Why we clean; What we clean.

1
Why we clean What we clean.

• Selecting a Winning Combination for Electronic
  Assembly

2
Why clean?
Performance Cosmetics
Contractual Reliability
It Pays to CLEAN
3
IPC/EIA J-STD 001/DRequires Clean BoardsClass B
C Electronics

• 8.3.1 No Particulate matter (all classes)
• No lint, solder splash, dross, wire clippings
• No loose or dislogable solder balls
• 8.3.2 Unless otherwise specified (all classes),
  assemblies shall be cleaned and be
• Free from flux residue (1X)
• lt 1.56 micrograms/cm2 NaCl equivalent ionizables

Appendix B standardizes a testing protocol to be
used when implementing new flux materials or
validating a cleaning process change SIR, ROSE,
Ion Chromatography
4
Confusion leads to poor choices

• Saving a dollar by not cleaning may cost 100s
  of repairs or worst, lost customers
• Exponential rule of repair
• Repair _at_ board level 1
• Repair _at_ assembly level 10
• Repair _at_ customer level 100

5
Soils to Clean
Dust Dirt Solder balls Oils Solder
Paste Plating salts Adhesives Finger
prints Fluxes
6
Flux Type Hand solder Wave solder Wire solder SMT Paste Notes
Water soluble -Must be cleaned About 1/3 of market Common Common Common Common Residues usually water soluble High temperature can change to non-water soluble Can use chemistry 1-5
No-clean low residue Common -Should be cleaned Common Available Unusual -because of dull solder Low solids no-cleans require heat to de-activate flux activity as the active agent evaporate only if heated
No-clean bulk Common Unusual because low residue is preferred Common Common High solids no-cleans encapsulate activators in hardened flux matrix Could be a rosin or resin based flux
R RMA RA RMA common Needs cleaning RMA on old military projects Common Common Mil-F-14256 military classifications R Rosin non-activated RMA Rosin mildly activated RA Rosin Fully activated
Lead-free Any of the above made For higher temperature
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Catagory Kyzen Petroferm Zestron other Applications Notes
Aqueous Water only Water tap Water - DI Water Soluble Fluxes Residues usually water soluble Heat usually required Sometimes need defoamer
Aqueous Mixtures Non-reactive I3330 Axarel EC-7R SP50 Vigon SC200 SC202 Some LF Fluxes, Most RMAs Work by dissolving may need heat Non-foaming neutral pH Does not affect metals Less aggressive Less complicated waste disposal
Aqueous Mixtures Reactive XJN, XJN, 4625 Hydrex LF New Atron 205, Vigon 200 ALL Fluxes Referred to as saponifier Amines react with flux High pH -10 to 12 Can attach metals Needs heat 125 to 200F More difficult to close loop
Organic Solvents Cybersol MegaSolv Lenium DS-100 IPA Toluene Water Soluble and RMA Some Lead-free no-clean No water water free Closed loop with Mega resins Combustible or flammable design Always closed-loop
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Soil type Key to success
Fluxes Process Flexibility Time, temp, concentration, Automation
Solder balls High energy, good flux cleaning
Solder paste High energy, Process Flexibility and Waste management
Dirt Dust High energy, Automation
Finger prints Polar/non-polar solvent
Plating salts Polar solvent - heated
Machine Oils lubricants Organic solvent unless water soluble
Adhesives Organic solvent, low temperatures
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Soil type Key to success AAT cleaner(s)
Reflowed Fluxes Process selection Time, temp, concentration, Automation Inline AquaTherm Mega X-Cleaner Emulsionator
Solder balls High energy, good flux cleaning Inline X-cleaner AquaTherm
Solder paste High energy, chemistry selection, waste management X-cleaner
Dirt Dust High energy Cyclone Inline X-cleaner AquaTherm
Finger prints Polar/non-polar solvent Mega AquaTherm Inline X-cleaner Emuslionator
Plating salts Polar solvent - heated Inline AquaTherm X-cleaner
Machine Oils lubricants Organic solvent unless water soluble Mega Emulsionator AquaTherm
Adhesives Organic solvent, wash and rinse, high energy, time, temp X-cleaner Emulusionator
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Critical Questions to answer in Selecting a
Winning Cleaning Process

• What are we cleaning?
• What standard(s) apply?
• What solvent are we using?
• What equipment is selected?
• How are we going to qualify
• and control the process?