Capillary assisted automated silver direct bond of chip-on-chip through a novel sponge dipping approach

Weber J, Rauh H, Leib J, März M (2026)

Publication Language: English

Publication Status: Submitted

Publication Type: Other publication type

Future Publication Type: Journal article

Publication year: 2026

DOI: 10.36227/techrxiv.176948352.23951073/v1

Abstract

Direct Bonding as a new joining technique is creating new great potentials and challenges. One challenge is the precise placement of more than one component before a temperature treatment. Due to the elimination of pastes which can tack chips temporarily, the chips need alternative ways to stick to the substrate until sintering. A novel capillary assisted approach for automated silver Direct Bonding in chip-on-chip assemblies effectively reduces placement errors, particularly when stacking thin chips. By integrating a water-soaked foam module into a conventional pick-and-place process, capillary forces help mitigate the missing vacuum release while stacking multiple chips. Experiments with three chip sizes demonstrate a significant increase in yield-reaching up to 100%-as well as notable improvements in both alignment accuracy and precision. This foam-dipping method is straightforward, cost-effective, and requires minimal modifications to existing assembly lines. It thus offers a promising solution for high-volume Direct Bonding applications, addressing key challenges such as replacing the tacking mechanism used in paste-based assemblies.

Authors with CRIS profile

Jonas Weber Lehrstuhl für Leistungselektronik (LEE) Hubert Rauh Lehrstuhl für Elektronische Bauelemente Martin März Lehrstuhl für Leistungselektronik (LEE)

Involved external institutions

Fraunhofer-Institut für Integrierte Systeme und Bauelementetechnologie (IISB) DE Germany (DE)

How to cite

APA:

Weber, J., Rauh, H., Leib, J., & März, M. (2026). Capillary assisted automated silver direct bond of chip-on-chip through a novel sponge dipping approach.

MLA:

Weber, Jonas, et al. Capillary assisted automated silver direct bond of chip-on-chip through a novel sponge dipping approach. 2026.

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