Maintenance-Free Dryer for Metallization Lines - Despatch Industries

Maintenance-FreeDryer forSolar CellMetallization LinesDaniel Ruf, Rick Steblay, Andrew Xi - Despatch Industries

introductionA state of the art metallization dryer should be capable of completely drying cells withoutcontamination of cells, the dryer or the environment. This poster illustrates how the Dritechdryer, through the innovative application of heating and airflow technologies eliminates internalcondensation. In addition, smoke and fumes are prevented from escaping into the environment. Underthe rigors of full production the dryer has demonstrated a virtual elimination of the need for cleaning.Dritech DesignWhen designing the DriTech dryer an emphasis was put on air fl ow management. Airfl ow is crucialin achieving complete removal of solvent and also in preventing any contamination from building up,especially since every month a typical single lane dryer has to remove over 400kg of solvent.clean Furnaceclean Facilityclean environment

To facility exhaust -no additionalabatement requiredVoc thermal oxidizerPoint of use VOC abatement isintegral part of DritechClean dryer and ductworkHybrid HeatingFast dryingThermal managementof surfacesSingle Pass HeatedProcess Gasthroughout DryerFast dryingends to center air FlowSolvent contained within the unit

Smoke containmentComparison of dryer with traditional air flow management (left)and advanced air flow management (right)DriTech prevents any smoke from escaping

Drying effectivenessAs a result of the advances made in air fl ow management, DriTech delivers unsurpassed dryingresults. Both in terms drying effectiveness as well as low temperature drying capability. The lowtemperature drying makes it possible to dry each paste at its ideal drying window without harminghigh temperature binders. It also leads to an enlarged process window which ensures completelydried cells at all times.Silver Paste Drying at 115°cDrying Efficiency95%90%85%80%75%70%65%60%55%50%+34%Traditional DryerDritechDriTech completelydries cells at just 115°Cpeak temperature

Drying Process WindowDriTech vs Traditional Dryer (Al paste)100%90%80%DriTech50°CDrying Efficiency70%60%50%40%ProcessWindow GainTraditional Dryer30%20%100 120 140 160 180 200Temperature in °CDritech opens drying process window by 50°C

High Volume Production resultsDriTech’s superior performance was validated at three solar cell manufacturing pilot sites. At eachsite no contamination was found even after millions of cells.Due to the consistent drying performance, DriTech was able to signifi cantly reduce the number oflow efficiency cells.1.7%reduction inlow efficiencycells

impact on Maintenance3 production installs>10 million cells>12 monthszero cleaninGcycleS reQUireDconclusionsDriTech with its innovative air flow management and hybrid heating technology provides a highlyfl exible drying solution that is able to deliver superior drying results without machine or facilitycontamination. Thus, DriTech is the ideal dryer choice for each print step.