SMT prototyping/DIY reflow ovens

[sean-h]

I always found the re-flowing bit was the easy bit, getting the correct amount of solder paste on the PCB's is the trick.

In the end I purchased a air driven liquid dispenser:

http://www.intertronics.co.uk/products/cjbe1113.htm

This is great and dispenses the correct amount of solder paste on each pad.
Using it by hand takes a while but rigging it upto a cnc machine works a treat.
I need to update my site with examples of it on a machine when I get time.

After using this I was just using tweezers to place the SMT components, but again plan on using the CNC machine as managed to get a cheap pickup pump on ebay which will do small components.

For re-flowing I purchased a small roaster oven for around £40.00 that goes upto 250c and used this. But again on ebay picked up a small conveyor reflow oven for a couple of hundred pounds which does the correct pre-heat and different heat areas.
Problem is with Lead Free components now becoming the norm apparently you need more heat

As far as making PCB's have manually etched for years and used up plenty of caustic soda and wasted many a PCB board!!!

Best find was replacing the caustic soda with Seno PCB apllicators.
http://www.rapidelectronics.co.uk/rk...9438&XPAGENO=1

I wasted so many PCB's getting the mixture correct using commercial developer products as well as caustic soda LOL!
I have never wasted a PCB with these applicators and it also does not burn your skin off!!

Am trying to perfect milling the PCB's via the CNC machine now to do away with chemicals completley.

Regards

Sean.

[bartman]

I'm struggling with a small project that needs SMD parts as well. Mr. E sent me this link which I think is helpful if you are going to do it by hand:

http://www.infidigm.net/articles/solder/

I make my own boards because I never need the quanity to make it worthwhile to have them done professionally.

I use the laser printer method with the special toner paper then iron it onto my board. Once you do a bit of experimenting to get the iron temps right it makes a fairly clean transfer. Recently I started using the green film that is also made by the same company in addition to the toner transfer and that works very well. Makes nice clean lines and no etching pitting like there is with just the toner being the resist.

Bart