This lets us drop another opamp into an LT1124 SO8 footprint. LT1124 has a nonstandard pinout, so few subs are available.
Did that come straight from the board house that way? If so, did they whine much about it? If not, what did you get, and what did you do to it?
They came just like that, no whining. We ordered 100 and they shipped us a couple hundred.
We thought they might be panelized, like these older ones,
but they routed them individually, somehow.
Why didn't you use flex?
Would that be better?
I fitted some mod boards to some telecoms gear back in the 90s. Similar to your little board but it used a flex substrate.
I cant remember whose gear it was, probably Nokia or Siemens. It worked ok out.
It'd be thinner. It looks kind of chunky in FR4. On a PCB of that size flex should be rigid enough. plus you can trim flex with scissors
The 'thick' board makes for a nice strong solder fillet which is very easy to do, at least manually.
I used this 'half PTH' method before, except in my case, the MSOP was mounted upside-down in a routed rectangular hole. If you're going to mess-up, do it properly.
Cheers
Nice. Layout person now remembers to look for "top view" label. ;)
Cheers
Phil Hobbs
My worst was a 208 pin 0.4mm pitch QFP that I decided should be 0.5mm :)
I saw one like that once, at a customer site. The FPGA was sitting on a golf-ball sized nest of red wires.
Den onsdag den 8. oktober 2014 21.03.21 UTC+2 skrev John Larkin:
We've gotten the footprint for a 676 pin FPGA upside-down once, I wouldn't try to rework that
-Lasse
In fact I attempted that, it was in the days when a 4-layer board was very expensive for us. But soldering 208 wires at 0.4mm was beyond even my - extensive - expertise at bodging.
google found a few pics
-Lasse
Darn, now you've put me off my afternoon banana.
Wow, a dead-bug FPGA.
How would one possibly do that? (Not that I ever hope to need to!)
Wow, The PCB of Cthulhu!
Cheers
Phil Hobbs
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