Electronics Forum | Fri Apr 23 13:31:20 EDT 2004 | russ
The toes of leaded devices are problematic in fillet formation. A lot of the time they have the copper from the lead exposed so it becomes oxidized and won't readily take solder. Normally this is of no concern if the heel and side fillets are forme
Electronics Forum | Tue Apr 11 10:30:46 EDT 2000 | Jeremy Smith
I am having a problem with some joints on a 100 pin pqfp and few different soics on one particular board. When viewed a 8x with a "Mantis" inspection scope the joints look as though they wetted to the ic leg but when probed the leg will pop loose.
Electronics Forum | Mon Nov 12 01:18:29 EST 2007 | sin4d
Hi, ALL I experience some QFP with wetting issue on the heel of the lead. There is no fillet wetting on the heel which causes reject bt the customer, but not all the QFP. Could anyone pls help what is the causes of this problem, it is due to oxidati
Electronics Forum | Mon Nov 12 10:57:23 EST 2007 | chineechooze
i will supply dah 3d chart to sol the problem foryou
Electronics Forum | Mon Nov 12 19:47:33 EST 2007 | sin4d
Hi, Thanks. Waitng for your reponse. BTW, if I were to perform a test as below will this give me some result to indicate if the component is defective. 1) Print solder paste on plain PCB without copper track. 2) Mount the QFP & reflow 3) If the sol
Electronics Forum | Tue Nov 13 22:20:50 EST 2007 | davef
We'd add poor thermal recipe development, focusing on some QPF but not others that may a have a peculiar plating that requires extended time above liquidus.
Electronics Forum | Mon Nov 12 09:22:41 EST 2007 | russ
Could be any one of the 3 you mentioned, need some details here, do you really think we can answer this question as it is? Now for your issue, what is the make up of the lead itself on the part? what is the reflow profile at this part? what is
Electronics Forum | Tue Apr 11 16:42:56 EDT 2000 | Chad Notebaert
I�m thinking �Poor intermatallic� It could be a few things. Lets start at the beginning. -Is your paste a 63/37 mixture? -Have you monitored you screen printing, Verify Solder deposition, Are you getting enough paste? -You say the solder looks like i
Electronics Forum | Tue Jul 17 10:25:59 EDT 2007 | hussman
You want to know which flux will over come thermal mass problems? That's easy - none.
Electronics Forum | Tue May 23 09:16:57 EDT 2006 | Steve
Had exactly the same type of issues. Tried everything from pre fluxing the pcb's , various ammendements to the oven profile and various pastes. Finally after a lot of help from multicore we settled on a paste by the code of cr39. A no clean flux wit
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