Impact of Prepreg Thickness and Thermal Stress on Thermomechanical Behavior of Printed Circuit Board Substrates

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21230%2F25%3A00384685" target="_blank" >RIV/68407700:21230/25:00384685 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1109/ISSE65583.2025.11120981" target="_blank" >https://doi.org/10.1109/ISSE65583.2025.11120981</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1109/ISSE65583.2025.11120981" target="_blank" >10.1109/ISSE65583.2025.11120981</a>

Result language

angličtina

Original language name

Impact of Prepreg Thickness and Thermal Stress on Thermomechanical Behavior of Printed Circuit Board Substrates

Original language description

This study investigated the thermomechanical behavior of conventional printed circuit board substrate materials, with a particular focus on thermal expansion in the z axis for various combinations of material configurations and thermal stress during manufacturing. The primary focus of this paper is the thermomechanical properties of the substrate FR4, with particular emphasis on the effects of the number of epoxy cores and prepreg layers in multilayer boards. Two additional substrate materials for single-layer boards were incorporated to highlight the differences in the thermomechanical properties between different substrates. CEM1, a potential lower-cost alternative to FR4, and G30, a substrate designed for hightemperature applications. To simulate thermal stress during the manufacturing process of printed circuit boards, selected boards were immersed in molten solder for a brief period of time. The coefficients of thermal expansion in the z-axis and the glass transition temperature were subsequently determined for the analyzed specimens by the thermomechanical analysis. The measurements demonstrated significant discrepancies between immersed and non-immersed specimens, including the extent of the post-curing and the shrinkage effects. The analyses demonstrated that both effects were amplified with a thicker prepreg layer. Conversely, relative z-axis expansion exhibited a minor decrease with increasing prepreg thickness. These findings offer valuable insights into the influence of material composition and layer configuration on the thermal stability of substrate, which in turn affects the reliability of the entire assembly over its lifetime.

Czech name

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Czech description

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Type

D - Article in proceedings

CEP classification

—

OECD FORD branch

20201 - Electrical and electronic engineering

Project

—

Continuities

S - Specificky vyzkum na vysokych skolach

Publication year

2025

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Article name in the collection

2025 International Spring Seminar on Electronics Technology (ISSE)

ISBN

979-8-3315-1216-3

ISSN

2161-2536

e-ISSN

2161-2528

Number of pages

6

Pages from-to

—

Publisher name

Institute of Electrical and Electronics Engineers

Place of publication

New York

Event location

Budapešť

Event date

May 14, 2025

Type of event by nationality

WRD - Celosvětová akce

UT code for WoS article

001585293500047