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April 2014

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Subject:
From:
lyonyuan <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, lyonyuan <[log in to unmask]>
Date:
Fri, 4 Apr 2014 23:26:42 +0800
Content-Type:
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text/plain (121 lines)
Thanks for the advise

Lyon yuan

-----Original Message-----
From: [log in to unmask] [mailto:[log in to unmask]] On Behalf Of
Stadem, Richard D.
Sent: Friday, April 4, 2014 11:19 PM
To: [log in to unmask]
Subject: Re: [TN] Press-fits connector

*	Wrap ESD-safe Kapton tape around the press-fit connector bodies, at
least two or three layers.
*	Use a Hakko tweezer-style iron to remove the wrong value parts. This
takes less than 1 second per part for removal. Keep a small amount of solder
on the inside of the tips as you go.
*	Throw the removed resistors away. Do not re-use.
*	If you can run the board back through reflow, then dispense a very
small amount of Type 4 or 5 solder paste on each pad with an automatic
dispenser (226 dots).
*	Create a pick and place program just for the 113-user resistor, take
care to route the placer around other components on the board. You may have
to manually dispense some pads.
*	Pick and place the correct value replacement components. Again, you
may need to manually place some components.
*	LIGHTLY spray flux over the entire CCA, on the SMT solder joints.
*	Run the assembly back through reflow.
*	Remove the tape from the connector bodies.
*	Wash twice, maybe three times. Perform ionograph cleanliness
testing.
*	Inspect and touchup.
*	Be sure you run two or three boards through the entire process and
perform 100% visual inspection and test on the two First Articles to make
sure there is no damage to the connector bodies or 	any other components
before reworking the entire lot this way.

Have fun with that. I am going ice fishing now. Beer and minnows and my
beagle, Ella, are waiting. Have a nice weekend.
Dean

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of lyonyuan
Sent: Friday, April 04, 2014 9:48 AM
To: [log in to unmask]
Subject: Re: [TN] Press-fits connector

Hi Steven,

The usage is 113 pcs/unit, it's hard to rework under manual rework

Lyon yuan

-----Original Message-----
From: Steve Gregory [mailto:[log in to unmask]]
Sent: Friday, April 4, 2014 10:24 PM
To: [log in to unmask]; lyonyuan
Subject: RE: [TN] Press-fits connector

Hi Lyon,

Don't mean to ask a dumb question, but why would you want to send the whole
board through reflow to rework it for a wrong value resistor?

In my experience it's always been a manual process to rework chip components
with wrong value. Can be a PIA, but it can go pretty quick with the right
solder tip for removal. For example, here's a Metcal tip for 0402's and
0603's:

http://www.okinternational.com/Hand_Soldering_Systems/id-SMTC-596/SMTC_R
ework_Cartridge_Slot__SMTC-596


Steve


-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of lyonyuan
Sent: Friday, April 4, 2014 7:03 AM
To: [log in to unmask]
Subject: [TN] Press-fits connector

Hi Guys,



Anyone to know if the material of housing of connector is LCP, if can endure
reflow process? Since we need rework some boards with wrong component for
res we don't want to remove those press fit connectors.



Lyon yuan





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