24 DESIGN007 MAGAZINE I DECEMBER 2024
collaborate. is approach has the potential to
eliminate even more undesired solutions from
inverse problems. Evaluating the trade-offs
between computational efficiency and accu-
racy improvements is essential in assessing the
feasibility and effectiveness of such protocols.
Key Points
• e inverse stackup optimization frame-
work solves the PCB stackup optimization
by incorporating a discrete domain hyper-
parameter optimization (HPO), which
searches for the best set of parameters in
an optimization problem.
• Besides parameter tuning, researchers also
apply HPO to address the analog device
sizing problem.
• HPO can be applied to automate the
stackup design to adjust the trace width,
clearance, and dielectric properties in
inverse optimization.
• e first stage involves sampling param-
eters globally to explore the search space.
• A machine learning model termed the
"learner" then identifies a limited set of
candidates within the input design space
whose predicted outputs closely align with
desired outcomes.
• e second stage selects the final stackup
design based on the initial results.
• A separate surrogate model, functioning as
an "evaluator," assesses the reduced candi-
date space generated in the first stage.
• One surrogate acts as a forward problem
proxy, identifying promising solutions,
while the other plays an advisory role,
effectively eliminating inaccurate or uncer-
tain outcomes. DESIGN007
Resources
• "Beyond Design: Stackup Planning: Three
Decades of Innovation," by Barry Olney
• "Machine Learning-Assisted Inverse Stack-Up
Optimization for Advanced Package Design" by
Chae Hyunsu, et al.
• "Two-Stage Surrogate Modeling for Data-
Driven Design Optimization with Application to
Composite Microstructure Generation" by Far-
had Pourkamali-Anaraki, et al.
Barry Olney is managing director of
In-Circuit Design Pty Ltd (iCD), Aus-
tralia, a PCB design service bureau
that specializes in board-level simu-
lation. The company developed
the iCD Design Integrity software,
incorporating the iCD Stackup, PDN, and CPW
Planner. You can download the software at
www.icd.com.au. To read past columns, click here.
