Wettability of CNT-Doped Solder under Isothermal Aging

2016 ◽  
Vol 857 ◽  
pp. 76-78
Author(s):  
Norliza Ismail ◽  
Roslina Ismail ◽  
Nur Izni Abd Aziz ◽  
Azman Jalar

Wettability for lead free solder 99.0Sn-0.3Ag-0.7Cu (SAC237) with addition of different weight percentage carbon nanotube after thermal treatment was investigated. SAC 237 solder powder with flux was mixed with 0.01%, 0.02%, 0.03% and 0.04% carbon nanotubes (CNTs) to form SAC-CNTs solder paste. Printed solder paste on test board with Cu surface finish was then reflow under 270°C temperature and isothermal aging at 150°C for 0,200 and 400 hours. Wettability of SAC-CNT solder was determined by measuring contact angle using optical microscope and image analyzer. As a result, from reflow process right through 400 hours of thermal aging, SAC237 with 0.04% CNT has the lowest contact angle as compared to other SAC-CNTs and SAC237 solder. As a conclusion, addition of carbon nanotubes into solder SAC237 improved their wettability on Cu substrate, especially at 0.04% of CNTs.

2016 ◽  
Vol 864 ◽  
pp. 175-179
Author(s):  
Mohamed Arif Azmah Hanim ◽  
M.N. Mohamad Aznan ◽  
R. Muhammad Raimi ◽  
A. Muhammad Azrol Amin

This study focused on the formation and growth of intermetallic compound (IMC) layer at the interfaces of pad finishes. The thickness of IMC layer, wetting angle, and defects such as floating IMC and voids formation after as reflow and isothermal aging were discussed. In this study, SAC237 (Sn: 99 wt.%, Ag: 0.3 wt.%, Cu: 0.7wt.%) reinforced with 0.01 wt.% of Multi-Walled Carbon Nanotubes (MWCNTs) were soldered on Electroless Nickel Immersion Gold (ENIG) and Immersion Tin (ImSn) pad finishes. Isothermal aging at 150°C for 400h, 800h, and 1200h were conducted after as reflow process. The IMC layer were analysed using optical microscope with image analyzer. The results shows the thickness of IMC layer for both ENIG and ImSn increased as the isothermal aging period increases. The increament was found from 1.49 μm to 1.73 μm for ENIG and 2.51 μm to 5.49 μm for ImSn. Floating IMC and voids formation were also observed on both pad finishes. Wetting angle for ENIG and ImSn varied from 16.21° to 36.85° and 24.27° to 34.41° respectively.


2015 ◽  
Vol 754-755 ◽  
pp. 546-550 ◽  
Author(s):  
Rita Mohd Said ◽  
Norainiza Saud ◽  
Mohd Arif Anuar Mohd Salleh ◽  
Mohd Nazree Derman ◽  
Mohd Izrul Izwan Ramli ◽  
...  

The effects of SiC on wettability and intermetallic compound (IMC) formation of Sn-Cu-Ni solder paste composite were systematically investigated. Lead-free solder paste composite was produced by mixing silicon carbide (SiC) particle with Sn-Cu-Ni (SN100C) solder paste. The wettability of composite solder was studied by observing the contact angle between solder and copper substrate. The IMC phase formation on copper substrate interface was identified using X-ray diffraction (XRD). The phase as detected in the composite solder is Cu6Sn5.The wettability of composite solder was observed through contact angle between solder and copper substrate and Sn-Cu-Ni + 1.0 wt.% SiC shows improvements in wetting angle and suppresses the IMCs formation.


2016 ◽  
Vol 2016 (1) ◽  
pp. 000117-000122 ◽  
Author(s):  
Cong Zhao ◽  
Thomas Sanders ◽  
Zhou Hai ◽  
Chaobo Shen ◽  
John L. Evans

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.


2013 ◽  
Vol 650 ◽  
pp. 194-199 ◽  
Author(s):  
M.A. Azmah Hanim ◽  
A. Ourdjini ◽  
I. Siti Rabiatul Aisha ◽  
O. Saliza Azlina

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.


2018 ◽  
Vol 280 ◽  
pp. 169-174 ◽  
Author(s):  
N.S. Mohamad Zaimi ◽  
Mohd Arif Anuar Mohd Salleh ◽  
Mohd Mustafa Abdullah Al Bakri ◽  
Rita Mohd Said ◽  
Norainiza Saud

A non metallic reinforcement has attracted most of the worldwide researchers to enhance solder performance. Silicon carbide (SiC) particle is a semiconductor which had been used as a non metallic reinforcement in this research study.The fabrication of Sn-0.7Cu lead free solder paste was done by mixing the solder powder with flux. Then, Sn-0.7Cu/SiC composite solder paste was prepared by mixing solder powder, flux and various weight percentage (wt%) of SiC. The amount of SiC particles added was 0, 0.25, 0.50, 0.75 and 1.0 wt%. The influence of SiC addition was analyzed based on its wettability, IMC layer formation and microhardness properties. The addition of SiC particles had decreased the contact angle as well as thinner the IMC layer. The morphology of IMC layer changed from scallop like shape to combination of scallop and planar like shape with the addition of SiC particle. Apart from that, the microhardness was enhanced with addition of SiC particle into Sn-0.7Cu lead free solder paste.


2016 ◽  
Vol 857 ◽  
pp. 73-75 ◽  
Author(s):  
Norliza Ismail ◽  
Roslina Ismail ◽  
Nik Khairul Amilin Nik Ubaidillah ◽  
Azman Jalar ◽  
Norazwani Muhammad Zain

The effect of substrate surface roughness on the wettability of SAC237 (Sn 99.9%, Ag 0.3%, Cu 0.7%) with difference percentage of CNT on copper substrate was investigated. Solder paste of SAC 237 without CNT, 0.01% and 0.04% of CNT were reflowed at 270°C on different surface roughness of Cu substrate (abrasive number 240, 400, 600, 800). Contact angle of soldered samples measured by Infinite Focus Microscope (IFM). As a result, contact angle value of investigated solders range 7° to 20°. Contact angle obtained decreases with the increasing surface roughness of Cu substrate. This demonstrates that rougher substrate enhance the wettability of the solders. Addition of CNT also effects the wettability of investigated solders. Higher composition of CNT show better wettability.


2014 ◽  
Vol 1678 ◽  
Author(s):  
Wesley D. Tennyson

ABSTRACTCarbon nanotubes (CNTs) have been shown to be a viable conductive additive in Li-Ion batteries [1]. By using CNTs battery life, energy, and power capability can all be improved over carbon black, the traditional conductive additive. A significantly smaller weight percentage (5% CNTs) is needed to get the same conductivity as 20% carbon black. Many of the previous efforts found that a combination of conductive additives was most advantageous [2]. Unfortunately many of these efforts did not attend to the unique challenge that dispersing nanotubes presents and used non-optimal methods to disperse CNTs (e.g. ball milling) [3,4]. With poor dispersion a stable and resilient conductive network in the cathode is hard to form with CNTs alone. Here we investigate the formation of LiFePO₄ with CNTs using a polyol process synthesis.


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