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Date:
November 04, 2009 07:39 AM
Author:
Craig
Subject: PLCC LED placement issues
We have started using an RGB LED and today ran the first boards down our line. I noticed an immediate issue with placing these. I'm using a quad QSP-2. The part sticks to the nozzle. The nozzles are clean. I have adjusted machine handling so that vacuum turns off before the head travels off the PCB after placement.
It is amazing, the part will stick to the nozzle after I have removed it from the machine. I also just took a spare nozzle and pressed it against these parts and it sticks in that application as well. I'm not sure what to do here. I dont think I can do anything with the equipment to correct this issue.
Any suggestions?
(http://www.smtnet.com/Forums/Index.cfm?CFApp=1&Message_ID=60298)
Date:
November 04, 2009 08:17 AM
Author:
bobpan
Subject: PLCC LED placement issues
Is there any sticky residue on the top of the part? Or maybe it has something to due with magnatism and maybe you could source a plastic nozzle instead of using the standard machine nozzles.
Good Luck
(http://www.smtnet.com/Forums/Index.cfm?CFApp=1&Message_ID=60300)
Date:
November 04, 2009 08:49 AM
Author:
kpm
Subject: PLCC LED placement issues
Its been a while since I've worked with a QSP-2 but I seem to remember that they should have a puff off value where the machine will actually blow the part off of the nozzle. I think it was adjustable under the component handling but I can't remember what it was called. I realize this isn't much help but maybe it will jog some one elses memory or you might be able to find it in your machine manual.
(http://www.smtnet.com/Forums/Index.cfm?CFApp=1&Message_ID=60302)
Date:
November 04, 2009 10:28 AM
Author:
Craig
Subject: PLCC LED placement issues
> Its been a while since I've worked with a QSP-2
> but I seem to remember that they should have a
> puff off value where the machine will actually
> blow the part off of the nozzle. I think it was
> adjustable under the component handling but I
> can't remember what it was called. I realize this
> isn't much help but maybe it will jog some one
> elses memory or you might be able to find it in
> your machine manual.
> Its been a while since I've worked with a QSP-2
> but I seem to remember that they should have a
> puff off value where the machine will actually
> blow the part off of the nozzle. I think it was
> adjustable under the component handling but I
> can't remember what it was called. I realize this
> isn't much help but maybe it will jog some one
> elses memory or you might be able to find it in
> your machine manual.
(http://www.smtnet.com/Forums/Index.cfm?CFApp=1&Message_ID=60306)
Date:
November 04, 2009 10:31 AM
Author:
Craig
Subject: PLCC LED placement issues
I'm not familiar with a puff off setting. I have tried some different things including release delay to shut the vacuum off before the nozzle lifts in the upward direction.
I tried to minimally overstroke the part hoping the paste tension would overcome my issue. Thanks for all the replies.
(http://www.smtnet.com/Forums/Index.cfm?CFApp=1&Message_ID=60307)
Date:
November 04, 2009 09:18 PM
Author:
isd.jww
Subject: PLCC LED placement issues
I only have first-hand experience with 2 pick-n-place machines, but both used a small pressure puff to insure part release. I haven't seen any software settings for this, but a small solenoid valve was dedicated to the operation. I recommend you look close at the hardware to try and find this valve (if it exists on your machine), it may not be working properly.
(http://www.smtnet.com/Forums/Index.cfm?CFApp=1&Message_ID=60319)
Date:
November 05, 2009 12:48 PM
Author:
adlsmt
Subject: PLCC LED placement issues
We have the same problems. We are using Universal equipment. In our case as I suspect in yours its a residue on the LED's not the machine.
(http://www.smtnet.com/Forums/Index.cfm?CFApp=1&Message_ID=60334)
Date:
November 05, 2009 04:38 PM
Author:
rdoss
Subject: PLCC LED placement issues
I don't recall where the puff off setting is either, but i know there is one. Find it and use that along with extending your pressing time. This will increase the time in which the nozzle holds the component in the solder. That, along with the puff off should be enough to overcome the residue. Both these settings should be in the component editor, but it has been a little while for me too. Good luck.
(http://www.smtnet.com/Forums/Index.cfm?CFApp=1&Message_ID=60337)
