Low temperature full wafer adhesive bonding of structured wafers

• Published in: Sensors and actuators. A, Physical Vol. 92; no. 1; pp. 235 - 241
• Main Authors: Niklaus, F., Andersson, H., Enoksson, P., Stemme, G.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Lausanne Elsevier B.V 01.08.2001; Elsevier Science
• Subjects: Adhesive bonding; Applied sciences; BCB; Bonding; Electronics; Exact sciences and technology; General equipment and techniques; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Lithography, masks and pattern transfer; Microelectronic fabrication (materials and surfaces technology); Physics; Polymer bonding; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Surface structures; Wafer bonding; Wafer bonding; BCB; Polymer bonding; Adhesive bonding; Surface structures; Bonding; Microelectronic fabrication; Void formwork; Fluidic element; Experimental study; Polymers; Surface structure
• ISSN: 0924-4247; 1873-3069; 1873-3069
• DOI: 10.1016/S0924-4247(01)00568-4

In this paper, we present a technology for void free low temperature full wafer adhesive bonding of structured wafers. Benzocyclobutene (BCB) is used as the intermediate bonding material. BCB bonds well with various materials and does not release significant amounts of by-products during the curing process. Thus void-free bond interfaces can be achieved. Cured BCB coatings have an excellent resistance to a variety of acids, alkalines and solvents and a high transparency for light across the visible spectrum, which makes it a good material for fluidic, optical and packaging applications. We demonstrate the fabrication of fluidic structures and the embedding of protruding surface structures. An important finding is that the pre-cured BCB coatings are extremely deformable and have a “liquid-like” behaviour during bonding.