Ever since I started working with surface mount parts, I've been dreaming about buying, or building my own pick and place machine. If I do decide build one, one essential component is the vacuum used to pick up and hold the SMD parts. The conventional solution is to use an external vacuum pump or, on some systems, a Venturi tube power by compressed air, a solenoid controlled valve, as various other bits of tubing and connectors to plumb it all together. This seemed a bit complicated to me, so I wondered if there was a simpler way.
A few moths back I saw an interesting device called a Micro Blower made by Murata Corp. To get an idea what the micro blower can do, check out the videos here. Mouser sells a development kit that includes the driver circuit needed to power the device for about $35, so I ordered one. It's rather intriguing device and, after playing with it a bit, I became convinced it might work as a vacuum source, too. But, since the micro blower seems to be engineered more to blow than to suck, I first needed to find a way to block off the input side of the pump so it could draw a vacuum. After several failed attempts, I finally wound up sealing the blower inside a stack of pieces cut from foam core board, like this:
Note: the can of Dr Pepper shown in the background is actually a small,7.5 ounce can, not a full size can, so the whole assembly is smaller than you might assume just looking at the photo.
As the photo above shows, I connected a small bit of plastic tubing to the outlet port on the micro blower and then used this to route air out of the sealed interior. Then, on the other side, I glued a 20 gauge dispensing needle to use as a suction nozzle for small, 0603 size SMD parts. The completed subassembly looks like this:
Finally, I hooked it up to an 18 volt, DC supply and ran a few tests using some 0603 size resistors inside a strip of 8mm feed tape as would be used in a pick and place machine. The results can be seen in the following video:
I still have to see if there is going to be enough suction to handle larger parts and develop a better housing, but I think the design has potential mostly because it's so light (a few grams) that it and it's driver board could be easily mounted directly on the head of the pick and place machine and then controlled with a simple electric signal to turn the vacuum on and off. No tubing, to solenoid valve and no noisy, external compressor or Venturi tube.