Passives in component libraries

[pigrew]

How are passive components usually handled in Altium?

I need to supply part numbers for passive components in my BOM, and I'm not sure of the best way to do that.

Do people make generic SMD components for each value in their libraries, and then manually edit the parameters of the instances in the schematic to set part numbers? Or create a component in a library for each specific manufacturer part number?

Or use internal part numbers that each list a choice of components?

Are there ways to suggest alternate part numbers in case the first choice is not available?

[ajb]

Manually editing parameters would require the least setup upfront, but would be a tremendous pain to maintain.  Adding a separate part to the library for each value requires more work up front, but makes for easier outputs and consistency control later on.  It also makes it easier to specify an EXACT part number where that's critical versus other places where there's some flexibility.

If you use a dbLib, you add a separate entry for each part number to the database, and link in the same footprint/symbols from those library files, so you're effectively generating however many different values you need parametrically.  I think you might be able to do similar things with Vaults, but I've never used them. 

Internal part numbers and pick lists can be a good way to go if you need to maintain part sourcing flexibility but can't necessarily rely on someone else to source acceptable alternates, but it may be easier to talk to your assembly house about alternate parts--they may already have suitable parts on hand or may get substantially different pricing than you do, so you may get better pricing if you let them know which specs are critical and let them shop around for you.  Just make it clear up front which parts must be fitted as spec'ed, which can be substituted with approval, and which are not critical (this will obviously depend on how much you trust your CM).

[voltsandjolts]

^^^ What he said.

For example:
A library of common Yageo 805 and 603 caps / resistors which all have Farnell and Digi-Key order codes:
https://www.eevblog.com/forum/altium/altium-standard-resistors-capacitors-and-inductors/msg840139/#msg840139

[pigrew]

For example:
A library of common Yageo 805 and 603 caps / resistors which all have Farnell and Digi-Key order codes:
https://www.eevblog.com/forum/altium/altium-standard-resistors-capacitors-and-inductors/msg840139/#msg840139

How did I miss that other thread? It answers what I was asking.

Anyway, for now I'll continue with using Altium's supplier search to create parts from Digikey, manually assign the footprint, assign a designator, delete the superfluous `Description' parameter, and copy-paste the symbol. I only use maybe 25 different values of passives on a given board, so it isn't such a huge pain. Come to think of it, I should figure out Altium scripting so that I can automate those tweaks after having it create the component.

I hadn't realized how the component database works. I'll likely switch to using that for passives, as it seems much more logical to only have to have a single instance of a particular symbol, but maybe stick with the normal libraries for things that don't have value variants (like IC or connectors). The only disadvantage is that it looks like a component can only have a single footprint listed? [For some components, I have footprints with larger pads in order to allow easier rework.]

[ajawamnet]

I've been an Altium owner user since the days of Protel back in 1995. I do about 130 designs a year.

I tried db linking back in 1998. Not so good. Tried it recently. Ehhh...

Vaults? Wow what a pain... and buggy too. Integrated Libs? Well, you have to blow them apart to edit/add. Variants? Make a new part/assembly number. I can't tell you how many of my clients got burned on that over the years and shipped the wrong "variant".

How I've done it since?  Use a real MRP (Material Requirements Planning) system/methodology:

see this:
http://www.ajawamnet.com/ajawamnet/parts/parts.htm

As you can tell that was written ages ago. Still works tho.. I only use it for internal stuff I do, tho it works well with my clients MRP.

Note the section: "The key point - during a design capture the design intent is paramount. At that point the designer is focused on circuit function not who makes it or where it's coming from.
Every schematic minimally contains:
- a reference designator, usually assigned automatically during an annotation update
- a part type callout"

Also - note the section on the old QualeCad for handbuilding proto's/one-offs... too bad Altium didn't buy that guy. I recall the Camtastic guy asking me "Who is this Protel company" back before they bought him... of course that turned out to be not such a great integration effort.

So - get the stupid out of the design flow. A resistor schematically is a squiggle, a cap two parallel lines. All I need to know when I'm designing. Ensure I don't turn keychains when the PCB is off to FAB...

One of my constant gripes is that more and more people rely on the software to do the engineering. Not so good. Reliance on Vaults, Dblinks, integrated supplier links etc... in a specific tool is not a good plan. Been there, done that.

My EDA tool?  I use it to capture a design and make it work. It's part of a work flow - just a part of the overall design and building pf a product.

Version control? Uh... you should be using a numbering scheme and structure for all the components in a product - not just the boards. I can locate a snapshot of a  design I did 15 years ago - mechanical, electrical, chemical, whatever... in about 20 seconds.

Parts management?  If you're in my realm, you have to be careful how you buy stuff. Problems from counterfeit part mitigation, supplier/mfg acquisitions, various issues with things like AVLs/DFARs, compliance with things like AS9100, etc... - I'd rather let that be in an MRP system. When I'm designing something I'm more concerned with fit and function than being a parts management guy...

And the majority of what I do requires things from either me or my mechanical guys. So again, a separate parts management system allows us management and  fusion of all the components - not just my silly board.


As to MRP and MRP II note the wiki stuff:
https://en.wikipedia.org/wiki/Manufacturing_resource_planning
https://en.wikipedia.org/wiki/Material_requirements_planning

Note all the issues that real MRP has to deal with. Altium? As the lady in the Akerman commercial mentions about getting her cable company to do her home security system ("they can barely keep my TV signal on") I'd prefer to let systems designed for managing parts handle that.

"Just a key field ma'am"... good relational database practice.

Altium getting into the areas of good design management (and as I've mentioned "takes more than PCB's to make a great product Bevis...") is like their foray into:

- FPGA's - that worked well - NOT
- embedded code development. Good lord, even the mfgs of the uC's/uP's have a hell of a time releasing bug free design environments.
- 3D? Christ Solidworks-Catia/Creo can barely handle that. Ask Airbus how well that worked for the A380 :

See https://en.wikipedia.org/wiki/Airbus_A380 - Production and delivery delays

"Initial production of the A380 was troubled by delays attributed to the 530 km (330 mi) of wiring in each aircraft. Airbus cited as underlying causes the complexity of the cabin wiring (98,000 wires and 40,000 connectors), its concurrent design and production, the high degree of customisation for each airline, and failures of configuration management and change control.[57][58] The German and Spanish Airbus facilities continued to use CATIA version 4, while British and French sites migrated to version 5.[59] This caused overall configuration management problems, at least in part because wire harnesses manufactured using aluminium rather than copper conductors necessitated special design rules including non-standard dimensions and bend radii; these were not easily transferred between versions of the software.[60]"

"Honey I shrunk the board"

"...no dear - you just shrunk your brain..."

"What makes an expert isn't so much what they know,
It's that they've done similar things so many times wrong
They know what not to do"



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