The method for making of low substrate of LCD device
Technical field
The invention relates to a kind of method for making of low substrate of LCD device, refer to a kind of method for making that improves the low substrate of LCD device of contraposition precision especially.
Background technology
LCD can be divided into passive type (Passive Matrix according to type of drive, PMLCD) with active (Active Matrix, AMLCD), and so-called active driving LCD, refer to that promptly (Thin Film Transistor is TFT) as the display of on-off element with thin film transistor (TFT).Single aperture ratio of pixels in the active driving LCD has direct relation with light number from penetrable viewing area in the backlight module.With identical power consumption, the aperture opening ratio of active driving LCD is high more, can improve the brightness that it shows more.
The notion that the LCD of general high aperture mainly designs is being utilized the overlapping of pixel electrode and signal line, covers the outer or edge of pixel with lighttight signal line, because the light leak zone of liquid crystal arrangement at random.Yet, black light shield layer (black matrix) to cover the light leak zone commonly used, normal with the contraposition of color filter film on real the work because of accurate inadequately, cause up and down or about contraposition be offset, the result tends to so produces capacitance variations, and influences the consistance that picture shows.
Simultaneously, general in the process of pixel electrode one patterned, when the photoresist that is coated on the ITO layer, cover when exposing by the part of light shield, formed photoresist pattern on the substrate, meeting is because of the part light leak of boundary rays in the exposure process, and feasible exposure precision (precision) reduces.So promptly cause the offset of overlapping on pixel electrode pattern and grid signal line pattern border, or the offset of overlapping on pixel electrode pattern and source electrode signal line pattern border.
As shown in the figure, Fig. 1 a is a pixel region planimetric map, in order to reach high aperture, general transparency electrode 100 can partially overlap on the zone of signal line 200 in design, yet because the resolution of pixel electrode light shield, and layer and layer aligning accuracy, side etching quantity variation etc. is considered, the width of signal line 200 can not be too little, otherwise the problem of transparent pixels electrode 100 and signal line 200 overlapping light leaks will occur.Fig. 1 b is the sectional view of A-A ' line segment among Fig. 1 a, wherein, when the contraposition of the transparent electrode layer 100 and second metal level 300 is offset, with make up and down or about each material interlayer alignment inaccurate, the formation lap is inconsistent, and produces the stray capacitance (parastic capacitance) 400,401 of different value, and cause total parasitic capacitance value instability, will have influence on the consistance of display frame.
Especially utilizing stepping exposure machine (stepper exposing device) when carrying out the continuous exposure of photoresist, exposure each time can make the inaccurate degree of contraposition build up, and stray capacitance also changes thereupon on the substrate and cause.
Therefore, when requiring to improve aperture opening ratio, if can reduce parasitic capacitance effect simultaneously, the display effect of active driving LCD will more be promoted.
Summary of the invention
The method for making of low substrate of LCD device of the present invention is to utilize the mode of back-exposure, and the collocation light shield uses and exposes, and forms pixel electrode.This method can make the lap between transparent pixels electrode and the signal line keep definite value, and can deviation not take place along with the problem of layer and interlayer alignment, and then promotes exhibit stabilization.
Simultaneously, utilize the inventive method to prepare low substrate of LCD device, can optionally adjust the width of signal line, and no longer by the aligning accuracy of transparent electrode layer and signal line, or the light shield resolution of transparent electrode layer decides, and therefore can obtain high aperture opening ratio.
In an aspect of the present invention, the method for making of low substrate of LCD device comprises the following steps: that (a) forms the first metal layer of an one patterned on a first surface of a substrate, one first insulation course, second metal level of one one patterned and one second insulation course, wherein the first metal layer is covered by first insulation course, second metal level is positioned on first insulation course, and second metal level is covered by second insulation course; (b) form a transparent electrode layer and a negative photoetching glue layer on second insulation course, wherein transparent electrode layer is between second insulation course and negative photoetching glue layer; (c) second surface from substrate exposes; (d) utilize a light shield to cover this negative photoetching glue layer, and this first surface expose certainly; And (e) remove unreacted negative photoetching glue, and carry out etching to form the transparency electrode of an one patterned.
In said method, preferablely more can comprise a step (f) afterwards in step (e), remove all negative photoresists.Simultaneously, the first metal layer of step (a) is preferably and can forms gate metal layer or grid conducting layer.In the present embodiment, the material of the first metal layer and second metal level is not limit, and preferablely can be lighttight metal material.
In another aspect of the present invention, the method for making of low substrate of LCD device comprises the following steps: that (a) forms the first metal layer of an one patterned on the first surface of a substrate, one first insulation course, second metal level of one one patterned and one second insulation course, wherein the first metal layer is covered by first insulation course, second metal level is positioned on first insulation course, and second metal level is covered by second insulation course; (b) coating one eurymeric photoresist layer on second insulation course; (c) second surface from substrate exposes; (d) utilize a light shield to cover this eurymeric photoresist layer, and this first surface expose certainly; (e) remove the eurymeric photoresist that has exposed; (f) form a transparent electrode layer on second insulation course and the eurymeric photoresist that is not removed; And (g) divest unreacted eurymeric photoresist, and be covered in this transparent electrode layer on this unreacted this eurymeric photoresist.
Same, preferable gate metal layer or the grid conducting layer of can be of the first metal layer of step in this method (a).
In another aspect of the present invention, the method for making of low substrate of LCD device comprises the following steps: that (a) forms first transparent electrode layer of an one patterned in a first surface of a substrate, one first insulation course, the metal level of one one patterned and one second insulation course, wherein first transparent electrode layer is covered by first insulation course, metal level is positioned on first insulation course, and metal level covered by second insulation course, and described metal level is light tight metal; (b) form one second transparent electrode layer and a negative photoetching glue layer on second insulation course, wherein second transparent electrode layer is between second insulation course and negative photoetching glue layer; (c) second surface from substrate exposes; And (d) remove unreacted negative photoetching glue, be retained in negative photoresist on this second insulation course then as this second transparent electrode layer of light shield etching, remove all negative photoetching glue layer with second transparency electrode (e) that forms an one patterned, so that the one patterned of second transparency electrode is more complete.
In an aspect more of the present invention, the method for making of low substrate of LCD device comprises the following steps: that (a) forms first conductive layer of an one patterned in a first surface of a substrate, one first insulation course, the metal level of one one patterned and one second insulation course, wherein first conductive layer is covered by first insulation course, and metal level is positioned on first insulation course, and metal level is covered by second insulation course, this first conductive layer is a palisade, and described metal level is light tight metal; (b) form a transparent electrode layer and a negative photoetching glue layer on second insulation course, wherein transparent electrode layer is between second insulation course and negative photoetching glue layer; (c) second surface from substrate exposes; And (d) remove unreacted negative photoetching glue, be retained in negative photoresist on this second insulation course then as this transparent electrode layer of light shield etching, remove all negative photoresists with the transparency electrode (e) that forms an one patterned, to form the transparency electrode of more complete one patterned.And in this method, first conductive layer can be light tight or semi-transparent conductive material, forms complete transparency electrode can keep simultaneously the photoresist of first conductive layer top in back-exposure, to be beneficial to.
In a plurality of methods of the invention described above, employed insulation course can be arbitrary suitable insulating material, for example organic material: acryl resin (acrylic resin) and polyimide resin (polyimide resin); Or inorganic material: SiO2, SiNx etc.And preferable, second insulation course can be a flatness layer.
In addition, in said method, transparent electrode layer can be arbitrary suitable material, preferable indium tin oxide (ITO) or the indium-zinc oxide (IZO) of can be.Simultaneously, transparency electrode can form by arbitrary applicable pattern in this method, is preferably with sputter to form.
Description of drawings
Fig. 1 a is a known pixel area planar figure.
Fig. 1 b is a known pixel zone sectional view.
Fig. 2 is a pixel region floor map.
Fig. 3 (a)-(f) is the making flow process sectional view of the embodiment of the invention 1.
Fig. 4 (a)-(f) is the making flow process sectional view of the embodiment of the invention 2.
Fig. 5 (a)-(e) is the making flow process sectional view of the embodiment of the invention 3.
Fig. 6 (a)-(e) is the making flow process sectional view of the embodiment of the invention 4.
Description of reference numerals:
Substrate 00 the first metal layer 10 first insulation courses 20
Second metal level, 30 second insulation courses, 40 transparent electrode layers 50
Negative photoetching glue layer 60 light shields 70
Eurymeric photoresist layer 61 first conductive layers 11 first transparent electrode layers 15
Transparency electrode 100 signal line 200 second metal levels 300
Stray capacitance 400,401
Embodiment
Because the inventive method mainly is the mode with back-exposure, the lifting of reaching the contraposition precision, however the problem that may run into is that common electrode lines may make that as using light-proof material pixel electrode area is cut apart.Therefore, the inventive method is utilized several different embodiments, and its different aspects are described.Below the position of each sectional view, be in Fig. 2 floor map B to the section of B ' line segment.
Embodiment 1
Please refer to Fig. 3 (a), a glass substrate 00 at first is provided, be formed with second metal level 30 and one second insulation course 40 of the first metal layer 10, one first insulation courses 20, one one patterned of an one patterned in the front of substrate 00 in regular turn.Wherein, the first metal layer 10 is covered by first insulation course 20, and second metal level 30 is positioned on first insulation course 20, and is covered by second insulation course 40.
Second insulation course 40 is a flatness layer 40 in this example.And wherein the first metal layer 10 can form gate metal layer or grid conducting layer.
Then, form a transparent electrode layer 50 and a negative photoetching glue layer 60 on flatness layer 40, wherein transparent electrode layer 50 is between flatness layer 40 and negative photoetching glue layer 60, shown in Fig. 3 (a).
The direction of arrow shown in Fig. 3 (b) is exposed from the back side of substrate 00, and can utilize the pattern of lighttight second metal level 30 in this example and the first metal layer 10 this moment, as the light shield of negative photoetching glue layer 60 exposure usefulness.Because be to adopt negative photoresist in the present embodiment, the photoresist that therefore shines light is partly understood polymerization reaction take place, forms insoluble polymkeric substance.Yet the part photoresist of the first metal layer 10 tops will be because of not being removed when developing to irradiation by light.
Therefore, in order to keep the part photoresist 60 of the first metal layer 10 tops, with the transparency electrode 50 that keeps this position, then need follow next step, directly expose from the front of substrate 00,70 of the light shields that use of arranging in pairs or groups this moment are to use the part photoresist 60 that can make the first metal layer 10 tops to shine light, and cover the pattern of the photoresist 60 of second metal level, 30 tops, as Fig. 3 (c).
Then, remove unreacted negative photoetching glue 60, form the photoresist of one patterned, as Fig. 3 (d), and carry out etching, with the transparency electrode 50 that forms an one patterned, as Fig. 3 (e) according to the photoresist pattern.Shown in Fig. 3 (f), remove unnecessary photoresist at last, promptly finish the one patterned of transparency electrode 50.
Embodiment 2
The preparation of substrate is described with embodiment 1.Please refer to Fig. 4.One glass substrate 00 at first is provided, on the front of substrate 00, is formed with second metal level 30 and one second insulation course 40 of the first metal layer 10, one first insulation courses 20, one one patterned of an one patterned in regular turn.Wherein, the first metal layer 10 is covered by first insulation course 20, and second metal level 30 is positioned on first insulation course 20, and is covered by second insulation course 40.
With embodiment 1, the second insulation course 40 is a flatness layer 40.And wherein the first metal layer 10 can form gate metal layer or grid conducting layer.
Then, coating one eurymeric photoresist layer 61 on flatness layer 40 is shown in Fig. 4 (a).The direction of arrow shown in Fig. 4 (b) is exposed from the back side of substrate 00, and is same, utilizes the pattern of lighttight second metal level 30 in this example and the first metal layer 10, as the light shield of eurymeric photoresist layer 61 exposure usefulness.
Be to adopt the eurymeric photoresist in the present embodiment, the photoresist part that therefore shines light can be developed agent or deluster and carve the jelly dissolving and remove.Yet the part photoresist of the first metal layer 10 tops will will influence the integrality of the transparency electrode coating of next step because of not remained with photoresist by light to irradiation.Therefore in order to remove the part eurymeric photoresist 61 of the first metal layer 10 tops, then need follow next step, directly expose, as Fig. 4 (c) from the front of substrate 00.70 of the light shields that use of arranging in pairs or groups this moment are to use the part photoresist 61 that can make the first metal layer 10 tops to shine light, and cover the pattern of the photoresist 61 of second metal level, 30 tops.
Remove the eurymeric photoresist 61 that has exposed then, then on flatness layer 40, can present the eurymeric photoresist 61 of one patterned, as Fig. 4 (d).Then on eurymeric photoresist 61 patterns and on the flatness layer 40 that exposes, comprehensive again coating last layer transparent electrode layer 50 is as Fig. 4 (e).Divest all eurymeric photoresists 61 at last, the partially transparent electrode layer 50 that can will be positioned on the eurymeric photoresist 61 also removes in the lump, and finishes the one patterned of transparency electrode, as Fig. 4 (f).
Same, the first metal layer is gate metal layer or grid conducting layer in this method.
Embodiment 3
Please refer to Fig. 5 (a), one glass substrate 00 at first is provided, be formed with first transparent electrode layer 15 of an one patterned in regular turn in the front of substrate 00, one first insulation course 20, the metal level 30 of one one patterned and one second insulation course 40, wherein first transparent electrode layer 15 is covered by first insulation course 20, and metal level 30 is positioned on first insulation course 20, and metal level 30 is covered by second insulation course 40.
Then, form one second transparent electrode layer 50 and a negative photoetching glue layer 60 on flatness layer 40, wherein second transparent electrode layer 50 is between flatness layer 40 and negative photoetching glue layer 60, shown in Fig. 5 (a).
The direction of arrow shown in Fig. 5 (b) is exposed from the back side of substrate 00, and same pattern with lighttight second metal level 30 and first transparent electrode layer 15 is as the light shield of negative photoetching glue layer 60 exposure usefulness.In this example, first transparent electrode layer 15 is printing opacity or semi-transparent material, when therefore exposing overleaf, part light still can see through first transparent electrode layer 15 and irradiation negative photoresist 60, make the part photoresist of first transparent electrode layer, 15 tops, will can when developing, be retained because of being produced polyreaction to irradiation by light.
Remove unreacted negative photoetching glue layer 60 then, then on flatness layer 40, can present the negative photoetching glue layer 60 of one patterned, shown in Fig. 5 (c).
Carry out the etching of second transparent electrode layer 50 again according to the pattern of photoresist 60, shown in Fig. 5 (d), remove all negative photoresists 60 at last, promptly form second transparency electrode 50 of an one patterned, shown in Fig. 5 (e).
Embodiment 4
The preparation of substrate is described with embodiment 1.Please refer to Fig. 6.One glass substrate 00 at first is provided, be formed with first conductive layer 11 of an one patterned in regular turn in the front of a substrate 00, one first insulation course 20, the metal level 30 of one one patterned and one second insulation course 40, wherein first conductive layer 11 is covered by first insulation course 20, metal level 30 is positioned on first insulation course 20, and metal level 30 is covered 40 by second insulation course.
With embodiment 1, the second insulation course 40 is a flatness layer 40.In addition, first conductive layer 11 is with semi-transparent or lighttight conductive material in this example, forms the conductive layer of a palisade external form.
Then, form a transparent electrode layer 50 and a negative photoetching glue layer 60 on flatness layer 40, wherein transparent electrode layer 50 is between flatness layer 40 and negative photoetching glue layer 60, shown in Fig. 6 (a).
The direction of arrow shown in Fig. 6 (b) is exposed from the back side of substrate 00.Same, with the pattern of first conductive layer 11 of lighttight metal level 30 and palisade, as the light shield of negative photoetching glue layer 60 exposure usefulness.In this example, first conductive layer 11 of palisade when part light is exposed overleaf, still can see through palisade and shine negative photoresist 60, keeping the photoresist of first conductive layer, 11 tops, and then helps forming complete transparency electrode.
Remove unreacted negative photoetching glue layer 60 then, then on flatness layer 40, can present the negative photoetching glue layer 60 of one patterned, shown in Fig. 6 (c).
Then, carry out the etching of second transparent electrode layer 50, shown in Fig. 6 (d), remove all negative photoresists 60 at last, can form second transparency electrode 50 of an one patterned, shown in Fig. 6 (e) according to the pattern of photoresist 60.
The foregoing description only has been convenience explanation and giving an example, and the interest field that the present invention advocated is from should being as the criterion so that claims are described, but not only limits to the foregoing description.