TWI530396B - Panel laminating method, panel assembly and electronic device - Google Patents

Description

Panel bonding method, panel assembly and electronic device

The present invention relates to a panel bonding method, and more particularly to a method of bonding two panels to each other and a panel assembly formed by the method.

Handheld touch devices, such as smart phones and tablet computers, have the advantages of multiple functions and portability, making this type of handheld touch devices more and more popular among consumers. . The handheld touch device is usually equipped with a display panel to display an image, and is equipped with a touch panel on a display panel to input an instruction with an image displayed on the display panel.

In order to attach the touch panel to the display panel, conventional techniques generally form a dam on the display panel to define a distribution area of Liquid Optical Clear Adhesive (LOCA). Next, the liquid optical clear adhesive is applied to a region of the display panel surrounded by the plastic frame to form a transparent adhesive layer. Then, the touch panel is stacked on the plastic frame and the transparent adhesive layer, and then passed through the ultraviolet light. The transparent adhesive layer is cured by irradiation, so that the touch panel is attached to the display panel by the cured transparent adhesive layer.

However, the material of the plastic frame must use a liquid optical transparent adhesive with a high viscosity coefficient, but it has the disadvantages of difficulty in defoaming and difficulty in coating, thereby increasing manufacturing complexity. In addition, the plastic frame must be disposed between the effective display area of the display panel and the edge of the display panel, which is disadvantageous for narrowing the frame of the handheld touch device. Moreover, since the transparent adhesive layer still has fluidity before uncured, any movement or shaking may cause the uncured transparent adhesive layer to overflow outside the plastic frame, thus requiring an additional cleaning step, thereby causing troubles in automated production. .

The present invention refers to a panel fitting method which can omit the conventional plastic frame and contribute to simplifying the manufacturing complexity.

The present invention refers to a panel assembly that can omit the conventional plastic frame and contribute to the design of the narrow bezel.

The present invention provides a panel bonding method comprising the following steps. A transparent adhesive layer is formed on a first panel. The at least partially transparent adhesive layer is pre-cured to increase the viscosity of the transparent adhesive layer. After pre-curing the transparent adhesive layer, a second panel is stacked on the transparent adhesive layer. After the second panel is stacked on the transparent adhesive layer, all of the transparent adhesive layer is cured, so that the second panel is attached to the first panel via the transparent adhesive layer.

The invention provides a panel assembly comprising a first panel, a transparent adhesive layer and a second panel. The transparent adhesive layer is disposed on the first panel. Second panel configuration On the transparent adhesive layer, it is attached to the first panel via a transparent adhesive layer. The clear adhesive layer is homogeneous and the periphery of the clear adhesive layer is substantially exposed.

The present invention provides an electronic device including a frame and the above-described panel assembly.

Based on the above, the present invention applies liquid optical transparent adhesive on the first panel to form a transparent adhesive layer, and immediately irradiates with ultraviolet light to reduce the fluidity of the transparent adhesive layer, so that the conventional use for preventing the overflow of the rubber can be omitted. The frame is sealed while preventing the uncured transparent layer from spilling over to other areas. In addition, the present invention can reduce the manufacturing complexity and facilitate the design of the narrow bezel by omitting the conventional plastic frame.

The above described features and advantages of the invention will be apparent from the following description.

102‧‧‧ first panel

104‧‧‧Transparent rubber layer

104a‧‧‧ Peripheral part

104b‧‧‧Central Part

104c‧‧‧Structural boundary

106‧‧‧ second panel

108‧‧‧ Panel assembly

200‧‧‧Electronic assembly

210‧‧‧Frame

212‧‧‧ accommodating space

220‧‧‧ first panel

230‧‧‧Transparent rubber layer

240‧‧‧ second panel

250‧‧‧Double-sided tape

260‧‧‧shell

S11~S15‧‧‧Steps

S21~S24‧‧‧Steps

1 is a flow chart of a panel bonding method according to an embodiment of the present invention.

2A to 2E are schematic cross-sectional views showing the steps of the panel bonding method of Fig. 1 in order.

3 is a flow chart of a panel bonding method according to another embodiment of the present invention.

4A to 4D are schematic cross-sectional views showing the steps of the panel bonding method of Fig. 3 in order.

FIG. 5 is a cross-sectional view of an electronic device according to another embodiment of the present invention.

1 is a flow chart of a panel bonding method according to an embodiment of the present invention. 2A to 2E are schematic cross-sectional views showing the steps of the panel bonding method of Fig. 1 in order. Referring to FIG. 1 and FIG. 2A, step S11 is performed to form a transparent adhesive layer 104 on a first panel 102. In step S11, as shown in FIG. 2A, a liquid optical clear adhesive (LOCA) may be applied on the first panel 102 to form a transparent adhesive layer 104.

Referring to FIG. 1 and FIG. 2B, after the transparent adhesive layer 104 is formed, step S12 is performed. In step S12, as shown in FIG. 2B, all of the transparent adhesive layer 104 is pre-cured immediately to increase the viscosity of the transparent adhesive layer 104, that is, to reduce the fluidity of the transparent adhesive layer 104. Pre-curing here uses very low doses of UV light. In particular, the initial environment employed herein is a low pressure (near vacuum) and UV-free environment, so that only a very low dose of ultraviolet light is required in the pre-curing step to reduce the flow of the transparent adhesive layer 104. Therefore, the initial environment used here requires UV light that is isolated from the background. The fluidity of the transparent adhesive layer 104 can be reduced by pre-curing to prevent the transparent adhesive layer 104 from flowing to other areas of the first panel 102, but still maintain the transparent adhesive layer 104 with sufficient fluidity. For example, the viscosity coefficient of the transparent adhesive layer 104 can be increased from 1000 to 5000 cps (centipoise) to 10,000 to 20,000 cps (centipoise) by pre-curing to increase the viscosity of the transparent adhesive layer 104, that is, to reduce The fluidity of the transparent adhesive layer 104.

Referring to FIG. 1 and FIG. 2C, after all the transparent adhesive layer 104 is pre-cured, step S13 is performed. In step S13, as shown in FIG. 2C, a second panel 106 is stacked on the transparent adhesive layer 104. In step S13, the second panel 106 can be in the true The transparent adhesive layer 104 is stacked on an empty environment to reduce air bubbles remaining in the transparent adhesive layer 104. In this embodiment, the first panel 102 can be a liquid crystal panel, and the second panel 106 can be a touch panel. The touch panel can include a protection substrate and a touch module overlapping the protection substrate. In another embodiment, the first panel 102 and the second panel 106 can be two transparent substrates of a touch panel.

Referring to FIG. 1 and FIG. 2D, after the second panel 106 is stacked on the transparent adhesive layer 104, step S14 is performed. In step S14, as shown in FIG. 2D, the peripheral edge portion 104a of the transparent adhesive layer 104 is pre-cured, wherein the peripheral portion 104a surrounds a central portion 104b of the transparent adhesive layer 104. The pre-cure here can be irradiated with a low dose of ultraviolet light, but this dose is still greater than the dose of ultraviolet light used for pre-curing in step S12. The pre-curing herein can further increase the viscous coefficient of the peripheral portion 104a of the transparent adhesive layer 104 to prevent the transparent adhesive layer 104 from overflowing to the non-display area around the first panel 102. In this embodiment, there will be a structural boundary 104c between the peripheral portion 104a and the central portion 104b due to the time difference of successive curings.

Referring to FIGS. 1 and 2E, after pre-curing the peripheral portion 104a of the transparent adhesive layer 104, step S15 is performed. In step S15, as shown in FIG. 2E, all of the transparent adhesive layer 104 is main-cured to increase the viscosity of the transparent adhesive layer 104, so that the second panel 106 is bonded to the first layer via the transparent adhesive layer 104. A panel 102. The primary cure here can be irradiated with a high dose of ultraviolet light, and this dose is greater than the dose of ultraviolet light used for pre-curing in step S12 (Fig. 2B) and step S14 (Fig. 2D). For example, when the transparent adhesive layer 104 is a liquid optical transparent adhesive of DuPont Model 2320, the violet used in the pre-curing in step S12 (Fig. 2B) The dose of external light irradiation is about 3000 mJ/cm 2 , and the dose of ultraviolet light used for pre-curing in step S14 (Fig. 2D) is about 3000 mJ/cm 2 , in step S15 (Fig. 2E). The dose of ultraviolet light used for the main curing is about 6000 mJ/cm 2 .

In another embodiment not shown, the step S14 (FIG. 2D) of the peripheral portion 104a of the pre-cured transparent adhesive layer 104 may be omitted, and all the steps S15 (FIG. 2E) of the main cured transparent adhesive layer 104 may be directly performed.

After completing step S11 to step S15 of FIG. 1, as shown in FIG. 2E, the first panel 102, the transparent adhesive layer 104, and the second panel 106 may constitute a panel assembly 108. Different from the conventional plastic frame surrounding the transparent adhesive layer to prevent the rubber from overflowing, the transparent adhesive layer 104 of the embodiment is homogeneous, and the periphery of the transparent adhesive layer 104 is substantially exposed without the conventional plastic frame. around. Therefore, the area around the first panel 102 can be omitted from the area originally reserved for the conventional plastic frame, which is advantageous for narrowing the non-display area around the first panel 102, thereby facilitating the design of the narrow bezel.

3 is a flow chart of a panel bonding method according to another embodiment of the present invention. 4A to 4D are schematic cross-sectional views showing the steps of the panel bonding method of Fig. 3 in order. Referring to FIG. 3 and FIG. 4A, step S21 is performed to form a transparent adhesive layer 104 on a first panel 102. In step S21, as shown in FIG. 4A, liquid optical clear adhesive (LOCA) may be applied on the first panel 102 to form a transparent adhesive layer 104.

Referring to FIG. 3 and FIG. 4B, after the transparent adhesive layer 104 is formed, step S22 is performed. In step S22, as shown in FIG. 4B, the peripheral edge portion 104a of the transparent adhesive layer 104 is pre-cured immediately, wherein the peripheral portion 104a surrounds the transparent adhesive. A central portion 104b of the layer 104 increases the viscosity of the peripheral portion 104a of the transparent adhesive layer 104, that is, reduces the fluidity of the peripheral portion 104a of the transparent adhesive layer 104. Pre-curing here uses very low doses of UV light. Specifically, the initial environment employed herein is a low pressure (near vacuum) and ultraviolet-free environment, so that only a low dose of ultraviolet light is required in the pre-curing step to reduce the peripheral portion 104a of the transparent adhesive layer 104. fluidity. Therefore, the initial environment used here requires UV light that is isolated from the background. The fluidity of the transparent adhesive layer 104 can be lowered by pre-curing to prevent the central portion 104b of the transparent adhesive layer 104 from flowing to other regions of the first panel 102, but still maintain the transparent adhesive layer 104 with sufficient fluidity. For example, the viscous coefficient of the peripheral portion 104a of the transparent adhesive layer 104 can be increased from 1000 to 5000 cps (centipoise) to 10,000 to 20,000 cps (centipoise) by pre-curing to increase the peripheral portion 104a of the transparent adhesive layer 104. The viscosity means to reduce the fluidity of the peripheral portion 104a of the transparent adhesive layer 104. In this embodiment, there will be a structural boundary 104c between the peripheral portion 104a and the central portion 104b due to the time difference of successive curings.

Referring to FIG. 3 and FIG. 4C, after all the transparent adhesive layer 104 is pre-cured, step S23 is performed. In step S23, as shown in FIG. 4C, a second panel 106 is stacked on the transparent adhesive layer 104. In step S23, the second panel 106 may be stacked on the transparent adhesive layer 104 in a vacuum environment to reduce air bubbles remaining in the transparent adhesive layer 104. In this embodiment, the first panel 102 can be a liquid crystal panel, and the second panel 106 can be a touch panel. The touch panel can include a protection substrate and a touch module overlapping the protection substrate. In another embodiment, the first panel 102 and the second panel 106 can be two transparent substrates of a touch panel.

Referring to FIG. 3 and FIG. 4D, after the second panel 106 is stacked on the transparent adhesive layer 104, step S24 is performed. In step S24, as shown in FIG. 4D, all of the main-curing transparent adhesive layer 104, that is, the peripheral portion 104a and the central portion 104b of the transparent adhesive layer 104 are added to increase the viscosity of the transparent adhesive layer 104. The second panel 106 is attached to the first panel 102 via the transparent adhesive layer 104. The primary cure here can be irradiated with a high dose of ultraviolet light, and this dose is greater than the dose of ultraviolet light used for pre-curing in step S22 (Fig. 4B). For example, when the transparent adhesive layer 104 is a liquid optical transparent adhesive of Model 2320 of DuPont, the dose of ultraviolet light used for pre-curing in step S22 (Fig. 4B) is about 3000 mJ/cm 2 . The dose of ultraviolet light used for the main curing in step S24 (Fig. 4D) is about 6000 mJ/cm 2 .

After completing step S21 to step S24 of FIG. 1, as shown in FIG. 4D, the first panel 102, the transparent adhesive layer 104, and the second panel 106 may constitute a panel assembly 108. Different from the conventional plastic frame surrounding the transparent adhesive layer to prevent the rubber from overflowing, the transparent adhesive layer 104 of the embodiment is homogeneous, and the periphery of the transparent adhesive layer 104 is substantially exposed without the conventional plastic frame. around. Therefore, the area around the first panel 102 can be omitted from the area originally reserved for the conventional plastic frame, which is advantageous for narrowing the non-display area around the first panel 102, thereby facilitating the design of the narrow bezel.

FIG. 5 is a cross-sectional view of an electronic device according to another embodiment of the present invention. Referring to FIG. 5, the electronic device 200 of the present embodiment can be fabricated by using the panel bonding method of the above embodiment. The electronic device 200 includes a frame 210, a first panel 220, a transparent adhesive layer 230, and a second panel 240. The frame 210 has an accommodation Space 212. The transparent adhesive layer 230 is disposed on the first panel 220. The second panel 240 is disposed on the transparent adhesive layer 230 to be attached to the first panel 220 via the transparent adhesive layer 230 . The first panel 220 is disposed in the accommodating space 212 , the transparent adhesive layer 230 is homogeneous, and the periphery of the transparent adhesive layer 230 is substantially exposed to the accommodating space 212 . In the present embodiment, the circumference of the second panel 240 is fixed to the frame 210 , wherein the second panel 240 can be attached to the bearing portion 214 of the frame 210 via the double-sided tape 250 . In addition, the electronic device 200 further includes a housing 260 , and the frame 210 is fixed to the housing 260 . In this embodiment, the first panel 220 can be a liquid crystal panel, and the second panel 240 can be a touch panel. The touch panel can include a protection substrate and a touch module overlapping the protection substrate. In another embodiment, the first panel 220 and the second panel 240 can be two transparent substrates of a touch panel.

In summary, the present invention applies liquid optical transparent adhesive on the first panel to form a transparent adhesive layer, and immediately irradiates with ultraviolet light to reduce the fluidity of the transparent adhesive layer, so that the conventionally used for preventing the rubber compound can be omitted. Spilled plastic frame while preventing the uncured clear adhesive layer from spilling into other areas. In addition, the present invention can reduce the manufacturing complexity and facilitate the design of the narrow bezel by omitting the conventional plastic frame.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

S11~S15‧‧‧Steps

Claims (12)

A panel bonding method comprises: forming a transparent adhesive layer on a first panel; pre-curing at least a portion of the transparent adhesive layer to increase the viscosity of the transparent adhesive layer; after pre-curing the transparent adhesive layer, a second panel is stacked on the transparent adhesive layer; after the second panel is stacked on the transparent adhesive layer, all of the transparent adhesive layer is mainly cured, so that the second panel is pasted through the transparent adhesive layer. To the first panel; and after the step of superposing the second panel on the transparent adhesive layer, and pre-curing the periphery of the transparent adhesive layer before the main step of curing the transparent adhesive layer. The panel bonding method according to claim 1, wherein in the step of forming the transparent adhesive layer, a liquid optical transparent adhesive is coated on the first panel to form the transparent adhesive layer. The method of panel bonding according to claim 1, wherein in the step of pre-curing the transparent adhesive layer, the transparent adhesive layer is irradiated with a first dose of ultraviolet light to completely cure the transparent adhesive layer. In the step of irradiating the transparent adhesive layer with a second dose of ultraviolet light, and the second dose is greater than the first dose. The method of panel bonding according to claim 1, wherein in the step of pre-curing the transparent adhesive layer, the transparent adhesive layer is irradiated with a first dose of ultraviolet light to pre-cure the periphery of the transparent adhesive layer. In the step of irradiating the periphery of the transparent adhesive layer with a second dose of ultraviolet light, in the main step of curing the transparent adhesive layer And irradiating all of the transparent adhesive layer with a third dose of ultraviolet light, the second dose being greater than the first dose, and the third dose being greater than the second dose. The method of panel bonding according to claim 1, wherein in the step of stacking the second panel on the transparent adhesive layer, the second panel is stacked on the transparent adhesive layer in a vacuum environment. on. The panel bonding method according to claim 1, wherein in the step of pre-curing the transparent adhesive layer, all of the transparent adhesive layer is pre-cured to increase the overall viscosity of the transparent adhesive layer. The panel bonding method according to claim 1, wherein in the step of pre-curing the transparent adhesive layer, the periphery of the transparent adhesive layer is pre-cured to increase the viscosity of the periphery of the transparent adhesive layer. A panel assembly includes: a first panel; a transparent adhesive layer disposed on the first panel, wherein the transparent adhesive layer has a central portion and a peripheral portion, the peripheral portion surrounding the central portion, and the periphery a structural boundary exists between the portion and the central portion; and a second panel disposed on the transparent adhesive layer to adhere to the first panel via the transparent adhesive layer, and the periphery of the transparent adhesive layer is substantially Exposed. The panel assembly of claim 8, wherein the first panel is a liquid crystal panel, and the second panel is a touch panel. The panel assembly of claim 9, wherein the touch panel further comprises a protection substrate and a touch module. The panel assembly of claim 8, wherein the first panel and the second panel are two transparent substrates of a touch panel. An electronic device comprising: a frame having an accommodating space; and the panel assembly according to claim 8 , wherein the first panel is disposed in the accommodating space, and the periphery of the second panel is fixed In the framework.