Where to source small quantities of out of stock ICs?

Hey everyone! It turns out that RS Americas can give a shipping confirmation without actually having components in stock. So, now I have a stack of boards with a critical IC missing (MAX17320G20). Are there online marketplaces where I could possibly buy someone’s overstock or excess parts? I’m sure these must exist, and I’d really rather complete my boards with this part rather than do a redesign with a sibling part. Thanks for your help/recommendations!

You could try backordering them from a larger distributor like Digi-key or Mouser.
I usually use find chips. com they are sometimes off on inventory levels.

Unfortunately, I have been having issues with parts going out of stock since mid april. It may take 6 months to a year for the chp fabs to catch up.

Welcome to Chipageddon.

Don’t try to buy off of Aliwhatever. 99% chance of getting fakes.

It looks like all the TQFN chips are out of stock everywhere and not scheduled until end of Dec 2021.

Is it possible you could design a little BGA to TQFN adaptor? The 30 WLP package seems to be in stock. I don’t know if you can make castellated pins that small, though.

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On the topic of adapters. The people at https://www.arieselec.com have a pretty good idea of what’s possible in making adapters. Depends on how desperate you are.

Do you have any tips for working with WLP or a suggested CE course segment to check out? This is the first board I’m making with QFN parts and 0402s, and while I do have an oven with temp profiles, and I can use leaded solder to make things easier, I’m still worried. I’m very unsure about working with BGA parts.

I suspect you’ll take what you can get, but how many do you actually need?

This has been a problem with Maxim parts for 30 years. The don’t seem to consider distribution channels in their planning. It’s why I stopped using them for anything that couldn’t support with a direct contract, or I couldn’t do a lifetime buy out of distribution before production.

They have a lot of cool parts. Not real useful if you can’t buy them. And you often can’t.

Been burned too many times, and watched others hit the same wall.

I looked at stock at a number of eastern European distos that I often find slow moving stock of popular parts and even they are out.

Rich

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Maxim was the only company I could find that had an integrated solution for battery capacity management, thermal/current/voltage overload safety, and balance charging. :frowning:

This design is for my dragon robot, so I only need to make 10-15 boards total (for the robot & spares in the future). I thought that after I got my order confirmed from RS, that I could proceed with fabrication, so that’s been a sad surprise. I knew this chip was low in stock, so it sucks that it’s gone out of stock in the meantime.

I looked at the WLP/QFN adapters, and I’m not sure they’ll be economical, since it seems like they’re custom made. I’m wondering if I could make a daughter card myself (since the 1wire part is in stock still, and it has the same pinout except that I2C lines get replaced with 1wire & the OD selector).

Alternatively, has anyone made a QFN daughter card? If I could get some vertical height, I could continue with QFN assembly and use a larger PCB mounted above the board to integrate the 1wire part and a 1wire adapter.

I (dimly) remember someone recently designed a small custom flex PCB adapter for this sort of thing. I want to day they were replacing a fine pitch BGA. I’ll see if I can find a reference.

Not the one I was thinking of, but might serve as inspiration:
https://hackaday.com/2019/07/29/micro-sized-flex-for-commercial-quality-bodging/

Rich

That device in BGA is a 0.4 mm pitch BGA with d=0.3mm balls. I believe that’s filled-via-in-pad territory. And then you have to get the QFN equivalent pad under that to make the conversion.

If this was a production run, I’d think this would be a time to make an “oopsie” board that you hook up to the primary board with patch wires. But for short-run proto where the board hasn’t been made yet, a re-layout is most likely the best way to go. Since it’s also for prototype, you can be sloppy and have more flux and bounce the chip while heating under a hot air tool to make the junction. Having a ENIG board helps, but you can also solder-wick the pads clean if you get a HASL board.

Pretty expensive and there is a very real risk of counterfeit/remarked parts. Q1 price from a disti is < $4. I would try to pay with something that has buyer protection like a credit card.

Do not design in Maxim as they do not care for small customers although there free sample service was one of the best, once you start producing and supplies get tight you can forget about it. Unfortunately I got the same bad experience with RS components and Digikey which show stock on their website but when it comes to delivering the goods they give a no-show.