Cleanliness And Lead Free Conformal Coating Processing

Lead Free Coating, Cleanliness and the Conformal Coating Process

Outline ,[object Object],[object Object],[object Object],[object Object],[object Object]

What is cleanliness? ,[object Object],[object Object],[object Object],[object Object]

What is Cleanliness? Imagine your bare printed circuit board Plating / Etch Salts Flux Residues Grease / finger salts Oils Soya Sauce

No-clean Flux Residues Grease / finger salts Hand cream Oils (eg. Wave, Silicone ) What is Cleanliness? Imagine your assembled printed circuit board

[object Object],[object Object],[object Object],What is Cleanliness?

[object Object],[object Object],[object Object],Why is Cleanliness Important?

[object Object],[object Object],The Effect of Ionic Contamination

[object Object],[object Object],[object Object],[object Object],Conformal Coating

Contaminant left on a coated board at 25 o C 50% RH

Moisture has “found” contaminant, and a blister has formed through osmotic pressure

The soluble contaminate has now formed a conductive fluid with the moisture

A dendrite is forming between tracks

[object Object],[object Object],[object Object],Conformal Coating

Corrosion On Pin Delamination Of Coating Coating Dissolving & Cracking In Circled Area

Non-ionic contamination ,[object Object],[object Object],[object Object],[object Object]

Where do residues come from? ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

So you’re told to use no clean ,[object Object],[object Object],[object Object],[object Object]

SMT with lead free solders ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Compare SnPb and SnAgCu ,[object Object],[object Object]

New Solder Paste chemistries ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Lead free and Tin Whiskers ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

SEM Photograph 150 and 900 magnification, 3 months aging Tin Whisker on Pure SnPb

Lead free and Dendrites ,[object Object]

Summary Lead free and Reliability ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Further Information ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Cleanliness And Lead Free Conformal Coating Processing

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Cleanliness And Lead Free Conformal Coating Processing