TWI470290B - Method of making a light guide plate, light guide plate and mask - Google Patents

Description

Light guide plate manufacturing method, light guide plate and cover plate

The invention relates to a method for manufacturing a light guide plate, in particular to a method for manufacturing a light guide plate with an optical microstructure.

Since the liquid crystal panel of a liquid crystal display (LCD) cannot be actively illuminated by itself, a backlight module (Backlight Module) is required to provide the light required for the liquid crystal display. The backlight module can be divided into a direct type backlight module and an edge light type backlight module according to the position of the light source.

The invention patent of No. I325502 discloses a light diffusing plate of a direct type backlight module, which comprises a transparent substrate and a plurality of optical structures. The thickness of the transparent substrate is between 1.5 and 2 millimeters (mm), and the optical structure is disposed on the light-emitting surface of the transparent substrate by printing, etching, hot rolling or the like.

Different from the direct-type backlight module, the edge-lit backlight module has a light source disposed on the side of the light guide plate, and the light guide guides the entire liquid crystal panel through the light guide plate, so that less light source can be used, saving cost and saving In addition, since the position of the light source does not affect the thickness of the backlight module, the thickness of the entire screen can be reduced. The edge-lit backlight module is particularly suitable for compact portable electronic products.

The light guide plate used in the edge-lit backlight module needs to meet the requirements of thin and fine optical structure. If the optical structure of the optical module of the direct-lit backlight module is directly applied to the light guide plate of the edge-lit backlight module, There are the following problems: the printed dot size and ink viscosity are not easy to control, the product is good The rate is low and gradually eliminated; the existing etching process is applied to the mold, the process includes coating photoresist, developing exposure, removing the photoresist layer, etc., and then manufacturing the light guide plate by hot stamping, the process is not only complicated but also manufactured. The optical structure of the light guide plate is about 150 micrometers (μm), which can no longer be broken. The hot rolling is easy to produce yellowing due to the use of additional materials, which affects the yield problem. In addition, there are still industry-recommended inkjet methods to produce fine spots, as well as the use of laser engraving highlights. However, the former has the same problem of yellowing of the material as the hot rolling method; although the latter can produce a fine optical structure, the process is quite time consuming and cannot be mass-produced.

From the above, it is known that a light guide plate manufacturing method requiring a fine optical structure still needs to be broken.

Accordingly, it is an object of the present invention to provide a light guide plate manufacturing method which can produce a fine optical structure and is suitable for rapid mass production.

Therefore, the method for manufacturing a light guide plate of the present invention comprises the following steps: (A) providing a substrate and a cover plate covered on the substrate, the cover plate being provided with a plurality of openings having a size of 10 to 150 micrometers, the substrate pair (B) etching the exposed portion of the substrate by plasma etching; and (C) removing the cover plate, which is a light guide plate having an optical structure.

Preferably, the cover plate comprises a metal layer having a thickness of 10 to 200 microns. More preferably, the metal layer material is selected from the group consisting of nickel, copper, aluminum, and stainless steel.

Preferably, the cover plate further comprises a polymer layer attached to the bottom surface of the metal layer and having a thickness of 10 to 400 μm. More preferably, the polymer layer material is selected from the group consisting of polyethylene (PE), polyethylene terephthalate (PET), and polyimine (PI).

Preferably, the surface of the electrode used in the plasma etching of the step (B) has a curved shape with a low central side and a side of the substrate and the cover plate disposed on the electrode due to gravity or outward extension. A pull-down effect is generated to adhere the substrate and the cover sheet to the electrode. Alternatively, the electrode used in the step (B) plasma etching provides static electricity so that the substrate and the cover plate are closely attached to the electrode. Alternatively, the step (B) of the plasma etching is provided on both sides of the machine with springs and clamps, and the clamps are placed on both sides of the cover plate to generate outward and downward force on the cover plate, thereby tightening The substrate is pressed to adhere the substrate to the electrode.

For the purpose of mass production, the plasma etching in the step (B) is to provide a plurality of layer electrodes in the etching chamber, and at the same time, a plurality of light guide plates are fabricated.

Preferably, the opening of the cover plate used in the present invention is formed by laser processing.

Preferably, the material of the substrate used in the present invention is selected from the group consisting of polymethyl methacrylate (PMMA) and polyethylene terephthalate (PET).

Another object of the present invention is to provide a light guide plate produced by the above-described light guide plate manufacturing method.

It is still another object of the present invention to provide a cover sheet for performing the above-described method of manufacturing a light guide plate. The utility model has the advantages that the light guide plate can be directly manufactured by using the design of the cover plate and the plasma etching technology, and the light guide plate having the fine optical structure can be mass-produced without the need to fabricate the film core and the process of performing the photoresist development and removal. Appropriate plasma etch parameters can be adjusted to a high etch selectivity of the hood to the substrate such that the hood of the present invention can be reused for a convenient and cost effective addition.

The above and other technical contents, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments.

Referring to FIG. 1, a preferred embodiment of a method of fabricating a light guide plate of the present invention comprises the following steps:

Step S1 - providing a substrate 1 as shown in FIG. 2 and a cover plate 2 covering the substrate 1 so that the substrate 1 and the cover plate 2 are attached to the electrodes 3 of the plasma etching system.

The material of the substrate 1 used in this embodiment may be polymethyl methacrylate (PMMA) or polyethylene terephthalate (PET).

The cover plate 2 is detailed as shown in FIG. 3, and includes a metal layer 21 having a thickness of 10 to 200 μm, a polymer layer 22 attached to the bottom surface of the metal layer 21 and having a thickness of 10 to 400 μm, and a majority The metal layer 21 and the opening 23 of the polymer layer 22 are passed through. The substrate 1 is correspondingly exposed at the opening 23 and thus exposed. The aforementioned polymer layer 22 can make the overall cover 2 have a better adhesion to the substrate 1, and provide a buffering and stabilizing effect in subsequent processes.

Each of the openings 23 of the cover panel 2 has a size between 10 and 150 micrometers, and can be formed by laser processing or drilling machine drilling; since the overall thickness of the cover panel 2 is relatively thin, regardless of the laser processing or drilling The hole drilling machine can be completed quickly.

The material of the metal layer 21 of the cover plate 2 may be nickel, copper, aluminum or stainless steel. The polymer layer 22 may be made of polyethylene (PE), polyethylene terephthalate (PET) or polyimine (PI).

Step S2: etching the exposed portion of the substrate 1 by plasma etching to obtain a result as shown in FIG.

In this embodiment, by controlling the plasma process parameters including the plasma gas type, the plasma gas flow rate, the pressure in the chamber 4, and the voltage of the electrode 3, etching is performed to produce a desired optical structural state, such as a V-groove, Cylindrical or conical grooves, etc. In addition, the high etching selectivity of the mask 2 to the substrate 1 can be adjusted by appropriate plasma etching parameters so that the mask 2 can be reused.

It is worth mentioning that, in order to provide a better adhesion effect of the substrate 1 and the cover plate 2 on the electrode 3, the electrode 3 used in the embodiment has a curved surface with a high central side and a low side as shown in FIG. The side of the substrate 1 and the cover 2 placed on the electrode 3 is pulled down by the gravity G, and the substrate 1 and the cover 2 are adhered to the electrode 3. Alternatively, by electrostatically supplying the electrode 3, the substrate 1 and the cover sheet 2 are adhered to the electrode 3 by static electricity. In addition, as shown in FIG. 6, at least one spring 51 and at least one clamp 52 are respectively disposed on both sides of the machine table 5, and the clamp 52 is clamped on both sides of the cover plate 2 to generate outwardly and The force pulled downward is thereby pressed against the substrate 1 to adhere the substrate 1 to the electrode 3.

Step S3 - removing the cover 2, leaving the substrate as shown in FIG. 7, which is the light guide 100 having the optical structure 10.

Further, in order to achieve mass production, in the actual operation of the present invention, as shown in FIG. 8, a plurality of layer electrodes 3 may be provided in the etching chamber 4, and a plurality of light guide plates 100 may be fabricated at the same time.

In summary, the method for manufacturing the light guide plate of the present invention utilizes the design of the cover plate 2, and the plasma etching technology, instead of the conventional process of performing photoresist development, removal, etc. Printing, inkjet, transfer, laser engraving and other shortcomings, can quickly mass produce light guide plate 100 with fine optical structure 10, the light guide plate 100 can be applied to edge-light backlight module or solar photovoltaic panel, and cover plate 2 It can be reused, is quite convenient and cost-effective, so it can achieve the object of the present invention.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent.

1. . . Substrate

10. . . Optical structure

100. . . Light guide

2. . . Cover plate

twenty one. . . Metal layer

twenty two. . . Polymer layer

3. . . electrode

4. . . Etching chamber

5. . . Machine

51. . . spring

52. . . Fixture

S1~S3. . . step

1 is a flow chart showing the steps of a preferred embodiment of a method for fabricating a light guide plate of the present invention; FIG. 2 is a schematic view showing a front view of the present embodiment before performing plasma etching; and FIG. 3 is a partially enlarged schematic view of a cover plate; 4 is a schematic view showing the plasma etching after the embodiment is performed; FIG. 5 is a schematic view showing the shape of the electrode used in the embodiment; and FIG. 6 is a view illustrating the substrate by using a spring and a clamp to sandwich the cover plate. FIG. 7 is a schematic view showing a light guide plate manufactured in the embodiment; and FIG. 8 is an electrode configuration type for explaining the effect of mass production in the actual operation of the embodiment. state.

S1~S3. . . step

Claims (12)

A method for manufacturing a light guide plate, comprising the steps of: (A) providing a substrate and a reusable cover plate covered on the substrate, the cover plate comprising a metal layer and provided with a plurality of sizes of 10 to 150 microns Opening the substrate, the substrate is exposed at the same opening; (B) etching the exposed portion of the substrate by plasma etching; and (C) removing the cover as another light guide process, the substrate is The light guide plate having an optical structure; wherein the plasma etching in the step (B) is to provide a plurality of layer electrodes in the etching chamber, and at the same time, a plurality of light guide plates are fabricated. The method of manufacturing a light guide plate according to the first aspect of the invention, wherein the metal layer has a thickness of 10 to 200 μm. The method of manufacturing a light guide plate according to claim 2, wherein the metal layer material is selected from the group consisting of nickel, copper, aluminum, and stainless steel. The method of manufacturing a light guide plate according to claim 2, wherein the cover plate further comprises a polymer layer attached to the bottom surface of the metal layer and having a thickness of 10 to 400 μm. The method for manufacturing a light guide plate according to claim 4, wherein the polymer layer material is selected from the group consisting of polyethylene (PE), polyethylene terephthalate (PET), and polyimine (PI). The group formed. The method of manufacturing a light guide plate according to any one of claims 1 to 5, wherein the step (B) each electrode used for plasma etching The surface has a curved shape with a central height and a low side, and the side of the substrate and the cover plate placed on the electrode is pulled down by gravity, so that the substrate and the cover plate are closely attached to the electrode. The method of manufacturing a light guide plate according to any one of claims 1 to 5, wherein each of the electrodes used in the step (B) plasma etching provides static electricity, and the substrate and the cover plate are closely attached to each other. On the electrode. The method of manufacturing a light guide plate according to any one of claims 1 to 5, wherein the step (B) is provided at each side of a machine platform where the electrodes are used for plasma etching, At least one spring coupled to the machine and at least one clamp disposed at an end of the spring, the clamps being clamped on both sides of the cover plate on each of the electrodes to generate outward and downward force on the cover plate Thereby, the substrate is pressed tightly to adhere the substrate to the corresponding electrode. The method of manufacturing a light guide plate according to any one of claims 1 to 5, wherein the opening of the cover plate is formed by a laser processing or drilling machine. The method of manufacturing a light guide plate according to the first aspect of the invention, wherein the material of the substrate is selected from the group consisting of polymethyl methacrylate (PMMA) and polyethylene terephthalate (PET). . A light guide plate produced by the method of manufacturing a light guide plate according to any one of claims 1 to 10. A cover sheet for performing the method of manufacturing a light guide plate according to any one of claims 1 to 10.