Site: Sevtchenko Institute of Applied Problems
State University of Belarus
Kurtchatova, 7
220064 Minsk
Belarus

Date Visited: October 26, 1993

Report Author: J.W. Doane

ATTENDEES

WTEC:

J.W. Doane
Z. Yaniv

HOSTS:

Dr. Anatoly A. Minko

Deputy Director
Telephone: 0172 775034
Fax: 0172 780417

Dr. Vladimir Bezborodov

Head, Chemistry Group
Telephone: 0172 785735

Dr. Sergei Yakovenko

Head, Electro-Optics and
Manager of EKMO Scientific and Engineering
Firm, Ltd., 220064 Minsk
Republic of Belarus
Telephone: 0172 785735
Fax: 0172 780417

BACKGROUND

The Research Institute of Applied Physics Problems of the Belarus State University (BSU) was organized in 1971. The mission of the institute is to promote fundamental and applied research, transfer the research results to industry, and create a modern educational scientific students' base. The research topics of the institute are determined by the diversity of specialists training in the natural sciences at BSU. Belarus State University has an enrollment of approximately 20,000 students. The Sevtchenko Institute is under the direction of Dr. Anatoly Minko and has a scientific staff of 20 professors and about 100 Ph.D. students. A majority of the research projects were developed in conjunction with industrial enterprises and used in the technological development of materials, apparatus, and so forth.

The institute is participating in a comprehensive program to develop industrial production materials, technological processes, and manufacturing equipment for the production of liquid crystal devices for years 1993-1995. The main purpose of this program is to organize a highly technological and well-equipped production line of liquid crystal information devices during the next three to four years in the Belarus Republic. A research and development program is planned for the mass production of liquid crystal displays. This program will include the synthesis and formulation of principal materials such as liquid crystal compositions and color filters.

The main collaborators in this extraordinary display development program are the following:

This highly-integrated effort contains all of the infrastructure necessary in the local area in or near Minsk for the production of MIM active matrix flat-panel displays. Integral already produces TN and STN displays. There are a number of small companies making LCDs (TN) on nonautomatic lines in the Minsk area. The main applications of these displays are in computers, portable equipment, televisions, and indicators (avionic).

The goal of this effort is to have a high-volume production of active matrix liquid crystal displays based on the MIM technology by 1995 according to the timeline diagram shown in Figure Sevtchenko.1.


Figure Sevtchenko.1. Timeline diagram.

The Sevtchenko Institute is part of the University of Belarus. It is a research arm of the university and interacts with the academic departments, such as physics and chemistry. Three groups in the institute contribute to the national display effort: the Liquid Crystal Program, the Color Filters Program, and the Optical Laboratory.

An organizational chart showing where students and faculty in the academic departments work in the Sevtchenko Institute is shown in Figure Sevtchenko.2. The institute also has a research staff.


Figure Sevtchenko.2. Organization chart.

RESEARCH AND DEVELOPMENT ACTIVITIES

Liquid Crystal Material Synthesis and Formulations

Under the direction of Dr. Vladimir Bezborodov, this is a nicely integrated program that incorporates aspects from innovative synthesis to the formulation of useful mixtures for displays.

Wide temperature range nematic materials with very large dielectric anisotropies. These materials are cyano- derivative of the 1, 3, 2--dioxaborinanes. Dr. Bezborodov is an inventor on U.S. Patent #4,853,150 on these materials. These materials are of high interest in the display community, and have been licensed internationally by chemical suppliers of liquid crystal display materials. The materials have a usually high dielectric constant that is very important for MIM technology because of the high capacitance of the MIM circuit. The basic structure is given in Figure Sevtchenko.3. High resistivity nematic TN materials for active matrix substrates. These are materials with resistivities as high as 1,014 ohm cm. The materials used as a starting base difluorobenzol (Figure Sevtchenko.4).


Figure Sevtchenko.3. Basic structure of Bezborodov material.


Figure Sevtchenko.4. Structure of high resistivity nematic TN material.

A temperature range of -40 degrees centigrade to 80 degrees centigrade is obtained. A response time of one second is obtained at a -30 degrees centigrade with these materials.

Ferroelectric liquid crystal materials. The temperature of the materials range from room temperature to 60 degrees centigrade.

Other liquid crystal materials synthesized in the laboratory can be found in the list of publications included in the references section at the end of this site report.

In this laboratory, the Sevtchenko Institute's scientists have the ability to produce large quantities of liquid crystal materials; they have developed simpler and faster processes to produce some of the materials. While they have some patents, their main interest is not necessarily to patent but to preserve the know-how. They are interested in enlarging their business. At this time they can produce materials from 200 gr quantities. They are interested in supply contacts for their materials, and will tailor liquid crystal mixtures for specific liquid crystal display needs.

The Optics Laboratory

This laboratory, headed by Dr. Sergei Yakovenko, performs optical measurements, studies of liquid crystal textures, response time studies where the researchers have obtained 100 žsec TN switching times for welding goggle applications, and defect analysis on LCDs. The scientists also have developed a passivation material coating that uses soda-lime glass for active matrix LCDs. The most important R&D results were in the use of normal glass for STN and AM liquid crystal displays. The passivation of NA+ glass was done using Al2O3 or Ta2O5. To keep the spacing using nonflat glass, they developed an etching process that creates spacers (one per pixel) without compromising the optical quality of the substrate. The same technique is applied to the multigap color filter plate. They obtain excellent results for 1.9 žm gap ferroelectric displays and 5.6 žm gap STN displays. The same technique is used for MIM active matrix LCDs.

Color Filter Laboratories

This laboratory is headed by Dr. V. Kisly (absent). The tour was conducted by Kuharchik Ludmila Vladorinisovna. In this lab, the scientists have produced a new color filter using a newly developed water-soluble negative photoresist (photosensitized material). The process includes the spinning of material, photodefinition, drying process (thermal), and passivation with a thin, transparent layer (organic). The process is repeated three times and a black matrix is obtained by overlapping (Figure Sevtchenko.5). No data is available on the UV stability.


Figure Sevtchenko.5. Color filter process.

SUMMARY

The Sevtchenko Institute is a key ingredient in flat-panel liquid crystal display development in Belarus. It is the source of liquid crystal materials for flat-panel displays, color filter development, and optics design of the liquid crystal cell. The institute is well integrated into the display production effort of the country. It also supplies trained personnel for the development of this effort. It is a beautiful example of a university working closely with industry and government.

REFERENCES

Bezborodov, V.S., and V.I. Lapanik. 1991. "Synthesis and mesomorphic properties of cyano derivatives of 2--(4--carbohydroxy-3--halogenphenyl)-5--alkyl-1,3,2--dioxaborinanes," Liq. Cryst. 10:803-807.

------. 1992. "Synthesis and mesomorphic properties of some derivatives of 2--methylcyclohex-2--ene-4--one-1--carboxylic and cis--2,6--dimethyl cyclohex-2--ene-4--one-1--carboxylic acids," Liq. Cryst. 11:385-399.

Bezborodov, V.S., V.M. Kondratenkov, V.I. Lapanik, and D. A. Trokhimets. 1991. "Synthesis and mesomorphic properties of 4--alkyl-3,4---disubstituted biphenyls and terphenyls," Liq. Cryst. 10:799-802.

Bezborodov, V.S., B.A. Konovalov, V.I. Lapanik, and A.A. Minko. 1989. "Synthesis, mesomorphic properties and potential applications of aryl esters of 4--n---alkylcyclohexene-1-- carboxylic acids in electrooptic displays," Liq. Cryst. 4:209-215.

Bezborodov, V.S., V.I. Lapanik, P.V. Adomenas, and R. Sirutkaitis. 1992. "Synthesis and mesomorphic properties of some 3--substituted-4--cyanophenyl esters, 4--cyano-3-- substituted-4--biphenyl esters of 4--(trans---4--alkylcyclohexyl) benzoic, 4--alkyl-3--substituted biphenyl-4--carboxylic, trans--- 4--alkylcyclohexanecarboxylic and 4--alkylbenzoic acids and electro-optic parameters of liquid-crystalline mixtures containing these compounds," Liq. Cryst. 11:373- 384.

Danilov, V.V. 1993. "Some Problems of Liquid Crystal Systems," Soviet Journal of Optical Technology. 7:8.

Belimenko, T.N., et al. "Liquid Crystal Modulator for IR Irradiation," Optical-Mechanical Industry.

Zhevlakov, A.P., et al. "The Operating of a Laser Beam Using PDLCs," Optical-Mechanical Industry.


Published: December 1994; WTEC Hyper-Librarian