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

Display Module

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

[0002] Providing holes in a frame improves the flexibility of the frame, but also 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 proposes a configuration in which the holes are filled with silicone.

[0003] International Publication WO2019 / 088372A1 (International Publication Date: May 9, 2019)

[0004] However, the above-mentioned conventional technology has the problem of degrading the appearance quality of the module in which the functional part is bonded to the frame. This is because the adhesive fills the holes in the frame, making the module thinner in the filled areas. Because the size or number of holes differs between the bending area and the non-bending area, the amount of adhesive filling differs between the bending area and the non-bending area, resulting in a difference in thickness within the module surface.

[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 unit laminated to the substrate and including a flexible display device, a first adhesive portion bonding an upper surface of the first portion to the display function unit and having a first height based on the upper surface of the first portion, and a second adhesive portion bonding an upper surface of the second portion to the display function unit and having a second height based on the upper surface of the second portion that is 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 portion laminated to the substrate and including a flexible display device, and an adhesive portion bonding the upper surface of the first portion and the upper surface of the second portion to the display function portion.

[0007] According to the present disclosure, the appearance quality of the display module can be improved.

[0008] 7 is a cross-sectional view showing a flat state of an example of a display module according to an embodiment of the present disclosure. FIG. 8 is a plan view showing an example of an arrangement of voids formed in a first portion shown in FIG. 1. FIG. 9 is a plan view showing an example of an arrangement of voids formed in a second portion shown in FIG. 1. FIG. 10 is a cross-sectional view showing a bent state of an example of a display module shown in FIG. 1. FIG. 11 is a cross-sectional view showing an example of a manufacturing method of the display module shown in FIG. 1. FIG. 12 is a graph showing a difference in thickness of an example of the display module shown in FIG. 1. FIG. 13 is a cross-sectional view showing a configuration of a comparative example of a display module. FIG. 14 is a graph showing a difference in thickness of the comparative example shown in FIG. 7. FIG. 8 is a cross-sectional view showing a flat state of an example of a display module according to an embodiment of the present disclosure.

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[0010] In the present disclosure, the "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, the "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 substrate 10 has voids 40 formed in at least the second portion 12 of the first portion 11 and the second portion 12, and the porosity of the second portion 12, determined based on the volume of the voids 40, is higher than the porosity of the first portion 11, determined based on the volume of the voids 40. In the present disclosure, "porosity" refers to a volume ratio, i.e., the proportion of voids 40 in a unit volume of each portion. The first portion 11 may or may not have voids 40. If the first portion 11 does not have voids 40, the volume of the voids 40 in the first portion 11 is 0, and the porosity is 0%. The second portion 12 may have a plurality of through holes belonging to the voids 40. The voids 40 may include blind holes. The substrate 10 may be a perforated metal plate and may include, for example, at least one of stainless steel, aluminum, copper, brass, iron, a nickel alloy, a chromium alloy, and titanium.

[0012] FIG. 2 is a plan view showing an example of the arrangement of voids formed in the first portion shown in FIG. 1 . FIG. 3 is a plan view showing an example of the arrangement of voids formed in the second portion shown in FIG. 1 . As shown in FIGS. 2 and 3 , a plurality of first through holes 41 belonging to the voids 40 are formed in the first portion 11, and a plurality of second through holes 42 belonging to the voids 40 are formed in the second portion 12. 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 of the first through holes 41 may be the same as the opening area of ​​each of the second through holes 42. In the present disclosure, "dense" means a high number density. In other words, the number of second through holes per unit area in the second portion may be greater than the number of first through holes per unit area in the first portion.

[0013] 1 , the substrate 10 may include a first region 10a, a second region 10b, and a third region 10c in this order in a plan view, with the first region 10a and the third region 10c comprising a first portion 11 and the second region 10b comprising a second portion 12. The first region 10a, the second region 10b, and the third region 10c may be continuous.

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

[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 an OCA. The adhesive film 30 has a thickness of 15 μm or more and 150 μm or less. The adhesive film 30 has an elastic modulus of 1.0×10 in an environment of 25° C. ４ Pa or more and 1.0 x 10 ７ The modulus of elasticity of the adhesive film in a −25° C. environment is 5.0×10 ４ Pa or more and 1.0 x 10 ６ 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 composed of a first adhesive portion 31, and the second adhesive region 30b may be composed of a 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 portion 11 and the second portion 12 of the substrate 10 may be determined depending on the amount by which the adhesive film 30 is pressed into the gap 40 in each portion. The difference in thickness of the substrate 10, i.e., the difference in thickness between the first portion 11 and the second portion 12, may be 1% or more and 50% or less of the thickness of the adhesive film 30.

[0017] 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 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 function unit 20 laminated to the substrate 10 and including a flexible display device 25, and an adhesive unit (adhesive film 30) that bonds the upper surfaces of the first portion 11 and the second portion 12 to the display function unit 20.

[0018] 4 is a cross-sectional view showing an example of the display module shown in FIG. 1 in a bent state. As shown in FIG. 4, the display module 100 may be foldable. For example, the second region 10b of the substrate 10 may be bendable so that the first region 10a faces the third region 10c. The adhesive film 30 and the display function unit 20 may bend to follow the substrate 10. For example, the display function unit 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 planar view. The flexible portion 25a may occupy the entire flexible display device 25, or may occupy only the portion that overlaps with the second portion 12 in a planar view.

[0019] (Manufacturing Method) FIG. 5 is a cross-sectional view showing an example of a manufacturing method for the display module shown in FIG. 1 . As shown in FIG. 6 , a substrate 10, an adhesive film 30, and a display function unit 20 are prepared (step S10). In step S10, the adhesive film 30 has a substantially uniform thickness. Next, the substrate 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, the pressure may be applied, for example, by rolling a roller 50 from one end of the display function unit 20 to the other. The pressure causes the adhesive film 30 to adhere the upper surface of the substrate 10 to the lower surface of the display function unit 20. The pressure also causes the portion of the adhesive film 30 placed over the void 40 to be pressed into the void 40. As a result, depending on the porosity of each portion of the substrate 10, the upper surface of the corresponding portion of the adhesive film 30 is lowered, and the second height h2 is smaller than the first height h1.

[0020] According to the configuration of 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 offsets the difference in the first height h1 and the second height h2 of the adhesive film 30, improving the uniformity of the thickness of the display module 100. Therefore, the appearance quality of the display module 100 is improved.

[0021] Note that, as described below, configurations have been devised that do not result in differences in the height of the adhesive film, but these have problems. For example, a configuration in which the adhesive film 30 is made difficult to press into each of the gaps 40 by making each gap 40 smaller results in a problem of reduced flexibility of the substrate 10. Reduced flexibility increases the probability of the display function unit 20 peeling off from the substrate 10. For example, a configuration in which the holes are filled with silicone or resin reduces the flexibility of the substrate 10 and complicates the manufacturing process, increasing manufacturing costs. In contrast, the configuration according to the present disclosure only requires different thicknesses of the substrate 10, thereby providing the benefits of maintaining the flexibility of the substrate 10 and avoiding increases in the manufacturing costs of the display module.

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

[0023] <Comparative Example> FIG. 7 is a cross-sectional view showing the configuration of a comparative example of a display module. As shown in FIG. 7, a display function unit 20 was bonded to a substrate 110 of 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 gap arrangement of the first portion 111 of the comparative example were identical to those of the first portion 11 of the example, and the porosity and gap arrangement of the second portion 112 of the comparative example were identical to those of the second portion 12 of the example. Furthermore, the adhesive film 30 and the display function unit 20 were identical between Example 1 and the comparative example. FIG. 8 is a graph showing the difference in thickness of the comparative example shown in FIG. 7. The vertical axis of FIG. 8 indicates the difference from the average thickness.

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

[0025] [Embodiment 2] Another embodiment of the present disclosure will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0026] 9 is a cross-sectional view showing an example of a display module according to an embodiment of the present disclosure in a flat state. As shown in Fig. 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. The display module 100 includes a third adhesive portion 33 that bonds an upper surface of the third portion 13 to the display function unit 20. The third adhesive portion 33 has a third height, measured from the upper surface of the third portion 13 as a reference, that is smaller than the first height h1 and greater than the second height h2.

[0027] In the present disclosure, the "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] The third portion 13 may or may not have voids 40 formed therein. The porosity of the third portion 13, which is determined based on the volume of the voids 40, is equal to or greater than the porosity of the first portion 11 and equal to or less than the porosity of the second portion 12. The third portion 13 may have a plurality of third through holes belonging to the voids 40 formed therein, and the plurality of second through holes 42 may be arranged more densely than the plurality of third through holes 43, and the plurality of third through holes 43 may be arranged more densely 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 a 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 this order, and the fourth region 10d and the fifth region 10e may be configured as the third portion 13. These regions may be continuous. Alternatively, 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 greater than the first porosity and less than the second porosity; a display function unit 20 laminated to the substrate 10 and including a flexible display device 25; and an adhesive unit (adhesive film 30) that bonds the top surface of the first portion 11, the top surface of the second portion 12, and the top surface of the third portion 13 to the display function unit 20.

[0031] Example 2 Example 2 was the same as Example 1 described above, except that a third portion 13 was provided between the first portion 11 and the second portion 12. In Example 2, the thickness of the third portion 13 was 140 nm. The porosity and pore arrangement of the third portion 13 were the same as those of the first portion 11 on the first portion 11 side and the same as those of the second portion 12 on the second portion 12 side, gradually transitioning from the first portion 11 side toward the second portion 12 side.

[0032] The appearance quality of the display module 100 according to the second embodiment was as good as the appearance quality of the display module 100 according to the first embodiment described above.

[0033] The present disclosure is not limited to the above-described embodiments, 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 the present disclosure. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment.

[0034] 10 Base material 10a First region 10b Second region 10c Third region 11 First portion 12 Second portion 13 Third portion 20 Display function portion 25 Flexible display device 25a Flexible portion 30 Adhesive film 31 First adhesive portion 32 Second adhesive portion 33 Third adhesive portion 40 Air gap 41 First through-hole 42 Second through-hole 100 Display module h1 First height h2 Second height h3 Third height

Claims

1. A flat substrate having a first portion and a second portion thicker than the first portion; a display function unit laminated to the base material and including a flexible display device; a first adhesive portion that bonds an upper surface of the first portion and the display function portion, the first adhesive portion having a first height relative to the upper surface of the first portion; a second adhesive portion that bonds an upper surface of the second portion and the display function portion, and that has a second height relative to the upper surface of the second portion that is smaller than the first height; a gap is formed in at least the second portion of the first portion and the second portion, A display module, wherein 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 formed therein that belong to the gap.

3. a plurality of first through holes belonging to the void are formed in the first portion, a plurality of second through holes belonging to the void are formed in the second portion, The display module according to claim 1 , wherein the second through-holes are arranged more densely than the first through-holes.

4. the substrate has a third portion that is thicker than the first portion and thinner than the second portion; 4. The display module according to claim 1, wherein the display module has a third adhesive portion that bonds the upper surface of the third portion to the display function portion, and the third adhesive portion has a third height, the third height being smaller than the first height and larger than the second height, based on the upper surface of the third portion.

5. the substrate includes 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 configured in the first portion, The display module according to claim 1 , wherein the second region is formed by the second portion.

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 adhesive film has a thickness of 15 μm or more and 150 μm or less.

8. The adhesive film has an elastic modulus of 1.0×10 Pa or more and 1.0×10 Pa or less in a 25°C environment, 7. The display module according to claim 6, wherein the adhesive film has a modulus of elasticity in a −25° C. environment of 5.0×10<4 > Pa or more and 1.0×10<6 > Pa or less.

9. 9. The display module according to claim 1, wherein the substrate includes at least one of stainless steel, aluminum, copper, brass, iron, a nickel alloy, a chromium alloy, and titanium.

10. 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 greater than the first porosity; a display function unit laminated to the base material and including a flexible display device; and an adhesive portion that bonds an upper surface of the first portion and an upper surface of the second portion to the display function portion.

11. A display module, a flat substrate having a first portion and a second portion thicker than the first portion; a display function unit laminated to the base material and including a flexible display device; a first adhesive portion that bonds an upper surface of the first portion and the display function portion, the first adhesive portion having a first height relative to the upper surface of the first portion; a second adhesive portion that bonds an upper surface of the second portion and the display function portion, and that has a second height relative to the upper surface of the second portion that is smaller than the first height; the substrate has a third portion that is thicker than the first portion and thinner than the second portion; The display module has a third adhesive portion that bonds the upper surface of the third portion to the display function portion, and the third adhesive portion has a third height, the third height being smaller than the first height and larger than the second height, based on the upper surface of the third portion.

12. A flat substrate having a first portion and a second portion thicker than the first portion; a display function unit laminated to the base material and including a flexible display device; a first adhesive portion that bonds an upper surface of the first portion and the display function portion, the first adhesive portion having a first height relative to the upper surface of the first portion; a second adhesive portion that bonds an upper surface of the second portion and the display function portion, and that has a second height relative to the upper surface of the second portion that is smaller than the first height; the substrate includes 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 configured in the first portion, A display module, wherein the second region is configured by the second portion.

13. A display module as described in claim 12, wherein the second region is bendable so that the first region faces the third region.

14. A flat substrate having a first portion and a second portion thicker than the first portion; a display function unit laminated to the base material and including a flexible display device; a first adhesive portion that bonds an upper surface of the first portion and the display function portion, the first adhesive portion having a first height relative to the upper surface of the first portion; a second adhesive portion that bonds an upper surface of the second portion and the display function portion, and that has a second height relative to the upper surface of the second portion that is smaller than the first height; The display module, wherein the substrate includes at least one of stainless steel, aluminum, copper, brass, iron, a nickel alloy, a chromium alloy, and titanium.