{"id":417624,"date":"2024-10-20T06:16:56","date_gmt":"2024-10-20T06:16:56","guid":{"rendered":"https:\/\/pdfstandards.shop\/product\/uncategorized\/bsi-pd-iec-tr-628662014-2\/"},"modified":"2024-10-26T11:42:09","modified_gmt":"2024-10-26T11:42:09","slug":"bsi-pd-iec-tr-628662014-2","status":"publish","type":"product","link":"https:\/\/pdfstandards.shop\/product\/publishers\/bsi\/bsi-pd-iec-tr-628662014-2\/","title":{"rendered":"BSI PD IEC\/TR 62866:2014"},"content":{"rendered":"
This Technical Report describes the history of the degradation of printed wiring boards caused by electrochemical migration, the measurement method, observation of the failure and remarks to testing in detail.<\/p>\n
PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
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4<\/td>\n | English CONTENTS <\/td>\n<\/tr>\n | ||||||
9<\/td>\n | FOREWORD <\/td>\n<\/tr>\n | ||||||
11<\/td>\n | INTRODUCTION <\/td>\n<\/tr>\n | ||||||
12<\/td>\n | 1 Scope 2 Electrochemical migration 2.1 Operation failure of electronic and electric equipment Figures Figure 1 \u2013 Main causes of insulation degradation in electronic equipment <\/td>\n<\/tr>\n | ||||||
13<\/td>\n | 2.2 Name change of migration causing insulation degradation and nature of the degradation 2.2.1 History of naming with migration causing insulation degradation 2.2.2 Process of degradation by migration 2.3 Generation patterns of migration <\/td>\n<\/tr>\n | ||||||
14<\/td>\n | Figure 2 \u2013 Generation patterns of migration <\/td>\n<\/tr>\n | ||||||
15<\/td>\n | 3 Test conditions and specimens 3.1 Typical test methods Tables Table 1 \u2013 Standards for migration tests <\/td>\n<\/tr>\n | ||||||
16<\/td>\n | 3.2 Specimens in migration tests 3.2.1 Design of test specimens Figure 3 \u2013 Basic comb pattern <\/td>\n<\/tr>\n | ||||||
17<\/td>\n | Figure 4 \u2013 Comb type fine pattern Table 2 \u2013 Standard comb type pattern (based on IPC-SM-840) Table 3 \u2013 Comb fine pattern (based on JPCA BU 01) <\/td>\n<\/tr>\n | ||||||
18<\/td>\n | Figure 5 \u2013 ECM group comb type pattern (mm) Figure 6 \u2013 Comb pattern for insulation resistance of flexible printed wiring board <\/td>\n<\/tr>\n | ||||||
19<\/td>\n | Figure 7 \u2013 Insulation evaluation pattern for through-holes and via holes <\/td>\n<\/tr>\n | ||||||
20<\/td>\n | Figure 8 \u2013 Details of the insulation evaluation pattern of Figure 7 (cross section of 4 and 5) Figure 9 \u2013 Test pattern of the migration study group Table 4 \u2013 Dimension of insulation evaluation pattern for through-holes <\/td>\n<\/tr>\n | ||||||
21<\/td>\n | 3.2.2 Specifications and selection of specimen materials <\/td>\n<\/tr>\n | ||||||
22<\/td>\n | 3.2.3 Remarks on the preparation of specimens 3.2.4 Storing of specimens 3.2.5 Pretreatment of the specimen (baking and cleaning) <\/td>\n<\/tr>\n | ||||||
23<\/td>\n | 3.2.6 Care to be taken in handling specimens 3.3 Number of specimens required in a test 3.3.1 Specifications given in JPCA ET 01 Table 5 \u2013 Surface pretreatment to printed wiring board <\/td>\n<\/tr>\n | ||||||
24<\/td>\n | 3.3.2 Number of specimens in a test 3.3.3 Number of specimens for the different evaluation purposes of a test Table 6 \u2013 Number of specimens (JPCA ET 01) Table 7 \u2013 Approximate number of specimens required depending on the purpose of the test <\/td>\n<\/tr>\n | ||||||
25<\/td>\n | 4 Test methods 4.1 General 4.2 Steady state temperature and humidity test and temperature-humidity cyclic test 4.2.1 Purpose and outline of the test <\/td>\n<\/tr>\n | ||||||
26<\/td>\n | 4.2.2 Test profile Figure 10 \u2013 Recommended profiles of increasing temperature and humidity <\/td>\n<\/tr>\n | ||||||
27<\/td>\n | Figure 11 \u2013 Humidity cyclic profile (12 h + 12 h) <\/td>\n<\/tr>\n | ||||||
28<\/td>\n | Figure 12 \u2013 Profiles of combined temperature-humidity cyclic test <\/td>\n<\/tr>\n | ||||||
29<\/td>\n | 4.2.3 Test equipment Figure 13 \u2013 Structure of steady state temperature-humidity test equipment <\/td>\n<\/tr>\n | ||||||
30<\/td>\n | 4.2.4 Remarks on testing <\/td>\n<\/tr>\n | ||||||
31<\/td>\n | Figure 14 \u2013 Specimen arrangement and air flow in test chamber Table 8 \u2013 Ionic impurity concentration of wick (10\u20136) <\/td>\n<\/tr>\n | ||||||
32<\/td>\n | 4.3 Unsaturated pressurized vapour test or HAST (highly accelerated temperature and humidity stress test) 4.3.1 Purpose and outline of the test Figure 15 \u2013 Effective space in a test chamber <\/td>\n<\/tr>\n | ||||||
33<\/td>\n | 4.3.2 Temperature-humidity-pressure profile Figure 16 \u2013 HAST profile <\/td>\n<\/tr>\n | ||||||
34<\/td>\n | 4.3.3 Structure of and remarks on the test equipment Figure 17 \u2013 Two types of HAST equipment and their structures <\/td>\n<\/tr>\n | ||||||
35<\/td>\n | Figure 18 \u2013 Difference in failure time among different test laboratories <\/td>\n<\/tr>\n | ||||||
36<\/td>\n | 4.3.4 Remarks on performing HAST Figure 19 \u2013 Colour difference of specimen surface among different laboratories (130\u00a0\u00b0C\/85\u00a0%RH\/DC 50\u00a0V) Table 9 \u2013 Insulation covering materials for cables for voltage application <\/td>\n<\/tr>\n | ||||||
37<\/td>\n | Figure 20 \u2013 Resistance and pull-strength of cables used in HAST (130\u00a0\u00b0C 85\u00a0%RH) <\/td>\n<\/tr>\n | ||||||
38<\/td>\n | 4.4 Saturated and pressurized vapour test 4.4.1 Purpose and outline of the test 4.4.2 Test profile 4.4.3 Remarks on test performing <\/td>\n<\/tr>\n | ||||||
39<\/td>\n | 4.5 Dew cyclic test 4.5.1 Purpose and outline of the test 4.5.2 Dew cycle test temperature-humidity profile Figure 21 \u2013Difference between unsaturated and saturation control of PCT equipment (relative humidity and average failure time) <\/td>\n<\/tr>\n | ||||||
40<\/td>\n | 4.5.3 Structure of the test equipment 4.5.4 Remarks on the test method Figure 22 \u2013 Temperature-humidity profile of dew cycle test Table 10 \u2013 Dew cycle test condition <\/td>\n<\/tr>\n | ||||||
41<\/td>\n | Figure 23 \u2013 Structure of dew test equipment <\/td>\n<\/tr>\n | ||||||
42<\/td>\n | Figure 24 \u2013 Dew-forming temperature and dew size <\/td>\n<\/tr>\n | ||||||
43<\/td>\n | 4.5.5 An example of migration in the solder flux from the dew cycle test Figure 25 \u2013 Board surface at the best dew formation condition Table 11 \u2013 Dew formation condition and dew size Table 12 \u2013 Dew cycle test condition <\/td>\n<\/tr>\n | ||||||
44<\/td>\n | Figure 26 \u2013 Surface state before test Figure 27 \u2013 Surface state after 27 h Figure 28 \u2013 SEM image of specimen surface after the test <\/td>\n<\/tr>\n | ||||||
45<\/td>\n | 4.6 Simplified ion migration tests 4.6.1 General 4.6.2 De-ionized water drop method Figure 29 \u2013 Element analysis of the surface after the test <\/td>\n<\/tr>\n | ||||||
46<\/td>\n | Figure 30 \u2013 Circuit diagram of water drop test Figure 31 \u2013 Migration generated in the water drop test <\/td>\n<\/tr>\n | ||||||
47<\/td>\n | 4.6.3 Diluted solution method Figure 32 \u2013 Electroerosion test method using the diluted solution <\/td>\n<\/tr>\n | ||||||
48<\/td>\n | 4.7 Items to be noted in migration tests Figure 33 \u2013 Current and concentration of electrolytic solution Figure 34 \u2013 Precipitation on a specimen and its element analysis <\/td>\n<\/tr>\n | ||||||
49<\/td>\n | Table 13 \u2013 Water quality for test Table 14 \u2013 Water quality change in steady-state temperature-humidity test (10\u20136) <\/td>\n<\/tr>\n | ||||||
50<\/td>\n | Table 15 \u2013 Ionic impurities in voltage applying cables (10\u20136) <\/td>\n<\/tr>\n | ||||||
51<\/td>\n | 5 Electrical tests 5.1 Insulation resistance measurement 5.1.1 Standards of insulation resistance measurement 5.1.2 Measurement method of insulation resistance Table 16 \u2013 Standards of insulation resistance measurement <\/td>\n<\/tr>\n | ||||||
52<\/td>\n | Figure 35 \u2013 An example of insulation resistance measurement outside of the chamber <\/td>\n<\/tr>\n | ||||||
53<\/td>\n | Figure 36 \u2013 Circuit diagram of insulation resistance measurement <\/td>\n<\/tr>\n | ||||||
54<\/td>\n | 5.1.3 Special remarks on insulation resistance measurement Figure 37 \u2013 Examples of leakage current characteristics <\/td>\n<\/tr>\n | ||||||
55<\/td>\n | Figure 38 \u2013 Relationship insulation resistance with charging time of capacitor mounted boards Figure 39 \u2013 Comparison of insulation resistance measurement inside and outside a test chamber <\/td>\n<\/tr>\n | ||||||
56<\/td>\n | Figure 40 \u2013 Relative humidity and insulation resistance <\/td>\n<\/tr>\n | ||||||
57<\/td>\n | 5.2 Measurement of dielectric characteristics 5.2.1 General 5.2.2 Dielectric characteristics of board surface Figure 41 \u2013 Effect of interruption of measurement on insulation resistance (variation of insulation resistance with the time left in atmospheric environment) <\/td>\n<\/tr>\n | ||||||
58<\/td>\n | 5.2.3 Migration and dielectric characteristics of the printed wiring board surface <\/td>\n<\/tr>\n | ||||||
59<\/td>\n | Figure 42 \u2013 Frequency response of dielectric characteristics of printed wiring board Figure 43 \u2013 Temperature response of dielectric characteristics of printed wiring board <\/td>\n<\/tr>\n | ||||||
60<\/td>\n | Figure 44 \u2013 Changes of static capacitance and tan \u03b4 \nof a specimen through a deterioration test <\/td>\n<\/tr>\n | ||||||
61<\/td>\n | 5.2.4 Evaluation of migration by AC impedance measurement Figure 45 \u2013 Test procedure of a dielectric characteristics test Figure 46 \u2013 Comparison of dielectric characteristics of two types of flux <\/td>\n<\/tr>\n | ||||||
62<\/td>\n | 6 Evaluation of failures and analysis 6.1 Criteria for failures Figure 47 \u2013 Measurement principle of EIS (Electrical Insulation System) Figure 48 \u2013 Gold (Au) plating, non-cleaning <\/td>\n<\/tr>\n | ||||||
63<\/td>\n | 6.2 Data analysis 6.2.1 Analysis of experimental data Figure 49 \u2013 Bath tub curve Table 17 \u2013 Criteria of migration failure by insulation resistance <\/td>\n<\/tr>\n | ||||||
65<\/td>\n | 6.2.2 Relationship of the parameters in the experimental data and an example of the analysis <\/td>\n<\/tr>\n | ||||||
66<\/td>\n | 6.2.3 Electric field strength distribution Figure 50 \u2013 Relation between the variation of insulation resistanceand the weight changes by water absorption <\/td>\n<\/tr>\n | ||||||
67<\/td>\n | 6.3 Analysis of specimen with a failure, methods of analysis and case study 6.3.1 General Figure 51 \u2013 Distribution of electric field between line and plane Figure 52 \u2013 Distribution of the electric field between lines <\/td>\n<\/tr>\n | ||||||
68<\/td>\n | 6.3.2 Cross section Figure 53 \u2013 Different observations of the same dendrite according todifferent cross section cutting planes <\/td>\n<\/tr>\n | ||||||
70<\/td>\n | Figure 54 \u2013 An example of angle lapping <\/td>\n<\/tr>\n | ||||||
71<\/td>\n | Figure 55 \u2013 Structure analysis of an angle lapped solder resist in the depth direction <\/td>\n<\/tr>\n | ||||||
72<\/td>\n | 6.3.3 Optical observation Table 18 \u2013 Various methods for optical observation of failures <\/td>\n<\/tr>\n | ||||||
74<\/td>\n | 6.3.4 Analysis methods 6.3.5 Defect observation and analysis Table 19 \u2013 Various methods for defect analysis <\/td>\n<\/tr>\n | ||||||
75<\/td>\n | Figure 56 \u2013 Observed images of dendrite with different illumination methods (without solder resist) Figure 57 \u2013 EPMA analysis of migration (dendrite) on a comb type electrode <\/td>\n<\/tr>\n | ||||||
76<\/td>\n | Figure 58 \u2013 EPMA analysis of migration (dendrite) in the solder resist <\/td>\n<\/tr>\n | ||||||
77<\/td>\n | Figure 59 \u2013 3D shape measuring system Figure 60 \u2013 Electrodes which migration was generated <\/td>\n<\/tr>\n | ||||||
78<\/td>\n | Figure 61 \u2013 3D observation of electrodes before and after the test <\/td>\n<\/tr>\n | ||||||
79<\/td>\n | 6.4 Special remarks on the migration phenomenon after the test Figure 62 \u2013 3D observation of dendrite Table 20 \u2013 Board specification and test conditions <\/td>\n<\/tr>\n | ||||||
80<\/td>\n | Table 21 \u2013 Effect of the overlap of electrodes Table 22 \u2013 Effect of the area of the conductor <\/td>\n<\/tr>\n | ||||||
81<\/td>\n | Table 23 \u2013 Effect of the shape of the tip of the electrodes <\/td>\n<\/tr>\n | ||||||
82<\/td>\n | Annex A (informative) Life evaluation A.1 Voltage dependence of life A.2 Temperature dependence of life A.3 Humidity dependence of life A.3.1 General <\/td>\n<\/tr>\n | ||||||
83<\/td>\n | A.3.2 Relation between temperature (\u00b0C), relative humidity (\u00a0%RH) and vapour pressure (hPa) A.4 Acceleration test of life and acceleration factor Figure A.1 \u2013 Temperature and saturated vapour pressure Table A.1 \u2013 Vapour pressure at test temperature and relative humidity <\/td>\n<\/tr>\n | ||||||
84<\/td>\n | A.5 Remarks <\/td>\n<\/tr>\n | ||||||
85<\/td>\n | Annex B (informative) Measurement of temperature-humidity B.1 Measurement of temperature and humidity B.1.1 General B.1.2 Commonly used temperature-humidity measurement systems and their merits B.1.3 Requirements for the humidity measurements in a steady-state temperature-humidity test chamber B.2 Typical methods of temperature and humidity measurement B.2.1 General <\/td>\n<\/tr>\n | ||||||
86<\/td>\n | B.2.2 Checking procedure for temperature measurement Table B.1 \u2013 Merits of and remarks on various humidity measuring methods (applicable to steady state temperature-humidity tests) <\/td>\n<\/tr>\n | ||||||
87<\/td>\n | B.2.3 Checking procedure for humidity measurement Figure B.1 \u2013 Specification of sensors used in the test and their shapes <\/td>\n<\/tr>\n | ||||||
88<\/td>\n | B.2.4 Derivation of temperature in a chamber Figure B.2 \u2013 Calculation method of the average temperature (humidity), the average maximum temperature (humidity) and the average minimum temperature (humidity) <\/td>\n<\/tr>\n | ||||||
89<\/td>\n | B.2.5 Definition of relative humidity in HAST Table B.2 \u2013 Derivation of relative humidity from dry-and-wet bulb humidity meter <\/td>\n<\/tr>\n | ||||||
90<\/td>\n | Figure B.3 \u2013 Relative humidity in a pressurized chamber <\/td>\n<\/tr>\n | ||||||
91<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Electrochemical migration in printed wiring boards and assemblies. Mechanisms and testing<\/b><\/p>\n |