TWI767555B - Cover plate structure and manufacturing method thereof - Google Patents

Abstract

The invention provides a cover plate structure and manufacturing method thereof. The cover plate structure includes a cover plate and a filling body. The cover plate has a through hole and the filling body is disposed in the through hole. The filling body has a corresponding first surface and a second surface. The first surface and the second surface respectively have a sub-wavelength structure, and the sub-wavelength structure is close to the air. The infrared rays can be directly injected into the sub-wavelength structure to improve the transmittance of infrared rays. At the same time, the filling body has a low transmittance in visible light, preventing the user from seeing the infrared sensor module component through the through hole.

Description

Cover plate structure and method of making the same

The invention relates to the technical field of infrared transmittance structures, in particular to a cover plate structure with high infrared transmittance and a manufacturing method thereof.

Data security and privacy protection for mobile devices are becoming more important these days. Iris recognition, facial recognition technology, posture detection, gesture detection and some biometric recognition systems in mobile devices all use infrared lenses.

In the above-mentioned technology, the infrared light-transmitting plate is used to extract the infrared signal light to detect and identify the user's iris or facial features. The mobile device will be automatically unlocked only if the characteristics of the authorized holder stored in the mobile device match.

The infrared sensor module needs to accurately determine the difference between different users, so as to avoid the wrong judgment and the risk of exposure of the data in the mobile device. If the detected features of the user's iris or face do not match the features of the authorized owner stored in the mobile device, the mobile device will not be unlocked to avoid data leakage.

Therefore, the requirements for the sensitivity and distance of the infrared detection function of mobile devices are also increasing day by day, that is, the requirements for the infrared transmittance will continue to increase. In terms of appearance, it is also necessary to achieve the effect of hiding the infrared detection hole, so as to enhance the appearance of the mobile device and maintain the privacy of the detection device.

One objective of the present invention is to provide a cover plate structure and a manufacturing method thereof, which can improve the transmittance of infrared rays.

Another object of the present invention is to improve the transmittance of infrared rays, and to reduce the transmittance of visible light by adjusting the refractive index setting of the cover structure, thereby maintaining the concealment effect of the infrared detection holes.

The invention provides a cover plate structure, which includes a cover plate and a filling body. The cover plate has a through hole, and the filling body is disposed in the through hole, the filling body has a corresponding first surface and a second surface, and the first surface and the second surface respectively have a primary wavelength structure, And the sub-wavelength structure is exposed in the air.

Through the above, when infrared rays are incident on the surface of the sub-wavelength structure from the air, the infrared rays travel to the bottom of the sub-wavelength structure and enter the filling body, and the infrared rays are not reflected from the surface of the sub-wavelength structure.

Further, the sub-wavelength structure includes a plurality of sub-wavelength substructures, each sub-wavelength substructure has a height, a length and a width, the height is less than 240nm, the length is less than 240nm, the width is less than 240nm, and every two The distance between the sub-wavelength substructures is less than 240 nm.

Furthermore, a plurality of the sub-wavelength sub-structures are arranged in an array and disposed on the first surface and the second surface.

Furthermore, the top of each sub-wavelength substructure and the surface of the cover plate are located on the same plane.

In addition, further, the filler has a transmittance of 100% to light with a wavelength of 850 nm to 900 nm.

Further, the filler has a transmittance of 1.04% to light with a wavelength of 550 nm.

Further, the refractive index of the filler is between 1.33 and 4.

Further, the Mohs hardness of the filler is greater than 3 (3H).

Further, the filler and the sub-wavelength structure are made of the same ink material, and the ink composition includes 55% to 60% of resin polymer, 25% to 10% of pigment and 20% to 30% of solvent.

In one embodiment, the cover plate structure further includes an ink layer, the ink layer is disposed on a surface of the cover plate, and the ink layer avoids the through hole.

Further, the ink layer includes a first ink part and a second ink part, one surface of the first ink part is attached to the surface and exposes the through hole; one surface of the second ink part is attached to the first ink part The other side of the ink portion exposes the through hole and the first ink portion around the hole.

Meanwhile, the present invention provides a method for manufacturing a cover plate structure, which includes the following steps:

a. Provide a cover and a drilling machine;

b. Use the drilling machine to form a through hole on the cover plate;

c. forming a filling body in the through hole, the filling body has a corresponding first surface and a second surface, and the first surface and the second surface respectively have a plurality of wavelength sub-structures arranged in an array .

Further, in one embodiment, the above-mentioned method step c, in the step of forming a filling body in the through hole, further includes the following steps:

c1. Provide an injection fixture and a filler;

c2. Put the cover on the injection fixture;

c3. Injection molding the filler to the through hole;

c4. Curing the filler;

c5. Remove the injection fixture;

c6. Provide a deburring machine;

c7. Use the deburring machine to cure the filler to deburr;

c8. The filler body after deburring is formed into a sub-wavelength structure;

c9. Complete the filling body in the through hole.

In addition, in another embodiment, the above-mentioned method step c, in the step of forming a filling body in the through hole, further includes the following steps:

c11. Provide a filler and a deburring machine;

c12. Curing the filler;

c13. Use the deburring machine to deburr the surface of the solidified oil film;

c14. Form sub-wavelength structures on the two surfaces corresponding to the filler;

c15. Provide an offline molding machine;

c16. Use the off-line molding machine to make the filling body with the diameter of the through hole;

c17. Insert the filler into the through hole;

c18. Complete the filling body in the through hole.

The cover plate structure of the present invention has the following advantages:

By preparing the sub-wavelength structures on the two surfaces of the filler, the transmittance of infrared rays can be effectively improved, and thereby the sensitivity and detection distance of the infrared sensing module can be effectively improved.

At the same time, by adjusting the pigment addition ratio of the filler, the transmittance of visible light can also be reduced, thereby maintaining the effect of hiding the infrared detection hole.

In order to make the purpose, technical solutions and advantages of the present application more clearly understood, the present application will be described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application.

Please refer to FIG. 1 , which is a schematic structural diagram of the cover plate structure of the present invention. A cover plate structure 1 of the present invention includes a cover plate 2 and a filling body 3 .

The cover plate 2 has a through hole 21. In this embodiment, the cover plate 2 can be made of soda lime glass or aluminosilicate glass. Generally, the transmittance of the infrared filler is 850 nanometers (nm) at the wavelength of light. ), the transmittance is greater than 84%, and the transmittance is less than 10% when the light wavelength is 550 nanometers (nm).

The filling body 3 is disposed in the through hole 21, and the filling body 3 has a corresponding first surface 31 and a second surface 32, and the first surface 31 and the second surface 32 respectively have the primary wavelength structure 4, And the sub-wavelength structure 4 is in contact with the air.

The sub-wavelength structure 4 includes a plurality of sub-wavelength sub-structures 41 arranged in an array and disposed on the first surface 31 and the second surface 32 . The top of each sub-wavelength substructure and the surface of the cover plate 2 are located on the same plane.

When infrared rays are incident on the surface of the sub-wavelength structure 4 from the air, the infrared rays travel to the bottom of the sub-wavelength structure 4 and enter the filling body 3 , and the infrared rays are not reflected from the surface of the sub-wavelength structure 4 .

Please refer to FIG. 2 and FIG. 3 , FIG. 2 is a schematic view of the structure of the filling body of the present invention, and FIG. 3 is an enlarged schematic view of part B in FIG. 2 . The refractive index of the sub-wavelength structure 4 on the top surface of the structure is the same as the refractive index of the environment, such as air, whose refractive index (n) is 1.0, and each sub-wavelength sub-structure 41 gets closer to the sub-wavelength sub-structure as light is incident. 41 At the bottom, its refractive index is the same as the filler 3 at the bottommost surface. The refractive index of the sub-wavelength structure 4 exhibits a graded change phenomenon (graded refractive index effect), mainly because the phenomenon occurs when the structure size is smaller than the incident wavelength.

In this embodiment, each of the sub-wavelength sub-structures 41 has a height H, a length L and a width W, the height H is less than 240 nm, the length L is less than 240 nm, the width W is less than 240 nm, and every second The distance D between the wavelength sub-structures 41 is less than 240nm, and its shape can be any shape, such as a long column shape, a cylindrical shape or a cone shape, etc. This embodiment is exemplified by the long column shape, but it is not limited to this, wherein The length L is the maximum length of the sub-wavelength substructure 41 ; the width W is the maximum width of the sub-wavelength substructure 41 ; the height H is the maximum height of the sub-wavelength substructure 41 .

Therefore, when infrared rays are incident on the surface of the sub-wavelength structure 4 from the air, the infrared rays travel to the bottom of the sub-wavelength structure 4 and enter the filling body 3 , during which no refraction occurs and the infrared rays are prevented from being reflected from the surface of the sub-wavelength structure 4 .

Please additionally refer to FIG. 4 , which is a schematic diagram of a curve of light wavelength and transmittance of the sub-wavelength structure of the present invention. The experiment of light wavelength and transmittance is carried out on two filling bodies 3, the two filling bodies 3 are the filling body 3 with the sub-wavelength structure 4 and the other filling body 3 without the sub-wavelength structure 4, respectively. Through the graph, when the light wavelength is from 500 nanometers (nm) to the light wavelength of 700 nanometers (nm), the two have almost the same transmittance. For example, when the light wavelength is 550 nanometers (nm), the two transmittances are Both were 1.04%. When the light wavelength is 700 nanometers (nm), the transmittance of the filling body 3 with the sub-wavelength structure 4 is greater than that of the other filling body 3 without the sub-wavelength structure 4, for example, when the light wavelength is 850 nanometers (nm), The transmittance of the filler 3 with the sub-wavelength structure 4 is 100%, and the transmittance of the other filler 3 without the sub-wavelength structure 4 is 85.17%, a difference of 14.83%.

That is to say, infrared rays enter and exit from the air and penetrate the filling body 3 with the sub-wavelength structure 4 without refraction and reflection, which can reduce light penetration more than the other filling body 3 without the sub-wavelength structure 4 . The loss phenomenon when the filler is penetrated.

It is further explained that when the infrared rays in the air are incident on the top of the sub-wavelength structure 4 located on the first plane 31, because the refractive index of the top of the sub-wavelength structure 4 is the same as that of the air, the infrared rays enter from the air. The top of the sub-wavelength structure 4 does not have any refraction phenomenon and no reflection phenomenon.

After the infrared rays are incident on the top of the sub-wavelength structure 4, the infrared rays are incident on the bottom of the sub-wavelength sub-structure 41. Because of the graded refractive index effect of the sub-wavelength structure 4, the refractive index at the bottom of the sub-wavelength sub-structure 41 is different from that of the filler. 3 have the same refractive index, so that when infrared rays enter the filling body 3 from the bottom of the sub-wavelength sub-structure 41 , there is no refraction phenomenon and no reflection phenomenon.

In addition, when infrared rays are emitted from the inside of the filling body 3 , the bottom refractive index of the sub-wavelength structure 4 of the second plane 32 is the same as the refractive index of the filling body 3 , so that the infrared rays reach the sub-wavelength from the filling body 3 When the substructure 41 is at the bottom, no refraction phenomenon and no reflection phenomenon occur.

After the infrared rays are injected into the bottom of the sub-wavelength structure 4, due to the graded index effect of the sub-wavelength structure 4, the refractive index of the top of the sub-wavelength structure 4 is the same as that of air, so that the infrared rays pass from the bottom of the sub-wavelength sub-structure 41. When the filling body 3 reaches the top and exits, no refraction phenomenon and no reflection phenomenon occur.

Therefore, infrared rays enter the surface of the sub-wavelength structure 4 of the first plane 31 from the air, enter the interior of the filling body 3 , and infrared rays are emitted from the interior of the filling body 3 to the surface of the sub-wavelength structure 4 of the second plane 32 . The transmittance of the filling body 3 having the sub-wavelength structure 4 is 100%, and infrared rays cannot be reflected from the surface of the sub-wavelength structure 4 .

In one embodiment, please refer to FIG. 1 , the filler 3 and the sub-wavelength structure 4 are both cured inks, the cured filler 3 has a higher refractive index, and the refractive index of the filler 3 ranges from 1.33 to In the interval of 4, the hardness is greater than Mohs hardness 3 (3H), and its composition includes 55% to 60% of resin polymer, 25% to 10% of pigment, 20% to 30% of solvent, wherein the resin polymer can be It is a polyester resin polymer or an epoxy resin polymer, the pigment can be phthalocyanine blue (C ₃₂ H ₁₆ CuN ₈ ), and the solvent can be hydrocarbon solvent, ketone solvent, alcohol solvent or vinegar solvent.

In addition, the filler 3 can be adjusted according to the required refractive index, such as adjusting the composition ratio of the filler 3 by infiltrating low or high refractive index substances.

Please refer to FIG. 5 and FIG. 6 , FIG. 5 is a schematic structural diagram of another embodiment of the present invention, and FIG. 6 is a cross-sectional view of the section line AA in FIG. 5 . In another embodiment, the cover structure 1 is used in a touch display panel module of a notebook computer, a tablet or a smart phone, mainly to improve the penetration of infrared rays for the infrared sensing module in the aforementioned products. However, in terms of appearance and visual effects, the user does not want to clearly see the infrared sensing module mechanism on the back. Therefore, the cover structure 1 further includes an ink layer 5, which is black. The ink layer 5 is disposed on a surface of the cover plate 2 , and the ink layer 5 avoids the through hole 21 . In this embodiment, the cover plate 2 is divided into a visible area 22 and a non-visible area 23 , the ink layer 5 is attached to the invisible area 23 and exposes the through hole 21 , and the filling body 3 is provided with the invisible area 23 . The through hole 21 in the region 23 .

Further, the ink layer 5 includes a first ink portion 51 and a second ink portion 52, one surface of the first ink portion 51 is attached to a surface of the substrate 2 and exposes the through hole 21; the second ink portion 51 One side of the ink portion 52 is attached to the other side of the first ink portion 51 , and the through hole 21 and the first ink portion 51 around the hole are exposed.

When the light entering the cover plate 2 is transmitted to the ink layer 5, it is absorbed, and no penetration phenomenon occurs, so that the infrared sensing module disposed under the cover plate 2 is not disturbed by other incident light.

Please refer to FIG. 7 , which is a schematic cross-sectional structure diagram of another embodiment of the present invention. In this embodiment, the filling body 3 fills the through hole 21 and the area where the ink layer 5 avoids the through hole 21 , that is, the surface of the sub-wavelength structure 4 prepared on the second surface 32 . , and the other side of the second ink portion 52 is located on the same plane.

When infrared rays are incident on the surface of the sub-wavelength structure 4 of the first plane 31 from the air, enter the interior of the filling body 3, and infrared rays are emitted from the interior of the filling body 3 to the surface of the sub-wavelength structure 4 of the second plane 32, the sub-wavelength structure 4 The structure 4 increases the transmittance of infrared rays to the filling body 3 to 100%.

Please refer to FIG. 8 . In addition, the present invention provides a method for fabricating a cover plate structure, which includes the following steps:

a. Provide a cover and a drill.

b. Use the drill to form a through hole on the cover.

c. forming a filling body in the through hole, the filling body has a corresponding first surface and a second surface, and the first surface and the second surface respectively have a plurality of wavelength sub-structures arranged in an array Subwavelength structure.

In the manufacturing method of this embodiment, when infrared rays are incident on the surface of the sub-wavelength structure from the air, the infrared rays travel to the bottom of the sub-wavelength structure and enter the filling body, during which refraction does not occur and the infrared rays are prevented from being reflected from the surface of the sub-wavelength structure. Make the filling body achieve complete penetration of infrared rays.

Please additionally refer to Figure 9. In addition, in step c, a production method is also included, and the production method includes the following steps:

c1. Provide an injection fixture and a filler.

c2. Put the cover on the injection fixture.

c3. Injection molding the filler body into the through hole.

c4. Curing the filler.

c5. Remove the injection fixture.

c6. Provide a deburring machine.

c7. Use the deburring machine to deburr the cured filler.

c8. The filler body after deburring is formed into a sub-wavelength structure.

In step c8, the production of the sub-wavelength structure is completed by processing methods such as etching, laser engraving, transfer printing or rolling.

c9. Complete the filling body in the through hole.

Please additionally refer to Figure 10. It is worth mentioning that in step c, another production method is provided, and the other production method includes the following steps:

c11. Provide a filler and a deburring machine.

c12. Curing the filler.

c13. Use the deburring machine to deburr the surface of the filler.

c14. Subwavelength structures are formed on the corresponding two surfaces of the filler.

In step c14, the sub-wavelength structure is produced by etching, laser engraving, transfer printing or rolling and other processing methods.

c15. Provide an off-line molding machine.

c16. Use the off-line molding machine to make the filling body with the diameter of the through hole.

c17. Insert the filler into the through hole.

c18. Complete the filling body in the through hole.

To sum up, by adjusting the refractive index of the filler, the transmittance of visible light can be reduced, thereby maintaining the effect of hiding the infrared detection hole, and at the same time, the sub-wavelength structure is prepared on both surfaces of the filler. , which can effectively improve the penetration rate of infrared rays.

The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced. without departing from the spirit and scope of the technical solutions of the present invention.

1: Cover structure 2: Cover 21: Through hole 22: Visible area 23: Non-visible area 3: Filler 31: First Surface 32: Second Surface 4: Subwavelength Structure 41: Subwavelength Substructure 5: ink layer 51: The first ink department 52: Second Ink Section H: height L: length W: width a~c: steps c1~c9: steps c11~c18: steps

FIG. 1 is a schematic structural diagram of the cover plate structure of the present invention. FIG. 2 is a schematic view of the structure of the packing body of the present invention. FIG. 3 is an enlarged schematic view of part B in FIG. 2 . FIG. 4 is a schematic diagram of a curve of light wavelength and transmittance of the sub-wavelength structure of the present invention. FIG. 5 is a schematic structural diagram of another embodiment of the present invention. FIG. 6 is a cross-sectional view of the section line AA in FIG. 5 . FIG. 7 is a schematic cross-sectional structure diagram of another embodiment of the present invention. 8 is a flow chart of the manufacturing method of the manufacturing method of the cover plate structure of the present invention. FIG. 9 is an actual manufacturing flow chart of the manufacturing method of the cover plate structure of the present invention. FIG. 10 is another actual manufacturing flow chart of the manufacturing method of the cover plate structure of the present invention.

1: Cover structure

2: Cover

21: Through hole

3: Filler

31: First Surface

32: Second Surface

4: Subwavelength Structure

41: Subwavelength Substructure

Claims (10)

A cover plate structure, comprising: a cover plate with a through hole; and a filling body disposed in the through hole, the filling body has a corresponding first surface and a second surface, the first surface and The second surfaces respectively have primary wavelength structures, and the secondary wavelength structures are exposed in the air; wherein, the secondary wavelength structures include a plurality of secondary wavelength substructures, and each secondary wavelength substructure has a height, a length and a width , the height is less than 240 nanometers (nm), the length is less than 240 nanometers (nm), the width is less than 240 nanometers (nm), and the distance between every two sub-wavelength substructures is less than 240 nanometers (nm); wherein , when infrared rays are incident on the surface of the sub-wavelength structure from the air, the infrared rays travel to the bottom of the sub-wavelength structure and enter the filling body, so that the incident infrared rays penetrate the filling body. The cover plate structure of claim 1, wherein a plurality of the sub-wavelength sub-structures are arranged in an array and are disposed on the first surface and the second surface. The cover plate structure according to claim 1, wherein the top of each sub-wavelength sub-structure is located on the same plane as the surface of the substrate. The cover plate structure of claim 1, wherein the filler has a transmittance of 100% to light with a wavelength of 850 nanometers (nm) to 900 nanometers (nm). The cover plate structure of claim 1, wherein the filler has a transmittance of 1.04% for light with a wavelength of 550 nanometers (nm). The cover plate structure according to claim 1, wherein the refractive index of the filler is between 1.33 and 4. The cover plate structure according to claim 1, wherein the Mohs hardness of the filling body is greater than 3 (3H). The cover plate structure according to claim 1, wherein the high infrared transmittance filled cover plate structure further comprises an ink layer, the ink layer is disposed on a surface of the substrate, and the ink layer avoids the through hole . The cover plate structure according to claim 8, wherein the ink layer includes a first ink portion and a second ink portion, one surface of the first ink portion is attached to the surface and exposes the through hole; the first ink portion One side of the two ink portions is attached to the other side of the first ink portion, and the through hole and the first ink portion around the hole are exposed. The cover plate structure according to claim 9, wherein the filling body fills the through hole and the region where the ink layer avoids the through hole, and the top of the sub-wavelength structure on the second surface is connected to the second surface. The other side of the ink portion is on the same plane.

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