Electronics Forum | Mon Dec 06 17:50:39 EST 1999 | Kantesh Doss
Christopher: Thank you for sharing your experience about the DPAK. Yes, out part has a heat sink at the bottom. Our stencil opening was 7 mils (in both X and Y) smaller than the pad size excepting that the stencil opening consisted of a series of zeb
Electronics Forum | Thu Dec 02 23:43:23 EST 1999 | Kantesh Doss
We have a serious misalignment problem of D-Pak components (Specifically Motorola's part number MJD-3055/MJD-2955)following reflow soldering process. We are using Alpha Metals UP78 solder paste. Our reflow oven is Nitrogen inerted and our oxygen leve
Electronics Forum | Fri Dec 03 18:01:56 EST 1999 | M Cox
Usually the alignment problem comes from pad design. The ground pad (largest) is too small. If that is the case (and even if it isn't) try placing a dot of SMT adhesive before placement (it will cure before reflow and hold the part in place). Goo
Electronics Forum | Sat Dec 04 09:23:20 EST 1999 | Christopher Lampron
Kantesh, Does this particular part have a heat sink across the bottom side of the component and does your pad size and stencil aperture match the component? I have just had a very similar problem with a DPAK. What we found was that the recomended pad
Electronics Forum | Sat Dec 04 09:42:18 EST 1999 | Chris McDonald
Just as explained in a follow-up you are getting too much paste on the pad. The pad is probably the right size but you cant have your aperature the same size as your pad. What we have done is put a Cross in the stencil. This will reduce the paste and
Electronics Forum | Fri Dec 10 10:25:59 EST 1999 | Wolfgang Busko
Hi Larry, you might find something looking for the thread "D-Pak misalignment Problem - Kantesh Doss 23:43:23 12/02/1999" Good luck Wolfgang
Electronics Forum | Wed Jul 09 14:47:39 EDT 2014 | deanm
I'm looking for a typical SMT placement defect rate from others in the field so I can judge whether or not we are in an acceptable range. If I give you a board with 200 components (0603, 0805, SOICs, 20mil MSOPs, tantalums, DPAKs and a few 20mil fin
Electronics Forum | Thu Dec 27 14:46:32 EST 2018 | emeto
Hi Prem, it will really help if you provide more pictures and metrics. Pad layout, part datasheet, stencil design and most of all picture of the misplaced part on the board. This looks like a very interesting case and I am willing to help you, but t
Electronics Forum | Mon Aug 17 11:35:57 EDT 2020 | artem
Hello, I have some troubles with my MyData TP11-UFP with the precision of the placement. All the parts which are mechanically centered are slightly misaligned. Attached are some pictures of 0603 and a SOT23 part. I have made the calibration but it
Electronics Forum | Mon Jan 09 21:37:35 EST 2023 | stephendo
Can you view the vision system screen where it recognizes the part? It should show the picture of the part as the camera sees it and show x's where it detects the features it is looking for. Some parts can show up strange on cameras. It might be havi
