ECN backcontact workshop Production of patterned Backcontact Foils

Transcription

1 ECN backcontact workshop 2014 Production of patterned Backcontact Foils Karlheinz Brust, KREMPEL SOLAR MATERIALS Vaihingen/Enz, Germany 1

2 experience, history Biography of Karlheinz Brust In 1984 diploma as Electrical Engineer (ENERGY technology) from Technical University of Darmstadt, Germany and Technical University of Hannover, Germany In start of professional carrier as assistant to the Technical Director at Krempel GmbH. work on new adhesive coating technologies, improvements of copper cladded films for printed circuits, production of fiber reinforced plastics, special laminates for diverse industries like automotive, transportation, aircraft. History of backsheet production of KREMPEL Since 1989 design and production of special products with fluoropolymer films Since 1992 production of backsheets for the photovoltaic industry based on PVF TEDLAR film, DUPONT; TPT In 2002 first projects for interconnecting solutions for PV modules Since June 2004 development of backsheets based on PVDF KYNAR film, ARKEMA. In 2008 successful introduction of trademark KPK and start of serial production of backsheets with 30 µm Kynar film. In 2008 founding member of a national working group backsheets in Germany (continued in IEC TC82 WG2 since 2010) In 2012 start of serial production of back contacting backsheets for MWT-technology Since 2012 supported by our KSM sales team with experienced young Chinese colleagues and KSM ZJG operators In 2013 publishing first draft of IEC Ed1 as common work of IEC working group in IEC TC82 WG2

3 Biography Karlheinz Brust studied Electrical Engineering at Technical University of Darmstadt, Germany and at Technical University of Hannover, Germany and gained his diploma 1984 on a study on partial discharge resistance of synthetic electrical insulating oils for high power transformers. His knowledge about high temperature resistant insulating materials influenced his decision to join August Krempel Soehne GmbH in Stuttgart, Germany. In the first period of his carrier he worked as assistant to the President (Technic) mainly on projects to establish new type of adhesives for the production of multilayer insulating films. As head of technology development his work was focused on the development of fiber reinforced plastics based on glass and carbon fibers, research on adhesiveless metal clad laminates for flexible printed circuits and semiflexible base materials. About 20 years back, he started the development of back sheets for the photovoltaic industry. Today he works as Technical Director in the business unit Solar Materials.. By end of 2008 he shared initiative for a working group in order to create a component standard for back and front sheets together with European colleagues from material suppliers, test institutes and PV module manufacturers. The work is continued in an International IEC working group in TC82 WG2 including partners from Asia and North America. k.brust@krempel-group.com

4 motivation, keywords minimize the material costs improve safety and performance ensure longevity in outdoor applications. respect functional layers electrical insulating, electrical conductive offer solutions for patterning we Need Everyone with Motivation for Optimizing the costs 4 quality still remains when price has been forgotten already

5 Krempel s world of technologies comitted to the promise of maintaining best product quality main technologies papermaking coating laminating impregnating founded 1871 family owned company HQ: Vaihingen/Enz; Germany. 5 more than 140 years of experience in materials

6 Krempel s world of technologies comitted to the promise of maintaining best product quality products/applications o E-grade paper o multilayer composites o UV-resistant insulatings o metal clad laminates o adhesive coatings transformers, motors motors, diverse PV modules electronics electronics / diverse 6 for 20 years supplier of backsheets for almost 30 years supplier of base materials for FPC

7 the back sheet as a multilayer insulating material The long-term reliability makes great demands on: weatherability of the materials >< combatibility of the materials non flammability/ flame resistance chemical resistance abrasion and scratch resistance Data sheets with properties measured as delivered are not sufficient. How does the back sheet behave after accelerated tests? Electrical safety is the topic! back sheet reliable structure with fluorpolymere films as protection layers on the polyester film 7 Quality ensures sunstainable success

8 principle multilayer structure of electrical insulation cell side Everything should be made as simple as possible, but not simpler Albert.Einstein. outer side 8 One single layer cannot provide the multifunctional performance

9 Combination of electrical conductive layer with the elctrical insulation cell side outer side 9 Good isn t good when better is required

10 list of components from back sheet to PV- system TPT, KPK TPE, KPE PPE, FPE, fpc back sheet encapsulant conductive paste anti-reflective doping silicon wafers cells stringers & cicuit materials glass aluminium frame junction box PV -module fixtures/frames inverters installation PV-system 10 The interfaces make it difficult

11 tailored product profile might ease substitution Universal solutions which satisfy the harshest conditions are too expensive where less exposure is assumed. Application-made backsheets offer the chance to cost less and have better performance for the specific application. substitution is possible due to optical aspects color, transparency, gloss functional aspects bonding (Jbox, encapsulant) barrier requirements reflectivity flammability arc resistance electr./mech. strength processability chemical reactions thermal shrinkage CTE (coeff.therm.exp) commercial aspects price/ availability 11 Sciene forgives for errors but not for any negligence

12 It is to expensive to use a unique type of material only Matured industries use a variety of products to cover the different requirements slot insulation of motors is designed with respect to temperature class of the motor with a range of 100 C up to more than 200 C The base material of flexible printed circuits is designed with respect to the mounting technology as crimping, soldering, adhesive bonding Different combinations of substrates and polymers are used: paper non wovens fabrics films PET PI PA EP PU The multilayer structures are sealed together by speciific adhesives: high temperature resistant. Combinations of substrates and polymers are used: paper non wovens fabrics Films and foils PET PI PEN EP PU others The multilayer structures are sealed together by speciific adhesives: high temperature resistant., hydrolytic resistant 12 variety is the smart solution

13 high performance materials require state-of-the art-technology the roll-to roll process of the backsheet production process conditions: clean room air conditioned constant vertical air flow automatic data recording automatic optical inspection technology: adjusted surface treatment sensitive tension control temperature control viscosity control selected coating system process steps: coating and lamination crosslinking of adhesive testing optical inspection slitting and packaging key elements of quality: materials process 13

14 check list for taylored solution Topics for development comparison standard/ foil based/ribbon based New module process concept/ modification Contact foil as inlay or combined with backsheet patterning inline / supplied with backsheet technology for patterning electrical connection by soldering/conductive adhesive type of metal foil type of polymer film compatibility with adhesives/ solderpastes, encapsulants efficiency durability foil based MWT technology patterning by chemical etching mechanical ablation 14 sustainable energy policy is linked to reliable materials sourcing

15 balancing the properties! Backsheets combine specific functional components; focusing on single properties blocks view on superior requirements of the whole unit. backsheets are used as electrical insulting material at the backside of the PV-module. bc-backsheets have to be considered sperately outdoor applications require UV-radiation resistant material; irradation doses depend on type of installation. A maiority of modules produced today have fluoro-based backsheets. better describtion of the application allows tailored structure of the multilayer and helps to reduce the cost by substitution and modifaction of single functional layers. Structuring costs needs to be seperated as specific part of the processing costs. 15 Safety first