Electronics Forum | Mon Feb 06 17:58:16 EST 2023 | davef
The September 29, 2022 Express Newsletter [ https://smtnet.com/express/index.cfm?fuseaction=archives&issue=20220929 ] has papers on chip cracking
Electronics Forum | Wed Feb 08 09:43:08 EST 2023 | charles_nguyen
Thank you for the above information but what I want to talk about is the PCB design aspect. Should there be any warning about it in the DFM?
Electronics Forum | Thu Feb 02 09:07:28 EST 2023 | charles_nguyen
Two types of land patterns used for surface mount pads are non-solder mask defined or NSMD pads and solder mask defined or SMD pads.Each type has its own advantages and disadvantages. There is a statement that SMD pad type may introduce stress concen
Electronics Forum | Fri Feb 17 19:23:05 EST 2023 | SMTA-64387083
Read the articles everyone else recommend. I haven't read of them but I will say this. A Solder Mask Defined pad is a copper flood that has much more thermal mass than a Non-Solder Mask Defined pad so it will heat and cool at a slower rate. I suspect
Electronics Forum | Thu Feb 02 10:10:20 EST 2023 | tommy_magyar
Perhaps google this, as you will find very interesting articles. For scientific explanation look up solder fatigue on Wikipedia with references added. A more in depth explanation you can find on the Digikey forum where you will find other people like
Electronics Forum | Wed Apr 13 21:17:18 EDT 2022 | stephendo
If it was ROHS, I would say that the pads are definitely dissolved away. And it sounds like that is the case here. Your best bet is if it is class 2 and the barrels are at least 50% then push for them to be accepted. If you are trying for more barr
Electronics Forum | Wed Nov 14 13:05:40 EST 2007 | rgduval
I had one project with micro-vias in 0805 and larger pads, with no issues. But my most recent project had vias that were larger than the 0402 pads that the via was in. To the point that for a number of the lands, there was no visible pads (a couple
Electronics Forum | Thu May 05 12:00:16 EDT 2005 | russ
Bad cleaning practice is suspect. It is believed that W.S. flux was used to solder adjacent components and then hand cleaned. This is not definite but it is pretty certain.
Electronics Forum | Sat Apr 19 12:00:07 EDT 2003 | modeltech
I am completely new to SMT design and for my next project I plan to use SMT for the first time. Since production volumes of the PCB's will be low, hand soldering is definitely an option, and will be necessary for my prototype PCB assembly. My proble
Electronics Forum | Tue Apr 27 07:46:14 EDT 2021 | jeremy_leaf
I have tried cleaning the pads. That was our first step. Ultrasonic cleaning in acetone and IPA, and also tried etching in a 10% HCL solution. Our board is definitely achieving the correct temperature.
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