0201 resistors PCB population

[Jester]

I'm working on a design that must be VERY compact. To fit the required components on the board will require 0201 resistors.

I have been using 0402 components for quite a while and the local CM's I use in USA and Canada have no quality issues when populating 0402 components. I have yet to have any boards built with 0201 devices, and would like to hear about your manufacturing experiences when using 0201 devices. Any issues or full steam ahead?

 

[ge]

0201 ... pain in the butt. They float easily on solder paste. Assembly houses hate them.

 

[ArticCynda]

General rule of thumb for 0201 or smaller: don't use them. High end P&P machines are required to populate them, they easily short or tombstone during soldering, and because of their size it's nearly impossible to rework them.

Assembly houses hate them.

That's an understatement. So expect price competitive assembly houses to refuse 0201, and expect very high assembly costs with those that do accept them.

If you're considering 0201 for the size, then keep in mind that the board space you save will be negligible while you're going to be all over your head in manufacturing problems. I no longer use parts smaller than 0603 (assembly houses favorite size) for large production runs, and so far haven't regretted the choice.

Summary tl;dr: don't do 0201 unless the cost of the final product isn't an issue.

 

[Makalro]

Hi. I just stumbled onto the site out of interest as I work for a contract electronics manufacturer. Reading this particular thread I'm not sure why it should be said that 'assembly houses hate' 0201 placement (?) It's not too cheap I grant you, and it depends on the particular assembly houses' standard of equipment and level of skill, but we successfully assembly a LOT of 0201's (alongside BGAs, micro BGAs, package on package etc) with very few issues.

 

[marce]

Had no problems with 0201's on very high density boards and 0402's are standard for decoupling on BGA boards. I would use an assembly house that can do them, many can...
The trouble with limiting to 0603's is they are no good for decoupling high density BGA's.
I have had many years of playing with SMD devices and reflow from the mid 80's and the only problems were not caused by the components sizes but by the assembly techniques be it incorrect solder paste deposition or incorrect reflow set up...

 

[D.A.(Tony)Stewart]

Lots of issues for orientation, shadow thermal effects of large parts, pad and track sizes and more.. Consult with IPC standards for design and DFM rules from Contract Mfg.

If you have a great design layout and good volume, then it is economical with the best sources. But if you ignore this , you may have much to learn.

 

[marce]

Designs regularly have chip components with one side connected to a solid copper pour, again in nearly 30 years with SMD only seen tombstoning a few times and again this was down to incorrect reflow, in these cases incorrect pre-heat causing a thermal shock almost as one end of the device heated up before the other, through a curtain of hot air... modern day equipment and assembly techniques have minimised all these problems. After all there are approx. 6 billion discrete components placed every day so plenty off feedback on assembly techniques.
My belief is if you are going to design PCBs then you should as part of your education learn about assembly techniques and the different ways of soldering available, also the importance of good stencil design...
Getting this lot of documentation is a good start, though the basic assembly and design specs (610, 6010-6013, 2221-2226) should be considered as required reading and reference.
https://portal.ipc.org/Purchase/ProductDetail.aspx?Product_code=4499ABA8-7C32-DD11-A3F8-001422202D38