Siemens Aktiengesellschaft

Hans Kruger

Roland Rubner

Hellmut Ahne

Wolfgang Pahl

Alois Stelzl

Waldemar Greubel

Frans Leenhouts

Wolfgang Welsch

Hinrich Heynisch

Wolfgang Kleeberg

Helmut Freller

Jurgen Machui

Gunter Baur

Peter Schack

Karl-Heinz Walter

Alois Schauer

Hubert Weber

Werner Cirkler

Klemens Hubner

Hans J Rolke

Andre Peetermans

Hans Schuster-Wolden

The electronic component, specifically a SAW component with conductive structures disposed on a substrate is encapsulated for protection against environmental influences. The electrically conductive structures are sealed with a gas diffusion-constricting protective layer formed with an electrochemical or ion bombardment process.

Method of producing an electronic component, in particular a surface

Contacts of SAW components are produced which are suitable for flip-chip mounting. Electrically conductive structures on a substrate are tightly encapsulated within a cover and contact pads of the electrically conductive structures are exposed in a window formed in the cover. Solderable layers are vapor deposited onto the contact pads of the electrically conductive structures after the cover is produced.

Method for the production of flip-chip mounting-ready contacts of

A waveguide laser having a discharge channel and two cooling channels formed in ceramic parts have the cooling channels being broader than the discharge channel, and the cooling profile parts which contain the cooling channels being soldered to both sides of the discharge profile part containing the discharge channel. The discharge profile part is formed of a channel part and a cover part.

Transversely excited waveguide laser

The invention relates to a method for the production of orientation layers for liquid crystal displays by applying a solution of an organic prepolymer to a transparent substrate and subsequently annealing the layer and subjecting it to an orientation treatment, wherein prepolymers of polyoxazoles, polythiazoles, polyimidazoles, polyoxazinones, polyoxazine diones or polyquinoxalines are used as the organic prepolymer. The method is particularly suitable for the preparation of orientation layers for glass-solder liquid crystal displays.

Method for producing orientation layers for liquid crystal displays and

The invention relates to a method for the preparation of thin polyimide layers by applying a solution of a polyimide prepolymer to a substrate, and subsequently annealing, and has as its object the provision of a method of this type in such a way that the preparation of layers with layer thicknesses of .ltoreq.0.2 .mu.m is made possible which layers have a homogeneous character and exhibit good adhesion. For this purpose, the invention provides that film-forming prepolymers of highly heat-resistant polyimides are used which prepolymers give off a high percentage of volatile products in annealing. The method according to the invention is particularly suitable for the production of orientation layers for liquid-crystal displays.

Method for the preparation of thin polyimide film

A liquid crystal display with a liquid crystal layer enclosed by two parallel plates which carry electrodes and on top thereof a first layer system of several dielectric electrodes having refractive indices smaller than 2.2 and a thickness of the layers above the base layer, under 200 nm. The liquid crystal display is characterized by the following features with respect to the first carrier plate.

Liquid-crystal display with reduced reflection

A liquid crystal display enclosing between two parallel plates a liquid crystal layer which can be switched between two optically different states. The plate surfaces facing each other each carry a matching layer on top of which are the electrodes. On top of the electrode is a first layer system with a dielectric layer and a topmost orientation layer. The refraction index n.sub.u of the substrata is smaller than the index n.sub.e of the electrode. The index of the matching layer has the following relationship: ##EQU1## The matching layer has a thickness d.sub.a, according to: ##EQU2## wherein .lambda.=550 nm, m=natural integer &gt;0, and nm=nanometer, The electrode has a thickness d.sub.e, according to: d.sub.e .ltoreq.30 nm or ##EQU3##

Low-reflection liquid-crystal display

The invention relates to a method for the preparation of orientation layers for liquid crystal displays wherein a solution of an organic prepolymer is applied to a transparent substrate, and the prepolymer is then annealed to result in the desired polymer, which is then subjected to an orientation treatment, and has the objective to develop a method of this type in such a manner that it is possible to prepare orientation layers which can be highly stressed thermally and are dimensionally stable, i.e., are not subject to changes of morphological structure even at temperatures of .gtoreq.420.degree. C. For this purpose, the invention employs prepolymers of polyquinazoline diones or polyisoindoloquinazoline diones. The method according to the invention is suited in particular for the preparation of orientation layers for glass solder, liquid crystal displays.

Method for the preparation of orientation layers for liquid crystal

Liquid crystal display with a liquid crystal layer which can be switched between two optically different states. Two support plates have the surfaces facing each other coated with an electrically conducting layer as well as an orientation layer with at least one orientation layer consisting of a polymer. The plates enclose the liquid-crystal layer. The polymer is liquid-crystalline and can be switched to the off-state and on-state--in the process of which it generates the rest state of the liquid-crystal layer in the off-condition and, in the on-condition, at least enhances the excited state of the liquid-crystal layer.

Liquid-crystal display having orienting polymer with flexible bridges

In order to bring about durable solder joints on transparent thin film electrodes which themselves are not solderable, the conductive layer is treated as follows. First, the conductive layer is applied in a vacuum and, more specifically, in the fully oxidized state, and then a solderable layer is generated on the conductive layer in the same vacuum. The electrode consists preferably of an indiumtin oxide and the solder layer consists of copper. The proposed coating technique is particularly simple since the solder layer requires neither an adhesion aid nor a corrosion protection layer. If it consists of copper, it can withstand without difficulty, if it is thick enough, even small thermal stresses such as occur for instance in the fabrication of liquid crystal displays with cementing frame. The layer system is particularly well suited for the electrode leads of electro-optical displays such as liquid crystal displays.

Solderable layer system, its use and method for manufacturing same

A device for capturing, guiding and concentrating light for coupling out of an outlet window comprising at least one flexible foil of synthetic material containing a fluorescent substance for converting ambient light into fluorescent light and means for forming an outlet for the fluorescent light. The device can include a second and/or a third flexible foil so that light going to the outlet windows passes through the second and third foils. In one embodiment, a pair of foils are arranged behind a liquid crystal display and each foil contains fluorescent material having a polarization plane extending at right angles to each other, an optical active layer is placed between the two foils which will rotate the direction of polarization and the means for forming an outlet is disposed on the outer surface of the one foil opposite from the liquid crystal cell so that a viewer sees the light modulated by the cell.

Arrangement for brightness gains of passive display units

A display device having a liquid crystal cell containing a medium, which can be switched zone-wise between at least two different optical states to form a light valve, a light trap in the form of a plate-shaped body disposed behind the liquid crystal cell when taken in a direction of observation of the device, the plate-shaped body having a material with an index of refraction greater than 1, containing fluorescent particles, and possessing a light emergent or outlet window at the rear of each switchable zone of the liquid crystal cell characterized by the light emergent or outlet windows comprising a groove in the plate and a light scattering surface disposed between the groove and the medium of the liquid crystal cell. Preferably, the grooves of each of the windows is disposed in a rear surface or side of the fluorescent plate and the scattering surface is arranged on a front surface of the plate and can either be formed by a pigment layer which has been silk screened on the front surface or a rough surface zone which has been embossed on the front surface.

Display device comprising a liquid crystal cell with light valves

An improved display device having a light valve unit or display and a fluorescent plate characterized by a frame member for holding the light valve unit and fluorescent plate with the exit windows of the fluorescent plate being aligned with the switchable zones of the light valve unit. Preferably, the frame member will pass light which will excite the fluorescent particles of the fluorescent plate but will not allow passage of the fluorescent light so that a high contrast of the display can be obtained. The frame, which is preferably molded of synthetic plastic, can contain fluorescent particles, which emit light at a frequency range that does not impair the optical contrast of the display and which can be utilized to charge a battery for an auxiliary illumination device.

Display device comprising a light valve unit in conjunction with the

A liquid crystal display device characterized by a liquid crystal cell having a layer of liquid crystal material, which is switchable on a zonal basis between various optical states, interposed between a front and rear carrier plates; a fluorescent plate which is disposed behind the rear carrier plate of a liquid crystal cell in the path of observation and has light emergent or exit windows disposed behind the switchable liquid crystal zones; and at least one supplemental light source in optical contact with the fluorescent plate to provide light for exciting fluorescent centers in the fluorescent plate. The fluorescent plate has silvered edge surfaces and consists of a material which has an index of refraction greater than 1 and contains the fluorescent centers which are excited by ambient light to emit a fluorescent light isotropically. Preferably, the liquid crystal layer is interposed between front and rear electrodes which control the optical properties of the layer. In one embodiment, the cell includes polarizers which coact with the liquid crystal layer to control the emission of light through the exit windows of the fluorescent plate. In another embodiment, the liquid crystal layer contains a pleochroic dye which will absorb the fluorescent light to a high degree while the layer is in an un-energized state and only absorbed the fluorescent light to a limited degree while the layer is in an excited state. The light exit windows may be provided with dielectric layers, which will reflect on a color selected basis so that the multi-colored displays are obtainable and the dielectric mirrors and the plane of the fluorescent plate may be arranged to enclose an angle of the polarization so that the light emerging from the exit windows is polarized.

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Munich, Germany

Hans Kruger