Electronics Forum | Wed Sep 08 17:34:26 EDT 1999 | Earl Moon
| | | | Hello: | | | | We are using a Heller 1500S reflow oven to solder surface mount parts. Just within the last two weeks, the larger I.C.'s are moving while going through the oven. The parts are checked for placement before putting into th
Electronics Forum | Wed Sep 08 20:26:30 EDT 1999 | Jackie Hsieh
| | | | | Hello: | | | | | We are using a Heller 1500S reflow oven to solder surface mount parts. Just within the last two weeks, the larger I.C.'s are moving while going through the oven. The parts are checked for placement before putting int
Electronics Forum | Wed Sep 18 12:31:16 EDT 2002 | dragonslayr
My suggestion is to conduct a Design For Manufacturing (DFM)study on the assembly in question. Pay particular attention to the pad sizes, component lead dimensions and satisfy yourself that those two factors are correct. Given that pads match compone
Electronics Forum | Thu Mar 25 23:23:00 EDT 2021 | llawrence
The QFP pitch is 0.5mm. Pad size is 1.475 x 0.3mm, and the new aperture size is 1.32 x 0.22mm. I'm not sure about whether or not it is lasered, but on the newly ordered stencil I selected the polishing option. Looks like the pad width is already 2/3
Electronics Forum | Tue Mar 28 08:29:04 EST 2006 | davef
Pad design - Standard IPC 20 pitch QFP Thermal pad design - Layout the thermal pad 0mm to 0.15mm larger per side (0mm to 0.30mm larger overall) than the exposed die pad on the package. �Larger than�, as opposed to the same size, is preferred. Obvio
Electronics Forum | Sun Apr 04 08:03:41 EDT 2004 | davef
There certainly is a problem, but it�s unclear from your description whether the source of the problem is: * Design * Soldering * Component quality * A combination Recognizing the SMT connectors see stress that other SMT component do not, you give t
Electronics Forum | Thu Jan 02 10:31:48 EST 2020 | slthomas
It is strange that you're having issues while using the same process parameters (including stencil) that worked successfully before. It doesn't guarantee that it's not one of those parameters changing in a manner that's not apparent, but it does sugg
Electronics Forum | Thu Jun 01 22:47:27 EDT 2023 | spoiltforchoice
most, possibly all of our clients, don't specify this kind of thing even when they are in fields where you might expect they should and should be aware of them. However if you cherry pick a couple of class 2 requirements such as offset and joint widt
Electronics Forum | Wed Oct 03 17:07:52 EDT 2001 | davef
We have had soldering problems with fine pitch QFP in the past [and probably will in the future]. Several questions leap to mind: * When you took your profile on the component pads, do you profile on the pads that did not solder well? * When you say
Electronics Forum | Wed Sep 08 21:32:46 EDT 1999 | Jason Nipper
| | | | | | Hello: | | | | | | We are using a Heller 1500S reflow oven to solder surface mount parts. Just within the last two weeks, the larger I.C.'s are moving while going through the oven. The parts are checked for placement before putting
