An Image-Based Effective Property Method for Strip Warpage Modeling

Warpage of electronic packages is the result of mismatch in the coefficient of thermal expansion (CTE) between the silicon die (CTE = 2.6ppm/ • C) and the substrate (CTE = 15-25 ppm/ • C). In ultra-thin packages, the reduced thicknesses can result in even higher package warpage due to the reduced flexural rigidity. Current approaches to minimize warpage include selecting constituent materials in the substrate with lower CTE as well as carrying out copper balancing of metal layers which are equidistant but on opposite sides of the core. In this work, we aim to optimize the metal density of the substrate layers by using an inverse design framework using Particle Swarm Optimization (PSO) with carefully selected constraints to minimize the rework required on the electrical tracing artwork. Results show that the inverse design framework is able to arrive at a 20% reduced warpage by changing local metal densities by just up to 5%. This is a significant reduction in warpage that is achievable by incorporating minor changes to the electrical artwork of the substrate. In future, this methodology can be applied to not only minimize warpage on ultra-thin packages but also enable even thinner ultra-thin package designs to be realized.

show abstract

Inverse Design for Low Warpage Ultra-Thin Packages Using Constrained Particle Swarm Optimization

Selvanayagam

Duong

Wilkerson

et al. 2021

IEEE Access

View full text Add to dashboard Cite

show abstract

Global Optimization of Surface Warpage for Inverse Design of Ultra-Thin Electronic Packages Using Tensor Train Decomposition

et al. 2022

View full text Add to dashboard Cite

As laptops get thinner and thinner, the electronic packages that go into these devices must shrink along the z-dimension as well. High warpage in these ultra-thin packages is the result of mismatch of coefficients of thermal expansion (CTE) between the silicon die (CTE = 2.6 ppm/C) and the organic substrate (CTE = 12 to 16 ppm/C) and the reduced flexural rigidity due to reduced thickness. This can result in decreased yield during assembly onto the board. Through the selection of low CTE materials and the implementation of stiffeners, warpage can be decreased. This work aims to optimize the metal density in the substrate to achieve low warpage. An inverse design framework is implemented to optimize the surface warpage profiles of the package using heuristic global optimization method viz. Particle Swarm Optimization (PSO) and Cross Entropy (CE) on a surrogate model that is built using finite element analysis (FEA), tensor train decomposition (TTD) and artificial neural networks (ANN). Results demonstrate that using this framework can result in more than 10% reduction in warpage by implementing up to 50% decrease in metal density on the ground and power layers in the substrate. Further analysis is required to determine the impact of these changes to signal and power integrity. In future, the framework can be implemented to realize even thinner packages without compromising on their functionality.INDEX TERMS Finite element analysis (FEA), global optimization, material characterization, particle swarm optimization (PSO), substrate, tensor train decomposition (TTD), warpage.

show abstract

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

customersupport@researchsolutions.com

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

An Image-Based Effective Property Method for Strip Warpage Modeling

Cited by 2 publications

References 5 publications

Inverse Design for Low Warpage Ultra-Thin Packages Using Constrained Particle Swarm Optimization

Inverse Design for Low Warpage Ultra-Thin Packages Using Constrained Particle Swarm Optimization

Global Optimization of Surface Warpage for Inverse Design of Ultra-Thin Electronic Packages Using Tensor Train Decomposition

Contact Info

Product

Resources

About