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)

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.

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.

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 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.

Effect of Isothermal Aging on the Growth and Morphology of the Intermetallic Compounds Formed at the Solder/Cu Interface of the Lead - Free Solder Joint

2007 ◽  
Vol 561-565 ◽  
pp. 2115-2118
Author(s):  
Yun Fu ◽  
Qi Zhang ◽  
Feng Sun ◽  
Hao Yu Bai
Keyword(s):  
Solder Joint ◽  
Intermetallic Compounds ◽  
Aging Time ◽  
Isothermal Aging ◽  
Lead Free ◽  
Intermetallic Compound Layer ◽  
Lead Free Solder ◽  
Cu Substrate ◽  
Cu6sn5 Layer ◽  
Free Solder

The growth and morphology of the intermetallic compounds (IMC) formed at the interface between the solder ( Sn–3.5Ag–0.5Cu ) and the Cu substrate of the lead - free solder joint have been investigated by means of isothermal aging at 125°C. The scalloped Cu6Sn5 intermetallic compound layer was formed at the interface between the solder and Cu substrate upon reflow. The thickness of Cu6Sn5 layer increased with aging time. Cu3Sn appeared between Cu6Sn5 layer and Cu substrate when isothermally aged for 100 hours. Compare to Cu6Sn5 , the thickness of Cu3Sn was rather low, and nearly did not increase with aging time. In this paper, the comparison was made among the Sn-Pb and the Sn-Ag-Cu(SAC) solders which were pre-treated differently before soldering.

scholarly journals INTERMETALLIC COMPOUNDS FORMATION OF SOLDER ALLOYS ON Ni/Au SURFACE FINISH COPPER

2020 ◽  
Vol 26 (4) ◽  
pp. 184-187
Author(s):  
Ngoc Binh Duong
Keyword(s):  
Intermetallic Compounds ◽  
Melting Temperature ◽  
Surface Finish ◽  
Copper Substrate ◽  
Lead Free ◽  
Lead Free Solder ◽  
Solder Alloys ◽  
Soldering Temperature ◽  
Substrate Interface ◽  
Free Solder

Intermetallic compounds (IMCs) formation between lead-free solder alloys (Sn-9Zn and Sn-8Zn-3Bi) and Ni/Au surface finish copper substrate were studied. Reaction between the solder and the substrate was carried out at regular soldering temperature, approx. 50 °C above the melting temperature of the solder alloys. Results indicated that Au-Zn was the IMC formed at the interface and the Au layer which is electro-plated on the substrate has completely dissolved into the solder alloys. The amount of Au available at the interface is an important factor that influent the morphology of the IMC with thicker Au layer on the substrate resulted in thicker layer of IMC at the interface. Although Bi does not taken part in the composition of IMC, it influent the formation of IMC, the IMC formed in the Sn9Zn/substrate interface was Au5Zn3, meanwhile it was g2-AuZn3 in the Sn-8Zn-3Bi/substrate interface.

IMC Growth Mechanisms of SAC305 Lead-Free Solder on Different Surface Finishes and Their Effects on Solder Joint Reliability of FCBGA Packages

2009 ◽  
Vol 6 (2) ◽  
pp. 119-124 ◽  
Author(s):  
Sang Ha Kim ◽  
Hiroshi Tabuchi ◽  
Chika Kakegawa ◽  
Han Park
Keyword(s):  
Solder Joint ◽  
Isothermal Aging ◽  
Lead Free ◽  
Lead Free Solder ◽  
Solder Joint Reliability ◽  
Joint Reliability ◽  
Surface Finishes ◽  
Cu3sn Layer ◽  
Cu6sn5 Layer ◽  
Free Solder

Intermetallic compound (IMC) growth behavior of lead-free solder plays an important role in ball grid array (BGA) solder joint reliability for flip chip BGA (FCBGA) packaging applications. The growth mechanism of IMC is reported based on a diffusion model. Thermal treatment such as accelerated thermal cycling (ATC) and isothermal aging exposure also contribute to the growth rate and morphology of lead-free solder IMC. Among the lead-free solder alloys, Sn-3.0wt.%Ag-0.5wt.%Cu (SAC305) solder is a promising substitute for Sn-Pb because of its good mechanical properties and wettability with current surface finishes. After thermal exposure, BGA solder joint reliability is degraded due to IMC formation and growth. In this study, two different thermal treatments, ATC and isothermal aging, and two different pad surface finishes, solder on pad (SOP) and electroless Ni immersion gold (ENIG), are considered in terms of IMC growth rate and mechanical solder joint reliability. An SOP finished interface forms a thin ε-phase Cu3Sn layer and a scallop-like η-phase Cu6Sn5 layer. In contrast, the ENIG finished interface forms a thick (Cu,Ni)6Sn5 IMC layer and prevents overall IMC growth. Different surface finished test vehicles are evaluated in an ATC test in a 0°C to 100°C temperature range and the Ni diffusion layer shows a longer solder joint fatigue lifetime than the nondiffusion barrier interface based on the micro cross-section and dye penetration analysis results. In an isothermal aging test at 100°C and 150°C, the aging temperature and time are valid factors to decide mechanical shock reliability. Interfacial fractures are found in the 100°C aged test vehicle due to easier crack propagation at the interface between the thin Cu3Sn layer and the scallop-like Cu6Sn5 layer based on SEM microstructure analysis results. Finally, this investigation proposes how to improve solder joint reliability and prevent interfacial fracture for SAC305 lead-free application.

Precise Quantitative Evaluation of Nano-Ordered Intermetallic Compounds in Sn-3.0Ag-0.5Cu Lead-Free Solder Bump by Using TEM

2008 ◽  
Vol 47-50 ◽  
pp. 907-911
Author(s):  
Chang Woo Lee ◽  
Y.S. Shin ◽  
J.H. Kim
Keyword(s):  
Intermetallic Compounds ◽  
Flip Chip ◽  
Solder Bump ◽  
Lead Free Solder ◽  
Growth Behaviour ◽  
Sic Particles ◽  
Imcs Growth ◽  
Ordered Intermetallic ◽  
Free Solder ◽  
The One

The growth behaviour of the intermetallic compounds (IMCs) in Pb-free solder bump is investigated. The Pb-free micro-bump, Sn-50%Bi, was fabricated by binary electroplating for flip-chip bond. The diameter of the bump is about 506m and the height is about 60 6m. In order to increase the reliability of the bonding, it is necessary to protect the growth of the IMCs in interface between Cu pad and the solder bump. For control of IMCs growth, SiC particles were distributed in the micro-solder bump during electroplating. The thickness of the IMCs in the interface was estimated by FE-SEM, EDS, XRF and TEM. From the results, The IMCs were found as Cu6Sn5 and Cu3Sn. The thickness of the IMCs decreases with increase the amount of SiC particles until 4 g/cm2. The one candidate of the reasons is that the SiC particles could decrease the area which be reacted between the solder and Cu layer. And another candidate is that the particle can make to difficult inter-diffusion within the interface.

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