PERC 电池组件载荷性能研究-曾雪华

CSIQ NASDAQ Listed MECHANICAL PERFORMANCE RESEARCH OF PERC MODULE Canadian Solar Inc. System technology center, Xuehua Zeng October 2018 2 PERC Cell introduction 01 Mechanical load test evaluation results 02 Conclusion 04 Study of analysis and countermeasure 03 3 CSI P4 Poly PERC Technology Front Rear State of the art MCCE Metal Catalyzed Chemical Etching PERC structure using ALD Al2O3 passivation 5 busbar design / MBB multi-busbar 9 Controlled LID/LeTiD Excellent low light response Lower temperature coefficient Enables Bifacial cells Main Characteristics 4 PERC Cell introduction – Structure PERC advantages Very low rear recombination, Voc increases 1020mV Long wave response increases, Isc increases 0.20.4A Reduce cell bow and operating temperature PERC Cell structure Bifacial PERC cell structure 5 CSI P4 Higher Output Power P4 has higher output power than standard mono P4 Ku module wattage is comparable to mono PERC 6K-P4 3K-P4 MBB 0 5 10 15 20 25 30 35 40 282W 282W 284W 286W 288W 290W ≥292W 0 5 10 15 20 25 30 35 40 296W 296W 298W 300W 302W 304W ≥306W Wattage higher than mono Wattage comparable to mono PERC 6 1. Temperature Coefficient Better Pmax Voc T.C. 2. NMOT Module temperature reduced by 2-3C 3. Shading tolerance Ku layout with better shading 4. Low Hot Spot risk Hotspot temperature reduced by 30C Mass production of P4 cells and modules in GW scale Wattage of 60-cell module achieves 300W, benchmark to mono PERC modules Additional benefits of Ku P4 module 7 Front Rear 300W/360W front wattage 705 bifaciality  World’s first to mass produce Poly bifacial modules  Combine with CSI’s GW capacity Ku -module technology  CSI P4 cells will be 100 bifacial in 2019 CSI P4 Enable Poly Bifacial Modules 8 PERC Cell introduction 01 Mechanical load test evaluation results 02 Conclusion 04 Study of analysis and countermeasure 03 9 Mechanical load test introduction Load direction Pressure Pa Duration time hour Front 2400 1 Back 2400 1 Front 2400 1 Back 2400 1 Front 5400 1 Back 2400 1 Internal Requirements No intermittent open-circuit fault detected during the test. No evidence of major visual defects, as defined in IEC 61215-1 Clause 8. Power degradation is less than 5 EL picture without abnormal micro-cracks IEC61215 power criteria not stringent enough 10 Mechanical load test result – PERC Cell module -4.38 -4.94 -0.38 PERC cells Standard BSF cells Inappropriately designed PERC modules can exhibit dendritic cracks, with almost 5 power loss after mechanical load test 11 PERC Cell introduction 01 Mechanical load test evaluation results 02 Conclusion 04 Study of analysis and countermeasure 03 12 Influence of contact depth to module mechanical resistance Possible mechanism Penetration depth of local rear side contacts influences module mechanical property. Example of laser cutting Example of local contact penetration The shallower the contact penetration, the more reliable after ML test. 13 Design of Experiment Parameter Variables Rear side passivation equipment 1 PECVD process 2 ALD process Al paste manufacturer 1 Al paste 2 Al paste Soldering technology stringer 1 Infrared 2 Induction） Unsoldered cells tape only Rear contact laser opening 1 Laser device 2 Laser device Anti-LID conditioning 1 CIR 2 LIR Laser opening under rear electrode Yes No 14 Influence of rear side passivation equipment No obvious difference between different passivation layer deposition equipment -1.7 -2.3 -1.8 -2.9 Equipment1 Equipment2 0.00 1.00 2.00 3.00 4.00 5.00 SP1 1 SP1 2 SP2 1 SP2 2 Power loss 15 Influence of cell aluminum paste No obvious difference between different Al paste manufacturer -1.77 Al paste 1 Al paste 2 0.00 1.00 2.00 3.00 4.00 5.00 SP2 1 SP2 2 SP4 1 SP4 2 Power loss -2.89 -3.82 -1.72 16 Influence of module soldering technology stringer IR thermal and induction soldering processes waive similar results. Extreme case with non-soldered cells also exhibit multiple cracks. -2.90 -1.30 -2.30 Stringer 2 Induction） Unsoldered cells tape only -1.74 -2.29 Stringer 1 Infrared 0.00 1.00 2.00 3.00 4.00 5.00 SP1 1 SP1 2 SP9 1 SP9 2 SP10 1 Power loss 17 Influence of rear contact opening laser equipment Rear contact depth and ablation laser equipment directly affect the module mechanical performance -2.78 SP3 Laser Device 1、 Pattern 800-200-700） -2.21 SP6 Laser Device 2、 Pattern 800-200-700） -4.82 -4.13 Device 2 Device 1 18 Influence of cell anti-LID process -3.94 CIR Current injection） -3.68 LIR Light exposure） -2.68 -3.45 0.00 1.00 2.00 3.00 4.00 5.00 SP7 1 SP7 2 SP8 1 SP8 2 LIR and CIR conditioning processes waive similar results. 19 Influence of rear contact pattern No laser opening under rear electrode Laser opening under rear electrode -0.61 -0.38 -3.41 -4.17 no laser line under rear electrode laser line under rear electrode Contact opening underneath rear side electrode critical for the module mechanical property； Laser line under the electrode can not be repaired during sintering as silver properties 20 PERC Cell introduction 01 Mechanical load test evaluation results 02 Conclusion 04 Study of analysis and countermeasure 03 21 Conclusion Details and innovations matter Key point No laser ablation under rear electrode Shallow rear local contact penetration, optimized laser opening patterns Suitable laser equipment CSI philosophy Design for reliability mechanical modeling during cell design stage. Strict reliability program 2-3 times IEC, combined stress sequences Module mechanical behavior knowledge critical for industry future  Thinner wafers and new module technologies