Solid-state growth kinetics of intermetallic compounds in Cu pillar solder flip chip with ENEPIG surface finish under 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 Ni3Sn4 at the Sn–3.5Ag solder∕Ni interface

Journal of Applied Physics ◽

10.1063/1.2149487 ◽

2005 ◽

Vol 98 (12) ◽

pp. 123527 ◽

Cited By ~ 42

Author(s):

M. O. Alam ◽

Y. C. Chan

Keyword(s):

Solid State ◽

Growth Kinetics ◽

State Growth ◽

Kinetics Of

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Solid state growth kinetics of complex intermetallics in the Pb-free ball grid array (BGA) solder joint for MEMS packaging

2006 8th Electronics Packaging Technology Conference ◽

10.1109/eptc.2006.342717 ◽

2006 ◽

Author(s):

M. Alam ◽

Yang Dan ◽

B. Wu ◽

Y. Chan ◽

L. Rufer ◽

...

Keyword(s):

Solid State ◽

Solder Joint ◽

Growth Kinetics ◽

Ball Grid Array ◽

Mems Packaging ◽

State Growth ◽

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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Morphology and growth kinetics of intermetallic compounds in solid-state interfacial reaction of electroless Ni-P with Sn-based lead-free solders

Journal of Electronic Materials ◽

10.1007/s11664-006-0202-1 ◽

2006 ◽

Vol 35 (1) ◽

pp. 181-188 ◽

Cited By ~ 25

Author(s):

M. L. Huang ◽

T. Loeher ◽

D. Manessis ◽

L. Boettcher ◽

A. Ostmann ◽

...

Keyword(s):

Solid State ◽

Intermetallic Compounds ◽

Interfacial Reaction ◽

Growth Kinetics ◽

Lead Free ◽

Lead Free Solders ◽

Electroless Ni ◽

Kinetics Of

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Effect of Soldier Bump Size On Interfacial Reactions During Soldering Between PB–Free Solder and Cu and Cu Ni/Pd/Au Surface Finishes

Jurnal Teknologi ◽

10.11113/jt.v52.118 ◽

2012 ◽

Author(s):

Nor Akmal Fadil ◽

Ali Ourdjini ◽

Azmah Hanim Mohamed Ariff ◽

Siti Rabiatul Aisha Idris

Keyword(s):

Intermetallic Compounds ◽

Surface Finish ◽

Isothermal Aging ◽

Flip Chip ◽

Electroless Nickel ◽

Lead Free ◽

Lead Free Solder ◽

Under Bump Metallization ◽

Surface Finishes ◽

Free Solder

Teknologi flip chip memberikan ketumpatan I/O yang sangat tinggi dan mengambil kira prestasi elektrikal yang paling baik dalam penyambungan komponen elektronik. Oleh itu, kajian tentang sebatian antara logam dilaksanakan untuk mengkaji kesan saiz bebola pateri bagi beberapa penyudahan permukaan, iaitu Kuprum dan Nikel tanpa elektrod/Palladium tanpa elektrod/Emas rendaman (ENEPIG). Pelogaman di bawah pateri (UBM) Ni/Pd/Au bagi aplikasi flip chip digunakan dengan sangat meluas dalam pembungkusan elektronik. Analisis FESEM dilakukan untuk menganalisis morfologi dan komposisi bagi sebatian antara logam (IMC). IMC yang terbentuk antara pateri Sn–Pb dan tanpa Pb dengan penyudahan permukaan kuprum semasa proses pematrian logam secara umumnya adalah (Cu, Ni)6Sn5 dan Cu6Sn5 dan Cu6Sn5. Sementara IMC utama yang terbentuk antara pateri Sn–Pb dan tanpa Pb dengan penyudahan permukaan ENEPIG adalah (Ni, Cu)3Sn4 dan Ni3Sn4. Hasil daripada analisis morfologi menggunakan FESEM dengan EDX menyatakan penuaan sesuhu pada suhu 150°C menyebabkan penebalan dan pengasaran struktur IMC serta menjadikan bentuknya kepada lebih sfera. Tebal IMC bagi kedua–dua penyudahan yang dikaji adalah lebih tinggi bagi bebola patri yang lebih kecil. Daripada hasil kajian juga, didapati bahawa kadar pertumbuhan IMC adalah lebih tinggi apabila pematrian dilakukan atas penyudahan kuprum berbanding ENEPIG. Hasil kajian juga menunjukkan ketebalan IMC adalah berkadaran dengan masa penuaan sesuhu. Kata kunci: Flip chip; Kumprum dan Nikel tanpa elektrod; Palladium tanpa elektrod; Emas rendaman (ENEPIG); Pelogaman di bawah pateri (UMB) Ni/Pd/Au Flip chip technology provides the ultimate in high I/O–density and count with superior electrical performance for interconnecting electronic components. Therefore, the study of the intermetallic compounds was conducted to investigate the effect of solder bumps sizes on several surface finishes which are copper and Electroless Nickel/Electroless Palladium/Immersion Gold (ENEPIG) which is widely used in electronics packaging as under–bump metallization (UBM) for flip–chip application nowadays. In this research, field emission scanning electron microscopy (FE–SEM) analyses were conducted to analyze the morphology and composition of intermetallic compounds (IMCs) formed at the interface between the solder and UBM. The IMCs between Sn–Pb and lead–free solder with Cu surface finish during reflowing were mainly (Cu, Ni)6Sn5 dan Cu6Sn5. While the main IMCs formed between Sn–Pb and lead–free solder on ENEPIG surface finish are (Ni, Cu)3Sn4 and Ni3Sn4. The results from FESEM with energy dispersive x–ray (EDX) have revealed that isothermal aging at 150°C has caused the thickening and coarsening of IMCs as well as changing them into more spherical shape. The thickness of the intermetallic compounds in both finishes investigated ware found to be higher in solders with smaller bump size. From the experimental results, it also appears that the growth rate of IMCs is higher when soldering on copper compared to ENEPIG finish. Besides that, the results also showed that the thickness of intermetallic compounds was found to be proportional to isothermal aging duration. Key words: Electroless nickel; electroless palladium; immersion gold (ENEPIG); flip chip; Ni/Pd/Au Under–bump metallization (UMB)

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