JESD22-A102-C - Accelerated Moisture Resistance - Unbiased Autoclave...

JESD22-A102-C - Accelerated Moisture Resistance - Unbiased Autoclave... ??ÎÄÓÉÐ?ÓêËë??Ï× pdfÎĵµ?ÉÄÜÔÚWAP?Ëä?ÀÀÌåÑé???Ñ????ÒéÄúÓÅÏÈÑ?ÔñTXT???òÏÂÔØÔ?ÎÄ?þµ????ú?é???? JEDEC STANDARD Accelerated Moisture Resistance Unbiased Autoclave JESD22-A102-C (Revision of JESD22-A102-B) DECEMBER 2000 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 reviewed and approved by the EIA General Counsel. JEDEC standards and publications are designed to serve the public interest through eliminating misunderstandings between manufacturers and purchasers, facilitating interchangeability and improvement of products, and assisting the purchaser in selecting and obtaining with minimum delay the proper product for use by those other than JEDEC members, whether the standard is to be used either domestically or internationally. 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Inquiries, comments, and suggestions relative to the content of this JEDEC standard or publication should be addressed to JEDEC Solid State Technology Association, 2500 Wilson Boulevard, Arlington, VA 22201-3834, (703)907-7560/7559 or www.jedec.org Published by JEDEC Solid State Technology Association 2000 2500 Wilson Boulevard Arlington, VA 22201-3834 This document may be downloaded free of charge, however EIA retains the copyright on this material. By downloading this file the individual agrees not to charge for or resell the resulting material. PRICE: Please refer to the current Catalog of JEDEC Engineering Standards and Publications or call Global Engineering Documents, USA and Canada (1-800-854-7179), International (303-397-7956) Printed in the U.S.A. All rights reserved PLEASE! DON??T VIOLATE THE LAW! This document is copyrighted by the Electronic Industries Alliance and may not be reproduced without permission. Organizations may obtain permission to reproduce a limited number of copies through entering into a license agreement. For information, contact: JEDEC Solid State Technology Association 2500 Wilson Boulevard Arlington, Virginia 22201-3834 or call (703) 907-7559 JEDEC Standard No. 22-A102-C Page 1 ACCELERATED MOISTURE RESISTANCE - UNBIASED AUTOCLAVE (From JEDEC Board Ballot JCB-00-55, formulated under the cognizance of the JC-14.1 Subcommittee on Reliability Test Methods for Packaged Devices.) 1 Purpose The " Unbiased Autoclave Test" is performed to evaluate the moisture resistance integrity of nonhermetic packaged solid state devices using moisture condensing or moisture saturated steam environments. It is a highly accelerated test which employs conditions of pressure, humidity and temperature under condensing conditions to accelerate moisture penetration through the external protective material (encapsulant or seal) or along the interface between the external protective material and the metallic conductors passing through it. This test is used to identify failure mechanisms internal to the package and is destructive. 2 Scope This test method applies primarily to moisture resistance evaluations and robustness testing. Samples are subjected to a condensing, highly humid atmosphere under pressure to force moisture into the package to uncover weaknesses such as delamination and metallization corrosion. This test is used to evaluate new packages or packages that have undergone changes in materials (e.g. mold compound, die passivation) or design (e.g. die/paddle sizes). However, this test should not be applied on laminate or tape based packages i.e. FR4 material, polyimide tape or equivalent. Some cautions should be considered when performing this test and evaluating test results. Failure mechanisms, both internal (e.g., due to plastic package swelling from saturation) and external (e.g. dendritic growth of conducting material between leads), may be produced which are not applicable to the intended application use conditions. Most semiconductor components are not rated for field applications conditions exceeding 95% RH, including condensing moisture such as rain or fog. The combination of high humidity, high temperature (>Tg) and high pressure may produce unrealistic material failures because absorbed moisture typically decreases the glass transition temperature for most polymeric materials. Extrapolation of autoclave test results to arrive at an application life should be accomplished with care. 3 Apparatus The test requires a pressure chamber capable of maintaining a specified temperature, and relative humidity. 3.1 Records A permanent record of the temperature profile for each test cycle is recommended, so the stress conditions can be verified. Test Method A102-C (Revision of Test Method A102-B) JEDEC Standard No. 22-A102-C Page 2 3 Apparatus (cont'd) 3.2 Devices under stress Devices under stress shall be no closer than 3 cm from the internal chamber surface, and must not be subjected to direct radiant heat. 3.3 Ionic contamination Ionic contamination of the test apparatus and storage chamber shall be controlled to avoid test artifacts. 3.4 Distilled or deionized water Distilled or deionized water with a minimum resistivity of 1 megaohm-cm at room temperature shall be used. 4 Test conditions Test conditions consist of a temperature, relative humidity, vapor pressure and duration. Table 1 ?ª Temperature, relative humidity and pressure2,3 Temperature1 Vapor pressure Relative 1 (psia/kPa) (dry bulb ?ãC) humidity (%) 100% 29.7/205 121 ?À 2 NOTES 1 Tolerances apply to the entire usable test area. 2 The test conditions are to be applied continuously except during any interim readouts. For interim readouts, devices should be returned to stress within the time specified in 5.2 3 Previous revisions of this document specified the following test conditions: Condition A B C D E F Duration 24 hours (-0,+2) 48 hours (-0, +2) 96 hours (-0, +5) 168 hours (-0, +5) 240 hours (-0, +8) 336 hours (-0, +8). The stress duration is specified by internal qualification requirements, JESD47 or the applicable procurement document. 96 hours duration is typical for this test. Test Method A102-C (Revision of Test Method A102-B) JEDEC Standard No. 22-A102-C Page 3 4 Test conditions (cont??d) CAUTION: For plastic-encapsulated microcircuits, it is known that moisture reduces the effective glass transition temperature of the molding compound. Stress temperatures above the effective glass transition temperature may lead to failure mechanisms unrelated to operational use. 5 Procedure The test devices shall be mounted in a manner which exposes them to the specified temperature and humidity conditions. Exposure of devices to ambient environments greater than 100 oC and less than 10% R.H. shall be avoided, particularly during stress ramp-up, ramp-down and the pre-readout drying period. Care should be taken through equipment control or cool down procedures to prevent destructive depressurization of the parts under test. Frequent cleaning of the test chamber is necessary to ensure elimination of contamination. 5.1 Test clock The test clock starts when the temperature and relative humidity reach the set points specified in clause 4.0 and stops at the beginning of ramp-down. 5.2 Readout Electrical test shall be performed not sooner than 2 hours and not later than 48 hours after the end of ramp-down with room temperature testing done first in the sequence of testing. Note: For intermediate readouts, devices shall be returned to stress within 96 hours of the end of ramp-down. The rate of moisture loss from devices after removal from the chamber can be reduced by placing the devices in sealed moisture barrier bags, the bags should be non-vacuum sealed without a N2 purge and without dessicant. When devices are placed in sealed bags, the "test window clock" runs at 1/3 of the rate of devices exposed to the laboratory ambient. Thus the test window can be extended to as much as 144 hours, and the time to return to stress to as much as 288 hours by enclosing the devices in sealed moisture barrier bags. Devices that exceed the test window clock or extension shall be removed from test and shall have new samples submitted for testing. Condensed moisture on the exterior surface of the device package may be removed through contact with an absorbing medium or isopropyl alcohol. Because the purpose of this test is to identify failure mechanisms internal to the package, cleaning of the packaged device or leads is permitted, providing it doesn??t induce anomalous failures or obscure valid failures. 5.3 Handling Hand-coverings which eliminate any source of ancillary contamination or ESD damage shall be used to handle devices and test fixtures. Contamination control is important in the application of this test method and any highly-accelerated moisture stress test. Test Method A102-C (Revision of Test Method A102-B) JEDEC Standard No. 22-A102-C Page 4 6 Failure criteria A device under accelerated moisture resistance shall be defined a failure if its parametric limits are exceeded, or its functionality cannot be demonstrated under nominal and worst-case conditions as specified in the applicable procurement document or data sheet. Electrical failures due to external package damage which are an artifact of the test method shall be excluded from the failure classification. 7 Safety Follow equipment manufacturer's recommendation and local safety regulations. 8 Summary The following details shall be specified in the applicable procurement document: (a) (b) Test duration. Measurements after test. Test Method A102-C (Revision of Test Method A102-B) ??TXTÓÉ??ÎÄ?â????ÏÂÔØ: