Liquid Crystal Measurement Instruments 2007 - Instec Inc

Liquid Crystal Cells and Cell Holder
Instec provides a lineup of empty liquid crystal test cells ideally suited for use with
the ALCT in addition to other LC research applications. When measuring a liquid crystal’s
parameters, sample preparation is as critical to the measurement as the testing
instrument itself. Instec’s cells are manufactured with patterned electrodes in industry
standard clean rooms and equipment. This yields a cell whose active sample area is
known precisely, has low parasitic capacitance, and can be completely filled with the LC
material under test.
Even so, the reliance on spacers to determine cell gap can lead to errors of several
percent. Thus for critical testing applications, Instec makes available calibrated cells
whose spacing have been individually measured both optically and electronically. Each
calibrated cell is then shipped along with its individual cell thickness and parasitic capacitance.
The adhesive of Instec cells can withstand up to 200ºC. Alignment layers are of 1º to
3º pre-tilt angles. Physical dimensions and spacing of cells vary depending on different
models. Cell gap tolerance is ±0.2 µm.
Image above is an example of
LC1, 90° twist aligned.
PI Type
Homogenous Alignment
90º Twist
Homogenous Alignment
Parallel
Homogenous Alignment
Anti-Parallel
Homogenous Alignment
Anti-Parallel
Homeotropic Alignment
Anti-Parallel
Part No
ITO Area
(mm)
Cell Spacing
(microns)
LC1-6.0
6.0 µm
5 X 5
LC1-6.8 6.8 µm
LC3-5.0
5 µm
LC2-5.0 5 µm
LC4-6.8
5 X 5
6.8 µm
LC2-9.0 9 µm
LC2-20.0 20 µm
SA025A04uG180 5 X 5 4 µm
SA100A09uG180 10 X 10 9 µm
SA100A18uG180 10 X 10 18 µm
SA025A04uT180 5 X 5 4 µm
SA100A09uT180 10 X 10 9 µm
SA100A18uT180 10 X 10 18 µm
No PI (Patterned ITO) SA100A04uNOPI 10 X 10 4 µm
In-Plane-Switching
Homogenous Alignment
Vertical Rubbing to Electric
Field
In-Plane-Switching
Homogenous Alignment
Parallel Rubbing to Electric
Field
IPS02A09uGVE 10 X 10 9 µm
IPS02A18uGVE 10 X 10 18 µm
IPS02A09uGPE 10 X 10 9 µm
IPS02A18uGPE 10 X 10 18 µm
ITO
Resistance
Cell Outer Dimensions
(mm) &
Cell Holder Model
100 Ω/□ 15.25 X 20.25 X 2.25
100 Ω/□ 15.25 X 17 X 1.5
30 Ω/□
21 X 25 X 1.5
Cell Holder: LCH2
Image above shows the structures
of LC2, LC3, and LC4 empty cells.
Image above shows the structures
of SA Series empty cells. Example
is SA100
LCH2
Instec LC cell holder, LCH2 accommodate various Instec empty cell models: SA025,
SA100, and IPS02. The cell holder can be used inside the Instec microscope hot and
cold stages. The LCH2 has external electrical grounding for electrical noise shielding.
The LCH2 can be used to attach electrodes to the LC Cells. Otherwise, solder or silver
epoxy can be used to attach wires.
How to Use Instec LC Cells
There are two openings on Instec liquid crystal cells. Heat the cell above the isotropic temperature of your LC material.
Then drop a very small amount of LC material on one opening of the Instec empty cell. The capillary force will suck LC
material into the empty cell. It may take a few minutes before the cell is fully filled. You can see the filling process at
"right" angle under light. Once the cell is filled, in order to get good alignment, please cool down slowly, especially during
the phase transition temperature.
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