DE2533749A1 - GAS DISCHARGE INDICATOR AND METHOD OF MANUFACTURING IT - Google Patents

Description

Patent attorneys

Dipl. Ing. H. Hauck

Dipl. Phys. W. Schmitz

Dipl. Ing. E. Graalfs

Dipl. Ing. W. Wehnert

Dipl. Phys. W. Carstens

8 Munich 2

Mozartstrasse 23

Panel Technology, Inc.

Toledo, Ohio, USA July 18, 1975

Lawyer File M-36ol

Gas discharge display panels and processes for their manufacture

The invention relates to a gas discharge display panel with two substrate plates, with a sealing device through which the Substrate plates are connected at a distance from one another and which delimits a thin gas discharge chamber, with one in the Gas discharge chamber located gas and with an electrode arrangement, with the parts of the gas volume to display the information can be ionized separately. The invention also relates to a method for producing such gas discharge display panels .

Processes for producing gas discharge display panels of the type described at the outset are known to the person skilled in the art. Both known methods, however, the display panels are manufactured piece by piece individually. There are individual glass substrates and / or ceramic substrates are used on which conductor tracks are printed. Then dielectric masks are over the

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Printed conductor tracks, and at the same time printed in openings provided in the conductor tracks for receiving the cathode electrodes. The cathode material, which later faces the gas or the gas mixture for the discharge, is printed on and the layers are fired together and cured. Such parts are then assembled, usually a Gas filler neck is used. In some cases, display panels that are free of nozzles have also been produced in which the gas-tight sealing of the two spaced apart substrates taking place at the end of production Use of a non-melted sealing frame takes place. The entire formed from the Sübstratplatten and the sealing frame Unit is evacuated and refilled with gas at increased temperature; then those between the electrode sets parts assembled at a distance are heated while the gas is retained in the assembly. This continues until the parts of the housing have become soft enough to reach a sealing temperature, so that sealing is achieved by melting the sealing frame the unity is obtained. That’s the finished scoreboard sealed. This process is difficult and cumbersome to carry out and cannot be used for joint editing Use individual scoreboards in batches.

In US Pat. No. 2,142 Io6 there is another gas discharge display device described. Small ones are used to make them

Glass panes that carry cathode elements of a predetermined shape and individual anode elements stacked in a pane.

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The spaces between the discs are around the perimeter sealed so that mutual contact between the electrodes is avoided. A small opening is left at one point of the circumference; this is done by the fact that when sealing this Point is omitted. This creates a connection to a main gas chamber, which runs through the entire arrangement surrounding glass envelope or a glass bulb is formed. According to US-PS 2 142 Io6, the glass bulb is then evacuated and with filled with suitable pressurized gas. A small opening is left free in the seal that seals the panes has been, the evacuation and refilling with gas takes place via these openings at the same time in the individual "gas discharge chambers" in the disks arranged at a distance from one another are trained. The small opening is then filled with a suitable sealing material, which is used during evacuation and during the subsequent Refilling with gas allows gas passage. Then the individual sealing body or sealing plug is gas-tight

tightly closed, for which purpose the sealing plug is loaded with electrons

firing heaters or other sealing devices j can be used.

The present invention represents a direct and significant one

Improvement of the method disclosed in the above-mentioned patent specification. Part of the known method is adopted and adapted to process thousands of individual discrete gas discharge display panels in one batch becomes possible. So far this has not been possible. Here is the

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(Yield considerably greater than with known processes.

A substantially bubble-free glass rod is shaped substantially in the shape of the edge of the gas discharge chamber and is in Air fused with the two opposing surfaces of the substrate plates. Between the ends of the glass rod a small opening, a small gap, is provided. Semi-finished scoreboards can be placed in large numbers in racks be stacked. A small glass rod bridges the ends of the glass rod. The glass rod holds the opposite one

jSubs stepping plate at a distance and is at the same time held in place by the same. The glass rod representing a sealing stopper has a slightly smaller diameter, so that there is no play between the opposing surfaces of the Substrate fits. It has a melting temperature that is slightly below the melting temperature of the curved, gas discharge chamber ! limiting glass rod lies. Both glasses, however, are of optical quality and have essentially bubble-free surfaces on the edges. The loosely placed glass rod (sealing plug) allows the joint evacuation of an entire batch (if desirable, even at bake-out temperature) and refilling one large number of individual display boards with a given gas mixture in a single operation.

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, In the conventional manufacture of gas discharge display panels with segment electrodes (especially alphanumeric display boards j the individual conductor tracks are first placed on the substrate

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! printed and burned. Then the mask and the cathode electrodes Parts printed on, i.e. the parts that are in direct conductive contact with the gas, printed on and cured. The cathode parts are printed on in the dielectric mask provided breakthroughs or openings. According to the invention, instead of ceramic substrates, simple and cheap glass substrates are used. The conductor elements that form the cathode electrodes that are later exposed to the gas are first printed and hardened at a higher temperature than before. This ensures that the conductor segments that the Form cathodes of the display panel, have a good and hard surface at the interface with the gas; this will be Sputtering problems kept as small as possible and the discharge properties of the scoreboards improved.

In the above-described sealing of display panels, it has been found that the use of im not fused together State of the sealing material applied by screen printing is less advantageous than the use of a preformed one Rods made of glasses with the properties required for fiber optics, i.e. glasses that do not contain gas have, through which the seal when heated

and / or evacuation could be moved or destroyed.

In the conventional production of gas discharge display panels, these are baked out in a vacuum to form enclosed gaseous ones Contaminants from the interior surfaces of the scoreboard

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remove. Baking out under vacuum takes a lot of time and is very expensive. Another beneficial feature of the method according to the invention is that several thousand units stacked in racks are arranged in a vacuum chamber will. Without heating, evacuation takes place so that essentially all impurities are free from the individual gas discharge display panels removed. Then the filling gas is introduced into the treatment chamber at room temperature, and thereby each of the gas charge display boards is filled at room temperature, i.e. normal temperature. This makes a real one Gas filling level ensured and the need for an exact and precise calibration at high gas filling temperatures not applicable. After the gas filling has been introduced into the units, they are heated by "Calarod" heaters in the treatment chamber, so that the small, Melt the sealing plug described above. This process can save the long time that would otherwise elapsed between filling and heating the chamber; This can reduce the time for a production run with thousands of Units in a single treatment chamber are reduced to less than 6 hours in which evacuation is performed, heating is carried out, is filled again with gas, etc. Since this sealing process is carried out at a slightly lower pressure than normal pressure, and since the volume of gas in the vacuum chamber can be greater than that in the total of the gas discharge display panels volume of gas contained, sufficient heating is obtained with a little negative pressure to clean the unit properly

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to obtain; the vacuum is worse than ideal and the cost and processing time are significantly reduced.

Another essential feature of the invention is the activation of small capsules containing mercury (mercury dispensers) using a laser beam. For this purpose, the display board is in each one with windows that are permeable to laser radiation of the two glass substrates. This allows the use of a laser beam to break the mercury capsule, without damaging the display board itself.

In known gas discharge display panels, the connection is made between the anode electrodes and external terminals for connection with operating voltages using small metallic brackets which are arranged between the two substrate plates. According to the invention, between the terminal ends of the anode electrode

assigned
Troden and / printed conductor ends of the cathode plate introduced a conductive epoxy material. According to the invention, this epoxy material is carefully cured, so that it is ensured that no bubbles touch the anode elements. Such bubbles would lead to hot spots and the destruction of the connection to the anodes.

A large number of cathode electrodes is thus used in accordance with the invention

and a dielectric mask printed on a single glass substrate and burned. The electrodes are printed on first

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and dried and formed at higher temperatures than the tem-; temperatures to which a mask and electrical cross-connections are later exposed, which harden at lower temperatures and be formed. After the electrodes, the dielectric masks and the cross connections between the equivalent ones have been completed Segment electrodes and other auxiliary conductors are simply scratched and divided into the glass plate, so that individual back substrates and electrode / mask assemblies are obtained, which are then made with similarly manufactured anode plate parts be assembled. The assembly of the individual units is carried out using a previously in the correct Shaped rod-shaped seal, wherein an opening remains free in the seal. Furthermore, when assembling into the Unit introduced a mercury storage capsule that can be broken by laser beams. When manufacturing the gas discharge display panel gas is introduced through the small gap left in the seal, and this gap is closed with a short sealing rod, over which and around which the evacuation and filling with gas (with final j in accordance with charging with gas). On the order of looo to 5ood

Units can be converted into one in a relatively short time

i batch are being processed.

The invention is explained in more detail below using an exemplary embodiment and with reference to the accompanying drawings In this shows:

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Fig. 1 shows a glass substrate on which a first pattern

conductive material is printed, there is such a pattern in the upper left corner of the Glass substrate shown in detail, while the dashed lines indicate the location of a large number indicate other such patterns, which are not shown in detail in FIG. 1 for the sake of clarity are shown;

FIG. 2 shows the glass substrate shown in FIG. 1, onto which

a first dielectric mask is printed on it (the dielectric is black in color, is but shown in white in Fig. 2);

Fig. 3 shows the glass substrate shown in Fig. 2 over

whose mask cross-connections producing conductor tracks are printed, which the various connect the elements shown (it goes without saying that the other fields of the Glass substrates are printed in a similar way);

4 shows the glass substrate after another one has been printed thereon

dielectric layer over that shown in FIG Cross-connecting conductors;

Fig. 5 is an exploded view showing the order

the assembly of the various parts into one unit, which is used for filling with gas and for Sealing in a batch together with other units is shown ready;

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Fig. 6 is a plan view of a fully assembled

Gas discharge display panel;

7 is a sectional view on an enlarged scale,

in which the attachment of the sealing rod is shown, which is in the now fused Sealing frame bridged the remaining space;

8 shows a section through an assembled unit

with a mercury capsule arranged in this and the ones aimed at this for destruction Laser beam;

Fig. 9 is a flow chart in which the individual printing and

Curing operations are shown that are used in the manufacture of the gas discharge display panels Find use.

In Fig. 1 a glass plate Io is shown, for example 25 χ 30 cm can be large and simple, i.e. can have normal strength. There are individual cathode electrode patterns on the glass plate Io 11-1, 11-2 ... 11-9 and cathode electrodes 12-1 to 12-N for decimal points imprinted. Each of the cathode electrode patterns represents a display location. The illustrated embodiment is designed for a nine-digit numeric display board (N = 9). The invention is equally applicable to alphanumeric segment display panels and also for matrix display units in which a matrix point is assigned to a point of intersection of two electrodes is to use. The cathode electrode patterns have cathode elec-

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Trode segments 13A, 13B, etc. on. These represent at the described Display panel represent the cathode electrode elements that define the glow discharge portions of the display panel. Some of the Cathode electrode segments, e.g., segment 13A, has another directly connected conductor section 14A which becomes a one Contact 15A forming enlarged conductor end leads. In the embodiment described, the corresponding Cathode electrode segments 13A of all of the cathode electrode patterns 11-1 to H-N are electrically connected to each other. There are some the corresponding cathode electrode segments are already connected to one another by the initial printing of the cathode electrodes, as can be seen from FIG. For example, the cathode electrode central segment 13C is all of the cathode electrode patterns shown as a horizontal, through-connected segment electrode, which is connected to a contact 15C via a conductor section 14C. Between the contacts for the cathode electrode segments Contacts formed by conductor surfaces are already printed on at the beginning, while those with anode elements in the course of manufacture connected, as will be explained. Similarly, the cathode electrode segment 13B is the cathode electrode pattern 11-1 with all cathode electrode segments of the letter B of the other cathode electrode pattern through one Conductor section 14B and connected via this to a contact 15B.

According to the invention, however, some of the cathode electrode segments are not directly connected to conductors that lead to the individual con-

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bars 15 run. In the illustrated embodiment, as shown in Fig. 2, a first dielectric mask 16 is over the Printed conductor segments of Fig. 1, with window-like openings 18-1 to 18-N, 19-1 to 19-N, 2o-1 to 2o-N, 21-1 to 21-N and 22-1 to 22-N remain blank. All of these are aligned with the conductor sections or conductor surfaces underneath. The openings are simply omitted locations in the dielectric mask 16. In addition to these, for the subsequent production of conductive ones Openings provided for cross connections, which will be explained in detail with reference to FIG. 3, are also the individual ones Cathode electrode segments 13A, 13B, etc. and the cathode electrodes left blank for the decimal points 12-1 ..., 12-N. As has already been stated above, these cathode elements no further conductive material is applied, as these have been formed at a higher temperature so that they are tempered and / or smooth surfaces are formed for the discharge per se. The openings 18-1 to 18-N, 19-1 to 19-N, 2o-1 to 2o-N, However, 21-1 to 21-N and 22-1 to 22-N are used to produce conductive cross connections and are therefore left open to a contact of conductor material, which is printed in the manner shown in Fig. 4, with the through these openings to enable accessible ladder elements. The printed conductor material forms electrical cross connections with the circuit shown in Fig. 3 shown pattern. The shapes of the conductor tracks can of course be chosen so that the printing of such cross-connections can be dispensed with entirely or as largely as possible. The dielectric Mask 16 is shown in white in the drawing, it understands

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however, that there is a black mask around the glow discharges to make it more visible at the cathode electrode segments. The cathode material is also white or has a silver color Appearance; in fact the cathode material is essentially silver in a suitable substrate. Clear, i.e. not permeable areas of the glass are also shown spotted. Of course, the anode glass substrate can be transparent be.

In addition to the openings required to produce the cross connections and the openings that are used to view the in direct conductive contact with the gas standing cathode electrode segments are required, two windows 25A, 25B are provided, through which the glass phthalate Io can be viewed directly. What for these windows are used, is described in more detail below.

Conventional reference marks are not shown in FIGS. 1 and 2, which serve to align the layers. These reference marks are simply marks that are in the on the glass plate Io applied dielectric material are imprinted. Similar reference marks are made after printing on the dielectric material printed on the glass plate Io in each later printed layer in order to ensure that they are aligned. Similar if further reference marks are printed in the next step, to ensure proper escape. Printing is primarily screen printing with stencils, etc. understand, however other printing methods can be used

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In Fig. 3 is a cross connection via the openings 19-1 to 19-N producing conductor designated 3o, while a one Establish a cross connection via the openings 18-1 to 18-N Head is designated 31. Similar conductors 32,33,34 to manufacture of cross connections are formed by printed conductive material on the dielectric layer. The printing is done simply by screen printing or by any other direct application of the conductive material to the dielectric surfaces of the substrate. The conductive material enters the openings and makes electrical contact with the previously printed conductor elements. Two conductors 36 and 36 to establish a cross connection are also on the conductor only printed to make cross connections between the conductor elements, as shown.

The cathode electrode segments formed of conductive material of each of the cathode electrode patterns for the different ones Display areas are not covered. These conductor elements continue to be exposed to the heat treatments necessary for hardening the dielectric layer 16 and the individual cross-connecting conductors are carried out (these heat treatments take place at lower temperatures).

In a final printing step, the last dielectric layer is created applied over the cross-connecting conductors to obtain windows 25A, 25B. This last imprint

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as is known, serves to prevent the conductor sections or conductor surfaces from glowing to prevent that are not supposed to glow.

As can be seen from Fig. 9, an important step is just now described manufacturing process of the back substrate that the cathode electrode segments of the display unit form Electrodes are printed in the first printing step. As can be seen from FIG. 9, this electrode is formed in a method step 5 at a much higher temperature than at conventional methods of manufacturing such display panels was possible. In other words: by the fact that the cathode electrode segments to be printed first and to create an improved interface between cathode and gas at a higher temperature are formed, the mask printed on at a later point in time can be cured at lower temperatures, without the conductivity of the different conductor elements is adversely affected, which serve to make the connections from the unit to the outside. How also can be seen from FIG. 9, the first mask is printed on in a two-stage operation; first the mask becomes a first Times imprinted, dried and then cured. Then the mask is printed a second time, dried and cured. Of course, the mask can also be applied all at once. In some cases the mask can be produced as a film and then applied to the substrate. However, it is important to ensure that the mask is of sufficient thickness to

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and that the adjacent cathode electrode segments separated only by a gap are separated by a physical barrier made of dielectric material. The second step is therefore an important one Safety measure that the dielectric between the ends of individual cathode electrode segments has a height that is large enough to form a barrier through which a short circuit between closely spaced cathode electrode segments avoided or kept very small.

The conductors are printed on to produce the cross-connections using the same conductive material that is used for the first printing of the conductive material. In either case, the conductive material is dried and then cured at higher temperatures. This material is a frit-based paste that can be applied as a thick film and preferably comprises silver. The printing of the third mask could indeed result in an overprinting of the cross connections
Heads are limited, but printing is done over the full area, as this gives even greater security
that a sufficient barrier is obtained between the individual cathode electrode segments of the substrate. Apart from the fact that by applying the cathode electrodes as the first layer, they can be dried and formed at a sufficiently high temperature so that a good, clean and smooth silver surface of the cathode electrodes is obtained,
the application of the cathode electrode in the first printing step has the advantage that mask areas can be built up that consist of

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sufficient barriers between the individual cathode electrode segments represent; this increases the risk of conductive connections being formed between the individual cathode electrode elements due to sputtering and the like. Reduced and the life of the display panel increased as a result.

As shown in box 18 of FIG. 9, the glass plate is torn along the dash-dotted line in FIGS and divided so that individual rear substrates are obtained, which are designated in FIG. 5 by 50. The back substrates

50 are not yet identical to one of those shown in FIG. 4 separated units. Also in Fig. 5 is a front substrate

51, on which individual anode elements 52-1, 5 2-2 to 52-N are printed. There is one for each display point Anode element is provided that the individual cathode electrode segments and can cover the cathode electrode for the decimal point at a given display location. The anode elements are formed from transparent tin oxide and are formed by printing this material on a glass substrate 53 of simple thickness and subsequent firing received. The printing and firing of these conductor elements can be quite similar to the printing of the cathode elements bearing rear substrate are carried out in batches. The use of tin oxide as a translucent anode material is known to the person skilled in the art and is not described in detail here. It should only be noted that the printing of the anode material for a large number of units on a thin glass substrate with a view to manufacturing the units

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- 18 is advantageous in larger games.

The front or upper substrate 51 with the anode elements is connected to the rear or lower substrate 5o by means of a sealing body 55 connected. This is brought into such a shape that its ends 56 and 57 by about 1.5 mm to 6 mm (1/16 to 1/4 Inches) apart. The sealing body 55 is simply placed on the rear one provided with the black dielectric mask Placed on the substrate and held in place by drying non-fused dielectric material. Be at the same time rod shaped spacers 58,59 at each of the ends of the unit and also temporarily held in place by pinning e.g. with unfused dielectric material. The rod-shaped spacers 58,59 are made of a hard one Type of glass manufactured that has a higher softening temperature than the sealing body 55. The sealing body 55 is made of a Type of glass manufactured as it is also used in glass fiber optics (i.e. bubble-free) and has a melting point (This must be achieved to seal the display panel) which is below the melting point of the glass plate Io and of the rod-shaped spacers 58,59 lies. Usually is the temperature used to seal the display panel is around 45o ° C.

There is also a small mercury capsule above window 25A 6o due to unfused dielectric material

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fixed. The latter has essentially the same composition like the dielectric forming the mask, but is not pigmented. A white unfused dielectric Material is therefore used to reduce the energy of a laser beam used to break the mercury capsule 60 is not absorbed by the black dielectric, which would generate heat in the black dielectric and the display panel would be destroyed. For this reason, the two windows 25A, 25B are also provided.

After the sealing body 55, the rod-shaped spacers 58, 59 and the mercury capsule 60 on the rear substrate 5o have been attached, the front substrate 51 with the anode elements is placed thereover, and weighed down with a weight. The entire assembly is then sent through a heating furnace so that the sealing body with the front substrate 51 and the rear substrate 5o is fused and connected. The arrangement then obtained is shown in FIG. The interior the gas discharge chamber can be reached through a small gap 65. A glass rod 66 that is roughly the same diameter How the spacers 58,59 comprises is simply about that between the back substrate 5o and the front substrate 51 is placed in the remaining gap and represents a sealing plug made of glass, to which reference is made in the box 23 of FIG is taken.

It goes without saying that the rod-shaped spacers 58,59

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not arranged within the later gas discharge channels will need and do not necessarily have to be arranged in the locations shown. These can run parallel to the horizontal sides of the sealing body 55 are arranged, are arranged parallel to all four sides of the sealing body, be arranged between the display points in the case of larger display panels (see US Pat. No. 3,499,167), they can even be outside the gas discharge ducts and are arranged parallel to the horizontal and / or vertical sides of the sealing body 55. Basically, the spacer can also have a shape running along the circumference of the display panel, that is to say a shape like the sealing body 55, the spacer having only slightly larger or smaller dimensions than the sealing body. The only important features of the spacer or the Spacers are those that, by their size, increase the length of the Discharge gap is given that they are made of a glass with a high melting point and that they have a fiber softening point which is located below the sealing body 55.

As shown in Fig. 6, every other one of the contacts 15 is with the cathode electrode assembly disposed on the back substrate 50 connected, while the intermediate contacts 15 are connected to associated anode elements. This latter connection is made using conductive connecting elements 7o-1, 7o-2, .... 7o-N, which consist of a extruded conductive silver epoxy material are made.

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This represents an advantage over the conventional metallic connection inserts that have previously been used for the same purpose. It is important that the epoxy material be cured at a temperature at which blistering does not occur. The current flowing in the thin tin oxide layers is possibly collected at individual points by means of bubbles, whereby the connection to these tin oxide layers deteriorates or is destroyed.

As can be seen from Fig. 8, the mercury capsule

on
a glass capillary tube / (outer diameter about 0.5 mm corresponding to 18 mils), which is permeable to laser energy. The mercury capsule is arranged between the window 25A and the rear substrate 5ο carrying the cathode electrode arrangement and a transparent section of the front substrate 51, which could also be referred to as a window, and is held in place by white dielectric material for assembly purposes. A block of aluminum or copper serves as a heat sink and should not have high reflectivity for safety reasons. Instead of a glass capsule, any other device that can be actuated by radiant energy can be used as the container from which the mercury can be released, for example the 15o device available from the Italian company SAES.

The filling gas for the display panel can be a mixture of neon and argon, e.g. 99.5% neon and 0.5% argon. As usual,

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radioactive krypton (krypton 85) can be added to the filling gas, to cut off the operating voltage. It should be noted that the scoreboard did not use two either Has contacts 15 that can be used to operate a discharge sustaining ignition cell, such as the Is known to those skilled in the art.

Wfe can be seen from Fig. 8, form in the described embodiment Edges 75 and 76 of the back substrate 5o and the front substrate 51 have a slot or notch, in which the glass rod 66 used as a sealing stopper Can find inclusion. This enables a simple mechanical holding of the spacer in the desired position achieved while the scoreboard is degassed and then refilled with gas. If desired, the top can be horizontal Side of the sealing body 55 are arranged closer to the edge, so that after softening of the sealing material of the sealing body 55 this, as shown in Fig. 8, is flattened, and the glass rod serving as a sealing plug can through a Adhesive material, such as unfused dielectric material, can be held in place. However, the sealing body 55 can also have a flat cross-section and, as above, be slightly thicker than the spacers 58,59. The assembled scoreboards with the glass rod 66 arranged in the slot or the notch and bridging the ends of the sealing body 55 are in Stainless steel racks stacked with the gap 65 facing up and the glass rod 66 attached. One Supplement, not shown in the drawing, made of high temperature

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temperature melting glass is between the lower edge of the front Substrate 51 and the lower edge of the rear substrate arranged so that the correct mutual position between The front and rear substrates are retained when the glass rod 66 is heated.

The sealing body 55 is made of bubble-free glass in order to avoid leaks. One used in fiber optics Glass like Corning Glass No. 757o in tube form with a clear Width of 0.8 mm ("corresponding to o33") works satisfactorily; it has a relatively low melting point of around 45o ° C. The glass rod 66 serving as a sealing plug, which is shown in FIG Way is arranged above the gap 65, has a fiber softening point which is below that of the sealing body 55 lies. A similar glass with a fiber softening point 2o to 3o ° lower is sufficient.

The filling of the display boards with gas is carried out as follows: the display panels are evacuated, the appropriate gas is introduced at room temperature to the appropriate pressure (approximately 12o torr), and the glass rod used as a sealing plug is heated so that the housing is closed with the desired gas filling will. If the procedure is as described above, the cycle lasts with 2,000 display boards produced per cycle 6 hours. Each treatment chamber can easily be designed so large that up to 5,000 display boards can be treated can. The duration of the cycle can also be reduced to 1-1 / 2 hours.

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are set. If scoreboards are not properly sealed, they will simply be treated again in the next cycle. That Gas used in the plant can be reused by operating two treatment chambers in parallel. After removal of the sealed scoreboards from the gas filling facility, each scoreboard is placed under a laser beam, which is sent through the window formed in the display panel to destroy the mercury capsule and that To release mercury so that it can spread in the housing. As usual, before releasing the mercury, the Scoreboard should be stored for some time to age.

For drying and shaping the first applied cathode electrode material a continuous furnace with a length of about 16 m (50 ft), with a throughput speed of 3o cm / min (1 ft./min) and with 15 heating zones with a maximum temperature of 100 ° C.

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Claims (5)

July 18, 1975 Attorney File M-36ol Claims f1.JGas discharge display panel with two substrate plates, with one \ - ' Sealing device by means of which the substrate plates are connected at a distance from one another and which delimits a thin gas discharge chamber, with one located in the gas discharge chamber Gas and with an electrode arrangement with which parts of the gas volume are ionized separately to display the information can be characterized in that the nozzle-free formed display panel has a first sealing body (55) which defines the edge of the gas discharge karamer Has shape; that the first sealing body (55) two at a distance from each other has arranged ends (56, 57) which delimit an opening (65) for evacuation and for charging with gas; that the display panel has a second sealing body (66) by one, the ends spaced from one another (56,57) of the first sealing body (55) is formed by a fusible bridging plug and is located opposite one another - 26 - 509887/0412 lowing surfaces of the two substrate plates (5o, 51) so arranged is that the opening (65) is sealed for charging with gas. 2. Gas discharge display panel according to claim 1, characterized in that that the sealing body (55) is made of essentially bubble-free glass. 3. Gas discharge display panel according to claim 1 or 2, characterized in that that the stopper is formed by a glass rod (66) between the opposing surfaces of the flat substrate plates (5o, 51) made of glass is arranged. 4. gas discharge display panel according to one of claims 1 to 3, characterized in that anode electrodes (52) on one of the substrate plates (51) and cathode electrodes (11) on the opposing second substrate plate (5o) are arranged so that the second substrate plate (5o) carries flat contacts (15); that among the contacts (15) are those which are connected to the cathode electrodes (13) carried by the second substrate plate (5o) are molded; that the substrate plates (5o, 51) by a Sealing device (55,66) are connected to one another, which together with the substrate plates (5o, 51) form a gas discharge chamber limit; that the second substrate plate is the flat contacts (15) on a protruding part of the same; and that between the substrate plates (5o, 51) bubble-free, conductive extruded material is arranged through which the anode - 27 - 509887/0 4 12 Electrodes (52) on the first substrate plate (51) with at least one (15B) of the Kontkate (15) on the protruding Section of the second substrate plate (5o) are connected. 5. Gas discharge display panel according to claim 4, characterized in that that the bubble-free, electrically conductive extruded material is silver in an epoxy carrier material that is between the two substrate plates (5o, 51) is inserted at the selected one of the contacts (15). 6. gas discharge display panel according to one of claims 1 to 5, characterized in that the cathode electrodes (11) are printed onto a glass substrate (5o) with a conductive silver paste which forms part of the display panel, and that the conductive silver paste is then heated to a firing temperature higher than any other temperature used in subsequent manufacturing steps of the display panel, so that porous areas of the cathode electrodes (11) are cleared and a smooth cathode surface is obtained. 7. gas discharge display panel according to one of claims 1 to 6, characterized in that the on the glass substrate (5o) printed cathode elements (11) lie in a common plane that between some of the cathode elements short distance is present, and that a dielectric layer (16) applied to the substrate of sufficient thickness and suitable shape forms a sputter barrier between the cathode elements with a small spacing. 509887/0412 -28- 8. gas discharge display panel according to one of claims 1 to 7, characterized in that a container (6o) which can be opened by laser energy is arranged in the gas discharge display panel is that in one of the substrate plates (51) at least one window (25) permeable to laser energy is provided, that the container (6o) which can be opened by laser energy is arranged in the gas discharge chamber near the window (25), and in that means are provided by which the container (6o) is in place between the window and the opposite one Substrate plate is held. 9. Gas discharge display panel according to claim 8, characterized in that that between the substrate plates (5o, 51) there is a discharge gap of about 0.5 mm (2o thousandths of an inch), that the container (6o) through a hollow capillary tube made of glass which is permeable to laser energy and has an outer diameter is formed of less than about 0.5 mm and a predetermined length; that the capillary tube is closed at both ends and filled with elemental mercury; and that the length of the capillary tube and the inner free cross section a hollow portion thereof are chosen so that a predetermined amount of liquid mercury absorption finds. Io. Method for manufacturing a gas discharge display panel according to one of claims 1 to 9, characterized in that for Seal the display panel away from the substrate panels - 29 509887/0412 held together by a sealing body, the circumferential shape of which is that of the gas discharge chamber and which forms the lateral boundary walls of the same; that the sealing body is shaped so that between its An opening remains at the ends through which the discharge chamber is in communication with the environment; and that the distant ends of the sealing body after filling the discharge chamber with ionizable gas by melting a sealing plug / are connected to each other so that the opening from the discharge chamber to the environment is closed will. 11. The method according to claim Io, characterized in that the Sealing plug is made of solid glass, the expansion properties of which are essentially those of the sealing body and which has a fiber softening temperature which is below the fiber softening temperature of the Sealing body lies. 12. The method according to claim 11, characterized in that the sealable display panel is first evacuated and then in an atmosphere of the desired ionizable filling gas and is brought / that then the stopper is heated to a temperature is below the fiber softening temperature of the sealing body and above the fiber softening temperature of the Plug lies, so that a predetermined volume of ionizable gas is enclosed in a gas-tight manner in the discharge chamber. - 3o - 509887/0412 - 3ο - 13. The method according to any one of claims Io to 12, characterized in that that for the purpose of connecting the substrate plates a relatively thin solid glass part according to the circumferential shape the Discharge Kanuner is formed, the ends of this glass part are kept at a distance, so that a Opening for evacuating and charging with gas is formed that the sealing body is sandwiched between the rigid substrate plates is arranged and heat is supplied, so that the sealing body with the opposing surfaces the rigid substrate plates is fused. 14. The method according to any one of claims Io to 13, characterized in that that spacers are applied to one of the rigid substrate plates that the spacers with a the height of the discharge space corresponding thickness are made, which is smaller than the thickness of the sealing body, and that during the heat treatment for connecting the rigid substrate plates, a pressure is exerted on them, so that the thickness of the sealing body decreases in the process of connecting the substrate plates. 15. The method according to any one of claims Io to 14, characterized in that that the stopper made of glass is a glass rod, and that the bridging of the ends of the sealing body is thereby carried out is that the glass stopper is placed between the rigid substrate plates. 509887/041 2 16. The method according to any one of claims Io to 15, characterized in that that a plurality of prepared sealable display panels are placed in a common chamber and then the process steps of arranging, filling with gas and heating take place. 17. The method according to claim 16, characterized in that the sealable display panels are stacked adjacent to one another that the stoppers made of solid glass are arranged in alignment with one another, and that at least During the heat treatment, a pressure is exerted on the stack, by means of which the display panels are tightly attached to one another being held. 18. The method according to any one of claims Io to 17, characterized in that that the evacuation and refilling with filling gas takes place at a temperature which is approximately the operating temperature corresponds to the scoreboard. 19. The method according to claim 18, characterized in that the filling gas is under slightly less than atmospheric pressure, and into the chamber for containing the stacked display panels a sufficient period of time is introduced during the heat treatment by which the glass stopper is melted over the opening and the gas is enclosed in a gas-tight manner in the display unit. - 32 - 509887/0412 20. The method according to any one of claims Io to 19, characterized in that that the glass stopper is held in place by the facing surfaces of the rigid substrate plates prior to the heat treatment. 21. The method according to any one of claims 17 to 2o, characterized in that that the display panels are stacked vertically with the opening facing up. 22. The method according to any one of claims 17 to 21, characterized in that that one of the rigid substrate plates is larger in the vertical direction than the other and that when stacking one non-meltable holding part is placed under this in order to displace the shorter of the rigid substrate plates impede. 23. The method according to any one of claims Io to 22, characterized in that that a window transparent to laser energy is formed in each of the two substrate plates, wherein the windows formed in the substrate plates face one another, that in the windows a mercury container is set up, and that after the opening is sealed gas-tight, a burst of laser energy is sent through one of the windows to release the mercury in the discharge chamber. 24. The method according to claim 23, characterized in that a glass permeable to laser energy is used as the mercury container - 33 509887/0412 - 33 capsule is used. 25. Mercury capsule, characterized by a hollow capillary tube made of glass, which is permeable to laser energy and
an outside diameter of less than about 0.5 mm (2o
Thousandths of an inch) and a predetermined length, the capillary tube being gas-tight at both ends and being filled with elemental mercury, and the length of the capillary tube and the free inner cross-section of the hollow part thereof being selected so that a predetermined amount of liquid mercury Takes place. 26. Method of introducing mercury into a flat, no-stud Gas discharge display panel with a pair of spaced apart opposed, more transparent to laser energy Windows formed in the glass panels forming the display panel, the windows external to the display area the display panel and being in the gas discharge medium in the space between the windows permeable to laser energy a mercury storage activatable by laser energy is arranged, characterized in that on the
Outside one of the windows a conductive metal block is placed and a beam of laser energy passes through it
the other of the windows is directed at the container which can be activated by laser energy, so that elemental mercury is released into the gas atmosphere of the display panel. - 34- 509887 / IH1? 27. The method according to claim 26, characterized in that the conductive metal block is made of aluminum and that the laser energy has a wavelength of about 1.0 µ. 5 0 9 8 8 7/0 A 1 2 Blank page