Disclosure of Invention
The invention provides a detection substrate and a manufacturing method thereof, a display back plate and a manufacturing method thereof.
The technical scheme of the invention is as follows:
the invention discloses a manufacturing method of a display back plate, which comprises the following steps:
s1: forming micro light-emitting diodes arranged in an array on a back plate substrate;
s2: manufacturing a detection substrate;
s3: attaching the detection substrate to the micro light-emitting diode, carrying out electrification detection, and removing the detection substrate after electrification is finished;
s4: scanning and observing the detection substrate, and analyzing and recording the coordinates of the damaged and missing areas of the micro light-emitting diode according to the scanning result;
s5: repairing the local part, repeating the step S3 and the step S4 after the repairing is finished, and continuing the next step when no micro light-emitting diode is missing or a damaged area exists;
s6: and packaging the display back plate.
Preferably, the step S2 specifically includes the following steps:
s21: forming a metal layer on a substrate;
s22: forming a plurality of transparent electrode layers which are arranged on the metal layer in an array mode, wherein the arrangement mode of the transparent electrode layers is consistent with that of the micro light-emitting diodes of the display back plate;
s23: and forming a transparent conductive adhesion layer on the transparent electrode layer.
Preferably, the adhesion force of the transparent conductive adhesion layer and the transparent electrode layer is larger than that of the transparent electrode layer and the metal layer, and the adhesion force of the substrate and the metal layer is larger than that of the transparent electrode layer and the metal layer.
Preferably, the transparent conductive adhesive layer is made of transparent conductive adhesive.
Preferably, the step S1 specifically includes the following steps:
s11: firstly, forming a plurality of bonding electrodes which are arranged on a backboard substrate in an array mode, and then forming a photosensitive conducting layer on the bonding electrodes;
s12: and placing a micro light-emitting diode on the photosensitive conductive layer.
Preferably, the step S4 specifically includes the following steps:
s41: scanning and observing the detection substrate, and analyzing a scanning result;
s42: if the detection substrate is observed to be free of the transparent electrode layer and the transparent conductive adhesion layer, the micro light-emitting diode corresponding to the region is normal; if the transparent electrode layer and the transparent conductive adhesion layer exist on the detection substrate, the micro light-emitting diode corresponding to the region is lost; if the micro light-emitting diode exists on the detection substrate, the micro light-emitting diode corresponding to the region is damaged;
s43: the coordinates of the damaged and missing areas of the micro-leds are recorded.
Preferably, the inspection substrate is subjected to scanning observation using an optical microscope or an electron microscope.
The invention also discloses a display back plate which is manufactured by the manufacturing method of the display back plate, and the method comprises the following steps: a backplane substrate;
bonding electrodes arranged in an array on the backplane substrate;
a photosensitive conductive layer on the bonding electrode;
a micro light emitting diode on the photosensitive conductive layer;
and a transparent conductive adhesive layer on the micro light emitting diode and a transparent electrode layer on the transparent conductive adhesive layer.
The invention also discloses a detection substrate for detecting the micro light-emitting diode display back plate, which comprises a substrate, a metal layer covering the substrate, a transparent electrode layer positioned on the metal layer and a transparent conductive adhesion layer positioned on the transparent electrode layer.
The invention also discloses a manufacturing method of the detection substrate, which specifically comprises the following steps:
s01: forming a metal layer on a substrate;
s02: forming a plurality of transparent electrode layers which are arranged on the metal layer in an array mode, wherein the arrangement mode of the transparent electrode layers is consistent with that of the micro light-emitting diodes of the display back plate;
s03: and forming a transparent conductive adhesion layer on the transparent electrode layer.
The invention can bring at least one of the following beneficial effects:
1. the positions of the micro light-emitting diodes which are missing and damaged are analyzed and distinguished by scanning and observing the electrified detection substrate, so that the micro light-emitting diodes can be replaced and repaired in time before packaging, and the repairing efficiency is improved;
2. and carrying out power-on detection on the micro light-emitting diode by using the detection substrate, and directly obtaining the transparent conductive adhesion layer and the transparent electrode layer which are formed above the micro light-emitting diode after the detection is finished.
Detailed Description
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following description will be made with reference to the accompanying drawings. It is obvious that the drawings in the following description are only some examples of the invention, and that for a person skilled in the art, other drawings and embodiments can be derived from them without inventive effort.
For the sake of simplicity, the drawings only schematically show the parts relevant to the present invention, and they do not represent the actual structure as a product. In addition, in order to make the drawings concise and understandable, components having the same structure or function in some of the drawings are only schematically illustrated or only labeled. In this document, "one" means not only "only one" but also a case of "more than one".
The technical solution of the present invention is described in detail with specific examples below.
The invention discloses a micro light-emitting diode display back plate, which comprises: the back plate comprises a back plate substrate 01, bonding electrodes 02 arranged on the back plate substrate 01 in an array mode, a photosensitive conducting layer 03 located on the bonding electrodes 02, micro light-emitting diodes 04 located on the photosensitive conducting layer 03, a transparent conducting adhesion layer 204 located on the micro light-emitting diodes 04, and a transparent electrode layer 203 located on the transparent conducting adhesion layer 204.
Aiming at a series of conditions of the micro light-emitting diodes 04 in the forming process of the backboard substrate 01, the invention provides the detection substrate 200 for carrying out power-on detection on the micro light-emitting diodes 04 which are not packaged on the display backboard so as to detect and distinguish the missing and damaged micro light-emitting diodes 04, so that the micro light-emitting diodes can be replaced and repaired in time before being packaged, and the defective rate of the display backboard is reduced.
The invention discloses a manufacturing method of a micro light-emitting diode display back plate, which gives consideration to the detection function in the manufacturing process and comprises the following steps:
s1: as shown in fig. 1 and 2, micro light emitting diodes 04 arranged in an array are formed on a backplane substrate 01.
Wherein, the step S1 specifically includes the following steps:
s11: as shown in fig. 1, a plurality of bonding electrodes 02 arranged in an array on a backplane substrate are first formed, and then a photosensitive conductive layer 03 on the bonding electrodes 02 is formed.
Firstly, a bonding electrode layer is coated on a backboard substrate 01, bonding electrodes 02 arranged in an array are formed in the modes of exposure, development and etching, and the array arrangement mode of the bonding electrodes 02 is consistent with the arrangement mode of the micro light-emitting diodes 04 on the display backboard.
Then, a photosensitive conductive layer 03 is formed above the bonding electrode 02, the photosensitive conductive layer 03 can be manufactured in a dispensing manner, the photosensitive conductive layer 03 is formed by mixing a photosensitive material and a conductive metal, the photosensitive material is used as a main material, the doped metal is used as an auxiliary material, and the photosensitive conductive layer 03 can be cured under illumination and can be conductive under the condition of electrification. Preferably, the photosensitive conductive layer 03 includes a photosensitive layer and metal balls doped in the photosensitive layer, or the photosensitive conductive layer 03 includes a photosensitive layer and layered nano silver doped in the photosensitive layer.
S12: as shown in fig. 2, a micro light emitting diode 04 is disposed on the photosensitive conductive layer 03.
The prepared micro light emitting diode 04 is transferred and placed on the photosensitive conductive layer 03 by a transfer head. After the micro light emitting diodes 04 are placed in a transferring manner, a series of conditions, including the condition that the micro light emitting diodes 04 are missing and damaged, may appear on the display back plate, as shown in fig. 2, the area a is the normal area of the micro light emitting diodes 04, the area B is the missing area of the micro light emitting diodes 04, and the area C is the damaged area of the micro light emitting diodes 04.
Aiming at a series of conditions appearing on the display backboard after the micro light-emitting diodes 04 are transferred, the detection substrate 200 is utilized to carry out power-on detection on the micro light-emitting diodes 04 so as to detect and distinguish the micro light-emitting diodes 04 which are missing and damaged, and the micro light-emitting diodes 04 can be replaced and repaired in time before being packaged.
S2: the detection substrate 200 is produced. The detection substrate 200 includes a substrate 201, a metal layer 202 covering the substrate 201, a transparent electrode layer 203 on the metal layer 202, and a transparent conductive adhesive layer 204 on the transparent electrode layer 203.
As shown in fig. 3, the step S3 specifically includes the following steps:
s21: forming a metal layer 202 on a substrate 201;
s22: forming a plurality of transparent electrode layers 203 which are arranged on the metal layer 202 in an array manner, wherein the arrangement manner of the transparent electrode layers 203 is consistent with the arrangement manner of the micro light-emitting diodes 04 on the display backboard;
s23: a transparent conductive adhesive layer 204 on the transparent electrode layer 203 is formed.
The metal layer 202 is covered on the substrate 201 on the whole surface, then a layer of transparent electrode material is coated on the metal layer 202, the whole layer of transparent electrode material is patterned to form transparent electrode layers 203 arranged in an array by means of wet etching, and the transparent electrode material used by the transparent electrode layers 203 can be ITO. Then, a transparent conductive adhesive layer 204 located on the transparent electrode layer 203 is formed by dispensing, where the transparent conductive adhesive layer 204 needs to have characteristics of transparency, conductivity and viscosity, and the material for making the transparent conductive adhesive layer 204 may be a transparent conductive adhesive or other materials meeting the characteristics.
It should be noted that, for the purpose of the detection substrate 200 to detect and resolve the missing and damaged micro leds 04, the adhesion between the transparent conductive adhesion layer 204 and the transparent electrode layer 203 is greater than the adhesion between the transparent electrode layer 203 and the metal layer 202, and the adhesion between the substrate 201 and the metal layer 202 is greater than the adhesion between the transparent electrode layer 203 and the metal layer 202, which will be further described when describing the detection method in detail in step S4.
S3: as shown in fig. 4, the detection substrate 200 is attached to the micro light emitting diode 04 to perform energization detection, and after the energization is completed, the detection substrate 200 is removed.
The detection substrate 200 is attached to the micro light-emitting diode 04, that is, the transparent conductive adhesive layer 204 is attached to the micro light-emitting diode 04, and due to the transparent electrode layer 203 and the transparent conductive adhesive layer 204 which are provided on the detection substrate 200, after the detection substrate 200 is attached to the micro light-emitting diode 04, the micro light-emitting diode 04 can form a complete power-on loop up and down and emit light, and after the power-on is completed and the light is illuminated, the detection substrate 200 is removed for the next specific detection and analysis.
S4: scanning observation is carried out on the detection substrate 200, and the coordinates of the damaged and missing areas of the micro light-emitting diodes 04 are analyzed and recorded according to the scanning result.
As shown in fig. 5, the step S5 specifically includes the following steps:
s41: the detection substrate 200 is scanned and observed, and the scanning result is analyzed.
S42: if no transparent electrode layer 203 and transparent conductive adhesive layer 204 are observed in the region a on the detection substrate 200, the micro light emitting diode 04 corresponding to the region a is normal; if the transparent electrode layer 203 and the transparent conductive adhesive layer 204 are observed in the region b on the detection substrate 200, the micro light emitting diode 04 corresponding to the region b is absent; if the micro light emitting diode 04 is observed to be adhered to the region c of the detection substrate 200, the micro light emitting diode 04 corresponding to the region c is damaged.
S43: the coordinates of the damaged and missing areas of the micro-leds 04 are recorded.
For the area a where the micro light emitting diode 04 is normal, the micro light emitting diode 04 emits light after being powered on, and the photosensitive conductive layer 03 located at the bottom of the micro light emitting diode 04 is cured after receiving light, so that the micro light emitting diode 04 is bonded on the bonding electrode 02. When the detection substrate 200 is removed, since the adhesion force between the transparent conductive adhesion layer 204 and the transparent electrode layer 203 is greater than the adhesion force between the transparent electrode layer 203 and the metal layer 202, and the adhesion force between the substrate 201 and the metal layer 202 is greater than the adhesion force between the transparent electrode layer 203 and the metal layer 202, the transparent conductive adhesion layer 204 will adhere to the transparent electrode layer 203 together and remain on the micro light emitting diode 04, the transparent electrode layer 203 is separated from the metal layer 202, and no transparent electrode layer 203 and no transparent conductive adhesion layer 204 exist in the area a corresponding to the detection substrate 200. After the detection substrate 200 is scanned and observed, the micro light emitting diodes 04 in the area a can be determined to be normal according to the scanning result.
For the area B where the micro light emitting diode 04 is absent, the detection substrate 200 attached thereon has no change in the area B, and when the detection substrate 200 is removed, the transparent electrode layer 203 and the transparent conductive adhesive layer 204 are still present in the corresponding area B on the detection substrate 200. After the detection substrate 200 is scanned and observed, the absence of the micro light emitting diode 04 in the area B can be determined according to the scanning result.
For the damaged region C of the micro light emitting diode 04, the interior of the micro light emitting diode 04 cannot be normally conducted to cause non-light emission, and the photosensitive conductive layer 03 at the bottom of the damaged micro light emitting diode 04 cannot be cured due to non-illumination, so that the micro light emitting diode 04 cannot be bonded on the bonding electrode 02. When the detection substrate 200 is removed, the micro light emitting diodes 04 adhered to the transparent conductive adhesive layer 204 are removed together with the detection substrate 200, and the micro light emitting diodes 04 exist in the region c corresponding to the detection substrate 200. After the detection substrate 200 is scanned and observed, the damage of the micro light emitting diode 04 in the region C can be determined according to the scanning result.
The coordinates of the damaged and missing areas of the micro-leds 04 from these analyses are then recorded.
The detection device used for detecting the substrate 200 is not limited in the present invention, and may be an optical microscope or an electron microscope, as long as the resolution of the detection device is sufficient to distinguish the substance on the detection substrate 200.
S5: and (4) repairing the local part, repeating the step (S3) and the step (S4) after the repairing is finished, and continuing to the next step when no micro light-emitting diode 04 is missing or damaged.
According to the obtained coordinate record, the damaged and missing areas of the micro light-emitting diodes 04 can be repaired in a targeted manner. In the invention, because the detection substrate 200 is used, the detection substrate 200 can directly take the damaged micro light-emitting diodes 04 away from the display backboard, and the step of transferring the damaged micro light-emitting diodes 04 away by using a transfer head is omitted, so that the micro light-emitting diodes 04 can be transferred to the damaged and missing areas for repair at one time by using the transfer head, and the repair by areas is not needed. After the repair is completed, the steps S3 and S4 are repeated to perform an overall inspection on the entire display backplane, and the display backplane after the repair is completed is shown in fig. 6.
S6: and packaging the display back plate.
When all the micro light-emitting diodes 04 are detected to be normal, the transparent conductive adhesive layer 204 is adhered to the upper parts of all the micro light-emitting diodes 04, the transparent electrode layer 203 is arranged above the transparent conductive adhesive layer 204, and the conductive electrode formed above the micro light-emitting diodes 04 can be directly obtained after the detection is finished. And packaging the display back plate after detection is finished, and finishing the manufacturing of the display back plate.
The invention also provides a detection substrate for detecting the micro light-emitting diode display back plate, and the detection substrate 200 comprises a substrate 201, a metal layer 202 covering the substrate 201, a transparent electrode layer 203 positioned on the metal layer 202, and a transparent conductive adhesion layer 204 positioned on the transparent electrode layer 203.
The invention also provides a manufacturing method of the detection substrate for detecting the micro light-emitting diode display back plate, which specifically comprises the following steps:
s01: forming a metal layer 202 on a substrate 201;
s02: forming a plurality of transparent electrode layers 203 which are arranged on the metal layer 202 in an array mode, wherein the arrangement mode of the transparent electrode layers is consistent with that of the micro light-emitting diodes 204 of the micro light-emitting diode display back plate;
s03: a transparent conductive adhesive layer 204 on the transparent electrode layer 203 is formed.
According to the invention, the detection substrate after being powered on is scanned, and whether the photosensitive conductive layer positioned at the bottom of the micro light-emitting diode is cured by illumination or not is observed and judged, and the transparent conductive adhesion layer and the transparent electrode layer on the detection substrate are influenced, so that the position of the missing and damaged micro light-emitting diode can be analyzed and distinguished, the micro light-emitting diode can be conveniently replaced and repaired in time before packaging, the repairing efficiency is improved, and meanwhile, the yield of the display back plate is also improved.
It should be noted that the above mentioned embodiments are only preferred embodiments of the present invention, but the present invention is not limited to the details of the above embodiments, and it should be noted that, for those skilled in the art, it is possible to make various modifications and amendments within the technical concept of the present invention without departing from the principle of the present invention, and various modifications, amendments and equivalents of the technical solution of the present invention should be regarded as the protection scope of the present invention.