scholarly journals Molten Lead-Free Solder Deposited by Inkjet Printing for Bonding of Thin-Film Solar Cell Modules

2016 ◽  
Vol 57 (6) ◽  
pp. 797-804
Author(s):  
Chien-Hsun Wang ◽  
Weng-Sing Hwang ◽  
Wen-Ming Chen ◽  
Ho-Lin Tsai ◽  
Cheng-Han Wu
Keyword(s):  
Thin Film ◽  
Solar Cell ◽  
Inkjet Printing ◽  
Thin Film Solar Cell ◽  
Lead Free ◽  
Lead Free Solder ◽  
Cell Modules ◽  
Molten Lead ◽  
Free Solder

Study of Micro Droplet Impingement Process of Molten Lead-Free Solder by Inkjet Printing Process

2011 ◽  
Vol 409 ◽  
pp. 437-442 ◽  
Author(s):  
Cheng Han Wu ◽  
Hsiao Lan Lin ◽  
Weng Sing Hwang
Keyword(s):  
Heat Transfer ◽  
Inkjet Printing ◽  
Lead Free ◽  
Orifice Diameter ◽  
Lead Free Solder ◽  
Interfacial Heat Transfer ◽  
Droplet Impingement ◽  
Printing Process ◽  
Molten Lead ◽  
Free Solder

An investigation of molten metal droplet impingement on substrate was conducted. Micro droplets of molten lead-free solder; Sn_3.0wt%Ag_0.5wt%Cu, were ejected at 230°C by using a piezoelectric inkjet printing process. The droplets were squeezed out from nozzle with orifice diameter of 50 µm by applying a voltage pulse of bipolar waveform. In this study, micro droplets with various velocities were deposited onto flat substrate. Spread factors of solders are at the range of 1.23-1.25. With the aid of numerical simulation, interfacial heat transfer coefficients between molten solders and substrate were observed to rise with droplet impact velocity. Though analyzing the data of simulation results, the mathematical relation between interfacial heat transfer coefficient and potential and kinetic energy shows the trend of direct proportion.

Study on electromigration in flip chip lead-free solder connections with 40 μm or 30 μm diameter on thin film ceramic substrates

2015 ◽  
Vol 2015 (1) ◽  
pp. 000799-000805
Author(s):  
Marek Gorywoda ◽  
Rainer Dohle ◽  
Bernd Kandler ◽  
Bernd Burger
Keyword(s):  
Thin Film ◽  
High Stability ◽  
Flip Chip ◽  
Lead Free ◽  
Published Data ◽  
Organic Substrates ◽  
Lead Free Solder ◽  
Ceramic Substrates ◽  
Solder Bumps ◽  
Free Solder

Electromigration comprises one of the processes affecting the long-term reliability of electronic devices; it has therefore been the focus of many investigations in recent years. In regards to flip chip packaging technology, the majority of published data is concerned with electromigration in solder connections to metallized organic substrates. Hardly any information is available in the literature on electromigration in lead-free solder connections on thin film ceramic substrates. This work presents results of a study of electromigration in lead-free (SAC305) flip chip solder bumps with a nominal diameter of 40 μm or 30 μm with a pitch of 100 μm on silicon chips assembled onto thin film Al2O3 ceramic substrates. The under bump metallization (UBM) comprised of a 5 μm thick electroless nickel immersion gold (ENIG) layer directly deposited on the AlCu0.5 trace. The ceramic substrates were metallized using a thin film multilayer (NiCr-Au(1.5 μm)-Ni(2 μm) structure on the top of which wettable areas were produced with high precision by depositing flash Au (60 nm) of the required diameter (40 μm or 30 μm). All electromigration tests were performed at the temperature of 125 °C. Initially, one chip assembly with 40 μm and one with 30 μm solder bumps was loaded with the current density of 8 kA/cm2 for 1,000 h. The assemblies did not fail and an investigation with SEM revealed no significant changes to the microstructure of the bumps. Thereafter seven chip assemblies with 40 μm solder bumps and five assemblies with 30 μm bumps were subjected to electromigration tests of 14 kA/cm2 or 25 kA/cm2, respectively. Six of the 40 μm-assemblies failed after 7,000 h and none of the 30 μm-assemblies failed after 2,500 h of test duration so far. Investigation of failed samples performed with SEM and EDX showed asymmetric changes of microstructure in respect to current flow. Several intermetallic phases were found to form in the solder. The predominant damage of the interconnects was found to occur at the cathode contact to chip; the Ni-P layers there showed typical columnar Kirkendall voids caused by migration of Ni from the layers into the solder. Failure of the contacts apparently occurred at the interface between Ni-P and solder. In summary, the results of the study indicate a very high stability of lead-free solder connections on ceramic substrates against electromigration. This high stability is primarily due to a better heat dissipation and thus to a relatively low temperature increase of the ceramic packages caused by resistive heating during flow of electric current. In addition, the type of the metallization used in the study seems to be more resistant to electromigration than the standard PCB metallization as it does not contain a copper layer.

Crystalline silicon on glass (CSG) thin-film solar cell modules

Solar Energy ◽  
2004 ◽  
Vol 77 (6) ◽  
pp. 857-863 ◽  
Author(s):  
M.A. Green ◽  
P.A. Basore ◽  
N. Chang ◽  
D. Clugston ◽  
R. Egan ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cell ◽  
Thin Film Solar Cell ◽  
Crystalline Silicon ◽  
Cell Modules

GS0414 Initial Corrosion Behavior of Stainless Steel in the Molten Lead-free Solder

2016 ◽  
Vol 2016.22 (0) ◽  
pp. _GS0414-1_-_GS0414-2_
Author(s):  
Kenji MIKI ◽  
Akira YAMAUCHI ◽  
Masashi KUROSE ◽  
Makoto NANKO
Keyword(s):  
Stainless Steel ◽  
Corrosion Behavior ◽  
Lead Free ◽  
Lead Free Solder ◽  
Molten Lead ◽  
Free Solder

20107 Observation of initial corrosion of carbon steel in molten lead-free solder

2015 ◽  
Vol 2015.21 (0) ◽  
pp. _20107-1_-_20107-2_
Author(s):  
Koudai UESUGI ◽  
Akira YAMAUCHI ◽  
Makoto NANKOU
Keyword(s):  
Carbon Steel ◽  
Lead Free ◽  
Lead Free Solder ◽  
Molten Lead ◽  
Free Solder
Sign in / Sign up

Export Citation Format

Share Document