Lowering temperature of Cu sinter bonding under low-pressure in ambient air by in-situ generation and reduction of Cu₂O nanoparticles

Oba, Miwa; Matsuda, Tomoki; Dougakiuchi, Masashi; Okubo, Shio; Kambara, Makoto

doi:https://doi.org/10.1007/s10854-025-14352-7

Lowering temperature of Cu sinter bonding under low-pressure in ambient air by in-situ generation and reduction of Cu₂O nanoparticles

Oba, Miwa; Matsuda, Tomoki; Dougakiuchi, Masashi et al.

Journal of Materials Science: Materials in Electronics, 2025, 36(291)

アクセス数:449件（2025-08-15 23:02 集計）

固定URL: https://hdl.handle.net/11094/100256

閲覧可能ファイル

ファイル	フォーマット	利用条件	サイズ	閲覧回数	利用開始日	説明	information
JMaterSciMaterElectron_36_291	pdf	なし	1.86 MB		2026.02.10

論文情報

ファイル出力 EndNote Basic出力 Mendeley出力

タイトル	Lowering temperature of Cu sinter bonding under low-pressure in ambient air by in-situ generation and reduction of Cu₂O nanoparticles
著者	著者名 Oba, Miwa
	NRID 1000030756333 1000030756333 ORCID 0000-0002-3978-0118 0000-0002-3978-0118 researchmap permalink tomokimatsuda tomokimatsuda Scopus Author ID 56430312900 56430312900 著者名 Matsuda, Tomoki
	著者名 Dougakiuchi, Masashi
	著者名 Okubo, Shio
	NRID 1000080359661 1000080359661 researchmap permalink pme305 pme305 著者名 Kambara, Makoto
内容	This version of the article has been accepted for publication, after peer review (when applicable) and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: https://doi.org/10.1007/s10854-025-14352-7.
抄録	Cu sinter bonding has emerged as a promising technology for highly reliable electronic packaging due to its low cost and excellent electrical and thermal conductivity. However, Cu particles are prone to oxidation, and their sinterability decreases significantly at lower temperatures, requiring high-pressure or controlled atmospheric conditions at elevated temperatures. This study investigated reducing the bonding temperature of Cu sinter bonding under low bonding pressure in ambient air by utilizing the in-situ oxidation and subsequent reduction of the Cu surface, leading to the formation of Cu nanoparticles. Slightly oxidized Cu particles were prepared through a plasma flash evaporation process under an Ar–H₂ plasma, followed by vacuum refrigeration. These particles were used to facilitate surface reactions with polyethylene glycol (PEG400) during the bonding process. We found that the prepared particles contributed to lowering the reduction temperature through the temporary formation of Cu₂O nanoparticles. These nanoparticles, precipitating above 160 °C from Cu complexed with PEG400, were subsequently reduced to Cu nanoparticles. The generated Cu nanoparticles acted as bridges among Cu fine particles, enhancing sinterability. Consequently, Cu–Cu sinter bonding was achieved at 220 °C under 0.3 MPa in ambient air, forming a sufficiently sintered Cu layer. This approach offers a pathway for low-temperature, low-pressure bonding suitable for industrial-scale applications.
出版者	Springer Science and Business Media LLC
収録物名	Journal of Materials Science: Materials in Electronics
巻(号)	36(291)
刊行年月	2025-02-10
言語	英語
ハンドルURL	https://hdl.handle.net/11094/100256
PISSN	09574522
eISSN	1573482X
関連情報 (isVersionOf)	DOI (出版社版) https://doi.org/10.1007/s10854-025-14352-7
アクセス権	embargoed access
権利情報	The full-text file will be made open to the public on 10 February 2026 in accordance with the publisher's policy.
出版タイプ	Accepted Manuscript
カテゴリ	学術雑誌論文 Journal Article

資源タイプ	学術雑誌論文
ローカル資源タイプ	学術雑誌論文
DCTERMS.bibliographicCitation	Journal of Materials Science: Materials in Electronics. 2025, 36(291)
DC.title	Lowering temperature of Cu sinter bonding under low-pressure in ambient air by in-situ generation and reduction of Cu₂O nanoparticles
DC.creator	Oba, Miwa
	Matsuda, Tomoki
	Dougakiuchi, Masashi
	Okubo, Shio
	Kambara, Makoto
DC.publisher	Springer Science and Business Media LLC
DC.language' scheme='DCTERMS.RFC1766	英語
DCTERMS.issued' scheme='DCTERMS.W3CDTF	2025-02-10
DC.identifier	https://doi.org/10.1007/s10854-025-14352-7
DC.description	This version of the article has been accepted for publication, after peer review (when applicable) and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: https://doi.org/10.1007/s10854-025-14352-7.
DCTERMS.abstract	Cu sinter bonding has emerged as a promising technology for highly reliable electronic packaging due to its low cost and excellent electrical and thermal conductivity. However, Cu particles are prone to oxidation, and their sinterability decreases significantly at lower temperatures, requiring high-pressure or controlled atmospheric conditions at elevated temperatures. This study investigated reducing the bonding temperature of Cu sinter bonding under low bonding pressure in ambient air by utilizing the in-situ oxidation and subsequent reduction of the Cu surface, leading to the formation of Cu nanoparticles. Slightly oxidized Cu particles were prepared through a plasma flash evaporation process under an Ar–H₂ plasma, followed by vacuum refrigeration. These particles were used to facilitate surface reactions with polyethylene glycol (PEG400) during the bonding process. We found that the prepared particles contributed to lowering the reduction temperature through the temporary formation of Cu₂O nanoparticles. These nanoparticles, precipitating above 160 °C from Cu complexed with PEG400, were subsequently reduced to Cu nanoparticles. The generated Cu nanoparticles acted as bridges among Cu fine particles, enhancing sinterability. Consequently, Cu–Cu sinter bonding was achieved at 220 °C under 0.3 MPa in ambient air, forming a sufficiently sintered Cu layer. This approach offers a pathway for low-temperature, low-pressure bonding suitable for industrial-scale applications.
DC.rights	The full-text file will be made open to the public on 10 February 2026 in accordance with the publisher's policy.
DC.format	100256
citation_title	Lowering temperature of Cu sinter bonding under low-pressure in ambient air by in-situ generation and reduction of Cu₂O nanoparticles
citation_author	Oba, Miwa
	Matsuda, Tomoki
	Dougakiuchi, Masashi
	Okubo, Shio
	Kambara, Makoto
citation_publisher	Springer Science and Business Media LLC
citation_language	英語
citation_date	2025-02-10
citation_journal_title	Journal of Materials Science: Materials in Electronics
citation_volume	36
citation_issue	291
citation_doi	https://doi.org/10.1007/s10854-025-14352-7
citation_public_url	https://hdl.handle.net/11094/100256

Lowering temperature of Cu sinter bonding under low-pressure in ambient air by in-situ generation and reduction of Cu₂O nanoparticles

閲覧可能ファイル

論文情報

論文詳細を表示