Soldering the gyros

Picture of the blank board

Pictures of the MLX gyro

Placing and soldering of the gyro

Put the gyro on the board, the cut corner of the gyro aligned to the cut corner of the board.

Be careful, in some cases, the dot-mark on the topside of the gyros can be misleading!

Use a good SMD-flux on the board and the sides of the gyro. I had good results with Edsyn FL22, but not so good with the Edsyn FL88 which vaporizes too fast. You need a fairly powerful soldering iron for the gyros, they are huge heat sinks. I used a 60 Watt iron at 360° C, which seems to be the minimum for that. Some have suggested to fix the gyro to the board with clothes-pegs or self-clamping tweezers. Make sure that the gyro sits flat on the board, otherwise you may get bridges between gyro and board which may be difficult to remove (see image below).

It works fairly well to flood the corner between the board and the gyro with solder, and then, using a lot of flux, to wipe the superfluous solder out of the corner using a pencil-tip soldering iron lengthwise.

Others reported good success with removing the superfluous solder with soldering-wick, but don't attempt to do this with a soldering-iron too weak, you could end up soldering your soldering-wick of the gyro.

It should look like this when finished. Measure the resistance between each contact of the gyro and the neighboring contacts to make sure you have no short-circuits other than the ones intended! Compare the images with the empty board above!

Short circuits between pins can be very hard to see because they can be below the gyro (like the rightmost two pins in the image). In this case, add more solder and flux, and remove the solder using soldering-wick or a pump or just the tip of your soldering-iron, and measure again. If you cannot remove the shortcircuit, use a hot air gun (cheap one from local DIY store for removing paint will do) and remove the gyro completely. Remove all solder from the bottom of the gyro and the board. if you cannot move the gyro freely over the board for placing again because it hangs just between the pads, you most likely have some solder still left on the gyro and/or the board.

Picture of the completed board