In a previous life we used a Camelot 1414 to do prototype boards, it work
pretty well but found the same problem with blocking and having to clean.
We use prefilled syringes to eliminate most of the problem with coining in
the pump but still had the problem occasionally but a lot less with the
prefilled syringes.
-----Original Message-----
From: Kasprzak, Bill (sys) USX [mailto:[log in to unmask]]
Sent: Wednesday, June 13, 2001 1:34 PM
To: [log in to unmask]
Subject: Re: [TN] High speed paste dispensing
Geez Paul,
I had not remembered all the great things you've done with dispensing paste.
But hey, I didn't mean for you to come out on a "comeback" tour. But, if you
can help, it sure would be appreciated.
Some data:
Device - Actel CQ-132 - 132 leads, .007-010 wide, 25 mil spacing
Part comes in a frame, parts are formed on a Fancort die.
Pad size - .015 wide by .110 long
Solder paste - R253NC, -325+500 mesh, Sn63, 86% metal content
Camalot 1414 dispenser with 635-2 HSV displacement pump fitted with a 23 AWG
"footed" needle (.013"/.33mm) ID
I applied 30 psi backpressure the syringe. (As a point of reference the
syringes were filled by transferring from a jar of paste to a 10 CC syringe)
On the Camalot I used an 80 msec dispense with a 200 m sec delay,
The dot pattern was staggered with 2 dots per pad 32 mils apart.
Given this, the dispenser would typically dispense 1 part (264 dots at a
11,000 - 12,000 dph rate). By the second part the paste would coin in the
pump above the needle. This would require a needle removal and cleanout.
Sometimes we couldn't even get through one full cycle before coining or
plugging would set in.
Made all the adjustments...Larger/smaller needle, faster/slower, finer pitch
paste, etc etc
all ended with the same result, would work for awhile (one part or so) then
coin/plug up.
Making a long story short, I couldn't get this to work repeatedly. Add to
the equation that we need to set this process up a few times a month for a
run of 8 parts or less. I kinda gave up out of frustration.
I only have one "wish". I need to make it work. So is there anything in this
data that jumps out as being out of line?
Didn't mean to drag you back into the fray but, I'd be privileged to get a
response.
Thanks.
Bill Kasprzak
Moog Inc., Electronic Assembly Engineering
> -----Original Message-----
> From: Paul Klasek [SMTP:[log in to unmask]]
> Sent: Wednesday, June 13, 2001 3:12 AM
> To: [log in to unmask]
> Subject: [TN] High speed paste dispensing
>
> Hell'oo Bill , did Yo' forget me that quickly ?
>
> Gemini keeps up with My19 (14000+/h) easy , years on , with Inge we
> threaded
> yarns mile long on this subject,
> piece of cake ; Steve even tracked some article in PCB Assembly by Chuck
> Bauer (ex SMTA pres.)
> when he was down here . We did DO actually even better than he said .
>
> Who needs to be converted from small runs on stencil drags (good for long
> runs/volumes, undisputed) ?
> Archives must be full of useful memos too .
>
> It is a very much a norm process , not only viable , no pitch, from Gemini
> up in line ,
> friend in Philips in Manila had a dozen of these sputters ; very much
> repeatable, us with 200g syringes,
> 1414 if You don't rush, Indium paste and custom syringes we developed
> with
> helpful folks in US.
>
> Used to run 24h round the clock, did not miss a beat , unless mistreated
> (dry , sleep mode best in say hourly wake up dots on side board, to keep
> nozzles clean.
>
> What can do Yo' in for mate ? , make a wish list (be specific);
> since brothers in arms woke me up to express myself (did my best to spare
> Yo).
>
>
> paul
>
>
>
> ..........................................................................
> ..
> ...........................................
>
> Hello all,
>
> I've been watching this thread for a few days now hearing about how solder
> paste can be dispensed from an automated system.
>
> My experience has not turned out very well with only very limited success.
> We have a Camalot 1414, even bought the special displacement pump designed
> for this application and attempted to dispense solder paste. I just could
> not get the system to be repeatable. Once I had a set up, repeating the
> next
>
> day or even the next hour was impossible. I tried different pastes,
> different particle sizes, needle sizes, etc. etc. One of the biggest
> problems that I had was coining. This is where the particles compressed to
> form a solid plug where the paste entered the dispensing needle.
>
> I gave up on this method, settling instead on using microstencils to apply
> paste.
>
> I would like to know of anyone who has had success with dispensing solder
> paste. I would like to know some particulars about the process. (paste,
> needle size, pump pressures, etc) I would not mind trying this again if I
> could just get some help with this.
>
> However, if you've never done this and you're thinking that this is a
> viable
>
> process, I am advising to be very careful about sales pitches that claim
> that solder paste dispensing can be done. I don't think that it is a
> repeatable process.
>
> Bill Kasprzak
> Moog Inc., Electronic Assembly Engineering
>
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