Novel halogen free epoxy resin for high performance electronic applications P.K.Dubey, Dr. Hitesh Soni*, Dr. M.Soni, Ms. Thipa Thai Organics Chemicals Co., Ltd. (Epoxy Division) Map Ta Phut-Rayong (Thailand) 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA Introduction: PWB, flip chip encapsulation, surface mounting adhesives, conformal and die coatings are major applications requiring FR epoxy resin Demand of halogen free fire retardant material due to environmental issues Lead free soldering calling for high heat resistance Miniaturization of electronic components requiring high thermal stability 14-11-2005 TRFA Annual meeting, Florida, USA

Conventional FR epoxy resins TRFA Annual meeting, Florida, USA Bromine containing Standard for many years and have environmental and thermal stability issue Filler containing Capable to achieve V-0 rating Problem of high viscosity, aggregation of filler and micro structural defects in cured resin Red phosphorous Suitable to achieve V-0 rating but have issue of pigmentation & handling Phosphorous additives Effective fire-retardants. Problem of high water affinity, risk of p-o-p or c-o-p bonds under humid condition along with low thermal stability 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA Mechanism of various flame retardant action 1. Halogen based flame retardant R-H + •X R• + HX HX + •OH H2O + •X 2. Filler based flame retandant Al(OH)3xH20 Al2O3 + H2O 3. Phosphorus based flame retardant Px H3POX H3POX + CH2–CH2 – H3PO4 + C - H2O 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA Present work Reactive phosphorous compound (DOPO) selected for study as fire-retardant Multifunctional EOCN and EBPN resins synthesized and suitably reacted with DOPO Phenolic compounds based on phenol Novolac, bis-phenol Novolac, O-cresol Novolac, and tris-phenols are selected as hardener. 2MI and TPP are used as catalyst All sets of combinations studied for thermal, mechanical, and electrical properties. 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA Epoxy Resin: YDBN 602 and YDBN 602P 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA Epoxy resin TOCN 4030 and TOCN 4030P 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA Phenolic Hardeners: Phenol Novolac-PN O-Cresol Novolac- OCN BPA Novolac- BPN Tris- Phenol- TP 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA Catalyst 2- Methyl Imidazole- 2MI Triphenyl Phosphine- TPP 14-11-2005 TRFA Annual meeting, Florida, USA

Reaction Mechanism of 2-MI with epoxy group Source: Farkas, A., Strohem, P.F., J.Appl. Polym. Sci., 1968, 12, p159   14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA mechanism of reaction between epoxy and phenol using TPP as catalyst Romanchick, W.A., Sohn, J.E., and Geibel, J.F., ACS Symposium Series 221-Epoxy Resin Chemistry II ( Ed: R.S.Bauer) American Chemical Society, Washington, D.C. 1982, p-85   14-11-2005 TRFA Annual meeting, Florida, USA

Basic Properties of Epoxy resins TRFA Annual meeting, Florida, USA Basic Property of Epoxy resins 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA Typical properties Epoxy resins Property TOCN 4030 YDBN 602 TOCN 4030P YDBN 602P Color yellow EEW 204 206 269 280 HyCl, ppm < 50 Ionic chlorine, ppm < 2 Total Chlorine, ppm 1099 1022 900 Residual ECH content, ppm < 5 Hello Physical properties are comparable 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA Typical properties Epoxy resins Property TOCN 4030 YDBN 602 TOCN 4030P YDBN 602P Viscosity @ 125oC 2006 1099 7160 3251 Softening point 82 72 92 83 Glass transition temperature 77 67 87 71 Phosphorus content 2.1 Mn 991 1007 1373 1130 Mw/Mn 3.00 4.57 2.55 4.28 Melt viscosity is low in case of YDBN resins in-spite of high Mw/Mn ratio. YDBN resins has lower softening point 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA Curing Behavior of Epoxy resins with Phenolic hardeners 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA OCN is fastest reactive phenolic hardener 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA YDBN 602 is more reactive because of better structural symmetry and low melt viscosity 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA 2MI is more reactive compared to TPP because of alkoxide ion formation and more basicity of the 2MI catalyst 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA Modified resins are lower in reactivity due to the presence of acidic Phosphorus compounds. 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA Possible reaction of Phosphorus Resin with Catalyst polymerization Ring cleavage 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA Phenolic reactivity trend- OCN>PN>TP>BPN 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA Thermal Property 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA Sample cured 175oC/6hrs Concentration of catalyst effect reactivity not the final crosslink structure 2-MI system gives higher Tg than TPP system 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA 6 hrs at 175oC is adequate curing schedule for full crosslinking YDBN system shows higher Tg compared to TOCN system 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA Sample cured 175oC/6hrs TP shows highest Tg(230-235oC) YDBN systems shows better Tg compared to TOCN system in all cases. Modified resins shows lower Tg-due to high EEW and polarity. Modified resins with 2MI catalyst shows Tg in range of 155-185oC depending on curing agent 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA Flammability And Thermal Degradation 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA Effect of Phosphorus content on flammability Phosphorus content YDBN 602-2MI TOCN 4030 –2MI YDBN 602-TPP TOCN 4030-TPP V-2 Burn 0.8 V-2 with low burning time 1.2 V-1 V-1 with dripping 1.5 V-0 with low average burning time . V-0 with high average burning time V-0 with low average burning time 2.0 V-0 V-O 1.5% Phosphorus is adequate to get flammability rating V-O YDBN resins shows better flammability rating compared to TOCN TPP catalyst shows better flammability rating than 2MI 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA YDBN resins shows better thermal degradation stability P- resins shows initial loss at low temperature but Tmax is higher than unmodified resins TPP cured system shows better overall degradation stability 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA YDBN 602 char yield is higher than TOCN 4030- better flammability. Incorporation of phosphorus increases char yield dramatically. TPP cured system shows better char yield than 2MI 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA Mechanical Property Property YDBN 602/PN/2MI TOCN 4030/PN/2MI YDBN 602P/PN/2MI TOCN 4030P/PN/2MI Ratio 100/50/1 100/52/1 100/35/1 100/37/1 Curing Schedule 120oC/15 min, 175oC/6 hrs 140oC/15 min, 175oC/6 hrs Glass fiber content, % 63 62 64 Tensile strength, Mpa 336 328 352 347 Tensile strain, % 1.54 1.61 1.63 1.36 Tensile modulus, Gpa 23.5 24.9 25.2 34.33 Flexural strength, Mpa 455 477 537 599 Flexural strain, % 1.96 2.07 1.97 Flexural modulus, Gpa 27 28 29 34 Water absorption after 8 hrs at 80oC, % 0.1042 0.0941 0.0848 0.0646 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA Electrical property Property YDBN 602 TOCN 4030 YDBN 602P TOCN 4030P Dielectric Constant at 1 MHz 4.26 3.84 4.22 4.09 Dielectric Strength(t-2mm), KV/mm 18.267 18.320 19.64 17.584 Volume resistivity ( 500V), ohm-cm 2.275x (10e-15) 1.957x(10e-15) 4.346x (10e-15) 4.60x (10e-15) 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA Conclusion: Halogen free YDBN-P and TOCN-P resins could be material of choice where high glass transition temperature (170-190oC) or flammability is desired for electrical and electronics applications. YDBN series of resins were found comparable to TOCN resins in terms of mechanical, electrical and thermal properties with distinct advantage of lower melt viscosity which could be advantageous for better wetting or lower coating thickness requirements. Curing agents could be selected depending on process/ performance requirements. TP has exhibited higher Tg with low melt viscosity where as low functionality PN could be used for moderate Tg requirement. 2MI as catalyst lead to higher Tg of cured matrix compared to TPP.   14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA Acknowledgement: Sincerely thanks Management of TOCC All Colleagues Somsak, Satid, Thithikan and Thaniya Mr. Wutti of Mettler Toledo, Thailand 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA Thank you 14-11-2005 TRFA Annual meeting, Florida, USA

TRFA Annual meeting, Florida, USA Any Question? 14-11-2005 TRFA Annual meeting, Florida, USA