How to correctly fill a BOM with split connectors

Question

I have to prepare the documentation for production. In our board we use a specific female header with 6 positions. Long story short, the buyer guys told me we will buy a 64-way connector and then it will be split up:

https://www.mouser.it/ProductDetail/Mill-Max/315-43-164-41-001000?qs=FG09h9tFCuBGctf6cn%2FLOw%3D%3D

Let's say I have the following BOM:

Ref      Q.ty     Mft.       Value
R1, R2   2                   1k 1% 1/10W
...
J1       1        Mill-Max   315-43-164-41-001000
...

I'm not sure how to address this scenario. The actual p/n to buy is correct (315-43-164-41-001000) but the quantity needed depends on the point of view:

• for the PCB is ONE item (but not the whole strip)
• for the buyer guys should be something like 64/6 (in order to buy the needed quantity for a given amount of boards)

How would you handle this scenario in order to make a clear and understandable documentation?

Answer 1

1. Don't.

   A 6-pin version exists: 315-43-106-41-001000, though it seems not stocked by Mouser. Digi-Key and others have it.

   Eliminates confusion, no assembler in the world will ask what you want done with this, or complain that it's a gross mismatch to footprint, etc. Maybe even automatic assembly can be done (if one happens to have a machine to grip and place those things..).

2. Put copious notes on it.

   If you're lucky, they'll read the notes (comment, description, extra column; text on the assembly drawings; txt file in the package; etc.) and figure it out. There is no standard for this, write it in however you like. Downside: all the extra noise may confuse the assembler, and English text might be ignored by overseas assemblers (particularly budget services that offer their proto process and nothing more).

3. Provide it in a separate material list.

   This is probably the least effective (read: most likely to get boards without connectors soldered into them), but it's a format where "rate" materials are standard (i.e., length of wire, etc.).

Answer 2

Digi-Key offers value added parts that are exactly what you want: standard headers split down to the length you want. They show as 0 stock level but as long as it says “value added item”, the stock level is not relevant. They almost always have stock of the “raw material” - long strips - to feed into their machines.

Answer 3

Assign two part numbers:

1. Incoming, off-the-shelf part, uncut
2. Cut part, ready for installation on board; prince includes the labor cost of cutting it; its BOM has a single line item: the first part number

The BOM for the assembly has the second part number.