Growth Kinetics of Intermetallic Compound and Interfacial Reactions in Pb-Free Flip Chip Solder Bump during Solid State Isothermal Aging

In the present work, the growth kinetics of intermetallic compound layer formed in Sn-3.5Ag flip chip solder joints by solid-state isothermal aging was examined at temperatures between 80 and 150 °C for 0 to 60 days. The bumping for the flip chip devices was performed using an electroless under bump metallization. The quantitative analyses were performed on the intermetallic compound layer thickness as a function of aging time and aging temperature. The layer growth of the Ni3Sn4 intermetallic compound followed a parabolic law within a given temperature range. As a whole, because the value of the time exponent (n) is approximately equal to 0.5, the layer growth of the intermetallic compound was mainly controlled by diffusion mechanism in the temperature range studied. The apparent activation energy of the Ni3Sn4 intermetallic was 49.63 kJ/mol.

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Solid-state growth kinetics of intermetallic compounds in Cu pillar solder flip chip with ENEPIG surface finish under isothermal aging

Journal of Materials Science Materials in Electronics ◽

10.1007/s10854-017-7086-0 ◽

2017 ◽

Vol 28 (17) ◽

pp. 12617-12629 ◽

Cited By ~ 4

Author(s):

Kelvin P. L. Pun ◽

M. N. Islam ◽

Chee Wah Cheung ◽

Alan H. S. Chan

Keyword(s):

Solid State ◽

Intermetallic Compounds ◽

Growth Kinetics ◽

Surface Finish ◽

Isothermal Aging ◽

Flip Chip ◽

Cu Pillar ◽

State Growth ◽

Kinetics Of

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Growth kinetics of the solid-state interfacial reactions in the Sn–Cu/Co and Sn/Co–Cu couples

Materials Chemistry and Physics ◽

10.1016/j.matchemphys.2011.07.042 ◽

2011 ◽

Vol 130 (1-2) ◽

pp. 651-656 ◽

Cited By ~ 30

Author(s):

Chao-hong Wang ◽

Chun-yi Kuo

Keyword(s):

Solid State ◽

Growth Kinetics ◽

Interfacial Reactions ◽

Kinetics Of

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Growth Kinetics of IMC Formed between Sn-3.5Ag-0.75Cu BGA Solder and Electroless Ni-P/Cu Substrate by Solid-State Isothermal Aging

Materials Science Forum ◽

10.4028/www.scientific.net/msf.449-452.893 ◽

2004 ◽

Vol 449-452 ◽

pp. 893-896 ◽

Cited By ~ 1

Author(s):

Jeong Won Yoon ◽

Chang Bae Lee ◽

Seung Boo Jung

Keyword(s):

Solid State ◽

Growth Kinetics ◽

Isothermal Aging ◽

Ball Grid Array ◽

Cu Substrate ◽

Diffusion Controlled ◽

Increasing Temperature ◽

Electroless Ni ◽

Kinetics Of ◽

Deposit Layer

The growth kinetics of intermetallic compound (IMC) layers formed between Sn-3.5Ag-0.75Cu BGA (ball grid array) solder and electroless Ni-P/Cu substrate by solid state isothermal aging were examined at temperatures between 70 and 170°C for 0 to 100 days. In the solder joints between the solder ball and electroless Ni-P/Cu pads, the IMC layer was (Cu,Ni)6Sn5. Also, a P-rich Ni layer formed at the interface between (Cu,Ni)6Sn5 and original Ni-P deposit layer because of the phosphorous accumulation. These IMC layer thicknesses increased linearly with the square root of aging time and the growth was faster for higher aging temperatures. On the contrary, the shear strength decreased with the increasing temperature and time. The growth of IMC layer was mainly controlled by diffusion-controlled mechanism over the temperature range studied. The apparent activation energy calculated for the growth of the (Cu,Ni)6Sn5 IMC was 69.75 kJ/mol.

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