TGV processing and filling method

Abstract

The invention discloses a TGV processing and filling method, which belongs to the technical field of TGV processing and filling, and comprises the following steps: laser induction, glass corrosion and front and back seed layer sputtering, placing a glass substrate on a carrying table, placing a silk-screen printing plate above the glass substrate by adopting a positioner, and accurately aligning the silk-screen printing plate with the glass substrate. The method comprises the following steps of: uniformly coating slurry on a loading platform, uniformly coating the slurry on the loading platform from left to right by using a rubber scraper to ensure that the slurry is filled in the graphic area of the silk-screen printing plate and one surface of the glass substrate is attached to the graphic area, so that a graph is attached to the surface of the glass substrate, and taking down the glass substrate to obtain the silk-screen printing plate. The glass substrate with the patterns distributed on one face is placed in a curing oven to be baked and cured, the solvent in the slurry is volatilized, metal is hardened, the seed layer on the cured glass substrate is removed through the wet etching technology, the technology is simplified, and the TGV machining and filling efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of TGV processing and filling, and in particular relates to a TGV processing and filling method. Background Art

[0002] As the size of AI chips and packaging substrates continue to increase, the requirements for packaging technology are becoming higher and higher. Therefore, TGV technology is also considered to be a key technology for the next generation of advanced packaging. TGV technology helps to increase the density of interlayer connections and improve the signal integrity of high-speed circuits. The reduction in connection spacing can reduce signal loss and interference, thereby improving overall performance.

[0003] At present, TGV technology is to make vertical tiny through holes on the glass substrate and fill the holes with conductive materials to achieve electrical connections at different levels. TGV usually uses high-quality borosilicate glass and quartz glass as the substrate, and realizes 3D interconnection through processes such as seed layer sputtering, electroplating filling, chemical mechanical planarization (CMP), and RDL rewiring.

[0004] Although TGV technology has many advantages, it also faces many challenges. Due to the complex manufacturing process, TGV technology is more prone to defects that may cause product failure. In addition, TGV is filled with copper to provide electrical connection between the front and back of the glass substrate. There are two forms of existing hole filling methods: one is to completely fill the through hole of the glass substrate with copper, and the other is to metallize the sidewalls and fill the rest of the glass substrate with dielectric material. When the copper filling cover layer is chemically mechanically planarized (CMP), cracks will appear in the glass substrate. At the same time, after copper is filled in the glass substrate, the difference in thermal expansion coefficient will cause stress cracks in the glass substrate, causing reliability problems.

[0005] The interposer is one of the important structures for implementing 2.5D and 3D packaging using TGV technology. Currently, the manufacturing process of conventional interposers has the following defects: First, its manufacturing process is relatively complicated. The electroplating process is used to fill TGV, which is time-consuming and has high equipment and potency costs. Second, after TGV hole filling, the CMP process is required to perform planarization, which increases the difficulty of the process. At the same time, the glass substrate itself is brittle, which greatly increases the risk of glass substrate breakage during the CMP process. Third, after copper filling, the thermal expansion coefficients of copper metal (CTE: 1.7E-5 / ℃) and glass substrate (CTE: 3E-6 / ℃) are quite different. During thermal cycling, stress cracks will be generated in the glass substrate, resulting in reduced reliability. Summary of the invention

[0006] The present invention overcomes the deficiencies of the prior art and provides a TGV processing and filling method to solve the problems existing in the prior art.

[0007] To achieve the above object, the technical solution adopted by the present invention is: a TGV processing and filling method, comprising the following steps:

[0008] S1, using a laser to perform laser modification on the surface of the glass substrate to form a modified area;

[0009] S2, etching the modified area on the glass substrate with an etching solution, and cleaning after etching;

[0010] S3, sputtering the front and back surfaces of the glass substrate using a PVD sputtering device to form a seed layer on the front and back surfaces of the glass substrate;

[0011] S4, placing the glass substrate on the stage, and using a positioner to place the screen printing plate on the glass substrate, so that the screen printing plate and the glass substrate are accurately aligned to ensure that the graphic area on the screen printing plate coincides with one side of the glass substrate;

[0012] S5. Apply the slurry evenly on the stage, and then use a rubber scraper to scrape from left to right to ensure that the pattern area of ​​the screen printing plate is full of slurry, and one side of the glass substrate is attached to the pattern area, so that the pattern is attached to the surface of the glass substrate, and then the glass substrate is removed;

[0013] S6, placing the glass substrate with the pattern on one side in a curing oven for baking and curing, so that the solvent in the slurry evaporates and the metal hardens;

[0014] S7, removing the seed layer on the solidified glass substrate by wet etching process;

[0015] S8. Repeat steps S4-S7 to process the other side of the glass substrate.

[0016] In a preferred embodiment of the present invention, in step S1, both the front and back surfaces of the glass substrate are subjected to modification treatment to form corresponding modified regions on the front and back surfaces of the glass substrate.

[0017] In a preferred embodiment of the present invention, in step S2, the glass substrate is placed in an etching solution to etch the glass in the modified area to form a through-hole structure.

[0018] In a preferred embodiment of the present invention, in step S4, the pattern area of ​​the screen printing plate is precisely aligned with the modified area of ​​the glass substrate.

[0019] In a preferred embodiment of the present invention, the slurry is silver slurry.

[0020] The present invention solves the defects existing in the background technology and has the following beneficial effects:

[0021] 1. The TGV processing and filling method of the present invention is simple to operate, and the screen printing process is used instead of the electroplating process, which can greatly save costs in operating equipment and materials. In addition, the total process steps are reduced, the CMP process is eliminated, and the TGV hole filling process and the RDL graphic process are combined into one, which saves production capacity and improves the processing efficiency of the glass substrate;

[0022] 2. After filling with silver paste, the thermal expansion coefficients of silver metal and glass are close, so the stress caused by temperature changes can be effectively reduced during the processing technology, the probability of stress cracks can be reduced, and the reliability of the glass substrate can be improved. In addition, the resistivity of copper and silver is very close, so the conductivity can be maintained at the same level without affecting the performance. DETAILED DESCRIPTION

[0023] The present invention is further described below in conjunction with specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0024] The present embodiment provides a TGV processing and filling method. The TGV processing and filling method is simple to operate and uses a screen printing process instead of an electroplating process, which can greatly save costs in operating equipment and using materials. The total process steps are reduced, and the CMP process is eliminated. At the same time, the TGV hole filling process and the RDL graphic process are combined into one, saving production capacity and improving the processing efficiency of the glass substrate.

[0025] In this embodiment, the TGV processing and filling method includes the following steps:

[0026] S1. Using a laser to modify the surface of a glass substrate. Under the action of the laser, the atoms of the glass substrate will generate high-frequency oscillations and rapidly heat up. When the energy exceeds the atomic bond energy, the atomic structure will change, thereby forming a modified area. In this embodiment, the front and back surfaces of the glass substrate will be laser modified to form modified areas on both sides of the glass substrate for subsequent operations.

[0027] S2, etching the modified area on the glass substrate with an etching liquid, and then cleaning it after etching. In this embodiment, the glass substrate is placed in the etching liquid, so that the glass in the modified area is etched to form a through-hole structure, while the unmodified area is relatively difficult to be etched, thereby ensuring the processing accuracy and efficiency. After the etching is completed, the glass substrate is taken out of the etching liquid, and then cleaned to remove the etching liquid and impurities on the glass substrate;

[0028] S3, using PVD sputtering equipment to sputter the front and back surfaces of the glass substrate to form seed layers on the front and back surfaces of the glass substrate. In actual use, a vacuum sputtering equipment is used to sputter the front and back surfaces of the glass substrate. After sputtering one side of the glass substrate is completed, the glass substrate is turned over and the other side of the glass substrate is sputtered, thereby forming seed layers on both sides of the glass substrate;

[0029] S4, placing the glass substrate on the stage, using a positioner to place the screen printing plate on the glass substrate, so that the screen printing plate and the glass substrate are accurately aligned, ensuring that the graphic area on the screen printing plate coincides with one side of the glass substrate. In this embodiment, the graphic area of ​​the screen printing plate is accurately aligned with the modified area of ​​the glass substrate, so that the graphic area can be smoothly attached to the modified area later;

[0030] S5. Apply the slurry evenly on the carrier, and then use a rubber scraper to scrape from left to right to ensure that the pattern area of ​​the screen printing screen is full of slurry, and one side of the glass substrate is attached to the pattern area, so that the pattern is attached to the surface of the glass substrate, and then the glass substrate is removed. At this time, the modified area of ​​the glass substrate is full of patterns, so that the RDL patterning process can be completed later;

[0031] S6, placing the glass substrate with the pattern on one side in a curing furnace for baking and curing, so that the solvent in the slurry evaporates and the metal hardens, and the RDL patterning process of the glass substrate is completed;

[0032] S7, removing the seed layer on the solidified glass substrate by wet etching process, thereby completing the filling process and patterning process on one surface of the glass substrate;

[0033] S8, repeating steps S4-S7 to process the other side of the glass substrate, and completing the filling process and patterning process on the other surface of the glass substrate.

[0034] In this embodiment, the slurry is silver slurry. After filling with silver slurry, since the thermal expansion coefficients of silver metal and glass are close, the glass substrate can effectively reduce the stress caused by temperature changes during the processing technology, reduce the probability of stress cracks, and improve the reliability of the glass substrate. In addition, the resistivity of copper and silver is very close, so the conductivity can be maintained at the same level without affecting the performance.

[0035] In summary, the TGV processing and filling method of this embodiment is simple to operate, and uses screen printing technology instead of electroplating technology, which can greatly save costs in operating equipment and materials used. In addition, the total process steps are reduced, the CMP process is eliminated, and the TGV hole filling process and RDL graphic process are combined into one, saving production capacity and improving the processing efficiency of the glass substrate.

[0036] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A TGV processing and filling method, characterized in that: The following steps are involved: S1, using a laser to perform laser modification on the surface of the glass substrate to form a modified area; S2, etching the modified area on the glass substrate with an etching solution, and cleaning after etching; S3, sputtering the front and back surfaces of the glass substrate using a PVD sputtering device to form a seed layer on the front and back surfaces of the glass substrate; S4, placing the glass substrate on the stage, and using a positioner to place the screen printing plate on the glass substrate, so that the screen printing plate and the glass substrate are accurately aligned to ensure that the graphic area on the screen printing plate coincides with one side of the glass substrate; S5. Apply the slurry evenly on the stage, and then use a rubber scraper to scrape from left to right to ensure that the pattern area of ​​the screen printing plate is full of slurry, and one side of the glass substrate is attached to the pattern area, so that the pattern is attached to the surface of the glass substrate, and then the glass substrate is removed; S6, placing the glass substrate with the pattern on one side in a curing oven for baking and curing, so that the solvent in the slurry evaporates and the metal hardens; S7, removing the seed layer on the solidified glass substrate by wet etching process; S8. Repeat steps S4-S7 to process the other side of the glass substrate.

2. A TGV processing and filling method according to claim 1, characterized in that: In step S1 , the front and back surfaces of the glass substrate are both subjected to modification treatment to form corresponding modified regions on the front and back surfaces of the glass substrate.

3. A TGV processing and filling method according to claim 1, characterized in that: In step S2, the glass substrate is placed in an etching solution to etch the glass in the modified area to form a through-hole structure.

4. A TGV processing and filling method according to claim 1, characterized in that: In step S4, the pattern area of ​​the screen printing plate is precisely aligned with the modified area of ​​the glass substrate.

5. A TGV processing and filling method according to claim 1, characterized in that: The slurry is silver slurry.