I'm quite happy working with most parts, but with 0201's I run into some issues.
1) When placing an 0201 on a fresh set of pads or cleaned set of pads, the 0201 sticks to my tweezers. Should I be using a sharp pick to move them into place instead of tweezers ? I have a puddle of (Amtech) flux on the destination but seems they come back up with tweezers after moving it into place.
2) When I'm attempting to stack a pair of 0201 to build up an R pair to form a different value
I can do it but, wow, it takes me a long time.
Soldering one end down with an iron, it will tend to "tombstone" due to surface tension of molten solder instead of lay flat
Any idea on how to leave it stay 'flat' ?
If I hot air this structure, they don't stay put either
Any ideas ?
I'll try a slightly thicker flux, and maybe slow down the air slightly
I'm working in usually a fairly high density area with many components since I like to lay the board out fairly compact
Even if you are in a Class 0 ESD safe environment and following all best practices, when dealing with 0201 components your tweezers/pick/anything metal even if stainless steel and otherwise ESD safe is going to attract the little boogers. I didn't do much surface mount work at sea but even through hole stuff can be a pain in the butt in the middle of the ocean rocking and rolling on a relatively small warship. Orangewood sticks were invaluable since their charge/attraction is negligible! Just ensure you are being mindful of FOD when sanding/shaping the tip for your applications... (If you think 0201's are bad play with MMIC's sometime. Wire bonds and the conductive/nonconductive epoxy are "fun")
Unless you're prototyping I'd advise against stacking parallel components to achieve desired resistance. You're far better off ordering a sample book so you have the values you need and then can reorder strips on a case by case basis as used.
A good trick to avoid tombstoning with an iron is to prefill one pad with solder, reflow while pressing down on the component with a tweezer/pick/orangewood stick, and not remove till solidified, then hit the other side with your iron. For hot air processes just prefill both sides, achieve solder melt, press down, allow to solidify, and then remove your holding instrument.
Hope this helps,
Dan
Second Chance Repairs