Autor según el artículo: Azam, S; Munshi, S; Hassan, MK; Fragoso, A
Departamento: Enginyeria Química
Autor/es de la URV: Fragoso Sierra, Alex
Palabras clave: X-ray diffraction Vibrations Sheet resistance Scanning electron microscope Resistivity Printed-circuit boards Printed circuit board Hydrophilicity Copper/fr4 composite Conductivity x-ray diffraction vibrations sheet resistance scanning electron microscope resistivity printed circuit board hydrophilicity fracture foils fatigue behavior conductivity
Resumen: Featured Application: Electrical and electronic devices that experience long-term vibrations. Electrical boards, also called printed circuit boards, constitute the basis of most electronic devices. These boards are mainly fabricated of thin copper films bonded to fiber epoxy laminates, such as FR4. Being the most important functional component of these devices, they sometimes undergo mechanical stresses such as shock and vibration during transport and operation that can induce electrical failure and malfunction; hence, studies addressing the effects of vibrations on their electrical properties have important applications. In this paper, small cantilever samples made of bare copper bonded to FR4 with three isolated rectangular zones were studied to analyze, for the first time, variations in electrical properties such as sheet resistance and resistivity before and after 200 k, 500 k, and 800 k vibration cycles at three different temperatures (25, 35, and 45 °C). A significant rise in resistance equivalent to 1657% of the initial value was observed from 0 to 800 k vibration cycles. These changes were accompanied by a 95% decrease in conductivity, from 4.1 × 107 to 2.3 × 106 S/m, whereas very little change in the electrical properties was observed due to temperature rise. Surface analysis by ESEM showed cracks ~1 µm in width and several millimeters in length with a crack density of ~8 cracks per mm after 800 k cycles. The surface composition (100% copper) was not altered even upon a high number of vibration cycles, and static drop contact angle measurements of 117–119 degrees indicated an increase in the hydrophobicity of the surface attributed to increased surface roughness and the accumulation of very small air bubbles on the cracks.
Áreas temáticas: Química Process chemistry and technology Physics, applied Materials science, multidisciplinary Materials science (miscellaneous) Materials science (all) Materiais Instrumentation General materials science General engineering Fluid flow and transfer processes Engineering, multidisciplinary Engineering (miscellaneous) Engineering (all) Engenharias ii Engenharias i Computer science applications Ciências biológicas iii Ciências biológicas ii Ciências biológicas i Ciências agrárias i Ciência de alimentos Chemistry, multidisciplinary Biodiversidade Astronomia / física
Acceso a la licencia de uso: https://creativecommons.org/licenses/by/3.0/es/
Direcció de correo del autor: alex.fragoso@urv.cat
Identificador del autor: 0000-0003-4839-6094
Fecha de alta del registro: 2024-07-20
Versión del articulo depositado: info:eu-repo/semantics/publishedVersion
Enlace a la fuente original: https://www.mdpi.com/2076-3417/13/13/7941
URL Documento de licencia: http://repositori.urv.cat/ca/proteccio-de-dades/
Referencia al articulo segun fuente origial: Applied Sciences-Basel. 13 (13): 7941-
Referencia de l'ítem segons les normes APA: Azam, S; Munshi, S; Hassan, MK; Fragoso, A (2023). Temperature-Dependent Sheet Resistance and Surface Characterization of Thin Copper Films Bonded to FR4 Composite under Mechanical Vibrations. Applied Sciences-Basel, 13(13), 7941-. DOI: 10.3390/app13137941
DOI del artículo: 10.3390/app13137941
Entidad: Universitat Rovira i Virgili
Año de publicación de la revista: 2023
Tipo de publicación: Journal Publications
Repositori URV