1、 FIELD CORRELATED LIFE TEST SUPPLEMENT TO SAE/USCAR-2 The research data, analysis, conclusion, opinions and other contents of this document are solely the product of the authors. Neither the Society of Automotive Engineers, Inc. (SAE) nor the United States Council for Automotive Research (USCAR) cer
2、tifies the compliance of any products with the requirements of nor makes any representations as to the accuracy of the contents of this document nor to its applicability for purpose. It is the sole responsibility of the user of this document to determine whether or not it is applicable for their pur
3、poses. Copyright 2004, USCAR All rights reserved. Printed in U.S.A. Issued December 2001 Revised June 2004 SAE/USCAR-20 Revision 1QUESTIONS REGARDING THIS DOCUMENT: (724) 772-8518 FAX (724) 776-3036 TO PLACE A DOCUMENT ORDER: (724) 776-4970 FAX (724) 776-0790 SUMMARY OF CONTENTS 1. SCOPE. 22. OUTLIN
4、E 43. REFERENCED DOCUMENTS 44. SAMPLES 45. EQUIPMENT 46. PROCEDURE 57. TEST CONDITIONS 78. CALCULATIONS 109. ACCEPTANCE CRITERIA. 1010. REPORT 10SAE/USCAR-20 Revision 1 Revised June 2004 FIELD CORRELATED LIFE TEST SUPPLEMENT TO SAE/USCAR-2 - 2 - *WARNING*No electrical terminal may be represented as
5、having met this USCAR/EWCAP specification unless conformance to all applicable requirements of this document have been verified and documented. At least the minimum applicable sample size set forth in each test must have been tested with no sample in the entire group tested failing to meet all appli
6、cable Acceptance Criteria for that test. All required verification and documentation must be done by the supplier of the part or parts. If testing is performed by another source, it does not relieve the primary supplier of responsibility for documentation of all test results and for verification tha
7、t all samples tested met all applicable Acceptance Criteria. 1. SCOPE 1.1 This life test for underhood/passenger/trunk connector systems may be used in place of Section 5.9.6, Connection System Electrical Table of SAE/USCAR-2. All other requirements of SAE/USCAR-2 remain applicable even when this te
8、st is used. Refer to SAE/USCAR-2 and Connector/Terminal Supplier for appropriate power rating and current cycle Testing. 1.2 When this life test is used in place of para. 5.9.6 of USCAR-2, complete Para 5.6.1- Sequence N (Thermal Shock) of SAE/USCAR-2 in its entirety in order to demonstrate capabili
9、ty to withstand the 10-cycle service (mate/un-mate) requirement. 1.3 This test specification details the procedure for testing the performance of electrical connections to a test sequence (FCLT Field Correlated Life Test) that has been correlated to automotive vehicle conditions. The correlation app
10、lies to crimps and interfaces used in automotive applications and has been established with thousands of samples and millions of product and vehicle environmental measurements. The testing is performed with mated connector assemblies. In general, testing of connections at two base temperatures, 85C
11、and 125C, through two cycles of the FCLT has been shown to correlate to at least 150,000 miles (240,000 kilometers). See Reference Documentation section for questions regarding correlation issues. 1.4 This test shall be performed a minimum of two times using separate sample sets, once at a base temp
12、erature of 85oC and once at a base temperature of 125oC. The base temperature is the temperature to be used in the thermal aging conditioning steps and as the upper temperature in thermal shock conditioning steps. (Both temperatures must be tested regardless of intended USCAR temperature or sealing
13、class, except when 85C testing is waived per paragraph 1.4.1) 1.4.1 The 85C test is included in USCAR 20 because some crimps perform worse at 85C than at 125C. In those cases where it has been demonstrated that the phenomenon does not exist for that design type, 85C testing for similar design types
14、can be waived for future testing of other connector assembly combinations.SAE/USCAR-20 Revision 1 Revised June 2004 FIELD CORRELATED LIFE TEST SUPPLEMENT TO SAE/USCAR-2 - 3 - 1.4.2 Necessary conditions to waive 85C FCLT: 1. The crimp has passed USCAR 21 2. The reference test produces acceptable crim
15、p results. 3. It has been demonstrated that the 85C results are not worse than the 125C results (i.e. the phenomenon does not exist) for a given terminal design type (consider this as reference test). The crimp being waived is similar to the part in the reference test. 1.4.3 The Definition of a term
16、inal similar to the reference test is as follows: Similar terminal crimp is defined as having the same: 1. Terminal stock thickness 2. Material (alloy and temper) 3. The same terminal plating 4. The same terminal conductor wing dimensions (except core conductor cross sectional area related dimension
17、s) and features (serrations, etc.) 1.4.4 Evaluation of whether the phenomenon exists. 1. Consider candidates for reference tests those where the maximum value of the 85C and 125C tests are each 2 mohm. 2. Plot the Crimp Resistance Cumulative Distribution for the 85 C and 125C cycle 2 FCLT results. (
18、this can easily be done using the Excel Rank and Percentile function). Plot the distributions with the resistance values on the abscissa (x-axis) and cumulative percent on the ordinate (y-axis). 3. Add 0.5 mohm to each of the 125C test results and plot this distribution on the same graph as the resu
19、lts from step 2. This will shift the 125C distribution by 0.5 mohm. 4. If the 85C distribution lies completely to the left of the shifted 125C distribution, then the phenomenon (85 C worse than 125C) will be deemed to not exist. If the 85 C plot touches or crosses the 125C shifted plot, then this te
20、st cannot be used to rule out the phenomenon. Reference paragraph 3 “USCAR 20 -85C Crimp Test Reduction Proposal” for further detail.1.5 Modification to tests and conditioning procedures contained in this document may be made to accommodate special situations. However, no field correlation can be as
21、sociated to these modifications. Such modifications shall be fully documented in the test report. 1.6 This procedure is valid for USCAR/EWCAP classes 1, 2, and 3. Correlation has not been established for class 4. Although class 1and 2 terminals may not be designed for continuous use at 125oC, condit
22、ioning at higher temperatures as directed in this procedure is necessary to properly accelerate aging. SAE/USCAR-20 Revision 1 Revised June 2004 FIELD CORRELATED LIFE TEST SUPPLEMENT TO SAE/USCAR-2 - 4 - 2. OUTLINE 2.1 General Diagrams are provided where necessary to clarify the details of the vario
23、us test procedures. The tests in each section must be performed in the order given unless otherwise specified in the test request/order. 3. REFERENCED DOCUMENTS SAE/USCAR-2 Performance Standard for Automotive Electrical Connector Systems. Copies are available from SAE at www.sae.org or (724) 776-497
24、0. “Lab-Field Correlation Program for Automotive Electrical Connections”, Forty-Sixth IEEE Holm Conference on Electrical Contacts. “USCAR 20 -85C Crimp Test Reduction Proposal”, March 30, 2004 proposal documentation, available at www.uscar.org 4. SAMPLES 4.1 The minimum sample size is at least 30 te
25、rminal pairs and at least 4 connector assemblies per base temperature and connection type. This normally requires a minimum of 33 terminated leads for each gender and temperature to be tested. Three samples are used for deduct measurements of each gender. Deduct samples will not be subjected to any
26、conditioning.4.2 Make terminated lead samples a minimum of 150 mm in length (ref. Figure 1). 4.3 The requestor should identify samples completely by description, part number, date code (as applicable), and revision letter, when the test request is submitted. Individual samples should be uniquely ide
27、ntified in a fashion suitable to the environmental conditioning that they will experience. 5. EQUIPMENT 5.1 Dry Circuit Resistance - Dry circuit conditions require that the maximum voltage impressed across the test sample be limited to 20 millivolts and the maximum current through the sample be limi
28、ted to 100 milliamperes. Measure resistances with a Micro-ohmmeter capable of satisfying the dry circuit conditions specified. The micro-ohmmeter must limit the open circuit voltage to 20 mV, limit the current applied to 100 mA, and use either offset compensation or current reversal methods to measu
29、re resistance. The 4-wire (Kelvin) connection method shall be used. SAE/USCAR-20 Revision 1 Revised June 2004 FIELD CORRELATED LIFE TEST SUPPLEMENT TO SAE/USCAR-2 - 5 - 5.2 Thermal Aging - the test chamber shall be capable of maintaining the specified temperature within 3C throughout the area where
30、the components are placed. Air circulation and thermal capacity shall be sufficient to assure a uniform temperature. 5.3 Random Vibration - Vibration equipment shall consist of an Electrodynamic vibration test system, vibration control system, accelerometer and signal conditioner capable of operatin
31、g and recording at the vibration range specified in paragraph 7.1.2. Mated connector assemblies must be mounted on fixtures for vibration testing. The fixtures must conform to the requirements of section 7.1.2.1. 5.4 Thermal Shock - The thermal shock equipment shall be set up such that samples can b
32、e transferred between temperature extremes within 30 seconds. 5.5 Temperature - Humidity - Use an automatic temperature/humidity chamber capable of maintaining 95-98 percent relative humidity and -40C to +85C 3 C. Maximum transfer time between temperature extremes is 5 minutes.5.6 Visual Inspection
33、- Unless otherwise specified, no special devices are required. To assist documentation, photography of the samples may be employed. 6. PROCEDURE 6.1 Unless otherwise specified, make all dry circuit resistance measurements at 23 5C. All test chamber temperature tolerances are 3C and all time toleranc
34、es are 5 minutes. Unless otherwise specified all resistance measurements are dry circuit resistances. 6.2 Visually examine each test specimen prior to conditioning noting any apparent defects. Following conditioning, re-examine each test specimen noting any additional defects. Samples may be disasse
35、mbled after the last cycle measurement in order to measure crimp resistances. 6.3 To establish a resistance base line measurement, solder the stripped ends of the test and deduct sample cables at a point on the cable 150 3mm from the rear edge of the terminal core crimp. All stranded wire ends shoul
36、d be soldered. Solder the crimps on the deduct samples. Crimp + cable resistance or soldered sample deduct resistance is measured between the cable end and a point on the terminal just in front of the core crimp for each crimp (see Figure 1). 6.4 Measure and record the deduct resistance of the 3 sam
37、ples with soldered crimps for each crimp type. Appropriate similar measurements should be made for header type connectors in order to obtain pin bulk material deducts. (ref. SAE/USCAR-2, para 5.1.5 Testing Headers & Direct Connect Components) SAE/USCAR-20 Revision 1 Revised June 2004 FIELD CORRELATE
38、D LIFE TEST SUPPLEMENT TO SAE/USCAR-2 - 6 - 6.5 Measure and record the crimp + cable resistance of each test sample. The crimp resistance value will be determined from this measurement minus the average deduct of the corresponding terminal type. (optional but recommended, and required for those test
39、s used as reference tests to waive future 85C testing of similar crimp designs). 6.6 Assemble the terminated leads to the corresponding connectors and mate the connectors. 6.7 Measure and record the overall resistance between the cable ends for each male-female connection (see Figure 2). The crimp-i
40、nterface-crimp value is determined from this measurement minus the average deduct of the corresponding terminal types. 6.8 Subject the samples to the first cycle as defined below. Note: for vibration conditioning, the connectors need to be attached to the vibration fixture prior to vibration and rem
41、oved from the fixture after vibration. The fixture numbers should be recorded. 6.9 Measure and record the overall resistance at the end of each cycle. Measurements may also be taken at the end of each conditioning step, but are not required unless directed by the OEM. 6.10 If para. 6.11 is to be com
42、pleted, disconnect the connector assemblies and remove the terminals from the connectors. 6.11 Measure and record each crimp + cable resistance (optional but recommended - required for those tests used as reference tests to waive future 85C testing of similar crimp designs).SOLDERED ENDCRIMP + CABLE
43、 RESISTANCEFigure 1: Crimp + Cable Resistance SAE/USCAR-20 Revision 1 Revised June 2004 FIELD CORRELATED LIFE TEST SUPPLEMENT TO SAE/USCAR-2 - 7 - S O L D E R E D E N D S O L D E R E D E N DO V E R A L L R E S I S T A N C EFigure 2: Overall Resistance 7. TEST CONDITIONS 7.1 Cycle Steps 7.1.1 Step 1
44、Thermal Aging 72 hours at base temperature 7.1.2 Step 2 Random Vibration 12 hours (4 hours/plane) 3.2g rms 7.1.2.1 Vibration Fixtures Connectors shall be restrained in a fashion that limits connector movement during vibration. Connector restraint shall be used on only one of the connectors of the ma
45、ting assembly. The restraint should not limit movement in any direction allowed by design clearances or interfere with any locking mechanism.Connectors shall be firmly clamped around the connector body but not distorted.Wires shall be clamped at approximately 35 mm from the point where they exit the
46、 corresponding connector. The clamping mechanism shall hold the wires firmly but not damage the insulation. Wires shall dress straight out of the back of the connector or as determined by design features such as strain reliefs. Vibration fixtures should have an identifying number. 7.1.2.2Breakpoint
47、Frequency, hertz Spectral Density Magnitude, g2 /hertz 10 .070 20 .070 40 .020 350 .020 550 .005 700 .001 750 .0001 2000 .0001 Table 1: Vibration Profile RMS g level = 3.2 gs SAE/USCAR-20 Revision 1 Revised June 2004 FIELD CORRELATED LIFE TEST SUPPLEMENT TO SAE/USCAR-2 - 8 - 7.1.2.3 The maximum g le
48、vel shall be limited to 3 times the rms level. 7.1.2.4 Tolerance shall be 4.0 dB from the reference spectrum level for the test frequency band 10 to 2000 hertz. 7.1.2.5 Below 10 hertz and above 2000 hertz, the vibration spectrum shall roll-off at the maximum capability of the control system. 7.1.2.6
49、 Unless otherwise specified, the test specimens shall be subjected to 4 hours 5 minutes of the above test regimen in each of three mutually perpendicular planes. 7.1.2.7 Unless otherwise specified, vibration testing shall take place at an ambient temperature of 23 5C. 7.1.3 Step 3 Thermal Shock 72 hours, 72 cycles from -40C to base temperature, typically 30 minutes at each temperature. Maximum transfer time between chambers is 30 seconds.Figure 3: Thermal Shock Cycle 7.1.4 Step 4 Temperature Humidity 24 ho
