Indeed , apart from dry air (Brian 's got a point on wet one)
(which can be relatively easy conditioned with ioniser),
the ancient dryers I used to box up did have boards through tunnel with
banks of fans blowing downwards ,
exiting air from bottom ;
with orientation of placement axis (more or less streamlined on better
designs) considered .
Not saying they could hit ATE straight on exit ,
but most of the underbelly waters was collected by gravity & constant
pressure .
Hand airline is a great spot test, but on volume laborious and dangerous
handling,
The high volume mid pressure fans should do the work .
Didn't do any validations on rotoknives; should work better than fans,
but by the time this technologies came the no clean saved us on class 2.
What is interesting, you said processed and TESTED ; with that much water in
place .
pk
-----Original Message-----
From: Michael Fenner [mailto:[log in to unmask]]
Sent: Friday, 10 March 2000 21:13
To: TechNet E-Mail Forum.; Paul Klasek
Subject: Re: 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?
................
>
##############################################################
TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
##############################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in
the body:
To subscribe: SUBSCRIBE TECHNET <your full name>
To unsubscribe: SIGNOFF TECHNET
##############################################################
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - contact Keach Sasamori at [log in to unmask] or
847-509-9700 ext.5315
##############################################################
|
