Optimal sintering technologies applied to inkjet-printed silver nanoparticles for microelectronics applications

Abstract : As an alternative technology to replace lithographic process, direct printing of conductive nanofluids can thus be used to fabricate high resolution patterns, such as antennas and conductive redistribution lines. In the past few years, the use of metallic nanoparticles has undergone major development in microelectronics thanks to sintering achievements. To preserve electronic components functionalities, thermal budget need to be carefully considered, and thus a limited sintering temperature below 300°C should be used when printing nanoparticles. Nonetheless, the absence of any compacting step requires an exploration of novel sintering approaches to achieve a sufficient coalescence. In this frame, several sintering processes (thermal oven, rapid thermal annealing, selective microwave and laser curing) have been investigated to optimize the annealing of those thin films. The aim of this work is to analyze the induced microstructure of the above-mentioned sintering processes, and to determine how electrical and mechanical characteristics are consequently impacted. According the sintering technique and process parameters, an average grain size up to one micron can been achieved from initial mean particle size of 40nm, without exceeding a temperature range of 300°C. The microstructure characterization has been performed using electron backscatter diffraction (EBSD) in a field emission gun scanning electron microscope. Microstructural evolution of various sintered inkjet-printed films has thus been correlated with electrical resistivity and with the Young's modulus determined by nanoindentation. A strong link between those three parameters was highlighted during experiments giving credit to either a surface or a fully volumetric sintering, according the process. Sintering is then mainly triggered respectively by surface mass transfer or by grain boundary diffusion. Particular interests are shown for selective sintering especially when using microwaves and laser. Silver thin-films with an electrical resistivity three times higher than the bulk can be reached in a few minutes for a Young's modulus of about 50 GPa. In the meantime, the convective rapid thermal processing exhibits a various electrical resistivity and grain size. A Young's modulus even close to the bulk can be obtained when using a fast temperature ramp at 150 °C/sec for 15 minutes. This microstructural tailoring of printed silver nanoparticles were successfully implemented in the post-process step to achieve 600 nm thick films with very low resistivity and improved mechanical stiffness.
Type de document :
Communication dans un congrès
International Conference on Sintering 2011, Aug 2011, Jeju, South Korea
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Contributeur : Romain Cauchois <>
Soumis le : jeudi 3 novembre 2011 - 16:06:38
Dernière modification le : mercredi 29 novembre 2017 - 10:07:58


  • HAL Id : emse-00638031, version 1



Romain Cauchois, Mohamed Saadaoui, Abdelwahhab Yakoub, Karim Inal, Béatrice Dubois-Bonvalot, et al.. Optimal sintering technologies applied to inkjet-printed silver nanoparticles for microelectronics applications. International Conference on Sintering 2011, Aug 2011, Jeju, South Korea. 〈emse-00638031〉



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