A double-layer placement algorithm for integrated circuit-based modules on printed circuit board

TL;DR

The paper tackles automatic placement of IC-based modules on PCBs by formulating a two-layer mixed-variable optimization that jointly considers top-layer centralized placement and bottom-layer pin-oriented placement. It combines a global placement stage guided by the Conjugate Sub-gradient Algorithm ($\text{CSA}$) and the Distribution Evolutionary Algorithm with a Population of Probability Models ($\text{DEA-PPM}$) with a cluster-based initialization, followed by a legalization stage to enforce overlap removal, spacing, and pin-nearness. The proposed framework—PA-ICM—demonstrates improvements in total wirelength and the ability to generate legal, design-rule-compliant placements on industrial PCB cases, while maintaining computational efficiency through partitioned initialization and legalization. These results indicate practical applicability for industrial PCB design workflows and provide a foundation for scaling to larger boards and integrating module-based design automation.

Abstract

Considering that the physical design of printed circuit board (PCB) follows the principle of modularized design, this paper proposes an automatic placement algorithm for functional modules. We first model the placement problem as a mixed-variable optimization problem, and then, developed tailored algorithms of global placement and legalization for the top-layer centralized placement subproblem and the bottom-layer pin-oriented placement subproblem. Numerical comparison demonstrates that the proposed mixed-variable optimization scheme can get optimized total wirelength of placement. Meanwhile, experimental results on several industrial PCB cases show that the developed centralized strategies can well accommodate the requirement of top-layer placement, and the pin-oriented global placement based on bin clustering contributes to optimized placement results meeting the requirement of pin-oriented design.

Figures (5)

• Figure 1: The Framework of the Proposed Method.
• Figure 2: The Flow Chart of the Legalization Process.
• Figure 3: Region Partitions and the Corresponding Overlapping Elimination Directions
• Figure 4: An comparative illustration for pre- and post-legalization placement results.
• Figure 5: The final placement results of the proposed algorithm.