Electronics SMD soldering

I have an 8 pad component that is 4mm by 4mm and I need to solder it to a PCB (wires arnt possible due to the fact that it is an acceleromenter and needs to be mounted flat). It only has 8 copper pads on the bottom no pins. I was going to use solder paste can someone confirm that this will work.

 

solderpaste should be ok... just remember tu use a microscope and clean out those extra "solderballs" wich tend to stay between the legs... those are nasty..

 

legs? what legs? As I mensioned above there are no legs

 

huh? isn't there some sor of legs.. you know.. wery small square ones...

what package is it?

 

nope no legs just copper pads on the bottom

 

If it used j legs, the legs will be curled under the chip. You can yse an iron to put a little solder on each pad, then place the chip over the pads and use a heat gun to reflow the solder.

The other possibility if it doesn't appear to have legs is that it is a BGA package. This could be a pain to work with. You basically have to align the solder balls on the bottom with the pads on the PCB. Once you are sure of it, use something to hold it in place, and stick it in a toster oven ensuring the board is perfectly level so the chip won't slide (unless your adhesive is really good). Once done, test and make sure it's OK. If not, I hope the glue is weak because you'll probally have to try and rework the job with a heat gun.

 

it isnt BGA. I know most of the packaging types and I have never see this one before

 

On the webby it is described as an LCC package. Though I am sure those are supposed to have legs.

 

LCC (leadless chip carrier) as it's name suggests, doesn't have legs (leads).

I've not thought about soldering these before, but from the look of them the only way I can see of using them is with solder paste. Apply some to the pads, and then reflow the joints using hot air. You might be able to hand solder them by using oversizing the pads so that you can apply a fine-bit iron.

For my next project I'm going to use some DPAK parts - and I'm still wondering how I'm going to solder the tab - presumably, you just use solder paste and a big soldering iron.

 

Some pics look like j-leads, others are a bit confusing. But I think the above info about the j-leads will work, though solder paste is a better bet. But I still reccomend an oven instead of a heat gun. The heat gun can blow things around if used improperly. They are fine for rework and removal, but I prefer an oven to do an inital solder using paste