A Unified Printed Circuit Board Routing Algorithm with Complicated Constraints and Differential Pairs

Abstract

The printed circuit board (PCB) routing problem has been studied extensively in recent years. Due to continually growing net/pin counts, extremely high pin density, and unique physical constraints, the manual routing of PCBs has become a time-consuming task to reach design closure. Previous works break down the problem into escape routing and area routing and focus on these problems separately. However, there is always a gap between these two problems requiring a massive amount of human efforts to fine-tune the algorithms back and forth. Besides, previous works of area routing mainly focus on routing between escaping routed ball-grid-array (BGA) packages. Nevertheless, in practice, many components are not in the form of BGA packages, such as passive devices, decoupling capacitors, and through-hole pin arrays. To mitigate the deficiencies of previous works, we propose a full-board routing algorithm that can handle multiple real-world complicated constraints to facilitate the printed circuit board routing and produce high-quality manufacturable layouts. Experimental results show that our algorithm is effective and efficient. Specifically, for all given test cases, our router can achieve 100% routability without any design rule violation while the other two state-of-the-art routers fail to complete the routing for some test cases and incur design rule violations.