University of Oulu

Acharya S, Sattar S, Chouhan SS, Delsing J. Detailed Characterization of a Fully Additive Covalent Bonded PCB Manufacturing Process (SBU-CBM Method). Processes. 2022; 10(4):636.

Detailed characterization of a fully additive covalent bonded PCB manufacturing process (SBU-CBM method)

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Author: Acharya, Sarthak1,2; Sattar, Shahid3; Chouhan, Shailesh Singh1;
Organizations: 1Embedded Internet System Lab, Department of Computer Science, Electrical & Space Engineering, Luleå University of Technology, 97187 Luleå, Sweden
2Department of Information Technology & Electrical Engineering, University of Oulu, 90570 Oulu, Finland
3Department of Physics & Electrical Engineering, Linnæus University, 39231 Kalmar, Sweden
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 3.3 MB)
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Language: English
Published: Multidisciplinary Digital Publishing Institute, 2022
Publish Date: 2022-09-05


To bridge the technology gap between IC-level and board-level fabrications, a fully additive selective metallization has already been demonstrated in the literature. In this article, the surface characterization of each step involved in the fabrication process is outlined with bulk metallization of the surface. This production technique has used polyurethane as epoxy resin and proprietary grafting chemistry to functionalize the surface with covalent bonds on an FR-4 base substrate. The surface was then metalized using an electroless copper (Cu) bath. This sequential growth of layers on top of each other using an actinic laser beam and palladium (Pd) ions to deposit Cu is analyzed. State-of-the-art material characterization techniques were employed to investigate process mechanism at the interfaces. Density functional theory calculations were performed to validate the experimental evidence of covalent bonding of the layers. This manufacturing approach is capable of adding metallic layers in a selective manner to the printed circuit boards at considerably lower temperatures. A complete analysis of the process using bulk deposition of the materials is illustrated in this work.

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Series: Processes
ISSN: 2227-9717
ISSN-E: 2227-9717
ISSN-L: 2227-9717
Volume: 10
Issue: 4
Article number: 636
DOI: 10.3390/pr10040636
Type of Publication: A1 Journal article – refereed
Field of Science: 216 Materials engineering
213 Electronic, automation and communications engineering, electronics
Funding: This research was funded by the Interreg Nord, European Regional Development Fund (ERDF) at (accessed on 15 March 2022).
Copyright information: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (