|
LC-TEC DISPLAYS’ modern cleanroom environment has a total area of 270m2
and houses a second-generation STN-LCD production-line with a high degree
of automisation. This allows for both high volume manufacturing together
with good cell quality & yield.
Flexographic printer with vertical hot-plate (to left) and robotic
handling of substrates at the LC-TEC facility.
The maximum manufacturing throughput of the LCD production-line is one
(1) panel per minute for substrate dimensions 16 * 14 inches, yielding
approximately 150,000 panels/year for single-shift operation (8 hours per
day). However, spare manufacturing capacity currently gives LC-TEC
DISPLAYS a large degree of flexibility to also focus on the manufacturing
of smaller batches of test cells for specific R&D projects.
Furthermore, the large cleanroom area readily permits the installation of
new manufacturing & testing equipment that may be required for the
development of such projects.
With regard to the general manufacturing steps, the process steps are
as follows:
1) 14 x 16 inch glass substrates (mother-plates)
ready-coated with ITO provided by our supplier.
2) ITO patterning
using wet chemical etching processes. Also applies to optical-shutter
devices where the ITO is removed from areas where the edges of the
glass substrates shall be bonded together in order to improve adhesion,
etc.
3) Insulation "hardcoat" layers (top-coat) and liquid crystal
alignment "polyimide" layers flexographically "off-set" printed onto the 14 x 16 inch
glass substrates. Many individual liquid crystal devices can
be "grown" on each 14 x 16 inch substrate simultaneously (depending
on size). High temperature curing of the hardcoat & polyimide layers
(typically in excess of 300 degrees centigrade for several
hours).
4) Edge seal "gasket" screen-printed onto 14 x 16 inch
substrates. Gasket defines edges of each individual liquid crystal display
device. Polyimide alignment layers on inner-surfaces of both substrates
mechnically rubbed using velvet-cloth in order to define alignment
directions of liquid crystal molecules.
5) Two pieces glass
substrates assembled together into pairs to form a "panel" and small
distance "spacers" placed in-between the glass substrates with an exact
diameter for accurate cell-gap control. Gasket adhesive thermally cured at
typically 175 degrees centigrade for several hours.
6)
Individual liquid crystal devices (optical-shutters/displays) cut from the
14 x 16 inch mother-panel. Many hundred individual pieces may be yielded
from each mother-panel depending on size of each device.
7)
Individual liquid crystal devices vacuum-filled with liquid crystal
(LC) material through a "filling-port" in the gasket edge
seal.
8) Filled liquid crystal devices mechanically pressed at room
temperature in order to squeeze out excess LC material and push the two
glass substrates together so that they make mechanical contact with the
"spacers" present in-between the glass plates.
9) Filling-port
sealed (end-seal) in order to prevent LC material from leaking out and
protect LC material from humidity.
These process steps are summarised in a diagram at the following link (Swedish).
A detailed technical description of the manufacturing capabilities
& volume capacities can be found at the following link (English).
Dry-spacer applicator (to right) in LC-Tec Display's manufacturing
facilities.
Over the past several years, LC-TEC DISPLAYS has focused on the
development of the bistable Cholesteric Liquid Crystal Display (Ch-LCD)
technology for large signboard applications (18 inch diagonal) and as such
also has a wide experience in the assembling of complete LCD modules such
as the application of driver TAB’s to LCD’s. LC-TEC DISPLAYS is now
mainly focusing on contract (LEGO)manufacturing of LCD components for
third-party customers.
Layout of the LCD production-line at the LC-Tec Displays
AB's facility.
LC-TEC DISPLAYS has a wide experience in working with projects where
initial manufacturing volumes may be modest but where immediate quality
and yield are crucial and which also involve a high degree of R&D
input in order to fully develop and optimise both the liquid crystal
technology and manufacturing processes.
Reference customers include LightSpace Technologies Inc ., USA which
involved an 18 month project in order to fully-develop and bring to the
market their proprietary liquid crystal technology. This project was
successfully completed in July 2004 and has lead to the commercial launch
of their DepthCube® 3D-Monitor product.
Other reference customers include ECSIBEO AB, Sweden which has an
ongoing active collaboration together with LC-TEC DISPLAYS. Technicians
from ECSIBEO are currently based at the LC-TEC DISPLAYS facility in order
to fully optimise the process parameters required to manufacture high
quality product based on their propriety ECS® liquid crystal technology.
The sister-company LC-TEC AUTOMATION focuses on supplying LCD
manufacturing equipment and has a long experience in the design,
manufacturing and installation of equipment for modern LCD manufacturing.
This partnership has proved invaluable when both modifications of existing
equipment as well as the installation of new equipment has been required
for specific projects at the LC-TEC DISPLAYS facility.
Summary of key issues
LC-TEC DISPLAYS possesses a modern STN-LCD production-line with a high
degree of automation, offering high volume manufacturing together with
high quality & yield.
LC-TEC DISPLAYS’ cleanroom is 270m2 in area and consequently there is
room for the installation of new equipment that may be required for
specific projects.
Spare manufacturing capacity currently gives LC-TEC DISPLAYS the
flexibility to also focus on the manufacturing of smaller batches of test
cells for specific R&D projects where initial volumes may be modest
but where quality & yield are crucial.
LC-TEC DISPLAYS has a proven track record in commercialising projects
which contain a high degree of R&D content as well as innovative
input.
LC-TEC DISPLAYS has a wide experience in the assembling of complete LCD
modules including the application of driver TAB’s to LCD’s.
The partnership together with the sister-company LC-TEC AUTOMATION
allows existing equipment to easily be modified as well as the
installation of new equipment for specific projects at the LC-TEC
DISPLAYS facility.
Products include liquid crystal optical shutters as well as signboard
& display products based both on the Ch-LCD technology as well as the
direct-driven TN technology. LC-TEC DISPLAYS also focuses on contract
(LEGO) manufacturing of LCD components for third-party customers.
©
Stephen Palmer 2009
|
