Electronics Forum | Wed Dec 08 19:50:34 EST 2004 | shen_zte
can anyone tell me the benifit of the solder mask onto pad(part) or pad defined by solder mask?and how to excute the SMT process ? thanks.
Electronics Forum | Fri Dec 10 08:42:37 EST 2004 | mattkehoe
We had some bad experiences trying to work with soldermask defined BGA pads. If the opening in the soldermask is right to the edge of the copper/pad without a space it can leave reside on the pad and nothing will stick to it. See http://www.sipad.com
Electronics Forum | Thu Dec 09 07:46:42 EST 2004 | davef
We did this for BGA pads, but have not thought about other types. So, this may or may not apply for those. Pad defined by:||Advantages||Disadvantages Non-solder mask||No point-of-stress concentration at edge mask and solder ball||Smaller pads have
Electronics Forum | Tue Feb 09 16:53:06 EST 2021 | SMTA-64387083
The size of the pad changes among the two. A solder mask defined pad will always be larger than a copper defined by your mask expansion setting. This will affect paste volume, if your standard paste aperture is designed for copper defined pads you m
Electronics Forum | Fri Jan 22 16:03:17 EST 2021 | SMTA-64387124
Does anyone see any issues in mixing SMD and NSMD pads within one BGA footprint. We have high current pads which we want to make SMD and the other signal pads to be NSMD
Electronics Forum | Fri Jan 29 16:17:13 EST 2021 | donnie15
The impact is low on larger pitches and pad sizes. as things get to the .4mm pitch the pad differences start affect your ball size and yields. The trace size going into the pads and the solder mask relief can cause some odd shaped pads with signif
Electronics Forum | Thu Sep 03 22:03:32 EDT 2020 | SMTA-64386139
Both conditions are acceptable for this bottom brazed flat pack package. The solder coverage must be within 0.070 inch of the lead/package interface per MIL-PRF-38535, paragraph A3.5.6.3.4.a. While that requirement could allow for a gold gap near t
Electronics Forum | Wed Jul 01 13:17:39 EDT 2015 | davef
Cheryl Tulkoff and Randy Schueller do a good job summarizing the thinks on pad cratering here: http://www.smta.org/chapters/files/uppermidwest_padcratering.pdf Potential Mitigations to Pad Cratering * Board Redesign * Solder mask defined vs. non-s
Electronics Forum | Fri Jan 06 05:03:11 EST 2012 | richieoreilly
Hi All, Just wondering if anyone is placing 0201 components in volume. If so What pad layout are you using, i.e. pad size, shape and spacing. Also are you pads and fiducials solder mask defined or copper defined. Can you also let me know the rough q
Electronics Forum | Wed Feb 29 06:33:49 EST 2012 | amitsindwani
Please define the defect in following conditions & link to IPC 610 clause/sub-clause no.: 1. 0603 component placed on 0805 PCB pad 2. 0805 component placed on 0603 PCB pad 3. 1206 component placed on 1210 PCB pad and 4. 1210 component placed on 1206
