U.S. Philips Corporation

Ties S Te Velde

Arie Slob

Karel E Kuijk

Martinus V Stroomer

Jean H Lorteije

Henricus F De Leeuw

Joannes L Van De Venne

Donald Robert Wolters

Adriana T Zegers Van Duijnhoven

Liquid crystal display devices having very small cell thicknesses are obtained by means of underetching techniques. Via etching holes (17, 29, 31) an auxiliary layer (27) between a supporting plate (2) and a cover plate (14) is removed. Dependent on the technique used spacers (18) are formed at the area of the etching holes or in between the etching holes. The device obtained has a uniform thickness over large surface areas.

Liquid crystal display device and method of manufacturing such a display

Liquid crystal display device

Liquid crystal display device (1) based on dielectric anisotropy in such thin layers that the effective optical path length difference between the two optical states is 1/2.lambda..sub.0 after reflection. A semiconductor body provided with drive elements (12) which is completely coated with a reflective layer (24) is used as a reflective substrate (6).

Electro-optic display device for use in the reflection mode

A psssive display device comprises a first supporting plate (10) and a second supporting plate (11) at least one of which is transparent. The device comprises display elements each having at least one fixed electrode (12, 13) and an electrode 16 which is arranged so as to be movable with respect to the said electrode (12, 13) and has apertures. The movable electrode 16 can be moved by electrostatic forces between two final positions determined by engaging surfaces (14, 15). In each of the final positions the movable electrode 16 engages an engaging surface (14, 15) whose surface structure is not congruent with that of the surface of the electrode so that a finite number of discrete engaging points is formed between the movable electrode and its engaging surfaces. Furthermore methods are described for manufacturing such a display device.

Passive display device having movable electrodes and method of

The display arrangement is provided with display elements which comprise a first and a second electrode, between which each a displaceable third electrode is present, and with a control voltage source, for selectively situating the third electrode near the first or second electrode, depending upon a voltage difference with the first or second electrode. In order to obtain a minimum or no cross-talk from selected display elements to adjacent selected or non-selected display elements, the display elements being arranged in a matrix in rows and columns, the voltage source supplies at least during the period (DT) of the information supply to the display elements (R1C1, R1C2, . . . R3C3) three values of control voltage (SC1, SC2, SC3) to at least one of the three electrodes.

Electroscopic picture display arrangement

A layer of liquid crystal is present between two supporting plates with a large number of picture electrodes arranged in rows and columns on at least one of the supporting plates. Strip-shaped row electrodes and strip-shaped column electrodes are provided between the respective rows and columns of the picture electrodes. The picture electrodes arranged in rows can be contacted with a respective row electrode by way of at least one micromechanical leaf spring which provides the liquid crystal with a sufficiently steep threshold with respect to the applied voltage, and provides the liquid crystal with a memory when the picture electrodes form picture elements of a display device. Because of this arrangement, the number of lines to be driven of the display device can be extended.

Display device with micromechanical leaf spring switches

A self-registering method of manufacturing an air-(vacuum) -insulated crossing multilayer wiring system of large density is disclosed. Between the lowermost and uppermost wiring layers an intermediate layer is provided in which recesses are formed between the intermediate layer and the lowermost wiring layer. By means of said recesses the intermediate layer can be removed entirely at the area of the crossings during the etching process, while elsewhere portions of the intermediate layer remain as supporting parts or as connecting members.

Method of manufacturing a wiring system

A blowable fuse is provided over a part of its length separately from the walls of an enveloping cavity and separated from a supporting member. As a result of this the fuse is readily thermally isolated so that it fuses more rapidly and with less energy. In addition, a semiconductor circuit element, for example a Schottky diode, can be realized below a bridging part of a conductor which serves as an upper wall of the cavity, which results in a high bit density.

Method of manufacturing programmable semiconductor device

A programmable semiconductor device having a microswitch (11) which over a part of its length is provided separately from a bridging conductor (10), for example, a word line and a supporting element. Since the dimensions of the switch (11) and the conductor (10) are independent of each other, the resistance of the conductor (10) may be low so that programmable memories having a high read-in and read-out rate are obtained. In addition the circuit element, for example a Schottky diode (3, 8) can be realized below the bridging part (12) of the conductor (10), which results in a high bit density. Since the switch (11) is present below the conductor (10) the assembly can be passivated in the unprogrammed state by means of a protective layer (20), so that the switch 11 is encapsulated in a hollow space (21).

Programmable semiconductor device and method of manufacturing same

On the facing surfaces of first and second supporting plates, where at least the first supporting plate is transparent, first and second electrodes, respectively, are provided with at least the first electrodes being transparent. An opaque liquid is present between the supporting plates. Third electrodes which can be moved between the first and second electrodes by electrostatic forces are connected to the second supporting plate. The third electrodes are formed by a display part having a large number of apertures of which the color of the side facing the first supporting plates is contrasted with the color of the liquid. A number of resilient elements is provided below the display part with one end connected to the display part and the other ends connected to pillars which are provided on the second supporting plate.

Passive display device

A display device having a transparent supporting plate which is provided with transflective regions. At a short distance from the first supporting plate resilient electrodes are connected which are manufactured from a partially reflective material. By varying the distance between the resilient electrodes and the transflective regions, the reflection of incident light can be controlled from zero to maximum intensity as a result of the occurring interference. Both monocolor and multicolor pictures can be displayed by means of such a display device. Such a display device is particularly suitable for use in a projection television device.

Method of manufacturing a display device

Display device with deformable reflective medium

A method for manufacturing an electrode which is secured to a supporting plate by means of flexible strip-shaped parts so as to be movable. The method includes the steps of providing a first layer of material which can be etched by means of a first etchant and a second layer which can be etched by means of a second etchant. The method also includes the step of providing by means of a photoetching method and a second etchant a plurality of apertures in the parts of the second layer which should not remain secured to the supporting plate. Parts of the first layer are removed by underetching by the apertures in the second layer with the first etchant.

Method of manufacturing an electrostatically controlled picture display

A method of manufacturing a semiconductor device having a multi-layer wiring system includes the steps of providing a first pattern of conductive regions on a major surface, providing an intermediate conductive layer over the major surface and the first pattern conductive regions, providing a second pattern of conductive tracks on the intermediate layer, and selectively etching the intermediate layer using the second pattern of tracks as an etching mask to completely remove the intermediate layer by underetching below portions of the second pattern tracks crossing over portions of the first pattern of conductive region where no electrical interconnection between the first and second conductive patterns is desired, while only partially removing the intermediate layer by underetching below portions of the second pattern of tracks crossing over portion of the first pattern of semiconductor regions where an electrical interconnection between the first and second conductor patterns is desired. In this manner, at least two separate parts of the first pattern of conductive regions are conductively connected at selected locations by a part of the second pattern of tracks in a method in which the conductive tracks of the uppermost level are used at a self-aligning etching mask.

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Ties S Te Velde