Does FTDI232 chip need programming before use?

CrossRoads: 0.05" and TQFP, 328P-AU space, is not too bad. Use a stencil, solder paste, and reflow oven. TSSOP is too small tho.

I see. You used a lot of itead PCB service. Have you considered using their assembly service to help you with the SSOP etc.?

Nope. I use cbas-usa in CA for assembling small stuff. Will occassionally buy small parts on DIP adapters from proto-advantage.com in CA. They'll buy the chips and install on adapters for you. Will get back to my ADC to SD card for playback thru DAC later project eventually.

Stuff for my own use or for planned kits, I stay away from the really small stuff . 0805 for Rs, Cs, DIPs when I can, larger size SMDs for chips.

Stuff I design for others, I warn them about small sizes and then they're on their own for assembly. Especially where a double sided board with components on both sides that has more parts than should be allowed in a design are used!

I soldered an FTDI TSSOP-28 using paste and a hot air gun, worked just fine, but my last board had a lot of fine-pitch chips (both sides) so I had the PCBA done for me.


Rob

I pay a lot more attention to pads & where traces come off the pads now, but I farm out assy where really small parts are used.
I have a 2560 mega on a board designed, will brave putting a chip on one of these weekends.

Need to remember to order a crystal also.

Rob,

That board looks great! Is there any particular rules you follow regarding orientation and spacing of your various components?

CR,

I am trying to make a design and go through some PCBA service with itead or seeed so that this device can be readily ordered by any physics teacher with my design files and BOM. Otherwise only those with a lot of knowledge of electronics can make and the device. I'll let you know how the PCBA process goes.

I've found that parts of 0805 size and SOIC pitch can be soldered OK with small amount of magnification, using fine tip soldering iron and solder. I tried some other techniques like solder paste and heat gun without consistent success, what really kicked my SMT into high gear was buying a cheapish stereo microscope, with wide field x10 eyepieces. With practice I can do QFP and TSSOP without problem, I am moving to 0603 part also.

That's ok for 1 offs, I wouldn't want to make multiple boards with that method. I think solder paste and reflow oven (toaster oven) is the way to go there.

I think without an effective SMT technique and cheap PCBs from China I would be doing a lot less hardware projects. I've nothing against DIP and 0.1 stripboard, I spent many a year building those, but now most of the chips I am interested in are not available in 0.1 packages.

Btw, Microchip do a USB-serial chip in SOIC package, MCP2200, which is pretty handy.

bobcousins,

Thanks. So with the MCP2200, how easy is it to install windows driver? Do you have experience using it on mac or linux?

Why is everyone replying this thread a Bob, Rob, or Robert?! ;)

Is there any particular rules you follow regarding orientation and spacing of your various components?

Yep, I place stuff wherever it fits :)

Obviously I pay attention to where things are in terms of trying to optimise traces, but these days I don't place anything on a grid or worry about orientation or anything that's not a specific technical thing.

And the old "vertical on one side and horizontal on the other side" has gone out the window as well, with large components totally blocking one side it's not practical any more IMO. That Mega2560 for example, you can't fit traces between the pins so almost that entire area is blocked on the top layer, no way to enforce "vertical only" rules.


Rob

liudr, So you're thinking folks will contact itead etc. to have them make 1 card from a set of gerber files and a BOM? I would think you'd have better luck getting a set of boards made up with at least all the SMD components, and let folks purchase that and complete the thru hole parts, or buy the whole thing as a complete assembly.

I would imagine instructors and schools will order more than a few dozen at a time the fully assembled boards and then box them with enclosures (drill one hole). They can't buy individual boards from itead but they can from whoever ordered a few dozen. I think maybe itead has 10 minimal order for PCBA.