A method for simultaneously processing blind holes and through holes on a glass substrate
By combining laser-induced modification and chemical etching, blind holes and through holes can be processed simultaneously on glass substrates, solving the problems of high processing accuracy and cost, and improving processing accuracy and electrical performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- 10TH RES INST OF CETC
- Filing Date
- 2026-01-26
- Publication Date
- 2026-06-09
AI Technical Summary
Existing technologies make it difficult to quickly and accurately process blind and through holes with high aspect ratios on glass substrates, and traditional methods suffer from high costs and difficulties in process alignment.
A laser-induced modification combined with chemical etching method is used to differentially modify different areas of blind holes and through holes on a glass substrate. The modified areas are formed by laser focusing, followed by annealing, and finally etching with chemical etching solution to achieve simultaneous processing of blind holes and through holes.
It improves processing accuracy and consistency, reduces material damage, reduces thermal stress cracking and mechanical damage, ensures the accuracy of hole diameter and depth, and enhances electrical performance and packaging reliability.
Smart Images
Figure CN122167033A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of three-dimensional integrated packaging adapter board manufacturing technology, and more specifically, to a method for simultaneously processing blind holes and through holes on a glass substrate. Background Technology
[0002] TGV stands for Vertical Electrical Interconnect Via. TGV blind vias are conductive holes that connect the surface and inner layers without penetrating the entire substrate. Located on the surface or bottom layer of the TGV glass substrate, they have a certain depth and are used to connect surface layer circuitry to underlying inner layer circuitry. The depth of these holes typically does not exceed a certain limit. In contrast to TSV, as a potential alternative to silicon substrates, through-glass via (TGV) three-dimensional interconnect technology is becoming a current research hotspot due to its numerous advantages.
[0003] The approximate range of applications for TGVs with blind and through holes includes: 3D integrated passive components on glass substrates, MEMS packaging with glass through holes, embedded glass fan-out, integrated antennas for TGVs, and multi-chip packaging on multi-layer glass substrates.
[0004] A key challenge facing TGV technology is the lack of a deep etching process similar to that used in silicon, making it difficult to rapidly fabricate high aspect ratio deep holes or trenches in glass. The key to manufacturing TGV blind and through-hole vias lies in precise perforation of the glass substrate; this often involves methods such as laser ablation, focused discharge machining, plasma etching, or laser-induced etching. Laser ablation forms through-holes by rapidly heating and evaporating the glass material using a laser, while laser-induced etching uses ultrashort pulse lasers to create specific modified regions in the glass, followed by chemical etching to complete the through-hole formation.
[0005] Fabricating blind vias and through-holes on the same substrate requires selective etching due to the isotropic nature of the TGV wet etching liquid. Typically, masks are used on the glass substrate to protect areas that do not require etching, enabling differentiated manufacturing of blind vias and through-holes. However, the mask material must be corrosion-resistant and precisely aligned to ensure the accurate position and shape of the holes. Traditional sandblasting and laser drilling methods also have certain limitations. Summary of the Invention
[0006] The technical problem to be solved by the present invention is to provide a method for simultaneously processing blind holes and through holes on a glass substrate, which effectively solves the technical problems of high cost and difficulty in process alignment caused by the properties of the glass substrate itself and the existing mask technology. The solution adopted by this invention to solve the technical problem is: A method for simultaneously processing blind vias and through vias on a glass substrate specifically includes the following steps: Step S1: Clean and dry the glass substrate using a cleaning solution; Step S2: Heat and control the temperature of the glass substrate; the temperature of the glass substrate after heating is 100-300℃; Step S3: Use laser equipment to perform laser-induced modification on the patterned areas of the pre-made through holes and pre-made blind holes in the glass substrate to form the through hole pattern modification area of the pre-made through holes and the blind hole pattern modification area of the pre-made blind holes. Step S4: After forming the through-hole pattern modification region of the pre-formed through-hole and the blind-hole pattern modification region of the pre-formed blind hole on the glass substrate, the glass substrate is annealed and cooled to room temperature. Step S5: Use chemical etching solution to etch the through-hole pattern modification area and blind hole pattern modification area of the glass substrate. Step S6: Clean the processed glass substrate to remove residual corrosion and complete the processing.
[0007] In some possible implementations, the cooling rate during annealing does not exceed 30°C / min.
[0008] In some possible implementations, when laser-induced modification is performed on the pre-fabricated through-hole image area, the laser is focused on the center position of the pre-fabricated through-hole pattern area, with the focal point located at 50% of the depth of the pre-fabricated through-hole, forming a through-hole pattern modification area.
[0009] In some possible implementations, when laser-induced modification is performed on the pre-fabricated blind hole pattern area, the laser is focused on the center position of the pre-fabricated blind hole pattern area, the focal point is located on one side of the glass substrate, and the opening of the blind hole is located on the focal point side, forming a blind hole pattern modification area with an opening.
[0010] In some possible implementations, the laser-induced modification of the pre-fabricated blind hole pattern region specifically includes the following steps: The laser focus is controlled to be located at the center of the glass substrate and pointing upwards. The laser equipment performs laser-induced modification on the pre-fabricated blind hole area on the front side of the glass substrate to form a pre-fabricated through hole modification area with an upward opening. The laser focus is controlled to be located at the center of the glass substrate and pointing downwards. The laser device performs laser-induced modification on the pre-fabricated through-hole area with an opening on the back of the glass substrate to form a pre-fabricated blind hole modification area II with an opening pointing downwards.
[0011] In some possible implementations, when performing laser-induced modification on the patterned area of pre-fabricated through holes or pre-fabricated blind holes, the laser focal length is 0.1~0.3mm, the laser energy is 5~30W, the pulse number is 1~3, the pulse width is 1000~1500fs, the frequency is 200~300kHz, the laser scanning speed is 2-4mm / s, and the laser processing acceleration is 20-30mm / s. 2 .
[0012] In some possible implementations, step S1 specifically includes the following steps: Step S11: Heat the cleaning solution to 50~60℃ and immerse the glass substrate in the solution for 5~10 minutes or use ultrasonic cleaning for 2~3 minutes. Step S12: Rinse with clean water; Step S13: Drying, the drying temperature is 90~100℃.
[0013] In some possible implementations, the cleaning solution comprises 3-5 parts deionized water, 2-5 parts fatty alcohol polyoxyethylene ether, 2-5 parts triethanolamine, and 1-2 parts EDTA complexing agent.
[0014] In some possible implementations, step S6 specifically refers to: The glass substrate, after laser-induced modification, is immersed in the chemical etching solution of an ultrasonic device to etch the glass substrate. The etching is stopped after the diameter of the through holes reaches the required level, and the blind holes also reach the same diameter and preset depth.
[0015] In some possible embodiments, the chemical etching solution comprises 100 parts of deionized water, 40 parts of hydrofluoric acid, and 8 parts of ammonium fluoride; when etching the glass substrate, the temperature of the chemical etching solution is 25°C to 30°C, the etching power is 200W, and the etching time is 2.5 hours.
[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention modifies different regions of pre-fabricated through holes and pre-fabricated blind holes on the same glass substrate, performs laser induction on glass layers of different depths, and then uses wet etching to realize the fabrication of blind holes and through holes on the same glass substrate, thus meeting the needs of three-dimensional packaging of different glass substrates. This invention uses different laser focusing methods to form differentiated induced modification regions on a glass substrate, ensuring that through-holes and blind holes are fabricated simultaneously; This invention reduces material damage, the number of material processing steps, thermal stress cracks, and mechanical damage; This invention significantly improves processing precision and consistency, as well as positional accuracy, which is crucial for high-density interconnects. The aperture and depth help improve electrical performance and package reliability. Attached Figure Description
[0017] Figure 1 This is a flowchart of the process of the present invention; Figure 2 Microscopic cross-sectional images of blind holes and through holes prepared using Example 1. Detailed Implementation
[0018] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. The terms "first," "second," and similar terms used in this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, "a" or "one," etc., do not indicate a quantity limitation, but rather indicate the existence of at least one. In the implementation of this application, "and / or" describes the association relationship of related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more. For example, multiple positioning posts refer to two or more positioning posts. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0019] The present invention will now be described in detail.
[0020] Example 1: like Figure 1 As shown, a method for simultaneously processing blind vias and through-holes on a glass substrate, wherein through-holes and blind vias are simultaneously processed on a 500µm glass substrate; specifically, the method includes the following steps: A 500µm thick glass substrate was ultrasonically cleaned in a cleaning solution and then dried in hot air. The cleaning solution was a mixed solution comprising deionized water, fatty alcohol polyoxyethylene ether, triethanolamine and EDTA complexing agent in a mass ratio of 4:3:2:1. Specifically, heat to 55℃, ultrasonically clean for 3 minutes, the ultrasonic machine has a working power of 100W, rinse twice with clean water after cleaning, and then dry at 90℃. The glass substrate is heated to 250°C at a rate of 20°C / min, and then placed on the stage of the laser equipment for laser modification. Specifically, the glass substrate is placed on the stage of the laser device, and the height of the stage is adjusted so that the laser focus is located at the center of the pre-fabrication depth of the through-holes and blind holes in the glass substrate, and the pre-fabrication through-hole area or pre-fabrication blind hole area is irradiated; the pre-fabrication through-hole area on the front side of the glass substrate is laser-induced modified using a femtosecond laser device to form a pre-fabrication through-hole modified area. The laser equipment is a femtosecond laser with a rated power of 30W. The operating parameters of the femtosecond laser equipment were adjusted as follows: laser focal length 0.25mm, laser energy 22W, pulse number 1, pulse width 1200fs, frequency 270kHz, laser scanning speed 4mm / s, and laser processing acceleration 30mm / s². 2 .
[0021] Specifically, the stage height is adjusted so that the laser focus is located 240µm above the center of the glass substrate. A femtosecond laser device is used to perform laser-induced modification on the pre-fabricated blind hole area on the front side of the glass substrate to form an upward-opening pre-fabricated through-hole modification area. Adjust the stage height so that the laser focus is located 350um downward from the center of the glass substrate (the focus is outside the glass substrate). Use a femtosecond laser device to perform laser-induced modification on the pre-fabricated through-hole area with an opening on the back of the glass substrate to form a pre-fabricated blind hole modification area II with a downward opening. By adjusting the height of the stage, the position of the glass substrate can be adjusted, allowing modification according to the depth of through holes or blind holes. The laser-induced modified glass substrate was placed in a temperature-controlled oven for annealing to eliminate the thermal stress generated by the laser. During annealing, the temperature was reduced from 250°C to room temperature at a cooling rate of 15°C / min.
[0022] The annealed glass substrate is immersed in the chemical etching solution of an ultrasonic device for etching. In some possible implementations, the chemical etching solution includes 100 parts deionized water, 40 parts hydrofluoric acid, and 8 parts ammonium fluoride. The temperature of the chemical etching solution is 25°C to 30°C. Under the condition that the ultrasonic power of the ultrasonic equipment is 200W, the glass substrate is etched continuously for 1.5 hours. The etching stops when the diameter of the through hole reaches 38 micrometers, and the blind holes also reach the same diameter and preset depth.
[0023] After etching, the glass substrate is placed in the cleaning tank of an ultrasonic cleaning device, using deionized water as the cleaning medium, and then dried after ultrasonic cleaning. The ultrasonic cleaning device has a working power of 80W, a cleaning time of 12 minutes, and a drying temperature of 100℃.
[0024] The results of this embodiment were observed using a Keyence VK-3000 microscope as follows: Figure 2 The through-hole has a depth of 477.12 μm and a diameter of 38.385 μm; the upward-opening blind hole has a depth of 233.749 μm and a diameter of 37.161 μm; the downward-opening blind hole has a depth of 135.915 μm and a diameter of 37.775 μm; the morphology of the blind holes and through holes is good.
[0025] Example 2: like Figure 1 As shown, the method for simultaneously processing blind holes and through holes on a glass substrate in this embodiment differs from the previous embodiment in that: during annealing, the substrate is cooled to room temperature at a cooling rate of 15°C / min; subsequently, the annealed glass substrate is immersed in the chemical etching solution of an ultrasonic device for etching; observed using a Keyence VK-3000 microscope, the etching time required to achieve a through hole diameter of approximately 38 micrometers is 2 hours, and the blind holes also achieve the same diameter, with good morphology for both blind holes and through holes.
[0026] Example 3: The difference between this embodiment and Embodiment 1 is that the laser energy is 20W; and the etching time used to achieve a through-hole diameter of approximately 38 micrometers was 2.2 hours, as observed by a Keyence VK-3000 microscope. At the same time, the blind holes also achieved the same diameter, and the morphology of the blind holes and through holes was good.
[0027] Comparative Example 1: The difference between this comparative example and Example 3 is that the cleaned and dried glass substrate is not heated, and the laser modification, etching, and cleaning operations are performed sequentially at room temperature; no annealing treatment is performed. Observation using a Keyence VK-3000 microscope revealed that the formed through-holes and blind holes had cracks on their surface.
[0028] This invention is not limited to the specific embodiments described above. The invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.
Claims
1. A method for simultaneously processing blind holes and through holes on a glass substrate, characterized in that, Specifically, the following steps are included: Step S1: Clean and dry the glass substrate using a cleaning solution; Step S2: Heat and control the temperature of the glass substrate; the temperature of the glass substrate after heating is 100-300℃; Step S3: Use laser equipment to perform laser-induced modification on the patterned areas of the pre-made through holes and pre-made blind holes in the glass substrate to form the through hole pattern modification area of the pre-made through holes and the blind hole pattern modification area of the pre-made blind holes. Step S4: After forming the through-hole pattern modification region of the pre-formed through-hole and the blind-hole pattern modification region of the pre-formed blind hole on the glass substrate, the glass substrate is annealed and cooled to room temperature. Step S5: Use chemical etching solution to etch the through-hole pattern modification area and blind hole pattern modification area of the glass substrate. Step S6: Clean the processed glass substrate to remove residual corrosion and complete the processing.
2. The method for simultaneously processing blind holes and through holes on a glass substrate according to claim 1, characterized in that, During annealing, the cooling rate should not exceed 30°C / min.
3. The method for simultaneously processing blind holes and through holes on a glass substrate according to claim 1, characterized in that, When performing laser-induced modification on the pre-fabricated through-hole image area, the laser is focused on the center position of the pre-fabricated through-hole pattern area, with the focal point located at 50% of the depth of the pre-fabricated through-hole, forming the through-hole pattern modification area.
4. The method for simultaneously processing blind holes and through holes on a glass substrate according to claim 3, characterized in that, When performing laser-induced modification on a pre-fabricated blind hole pattern area, the laser is focused on the center of the pre-fabricated blind hole pattern area, with the focal point located on one side of the glass substrate. The opening of the blind hole is located on the focal point side, forming a blind hole pattern modification area with an opening.
5. A method for simultaneously processing blind holes and through holes on a glass substrate according to claim 4, characterized in that, When performing laser-induced modification on the prefabricated blind hole pattern area, the specific steps include: The laser focus is controlled to be located at the center of the glass substrate and pointing upwards. The laser equipment performs laser-induced modification on the pre-fabricated blind hole area on the front side of the glass substrate to form a pre-fabricated through hole modification area with an upward opening. The laser focus is controlled to be located at the center of the glass substrate and pointing downwards. The laser device performs laser-induced modification on the pre-fabricated through-hole area with an opening on the back of the glass substrate to form a pre-fabricated blind hole modification area II with an opening pointing downwards.
6. A method for simultaneously processing blind holes and through holes on a glass substrate according to claim 4, characterized in that, When performing laser-induced modification on the patterned areas of pre-formed through holes or pre-formed blind holes, the laser focal length is 0.1~0.3mm, the laser energy is 5~30W, the pulse number is 1~3, the pulse width is 1000~1500fs, the frequency is 200~300kHz, the laser scanning speed is 2-4mm / s, and the laser processing acceleration is 20-30mm / s. 2 .
7. A method for simultaneously processing blind holes and through holes on a glass substrate according to claim 1, characterized in that, Step S1 specifically includes the following steps: Step S11: Heat the cleaning solution to 50~60℃ and immerse the glass substrate in the solution for 5~10 minutes or use ultrasonic cleaning for 2~3 minutes. Step S12: Rinse with clean water; Step S13: Drying, the drying temperature is 90~100℃.
8. A method for simultaneously processing blind holes and through holes on a glass substrate according to any one of claims 1-7, characterized in that, The cleaning solution comprises 3-5 parts deionized water, 2-5 parts fatty alcohol polyoxyethylene ether, 2-5 parts triethanolamine, and 1-2 parts EDTA complexing agent.
9. A method for simultaneously processing blind holes and through holes on a glass substrate according to any one of claims 1-8, characterized in that, Step S6 specifically refers to: The glass substrate, after laser-induced modification, is immersed in the chemical etching solution of an ultrasonic device to etch the glass substrate. The etching is stopped after the diameter of the through holes reaches the required level, and the blind holes also reach the same diameter and preset depth.
10. A method for simultaneously processing blind holes and through holes on a glass substrate according to claim 9, characterized in that, The chemical etching solution comprises 100 parts of deionized water, 40 parts of hydrofluoric acid, and 8 parts of ammonium fluoride. When etching the glass substrate, the temperature of the chemical etching solution is 25°C to 30°C, the etching power is 200W, and the etching time is 2.5 hours.