TWI497533B - Method for fabricating patterned transparent electrodes with low surface roughness - Google Patents

Description

Method for manufacturing patterned transparent electrode with low surface roughness

The invention relates to a method for manufacturing a patterned transparent electrode, in particular to a method for manufacturing a patterned transparent electrode capable of reducing surface roughness.

Transparent electrodes are used in a wide range of applications, such as liquid crystal panels, touch screens, and solar cells. In order to meet the needs of various uses, transparent electrodes can be fabricated by various manufacturing methods. For example, conductive ink can be filled into the patterned ink tank on the substrate by screen printing or inkjet printing. There is often a problem that the surface of the transparent electrode and the substrate are not flat.

For example, if the injection amount of conductive ink is not precisely controlled, it often causes the conductive ink to overflow or splash on the surface of the substrate. At this time, it is necessary to use a doctor blade to remove the conductive ink remaining on the surface of the substrate, or It is necessary to use ink to absorb excess conductive ink remaining on the surface of the substrate to maintain the flatness of the substrate surface.

In summary, according to the conventional transparent electrode manufacturing method, After the patterned ink structure is formed on the surface of the substrate, it is still necessary to use various post-treatment methods such as scraping or surface adsorption to effectively reduce the surface roughness of the substrate surface. However, none of these methods can achieve the desired surface flatness in a single process, and it takes a considerable amount of process time and cost for the process of manufacturing a transparent electrode.

The invention relates to a method for manufacturing a patterned transparent electrode with low surface roughness. By controlling the amount of ink of the conductive ink and matching the precise alignment, the conductive ink can be completely filled in the groove of the substrate without additional The ink in the non-groove portion is removed, thereby reducing the processing time and reducing the surface roughness between the transparent electrode and the substrate, and using a simple surface modification process to improve the surface roughness to several tens of nanometers in a single process. Can achieve the purpose of reducing costs and simplifying the process.

The present invention provides a method for fabricating a patterned transparent electrode having a low surface roughness, comprising the steps of: providing a patterned substrate, forming a pattern on the patterned substrate by a plurality of grooves; providing a patterned template, patterning the template Having at least one pattern opening corresponding to the shape of the pattern; filling a conductive ink in the grooves, placing the patterned template on the pattern surface of the patterned substrate and performing alignment, introducing conductive ink to pass the conductive ink At least one pattern opening is filled in the grooves; and a surface flatness modification treatment is performed, which is applied to the pattern surface by a hot pressing technique or a coating technique to reduce the surface roughness of one of the transparent electrodes formed by the conductive ink.

With the implementation of the present invention, at least the following advancements can be achieved: 1. The conductive ink can be completely filled in the groove of the patterned substrate, and then subjected to a simple surface modification treatment by hot pressing technology or coating technology, which can further reduce the surface roughness between the transparent electrode and the substrate; The process time can be shortened by eliminating unnecessary conductive ink in the non-groove portion.

In order to make those skilled in the art understand the technical content of the present invention and implement it, and according to the disclosure, the patent scope and the drawings, the related objects and advantages of the present invention can be easily understood by those skilled in the art. The detailed features and advantages of the present invention will be described in detail in the embodiments.

10‧‧‧ patterned substrate

11‧‧‧ Groove

20‧‧‧Web Edition

21‧‧‧Grid

22‧‧‧Photomask

23‧‧‧ pattern opening

30‧‧‧vacuum suction cup

31‧‧‧ Alignment device

40‧‧‧Conductive ink

50‧‧‧ scraper

61‧‧‧Upper plate

62‧‧‧ Lower plate

71‧‧‧Upper wheel

72‧‧‧Lower scroll

1 is a flow chart of a method for manufacturing a patterned transparent electrode having a low surface roughness according to an embodiment of the present invention; FIG. 2A is a plan view of a patterned substrate according to an embodiment of the present invention; FIG. 2B is a view of an embodiment of the present invention; A partial cross-sectional view of a patterned substrate; FIG. 3 is a schematic view of a screen of the embodiment of the present invention; FIG. 4 is a schematic view of a photomask according to an embodiment of the present invention; FIG. 6 is a schematic view showing a patterning template using a screen as an embodiment of the present invention; and FIG. 7 is a schematic diagram of a patterned substrate filled with conductive ink according to an embodiment of the present invention; 8A is a schematic view showing a surface flatness modification process using a flat plate hot pressing technique according to an embodiment of the present invention; and FIG. 8B is a roller flat heat modification technology for performing surface flatness modification according to an embodiment of the present invention; Schematic diagram of the process.

As shown in FIG. 1, the embodiment provides a method for fabricating a patterned transparent electrode having a low surface roughness, comprising the steps of: providing a patterned substrate (step S10); providing a patterned template (step S20); filling in The conductive ink is in the groove (step S30); and the surface flatness modification process is performed (step S40).

Providing a patterned substrate (step S10): as shown in FIGS. 2A and 2B, which is a patterned substrate 10, a plurality of grooves 11 are formed on the substrate by exposure, development, and etching techniques in advance to form a pattern. Alternatively, the lens 11 may be formed on the substrate by techniques such as laser or imprint. The material of the patterned substrate 10 can be selected from a flexible substrate, a glass or a germanium wafer, and the flexible substrate is, for example, PET, but is not limited thereto.

A patterned template is provided (step S20): the patterned template has at least one pattern opening corresponding to the shape of the pattern on the patterned substrate 10. As shown in FIG. 3, the patterned template can be a screen 20, which is typically used in screen printing 20 in screen printing technology. The pattern opening in the screen 20 is composed of a plurality of grids 21. For example, if the groove 11 on the patterned substrate 10 is a plurality of hexagonal patterns formed in a honeycomb shape, the plurality of meshes 21 may also form a plurality of hexagonal patterns such as honeycombs.

As also shown in FIG. 4, the patterned template may also be a mask 22 having a pattern opening 23 corresponding to the pattern of the patterned substrate 10. In combination with different technical processes, a screen 20 or a reticle 22 can be used as a patterning template. Those skilled in the art should be able to easily understand that they can use appropriate materials or components for patterning. template.

The conductive ink is filled in the recess (step S30): the conductive ink can be completely filled into the recess 11 by a doctor blade coating technique, a screen printing technique or an inkjet printing technique.

As shown in FIG. 4, FIG. 5, and FIG. 6, the patterned template having the pattern opening 23 can be placed on the pattern surface of the patterned substrate 10 and aligned, and the conductive ink 40 can be introduced to transmit the conductive ink 40. The pattern opening 23 is filled in the groove 11. The alignment between the patterned template and the patterned substrate 10 can be achieved using a vacuum chuck 30, such as placing the patterned substrate 10 on the vacuum chuck 30 below the patterned template to vacuum adsorb and fix the pattern using a vacuum adsorption device. The position of the substrate 10 is adjusted, and a pair of bit devices 31 are disposed around the patterned substrate 10 on the vacuum chuck 30 so that the patterned template can be placed on the pattern surface of the patterned substrate 10 and paired with the patterned substrate 10. Bit.

For example, the alignment device 31 may be a positioning rod provided with a protrusion around the patterned substrate 10, and a positioning hole (not shown) is disposed on the patterned template at a position that does not affect the pattern. When positioning is performed, only the positioning rod needs to be inserted into the positioning hole, that is, the pattern opening 23 of the patterned template can be aligned with the pattern on the patterned substrate 10.

After the alignment is completed, the conductive ink 40 can be introduced over the patterned template, and the conductive ink 40 is completely filled into the recess 11 of the patterned substrate 10 through the pattern opening 23. For example, when the patterned template is the reticle 22, the conductive ink 40 can be filled into the recess 11 through the pattern opening 23 of the reticle 22 by a doctor blade coating technique or an inkjet printing technique. Since the volume of the groove 11 can be accurately calculated, the amount of ink of the conductive ink 40 can be controlled, and the accurate alignment technique can be used to avoid the guide. The effect of the electric ink 40 overflowing outside the groove 11.

As shown in FIGS. 6 and 7, when the patterned template is the screen 20, the pattern opening of the screen 20 is composed of a plurality of grids 21 (as shown in FIG. 3), since the pair can be utilized. The bit device makes the pattern opening on the screen 20 coincide with the pattern on the patterned substrate 10, and then controls the downforce of the blade 50 and the process parameters by controlling the influence of the surface tension and controlling the amount of ink of the conductive ink 40. The conductive ink 40 fills the recess 11 through a fine mesh. In addition to filling the recesses 11, the conductive ink 40 can be prevented from overflowing or spilling out of the recesses 11, so that it is not necessary to remove the ink residue of the non-groove 11 portions, thereby reducing the processing time. .

The surface flatness modification treatment (step S40): the surface flatness modification treatment may be applied to the pattern surface of the patterned substrate 10 by a hot pressing technique or a coating technique to reduce the surface roughness of the transparent electrode formed by the conductive ink 40. . As shown in FIG. 1, FIG. 8A, and FIG. 8B, after performing step S30, the patterned substrate 10 filled with the conductive ink 40 can be thermocompression-bonded by a hot pressing technique. During the hot pressing process, the heat can cause the conductive ink 40 to dry and form a transparent electrode at the groove 11, while the pressure applied to the patterned substrate 10 can achieve the effect of reducing the surface roughness.

The hot pressing technique can be, for example, a flat plate hot pressing technique or a roller hot pressing technique. As shown in FIG. 8A, the flat plate hot pressing technique is to place the patterned substrate 10 filled with the conductive ink 40 between an upper plate 61 and a lower plate 62 of the hot press, and then pressurize the upper plate 61 and the lower plate 62. The substrate 10 is patterned to form a transparent electrode.

Similarly, as shown in FIG. 8B, the roller hot pressing technique places the patterned substrate 10 filled with the conductive ink 40 between an upper roller 71 and a lower roller 72 of the hot rolling roller machine, when the patterned substrate 10 is patterned. When being conveyed between the upper roller 71 and the lower roller 72, the upper roller 71 and the lower roller 72 are heat-pressed on the patterned substrate 10 to form Transparent electrode.

When the surface flatness modification treatment is performed using a coating technique, a polymer material having conductivity and light transmittance (for example, a light transmittance of 90% or more) may be applied to the entire pattern surface of the patterned substrate 10 to be utilized. The polymer material fills the uneven structure of the conductive ink and/or the patterned substrate 10, thereby reducing the surface roughness of the transparent electrode made of conductive ink. The coating technique can be selected from a spin coating technique, a wire bar coating technique or a slot die coating technique.

More preferably, the width of the recess 11 on the patterned substrate 10 can be designed and optimized such that the conductive ink 40 is completely filled in the recess 11 to improve the surface flatness of the patterned substrate 10. When the surface flatness modification treatment is performed, the conductive surface 40 in the groove 11 and the patterned substrate 10 can have the same surface height, and the surface roughness can be reduced to several tens of nanometers or less, which can effectively reduce the surface roughness. degree.

The conductive ink 40 may be selected from a metal nanoparticle paste or a metal nanoparticle ink. Alternatively, a suitable substrate material and conductive ink 40 may be used to form a transparent electrode 3D structure or a flexible transparent electrode. Moreover, since the surface roughness of the surface of the patterned substrate 10 can be reduced by using a hot pressing technique or a coating technique, the surface flatness of the substrate can be effectively improved in a single process, thereby achieving the effects of simplifying the process and shortening the process time.

The embodiments are described to illustrate the features of the present invention, and the purpose of the present invention is to enable those skilled in the art to understand the present invention and to implement the present invention without limiting the scope of the present invention. Equivalent modifications or modifications made by the spirit of the disclosure should still be included in the scope of the claims described below.

S10‧‧‧ Provide patterned substrate steps

S20‧‧‧ provides patterned template steps

S30‧‧‧Filling conductive ink into the groove

S40‧‧‧ Surface smoothness modification processing steps

Claims (11)

A method for fabricating a patterned transparent electrode having a low surface roughness, comprising the steps of: providing a patterned substrate having a pattern formed by a plurality of grooves; providing a patterned template having a patterned template At least one pattern opening corresponding to the pattern shape; filling a conductive ink in the grooves, placing the patterned template on the pattern surface of the patterned substrate and aligning the conductive ink The conductive ink is filled into the recesses through the at least one pattern opening; and the surface flatness modification treatment is performed on the pattern surface by a hot pressing technique or a coating technique to reduce the formation of the conductive ink. The surface roughness of the transparent electrode. The method for manufacturing a patterned transparent electrode according to claim 1, wherein the step of filling the conductive ink into the grooves is performed by using a knife coating technique, a screen printing technique or an inkjet printing technique. The ink is completely filled in the grooves. The method for manufacturing a patterned transparent electrode according to claim 1, wherein the patterned template is a mask, and the conductive ink is filled in the grooves by a blade coating technique or an inkjet printing technique. The conductive ink is filled into the grooves through the at least one pattern opening of the reticle. The method for manufacturing a patterned transparent electrode according to claim 1, wherein the patterned template is a screen, and the pattern opening of the screen is composed of a plurality of grids, and the conductive ink is filled in the screen. When the grooves are formed, the conductive ink passes through the These grids fill in the grooves. The method for manufacturing a patterned transparent electrode according to claim 1, wherein the patterned substrate is made of a flexible substrate, a glass or a germanium wafer. The method for producing a patterned transparent electrode according to claim 1, wherein the conductive ink is a metal nanoparticle paste or a metal nanoparticle ink. The method for manufacturing a patterned transparent electrode according to any one of the preceding claims, wherein the patterned substrate is vacuum-adsorbed to the patterned substrate when the patterned template is aligned with the patterned substrate. A vacuum chuck is disposed, and a pair of positioning means is disposed around the patterned substrate to align with the patterned template. The method for manufacturing a patterned transparent electrode according to claim 7, wherein the hot pressing technique is a flat plate hot pressing technique or a roller hot pressing technique, which is thermocompression bonded to the patterned substrate filled with the conductive ink. The method for manufacturing a patterned transparent electrode according to claim 8, wherein the flat hot pressing technique places the patterned substrate filled with the conductive ink on a flat plate and a flat plate on one of the hot presses. . The method for manufacturing a patterned transparent electrode according to claim 8, wherein the roller hot pressing technology places the patterned substrate filled with the conductive ink on one of a hot rolling roller and a roller. between. The method for manufacturing a patterned transparent electrode according to claim 7, wherein the coating technique is a spin coating technique, a wire bar coating technique or a slot die coating technique, and the conductive coating is used. A polymer material that is transparent and translucent is applied to the pattern surface.