* 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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