Crosslinkable deoxidizing hybrid adhesive of epoxy–diacid for electrical interconnections in semiconductor packaging

Abstract

For electrical interconnections in semiconductor packaging, epoxy-based pastes have recently attracted considerable interest due to their excellent adhesion to various substrates and their reasonable electrical and mechanical properties, especially when combined with deoxidizing agents (to remove metallic oxides). Here, epoxy-diacid-based hybrid pastes were examined to achieve a deoxidizing capability for eliminating Sn-based solder oxides and adhesion between microchip and substrate as a one-step process. Onset, exothermic peak and end temperatures of the reaction between epoxy and diacids were systematically probed using DSC, rheometry and Fourier transform infrared (FTIR) spectroscopy. The last moment of the adhesive reaction during heating substantially enhanced the thermal and mechanical properties of the epoxy-diacid adhesive despite the absence of exothermic enthalpy detected by DSC. The glass transition temperature (T g ) and Young's modulus gradually decreased as a function of aliphatic chain length of diacids except when the length was extremely short and voids were produced. Soldering (wetting) and deoxidizing capabilities of the hybrid adhesive were observed via optical microscopy and FTIR. The correlation between the reaction, T g , conversion and viscosity was also investigated. Lastly, complete wetting and electrical interconnection with good mechanical robustness were achieved for a commercial chip/substrate set by flip-chip bonding.

Matrix–particle interactions in catalyzed and uncatalyzed copper‐filled epoxy matrix composites

“…Then it would be expected that the copper complexes can be initiators of the curing reaction. On the other hand, an epoxy system cured with an anhydride has been extensively studied in relation to its good properties and its possible applications in electronics or reinforced pipe production, for example. In fact, it has been observed that the copper particles can catalyze the curing reaction in an epoxy–anhydride system.…”

Chemical reactions affecting halloysite dispersion in epoxy nanocomposites

“…Other changes which can be mentioned are the appearance of two peaks at 2855 and 1725 cm −1 and the disappearance of the peak at 2835 cm −1 . While those peaks around 2830–2860 cm −1 correspond to CH moieties, the peak at 1725 cm −1 is assigned to the CO group . The appearance of the 1725 cm −1 peak is due to the chain scission phenomena which is associated with the formation of carbonyls in epoxy systems, so it can be deduced that DGEBA molecules undergo a degradation process owing to the elevated temperature locally achieved when tip sonicating the sample.…”

Thermochemical Mechanism of the Epoxy-Glutamic Acid Reaction with Sn-3.0 Ag-0.5 Cu Solder Powder for Electrical Joining

“…Over the last few decades, epoxy-based solder pastes (ESPs) have generated considerable interest as a leading option to overcome the disadvantages of commercial solder pastes. Eom et al have conducted extensive research on the mechanism of the reaction between epoxy-based resins and solders [ 5 , 6 , 7 , 8 ] and their thermomechanical and electrical properties for their application as conductive adhesives for electronic packaging [ 9 , 10 , 11 , 12 , 13 ]. The authors also proposed a working mechanism for a formulation consisting of epoxy resins, curing agents, catalysts, reductants such as carboxylic acids, and solder powder [ 9 , 10 ].…”