Electronics Forum | Wed Jul 19 12:54:04 EDT 2023 | calebcsmt
Since side fillets are not a requirement for QFNs/BTCs due to some packages not having wettable side terminations, how does one determine if the side terminations are actually solderable/designed for wetting? Is it simply if the side terminations
Electronics Forum | Mon Mar 26 11:20:39 EST 2001 | dblsixes
The pads are 0.070 x 0.012 ... as spec'ed, and as measured. The pad extends approximately 0.017 behind where the Class 3 fillet is required to be. (It used to be 0.037 on an older design that exhibited similar, but not as bad of heel fillets.)
Electronics Forum | Mon Jan 12 08:56:09 EST 2004 | Paul F
Is anyone having issues with fillet inspection on AOI machines due to poor toe fillets caused by exposed base metal? We're just getting into AOI now and QFP inspection is proving difficult.
Electronics Forum | Thu Jan 08 14:33:50 EST 2004 | dwzeek
Toe fillets are not required per IPC. Toe fillets could be used as a process indicator, if you desire; I would not. Gull wing leads are typically cut off on the ends when manufactured; this exposes the non-plated material in the lead, typically coppe
Electronics Forum | Sat Mar 06 17:45:29 EST 2010 | isd_jwendell
Unfortunately, what you are calling a good fillet is not a good fillet. Solder on the top of the IC lead does not help to make a good connection. The most important fillet is the one located at the heel (think of the IC lead where it meets the PCB as
Electronics Forum | Thu Mar 22 17:31:08 EST 2001 | davef
Hold off on the sharp knife for little bit. [Yano, I get "queasy" when I see much of my blood, but other people�s blood doesn�t bother me much. Weird, eh?] [Oh bye-da-bye, I didn�t win the bar bet on "Ground Hog Day". I didn�t loose it either. T
Electronics Forum | Wed Mar 22 01:24:54 EST 2006 | Joseph
Dear all, Referring technical report from Vitronics Soltec, "Pad lifting, fillet lifting and fillet tearing issues in LF soldering". The use of LF solder alloys today has brought about a recurrence of this crack formation, called fillet tearing. The
Electronics Forum | Tue Jun 28 12:12:17 EDT 2005 | Paul
I'm with DaveF on this one. I think you'll be trying solve this one for a long time. Alloy42 just doesn't like to be soldered. What exactly is the issue? Lack of a toe fillets at on the cropped lead? There is no spec for a toe fillet other than to
Electronics Forum | Fri Jan 26 16:24:10 EST 2007 | Bob R.
Whether there's a fillet or not depends on the component type. Most have a fillet but some, such as QFN's, don't necessarily have one. Have a look at IPC-610D Workmanship Standards to understand when you should expect one and when you shouldn't. T
Electronics Forum | Thu Nov 07 12:35:38 EST 2002 | slthomas
Sounds like you're talking about the "heel" of the lead not being soldered, in other words, no heel fillet, which IS necessary. That problem, for us, was attributed primarily to poor layout (insufficient length of pad extension to provide room for
