I would agree, except that, by definition, if one is drying, then there must be lots of humidity about, converted from liquid to vapour phase. Batch drying machines using high-energy rotary hot-air air knives with the boards in propylene baskets have never demonstrated a measurable static with hundreds in service. It
is possible to be more royalist than the king.
"Cecilia Alkhagen (EMW)" wrote:
> Hello!
>
> Following your discussions on ESD-safety and airguns, I wonder if there is a problem in the drying step in an inline cleaner with ESD. The conveyer is grounded, but is that enough if hot, dry air is used to dry the boards? The humidity must be quite low in the drying zone, could that cause electrostatic bulid up?
>
> /Cecilia Alkhagen
>
> -----Original Message-----
> From: Michael Fenner [mailto:[log in to unmask]]
> Sent: Friday, March 10, 2000 11:13 AM
> To: [log in to unmask]
> Subject: Re: [TN] High Pressure Air Dry for PWBs - creates ESD?
>
> A passing thought, which contributes nothing to this debate:
> I recall touring the newly installed line of a major multinational where they were showing me
> their latest aqueous cleaning and drying line costing several $100,000. This took a couple of
> hours and included state of the art off line test equipment capable of looking at the tiniest
> amount of ionic contamination.
> All was extremely wonderful and impressive with zero contamination zero down the drain zero up
> the stack etc.
> The final call of the day was to the newly named and clearly just cobbled together "ultimate
> Test zone" where they had made the most important discovery of all: blowing the just processed
> and tested boards off with a hand held airline was still able to remove large gobs of water from
> under components.....
>
> Have a good weekend
>
> Mike
>
> ----- Original Message -----
> From: Paul Klasek <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Friday, March 10, 2000 2:27 AM
> Subject: Re: [TN] High Pressure Air Dry for PWBs - creates ESD?
>
> > Apart from Mike's & Frank's ; Doug, let's take the work personally :
> >
> > Imagine the 2M picture :
> > There is Doug, justly frrreshly pooped from clean bath , ready for drying .
> > Presses button ; comes out AN AIR GUN ,
> > which with the below mentioned deafening noise commences it's task with
> > pitiful efficiency and truckloads of entailed negatives .
> > Happy ? No ?
> >
> > Ok , lets have 3M picture :
> > As above , Doug whistles high C voice command , and, viola, the LARGE DIA
> > CENTRIFUGE WITH FILTER,
> > aka common kitchen window fan , with variable speed to validate the optimal
> > VOLUME flow,
> > commences it's task .
> > Doug is dry in seconds (60 of 'em), ready for his favorite "watering" hole .
> >
> > "do not to others you'd whish not to yourself"
> >
> > amen
> >
> > PS
> > yes emitting needle spicing the air with occasional ozone molekule won't
> > hurt.
> > Desist the lavender oil capillary .
> >
> >
> > -----Original Message-----
> > From: Douglas Pauls [mailto:[log in to unmask]]
> > Sent: Friday, 10 March 2000 7:53
> > To: [log in to unmask]
> > Subject: Re: [TN] High Pressure Air Dry for PWBs - creates ESD?
> >
> >
> > In a message dated 3/9/00 1:47:13 PM Eastern Standard Time,
> > [log in to unmask] writes:
> >
> > > Our current method of drying PWBs after cleaning is to blow them dry with
> > a
> > > standard air gun with up to 125 psi of air. Other than the sound level
> > > which can be deafening does this create an ESD problem with static
> > generated
> > > by the fast moving air? What are the best methods of noise and static
> > > abatement?
> ................
> >
>
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