Aerosol Jet Printing of a Benzocyclobutene‐Based Ink as Adhesive Material for Wafer Bonding Application

Abstract

Aerosol jet printing (AJP) is an emerging additive manufacturing technology that is gaining increasing attention in the electronic field. Several studies have been carried out on the AJP of conductive, semiconductive, and dielectric polymers for electronic applications. However, wafer bonding is an application that is still uncovered by literature. Therefore, in this work, the AJP of benzocyclobutene (BCB) as a polymeric adhesive for wafer bonding is presented for the first time. A thorough characterization of the processing parameters is carried out to identify the most ideal conditions for printing at a relatively high speed. Then, square patterns are printed, proving the versatility of the AJP technology in terms of the reachable thickness of the deposited BCB patterns. Complex patterns with a resolution of ≈60 µm are also printed. The bonding properties of the BCB are characterized from a morphological and mechanical point of view. In particular, the shear strength of the BCB coatings deposited with AJP is ≈39 MPa and it is comparable with the shear strength of BCB coating deposited by spin‐coating. Consequently, AJP represents a valid alternative for the deposition of polymeric adhesive for wafer bonding.

River valley-inspired, high-sensitivity, and rapid-response capacitive three-dimensional force tactile sensor based on U-shaped groove structure

“…Owing to the limited flexibility and lack of dexterousness, applications of conventional 3D-force tactile sensors prepared from rigid materials are restricted [12]. In comparison, flexible sensors possess lightness, higher flexibility and sensitivity, better integration, and wearing comfort [13,14], and are ideal candidates in the field of wearable devices [15][16][17][18][19][20][21], smart robotics [22][23][24], human-machine interaction [25][26][27][28], and monitoring detection [29][30][31][32][33][34].…”