1、JEDEC PUBLICATION Characterization and Monitoring of Thermal Stress Test Oven Temperatures JEP153A (Revision of JEP153, January 2008) MARCH 2014 JEDEC SOLID STATE TECHNOLOGY ASSOCIATION NOTICE JEDEC standards and publications contain material that has been prepared, reviewed, and approved through th
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7、ndards and Documents for alternative contact information. Published by JEDEC Solid State Technology Association 2014 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 th
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9、te Technology Association 3103 North 10th Street Suite 240 South Arlington, VA 22201-2107 or refer to www.jedec.org under Standards-Documents/Copyright Information. JEDEC Publication No. 153A -i- CHARACTERIZATION AND MONITORING OF THERMAL STRESS TEST OVEN TEMPERATURES Contents Foreword ii Introducti
10、on ii 1 Scope 1 2 Terms and Definitions 1 3 References 2 4 Characterization Requirements 2 4.1 General requirements 2 4.2 Characterization Requirements for fixed temperature convection ovens including freezers 4 4.3 Characterization Requirements for temperature cycle chamber single and dual zone 6 4
11、.4 Requirements for temperature chambers with bias 7 4.5 Characterization Requirements for belt reflow systems 7 5 Monitoring Requirements 9 6 Summary / Reporting 9 Annex A Monitoring 10 Annex B Reference to other documents 11 Annex C Differences between revisions 12 JEDEC Publication No. 153A -ii-
12、CHARACTERIZATION AND MONITORING OF THERMAL STRESS TEST OVEN TEMPERATURES Foreword This document provides an industry standard method for characterization and monitoring thermal stress test oven temperatures. The procedures described in this document should be used to insure thermal stress test condi
13、tions are being achieved and maintained during various test procedures. Introduction JEDEC has a series of thermal stress tests and procedures that require specific temperatures be met and controlled within specified limits. The characterization and monitoring methods described in this test procedur
14、e should insure that the devices under test (DUT) achieve the correct temperatures and tolerances while being stressed within the specific thermal test oven or chamber. JEDEC Publication No. 153A Page 1 CHARACTERIZATION AND MONITORING OF THERMAL STRESS TEST OVEN TEMPERATURES (From JEDEC Board ballot
15、 JCB-13-67, formulated under the cognizance of the JC-14.1 Subcommittee on Reliability Test Methods for Packaged Devices.) 1 Scope This document specifies a uniform and reproducible method of confirming that temperature test chambers meet the requirements specified in thermal stress test procedures.
16、 This publication is intended for users when conducting one of the following procedures: monitoring (in situ and non in situ), characterization (e.g., for evaluation, release/acceptance and during development as well as for test set up). The document is applicable to the following type of equipment:
17、 temperature cycle chamber single zone, temperature cycle chamber dual zone, fixed convection oven with or without bias, fixed freezer, belt reflow ovens (used for preconditioning). Hot-plate systems and temperature-humidity chambers or HAST chambers are not covered by this document. Some remarks ma
18、y highlight the differences or challenges associated with these systems. 2 Terms and definitions characterization: A description of the characteristics of a product or process by mathematical modeling, design of experiments, or statistical data evaluation. NOTE Methods of statistical data evaluation
19、 are described in EIA557 and JEP132. convection oven: A controlled-temperature chamber in which the heat is transferred by air flow, rather than by conduction or radiation. NOTE The chamber must be capable of maintaining specified temperatures over the entire working area. fixed freezer: A controlle
20、d-temperature chamber capable of maintaining specified subfreezing temperatures over the entire working area. load map: A map of the positions where devices are placed for testing within the working area. NOTE See Figure 1 for an example. JEDEC Publication No. 153A Page 2 2 Terms and definitions (co
21、ntd) monitoring: Using a program for observing, and often controlling, a device or equipment. temperature profile: (1) A graphical portrayal of temperature experienced by an assembly as it passes through a soldering process. (2) A graphical portrayal of the spatial temperature distribution in an ove
22、n. working area: The portion of a chamber, used for stress testing, that meets the calibration requirements. 3 References IEC 60068-3-5, Environmental testing. Guidance. Confirmation of the performance of temperature chambers JEP140, Beaded Thermocouple Temperature Measurement of Semiconductor Packa
23、ges J-STD-020, JOINT IPC/JEDEC Standard For Moisture/Reflow Sensitivity Classification for Nonhermetic Solid State Surface-Mount Devices JESD47, Stress-Test-Driven Qualification of Integrated Circuits JESD22A104, Temperature Cycling JESD22A105; Power and Temperature Cycling JESD22A113, Preconditioni
24、ng of Plastic Surface Mount Devices Prior to Reliability Testing 4 Characterization requirements 4.1 General requirements When chambers are used, the following requirements are examples of best practice and should be used as guideline: a) specimens under test shall be located only within the working
25、 area (see Figure 1); b) the controls for the chamber shall be capable of maintaining the temperature of a reference point within 2C of the set point in an unloaded condition. This requirement does not apply for T/C chambers; c) permissible temperature variation in environmental chambers: temperatur
26、e on the test specimens within the working area must be maintained per the requirement of the stress test; d) the working space has to be defined depending on the requirements of the stress test; e) sensors have to be chosen according to the required resolution. JEDEC Publication No. 153A Page 3 4 C
27、haracterization requirements (contd) 4.1 General requirements (contd) Thermocouples can be reused, if desired, after profile development by removing them from the test parts. Verify the thermocouple operation and calibration status before reuse. For details on calibration see reference 1. ChamberWor
28、king areawithin chamberParts within working areaFigure 1 Parts within working area JEDEC Publication No. 153A Page 4 4.1 General requirements (contd) 4.1.1 Typical profile characterization procedure Heat the oven until the complete working area meets oven set-up parameters (e.g., target temperature)
29、. The procedure may require several trials of locating the DUTs until all devices can be brought to the required temperature. It should be taken into account that the thermal response of parts on the inner trays of a stack of trays could be slow. Especially for temperature cycle stress this could re
30、sult in too low Tmax values. Run oven using test load with thermocouples. Compare the actual data for each of the thermocouples to the profile requirements. If the data from all thermocouples meets all the profile requirements then record/store the oven set-up parameters along with the actual profil
31、e data and the characterization is complete. If the data from any of the thermocouples does not meet any of the profile requirements then the oven set-up parameters must be adjusted and the characterization repeated until all profile requirements are met. For positions of the sensors (thermo element
32、) see 4.2 4.5. Re-characterization is recommended a) in case of equipment changes affecting the process, b) after one year as part preventive maintenance, c) in case of deviations detected by monitoring, d) when new test sample configuration or load is changed from which has been characterized (char
33、acterization for test set up) unless, when applicable, the initial test set up covers the worst case of maximum thermal load allowed for the test oven. 4.2 Characterization requirements for fixed temperature convection ovens including freezers The specified test temperature is the ambient temperatur
34、e to which all devices in the working area of the chamber shall be exposed. The temperature range is based on the test methods tolerance requirements. This shall be assured by making whatever adjustments are necessary in the chamber profile, loading, location of control or monitoring instruments, an
35、d the flow of air or other suitable gas or liquid chamber medium. Therefore, characterization shall be accomplished in the chamber in a loaded condition as used (any characterization mode must be representative of chamber loading for the specific test), and in a non powered configuration. The charac
36、terization sensors located on the part or board within the working area (JEP140) has to represent the temperature range of the working area. A load map for the characterization must be generated upon completion. JEDEC Publication No. 153A Page 5 4.2 Characterization requirements for fixed temperatur
37、e convection ovens including freezers (contd) 4.2.1 Parameter to be measured is the temperature stability over time. The output of the temperature measuring system determine, after chamber stabilization, the achieved temperature, temperature fluctuation and temperature gradient of the working space.
38、 Uncertainty of measurement of the temperature measuring system should be evaluated. 4.2.2 Verification of test condition requirements Test temperatures: at test condition Loading condition: as under test for characterization of test set up, maximum thermal load allowed for equipment characterizatio
39、n. Test time: Start when test conditions have been verified with the load under the desired configuration. A reference point of the profile should be recorded regularly. Measurement period: follow equipment manual or manufacturers recommendation, if not specified recommendation is to start with 1/we
40、ek 4.2.3 Position thermo element (sensor) The positions of the sensors should be chosen depending on volume and size of the working area. The distribution should be chosen from one of the following options: a) Temperature measuring sensors are located on a test sample in each corner and in the cente
41、r of the working space (see Figure 2, minimum 9 sensors). b) For larger temperature chambers, additional sensors should be located across the test samples within the chamber including multiple shelf (e.g., additional sensors at the center of each wall of the working area). Dependent on chamber loadi
42、ng and set up, alternative positions for sensors may be needed to best characterize the load. JEDEC Publication No. 153A Page 6 4.2 Characterization requirements for fixed temperature convection ovens including freezers (contd) 4.2.3 Position thermo element (sensor) (contd) T6 T7T8T9T5T1 T2T3T4Chamb
43、erWorking area wit h in ch am b erThe thermocouples shall be attached to the center of the test parts according to JEP140. Figure 2 Positions thermo elements option A 4.3 Characterization Requirements for temperature cycle chamber single and dual zone Parameter to be measured in addition to the para
44、meters from 4.2: heat-up-rate from Tmin+10% to Tmax-10% 1)including linearity 2)for fast and slow ramp, cool-down-rate from Tmax-10% to Tmin+10% 1)including linearity 2)for fast and slow ramp. For equipment characterization the longest soak mode should be chosen. For test set up the soak mode chosen
45、 should be representative of the soak mode of the stress test to be performed. Stability at Tmin and Tmax. 1) Remark: rates should be measured in the recommended minimum linearity range between 10% and 90% of (Tmax Tmin) to avoid that non linearity and fluctuation at the boundary values disturb the
46、measurement results. See also JESD22A104 and A105. 2) Remark: Linearity is the goodness of fit in the recommended minimum linearity range between the 10% and the 90% value for a straight line. JEDEC Publication No. 153A Page 7 4.3 Characterization Requirements for temperature cycle chamber single an
47、d dual zone (contd) 4.3.1 Verification of test condition requirements Same as 4.2 4.3.2 Position thermo element (sensor) Same as 4.2 4.4 Requirements for temperature chambers with bias For steady state temperature bias chambers the regulations of clause 4.1 and 4.2 apply. Before each test the influe
48、nce of the device under test on the temperature has to be characterized because heat dissipation can have major influence on the chamber temperature. In some cases the chamber has to cool the device to reach the planned stress temperature. To adjust the chamber temperature to the intended junction t
49、emperature the following equation could be used: Tj= Tchamber+ P Rj with Tj: junction temperature of the device (C) P power dissipation (Watt) Rj thermal resistance of the device For temperature cycling with bias the regulation of clause 4.3 applies. 4.5 Characterization Requirements for belt reflow systems Belt reflow systems, typically used during Moisture Sensitivity Level testing and preconditioning, simulate the high temperature solder reflows that surface mount devices are exposed to during board assembly. MSL testing according to test spe
