gent, ELIS-TFCG/IMEC, 9000
Gent, Belgium
In microelectronics microvias play a key role in miniaturization of printed circuit on board (PCB) in order
to fabricate faster, smaller and lighter electronic systems such as sensors and computing applications. In
the current work an excimer laser is used to generate high-density arrays of microvias. These are opened
in the dielectric of the resin coated copper (RCC)down to the underlying copper. Different parameters
(diameter of the vias, demagnification, number of pulses, fluence) are optimized in order to obtain
microvias with optimal shape aspect and shape ratio (>1.00). The microvias are studied after their plating
(electroless and electroplating) and cross-section making. The shape aspect and the shape ratio are
investigated by means of profile measurements and optical inspection. We will discuss the impact of
different parameters on the shape of our formed vias, therefore will come out with a conclusion on the
facilities and limits of plating. The results of the plating are such that we observe uniformity of thickness
of the plated copper (15-20 micron)which assures a good interconnection between the upper and the
underlying circuitry.