JP2016200633A - Patterning method of both surfaces of glass substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and reliably form the same pattern on both surfaces of a glass substrate by a photolithographic process.SOLUTION: A patterning method of both surfaces of a glass substrate is provided for forming the same pattern on both surfaces of a glass substrate 1 by a photolithographic process. After transparent conductive oxide layers 5, 6 and resist layers 4, 7 are successively formed on both surfaces 1a, 1b of a glass substrate 1, the resist layers 4, 7 on one surface 1a side and the other surface 1b side of the glass substrate 1, respectively, are simultaneously exposed by irradiating the glass substrate with ultraviolet rays 3 through a mask 2 on only the one surface 1a side of the glass substrate 1.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a manufacturing technique for forming the same pattern on both surfaces of a glass substrate.

  Various electronic devices such as a liquid crystal display and a touch panel incorporate a glass substrate on which a predetermined pattern such as a transparent electrode is formed on both sides. As a method of patterning on a glass substrate, a photolithography method is often used in consideration of pattern accuracy and mass productivity.

  And depending on an electronic device, it may be necessary to form the same pattern (a plane symmetrical pattern) on both surfaces of a glass substrate.

  As a method of forming the same pattern on both surfaces of the glass substrate by photolithography, for example, a method described in the column of the prior art in Patent Document 1 can be cited. That is, this document discloses a method of separately performing patterning of the first surface and patterning of the second surface of the glass substrate using a photolithography method.

  In the above method, first, a thin film (one is a metal thin film and the other is a transparent conductive film) is formed on both surfaces of a glass substrate, and a resist is applied on the thin film on the first surface side of the glass substrate. Next, a mask is overlaid on the resist and exposed. Thereafter, the exposed photosensitive portion of the resist is removed with a developer. And after apply | coating a protective film to the thin film of the 2nd surface side of a glass substrate, the thin film exposed from the removed photosensitive part in the 1st surface side of a glass substrate is removed by an etching. In this manner, a predetermined pattern made of a thin film is formed on the first surface of the glass substrate. And also about the thin film of the 2nd surface of a glass substrate, the process similar to a 1st surface is repeated and the predetermined pattern which consists of a thin film is formed.

Japanese Examined Patent Publication No. 6-36467

  However, in the case of the patterning method disclosed in Patent Document 1, the position of the mask superimposed on the second surface of the glass substrate may be shifted from the position of the mask superimposed on the first surface of the glass substrate. In this case, there is a problem that the positions of the patterns formed on both surfaces of the glass substrate are shifted.

  On the other hand, in order to eliminate misalignment of the mask, time and skill are required for the mask alignment operation. Therefore, it is not possible to easily eliminate the mask misalignment on both surfaces of the glass substrate, and the above-described problem of pattern defects may occur.

  In addition, Patent Document 1 discloses that a thin film formed on both surfaces of a glass substrate is simultaneously patterned by laser light instead of photolithography, but in consideration of pattern accuracy and mass productivity. It is considered difficult to put into practical use. Therefore, it is desired to solve the above problem by photolithography.

  In view of the above circumstances, an object of the present invention is to easily and surely form the same pattern on both surfaces of a glass substrate by a phytolithography method.

  In order to solve the above-mentioned problems, the present invention is a patterning method on both sides of a glass substrate that forms the same pattern on both sides of the glass substrate by photolithography, and (1) patterned on both sides of the glass substrate. A step of forming a transparent conductive oxide layer, (2) a step of forming a resist layer on both surfaces of the glass substrate, and (3) light that can be transmitted through the glass substrate, the transparent conductive oxide layer, and the resist layer. And (1) to (3) in the order of irradiating through a mask only from one side of the glass substrate and simultaneously exposing the resist layers on both sides of the glass substrate.

  According to such a configuration, the resist layers on both sides of the glass substrate can be exposed simultaneously with the mask disposed only on one side of the glass substrate. At this time, since the resist layers on both sides of the glass substrate are exposed using a mask arranged on one side of the glass substrate, the same photosensitive portion is formed on each resist layer. Therefore, if various processes such as development and etching are performed based on the photosensitive portion thus formed, the same pattern made of the transparent conductive oxide can be easily and reliably formed on both surfaces of the glass substrate.

  In the above configuration, after the step of exposing the resist layer, (1) a step of removing a part of the resist layer on both surfaces of the glass substrate with a developer, and (2) a resist layer removing portion on both surfaces of the glass substrate. A step of removing the transparent conductive oxide layer exposed from the substrate with an etching solution, and (3) a step of removing the remainder of the resist layer on both surfaces of the glass substrate with the resist stripping solution in the order of (1) to (3). Furthermore, it is preferable to include.

  If it does in this way, each process of image development, an etching, and resist peeling can be advanced simultaneously with respect to both surfaces of a glass substrate. Therefore, compared with the case where development, etching, and resist removal are performed on one surface of the glass substrate, and then development, etching, and resist removal are performed on the other surface of the glass substrate. Therefore, the working time can be greatly reduced.

  In this case, the glass substrate is preferably immersed in each of the developer, the etching solution, and the resist stripping solution.

  If it does in this way, it will become easy to make each liquid of a developing solution, an etching liquid, and a resist stripping solution contact simultaneously on both surfaces of a glass substrate.

  In the above structure, in at least one of the step of forming the transparent conductive oxide layer, the step of forming the resist layer, and the step of exposing the resist layer, the glass substrate is placed on the supporting glass, The substrate may be processed.

  In this way, since the glass substrate is firmly supported by the supporting glass, handling of the glass substrate is facilitated even when the glass substrate is thin.

  In this case, the step of forming the resist layer includes (1) a step of placing the glass substrate on the supporting glass with the first surface of the glass substrate facing up, and (2) placing the glass substrate on the supporting glass. A step of applying a resist on the first surface in a state; (3) a step of heating the resist on the first surface while the glass substrate is placed on the supporting glass; and (4) a glass substrate and supporting glass. And (5) a step of placing the glass substrate on the supporting glass with the second surface of the glass substrate facing up, and (6) a second state in which the glass substrate is placed on the supporting glass. (7) A step of applying a resist on the surface, (7) a step of separating the glass substrate and the supporting glass, and (8) a step of heating the resist on the second surface in the order of (1) to (8). It is preferable to include.

  Here, when the resist is applied to the glass substrate and then heated (prebaked), the resist adheres to the glass substrate and a strong resist layer is formed. Therefore, prebaking is usually performed. Moreover, when a glass substrate is thin, it is preferable to handle a glass substrate in the state which mounted the glass substrate on support glass at each process. However, when the glass substrate with the resist coated on the second surface is heated (prebaked) in a state where the first surface of the glass substrate on which the resist layer is formed is in contact with the supporting glass, the first surface and the supporting surface are supported. There is a possibility that the glass adheres to the resist layer and cannot be separated. Therefore, as in the above configuration, it is preferable to separate the glass substrate and the supporting glass and heat the resist on the second surface during the second pre-bake (step (8) above). If it does in this way, the malfunction that a glass substrate adheres to support glass can be avoided.

  In this case, the step of heating the resist on the second surface is preferably performed with the glass substrate standing.

  If it does in this way, it can heat in the state which suppressed the range which the 1st surface and 2nd surface of a glass substrate contact with another member to the minimum. That is, it is possible to easily prevent the glass substrate from adhering to another member via the resist layer on the first surface or the second surface.

  As described above, according to the present invention, the same pattern can be easily and reliably formed on both surfaces of a glass substrate by phytolithography.

It is a figure which shows the flow of the patterning method of both surfaces of the glass substrate which concerns on the 1st Embodiment of this invention. It is a figure which shows the exposure process included in the patterning method of 1st Embodiment. It is a figure which shows the image development process included in the patterning method of 1st Embodiment. It is a figure which shows the etching process included in the patterning method of 1st Embodiment. It is a figure which shows the resist layer peeling process included in the patterning method of 1st Embodiment. It is a figure which shows the flow of the resist layer formation process included in the patterning method of both surfaces of the glass substrate which concerns on the 2nd Embodiment of this invention. It is a figure which shows the 1st prebaking included in the patterning method of 2nd Embodiment. It is a figure which shows the 2nd prebaking included in the patterning method of 2nd Embodiment.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

<First Embodiment>
As shown in FIG. 1, the method for patterning both surfaces of a glass substrate according to the first embodiment of the present invention includes an electrode layer forming step S1 for forming electrode layers to be patterned on both surfaces of the glass substrate, and both surfaces of the glass substrate. A resist layer forming step S2 for forming a resist layer, an exposure step S3 for exposing the resist layers on both sides of the glass substrate, a developing step S4 for dissolving and removing the photosensitive portions of the resist layers on both sides of the glass substrate with a developer, and glass Etching step S5, in which the electrode layer exposed from the photosensitive part (removed part) removed on both sides of the substrate is removed with an etching solution, and the non-photosensitive part (remaining part) of the resist layer on both sides of the glass substrate is removed with a resist stripping solution. The resist layer peeling step S6 to be performed and the cleaning step S7 for cleaning the glass substrate are included in this order. Hereinafter, each process is demonstrated in order.

(1) Electrode layer formation process In electrode layer formation process S1, after forming the transparent conductive oxide layer as an electrode layer in the 1st surface of a glass substrate, the transparent conductivity as an electrode layer in the 2nd surface of a glass substrate. An oxide layer is formed. In addition, you may form a transparent conductive oxide layer simultaneously in the 1st surface and 2nd surface of a glass substrate.

  As a method for forming the transparent conductive oxide layer, sputtering, vapor deposition, coating, spin coating, spraying, or the like is used. The transparent conductive oxide layer is made of, for example, ITO or AZO.

  Here, the glass substrate preferably has a thickness of 0.04 to 3 mm. Moreover, in this embodiment, in order to raise the transmittance | permeability of the ultraviolet-ray used by exposure process S3 mentioned later, content of the iron component in a glass composition is restrict | limited in a glass substrate. For example, the iron component in the glass composition is preferably 1000 ppm or less, more preferably 500 ppm or less, and most preferably 400 ppm or less.

(2) Resist layer forming step In the resist layer forming step S2, a resist is applied to the first surface with the first surface of the glass substrate facing up, and then the resist on the first surface is heated ( First pre-bake). Next, the glass substrate is turned over, and the resist on the second surface is applied with the second surface of the glass substrate facing up, and then the resist on the second surface is heated (second prebaking). . By such pre-baking, the resist adheres to the surface of the glass substrate, and a strong resist layer is formed. The heating temperature at the time of prebaking is, for example, 70 to 150 ° C.

  Examples of the resist include a liquid photoresist manufactured by Tokyo Ohka Kogyo Co., Ltd. The resist applied to the first surface and the second surface may be different, but in this embodiment, the resist is the same. Note that the resist is applied by, for example, spin coating. As the resist, a dry film resist may be used instead of the coating type.

(3) Exposure process In exposure process S3, the ultraviolet-ray which can permeate | transmit a glass substrate, a transparent conductive oxide layer, and a resist layer is used. Here, in this embodiment, if the transmittance of ultraviolet rays of the glass substrate is 20% or more, the ultraviolet rays are “light that can be transmitted through the glass substrate”. The transmittance is a value of the wavelength of ultraviolet rays used in the exposure step S3. The ultraviolet transmittance of the glass substrate is preferably 30% or more, more preferably 50% or more, and most preferably 75% or more. On the other hand, in this embodiment, if the ultraviolet transmittance of the resist layer and the transparent conductive oxide layer is 10% or more, the ultraviolet light is “light that can be transmitted through the resist layer and the transparent conductive oxide layer”. The transmittance is a value of the wavelength of ultraviolet rays used in the exposure step S3. The ultraviolet transmittance of the resist layer and the transparent conductive oxide layer is preferably 20% or more.

  Specifically, in the exposure step S3, the mask 2 is disposed above the first surface 1a of the glass substrate 1 as shown in FIG. In the mask 2, a blocking layer 2 a that blocks the ultraviolet light 3 is formed on a glass substrate 2 b that transmits the ultraviolet light 3 in a predetermined pattern. The ultraviolet ray 3 is irradiated from the first surface 1 a side of the glass substrate 1 through the mask 2 in a state where the blocking layer 2 a side of the mask 2 is opposed to the first surface 1 a of the glass substrate 1. Part of the irradiated ultraviolet rays 3 first passes through the portion of the mask 2 where the blocking layer 2a is not formed, and is irradiated onto the resist layer 4 formed on the first surface 1a of the glass substrate 1. Thereafter, a part of the irradiated ultraviolet rays 3 sequentially passes through the resist layer 4 and the transparent conductive oxide layer 5 on the first surface 1 a side and reaches the glass substrate 1. Further, a part of the irradiated ultraviolet rays 3 sequentially passes through the glass substrate 1 and the transparent conductive oxide layer 6 on the second surface 1b side, and reaches the resist layer 7 on the second surface 1b side. As a result, the resist layer 4 on the first surface 1a side and the resist layer 7 on the second surface 1b side are exposed simultaneously, and a photosensitive portion (cross-hatched in the figure) is formed on a part of each of the resist layers 4 and 7. 4a and 7a are formed. Since the photosensitive portions 4a and 7a are simultaneously formed by the ultraviolet rays 3 transmitted through the mask 2 disposed above the first surface 1a, they have the same pattern shape with substantially no displacement. Therefore, if the transparent conductive oxide layers 5 and 6 are processed based on the photosensitive portions 4a and 7a as described later, the same electrode pattern can be easily and reliably formed on both surfaces of the glass substrate 1. .

Here, an example of preferable ultraviolet irradiation conditions is shown below.
UV wavelength: i-line (wavelength 365 nm), h-line (wavelength 405 nm) or g-line (wavelength 436 nm)
-UV irradiation energy: 200-400mJ
-UV irradiation time: 6-12 seconds

  Although the glass substrate 1 and the mask 2 may be in contact with each other as in the illustrated example, it is preferable that the glass substrate 1 and the mask 2 are not in contact with each other. In this case, a spacer is provided between the glass substrate 1 and the mask 2 outside the range of the region to be exposed (for example, the peripheral edge of the glass substrate 1) so that the distance between the glass substrate 1 and the mask 2 is constant. It is preferable to arrange. Further, it is preferable to arrange an ultraviolet absorbing plate (not shown) below the resist layer 7 so that the ultraviolet light 3 transmitted through the resist layer 7 on the second surface 1b side is reflected and does not form return light.

(4) Development Step In the development step S4, as shown in FIG. 3, the glass substrate 1 is immersed in the developer 8, and the photosensitive portion 4a (see FIG. 2) of the resist layer 4 on the first surface 1a is The photosensitive portion 7a (see FIG. 2) of the resist layer 7 on the second surface 1b is simultaneously dissolved and removed. As a result, of the resist layers 4 and 7, only the non-exposed portions 4b and 7b that are not exposed remain. Examples of the developer 8 include an aqueous tetramethylammonium hydroxide solution and an aqueous potassium hydroxide solution.

(5) Etching Step In the etching step S5, first, the glass substrate is heated (post-bake) before the glass substrate is immersed in the etching solution. Thereby, a glass substrate and a resist layer are stuck, and it can suppress that an etching liquid penetrates between a glass substrate and a resist layer. The heating temperature during post-baking is, for example, 100 to 200 ° C.

  Next, as shown in FIG. 4, the glass substrate 1 is immersed in an etching solution 9, and a resist is selected from the transparent conductive oxide layer 5 on the first surface 1a and the transparent conductive oxide layer 6 on the second surface 1b. The exposed portions of the layers 4 and 7 that are not covered with the non-photosensitive portions 4b and 7b (the portions corresponding to the photosensitive portions 4a and 7a in FIG. 2) are dissolved and removed.

  Examples of the etching solution include a hydrofluoric acid aqueous solution, a nitric acid aqueous solution, a hydrochloric acid aqueous solution, a ferric chloride aqueous solution, an oxalic acid aqueous solution, and a mixed solution thereof. As an etching method, in addition to the method of immersing in an etching solution, etching is performed by partially applying the etching solution with a brush, brush, roller, spray, or the like, or a fluorine-containing compound (for example, carbon tetrafluoride). Or a method of etching (dry etching) in plasma.

(6) Resist layer peeling process In resist layer peeling process S6, as shown in FIG. 5, the glass substrate 1 is immersed in the resist peeling liquid 10, and the non-photosensitive part 4b (FIG. 4) of the resist layer 4 of the 1st surface 1a. And the non-photosensitive portion 7b (see FIG. 4) of the resist layer 7 on the second surface are simultaneously removed to expose the patterned transparent conductive oxide layers 5 and 6.

  Examples of the resist stripping solution include an aqueous potassium hydroxide solution.

(7) Cleaning Step Finally, in the cleaning step S7, the glass substrate is cleaned to complete a glass substrate having the same electrode pattern made of a transparent conductive oxide formed on both sides.

  A cleaning process for cleaning the glass substrate may be added after the development process S4 and the etching process S5.

<Second Embodiment>
The patterning method according to the second embodiment of the present invention is different from the patterning method according to the first embodiment in that the glass substrate is placed on a supporting glass in the resist layer forming step S2 and the exposure step S3. There is a place to process. This is particularly effective when the glass substrate is thin (for example, the thickness is 500 μm or less). In addition, in FIGS. 6-8 mentioned later, illustration of the transparent conductive oxide layer formed in both surfaces of the glass substrate is abbreviate | omitted.

  Specifically, as shown in FIG. 6, in the resist layer forming step S <b> 2, first, the first surface 1 a is placed in a state where the glass substrate 1 with the first surface 1 a is placed on the support glass 11. A resist layer 4 is formed on the substrate (S21). In this state, the resist layer 4 on the first surface 1a is heated to perform first prebake (S22). After the first pre-bake, the glass substrate 1 and the support glass 11 are separated (S23). The separated glass substrate 1 is inverted, and the glass substrate 1 with the second surface 1b facing up is placed again on the support glass 11 (S24). In this state, the resist layer 7 is formed on the second surface 1b (S25). Thereafter, the glass substrate 1 and the supporting glass 11 are separated again (S26). The resist layer 7 on the second surface 1b of the separated glass substrate 1 is heated and second prebaking is performed (S27). If it does in this way, the glass substrate 1 and the support glass 11 will be isolate | separated at the time of the 2nd prebaking which will be in the state by which the resist layer was formed in both surfaces of the glass substrate 1. FIG. Therefore, it is possible to avoid a situation in which the glass substrate 1 and the support glass 11 are bonded to each other by the resist layers 4 and 7 along with the heating during the second pre-bake.

  Here, the surface roughness Ra of the mating surface of the glass substrate (the surface on the side in contact with the support glass) and the mating surface of the support glass (the surface on the side in contact with the glass substrate) is 2.0 nm or less, respectively. Yes. In this embodiment, the mating surface of the glass substrate is the surface of the transparent conductive oxide layer formed on the second surface and the surface of the resist layer formed on the first surface, and the mating surface of the supporting glass is the supporting surface. It becomes the surface (upper surface) of the glass. The value of Ra is preferably 1.0 nm or less, more preferably 0.5 nm or less, and most preferably 0.2 nm or less. As the value of Ra is decreased, the laminated glass substrate and the supporting glass can be firmly adhered to each other.

  Further, the thickness of the supporting glass is preferably larger than the thickness of the glass substrate. Specifically, the thickness of the support glass is, for example, 0.4 to 2.0 mm. Furthermore, it is preferable that the area of the mating surface of the supporting glass is larger than the area of the mating surface of the glass substrate. In addition, the area of the mating surface of the support glass may be the same as the area of the mating surface of the glass substrate, or may be smaller than the area of the mating surface of the glass substrate.

  In the present embodiment, the first pre-bake and the second pre-bake are performed as follows. That is, as shown in FIG. 7, in the first pre-bake, the glass substrate 1 placed on the support glass 11 is heated by the hot plate 12. On the other hand, as shown in FIG. 8, in the second pre-bake, a plurality of glass substrates 1 separated from the support glass 11 are accommodated while standing in a basket 13 with an interval between them, and in a clean oven 14. Heating. Although not shown, the basket 13 has a plurality of holding grooves that hold both sides and lower sides of the glass substrate 1. Each glass substrate 1 is held in a state in which both sides and lower sides are fitted in holding grooves. Note that the lower side of the glass substrate 1 may be held by a plane, and only both sides may be held by holding grooves.

  In the exposure step S3 after the second pre-bake, the glass substrate with the first surface (or the second surface) is placed on the support glass, as in the resist layer forming step S2. In this state, a mask is disposed above the first surface (or the second surface) and exposure is performed. After the exposure, the glass substrate and the supporting glass are separated.

  After the exposure step S3, the steps of the development step S4, the etching step S5, the resist layer peeling step S6, and the cleaning step S7 are performed on the glass substrate separated from the supporting glass as described in the first embodiment. Run. That is, the glass substrate separated from the supporting glass is sequentially immersed in a developer, an etching solution, and a resist stripping solution to produce a glass substrate on which the same electrode pattern made of a transparent conductive oxide is formed on both sides.

  In addition, this invention is not limited to said embodiment, It can implement with a various form.

  In the above-described embodiment (second embodiment), the case where processing is performed in a state where the glass substrate is placed on the supporting glass in the resist layer forming step S2 and the exposure step S3 has been described. However, in the electrode layer forming step S1 The treatment may be performed in a state where the glass substrate is placed on the supporting glass. That is, the transparent conductive oxide layer is formed on the first surface in a state where the glass substrate having the first surface is placed on the support glass. Thereafter, the glass substrate and the supporting glass are separated, and the glass substrate with the second surface facing up is placed again on the supporting glass, and in this state, a transparent conductive oxide layer is formed on the second surface. .

  In the above-described embodiment (second embodiment), the case where a plurality of glass substrates are stood in a basket and batch-processed when the second pre-bake is heated has been described. When heating or immersing in each solution of developer, etching solution and resist stripping solution, a plurality of glass substrates may be stood in a basket and batch-processed.

  Further, in the above embodiment, the case where a positive type resist in which the exposed portion is removed by the developer is used as the resist, but a negative type resist in which the unexposed portion is removed by the developer. May be used.

DESCRIPTION OF SYMBOLS 1 Glass substrate 2 Mask 3 Ultraviolet rays 4 and 7 Resist layers 5 and 6 Transparent conductive oxide layer 8 Developer 9 Etching solution 10 Resist stripping solution 11 Support glass 12 Hot plate 13 Basket 14 Clean oven

Claims (6)

A patterning method on both sides of a glass substrate that forms the same pattern on both sides of the glass substrate by photolithography,
Forming a transparent conductive oxide layer to be patterned on both surfaces of the glass substrate;
Forming a resist layer on both sides of the glass substrate;
A step of irradiating light that can pass through the glass substrate, the transparent conductive oxide layer, and the resist layer from only one side of the glass substrate through a mask, and simultaneously exposing the resist layers on both sides of the glass substrate. In this order, and a patterning method for both surfaces of the glass substrate. After the step of exposing the resist layer,
Removing part of the resist layer on both sides of the glass substrate with a developer;
Removing the transparent conductive oxide layer exposed from the removed portion of the resist layer on both surfaces of the glass substrate with an etching solution;
The method for patterning both surfaces of a glass substrate according to claim 1, further comprising a step of removing the remainder of the resist layer on both surfaces of the glass substrate with a resist stripping solution in this order.   The method for patterning both surfaces of a glass substrate according to claim 2, wherein the glass substrate is immersed in each of the developer, the etching solution, and the resist stripping solution. In at least one of the step of forming the transparent conductive oxide layer, the step of forming the resist layer, and the step of exposing the resist layer,
The said glass substrate is processed in the state which mounted the said glass substrate in support glass, The patterning method of the glass substrate both sides of any one of Claims 1-3 characterized by the above-mentioned. Forming the resist layer comprises:
Placing the glass substrate on the support glass with the first surface of the glass substrate facing up;
Applying the resist on the first surface in a state where the glass substrate is placed on the supporting glass;
Heating the resist on the first surface in a state where the glass substrate is placed on the supporting glass;
Separating the glass substrate and the supporting glass;
Placing the glass substrate on the support glass with the second surface of the glass substrate facing up;
Applying the resist on the second surface in a state where the glass substrate is placed on the supporting glass;
Separating the glass substrate and the supporting glass;
The method of patterning both surfaces of the glass substrate according to claim 4, further comprising the step of heating the resist on the second surface in this order.   6. The method for patterning both surfaces of a glass substrate according to claim 5, wherein the step of heating the resist on the second surface is performed in a state where the glass substrate is erected.

Images