JPH08286200A - Thick-film element circuit and display device using the circuit and their production - Google Patents

Abstract

PURPOSE: To provide a display device having high fineness and high grade by eliminating the variations in electric characteristics and the variations in the luminance of thick-film element circuits and pixels having a small size and excellent characteristics by suppressing the variation in the sizes of the thick-film elements. CONSTITUTION: Baked Ag electrode wiring patterns 32 are formed on a glass substrate 31 and an insulating layer 34 partially having through-holes is formed thereon by covering the substrate with insulator paste contg. a photosensitive org. material, then subjecting the paste to exposing with UV, developing and baking. Resistance paste having the softening point lower than the softening point temp. of the insulating layers in inserting into the through- hole parts in contact with the lower layer parts and is baked. The element surfaces are recessed to a recessed shape by the shrinkage of the paste after the baking and, therefore, the resistance paste is again inserted into the through-hole parts and is baked, by which the thick-film resistance elements 33 for limiting operating current are formed. The substrate is thereafter overcoated further with the insulating layers 34, and the through-holes are provided on the terminals of the thick-film resistance elements 33. Electrode pads 35 are inserted into these through-holes and the thick-film resistance elements are arranged in the lower layer parts of partition walls 36 of display cells.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric circuit element, a semiconductor element, a laminated circuit using a thick film printing technique, a thick film element circuit useful for a display device using the same, and a display device using the same. The present invention relates to a manufacturing method thereof.

[0002]

2. Description of the Related Art In recent years, with the development of high-density packaging technology for circuits due to the development of integrated circuit technology, electronic circuits using thick-film elements and thick-film printing technology have been receiving attention. In addition, there is a demand for larger and higher-definition displays compatible with high-definition broadcasting and multimedia, and thick-film element circuits and thick-film printing technologies are drawing attention as elemental technologies for manufacturing self-luminous flat panel displays. Has been done.

The conventional thick film element, thick film printing technology, and self-luminous flat panel display will be described below. FIG. 4 shows a sectional view of a conventional thick film element. The conventional thick film element has an electrode wiring pattern 4 formed on the substrate 41.
A thick film paste is screen-printed on the second film to form a thick film element 43, and then a paste containing a low melting point glass as a main component is printed and baked to overcoat the insulating layer 44. .

Next, FIG. 5 (a) is a plan view of a conventional self-luminous flat panel display, and FIG. 5 (b) is FIG.
The sectional view of the arrow line of (a) is shown. In a conventional panel, an operating current limiting element 53 is formed on an electrode wiring pattern 52 formed on a substrate 51, and then an insulating layer 54 is overcoated, and a through hole is provided on a terminal of the operating current limiting element 53. It has a configuration in which the electrode pad 55 is inserted,
The thick film element is arranged in the lower layer portion inside the display cell.

[0005]

However, in the above-mentioned conventional structure, when the element is formed, the pattern of the element is screen-printed with the paste on the substrate, so that the bleeding or slack of the pattern occurs due to the printing. However, there is a problem in that the characteristics of the element greatly vary due to the large variation in the shape of the pattern after printing and the low dimensional accuracy. Further, in the conventional manufacturing method, since the softening point temperature of the glass component contained in the insulating layer and the softening point temperature of the glass component contained in the element are close to each other, at the interface between the insulating layer and the element each time heat treatment is performed in the furnace. There is a problem in that the characteristics of the device largely change due to interaction such as diffusion. Furthermore, in the DC drive type self-luminous flat display,
Since the current limiting resistance circuit is arranged in each display cell, it is difficult to miniaturize the display cell, and it is very difficult to realize a high-definition display.

In order to solve the above conventional problems, the present invention realizes a thick film element having excellent dimensional accuracy.
It is an object of the present invention to provide a thick film element circuit with less characteristic variation and to realize miniaturization of a display cell by forming a wiring circuit or an element circuit under or inside a partition of each display cell.

[0007]

In order to achieve the above object, a thick film element circuit of the present invention is a thick film element circuit having an electrode wiring pattern formed on a substrate and a thick film element thereon. The thick film element circuit is provided with an insulating layer on a portion of the electrode wiring pattern, and is formed on another portion of the electrode wiring pattern that is in contact with a lower layer portion excluding the insulating layer portion. A thick film element, wherein the insulating layer has a smooth surface without overlapping on the thick film element, and the softening point temperature of the insulating layer is higher than the softening point temperature of the thick film element, To do.

In the above structure, the thick film element circuit is formed in a portion in contact with the first insulating layer portion partially formed on the electrode wiring pattern and the lower layer portion excluding the first insulating layer. The second insulating layer is partially formed on the first thick film element, and the second thick film element is formed in a portion in contact with the lower layer portion excluding the second insulating layer. It is preferable that the film element has two or more layers having a laminated structure in which the surface of the first thick film element is partially or wholly or over two or more first thick film elements.

Next, the method of manufacturing the thick film element circuit of the present invention is as follows.
On the electrode wiring pattern formed on the substrate, the insulating layer is patterned to form a through hole exposing the lower layer portion, and after inserting a thick film paste into the through hole,
It is characterized by firing.

In the above manufacturing method, it is preferable that the method of patterning the insulating layer to form the through hole is a chemical etching method or a physical etching method after covering the entire surface of the substrate with the insulating layer.

Further, in the above-mentioned manufacturing method, the method of patterning the insulating layer to form the through holes is such that after covering the entire surface of the substrate with an insulating paste containing a photosensitive organic material,
A method of exposing and developing and baking is preferable.

Further, in the above manufacturing method, the thick film paste material to be inserted into the through hole of the insulating layer is at least one substance selected from a conductor, a resistor, a semiconductor, a high dielectric and a ferroelectric. preferable.

Next, in the display device of the present invention, as a thick film element circuit of a display cell, an insulating layer is provided on a part of the electrode wiring pattern, and the insulating layer portion is the other part of the electrode wiring pattern. A thick film element formed in a portion in contact with the lower layer portion, the insulating layer having a smooth surface without overlapping on the thick film element, and the softening point temperature of the insulating layer is a thick film element. An operating current limiting circuit is provided by using a thick film element circuit having a temperature higher than the softening point temperature of the above.

In the above structure, the thick film element circuit is formed in a portion in contact with the first insulating layer portion partially formed on the electrode wiring pattern and the lower layer portion excluding the first insulating layer. The second insulating layer is partially formed on the first thick film element, and the second thick film element is formed in a portion in contact with the lower layer portion excluding the second insulating layer. It is preferable that the film element has two or more layers having a laminated structure in which the surface of the first thick film element is partially or wholly or over two or more first thick film elements.

Next, the self-luminous flat panel display device of the present invention is a display device having a partition wall for separating display cells on a substrate, wherein at least one of each element of the wiring circuit or the wiring pattern is below or inside the partition wall. It is characterized in that it is formed in.

Next, in the method of manufacturing a display device of the present invention, the method of manufacturing the wiring circuit of the display cell is a method of manufacturing a circuit element and a wiring circuit by the method according to any one of claims 3 to 6. Is preferred.

[0017]

According to the thick film element circuit of the present invention described above, the thick film element circuit is provided with an insulating layer on a part of the electrode wiring pattern, and the insulating layer portion is formed on the other part of the electrode wiring pattern. A thick film element formed in a portion in contact with the lower layer portion is removed, the insulating layer has a smooth surface without overlapping on the thick film element, and the softening point temperature of the insulating layer is Since the temperature is higher than the softening point temperature, the dimensional accuracy of the thick film element is improved, so that it is possible to realize a circuit element with less variation in characteristics. Further, by firing the thick film paste of the element at a temperature lower than the softening point temperature of the insulating layer, the interfacial reaction is suppressed and the process variation of the characteristics can be suppressed.

In the above description, the thick film element circuit is formed on the first insulating layer portion partially formed on the electrode wiring pattern and on the first layer formed in contact with the lower layer portion excluding the first insulating layer. A second insulating layer is partially formed on the thick film element, and the second thick film element is formed in a portion in contact with the lower layer portion excluding the second insulating layer. According to a preferable example in which a part of the surface of the first thick film element or all or two or more laminated structures extending over two or more first thick film elements are provided, the dimensional accuracy of the thick film element is further improved. Therefore, it is possible to realize a circuit element with less variation in characteristics.

Next, according to the method of manufacturing a thick film element circuit of the present invention, the insulating layer is patterned on the electrode wiring pattern formed on the substrate so as to form a through hole exposing the lower layer portion, By inserting the thick film paste into the through holes and baking the paste, a thick film element circuit can be manufactured efficiently and rationally.

According to a preferred example of the above method, in which the method of patterning the insulating layer to form the through holes is a chemical etching method or a physical etching method after covering the entire surface of the substrate with the insulating layer. Thick film element circuits can be manufactured efficiently and rationally.

In the above method, the method of patterning the insulating layer to form the through holes is a method of covering the entire surface of the substrate with an insulating paste containing a photosensitive organic material, exposing and developing, and baking. According to this, the thick film element circuit can be manufactured more efficiently and rationally.

In the above method, the thick film paste material to be inserted into the through hole of the insulating layer is a conductor, a resistor,
According to the preferable example of at least one substance selected from semiconductors, high dielectrics and ferroelectrics, thick film element circuits can be manufactured more efficiently and rationally.

Further, miniaturization of the cell can be realized by forming a wiring circuit or an element in or under the partition for separating the display cells.

[0024]

EXAMPLES The present invention will be described in more detail below with reference to examples. (Embodiment 1) FIG. 1 is a sectional view showing an embodiment of a thick film element circuit according to the present invention. Baking A on the glass substrate 11
A glass insulating layer 13 having an electrode wiring pattern 12 (line width 100 μm, distance between electrodes 200 μm) and partially having through holes (width 100 μm, length 260 μm, depth 15 μm) is formed on the glass insulating layer 13 with a molecular weight of about 5,000. 40% by weight of methyl methacrylate oligomer + benzophenone:
5% by weight of a polymerization initiator consisting of Michler's ketone = 4: 1
+ A photosensitive vehicle consisting of 55 wt% butyl carbitol solvent and a glass frit are mixed in a ratio of 4: 6 to form a paste, and the substrate surface is covered with this paste.
A resist paste having a softening point (440 ° C.) lower than the softening point temperature (550 ° C.) of the insulating layer is formed in a through hole portion which is in contact with the lower layer portion by V exposure development and baking at 600 ° C. It was inserted and fired at 500 ° C. After firing, the device surface is thick film device 1 due to shrinking of the paste.
As in the case of 4a, since the central portion is recessed at a depth of about 5 μm, the resistance paste was inserted again, followed by firing at 500 ° C. and stacking the thick film element 14b to form the thick film element 14. As a result, a thick film element circuit having a smooth surface without the insulating layer overlapping the thick film element could be manufactured.

The variation of the geometrical dimensions and the resistance value according to the present embodiment are shown in Table 1 in comparison with the variation of the geometrical dimensions and the resistance value of the prior art.

[0026]

[Table 1]

As is clear from (Table 1), the thick film element circuit according to the present example has an excellent effect in that the dimensional accuracy of the element is excellent and the characteristic variation is very small.

As described above, according to this embodiment, the softening point is formed in the insulating layer having a through hole partially on the electrode wiring pattern on the substrate and the through hole portion which is in contact with the lower layer portion excluding the insulating layer portion. By providing a thick film element having a temperature lower than that of the insulating layer, the insulating layer has a smooth surface without overlapping on the thick film element, has excellent dimensional accuracy of the element, and has very little variation in characteristics. And a thick film element circuit can be realized.

In this embodiment, the thick film element circuit is
Although the insulating layer and the thick film element are included in one layer, the insulating layer portion of the lower layer portion having a through hole partially on the electrode wiring pattern and the through hole portion contacting the lower layer portion excluding the insulating layer of the lower layer portion The insulating layer of the upper layer is partially formed on the formed thick film element of the lower layer, and the thick layer element of the upper layer is formed on the portion contacting the lower layer excluding the insulating layer of the upper layer. The thick film element in the upper layer portion may have at least a part of the surface of the thick film element in the lower layer portion, or may have two or more laminated structures that extend over two or more thick film elements in the lower layer portion. Further, in the present embodiment, the method of forming the through hole of the insulating layer on the substrate is a method of covering the substrate with an insulating paste containing a photosensitive organic material, followed by UV exposure development and baking. Wet etching method may be used. Further, in the present embodiment, the method of forming the through hole of the insulating layer on the substrate is a method of covering the substrate with an insulating paste containing a photosensitive organic material, followed by UV exposure development and baking. It is also possible to adopt a dry etching method using. Further, in the present embodiment, the method of forming the through hole of the insulating layer on the substrate is a method of covering the substrate with an insulating paste containing a photosensitive organic material, followed by UV exposure development and baking. It is obvious that a sandblast method, which is a static etching, may be used.

(Embodiment 2) FIG. 1 is a sectional view showing an embodiment of a thick film element circuit according to the present invention. In FIG. 1, a baked Ag electrode wiring pattern 12 (line width 3 mm, distance between electrodes 5 mm) is formed on a glass substrate 11, and a through hole (width 3 μm, length 9 m, depth 0.5 m) is partially formed thereon.
m) is formed by covering the substrate with an insulating paste containing a photosensitive organic material, followed by UV exposure development and baking, and softening the insulating layer in the through-hole portion in contact with the lower layer portion. A thick film paste having a softening point lower than the point temperature was inserted and fired. After firing, the device surface was recessed due to shrinking of the paste, so that the thick film paste was inserted again and fired to manufacture the thick film device 14. As a result, a thick film element circuit having a smooth surface without the insulating layer overlapping the thick film element could be manufactured.

The above is the same as the first embodiment. The difference from Example 1 is that the resistance paste is an oxide semiconductor (Ba _(1-x) Ce _x TiO ₃ having thermistor characteristics:
x = 0.001) A thick film paste composed of 48% by weight + 12% by weight of glass frit + 40% by weight of photosensitive vehicle.

The temperature characteristics of the resistance of the thermistor according to this embodiment are shown in FIG. As described above, a circuit board containing a thermistor element can be realized by inserting the paste containing the oxide semiconductor having the thermistor characteristic into the through hole portion of the insulating layer and firing the paste.

In Example 2, the thick film element is an oxide semiconductor having thermistor characteristics, but it may be an oxide semiconductor having varistor characteristics. Example 2
In the above, the thick film element is an oxide semiconductor having thermistor characteristics, but it may be an oxide semiconductor having a large Hall coefficient. Further, in Example 2, the thick film element is an oxide semiconductor having a thermistor characteristic, but it is clear that it may be a compound semiconductor having a photoconductive characteristic.

(Embodiment 3) In FIG. 3A, the thick film element circuit according to the present invention is used to provide an operation current limiting circuit, and the elements and wiring patterns of the wiring circuit are formed below the partition wall. FIG. 3B is a plan view showing an embodiment of a self-luminous flat panel display device having a structure, and FIG.
It is sectional drawing of the arrow line of (a).

An operating current limiting thick film resistance element 33 is formed on an electrode wiring pattern 32 formed on a substrate 31,
After that, the insulating layer 34 is overcoated, a through hole is provided on the terminal of the thick film resistance element 33, and the electrode pad 35 is inserted, and the thick film resistance element is formed in the lower layer portion of the partition wall of the display cell. It has a configuration arranged. 36 is a partition wall made of opaque glass.

Table 2 shows variations in the resistance value and the luminance for limiting the discharge current of each display cell according to the present embodiment in comparison with the conventional one.

[0037]

[Table 2]

As is clear from this (Table 2), the display device having the thick film element circuit using the structure according to the present embodiment is excellent in that there is very little variation in the luminance characteristics of the respective display cells. The effect is obtained. Further, since the display device using the configuration according to the present embodiment has a small size of the display cell, it is possible to form a dot matrix with a narrow pitch, and to realize a high-definition self-luminous flat panel display device. Is possible.

In the third embodiment, the elements and wiring patterns of the wiring circuit are arranged under the partition, but it is obvious that they may be arranged inside the partition.

[0040]

As described above, according to the present invention, an insulating layer partially having a through hole is formed on an electrode wiring pattern formed on a substrate and a through hole portion contacting a lower layer portion excluding the insulating layer portion. By providing a thick film element having a softening point temperature lower than that of the insulating layer, the insulating layer has a smooth surface without overlapping on the thick film element, has excellent dimensional accuracy of the element and has very little variation in characteristics. Devices and thick film device circuits can be realized. Furthermore, by providing at least one of each element of the wiring circuit or the wiring pattern using the thick film element circuit below or inside the partition wall, the display device has an excellent high definition capable of downsizing the display cell. It is possible to realize a self-luminous flat panel display device.

[Brief description of drawings]

FIG. 1 is a sectional view of a thick film element circuit according to a first embodiment of the present invention.

FIG. 2 is a temperature characteristic diagram of resistance of a thermistor according to a second embodiment of the present invention.

3A is a plan view of a self-luminous flat panel display device according to a third embodiment of the present invention, and FIG. 3B is a sectional view of the same.

FIG. 4 is a sectional view of a conventional thick film element circuit.

5A is a plan view of a conventional self-luminous flat panel display, and FIG. 5B is a sectional view of the same.

[Explanation of symbols]

 11 substrate 12 electrode pattern 13 insulating layer 14, 14a, 14b thick film element 31 substrate 32 electrode pattern 33 resistance element 34 insulating layer 35 electrode pad 36 partition wall 41 substrate 42 electrode pattern 43 insulating layer 44 thick film element 51 substrate 52 electrode pattern 53 Resistance element 54 Insulation layer 55 Partition wall

Claims (9)

[Claims] 1. A thick film element circuit comprising an electrode wiring pattern formed on a substrate and a thick film element thereon, wherein the thick film element circuit comprises an insulating layer on a part of the electrode wiring pattern. A thick film element formed on a portion of the electrode wiring pattern that is in contact with a lower layer portion other than the insulating layer portion, and the insulating layer does not overlap the thick film element. A thick film element circuit having a smooth surface and having a softening point temperature of the insulating layer higher than that of the thick film element. 2. A thick film element circuit, wherein a first insulating layer portion partially formed on an electrode wiring pattern and a first insulating layer portion formed in contact with a lower layer portion excluding the first insulating layer are provided. The second insulating layer is partially formed on the thick film element, and the second thick film element is formed in the portion in contact with the lower layer portion excluding the second insulating layer. 2. The thick film element circuit according to claim 1, wherein the thick film element circuit has two or more layers having a laminated structure extending over a part or all of the surface of the first thick film element or two or more first thick film elements. 3. An insulating layer is patterned on an electrode wiring pattern formed on a substrate so as to form a through hole exposing a lower layer portion, a thick film paste is inserted into the through hole, and then firing is performed. A method of manufacturing a thick film element circuit having a feature. 4. The thick film element circuit according to claim 3, wherein the method of patterning the insulating layer to form a through hole is a chemical etching method or a physical etching method after covering the entire surface of the substrate with the insulating layer. Manufacturing method. 5. The method of forming a through hole by patterning an insulating layer is a method of covering the entire surface of a substrate with an insulating paste containing a photosensitive organic material, exposing and developing, and baking. Method of manufacturing thick film element circuit. 6. The thickness according to claim 3, wherein the thick film paste material to be inserted into the through hole of the insulating layer is at least one substance selected from a conductor, a resistor, a semiconductor, a high dielectric and a ferroelectric. Membrane element circuit manufacturing method. 7. A display device comprising an operating current limiting circuit by using the thick film element circuit according to claim 1 as a wiring circuit of a display cell. 8. A display device having a partition wall for separating display cells on a substrate, wherein at least one of each element of the wiring circuit or the wiring pattern is formed below or inside the partition wall. Light emitting flat panel display device. 9. The display device according to claim 7, wherein the method for producing a wiring circuit for a display cell is a method for producing a circuit element and a wiring circuit by the method according to any one of claims 3 to 6. Production method.