WO2014181790A1

WO2014181790A1 - Glass film laminate

Info

Publication number: WO2014181790A1
Application number: PCT/JP2014/062230
Authority: WO
Inventors: 保弘松本; 隆雄岡
Original assignee: 日本電気硝子株式会社
Priority date: 2013-05-07
Filing date: 2014-05-07
Publication date: 2014-11-13
Also published as: JP6237623B2; JPWO2014181790A1; KR102156555B1; TWI594881B; TW201509649A; KR20160005000A; CN105143136B; CN105143136A

Abstract

A glass film laminate (1) produced by overlaying a glass film (3) that has a thickness of 200 μm or less and has flexibility on a support glass (2) that supports the glass film (3), wherein the surface roughness (Ra) of each of a contact surface (3a) of the glass film (3) and a contact surface (2a) of the support glass (2), which are surfaces that are to be contacted with each other, is adjusted to 2.0 nm or less and the contact surfaces (3a, 2a) are surface-contacted with each other. In the glass film laminate (1), a protrusion (2b) is formed on the contact surface (2a) of the support glass (2), and the protruded size (H) which is the height of the protrusion (2b) above the contact surface (2a) is adjusted to 0.3 to 5 μm.

Description

Glass film laminate

The present invention relates to a glass film laminate in which a flexible glass film having a thickness of 200 μm or less and a supporting glass that supports the glass film are overlapped.

As is well known, the liquid crystal panel includes two glass substrates: a TFT substrate on which a thin film transistor and a transparent electrode are patterned, and a color filter substrate on which BM, RGB, and photo spacers are patterned. Both substrates are bonded to each other with a sealing material applied along these peripheral portions, and a liquid crystal material is sealed in a region surrounded by the sealing material between the substrates.

Here, the cell gap, which is the distance between the substrates, is required to be maintained uniformly with a predetermined dimension. However, when bubbles or foreign substances are mixed in the substrate, protrusions bulging in a convex shape are formed on the surface of the substrate, and the cell gap is locally uneven. An allowable value of the protrusion dimension of the protrusion is generally less than 0.3 μm, and if it exceeds this, display unevenness such as a spot or a black spot occurs in the image when the liquid crystal panel is turned on. In addition, when a foreign substance such as glass powder adheres to the surface of the glass to form a protrusion, it becomes difficult to form a circuit on the surface of the glass substrate, resulting in a failure. Therefore, a defective substrate on which a protrusion exceeding the allowable value is formed cannot be used as a glass substrate for a product.

Therefore, it has been studied to use this defective substrate as a supporting glass for a glass film laminate, not as a glass substrate for products. The glass film laminate is formed of a mating surface, which is a surface on the side in contact with each other, of each of the flexible glass film having a reduced thickness (for example, a plate thickness of 200 μm) and the supporting glass that supports the glass film. The surface roughness Ra is set to 2.0 nm or less, and both the mating surfaces are brought into surface contact with each other so that the glass film and the supporting glass are superposed (see Patent Document 1).

According to this glass film laminate, by overlapping with the supporting glass, the pliable property of the glass film is temporarily eliminated, and both the glasses are appropriately adhered and behave as an integral one. For this reason, the handling of the glass film in the manufacturing process of a plate glass product becomes very simple. Furthermore, it is not necessary to use a binder such as an adhesive to bring the two glasses into close contact with each other, and the glass film and the supporting glass can be easily peeled at a desired timing.

JP 2011-183792 A

Here, the following is mentioned as one of the aspects which manufacture a plate glass product using the glass film laminated body which used the bad board | substrate as support glass. That is, in the production of a liquid crystal panel, two glass film laminates using a defective glass substrate having protrusions as a supporting glass were prepared, one of which was flown into the TFT process and the other into the color filter process. Circuits are formed on the film, which are used as a TFT substrate and a color filter substrate, respectively. Then, in the cell process, after applying the sealing material and dropping the liquid crystal material, the laminates are bonded so that the TFT substrate and the color filter substrate face each other. Thereafter, in each of the laminates, the defective substrate is peeled off, and only two glass substrates of the TFT substrate and the color filter substrate are bonded.

In this way, it was assumed that defective substrates that could not be used for products could be used effectively as support glass. However, a part of the liquid crystal panel manufactured according to such an embodiment is a TFT substrate or a color filter substrate after being peeled from the substrate due to a protrusion exceeding an allowable value formed on a defective substrate. In this case, the convex portion may remain at the portion overlapping the protrusion. As a result, there is a problem that the cell gap is locally non-uniform, resulting in deterioration of the quality of the completed liquid crystal panel or being unusable as a product.

In addition, such a problem is not only when using a defective glass substrate for a liquid crystal panel as a support glass of a glass film laminate, but also by forming projections exceeding an allowable value, for various displays, The same problem occurs when a glass substrate that cannot be used for sensors, covers, etc. is used as support glass.

This invention made | formed in view of the said situation provides the glass film laminated body suitable for manufacture of the said liquid crystal panel, when manufacturing a liquid crystal panel using the glass film laminated body which used the defective glass substrate as support glass. This is a technical issue.

The present invention devised to solve the above problems is a surface on the side in contact with each other of a flexible glass film having a thickness of 200 μm or less and a supporting glass that supports the glass film. In a glass film laminate in which the glass film and the supporting glass are superposed by bringing the surface roughness Ra of the mating surface to 2.0 nm or less and bringing the both mating surfaces into surface contact, the mating surface of the supporting glass A protrusion is formed, and the protrusion dimension from the mating surface of the protrusion is characterized by 0.3 to 5 μm. Here, regarding the supporting glass, “surface roughness Ra of the mating surface” refers to the value of Ra when the surface roughness is measured by excluding the portion where the protrusion is formed on the mating surface. In addition, the “projection dimension” refers to the largest of the projection dimensions of each projection when a plurality of projections are formed on the mating surface.

According to such a configuration, when the glass film and the supporting glass are peeled off, it is possible to avoid a convex portion remaining in a portion that overlaps the protrusion in the glass film, and a liquid crystal panel provided with the glass film It was possible to prevent the deterioration of quality. It is assumed that such an effect is obtained for the following reason. That is, when a glass film is overlaid on the supporting glass on which the protrusions are formed, the portion overlapping the protrusions is protruded by the protrusions themselves or bubbles that have entered between the glass film and the supporting glass in the vicinity of the protrusions. Part is formed. However, after the glass film and the supporting glass are peeled off, atmospheric pressure is uniformly applied to the surface of the flexible glass film, so that the convex portion becomes flat or substantially flat. It is assumed that it has been restored. As a condition for restoring the convex portion to such a state, it is considered that the projecting dimension from the mating surface of the projection is 5 μm or less. As mentioned above, according to this glass film laminated body, it becomes possible to implement suitably a liquid crystal panel.

In the above configuration, the supporting glass is preferably a recycled product.

In this way, as long as this supporting glass is recycled, a glass film laminate suitable for manufacturing a liquid crystal panel can be repeatedly produced. Further, by using it for recycling, it is possible to avoid an increase in manufacturing cost.

As described above, according to the glass film laminate of the present invention, it is possible to suitably manufacture a liquid crystal panel.

It is a vertical side view which shows the glass film laminated body which concerns on embodiment of this invention. It is the enlarged view which expanded the A section in FIG. 1a, Comprising: It is a figure which shows the vicinity of the processus | protrusion formed in support glass. It is a figure which shows the Z1-Z1 cross section in FIG. 1b. It is a figure which shows the vicinity of the processus | protrusion formed in support glass. It is a figure which shows the Z2-Z2 cross section in FIG. 2a. It is a vertical side view which shows the manufacturing process of the liquid crystal panel using the glass film laminated body which concerns on embodiment of this invention. It is a vertical side view which shows the manufacturing process of the liquid crystal panel using the glass film laminated body which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, in embodiment described below, the defective glass substrate which cannot be employ | adopted as a glass substrate for liquid crystal panels is used as support glass of a glass film laminated body. However, as will be described later, the glass film laminate according to the present invention is not limited to such a configuration.

FIG. 1a is a longitudinal side view showing a glass film laminate according to an embodiment of the present invention. As shown in the figure, the glass film laminate 1 includes the surfaces of the

mating surfaces

3a and 2a that are the surfaces of the glass film 3 and the supporting glass 2 that supports the glass film 3 that are in contact with each other. The supporting glass 2 and the glass film 3 are superposed by setting the roughness Ra to 2.0 nm or less and bringing the

mating surfaces

3a and 2a into surface contact. The support glass 2 and the glass film 3 can be made of various materials such as soda lime glass and alkali-free glass, but alkali-free glass is used from the viewpoint of strength and durability. Is preferred.

As shown in FIG. 1b (enlarged view of portion A in FIG. 1a) and FIG. 1c (cross-section Z1-Z1 in FIG. 1b), the support glass 2 is a mating surface that becomes a surface in contact with the glass film 3 2a is formed with a projection 2b having a projection dimension H from the mating surface 2a of 0.3 to 5 μm, which exceeds an allowable value, and cannot be used as a glass substrate for a liquid crystal panel ( TFT substrate or color filter substrate). The protrusion 2b is formed by the bulging of the mating surface 2a by the bubbles B mixed in the support glass 2. Here, the surface roughness Ra in the mating surface 2a is a value of Ra when the surface roughness (arithmetic average roughness) is measured excluding the portion where the protrusion 2b is formed. Moreover, this support glass 2 is a product for recycling, and is repeatedly used for the production of the glass film laminate 1. Further, in the present embodiment, the supporting glass 2 having a thickness of 0.3 to 0.7 mm is used.

Further, in the present embodiment, the protrusion 2b is formed due to the bubbles B mixed in the support glass 2, but in addition to this, foreign matters mixed in the support glass 2 and FIGS. 2a and 2b. As shown in (cross section Z2-Z2 in FIG. 2a), the protrusion 2b may be formed due to the deposit 8 (for example, glass powder) adhering to the mating surface 2a. Further, in FIG. 1a, only one protrusion 2b is shown for convenience of explanation, but in practice, a large number of protrusions 2b are usually formed on the mating surface 2a.

Here, regarding the mating surface 2a of the support glass 2, the number of protrusions 2b formed per 10 cm ² is preferably 2 or less, and most preferably one. The maximum width of the protrusion 2b is preferably in the range of 10 μm to 100 μm. Furthermore, when the thickness of the glass film 3 to be overlaid on the supporting glass 2 exceeds 100 μm, the protrusion dimension H from the mating surface 2a of the protrusion 2b is preferably in the range of 0.3 μm to 2.5 μm.

The glass film 3 has a thickness of 200 μm or less and has flexibility. The glass film 3 superimposed on the supporting glass 2 includes (1) a protrusion 2b formed on the mating surface 2a of the supporting glass 2, and (2) the vicinity of the protrusion 2b shown in FIGS. 1b and 1c. , The convex portion 3b is formed by both (1) and (2) with the bubble (not shown) that has entered between the mating surfaces 2a and 3a.

Here, in the glass film laminate 1, for each of the glass film 3 and the support glass 2, the surface roughness Ra of the mating surfaces 3a and 2a that are the surfaces in contact with each other is 2.0 nm or less. Thus, an appropriate adhesion force is generated between the two

glasses

2 and 3. This adhesion force is assumed to be generated due to hydrogen bonding. Further, it is not necessary to use a binder such as an adhesive in order to bring the two

glasses

2 and 3 into close contact with each other, and the glass film 3 and the supporting glass 2 can be easily peeled at a desired timing.

Hereinafter, the manufacturing process and operation in the case of manufacturing a liquid crystal panel using the glass film laminate 1 will be described with reference to the accompanying drawings. In addition, in the manufacturing process of the liquid crystal panel demonstrated below, the glass film 3 with which the said glass film laminated body 1 was equipped is a TFT substrate.

First, in addition to the glass film laminate 1 described above, a glass film laminate 5 in which a supporting glass 6 and a color filter substrate 7 as a glass film are newly laminated as shown in FIG. . Each of the support glass 6 and the color filter substrate 7 has a surface roughness Ra of the mating surfaces 6a and 7a that are the surfaces in contact with each other, like the support glass 2 and the TFT substrate 3 in the glass film laminate 1. 2.0 nm or less, and the support glass 6 and the color filter substrate 7 are in close contact with each other. In the present embodiment, the support glass 6 is a defective glass substrate that cannot be used as a product for a liquid crystal panel, like the support glass 1, and the projection 6 b formed on the mating surface 6 a of the support glass 6. The protruding dimension is 0.3 to 5 μm. The support glass 6 is a recycled product.

Then, the two

glass film laminates

1 and 5 are bonded together with a sealing material 4 (for example, an ultraviolet curable resin) interposed therebetween so that the TFT substrate 3 and the color filter substrate 7 face each other. The sealing material 4 is applied along the peripheral edges of both the

substrates

3 and 7, and a liquid crystal material L is enclosed between the TFT substrate 3 and the color filter substrate 7 in a region surrounded by the sealing material 4. Is done.

At this time, the TFT substrate 3 in the glass film laminate 1 is formed with a convex portion 3b due to the protrusion 2b formed on the mating surface 2a of the supporting glass 2 (defective glass substrate). Similarly, the color filter substrate 7 in the glass film laminate 5 is also formed with a convex portion 7b due to the protrusion 6b formed on the mating surface 6a of the support glass 6 (defective substrate). For these reasons, the cell gap S, which is the distance between the TFT substrate 3 and the color filter substrate 7, is locally uneven.

However, as shown in FIG. 3b, in each of the two

glass film laminates

1 and 5, the supporting

glasses

2 and 6 are peeled off, and only the two substrates of the TFT substrate 3 and the color filter substrate 7 are bonded together. In this state, as shown by a two-dot chain line in the figure, the convex portions 3b and the convex portions 7b are restored to a flat or substantially flat state, and the

convex portions

3b and 7b are formed on both

substrates

3 and 7. It can avoid remaining.

It is assumed that such an effect is obtained for the following reason. That is, after the

substrates

3 and 7 and the supporting

glasses

2 and 6 are peeled off, the atmospheric pressure P is uniformly applied to the surfaces of both the

substrates

3 and 7 which are flexible glass films, and the projections are convex. It is assumed that the

parts

3b and 7b are deformed. As a condition for restoring the

protrusions

3b and 7b to such a state, it is considered that the protrusion dimension H from the mating surfaces 2a and 6a of the

protrusions

2b and 6b is 5 μm or less. It is done.

From the above, when a liquid crystal panel is manufactured using the

glass film laminates

1 and 5, it is avoided that display unevenness such as a spot or a black spot occurs in an image when the completed liquid crystal panel is turned on. In addition, since the deterioration of the quality of the liquid crystal panel can be prevented, the liquid crystal panel can be preferably manufactured.

When the protrusion 2b is formed by adhesion of glass powder, the tip (top) of the protrusion 2b tends to have a sharp shape, and the protrusion 2b and the TFT substrate 3 are likely to be in point contact. On the other hand, when the number of protrusions 2b formed per 10 cm ² on the mating surface 2a is two or less, the number of protrusions 3b formed on the TFT substrate 3 is reduced. Further, when the maximum width of the protrusion 2b is in the range of 10 μm to 100 μm, the contact area between the protrusion 2b and the TFT substrate 3 is sufficiently small. Therefore, in these cases, it is possible to more suitably prevent the protrusions 3b from remaining in the TFT substrate 3 after being peeled from the support glass 2.

Further, regarding the relationship between the thickness of the glass film 3 and the protrusion dimension H from the mating surface 2a of the protrusion 2b, as described above, when the thickness of the glass film 3 exceeds 100 μm, the protrusion dimension H is 0.3 μm to If it is in the range of 2.5 μm, it is possible to more effectively avoid the remaining protrusions 3b. When the thickness of the glass film 3 exceeds 100 micrometers, there exists a possibility that the convex part 3b may remain in the TFT substrate 3 after making it peel from the support glass 2. FIG. Therefore, compared with the case where the thickness of the glass film 3 is 100 μm or less, it is possible to adopt a glass having a small protrusion dimension H as the support glass 2 and to suppress the protrusion of the protrusion 3 b overlapping the protrusion 2 b to be small. preferable.

Further, since the supporting glasses 2 and 6 (defective glass substrates) are recycled products, as long as these supporting

glasses

2 and 6 are recycled, the

glass film laminates

1 and 5 suitable for manufacturing a liquid crystal panel are provided. It becomes possible to produce it repeatedly. In addition, by using it for recycling, an increase in manufacturing cost can be avoided.

Here, the glass film laminate according to the present invention is not limited to the configuration described in the above embodiment. For example, in the above embodiment, the supporting glass in which protrusions exceeding the allowable value (projection dimension is 0.3 to 5 μm) are formed on both of the two glass film laminates bonded together with the sealing material interposed therebetween. I use it. However, the present invention is not limited to this. Only one of the glass film laminate on the TFT substrate side and the glass film laminate on the color filter substrate side has a protrusion exceeding the allowable value as the supporting glass (however, from the mating surface). It is also possible to use a projection having a protrusion dimension of 0.3 to 5 μm.

Further, in the above embodiment, a defective glass substrate that cannot be used for a liquid crystal panel is used as a supporting glass, but this is not a limitation, and by forming protrusions, various displays, sensors, A glass substrate that cannot be used for a cover or the like may be used as the supporting glass.

As an example of the present invention, a glass film laminate using a defective glass substrate as a supporting glass was used and described in the above embodiment under four conditions (three examples and one comparative example). A liquid crystal panel was produced in the same manner as in the manufacturing process, and the quality of the produced liquid crystal panel was verified. The implementation conditions for verification are shown below.

The glass film used in each condition (in this verification, TFT substrate) and the supporting glass (defective glass substrate) are non-alkali glass (product name: OA-10G) manufactured by Nippon Electric Glass Co., Ltd. The size (horizontal dimension, vertical dimension, thickness dimension) and the projecting dimension of the projection formed on the mating surface of the supporting glass from the mating surface are as shown in Table 1 below.

The surface roughness Ra on the mating surface of the glass film and the supporting glass is determined by using the concentration of the etching solution when the glass formed by the overflow down draw method is used unpolished or when polishing and chemical etching are performed. It was controlled by adjusting the temperature and processing time.

For the measurement of the surface roughness Ra, a scanning probe microscope (NanoNaviII / S-image) manufactured by SII was used, scanning area: 2000 nm, scanning frequency: 0.95 Hz, scanning data number X (lateral direction): 256 , Y (longitudinal direction): Measurement was performed under the condition of 256. In each of the supporting glass and the glass film, the surface roughness Ra was measured at a total of two points, that is, one point at the center and one point at the corner, and the average value was defined as the surface roughness Ra.

Then, after the glass film and the supporting glass were washed and dried, 100 liquid crystal panels were produced for each of the four conditions in the same manner as the manufacturing process described in the above embodiment. Thereafter, out of the 100 liquid crystal panels produced, the number of liquid crystal panels in which display unevenness occurred during lighting was counted, and the quality of the display was determined by determining the occurrence rate of display unevenness. Table 1 below shows the results of the verification.

As is clear from Table 1, in Comparative Example 1, display unevenness occurred in the liquid crystal panel at an occurrence rate of 100%. On the other hand, in Examples 1 to 3, the rate of occurrence of display unevenness was 20% or 0%, and a high-quality liquid crystal panel could be produced compared to the comparative example. In Examples 1 to 3, as described in the above embodiment, after the glass film (TFT substrate) was peeled off from the supporting glass (defective glass substrate), it was formed at a portion overlapping the protrusion. It is assumed that the raised convex portion is restored to a flat or substantially flat state by atmospheric pressure. Further, from the comparison of the protrusion dimensions of the protrusions in Comparative Example 1 and Examples 1 to 3, as a condition for restoring the protrusions to such a state, the protrusion dimensions from the mating surfaces of the protrusions in the support glass are 5 μm. It is considered that the conditions are as follows.

From the above, it is presumed that the liquid crystal panel can be suitably manufactured according to the glass film laminate of the present invention.

1 Glass film laminate 2 Support glass (defective glass substrate)
2a Matching surface 2b Protrusion 3 Glass film (TFT substrate)
3a Matching surface 3b Convex 4 Sealing material 5 Glass film laminate 6 Support glass 6a Matching surface 6b Protrusion 7 Glass film (color filter substrate)

7a Matching surface

7b Protruding part 8 Deposit S Cell gap H Projection size of projection from mating surface L Liquid crystal material B Bubble P Atmospheric pressure

Claims

For each of the flexible glass film having a thickness of 200 μm or less and the supporting glass that supports the glass film, the surface roughness Ra of the mating surface that is the surface in contact with each other is 2.0 nm or less, In the glass film laminate in which the glass film and the support glass are overlapped by bringing the two mating surfaces into surface contact,
A glass film laminate, wherein protrusions are formed on a mating surface of the supporting glass, and a projecting dimension of the projections from the mating surface is 0.3 to 5 μm.
The glass film laminate according to claim 1, wherein the supporting glass is a recycled product.