Scanning Electron Microscope
EM-30PLUS Operating Manual
48
②
Cut out the substrate/Wafer on which dispersed specimen is adhered
③ Fix it with conductive adhesive
3.4.3 Measurement of WD
Measure its height with adjusting the screw position for WD after putting the specimen on
provided stub.
When mounting housing cover, the uppermost part is W.D. 7mm, but, it is W.D. 10mm when
disassembling housing cover.
When measuring a large WD (about over 15mm), put the sample on the sample mount of
WD 50mm provided. The height of sample used at this time should be within 0mm ~
43mm.
When using WD 50mm sample mount, WD=(50mm – sample height(mm))
Multi Holder
WD
50mm Sample Mount
WD(Working Distance) refers to the distance between specimen and objective lens.
WD value
Advantages
Disadvantages
When WD is high
Image depth is enhanced
Resolution is degraded
When WD is low
Resolution increases
Image depth is degraded
In order to acquire images of high magnification and analyze EDS component, about
7~10mm of height of WD is recommended.
When you observe the ferromagnetic specimens like Ni, Cr, it is hard to observe images
if WD is small as stig value keeps changing due to magnetism of specimens. In this case,
set WD big so that specimen properties might not have much effect on stig.
