IPC SM 839 : 0

Acknowledgement
1.0 Scope
1.1 Introduction
2.0 Applicable documents
3.0 Solder mask over bare copper
3.1 Metallic resist stripping
3.1.1 Peroxide
3.1.2 Non-peroxide
3.1.3 Detection of residuals
3.1.4 Removal of residuals
3.2 Stripping organic resists
3.2.1 Solvent processed resists
3.2.2 Aqueous processed resists
3.2.3 Removing resist residues
3.2.4 Effectiveness of organic resist stripping
3.3 Board handling after resist stripping
3.4 Pre-solder mask surface preparation
3.4.1 Mechanical methods
3.4.1.1 Mechanical scrubbing
3.4.1.2 Pumice scrubbing
3.4.2 Chemical cleaning
3.4.3 Chemical coating
3.4.3.1 Copper oxides
3.4.3.2 Antioxidants/antitarnish agents
3.4.4 Final rinse
3.4.5 Drying
3.5 Pre-solder mask cleanliness testing
3.5.1 Water break test
3.5.2 Solderability test
3.5.3 Ionics
3.5.3.1 Ionic extraction
3.5.3.2 Conductivity meter
3.5.3.3 Static volume extraction
3.5.3.4 Dynamic ionic extraction
3.5.4 Organics
3.5.5 Moisture and insulation resistance (M & IR)
3.6 Storage prior to solder mask application
3.7 Application of solder masks
3.8 Pre-solder leveling problems
3.9 Solder leveling processes
3.9.1 Background
3.9.2 Inspection and preclean
3.9.3 Fluxing
3.9.4 Solder coating
3.9.5 Solder leveling
3.10 Post-solder leveling cleaning
3.11 Post-solder leveling problems
4.0 Solder mask over tin/lead
4.1 Fusing fluid cleaning
4.1.1 Residues and problems
4.1.2 Test methods for residual detection
4.1.3 Method of removal
4.2 Board handling
4.3 Pre-solder mask cleaning
4.3.1 Mechanical methods
4.3.2 Spray cleaning
4.3.2.1 Solvent
4.3.2.2 Aqueous
4.4 Pre-solder mask cleanliness testing
4.5 Application of solder mask
4.6 Trouble shooting guide - cured solder mask
5.0 Notes
5.1 Cleanliness test equipment

Covers all aspects, both method and degree, of the cleaning process that is associated with the application of a permanent polymer coating (solder mask) to printed boards. This includes the maintenance of the cleanliness level of coated boards during the storage and handling that occur prior to the component assembly operation and, also during the coating application and cure processes. It also deals with maintaining the soldered assembly at a degree of cleanliness that is consistent with the end-product applications.