next topic »

[on:]

Hi all,

I just ordered 6 of these accelerometers http://www.bosch-sensortec.com/content/language1/downloads/BST-BMA150-DS000-07.pdf. But i just ordered the sensors themselves, not placed on a breakboard.

How would i connect a wire to them? there only 3 x 3 mm?

Excuse me f this rather obvious (and stupid).

[Reply #1 on:]

Maybe these videos at YouTube can help you:

How to Solder an SMD LED to Magnet Wire - YouTube


Soldering 0402 SMD LEDs for lighting - YouTube


There are many more over there.

[Reply #2 on:]

I forgot to say that I am doing just the same thing.

I am soldering 4 AWG 30 Kynar wires to a 3mm x 3mm SMD bicolor LED pins. It is possible, use a good magnifying glass and solder flux.

[Reply #3 on:]

Oof, the no-lead type of chips with the pads underneath and nothing exposed for you to look at... Never done one myself, but I think a hotplate for solder reflow is the best option.  Maybe pre-tin the pads and sop up excess solder with wick, carefully place the chip on the pads (with good magnification and a steady hand/good tweezers) while heating the board on a hotplate.

Like what they talk about here: http://www.sparkfun.com/tutorials/59

OTOH, I'm not sure but maybe you could get by with long PCB traces coming out, pre-tinned with solder, add flux before laying down the chip and try applying the soldering iron tip to the traces hoping the solder will reflow underneath the pads with the help of the flux (without needing a hotplate).

[Reply #4 on:]

I was able to accomplish this using the exact method that spirilis described using a hot plate. I did however have a couple short out during testing because it's very difficult cleaning out any leftover flux from underneath them. That's another pitfall to watch out for.

I'd also agree that using long traces would be a good fallback plan.

[Reply #5 on:]

for dead bug, tin pad, tin wire melt together, and be really steady with it

for board mounting these beasts I have tinned pads with minimal solder, fluxed part and used a heat gun and tweezers before, its wonky, its scary, its possible, though in best case I would rather use something without forced air heat, like a hotplate, or IR

course your best bet when you get to that is solder paste, though I know its a PITA to keep around the house for one or 2 things once in a while ...

[Reply #6 on:]

I was able to accomplish this using the exact method that spirilis described using a hot plate. I did however have a couple short out during testing because it's very difficult cleaning out any leftover flux from underneath them. That's another pitfall to watch out for.

I'd also agree that using long traces would be a good fallback plan.

Excess flux is a good thing - excess solder is a problem as it will cause shorts.  Surface mount soldering is very reliable when done properly (by machine...).  It relies on the right amount of solder paste on the pads before heating - moral: use less solder.

[Reply #7 on:]

Thanks to all,

I'll try and solder one, if i fail i thinks i have to get some sensors on a breakoutboard.