1、_ SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising there
2、from, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions. Copyright 2013 SAE International All rights reserved. No part of this p
3、ublication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-497
4、0 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/J3014_201303 SURFACE VEHICLE RECOMMENDED PRACTICE J3014 MAR2013 Issued 2013-03 Hi
5、ghly Accelerated Failure Test (HAFT) for Automotive Lamps with LED Assembly RATIONALE Highly accelerated failure test (HAFT), or sometimes referred as accelerated life test (ALT) or highly accelerated life test (HALT) has been an industrys practice for long period time, both in automotive lighting a
6、s well as in general lighting applications. The purpose of HALT is to identify defined failures that may relate to the “weakest link“, quality or design faults, or claimed life of the products. With fast growth of LED sources being used in the lighting applications, the lumen maintenance alone may n
7、ot be the measure of reliability. Other types of failures, within the LED lamp assembly, must be identified as a quality or reliability concern. HAFT is intended to identify LED lamp assembly failure modes; the test results do not and should not be used to predict operational life of the product. Fo
8、r practical reasons, the HAFT should be completed within a one-day period. With all possible impact from environment and usage in automotive applications, it is identified based on the known best practice in the industry that three major stressors can be used to induce earlier failures. These stress
9、ors are temperature, vibration, and input voltage to LED source assembly. This test is used to realize the operating and destructive limits of a product, when subjected to thermal, electrical and vibration loads. Humidity is not considered as an independent stressor because it is a function of tempe
10、rature and the formation of condensation naturally occurs as temperatures are lowered. Controlling humidity requires air exchange and conditioning. Controlling humidity during temperature changes is slow and mechanically challenging. During rapid thermal transitions it is not possible to control hum
11、idity. The HAFT test will produce rapid uncontrolled humidity swings as temperature changes and will be a stressor on the DUT, but it will not be specified as a variable in the test. The analysis of the test results may also help recognize variations and uncover factors that may affect the intended
12、performance. The sequences or combinations of applied stressors to the DUT are recommended based on the current practices. SAE J3014 Issued MAR2013 Page 2 of 7 TABLE OF CONTENTS 1. SCOPE 2 2. REFERENCES 2 2.1 Applicable Documents 2 2.2 Related Documents . 3 3. DEFINITIONS . 3 4. MARKINGS . 4 5. TEST
13、S . 4 5.1 Test Equipment . 4 5.2 Sample Size 4 5.3 Test Fixture . 4 5.4 Test Procedure 4 6. COMMON FAILURE MODES AND RECOMMENDATIONS 5 6.1 General Overview 5 6.2 Procedure for Addressing Common Failure Modes 6 6.3 Analysis . 6 7. NOTES 6 7.1 Marginal Indicia . 6 FIGURE 1 HAFT PROFILE 7 TABLE 1 POWER
14、 CYCLE 5 1. SCOPE This SAE Recommended Practice provides test procedures, requirements, and equipment recommendations for the methods of the measurement that characterizes potential design failures by utilizing a step stress approach to subject a device under test to thermal, vibration, and electric
15、al stresses of types and levels beyond what it may see in actual use, but which will rapidly induce failure modes, allowing them to be detected and corrected. 2. REFERENCES 2.1 Applicable Documents The following publications form a part of this specification to the extent specified herein. Unless ot
16、herwise indicated, the latest issue of SAE publications shall apply. 2.1.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. SAE J387 Terminology - Motor Vehicle
17、Lighting SAE J575 Test Methods and Equipment for Lighting Devices and Components for Use on Vehicles Less Than 2032 mm in Overall Width SAE J3014 Issued MAR2013 Page 3 of 7 2.1.2 Other Publications Available at Qualmark, 10390 East 48th Avenue, Denver, CO 80238, http:/ HALT Testing Guidelines, Docum
18、ent 933-0336_04_Qualmark-HALT-Testing-Guideline.pdf HALT and HASS in IPC 9592A 2.2 Related Documents The following publications are provided for information purposes only and are not a required part of this SAE Technical Report. 2.2.1 SAE Publications Available from SAE International, 400 Commonweal
19、th Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. SAE J2357 Application Guidelines for Electronically Driven and/or Controlled Exterior Automotive Lighting Equipment 3. DEFINITIONS 3.1 OPERATING LIMITS Product ceases to operate
20、 as intended when subjected to the stressor load, but resumes operating when the stressor load is removed. 3.2 DESTRUCTIVE LIMITS Product ceases to operate as intended even after the stressor load is removed. 3.3 DUT An acronym for “device under test”. 3.4 LED ASSEMBLY A lighting functional componen
21、t consisting of LED(s), drive and control circuit components, printed circuit board (PCB, if applicable), and interconnects to the circuit. 3.5 HALT An acronym for “highly accelerated life test” 3.6 ALT An acronym for “accelerated life test” 3.7 HAFT An acronym for “highly accelerated failure test”
22、SAE J3014 Issued MAR2013 Page 4 of 7 4. MARKINGS There is no marking requirement for the device(s) under test. However, it is recommended that each DUT be individually marked and tracked throughout the tests. 5. TESTS 5.1 Test Equipment It is recommended to conduct HAFT in the combined environmental
23、 chamber with the following specifications. 5.1.1 Thermal Capability Operating between -100 to +200 C with a ramp rate of greater or equal to 40 C per minute. 5.1.2 Vibration Capability Omni-axial (6 degrees of freedom) repetitive shock system with 50 Grmscapability between 2 and 2000 Hz frequency.
24、5.1.3 Power Supply It is programmable with capability of providing a minimum of 0 24 VDC. It is equipped with the monitoring system capable of determining the proper current draw and operation of the DUT, if applicable. 5.1.4 Photometry The equipment does not need to have photometric test capability
25、. The light output of DUT is visually monitored. 5.2 Sample Size It is recommended that minimum of 3 pieces of DUTs be used in the HAFT. It is recommended that the DUTs are tested sequentially. 5.3 Test Fixture The fixture for vibration test specified in SAE J575 shall be used. 5.4 Test Procedure Th
26、e DUT mounted on a test fixture shall be securely fastened to the vibration table and subjected to the HAFT profile shown in Figure 1. If any failure occurs refer to Section 6. 5.4.1 Power Cycle The DUT shall be powered with the sequence shown in Table 1. Each power cycle is 10 minutes. Monitor curr
27、ent to detect abnormal behavior of the DUT. If outage signal or other output is available from the DUT, monitor the signal for abnormal behavior. If the DUT has two levels driven with Pulse Width Modulation (PWM) for two lamp functional applications, alternate between high output drive mode (e.g., s
28、top function) for 1 power cycle (10 min) and low output drive mode (e.g., tail function) for 1 power cycle (10 min), continuously. SAE J3014 Issued MAR2013 Page 5 of 7 TABLE 1 - POWER CYCLE Nominal Voltage (e.g., 13.5V) Minimum Voltage (e.g., 9.0V) Nominal Voltage (e.g., 13.5V) Maximum Voltage (e.g.
29、, 16.0V) DUT OFF 2 min 2 min 2 min 2 min 2 min 5.4.2 Temperature Cycle Simultaneous with the power cycle, perform temperature operational cycle shown in Figure 1. The thermal cycle shall start from room temperature. Then it is reduced to the lower limit Tminas quickly as possible (see Section 5.1.1)
30、. The DUTs remain at the lower limit for 10 minutes. Then the temperature is raised to the upper limit Tmax. The recommended lower and upper limits are: Tmin= -40 C, Tmax= 85 C or specified by the test requester (reference to SAE J2357). Recommended temperature dwell in the transitions between lower
31、 and upper limit is 10 minutes. After completion of 6 temperature cycles (60 minutes duration), the temperature shall be maintained at room temperature for the duration of vibration cycle (50 minutes). 5.4.3 Vibration Cycle Following the completion of temperature cycle, perform vibration step stress
32、 to cycle DUTs in vibration steps at ambient temperature up to 50 Grms. Recommended vibration steps are 10 Grmswith a dwell of 10 minutes shown in Figure 1. The duration of vibration cycle is 50 minutes. 5.4.4 Combination of Temperature and Vibration Cycle Following the completion of the vibration c
33、ycle, perform combined temperature and vibration cycle while sequencing power cycle of the DUT for duration of 100 minutes (Figure 1). 5.4.5 Combination of Temperature and Vibration Cycle with Sever Power Level Changes If no anomalies occur during the test described in Section 5.4.4, continue temper
34、ature cycle with vibration at 50 Grms(Figure 1) while operating the DUT for 2 power cycles (20 minutes). Then increase maximum voltage by 2 V, decreasing the minimum voltage by 2 V for 1 power cycle (10 minutes), then repeat the same increment of maximum voltage increase and minimum voltage decrease
35、 for 2 power cycles (20 minutes). If still no anomalies occur during the test, increase Tmaxto Tmax+g39T, and increase the voltage to 24 V and continue the test until failure occurs, where ;#23#23#23g39T = specified by the test requester. If PWM circuit is used within DUT, only operate in high outpu
36、t drive mode for the test in this Section. 6. COMMON FAILURE MODES AND RECOMMENDATIONS 6.1 General Overview HAFT is used to realize the operating and destructive limits of a component or system, when subjected to thermal, electrical and vibration stressors. The analysis of the test results may also
37、help recognize variations and uncover factors that may affect the intended performance. Consequently, HAFT does not have a PASS/FAIL criteria; conclusion of testing corresponds to the limits defined in Section 5. At the discretion of the operator, the test sequence may be halted momentarily for insp
38、ection of the DUT. SAE J3014 Issued MAR2013 Page 6 of 7 6.2 Procedure for Addressing Common Failure Modes 6.2.1 Broken Attachments Suspend test, re-attach by alternate method and continue test. 6.2.2 Loose Circuit Boards or Internal Components Note failure(s), continue test. 6.2.3 LED Illumination I
39、ntermittent changes, note failure(s), continue test. If visible variation of LED light output occurs, then stop test of failed DUT, replace with new DUT and continue test. 6.2.4 Thermal Shut-Down Either at high temperature or high voltage, note failure, continue test. 6.2.5 Non Operation at Voltage
40、Extreme Note failure(s), if recoverable, continue test. 6.2.6 Current Changes Radically Note change, continue test. 6.2.7 Catastrophic Failure Suspend test of failed DUT, replace with new DUT and continue test. 6.2.8 Non-LED light source failure Note failure, continue test. 6.3 Analysis Engineering
41、judgment should be used on all other failures. If DUT can recover from the failure, continue with testing. 7. NOTES 7.1 Marginal Indicia A change bar (l) located in the left margin is for the convenience of the user in locating areas where technical revisions, not editorial changes, have been made t
42、o the previous issue of this document. An (R) symbol to the left of the document title indicates a complete revision of the document, including technical revisions. Change bars and (R) are not used in original publications, nor in documents that contain editorial changes only. SAE J3014 Issued MAR20
43、13 Page 7 of 7 -80-60-40-200204060801001200 20 40 60 80 100 120 140 160 180 200 220 240Time (minutes)Temperature & Vibration (oC, Grms)0102030405060708090100Voltage (volts)Voltage Temperature VibrationFIGURE 1 HAFT PROFILE PREPARED BY THE SAE TEST METHODS AND EQUIPMENT SUBCOMMITTEE OF THE SAE LIGHTING TECHNICAL COMMITTEE
