TWI534507B - Display device and manufacturing method thereof - Google Patents

Description

Display device and method of manufacturing same

The present invention relates to a display device and a method of fabricating the same, and more particularly to a display device having a polarizing plate and a method of fabricating the same.

The upper polarizing plate, the lower polarizing plate, and the liquid crystal panel can be combined into a liquid crystal display device. The transmission direction of the upper polarizing plate generally extends along the long side, and the extending direction of the lower polarizing plate generally extends along the short side, wherein the upper polarizing plate and the lower polarizing plate are arranged in a manner different from each other by 90 degrees, thus causing the upper polarizing plate and the lower polarizing plate. The amount of shrinkage of the polarizing plate is different, so that the liquid crystal display device is prone to warpage.

Therefore, there is a need to propose a solution that can reduce the amount of warpage of a liquid crystal display device.

Therefore, the present invention provides a display device and a method of fabricating the same that can reduce the amount of warpage of the display module.

According to an embodiment of the invention, a display device is proposed. The display device includes a display panel, a first polarizing plate, a first bonding layer, a second polarizing plate, and a second bonding layer. The display panel has opposite first and second sides. The first polarizing plate has a first contraction force. The first adhesive layer is formed on the first display panel The first adhesive layer has a first strength between the surface and the first polarizing plate. The second polarizing plate has a second contraction force. The second adhesive layer is formed between the second surface of the display panel and the second polarizing plate, and the second adhesive layer has a second strength. The first ratio of the first contraction force to the second contraction force and the second ratio of the second intensity to the first intensity are both greater than one.

According to another embodiment of the present invention, a method of fabricating a display device is presented. The manufacturing method includes the following steps. A display panel, a first polarizing plate, a first bonding layer, a second polarizing plate and a second bonding layer are provided. The display panel has a first surface and a second surface. The first polarizing plate has a first surface. The first adhesive layer is formed between the first surface of the display panel and the first polarizing plate, the first adhesive layer has a first strength, and the second polarizing plate has a second contraction force, wherein a first ratio of the contraction force and the second contraction force and a second ratio of the second intensity to the first intensity are greater than 1; forming a first adhesive layer between the first surface of the display panel and the first polarizing plate to Bonding the display panel to the first polarizing plate; and forming a second bonding layer between the second surface of the display panel and the second polarizing plate to bond the display panel and the second polarizing plate.

In order to better understand the above and other aspects of the present invention, the preferred embodiments are described below, and in conjunction with the drawings, the detailed description is as follows:

100‧‧‧ display device

110‧‧‧ display panel

110u‧‧‧ first side

110b‧‧‧ second side

120‧‧‧First polarizer

121‧‧‧First polarizer

121s‧‧‧Longside

122‧‧‧First protective film

123‧‧‧Second protective film

130‧‧‧First adhesive layer

140‧‧‧Second polarizer

141‧‧‧Second polarizer

141s‧‧‧ Short side

142‧‧‧ Third protective film

143‧‧‧4th protective film

150‧‧‧Second adhesive layer

F1‧‧‧First contraction force

F2‧‧‧second contraction force

R‧‧‧ ratio

R1‧‧‧ first ratio

R2‧‧‧ second ratio

S1‧‧‧ first intensity

S2‧‧‧second intensity

MD1, MD2‧‧‧ transmission direction

1A is a cross-sectional view of a display device in accordance with an embodiment of the present invention.

FIG. 1B is a plan view showing the display device of FIG. 1A.

1A is a cross-sectional view of a display device 100 according to an embodiment of the invention, and FIG. 1B is a plan view of the display device 100 of FIG. 1A. The display device 100 includes a display panel 110 , a first polarizing plate 120 , a first adhesive layer 130 , a second polarizing plate 140 , and a second adhesive layer 150 .

The display panel 110 is, for example, a liquid crystal display panel, but may be other types of display panels. The display panel 110 has a first surface 110u and a second surface 110b opposite to each other. The first polarizing plate 120 and the first bonding layer 130 are located on the first surface 110u, and the second polarizing plate 140 and the second bonding layer 150 are located on the second surface 110b. In one embodiment, the first surface 110u is the display surface of the display panel 110. In another embodiment, the second surface 110b is the display surface of the display panel 110.

As shown in the enlarged view of FIG. 1A, the first polarizer 120 includes a first polarizer 121, a first protective film 122, and a second protective film 123, wherein the first polarizer 121 is located at the first protective film 122 and the second protection. The films 123 are protected by the first protective film 122 and the second protective film 123. As shown in FIG. 1B, the transmission direction MD1 of the first polarizer 121 of the first polarizing plate 120 is in the X-axis direction, for example, along the long side 121s direction of the first polarizer 121.

The material of the first protective film 122 and/or the second protective film 123 is, for example, a cellulose resin such as triacetyl cellulose, a polyester resin, a polyether oxime resin, a polyfluorene resin, a polycarbonate resin, a polyamide resin, or the like. Polyimine resin, polyolefin resin, (meth)acrylic resin, cyclic polyolefin resin (nortenyl resin), polyarylate resin, polystyrene resin, polyvinyl alcohol resin or a combination thereof.

The first polarizing plate 120 has a first contraction force. In one embodiment, a lifting force generated by the warpage of the first polarizing plate 120 at one hour of baking at about 80 degrees Celsius is defined as the first contracting force.

The first adhesive layer 130 is formed between the first surface 110u of the display panel 110 and the first polarizing plate 120 to bond the first surface 110u of the display panel 110 with the first polarizing plate 120, and can reduce the warpage of the display device 100. the amount. The first adhesive layer 130 has a first strength. The first strength can be defined by at least one of gel fraction, viscoelasticity and shear stress. When the gel fraction, viscoelasticity or shear stress of the first adhesive layer 130 is larger, it indicates that the first strength of the first adhesive layer 130 is stronger; otherwise, the weaker.

As shown in the enlarged view of FIG. 1A, the second polarizing plate 140 includes a second polarizer 141, a third protective film 142, and a fourth protective film 143, wherein the second polarizer 141 is located at the third protective film 142 and the fourth protection. The membranes 143 are protected by the third protective film 142 and the fourth protective film 143. As shown in FIG. 1B, the transmission direction MD2 of the second polarizer 141 of the second polarizing plate 140 is, for example, the Y-axis direction, which is, for example, in the direction of the short side 141s of the second polarizer 141. The material of the third protective film 142 and/or the fourth protective film 143 may be similar to the first protective film 122 and/or the second protective film 123, and thus will not be described again.

The second polarizing plate 140 has a second contraction force. In one embodiment, a lifting force generated by the warpage of the second polarizing plate 140 at one hour of baking at about 80 degrees Celsius is defined as a second contracting force. Since the length of the second polarizer 141 in the transport direction MD2 is shorter than the length of the first polarizer 121 in the transport direction MD1, the second contraction force of the second polarizer 140 is smaller than the first contraction force of the first polarizer 120.

The second adhesive layer 150 is formed between the second surface 110b of the display panel 110 and the second polarizing plate 140 to bond the second surface 110b of the display panel 110 with the second polarizing plate 140, and can reduce the warpage of the display device 100. the amount. The second adhesive layer 150 has a second strength. The second strength can be defined by at least one of gel fraction, viscoelasticity and shear stress. When the gel fraction, viscoelasticity or shear stress of the second adhesive layer 150 is larger, it indicates that the second strength of the second adhesive layer 150 is stronger;

In one embodiment, the first adhesive layer 130 and/or the second adhesive layer 150 may be a pressure sensitive adhesive, and the material thereof may include, for example, (meth) acrylate, a crosslinking agent or other suitable materials, wherein The (meth) acrylate is, for example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate or monoethyl hexyl (meth) acrylate, and the like. For example, it is an epoxy type crosslinking agent, an isocyanate type crosslinking agent, or an imide type crosslinking agent. In an embodiment, the first adhesive layer 130 and/or the second adhesive layer 150 may further comprise other additives, such as a decane coupling agent, an antistatic agent, and the like.

The relationship between the first contraction force F1, the second contraction force F2, the first intensity S1, and the second intensity S2 in the embodiment of the present invention is as shown in the following formulas (1) and (2).

As shown in the formula (1), the first contraction force F1 of the first polarizing plate 120 is greater than the second contraction force F2 of the second polarizing plate 140, and thus the first ratio R1 is greater than 1. As shown in the formula (2), the second strength S2 of the second adhesive layer 150 is greater than the first intensity S1 of the first adhesive layer 130, and thus the second ratio R2 is greater than 1.

The first contraction force F1, the second contraction force F2, the first intensity S1, and the second intensity S2 simultaneously match the above (1) and (2). In detail, when the first contraction force F1 of the first polarizing plate 120 is greater than the second contraction force F2 of the second polarizing plate 140, the first strength S1 of the first adhesive layer 130 for bonding the first polarizing plate 120 is smaller than The second strength S2 of the second adhesive layer 150 for bonding the second polarizing plate 140.

Since the second intensity S2 of the second adhesive layer 150 is larger (relative to the first intensity S1), the resistance of the second polarizing plate 140 to warp deformation can be increased, thereby reducing the amount of warpage of the second polarizing plate 140. At the same time, since the first intensity S1 of the first adhesive layer 130 is small (compared to the second intensity S2), the first polarizing plate 130 can be allowed to slightly slip to reduce the warpage of the first polarizing plate 130. In this way, the overall amount of warpage of the display device 100 can be reduced. In one embodiment, the first ratio R1 is proportional to the second ratio R2, that is, the larger the first contraction force F1 is, the larger the second intensity S2 is, or the smaller the second contraction force F2 is, the first intensity is The smaller S1 is.

The first intensity S1 represents the shear stress value of the first adhesive layer 130, which may be between 1 and 3 N (Newtons). If the first strength S1 is too low, the durability is insufficient, and if it is too high, it cannot reach an appropriate ratio with the second strength S2 of the second adhesive layer 150. The second strength S2 represents the shear stress value of the second adhesive layer 150, which may be between 4 and 6 N (Newtons). If the second strength S2 is too low, there is a case where the shrinkage cannot be suppressed, and if it is too high, the first strength S1 cannot be brought to an appropriate ratio. Based on the above range of shear stress values, the second ratio R2 can be between 2 and 4, and a suitable bonding effect can be obtained to reduce the amount of warpage of the display device 100.

In addition, in this embodiment, the ratio of the first ratio R1 to the second ratio R2 R (= R 1 / R 2 ) may be between 0.1 and 1.0, and this numerical range can effectively reduce the warpage of the display device 100. The warpage test of the display device 100 of the embodiment of the present invention will be described below.

Please refer to Tables 1, 2 and 3 below. Table 1 lists the four adhesive layers with different strengths selected, Table 2 lists the five polarizing plates with different shrinkage forces, and Table 3 lists the adhesive layers of Table 1 and the polarizing plates of Table 2. Several different combinations of test combinations.

As shown in the above table 3, with the combination of the display panel 100 of the first group, the first polarizing plate 120 selects the B1 of the second polarizing plate 120, the second polarizing plate 140 selects the B3 of the second polarizing plate 140, and the first adhesive layer 130 selects the first one. A3, and the second adhesive layer 150 selects A2 of Table 1; in the selection mode, the ratio R is about 0.28. After the display panel 100 of the first group is baked at a temperature of about 80 degrees Celsius, the amount of warpage of the display device 100 is less than the allowable value (Table 3 is indicated by "OK"). In one embodiment, if the amount of warpage of the four corners of the display panel 100 after baking is less than 0.5 mm, it is judged as "OK", and vice versa. The selection mode and result judgment of other groups are similar to the first group, and will not be described again.

As shown in Table 3 above, when the ratio R is between 0.12 and 0.62, the amount of warpage of the display panel 100 is within an expected or allowable range. Although the above table 3 only lists some of the array test groups of the display panel 100, in practice, when the ratio R is between 0.1 and 1.0, the amount of warpage of the display panel 100 is within an expected or allowable range.

In conclusion, the present invention has been disclosed in the above preferred embodiments, and is not intended to limit the present invention. A person skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

100‧‧‧ display device

110‧‧‧ display panel

110u‧‧‧ first side

110b‧‧‧ second side

120‧‧‧First polarizer

121‧‧‧First polarizer

122‧‧‧First protective film

123‧‧‧Second protective film

130‧‧‧First adhesive layer

140‧‧‧Second polarizer

141‧‧‧first polarizer

142‧‧‧ Third protective film

143‧‧‧4th protective film

150‧‧‧Second adhesive layer

Claims (10)

A display device includes: a display panel having a first surface and a second surface; a first polarizing plate having a first contraction force; and a first adhesive layer formed on the display panel Between one side and the first polarizing plate, the first adhesive layer has a first strength; a second polarizing plate has a second contraction force; and a second adhesive layer is formed on the display panel. Between the two sides and the second polarizing plate, the second adhesive layer has a second strength; wherein a first ratio of the first contracting force to the second contracting force and the second intensity and the first intensity A second ratio is greater than one. The display device of claim 1, wherein the first ratio is proportional to the second ratio. The display device of claim 1, wherein a ratio of the first ratio to the second ratio is between 0.1 and 1.0. The display device of claim 1, wherein the second ratio is between 2.0 and 4.0. The display device of claim 1, wherein the first surface is a display surface of the display panel. A method for manufacturing a display device includes: providing a display panel, a first polarizing plate, a first bonding layer, a second polarizing plate, and a second bonding layer, the display panel having a first side and a first surface The first polarizing layer has a first contracting force. The first bonding layer is formed between the first surface of the display panel and the first polarizing plate. The first bonding layer has a first strength. The second adhesive layer has a second strength, and the second polarizing plate has a second contraction force, wherein a first ratio of the first contraction force to the second contraction force and the second intensity and the first a second ratio of a strength is greater than 1; forming the first adhesive layer between the first surface of the display panel and the first polarizing plate to bond the display panel and the first polarizing plate; The second adhesive layer is disposed between the second surface of the display panel and the second polarizing plate to bond the display panel and the second polarizing plate. The manufacturing method of claim 6, wherein the first ratio is proportional to the second ratio. The manufacturing method of claim 6, wherein the ratio of the first ratio to the second ratio is between 0.1 and 1.0. The manufacturing method of claim 6, wherein the second ratio is between 2.0 and 4.0. The manufacturing method of claim 6, wherein the first surface is a display surface of the display panel.