SOL230H - Lead-free Pure Silver Tabbing Conductor Brochure

Lead-free Back-side Silver Tabbing Conductor for Conventional Solar Cells and Passivated SurfacesSOL230H is a well-established paste for back-side metalization of conventional solar cells and also suitable as back-side metalization paste for cells with passivated surfaces, where it shows good adhesion properties. The paste is both lead and cadmium free and suitable for mono and multicrystalline solar cell wafers. SOL230H is a robust paste that can be processed on textured or untextured wafers and allows the use of lead or lead-free solder ribbons. Benchmark testing against a commonly used tabbing silver paste showed several advantages for SOL230H using a variety of conditions. The benefits include greatly improved adhesion and reduced paste consumption. This series of paste is also available in other versions based on customer’s process requirements.Product Spotlight SOL230HKey Benefits• Wide processing window • Excellent solderability, adhesion and conductivity• Pb free solders on both textured and untextured wafers• Significantly reduced lay downs• Excellent coverage and easy printability• Co-fireable with back Al and front Ag pastes• Pb and Cd freeAdhesion and SolderabilityThe increase in adhesion demonstrates a better quality solder joint. The effect of humidity or contaminants on the integrity of the solder joint is minimized giving reliable thermal cycling and lifetime testing results. Adhesion testing with a GP-Stab tester with Sn62Pb36Ag2 solder @ 270°C with Kester 961-E flux was used to measure the peak adhesion strength between solder ribbon (ECu 2,0mm x 150 µm) and back contact metallization (1.5 – 2 cm section). Initial force measurement showed with a 6.0 µm fired film thickness an average value of 6.2 N and with a 7.5 µm fired film thickness an average of 8.2 N with SOL230H. Coverage and Cost SavingsIncreased paste coverage with superior results provides a high quality, cost effective solution to any solar cell manufacturer. With rising costs of precious metals, SOL230H can provide savings with improved performance. Coverage with SOL230H provides 95 cm2/gm, which is significantly better than competitor materials. Increased paste coverage translates into lower paste consumption.Leach ResistanceTestings of leach resistance of SOL230H with Sn63Pb37 solder @ 260°C, (5s-DipFlux: Kester 961-E) demonstrates excellent results. SOL230H Reference paste Busbar pads after testing of leach resistanceRecommended Processing GuidelinesPrinting: Screen Parameter Recommendations:• 200-230 mesh stainless steel screen • 10 – 15 µm emulsionPrinting Speed: 100 – 250 mm/s 1.0 barDrying: Typically dried in an IR dryer with a set point of 250 – 300°C in less than 20 seconds.Firing: IR furnace with actual wafer; Peak Temperature at 725 – 825°C.Thickness: 7 – 10 µm (fired)Storage: Store in a dry location at 5°C – 25°C. DO NOT REFRIGERATE.Allow paste to come to room temperature prior to opening. Spatulate well before using.Q3/2012. Data subject to modifications and amendments.AmericasHeraeus Precious MetalsNorth America Conshohocken LLCPhotovoltaics Business UnitPhone: +1 (610) 825-6050pv.techservice@heraeus.comEuropeHeraeus Precious Metals GmbH & Co. KG Photovoltaics Business UnitPhone: +49 (6181) 35-3544pv-info@heraeus.comAsia - SingaporeHeraeus Materials Singapore Pte Ltd.Phone: +65-6571-7888pv.hmsl@heraeus.comAsia - TaiwanHeraeus Materials Technology Taiwan Ltd.Phone: + 886-3-321-9937pv.hmtt@heraeus.comAsia - ChinaHeraeus Materials Technology Shanghai Ltd.Phone: + 86 (21) 3357-5688pv.hmts@heraeus.comAsia - JapanHeraeus KKPhone: + 81-29-889-1742info.hkk@heraeus.comwww.pvsilverpaste.com