Influence of the P content on phase formation in the interfacial reactions between Sn and electroless Co(P) metallization on Cu substrate

Microstructure and morphology of interfacial intermetallic compound CoSn3 in Sn–Pb/Co–P solder joints

“…CoSn, CoSn 2 , and CoSn 3 IMCs have been observed in various Co/Sn solder joints [27][28][29][30][31][32][33][34][35][36]. CoSn 3 appears most frequently at the interface of Co/Sn joints, and it has a strong impact on the shear strength of the joints [5,27,[30][31][32][33].…”

“…Recently, Co-based UBM has attracted considerable interest because of slow interfacial reaction between Co-based UBM and solders, large joint strength, good joint reliability, and acceptable wettability [26][27][28][29][30][31][32][33][34][35][36][37][38]. Electroless Co-Ni-P metallization has been studied, and Co-Ni-P has shown a slower consumption rate and better resistance to joint-strength degradation during a long-term thermal aging in comparison with Ni-P [26].…”

“…CoSn 3 appears most frequently at the interface of Co/Sn joints, and it has a strong impact on the shear strength of the joints [5,27,[30][31][32][33]. However, microstructure and morphology of CoSn 3 interfacial IMC have not been fully investigated in the literature.…”

Effect of pH, Surfactant, and Heat Treatment on Morphology, Structure, and Hardness of Electrodeposited Co-P Coatings

“…Phosphorus is one of the most important alloying elements for Co coatings. Nano-crystalline Co-P coatings are relatively new alloy films, which are often applied via electrodeposition ( as well as electroless deposition techniques (Ref [15][16][17][18]. High current efficiency, the possibility to obtain thick coatings with no voids and microcracks, fewer significant environmental impacts, high hardness and wear resistance, proper ductility and thermal stability, noticeable corrosion resistance, and ability to improve properties by heat treatment, all have made nano-crystalline Co-P electrodeposits suitable substitute for the hard chromium coatings ( Ref 2,3,5,15,19).…”

Strong effects of minor Ga addition on liquid-state Sn–Ga/Co interfacial reactions

“…In addition, Co also possesses a better electromigration resistance than Cu and Ni. The electroless deposition technologies of Co alloys were also developed [17,18]. The recent studies found that minor Cu or Zn addition can effectively suppress the interfacial CoSn 3 growth [19,20].…”