Manufacturing method of glass through hole

Abstract

The embodiment of the invention provides a manufacturing method of a glass through hole, which is used for solving the technical problem that a glass through hole with an ultrahigh depth-diameter ratio cannot be manufactured according to a pre-designed scheme in an existing manufacturing method of the glass through hole. According to the manufacturing method of the glass through hole, before laser-induced modification, exposed prefabricated through hole graphical areas are formed on the front face and the back face of a glass substrate through the micron-order photoresist mask technology, and meanwhile a photoresist layer with the thickness not smaller than 5 micrometers is formed on the surface, outside the prefabricated through hole graphical areas, of the glass substrate. In the laser-induced modification stage, laser with higher irradiation power can be used for deeply modifying the glass material in the prefabricated through hole patterned area to form a prefabricated through hole modified area. In the chemical etching stage, the surface of the glass substrate outside the prefabricated through hole modified area is covered with the anti-corrosion photoresist layer, and etching liquid only acts on the prefabricated through hole modified area, so that the phenomenon that the thickness of the glass substrate is reduced in the etching process is effectively prevented.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated circuit packaging, and in particular to a method for manufacturing a through-glass via. Background Art

[0002] With the rapid development of semiconductor applications, the market demand for high integration and high performance of electronic devices continues to increase. However, traditional two-dimensional packaging technology is difficult to meet this development trend due to the physical size limitations of the packaging substrate. For this reason, three-dimensional integration and advanced packaging technology (3D-stacking and AdvancedPackaging) based on through silicon vias (TSV) came into being. This technology introduces a vertical through-hole structure between multi-layer substrates to achieve high-density electrical interconnection, thereby significantly improving the integration and performance of the device.

[0003] Due to the semiconductor properties of silicon materials, the sidewalls of silicon vias must undergo strict insulation treatment, which not only increases the complexity of the manufacturing process, but also significantly increases the manufacturing cost, especially when the aperture is extremely small. In contrast, through-glass via (TGV) technology has become another option besides through-silicon via (TSV) technology due to the natural insulation of glass and relatively low processing costs, and has significant advantages in high-performance device applications. However, to achieve ultra-high-density electrical interconnection, it is necessary to form glass vias with ultra-high aspect ratio (≥75:1) on the glass substrate through glass via (TGV) technology to provide more electrical connection paths on a limited substrate area. This ultra-high aspect ratio glass via not only meets the needs of high-density interconnection, but also effectively utilizes the electrical insulation properties of glass to reduce signal interference and improve the transmission quality of RF signals.

[0004] However, in the process of implementing the technical solution in the embodiment of the present invention, the inventors found that the existing method for manufacturing through-glass vias has at least the following technical problems:

[0005] The chemical etching rate of the modified area of ​​the prefabricated through hole formed by a picosecond laser is too low, the through hole etching takes a long time, and there is thinning during the etching process of the glass substrate, making it impossible to make a glass through hole with an ultra-high aspect ratio according to the pre-designed plan. Summary of the invention

[0006] In view of this, an object of an embodiment of the present invention is to provide a method for manufacturing a through-glass via to solve the technical problem that the existing method for manufacturing a through-glass via cannot manufacture a through-glass via with an ultra-high aspect ratio according to a pre-designed solution.

[0007] In order to achieve the above purpose, the technical solutions adopted in the embodiments of the present invention are as follows:

[0008] An embodiment of the present invention provides a method for manufacturing a through-glass via, comprising the following steps:

[0009] Firstly, the glass substrate is ultrasonically cleaned using a mixed cleaning solution consisting of deionized water, alcohol and acetone, and then the cleaned glass substrate is dried;

[0010] The glass substrate is subjected to mask processing by using a photoresist mask technology to form an exposed prefabricated through-hole patterned area and a protection area covered by a photoresist layer having a thickness of not less than 5 μm on both sides of the glass substrate;

[0011] Using a femtosecond laser, at a laser irradiation power of 80 to 100% of the irradiation power of the device, laser-induced modification is performed on the prefabricated through hole patterned regions on the front and back sides of the glass substrate to form prefabricated through hole modified regions;

[0012] The glass substrate after laser induced modification is placed in a cleaning tank of an ultrasonic device for cleaning to remove impurities generated by the laser induced modification, and then dried after cleaning;

[0013] Placing the dried glass substrate into an etching tank of an ultrasonic etching device for etching until a glass through hole is formed on the glass substrate;

[0014] The photoresist layer on the etched glass substrate is removed and ultrasonic cleaning is performed.

[0015] Optionally, the thickness of the photoresist layer formed in the step of performing mask processing on the glass substrate using a photoresist mask technology is 10-15 μm.

[0016] Optionally, the photoresist used in the step of performing mask processing on the glass substrate using a photoresist mask technology is a positive photoresist.

[0017] Optionally, the components of the positive photoresist have a mass ratio of: 17% naphthoquinone, 63% phenolic resin, 18% ethylene glycol monomethyl ether acetate, and the remainder is a leveling agent, a plasticizer and a surfactant.

[0018] Optionally, in the step of using a femtosecond laser to perform laser-induced modification on the prefabricated through-hole patterning areas on the front and back sides of the glass substrate at a laser irradiation power of 80 to 100% of the irradiation power of the device, the working parameters of the femtosecond laser are:

[0019] The number of laser pulses is 2, the processing type is perforation, the laser focal length is 3.6-3.9 mm, the laser irradiation power is 80-100% of the equipment power, the scanning speed is 20 mm / s, and the acceleration is 200 mm / s 2 .

[0020] Optionally, the etching solution used in the step of placing the dried glass substrate into an etching tank of an ultrasonic etching device for etching treatment is a hydrofluoric acid etching solution.

[0021] Optionally, the hydrofluoric acid content in the hydrofluoric acid etching solution is 10-15%.

[0022] Compared with the existing method for making through-glass holes, the method for making through-glass holes in the embodiment of the present invention forms exposed prefabricated through-hole patterned areas on both sides of the glass substrate by using micron-level photoresist mask technology before laser induced modification, and forms a photoresist layer with a thickness of not less than 5 μm on the surface of the glass substrate outside the prefabricated through-hole patterned area. The photoresist layer around the prefabricated through-hole patterned area can block laser irradiation to a certain extent, so that a laser with higher irradiation power can be used to deeply modify the glass material in the prefabricated through-hole patterned area during the laser induced modification stage, thereby forming the prefabricated through-hole modified area with higher graphic accuracy and stronger etchability. In the chemical etching stage, since the surface of the glass substrate outside the prefabricated through-hole modified area is covered with the anti-corrosion photoresist layer, the etching liquid only acts on the prefabricated through-hole modified area, thereby effectively preventing the glass substrate from reducing in thickness during the etching process. At the same time, the modified area of ​​the prefabricated through hole after deep modification is more etchable, so that a glass through hole with an ultra-high aspect ratio (≥75:1) can be processed according to a pre-designed plan in a shorter time.

[0023] Therefore, the method for manufacturing a through-glass via in the embodiment of the present invention can not only consistently process a through-glass via with an ultra-high aspect ratio according to a pre-designed scheme, but also can manufacture a through-glass via with an ultra-high aspect ratio that meets the requirements of high-density interconnection at a higher etching rate and a shorter etching time. The prepared through-glass via with an ultra-high aspect ratio has excellent electrical performance and structural reliability, can be widely used in the field of high-density interconnection, and provides strong support for the integration and performance improvement of electronic devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 A schematic flow chart of a method for manufacturing a through-glass via in an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with practical applications and with reference to the drawings of the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] A glass substrate with a through-glass hole manufactured by a method for manufacturing a through-glass hole in an embodiment of the present invention is used for high-density interconnection in the field of electronic devices.

[0028] The existing method for manufacturing through-glass vias has the technical problem of being unable to manufacture through-glass vias with ultra-high aspect ratios according to a pre-designed solution, which limits its application in the field of three-dimensional packaging.

[0029] During the process of in-depth research on the existing through-glass via manufacturing method, the inventors found that the reason why the existing manufacturing method cannot form a through-glass via with an ultra-high aspect ratio according to a pre-designed plan is not because chemical etching will inevitably lead to thinning of the glass substrate, but because the entire glass substrate is immersed in an etching solution to perform through-glass via etching in a local area, resulting in both the processed area and the non-through-hole processing area being exposed to a corrosive environment, ultimately causing the thickness of the glass substrate to be reduced.

[0030] The inventors further discovered that the laser used in the existing manufacturing method is a picosecond laser, which is the most advanced micro-nano processing technology, and its processing accuracy and controllability have great limitations. In order to ensure that the prefabricated through-hole modified area formed by laser modification has a certain graphic accuracy, a lower irradiation power is usually used to modify the glass material in the prefabricated through-hole patterned area of ​​the glass substrate, which results in a weaker degree of modification of the glass material in the prefabricated through-hole modified area, poor etchability, and low etching efficiency, which prolongs the immersion time of the glass substrate in the etching solution, exacerbating the technical problem of thickness reduction.

[0031] The inventors found in the process of implementing the technical solution in the embodiment of the present invention that the photoresist not only has corrosion resistance, but also can block laser penetration to a certain extent, and is easy to clean after processing. If a photoresist layer of suitable thickness is covered on both sides of the glass substrate, and the prefabricated through-hole patterned area is exposed, physical protection can be formed for the non-through-hole processing area, so that laser modification and chemical etching only act on the through-hole processing area, and the thickness of the glass substrate will not change during the glass through-hole processing. At the same time, the photoresist layer can block laser penetration, so that a higher power laser can be used in the laser modification stage, and the etchability of the prefabricated through-hole modified area is improved.

[0032] Based on the above understanding, the inventor provides a method for manufacturing a through-glass via. The method forms exposed prefabricated through-hole patterned areas on both sides of a glass substrate, and forms a photoresist layer with a thickness of not less than 5 μm on the surface of the glass substrate outside the prefabricated through-hole patterned areas, thereby exposing the through-hole processing area for processing and protecting the non-through-hole processing area to prevent its thickness from being affected by chemical etching, thereby being able to process a through-glass via with an ultra-high aspect ratio (≥75:1) in a relatively short time according to a pre-designed scheme.

[0033] The technical solution of the present invention will be described below in conjunction with the accompanying drawings and embodiments.

[0034] Figure 1 A schematic flow chart of a method for manufacturing a through-glass via in an embodiment of the present invention is shown.

[0035] Now refer to Figure 1 As shown, an embodiment of the present invention provides a method for manufacturing a through-glass via, comprising the following steps:

[0036] S110, firstly using a mixed cleaning solution consisting of deionized water, alcohol and acetone to perform ultrasonic cleaning on the glass substrate, and then drying the cleaned glass substrate;

[0037] The specific implementation process of step S110 may be:

[0038] According to the material and surface characteristics of the glass substrate, suitable deionized water, alcohol and acetone are selected and mixed in proportion to prepare a mixed cleaning solution;

[0039] After adding a predetermined amount of mixed cleaning solution into the cleaning tank of the ultrasonic cleaning device, the cleaning power and frequency of the ultrasonic cleaning device are set according to the cleaning requirements of the glass substrate. The setting of the cleaning power and frequency should take into account both the ability to effectively remove surface impurities and the need to avoid damaging the glass substrate;

[0040] After the glass substrate is immersed in the mixed cleaning solution in the cleaning tank, an ultrasonic cleaning device is turned on to clean the glass substrate until there is no impurity or dirt on the surface of the glass substrate;

[0041] The cleaned glass substrate is placed in a clean dry environment, such as hot air circulation drying equipment, infrared drying equipment or natural drying environment, and dried for a predetermined time until no residual solvent and moisture are left on the surface of the glass substrate, thereby obtaining the glass substrate with a clean surface.

[0042] The glass substrate with a clean surface obtained in step S110 has good interface bonding ability and good adhesion to the photoresist.

[0043] S120, performing mask processing on the glass substrate using a photoresist mask technology to form an exposed prefabricated through-hole patterning area and a protection area covered by a photoresist layer having a thickness of not less than 5 μm on both sides of the glass substrate;

[0044] The specific implementation process of step S120 may be:

[0045] By a coating process, such as a spin coating process, a spray coating process or a dip coating process, photoresist is evenly coated on both sides of the glass substrate to form a photoresist layer of a certain thickness;

[0046] Performing a soft baking process on the glass substrate coated with the photoresist layer to remove the solvent in the photoresist and achieve preliminary curing of the photoresist layer;

[0047] Aligning a mask having a prefabricated through-hole pattern with the glass substrate coated with the photoresist layer to ensure accurate transfer of the pattern;

[0048] Using ultraviolet light exposure equipment to expose the photoresist layer under the mask to form a prefabricated through-hole pattern outline, and then using a developer to dissolve the photoresist within the prefabricated through-hole pattern outline to form an exposed prefabricated through-hole patterned area;

[0049] The glass substrate forming the prefabricated through-hole patterned area is subjected to a hardening baking treatment to evaporate the solvent, developer and water in the prefabricated through-hole patterned area, and further solidify the photoresist layer to enhance the adhesion strength between the photoresist layer and the glass substrate.

[0050] The thickness of the photoresist layer on the glass substrate after the hardening baking treatment is not less than 5 μm, and has sufficient anti-etching ability and certain anti-laser irradiation ability. After many experiments, it has been proved that the anti-corrosion effect provided by the photoresist layer with a thickness of less than 5 μm is limited, which is not enough to ensure the effective anti-etching protection of the glass substrate in the non-through hole processing area during the chemical etching process.

[0051] In the embodiment of the present invention, the thickness of the photoresist layer is preferably 10-15 μm. The photoresist layer of 10-15 μm can provide sufficient anti-laser irradiation protection for the glass substrate around the prefabricated through-hole patterning area during the laser induced modification stage, and at the same time, form effective anti-etching protection for the glass substrate in the non-through-hole processing area during the chemical etching stage, and facilitate removal from the surface of the glass substrate after chemical etching.

[0052] In the embodiment of the present invention, the photoresist used can be a positive photoresist or a negative photoresist. Since the positive photoresist has good corrosion resistance to hydrofluoric acid, the photoresist layer formed by the positive photoresist has a stronger anti-etching protection ability for the glass substrate in the non-through hole processing area, so the photoresist is preferably a positive photoresist.

[0053] The mass ratio of the components of the positive photoresist is: 17% of diazonaphthoquinone, 63% of phenolic resin, 18% of ethylene glycol monomethyl ether acetate, and the balance is a leveling agent, a plasticizer and a surfactant. The positive photoresist with this mass ratio of components has good adhesion, corrosion resistance and suitable rheological properties. The photoresist layer formed by the positive photoresist can provide a uniform and solid protective layer for the glass substrate in the non-through hole processing area, and has sufficient corrosion resistance to ensure that the glass substrate in the non-through hole processing area is not affected during the laser induced modification and chemical etching stages.

[0054] The specific preparation process of positive photoresist can be: according to the formula ratio, diazonaphthoquinone, phenolic resin, ethylene glycol monomethyl ether acetate and other raw materials are mixed, and appropriate amounts of leveling agent, plasticizer and surfactant are added to adjust the viscosity and rheological properties of the photoresist.

[0055] Through step S120, an exposed prefabricated through hole patterned area and a protective area covered by a photoresist layer with a thickness of not less than 5 μm are formed on both sides of the glass substrate, so that the through hole processing area of ​​the glass substrate is separated from the non-through hole processing area, ensuring that subsequent laser modification and chemical etching processes only act on the prefabricated through hole patterned area, and the size of the glass substrate in the non-through hole processing area is not affected, so that an ultra-high aspect ratio glass through hole can be processed on the glass substrate according to a pre-designed plan.

[0056] S130, using a femtosecond laser, with a laser irradiation power of 80 to 100% of the irradiation power of the device, to perform laser induced modification on the prefabricated through hole patterned areas on the front and back sides of the glass substrate to form prefabricated through hole modified areas;

[0057] In the embodiment of the present invention, the laser used is a femtosecond laser. Compared with a picosecond laser, a femtosecond laser has an ultra-short pulse time and high energy density, which allows the surface of the material to be heated to a high temperature in an instant and then cooled rapidly, thereby uniformly and deeply changing the material structure of the prefabricated through-hole patterning area in a thermal cycle, significantly improving its sensitivity to chemical etching and making it easier to be uniformly removed. At the same time, the use of a femtosecond laser for laser-induced modification can also accurately control the diameter size of the prefabricated through-hole modified area.

[0058] The specific implementation process of step S130 may be:

[0059] Adjust the working parameters of the femtosecond laser, including the number of laser pulses, processing type, laser focal length, laser irradiation power, scanning speed, acceleration, etc. Among them, the laser irradiation power is 80-100% of the equipment irradiation power.

[0060] Placing the glass substrate with its front side facing upward on a stage of a laser device, and using a femtosecond laser to perform laser-induced modification on the prefabricated through-hole patterned region on the front side of the glass substrate to form the prefabricated through-hole modified region on the front side;

[0061] The glass substrate is turned over and placed with the back side facing upward, and a femtosecond laser is used again to perform laser-induced modification on the prefabricated through-hole patterned region on the back side of the glass substrate to form the prefabricated through-hole modified region on the back side.

[0062] The working parameter setting of the femtosecond laser is directly related to the material modification quality of the prefabricated through hole pattern forming area. In order to improve the material modification quality of the prefabricated through hole pattern forming area, the working parameters of the femtosecond laser can be specifically:

[0063] The number of laser pulses is 2, the processing type is perforation, the laser focal length is 3.6-3.9 mm, the laser irradiation power is 80-100% of the equipment irradiation power, the scanning speed is 20 mm / s, and the acceleration is 200 mm / s 2 .

[0064] By optimizing and selecting the working parameters of the femtosecond laser, the femtosecond laser can make full use of the technical characteristics of ultra-short pulse time and high energy density, accurately irradiate the prefabricated through hole patterning area of ​​the glass substrate, and uniformly and deeply change the material structure of the prefabricated through hole patterning area in a thermal cycle manner, thereby significantly improving its sensitivity to chemical etching, making it easier to remove it uniformly through chemical etching, thereby improving the etching rate in the subsequent chemical etching stage, and significantly shortening the etching time for forming the glass through hole.

[0065] Based on the optimized selection of the working parameters of the femtosecond laser, the prefabricated through-hole patterned area of ​​the glass substrate can be quickly and efficiently laser-induced modified by a single irradiation method, thereby improving the modification efficiency, while ensuring that the modified area has the uniformity and consistency required for rapid etching, and ensuring that the diameter of the glass through-hole formed by chemical etching is controllable. The single irradiation modification method makes the glass through-hole manufacturing method in the embodiment of the invention more suitable for large-scale manufacturing of high-density interconnected glass substrates.

[0066] Through step S130, a femtosecond laser is used to uniformly and consistently perform deep modification on the prefabricated through hole patterning areas on the front and back sides of the glass substrate, so that the sensitivity of the formed prefabricated through hole modified areas to chemical etching is significantly improved, making the subsequent chemical etching treatment more uniform and precise, which not only improves the inner wall quality of the formed glass through hole, but also ensures that the diameter of the formed glass through hole is close to the designed size.

[0067] S140, placing the glass substrate after laser induced modification in a cleaning tank of an ultrasonic device for cleaning to remove impurities generated by the laser induced modification, and drying after the cleaning is completed;

[0068] The specific implementation process of step S140 may be:

[0069] Immersing the laser-induced modified glass substrate in a cleaning solution in a cleaning tank of an ultrasonic device, turning on the ultrasonic cleaning device, and cleaning the glass substrate until there is no impurity on the surface of the glass substrate;

[0070] The cleaned glass substrate is placed in a drying device and dried for a predetermined time until no residual solvent or water remains on the surface of the glass substrate.

[0071] The glass substrate after laser induced modification is cleaned in step S140 to remove impurities in the modified area of ​​the prefabricated through hole, which not only reduces the difficulty of chemical etching but also improves the uniformity of chemical etching.

[0072] S150, placing the dried glass substrate into an etching tank of an ultrasonic etching device for etching until a through-glass hole is formed on the glass substrate;

[0073] In the embodiment of the present invention, the etching solution used may be an acidic etching solution or an alkaline etching solution, depending on the corrosion resistance of the photoresist.

[0074] Compared with sodium hydroxide etching solution, hydrofluoric acid etching solution has higher selectivity and faster corrosion rate, and can achieve high-efficiency, high-precision and uniform etching of the prefabricated through-hole modified area, thereby improving the hole-forming quality of the glass through-hole. Therefore, the etching solution is preferably hydrofluoric acid etching solution.

[0075] Compared with hydrofluoric acid etching solutions with other contents, the hydrofluoric acid etching solution with a hydrofluoric acid content of 10-15% has good etching selectivity, and selectively acts only on the prefabricated through-hole modified area during the etching process.

[0076] The specific implementation process of step S150 may be:

[0077] The dried glass substrate is placed in an etching liquid in an etching tank of an ultrasonic etching device. Since the non-through-hole processing area of ​​the glass substrate is covered with a corrosion-resistant photoresist layer, the etching liquid has no etching effect on it, while the prefabricated through-hole modified area is exposed and surrounded by the etching liquid, and the etching liquid selectively acts only on the prefabricated through-hole modified area; the ultrasonic etching device is turned on, and the cavitation effect and micro-jet effect of the ultrasonic wave are used in coordination with chemical etching to enhance the mixing and reaction uniformity of the etching liquid, so that the material in the prefabricated through-hole modified area is selectively, uniformly and finely removed, and finally a glass through-hole with a designed diameter size is etched on the glass substrate.

[0078] Through step S150, a glass through hole of a designed diameter size is etched on the glass substrate. During the chemical etching process, the glass substrate in the non-through hole processing area is protected by the corrosion resistance of the photoresist layer and is not etched by the etching liquid. The thickness of the glass substrate remains unchanged, and then an ultra-high aspect ratio glass through hole is processed on the glass substrate according to the pre-designed scheme.

[0079] S160, removing the photoresist layer on the etched glass substrate and performing ultrasonic cleaning.

[0080] The specific implementation process of step S150 may be:

[0081] According to the type and characteristics of the photoresist covering the glass substrate, a suitable adhesive remover, such as an organic solvent or an alkaline solution, is selected, and the adhesive remover is covered on the periphery of the photoresist layer on the glass substrate to gradually remove the photoresist layer.

[0082] The glass substrate with the photoresist layer removed is placed in a cleaning tank of an ultrasonic device for cleaning to remove residues on the surface of the glass substrate.

[0083] In the method for manufacturing a through-glass hole in an embodiment of the present invention, before laser induced modification, a micron-level photoresist mask technology is used to form exposed prefabricated through-hole patterned areas on both sides of the glass substrate, and a photoresist layer with a thickness of not less than 5 μm is formed on the surface of the glass substrate outside the prefabricated through-hole patterned area. In this way, the through-hole processing area of ​​the glass substrate is separated from the non-through-hole processing area, ensuring that the subsequent laser modification and chemical etching processes only act on the prefabricated through-hole patterned area, and the size of the glass substrate in the non-through-hole processing area is not affected, so that an ultra-high aspect ratio through-glass hole can be processed on the glass substrate according to a pre-designed scheme.

[0084] Firstly, ultrasonic cleaning is used to clean the surface of the glass substrate to improve the interface bonding force between the glass substrate and the photoresist.

[0085] Secondly, on both sides of the glass substrate, a photoresist layer with a thickness of not less than 5 μm is covered by using a micron-level photoresist mask technology, and an exposed micron-level precision prefabricated through-hole patterned area is formed by a development process. In this way, the through-hole processing area of ​​the glass substrate is exposed, and the non-through-hole processing area is physically protected.

[0086] Secondly, due to the presence of the photoresist layer, the prefabricated through hole patterning area is accurately marked, and the photoresist layer around the prefabricated through hole patterning area can block the irradiated laser from passing through. Therefore, in the laser induced modification stage, a femtosecond laser is used with 80 to 100% of the device power to deeply modify the glass material in the prefabricated through hole patterning area on the front and back sides of the glass substrate, so that the formed prefabricated through hole modified area has not only high precision but also good etchability.

[0087] Subsequently, because the non-through hole processing area is covered with a corrosion-resistant photoresist layer, in the chemical etching stage, the etching solution selectively acts only on the prefabricated through hole modification area, and the concentration of the corrosive components in the etching solution decreases slowly, so that the glass through hole etching can be completed in a shorter time at a faster etching rate. At the same time, chemical etching will not affect the size of the glass substrate in the non-through hole processing area protected by the corrosion resistance of the photoresist layer. Therefore, through chemical etching, an ultra-high aspect ratio glass through hole can be processed on the glass substrate according to a pre-designed scheme.

[0088] Finally, the photoresist layer on the etched glass substrate is removed, and ultrasonic cleaning is performed to obtain a glass substrate for high-density interconnection.

[0089] Through this working mechanism, the method for manufacturing a through-glass via in an embodiment of the present invention can process an ultra-high aspect ratio through-glass via on a glass substrate according to a pre-designed scheme in a relatively short period of time, thereby meeting the requirements of electronic devices for glass substrates with high-density interconnection.

[0090] Compared with the existing method for making glass through holes, the method for making glass through holes in the embodiment of the present invention forms exposed prefabricated through hole patterned areas on both sides of the glass substrate by adopting micron-level photoresist mask technology before laser induced modification, and forms a photoresist layer with a thickness of not less than 5 μm on the surface of the glass substrate outside the prefabricated through hole patterned area. The photoresist layer around the prefabricated through hole patterned area can block laser irradiation to a certain extent, so that a laser with higher irradiation power can be used to deeply modify the glass material in the prefabricated through hole patterned area during the laser induced modification stage, thereby forming a prefabricated through hole modified area with higher graphic accuracy and stronger etchability. In the chemical etching stage, since the surface of the glass substrate outside the prefabricated through hole modified area is covered with a corrosion-resistant photoresist layer, the etching liquid only acts on the prefabricated through hole modified area, thereby effectively preventing the glass substrate from reducing in thickness during the etching process. At the same time, the modified area of ​​the prefabricated through hole after deep modification is more etchable, so that a glass through hole with an ultra-high aspect ratio (≥75:1) can be processed according to a pre-designed plan in a shorter time.

[0091] Therefore, the method for manufacturing a through-glass via in the embodiment of the present invention can not only consistently process a through-glass via with an ultra-high aspect ratio according to a pre-designed scheme, but also can manufacture a through-glass via with an ultra-high aspect ratio that meets the requirements of high-density interconnection at a higher etching rate and a shorter etching time. The prepared through-glass via with an ultra-high aspect ratio has excellent electrical performance and structural reliability, can be widely used in the field of high-density interconnection, and provides strong support for the integration and performance improvement of electronic devices.

Claims

1. A method for manufacturing a through-glass hole, characterized in that: The following steps are involved: Firstly, the glass substrate is ultrasonically cleaned using a mixed cleaning solution consisting of deionized water, alcohol and acetone, and then the cleaned glass substrate is dried; The glass substrate is subjected to mask processing by using a photoresist mask technology to form an exposed prefabricated through-hole patterned area and a protection area covered by a photoresist layer having a thickness of not less than 5 μm on both sides of the glass substrate; Using a femtosecond laser, at a laser irradiation power of 80 to 100% of the irradiation power of the device, laser-induced modification is performed on the prefabricated through hole patterned regions on the front and back sides of the glass substrate to form prefabricated through hole modified regions; The glass substrate after laser induced modification is placed in a cleaning tank of an ultrasonic device for cleaning to remove impurities generated by the laser induced modification, and then dried after cleaning; Placing the dried glass substrate into an etching tank of an ultrasonic etching device for etching until a glass through hole is formed on the glass substrate; The photoresist layer on the etched glass substrate is removed and ultrasonic cleaning is performed.

2. The method for manufacturing a through-glass via according to claim 1, characterized in that: The thickness of the photoresist layer formed in the step of performing mask processing on the glass substrate using a photoresist mask technology is 10-15 μm.

3. The method for manufacturing a through-glass via according to claim 1, characterized in that: The photoresist used in the step of performing mask processing on the glass substrate using the photoresist mask technology is a positive photoresist.

4. The method for manufacturing a through-glass via according to claim 3, characterized in that: The components of the positive photoresist have a mass ratio of: 17% of naphthoquinone, 63% of phenolic resin, 18% of ethylene glycol monomethyl ether acetate, and the remainder is a leveling agent, a plasticizer and a surfactant.

5. The method for manufacturing a through-glass via according to any one of claims 1 to 4, characterized in that: In the step of using a femtosecond laser to perform laser-induced modification on the prefabricated through-hole patterning areas on the front and back sides of the glass substrate at a laser irradiation power of 80 to 100% of the irradiation power of the equipment, the working parameters of the femtosecond laser are: The number of laser pulses is 2, the processing type is perforation, the laser focal length is 3.6-3.9 mm, the laser irradiation power is 80-100% of the equipment power, the scanning speed is 20 mm / s, and the acceleration is 200 mm / s 2 .

6. The method for manufacturing a through-glass via according to any one of claims 1 to 4, characterized in that: The etching solution used in the step of placing the dried glass substrate into an etching tank of an ultrasonic etching device for etching treatment is a hydrofluoric acid etching solution.

7. The method for manufacturing a through-glass via according to claim 6, characterized in that: The hydrofluoric acid content in the hydrofluoric acid etching solution is 10-15%.

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