Display module

Abstract

A display module (100) comprises: a planar base material (10) which has a first portion (11) and a second portion (12) that is thicker than the first portion (11); a first adhesion portion (31) which adheres a display function portion (20) to an upper surface of the first portion (11), and in which the height thereof based on the upper surface of the first portion (11) is a first height (h1); and a second adhesion portion (32) which adheres the display function portion (20) to an upper surface of the second portion (12), and in which the height thereof based on the upper surface of the second portion (12) is a second height (h2) that is lower than the first height (h1).

Description

Technical Field

[0001] The present disclosure relates to a display module.

Background Art

[0002] Providing holes in a frame improves the flexibility of the frame, but on the other hand, reduces the impact resistance of the frame. Therefore, there is a configuration in which large holes are provided in the bending region and small holes or no holes are provided in the non-bending region. Patent Document 1 discloses a flexible frame including a rigid portion without holes and a flexible portion with holes, and presents a configuration in which the holes are filled with silicone.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the conventional technology as described above has a problem that the appearance quality of the module in which the functional part is adhered to the frame deteriorates. This is because the adhesive fills the holes in the frame, and in the filled area, the thickness of the module becomes thinner by the filled amount. Since the size or number of holes is different between the bending region and the non-bending region, the filling amount of the adhesive is different between the bending region and the non-bending region, and as a result, a difference in thickness occurs within the module surface.

Means for Solving the Problems

[0005] A display module according to one aspect of the present disclosure comprises a flat substrate having a first portion and a second portion thicker than the first portion; a display function section laminated on the substrate and including a flexible display device; a first adhesive portion bonding the upper surface of the first portion to the display function section, with a height of the upper surface of the first portion being a first height; and a second adhesive portion bonding the upper surface of the second portion to the display function section, with a height of the upper surface of the second portion being a second height smaller than the first height.

[0006] A display module according to one aspect of the present disclosure comprises a substrate having a first portion having a first porosity and a second portion having a second porosity that is thicker than the first portion and higher than the first porosity; a display function section laminated on the substrate and including a flexible display device; and an adhesive section bonding the upper surface of the first portion and the upper surface of the second portion to the display function section. [Effects of the Invention]

[0007] According to this disclosure, the appearance quality of the display module can be improved. [Brief explanation of the drawing]

[0008] [Figure 1] This is a cross-sectional view showing a flat state of an example of a display module according to one embodiment of the present disclosure. [Figure 2] This is a plan view showing an example of the arrangement of voids formed in the first portion shown in Figure 1. [Figure 3] This is a plan view showing an example of the arrangement of voids formed in the second portion shown in Figure 1. [Figure 4] Figure 1 is a cross-sectional view showing the bent state of an example of a display module. [Figure 5] Figure 1 is a cross-sectional view showing an example of a manufacturing method for the display module shown. [Figure 6] This graph shows the difference in thickness of the display module embodiment shown in Figure 1. [Figure 7]This is a cross-sectional view showing the configuration of an example of a display module. [Figure 8] Figure 7 is a graph showing the difference in thickness between the comparative examples. [Figure 9] This is a cross-sectional view showing a flat state of an example of a display module according to one embodiment of the present disclosure. [Modes for carrying out the invention]

[0009] [Embodiment 1] (Cross-sectional configuration) Figure 1 is a cross-sectional view showing a flat state of an example of a display module according to one embodiment of the present disclosure. As shown in Figure 1, the display module 100 includes a flat substrate 10 having a first portion 11 and a second portion 12 that is thicker than the first portion 11; a display function section 20 laminated on the substrate 10 and including a flexible display device 25; a first adhesive section 31 that adheres the upper surface of the first portion 11 to the display function section 20, with a height of first height h1 relative to the upper surface of the first portion 11; and a second adhesive section 32 that adheres the upper surface of the second portion 12 to the display function section 20, with a height of second height h2 that is smaller than the first height h1 relative to the upper surface of the second portion 12.

[0010] In this disclosure, "first height h1" is the distance from the upper surface of the first portion 11 to the upper surface of the first adhesive portion 31. Similarly, "second height h2" is the distance from the upper surface of the second portion 12 to the upper surface of the second adhesive portion 32. The first portion 11 is a so-called "non-flexible region" or "rigid portion," and the second portion 12 is a so-called "flexible region" or "flexible portion."

[0011] The base material 10 has voids 40 formed in at least the second part 12 of the first part 11 and the second part 12, and the porosity of the second part 12, determined based on the volume of voids 40, is higher than the porosity of the first part 11, determined based on the volume of voids 40. In this disclosure, "porosity" means volume ratio, i.e., the ratio of voids 40 to the unit volume of each part. Voids 40 may or may not be formed in the first part 11. If there are no voids 40 in the first part 11, the volume of voids 40 in the first part 11 is 0, and the porosity is 0%. Multiple through holes belonging to the voids 40 may be formed in the second part 12. The voids 40 may include non-through holes. The base material 10 may be a perforated metal plate, for example, stainless steel vinegar, It may contain at least one of aluminum, copper, brass, iron, nickel alloy, chromium alloy, and titanium.

[0012] Figure 2 is a plan view showing an example of the arrangement of voids formed in the first part shown in Figure 1. Figure 3 is a plan view showing an example of the arrangement of voids formed in the second part shown in Figure 1. As shown in Figures 2 and 3, the first part 11 has a plurality of first through-holes 41 belonging to the void 40, and the second part 12 has a plurality of second through-holes 42 belonging to the void 40, and the plurality of second through-holes 42 may be arranged more densely than the plurality of first through-holes 41. The opening area of ​​each first through-hole 41 may be the same as the opening area of ​​each second through-hole 42. In this disclosure, "dense" means a high number density. That is, the number of second through-holes per unit area in the second part may be greater than the number of first through-holes per unit area in the first part.

[0013] Referring again to Figure 1, the substrate 10 includes a first region 10a, a second region 10b, and a third region 10c in this order in a plan view, and the first region 10a and the third region 10c may be composed of a first part 11, and the second region 10b may be composed of a second part 12. The first region 10a, the second region 10b, and the third region 10c may be continuous.

[0014] As an example, the display functional unit 20 may include a window film 21, an adhesive film 22, a touch panel device with a polarizing plate 23, an adhesive film 24, a flexible display device 25, an adhesive film 26, and a cushion layer 27 from the display surface side toward the substrate 10 side. The adhesive films 22, 24, 26 may be OCA (Optical Clear Adhesive). When the flexible display device 25 incorporates a touch panel device, instead of the touch panel device with a polarizing plate 23 and the adhesive film 24, a simple polarizing plate may be directly attached to the flexible display device 25. The flexible display device 25 may be an organic LED display device or a quantum dot display device. The cushion layer 27 may include PET (polyethylene terephthalate) or thin stainless steel such as 30 μm.

[0015] The display module 100 includes an adhesive film 30 having a first adhesive portion 31 and a second adhesive portion 32. The adhesive film 30 may be OCA. The thickness of the adhesive film 30 is 15 μm or more and 150 μm or less. The elastic modulus of the adhesive film 30 at 25°C environment is 1.0×10 4 Pa or more and 1.0×10 7 Pa or less, and the elastic modulus of the adhesive film at -25°C environment is 5.0×10 4 Pa or more and 1.0×10 6 Pa or less. The adhesive film 30 includes a first adhesive region 30a, a second adhesive region 30b, and a third adhesive region 30c in this order corresponding to the substrate 10, and the first adhesive region 30a and the third adhesive region 30c may be constituted by the first adhesive portion 31, and the second adhesive region 30b may be constituted by the second adhesive portion 32. The first adhesive region 30a, the second adhesive region 30b, and the third adhesive region 30c may be continuous.

[0016] The difference in thickness between the first part 11 and the second part 12 of the substrate 10 may be determined according to the filling amount in which the adhesive film 30 is pushed into the gap 40 in each part. The difference in thickness of the substrate 10, that is, the difference in thickness between the first part 11 and the second part 12, may be 1% or more and 50% or less of the thickness of the adhesive film 30.

[0017] In other words, the display module 100 according to one aspect of the present disclosure includes a base material 10 having a first portion 11 with a first porosity and a second portion 12 that is thicker than the first portion 11 and has a second porosity higher than the first porosity, a display functional portion 20 laminated on the base material 10 and including a flexible display device 25, and an adhesive portion (adhesive film 30) that adheres the upper surfaces of the first portion 11 and the second portion 12 and the display functional portion 20.

[0018] FIG. 4 is a cross-sectional view showing a bent state of an example of the display module shown in FIG. 1. As shown in FIG. 4, the display module 100 may be foldable. For example, the base material 10 may be bendable such that the second region 10b faces the third region 10c with the first region 10a. The adhesive film 30 and the display functional portion 20 can bend following the base material 10. Further, for example, the display functional portion 20 may include a bendable flexible portion 20a. In particular, the flexible display device 25 may include a bendable flexible portion 25a. In this case, the second portion 12 may overlap the flexible portions 20a and 25a in a plan view. The flexible portion 25a may occupy the entire flexible display device 25 or only the portion that overlaps the second portion 12 in a plan view.

[0019] (Manufacturing method) Figure 5 is a cross-sectional view showing an example of a method for manufacturing the display module shown in Figure 1. As shown in Figure 6, a base material 10, an adhesive film 30, and a display function unit 20 are prepared (step S10). In step S10, the thickness of the adhesive film 30 is approximately uniform. Next, the base material 10, the adhesive film 30, and the display function unit 20 are stacked in this order and pressure is applied (step S20). In step S20, pressure may be applied, for example, by rolling a roller 50 from one end to the other of the display function unit 20. Due to the pressure, the adhesive film 30 adheres to the upper surface of the base material 10 and to the lower surface of the display function unit 20. Also, due to the pressure, the portion of the adhesive film 30 placed on the void 40 is pushed into the void 40. As a result, the upper surface of the corresponding portion of the adhesive film 30 is lowered according to the void ratio of each portion of the base material 10, and the second height h2 is smaller than the first height h1.

[0020] According to one aspect of the present disclosure, the difference in thickness between the first portion 11 and the second portion 12 of the base material 10 cancels out the difference between the first height h1 and the second height h2 of the adhesive film 30, thereby improving the uniformity of the thickness of the display module 100. Consequently, the appearance quality of the display module 100 is improved.

[0021] Furthermore, configurations in which there is no difference in the height of the adhesive film have also been considered, but these have problems. For example, in a configuration in which the adhesive film 30 is not easily pressed into each of the voids 40 by making each of the voids 40 smaller, there is a problem that the flexibility of the base material 10 decreases. This decrease in flexibility increases the probability of defects in which the display function part 20 peels off from the base material 10. For example, in a configuration in which the holes are filled with silicone or resin, there is a problem that the flexibility of the base material 10 decreases, and the manufacturing process becomes more complex, increasing manufacturing costs. In contrast to these, the configuration according to this disclosure only requires a difference in the thickness of the base material 10, so there is a benefit in that the flexibility of the base material 10 can be maintained, and an increase in the manufacturing cost of the display module can be avoided.

[0022] <Example 1> Figure 6 is a graph showing the difference in thickness of the display module embodiment shown in Figure 1. The vertical axis of Figure 6 shows the difference from the average thickness. In this embodiment 1, the thickness of the first part 11 was 130 μm, and the thickness of the second part 12 was 150 μm. The porosity of the second part 12 was greater than that of the first part 11.

[0023] <Comparative Example> Figure 7 is a cross-sectional view showing the configuration of a comparative example of the display module. As shown in Figure 7, a display function unit 20 was bonded to a substrate 110 with a uniform thickness via an adhesive film 30. The substrate 110 of the comparative example had a first portion 111 with a thickness of 130 μm and a second portion 112 with a thickness of 130 μm. The porosity and void arrangement of the first portion 111 of the comparative example were the same as those of the first portion 11 of the example, and the porosity and void arrangement of the second portion 112 of the comparative example were the same as those of the second portion 12 of the example. The adhesive film 30 and the display function unit 20 were the same in Example 1 and the comparative example. Figure 8 is a graph showing the difference in thickness of the comparative example shown in Figure 7. The vertical axis of Figure 8 shows the difference from the average thickness.

[0024] As shown in Figure 6, the in-plane thickness difference of the display module 100 in the embodiment was only about 2 μm. On the other hand, as shown in Figure 8, the in-plane thickness difference of the display module in the comparative example was about 20 μm.

[0025] [Embodiment 2] Other embodiments of this disclosure are described below. For the sake of clarity, components having the same function as those described in the above embodiments are denoted by the same reference numerals, and their descriptions are not repeated.

[0026] Figure 9 is a cross-sectional view showing a plan view of an example of a display module according to one embodiment of the present disclosure. As shown in Figure 9, the base material 10 has a third portion 13 that is thicker than the first portion 11 and thinner than the second portion 12, and the display module 100 has a third adhesive portion 33 that adheres the upper surface of the third portion 13 to the display function portion 20, and the third adhesive portion 33 has a third height that is less than the first height h1 and greater than the second height h2, with respect to the upper surface of the third portion 13.

[0027] In this disclosure, “third height h3” is the distance from the upper surface of the third portion 13 to the upper surface of the third adhesive portion 33. The third portion 13 is a so-called “boundary portion” or “transition portion”.

[0028] A void 40 may or may not be formed in the third part 13. The porosity of the third part 13, determined based on the volume of the void 40, is greater than or equal to the porosity of the first part 11 and less than or equal to the porosity of the second part 12. A plurality of third through holes belonging to the void 40 may be formed in the third part 13, and the plurality of second through holes 42 may be more densely arranged than the plurality of third through holes 43, and the plurality of third through holes 43 may be more densely arranged than the plurality of first through holes 41.

[0029] The third portion 13 may be located between the first portion 11 and the second portion 12. In plan view, the substrate 10 includes the first region 10a, the fourth region 10d, the second region 10b, the fifth region 10e, and the third region 10c in that order, and the fourth region 10d and the fifth region 10e may be composed of the third portion 13. These regions may be continuous. Not limited to this, the thickness and porosity of the substrate 10 may transition stepwise or gradually from the first portion 11 to the second portion 12. The adhesive film 30 may have a third adhesive portion 33.

[0030] In other words, a display module 100 according to one aspect of the present disclosure comprises a substrate 10 having a first portion 11 having a first porosity, a second portion 12 that is thicker than the first portion 11 and has a second porosity higher than the first porosity, and a third portion 13 that is thicker than the first portion, thinner than the second portion, and has a third porosity between the first and second porosities; a display function section 20 laminated on the substrate 10 and including a flexible display device 25; and an adhesive section (adhesive film 30) that adheres the upper surface of the first portion 11, the upper surface of the second portion 12, and the upper surface of the third portion 13 to the display function section 20.

[0031] <Example 2> This embodiment 2 was identical to the previously described embodiment 1, except that a third portion 13 was provided between the first portion 11 and the second portion 12. In this embodiment 2, the thickness of the third portion 13 was 140 nm. The porosity and void arrangement of the third portion 13 were the same as those of the first portion 11 on the first portion 11 side, the same as those of the second portion 12 on the second portion 12 side, and gradually transitioned from the first portion 11 side to the second portion 12 side.

[0032] The appearance quality of the display module 100 according to this embodiment 2 was as good as that of the display module 100 according to the above-described embodiment 1.

[0033] This disclosure is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of this disclosure. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment. [Explanation of Symbols]

[0034] 10 Base material 10a 1st area 10b 2nd area 10c 3rd area 11 Part 1 12 Part 2 13 Part 3 20 Display function section 25 Flexible display devices 25a Flexible part 30 Adhesive film 31 1st adhesive part 32 2nd adhesive part 33 Third adhesive part 40 void 41 First through hole 42 Second through hole 100 Display Modules h1 First height h2 Second height h3 Third height

Claims

1. A flat base plate having a first portion and a second portion that is thicker than the first portion, A display function unit, which is laminated on the aforementioned substrate and includes a flexible display device, The upper surface of the first part and the display function part are bonded together, and the first bonding part has a height of the upper surface of the first part as the reference height, The upper surface of the second part and the display function part are bonded together, and the second bonding portion has a second height that is smaller than the first height, with respect to the upper surface of the second part as the reference point. A void is formed in at least the second portion of the first and second portions. A display module in which the porosity of the second portion, determined based on the volume of the void, is higher than the porosity of the first portion, determined based on the volume of the void.

2. The display module according to claim 1, wherein the second portion has a plurality of through holes belonging to the void.

3. The first portion has a plurality of first through holes belonging to the void, The second portion has a plurality of second through holes belonging to the void, The display module according to claim 1, wherein the plurality of second through holes are arranged more closely together than the plurality of first through holes.

4. The substrate has a third portion that is thicker than the first portion and thinner than the second portion. The display module according to any one of claims 1 to 3, wherein the display module includes a third adhesive portion that adheres the upper surface of the third portion to the display function portion, and the height of the third adhesive portion is a third height which is smaller than the first height and larger than the second height, with respect to the upper surface of the third portion.

5. The substrate comprises a first region, a second region, and a third region in this order in a plan view. The first region and the third region are composed of the first part, The display module according to any one of claims 1 to 3, wherein the second region is comprised of the second part.

6. The display module according to claim 1, comprising an adhesive film having the first adhesive portion and the second adhesive portion.

7. The display module according to claim 6, wherein the thickness of the adhesive film is 15 μm or more and 150 μm or less.

8. The elastic modulus of the adhesive film at a 25°C environment is 1.0 × 10⁴ Pa or more and 1.0 × 10⁷ Pa or less. The display module according to claim 6, wherein the elastic modulus of the adhesive film in a -25°C environment is 5.0 × 10⁴ Pa or more and 1.0 × 10⁶ Pa or less.

9. The display module according to any one of claims 1 to 3 or 6 to 8, wherein the substrate comprises at least one of stainless steel, aluminum, copper, brass, iron, nickel alloy, chromium alloy, and titanium.

10. A substrate having a first portion having a first porosity, and a second portion that is thicker than the first portion and has a second porosity higher than the first porosity, A display function unit, which is laminated on the aforementioned substrate and includes a flexible display device, A display module comprising the upper surface of the first part and an adhesive portion that bonded the upper surface of the second part to the display function unit.

11. A display module, A flat base plate having a first portion and a second portion that is thicker than the first portion, A display function unit, which is laminated on the aforementioned substrate and includes a flexible display device, The upper surface of the first part and the display function part are bonded together, and the first bonding part has a height of the upper surface of the first part as the reference height, The upper surface of the second part and the display function part are bonded together, and the second bonding portion has a second height that is smaller than the first height, with respect to the upper surface of the second part as the reference point. The substrate has a third portion that is thicker than the first portion and thinner than the second portion. The display module includes a third adhesive portion that bonds the upper surface of the third portion to the display function portion, wherein the height of the third adhesive portion relative to the upper surface of the third portion is a third height which is smaller than the first height and larger than the second height.

12. A flat base plate having a first portion and a second portion that is thicker than the first portion, A display function unit, which is laminated on the aforementioned substrate and includes a flexible display device, The upper surface of the first part and the display function part are bonded together, and the first bonding part has a height of the upper surface of the first part as the reference height, The upper surface of the second part and the display function part are bonded together, and the second bonding portion has a second height that is smaller than the first height, with respect to the upper surface of the second part as the reference point. The substrate comprises a first region, a second region, and a third region in this order in a plan view. The first region and the third region are composed of the first part, A display module in which the second region is composed of the second part.

13. The display module according to claim 12, wherein the second region is bendable such that the first region faces the third region.

14. A flat base plate having a first portion and a second portion that is thicker than the first portion, A display function unit, which is laminated on the aforementioned substrate and includes a flexible display device, The upper surface of the first part and the display function part are bonded together, and the first bonding part has a height of the upper surface of the first part as the reference height, The upper surface of the second part and the display function part are bonded together, and the second bonding portion has a second height that is smaller than the first height, with respect to the upper surface of the second part as the reference point. The display module comprises a base material including at least one of stainless steel, aluminum, copper, brass, iron, nickel alloy, chromium alloy, and titanium.

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