The short answer: Yes. If you want prototype assemblers like Screaming Circuits to install it, it must go in the bill of materials.

For the most part, we solder through-hole and surface mount components on PCBs. As most everyone knows, all those parts need to be put in the bill of materials (BoM). The BoM is a list of all of the components to be placed on the PCB. The file typically includes an index number, the number of times a specific component will be used on the board, the reference designator from the schematic, the component manufacturer, and the manufacturer’s part number.

If a specific component is used more than once — a common bypass capacitor, for example — it will take only one line in the BoM. One field in the BoM will list the number of times the component is used, and another field will list all of  the reference designators for that part number.

You may also want to include alternate parts for components likely to go out of stock. Passives, like capacitors and resistors, are notorious for going out of stock without notice. Invariably, though, there will be a half-dozen nearly identical parts that will fit the bill just as well. Create an alternates list so your purchasing folks or manufacturer won’t get stuck not knowing if a substitute is valid or not.

But what about things that aren’t soldered, like nuts and bolts, double-stick tape, or display panels and such? Where do they go? The quick answer is they go in the BoM like all the other parts. Manufacturers build from the BoM. That means that if it’s not in the BoM, they won’t know to install it.

Some of these parts are nonstandard and can’t easily be quoted online, but they still need to be in the BoM. If you have such things, give your manufacturer a call to see how much it will cost and they can assemble it. Then either put the reference designator in the silkscreen or offer an assembly drawing with a reference designator for whatever it is.

That means a set of bolts might be BT1, BT2, BT3 …. Washers could be W1, and nuts N1. A glue dot could be G1. It doesn’t matter that much. Just make sure the reference designator in the BoM matches that on the silkscreen or in an assembly drawing.

If it requires hand operations like double-stick tape under a display, again check with your customer service rep first, but then put the display and tape in the BoM and provide any non-obvious information in an assembly drawing or special instructions.