Pick & Place
Next is the painstaking bit. Picking and placing components. The larger flatter components are relatively easy.Most of the parts were, thankfully, only 0603s – 0603 refers to the SMD package size. You can work with 0603 fairly easily, but you can also get the smaller 0402
and things get a little crazy when you get down to 0201. There’s even a 008004 standard, which comes in at .2mm by .1mm. See here for some other sizes.
Of course, some parts can be placed in any orientation. Resistors and most capacitors can be placed rotated, upside-down or right-side-up,
but the package has really been designed to be placed with the label at the top.You can flip them around easily like this, but be careful as they can end up flying across the room. And forget ever trying to find even a 603.The amount of solder paste is also important. This is the perfect amount of solder.Whereas in other areas there were large spread-out blobs. This was because I made several passes with the solder screeder.It’s not a huge drama, but it will more than likely increase your time fixing up soldering issues. You’ll discover later how this can affect the final result.
Try to firmly place components down vertically. If you come in from the side, you risk pushing solder paste around. This is often hard to do, especially with a shakey hand.When placing MCUs, it’s pretty important to line up accurately. The more the pins line-up with the pads, the less chance there will be for soldering bridges. Of course these need to be placed with the correct orientation.Along with buzzers, diodes, MosFETs & LEDs. Back in Weekly Roundup #47 we saw the LEDtwee Kickstarter. Essentially a pair of tweezers that tell you the correct LED orientation. They come in handy with this sort of thing.