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asimov_18
06-10-2010, 09:30 PM
Hi Guys this really seemed interesting.

http://chiphacker.com/questions/1184/diy-smt-reflow-toaster-oven-skillet-or

or one could try this as well

http://www.circuitcellar.com/avr2004/DA3788.html


Asimov

vikas
10-05-2010, 07:58 AM
I two weeks back did my first SMT board but used a Hot plate ( costed about Rs 1000 ) , Though i had to indianize the results were extremely good, Looking at the PCB made no one can say it was done on a hot plate. I was extremely happy.

It took 15 minutes from blank pcb , component mounting to soldering. no more DIP for me ... too time consuming.

Will post a article about it , a few things which work for the US guys and dont for us.

asimov_18
10-05-2010, 12:26 PM
Hi Vikas,
Where did u buy the solder and paste mixture? What was the cost for it?


Asimov

vikas
10-05-2010, 12:32 PM
I bought the paste locally and looks like tps is selling it for much cheaper

http://www.onlinetps.com/shop/index.php?main_page=product_info&cPath=164&products_id=735
http://www.onlinetps.com/shop/index.php?main_page=product_info&cPath=164&products_id=734

I then mixed solder and flux, so that it can be pushed through a syringe ... Then used a medical syringe to apply it to the pads.

avinash_g
12-03-2010, 12:53 PM
@Asimov18

The paste is available at any mobile repair shop. I bought one for Rs 75 as small pack of about 50gms.

The same one that is available at TPS are available as follows

* Paste = Rs 60, Flux = Rs 20 in our local market.

I was thinking of buying a reflow oven from China the cost is approx Rs. 27,000 + Shipping + Duties/taxes. But today I got excited to do a reflow using a skillet but got too hot and burnt the PCB!

http://extremeelectronics.co.in/electronics/Images/SDBoardBurnt.jpg
http://extremeelectronics.co.in/electronics/Images/SDBoardBurnt2.jpg

And the plate fell from by hands and every components bounced off!

The actual PCB was like this
http://extremeelectronics.co.in/wp-content/uploads/2010/12/MicroSDBreakoutIso.jpg

vikas
12-04-2010, 02:44 AM
You need to buy SMD flux , DO NOT USE CHEAP FLUX which comes in metal circular box.

@Avinash - I have had very good results with Hot plate ( rs 1000 ) , with results not differentiable form professional job . After such results i had dropped my importing Reflow oven from china plan.

But you need to monitor it while soldering , when all the solder becomes liquid switch it off and dont move PCB's till its cool enough.

Here is a pic of something which i did , the 3.3v rect is the wrong part number hence manually soldered later on.


http://www.ngcoders.com/temp/custom_pen_drive.jpg

avinash_g
12-04-2010, 08:15 AM
Can you give a little detail on the hot plate. Becasue I have never seen a hot plate (expect on net). For what actual purpose it is used and where I can find one. I need it urgently.

And Rs 20 flux is the flux used in SMT only, I got it from a mobile repair shop. It same as shown in Online TPS.

vikas
12-04-2010, 08:48 AM
They are available at most electric appliance shops

http://cgi.ebay.in/SINGLE-ELECTRIC-PORTABLE-STOVE-HOT-PLATE-COOKER-/310274697410?pt=LH_DefaultDomain_203&hash=item483dd028c2

Should cost about Rs 1000 + .

avinash_g
12-08-2010, 09:35 AM
I tried a Normal Cloth Iron for reflow and results were satisfactory. I have a Induction cooker in Order may be that work out more perfectly.

Nivedita
12-15-2010, 02:50 PM
I tried a Normal Cloth Iron for reflow and results were satisfactory. I have a Induction cooker in Order may be that work out more perfectly.

Induction cooker may not give good results. Do post your experience if by now you have used it.

In my view:
1.Hand soldering of SMD parts (except ICs) is best solution
2. For SMD fine pitch ICs,solder paste is the only reliable solution (if the paste printing and reflow setup is good)

MohitM
12-15-2010, 04:46 PM
I am quite sure the induction cooker won't work. Induction heating will only work on ferromagnetic material. Secondly, it also generate eddy currents. And you really wouldn't be wanting large unknown currents flowing all over your circuit. The alternative would be keeping a plate of iron on top of the heater and then putting your PCB on top of this plate. The iron plate heats up and therefore your PCB.

avinash_g
12-19-2010, 10:09 AM
Canceled induction cooker plan. For the moment leave it to the EMS.

I just wanted to experiment because it will help prototype new products and some on demand manufacturing. But leaving it to EMS for now.