Dry type hole filling process and device
By employing plasma cleaning, vacuum deposition, ultrasonic dispersion, and sintering techniques in the dry-filling process, the problems of uneven filling and insufficient density of large aspect ratio holes have been solved, achieving efficient and uniform nanoparticle filling and improving the quality and efficiency of microelectronic packaging.
Patent Information
- Application Number
- CN202511425466.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-30
- Publication Date
- 2026-01-09
AI Technical Summary
Existing via filling technologies in the field of microelectronic packaging have problems such as uneven filling of large aspect ratio holes, insufficient density, environmental pollution and high cost. In particular, traditional wet processes suffer from uneven filling, organic solvent pollution and high temperature damage to the substrate when the aspect ratio exceeds 100:1, while dry technology results in low micropore filling rate due to excessively large particle size.
A dry process consisting of plasma cleaning, vacuum negative pressure aerosol deposition, ultrasonic dispersion, and sintering is adopted. By alternating high-pressure pulse heating and ultrasonic waves, uniform deposition and sintering of nanoparticles are achieved. Combined with the removal of the polymer layer by low-temperature decomposition, problems such as uneven filling and large porosity are solved.
It achieves uniform filling of high aspect ratio holes, improves the density and conductivity of the filling, reduces post-processing steps, and improves filling efficiency and substrate surface cleanliness.
Smart Images
Figure CN121289481A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of microelectronics technology, and in particular to a dry via filling process. Background Technology
[0002] With the increasing demands of applications and the rapid development of electronic products, higher requirements are being placed on the transmission speed, frequency of use, and integration of components. TSV and TGV, as emerging technologies, are particularly suitable for components requiring high speed, high frequency, and high density, playing a crucial role. However, existing via filling technologies, such as wet electroplating and adhesive filling methods, generally suffer from environmental pollution, high costs, or difficulty in filling vias with large aspect ratios. Vias with a large aspect ratio are defined as those with a depth-to-diameter ratio greater than 20:1. Especially in the field of microelectronic packaging, traditional wet processes face bottlenecks such as uneven filling, organic solvent contamination, and high-temperature damage to the substrate when the aspect ratio exceeds 100:1. Current dry technologies use excessively large particles, such as particles with a diameter greater than 50mm, resulting in low micropore filling rates and insufficient density.
[0003] Specifically, there are many problems in TGV and TSV via filling. Currently, the commonly used TSV via filling methods include blind via filling and through-hole filling. Blind via filling is difficult and often requires breakthrough improvements, such as changing the slope of the insulating layer inside the hole, eliminating residual bubbles at the bottom of the blind via, and improving the composition of the electroplating solution. These improvements are time-consuming, labor-intensive, and have unsatisfactory results. In contrast, through-hole filling is less difficult and easier to operate, but it faces the problem of an excessively thick surface Cu layer and low filling rate. Existing technologies can improve the filling effect through bottom bonding and electrochemical plating, but the process is still relatively cumbersome. TGV via filling uses a metal filling scheme, which requires ensuring that the filling material can uniformly and densely fill the vias to avoid voids or gaps. Whether electroplating or using conductive metal adhesive, problems such as uneven filling or poor bonding with the glass substrate are faced. Summary of the Invention
[0004] To address the aforementioned shortcomings, the present invention aims to propose a dry pore-filling process. Existing improved solutions take into account adaptability to high aspect ratios, uniform dispersion of nanoparticles, and activation treatment of pore walls. This is achieved through a pure dry process involving plasma cleaning, vacuum negative pressure aerosol deposition, ultrasonic dispersion, and sintering. The simultaneous deposition and pore-filling sintering solves the problems of uneven filling and large pore size in existing pore-filling processes.
[0005] To achieve this objective, the present invention adopts the following technical solution:
[0006] A dry filling process includes the following steps:
[0007] S1. Substrate cleaning: Place the substrate to be filled into a plasma cleaner for plasma cleaning, and then cover the surface of the substrate with a low-temperature decomposition polymer layer.
[0008] S2. Preheating the substrate: The substrate is preheated by setting a preset temperature curve and using a high-voltage pulse heating method.
[0009] S3, Nanoparticle generation: Nanoparticles are continuously generated through a nanoparticle generation device;
[0010] S4. Vacuum environment deposition: In a vacuum environment, the nano-metal particles generated in step S3 are deposited into the holes to be filled in the substrate through a dry aerosol nozzle, so that the holes to be filled in the substrate are filled with nano-metal particles.
[0011] S5. Ultrasonic assisted dispersion and sintering: At the same time or after step S4, ultrasonic waves are applied to the area to be filled by an ultrasonic device to make the nano-metal particles in the pores disperse evenly; when the nano-metal particles are uniformly deposited to a preset thickness, ultrasonic assisted dispersion stops, and high-pressure pulse heating is used to sinter the nano-metal particles. The high-pressure pulse heating and ultrasonic dispersion actions are alternated in time.
[0012] S6. Remove excess particles. After filling the holes, heat to 180°C. The low-temperature decomposition of the polymer layer vaporizes and removes residual particles from the surface.
[0013] Preferably, during the nanoparticle deposition process, intermittent high-voltage pulsed current is applied to the deposited particle layer to achieve instantaneous selective sintering of the particles using the pulsed Joule heating effect;
[0014] A pulsed electric field is applied using a non-contact electrode; pulsed discharge and ultrasonic dispersion are performed alternately in time, with the pulse width being 10-500 μs and the interval time being 100-1000 μs;
[0015] The amplitude of the pulse current is 50-1000A, and the voltage is 5-50V.
[0016] Preferably, using array nozzles such as 3×3 or 2×2 to deposit and fill holes in blocks can achieve hole filling on large substrates.
[0017] Preferably, the depth-to-diameter ratio of the filled hole is 1:1 to 500:1.
[0018] Furthermore, in steps S3 and S4, the diameter of the nanoparticles used in the dry aerosol is 1–50 nm, and the nozzle diameter is 1–500 μm.
[0019] The materials used in dry aerosols are one or more interconnecting and filling materials selected from nano-silver, nano-copper, and nano-nickel.
[0020] Furthermore, the plasma cleaning time is 0-2 minutes, and the atmosphere is argon or nitrogen.
[0021] Furthermore, the nano-generation device is a spark ablation method, employing one of the following: physical vapor deposition, laser ablation, or chemical vapor deposition.
[0022] Furthermore, the relationship between the time T required for hole filling and the following is:
[0023] In the formula, r is the pore diameter, h is the pore depth, τ is the particle deposition rate per second, and β is the pore shape correction factor.
[0024] In the formula, N0 is a constant representing the total number of particles generated by spark ablation per unit time, N is the initial particle concentration, and Q is the gas volume flow rate.
[0025] Furthermore, the material used for low-temperature decomposition of the polymer is polypropylene or polyoxymethylene;
[0026] Low-temperature decomposition polymers are formed on the surface of a substrate by spin coating or spray coating.
[0027] The purpose of this invention is to provide an adaptive high-precision line repair device:
[0028] To achieve this objective, the present invention adopts the following technical solution:
[0029] An apparatus for a dry hole-filling process includes: an ultrasonic device, a platform, a substrate to be filled, an aerosol nozzle, a vacuum port, a sealed cavity, an electrically conductive metal sheet, a controller, an industrial computer, a CCD camera, a nanoparticle generator, and a gas cylinder.
[0030] A platform is set up inside the sealed cavity, the ultrasonic device is coupled to the platform, and the substrate to be filled is fixed on the platform;
[0031] The aerosol nozzle is mounted inside the sealed cavity, and the aerosol nozzle is located inside the sealed cavity; a vacuum port is provided at the bottom of the sealed cavity;
[0032] Non-contact electrodes are provided at the bottom and top of the substrate to be filled. The non-contact electrodes are used for high-voltage pulse heating.
[0033] The CCD camera is installed inside the sealed cavity and is used to observe the filling situation inside the sealed cavity.
[0034] The controller, industrial computer, nanoparticle generator, and gas cylinder are all located outside the sealed cavity. The outlet of the nanoparticle generator is connected to the inlet of the aerosol nozzle, and the gas cylinder is connected to the inlet of the nanoparticle generator.
[0035] The industrial computer and the controller are connected by signal, and the controller is connected by signal to the ultrasonic device. The controller is used to control the working status of the ultrasonic device.
[0036] One of the above technical solutions includes the following beneficial effects: Preheating the substrate using high-pressure pulse heating allows it to reach a suitable temperature, which facilitates the subsequent sintering of nano-metal particles. Preheating can transform the morphology of metal particles in the coating, suppress differences in diffusion rates between metals, enhance sintering strength, and reduce surface defects on the substrate, making it smoother and more even, which is beneficial for improving the filling quality and the bonding force between the substrate and the filler material. Continuous generation of nanoparticles can provide suitable filling material for the filling process. Nanoparticles have a large specific surface area and good flowability, allowing them to fill the small holes better. Vacuum deposition can reduce the influence of air impurities on the filling process and improve the filling quality. Depositing nano-metal particles into the holes to be filled through a dry aerosol nozzle enables precise filling. Ultrasonic-assisted dispersion can ensure uniform dispersion of nano-metal particles within the holes, preventing particle agglomeration and thus improving the uniformity and density of the filling. The alternation of high-pressure pulse heating and ultrasonic dispersion in time facilitates timely sintering after uniform particle dispersion, resulting in good bonding between nano-metal particles and between the particles and the substrate, improving the strength and conductivity of the filling. After the filling is completed, the temperature is raised to 180°C. The low-temperature decomposition of the polymer layer vaporizes and removes the residual particles on the surface, making the substrate surface clean and tidy, without the need for additional complicated post-processing steps. Attached Figure Description
[0037] Figure 1 This is a flowchart illustrating the overall steps of the present invention;
[0038] Figure 2 This is a schematic diagram of the processing apparatus of the present invention.
[0039] The components include: ultrasonic device 1, platform 2, substrate for filling holes 3, aerosol nozzle 4, vacuum port 5, polymer layer 6, sealed cavity 7, electrically conductive metal sheet 8, controller 9, industrial computer 10, CCD camera 11, nanoparticle generator 12, and gas cylinder 13. Detailed Implementation
[0040] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.
[0041] like Figure 1 As shown, a dry filling process includes the following steps:
[0042] S1. Substrate cleaning: Place the substrate to be filled into a plasma cleaner for plasma cleaning, and then cover the surface of the substrate with a low-temperature decomposition polymer layer.
[0043] S2. Preheating the substrate: The substrate is preheated by setting a preset temperature curve and using a high-voltage pulse heating method.
[0044] S3, Nanoparticle generation: Nanoparticles are continuously generated through a nanoparticle generation device;
[0045] S4. Vacuum environment deposition: In a vacuum environment, the nano-metal particles generated in step S3 are deposited into the holes to be filled in the substrate through a dry aerosol nozzle, so that the holes to be filled in the substrate are filled with nano-metal particles.
[0046] S5. Ultrasonic assisted dispersion and sintering: At the same time or after step S4, ultrasonic waves are applied to the area to be filled by an ultrasonic device to make the nano-metal particles in the pores disperse evenly; when the nano-metal particles are uniformly deposited to a preset thickness, ultrasonic assisted dispersion stops, and high-pressure pulse heating is used to sinter the nano-metal particles. The high-pressure pulse heating and ultrasonic dispersion actions are alternated in time.
[0047] S6. Remove excess particles. After filling the holes, heat to 180°C. The low-temperature decomposition of the polymer layer vaporizes and removes residual particles from the surface.
[0048] Preheating the substrate using high-pressure pulse heating can bring it to a suitable temperature, which is beneficial for the subsequent sintering of nano-metal particles. Preheating can transform the morphology of metal particles in the coating, suppress the difference in diffusion rate between metals, enhance sintering strength, and reduce surface defects on the substrate, making it smoother and more even. This is beneficial for improving the filling quality and the bonding force between the substrate and the filler material.
[0049] Continuous generation of nanoparticles provides a suitable filling material for pore filling. Nanoparticles possess a large specific surface area and good flowability, enabling them to fill small pores more effectively. Vacuum deposition reduces the impact of airborne impurities on the filling process, improving filling quality. Precise filling can be achieved by depositing nano-metal particles into the pores through a dry aerosol nozzle.
[0050] Ultrasonic-assisted dispersion ensures uniform dispersion of nano-metal particles within the pores, preventing particle agglomeration and thus improving the uniformity and density of the filling. The alternating high-pressure pulse heating and ultrasonic dispersion facilitates timely sintering after uniform particle dispersion, resulting in strong bonding between nano-metal particles and between the particles and the substrate, enhancing the strength and conductivity of the filled pores. High-frequency pulses generate instantaneously extremely high temperatures at particle contact points, causing surface melting and diffusion, achieving densification.
[0051] After the vias are filled, the temperature is raised to 180°C. The low-temperature decomposition and vaporization of the polymer layer removes residual particles from the surface, resulting in a clean and tidy substrate surface without the need for additional complex post-processing steps.
[0052] Preferably, during the nanoparticle deposition process, intermittent high-voltage pulsed current is applied to the deposited particle layer to achieve instantaneous selective sintering of the particles using the pulsed Joule heating effect;
[0053] A pulsed electric field is applied using a non-contact electrode; pulsed discharge and ultrasonic dispersion are performed alternately in time, with the pulse width being 10-500 μs and the interval time being 100-1000 μs;
[0054] The amplitude of the pulse current is 50-1000A, and the voltage is 5-50V.
[0055] The sintering and diffusion of deposited particles promotes the dense packing of subsequent particles, solving the problems of uneven filling and large porosity in existing pore-filling processes.
[0056] Preferably, using array nozzles such as 3×3 or 2×2 to deposit and fill holes in blocks can achieve hole filling on large substrates.
[0057] Simultaneous multi-hole filling greatly improves the filling efficiency.
[0058] Preferably, the depth-to-diameter ratio of the filled hole is 1:1 to 500:1.
[0059] Furthermore, in steps S3 and S4, the diameter of the nanoparticles used in the dry aerosol is 1–50 nm, and the nozzle diameter is 1–500 μm.
[0060] The materials used in dry aerosols are one or more interconnecting and filling materials selected from nano-silver, nano-copper, and nano-nickel.
[0061] Smaller nanoparticles are less likely to form voids and cause blockages, thus promoting tighter filling.
[0062] Furthermore, the plasma cleaning time is 0-2 minutes, and the atmosphere is argon or nitrogen.
[0063] Cleaning the substrate surface facilitates the bonding of particles and pores.
[0064] Furthermore, the nano-generation device is a spark ablation method, employing one of the following: physical vapor deposition, laser ablation, or chemical vapor deposition.
[0065] The generation of pure nanoparticles, free of impurities, is beneficial to the strength and conductivity of the pores.
[0066] Furthermore, the relationship between the time T required for hole filling and the following is:
[0067] In the formula, r is the pore diameter, h is the pore depth, τ is the particle deposition rate per second, and β is the pore shape correction factor.
[0068] In the formula, N0 is a constant representing the total number of particles generated by spark ablation per unit time, N is the initial particle concentration, and Q is the gas volume flow rate.
[0069] Determining the deposition time for each well helps in determining the well filling process and improving efficiency.
[0070] Furthermore, the material used for low-temperature decomposition of the polymer is polypropylene or polyoxymethylene;
[0071] Low-temperature decomposable polymers are formed on the surface of a substrate using spin coating or spray coating methods to create a low-temperature decomposable polymer layer.
[0072] An apparatus for a dry hole filling process includes: an ultrasonic device 1, a platform 2, a substrate to be filled 3, an aerosol nozzle 4, a vacuum port 5, a sealed cavity 7, an electrically conductive metal sheet 8, a controller 9, an industrial computer 10, a CCD camera 11, a nanoparticle generator 12, and a gas cylinder 13.
[0073] A platform 2 is set inside the sealed cavity 7, the ultrasonic device 1 is coupled to the platform 2, and the substrate 3 to be filled is fixed on the platform 2;
[0074] The aerosol nozzle 4 is mounted inside the sealed cavity 7, and the aerosol nozzle 4 is located in the sealed cavity 7; a vacuum port is provided at the bottom of the sealed cavity 7.
[0075] Non-contact electrodes 8 are provided at the bottom and top of the substrate 3 to be filled. The non-contact electrodes 8 are used for high-voltage pulse heating.
[0076] The CCD camera 11 is installed inside the sealed cavity 7 and is used to observe the filling condition inside the sealed cavity 7.
[0077] The controller 9, industrial computer 10, nanoparticle generator 12 and gas cylinder 13 are all located outside the sealed cavity 7. The outlet of nanoparticle generator 12 is connected to the inlet of aerosol nozzle, and gas cylinder 13 is connected to the inlet of nanoparticle generator 12.
[0078] The industrial computer 10 and the controller 9 are connected by signals. The controller 9 is connected by signals to the ultrasonic device 1. The controller 9 is used to control the working status of the ultrasonic device 1.
[0079] This device, through the synergistic effect of vacuum environment, ultrasonic assistance, pulse heating, real-time monitoring and automated control, can significantly improve the accuracy, density and stability of hole filling, providing reliable equipment support for efficient and high-quality dry hole filling processes.
[0080] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of the invention and should not be construed as limiting the scope of protection of the invention in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of the invention without inventive effort, and these embodiments will all fall within the scope of protection of the present invention.
Claims
1. A dry cavitation filling process, characterized in that, Includes the following steps: S1. Substrate cleaning: Place the substrate to be filled into a plasma cleaner for plasma cleaning, and then cover the surface of the substrate with a low-temperature decomposition polymer layer. S2. Preheating the substrate: The substrate is preheated by setting a preset temperature curve and using a high-voltage pulse heating method. S3, Nanoparticle generation: Nanoparticles are continuously generated through a nanoparticle generation device; S4. Vacuum environment deposition: In a vacuum environment, the nano-metal particles generated in step S3 are deposited into the holes to be filled in the substrate through a dry aerosol nozzle, so that the holes to be filled in the substrate are filled with nano-metal particles. S5. Ultrasonic assisted dispersion and sintering: At the same time or after step S4, ultrasonic waves are applied to the area to be filled by an ultrasonic device to make the nano-metal particles in the pores disperse evenly; when the nano-metal particles are uniformly deposited to a preset thickness, ultrasonic assisted dispersion stops, and high-pressure pulse heating is used to sinter the nano-metal particles. The high-pressure pulse heating and ultrasonic dispersion actions are alternated in time. S6. Remove excess particles. After filling the holes, heat to 180°C. The low-temperature decomposition of the polymer layer vaporizes and removes residual particles from the surface.
2. The dry filling process according to claim 1, characterized in that, During the nanoparticle deposition process, intermittent high-voltage pulsed current is applied to the deposited particle layer that has reached the required thickness, and the instantaneous selective sintering of the particles is achieved by utilizing the pulsed Joule heating effect. A pulsed electric field is applied using non-contact electrodes; The pulsed discharge and ultrasonic dispersion actions alternate in time, with the pulse width being 10-500 μs and the interval time being 100-1000 μs; The amplitude of the pulse current is 50-1000A, and the voltage is 5-50V.
3. The dry filling process according to claim 1, characterized in that, By using array nozzles in 3×3, 2×2, etc., to deposit and fill holes in sections, it is possible to achieve hole filling on large substrates.
4. The dry filling process according to claim 1, characterized in that, The depth-to-diameter ratio of the filled holes is 1:1 to 500:
1.
5. The dry filling process according to claim 1, characterized in that, In steps S3 and S4, the diameter of the nanoparticles used in the dry aerosol is 1-50 nm, and the nozzle diameter is 1-500 μm. The materials used in dry aerosols are one or more interconnecting and filling materials selected from nano-silver, nano-copper, and nano-nickel.
6. The dry filling process according to claim 1, characterized in that, The plasma cleaning time is 0-2 minutes, and the atmosphere is argon or nitrogen.
7. The dry filling process according to claim 1, characterized in that, The nano-generation device is a spark ablation method, employing one of the following: physical vapor deposition, laser ablation, or chemical vapor deposition.
8. The dry filling process according to claim 1, characterized in that, The relationship between the time T required for hole filling and the following is: In the formula, r is the pore diameter, h is the pore depth, τ is the particle deposition rate per second, and β is the pore shape correction factor. In the formula, N0 is a constant representing the total number of particles generated by spark ablation per unit time, N is the initial particle concentration, and Q is the gas volume flow rate.
9. The dry filling process according to claim 1, characterized in that, The materials that decompose polymers at low temperatures are polypropylene or polyoxymethylene; Low-temperature decomposition polymers are formed on the surface of a substrate by spin coating or spray coating.
10. An apparatus for implementing the dry filling process according to any one of claims 1-9, characterized in that, include: Ultrasonic device, platform, substrate for filling holes, aerosol nozzle, vacuum port, sealed cavity, electrically conductive metal sheet, controller, industrial computer, CCD camera, nanoparticle generator and gas cylinder; A platform is set up inside the sealed cavity, the ultrasonic device is coupled to the platform, and the substrate to be filled is fixed on the platform; The aerosol nozzle is mounted inside the sealed cavity, and the aerosol nozzle is located inside the sealed cavity; a vacuum port is provided at the bottom of the sealed cavity; Non-contact electrodes are provided at the bottom and top of the substrate to be filled. The non-contact electrodes are used for high-voltage pulse heating. The CCD camera is installed inside the sealed cavity and is used to observe the filling situation inside the sealed cavity. The controller, industrial computer, nanoparticle generator, and gas cylinder are all located outside the sealed cavity. The outlet of the nanoparticle generator is connected to the inlet of the aerosol nozzle, and the gas cylinder is connected to the inlet of the nanoparticle generator. The industrial computer and the controller are connected by signal, and the controller is connected by signal to the ultrasonic device. The controller is used to control the working status of the ultrasonic device.