IEC 61192-5 : 1.0

WORKMANSHIP REQUIREMENTS FOR SOLDERED ELECTRONIC ASSEMBLIES - PART 5: REWORK, MODIFICATION AND REPAIR OF SOLDERED ELECTRONIC ASSEMBLIES

International Electrotechnical Committee

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FOREWORD 1 Scope 2 Normative references 3 Terminology    3.1 Terms and definitions    3.2 Abbreviations 4 Classification of rework activities    4.1 Pre-soldering rework    4.2 Post-soldering rework    4.3 Essential prerequisites for successful and         reliable rework 5 Pre-soldering rework    5.1 General    5.2 Reworking solder paste and non-conducting adhesive         deposits         5.2.1 General         5.2.2 General misalignment or smudging of deposits         5.2.3 Local misalignment or smudging of deposit         5.2.4 General paste or adhesive quantity incorrect         5.2.5 Local paste or adhesive quantity incorrect    5.3 Reworking placed components         5.3.1 General overall component misalignment         5.3.2 Local component misalignment    5.4 Realigning components after curing thermoplastic         adhesive    5.5 Realigning components after curing thermosetting         adhesive 6 Factors affecting post-soldering rework    6.1 Component marking and unmarked components    6.2 Reuse of removed components    6.3 Sensitive components    6.4 Printed board layout design and space constraints    6.5 Heat-sink effects    6.6 Printed board material type    6.7 Solder resist material and aperture size    6.8 Reworking individual fine pitch device leads    6.9 Reworking grid arrays 7 Preparation for post-soldering rework and repair    7.1 Electrostatic precautions    7.2 Avoiding exposure of components to contaminants    7.3 Removal of conformal coating    7.4 Unsuitable components    7.5 Cleaning prior to rework    7.6 Protecting adjacent sensitive components    7.7 Baking of assemblies prior to component replacement    7.8 Preheating large multilayer boards    7.9 Preheating replacement sensitive components 8 Post-soldering rework    8.1 General    8.2 Component realignment (tweaking)    8.3 Component removal    8.4 Removal of adjacent components    8.5 Reuse of components    8.6 Addition of flux and solder    8.7 Topping-up    8.8 Removal of excess solder from joints    8.9 Preparation of lands before component replacement    8.10 Component replacement    8.11 Cleaning (if required)    8.12 Visual inspection and electrical testing    8.13 Checking thermal integrity of solder joints    8.14 Replacement of local conformal coating (if required) 9 Selection of rework equipment, tools and methods    9.1 General    9.2 Matching rework equipment to component and         printed-board prerequisites         9.2.1 General         9.2.2 Selection based on component types on the                printed board         9.2.3 Selection based on printed-board laminate                material type         9.2.4 Selection based on assembly structure and                soldering processes 10 Manual rework tools and methods    10.1 General    10.2 Miniature conventional (stored energy) soldering         irons    10.3 Directly heated soldering irons    10.4 Hot air/gas pencils    10.5 Heated tweezers    10.6 Soldering irons with special tips 11 Mechanized and programmable rework machines    11.1 General    11.2 Hot air rework machines    11.3 Focused infrared (IR) equipment    11.4 Thermode (heated electrode) equipment    11.5 Laser equipment for de-soldering 12 Ancillary tools and equipment    12.1 Conventional soldering irons    12.2 Hotplates    12.3 Pneumatic dispensers    12.4 De-soldering tools, as used for through-hole         assemblies    12.5 Tweezers and vacuum pencils    12.6 Solder pots    12.7 Copper braid 13 Rework recording procedures    13.1 General    13.2 Anomaly charts    13.3 Travelling documents    13.4 Rework status 14 Training of operators and inspectors 15 Field repair Bibliography

Abstract

Provides information and requirements that are applicable to modification, rework and repair procedures for soldered electronic assemblies. It is applicable to specific processes used to manufacture soldered electronic assemblies where components are attached to printed boards and to the relevant parts of resulting products.