Thanks Yordan & everyone else.
(Bill, I still can't open your link...a common problem I had trying to
open a PDF file where it uses an ActiveX component...more work for a
rainy "maintenance" day)
You are correct! Shortly after sending this e-mail off, I did more
digging into specs & talking to our in-house assembly people.
Appears we initially assumed this connector to come in the reel with the
saddles DOWN, but they are mounted UP! This means we do NOT need any
fixturing as I proposed. As long as the panel has a milled out pocket
for the connector, the saddles (x2) will rest on the panel & hold the
connector in place, during pick & place, then reflow, placing the pin
datum at the same plane as the PCB connector pads.
This is a Compact Flash (CF) 50 pin connector, single sided. We went
with the saddles down because the left pin is numbered #1 & the right is
#50, (in the AVX mech spec) so that led us to position it with the
saddles down. The connector by itself is not polarized, but when you
install it into the CF enclosure, it now becomes polarized to prevent
the CF card from being installed upside down into the PC CF slot.
We can install it this way, as long as we don't get hung up on the AVX
spec denoting pin 1 being totally opposite from ours. I guess I should
note that in the NOTES section of our assembly drawing so in case these
stop working, down the road, some inspector doesn't flag the connector
being reversed as the cause.
Surprised that AVX does denote pin #'s on this connector as many don't.
Not to is probably the safest way to go as its up to each
user/application to number pins the way they want. They may just to
confirm orientation for correct dimensions being read.
The issues related to fixturing was noted & good points to consider. The
margins on this product are not that lucrative so as to cover the
additional costs of fixturing, manual preparation, etc. When I design
PCB's I don't like to incur any additional or special handling, not to
mention fixturing. I like to keep yields up & make the assemblers life
easy, not to mention test & ongoing support & maintenance towards
product end-of-life.
Many thanks again.
Regards
TDK
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Yordan Venev
Sent: Friday, January 06, 2006 4:30 AM
To: [log in to unmask]
Subject: Re: [TN] SMT Connector Assembly Question
Terry,
As per the data sheet provided on the AVX website
(http://www.avxcorp.com/docs/Catalogs/5611.pdf), the single sided
connector
should have the side supports at the same Datum as the PCB Top side and
contact pins plane. That should allow automatic P&P and reflow without
additional support! If as you say, that's not the case then here is my
experience what we used for a similar connector (it had the supports,
but
the PCB was not designed accordingly) - PCMCIA 68-pin, single sided. The
support plate/frame was FR4 one milled appropriately. It had positioning
pins, thus we used it trough the entire SMT process - paste printing,
P&P
assembling and reflow. The cons are:
1. The nest (if needed) for the PCB panel in the support plate must be
milled very accurately.
2. The PCB panel must lay perfectly flat on the support plate
(especially
where the connector is situated). I suppose the PCB thickness is ~ 0.5
mm
(0.020') and you may need to use tape to hold it down, especially during
reflow.
3. During the reflow process deformation may occur due to the different
expansion ratio (due to the different thickness) which will lead to not
correct positioning of the connector.
So, basically it's a tricky task! The best way is to take advantage as
much
as possible of the wetting force of the pins towards the PCB pads and
provide just a little additional support to the connector.
Best regards,
Yordan Venev
Manufacturing Manager
********************************************************
CENTILLION LTD.
7-th km Tzarigradsko shosse Blvd.
ATM Center
1784 Sofia, BULGARIA
Tel. :(+359 2) 974 47 51, 965 84 95, 965 58 85
Fax :(+359 2) 974 47 52
mail to: [log in to unmask] <mailto:[log in to unmask]>
www.centillion-bg.com <http://www.centillion-bg.com>
-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Terry Kozlyk
Sent: Thursday, January 05, 2006 6:34 PM
To: [log in to unmask]
Subject: [TN] SMT Connector Assembly Question
Technet;
I have a fine pitch single sided 50 pin edge connector to assemble onto
the edge of a PCB. It overhangs the PCB edge.
This is a SMT which is pick & placed from a reel.
Actually this is a single-sided 50 pin Compact Flash Connector from AVX
Series 5611 Receptacle Connector.
This PCB is panelized. This connector has 2 supports on each side but
the support plane is at the same Datum as the PCB bottom side
( DATUM A).
So the panel must have a milled out pocket for this connector to sit in.
Question is;
What is the best way to support this connector during pick & place, then
into reflow?
The pocket above is only a clearance & provides no support to hold the
connector in place.
The only thing I see now is having a bare FR4 panel underneath this PCB
to provide support for the connector.
Any thoughts are much appreciated.
Regards
Terry (TDK)
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