WO2019206417A1 - Electrically conductive adhesive for attaching solar cells - Google Patents
Electrically conductive adhesive for attaching solar cells Download PDFInfo
- Publication number
- WO2019206417A1 WO2019206417A1 PCT/EP2018/060765 EP2018060765W WO2019206417A1 WO 2019206417 A1 WO2019206417 A1 WO 2019206417A1 EP 2018060765 W EP2018060765 W EP 2018060765W WO 2019206417 A1 WO2019206417 A1 WO 2019206417A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- meth
- electrically conductive
- acrylate
- silver coated
- composition according
- Prior art date
Links
- 239000000853 adhesive Substances 0.000 title description 25
- 230000001070 adhesive effect Effects 0.000 title description 25
- 239000000203 mixture Substances 0.000 claims abstract description 114
- NIXOWILDQLNWCW-UHFFFAOYSA-M Acrylate Chemical compound [O-]C(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-M 0.000 claims abstract description 97
- 239000000178 monomer Substances 0.000 claims abstract description 42
- 239000011231 conductive filler Substances 0.000 claims abstract description 31
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 claims abstract description 28
- 239000011347 resin Substances 0.000 claims abstract description 20
- 229920005989 resin Polymers 0.000 claims abstract description 20
- JOYRKODLDBILNP-UHFFFAOYSA-N Ethyl urethane Chemical compound CCOC(N)=O JOYRKODLDBILNP-UHFFFAOYSA-N 0.000 claims abstract description 16
- -1 polybutylene Polymers 0.000 claims abstract description 16
- RRHGJUQNOFWUDK-UHFFFAOYSA-N Isoprene Chemical compound CC(=C)C=C RRHGJUQNOFWUDK-UHFFFAOYSA-N 0.000 claims abstract description 12
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 10
- 239000004593 Epoxy Substances 0.000 claims abstract description 8
- 229920001296 polysiloxane Polymers 0.000 claims abstract description 7
- 125000000383 tetramethylene group Chemical group [H]C([H])([*:1])C([H])([H])C([H])([H])C([H])([H])[*:2] 0.000 claims abstract description 6
- 150000002148 esters Chemical class 0.000 claims abstract description 5
- 229920001748 polybutylene Polymers 0.000 claims abstract description 5
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical group [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 claims description 67
- 229910052709 silver Inorganic materials 0.000 claims description 67
- 239000004332 silver Substances 0.000 claims description 67
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 21
- PNEYBMLMFCGWSK-UHFFFAOYSA-N Alumina Chemical compound [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 15
- 239000010949 copper Substances 0.000 claims description 15
- 239000011521 glass Substances 0.000 claims description 12
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 11
- 229910019142 PO4 Inorganic materials 0.000 claims description 11
- 229910052802 copper Inorganic materials 0.000 claims description 11
- 229910002804 graphite Inorganic materials 0.000 claims description 11
- 239000010439 graphite Substances 0.000 claims description 11
- 239000000463 material Substances 0.000 claims description 11
- 239000010452 phosphate Substances 0.000 claims description 11
- 229910052782 aluminium Inorganic materials 0.000 claims description 9
- 239000004411 aluminium Substances 0.000 claims description 9
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 9
- 229920000642 polymer Polymers 0.000 claims description 9
- XMNIXWIUMCBBBL-UHFFFAOYSA-N 2-(2-phenylpropan-2-ylperoxy)propan-2-ylbenzene Chemical compound C=1C=CC=CC=1C(C)(C)OOC(C)(C)C1=CC=CC=C1 XMNIXWIUMCBBBL-UHFFFAOYSA-N 0.000 claims description 7
- 125000001931 aliphatic group Chemical group 0.000 claims description 7
- 150000002978 peroxides Chemical group 0.000 claims description 7
- 229910052799 carbon Inorganic materials 0.000 claims description 6
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 claims description 6
- 239000002318 adhesion promoter Substances 0.000 claims description 5
- 229910052582 BN Inorganic materials 0.000 claims description 4
- PZNSFCLAULLKQX-UHFFFAOYSA-N Boron nitride Chemical compound N#B PZNSFCLAULLKQX-UHFFFAOYSA-N 0.000 claims description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 4
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 4
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 claims description 4
- 229910021502 aluminium hydroxide Inorganic materials 0.000 claims description 4
- 239000006229 carbon black Substances 0.000 claims description 4
- 229910021389 graphene Inorganic materials 0.000 claims description 4
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 4
- 150000004756 silanes Chemical class 0.000 claims description 4
- 239000011133 lead Substances 0.000 claims description 3
- 238000007639 printing Methods 0.000 claims description 3
- NMOALOSNPWTWRH-UHFFFAOYSA-N tert-butyl 7,7-dimethyloctaneperoxoate Chemical compound CC(C)(C)CCCCCC(=O)OOC(C)(C)C NMOALOSNPWTWRH-UHFFFAOYSA-N 0.000 claims description 3
- NRVPUUQJAIZCIX-UHFFFAOYSA-N (4-tert-butylcyclohexyl) (4-tert-butylcyclohexyl)oxycarbonyloxy carbonate 2-methylbutan-2-yl 7,7-dimethyloctaneperoxoate Chemical compound CCC(C)(C)OOC(=O)CCCCCC(C)(C)C.CC(C)(C)C1CCC(CC1)OC(=O)OOC(=O)OC1CCC(CC1)C(C)(C)C NRVPUUQJAIZCIX-UHFFFAOYSA-N 0.000 claims description 2
- YKTNISGZEGZHIS-UHFFFAOYSA-N 2-$l^{1}-oxidanyloxy-2-methylpropane Chemical group CC(C)(C)O[O] YKTNISGZEGZHIS-UHFFFAOYSA-N 0.000 claims description 2
- ZACVGCNKGYYQHA-UHFFFAOYSA-N 2-ethylhexoxycarbonyloxy 2-ethylhexyl carbonate Chemical compound CCCCC(CC)COC(=O)OOC(=O)OCC(CC)CCCC ZACVGCNKGYYQHA-UHFFFAOYSA-N 0.000 claims description 2
- 229910001128 Sn alloy Inorganic materials 0.000 claims description 2
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims description 2
- 125000003118 aryl group Chemical group 0.000 claims description 2
- NSGQRLUGQNBHLD-UHFFFAOYSA-N butan-2-yl butan-2-yloxycarbonyloxy carbonate Chemical compound CCC(C)OC(=O)OOC(=O)OC(C)CC NSGQRLUGQNBHLD-UHFFFAOYSA-N 0.000 claims description 2
- 150000007942 carboxylates Chemical class 0.000 claims description 2
- 229910017052 cobalt Inorganic materials 0.000 claims description 2
- 239000010941 cobalt Substances 0.000 claims description 2
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 2
- LSXWFXONGKSEMY-UHFFFAOYSA-N di-tert-butyl peroxide Chemical compound CC(C)(C)OOC(C)(C)C LSXWFXONGKSEMY-UHFFFAOYSA-N 0.000 claims description 2
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims description 2
- 229910052737 gold Inorganic materials 0.000 claims description 2
- 239000010931 gold Substances 0.000 claims description 2
- QWVBGCWRHHXMRM-UHFFFAOYSA-N hexadecoxycarbonyloxy hexadecyl carbonate Chemical compound CCCCCCCCCCCCCCCCOC(=O)OOC(=O)OCCCCCCCCCCCCCCCC QWVBGCWRHHXMRM-UHFFFAOYSA-N 0.000 claims description 2
- 229910052742 iron Inorganic materials 0.000 claims description 2
- 229910052759 nickel Inorganic materials 0.000 claims description 2
- 229910052697 platinum Inorganic materials 0.000 claims description 2
- BWJUFXUULUEGMA-UHFFFAOYSA-N propan-2-yl propan-2-yloxycarbonyloxy carbonate Chemical compound CC(C)OC(=O)OOC(=O)OC(C)C BWJUFXUULUEGMA-UHFFFAOYSA-N 0.000 claims description 2
- WYKYCHHWIJXDAO-UHFFFAOYSA-N tert-butyl 2-ethylhexaneperoxoate Chemical compound CCCCC(CC)C(=O)OOC(C)(C)C WYKYCHHWIJXDAO-UHFFFAOYSA-N 0.000 claims description 2
- GJBRNHKUVLOCEB-UHFFFAOYSA-N tert-butyl benzenecarboperoxoate Chemical compound CC(C)(C)OOC(=O)C1=CC=CC=C1 GJBRNHKUVLOCEB-UHFFFAOYSA-N 0.000 claims description 2
- CSKKAINPUYTTRW-UHFFFAOYSA-N tetradecoxycarbonyloxy tetradecyl carbonate Chemical compound CCCCCCCCCCCCCCOC(=O)OOC(=O)OCCCCCCCCCCCCCC CSKKAINPUYTTRW-UHFFFAOYSA-N 0.000 claims description 2
- 229910052725 zinc Inorganic materials 0.000 claims description 2
- 239000011701 zinc Substances 0.000 claims description 2
- 239000002245 particle Substances 0.000 description 15
- ZJCCRDAZUWHFQH-UHFFFAOYSA-N Trimethylolpropane Chemical compound CCC(CO)(CO)CO ZJCCRDAZUWHFQH-UHFFFAOYSA-N 0.000 description 14
- 239000000523 sample Substances 0.000 description 12
- 238000000034 method Methods 0.000 description 10
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 8
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 7
- 229910052710 silicon Inorganic materials 0.000 description 7
- 239000010703 silicon Substances 0.000 description 7
- 238000012360 testing method Methods 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 5
- 239000002184 metal Substances 0.000 description 5
- 230000035882 stress Effects 0.000 description 5
- ZDQNWDNMNKSMHI-UHFFFAOYSA-N 1-[2-(2-prop-2-enoyloxypropoxy)propoxy]propan-2-yl prop-2-enoate Chemical compound C=CC(=O)OC(C)COC(C)COCC(C)OC(=O)C=C ZDQNWDNMNKSMHI-UHFFFAOYSA-N 0.000 description 4
- OYKPJMYWPYIXGG-UHFFFAOYSA-N 2,2-dimethylbutane;prop-2-enoic acid Chemical compound OC(=O)C=C.OC(=O)C=C.OC(=O)C=C.CCC(C)(C)C OYKPJMYWPYIXGG-UHFFFAOYSA-N 0.000 description 4
- HCLJOFJIQIJXHS-UHFFFAOYSA-N 2-[2-[2-(2-prop-2-enoyloxyethoxy)ethoxy]ethoxy]ethyl prop-2-enoate Chemical compound C=CC(=O)OCCOCCOCCOCCOC(=O)C=C HCLJOFJIQIJXHS-UHFFFAOYSA-N 0.000 description 4
- NQGDHQASSFDDLD-UHFFFAOYSA-N 3-[2,2-dimethyl-3-(3-prop-2-enoyloxypropoxy)propoxy]propyl prop-2-enoate Chemical compound C=CC(=O)OCCCOCC(C)(C)COCCCOC(=O)C=C NQGDHQASSFDDLD-UHFFFAOYSA-N 0.000 description 4
- FIHBHSQYSYVZQE-UHFFFAOYSA-N 6-prop-2-enoyloxyhexyl prop-2-enoate Chemical compound C=CC(=O)OCCCCCCOC(=O)C=C FIHBHSQYSYVZQE-UHFFFAOYSA-N 0.000 description 4
- CIBSHGQCRWLUSX-UHFFFAOYSA-N OC(=O)C=C.OC(=O)C=C.OC(=O)C=C.CCC(CO)(CO)CO.CCC(CO)(CO)CO Chemical compound OC(=O)C=C.OC(=O)C=C.OC(=O)C=C.CCC(CO)(CO)CO.CCC(CO)(CO)CO CIBSHGQCRWLUSX-UHFFFAOYSA-N 0.000 description 4
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 4
- HVVWZTWDBSEWIH-UHFFFAOYSA-N [2-(hydroxymethyl)-3-prop-2-enoyloxy-2-(prop-2-enoyloxymethyl)propyl] prop-2-enoate Chemical compound C=CC(=O)OCC(CO)(COC(=O)C=C)COC(=O)C=C HVVWZTWDBSEWIH-UHFFFAOYSA-N 0.000 description 4
- KNSXNCFKSZZHEA-UHFFFAOYSA-N [3-prop-2-enoyloxy-2,2-bis(prop-2-enoyloxymethyl)propyl] prop-2-enoate Chemical class C=CC(=O)OCC(COC(=O)C=C)(COC(=O)C=C)COC(=O)C=C KNSXNCFKSZZHEA-UHFFFAOYSA-N 0.000 description 4
- VEBCLRKUSAGCDF-UHFFFAOYSA-N ac1mi23b Chemical compound C1C2C3C(COC(=O)C=C)CCC3C1C(COC(=O)C=C)C2 VEBCLRKUSAGCDF-UHFFFAOYSA-N 0.000 description 4
- 229910021419 crystalline silicon Inorganic materials 0.000 description 4
- 230000007423 decrease Effects 0.000 description 4
- 125000004386 diacrylate group Chemical group 0.000 description 4
- 238000007865 diluting Methods 0.000 description 4
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 4
- 230000007774 longterm Effects 0.000 description 4
- YDKNBNOOCSNPNS-UHFFFAOYSA-N methyl 1,3-benzoxazole-2-carboxylate Chemical compound C1=CC=C2OC(C(=O)OC)=NC2=C1 YDKNBNOOCSNPNS-UHFFFAOYSA-N 0.000 description 4
- 229940068918 polyethylene glycol 400 Drugs 0.000 description 4
- FTALTLPZDVFJSS-UHFFFAOYSA-N 2-(2-ethoxyethoxy)ethyl prop-2-enoate Chemical compound CCOCCOCCOC(=O)C=C FTALTLPZDVFJSS-UHFFFAOYSA-N 0.000 description 3
- 229910002012 Aerosil® Inorganic materials 0.000 description 3
- IAXXETNIOYFMLW-COPLHBTASA-N [(1s,3s,4s)-4,7,7-trimethyl-3-bicyclo[2.2.1]heptanyl] 2-methylprop-2-enoate Chemical compound C1C[C@]2(C)[C@@H](OC(=O)C(=C)C)C[C@H]1C2(C)C IAXXETNIOYFMLW-COPLHBTASA-N 0.000 description 3
- 230000003247 decreasing effect Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 229940119545 isobornyl methacrylate Drugs 0.000 description 3
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 150000003254 radicals Chemical class 0.000 description 3
- PSGCQDPCAWOCSH-UHFFFAOYSA-N (4,7,7-trimethyl-3-bicyclo[2.2.1]heptanyl) prop-2-enoate Chemical compound C1CC2(C)C(OC(=O)C=C)CC1C2(C)C PSGCQDPCAWOCSH-UHFFFAOYSA-N 0.000 description 2
- LAIJAUHBAWLPCO-UHFFFAOYSA-N (4-tert-butylcyclohexyl) prop-2-enoate Chemical compound CC(C)(C)C1CCC(OC(=O)C=C)CC1 LAIJAUHBAWLPCO-UHFFFAOYSA-N 0.000 description 2
- YMZIFDLWYUSZCC-UHFFFAOYSA-N 2,6-dibromo-4-nitroaniline Chemical compound NC1=C(Br)C=C([N+]([O-])=O)C=C1Br YMZIFDLWYUSZCC-UHFFFAOYSA-N 0.000 description 2
- CEXQWAAGPPNOQF-UHFFFAOYSA-N 2-phenoxyethyl 2-methylprop-2-enoate Chemical compound CC(=C)C(=O)OCCOC1=CC=CC=C1 CEXQWAAGPPNOQF-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 239000004322 Butylated hydroxytoluene Substances 0.000 description 2
- NLZUEZXRPGMBCV-UHFFFAOYSA-N Butylhydroxytoluene Chemical compound CC1=CC(C(C)(C)C)=C(O)C(C(C)(C)C)=C1 NLZUEZXRPGMBCV-UHFFFAOYSA-N 0.000 description 2
- WOBHKFSMXKNTIM-UHFFFAOYSA-N Hydroxyethyl methacrylate Chemical compound CC(=C)C(=O)OCCO WOBHKFSMXKNTIM-UHFFFAOYSA-N 0.000 description 2
- 150000001252 acrylic acid derivatives Chemical class 0.000 description 2
- 125000005396 acrylic acid ester group Chemical group 0.000 description 2
- 230000032683 aging Effects 0.000 description 2
- 229920003232 aliphatic polyester Polymers 0.000 description 2
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 2
- 229940095259 butylated hydroxytoluene Drugs 0.000 description 2
- 235000010354 butylated hydroxytoluene Nutrition 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 239000004020 conductor Substances 0.000 description 2
- 125000004122 cyclic group Chemical group 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- GMSCBRSQMRDRCD-UHFFFAOYSA-N dodecyl 2-methylprop-2-enoate Chemical compound CCCCCCCCCCCCOC(=O)C(C)=C GMSCBRSQMRDRCD-UHFFFAOYSA-N 0.000 description 2
- 238000009472 formulation Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- PBOSTUDLECTMNL-UHFFFAOYSA-N lauryl acrylate Chemical compound CCCCCCCCCCCCOC(=O)C=C PBOSTUDLECTMNL-UHFFFAOYSA-N 0.000 description 2
- 239000006254 rheological additive Substances 0.000 description 2
- 238000000518 rheometry Methods 0.000 description 2
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- 239000003381 stabilizer Substances 0.000 description 2
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- 239000000126 substance Substances 0.000 description 2
- MUTNCGKQJGXKEM-UHFFFAOYSA-N tamibarotene Chemical compound C=1C=C2C(C)(C)CCC(C)(C)C2=CC=1NC(=O)C1=CC=C(C(O)=O)C=C1 MUTNCGKQJGXKEM-UHFFFAOYSA-N 0.000 description 2
- 238000005382 thermal cycling Methods 0.000 description 2
- 230000000930 thermomechanical effect Effects 0.000 description 2
- DMWVYCCGCQPJEA-UHFFFAOYSA-N 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane Chemical compound CC(C)(C)OOC(C)(C)CCC(C)(C)OOC(C)(C)C DMWVYCCGCQPJEA-UHFFFAOYSA-N 0.000 description 1
- NXBXJOWBDCQIHF-UHFFFAOYSA-N 2-[hydroxy-[2-(2-methylprop-2-enoyloxy)ethoxy]phosphoryl]oxyethyl 2-methylprop-2-enoate Chemical compound CC(=C)C(=O)OCCOP(O)(=O)OCCOC(=O)C(C)=C NXBXJOWBDCQIHF-UHFFFAOYSA-N 0.000 description 1
- 229910002016 Aerosil® 200 Inorganic materials 0.000 description 1
- 229910002018 Aerosil® 300 Inorganic materials 0.000 description 1
- 101001073212 Arabidopsis thaliana Peroxidase 33 Proteins 0.000 description 1
- 101001123325 Homo sapiens Peroxisome proliferator-activated receptor gamma coactivator 1-beta Proteins 0.000 description 1
- CERQOIWHTDAKMF-UHFFFAOYSA-M Methacrylate Chemical compound CC(=C)C([O-])=O CERQOIWHTDAKMF-UHFFFAOYSA-M 0.000 description 1
- 102100028961 Peroxisome proliferator-activated receptor gamma coactivator 1-beta Human genes 0.000 description 1
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 1
- 229910007116 SnPb Inorganic materials 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- 229910021417 amorphous silicon Inorganic materials 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- SVPXDRXYRYOSEX-UHFFFAOYSA-N bentoquatam Chemical compound O.O=[Si]=O.O=[Al]O[Al]=O SVPXDRXYRYOSEX-UHFFFAOYSA-N 0.000 description 1
- 230000000740 bleeding effect Effects 0.000 description 1
- 238000004132 cross linking Methods 0.000 description 1
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- 238000000937 dynamic scanning calorimetry Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- UHESRSKEBRADOO-UHFFFAOYSA-N ethyl carbamate;prop-2-enoic acid Chemical class OC(=O)C=C.CCOC(N)=O UHESRSKEBRADOO-UHFFFAOYSA-N 0.000 description 1
- 230000006355 external stress Effects 0.000 description 1
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- 238000010304 firing Methods 0.000 description 1
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- 229910052757 nitrogen Inorganic materials 0.000 description 1
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- YNXCGLKMOXLBOD-UHFFFAOYSA-N oxolan-2-ylmethyl prop-2-enoate Chemical compound C=CC(=O)OCC1CCCO1 YNXCGLKMOXLBOD-UHFFFAOYSA-N 0.000 description 1
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- DQZNLOXENNXVAD-UHFFFAOYSA-N trimethoxy-[2-(7-oxabicyclo[4.1.0]heptan-4-yl)ethyl]silane Chemical compound C1C(CC[Si](OC)(OC)OC)CCC2OC21 DQZNLOXENNXVAD-UHFFFAOYSA-N 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J9/00—Adhesives characterised by their physical nature or the effects produced, e.g. glue sticks
- C09J9/02—Electrically-conducting adhesives
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F265/00—Macromolecular compounds obtained by polymerising monomers on to polymers of unsaturated monocarboxylic acids or derivatives thereof as defined in group C08F20/00
- C08F265/04—Macromolecular compounds obtained by polymerising monomers on to polymers of unsaturated monocarboxylic acids or derivatives thereof as defined in group C08F20/00 on to polymers of esters
- C08F265/06—Polymerisation of acrylate or methacrylate esters on to polymers thereof
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
- H01B1/20—Conductive material dispersed in non-conductive organic material
- H01B1/22—Conductive material dispersed in non-conductive organic material the conductive material comprising metals or alloys
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F2/00—Processes of polymerisation
- C08F2/44—Polymerisation in the presence of compounding ingredients, e.g. plasticisers, dyestuffs, fillers
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
- C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
- C08F220/10—Esters
- C08F220/12—Esters of monohydric alcohols or phenols
- C08F220/16—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms
- C08F220/18—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms with acrylic or methacrylic acids
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K3/00—Use of inorganic substances as compounding ingredients
- C08K3/01—Use of inorganic substances as compounding ingredients characterized by their specific function
- C08K3/013—Fillers, pigments or reinforcing additives
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/04—Oxygen-containing compounds
- C08K5/14—Peroxides
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J161/00—Adhesives based on condensation polymers of aldehydes or ketones; Adhesives based on derivatives of such polymers
- C09J161/04—Condensation polymers of aldehydes or ketones with phenols only
- C09J161/06—Condensation polymers of aldehydes or ketones with phenols only of aldehydes with phenols
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J175/00—Adhesives based on polyureas or polyurethanes; Adhesives based on derivatives of such polymers
- C09J175/04—Polyurethanes
- C09J175/14—Polyurethanes having carbon-to-carbon unsaturated bonds
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J4/00—Adhesives based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond ; adhesives, based on monomers of macromolecular compounds of groups C09J183/00 - C09J183/16
- C09J4/06—Organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond in combination with a macromolecular compound other than an unsaturated polymer of groups C09J159/00 - C09J187/00
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02S—GENERATION OF ELECTRIC POWER BY CONVERSION OF INFRARED RADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, e.g. USING PHOTOVOLTAIC [PV] MODULES
- H02S20/00—Supporting structures for PV modules
- H02S20/20—Supporting structures directly fixed to an immovable object
- H02S20/22—Supporting structures directly fixed to an immovable object specially adapted for buildings
- H02S20/23—Supporting structures directly fixed to an immovable object specially adapted for buildings specially adapted for roof structures
- H02S20/25—Roof tile elements
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02S—GENERATION OF ELECTRIC POWER BY CONVERSION OF INFRARED RADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, e.g. USING PHOTOVOLTAIC [PV] MODULES
- H02S40/00—Components or accessories in combination with PV modules, not provided for in groups H02S10/00 - H02S30/00
- H02S40/30—Electrical components
- H02S40/36—Electrical components characterised by special electrical interconnection means between two or more PV modules, e.g. electrical module-to-module connection
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K30/00—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation
- H10K30/80—Constructional details
- H10K30/88—Passivation; Containers; Encapsulations
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J2203/00—Applications of adhesives in processes or use of adhesives in the form of films or foils
- C09J2203/322—Applications of adhesives in processes or use of adhesives in the form of films or foils for the production of solar panels
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B10/00—Integration of renewable energy sources in buildings
- Y02B10/10—Photovoltaic [PV]
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/549—Organic PV cells
Definitions
- the present invention relates to an electrically conductive adhesive for attaching solar cells together in a shingled photovoltaic module, wherein the adhesive has the required electrical and mechanical properties.
- a solar cell or photovoltaic cell is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect.
- Solar cells are the building blocks of the photovoltaic modules, otherwise known as solar panels, in order to increase the voltage delivered by individual solar cells.
- FIG 1 The general structure of a solar cell is illustrated in figure 1 .
- Most of the solar cells (1 ) produced today consist of crystalline silicon.
- Metal contacts, busbars (2) and fingers (3), are both printed on the silicon wafer. These metallic contacts are necessary to collect the current generated by a solar cell.
- Figure 1 a illustrates basic configuration with three busbars and figure 1 b illustrates basic configuration with four busbars.
- Fingers are linear areas of metallization that collect current to deliver it to the busbars, which are connected directly to the external leads, via ribbons (5) for example.
- a conventional solar cell, including ribbons (5) is illustrated in figure 2.
- a high temperature firing pastes are used as finger and busbar material, and the ribbons (5) are attached by means of a soldering process.
- electrically conductive adhesives (4) can be used to bond heat sensitive heterojunction crystalline cells (with a-Si layer present).
- the ribbons are on top of the bus bars in the conventional photovoltaic module, and cause a shadow area to the solar cell leading to decrease the efficiency of the photovoltaic module.
- solar cells can be arranged in series-connected in an overlapping shingle pattern.
- Shingles are typically made by cutting/dicing crystalline silicon cells along a plurality of lines parallel to a long edge of each wafer to form a plurality of rectangular silicon solar cells each having substantially the same length along its long axis.
- more shingles typically 5 or 6 for a six-inch wafer (approx. 156 mm)
- the cells can be full square as well as pseudo-square, in the latter cut-cells with chamfered corners may be obtained.
- the first and second silicon solar cells are bonded to each other at the overlapping portions of the solar cells with an electrically conductive material (4) in shingle structure.
- the conductive material can be deposited in different patterns.
- Electrically conductive adhesive as a material to bond the solar cells together have the advantage that they overcome mechanical stresses, which build up due to CTE (coefficient of thermal expansion) mismatch between the different materials used in a photovoltaic assembly.
- Figure 3 illustrates a shingled photovoltaic module.
- Prior art describes various different kind of electrically conductive adhesives, which can be used in solar cells and to form photovoltaic modules. Many of these electrically conductive adhesives are epoxy or silicone based adhesives. However, a long curing time is often required for some adhesives described in the prior art before the adhesive reaches its full mechanical and electrical properties.
- the photovoltaic modules are subjected to a temperature changes and high mechanical stresses over their life cycle. These factors have a negative effect on the lifetime of the photovoltaic module, and also set requirements for the electrically conductive adhesive used in the solar cells and/or photovoltaic cells.
- the adhesives may not have the required thermo-mechanical properties.
- Required thermal-elastic properties for the electrically conductive adhesive composition are correct modulus, specified glass transition temperature, and specified coefficient of thermal expansion in order to pass the thermo-mechanical load reliability test designed for the photovoltaic modules. If the adhesive material is too rigid (too high modulus) the power output loss of the photovoltaic module may occur when applying external stresses to the module (eg. after application of mechanical load or after thermal cycling).
- Figure 1 illustrates a structure of ordinary silicon solar cells.
- Figure 2 illustrates a conventional photovoltaic module.
- FIG. 3 illustrates a shingled photovoltaic module.
- the present invention relates to an electrically conductive composition
- an electrically conductive composition comprising a) a resin selected from the group consisting of epoxy (meth)acrylate, (poly)ester (meth)acrylate, urethane (meth)acrylate, silicone (meth)acrylate, poly(iso)butylene (meth)acrylate, (poly)isoprene (meth)acrylate, polybutylene (meth)acrylate and mixtures thereof; b) an acrylic monomer; c) an electrically conductive filler; and d) a curing agent.
- the present invention also encompasses a cured product of the electrically conductive composition according to the present invention.
- the present invention also relates to use of the electrically conductive composition according to the present invention or use of the cured product according to the present invention in a solar cell and/or a photovoltaic module.
- the present invention also relates to a photovoltaic module, comprising a series-connected string of two or more photovoltaic cells in a shingle pattern having an electrically conductive bonding between said two or more solar photovoltaic cells, wherein said electrically conductive bonding is formed with an electrically conductive composition according to the present invention.
- (meth)acrylate covers both acrylate and methacrylate.
- the present invention relates to an electrically conductive composition
- an electrically conductive composition comprising a) a resin selected from the group consisting of epoxy (meth)acrylate, (poly)ester (meth)acrylate, urethane (meth)acrylate, silicone (meth)acrylate, poly(iso)butylene (meth)acrylate,
- the Applicant has discovered that the electrically conductive composition according to the present invention provides fast curing, stress release, long term bonding strength to metal part of the silicon solar cells, reliable connection and low electrical contact resistance to the metal parts of the solar cell despite of low to medium silver quantity.
- the electrically conductive composition according to the present invention comprises a resin selected from the group consisting of epoxy (meth)acrylate, (poly)ester (meth)acrylate, urethane (meth)acrylate, silicone (meth)acrylate, poly(iso)butylene (meth)acrylate,
- thermoset acrylate resins have the advantage that they can vary between very rigid to very flexible materials. Furthermore, a resin having a low Tg value is preferred, this is because resin having a low Tg value provides a desired flexibility to the composition in order to pass the solar module reliability testing.
- the resin used in the present invention has a Tg value 15 °C or less.
- the adhesive cannot be too flexible, because stable electrical contacts to a solar cell are difficult to maintain. Therefore, the formed contacts need to be flexible enough but having some rigidity to provide stability to the structure.
- the contact resistance of the adhesive to the solar cell tends to increase during thermocycling between -40°C and 85°C and/or during ageing at 85°C in high humidity environments (85% humidity). This is causing power output of modules to decrease during these reliability conditions. Therefore, it is important to provide adhesive having desired flexibility.
- the resin is a (poly)(iso)butylene (meth)acrylate, a (poly)isoprene (meth)acrylate or an urethane (meth)acrylate, more preferably an aliphatic or aromatic urethane (meth)acrylate or an aliphatic polyester based urethane di(meth)acrylate oligomer, more preferably an aliphatic urethane (meth)acrylate or an aliphatic polyester based urethane di(meth)acrylate oligomer or a mixture thereof.
- Urethane acrylates and especially aliphatic urethane di(meth)acrylates are preferred because they have low Tg value, and they can provide the desired flexibility to the composition.
- Suitable commercially available resins for use in the present invention include, but are not limited to Ebecryl 8232, Ebecryl 230, Ebecryl 4744, Ebecryl 3639, Ebecryl 3708 from Allnex; Genomer 2253, Genomer 3457, Genomer 4215 and Genomer 4230 from Rahn; and CN9002, CN9021 , CN9014, SR 307, CN 307 from Arkema; EPION 400V from Kaneka and UC-102, UC-102M, UC-203 and UC-203M from Kuraray.
- An electrically conductive composition according to the present invention comprises a resin from 10 to 65% by weight of the total weight of the composition, preferably from 10 to 55%, more preferably from 1 1 to 45% and even more preferably from 12 to 35%.
- the electrically conductive composition according to the present invention comprises an acrylic monomer, which is and acts as a reactive diluent.
- Suitable acrylic monomer for use in the present invention may be a mixture of one type of acrylic monomers or a mixture of different kind of acrylic monomers.
- the acrylic monomer is at least one (meth)acrylate monomer having two or more (meth)acrylate groups.
- the acrylic monomer is a mixture of at least one (meth)acrylate monomer having two or more (meth)acrylate groups and a (meth)acrylate functionalized phosphate ester.
- the acrylic monomer is a mixture of at least one (meth)acrylate monomer having two or more (meth)acrylate groups and at least one (meth)acrylate monomer having one (meth)acrylate group and a (meth)acrylate functionalized phosphate ester.
- acrylic monomers are preferred because the presence of functionalized phosphate ester acrylic monomer promotes the adhesion, and the presence of two or more acrylic groups promotes ideal cure shrinkage, and therefore, provides low resistance.
- Suitable (meth)acrylate monomer having one (meth)acrylate group for use in the present invention is preferably selected from the group consisting of isobornyl acrylate, isobornyl methacrylate, 2-(2-ethoxyethoxy) ethylacrylate, lauryl acrylate, lauryl methacrylate, acrylic acid ester, cyclic trimethylolpropane formal acrylate, 4-tert-butylcyclohexylacrylate, 2- phenoxyethylacylate, 2-phenoxyethylmethacrylate, tetrahydrofurfuryl acrylate, 3,3,5- trimethylcyclohexyl acrylate and mixtures thereof.
- monofunctional (meth)acrylate monomers are preferred because they have good diluting properties and good compatibility with the composition according to the present invention.
- isobornyl methacrylate is preferred because it has ideal diluting properties for the composition according to the present invention.
- Suitable commercially available (meth)acrylate monomers having one (meth)acrylate group for use in the present invention include, but are not limited to SR256, SR489, SR395, SR440, SR335, SR285, SR423D, SR550 from Arkema; Miramer M170, M1084 from Miwon Specialty Chemical Co., Ltd., IBXA from Osaka Organic Chemical Ind.; Genomer 121 , Genomer 121 M from Rahn; and IBOA from Osaka Organic Chemical ltd.
- Suitable (meth)acrylate monomer having two or more (meth)acrylate groups for use in the present invention is preferably selected from the group consisting of 1 ,6-hexanediol diacrylate, trimethyl propane triacrylate, trimethylol propane (EO) 3 triacrylate, trimethylol propane (EO)g triacrylate, pentaerythritol triacrylate, di-trimethylolpropane triacrylate, ethoxylated pentaerythritol tetraacrylate, neopentyl glycolpropoxylate diacrylate, polyethylene glycol 400 diacrylate, tetra(ethylene glycol) diacrylate, tripropyleneglycol diacrylate, hydroxyl pivalic neopentyl glycol diacrylate, tricyclodecane dimethanol diacrylate and mixtures thereof.
- These multifunctional (meth)acrylate monomers are preferred because they have good diluting properties and good compatibility with the composition according to the present invention
- Suitable commercially available (meth)acrylate monomers having two or more (meth)acrylate groups for use in the present invention include, but are not limited to SR238, SR833S, SR834, SR355, SR 285, SR 248, SR 259, SR 9003 and SR494 from Arkema; and Miramer M202, M220, M222, M232 from Miwon Specialty Chemical Co. Ltd.
- a (meth)acrylate functionalised phosphate ester can be used in the present invention as an acrylic monomer.
- Suitable phosphate ester of (meth)acrylate may have the following general structure
- R" H or CH 3
- R' alkyl
- R' -CH 2 CH 2 0- or
- R' -CH 2 CH 2 CH 2 CH 2 CH 2 C(0)0CH 2 CH 2 0-
- phosphate esters of (meth)acrylate suitable for use in the present invention are:
- Suitable phosphate ester of (meth)acrylate for use in the present invention is phosphoric acid 2-hydroxy ethyl methacrylate.
- Phosphoric acid 2-hydroxy ethyl methacrylate is particularly preferred because of its diluting properties, and in addition it provides good adhesion properties.
- Suitable commercially available phosphate ester of (meth)acrylates for use in the present invention include, but are not limited to Ebecryl 168, Ebecryl 170, Ebecryl 171 from Allnex; Kayamer PM-2, Kayamer PM-21 from Nippon Kayaku co.Ltd; Genorad 40 from Rahn; SR9050, SR9051 , SR9054 from Arkema; and PAM100, PAM200 from Rodia.
- an acrylic monomer is at least one (meth)acrylate monomer having two or more (meth)acrylate groups selected from the group consisting of 1 ,6-hexanediol diacrylate, trimethyl propane triacrylate, trimethylol propane (EO)3 triacrylate, trimethylol propane (EO)g triacrylate, pentaerythritol triacrylate, di-trimethylolpropane triacrylate, ethoxylated pentaerythritol tetraacrylate, neopentyl glycolpropoxylate diacrylate, polyethylene glycol 400 diacrylate, tetra(ethylene glycol) diacrylate, tripropyleneglycol diacrylate, hydroxyl pivalic neopentyl glycol diacrylate, tricyclodecane dimethanol diacrylate and mixtures thereof.
- an acrylic monomer is a mixture of at least one (meth)acrylate monomer having two or more (meth)acrylate groups selected from the group consisting of 1 ,6- hexanediol diacrylate, trimethyl propane triacrylate, trimethylol propane (EO)3 triacrylate, trimethylol propane (EO)g triacrylate, pentaerythritol triacrylate, di-trimethylolpropane triacrylate, ethoxylated pentaerythritol tetraacrylate, neopentyl glycolpropoxylate diacrylate, polyethylene glycol 400 diacrylate, tetra(ethylene glycol) diacrylate, tripropyleneglycol diacrylate, hydroxyl pivalic neopentyl glycol diacrylate, tricyclodecane dimethanol diacrylate and mixtures thereof, and a (meth)acrylate functionalized phosphate ester selected from
- an acrylic monomer is a mixture of at least one (meth)acrylate monomer having two or more (meth)acrylate groups selected from the group consisting of 1 ,6- hexanediol diacrylate, trimethyl propane triacrylate, trimethylol propane (EO)3 triacrylate, trimethylol propane (EO)g triacrylate, pentaerythritol triacrylate, di-trimethylolpropane triacrylate, ethoxylated pentaerythritol tetraacrylate, neopentyl glycolpropoxylate diacrylate, polyethylene glycol 400 diacrylate, tetra(ethylene glycol) diacrylate, tripropyleneglycol diacrylate, hydroxyl pivalic neopentyl glycol diacrylate, tricyclodecane dimethanol diacrylate and mixtures thereof and at least one (meth)acrylate monomer having one (meth)acrylate group selected from the group consisting of isoborn
- An electrically conductive composition according to the present invention comprises an acrylic monomer from 1 to 65% by weight of the total weight of the composition, preferably from 5 to 60%, more preferably from 10 to 55% and even more preferably from 15 to 50%.
- the quantity of the acrylic monomer is less than 1 % there is no physical effect to the composition.
- the electrically conductive composition according to the present invention comprises an electrically conductive filler.
- Suitable electrically conductive filler for use in the present invention can exist in a variety of shapes, e.g., as substantially spherical particles, as irregular shaped particles, oblong particles, flakes (e.g., thin, flat, single crystal flakes), and the like.
- the electrically conductive filler may be for example a mixture of spherical particles and flake particles.
- Suitable electrically conductive filler for use in the present invention have preferably an average particle size in the range of from 300 nm to 50 micron, preferably from 500 nm to 40 micron and more preferable from 500 nm to 30 micron.
- the particle size is measured by particle size analyser and the particle shape is analysed by scanning electron microscope. In short scattered laser lights from the particles are detected an array of detectors. Theoretical calculation is carried out to fit the measured distribution of scattered light intensity. During the fitting process the particle size distribution is deduced and D10, D50, D90 etc. values are calculated accordingly.
- Suitable electrically conductive filler for use in the present invention may be a mixture of particles having a small particle size and particles having a larger particle size.
- Suitable electrically conductive filler is selected from the group consisting of silver, nickel, carbon, carbon black, graphite, graphene, copper, gold, platinum, aluminium, iron, zinc, cobalt, lead, tin alloys, silver coated copper, silver coated graphite, silver coated polymers, silver coated aluminium, silver coated glass, silver coated carbon, silver coated boron nitride, silver coated aluminium oxide, silver coated aluminium hydroxide and mixtures thereof.
- Silver coated polymers may be acrylic polymers and/or silicone based polymers.
- electrically conductive filler is selected from the group consisting of silver, carbon black, graphite, graphene, copper, silver coated copper, silver coated graphite, silver coated polymers, silver coated aluminium, silver coated glass, silver coated carbon, silver coated boron nitride, silver coated aluminium oxide, silver coated aluminium hydroxide and mixtures thereof, more preferably electrically conductive filler is selected from the group consisting of silver, silver coated copper, silver coated graphite, silver coated polymers, silver coated aluminium, silver coated glass and mixtures thereof.
- Silver is preferred because it’s good electrical performance.
- Silver coated fillers are preferred because of their lower cost (compared to silver). Furthermore, these preferred electrically conductive fillers do not have pot life issues when used in free radical cure acrylic formulations.
- Suitable commercially available electrically conductive fillers for use in the present invention include, but are not limited to silver: AA3462, AA-5124, AA-192N, C-1284P, C-0083P, P543- 14 from Metalor; KP84, KP74, KP29 from Ames Goldsmidth; silver coated copper: CGF-DAB- 121 B from Dowa; AgCu0810 or AgCu0305 from Ames Goldsmidth; silver coated glass: CONDUCT-O-FILTM SG15F35 from Potters Industries Inc.; silver coated polymer: SphericaTM 30.22 from Mosaic Solutions; silver coated graphite: P594-5 from Metalor; silver coated Al: CONDUCT-O-FILTMSA325S20 from Potters Industries Inc.
- An electrically conductive composition according to present invention comprises an electrically conductive filler from 10 to 70% by weight of the total weight of the composition, preferably from 20 to 65% and more preferably from 30 to 60%.
- the composition does not provide required electrical conductivity. On the other hand, if the quantity of the electrically conductive filler is above 70%, the composition is no longer cost effective. Furthermore, generally lower electrically conductive filler quantity decreases the overall weight of the solar cell/photovoltaic module, and reduces the overall costs.
- the Applicant has found out that the flexibility of the adhesive can be modified even further by reducing the quantity of the electrically conductive fillers and to increase the quantity of the resin matrix.
- the composition according to the present invention is able to overcome the accumulated mechanical stresses in the photovoltaic modules.
- the combination of low to mid-range quantity of the electrically conductive fillers, resin and acrylic monomer mixture as described in the present invention have a key role to lead good electrical properties and good adhesion properties, in addition to good application properties.
- low to mid-range quantity of the electrically conductive fillers reduces the overall costs.
- Suitable electrically conductive fillers for use in the present invention include also silver coated/plated particulate, wherein the underlying particulate can be a wide variety of materials, as long as the silver coating/plating substantially coats the underlying particulate, such that the resulting composition comprises silver-covered particles distributed throughout.
- the electrically conductive filler is a silver coated particle
- the silver quantity is from 10 to 70% by weight of the total weight of the electrically conductive filler, preferably from 10 to 65% and more preferably from 10 to 60%.
- electrically conductive filler has a tap density from 0.7 g/cm 3 to 6.0 g/cm 3 , preferably from 1.0 g/cm 3 to 5.5 g/cm 3 , more preferably from 1 .0 g/cm 3 to 4.0 g/cm 3 .
- the tap density is determined in accordance to ISO 3953 typically using a 25 cm 3 graduated glass cylinder.
- the principle of the method specified is tapping a specified amount of powder in a container by means of a tapping apparatus until no further decrease in the volume of the powder takes place.
- the mass of the powder divided by its volume after the test gives its tap density.
- the Applicant has surprisingly found out that the combination of aliphatic urethane di(meth)acrylate, acrylic monomer mixture and low to mid-range electrically conductive filler quantity works well together to provide low electrical contact resistance to metal parts of silicon solar cell, stress release, long term bonding strength to metal part of silicon solar cells and fast curing.
- the electrically conductive composition according to the present invention comprises a curing agent.
- any conventional curing agent suitable for (meth)acrylate resins can be used in the present invention.
- suitable curing agents for use in the present invention are peroxides and azo compounds.
- the curing agent used in the present invention is a peroxide.
- Suitable peroxide for use in the present invention is selected from the group consisting of tert- butyl peroxy 2-ethylhexanoate, di-tert-butyl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxyneodecanoate, 2,5-dimethyl-2,5(tert-butyl peroxy) hexane, dicumyl peroxide, tert-amyl- peroxyneodecanoate di(4-tert-butylcyclohexyl)peroxydicarbonate, di-sec-butyl peroxydicarbonate, diisopropyl peroxydicarbonate, di(2-ethylhexyl)peroxydicarbonate, dicetyl peroxydicarbonate, dimyristyl peroxydicarbonate) and mixtures thereof.
- Tert-butyl peroxyneodecanoate is one preferred peroxide because it has good compatibility with the composition and it provides ideal fast curing speed.
- Suitable commercially available peroxides for use in the present invention include, but are not limited to Luperox 10, Luperox 26, Luperox Dl, Luperox P and dicumyl peroxide from Arkema; and Trigonox 101 from AzkoNobel.
- An electrically conductive composition according to the present invention comprises a peroxide from 0.1 to 3% by weight of the total weight of the composition, preferably from 0.2 to 2%.
- An electrically conductive composition according to the present invention may further comprise an adhesion promoter.
- Suitable adhesion promoter for use in the present invention is selected from the group consisting of epoxy functional silanes, (meth)acrylic functional silanes, carboxylates and mixtures thereof.
- Suitable commercially available adhesion promotors for use in the present invention include, but are not limited to Silquest A-187, Silquest A-1 100, Silquest A-1 106, Silquest A- 1 1 10, Silquest A1 120, Silquest A1 130, Silquest A-1 170, Silquest A2120, Silquest A-174 (acrylic functional silane) and Silquest A-186 from Momentive; and BYK 4509, 4510, 451 1 , 4512 from Altana.
- An electrically conductive composition according to the present invention may comprise an adhesion promoterfrom 0.01 to 10% by weight of the total weight of the composition, preferably from 0.05 to 5% and more preferably from 0.1 to 3.5%.
- An electrically conductive composition according to the present invention may further comprise rheological additives such as bentone (such as Bentone 27, Bentone 38 and Bentone SD-2 from Elemenits Specialities), silica, fumed silica (such as Aerosil 200, Aerosil 300, Aerosil COK 84, Aerosil R71 1 and Aerosil R7200 from Evonik), fused silica (such as FB-5SDC, FB-7SDC, and FB-9454 from DENKA) and aluminium oxide (such as AE 9104 from Admatechs Co., LTD and Aeroxide Alu C, Aeroxide Alu 130 and Aeroxide Alu 65 from Evonik).
- bentone such as Bentone 27, Bentone 38 and Bentone SD-2 from Elemenits Specialities
- silica such as Aerosil 200, Aerosil 300, Aerosil COK 84, Aerosil R71 1 and Aerosil R7200 from Evonik
- fused silica such as FB-5SDC,
- An electrically conductive composition according to the present invention may further comprise wetting and dispersing agents such as BYK W903 from Altana.
- An electrically conductive composition according to the present invention may further comprise rheology additives such as BYK-41 1 , BYK E-41 1 , BYK-430, BYK-430, BYK-431 and BYK- R605 from Altana; and Thixatrol P220X-MF, Thixatrol Plus, and Thixatrol PM 8054 From Elementis.
- rheology additives such as BYK-41 1 , BYK E-41 1 , BYK-430, BYK-430, BYK-431 and BYK- R605 from Altana; and Thixatrol P220X-MF, Thixatrol Plus, and Thixatrol PM 8054 From Elementis.
- An electrically conductive composition according to the present invention may further comprise a radical stabilizer such as BHT (butylated hydroxytoluene) or alternative radical stabilizers such as Genorad 16, Genorad 18, Genorad 21 and Genorad 22 from Rahn.
- a radical stabilizer such as BHT (butylated hydroxytoluene) or alternative radical stabilizers such as Genorad 16, Genorad 18, Genorad 21 and Genorad 22 from Rahn.
- An electrically conductive composition according to the present invention may be applied by using any of the following techniques time pressure dispense, jet dispense, auger dispense, stencil printing and screen printing.
- the viscosity of the electrically conductive composition according to the present invention needs to be adjusted to be suitable for the selected application method.
- viscosity tolerated for stencil or screen printing may be slightly higher than viscosity needed in dispensing method.
- Optimizing rheology to make it suitable for the targeted application can be done by slightly increasing/decreasing the quantity of the acrylic monomers or by using small quantities of rheological additives.
- the present invention relates to a cured product of the electrically conductive composition according to the present invention.
- the composition according to the present invention may be cured thermally.
- the electrically conductive adhesive according to the present invention having the required electrical and mechanical properties can be used in a shingled photovoltaic module wherein the crystalline silicon based solar singles are attached to each other by using the electrically conductive adhesive.
- the present invention encompasses the use of the electrically conductive composition according to the present invention in a solar cell and/or a photovoltaic module.
- the present invention encompasses the use of cured electrically conductive composition according to the present invention in a solar cell and/or a photovoltaic module.
- the electrically conductive composition according to the present invention is used as an interconnection material in the photovoltaic module, wherein the solar cells are shingled.
- a shingled structure is illustrated in figure 3.
- the electrically conductive composition according to the present invention may be used to bond ribbons to the solar cells as shown in figure 2.
- the present invention also relates to a photovoltaic module, comprising a series-connected string of two or more solar cells in a shingle pattern having an electrically conductive bonding between said two or more solar cells, wherein said electrically conductive bonding is formed with an electrically conductive composition according to the present invention.
- Shingle structure is illustrated in figure 3.
- the electrically conductive composition according to the present invention can be applied by dispensing, jetting or printing to solar cells.
- compositions are prepared by mixing all ingredients together to form a homogenous mixture.
- Viscosity was measured on a Rheometer from TA instruments Rheometer HR-1 or Q-2000 using a plate-plate geometry with a 2 cm in diameter plate at a 200 micron gap and shear rates of 1 .5 s-1 or 15 s-1 . Viscosity units are reported in Pa.s. Volume resistivity (VR) was measured as follows:
- Samples were prepared for the compositions according to the examples above and deposited on a glass plate (by drawing down a strip of material onto the surface of a glass slide with strip dimensions of about 5 cm in length, 5 mm in width and about 50 micron in thickness) and cured and dried (according to the requirement for the used resin). Glass plates were cooled to room temperature, before measurement.
- the electrical contact resistance was determined by dispensing the conductive adhesive in a TLM structure on a 1 .5 mm wide busbar of a c-Si wafer.
- a TLM structure was obtained by contacting 7 Ag plated Cu tabs (2 mm wide, 1 micron Ag coating) to the test layer, wherein the contact tabs exhibit increasing distances between the contact tabs going from about 3 mm to about 18 mm.
- the resistance between the neighbouring contact tabs was measured by using Keithley four-point probes and a Keithley 2750 multimeter and plotted as a function of the distance.
- the contact resistance value is the half of the intercept from the curve obtained from that plot.
- the average contact resistance (arithmetic average) is reported in mohm. If no linear relation could be found because of bad ohmic contacts meaning an rsq value of less than 0.9, “no fit” was mentioned.
- the stability of the electrical contact resistance was determined by accelerated ageing testing (85° C , relative humidity of 85% and -40,85°C thermal cycling) using the TLM test setup as described above.
- DSC has been measured by using Dynamic Scanning Calorimetry Q2000 from TA Instruments.
- the basic principle underlying this technique is that when the sample undergoes a phase transitions, more or less heat will be needed compared to the reference to keep the reference and the sample at the same temperature. Whether less or more heat must flow to the sample depends on whether the process is exothermic or endothermic.
- Weight of the analysed uncured material in the sample pan is 5 to 20 mg.
- An open aluminium sample pan is used and sample is subjected to dynamic heating where sample is heated from room temperature to 250°C at 10°C/min heating rate under continuous nitrogen flow of 50 mL/min. This allows to follow the cure behaviour which is an exothermic reaction. Peak temperature of the exothermic reaction is reported in °C.
- Dynamic mechanical analysis is performed to measure the Storage Modulus (E- modulus) value which is the elastic response of material by using TA instruments DMA Q800 or DMA 2980. Storage Modulus units are reported in MPa.
- the mini-modules were built up out of five shingles.
- mono crystalline PERC solar cells were used.
- bussing the string a SnPb/Cu ribbon was used.
- the amount of ECA was 6mg per shingle.
- the ECA curing temperature was 150°C.
- Mini-modules were assembled with glass, EVA and back sheet foil in a laminator at 140°C for 20min. The mini-module performance was tested with the Meyer Berger Spotlight cell tester.
- the power output (Pmax) of the five-shingle module was monitored during reliability. To mimic the effect of outdoor conditions, the mini-modules were cycled between -40°C and 85°C, according to IEC 61215:2005 standard. The difference between the initial power output (D Pmax) of the shingle-cell module and after 600 cycles -40°C/85°C are shown.
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Abstract
The present invention relates to an electrically conductive composition comprising a) a resin selected from the group consisting of epoxy (meth)acrylate, (poly)ester (meth)acrylate, urethane (meth)acrylate, silicone (meth)acrylate, poly(iso)butylene (meth)acrylate, (poly)isoprene (meth)acrylate, polybutylene (meth)acrylate and mixtures thereof; b) an acrylic monomer; c) an electrically conductive filler; and d) a curing agent. The composition is particularly suitable for use in a solar cell and/or a photovoltaic module, especially in the photovoltaic module, wherein the solar cells are shingled.
Description
Electrically conductive adhesive for attaching solar cells
Technical field
The present invention relates to an electrically conductive adhesive for attaching solar cells together in a shingled photovoltaic module, wherein the adhesive has the required electrical and mechanical properties.
Background
A solar cell or photovoltaic cell, is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect. Solar cells are the building blocks of the photovoltaic modules, otherwise known as solar panels, in order to increase the voltage delivered by individual solar cells.
The general structure of a solar cell is illustrated in figure 1 . Most of the solar cells (1 ) produced today consist of crystalline silicon. Metal contacts, busbars (2) and fingers (3), are both printed on the silicon wafer. These metallic contacts are necessary to collect the current generated by a solar cell. Figure 1 a illustrates basic configuration with three busbars and figure 1 b illustrates basic configuration with four busbars. Fingers are linear areas of metallization that collect current to deliver it to the busbars, which are connected directly to the external leads, via ribbons (5) for example. A conventional solar cell, including ribbons (5) is illustrated in figure 2. In a conventional photovoltaic module, a high temperature firing pastes are used as finger and busbar material, and the ribbons (5) are attached by means of a soldering process. In addition to soldering, electrically conductive adhesives (4) can be used to bond heat sensitive heterojunction crystalline cells (with a-Si layer present). The ribbons are on top of the bus bars in the conventional photovoltaic module, and cause a shadow area to the solar cell leading to decrease the efficiency of the photovoltaic module.
In order to increase the power output of the conventional photovoltaic modules, solar cells can be arranged in series-connected in an overlapping shingle pattern. Shingles are typically made by cutting/dicing crystalline silicon cells along a plurality of lines parallel to a long edge of each wafer to form a plurality of rectangular silicon solar cells each having substantially the same length along its long axis. In this way more shingles (typically 5 or 6 for a six-inch wafer (approx. 156 mm)) are cut/diced from the originally printed cell. The cells can be full square as well as pseudo-square, in the latter cut-cells with chamfered corners may be obtained. The first and second silicon solar cells are bonded to each other at the overlapping portions of the solar cells
with an electrically conductive material (4) in shingle structure. The conductive material can be deposited in different patterns. Electrically conductive adhesive as a material to bond the solar cells together have the advantage that they overcome mechanical stresses, which build up due to CTE (coefficient of thermal expansion) mismatch between the different materials used in a photovoltaic assembly. Figure 3 illustrates a shingled photovoltaic module.
Prior art describes various different kind of electrically conductive adhesives, which can be used in solar cells and to form photovoltaic modules. Many of these electrically conductive adhesives are epoxy or silicone based adhesives. However, a long curing time is often required for some adhesives described in the prior art before the adhesive reaches its full mechanical and electrical properties.
The photovoltaic modules are subjected to a temperature changes and high mechanical stresses over their life cycle. These factors have a negative effect on the lifetime of the photovoltaic module, and also set requirements for the electrically conductive adhesive used in the solar cells and/or photovoltaic cells.
One other limitation described in prior art is that the adhesives may not have the required thermo-mechanical properties. Required thermal-elastic properties for the electrically conductive adhesive composition are correct modulus, specified glass transition temperature, and specified coefficient of thermal expansion in order to pass the thermo-mechanical load reliability test designed for the photovoltaic modules. If the adhesive material is too rigid (too high modulus) the power output loss of the photovoltaic module may occur when applying external stresses to the module (eg. after application of mechanical load or after thermal cycling).
Therefore, there is still a need for an electrically conductive adhesive composition, which has improved long-term bonding strength (long-term adhesion), in particular, if such components and/or substrates will undergo temperature changes during their life-cycle. Furthermore, there is also a need for low cost electrically conductive adhesive composition, which provides the above-mentioned properties.
Short description of the figures
Figure 1 illustrates a structure of ordinary silicon solar cells.
Figure 2 illustrates a conventional photovoltaic module.
Figure 3 illustrates a shingled photovoltaic module.
Summary of the invention
The present invention relates to an electrically conductive composition comprising a) a resin selected from the group consisting of epoxy (meth)acrylate, (poly)ester (meth)acrylate, urethane (meth)acrylate, silicone (meth)acrylate, poly(iso)butylene (meth)acrylate, (poly)isoprene (meth)acrylate, polybutylene (meth)acrylate and mixtures thereof; b) an acrylic monomer; c) an electrically conductive filler; and d) a curing agent.
The present invention also encompasses a cured product of the electrically conductive composition according to the present invention.
The present invention also relates to use of the electrically conductive composition according to the present invention or use of the cured product according to the present invention in a solar cell and/or a photovoltaic module.
The present invention also relates to a photovoltaic module, comprising a series-connected string of two or more photovoltaic cells in a shingle pattern having an electrically conductive bonding between said two or more solar photovoltaic cells, wherein said electrically conductive bonding is formed with an electrically conductive composition according to the present invention.
Detailed description of the invention
In the following passages the present invention is described in more detail. Each aspect so described may be combined with any other aspect or aspects unless clearly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features indicated as being preferred or advantageous.
In the context of the present invention, the terms used are to be construed in accordance with the following definitions, unless a context dictates otherwise.
As used herein, the singular forms“a”,“an” and“the” include both singular and plural referents unless the context clearly dictates otherwise.
The terms“comprising”,“comprises” and“comprised of” as used herein are synonymous with “including”,“includes” or“containing”,“contains”, and are inclusive or open-ended and do not exclude additional, non-recited members, elements or method steps.
The recitation of numerical end points includes all numbers and fractions subsumed within the respective ranges, as well as the recited end points.
All percentages, parts, proportions and then like mentioned herein are based on weight unless otherwise indicated.
When an amount, a concentration or other values or parameters is/are expressed in form of a range, a preferable range, or a preferable upper limit value and a preferable lower limit value, it should be understood as that any ranges obtained by combining any upper limit or preferable value with any lower limit or preferable value are specifically disclosed, without considering whether the obtained ranges are clearly mentioned in the context.
All references cited in the present specification are hereby incorporated by reference in their entirety.
Unless otherwise defined, all terms used in disclosing the invention, including technical and scientific terms, have the meaning as commonly understood by one of the ordinary skill in the art to which this invention belongs to. By means of further guidance, term definitions are included to better appreciate the teaching of the present invention.
In the following text the term (meth)acrylate covers both acrylate and methacrylate.
The present invention relates to an electrically conductive composition comprising a) a resin selected from the group consisting of epoxy (meth)acrylate, (poly)ester (meth)acrylate, urethane (meth)acrylate, silicone (meth)acrylate, poly(iso)butylene (meth)acrylate,
(poly)isoprene (meth)acrylate, polybutylene (meth)acrylate and mixtures thereof; b) an acrylic monomer; c) an electrically conductive filler; and d) a curing agent.
Surprisingly, the Applicant has discovered that the electrically conductive composition according to the present invention provides fast curing, stress release, long term bonding strength to metal part of the silicon solar cells, reliable connection and low electrical contact resistance to the metal parts of the solar cell despite of low to medium silver quantity. Some of these aspects are illustrated in figure 3.
The electrically conductive composition according to the present invention comprises a resin selected from the group consisting of epoxy (meth)acrylate, (poly)ester (meth)acrylate, urethane (meth)acrylate, silicone (meth)acrylate, poly(iso)butylene (meth)acrylate,
(poly)isoprene (meth)acrylate, polybutylene (meth)acrylate and mixtures thereof.
Above listed thermoset acrylate resins have the advantage that they can vary between very rigid to very flexible materials. Furthermore, a resin having a low Tg value is preferred, this is because resin having a low Tg value provides a desired flexibility to the composition in order to pass the solar module reliability testing.
Preferably, the resin used in the present invention has a Tg value 15 °C or less.
However, the adhesive cannot be too flexible, because stable electrical contacts to a solar cell are difficult to maintain. Therefore, the formed contacts need to be flexible enough but having some rigidity to provide stability to the structure. Furthermore, it is known that the contact resistance of the adhesive to the solar cell tends to increase during thermocycling between -40°C and 85°C and/or during ageing at 85°C in high humidity environments (85% humidity). This is causing power output of modules to decrease during these reliability conditions. Therefore, it is important to provide adhesive having desired flexibility.
Preferably, the resin is a (poly)(iso)butylene (meth)acrylate, a (poly)isoprene (meth)acrylate or an urethane (meth)acrylate, more preferably an aliphatic or aromatic urethane (meth)acrylate or an aliphatic polyester based urethane di(meth)acrylate oligomer, more preferably an aliphatic urethane (meth)acrylate or an aliphatic polyester based urethane di(meth)acrylate oligomer or a mixture thereof.
Urethane acrylates, and especially aliphatic urethane di(meth)acrylates are preferred because they have low Tg value, and they can provide the desired flexibility to the composition.
Suitable commercially available resins for use in the present invention include, but are not limited to Ebecryl 8232, Ebecryl 230, Ebecryl 4744, Ebecryl 3639, Ebecryl 3708 from Allnex; Genomer 2253, Genomer 3457, Genomer 4215 and Genomer 4230 from Rahn; and CN9002, CN9021 , CN9014, SR 307, CN 307 from Arkema; EPION 400V from Kaneka and UC-102, UC-102M, UC-203 and UC-203M from Kuraray.
An electrically conductive composition according to the present invention comprises a resin from 10 to 65% by weight of the total weight of the composition, preferably from 10 to 55%, more preferably from 1 1 to 45% and even more preferably from 12 to 35%.
If the quantity of the resin is too high, the resulting composition results in a very low filled formulation regarding electrically conductive filler, and conductivity properties are negatively affected. On the other hand, too low resin quantity does not provide a required adhesion strength.
The electrically conductive composition according to the present invention comprises an acrylic monomer, which is and acts as a reactive diluent. Suitable acrylic monomer for use in the present invention may be a mixture of one type of acrylic monomers or a mixture of different kind of acrylic monomers.
In one embodiment the acrylic monomer is at least one (meth)acrylate monomer having two or more (meth)acrylate groups.
Alternatively, in another embodiment the acrylic monomer is a mixture of at least one (meth)acrylate monomer having two or more (meth)acrylate groups and a (meth)acrylate functionalized phosphate ester.
Alternatively, yet in another embodiment the acrylic monomer is a mixture of at least one (meth)acrylate monomer having two or more (meth)acrylate groups and at least one (meth)acrylate monomer having one (meth)acrylate group and a (meth)acrylate functionalized phosphate ester.
The above listed combinations of acrylic monomers are preferred because the presence of functionalized phosphate ester acrylic monomer promotes the adhesion, and the presence of two or more acrylic groups promotes ideal cure shrinkage, and therefore, provides low resistance.
Suitable (meth)acrylate monomer having one (meth)acrylate group for use in the present invention is preferably selected from the group consisting of isobornyl acrylate, isobornyl methacrylate, 2-(2-ethoxyethoxy) ethylacrylate, lauryl acrylate, lauryl methacrylate, acrylic acid ester, cyclic trimethylolpropane formal acrylate, 4-tert-butylcyclohexylacrylate, 2- phenoxyethylacylate, 2-phenoxyethylmethacrylate, tetrahydrofurfuryl acrylate, 3,3,5- trimethylcyclohexyl acrylate and mixtures thereof.
These monofunctional (meth)acrylate monomers are preferred because they have good diluting properties and good compatibility with the composition according to the present invention. Particularly, isobornyl methacrylate is preferred because it has ideal diluting properties for the composition according to the present invention.
Suitable commercially available (meth)acrylate monomers having one (meth)acrylate group for use in the present invention include, but are not limited to SR256, SR489, SR395, SR440, SR335, SR285, SR423D, SR550 from Arkema; Miramer M170, M1084 from Miwon Specialty Chemical Co., Ltd., IBXA from Osaka Organic Chemical Ind.; Genomer 121 , Genomer 121 M from Rahn; and IBOA from Osaka Organic Chemical ltd.
Suitable (meth)acrylate monomer having two or more (meth)acrylate groups for use in the present invention is preferably selected from the group consisting of 1 ,6-hexanediol diacrylate, trimethyl propane triacrylate, trimethylol propane (EO)3 triacrylate, trimethylol propane (EO)g triacrylate, pentaerythritol triacrylate, di-trimethylolpropane triacrylate, ethoxylated pentaerythritol tetraacrylate, neopentyl glycolpropoxylate diacrylate, polyethylene glycol 400 diacrylate, tetra(ethylene glycol) diacrylate, tripropyleneglycol diacrylate, hydroxyl pivalic neopentyl glycol diacrylate, tricyclodecane dimethanol diacrylate and mixtures thereof.
These multifunctional (meth)acrylate monomers are preferred because they have good diluting properties and good compatibility with the composition according to the present invention.
Suitable commercially available (meth)acrylate monomers having two or more (meth)acrylate groups for use in the present invention include, but are not limited to SR238, SR833S, SR834, SR355, SR 285, SR 248, SR 259, SR 9003 and SR494 from Arkema; and Miramer M202, M220, M222, M232 from Miwon Specialty Chemical Co. Ltd.
A (meth)acrylate functionalised phosphate ester can be used in the present invention as an acrylic monomer. Suitable phosphate ester of (meth)acrylate may have the following general structure
R" = H or CH3
R' = alkyl or
R' = -CH2CH20- or
R' = -CH2CH2CH2CH2CH2C(0)0CH2CH20-
Specific non-limiting examples of phosphate esters of (meth)acrylate suitable for use in the present invention are:
Suitable phosphate ester of (meth)acrylate for use in the present invention is phosphoric acid 2-hydroxy ethyl methacrylate. Phosphoric acid 2-hydroxy ethyl methacrylate is particularly preferred because of its diluting properties, and in addition it provides good adhesion properties.
Suitable commercially available phosphate ester of (meth)acrylates for use in the present invention include, but are not limited to Ebecryl 168, Ebecryl 170, Ebecryl 171 from Allnex; Kayamer PM-2, Kayamer PM-21 from Nippon Kayaku co.Ltd; Genorad 40 from Rahn; SR9050, SR9051 , SR9054 from Arkema; and PAM100, PAM200 from Rodia.
In one embodiment, an acrylic monomer is at least one (meth)acrylate monomer having two or more (meth)acrylate groups selected from the group consisting of 1 ,6-hexanediol diacrylate, trimethyl propane triacrylate, trimethylol propane (EO)3 triacrylate, trimethylol propane (EO)g triacrylate, pentaerythritol triacrylate, di-trimethylolpropane triacrylate, ethoxylated pentaerythritol tetraacrylate, neopentyl glycolpropoxylate diacrylate, polyethylene glycol 400 diacrylate, tetra(ethylene glycol) diacrylate, tripropyleneglycol diacrylate, hydroxyl pivalic neopentyl glycol diacrylate, tricyclodecane dimethanol diacrylate and mixtures thereof.
In another embodiment, an acrylic monomer is a mixture of at least one (meth)acrylate monomer having two or more (meth)acrylate groups selected from the group consisting of 1 ,6- hexanediol diacrylate, trimethyl propane triacrylate, trimethylol propane (EO)3 triacrylate, trimethylol propane (EO)g triacrylate, pentaerythritol triacrylate, di-trimethylolpropane triacrylate, ethoxylated pentaerythritol tetraacrylate, neopentyl glycolpropoxylate diacrylate, polyethylene glycol 400 diacrylate, tetra(ethylene glycol) diacrylate, tripropyleneglycol diacrylate, hydroxyl pivalic neopentyl glycol diacrylate, tricyclodecane dimethanol diacrylate and mixtures thereof, and a (meth)acrylate functionalized phosphate ester selected from
In another embodiment, an acrylic monomer is a mixture of at least one (meth)acrylate monomer having two or more (meth)acrylate groups selected from the group consisting of 1 ,6- hexanediol diacrylate, trimethyl propane triacrylate, trimethylol propane (EO)3 triacrylate, trimethylol propane (EO)g triacrylate, pentaerythritol triacrylate, di-trimethylolpropane
triacrylate, ethoxylated pentaerythritol tetraacrylate, neopentyl glycolpropoxylate diacrylate, polyethylene glycol 400 diacrylate, tetra(ethylene glycol) diacrylate, tripropyleneglycol diacrylate, hydroxyl pivalic neopentyl glycol diacrylate, tricyclodecane dimethanol diacrylate and mixtures thereof and at least one (meth)acrylate monomer having one (meth)acrylate group selected from the group consisting of isobornyl acrylate, isobornyl methacrylate, 2-(2- ethoxyethoxy) ethylacrylate, lauryl acrylate, lauryl methacrylate, acrylic acid ester, cyclic trimethylolpropane formal acrylate, 4-tert-butylcyclohexylacrylate, 2-phenoxyethylacylate, 2- phenoxyethylmethacrylate, tetrahydrofurfuryl acrylate, 3,3,5-trimethylcyclohexyl acrylate and mixtures thereof and a (meth)acrylate functionalized phosphate ester selected from
An electrically conductive composition according to the present invention comprises an acrylic monomer from 1 to 65% by weight of the total weight of the composition, preferably from 5 to 60%, more preferably from 10 to 55% and even more preferably from 15 to 50%.
If the quantity of the acrylic monomer is less than 1 % there is no physical effect to the composition. On the other hand, if the quantity exceeds 65% the composition will be adversely affected: there will be out gassing, bleeding, no cross-linking (more homopolymerisation takes a place) and therefore, the structure is not building up, and furthermore, the viscosity of the composition will not be ideal.
The electrically conductive composition according to the present invention comprises an electrically conductive filler.
Suitable electrically conductive filler for use in the present invention can exist in a variety of shapes, e.g., as substantially spherical particles, as irregular shaped particles, oblong
particles, flakes (e.g., thin, flat, single crystal flakes), and the like. The electrically conductive filler may be for example a mixture of spherical particles and flake particles.
Suitable electrically conductive filler for use in the present invention have preferably an average particle size in the range of from 300 nm to 50 micron, preferably from 500 nm to 40 micron and more preferable from 500 nm to 30 micron.
The particle size is measured by particle size analyser and the particle shape is analysed by scanning electron microscope. In short scattered laser lights from the particles are detected an array of detectors. Theoretical calculation is carried out to fit the measured distribution of scattered light intensity. During the fitting process the particle size distribution is deduced and D10, D50, D90 etc. values are calculated accordingly.
Suitable electrically conductive filler for use in the present invention may be a mixture of particles having a small particle size and particles having a larger particle size.
Suitable electrically conductive filler is selected from the group consisting of silver, nickel, carbon, carbon black, graphite, graphene, copper, gold, platinum, aluminium, iron, zinc, cobalt, lead, tin alloys, silver coated copper, silver coated graphite, silver coated polymers, silver coated aluminium, silver coated glass, silver coated carbon, silver coated boron nitride, silver coated aluminium oxide, silver coated aluminium hydroxide and mixtures thereof.
Silver coated polymers may be acrylic polymers and/or silicone based polymers.
Preferably electrically conductive filler is selected from the group consisting of silver, carbon black, graphite, graphene, copper, silver coated copper, silver coated graphite, silver coated polymers, silver coated aluminium, silver coated glass, silver coated carbon, silver coated boron nitride, silver coated aluminium oxide, silver coated aluminium hydroxide and mixtures thereof, more preferably electrically conductive filler is selected from the group consisting of silver, silver coated copper, silver coated graphite, silver coated polymers, silver coated aluminium, silver coated glass and mixtures thereof.
Silver is preferred because it’s good electrical performance. Silver coated fillers are preferred because of their lower cost (compared to silver). Furthermore, these preferred electrically conductive fillers do not have pot life issues when used in free radical cure acrylic formulations.
Suitable commercially available electrically conductive fillers for use in the present invention include, but are not limited to silver: AA3462, AA-5124, AA-192N, C-1284P, C-0083P, P543- 14 from Metalor; KP84, KP74, KP29 from Ames Goldsmidth; silver coated copper: CGF-DAB- 121 B from Dowa; AgCu0810 or AgCu0305 from Ames Goldsmidth; silver coated glass: CONDUCT-O-FIL™ SG15F35 from Potters Industries Inc.; silver coated polymer: Spherica™
30.22 from Mosaic Solutions; silver coated graphite: P594-5 from Metalor; silver coated Al: CONDUCT-O-FIL™SA325S20 from Potters Industries Inc.
An electrically conductive composition according to present invention comprises an electrically conductive filler from 10 to 70% by weight of the total weight of the composition, preferably from 20 to 65% and more preferably from 30 to 60%.
If the quantity of the electrically conductive filler is below 10%, the composition does not provide required electrical conductivity. On the other hand, if the quantity of the electrically conductive filler is above 70%, the composition is no longer cost effective. Furthermore, generally lower electrically conductive filler quantity decreases the overall weight of the solar cell/photovoltaic module, and reduces the overall costs.
The Applicant has found out that the flexibility of the adhesive can be modified even further by reducing the quantity of the electrically conductive fillers and to increase the quantity of the resin matrix. The composition according to the present invention is able to overcome the accumulated mechanical stresses in the photovoltaic modules.
Furthermore, the combination of low to mid-range quantity of the electrically conductive fillers, resin and acrylic monomer mixture as described in the present invention have a key role to lead good electrical properties and good adhesion properties, in addition to good application properties. At the same time low to mid-range quantity of the electrically conductive fillers reduces the overall costs.
Suitable electrically conductive fillers for use in the present invention include also silver coated/plated particulate, wherein the underlying particulate can be a wide variety of materials, as long as the silver coating/plating substantially coats the underlying particulate, such that the resulting composition comprises silver-covered particles distributed throughout.
In an event the electrically conductive filler is a silver coated particle, the silver quantity is from 10 to 70% by weight of the total weight of the electrically conductive filler, preferably from 10 to 65% and more preferably from 10 to 60%.
Preferably, electrically conductive filler has a tap density from 0.7 g/cm3 to 6.0 g/cm3, preferably from 1.0 g/cm3 to 5.5 g/cm3, more preferably from 1 .0 g/cm3 to 4.0 g/cm3.
The tap density is determined in accordance to ISO 3953 typically using a 25 cm3 graduated glass cylinder. The principle of the method specified is tapping a specified amount of powder in a container by means of a tapping apparatus until no further decrease in the volume of the powder takes place. The mass of the powder divided by its volume after the test gives its tap density.
The Applicant has surprisingly found out that the combination of aliphatic urethane di(meth)acrylate, acrylic monomer mixture and low to mid-range electrically conductive filler quantity works well together to provide low electrical contact resistance to metal parts of silicon solar cell, stress release, long term bonding strength to metal part of silicon solar cells and fast curing.
The electrically conductive composition according to the present invention comprises a curing agent.
Any conventional curing agent suitable for (meth)acrylate resins can be used in the present invention. Examples of suitable curing agents for use in the present invention are peroxides and azo compounds. Preferably, the curing agent used in the present invention is a peroxide.
Suitable peroxide for use in the present invention is selected from the group consisting of tert- butyl peroxy 2-ethylhexanoate, di-tert-butyl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxyneodecanoate, 2,5-dimethyl-2,5(tert-butyl peroxy) hexane, dicumyl peroxide, tert-amyl- peroxyneodecanoate di(4-tert-butylcyclohexyl)peroxydicarbonate, di-sec-butyl peroxydicarbonate, diisopropyl peroxydicarbonate, di(2-ethylhexyl)peroxydicarbonate, dicetyl peroxydicarbonate, dimyristyl peroxydicarbonate) and mixtures thereof.
Tert-butyl peroxyneodecanoate is one preferred peroxide because it has good compatibility with the composition and it provides ideal fast curing speed.
Suitable commercially available peroxides for use in the present invention include, but are not limited to Luperox 10, Luperox 26, Luperox Dl, Luperox P and dicumyl peroxide from Arkema; and Trigonox 101 from AzkoNobel.
An electrically conductive composition according to the present invention comprises a peroxide from 0.1 to 3% by weight of the total weight of the composition, preferably from 0.2 to 2%.
An electrically conductive composition according to the present invention may further comprise an adhesion promoter.
Suitable adhesion promoter for use in the present invention is selected from the group consisting of epoxy functional silanes, (meth)acrylic functional silanes, carboxylates and mixtures thereof.
Suitable commercially available adhesion promotors for use in the present invention include, but are not limited to Silquest A-187, Silquest A-1 100, Silquest A-1 106, Silquest A- 1 1 10, Silquest A1 120, Silquest A1 130, Silquest A-1 170, Silquest A2120, Silquest A-174 (acrylic functional silane) and Silquest A-186 from Momentive; and BYK 4509, 4510, 451 1 , 4512 from Altana.
An electrically conductive composition according to the present invention may comprise an adhesion promoterfrom 0.01 to 10% by weight of the total weight of the composition, preferably from 0.05 to 5% and more preferably from 0.1 to 3.5%.
If the quantity of an adhesion promoter exceeds 10% other properties of the composition will be negatively affected, leading to decreased adhesion strength and decreased electrical conductivity.
An electrically conductive composition according to the present invention may further comprise rheological additives such as bentone (such as Bentone 27, Bentone 38 and Bentone SD-2 from Elemenits Specialities), silica, fumed silica (such as Aerosil 200, Aerosil 300, Aerosil COK 84, Aerosil R71 1 and Aerosil R7200 from Evonik), fused silica (such as FB-5SDC, FB-7SDC, and FB-9454 from DENKA) and aluminium oxide (such as AE 9104 from Admatechs Co., LTD and Aeroxide Alu C, Aeroxide Alu 130 and Aeroxide Alu 65 from Evonik).
An electrically conductive composition according to the present invention may further comprise wetting and dispersing agents such as BYK W903 from Altana.
An electrically conductive composition according to the present invention may further comprise rheology additives such as BYK-41 1 , BYK E-41 1 , BYK-430, BYK-430, BYK-431 and BYK- R605 from Altana; and Thixatrol P220X-MF, Thixatrol Plus, and Thixatrol PM 8054 From Elementis.
An electrically conductive composition according to the present invention may further comprise a radical stabilizer such as BHT (butylated hydroxytoluene) or alternative radical stabilizers such as Genorad 16, Genorad 18, Genorad 21 and Genorad 22 from Rahn.
An electrically conductive composition according to the present invention may be applied by using any of the following techniques time pressure dispense, jet dispense, auger dispense, stencil printing and screen printing.
The viscosity of the electrically conductive composition according to the present invention needs to be adjusted to be suitable for the selected application method. Generally, viscosity tolerated for stencil or screen printing may be slightly higher than viscosity needed in dispensing method. Optimizing rheology to make it suitable for the targeted application can be done by slightly increasing/decreasing the quantity of the acrylic monomers or by using small quantities of rheological additives.
If viscosity is too high, (a viscosity at 25°C above 100 Pa.s or 100,000 cPoise as measured by rheometer at 15s-1 ), the application of the electrically conductive adhesive in a high speed process will become problematic.
The present invention relates to a cured product of the electrically conductive composition according to the present invention. The composition according to the present invention may be cured thermally.
The electrically conductive adhesive according to the present invention having the required electrical and mechanical properties can be used in a shingled photovoltaic module wherein the crystalline silicon based solar singles are attached to each other by using the electrically conductive adhesive.
The present invention encompasses the use of the electrically conductive composition according to the present invention in a solar cell and/or a photovoltaic module.
The present invention encompasses the use of cured electrically conductive composition according to the present invention in a solar cell and/or a photovoltaic module.
Preferably, the electrically conductive composition according to the present invention is used as an interconnection material in the photovoltaic module, wherein the solar cells are shingled. A shingled structure is illustrated in figure 3.
In one embodiment, the electrically conductive composition according to the present invention may be used to bond ribbons to the solar cells as shown in figure 2.
The present invention also relates to a photovoltaic module, comprising a series-connected string of two or more solar cells in a shingle pattern having an electrically conductive bonding between said two or more solar cells, wherein said electrically conductive bonding is formed with an electrically conductive composition according to the present invention. Shingle structure is illustrated in figure 3.
The electrically conductive composition according to the present invention can be applied by dispensing, jetting or printing to solar cells.
Examples
The example compositions are prepared by mixing all ingredients together to form a homogenous mixture.
Test methods:
Viscosity was measured on a Rheometer from TA instruments Rheometer HR-1 or Q-2000 using a plate-plate geometry with a 2 cm in diameter plate at a 200 micron gap and shear rates of 1 .5 s-1 or 15 s-1 . Viscosity units are reported in Pa.s.
Volume resistivity (VR) was measured as follows:
Samples were prepared for the compositions according to the examples above and deposited on a glass plate (by drawing down a strip of material onto the surface of a glass slide with strip dimensions of about 5 cm in length, 5 mm in width and about 50 micron in thickness) and cured and dried (according to the requirement for the used resin). Glass plates were cooled to room temperature, before measurement.
Volume resistivity was calculated from equation VR = (width of the sample (cm) x thickness of the sample (cm) x Resistance (Ohm)) / length of the sample (cm). Where the resistance in ohm was measured by using a Keithley 2010 multimeter and a 2 point resistance probe. Volume resistivity units are reported in Ohm. cm
Electrical contact resistance (CR)
The electrical contact resistance was determined by dispensing the conductive adhesive in a TLM structure on a 1 .5 mm wide busbar of a c-Si wafer. A TLM structure was obtained by contacting 7 Ag plated Cu tabs (2 mm wide, 1 micron Ag coating) to the test layer, wherein the contact tabs exhibit increasing distances between the contact tabs going from about 3 mm to about 18 mm. The resistance between the neighbouring contact tabs was measured by using Keithley four-point probes and a Keithley 2750 multimeter and plotted as a function of the distance. The contact resistance value is the half of the intercept from the curve obtained from that plot. The average contact resistance (arithmetic average) is reported in mohm. If no linear relation could be found because of bad ohmic contacts meaning an rsq value of less than 0.9, “no fit” was mentioned.
The stability of the electrical contact resistance was determined by accelerated ageing testing (85° C , relative humidity of 85% and -40,85°C thermal cycling) using the TLM test setup as described above.
DSC has been measured by using Dynamic Scanning Calorimetry Q2000 from TA Instruments. The basic principle underlying this technique is that when the sample undergoes
a phase transitions, more or less heat will be needed compared to the reference to keep the reference and the sample at the same temperature. Whether less or more heat must flow to the sample depends on whether the process is exothermic or endothermic. Weight of the analysed uncured material in the sample pan is 5 to 20 mg. An open aluminium sample pan is used and sample is subjected to dynamic heating where sample is heated from room temperature to 250°C at 10°C/min heating rate under continuous nitrogen flow of 50 mL/min. This allows to follow the cure behaviour which is an exothermic reaction. Peak temperature of the exothermic reaction is reported in °C.
Dynamic mechanical analysis (DMA) is performed to measure the Storage Modulus (E- modulus) value which is the elastic response of material by using TA instruments DMA Q800 or DMA 2980. Storage Modulus units are reported in MPa.
Thin film samples with the following dimensions: width 8-10mm, length 13-15mm and thickness 150-200 micron, were measured by using Film Tension clamp. Samples were cured for 15 min at 150 or 180°C.
Power output of mini-modules:
The mini-modules (single-cell modules) were built up out of five shingles. For the single-cell modules, mono crystalline PERC solar cells were used. For bussing the string, a SnPb/Cu ribbon was used. The amount of ECA was 6mg per shingle. The ECA curing temperature was 150°C. Mini-modules were assembled with glass, EVA and back sheet foil in a laminator at 140°C for 20min. The mini-module performance was tested with the Meyer Berger Spotlight cell tester. The power output (Pmax) of the five-shingle module was monitored during reliability. To mimic the effect of outdoor conditions, the mini-modules were cycled between -40°C and 85°C, according to IEC 61215:2005 standard. The difference between the initial power output (D Pmax) of the shingle-cell module and after 600 cycles -40°C/85°C are shown.
Table 1
*ln the above examples contact resistance (CR) was measured using 1 ,2 mm wide Ag coated Cu ribbon (instead of 2 mm) and 0,7 mm wide busbar (instead of 1.5 mm).
Table 2
*ln the above examples contact resistance (CR) was measured using 1 ,2 mm wide Ag coated Cu ribbon (instead of 2 mm) and 0,7 mm wide busbar (instead of 1.5 mm).
Table 3
Table 4
Table 5
Claims
1. An electrically conductive composition comprising a) a resin selected from the group consisting of epoxy (meth)acrylate, (poly)ester (meth)acrylate, urethane (meth)acrylate, silicone (meth)acrylate, poly(iso)butylene (meth)acrylate, (poly)isoprene (meth)acrylate, polybutylene (meth)acrylate and mixtures thereof; b) an acrylic monomer; c) an electrically conductive filler; and d) a curing agent.
2. An electrically conductive composition according to claim 1 , wherein said acrylic monomer is at least one (meth)acrylate monomer having two or more (meth)acrylate groups; or a mixture of at least one (meth)acrylate monomer having two or more (meth)acrylate groups and a (meth)acrylate functionalized phosphate ester; or a mixture of at least one (meth)acrylate monomer having two or more (meth)acrylate groups and at least one (meth)acrylate monomer having one (meth)acrylate group and a (meth)acrylate functionalized phosphate ester.
3. An electrically conductive composition according to claim 1 or 2, wherein said acrylic monomer is present from 1 to 65% by weight of the total weight of the composition, preferably from 5 to 60%, more preferably from 10 to 55% and even more preferably from 15 to 50%.
4. An electrically conductive composition according to any of claims 1 to 3, wherein said resin is an urethane (meth)acrylate, preferably an aliphatic or aromatic urethane (meth)acrylate, more preferably an aliphatic urethane (meth)acrylate and even more preferably an aliphatic urethane di(meth)acrylate.
5. An electrically conductive composition according to any of claims 1 to 4, wherein said resin is present from 10 to 65% by weight of the total weight of the composition, preferably from 10 to 55%, more preferably from 1 1 to 45% and even more preferably from 12 to 35%.
6. An electrically conductive composition according to any of claims 1 to 5, wherein said electrically conductive filler is selected from the group consisting of silver, nickel, carbon, carbon black, graphite, graphene, copper, gold, platinum, aluminium, iron, zinc, cobalt, lead, tin alloys, silver coated copper, silver coated graphite, silver coated polymers, silver coated aluminium, silver coated glass, silver coated carbon, silver coated boron nitride, silver coated aluminium oxide, silver coated aluminium hydroxide and mixtures thereof, preferably electrically conductive filler is selected from the group consisting of silver, carbon black, graphite, graphene, copper, silver coated copper, silver coated graphite, silver coated polymers, silver coated aluminium, silver coated glass, silver coated carbon, silver coated boron nitride, silver coated aluminium oxide, silver coated aluminium hydroxide and mixtures thereof, more preferably electrically conductive filler is selected from the group consisting of silver, silver coated copper, silver coated graphite, silver coated polymers, silver coated aluminium, silver coated glass and mixtures thereof.
7. An electrically conductive composition according to any of claims 1 to 6, wherein said electrically conductive filler is present from 10 to 70% by weight of the total weight of the composition, preferably from 20 to 65% and more preferably from 30 to 60%.
8. An electrically conductive composition according to any of claims 1 to 7, wherein said curing agent is a peroxide selected from the group consisting of tert-butyl peroxy 2- ethylhexanoate, di-tert-butyl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxyneodecanoate, 2,5-dimethyl-2,5(tert-butyl peroxy) hexane, dicumyl peroxide, tert-amyl-peroxyneodecanoate di(4-tert-butylcyclohexyl)peroxydicarbonate, di-sec- butyl peroxydicarbonate, diisopropyl peroxydi carbon ate, di(2- ethylhexyl)peroxydicarbonate, dicetyl peroxydicarbonate, dimyristyl peroxydicarbonate) and mixtures thereof.
9. An electrically conductive composition according to any of claims 1 to 8, wherein said curing agent is present from 0.1 to 3% by weight of the total weight of the composition, preferably from 0.2 to 2%.
10. An electrically conductive composition according to any of claims 1 to 9, wherein said composition further comprises an adhesion promoter from 0.01 to 10% by weight of the total weight of the composition, preferably from 0.05 to 5% and more preferably from 0.1 to 3.5%.
1 1. An electrically conductive composition according to claim 10, wherein said adhesion promoter is selected from the group consisting of epoxy functional silanes, (meth)acrylic functional silanes, carboxylates and mixtures thereof.
12. A cured product of the electrically conductive composition according to any of claims 1 to 1 1.
13. Use of the electrically conductive composition according to any of claims 1 to 11 or use of the cured product according to claim 12 in a solar cell and/or a photovoltaic module.
14. Use according to claim 13, as an interconnection material in the photovoltaic module, wherein the solar cells are shingled.
15. A photovoltaic module, comprising a series-connected string of two or more solar cells in a shingle pattern having an electrically conductive bonding between said two or more solar cells, wherein said electrically conductive bonding is formed with an electrically conductive composition according to any of claims 1 to 11 or claim 12.
16. A photovoltaic module according to claim 15, wherein said electrically conductive composition is applied by dispensing, jetting or printing to a solar cells.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201880092728.8A CN112020749B (en) | 2018-04-26 | 2018-04-26 | Conductive adhesive for attaching solar cells |
| JP2020559436A JP7242704B2 (en) | 2018-04-26 | 2018-04-26 | Conductive adhesive for bonding solar cells |
| PCT/EP2018/060765 WO2019206417A1 (en) | 2018-04-26 | 2018-04-26 | Electrically conductive adhesive for attaching solar cells |
| KR1020207030552A KR102578460B1 (en) | 2018-04-26 | 2018-04-26 | Electrically conductive adhesive for attaching solar cells |
| US17/080,644 US20210139750A1 (en) | 2018-04-26 | 2020-10-26 | Electrically conductive adhesive for attaching solar cells |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
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| PCT/EP2018/060765 WO2019206417A1 (en) | 2018-04-26 | 2018-04-26 | Electrically conductive adhesive for attaching solar cells |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US17/080,644 Continuation US20210139750A1 (en) | 2018-04-26 | 2020-10-26 | Electrically conductive adhesive for attaching solar cells |
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| Publication Number | Publication Date |
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| WO2019206417A1 true WO2019206417A1 (en) | 2019-10-31 |
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| PCT/EP2018/060765 WO2019206417A1 (en) | 2018-04-26 | 2018-04-26 | Electrically conductive adhesive for attaching solar cells |
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| Country | Link |
|---|---|
| US (1) | US20210139750A1 (en) |
| JP (1) | JP7242704B2 (en) |
| KR (1) | KR102578460B1 (en) |
| CN (1) | CN112020749B (en) |
| WO (1) | WO2019206417A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3940035A1 (en) * | 2020-07-13 | 2022-01-19 | Heraeus Deutschland GmbH & Co. KG | Electrically conductive adhesive |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| US11961629B1 (en) * | 2022-12-08 | 2024-04-16 | Geckos Technology Corp. | Antioxidant conductive thermal paste and method of manufacturing the same |
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| US20080099733A1 (en) * | 2006-10-31 | 2008-05-01 | Cheil Industries, Inc. | Anisotropic conductive film composition |
| WO2010048387A1 (en) * | 2008-10-22 | 2010-04-29 | Ferro Corporation | Electrically conductive polymeric compositions, contacts, assemblies, and methods |
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| US4400577A (en) * | 1981-07-16 | 1983-08-23 | Spear Reginald G | Thin solar cells |
| US5395876A (en) * | 1993-04-19 | 1995-03-07 | Acheson Industries, Inc. | Surface mount conductive adhesives |
| JPH11269452A (en) * | 1998-03-25 | 1999-10-05 | Sumitomo Bakelite Co Ltd | Die attach paste |
| US6214433B1 (en) * | 1999-10-04 | 2001-04-10 | Dsm N.V. | Radiation-curable coatings for optical discs and optical discs incorporating such coatings |
| JP4491873B2 (en) | 1999-12-03 | 2010-06-30 | 株式会社ブリヂストン | Anisotropic conductive film |
| US7422707B2 (en) * | 2007-01-10 | 2008-09-09 | National Starch And Chemical Investment Holding Corporation | Highly conductive composition for wafer coating |
| CN101475780B (en) * | 2009-01-14 | 2012-03-14 | 长兴化学工业股份有限公司 | Solvent-free conductive adhesive constituent and solar energy cell assembly with the same |
| JP5674291B2 (en) * | 2009-07-30 | 2015-02-25 | 電気化学工業株式会社 | Temporary fixing adhesive composition, temporary fixing method, surface protection method |
| JP6154625B2 (en) * | 2013-03-01 | 2017-06-28 | デクセリアルズ株式会社 | Conductive adhesive, solar cell module, and method for manufacturing solar cell module |
| CN104250523B (en) * | 2013-06-25 | 2019-06-25 | 日立化成株式会社 | Connecting material, solar battery connecting material, solar cell module and its manufacturing method |
| JP2015228457A (en) * | 2014-06-02 | 2015-12-17 | デクセリアルズ株式会社 | Conductive adhesive for solar cell, solar cell module, and manufacturing method of solar cell module |
| JP2016029134A (en) * | 2014-07-22 | 2016-03-03 | 日立化成株式会社 | Connection material and solar cell module |
| CN108350105B (en) * | 2015-11-26 | 2020-10-13 | 三键有限公司 | Thermosetting composition and conductive adhesive using same |
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2018
- 2018-04-26 KR KR1020207030552A patent/KR102578460B1/en active IP Right Grant
- 2018-04-26 CN CN201880092728.8A patent/CN112020749B/en active Active
- 2018-04-26 WO PCT/EP2018/060765 patent/WO2019206417A1/en active Application Filing
- 2018-04-26 JP JP2020559436A patent/JP7242704B2/en active Active
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2020
- 2020-10-26 US US17/080,644 patent/US20210139750A1/en active Pending
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| US4999136A (en) * | 1988-08-23 | 1991-03-12 | Westinghouse Electric Corp. | Ultraviolet curable conductive resin |
| US20080099733A1 (en) * | 2006-10-31 | 2008-05-01 | Cheil Industries, Inc. | Anisotropic conductive film composition |
| WO2010048387A1 (en) * | 2008-10-22 | 2010-04-29 | Ferro Corporation | Electrically conductive polymeric compositions, contacts, assemblies, and methods |
Cited By (1)
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|---|---|---|---|---|
| EP3940035A1 (en) * | 2020-07-13 | 2022-01-19 | Heraeus Deutschland GmbH & Co. KG | Electrically conductive adhesive |
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| Publication number | Publication date |
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| JP2021529841A (en) | 2021-11-04 |
| CN112020749A (en) | 2020-12-01 |
| US20210139750A1 (en) | 2021-05-13 |
| CN112020749B (en) | 2023-12-22 |
| KR20210006343A (en) | 2021-01-18 |
| KR102578460B1 (en) | 2023-09-14 |
| JP7242704B2 (en) | 2023-03-20 |
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