I think we can all agree that the whole point of bypass capacitors in high speed digital logic is to present a low impedance to the logic circuit. For that reason, even when using wire-wrap boards I always soldered the capacitors into place on the side of the board opposite the IC sockets. Adding extra wire, and wire that might be more than a straight line is antithetical to a bypass capacaitor's purpose.

Completely agree... So the best thing to do is to solder the caps to the underside pins?

 

That seems the best solution.

 

SA05 package (grid is 0.2"):

I think I would solder these between those pins underneath the board.

 

Completely agree... So the best thing to do is to solder the caps to the underside pins?

?
http://forum.allaboutcircuits.com/t...ocket-in-a-strange-place.127524/#post-1040673

 

Why the leads? It's the capacitor itself that is too big, but it's a standard ceramic one. The lead is very thin and can fit anywhere. This board requires a capacitor to be under each IC, and I can't find a capacitor that small. This board is so strange, I think it might have been made for a special purpose...

I see the problem now. I just assumed it was a lead size problem.

I remember that companies used to make very low profile caps similar to bus bars. I am guessing that this is what the board was made for. It seems to me that most of the time that the IC and cap are in different columns of the board so they do not interfere with each other. If a location is a wide (0.6") IC then you may have to rely on a nearby bypass cap or sacrifice an IC location just for a bypass cap. You do not need a cap for literally every IC.

Note: I would _not_ solder the caps to pins of the board. That is why there are power and ground planes connecting to the capacitor pins. You are already wiring the rest of the circuit with long wires anyway so another 1/2 inch of wire to the power pin of an IC is no big deal. We are not talking GHz here or we wouldn't be using wire-wrap.