Effect of Nickel Doping on Interfacial Reaction between Lead-Free Solder and Ni-P Substrate

2012 ◽  
Vol 488-489 ◽  
pp. 1375-1379 ◽  
Author(s):  
O. Saliza Azlina ◽  
A. Ourdjini ◽  
I. Siti Rabiatull Aisha
Keyword(s):  
Isothermal Aging ◽  
Environmental Concern ◽  
Aging Treatment ◽  
Electroless Nickel ◽  
Lead Free ◽  
Lead Free Solder ◽  
Reflow Soldering ◽  
Nickel Doping ◽  
Free Solder ◽  
Sac Solder

Due to environmental concern, lead-free solder are taking the place of eutectic Sn-Pb solder in electronic packaging industry. Among various lead free alloys, Sn–Ag–Cu (SAC) alloys are leading lead-free candidate solders for various applications because it is offered better properties. This study investigates the interfacial reactions during reflow soldering and isothermal aging between Sn-3.0Ag-0.5Cu (SAC305) and Sn-3.0Ag-0.5Cu-0.05Ni (SACN30505) on electroless nickel/ immersion palladium/immersion gold (ENEPIG) surface finish. The substrates were subjected to isothermal aging at 125°C for up to 2000 hours with solder size diameter of 500μm. The results indicated that after reflow soldering, (Cu, Ni)6Sn5 IMC is formed between solder and substrate while after aging treatment a new IMC was formed between (Cu, Ni)6Sn5 and substrate known as (Ni, Cu)3Sn4. Moreover, after soldering and isothermal aging, Ni-doped (SACN) solder represents a thicker IMC compared to SAC solder. Aging time of solder joints results in an increase of IMC’s thickness and changes their morphologies to become more spherical, dense and with larger grain size. In addition, the results also revealed that the thickness of intermetallics formed is proportional to the aging duration.

Effect of Different Aging Temperatures on Interfacial Reaction between SAC305 and ENEPIG Surface Finish

2011 ◽  
Vol 415-417 ◽  
pp. 1181-1185 ◽  
Author(s):  
Osman Saliza Azlina ◽  
Ali Ourdjini ◽  
Siti Rabiatull Aisha Idris ◽  
Mohd Ariff Azmah Hanim
Keyword(s):  
Isothermal Aging ◽  
Aging Treatment ◽  
Electroless Nickel ◽  
Lead Free ◽  
Green Product ◽  
Hazardous Substance ◽  
Lead Free Solder ◽  
Reflow Soldering ◽  
Packaging Industry ◽  
Free Solder

In electronic packaging industry, they are now driven technology to green product by replacing leaded-solder with lead-free solder in order to fulfill the European Restriction of Hazardous Substance (RoHS) compliance. Thus, Sn-Ag-Cu lead-free solder family is one of candidates can fulfill this requirement. This study investigates the interfacial reactions during reflow soldering and isothermal aging between Sn-3.0Ag-0.5Cu (SAC305) and electroless nickel/ immersion palladium/immersion gold (ENEPIG). Reliability of solder joint is also examined by performing solid state isothermal aging at 125°C and 150°C for up to 2000 hours. The results revealed that after reflow soldering, (Cu, Ni)6Sn5 IMC is formed between solder and substrate while after aging treatment another IMC was found between (Cu, Ni)6Sn5 and substrate known as (Ni, Cu)3Sn4. Aging time and temperature of solder joints results in an increase of IMC’s thickness and changes their morphologies to become more spherical, dense and with larger grain size. In addition, the results also revealed that the thickness of intermetallics formed is proportional to the aging duration and temperature.

Nanoindentation Measurements of the Mechanical Properties of Individual Phases Within Lead Free Solder Joints Subjected to Isothermal Aging

2018 ◽  
Author(s):  
Abdullah Fahim ◽  
Sudan Ahmed ◽  
Jeffrey C. Suhling ◽  
Pradeep Lall
Keyword(s):  
Mechanical Properties ◽  
Isothermal Aging ◽  
Solder Joints ◽  
Bulk Solder ◽  
Lead Free ◽  
Nanoindentation Test ◽  
Lead Free Solder ◽  
Free Solder ◽  
The Individual ◽  
Sac Solder

Exposure of lead free solder joints to high temperature isothermal aging conditions leads to microstructure evolution, which mainly includes coarsening of the intermetallic (IMC) phases. In our previous work, it was found that the coarsening of IMCs led to degradation of the overall mechanical properties of the SAC solder composite consisting of β-Sn matrix and IMC particles. However, it is not known whether the isothermal aging changes properties of the individual β-Sn and IMC phases, which could also be affecting to the overall degradation of properties. In this study, the aging induced variations of the mechanical properties of the β-Sn phase, and of Sn-Cu IMC particles in SAC solder joints have been explored using nanoindentation. SAC solder joints extracted from SuperBGA (SBGA) packages were aged for different time intervals (0, 1, 5, 10 days) at T = 125 °C. Nanoindentation test samples were prepared by cross sectioning the solder joints, and then molding them in epoxy and polishing them to prepare the joint surfaces for nanoindentation. Multiple β-Sn grains were identified in joints using optical polarized microscopy and IMCs were also observed. Individual β-Sn grains and IMC particles were then indented at room temperature to measure their mechanical properties (elastic modulus and hardness) and time dependent creep deformations. Properties measured at different aging time were then compared to explore aging induced degradations of the individual phases. The properties of the individual phases did not show significant degradation. Thus, IMC coarsening is the primary reason for the degradation of bulk solder joint properties, and changes of the properties of the individual phases making up the lead free solder material are negligible.

Reliability Analysis of Lead-Free Solder Joints with Solder Doping on Harsh Environment

2016 ◽  
Vol 2016 (1) ◽  
pp. 000117-000122 ◽  
Author(s):  
Cong Zhao ◽  
Thomas Sanders ◽  
Zhou Hai ◽  
Chaobo Shen ◽  
John L. Evans
Keyword(s):  
Surface Finish ◽  
Isothermal Aging ◽  
Electroless Nickel ◽  
Lead Free ◽  
Lead Free Solder ◽  
Solder Paste ◽  
Surface Mount ◽  
Surface Finishes ◽  
Free Solder ◽  
Immersion Silver

Abstract This paper investigates the effect of long term isothermal aging and thermal cycling on the reliability of lead-free solder mixes with different solder compositions, PCB surface finishes, and isothermal aging conditions. A variety of surface mount components are considered, including ball grid arrays (BGAs), quad flat no-lead packages (QFNs) and 2512 Surface Mount Resistors (SMRs). 12 lead-free solder pastes are tested; for BGA packages these are reflowed with lead-free solder spheres of SAC105, SAC305 and matched doped solder spheres (“matched” solder paste and sphere composition). Three surface finishes are tested: Organic Solderability Preservative (OSP), Immersion Silver (ImAg), and Electroless Nickel Immersion Gold (ENIG). All test components are subjected to isothermal aging at 125°C for 0 or 12 months, followed by accelerated thermal cycle testing from −40°C to 125°C. Data from the first 1500 cycles is presented here, with a focus on the effect of surface finish on package reliability. Current results demonstrate that the choice of surface finish has a strong effect on reliability. However, different solder materials appear to show different reliability trends with respect to the surface finishes, and the reliability trends of BGA and SMR packages also diverge.

scholarly journals Effect of Isothermal Aging 2000 Hours on Intermetallics Formed between Ni-Pd-Au with Sn-4Ag-0.5Cu Solders

2013 ◽  
Vol 650 ◽  
pp. 194-199 ◽  
Author(s):  
M.A. Azmah Hanim ◽  
A. Ourdjini ◽  
I. Siti Rabiatul Aisha ◽  
O. Saliza Azlina
Keyword(s):  
Aging Time ◽  
Isothermal Aging ◽  
Growth Process ◽  
Electroless Nickel ◽  
Gold Surface ◽  
Lead Free ◽  
Lead Free Solder ◽  
Reflow Process ◽  
Dense Structure ◽  
Free Solder

The present study investigated the effect of isothermal aging up to 2000 hours on the intermetallics formed between Sn-4Ag-0.5Cu lead free solder on electroless nickel electroless palladium immersion gold surface finish (Ni-Pd-Au). For all parameters, aging have an effect of changing the intermetallic morphology to coarser and dense structure. The intermetallic compound formed for the interconnection of the lead free solder changes with increased aging time from (Cu,Ni)6Sn5 compound to (Ni,Cu)3Sn4. At the end of the 2000 hours aging time, it changes to Ni3Sn4. This is the effect of Cu element availability during the intermetallics growth process. Starting from as reflow process, (Pd, Ni)Sn4 intermetallics formed near the interface of the solder joint. The formation of the (Pd, Ni)Sn4 intermetallics act like a diffusion barrier to slow down the growth of interface intermetallics. Lastly, Au element was detected in the Pd-Sn based intermetallic after aging more than 1000 hours.

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

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)

Microstructure Comparison of Soldered Joints Using Electrochemical Selective Etching

2012 ◽  
Vol 729 ◽  
pp. 367-372 ◽  
Author(s):  
Tamás Hurtony ◽  
Attila Bonyár ◽  
Péter Gordon
Keyword(s):  
Cross Section ◽  
Electrochemical Etching ◽  
Lead Free ◽  
Lead Free Solder ◽  
Cross Sectional ◽  
Reflow Soldering ◽  
Solder Bumps ◽  
Lead Free Solder Alloy ◽  
Free Solder ◽  
Sac Solder

The microstructure of the commonly used SnAgCu (SAC) lead free solder alloy was investigated. SAC solder bumps were soldered by two different soldering techniques (Vapor Phase Soldering (VPS), Laser reflow). Since the soldering profile of the VPS method is considerably different from the temperature profile of the laser reflow soldering, the created microstructures are expected to be diverse. Selective electrochemical etching was applied on cross sectional samples in order to extract the tin from the cross sectioning plane. In this manner the spatial structure of Cu6Sn5and the Ag3Sn intermetllic compounds (IMCs) was highlighted. The microstructures of the samples were analyzed with optical microscopy and Scanning Electron Microscope (SEM) on cross-section samples. The composing elements were identified by SEM-EDS.

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