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SMT LEAD FREE PRINTING

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Simon

#43157

SMT LEAD FREE PRINTING | 3 August, 2006

Curious if anyone knows... When switching back and forth from Leaded paster to Lead free if cleaned with alcohol can the same squeegees be used? If so could anyone direct me to any links that would back this up. Thanks, Simon SMT Tech, Edge Tech Industries

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#43160

SMT LEAD FREE PRINTING | 3 August, 2006

Good morning, I am unaware of any links but to prevent any concerns we went out and purchased seperate squeegees from (http://www.transitionautomation.com/squeegee.html) and they are marked appropriately and kept seperate cabinet away from Leaded squeegees, I do not believe they that expensive. Good luck with your lead free process.

Have a great day.

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#43163

SMT LEAD FREE PRINTING | 3 August, 2006

Is your squeegee cleaning process adequate to guarantee no transfer of paste residue between jobs? Personally I wouldn't risk it, but then again it's easy for me to say since we don't do lead free.

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SWAG

#43169

SMT LEAD FREE PRINTING | 3 August, 2006

Sorry - don't know of any studies/papers. Having dedicated blades and holders for lead free is best. Also, our customer for lead free requires a line change-over check-off sheet that we follow, sign and keep with all the paperwork for the order. This sheet is the step-by-step process for insuring the line (printers in particular) are as free of lead paste as possible. We require on this sheet that the operators clean the blades and holders in the UT cleaner even though they are dedicated lead-free (could have been used for leaded stuff when no-one is looking - you know how that goes). Anyhow, this cleaning list + dedicated blades made our customer happy.

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#43193

SMT LEAD FREE PRINTING | 4 August, 2006

RoHS actually allows for up to 0.1% lead in solder. Unless you are really sloppy at cleaning your tools it would be very unlikely that you would get 0.1% lead into your lead-free process (remember leaded solder is only about 50% lead).

Regards,

Bert

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