Composite glass substrate and method of manufacture

Abstract

The application discloses a kind of composite glass substrate and manufacturing method, including intermediate glass substrate;Two sides of intermediate glass substrate are respectively provided with first glass substrate and second glass substrate;First glass substrate is provided with first pattern;Second glass substrate is provided with second pattern;First glass substrate and intermediate glass substrate are connected between being provided with first bonding glue;Second glass substrate and intermediate glass substrate are connected between being provided with second bonding glue.Through the double-sided pattern of the thickness exceeding the substrate range of single-side projection exposure machine being divided into three parts, the substrate thickness of the first glass substrate and the second glass substrate where the upper and lower patterns are located satisfies the substrate thickness range of exposure machine, and the single-sided pattern can be completed by the single-side projection exposure machine to prepare the double-sided high-resolution pattern, which improves the resolution of single-sided pattern.The alignment and overall structure preparation of double-sided pattern are completed by intermediate glue bonding, which reduces the cost of double-sided photolithography process.

Description

Technical Field

[0001] This invention belongs to the field of optical glass, specifically to a composite glass substrate and its manufacturing method. Background Technology

[0002] In existing technologies, processing double-sided structural patterns on optical glass surfaces requires the application of photolithography and etching techniques. The processing steps for the first side include: cleaning, resist coating, pre-baking, exposure, development, post-baking, etching, and resist removal. The processing steps for the second side are essentially the same, but an alignment process is added before exposure to align the alignment marks on the second side's mask with the marks formed on the glass substrate by the first side's mask. For glass substrates thicker than 2mm, exceeding the thickness range of projection exposure machines, single-sided exposure cannot be completed using a projection exposure machine; only proximity or contact exposure machines can be used. The resolution of proximity or contact exposure machines is lower than that of projection exposure machines, failing to meet the requirements for high-resolution pattern design. During the exposure of the second side, the alignment lens light from a single-sided exposure machine must pass through the glass substrate to identify the alignment marks. Due to light refraction, the alignment mark positions are distorted, affecting alignment accuracy. Therefore, a specialized double-sided exposure machine is required for the double-sided alignment process. Furthermore, when processing the second side of the pattern, it is also necessary to protect the first side of the pattern from damage during the processing of the second side, which is technically challenging. Summary of the Invention

[0003] To address the problems existing in the prior art, the present invention provides a composite glass substrate and a manufacturing method to solve the aforementioned problems.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A composite glass substrate, comprising an intermediate glass substrate;

[0006] A first glass substrate and a second glass substrate are respectively disposed on both sides of the intermediate glass substrate.

[0007] A first pattern is provided on the first glass substrate; a second pattern is provided on the second glass substrate;

[0008] A first bonding adhesive is provided between the first glass substrate and the intermediate glass substrate for connection; a second bonding adhesive is provided between the second glass substrate and the intermediate glass substrate for connection.

[0009] Preferably, the transmittance of the first bonding adhesive and the second bonding adhesive at the working wavelength is greater than the transmittance of the intermediate glass substrate, the first glass substrate and the second glass substrate at the working wavelength.

[0010] Preferably, the first and second patterns are formed by photoresist or by etching to remove the photoresist.

[0011] Preferably, the thickness of the intermediate glass substrate, the first glass substrate, and the second glass substrate is in the range of 100-2000 μm.

[0012] Preferably, the thickness range of the first bonding adhesive and the second bonding adhesive is 10-1000 μm.

[0013] Preferably, the first bonding adhesive, the second bonding adhesive, the intermediate glass substrate, the first glass substrate, and the second glass substrate have the same refractive index.

[0014] A method for manufacturing a composite glass substrate includes the following steps:

[0015] Step 1: Expose the first pattern to one side of the first glass substrate at the positions of the left and right alignment marks on the photomask, and expose the second pattern to one side of the second glass substrate at the positions of the left and right alignment marks on the photomask, leaving left and right alignment marks in the same position on the first and second patterns.

[0016] Step 2: The other side of the first glass substrate and one side of the intermediate glass substrate are connected using the first bonding adhesive.

[0017] Step 3: Connect the other side of the intermediate glass substrate to the other side of the second glass substrate using the second bonding adhesive.

[0018] Preferably, in step 1, the first pattern and the second pattern are exposed through a mask by a projection exposure machine or a contact exposure machine.

[0019] Preferably, in step 2, the intermediate glass substrate is vacuum-adsorbed onto the vacuum holder, and the first glass substrate is vacuum-adsorbed onto the vacuum holder suction cup, with the surface of the first pattern on the first glass substrate facing down.

[0020] A UV-curable adhesive is applied to the surface of the first glass substrate. The adhesive is then pressed open by an imprinting device and cured by UV light to complete the first bonding adhesive application.

[0021] Preferably, in step 3, the second glass substrate is vacuum-adsorbed onto the vacuum holder, with the second pattern on the second glass substrate facing upwards, and the second bonding adhesive structure is placed on the vacuum holder suction cup with the first pattern facing downwards; a pre-set UV-curable adhesive is applied to the plane of the middle glass substrate.

[0022] Adjust the position of the vacuum clamping cup so that the left and right alignment marks of the first pattern and the left and right alignment marks of the second pattern are aligned respectively;

[0023] The embossing equipment presses the adhesive onto the surface, and the adhesive is cured by ultraviolet light, completing the first bonding process.

[0024] Compared with the prior art, the present invention has the following beneficial technical effects:

[0025] This invention provides a composite glass substrate. By dividing a double-sided pattern, whose thickness exceeds the substrate thickness range of a single-sided projection lithography machine, into three parts, the thicknesses of the first and second glass substrates containing the upper and lower patterns meet the substrate thickness range of the lithography machine. The single-sided pattern can be fabricated using a single-sided projection lithography machine to achieve high-resolution double-sided pattern fabrication, thus improving the resolution of the single-sided pattern. Intermediate adhesive bonding completes the alignment of the double-sided patterns and the fabrication of the overall structure, reducing the cost of the double-sided photolithography process.

[0026] This invention provides a method for manufacturing a composite glass substrate, overcoming the difficulty of single-sided projection exposure machines in exposing substrates exceeding their thickness range. First, a single-sided projection exposure machine is used to prepare high-resolution patterns on both sides. Then, utilizing the transparency of the adhesive and glass, two bonding operations and one alignment are performed, enabling the single-sided exposure machine to complete the double-sided pattern exposure and the bonding equipment to complete the alignment process. This avoids contact and damage to the pattern on one side during the preparation of the second side. The bonding and alignment process effectively reduces the distortion of the alignment mark position caused by light refraction when the alignment lens passes through the thick glass substrate during alignment mark recognition, thus improving alignment accuracy. Attached Figure Description

[0027] Figure 1 A schematic diagram of a double-sided patterned composite glass substrate structure;

[0028] Figure 2 Flowchart for manufacturing double-sided patterned composite glass substrates;

[0029] Figure 3 This is a schematic diagram of the bonding between the first pattern and the first glass substrate;

[0030] Figure 4 This is a schematic diagram of the bonding between the second pattern and the second glass substrate.

[0031] In the attached diagram: 1. First pattern; 2. First glass substrate; 3. First bonding adhesive; 4. Intermediate glass substrate; 5. Second pattern; 6. Second glass substrate; 7. Second bonding adhesive; 8. Vacuum holder; 9. Vacuum holder suction cup. Detailed Implementation

[0032] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0033] like Figure 1As shown, the present invention discloses a composite glass substrate structure with double-sided patterns, comprising the following structure: an upper layer consisting of a first glass substrate 2 and a first pattern 1, a first bonding adhesive 3, an intermediate glass substrate 4, a second bonding adhesive 7, a second glass substrate 6, and a second pattern 5. The first pattern 1 and the second pattern 5 can be patterns formed by photoresist, or patterns formed after etching and photoresist removal. The thicknesses of the first glass substrate 2, the second glass substrate 6, and the intermediate glass substrate 4 range from 100-2000 μm, and the thicknesses of the first bonding adhesive 3 and the second bonding adhesive 7 range from 10-1000 μm. The refractive indices of the first bonding adhesive 3 and the second bonding adhesive 7 can be the same as or different from those of the glass. Under the premise of ensuring that the optical path 1 (glass thickness * glass refractive index) through the glass and the optical path 2 ((h1+h+h2) * glass refractive index + (t1+t2) * bonding adhesive refractive index) through the composite structure are both present, the individual layer structures can be arbitrarily combined within the thickness range. The composite structure thickness is 320-8000 μm.

[0034] like Figure 2 As shown, the manufacturing method of the composite glass substrate structure with double-sided patterns of the present invention includes the following process: Step 1, providing a first glass substrate 2, a second glass substrate 6, and a first pattern 1 and a second pattern 5, wherein the left and right alignment marks on the corresponding photomask are at the same position, and the exposure process is completed by a projection exposure machine or a contact exposure machine.

[0035] Step 2: First bonding adhesive 3, first glass substrate 2 and first pattern 1 are bonded to intermediate glass substrate 4. The bonding process utilizes imprinting equipment and polymer adhesive. The overall thickness uniformity of the upper surface of the first pattern 1 and the lower surface of the intermediate glass substrate 4 is + / - 3 μm.

[0036] Step 3: The second bonding adhesive 7, the second glass substrate 6, and the second pattern 5 are bonded to the combined structure of Step 2. During the bonding process, an alignment process is added for the alignment marks of the first pattern 1 and the second pattern 5. The other bonding processes are the same as in Step 2. The overall thickness uniformity of the upper surface of the first pattern 1 and the lower surface of the second pattern 5 is + / - 3 μm.

[0037] The first bonding adhesive 3 and the second bonding adhesive 7 of this invention utilize ultraviolet-curable adhesive as the bonding agent and an imprinting device as the bonding device to complete the adhesive thickness control, alignment, and curing process. Specifically, the adhesive is required to have a transmittance greater than that of glass at the working wavelength. This fully utilizes the transparency of the glass substrate and the property that the ultraviolet-curable adhesive can replace part of the glass optical path. The double-sided alignment accuracy in the imprinting device is 1µm.

[0038] like Figure 3As shown, the intermediate glass substrate 4 is vacuum-adsorbed onto the vacuum holder 8, and the first glass substrate 2 and the first pattern 1 are vacuum-adsorbed onto the vacuum holder 9, with the first pattern 1 facing downwards. A preset mass of UV-curable adhesive is applied to the plane 2 of the first glass substrate. The next step involves an imprinting device to spread the adhesive, with an area consistent with the first glass substrate 2 and a thickness meeting preset requirements. Finally, the adhesive is UV-cured, completing the first bonding adhesive 3.

[0039] like Figure 4 As shown, the second glass substrate 6 and the second pattern 5 are vacuum-adsorbed onto the vacuum holder 8, with the second pattern 5 facing upwards. After focusing the left and right objective lenses below, the left and right alignment marks on the second pattern 5 can be clearly identified, and these alignment marks are stored on the display screen. The second bonding adhesive 7 structure is placed on the vacuum holder 9, with the first pattern 1 facing downwards. A preset amount of UV-curable adhesive is then applied to the plane of the second glass substrate 6. Next, the X and Y angles of the vacuum holder are adjusted so that the left and right alignment marks of the first pattern 1 are clearly visible on the display screen, and simultaneously aligned with the left and right marks of the second pattern 5. Next, the imprinting device imprints the adhesive, with an area consistent with the second glass substrate 6 and a thickness meeting the preset requirements. Finally, the adhesive is cured with UV light, completing the second bonding adhesive 7.

Claims

1. A composite glass substrate, characterized by, The intermediate glass substrate (4) is provided with a first glass substrate (2) and a second glass substrate (6) on both sides respectively; The first glass substrate (2) is provided with a first pattern (1); and the second glass substrate (6) is provided with a second pattern (5); The first glass substrate (2) and the intermediate glass substrate (4) are connected by the first bonding glue (3); and the second glass substrate (6) and the intermediate glass substrate (4) are connected by the second bonding glue (7); The first bonding glue (3) and the second bonding glue (7) have a light transmittance at a working wavelength, which is greater than that of the intermediate glass substrate (4), the first glass substrate (2) and the second glass substrate (6) at the working wavelength; The first pattern (1) and the second pattern (5) are formed by photoresist or etching. The thickness of the intermediate glass substrate (4), the first glass substrate (2) and the second glass substrate (6) ranges from 100 to 2000 um.

2. The composite glass substrate of claim 1, wherein, The thickness of the first bonding glue (3) and the second bonding glue (7) ranges from 10 to 1000 um.

3. The composite glass substrate of claim 1, wherein, The first bonding glue (3), the second bonding glue (7), the intermediate glass substrate (4), the first glass substrate (2) and the second glass substrate (6) have the same refractive index.

4. The composite glass substrate of claim 1, wherein, The method comprises the following steps, 5. A method of manufacturing a composite glass substrate, characterized by, In step 1, the first pattern (1) and the second pattern (2) are exposed on one side of the first glass substrate (2) and the second glass substrate (6) respectively by a mask, and the first pattern (1) and the second pattern (2) have the same left-right alignment marks; In step 2, the other side of the first glass substrate (2) and one side of the intermediate glass substrate (4) are connected by the first bonding glue (3); In step 3, the other side of the intermediate glass substrate (4) is connected to the other side of the second glass substrate (6) by the second bonding glue (7). In step 1, the first pattern (1) and the second pattern (2) are exposed by a mask through a projection exposure machine or a contact exposure machine.

6. The method of claim 5, wherein In step 2, the intermediate glass substrate (4) is vacuum adsorbed on a vacuum fixing device (8), the first glass substrate (2) is vacuum adsorbed on a vacuum fixing chuck (9), and the side of the first glass substrate (2) on which the first pattern (1) is located faces downward; 7. The method of claim 5, wherein In step 3, the second glass substrate (6) is vacuum adsorbed on the vacuum fixing device (8), the side of the second glass substrate (6) on which the second pattern (5) is located faces upward, the second bonding glue (7) is arranged on the vacuum fixing chuck (9), the side of the first pattern (1) faces downward, and the intermediate glass substrate (4) is dotted with preset ultraviolet curing glue; The position of the vacuum fixing chuck (9) is adjusted so that the left-right alignment marks of the first pattern (1) and the left-right alignment marks of the second pattern (5) are aligned respectively.

8. The method of claim 5, wherein ​ ​ The imprinting device imprints the glue, the ultraviolet light cures the glue, and the first bonding glue (3) is completed.

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