Excelitas Technologies Improved Surface Cure with UVC LED

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1 Excelitas Technologies Improved Surface Cure with UVC LED Marvin Ruffin Business Development Manager UV LED Solu:ons

2 Who We Are Lumen Dynamics was acquired by Excelitas Technologies Company in November 2013 Excelitas has over 5,000 employees worldwide Global network of design and manufacturing loca:ons in the Americas, Europe and Asia Design and crea:on of innova:ve UV curing solu:ons since 1984 Over 35,000 UV curing systems currently being used in more than 50 countries Lamp and LED UV systems

3 UV LED for Curing ApplicaAons LED systems have many func:onal advantages over lamp-based systems! Longer life, reduced energy, lower heat, lower maintenance, instant on/off, Hg free Formula:on modifica:on has enabled the use of many UV LED curable materials in commercial applica:ons! Digital print, electronics assembly, op:cal bonding, medical device manufacture

4 Surface Cure Remains a Challenge Free radical adhesives are suscep:ble to curing with a tacky surface when exposed to air (oxygen inhibi:on) Current Techniques for Improving Surface Cure! Formula:on modifica:on! Iner:ng (gas, wax, film)! High irradiance curing! Exposure to short wavelength UV

5 Is LED an opaon for surface cure? We know short wavelength UV is useful for improving surface cure! < 350nm is required Commercially available UV LED curing systems currently do not cover the UVC spectrum UVC LEDs now available from mul:ple manufactures! Opportunity to benchmark technology Current LED curing solutions lack UVC Post cure or in line exposure to deep UV LEDs is an aeracave soluaon to achieve surface cure taking full advantage of LED benefits.

6 EvoluAon of UVC LEDs LED efficiency and life:me con:nue to improve at a steady rate Technology breakthroughs 2014/2015 Increased R&D spending Many new deep UV manufacturers Mul:ple wavelengths available but 280nm is most efficient * Source: AquiSense Technologies, July 2015

7 First cure trials performed LED Optical Spectrum CW Wavelength (nm) Irradiance Profile of UV LED system 285nm LED array constructed! Irradiance achieved: 40mW/cm2 Mul:ple adhesives & conformal coa:ngs selected for trials Samples exposed to UVA/UVV LED radia:on with a UVC LED post cure

8 EvaluaAon Method SelecAon criterion! Adhesive and conformal coa:ng samples that were difficult to cure with commercially available 365nm and 400nm light sources were chosen for further evalua:on A scale between 0 and 5 has been adopted! 5 is tack free (hard/strong surface; the best surface cure achievable)! 4 is tack free! 0 is wet surface! 0 < 1 < 2 < 3 < 4 < 5 VerificaAon of results! A UVC lamp was used to determine irradiance threshold needed to impact surface cure

9 Experimental Results - adhesive Sample # UVA/UVV LED Dose (J/cm^2) Deep UV LED Dose (J/cm^2) Surface cure raang A (1) 30 0 A (1a) B (1) 34 0 B (1a) B (2) Two adhesive samples were selected (Sample A & B) Large UVA/UVV dose s:ll leg a wet surface Tack free surface was achieved with 285nm LED exposure Significantly reduced UVA/UVV dose is necessary with combined UVC exposure

10 Experimental Results conformal coaang Sample # UVA/UVV LED Dose (J/cm^2) Deep UV LED Dose (J/cm^2) Surface cure raang C (1) 65 1 C (2) D (1) 46 2 D (2) Two conformal coa:ng samples were selected (Sample C & D)! Dual cure formula:ons Large UVA/UVV dose s:ll leg a wet surface Improved surface cure was achieved with 285nm LED exposure with reduced UVA/UVV dose requirements! Results comparable to UVC lamp exposure (low pressure)! Reduced wait :mes

11 Promising Results Adhesive significant improvement in surface cure where UVA and UVV (365nm & 400nm) LED falls short Improved cure efficiency with deep UV post cure in samples where very high peak irradiance and long UVA/UVV exposures are needed Conformal CoaAng Reduces wai:ng :me for even those coa:ngs reformulated for UVA/UVV LED (8-12 hour post cure is eliminated) Tack free surface is achieved in very short dura:on used deep UV post cure

12 The path forward Current advances in UVC LED technology may benefit UV curing industry! Improved surface cure! Minimize need for complex formula:on modifica:on Rapid advancement in core technology Improved power output (>10x in last few years) Increase current densi:es & life:me Decreasing LED die costs as yields improve Commercial success will depend on advanced system design op:mized for the applica:on Balance cost vs. performance Further cure trials are necessary

13 Thank You QuesAons? Contact: Marvin Ruffin Business Development Manager UV LED Solu:ons Excelitas Technologies 13

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