CN111845076B - A substrate and method for judging pixel printing defects - Google Patents

Abstract

The invention relates to the technical field of inkjet printing, and specifically discloses a substrate for judging pixel printing defects. same; pixel slots in the same area have the same height, and pixel slots in the same area have the same interval; pixel slots in different areas have different heights, or pixel slots in different areas have different intervals, or pixels in different areas The heights of the grooves are different and the spacing of the pixel grooves is different. The pixel substrate provided by the present invention judges whether the bridging is caused by the deviation of the droplet drop point by printing on areas with different pixel groove intervals, and judges whether the bridging is caused by excessive ink jetting by printing on areas with different heights of the pixel grooves As a result, the provided substrate can quickly determine the cause of the bridging defect.

Description

A substrate and method for judging pixel printing defects

technical field

The invention relates to the technical field of inkjet printing, and in particular, to a substrate and a method for judging pixel printing defects.

Background technique

As shown in FIGS. 1-2 , in the existing OLED or quantum dot inkjet printing process, droplets are ejected into pixel grooves defined by photoresist through a piezoelectric nozzle 105 . In the printing process, factors such as process parameters and mechanical precision will cause defects such as uneven pixel brightness and color mixing in the final device. Most of the defects can be observed by a CCD high-speed camera after printing. As shown in Figure 3, the common defects are scatter, non-wetting, and bridging defects. Among them, non-wetting defects are caused by poor wettability of the inkjet ink and the bottom surface of the pixel groove. Scatter defects It is caused by the offset of the droplet landing point. However, it is difficult to judge the cause of the bridging defect. The offset of the printing landing point position or the excessive volume of the droplet sprayed into the pixel tank will cause bridges between adjacent pixels. Defects

How to quickly and accurately judge the causes of bridging defects will be of great significance.

SUMMARY OF THE INVENTION

The first object of the present invention is to provide a substrate for judging pixel printing defects, which can quickly and accurately judge the causes of bridging defects.

In order to achieve the above purpose, the technical solution provided by the present invention is: a substrate for judging pixel printing defects, comprising a substrate body, the substrate body is provided with several regions, and the regions are provided with a plurality of pixel grooves, The openings of the pixel slots are of the same size;

The pixel grooves in the same area have the same height, and the pixel grooves in the same area have the same interval;

Pixel grooves in different regions have different heights, or pixel grooves in different regions have different intervals, or pixel grooves in different regions have different heights and different pixel groove intervals.

Further, the substrate body has a first area, a second area and a third area, and the first area, the second area and the third area respectively have a plurality of pixel grooves;

The height of the pixel grooves in the first area is the same as the height of the pixel grooves in the second area, and the pixel groove spacing distance in the first area is greater than the pixel groove spacing distance in the second area;

The pixel groove spacing distance of the first area is the same as the pixel groove spacing distance of the third area, and the pixel groove height of the first area is smaller than the pixel groove height of the third area.

Further, the second area is divided into several second sub-areas, the second sub-areas have a predetermined distance, and the pixel groove interval of each of the second sub-areas is different, so as to be far away from the first area. The direction is decreasing in turn;

The third area is divided into several third sub-areas, the third sub-areas have a predetermined distance between them, and the pixel groove heights of each of the third sub-areas are different, and the heights of the pixel grooves are gradually increased in the direction away from the first area. .

Further, the substrate body includes 1800×1800 pixel grooves, the first area includes 400×1800 pixel grooves, and the pixel groove interval in the first area is 40um and the height is 1um;

The second area includes three second sub-areas, each of the second sub-areas includes 400×800 pixel grooves, the height of the pixel grooves of the second sub-area is 1um, and the three second sub-areas The pixel slot intervals of the area are 30um, 20um and 15um respectively;

The third area includes three third sub-areas, each of the third sub-areas includes 400×800 pixel grooves, and the pixel groove interval of the third sub-area is 40um. The pixel slot heights of the regions are 1.3um, 2um and 3um, respectively.

Further, the substrate body is provided with a positioning cross target.

The second object of the present invention is to provide a method for judging pixel printing defects, including:

Printing is performed on the above-mentioned substrate, and pixel printing defects are determined according to the pixel printing result.

Further, the method for judging pixel printing defects includes:

Printing is performed on the first printing area of the substrate. If a bridging phenomenon occurs in the printing result, the interlaced printing method is used to print in the first printing area. If a bridging phenomenon occurs in the printing result, it is determined that the printing defect is the presence of droplets. deviation.

Further, if there is no bridging phenomenon in the result of printing in the interlaced printing method, the second printing area on the substrate is selected for interlaced printing, and if the bridging phenomenon occurs in the printing result, it is determined that the printing defect is the presence of droplets. deviation,

Wherein, the pixel groove height of the second printing area is the same as the pixel groove height of the first printing area, and the pixel groove interval of the second printing area is smaller than the pixel groove interval of the first printing area;

Repeatedly select a print area with a smaller interval between pixel grooves in the previous print area for interlaced printing, until a bridge phenomenon occurs in the print result, or until the pixel groove interval in the selected print area is the smallest.

Further, when the interlaced printing is performed in the printing area with the smallest pixel slot interval, and the printing result does not have a bridging phenomenon, then the third printing area is selected for printing, and if the printing result does not have a bridging phenomenon, then the printing defect is judged. Because the amount of ink jetting is too large,

Wherein, the height of the pixel grooves of the third printing area is greater than the height of the pixel grooves of the first printing area, and the interval of the pixel grooves of the third printing area is the same as the interval of the pixel grooves of the first printing area.

Further, if a bridging phenomenon occurs in the result of printing in the third printing area, select a printing area with a height greater than the pixel groove height of the third printing area for printing, until the printing result does not have a bridging phenomenon, or until the selection is made. The pixel bin height of the print area is the largest.

Beneficial effects of the present invention:

In the pixel substrate provided by the present invention, a plurality of areas with different pixel groove intervals and areas with different pixel groove heights are arranged on the substrate. By printing on the areas with different pixel groove intervals, it is judged whether the bridging is caused by the deviation of the droplet drop point. Print on areas with different heights of pixel grooves to determine whether bridging is caused by excessive ink jetting. The provided substrate can inspect all defects in printing, and can quickly determine the cause of bridging defects. In addition, this kind of The method of using the substrate to determine defects does not need to add other additional inspection equipment, and only needs the substrate to complete the defect inspection on the existing equipment.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained according to the structures shown in these drawings without creative efforts.

1 is a schematic diagram of an inkjet printing process;

2 is a top view of an inkjet printing process;

Fig. 3 is a kind of inkjet printing defect schematic diagram;

4 is a schematic diagram of an inkjet printing bridge defect;

Figure 5 is a schematic diagram of a drop point deviation judgment;

6 is an embodiment of a substrate of the present invention;

7 is a schematic diagram of a substrate design definition for pixel printing according to an embodiment of the present invention;

8 is a flowchart of a defect judgment method according to an embodiment of the present invention;

9 is a schematic diagram of interlaced printing according to an embodiment of the present invention;

10 is a schematic diagram of bridging defects in interlaced printing according to an embodiment of the present invention;

FIG. 11 is a schematic diagram of a pixel groove in a fifth region according to an embodiment of the present invention.

Reference number:

100-substrate; 101-pixel slot; 102-cross target; 103-Bank; 104-ink drop; 105-printer;

200-first area; 300-second area; 400-third area; 500-fourth area; 600-fifth area; 700-sixth area; 800-seventh area.

Detailed ways

In inkjet printing, the offset of the landing point position of the inkjet printing or the excessive volume of the ink droplets 104 ejected into the pixel groove will cause a bridge defect between adjacent pixels, as shown in FIG. 4 . If the cause of the bridging defect is due to the deviation of the drop point position of the ink droplet, the method of analyzing the liquid drop point in the general inkjet printing process is generally to print on a flat photoresist material without pixels, and then compare the actual drop point position with the actual drop point position. The ideal positions are compared, as shown in Figure 5. However, this method is limited by the irregularity of the droplet profile caused by the surface cleanliness and roughness of the photoresist material. When this happens, the CCD visual recognition algorithm is used to identify the droplet profile of the liquid. reliability will be affected. If it is inferred that the cause of the bridging is the excessive amount of ink, the general detection scheme is to reduce the number of ink drops. However, when the liquid volume is reduced by one or more drops, the bridging problem still occurs, so it is difficult to identify the bridging. Causes.

In order to solve the above problems, the present invention provides an embodiment of a substrate for judging pixel printing defects, and an embodiment of a method for judging pixel printing defects by using the substrate.

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relationship between various components under a certain posture (as shown in the accompanying drawings). The relative positional relationship, the movement situation, etc., if the specific posture changes, the directional indication also changes accordingly.

It will also be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.

In addition, the descriptions involving "first", "second", etc. in the present invention are only for descriptive purposes, and should not be understood as indicating or implying their relative importance or implying the number of indicated technical features. Thus, a feature defined as "first" and "second" may expressly or implicitly include at least one of that feature. In addition, the technical solutions between the various embodiments can be combined with each other, but must be based on the realization by those of ordinary skill in the art. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that the combination of such technical solutions does not exist. , is not within the scope of protection required by the present invention.

FIG. 6 is an embodiment of a substrate for judging pixel printing defects provided by the present invention.

Please refer to FIG. 6 , which specifically includes a substrate 100 . The substrate 100 has 1800×1800 pixel grooves 101 , and the pixel grooves on the substrate 100 are divided into seven types of pixel areas, namely a first area 200 , a second area 300 , and a third area. Area 400 , fourth area 500 , fifth area 600 , sixth area 700 and seventh area 800 .

The heights of the pixel grooves 101 in the second area 300 , the third area 400 and the fourth area 500 are the same as the heights of the pixel grooves 101 in the first area 200 , but at different intervals. The second area 300 , the third area 400 and the fourth area 500 are used to determine whether the bridging defect is caused by the deviation of the droplet landing point. In order to improve the resolution of detecting droplet landing point offset, multiple areas with different pixel densities are designed to accurately determine the tolerance limit for the existing printing landing point offset.

If the defect of "bridging" is due to the large total volume of jetted ink, then a substrate with the same pixel density and pixel groove opening area as the original substrate can be designed, but the pixel groove depth is larger, so it can withstand more ink and reduce the Risk of "bridging". For example, the interval between the pixel grooves 101 of the fifth area 600 , the sixth area 700 and the seventh area 800 is the same as that of the pixel grooves 101 of the first area 200 , and the heights are different. The fifth area 600 , the sixth area 700 and the seventh area 800 are used to determine whether the bridging defect is caused by an excessive amount of ink ejection.

Specifically, the number of pixel grooves 101 in the first area 200 is 400×1800, the height of the pixel grooves 101 is 1 μm, and the interval between the pixel grooves 101 is 40 μm; the number of pixel grooves 101 in the second area 300 is 400×800 , the height of the pixel grooves 101 is 1um, and the interval between the pixel grooves 101 is 30um; the number of pixel grooves 101 in the third area 400 is 400×800, the height of the pixel grooves 101 is 1um, and the interval between the pixel grooves 101 is 20um; the fourth area The number of pixel slots 101 in 500 is 400×800, the height of pixel slot 101 is 1um, and the interval between pixel slots 101 is 15um; the number of pixel slots 101 in the fifth area 600 is 400×800, and the height of pixel slot 101 is 1.3um, the pixel groove 101 interval is 40um; the number of pixel grooves 101 in the sixth area 700 is 400×800, the height of the pixel groove 101 is 2um, and the pixel groove 101 interval is 40um; the seventh area 800 has 101 pixel grooves The number is 400×800, the height of the pixel grooves 101 is 3um, and the interval between the pixel grooves 101 is 40um. The difference between the regions lies in the height of the pixel groove 101 and the interval between the pixel grooves along the short axis direction.

The definition of the pixel slot interval and pixel slot height mentioned here is shown in Figure 7. The pixel slot 101 is surrounded by Bank103, where A and C are the dimensions of the pixel slot 101, A is the width of the pixel slot 101, and C is the pixel slot 101. length. B and D are the cycles of pixels repeating in the X&Y direction, and the height of the pixel slot 101 is defined as E in the figure, which is the height of the Bank 103 . The interval is the value of B minus the value of A in the figure, that is, the value of B-A is the interval.

In one embodiment, the substrate 100 is rectangular, and four corners of the substrate 100 are respectively provided with positioning cross targets 102 for positioning.

In one embodiment, the substrate 100 can be cleaned, reused, stored in a nitrogen environment for a long period of time without aging, and the selection of the photoresist material should be the same as that of the normal process substrate.

Using the above embodiment of the substrate 100 to determine the cause of the defect, an embodiment of a defect determination method is provided, and the specific process is shown in FIG. 8 .

Please refer to Figure 8, which includes the following steps:

10. Interlaced printing judgment defects

Conventional printing is performed on the first area 200. If the bridging phenomenon as shown in FIG. 4 occurs in the printing result, the first area 200 is printed again by the method of interlaced printing. The method of interlaced printing is shown in FIG. 9. The row of pixel grooves is printed. If a bridge phenomenon occurs in the printing result, that is, there are ink droplets 104 in the adjacent pixel grooves of the pixel grooves originally to be printed, as shown in FIG.

In this embodiment, the printing mode of two lines is selected, but it is not limited to only be separated by two lines. In other embodiments, the number of spaced lines can be selected as required.

20. Select a print area with a smaller density for interlaced printing to judge defects

If there is no bridging phenomenon in the result of interlaced printing in the first area 200, the possible reason is that the deviation of the droplet landing point is relatively small, which is not enough to cause the ink droplet 104 to fall into the adjacent pixel groove. In this case At the same time, it is possible to use a substrate with a higher pixel density and a constant pixel groove area, while still using interlaced printing to determine defects. That is, the second area 300 with a pixel density greater than that of the first area 200 is selected for interlaced printing. If there is a bridging phenomenon in the printing result, it is determined that the printing defect is a deviation of the droplet landing point. If the printing result does not have a bridging phenomenon, the third area 400 with a density greater than the second area 300 is continuously selected for interlaced printing.

This design of various regions with different pixel densities can improve the resolution of detecting droplet landing point offset, and can be used to accurately determine the tolerance limit for printing landing point offset.

30. Select printing areas with different pixel slot capacities for printing to determine defects

If no ink droplets 104 are found in adjacent pixel grooves for interlaced printing after changing the pixel density for many times, that is, there is no bridging phenomenon, then it can be preliminarily determined that the cause of the bridging is not a problem of droplet drop point deviation. In this embodiment, if the fourth area 500 is selected for interlaced printing and still no bridging phenomenon occurs, it can be preliminarily determined that the cause of the bridging is not a problem of the drop point deviation.

Therefore, a region with the same density as the first region 200, but with a different height, which can accommodate more ink droplets 104, is selected for defect judgment. For example, the fifth region 600 is selected. As shown in FIG. 11 , the pixel density of the fifth region 600 and the opening area of the pixel groove are the same as those of the first region 200 , but the depth of the pixel groove in the figure is larger. If normal printing is performed on the fifth area 600 shown in FIG. 11 , no bridging problem is found, so it can be finally determined that the bridging is caused by an excessive amount of ink ejection. In order to improve the resolution of detecting the maximum ink volume of the pixel grooves, a plurality of areas with different depths of the pixel grooves can be designed on the detection substrate, for example, the sixth area 700 and the seventh area 800 .

To sum up, in the embodiment of the present invention, by performing interlaced printing on multiple areas with different pixel densities, it is determined whether the bridging is caused by the deviation of the droplet landing point. Whether it is caused by excessive ink jetting, the provided substrate can inspect all defects in printing, and can quickly determine the cause of bridging defects.

The above descriptions are only the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Under the inventive concept of the present invention, the equivalent structural transformations made by the contents of the description and drawings of the present invention, or the direct/indirect application Other related technical fields are included in the scope of patent protection of the present invention.

Claims (10)

1. A substrate for judging pixel printing defects, characterized in that it comprises a substrate body, and the substrate body is provided with several regions, wherein a plurality of pixel grooves are provided in the regions, and the size of the opening of the pixel grooves same; The pixel grooves in the same area have the same height, and the pixel grooves in the same area have the same interval; Pixel grooves in different regions have different heights, or pixel grooves in different regions have different intervals, or pixel grooves in different regions have different heights and different pixel groove intervals. 2 . The substrate for judging pixel printing defects according to claim 1 , wherein the substrate body has a first area, a second area and a third area, the first area and the second area are 2 . and a plurality of pixel slots are respectively provided in the third area; The height of the pixel grooves in the first area is the same as the height of the pixel grooves in the second area, and the pixel groove spacing distance in the first area is greater than the pixel groove spacing distance in the second area; The pixel groove spacing distance of the first area is the same as the pixel groove spacing distance of the third area, and the pixel groove height of the first area is smaller than the pixel groove height of the third area. 3 . The substrate for judging pixel printing defects according to claim 2 , wherein the second area is divided into a plurality of second sub-areas, and the second sub-areas have a predetermined distance, each The pixel groove intervals of each of the second sub-regions are different, and decrease sequentially in the direction away from the first region; The third area is divided into several third sub-areas, the third sub-areas have a predetermined distance between them, and the pixel groove heights of each of the third sub-areas are different, and the heights of the pixel grooves are gradually increased in the direction away from the first area. . 4 . The substrate for judging pixel printing defects according to claim 3 , wherein the substrate body comprises 1800×1800 pixel grooves, the first region comprises 400×1800 pixel grooves, and the 4 . The pixel groove interval of the first area is 40um, and the height is 1um; The second area includes three second sub-areas, each of the second sub-areas includes 400×800 pixel grooves, the height of the pixel grooves of the second sub-area is 1um, and the three second sub-areas The pixel slot intervals of the area are 30um, 20um and 15um respectively; The third area includes three third sub-areas, each of the third sub-areas includes 400×800 pixel grooves, and the pixel groove interval of the third sub-area is 40um. The pixel slot heights of the regions are 1.3um, 2um and 3um, respectively. 5 . The substrate for judging pixel printing defects according to claim 1 , wherein the substrate body is provided with a positioning cross target. 6 . 6. A method for judging pixel printing defects, comprising: Printing is performed on the substrate according to any one of claims 1-5, and pixel printing defects are determined according to the pixel printing result. 7. The method for judging pixel printing defects according to claim 6, wherein the method for judging pixel printing defects comprises: Printing is performed on the first printing area of the substrate. If a bridging phenomenon occurs in the printing result, the interlaced printing method is used to print in the first printing area. If a bridging phenomenon occurs in the printing result, it is determined that the printing defect is the presence of droplets. deviation. 8. A method for judging pixel printing defects according to claim 7, characterized in that, if no bridging phenomenon occurs in the result of printing in the interlaced printing mode, the second printing area on the substrate is selected to perform interlaced printing, If there is a bridging phenomenon in the printing result, it is determined that the printing defect is a deviation of the droplet landing point, Wherein, the pixel groove height of the second printing area is the same as the pixel groove height of the first printing area, and the pixel groove interval of the second printing area is smaller than the pixel groove interval of the first printing area; Repeatedly select a print area with a smaller interval between pixel grooves in the previous print area for interlaced printing, until a bridge phenomenon occurs in the print result, or until the pixel groove interval in the selected print area is the smallest. 9. The method for judging pixel printing defects according to claim 8, wherein when the interlaced printing is performed in the printing area with the smallest pixel groove interval, and the printing result does not have a bridging phenomenon, the third printing area is selected. Printing is performed, and if there is no bridging phenomenon in the printing result, it is determined that the printing defect is that the ink ejection amount is too large, Wherein, the height of the pixel grooves of the third printing area is greater than the height of the pixel grooves of the first printing area, and the interval of the pixel grooves of the third printing area is the same as the interval of the pixel grooves of the first printing area. 10. The method for judging pixel printing defects according to claim 9, wherein if a bridging phenomenon occurs in the result of printing in the third printing area, the height of the pixel groove is selected to be greater than that of the third printing area. The selected print area is printed until no bridging phenomenon occurs in the print result, or until the height of the pixel slot in the selected print area is maximum.

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