smt assembly of 0201's:  is this standard easy no-risk tech these days? - Page 1
Forum section: electronics / general

author: frogblender
author_rank: Regular Contributor
timestamp: July 29, 2021, 12:29:58 am
content: Back in the old days, 0201's were a pain in la derrier - yields were lousy, tombstoning was rampant, and at the end of the day, for some reason, if you looked in the bottom of the SMT machine with a magnifying glass, there'd be a bunch of stray orphans down there. And that's if you could even find an SMT assembler who could do 0201.But seems like these days, every smt assembler offers 0201, and in the last bunches of boards I've had done, the 0201 defect rate was exactly 0.0%.So has mankind solved 0201? Is there any professional SMT shop that does NOT offer 0201?

author: Mangozac
author_rank: Frequent Contributor
timestamp: July 29, 2021, 01:17:09 am
content: Quote from: frogblender on July 29, 2021, 12:29:58 amMy business doesn't and I knowplentyof other professional businesses who don't either. Even those who have 0201 capable machines often don't want the headache of dealing with such small parts. 0201 size parts are only really useful to high volume and/or extremely space constrained designs.

author: ANTALIFE
author_rank: Frequent Contributor
timestamp: July 29, 2021, 01:38:15 am
content: Yea lot's of places say they can do it, but like with any fine pitch components there is more upfront work to get reliability up

author: SMTech
author_rank: Frequent Contributor
timestamp: July 29, 2021, 07:42:40 am
content: As a small SMT/Assembly house I would currently decline 0201, while our P&P would claim to handle both 0201 and 01005 I'm frankly doubtful the feeders truly deliver the performance required and as none of our clients have so much as asked, we don't have the nozzles either (and they are expensive. There are other issues too, I have no interest in in printing with large numbers of something that small using manual or semi-automatic printers and also I'd want the designer to have prior knowledge and experience of working with tiny parts so we're not fighting issues caused by layout or pad design. Printing gets super critical at finer pitches, this is where you start needing multilevel stencils &/or dispense option on the printer/placement machine to add extra paste to larger parts.Interestingly not one of our clients has dipped below 0402 and even then they only dabble so its not an issue I have to deal with. The one exception was some tiny ESD suppression diodes we placed recently, the stencil manufacturer we used chose to address this by making the stencil 80microns thick but I'm not sure a more expensive/technical supplier would have made the same choice and had I realised those parts were on the BOM the stencil would at least have been quoted elsewhere.

author: Siwastaja
author_rank: Super Contributor
timestamp: July 29, 2021, 03:01:55 pm
content: We deal with a very small local CM (not because of shiny production capabilities; but because they are local, and super fast for batches of tens to hundreds, much better than me doing dozens of boards by hand all night long) that definitely can't do 0201 because even 0402 is a PITA for them so they prefer 0603 in the designs. The problem isn't the pick & place accuracy itself, it never is; the problem is in paste printing, and thefeeders.Even if you were able to find a few cheap fabs that seemingly reliably do 0201, keeping it to 0402 if you just can means practically 99.9% of fabs can do it with no extra hassle, at no extra cost, no extra delays. Having multiple options is always a good risk management strategy, what if you need to change the fabs suddenly?

author: SiliconWizard
author_rank: Super Contributor
timestamp: July 29, 2021, 07:00:48 pm
content: Also, do not assume that reliable assembly of 0201 *only* depends on the assembly house. The PCB layout must be carefully done to limit the possibility of tombstoning.Preferably, when you're dealing with such small parts and high-density boards, pick an assembly house you're confident in (and of course that has the technical ability), and submit your layout to them BEFORE finishing it. Have them point out the possible culprits. If they don't want to/or don't know how to help you with this, pick another.

author: Mangozac
author_rank: Frequent Contributor
timestamp: July 29, 2021, 10:06:42 pm
content: Also, another good reason to not use 0201 isn't assembly but rather any repair/rework/returns afterwards. Why make life any harder by using smaller components than necessary in a design?

author: 48X24X48X
author_rank: Frequent Contributor
timestamp: July 30, 2021, 05:42:11 am
content: Not everything can be "0201". Going smaller mean, the rating also reduces. Instead of getting 25/50V rated for your regular 0603, you will get something way much lower. If you are making commercial mass production gadgets with minimum size as a main target, then it's something that is unavoidable.

author: Clif
author_rank: Newbie
timestamp: August 18, 2021, 06:25:03 am
content: In china, many EMS companies such as FOXCONN, LUXSHARE have used 0201 for a long time, 01005 has also entered mass production, now there are going to phase in 008004/009005 package.

author: KE5FX
author_rank: Super Contributor
timestamp: August 18, 2021, 06:53:02 am
content: Once you're old enough to require a microscope for 0402 work, you might as well use 0201s. They aren't any harder to place or rework by hand than 0402s, IMO. Assembly houses that can't deal with 0201s aren't going to be at the top of my list for 0402-based designs either.As for tombstoning, that's easy enough to avoid by balancing heat capacity between the pads. If you have a lot more copper on one pad than you do on the other, then you can expect tombstoning. If you don't, then tombstoning won't be a major issue. It's not really a property of the component size.

author: Miti
author_rank: Super Contributor
timestamp: August 24, 2021, 11:03:49 pm
content: Our customers requested and we replaced the machines to accommodate. We do 0201 and 01005 very successfully.