Electronics Forum | Thu Apr 12 20:32:31 EDT 2007 | davef
On one hand, nothing in 8.2.5.4 that states that you need a heel fillet. It only talks to the length of the side fillet. On the other hand, we suggest that you should use 8.2.5.6 to determine if your heel fillet is acceptable, after you have determ
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
Electronics Forum | Fri Nov 22 16:59:43 EST 2019 | dwl
I'm worried about the voids that you have on the heel fillet of the leads. Off the top of my head, I don't recall if/what the IPC spec is for voids in gull lead fillets is but my gut instinct is that you're compromising the mechanical strength of the
Electronics Forum | Fri Mar 23 18:55:30 EST 2001 | davef
Consider posting actual measurements of your pads, component leads, and apertures.
Electronics Forum | Thu Mar 22 08:54:06 EST 2001 | dblsixes
I'm not familiar with Laser Soldering. I don't believe it to be a problem with the QFP themselves, since the two plastic parts are from different vendors in the same package. We also are having similar problems with other plastic parts on other boa
Electronics Forum | Thu Mar 22 16:06:22 EST 2001 | dblsixes
Our next plan of attack is to dog-bone the solder aperature. By reducing the width of the solder paste at the heel, we hope to slow the flow up the leg of the pin while the temperature of the pad catches up. We have boards that were HASL ...
Electronics Forum | Sat Mar 24 16:34:06 EST 2001 | Stefan
Can you increase the placement force on your P&P machine? It should squeeze the solder paste to all sides including the heel.
Electronics Forum | Wed Mar 21 20:40:28 EST 2001 | dblsixes
We are building a monster ... Dimensions are 10" x 7" ... 12 layers ... A Logic Assembly with a Power Supply all rolled into one ... The Power Supply is in one section of the board, the logic in the other section ... The Power Supply obviously has a
Electronics Forum | Thu Mar 22 15:44:50 EST 2001 | pteerink
I have a board with QFP240 plastic package exhibiting the same characteristics. Minimum heel fillet that doesn't change with stencil mods, paste change, profile change etc ( I am working to class 2, though, so my pass spec, although they are not pret
Electronics Forum | Thu Mar 22 15:45:20 EST 2001 | pteerink
I have a board with QFP240 plastic package exhibiting the same characteristics. Minimum heel fillet that doesn't change with stencil mods, paste change, profile change etc ( I am working to class 2, though, so mine pass spec, although they are not pr
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