| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 2<\/td>\n | undefined <\/td>\n<\/tr>\n | ||||||
| 4<\/td>\n | CONTENTS <\/td>\n<\/tr>\n | ||||||
| 7<\/td>\n | FOREWORD <\/td>\n<\/tr>\n | ||||||
| 9<\/td>\n | INTRODUCTION <\/td>\n<\/tr>\n | ||||||
| 10<\/td>\n | 1 Scope 2 Normative references 3 Terms, definitions and abbreviated terms <\/td>\n<\/tr>\n | ||||||
| 11<\/td>\n | 3.1 Terms and definitions related to management 3.2 Technical terms and definitions <\/td>\n<\/tr>\n | ||||||
| 12<\/td>\n | 3.3 Abbreviated terms 4 Failure mode electrochemical migration 4.1 Background of electrochemical migration <\/td>\n<\/tr>\n | ||||||
| 13<\/td>\n | Figures Figure 1 \u2013 Principal reaction mechanism of ECM Figure 2 \u2013 Uncertainty in local conditions determines ECM failures <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | 4.2 Complexity of electrochemical migration Figure 3 \u2013 Occurrence of ECM failures during humidity tests <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | 4.3 Conductive anodic filament (CAF) and anodic migration phenomena (AMP) Figure 4 \u2013 VENN diagram showing the factors influencing ECM <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | 4.4 Creep corrosion Figure 5 \u2013 Occurrence of CAF and AMP <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | 5 Electrochemical migration and relevance of ionic contamination 5.1 General aspects 5.2 Background of ionic contamination measurement Figure 6 \u2013 Creep corrosion caused by corrosive gases <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | Figure 7 \u2013 Ionic contamination measurement <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | 5.3 Restrictions and limitations of ionic contamination measurement for no-clean assemblies 5.3.1 Factors determining the result Figure 8 \u2013 Principal operation mode (fluid flow) of ROSE <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | 5.3.2 Influence by solvent on measurement of no-clean assemblies Figure 9 \u2013 Effect of solvent composition on the obtained ROSE results Figure 10 \u2013 Effect of solvent composition on the obtained ion chromatography result <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | 5.3.3 Influence of extraction time on measurement of no-clean assemblies Figure 11 \u2013 Comparison of ROSE values with different solvent mixtures and material variations of the CBA <\/td>\n<\/tr>\n | ||||||
| 24<\/td>\n | 5.3.4 Influence by assembly and interconnect technology on measurement of no-clean assemblies Figure 12 \u2013 Variation in ROSE values depending on technology used <\/td>\n<\/tr>\n | ||||||
| 25<\/td>\n | Figure 13 \u2013 Destructive action of solvent on resin matrix Figure 14 \u2013 Comparison of the resin change <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | 5.3.5 Ion chromatography of no-clean assemblies CBA Figure 15 \u2013 Destructive action of solvent on resin matrix and chipping effect <\/td>\n<\/tr>\n | ||||||
| 28<\/td>\n | Tables Table 1 \u2013 List of ions based on IPC-TM650, 2.3.28 [21] <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | Table 2 \u2013 Fingerprint after ion chromatography of no-clean assembly shown in Figure 16 <\/td>\n<\/tr>\n | ||||||
| 30<\/td>\n | 5.4 Restrictions and limitations of Ionic contamination measurement for cleaned products 5.4.1 Ionic contamination of unpopulated CBs (bare board, state of delivery) Figure 16 \u2013 Assembly manufactured with 2x SMT and 1x THT process for the connector <\/td>\n<\/tr>\n | ||||||
| 31<\/td>\n | Figure 17 \u2013 Comparison of SPC-charts from 1-year monitoring of different CB suppliers and two different iSn final finish processes <\/td>\n<\/tr>\n | ||||||
| 32<\/td>\n | Figure 18 \u2013 Differences in ROSE values for unpopulated CBs depending on the extraction method <\/td>\n<\/tr>\n | ||||||
| 33<\/td>\n | Table 3 \u2013 Fingerprint after ion chromatography of bare CBs (state of delivery) <\/td>\n<\/tr>\n | ||||||
| 34<\/td>\n | 5.4.2 Ionic contamination of electronic and electromechanic components Figure 19 \u2013 Reduction of ionic contamination on bare CBs (state of delivery from CB supplier) by leadfree reflow step without solder paste or components <\/td>\n<\/tr>\n | ||||||
| 35<\/td>\n | Figure 20 \u2013 Influence of components on the ionic contamination based on B52\u2011standard <\/td>\n<\/tr>\n | ||||||
| 36<\/td>\n | 5.4.3 Ionic contamination of cleaned CBAs Figure 21 \u2013 Formation of a white veil or residue on MLCCs during active humidity test <\/td>\n<\/tr>\n | ||||||
| 37<\/td>\n | Table 4 \u2013 Fingerprint after ion chromatography of a bare CB and the respective PBA in uncleaned and cleaned condition <\/td>\n<\/tr>\n | ||||||
| 38<\/td>\n | Figure 22 \u2013 Chromatogram derived from ion chromatography measurement of a cleaned CBA <\/td>\n<\/tr>\n | ||||||
| 39<\/td>\n | 5.5 How to do \u2013 Guidance to use cases 5.5.1 When is the use of ROSE measurements reasonable? Table 5 \u2013 Fingerprint after ion chromatography of an uncleaned CBA compared to the cleaned CBA and after removing the components <\/td>\n<\/tr>\n | ||||||
| 41<\/td>\n | 5.5.2 When is the use of ion chromatography reasonable? 5.5.3 At what point in the manufacturing sequence ionic contamination measurements are carried out, if a fingerprint or the basis for process control is to be established? <\/td>\n<\/tr>\n | ||||||
| 42<\/td>\n | 5.5.4 How is the sampling for ROSE and IC done? 5.5.5 How is a product-specific process control limit based on ROSE determined? 5.6 Examples for good practice 5.6.1 Ways to achieve objective evidence <\/td>\n<\/tr>\n | ||||||
| 43<\/td>\n | 5.6.2 Introduction of a new product family with new materials Figure 23 \u2013 Approach for achieving objective evidence for a qualified manufacturing process in the automotive industry <\/td>\n<\/tr>\n | ||||||
| 44<\/td>\n | 5.6.3 Adaptation of an ECU for a new vehicle type Figure 24 \u2013 ROSE as process control tool <\/td>\n<\/tr>\n | ||||||
| 45<\/td>\n | 6 Surface insulation resistance (SIR) 6.1 SIR \u2013 An early stage method to identify critical material combinations and faulty processing 6.2 Fundamental parameters of influence on SIR 6.2.1 General aspects <\/td>\n<\/tr>\n | ||||||
| 46<\/td>\n | Figure 25 \u2013 View on SIR measurement <\/td>\n<\/tr>\n | ||||||
| 47<\/td>\n | Figure 26 \u2013 Principal course of SIR curves Figure 27 \u2013 Response graph concerning stabilized SIR-value after 168 h from a DoE with B53-similar test coupons (bare CB) <\/td>\n<\/tr>\n | ||||||
| 48<\/td>\n | 6.2.2 Influence of climate Figure 28 \u2013 SIR measurement with B24-CB, no-clean SMT solder paste <\/td>\n<\/tr>\n | ||||||
| 49<\/td>\n | 6.2.3 Influence of voltage <\/td>\n<\/tr>\n | ||||||
| 50<\/td>\n | 6.2.4 Influence of distance Figure 29 \u2013 Increase in ECM propensity depending on voltage applied (U) and Cu-Cu distances (d) of comb structures <\/td>\n<\/tr>\n | ||||||
| 51<\/td>\n | 6.2.5 The limit 100 M\u2126 and optical inspection Figure 30 \u2013 Layout of B53 test coupon <\/td>\n<\/tr>\n | ||||||
| 52<\/td>\n | 6.2.6 Influence of materials <\/td>\n<\/tr>\n | ||||||
| 53<\/td>\n | 6.3 Harmonization of SIR test conditions for characterization of materials for automotive applications 6.4 Different steps of SIR testing 6.4.1 General procedure Table 6 \u2013 Common test conditions for basic material evaluation <\/td>\n<\/tr>\n | ||||||
| 54<\/td>\n | 6.4.2 Base material 6.4.3 Solder mask and final finish <\/td>\n<\/tr>\n | ||||||
| 55<\/td>\n | 6.4.4 SMT solder paste 6.4.5 THT fluxes Figure 31 \u2013 B53 with solder mask, partially covered and fully covered comb structures <\/td>\n<\/tr>\n | ||||||
| 56<\/td>\n | 6.4.6 Encapsulations and adhesives 6.4.7 Process qualification at CB manufacturer <\/td>\n<\/tr>\n | ||||||
| 57<\/td>\n | 7 Comprehensive SIR testing \u2013 B52-approach 7.1 General aspects Table 7 \u2013 Recommended SIR test conditions for basic material- and process release for the outer layer manufactured by a CB supplier <\/td>\n<\/tr>\n | ||||||
| 58<\/td>\n | 7.2 The main B52 test board Figure 32 \u2013 B52 CBA after SMT process, layout slightly adapted to fulfil company internal layout rules <\/td>\n<\/tr>\n | ||||||
| 59<\/td>\n | 7.3 The test patterns Figure 33 \u2013 Pattern of B52 CB, layout slightly adapted to fulfill company internal layout rules <\/td>\n<\/tr>\n | ||||||
| 60<\/td>\n | Table 8 \u2013 List of materials for components with recommendations for minor adaptations <\/td>\n<\/tr>\n | ||||||
| 61<\/td>\n | 7.4 Processing of B52 boards 7.5 Sample size for SIR testing of B52 test coupons 7.6 Preparation for SIR testing <\/td>\n<\/tr>\n | ||||||
| 62<\/td>\n | 7.7 Sequence of SIR testing Table 9 \u2013 Sequence for SIR testing of B52-CBAs for general material- and process qualification <\/td>\n<\/tr>\n | ||||||
| 63<\/td>\n | Figure 34 \u2013 Positive example of comprehensive SIR tests obtained for qualification of a SMT process Figure 35 \u2013 Negative example of a contaminated B52-sample, tested by the sequence of constant climate and cyclic damp heat climate <\/td>\n<\/tr>\n | ||||||
| 64<\/td>\n | 7.8 Evaluation 8 Example for good practice 8.1 Methodology for material and process qualification, process control 8.2 Step 1 \u2013 Material qualification <\/td>\n<\/tr>\n | ||||||
| 65<\/td>\n | Figure 36 \u2013 SIR test coupon, similar to B53, for principal material qualification Figure 37 \u2013 SIR test with constant climate and cyclic damp heat condition <\/td>\n<\/tr>\n | ||||||
| 66<\/td>\n | 8.3 Step 2 \u2013 Product design verification and process validation Figure 38 \u2013 B52 test board and example of SIR curve Figure 39 \u2013 Example of the product that was realized by the released materials and process <\/td>\n<\/tr>\n | ||||||
| 67<\/td>\n | 8.4 Step 3 \u2013 Definition of process control limits Figure 40 \u2013 Ionic contamination test results from 4 repetitions of PV samples Figure 41 \u2013 Results of ionic residue testing and calculation of upper control limit (UCL) <\/td>\n<\/tr>\n | ||||||
| 68<\/td>\n | Figure 42 \u2013 Run chart derived from 2 samples per month during mass production <\/td>\n<\/tr>\n | ||||||
| 69<\/td>\n | Annex A (informative)SIR measurement for SMT solder paste \u2013 Representative example A.1 Purpose A.2 Equipment A.3 Example of an instruction how to perform the test <\/td>\n<\/tr>\n | ||||||
| 72<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Printed board assemblies – Electrochemical reliability and ionic contamination on printed circuit board assemblies for use in automotive applications. Best practices<\/b><\/p>\n |