Agree, Steve, the Okla man should be completed with an Oz man. I'll try to pull him back to the 'family'.
Ingemar
-----Original Message-----
From: Stephen R. Gregory [mailto:[log in to unmask]]
Sent: den 12 juni 2001 14:45
To: [log in to unmask]
Subject: Re: [TN] Looking for a "special" solder paste dispenser
Hi Bill!
Here's a old post from one of the dispensing "Gurus", Paul Klasek. They don't
own a single stencil and have been doing all their SMT with dispensing solder
paste...wish Paul was back up on the list...
-Steve Gregory-
Zoran Raich[SMTP:[log in to unmask]]>
Sent: Wednesday, 3 February 1999 9:04>
To: [log in to unmask]>
Subject:
Re: [TN] SMT dispensing systems
Hi Wade,
We are using a Camalot Gemini dispensing system. I being the most sceptical
out of Paul Klasek and myself am now very much sold on dispensing systems for
Sodder Paste as you guys call it. It has totally blown away my theories a had
about screen printing.
To give you some of the Benefits,
The good Points
1: Solder Paste Wastage calculated at 4% (Call me inefficient but we had
approx 30% with screen printing in past lives).Can be less still with better
syringe (individual light (4 pumps) monitoring
2: Safety, operators prefer handling the tubes and is very clean with no
mess.We went with 55cc EFD barrels , 2 mounted on back plane (on 644 pump
2inback , 2 in front ) ,200gr each ; 2 of them on back plane last a shift .
Paradise .
3: Deposition Control. Ever had the problem where you wanted to control the
amount paste using stencils but could not or were limited due to fine pitch
constraints and aspect ratios (Stepped stencils can be a nightmare). It is
interesting to note that coplaniarity issues with finer pitch devices and
other IC's are negated dut to the dot height which eliminates dry joints due
to coplaniarity issues.This was one of major considerations (fill in hole)
for example pth anchoring of SMD connectors ;(those which should be on
Steve's toshiba's mother of all boards ) ;the flexibility of tuning (hunting
down the illusive balls) is tremendous ;you can dispense even on solder mask
to let it creep up the fillet .
4: Flexibility with regards to frequent design changes, no need to buy
multiple stencils through alpha, beta and production stages.
5: No cleaning of stencils or blocked apertures.
6: Paste rheology does not play a large role in dispensing negating the need
to constantly work the paste during screen printing to achieve a consistant
deposit (Mainly concerned with fine pitch)
7: Change over time between one product and another is as quick as loading
another program and changing the Conveyor width (Again no need for stencil
maintenance).
The Not so Good Points
1: The solder paste is more expensive for -400 to +500 Mesh (Negated somewhat
buy the wastage and waste handling but unfortunately the accountants do not
see this, I suspect it has something to do with the personality bypass
operation they have after certification) I think he says in the end it's the
same on paste cost .
2: Programming can take a couple of hours to do depending on how many
components there are but compared to stencils if you take into account the
time taken to do aperture reductions and adjustements creating gerbers
emailing them to stencil suppliers liasing with stencil suppliers creating
purchase orders la di da etc etc programming time is not as bad as you first
imagine.
(Gosh ; he's really picky ; how often do you run new board in ?And 2 hours
beats 2 days on stencil if yo're that fast , (+ COST ; and pray you dead
right on those apertures ) .
3: You do sometimes get a missing dot here and there but nothing of major
concern a little process control fixes this.We started with 325-500 mesh
stock ; which we still unfortunately have touse up ;the 400-500 ind NC-SMQ90
is faultless (running a week on three shiftswithout cartridge and needle
clean)We did validate it already ; did not implement in production yet .
4: It is slower than screen printing, you can not put them in front of fast
chip shooters and utilise SMT machines effectively. We are on our boards
getting approximately 70% of tact.
So please note it depends on your production requirements, we are currently
looking at buying the fastest dispenser on the market to take up this
issue.This one is again in the take-off stage :We have here My19 with hydra
and getting one more as it's from our opinionideal (almost 300 feeders) for a
real bad mix as we have ;and once we deploy dual needles ( on 0805's or 603's
; 1206's ; you name it keep them in parallel orientation on design) ; the
Gemini will comfortably keep up with My .
Presently because this place is for god (chairman) knows what reason going
through the stratosphere;we have little time to tingle the toys ; we can't
get on them because production sits on it 24 hours 7days almost .That should
change this year as Zoran goes to NW (kick tyres as he says) of XYFlex for
this application .With him around I have more time for battles with R&D's
dreams (they call it manufacturable designs) . These are some of the more
obvious things which may be food for thought and help in the decision making
process.
Regards
Zoran Raich
ResMed Ltd
www.resmed.com.au
To sum it up Wade ; yo're on perfectly right line ; local subs think the same
way ; on small runs the stencil pains are unbearable ;and with US market ; as
Steve said ; I'm surprised you don't have dispensing lines by dozen's .
Resent this mail to Indium guys ; (William Jackson . MD ;[log in to unmask]
; http://www.indium.com <http://www.indium.com/> ; ) ;if you don't get reply from Bill this week ;ask
for resmed's 55cc 400-500 mesh ' ( I can not fault that paste, and did I try
!) ; get from camelot (speedline mayhem now) the 644 head (last quoteI've
heard was US $ 16K) ;with 4 extra cartridges ( $ 6+K more ) to rotate in
maintenance cycle and yo're in business
As you have likely already 642 head you can start with that ( no room for
dual needles ) ;on mostly single 21 gauge we do , ( buy few of them
operators will shear few of them on learning curve ) .Once you gain
experience and establish dot sizing and spreads and component library the
programming of new board should be less than 2 hours .To get there will take
you about a month of clean time .If you have $ 5K spare I can send you a
fellow with more than decade experience on Gem's ; or come myself ; or send
another wise guy who started it all up with me .That is for ticket; food and
place in the garage for sleepin' bag .See you Wade
Paul Klasek
http://www.resmed.com <http://www.resmed.com/>
PS good to see subs waking up ; I'll try to dig up for you old camelot's
charts of savings, line by line dispensing X printing .It's an eye opener I
validated and verified last year as factual ( no wool ;no bull )
PPS Bill , any chance to "lend" Wade few of those 55cc barrels (400-500) for
all of this good will ? Please .They go usually to Advaced Material
Technologies - Aust .Thanks A lot
PPPS If you've read the article from Chuck Bauer (smta) in Advanced Packaging
(I think Steve's got a copy) ; I'd have to clarify it as Chuck painted it
with bit to loose brush strokes ;some less correct than others ; let me know
if you need any details (lets digitize) .
NB almost forgot ; auger is the only way .As far as I see it ; there's only
one on top = you got it ; II with stated 45K speed it is .When I calculated
the balance you need on average mix 4x dispensing speed than p&p .That is
apples with apples = stated x stated ; or actual x actual .the dual needle
will get you to 60K with 644 ; design plays a role .
From: Wade Oberle[SMTP:[log in to unmask]]
Sent: Wednesday, February 03, 1999 3:13 AM
To: [log in to unmask]
Subject: [TN] SMT dispensing systems>
Dear Technetters,
I'm interested in who are the 'major players' in the SMT dispensing business.
In my opinion, Camalot and Asymtek are on the top tier. I'd be interested to
here other opinions and experience.
Regards,
Wade Oberle
414-947-3477
[log in to unmask]
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