1、JEDEC STANDARD Terms, Definitions and Units Glossary for LED Thermal Testing JESD51-53 MAY 2012 JEDEC SOLID STATE TECHNOLOGY ASSOCIATION NOTICE JEDEC standards and publications contain material that has been prepared, reviewed, and approved through the JEDEC Board of Directors level and subsequently
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5、cification and application, principally from the solid state device manufacturer viewpoint. Within the JEDEC organization there are procedures whereby a JEDEC standard or publication may be further processed and ultimately become an ANSI standard. No claims to be in conformance with this standard ma
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7、rmation. Published by JEDEC Solid State Technology Association 2012 3103 North 10th Street Suite 240 South Arlington, VA 22201-2107 This document may be downloaded free of charge; however JEDEC retains the copyright on this material. By downloading this file the individual agrees not to charge for o
8、r resell the resulting material. PRICE: Contact JEDEC Printed in the U.S.A. All rights reserved PLEASE! DONT VIOLATE THE LAW! This document is copyrighted by JEDEC and may not be reproduced without permission. For information, contact: JEDEC Solid State Technology Association 3103 North 10th Street
9、Suite 240 South Arlington, VA 22201-2107 or refer to www.jedec.org under Standards-Documents/Copyright Information. JEDEC Standard No. 51-53 -i- TERMS, DEFINITIONS AND UNITS GLOSSARY FOR LED THERMAL TESTING ( Contents Foreword. ii Introduction. ii 1 Scope1 2 Normative References1 3 Terms and Definit
10、ions2 JEDEC Standard No. 51-53 -ii- Foreword In order to facilitate the communication of thermal and radiometric/photometric measurement and data information of power LEDs, a clear and well-defined language is necessary. This collection of terms and definitions will help to describe the thermal perf
11、ormance of LED packages and LED assemblies more accurately. Introduction This document has been prepared by the JEDEC JC-15 Committee on Thermal Characterization therefore it is focused on thermal characterization of LEDs as special, packaged discrete semiconductor devices. It also provides referenc
12、e to light measurement to the extent required for thermal characterization of LEDs. Thus, this document should be used in conjunction with the JESD51-50 through JESD51-52 series of standards. This document is also aimed at experts performing light output measurements of LEDs when during such measure
13、ments dedicated attention is paid to thermal issues as well. Therefore terms commonly used both in thermal testing and optical testing are collected here with common definitions coherent with the ones usual in the thermal and optical testing. JEDEC Standard No. 51-53 Page 1 TERMS, DEFINITIONS AND UN
14、ITS GLOSSARY FOR LED THERMAL TESTING (From JEDEC BoD ballot JCB-12-06, formulated under the cognizance of the JC-15 Committee on Thermal Characterization Techniques for Semiconductor Packages.) 1 Scope This document provides a unified collection of the commonly used terms and definitions in the area
15、 of LED thermal measurements. The terms and definitions provided herein extend beyond those used in the JESD51 family of documents, especially in JESD51-13, in order to include other often used terms and definitions in the area of light output measurements of LEDs. Definitions, symbols and notations
16、 regarding light output measurements used here are consistent with those defined in JESD77C.01 and with those defined by CIE (International Commission on Illumination), especially in the International Lighting Vocubulary, CIE S 017/E:2011 ILV and in the CIE 127-2007 document as well as in some other
17、 relevant standards of other standardization bodies from the solid-state lighting industry, e.g., ANSI/IESNA RP 16-05. 2 Normative references The following normative documents contain provisions that, through reference in this text, constitute provisions of this guideline. For dated references, subs
18、equent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest editi
19、on of the normative document referred to applies. JESD51-50, Overview of Methodologies for the Thermal Measurement of Single- and Multi-Chip, Single- and Multi-PN-Junction Light-Emitting Diodes (LEDs). JESD51-51, Implementation of the Electrical Test Method for the Measurement of the Real Thermal Re
20、sistance and Impedance of Light-emitting Diodes with Exposed Cooling Surface. JESD51-52, Guidelines for Combining CIE 127-2007 Total Flux Measurements with Thermal Measurements of LEDs with Exposed Cooling Surface. JESD51, Methodology for the Thermal Measurement of Component Packages (Single Semicon
21、ductor Devices). JESD51-1, Integrated Circuit Thermal Measurement Method - Electrical Test Method. JESD51-12, Guidelines for Reporting and Using Electronic Package Thermal Information. JEDEC Standard No. 51-53 Page 2 2 Normative references (contd) JESD51-13, Glossary of Thermal Measurement Terms and
22、 Definitions. JESD51-14, Transient Dual Interface Test Method for the Measurement of the Thermal Resistance Junction to Case of Semiconductor Devices with Heat Flow Trough a Single Path. JESD15-1, Compact Thermal Model Overview. JESD15-3, Two-Resistor Compact Thermal Model Guideline. JESD77C.01, Ter
23、ms, Definitions, and Letter Symbols for Discrete Semiconductor and Optoelectronic Devices. CIE S 017/E:2011 ILV: International Lighting Vocabulary. CIE 127:2007 Technical Report: Measurement of LEDs, ISBN 978 3 901 906 58 9. ANSI/IESNA IES Nomenclature Committee, IES RP-16-10, Nomenclature and Defin
24、itions of for Illuminating Engineering, ISBN 978-0-87995-208-2 3 Terms and definitions For the purpose of this publication, the following terms and definitions apply. For terms and definitions not listed refer to JESD51-13 and ANSI/IESNA RP 16-05. The symbols most frequently used in the JESD51-50 se
25、ries of documents are summarized in Table 1. AC LED: An LED designed to be driven by a sinusoidal alternating current (AC) power source, typically having an operational frequency and voltage equal to the frequency and voltage of the mains (50/60 Hz, 230/120 V). anode: An electrode of an LED that, in
26、 the forward mode of operation, is connected to a positive potential with respect to the potential of the cathode electrode. NOTE In the case of a single pn-junction diode, the anode electrode of the package is in ohmic contact with the p-doped side of the semiconductor pn-junction. cathode: An elec
27、trode of an LED that, in the forward mode of operation, is connected to a negative potential with respect to the potential of the anode electrode. NOTE In the case of a single pn-junction diode, the cathode electrode of the package is in ohmic contact with the n-doped side of the semiconductor pn-ju
28、nction. JEDEC Standard No. 51-53 Page 3 3 Terms and definitions (contd) change of junction temperature (TJ): The difference between two steady-state values of the temperature of that same junction. NOTE TJis measured in Kelvins K or in degrees Celsius C. DC LED: An LED device designed to be driven b
29、y a constant, steady forward current. efficacy: See luminous efficacy (of a source of light) electrical power (supplied to an LED) (Pel): The product of the forward voltage and the forward current. NOTE Electrical power is measured in watts W. emitted optical power (Popt): Synonym for total radiant
30、flux. energy conversion efficiency: Synonym for radiant efficiency. ensemble characteristic: Measured characteristic (such as forward voltage, junction temperature, luminous flux, temperature sensitivity of forward voltage) of an LED ensemble, considered as a single, average quantity as if it was me
31、asured as a single characteristic of an equivalent single pn-junction LED. forward current (IF): The current flowing from the p-type region to the n-type region. NOTE 1 Forward current is measured in amps A. NOTE 2 In case of LED ensembles without any access to individual anodes and cathodes or thei
32、r associated regions, the forward voltage is an ensemble characteristic of such a device. forward voltage (VF): A positive anode-to-cathode voltage. NOTE 1 At high forward current, the value of the forward voltage varies typically between 2 V and 4 V for single pn-junction LEDs, depending on the col
33、or of the LED. NOTE 2 In the case of constant forward current, the forward voltage almost linearly depends on the junction temperature. NOTE 3 In the case of LED ensembles without any access to individual anodes and cathodes, the forward voltage is an ensemble characteristic of such a device. NOTE 4
34、 Forward voltage is measured in volts V. goniophotometer: A photometer system used to measure the spatial distribution (directional distribution) of light sources, luminaries, etc. JEDEC Standard No. 51-53 Page 4 3 Terms and definitions (contd) integrating sphere: A hollow sphere whose internal surf
35、ace is a diffuse reflector that is as spectrally nonselective as possible. NOTE 1 Two principal uses are to geometrically sum the spatial total flux emitted by a radiator and to eliminate the spatial and polarization inhomogeneities of radiation at the input to optical instruments (such as detectors
36、). NOTE 2 An integrating sphere is also known as an Ulbrichts sphere. It is equipped with ports to mount optical instruments (e.g., a detector) and the DUT. junction: The operating portion of the active LED chip in a single-chip LED; practically it is a semiconductor pn-junction. junction temperatur
37、e (TJ): The temperature of the operating portion of the active LED chip, which is assumed to be a uniform, single value. NOTE 1 Its average value is considered to be an ensemble characteristic of an LED ensemble in which only single anode and cathode electrodes are provided to power the entire array
38、 of elementary LEDs. NOTE 2 Junction temperature is measured in degrees Celsius C. K factor; K-factor (K): The change in junction temperature divided by the change in a temperature-sensitive parameter (TSP) in the linear region of the TSP-temperature characteristic. NOTE 1 The temperature-sensitive
39、parameter (TSP) of semiconductor diodes is the forward voltage. K factor calibration: The measurement and data-reduction process that results in values of K factor for the semiconductor device under test. LED: See light-emitting diode LED ensemble: A multiple pn-junction single-chip device; a multic
40、hip single-package; or a single-assembly device. light: Electromagnetic radiation in the visible range of the optical spectrum, typically with a wavelength between 380 nm and 770 nm. NOTE See also IESNA RP 16-05. light-emitting diode (LED): A pn-junction semiconductor device emitting optical radiati
41、on in the visible range of wavelength; it is either a single pn-junction single-chip device or an LED ensemble used as a point-like single light source. NOTE As opposed to the definition of CIE 127:2007, the term is restricted to devices emitting visible light. JEDEC Standard No. 51-53 Page 5 3 Term
42、s and definitions (contd) luminous efficacy (of a source of light) (v): The total luminous flux emitted divided by the total lamp power input. NOTE 1 vis measured in lumens per watt lm/W. NOTE 2 See also CIE S 017/E:2011 ILV and IES RP-16-10 luminous flux (v): Synonym for total luminous flux. optica
43、l power (Popt): Synonym for total radiant flux. parameter stabilization: The operation of the DUT for a sufficient period of time such that the parameters to be tested are constant. photometer: An optical detector with a spectral responsivity matched to the V() visibility function of photopic vision
44、. radiant efficiency (e): The emitted radiant power of an LED divided by the electrical power supplied to the LED. NOTE Radiant efficiency is also known as energy conversion efficiency or wall-plug efficiency. radiant flux (e): Synonym for total radiant flux. radiant power (e): Synonym for total rad
45、iant flux. radiometer: An optical detector with a uniform spectral responsivity. standard LED: A seasoned, carefully selected, and stable LED whose current and temperature are stabilized in order to provide stable, repeatable light output and whose emitted flux values (radiant flux and luminous flux
46、) are known and provided as certified values. NOTE 1 A standard LED is used as a reference light-source standard for light-output measurements, NOTE 2 Standard LEDs are usually traceable to a standard of a national testing laboratory such as the National Institute of Science and Technology (NIST). s
47、tationary state: The state of an AC-driven LED in which its voltage, current, power, and junction temperature waveforms have stabilized their shape; i.e., the corresponding periodic time functions do not change. steady-state: Describing conditions that are constant and stable. temperature-sensitive
48、parameter (TSP): An electrical parameter of a semiconductor device that varies directly with junction temperature in a linear or very nearly linear fashion. JEDEC Standard No. 51-53 Page 6 3 Terms and definitions (contd) temperature sensitivity of forward voltage (SVF): The change of the forward vol
49、tage induced by a 1 C change of the junction temperature in a forced-forward-current mode of operation. NOTE 1 The temperature sensitivity of the forward voltage is the reciprocal of the K factor of pn-junctions. NOTE 2 If the device under test is an LED ensemble in which the multiple pn-junctions are connected in series and there is no individual electrical access to single pn-junctions, this quantity is an ensemble characteristic of the device. NOTE 3 The temperature sensitivity of forward voltage is measured in millivolts per kelvin mV/K or in millivolt
