I have been doing PCB assembly for years. Over the years I have tried various equipment. Therefore I figured I would share what I learned.

Note if you want to get into populating PCBs using paste and reflow oven. Then the most important thing is to get a good reflow oven. A bad reflow oven will make bad PCBs even if everything else is done perfect. Therefore start your collection with a good reflow oven. After you have good reflow oven then you can get good stencil printer. Only after you have those two problems solved should you look at a pick and place machine.

Stencil Printer

So I have tried various stencil printers from framed to frameless ones. Generally what I have found is that anything on Ebay for less than $500 is pure junk and a waste of money. You are better off using tape and carboard.

With that said I found that I no longer use framed stencils, they are just too bulky and I find that cheap framed stencils do not have the tension I like on the stencils. Therefore I find it is best to use a frameless stencil printer. My favorite frameless stencil printer is the NeoDen one.

This stencil printer is close to $900 with shipping but it works unlike the cheap ones you find else where.

One lesson learned on the stenciling of PCBs is to keep the back side of the stencil clean. I find every few panels I will go and clean paste build up off the back side of the stencil. I often get paste on the back side because the stencil does not lay flat on the panel as I squeegee the paste. Note this is often because I do not take the time to setup the stencil printer perfect when only doing a few boards.

Reflow Oven

I brought a T962A and then spent hours doing all the hacks and upgrades. In the end the oven was junk, it would burn PCBs and then a few millimeters away the solder paste had not melted. Stay away from the IR reflow ovens like the T962.

Note I would stay away from IR ovens if at all possible, including IR conveyor ovens. One issue with IR heat is the color of the solder paste on your PCB will make a difference. That is a black PCB will get hotter for the same time under IR heat than a green or white one will.

I had looked at the Neoden IN6 reflow oven and would like to test one however the price was out of my range. Therefore I took a 1/4 size convections oven and converted it.

This basically involved removing everything but door and outside enclosure and then making my own heat box with minimal mass, and then adding extra heating elements.

Note reflowing PCBs and burning off solder flux smells awful. Therefore make sure any reflow oven you purchase or build has a method to vent the smell and/or filter the smell out of the air.

The reflow oven is the most important part of PCB population. There is nothing worse than running batch of boards where the reflow ramp rate was wrong and you got a mess of solder balls or unsoldered parts.

Pick and Place

Several years back I built a pick and place machine and used OpenPnP. The net result is that a pick and place without reel feeders is pretty much useless. You often can hand place parts quick than trying to setup the cut tapes and strips on the pick and place. Therefore do not ever buy a pick and place that does not have reel feeders.

I ended up buying a used Manncorp pick and place and have used it for years now. It is a great machine and works wonderful. I got it cheap and have been happy with it. I have found that even with this machine, strip feeders and cut tapes is not worth the effort. As such for large ICs and cut tape parts I still populate by hand using tweezers.

I have looked at the NeoDen pick and place machines, and friend of mine has purchased the entire NeoDen line (S1 and IN6). I will update you as I get more information on how the NeoDen works.