Features of a Superior Carbon Coater: the Emitech K950x
These notes relate directly to the Emitech K950, but they are largely applicable to other Emitech vacuum evaporators.
The K950X and the K575X have been replace by KQ150T.
The K950x specifications include all the components and facilities required for a top quality carbon coater for electron microscopy:
- Turbo high vacuum pump for rapid pumping, completely oil-free, no warm up, no water connection, low maintenance.
- Quiet backing pump, Edwards - most reliable manufacturer. Fast roughing pump cycle.
- Long working distance within chamber - up to 130mm maximum - 100mm may be the most used distance. The longer distance makes for greater coating uniformity, but thickness drops off with the square of distance.
- Rotate and tilt stage are included as standard. Rotating during coating improves coating uniformity. Obviously non-uniformity during one coating run is related to source - specimen distance. Placing a single specimen slide a little off-centre and rotating improves uniformity. When coating many slides, using a concave arrangement, with slides always perpendicular to the source, improves coating uniformity and allows more slides to be coated in one run.
- The electrodes are external to the glass cylinder and enter through the chamber’s lid. This arrangement makes the entire internal diameter of the glass cylinder available for specimen arrangements.
- Three voltages may be selected: 5, 15 and 25V. Low voltage gives better control for metal evaporation. 25V is best for carbon/graphite, as contact is too easily lost at a low voltage. We have the best choice for all conditions.
- Digital electronics: easy read-outs and repairs amount to swapping a board - we have never needed to supply a swap board to anybody!
- Maintenance amounts to: changing the turbo pump cartridge (annually); changing mechanical pump oil (annually); cleaning the glass cylinder and coating this with diluted detergent (after a run or two); cleaning the rest of the chamber after ~50 runs.
Coating uniformity and 'duty cycle'
Uniformity of thickness depends on the set-up within the chamber. This coater has chamber size, good working distance and a rotation/tilt mechanism that make uniform coating thickness easy, even when coating several slides in one operation. Coatings may be made in under 10 minutes for the complete 'duty cycle': setting up of rods, placing specimen, pumping, out-gasing, coating and venting - assuming a reasonably dry chamber. These coatings will be perfect under SEM and for microanalyses. Slightly longer pumping will result in the very best grain when viewed in TEM.
As supplied, the instrument requires minimal setting up and should be fully functional within half an hour. If required, ProSciTech will obtain any technical information from Emitech overnight. All parts are fully guaranteed for two years.