Electronics Forum | Wed Sep 07 10:41:24 EDT 2005 | D.B. Cooper
We've seen the same thing - leads of QFPs not as strong as we'd like them to be. In the past 4 years no problem, this Spring they start failing. Touch a solder iron to it and it solders fine. After crunching some data, we found that both QFPs fail
Electronics Forum | Fri Jun 02 15:53:51 EDT 2000 | James Burrell
I'm considering using Delmat, or some equivalent material, as a stiffener for rather large pcb, but I don't know the material properties. Specifically I'm interested in: Young's Modulus, E Poisson Ratio, nu Density, rho Strength, Thanks, Jim
Electronics Forum | Tue Oct 27 05:51:28 EST 1998 | jacqueline coia
Could you please tell what are the current avaliable standards, if any (BSI/IPC) for a measurement value on the mechanical pull strength on SMT IC leads after reflow. Thanks in advance, Jack.
Electronics Forum | Wed Mar 30 16:46:03 EST 2005 | chunks
There is no spec because solder is designed to provide an electrical connection not a mechanical connection to hold the part on. If it where mechanical we�d be welding our parts on. Your pad width and length are derived from your component manufact
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 | Wed Sep 05 10:13:21 EDT 2007 | slthomas
When I worked for a med. device company it was always great fun to observe the UL testing. Everyone would gather around the stairwell and say bon voyage to an $8k piece of gear. This was NOT a test of the mechanical strength of soldered connections
Electronics Forum | Thu Sep 06 10:12:27 EDT 2007 | slthomas
"...but it would also be testing if they had enough mechanical strength to hold the components on." Only if you take the time to observe the results. :) Your point is well taken, but these guys were only interested in seeing if any failure modes pro
Electronics Forum | Thu Jul 12 05:22:00 EDT 2012 | rob
Hi George, The extra pad is just for mechanical strength, it's not connected. As the Liteon LED is just a side view & nothing special you may get lucky and find that a someone like Rohm, Avago or Osram make something without the centre pad that stil
Electronics Forum | Wed Jul 17 10:22:36 EDT 2013 | ericrr
argh! the 6 ends of the resistors soldered to another though hole part to give the pcb track mechanical strength or are they just soldered to a remote pad, so if the resistors are knocked it has the possibly of ripping the track from the pcb.
Electronics Forum | Sat Oct 19 04:18:17 EDT 2019 | SMTA-Davandran
Dear Dave, Thank you for your advice on this issue. Shall butt connector withstand high mechanical strength after increase paste volume.
