TeraLED. Thermal and Radiometric Characterization of LEDs. Technical Specification.

Transcription

1 TeraLED Thermal and Radiometric Characterization of LEDs Technical Specification M E C H A N I C A L A N A L Y S I S

2 TeraLED HARDWARE OPTIONS Depending on the dimensions and power level of the LED or LED module to be tested, appropriate measurement environment is needed. The T3Ster TeraLED system, offering two different integrating spheres with appropriate temperature controlled cold plates as DUT holders meets these needs and supports the measurement of a wide range of LED devices. 030cm integrating sphere for LEDs and LED modules up to 55mm in diameter, ~10 W dissipated power and 3300 lm. Temperature control of the LED under test is provided with a Peltier-based cold plate. 050cm integrating sphere for LEDs and LED modules up to 120mm in diameter, 50 W dissipated power and 9000 lm. Temperature control of the LED under test is provided with a liquid cooled cold plate. 2

3 TeraLED SOFTWARE SUITE 2.0 Fully automated measurements are controlled by the TeraLED Measurement Control Tool that masters all hardware parts connected to the TeraLED system, such as T3Ster, and T3Ster Booster, as well as supported spectrometer types, and supported liquid based thermostats. For fair comparison between LEDs, the software enables performing measurements at preset real junction temperature values. The real junction temperature and the real thermal resistance of LED packages are identified according to the latest LED thermal testing standard JEDEC JESD All light output characteristics are measured according to the recommendations of the JEDEC JESD51-52 standard. Following the recommendations of this optical measurement results can be presented as function of the LED forward current and the reference or junction temperature. As part of the TeraLED Software Suite, the TeraLED View Results Presentation Tool is provided to visualize all measurement results of the T3Ster TeraLED setup. Characteristic plots, detailed thermal and optical test reports can be exported and/or copied to Windows clipboard. 3

4 Power Junction Temperature Package Dynamic Model e.g. for CFD simulation Structure Function Pulse thermal resistance Light Output Characteristics Complex locus e.g. for all HB LEDs e.g. for Z th of AC LEDs e.g. for failure analysis in LM80 testing e.g. for PWM dimmed LED applications T3Ster TeraLED: Comprehensive Solution compliant with the JEDEC JESD51-51 and JESD51-52 standards with full support of the JESD51-14 standard LED package compact thermal model is directly exportable from T3Ster Master to FloTHERM for CFD simulations. The TeraLED View tool provides LED data that can be used in the LED module of FloEFD v12 for LED thermal simulations completed with hot lumen calculations. TeraLED Thermal Measurements Processed T3Ster Master Software Failure analysis T3Ster LED component measured for Thermal Characteristics and Light Output junction Thermal Model Created case Delemination from the MCPCB: a failure CFD simulation FloTHERM FloEFD Thermal Simulation of Systems and Sub-Systems Integrated Design Flow for LED based products: Testing Modeling Simulation 4

5 T3STER TERALED 30P/50L TECHNICAL SPECIFICATIONS Optical Characteristics 1, 2, 3, 4 Maximum (up to) 5 Ø 300mm Sphere Ø 500mm Sphere Radiant Power Ф e = P opt [W] 9 20 Luminous Flux 6 Ф V [lm] Color Coordinates 7 x, y Further measured/derived quantities include 8 : Scotopic Flux (Ф V [lm]), Radiant Efficiency (η e [%]), Luminous Efficacy (η V [lm/w]), Correlated Color Temperature (CCT [K]) Spectral Characteristics 9 Performance depends on the spectrometer connected to the TeraLED system Electrical Characteristics 1, 10, 11 Forward Voltage (V F [V]) Forward Current (I F [A]) Minimum Maximum Minimum Maximum TeraLED standalone TeraLED + T3Ster TeraLED + T3Ster + Booster , 13, 14 Thermal Characteristics Unit-Step Thermal Response Thermal Resistance Junction Temperature 15 Thermal Impedance, time domain Thermal Impedance, frequency domain 16 Thermal Time Constant Spectrum Pulse Thermal Resistance 17 Differential/Integral Structure Function Derating Curve ΔT(t) R th [K/W] T J [ C] Z th (t) [K/W] Z th (ω) [K/W] Available in combination with T3Ster (and Booster) equipment. Thermal evaluation with T3Ster Master software. R thjc identification according to JEDEC JESD51-14 Thermostat Characteristics Temperature T ref [ C] Accuracy 18 Maximum heat sinking capacity [W] Minimum Maximum 30P (d = 55 mm) L (d = 120 mm)

6 1. Measurement sequence: light, forward current, temperature. 2. Light output characteristics are obtained from optical filter based measurements. Luminous flux is measured with a V(λ) filter matched to the CIE V(λ) function with spectral mismatch error f 1 1.5%. For other filters the spectral mismatch error is smaller than 5..8%. Measurement of light output characteristics complies with the JEDEC JESD51-52 standard (extension of the CIE recommendations for thermal measurements of power LEDs). 3. Optical measurements are based on JESD51-52 and CIE standards using the strict substition method for total flux measurements. The system is pre-calibrated with traceable standard LEDs of different colors. 4. As a result of a combined T3Ster-TeraLED measurement setup all relevant optical characteristics can be plotted as function of real junction temperature, reference temperature (thermostat temperature, between 10 C and 90 C) and current (as specified above). Each relevant characteristic plot can be displayed in absolute and relative scale as well. 5. There are different photocurrent measurement ranges. The specified limits correspond to the highest range. Depending on the current sphere coating status and filter transmission characteristics these limits can be different they are valid for the off-the-shelf state. 6. For a CCT=2700K warm white LED and CIE observer. The detector system (sphere + filter + photodetector) is matched to the CIE V(λ) function. The entire radiometric/ photometric setup is NIST traceable. Assumed efficacy of source of radiation of the LED under test is 360 lm/w. 7. Derived from the corresponding measured total flux values (using the color matching functions describing the CIE observer). Color coordinates can be determined for up to 3 digits. 8. Derived from the corresponding measured total flux values (CIE observer) and the measured electrical characteristics. 9. Available only if external spectrometer is physically attached to the SMA905 fiber optics port of the TeraLED sphere and the TeraLED control software is configured to handle spectrometers. The TeraLED measurement control software supports different spectrometers of Ocean Optics through an open software interface. For the spectrometer software interface specificiation refer to the TeraLED Measurement Control Software Reference Guide. Measured spectra are processed only if that software feature is licensed. 10. Maximum forward voltage and forward current depend on the hardware used (standalone TeraLED, T3Ster+TeraLED, T3Ster+Booster+TeraLED). 11. For thermal transient measurements with a forward voltage V F > 5V an external pre-scaler of applicable ratio is necessary to scale down the voltage to the input range of the T3Ster measurement channel (0..5V). In a setup containing a Booster a pre-scaler is not always necessary; however, for V F values far from full scale it is highly advised to use a pre-scaler in order to minimize the noise. 12. Different types of Booster equipment allow different voltage/current limits. 13. Thermal measurements are based on the JEDEC JESD51-1 static test method and its JEDEC JESD51-14 compliant transient extension and JEDEC JESD51-51 LED thermal testing standard. Primary measured quantity is ΔV F (t) function. After a JEDEC JESD51-1/JESD51-51 compliant K-factor calibration this is converted to ΔT J (t) as follows: ΔT J (t)= K(ΔV F (t)). This is converted to Z th (t) function as follows: Z th (t)= ΔT J (t)/δp H where ΔP H is the change of the heating power calculated as follows: ΔP H = (I H I M )ΔV F P opt, where I H and I M are the heating and measuring current in accordance with the JEDEC JESD51-51 standard, respectively. The measured total thermal resistance is the steady-state value of the measured thermal impedance: R th = Z th (t = ) = Z th (ω = 0). P opt is measured according to JEDEC JESD T3Ster provides several thermal transient measurement modes: Cooling transient (default, preferred method and mandatory when combined with light output measurements): complete step response transient function, see also the JEDEC JESD51-51 standard for thermal characterization of LEDs Heating transient (not preferred for LEDs): complete step response transient function Single pulse transient: transient response to a single pulse (width of the single pulse is programmable). Length of the measured transient response is programmable in all modes. For complete specification see T3Ster Technical Specifications. In a combined TeraLED + T3Ster setup, the automated measurement provides cooling transients only. 15. T J = T ref +ΔT where T ref is the reference temperature the actual value of the programmed cold plate temperature. Choose the change level of the heating power applied at the LED junction such that a recommended minimum change of 3 C of junction temperature is obtained. Junction temperature measurement parameters are also determined by the properties of the cold plate in use. 16. Frequency domain representation of the thermal impedance (a complex quantity, function of angular frequency), derived directly from the measured Z th (t) thermal impedances. Presented in the form of Nyquist diagrams, also known as complex loci. Derived both for driving point and transfer impedances. Its zero frequency value is equal to the steadystate thermal resistance: Z th (ω = 0) = R th. 17. Defined and calculated only for driving point thermal impedances. 18. The given accuracy for Peltier element-cooled cold plates is valid for the measured temperature. 19. The heat sinking capacity depends on the temperature of both the internal and the external side of the Peltier element (T ref and T amb, respectively). 20. For 50L systems we deliver a Ø 120mm liquid-cooled cold plate that can be connected to an external thermostat, and a Peltier element-cooled cold plate with a mechanical fixture fitting the DUT port of the integrating sphere used. Technically this latter cold plate is equivalent to the one used with the 30P system. 21. Advised limits for safe operation. Actual limits depend on the properties of the external liquid based thermostat used. Maximum allowed coolant temperature is 150 C. Do not set the temperature below dew point to avoid moisture condensation. Dripping water may damage the paint inside the integrating sphere. 22. Typical value, actual accuracy depends on the temperature control unit of the external liquid based thermostat used. 23. Actual upper limit depends on the coolant and the properties of the external liquid based thermostat used. For the latest product information, call us or visit: 2013 Mentor Graphics Corporation, all rights reserved. This document contains information that is proprietary to Mentor Graphics Corporation and may be duplicated in whole or in part by the original recipient for internal business purposes only, provided that this entire notice appears in all copies. In accepting this document, the recipient agrees to make every reasonable effort to prevent unauthorized use of this information. All trademarks mentioned in this document are the trademarks of their respective owners. MGC