Sacrificial adhesive bonding: a powerful method for fabrication of glass microchips

• Grant number: 15/15714-4
• Support Opportunities: Regular Research Grants - Publications - Scientific article
• Start date: September 01, 2015
• End date: February 29, 2016
• Field of knowledge: Interdisciplinary Subjects
• Principal Investigator: Emanuel Carrilho
• Grantee: Emanuel Carrilho
• Host Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

A new protocol for fabrication of glass microchips is addressed in this research paper. Initially, the method involves the use of an uncured SU-8 intermediate to seal two glass slides irreversibly as in conventional adhesive bonding-based approaches. Subsequently, however, an additional step removes the adhesive bonding from the channels. This step relies on a selective developer to remove the SU-8 inside microchannel, generating glass-like surface properties as demonstrated by specific tests. Named sacrificial adhesive bonding (SAB), the protocol meets the requirements of the ideal technique such as throughput, relatively low cost, feasibility for ultra large-scale integration (ULSI), and high adhesion strength, supporting pressures on the order of 5 MPa. Furthermore, SAB eliminates the use of high temperature, pressure, or potential, enabling the deposition of thin films for electrical or electrochemical experiments. Finally, this protocol is an improvement on SU-8-based bondings described in the literature. Aspects such as substrate/resist adherence, formation of bubbles, and thermal stress were effectively solved by using simple and inexpensive alternatives. (AU)