Electronics > Beginners
Smd 0402 / 0603 assembly considerations
made2hack:
Hi all,
Newbie question. What questions or considerations should I be aware of if I want an assembly house to pick n place really small parts? 0402 / 0603 (metric I think). Sizes such as 0.5mm x 0.25mm leds.
Do pnp machines not care? are nozzles small enough? Does it matter the spacing between components?
Essentially what questions should I ask the assembly house? Or what documentations should I find on their spec pages?
Berni:
Any modern pick and place house should be able to handle 0402 these days.
Pick and place machines grab parts from the top anyway so no special spacing requirements. Its mostly just the typical stuff of getting your footprint correct so that you don't get too many failures in the form of components shifting out of place, lifting up on end etc... These sort of 'thombstoning' problems tend to be more common with tiny parts.
made2hack:
ok
thx. Who has precedence in design rules? The pcb house? Or the assembly house? Or do they tend to be identical? (ie min trave width, spacing, etc)
mvs:
--- Quote from: made2hack on January 09, 2020, 11:57:32 am ---ok
thx. Who has precedence in design rules? The pcb house? Or the assembly house? Or do they tend to be identical? (ie min trave width, spacing, etc)
--- End quote ---
Trace width/spacing is important only for PCB fab. Assembly house is more interested in component clearance / rotation, pad dimensions, thermals, pcb panel size, rails, feducials, etc.
Dave has some videos about design for manufacture on youtube.
Berni:
Its the PCB house that is actually manufacturing your board so they say what they can produce. Tho its mostly a matter of what is cost effective for you rather than what they can do.
A lot of PCB houses will do 0.075/0.075 mm track/space with 0.1mm holes and 16 layers. But expect a small prototype run of 5 boards to cost you about 1000 to 5000 USD. The larger features and tolerances you can have the cheaper the board is going to be. Meet the lowest spec dimension rules and you can get 10 boards made for <5 USD
All that matters for the assembly house is that you provide them with good documentation. Having components consistently rotated in libraries, good descriptions and part numbers, well organized BOM, assembly drawing printouts for them to double check. Even a 3D render of both sides of the board can be helpful to them (If your CAD tool has 3D support). The easier you make it for them the less time you are going to waste talking to them and explaining stuff and less likely its going to be they are going to assemble your board wrong.
Navigation
[0] Message Index
[#] Next page
Go to full version