WO2014204117A1 - Method of forming insulation layer and touch screen manufactured using same - Google Patents

Abstract

The present invention relates to a method of forming an insulation layer for insulating a conductive pattern and a bridge electrode of a touch screen, the method comprising the steps of: heating a substrate on which the conductive pattern is formed; forming a first pattern and a second pattern in consecutive order on the heated substrate using a conductive composite; and hardening the first pattern and the second pattern, wherein the first pattern has a groove part so as not to overlap adjacent patterns and the second pattern is formed in the groove part of the first pattern. The present invention also relates to a touch screen including the insulation layer formed using the method.

Description

Insulation layer forming method and touch screen manufactured using the same

The present invention relates to an insulating layer forming method for insulating a conductive electrode of a touch screen and a bridge electrode, and to a touch screen manufactured using the method.

Recently, display devices such as liquid crystal displays, electroluminescent displays, and plasma display panels have been attracting attention due to their fast response speed, low power consumption, and excellent color reproducibility. . Such display devices have been used in various electronic products such as TVs, computer monitors, notebook computers, mobile phones, refrigerator displays, personal digital assistants, and automated teller machines. In general, such display devices configure an interface with a user by using various input devices such as a keyboard, a mouse, and a digitizer.

However, the use of separate input devices such as a keyboard and a mouse has a problem of causing user dissatisfaction due to inconvenience of taking up space and learning how to use. Thus, there is an increasing demand for an input device that is convenient, simple and can reduce malfunctions. In accordance with such a request, a touch screen has been proposed in which a user directly contacts a screen with a hand or a pen to input information.

The touch screen has been applied to various display devices due to the convenience of inputting without using a separate input device and the user's convenience of quick and easy operation through contents displayed on the screen.

On the other hand, according to the trend of thinning of display devices recently, a thin touch screen is required, and according to this trend, single-sided single-sided touch screens have been developed.

1 shows an example of a conventional single-sided single-sheet touch screen. As shown in FIG. 1, the single-sided single-sheet touch screen includes a substrate (not shown), a conductive pattern 20 formed on the substrate, an insulating layer 30, and a bridge electrode 40. Such a single-sided single-sheet touch screen is generally manufactured through forming a conductive pattern on a substrate, forming an insulating layer, and forming a bridge electrode.

The conductive patterns 20 are connected to each other in the x-axis direction, but are separated from each other in the y-axis direction. In addition, the bridge electrode 40 is for connecting the separated y-axis conductive pattern, and is generally formed using a conductive polymer or silver nanowires. In this case, in order to separate the conduction between the conductive pattern and the bridge electrode, an insulating layer 30 is formed between the conductive pattern and the bridge electrode.

Such a single-sided single-sheet touch screen is generally manufactured by forming a conductive pattern on a substrate, forming an insulating layer, and forming a bridge electrode, wherein the insulating layer 30 is formed of an insulating composition. It was formed by printing in a predetermined pattern shape on the conductive pattern using a printing process such as inkjet, screen, and the like.

However, in the case of using the conventional method of forming an insulating layer, a problem that a coffee ring phenomenon occurs in which the edge height is larger than the height of the center part after drying due to the difference in evaporation rate between the inside and the outside of the pattern during curing of the insulating layer. There is this. When the coffee ring phenomenon occurs, there is a problem in that the bridge electrode is broken or the connection state is worsened due to a high step. In addition, when the metal mesh is used as the conductive pattern, a phenomenon occurs in which the ink composition flows through the metal mesh pattern during formation of the insulating layer pattern, making it difficult to form the pattern accurately at a desired position. Since the bridge electrodes to be connected are not in contact with the conductive pattern, problems such as impairing the function of the touch sensor may occur.

The present invention is to solve the above problems, by proceeding the patterning in two steps, to prevent the occurrence of a coffee ring (coffee ring) phenomenon to form an insulating layer with a uniform thickness, the insulating layer forming composition The present invention provides a method for forming an insulating layer capable of forming a stable pattern at a desired position by preventing flow of conductive patterns formed on the substrate and an insulating layer formed by using the same.

In order to solve the above problems, the first aspect of the present invention is an insulating layer forming method for insulating the conductive pattern of the touch screen and the bridge electrode, heating the substrate on which the conductive pattern is formed, insulating on the heated substrate Sequentially forming a first pattern and a second pattern using a composition, and curing the first pattern and the second pattern, wherein the first pattern includes a groove portion so that adjacent patterns do not overlap, The second pattern is formed in the groove portion of the first pattern provides an insulating layer forming method.

According to a second aspect of the present invention, an insulating layer is interposed between a substrate, a conductive pattern formed on the substrate, a bridge electrode formed on the conductive pattern, and the conductive pattern and the bridge electrode, and insulates the conductive pattern and the bridge electrode. In the touch screen comprising a layer, the insulating layer is formed by the method for forming an insulating layer according to the present invention, and provides a touch screen, characterized in that the vertical cross-section of the insulating layer is convex.

In order to solve the above problems, the first aspect of the present invention is an insulating layer forming method for insulating the conductive pattern of the touch screen and the bridge electrode, heating the substrate on which the conductive pattern is formed, insulating on the heated substrate Sequentially forming a first pattern and a second pattern using a composition, and curing the first pattern and the second pattern, wherein the first pattern includes a groove portion so that adjacent patterns do not overlap, The second pattern is formed in the groove portion of the first pattern provides an insulating layer forming method.

According to a second aspect of the present invention, an insulating layer is interposed between a substrate, a conductive pattern formed on the substrate, a bridge electrode formed on the conductive pattern, and the conductive pattern and the bridge electrode, and insulates the conductive pattern and the bridge electrode. In the touch screen comprising a layer, the insulating layer is formed by the method for forming an insulating layer according to the present invention, and provides a touch screen, characterized in that the vertical cross-section of the insulating layer is convex.

1 is a view showing an embodiment of a single-sided single-sheet touch screen.

2A illustrates an example in which the first pattern has a dot shape.

2B illustrates an example in which the second pattern has a dot shape.

3A illustrates an example in which the first pattern has a line shape.

3B illustrates an example in which the second pattern has a line shape.

4A is data obtained by measuring a horizontal cross section of an insulating layer formed by the insulating layer forming method according to Example 1. FIG.

4B is data obtained by measuring the vertical cross section of the insulating layer formed by the insulating layer forming method according to Example 1. FIG.

5A is data obtained by measuring a horizontal cross section of an insulating layer formed by the insulating layer forming method according to Comparative Example 1. FIG.

5B is data obtained by measuring the vertical cross section of the insulating layer formed by the insulating layer forming method according to Comparative Example 1. FIG.

6A is data obtained by measuring a horizontal cross section of an insulating layer formed by the insulating layer forming method according to Comparative Example 2. FIG.

6B is data obtained by measuring the vertical cross section of the insulating layer formed by the insulating layer forming method according to Comparative Example 2. FIG.

7A is data obtained by measuring a horizontal cross section of an insulating layer formed by the insulating layer forming method according to Comparative Example 3. FIG.

7B is data obtained by measuring the vertical cross section of the insulating layer formed by the insulating layer forming method according to Comparative Example 3. FIG.

8 illustrates a phenomenon in which an insulating composition flows through a mesh of a substrate when forming an insulating layer according to Comparative Example 1 when the temperature of the substrate is room temperature.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. In addition, the embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art. Shape and size of the elements in the drawings may be exaggerated for more clear description.

The inventors of the present invention, to minimize the coffee ring phenomenon, to prevent the insulating layer forming composition flows through the conductive pattern, to develop a method for forming an insulating layer having a uniform thickness and shape on the conductive pattern formed substrate As a result, the present invention was completed.

The method of forming an insulating layer according to the present invention includes heating a substrate having a conductive pattern, sequentially forming a first pattern and a second pattern using an insulating composition on the heated substrate, and forming the first pattern and the first pattern. 2 hardening the pattern. In this case, the first pattern includes a groove portion so that adjacent patterns do not overlap, and the second pattern is formed in the groove portion of the first pattern.

In the present specification, the groove means an empty space in which the insulating composition is not applied in the first pattern. In addition, in the present invention, the first pattern may be formed in the groove portion and a plurality of dot shapes or line shapes that do not overlap each other.

Hereinafter, the method for forming an insulating layer of the present invention will be described in more detail.

First, a step of heating the substrate on which the conductive pattern is formed is performed. As described above, since the patterning process for forming the insulating layer is performed after heating the substrate on which the conductive pattern is formed, the insulating composition may prevent a shape flowing along the conductive pattern on the substrate, thereby forming a stable pattern.

At this time, the heating of the substrate is preferably heated to a temperature range of, for example, 40 ℃ to 80 ℃, 50 ℃ to 70 ℃ or 55 ℃ to 65 ℃. According to the researches of the present inventors, when the heating temperature of the substrate on which the conductive pattern is formed satisfies the numerical range, it is possible to minimize the coffee phenomenon and to form the insulating layer thickness uniformly.

Meanwhile, the conductive pattern formed on the substrate may be formed using materials generally used for forming a conductive pattern in the art, for example, a metal mesh, a metal-containing paste, or the like. It is not particularly limited.

Next, a first pattern and a second pattern are sequentially formed on the heated substrate using an insulating composition.

In this case, the method of forming the first pattern and the second pattern may be performed by, for example, a method of ejecting droplets of the insulating composition using inkjet printing, and the first pattern and the second pattern formed of the ejected droplets. The pattern may be dot or line shape. In particular, in the insulating layer forming method according to the present invention, it is more preferable that the first pattern and the second pattern have a dot shape in view of easier formation of a precise pattern at a desired position.

Meanwhile, in the present invention, the first pattern is formed to include a groove portion so that adjacent patterns do not overlap, and the second pattern is formed in the groove portion of the first pattern. That is, the first pattern may have a plurality of dot shapes or line shapes that do not overlap each other.

On the other hand, the first pattern may be formed so that each dot or line does not overlap each other, and only has an empty space, that is, a groove portion between the dots and the dots or between the lines and the lines, and the pitch, size, or line width is particularly limited. It doesn't happen. However, in consideration of the thickness of the insulating layer, the pitch of the first pattern may be, for example, about 200 μm to 400 μm, 250 μm to 380 μm, or about 280 μm to 350 μm. When the pitch of the first pattern satisfies the above range, an appropriate space for forming the second pattern is secured, and the thickness and shape of the entire insulating layer are good.

Next, the second pattern is formed in the groove portion of the first pattern. In this case, the second pattern may be configured in a plurality of dot shapes or line shapes, and the shape, size, or pitch thereof is not particularly limited. However, in consideration of the thickness and shape of the insulating layer, the pitch of the second pattern is preferably about 0.5 to 1 times the first pattern pitch. When the pitch of the second pattern satisfies the numerical range, the thickness of the insulating layer can be formed uniformly, and the shape of the insulating layer can be accurately formed. Here, as the pitch of the second pattern is smaller than the pitch of the first pattern, more insulating composition may be included in the groove portion.

Hereinafter, the shape, pitch, size, etc. of the first pattern and the second pattern will be described in more detail with reference to FIGS. 2A, 2B, 3A, and 3B.

2A and 2B illustrate an example in which the first pattern and the second pattern have a dot shape. When the first pattern and the second pattern have a dot shape, the pitch is the distance between the centers of the dot shapes adjacent to each other in the horizontal or vertical direction from the center of one dot shape, as shown in FIGS. 2A and 2B. Means (100, 200).

Meanwhile, when the first pattern and the second pattern have a dot shape, the size of the first pattern dot may be, for example, 0.8 to 1 times the first pattern pitch, and the size of the second pattern dot may be, for example. For example, the size of the first pattern dot may be 0.5 to 1 times. When the dot size of the first pattern and the second pattern satisfies the numerical range, when the pattern is formed into a dot shape, the dot size of the first pattern and the second pattern may be appropriately adjusted to form an insulating layer having a uniform thickness. There is an advantage. Here, the size of a dot means the long diameter 300 in each dot, as shown to FIG. 2A.

3A and 3B illustrate an example in which the first pattern and the second pattern have a line shape. When the first pattern and the second pattern have a line shape, the pitch is a distance between the line width centers of one line and the line width centers of adjacent lines as shown in FIGS. 3A and 3B. it means.

In addition, when the first pattern and the second pattern have a line shape, the width of the first pattern line may be, for example, 0.8 to 1 times the first pattern pitch, and the width of the second pattern line may be, for example. For example, the width of the first pattern line may be 0.5 to 1 times. When the width of the first pattern and the second pattern line satisfies the numerical range, when the pattern is formed into a line shape, the line widths of the first pattern and the second pattern may be appropriately adjusted to form an insulating layer having a uniform thickness. There is an advantage. Here, the width of a line means the line width 600 in each line, as shown to FIG. 3A.

According to the research of the present inventors, when forming the patterning of the insulating layer composition on the substrate in two steps as described above, the difference in the evaporation rate between the edge portion and the center of the formed insulating layer is reduced to prevent the occurrence of the coffee ring phenomenon It turns out that you can. In addition, when patterning is performed on the heated substrate as described above, it is possible to form a stable pattern by preventing the shape of the insulating composition for forming the insulating layer flowing through the conductive pattern on the substrate.

Through the above process, when the first pattern and the second pattern are formed on the substrate, the first pattern and the second pattern are cured.

Curing the first pattern and the second pattern may be performed using any method that is well known in the art, but for example, an oven or a hot plate may be used. In addition, the curing may be performed for 5 minutes to 90 minutes at a temperature in the range of 100 ℃ to 180 ℃, for example.

On the other hand, in the present invention, the insulating composition for forming the first pattern and the second pattern can be used without limitation as long as it is well known in the art, for example, novolak-type epoxy resin, boiling point is 170 ℃ or more It may contain a high boiling point solvent, a low boiling point solvent having a boiling point of 100 ° C. or higher and lower than 170 ° C. and a curing agent.

More specifically, the novolak-type epoxy resin is intended to impart insulating properties, for example, it may be a phenol novolak-type epoxy resin, cresol novolak-type epoxy resin or BPA- novolak-type epoxy resin, but is not limited thereto. It is not. In particular, in this invention, it is preferable that the said novolak-type epoxy resin is a phenol novolak-type epoxy resin. It is because the film | membrane characteristic of the insulating layer formed using the insulating composition containing the said phenol novolak-type epoxy resin is more excellent.

In this case, commercially available products that can be used as the novolac epoxy resin include, for example, Epikote 631, Epikote 678, Epikote 690 (hexion), EPPN-501H, or EPPN-502H (Nagase).

In addition, the solvent is to impart fairness when the patterning is performed by an inkjet process, and may be made of a high boiling point solvent and a low boiling point solvent.

At this time, the high boiling point solvent means that the boiling point is 170 ℃ or more, for example, ethylene glycol monobutyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether acetate, Ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether Dipropylene glycol monoethyl ether acetate, dipropylene glycol propyl ether acetate, dipropylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether (diethylene glycol monomethyl ether), diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol mono Hexyl ether (diethylene glycol monohexyl ether), triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, triethylene With glycol monopropyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monomethyl ether and tripropylene glycol monobutyl ether Done It can be used at least one selected from the group, but is not limited to this.

In addition, the low boiling point solvent means a solvent having a boiling point of 100 ° C. or more and less than 170 ° C., for example, diethylene glycol dimethylether, diethylene glycol diethylether, or methyl ethyl ketone ( methyl ethyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanon, ethyl lactate, methyl lactate (methyl lactate), propyl lactate, butyl lactate, propylene glycol methyl ether acetate, ethylene glycol monomethyl ether acetate, ethylene glycol Ethylene glycol ethyl ether acetate, propylene glycol monobutyl ether acetate, ethyl iso-buty ether, ethyl ethoxy propionate, methoxy propanol, butoxy propanol, 2-butoxy ethanol, butyl acetate , 1-butoxy-2-propanol, dimethyl ketone, methyl butyl ketone and methyl hexyl ketone selected from the group consisting of It may be more than, but is not limited thereto.

In particular, in the present invention, the weight ratio of the high boiling point solvent and the low boiling point solvent in the solvent may be 85 to 99: 1 to 15 or 87 to 95: 5 to 13. When the weight ratio of the high boiling point solvent and the low boiling point solvent satisfies the numerical range, there is an advantage that stable jetting is possible.

In addition, the total content of the high boiling point solvent and the low boiling point solvent in the insulating composition is 80 parts by weight to 570 parts by weight, 100 parts by weight to 450 parts by weight, or 150 parts by weight to 400 parts by weight based on 100 parts by weight of the phenol novolac-type epoxy resin. It may be part by weight. When the content of the solvent satisfies the numerical range, since the viscosity of the ink maintains an appropriate level, the jetting property is excellent, and drying after patterning is easy.

Next, the curing agent is for curing the insulating layer, examples of the curing agent for the epoxy resin, imidazole series curing agent; Amine based curing agents such as aliphatic, aromatic or modified aliphatic polyamines; Aromatic or alicyclic acid anhydride curing agents; Mercaptan-based curing agents; Or an isocyanate curing agent, but is not limited thereto.

In particular, it is preferable that the hardening | curing agent contained in the insulating composition used for the insulating layer forming method which concerns on this invention is an imidazole series hardening | curing agent. This is because the imidazole-based curing agent has a high storage stability of the ink and a curing reaction occurs quickly, and thus has an advantage of excellent insulation properties of the film.

More specifically, the imidazole curing agent is, for example, 2-methylimidazole, 2-undecylimidazole, 2-ethyl-4-methylimidazole ( 2-ethyl-4-methylimidazole), 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimida Sol (1-benzyl-2-methylimidazole), 1-benzyl-2-phenylimidazole, 1,2-dimethylimidazole, 1-sia 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 2,4-diamino -6- [2'-methylimidazolyl- (1 ')]-ethyl-s-triazine (2,4-diamino-6- [2'-methylimidazolyl- (1')]-ethyl-s-triazine ) 2-phenyl-4,5-dihydroxymethylimidazole (2-phenyl-4,5- dihydroxymethylimidazole) and 2-phenyl-4-methyl-5-hydroxymethylimidazole (2-phenyl-4-methyl-5-hydroxymethylimidazole), but may not be limited thereto.

In particular, in the present invention, the curing agent is 1-cyanoethyl-2-phenylimidazole (1-cyanoethyl-2-phenylimidazole, 2PZCN) or 2-ethyl-4-methylimidazole (2-ethyl-4 more preferred is -methylimidazole, 2E4MZ). This is because, when the curing agent is used, the storage stability of the ink is high and the curing reaction occurs quickly, so that the insulating property of the film is more excellent.

In particular, in the insulating layer forming method according to the invention, the insulating composition comprises 100 parts by weight of phenol novolak-type epoxy resin, 80 parts by weight to 570 parts by weight of solvent and 1 part by weight to 10 parts by weight of the curing agent, wherein It is preferable that the weight ratio of the high boiling point solvent and the low boiling point solvent in the solvent is 85 to 99: 1 to 15.

If necessary, the insulating composition used in the method for forming an insulating layer according to the present invention may further include a surfactant for improving the spreadability of the ink when performing the inkjet process, an adhesion promoter for improving the adhesion (adhesion promoter) And the like may be further included. In addition, additives such as surfactants or adhesion promoters are preferably added in an amount of 5 parts by weight or less based on the entire insulating composition.

As described above, the insulating layer formed by the insulating layer forming method according to the present invention prevents the ringing phenomenon to form an insulating layer having a uniform thickness, thereby stably forming a bridge electrode formed on the insulating layer, thereby improving electrical conductivity. There is an excellent effect.

In addition, the insulating layer formed by the method for forming an insulating layer according to the present invention has the advantage that it is possible to improve the productivity by forming a stable pattern at a desired position.

In addition, unlike the insulating layer formed by the conventional method, the insulating layer formed by the method for forming an insulating layer according to the present invention has a vertical cross section formed in a convex shape, thereby insulating the conductive pattern of the touch screen from the bridge electrode. It can be used very usefully as an insulating layer.

That is, the insulating layer according to the present invention formed by the above method is a convex shape in the vertical cross section, the thickness difference between the central portion and the edge portion of the vertical cross section, for example, 50nm to 150nm, 50nm to 130nm or 50nm to 100nm range Can be. When the thickness difference between the center portion and the edge portion of the insulation layer cross section satisfies the numerical range, it means that the thickness of the insulation layer is uniform. Therefore, when it is applied to the touch screen, the film strength is excellent and the coffee ring phenomenon occurs. This is because an excellent insulation effect can be obtained.

In this case, the thickness of the insulating layer may be, for example, 100 nm to 2 μm, 200 nm to 1500 nm, or 400 nm to 1200 nm, but is not limited thereto.

Next, the present invention is a substrate, a conductive pattern formed on the substrate, a bridge electrode formed on the conductive pattern and the insulating layer interposed between the conductive pattern and the bridge electrode, and insulates the conductive pattern and the bridge electrode It provides a touch screen that includes. At this time, the insulating layer is formed by the method for forming an insulating layer according to the present invention, characterized in that the vertical cross section of the insulating layer is convex.

In this case, the insulating layer for insulating the conductive pattern and the bridge electrode in the touch screen of the present invention, the thickness difference between the center and the edge portion of the vertical cross-section may be 50nm to 150nm, 50nm to 130nm or 50nm to 100nm range. In particular, in the present invention, the thickness difference between the center portion and the edge portion of the insulating layer is preferably in the range of 50nm to 100nm. This is because, when the thickness difference between the center portion and the edge portion of the insulating layer cross section satisfies the numerical range, it means that the thickness of the insulating layer is uniform, so that the role of the insulating layer can be fulfilled. That is, since the role of the insulating layer is to separate the conductive pattern and the bridge electrode in the x-axis direction, in order for the insulating layer to exhibit an insulating effect, the insulating layer should have excellent film strength. In one case, the film strength can be further improved. In addition, when the thickness of the insulating layer is not uniform, there is a problem that a coffee ring phenomenon is likely to occur, and thus may not exhibit an insulating effect. Because, the bridge electrode for connecting the conductive pattern in the y-axis direction is formed on the insulating layer, because when the coffee ring phenomenon as described above occurs, the boundary between the conductive pattern and the bridge electrode is broken.

On the other hand, the edge portion is about 20% area of the outer edge of each pattern of the insulating layer, the central portion means a portion excluding the edge portion of each pattern of the insulating layer.

In addition, the thickness of the insulating layer is preferably higher than the conductive pattern in the x-axis direction, for example, may be 100nm to 2㎛, 200nm to 1500nm or 400nm to 1200nm, but is not limited thereto. In particular, in the present invention, the thickness of the insulating layer is preferably 400nm to 1200nm. This is because when the thickness of the insulating layer satisfies the numerical range, it is possible to prevent the energization between the x-y-axis conductive patterns and to form a bridge electrode that connects the y-axis conductive patterns.

Example 1

(1) Preparation of insulating composition

26.2% by weight of Epikote 631 (manufactured by hexion), a phenol novolak type epoxy resin, 53.7% by weight of diethylene glycol monobutyl ether acetate, 14.4% by weight of diethylene glycol methyl butyl ether, and 3.9% by weight of methyl cellosolve acetate Thereafter, 0.3% by weight of KBM 503 as an adhesion promoter and 0.2% by weight of BYK 330 as a surfactant are added. Next, 1.3 wt% of 1-cyanoethyl-2-phenylimidazole was added as a curing agent and stirred for 2 hours to prepare an insulating composition.

(2) insulation layer pattern formation

In the state which heated the board | substrate to 60 degreeC, the said 1st pattern was patterned in the shape of a dot on the copper mesh board | substrate using the said insulating composition. At this time, the long diameter of the first pattern is 250㎛, the pitch of the first pattern is formed to be 300㎛, 1.2 times the first pattern long diameter. Next, before the insulating composition on which the first pattern was patterned was cured, the second pattern was patterned in a dot shape while the substrate was heated to 60 ° C. The long diameter and the pitch of the second pattern were the same as the first pattern. The oven was then cured at 150 ° C. for 15 minutes using an oven.

Comparative Example 1

After preparing the insulating composition in the same manner as in Example 1, patterning was performed at one time using the insulating composition at room temperature. The oven was then cured at 150 ° C. for 15 minutes using an oven.

Comparative Example 2

After the insulating composition was prepared in the same manner as in Example 1, patterning was performed at one time using the insulating composition while the substrate was heated to 85 ° C. The oven was then cured at 150 ° C. for 15 minutes using an oven.

Comparative Example 3

In the state which heated the board | substrate to 60 degreeC, the said 1st pattern was patterned in the shape of a dot on the copper mesh board | substrate using the said insulating composition. At this time, the long diameter of the first pattern is 170㎛, the pitch of the first pattern is formed to be 255㎛, 1.5 times the first pattern long diameter. Next, before the insulating composition on which the first pattern was patterned was cured, the second pattern was patterned in a dot shape while the substrate was heated to 60 ° C. The long diameter and the pitch of the second pattern were the same as the first pattern. The oven was then cured at 150 ° C. for 15 minutes using an oven.

Experimental Example

Measurement of cross section shape of insulation layer

Horizontal cross-section and vertical cross-sectional shapes of the insulating layers formed according to Example 1 and Comparative Examples 1 to 3 were measured using a three-dimensional shape measuring instrument. The measurement results are as shown in Figs. 4A to 7B.

4A, 5A, 6A, and 7A show horizontal cross-sectional shapes of the insulating layer, and FIGS. 4B 5B, 6B and 7B show vertical cross-sectional shapes of the insulating layer. 4A, 5A, 6A, and 7A, the right reference bar indicates the height of the insulating layer, wherein the red portion is higher and the blue portion is lower.

Referring to FIG. 4A, which shows a horizontal cross-sectional shape of the insulating layer according to Example 1, the overall green color is shown evenly, and referring to FIG. 4B, which shows a vertical cross-sectional shape of the insulating layer according to Example 1, a convex shape is shown. It can be seen that.

On the other hand, referring to FIGS. 5A, 6A, and 7A which show horizontal cross-sectional shapes of the insulating layers according to Comparative Examples 1 to 3, the edges of the insulating layers are shown in red, and the central portions are blue. It can be seen that the height of the edge portion is higher than that of the center portion. 5B, 4B and 7A showing the vertical cross-sectional shapes of the insulating layers according to Comparative Examples 1 to 3, it can be seen that the concave shape is shown.

That is, in the insulating layer according to Example 1 in which the insulating layer was formed by the insulating layer forming method according to the present invention, the coffee layer did not occur, the thickness of the insulating layer was uniformly formed, and the insulating composition was stably patterned. Formed.

However, in the case of the insulating layer according to Comparative Example 1 in which patterning was performed at one time, a coffee ring shape in which the insulating layer thickness was not uniform occurred. In addition, in the case of the insulating layer according to Comparative Example 2 in which the substrate heating temperature is also higher than Example 1 at the same time as the patterning, drying is accelerated and the periphery height of the pattern is rapidly increased, which is more than that of Comparative Example 1. Severe coffee ring phenomenon occurred. In addition, in the case of the insulating layer according to Comparative Example 3, it can be seen that more severe coffeering occurs in all sections.

Measurement of flow of insulating composition during patterning

10 seconds after forming an insulating layer on a metal mesh substrate at room temperature using an inkjet head, the insulating composition prepared according to Example 1 and Comparative Examples 1 to 3 was measured at the front of the substrate using a CCD camera (sony). It is.

In the case of Example 1 and Comparative Examples 2 and 3, the shape in which the insulating composition flows in the copper mesh substrate was not observed. However, in the comparative example 1, as shown in FIG. 8, drying of the ink was delayed and the phenomenon in which the insulating composition flows through the mesh in the copper mesh substrate was observed.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and variations can be made without departing from the technical spirit of the present invention described in the claims. It will be obvious to those who have ordinary knowledge of.

[Description of the code]

20: conductive pattern

30: insulation layer

40: bridge electrode

100: pitch of the first pattern when the pattern is dot-shaped

200: pitch of the second pattern when the pattern is dot-shaped

300: long diameter of dot shape

400: pitch of the first pattern when the pattern is a line shape

500: pitch of the second pattern when the pattern is line-shaped

600: width of the line shape

Claims (21)

Insulating layer forming method to insulate the conductive electrode of the touch screen and the bridge electrode, Heating the substrate on which the conductive pattern is formed; Sequentially forming a first pattern and a second pattern on the heated substrate using an insulating composition; And Hardening the first pattern and the second pattern; The first pattern includes a groove portion so that adjacent patterns do not overlap, And the second pattern is formed in the groove portion of the first pattern. The method of claim 1, The heating step is an insulating layer forming method, characterized in that performed at 40 ℃ to 80 ℃. The method of claim 1, The pitch of the first pattern is an insulating layer forming method, characterized in that the range of 200㎛ to 400㎛. The method of claim 1, The pitch of the second pattern is an insulating layer forming method, characterized in that 0.5 to 1 times the first pattern pitch. The method of claim 1, The forming of the first pattern and the second pattern is performed by a method of ejecting droplets of the insulating composition using inkjet printing. The method of claim 5, The first pattern and the second pattern formed of the discharged droplets have a dot shape or a line shape. The method of claim 6, When the first pattern has a dot shape, the size of the first pattern dot is 0.8 to 1 times the first pattern pitch. The method of claim 7, wherein When the second pattern has a dot shape, the size of the second pattern dot is 0.5 to 1 times the size of the first pattern dot. The method of claim 6, When the first pattern has a line shape, the width of the line is 0.8 to 1 times the pitch of the first pattern. The method of claim 9, When the second pattern has a line shape, the width of the second pattern line is 0.5 to 1 times the width of the first pattern line. The method of claim 1, The conductive pattern is formed of a metal mesh (mesh). The method of claim 1, The insulating composition is an insulating layer forming method comprising a novolak-type epoxy resin, a high boiling point solvent having a boiling point of 170 ℃ or more, a low boiling point solvent having a boiling point of 100 ℃ or more and less than 170 ℃. The method of claim 12, The insulating composition is 100 parts by weight of a novolak-type epoxy resin; 80 parts by weight to 570 parts by weight of a solvent; And 1 to 10 parts by weight of a curing agent, An insulating layer forming method wherein the weight ratio of the high boiling point solvent and the low boiling point solvent in the solvent is 85 to 99: 1 to 15. The method of claim 12, The novolak-type epoxy resin is a phenol novolak-type epoxy resin, cresol novolak-type epoxy resin or BPA- novolak-type epoxy resin insulating layer forming method. The method of claim 12, The curing agent is an insulating layer forming method of the imidazole series curing agent. It is formed by the insulating layer forming method according to any one of claims 1 to 15, An insulating layer, wherein the vertical cross section is convex. The method of claim 16, The insulating layer is an insulating layer, characterized in that the thickness difference of the central portion and the edge portion of the vertical cross-section ranges from 50nm to 150nm. The method of claim 16, The insulating layer has a thickness of 100nm to 2㎛. Board; A conductive pattern formed on the substrate; A bridge electrode formed on the conductive pattern; And In the touch screen interposed between the conductive pattern and the bridge electrode, the touch screen including an insulating layer for insulating the conductive pattern and the bridge electrode, The insulating layer is formed by the insulating layer forming method according to any one of claims 1 to 15, And a vertical cross section of the insulating layer is convex. The method of claim 19, The thickness difference between the center portion and the edge portion of the vertical cross-section of the insulating layer is 50nm to 150nm range. The method of claim 19, The thickness of the insulating layer is 100nm to 2㎛ touch screen.

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