AAU SatLab Cleanroom

The cleanrom in the old Ørsted attitude control research laboratory at AAU has been completely re-fitted as a satellite integration facility. Its purpose is to provide a non-contaminated anti-static environment for electronics integration such as space flight quality soldering with dedicated tools and equipment for quality inspection.

The Airlock

All access to the cleanroom goes via the airlock where any contaminating pieces of clothing are replaced or covered. The airlock has a non-clean and a clean side on either side of a bench. Hats and coats are applied on the non-clean side and cleanroom shoes are applied on the clean side. A sticky mat ensures that contamination from the non-clean floor is not carried into the cleanroom itself.

Space Qualified Soldering

The cleanroom is equipped with a Weller Micro Rework Station (WMRS) for precision soldering of printed circuit boards. Combined with the Mantis Elite stereo microscope it makes an ideal platform for soldering fine-pitch devices with feature sizes smaller than .2 mm.

Soldering Tin Bath

Pre-tinning components prior to mounting on PCBs is essential to the final result and in consequence a solder pot is installed. The pot contains solder tin of the same alloy as used for mounting devices onto the PCBs, and after pre-processing a component pin with IPA and pure rosin flux the pin is dipped in the liquid tin for a couple of seconds. The residual flux is removed with IPA leaving the pin all shiny as the low-quality soldering tin that the component producers adds has been replaced with space-grade tin.

Defined Procedures

Entering cleanroom
1. Ensure that cleanroom lights are turned on (switch outside)
2. Enter airlock of the cleanroom
3. Close door
4. Stay on the dirty side of the bench
5. Remove dirty shoes
6. Take and wear hat
7. Take and wear a cleanroom coat
8. Take cleanroom shoes
9. As you apply shoes stop over the bench onto the clean mat
10. Enter cleanroom quickly
11. Close the door behind you (there is an over-pressure)

Leaving cleanroom
1. Ensure that all equipment that you used is turned off
2. If you are the last to leave then ensure that ALL equipment is turned off
3. Enter into airlock and close door behind you to maintain over-pressure
4. Step over bench
5. Remove shoes
6. Remove cleanroom coat
7. Remove and discard hat
8. Leave the airlock, closing the door behind you
9. If you are the last to leave ensure that the light is turned off

Taking equipment into cleanroom
1. Inform a satellite VIP that you wish to take the equipment inside
2. Wipe clean all exposed surfaces of the equipment on the table to the right of the airlock entry (outside)
3. Vacuum dust out of any enclosures (laptop fans for example)
4. There is MINIMAL PAPER allowed inside the cleanroom
5. There is NO CARDBOARD allowed inside the cleanroom
6. Only LINT FREE tissues allowed inside the cleanroom (provided)
7. Carry equipment as you enter the cleanroom in the usual manner

Cleaning aluminium boxes and parts
1. Disassemble parts are far as possible
2. Wear gloves
3. Use wire wool to scrub surfaces, in ONE direction only, under running warm water (sink in syslab)
4. Dry parts thoroughly
5. Clean thoroughly with IPA tissues
6. Store on tissues in cleanroom Alternatively: Instead of steps 3,4,5 use the ultrasound bath, however, note that it is small, and dangerous to put hand in when it is in operation (and not too good when not in operation).

Procedures orginally from Jason Page, ESA.
Edited and written down by Neil Melville, ESA.
Adapted for AAU SatLab Cleanroom by Karl Kaas Laursen, AAU.