EP1164623A2 - Channel plate made of glass for flat panel displays and method for producing the same - Google Patents

Abstract

The device has a number of parallel channels (2) separated by vertical plates (1) and formed in a glass substrate (4) in microstructured form. Electrode tracks formed on the floors (3) of the channels are fed out in an edge region (4b,4c). The transition from the channel floors to the edge region is shaped so that there is no step between the channel floors and the edge region irrespective of manufacturing tolerances. Independent claims are also included for the following: a method of manufacturing a glass channel plate for flat display screen.

Description

The invention relates to a channel plate made of glass for flat screens, which has a plurality of parallel channels separated by webs, which are microstructured in a flat glass substrate, and which has an edge area on which are located on the channel floors Electrode tracks can be led out,

The invention further relates to a method for producing such Channel plate.

Display panels of flat screens, as they are typically used in modern Plasma television screens are required, the so-called plasma display Panel = PDP or Plasma Addressed Liquid Crystal = PALC, need for Their function is called channel plates, which are microstructures of high precision Form of several, parallel microchannels that pass through Webs are separated.

Such a channel plate is shown in detail in FIG. 3 in principle on a greatly enlarged scale. The apparent from this figure, channel-shaped microstructure must be made inexpensively and in large numbers for different display sizes (diagonal screen sizes up to 60 "or larger), depending on the screen size, the structure dimensions are in the following ranges: flight pitch X = 50 to 1000 μ m, ridge height Y = 50th - 300 µ m and web width Z = 20 - 100 µ m. For a 42 "HiVision PDP display, for example, there are approx. 5760 channels with a pitch of the webs" X ", the so-called pitch, of approx. 161 µ m to manufacture a web height "Y" of 150 μ m and a land width "Z" of 30 μ m with tolerances of a few μ m approximately 520 mm in length.

In the channels between the rib-shaped webs, depending on the display type, each applied between zero and three conductor tracks as electrodes.

The structure of these modern flat screens, especially the channel plate, is known.

Various methods for forming the channel structure are known become. In one method, the webs are formed with channels in the Screen printing process in several layers one after the other on a flat Glass substrate applied. This process is very complex and expensive.

In another method, the channel structures in the flat Molded glass substrate.

This shaping can be done in different ways.

It is known to pass through the channel microstructures by hot forming To produce embossing.

It is also known to sandblast over a mirostructured mask to generate the channel microstructures.

Attempts have also been made to grind the channels structure. Grinding is preferably a highly precise one Multi-disc grinding tool used that several on a common Spindle, with high precision axially spaced apart by spacer rings arranged precision grinding wheels. Because the channels are very fine are structured and have very small distances from each other Manufacture of the duct plates by grinding using the multi-disc grinding tool difficulties in that the individual Grinding wheels of the multi-wheel grinding tool are not in accordance small axial distances can be arranged to each other. For this The distance between the individual grinding wheels is therefore an integer Multiple of the pitch "X" of the webs. Because the length of the Multi-disc grinding tool due to the vibration behavior of the Machining spindle and is limited by the speed, takes place Production of the channel plates then by so-called offset grinding, at due to the multiple overflow of the multi-disc grinding tool Channel plate is structured. Between the individual overflows that will Multi-disc grinding tool offset at right angles to the longitudinal axis of the channel exactly around the pitch to be manufactured.

The channel plates have a flat edge area on at least one side, on which the metallic, if applicable, attached to the channel floors Electrode tracks are brought out for connection purposes. The upper level the flat edge area is at the target height of the channel floors to be formed. The channels are described by the Methods formed in the flat glass substrate, then the depth of the Channels, due to unavoidable manufacturing tolerances, differ, i.e. the height of the channel floors fluctuates with respect to the upper level of the Edge area and there are transition stages that adversely affect the photolithographic structuring of the metallic electrode tracks and their mechanical resilience against tensile and compressive stress.

The invention is based on the object, the one mentioned Channel plate made of glass so that the electrode leads are trouble-free structured and mechanically strong enough.

This object is achieved according to the invention on the basis of a Channel plate made of glass for flat screens, which a variety of parallel extending, separated by webs channels, which in a flat Glass substrate are microstructured, and which have an edge area has, on which electrode tracks located on the channel floors are lead out, in that the transition from the channel floors to the Edge area is shaped so that regardless of manufacturing tolerances Step occurs between the channel floors and the edge area.

The inventive design of the channel plate is a unproblematic electrode lead-out on the connection edge area given.

According to a first further development, the construction of the channel plate is Invention made such that the smooth transition to the edge area a ramp-shaped flattening, sloping towards the edge on a flat section has, with the highest point, which is a predetermined amount higher and a lowest point that is a predetermined amount lower than the intended one The target height of the channel floors is.

This can result in manufacturing tolerances when shaping the channel structures be caught in both directions.

The arrangement is preferably such that the highest point of the Ramp at the top edge of the web and the lowest point at least around the double the manufacturing tolerance is lower than the nominal height of the channel floors.

According to a second development of the invention, the channel plate can be so be designed so that the edge region at substantially the same height as the top edge of the web lies and a rounded transition from the channel floor to Edge area is formed.

In both embodiments, the smooth transitions are preferred ground in, which is particularly economical to achieve in terms of production technology is, in particular if according to an embodiment of the invention Channel structure is ground into the glass substrate. It is Appropriately, the glass substrate at least on the side on which the Grinding process starts, is ground to the extent that the tolerances in the Reduce depth of channels.

• Bereitstellen einer flachen Rechteck-Glasplatte mit vorgegebenen Abmessungen,
• Ausformen eines sprunglosen Überganges zwischen dem Bereich der Glasplatte, in dem die Kanäle einzuarbeiten sind und mindestes einem der Randbereiche, in den die Kanäle einmünden, und
• Ausformen der Kanäle in der Glasplatte, vorzugsweise durch Einschleifen.

With regard to the method for producing the channel plates according to the invention, the aforementioned object is achieved according to the invention with the steps:

• Providing a flat rectangular glass plate with predetermined dimensions,
• Forming a jump-free transition between the area of the glass plate in which the channels are to be incorporated and at least one of the edge areas in which the channels open, and
• Form the channels in the glass plate, preferably by grinding.

Further embodiments of the invention are in the subclaims are marked and are described in more detail in the following description of the figures explained.

Using two embodiments shown in the drawings the invention explained in more detail.

Fig. 1

eine Draufsicht auf eine Kanalplatte mit eingebrachter Kanalstruktur und einem gemäß einer ersten Ausführungsform rampenförmig abgeschliffenen Randbereich, auf den Elektrodenbahnen herausführbar sind,

Fig. 2

in einer prinzipiellen Querschnittsdarstellung durch die Kanalplatte nach Fig. 1 eine zweite Ausführungsform zum Einschleifen eines kontinuierlichen Überganges zwischen den strukturierten Kanalböden und dem Randbereich, auf den Elektrodenbahnen herausführbar sind, und

Fig. 3

die Kanalstruktur einer Kanalplatte in einer prinzipiellen, idealisierten perspektivischen Darstellung.

Show it:

Fig. 1

2 shows a plan view of a channel plate with an inserted channel structure and an edge region, which, according to a first embodiment, is ground in a ramp shape, on which electrode tracks can be led out,

Fig. 2

1 shows a basic cross-sectional view through the channel plate according to FIG. 1, a second embodiment for grinding in a continuous transition between the structured channel floors and the edge region on which electrode tracks can be led out, and

Fig. 3

the channel structure of a channel plate in a basic, idealized perspective representation.

3 shows the in an enlarged, highly idealized representation Structure of a duct plate for modern flat screens. This channel plate has a plurality of parallel channels separated by webs 1 2 on. On the bottom 3 of the channels, depending on the display type and design, 0 - 3 electrodes applied.

Such a glass plate is produced in the following steps:

First, a flat rectangular glass plate 4, the glass substrate, with given dimensions according to the required screen size, provided. This glass plate is preferably made by floating or pulling made and preferably consists of borosilicate glass.

Glass plates produced in this way typically have on their surface wavy bumps with long wavelength, the so-called "Warp" and a ripple with a very small wavelength. By grinding one or both sides of the glass surface in the The next step is to minimize warps and ripple and thus a reduction in the tolerance field of the structured channel plate.

When using a suitable grinding wheel, the plane-ground glass surface when using the duct plate in one PALC display minimizes distracting stray radiation, and thus the contrast increased.

The structuring of the channels 2 in the flat-ground glass plate 4 in its active region 4 a is carried out according to one of the methods described at the outset, preferably by grinding in the channels using a high-precision multi-disc grinding tool.
Such high-precision multi-wheel grinding modules typically have a plurality of precision grinding wheels mounted on a common spindle, with high precision axially spaced apart by spacer rings, for simultaneous grinding of microstructures running parallel to one another in a workpiece. The grinding wheels must have a high-precision mutual distance with very small tolerances. For the reasons mentioned at the beginning, the channel structure is ground in by the so-called offset grinding described there.

The channels 2 are then, depending on the display version, the metallic ones Conductor tracks introduced as electrodes. The application of the metallic Conductors are expediently made using external currentless and galvanic process for metal deposition with photolithographic Structuring of the electrode areas according to the older German Patent application 198 41 900.7-33, the disclosure of which is also by Reference to the disclosure content of the present application is made. Other processes, such as sputtering and vapor deposition, are also possible.

These metallic conductor tracks must be made from the Channel floors 3 are led out to an edge region of the channel plate, the upper surface of the edge area at the desired height of the channel floors 3 lies. The following problem arises.

Due to the unavoidable delivery tolerances at Grinding process or the other shaping processes result different heights of channel floor 3 and the edge area of the Channel plate, i.e. it arises between the edge area on which the Electrodes are led out one step. This level affects the photolithographic structuring of the electrodes when the Traces negative. For example, paint accumulates in concave corners and no paint covering of convex corners. this leads to for short-circuits and interruptions in the metallic conductor tracks. Also the deposited electrodes become loxal with tensile and compressive stresses burdened higher. According to the invention there is therefore a smooth transition molded between the connection area and the channel floors, preferably ground. In the example of FIG. 1, the Channel plate 4 before structuring, for example by a grinding wheel corresponding width and contour, starting from the top of the duct plate, a flat oblique to the edge ramp 4 b formed, which opens into a flat connection area 4 c, the deeper than the target height of the channel floors 3 is. This ensures that the metallic conductor tracks of the electrodes no jump between the channel bottom and must overcome border area, not even within the specified tolerances fluctuating actual height of the channel floors.

The transition between the edge area at an obtuse angle 4 b, c and channel floor 3 ensures a significantly better photolithographic Structurability of the electrode and less stress on the finished one Electrode so that no short circuits and interruptions occur and the Risk of breakage of the electrodes is significantly reduced. This measure leads therefore to an increased yield in the production of the channel plates.

The slope of the ramp 4 b is for example 3 ° and the lowest point of the ramp located opposite the desired height of the channel bottom 3 by, for example, 10 μ m deep. Preferably, the ramp slope 4 b is shaped so that the lowest point is twice the manufacturing tolerance lower than the desired channel floor height.

Another way to increase the photolithographic structurability improve and reduce the stress on the electrodes in it, a continuous transition between the surface of the glass plate 4 and the channel floor. This can be achieved, for example, by as shown in FIG. 2 before the structuring of the channels begins 2 with the grinding wheel 5 of a grinding tool at speed in the Glass plate 4 sticks from above or at a certain angle.

The radius of the disk 5 thus forms in the edge region 4 b of the structure from. This radius also leads to a continuous transition between the channel floor and the glass surface of the channel plate in the edge area 4 b. For this reason, the load on the electrode can also occur be reduced. Another advantage of immersing with the grinding wheel 5 in the glass plate 4 is that in addition to a separate Edge processing can be dispensed with. Thus, another manufacturing or Process step omitted.

The edge area can also be used to store and support a microsheet (Thin glass) or as mechanical support for a cover glass.

Claims (10)

Channel plate made of glass for flat screens, which has a plurality of parallel channels (2) separated by webs (1), which are microstructured in a flat glass substrate (4), and which has an edge area (4b, 4c) on which Electrode tracks located on the channel floors (3) can be led out, characterized in that the transition from the channel floors to the edge area (4b, 4c) is shaped such that no step occurs between the channel floors and the edge area regardless of manufacturing tolerances. Duct plate according to claim 1, characterized in that the stepless transition to the edge area has a ramp-shaped flattening (4 b) falling towards the edge onto a flat section (4 c), with the highest point being a predetermined amount higher and a lowest Point that is a predetermined amount lower than the intended target height of the channel floors (3). Duct plate according to claim 2, characterized in that the highest point lies at the level of the upper edge of the web. Duct plate according to claim 1, characterized in that the edge region lies essentially at the same height as the top edge of the web and a rounded transition from the duct base (3) to the edge region is formed. Duct plate according to one of claims 1 to 4, characterized in that the stepless transition is ground. Channel plate according to one of claims 1 to 5, characterized in that the channel structure is ground into the glass substrate (4). Channel plate according to one of claims 1 to 6, characterized in that the glass substrate (4) is plane-precision ground on at least one side. Method for producing the channel plate for flat screens according to one of claims 1 to 7, comprising the steps: Providing a flat rectangular glass plate with predetermined dimensions, Forming a seamless transition between the area of the glass plate in which the channels are to be incorporated and at least one of the edge areas into which the channels open, and Form the channels in the glass plate, preferably by grinding. The method of claim 8, wherein the molding of a non-jump Transition by grinding in an edge area on at least one Side of the glass plate into which the channels open, one ramp-shaped, sloping towards the edge on a flat section Has flattening, with the highest point being around a given one Measure higher and the lowest point by a given amount is lower than the nominal height of the channel floors. The method of claim 8, wherein the molding of a non-jump Transition takes place in such a way that the discs of a multi-disc grinding tool at the start of grinding in the channels under Speed vertically from above or at a certain angle in the Glass plate are pierced.

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