WO2015062068A1

WO2015062068A1 - Patterning method and application for forming conductive functional pattern

Info

Publication number: WO2015062068A1
Application number: PCT/CN2013/086412
Authority: WO
Inventors: 周忠
Original assignee: 深圳市海富莱电子有限公司
Priority date: 2013-11-01
Filing date: 2013-11-01
Publication date: 2015-05-07

Abstract

Disclosed in the present invention are a patterning method and application for forming a conductive functional pattern. The method comprises: preparing a conductive layer on the surface of a substrate, covering the surface of the conductive layer with a capping layer, then irradiating the conductive layer provided with the capping layer using UV light of a specific wavelength, and removing the capping layer to form a desired conductive functional pattern. The patterning method utilizes the photosensitive characteristic of a conductive high molecular polymer with respect to UV irradiation under the specific wavelength to completely or partially remove the conductivity of the uncapped conductive high molecular polymer. Also, the conductive functional pattern can be obtained simply by means of the shielding and UV irradiation of the conductive layer. The conductive functional pattern obtained in such way has the advantages of small chromatic aberration, good photosensitive conductivity, and stable conductivity upon photosensitive etching. Additionally, the preparation process has easily controlled requirements, is simple, low in cost, and suitable for industrial production. Furthermore, the patterning method can be applied in such fields as capacitive touch screens, OLED (Organic Light Emitting Diode) displays, electronic labels and EL (electroluminescence) cold optical glass.

Description

Graphical method and application for forming conductive functional patterns

The invention belongs to the field of transparent conductive materials, and in particular relates to a graphic method and application for forming a conductive functional pattern. Background technique

Indium oxide materials used in conventional indium tin oxide (ITO) coatings are expensive, and as a rare metal, indium is mainly produced in China and is expected to be depleted by 2020. In addition, because ITO materials are relatively fragile, the cost of producing larger-sized conductive electrodes will be higher, and they cannot be used in the case of bending, deformation, and folding. Therefore, various countries are vigorously developing various new technologies and new products. It is intended to replace ITO as a new choice for transparent conductive electrodes. Since 2009, these technologies have entered the trial phase, but due to their high cost, large equipment investment, and graphical defects, industrial mass production has not been realized, so shipments are extremely small.

In recent years, with the development of conductive polymer technology, organic conductive high molecular polymers have begun to be used in place of ITO. This is because organic conductive high molecular polymers have a series of advantages over ITO, for example, they are softer than ITO films, are less prone to micro cracks, have a longer service life, and can be directly coated on a substrate. It has higher film production properties in air and at a lower temperature than ITO. In addition, in combination with various substrates, flexible transparent conductive electrodes can be prepared to achieve bending, deformation, etc., and are applied in more fields. Therefore, the replacement of ITO as a transparent conductive electrode material by an organic conductive high molecular polymer will cause a revolutionary development in the electronics industry.

However, the widespread use of organic conductive high molecular polymers on transparent conductive electrodes still has difficulty in patterning. For example: When the laser is used to ablate the conductive polymer, the processing time of the nonlinear pattern is sharp due to the sharp reduction in the efficiency of the nonlinear pattern processing. The increase has brought difficulties to large-scale industrial production, and the complicated technological process steps in the prior art have undoubtedly further increased the difficulty of industrial production. In addition, the pattern formed by etching in practical applications not only has poor conductivity stability, but also has a large color difference of the pattern formed by etching, such as ΔΕ and ALab value, which does not meet the production requirements, seriously affects the visual effect, causes product defects, and even cannot be used. . Summary of the invention

SUMMARY OF THE INVENTION The object of the present invention is to overcome the above-mentioned deficiencies of the prior art, and to provide a patterning method for forming a conductive functional pattern by directly shielding a conductive layer and using UV light of a wavelength of 100-400 nm to obtain a conductive functional pattern.

Another object of the present invention is to provide an application of a patterning method of forming the conductive functional pattern. In order to achieve the above object, the technical solution of the present invention is as follows:

A graphical method of forming a conductive functional pattern includes the following steps:

Coating the conductive high molecular polymer slurry on the surface of the substrate to form a conductive layer and curing it;

Masking the prepared pattern template on the surface of the conductive layer to form a mask layer;

The conductive layer provided with the covering layer is irradiated with UV light having a wavelength of 100-400 nm, and then the covering layer is removed to obtain a conductive functional pattern.

And, the above-described patterning method of forming a conductive function pattern is applied to a capacitive touch screen, an OLED display, an electronic tag, and an EL luminescent film.

The above-mentioned patterning method for forming a conductive functional pattern utilizes the photosensitive property of the conductive high molecular polymer to UV light at a wavelength of 100-400 nm, so that the uncovered conductive high molecular polymer loses all or part of the conductive property, and only the conductive layer is required. The conductive functional pattern can be obtained by shielding treatment and UV illumination, so that not only the chromatic aberration of the formed conductive functional pattern is almost completely eliminated, but also the photosensitive conductive performance is good, and the conductive property is stabilized by photosensitive etching. At the same time, the preparation method is simple, the conditions are easy to control, the cost is low, and the method is suitable for industrial production. The above-mentioned patterning method for forming a conductive function pattern can be applied to a capacitive touch screen, an OLED display, an electronic label, and an EL luminescent sheet, thereby reducing chromatic aberration and production cost of the above products, simplifying the preparation process of the above products, and further improving the conductive stability thereof. Sex and yield. DRAWINGS

1 is a process flow diagram of a patterning method for forming a conductive function pattern according to an embodiment of the present invention. detailed description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly, the present invention will be further described in detail below with reference to the embodiments and the accompanying drawings. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Another object of the present invention is to provide an application of a patterning method of forming a conductive functional pattern. In order to achieve the above object, the technical solution of the present invention is as follows:

A graphical method for forming a conductive functional pattern, the flow of the graphical method is as shown in FIG. 1, and includes the following steps:

501. Applying a conductive polymer slurry to a surface of the substrate to form a conductive layer and curing the layer;

502. Shielding the prepared pattern template on the surface of the conductive layer to form a mask layer;

503. The conductive layer with the cover layer is irradiated with UV light of a wavelength of 100-400 nm, and then the cover layer is removed to obtain a conductive functional pattern.

In the above step S01, the substrate is one of a glass type, a wafer type, a polyester type, and a polyolefin type. As a preferred embodiment, the substrate is preferably a film or sheet of polyethylene terephthalate which is easy to form a flexible substrate. Specifically, the substrate is a polyethylene terephthalate (PET) film.

In the above step S01, the conductive high molecular polymer is one or a mixture of two or more of polypyrrole, polyaniline, polythiophene, polypyrrole derivative, polyaniline derivative, and polythiophene derivative. Such an organic conductive high molecular polymer has a large conjugated system, so that π electrons tend to occur along the polymer chain. Delocalization, it is this flow of π electrons that promotes the material to exhibit good electrical conductivity, and the organic conductive high molecular polymer has good flexibility and long service life, and is easy to handle during coating, suitable for scale production. .

As a preferred embodiment, the above conductive high molecular polymer is poly(3,4-dialkoxyoxythiophene) and/or a derivative thereof having good solubility, high electrical conductivity and environmental stability, such as CLEVIOS P HC V4 or CLEVIOS P Η500. Of course, the conductive high molecular polymer may be used singly or in combination of a plurality of types, or may be formed into a water-based dispersion or may be mixed with a suitable solvent and an additive to form a composite formulation.

In the above step S01, the conductive polymer slurry has a weight percentage of 60 to 90%. This is because when the content of the conductive high molecular polymer slurry is less than 60% by weight, the conductive layer is likely to be unevenly coated, and the conductive stability is poor when used, and the color difference is large; when the content is more than 90% by weight, the conductive is conductive. High molecular weight polymers are more difficult to achieve the desired high transparency, such as a coating with a transmittance higher than 85%.

Of course, the above slurry may be used after filtration or may be used as it is. However, in order to obtain a high-quality conductive function pattern, the slurry is subjected to filtration treatment before coating the surface of the substrate. The specific filtration treatment, such as filtration through a filter cloth made of nylon or polyester, is a prior art and will not be described herein. Similarly, the coating method may be a conventional method such as brushing, spraying, spin coating or roll coating, and will not be described herein. In addition, the embodiment of the present invention uses a coater to complete the entire coating process.

The curing process in the above step S01 is specifically: transferring the substrate coated with the conductive layer to a baking device for baking at a baking temperature of 60-150 ° C to cure the conductive layer. Of course, the curing treatment in this embodiment can also be carried out by a conventional method such as heating on a hot air or a hot plate at 80 ° C to 180 ° C for 5 min to 1 min. In addition, since the UV light transmittance varies with the thickness of the conductive layer, in order to reduce or even eliminate the chromatic aberration of the conductive pattern, the thickness of the conductive layer formed after the curing treatment is 0.1 to 1 μm, and more preferably 10 to 500 nm.

In the above step S02, according to the actual circuit pattern of the printed circuit board, the specific circuit diagram is copied onto the template with the light transmittance of 0%, that is, the positive image template is obtained. The preparation process of the positive template is a conventional method, and will not be described herein. Then, the prepared positive template is directly covered on the surface of the conductive layer or will be transparent. The material having a light transmittance of 0% is directly applied to the surface of the conductive layer in accordance with the specific shape of the wiring pattern, thereby forming a covering layer. Thus, the cover layer protects the covered portion of the conductive layer from the next step of UV illumination by covering. In addition, the positive template may be a film template, a chrome plate or various protective glues.

In general, the minimum line width of a transparent conductive film for a display such as an LCD or an organic EL varies depending on the screen size and resolution of the display, and is approximately 2-500 μm. Therefore, in order to meet the requirements of the size and resolution of the above display screen, the minimum line width of the above wiring pattern must be 500 μηι or less. At the same time, in order to avoid the occurrence of a phenomenon that the line is easily broken when the line fluctuates instantaneously, and the resistance of the line is increased, the embodiment of the present invention further reduces the cross-sectional area of the line, that is, the line width. In a preferred embodiment, the minimum line width is preferably 300 μηι or less, and the further line width is more preferably 30 μηι or less.

In the above step S03, the conductive layer provided with the mask layer is irradiated with UV light having a wavelength of 100 to 400 nm, that is, photolithography is performed. Of course, the ultraviolet light source used is not limited herein, and high-order harmonic light used for excimer lasers and YAG lasers can be used.

As a preferred embodiment, the wavelength of the UV light used in the photolithography is preferably 150 to 254 nm. This is because in the range of 150-254 nm, the organic conductive high molecular polymer has a strong ultraviolet light absorbing ability, which causes it to decompose into ions, free atoms, and excited molecules or electrons, and oxygen molecules in the air In the wavelength range, it also has strong absorption capacity, which causes the oxygen molecules to decompose to produce extremely active atomic oxygen. Under the action of atomic oxygen, the conductive high molecular polymer is also prone to degradation and chain scission, which leads to the breakage of the flow chain of π electrons, and finally It loses its electrical conductivity. In addition, when the wavelength is less than 150 nm, the irradiation intensity of UV is easily lost, and the resistance of the conductive high molecular polymer is not easily increased. When the wavelength is greater than 254 nm, the absorption efficiency of the conductive polymer is insufficient for UV, and the same cannot be achieved. The resistance of the organic conductive high molecular polymer is effectively increased.

The above-mentioned patterning method for forming a conductive functional pattern utilizes an organic conductive polymer at 150-254 nm wavelength to easily absorb ultraviolet light to cause degradation and chain scission, thereby causing the π electron flow chain to be broken, thereby unpolymerizing the uncovered conductive polymer. The material loses its conductivity in whole or in part. At the same time, the patterning method only needs to shield the conductive layer by UV illumination to obtain a conductive functional pattern, so that not only the chromatic aberration of the formed conductive functional pattern is almost completely eliminated, but also the photosensitive conductive property is good, after photosensitive etching The conductivity is stable. At the same time, the preparation method is simple, the conditions are easy to control, the cost is low, and the method is suitable for industrial production.

In addition, since the above-described patterning method for forming a conductive function pattern has the advantages as described above, the embodiment of the present invention further provides an application for a capacitive touch screen, an OLED display, an electronic label, and an EL luminescent sheet, thereby reducing The color difference and production cost of the above products simplifies the preparation process of the above products, and further improves the electrical conductivity stability and yield.

The present invention will now be further described in detail by taking a graphical method and application for forming a conductive functional pattern as an example. Example 1

511. Select PET sheet as the substrate, and apply CLEVIOS PH 500 (including poly(3,4-ethylenedioxythiophene)) conductive polymer slurry prepared by HCStarck Co., Ltd. to the surface to obtain a thickness of 500 nm conductive layer, and then the conductive layer is baked in a clean oven at 110 ° C for 10 minutes;

512. Covering the prepared circuit pattern pattern template on the surface of the baked conductive layer to form a covering layer;

513. On the cover layer, a UV light irradiation device having a wavelength of 222 nm and an irradiation energy of 10000 mJ/cm ² was irradiated for 3 minutes, and then the cover layer was removed, thereby obtaining a conductive function pattern of the wiring pattern. Example 2

A patterning method for forming a conductive functional pattern, the specific steps of which are similar to those of Embodiment 1, except that the conductive polymer slurry selected in Embodiment 2 is Pan-t Panipol (including polyaniline) manufactured by Panipol Corporation. Further, Example 2 was irradiated for 3 minutes using a UV light irradiation device of 254 nm and an irradiation energy of 12000 mJ/cm ² . Specific steps are as follows: 521. Select PET sheet as the substrate, apply Pan-t Panipol (including polyaniline) conductive polymer slurry prepared by Panigol to the surface to obtain a conductive layer with a thickness of 500 nm, and then clean the conductive layer. Hot baking in an oven at 110 ° C for 10 minutes;

522. Covering the prepared circuit pattern pattern template on the surface of the baked conductive layer to form a covering layer;

523. On the cover layer, a UV light irradiation device of 254 nm and an irradiation energy of 12000 mJ/cm ^{2 was used} for 3 minutes, and then the cover layer was removed, thereby obtaining a conductive function pattern of the wiring pattern. Example 3

A patterning method for forming a conductive functional pattern, the specific steps of which are similar to those of Embodiment 1, except that the polymer slurry selected in Embodiment 3 is CLEVIOS P HC V4 (including poly(3, manufactured by HCStarck). 4-Ethylenedioxythiophene)), and Example 3 was irradiated with a UV light irradiation device of 185 nm and an irradiation energy of 8000 mJ/cm ² . Specific steps are as follows:

531. Select PET sheet as the substrate, and coat the surface of CLEVIOS P HC V4 (including poly(3,4-ethylenedioxythiophene)) polymer slurry prepared by HCStarck to obtain a thickness of 500 nm. Conductive layer, and then the conductive layer is baked in a clean oven at 110 ° C for 10 minutes;

532. Covering the prepared circuit pattern pattern template on the surface of the baked conductive layer to form a covering layer;

533. On the cover layer, a UV light irradiation device of 185 nm and an irradiation energy of 8000 mJ/cm ^{2 was used} for 3 minutes, and then the cover layer was removed to obtain a conductive function pattern of the wiring pattern. Comparative Example 1

A patterning method for forming a conductive functional pattern, the specific steps of which are similar to those of Embodiment 1, except that the conductive polymer slurry selected in Comparative Example 1 is Pan-t Panipol (including polyaniline) manufactured by Panipol Corporation. And Comparative Example 1 was irradiated for 3 minutes using a UV light irradiation device of 365 nm and an irradiation energy of 20,000 mJ/cm ² . Specific steps are as follows: 51. Select PET sheet as the substrate, apply Pan-t Panipol (including polyaniline) conductive polymer slurry prepared by Panigol to the surface to obtain a conductive layer with a thickness of 500 nm, and then clean the conductive layer. Hot baking in an oven at 110 ° C for 10 minutes;

52. Covering the prepared circuit pattern pattern template on the surface of the baked conductive layer to form a covering layer;

53. On the cover layer, a UV light irradiation device of 365 nm and an irradiation energy of 20,000 mJ/cm ^{2 was used} for 3 minutes, and then the cover layer was removed to obtain a conductive function pattern of the wiring pattern. Comparative Example 2

A patterning method for forming a conductive functional pattern, the specific steps of which are similar to those of Embodiment 1, except that: the conductive high molecular polymer slurry selected in Comparative Example 2 is CLEVIOS PH 500 prepared by HC Starck Co., Ltd. (including poly(3) 4-ethylidene dioxythiophene.), and Comparative Example 2 was irradiated for 3 minutes using a UV light irradiation device of 254 nm and an irradiation energy of 1000 mJ/cm ² . Specific steps are as follows:

51. Select PET sheet as the substrate, and coat the surface of CLEVIOS PH 500 (including poly(3,4-ethylenedioxythiophene)) conductive polymer slurry prepared by HCStarck to obtain a thickness of 500 nm. a conductive layer, and then the conductive layer is baked in a clean oven at a temperature of 110 ° C for 10 minutes;

53. On the cover layer, a UV light irradiation device of 254 nm and an irradiation energy of 1000 mJ/cm ^{2 was used} for 3 minutes, and then the cover layer was removed to obtain a conductive function pattern of the wiring pattern. Comparative Example 3

A patterning method for forming a conductive function pattern, the specific steps of which are similar to those of Embodiment 1, except that: Comparative Example 3 employs a conventional yellow light etching method. Specific steps are as follows:

S1. Select PET sheet as the substrate, and apply CLEVIOS PH 500 (including poly(3,4-ethylenedioxythiophene)) conductive polymer slurry prepared by HCStarck Co., Ltd. to the surface to obtain a thickness of 500 nm. a conductive layer, and then the conductive layer is baked in a clean oven at a temperature of 110 ° C for 10 minutes; 52. Applying a photoresist to the surface of the conductive layer, and then masking the prepared pattern pattern template on the surface of the coated photoresist to form a mask layer;

53. On the cover layer, the photosensitive paste was exposed and cured by using a UV light irradiation device of 365 nm and an irradiation energy of 20,000 mJ/cm ² for 0.5 minute.

54. After removing the circuit pattern pattern template, after cleaning with acid and alkali, the conductive layer under the photosensitive adhesive in the exposed area is peeled off by the damage of the photosensitive adhesive, and the conductive functional pattern of the circuit diagram is obtained. Performance Testing:

The conductive functional patterns of the wiring patterns prepared in the above Examples 1 to 3 and Comparative Examples 1 to 3 were subjected to correlation performance tests. The test method is as follows:

(1) Photosensitive conductive effect: The effect of photosensitive conductivity change is evaluated by a multimeter to test the sheet resistance between two square patterns after UV light irradiation, wherein the evaluation criteria are as follows:

1 is greater than 2Χ10 ⁸ Ω: good

2 2Χ 10 ⁷ - 2Χ 10 ⁸ Ω: General

3 is less than 2Χ10 ⁷ Ω: Poor

(2) Color difference effect: The color density of transmitted light is measured by X-rite color calibrator, and the change of color difference on the conductive layer is measured according to the difference in color of the conductive layer before and after the irradiation. The evaluation criteria are as follows:

1 is less than 0.1: good

(2) 0.2-0.3: General

3 is greater than 0.3: poor

(3) Conductive stability effect: After placing the prepared substrate in 60 ° C, placed in a 90% constant temperature and humidity chamber for 240 hours, the test resistance value is taken out, and the placed resistance value R2 and the resistance before placement The value R1 is compared (R2/R1) and the evaluation criteria are as follows: 2 1.3-0.4 : General

3 is greater than 1.5: poor

Through the above tests, the results of each test are shown in Table 1 below, where P1 is expressed as: CLEVIOS P HC V4; P2 is expressed as: polyaniline; P3 is expressed as: CLEVIOS PH 500.

Table 1

It can be seen from the above Table 1 that the conductive patterns provided in Examples 1 to 3 are light-irradiated by a specific UV light, have a small color difference, have good photosensitive conductivity, and are stable in electrical conductivity after photosensitive etching. When the UV light was irradiated at a wavelength of 365 nm in Comparative Example 1, since the absorption of ultraviolet light by the conductive polymer material was insufficient at this wavelength, the effect of loss of conductivity was poor; Comparative Example 2 employed 1000 mJ/cm ^{2 .} The irradiation of the UV light irradiation device is also insufficient due to insufficient intensity of ultraviolet light absorption, and the effect of loss of conductivity is poor. In Comparative Example 3, the conventional etching method is used, and the conductive layer is peeled off and destroyed, although the effect of loss of conductivity is achieved. However, the color difference is very obvious and cannot meet the requirements of actual production for the senses. The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. Within the scope.

Claims

Claim

A graphical method of forming a conductive functional pattern, comprising the steps of:

2. The patterning method for forming a conductive functional pattern according to claim 1, wherein the wavelength is 150-254 nm.

3. The patterning method for forming a conductive function pattern according to claim 1, wherein the conductive polymer slurry has a weight percentage of 60 to 90%.

The patterning method for forming a conductive functional pattern according to any one of claims 1 to 3, wherein the conductive high molecular polymer is polypyrrole, polyaniline, polythiophene, polypyrrole derivative, One or more complexes of a polyaniline derivative and a polythiophene derivative.

The patterning method for forming a conductive functional pattern according to claim 4, wherein the conductive polymer is poly(3,4-dialkoxyoxythiophene) and/or a derivative thereof.

6. The patterning method for forming a conductive functional pattern according to claim 5, wherein the conductive layer after the curing treatment has a thickness of 1 ηηι to 10 μm.

The patterning method for forming a conductive functional pattern according to any one of claims 1 to 3, wherein the substrate is selected from the group consisting of glass, wafer, polyester, and polyolefin.

The patterning method for forming a conductive function pattern according to any one of claims 1 to 3, wherein the conductive function pattern is a line pattern of a line width of 2-500 μηι.

9. The method of forming a conductive functional pattern according to claim 8, wherein the minimum line width of the wiring pattern is 30 μηι or less.

10. The patterning method for forming a conductive function pattern according to any one of claims 1 to 9, which is applied to electricity Touch screen, OLED display, electronic label and EL luminescent film.