It seems like the recipe for Superior Circuit Boards is bugged. This recipe requires Silver Plate, but it does not accept Silver Plate. Other recipes that require Silver Plate (like Silver Wire) don't have this problem.

It seems that this particular recipe requires a version of Silver Plate that is not in the game. When copying the recipe to a requester chest (copying it's required items to it) it also requests Silver Plates that the game does not seem to link to plates in the logistic network (whereas with silver wire that problem does not occur).

Furthermore, when a recipe is copied to a requester chest (like Silver Wire), if you click on any of the requested items it will show that item in a menu (and highlight it). This does not happen when Superior Boards are used as the recipe. Clicking on silver plate does show the right sub-categorie (metal. casting), but does not highlight the silver plate.

It seems that somehow the recipe is linked to a version of silver plate that is not part of the game.

This issue has already been reported.
It's not a Bob's Mods issue. The Superior Circuit Board costs Gold in my mods, not silver.
I think it might be Angel's mods that changes it to silver, but I'm still not sure why the assembling machine won't let you put the silver in.

Bob's mods also does not have Silver wire. it has Copper (vanilla), Tinned, Plastic coated, and Gold plated wires.
Also Metal casting is also not part of my mods.