{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,8]],"date-time":"2026-01-08T18:56:37Z","timestamp":1767898597020,"version":"3.49.0"},"reference-count":22,"publisher":"MDPI AG","issue":"24","license":[{"start":{"date-parts":[[2021,12,15]],"date-time":"2021-12-15T00:00:00Z","timestamp":1639526400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Compete 2020","award":["POCI-01-0247-FEDER-39479"],"award-info":[{"award-number":["POCI-01-0247-FEDER-39479"]}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia","doi-asserted-by":"publisher","award":["UIDB\/05256\/2020"],"award-info":[{"award-number":["UIDB\/05256\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia","doi-asserted-by":"publisher","award":["UIDP\/05256\/2020"],"award-info":[{"award-number":["UIDP\/05256\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>Driven by the need to deliver new, lead-free, eco-friendly solder pastes for soldering electronic components to Printed Circuit Boards (PCB), electrically conductive adhesives (ECAs) based on epoxy, carbon nanotubes (CNT), and exfoliated graphite (EG) were designed. The rheology of the adhesives prepared is paramount for the success of the deposition process, which is based on stencil printing. Thus, a rheological analysis of the process was first performed. Then, an experimental protocol was defined to assess the relevant viscoelastic characteristics of the adhesives for stencil printing application. Different composite formulations of epoxy\/CNT\/EG were produced. Their rheological characteristics were established following the designed protocol and benchmarked with a commercial solder paste. The thermal and electrical properties of the composite formulations were also characterized. As a result, a new, electrically conductive adhesive was delivered with potential to be an eco-friendly alternative to the solder paste currently used in stencil printing of PCB.<\/jats:p>","DOI":"10.3390\/ma14247734","type":"journal-article","created":{"date-parts":[[2021,12,15]],"date-time":"2021-12-15T09:02:19Z","timestamp":1639558939000},"page":"7734","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Rheologically Assisted Design of Conductive Adhesives for Stencil Printing on PCB"],"prefix":"10.3390","volume":"14","author":[{"given":"\u00c2ngelo D. M.","family":"Silva","sequence":"first","affiliation":[{"name":"Instituto de Pol\u00edmeros e Comp\u00f3sitos (IPC), Universidade do Minho, 4804-533 Guimar\u00e3es, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3614-6485","authenticated-orcid":false,"given":"Mariana M.","family":"Silva","sequence":"additional","affiliation":[{"name":"Instituto de Pol\u00edmeros e Comp\u00f3sitos (IPC), Universidade do Minho, 4804-533 Guimar\u00e3es, Portugal"}]},{"given":"Hugo","family":"Figueiredo","sequence":"additional","affiliation":[{"name":"Bosch Car Multimedia Portugal SA (CM\/MFT1), 4705-820 Braga, Portugal"}]},{"given":"Isabel","family":"Delgado","sequence":"additional","affiliation":[{"name":"Bosch Car Multimedia Portugal SA (CM\/MFT1), 4705-820 Braga, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1090-608X","authenticated-orcid":false,"given":"Paulo E.","family":"Lopes","sequence":"additional","affiliation":[{"name":"Instituto de Pol\u00edmeros e Comp\u00f3sitos (IPC), Universidade do Minho, 4804-533 Guimar\u00e3es, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3538-5804","authenticated-orcid":false,"given":"Maria C.","family":"Paiva","sequence":"additional","affiliation":[{"name":"Instituto de Pol\u00edmeros e Comp\u00f3sitos (IPC), Universidade do Minho, 4804-533 Guimar\u00e3es, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9936-8088","authenticated-orcid":false,"given":"Loic","family":"Hilliou","sequence":"additional","affiliation":[{"name":"Instituto de Pol\u00edmeros e Comp\u00f3sitos (IPC), Universidade do Minho, 4804-533 Guimar\u00e3es, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2021,12,15]]},"reference":[{"key":"ref_1","unstructured":"(2021, May 07). What Is Surface Mount Technology?. Available online: https:\/\/www.kynix.com\/Blog\/What-Is-SMT-Surface-Mount-Technology-Vedio.html."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Lopes, P.E., Moura, D., Hilliou, L., Krause, B., P\u00f6tschke, P., Figueiredo, H., Alves, R., Lepleux, E., Pacheco, L., and Paiva, M.C. (2020). Mixed Carbon Nanomaterial\/Epoxy Resin for Electrically Conductive Adhesives. J. Compos. Sci., 4.","DOI":"10.3390\/jcs4030105"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"38","DOI":"10.1108\/09540911211198540","article-title":"A review of stencil printing for microelectronic packaging","volume":"24","author":"Kay","year":"2012","journal-title":"Solder. Surf. Mt. Technol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"784","DOI":"10.1016\/j.matdes.2012.11.036","article-title":"Rheological characterization of a novel isotropic conductive adhesive\u2014Epoxy filled with metal-coated polymer spheres","volume":"46","author":"Nguyen","year":"2013","journal-title":"Mater. Des."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"3812","DOI":"10.1016\/j.matdes.2009.01.028","article-title":"Rheological characterisation and printing performance of Sn\/Ag\/Cu solder pastes","volume":"30","author":"Durairaj","year":"2009","journal-title":"Mater. Des."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"121","DOI":"10.1007\/s00397-008-0301-4","article-title":"Leveling and thixotropic characteristics of concentrated zirconia inks for screen-printing","volume":"48","author":"Phair","year":"2008","journal-title":"Rheol. Acta"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1108\/SSMT-10-2016-0022","article-title":"Investigating the thixotropic behaviour of Type 4 solder paste during stencil printing","volume":"29","author":"Krammer","year":"2017","journal-title":"Solder. Surf. Mt. Technol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"525","DOI":"10.1007\/BF02670655","article-title":"Rheological characterization of solder pastes","volume":"23","author":"Lapasin","year":"1994","journal-title":"J. Electron. Mater."},{"key":"ref_9","first-page":"107","article-title":"Analytical engineering model of the screen printing process. Part I","volume":"31","author":"Riemer","year":"1988","journal-title":"Solid State Technol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"358","DOI":"10.1109\/33.56169","article-title":"A study of the off-contact screen printing process. I. Model of the printing process and some results derived from experiments","volume":"13","author":"Owczarek","year":"1990","journal-title":"IEEE Trans. Compon. Hybrids Manuf. Technol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"34","DOI":"10.1007\/BF00208132","article-title":"Flow processes in solder paste during stencil printing for SMT assembly","volume":"6","author":"Mannan","year":"1995","journal-title":"J. Mater. Sci. Mater. Electron."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"188","DOI":"10.1016\/j.jmapro.2019.06.021","article-title":"Numerical investigation on the effect of the printing force and squeegee geometry on stencil printing","volume":"45","author":"Krammer","year":"2019","journal-title":"J. Manuf. Process."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"3189","DOI":"10.1016\/j.matdes.2011.02.045","article-title":"Evaluation of rheological properties of lead-free solder pastes and their relationship with transfer efficiency during stencil printing process","volume":"32","author":"Amalu","year":"2011","journal-title":"Mater. Des."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"374","DOI":"10.1007\/s00397-005-0053-3","article-title":"Rheological characterization of a solder paste for surface mount applications","volume":"45","author":"Billotte","year":"2005","journal-title":"Rheol. Acta"},{"key":"ref_15","first-page":"e55377","article-title":"Challenges in Rheological Characterization of Highly Concentrated Suspensions\u2014A Case Study for Screen-printing Silver Pastes","volume":"122","author":"Willenbacher","year":"2017","journal-title":"J. Vis. Exp."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Mewis, J., and Wagner, N.J. (2012). Colloidal Suspension Rheology, Cambridge University Press.","DOI":"10.1017\/CBO9780511977978"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1108\/09540910210416422","article-title":"Correlation of solder paste rheology with computational simulations of the stencil printing process","volume":"14","author":"Durairaj","year":"2002","journal-title":"Solder. Surf. Mt. Technol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"274","DOI":"10.1039\/b517840a","article-title":"Yield stress and thixotropy: On the difficulty of measuring yield stresses in practice","volume":"2","author":"Mewis","year":"2006","journal-title":"Soft Matter"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"100758","DOI":"10.1016\/j.cossms.2019.06.002","article-title":"Designing and transforming yield-stress fluids","volume":"23","author":"Nelson","year":"2019","journal-title":"Curr. Opin. Solid State Mater. Sci."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Costa, S., Teixeira, P., Covas, J.A., and Hilliou, L. (2019). Assessment of Piezoelectric Sensors for the Acquisition of Steady Melt Pressures in Polymer Extrusion. Fluids, 4.","DOI":"10.3390\/fluids4020066"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"283","DOI":"10.1007\/s00397-017-1002-7","article-title":"A review on wall slip in high solid dispersions","volume":"56","author":"Cloitre","year":"2017","journal-title":"Rheol. Acta"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1295","DOI":"10.1122\/1.1795171","article-title":"Slip and flow in pastes of soft particles: Direct observation and rheology","volume":"48","author":"Meeker","year":"2004","journal-title":"J. Rheol."}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/14\/24\/7734\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T07:48:19Z","timestamp":1760168899000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/14\/24\/7734"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,12,15]]},"references-count":22,"journal-issue":{"issue":"24","published-online":{"date-parts":[[2021,12]]}},"alternative-id":["ma14247734"],"URL":"https:\/\/doi.org\/10.3390\/ma14247734","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,12,15]]}}}