OVERVIEW OF PLASTIC SUBSTRATES FOR PRINTED ELECTRONICS Robert Rus:n Sr. Applica+on and Market Development Manager Special thanks to: Karl Rakos Bill MacDonald
Melinex polyester film Mylar polyester film Teijin Tetoron polyester film Teonex PEN polyester film How many times a day do you rely on PET and PEN polyester films from DuPont Teijin Films?
DTF s Flexible Electronics Defini+on Flexible Electronics includes any market or applica+on in which electronic components are manufactured, either printed or not, directly on flexible film providing manufacturing or end use benefits. Plastic Electronics is a state of mind Professor Donal Bradley
Current targeted Flex Electronic markets Flex Display Electrophore+c, electrochromic, electrowegng, OLED, flexible backplanes Touch Screen Mainly projected capaci+ve Smart Cards Ligh+ng Solid state either LED or OLED Ac+ve Windows Medical
Printed Electronics Exist Today Membrane Touch Switch Automo+ve MTS, eg seat sensors PEN allows higher temperature specifica+ons Flexible Printed Circuits / Flat Flexible Cable Automo+ve wiring harness replacement with flat cables LED rear light clusters and daylight running lights Op+cal Displays Electroluminescent lamps and next genera+on displays
Printed Electronics Today Security, ID, health cards Passports Protective Labels Medical Test strips
Displays (Flat Panel & Flexible) LCD Reflector Prism Light Gain Diffuser Diffuser Protect Films Touch Screen Flexible Display Smart Phones E Readers Tablets Touch Screen
Solid State Ligh+ng OLED Diffuser Reflector Barrier base film LED Diffuser Reflector
Durable Cards Na+onal ID University & College ID Driver Licenses Financial Smart Cards Transit Overlay Core
Emerging Printed Electronics
DTF substrates enabling device development DTF has been very ac+ve in the Flexible Displays arena for a number of years and have a proven track record in high quality substrates for flexible displays ITRI Flexible Displays Center Plas.c Logic Kent Display 1.E-05 W=100um Vsd=10.1V 1.E-06 Isd/(W/L) (A) 1.E-07 1.E-08 1.E-09 1.E-10 1.E-11 1.E-12 1.E-13 W [ m] L [ m] 100.0 1.0 100.0 2.0 100.0 5.0 100.0 10.0 100.0 20.0 100.0 50.0 100.0 100.0 1.E-14-10 0 10 20 30 40 Vg(V) Polymer Vision HP/SAIL Process Samsung Electronics Pictures courtesy of companies named above
Emerging Printed Electronics
(Flexible) Electronics Thin Film Transistors Printed Electronics Sensors Slide shown courtesy of Flexible Display Centre, ASU
Factors Influencing Substrate Choice Property Set Simple circuitry Organic AM backplanes More demanding property set Inorganic AM backplanes Increasing complexity of substrate structure OLED Lighting
Key Challenges for Engineered Substrates into Flexible Electronics Applica+ons Low Coefficient of Thermal Expansion Low Shrinkage Upper Temperature for Processing Surface smoothness Barrier Solvent Resistance Moisture Resistance Clarity Rigidity Conduc+ve layers Commercial availability Substrates for the more demanding applica+ons are likely to be mul+layer structures containing both organic and inorganic layers
Factors Influencing Film Choice Substrate Proper+es Films grouped by thermal properties Temp C 400 350 300 250 200 150 100 50 0 Semi-crystalline Amorphous Amorphous,solvent cast Tg C Tm C PET PEN Polycarbonate Polyarylate Polyethersulphone Fluorene Polyester Polyimide Substrates
Surface Roughness and Quality
Surface analysis Regular Printer Paper
Surface analysis Tyvek Graphic Paper Is porosity a factor in your design?
Surface analysis Tyvek Graphic Paper
Stainless Steel Stainless steel Requires planarising coa+ng and insula+ng coa+ng Picture courtesy of UDC
Surface analysis Display Grade PET Film Note: scale is now +/- 15 nm
Melinex ST506 Benefit of Planarisa+on Pretreat on Melinex ST506 gives good adhesion to subsequent coatings But at expense of surface roughness Ra 1.53nm Sample size 594micron Planarised Melinex ST506 Very smooth surface-on a par with Polished glass mirror Ra 0.6nm Sample size 608 microns
Enhancing Surface Roughness with Fillers Unfilled Clear Handlable Slightly Hazy Increasing Roughness Hazy Matte Rough Handleable Very Hazy
Surface Roughness from Addi+ve Packages Standard Packaging Film Electronics Grade Film White Opaque Film Laminating Film
Does Rougness Impact Circuitry? QVGA asi TFT array built on PEN Planariser Uncoated Heat stabilised PEN Planarised Heat stabilised PEN Slide shown courtesy of Flexible Display Centre, ASU
Surface Energy
Surface Energy dynes/cm2, D2578 45 40 35 30 25 20 15 10 5 0 PET LDPE BOPP HDPE OPS Cell PVC
Effect of Surface Energy and Primer Chemistry Surface chemistry and surface energy play a major role in adhesion, interlayer stress, and print quality.
Mismatched Surface Chemistry Silver ink, screen printed on PET, with mismatched solvent system. Must System design your materials to match INKS to substrate