Optimal Double Via Insertion With On-Track Preference

As on-track double vias take less routing resources and have better electrical characteristics, we study in this paper the problem of double via insertion with a preference for on-track double vias (DVI/ON) in a postrouting stage. The primary goal is to insert as many double vias as possible, and maximizing the number of on-track double vias is a secondary objective. We present a zero-one integer linear program-based approach to optimally solve the DVI/ON problem. Moreover, we also discuss a special case of the DVI/ON problem and present a maximum-weighted bipartite matching-based optimal approach. Experimental results indicate that our approaches outperform existing algorithms in terms of solution quality.