Capuz, GiovanniGiovanniCapuzDaily, R.R.DailyWang, T.T.WangStruyf, HerbertHerbertStruyfMiller, AndyAndyMillerRebibis, Kenneth JuneKenneth JuneRebibis2026-10-292026-10-292013https://imec-publications.be/handle/20.500.12860/60656<jats:title>ABSTRACT</jats:title> <jats:p>Conceptualization of the No-Flow (NUF) or any pre-applied underfill in encapsulating bump joints in flip chip and 3D IC; defined the direction of industry in manufacturability of scaling 3D IC. It replaces capillary underfill (CUF) which is process time and real-state consuming. Not to mention the overflow for thin die stack platform.</jats:p> <jats:p>One single event in a very short process called the Thermo-Compression Bonding (TCB), where you apply heat and pressure force in joining 2 die in D2D configuration, will make or break an effective stacking and good bump joint.</jats:p> <jats:p>Interaction of the underfill material behavior, the bond profile and the tool used is the purpose of this paper.</jats:p> <jats:p>First of all, No-Flow should be applied or be dispenseable. Material viscosity has to be in process-able range in which volume control can be a challenge. Filler has its purpose of lowering CTE but may pose issues in filler entrapment and viscosity.</jats:p> <jats:p>The isothermal viscosity at lower temperature ranges help to define dispense process. Dispensing process should prevent No-Flow underfill from starting the gelation or curing in which jet dispense process uses nozzle heat. Jet dispensing is very much preferable in terms of volume control accuracy especially for a sub-milligram requirements of low profiled 3D IC stacks.</jats:p> <jats:p>Fluxing is a major component in the NUF to aid the bump joining process but the effect of volatility of the material might affect voiding.</jats:p> <jats:p>Ramp rate and dwell time of force and heat that influence bump connection and material cure will impact how good the bump formation will be.</jats:p> <jats:p>This paper will also take a look on the cure rate and dynamic change in viscosity with a corresponding bond profile coinciding with the melting of bump.</jats:p>enProceedings paper10.37665/waveyiy82829