Method for applying a dry film and use thereof

Abstract

The application provides a dry film pasting method and application thereof, and the method comprises the following steps: placing a dry film in a constant temperature and humidity environment for treatment to eliminate internal stress, and obtaining a pretreated dry film; cleaning and drying a substrate to obtain a pretreated substrate; laminating the adhesive layer of the pretreated dry film with the pretreated substrate, and then performing n times of pressing under vacuum conditions to obtain an intermediate; wherein n is greater than or equal to 2, and the pressing pressure of the nth pressing is greater than that of the (n-1)th pressing; and curing and shaping the intermediate to complete dry film pasting. Through the design and joint action of the process steps, the bubble occurrence rate of the dry film pasting is significantly reduced, the wrinkle defects are effectively inhibited / avoided, the dry film pasting quality is improved, and the product quality and the qualified rate are significantly improved. The dry film pasting method can be applied to the dry film lamination process of high-density lines and deep holes, and has the characteristics of simple operation and strong adaptability.

Description

Technical Field

[0001] This invention belongs to the field of electronic material manufacturing technology, specifically relating to a method for applying dry film and its application. Background Technology

[0002] Dry film, as a key material in chip and circuit board manufacturing, plays an important role in semiconductor processing and insulation protection between different RDL layers. The bonding quality of dry film directly affects the subsequent processing and application performance.

[0003] Dry film application is typically performed using a laminating machine in the industry. For example, CN101738865A discloses a dry laminating process, which includes the following steps: (1) providing a wafer with a semiconductor structure to be photolithographically etched, and coating a layer of passivated adhesive on the wafer surface to form an adhesive layer; (2) sending the wafer into a heating furnace to heat and dry the adhesive; (3) sending the wafer into a laminating machine for rolling and laminating, specifically including: heating the wafer stage of the laminating machine to 55-65°C, and then heating the pressing rollers to 65-75°C to roll and shape the dry film of the required thickness onto the wafer surface; (4) sending the laminated wafer into a curing oven to dry and harden the film. CN115527895A discloses a wafer lamination method. The wafer lamination equipment includes a first plate with a groove, a feeding mechanism, and a cutting mechanism. The method includes the following steps: S1, preparing the wafer lamination equipment and a dry film of a preset thickness; S2, placing the wafer in the groove; S3, using the feeding mechanism to attach the dry film onto the wafer; S4, using a cutting tool to cut the dry film along the edge of the wafer; S5, sequentially exposing and developing the dry film to form a preset pattern on the dry film; S6, electroplating the preset pattern area; S7, removing the film. CN115226318A discloses a method for manufacturing a solder resist layer on a circuit board, including using a vacuum hot-pressing machine to vacuum hot-press a dry solder resist film onto the surface of a circuit board blank. The method comprises three stages: film application, film pressing, and leveling. In the film application stage, the vacuum degree is 3±0.1 hpa, the temperature is 30-80℃, and the film application pressure is 0.2-0.4 MPa. In the film pressing stage, the temperature is 50-80℃, and the film pressing pressure is 6-8 kgf / cm². 2 The pressing time is 20-60 seconds.

[0004] Existing dry film lamination methods mostly employ direct lamination, which has the following drawbacks: air bubbles appear after lamination, affecting subsequent exposure and development; moreover, dry film wrinkles and uneven adhesive flow are prone to occur after lamination, reducing product yield. Therefore, how to reduce the occurrence of air bubbles and wrinkles in dry film lamination is an urgent problem to be solved in this field. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a method for applying dry film and its application. Through the design and combined effect of process steps, the bubble rate of dry film application is effectively reduced, wrinkle defects can be reduced / avoided, and the dry film application quality and product quality are significantly improved.

[0006] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for applying a dry film, the method comprising the following steps: The dry film is left to stand in a constant temperature and humidity environment to eliminate internal stress, thus obtaining a pretreated dry film. The substrate is cleaned and dried to obtain a pretreated substrate; The adhesive layer of the pretreated dry film is bonded to the pretreatment and then pressed under vacuum conditions n times to obtain an intermediate; wherein, n≥2, and the pressure of the nth pressing is greater than the pressure of the (n-1)th pressing. The intermediate is cured and shaped to complete the dry film application.

[0007] This invention proposes a step-by-step dry film lamination method, comprising four steps: dry film preparation (obtaining a pretreated dry film), substrate pretreatment (obtaining a pretreated substrate), gradient pressure lamination (obtaining an intermediate), and curing and shaping. Specifically, in the dry film preparation step, static treatment in a constant temperature and humidity environment eliminates internal stress in the dry film caused by environmental changes, preventing shrinkage or stretching deformation during subsequent lamination and ensuring the stability of the dry film. In the substrate pretreatment step, oil and impurities on the substrate surface are removed, and surface roughness is controlled, providing good surface conditions for dry film lamination. In the gradient pressure lamination step, by setting n laminations and designing the pressure of the nth lamination to be greater than the pressure of the (n-1)th lamination, a gradient pressure is formed, allowing the dry film to gradually adhere to the substrate from the initial contact point. Combined with a vacuum adsorption environment, air between the dry film and the substrate can be effectively expelled, preventing bubble formation. In the curing and shaping step, the adhesive layer is fully cured, avoiding the impact of oxidation reactions on the dry film performance, improving the bonding strength between the dry film and the substrate, and preventing later delamination.

[0008] This invention, through the design and combined effect of process steps, can significantly reduce the bubble rate of dry film lamination, reduce / avoid wrinkle defects, and significantly improve dry film lamination quality and product quality. It is suitable for dry film lamination processes of high-density circuits and deep holes, and features simple operation and strong adaptability.

[0009] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0010] As a preferred embodiment of the present invention, the dry film includes a photosensitive dry film or a non-photosensitive dry film.

[0011] As a preferred embodiment of the present invention, the thickness of the dry film is 10-50 μm.

[0012] As a preferred embodiment of the present invention, the temperature of the constant temperature and humidity environment is 20-25℃.

[0013] As a preferred embodiment of the present invention, the relative humidity of the constant temperature and humidity environment is 50-60%.

[0014] As a preferred embodiment of the present invention, the settling time is 6-24 hours.

[0015] As a preferred embodiment of the present invention, the substrate includes any one of a ceramic substrate, a silicon-based wafer, a glass-based wafer, or a circuit board.

[0016] As a preferred embodiment of the present invention, the cleaning process includes sequential ultrasonic degreasing and water washing.

[0017] As a preferred embodiment of the present invention, the ultrasonic degreasing is performed in an alkaline solution. Deep cleaning of the substrate ensures surface cleanliness, thereby guaranteeing its adhesion to the dry film.

[0018] As a preferred embodiment of the present invention, the frequency of the ultrasonic degreasing is 20-60 kHz.

[0019] As a preferred embodiment of the present invention, the ultrasonic degreasing time is 5-10 min.

[0020] As a preferred embodiment of the present invention, the drying process includes the steps of sequential nitrogen blowing and heating drying.

[0021] As a preferred embodiment of the present invention, the heating and drying temperature is 100-140℃.

[0022] As a preferred embodiment of the present invention, the heating and drying time is 5-20 min.

[0023] As a preferred embodiment of the present invention, the pressing is performed under a vacuum degree ≤ 3 torr.

[0024] As a preferred embodiment of the present invention, the temperature of the pressing film stage during the pressing process is 60-140°C.

[0025] In a preferred embodiment of the present invention, n is 2 or 3. By employing a step-by-step pressing method, gradient pressure pressing and leveling are used to increase the bonding force and reduce the frequency of air bubbles and wrinkles.

[0026] In a preferred embodiment of the present invention, n is 3.

[0027] As a preferred embodiment of the present invention, the pressure of the first pressing is 0.2-0.4 MPa.

[0028] As a preferred embodiment of the present invention, the time for the first pressing is 10-60 s.

[0029] As a preferred embodiment of the present invention, the pressure of the second pressing is 0.3-0.5 MPa.

[0030] As a preferred embodiment of the present invention, the time for the second pressing is 10-60 s.

[0031] As a preferred embodiment of the present invention, the pressure of the third pressing is 0.4-0.6 MPa.

[0032] As a preferred embodiment of the present invention, the time for the third pressing is 10-60 s.

[0033] As another preferred embodiment of the present invention, n is 2; wherein, the pressure of the first pressing is 0.3-0.6 MPa, and the time of the first pressing is 10-60 s. The pressure of the second pressing is 0.5-0.8 MPa, and the time of the second pressing is 10-80 s.

[0034] As a preferred embodiment of the present invention, the curing and shaping are carried out in an inert atmosphere.

[0035] As a preferred technical solution of the present invention, the curing and shaping includes a first stage of temperature holding, a second stage of temperature holding, and a third stage of temperature holding with the temperature increasing sequentially.

[0036] As a preferred embodiment of the present invention, the temperature of the section holding the temperature is 60-120℃.

[0037] As a preferred embodiment of the present invention, the holding time is 10-60 min.

[0038] As a preferred embodiment of the present invention, the temperature of the two-stage temperature holding is 120-180℃.

[0039] As a preferred embodiment of the present invention, the holding time for the two stages is 10-60 min.

[0040] As a preferred embodiment of the present invention, the temperature of the three-stage temperature holding is 180-220℃.

[0041] As a preferred embodiment of the present invention, the holding time for the three temperature stages is 30-150 min.

[0042] As a preferred embodiment of the present invention, the method includes the following steps: The dry film is left to stand in a constant temperature and humidity environment of 20-25℃ and 50-60% for 6-24 hours to eliminate internal stress and obtain a pretreated dry film. The substrate is placed in an alkaline solution and ultrasonically degreased at a frequency of 20-60 kHz for 5-10 min, then washed with water, dried with nitrogen, and heated to 100-140℃ for 5-20 min to obtain a pretreated substrate. After the adhesive layer of the pretreated dry film is bonded to the pretreated substrate, it is pressed in a vacuum pressing device. The pressing includes: first applying a pressure of 0.2-0.4 MPa for 10-60 s, releasing the pressure, then applying a pressure of 0.3-0.5 MPa for 10-60 s, releasing the pressure, and then applying a pressure of 0.4-0.6 MPa for 10-60 s, releasing the pressure, to obtain an intermediate. During the pressing process, the vacuum degree is controlled to be ≤3 torr, and the temperature of the film pressing stage is 60-140℃. The intermediate is cured and shaped in an inert atmosphere. The curing and shaped process includes: first, heating the temperature to 60-120°C at a rate of 1-5°C / min and holding it at that temperature for 10-60 min; then heating the temperature to 120-180°C at a rate of 1-5°C / min and holding it at that temperature for 10-60 min; then heating the temperature to 180-220°C at a rate of 1-5°C / min and holding it at that temperature for 30-150 min; cooling is then performed to complete the dry film adhesion.

[0043] In a second aspect, the present invention provides an application of the dry film lamination method as described in the first aspect in chip manufacturing, circuit board manufacturing or semiconductor processing.

[0044] Compared with the prior art, the present invention has at least the following beneficial effects: The dry film lamination method provided by this invention significantly reduces the bubble rate during dry film lamination through the design and combined effect of process steps, achieving a bubble rate of <1%, and as low as ≤0.5%. It also effectively suppresses / avoids wrinkling defects, thereby improving dry film lamination quality and significantly enhancing product quality and yield. This dry film lamination method is applicable to dry film lamination processes for high-density circuits and deep vias, and features simple operation and strong adaptability. Detailed Implementation

[0045] To facilitate understanding of the present invention, specific embodiments are provided to further illustrate the technical solution of the present invention. Those skilled in the art should understand that the embodiments are merely illustrative of the present invention and should not be considered as specific limitations thereof.

[0046] The terms “comprising,” “including,” “having,” “containing,” or any other variations thereof, as used herein, are intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that includes the listed elements is not limited to those elements and may also include other elements not expressly listed or elements inherent to such composition, step, method, article, or apparatus.

[0047] In this invention, features marked with "one," "two," or "three" may explicitly or implicitly include one or more of those features, used to distinguish and describe features, without any order or emphasis. In the description of this invention, unless otherwise stated, "multiple" means two or more.

[0048] This invention has revealed the following defects in existing dry film lamination processes: 1. Incomplete cleaning of the work surface, leaving residual oil, impurities, etc., leads to numerous air bubbles after dry film lamination, affecting subsequent exposure and development effects; 2. Uneven pressure and temperature control during the lamination process easily causes problems such as air bubbles, dry film wrinkles, and uneven film flow; In existing dry film lamination processes, the area affected by air bubbles and wrinkles reaches 3-5%, seriously impacting product qualification rates.

[0049] To overcome the shortcomings of existing technologies where dry film application easily results in air bubbles and wrinkles, a specific embodiment of the present invention provides a method for applying dry film, the method comprising the following steps: The dry film is left to stand in a constant temperature and humidity environment to eliminate internal stress, thus obtaining a pretreated dry film. The substrate is cleaned and dried to obtain a pretreated substrate; The adhesive layer of the pretreated dry film is bonded to the pretreatment and then pressed under vacuum conditions n times to obtain an intermediate; wherein, n≥2, and the pressure of the nth pressing is greater than the pressure of the (n-1)th pressing. The intermediate is cured and shaped to complete the dry film application.

[0050] This invention proposes a step-by-step dry film lamination method, comprising four steps: dry film preparation to obtain a pretreated dry film, substrate pretreatment to obtain a pretreated substrate, gradient pressure lamination to obtain an intermediate, and curing and shaping. Specifically, in the dry film preparation step, the dry film is placed in a constant temperature and humidity environment for static treatment, which eliminates the internal stress caused by environmental changes and avoids shrinkage or stretching deformation during subsequent lamination, thereby ensuring the stability of the dry film. In the substrate pretreatment step, cleaning and drying remove oil and impurities from the substrate surface, while controlling surface roughness to provide good surface conditions for dry film lamination. In the gradient pressure lamination step, by designing the pressure of the nth lamination to be greater than the pressure of the (n-1)th lamination, the gradient pressure setting allows the dry film to gradually adhere to the substrate from the initial contact point. Combined with a vacuum adsorption environment, this effectively removes air between the dry film and the substrate, preventing bubble formation. Ideally, in the curing and shaping step, the adhesive layer is fully cured to avoid the impact of oxidation on the dry film performance, improve the bonding strength between the dry film and the substrate, and prevent delamination later. This invention, through the design and combined action of process steps, can significantly reduce the bubble rate in dry film lamination and reduce / avoid wrinkle defects, thereby significantly improving dry film lamination quality and product quality. The method of this invention is particularly suitable for dry film lamination processes involving high-density circuitry and deep vias, and features simple operation and strong adaptability.

[0051] In a preferred embodiment, the dry film includes a photosensitive dry film or a non-photosensitive dry film.

[0052] In a preferred embodiment, the thickness of the dry film is 10-50 μm, for example, it can be 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm or 45 μm, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, but preferably 12-40 μm.

[0053] In a preferred embodiment, the temperature of the constant temperature and humidity environment is 20-25°C, for example, it can be 21°C, 22°C, 23°C or 24°C, as well as specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0054] In a preferred embodiment, the relative humidity of the constant temperature and humidity environment is 50-60%, for example, it can be 52%, 55% or 58%, and specific values ​​between the above points are not exhaustively listed in this invention for the sake of space and for the sake of brevity.

[0055] In a preferred embodiment, the settling time is 6-24 h, for example, 8 h, 12 h, 16 h or 20 h, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, but 6-16 h is preferred.

[0056] In a preferred embodiment, the settling process further includes a step of removing the protective film from the dry film to expose the adhesive layer.

[0057] In a preferred embodiment, the substrate includes any one of a ceramic substrate, a silicon-based wafer, a glass-based wafer, or a circuit board.

[0058] In a preferred embodiment, the cleaning includes sequential ultrasonic degreasing and water washing steps.

[0059] In a preferred embodiment, the ultrasonic degreasing is performed in an alkaline solution.

[0060] In a preferred embodiment, the frequency of the ultrasonic degreasing is 20-60 kHz, for example, it can be 25 kHz, 30 kHz, 35 kHz, 40 kHz, 45 kHz, 50 kHz or 55 kHz, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0061] In a preferred embodiment, the ultrasonic degreasing time is 5-10 min, for example, 5 min, 6 min, 7 min, 8 min or 9 min, and specific point values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific point values ​​included in the range.

[0062] In a preferred embodiment, the water washing is performed using deionized water.

[0063] In a preferred embodiment, the drying process includes sequential nitrogen blowing and heating drying steps.

[0064] In a preferred embodiment of the present invention, the substrate pretreatment step includes a combination of sequential ultrasonic degreasing, water washing, nitrogen drying, and heat drying processes to thoroughly remove oil and impurities from the substrate surface while controlling surface roughness and providing good surface conditions for dry film bonding. Ultrasonic degreasing utilizes the cavitation effect generated by high-frequency vibration to quickly remove oil; water rinsing avoids residual degreasing agent from adversely affecting the adhesive layer; nitrogen drying and heat drying ensure the substrate surface is dry and prevent moisture from causing air bubbles.

[0065] In a preferred embodiment, the heating and drying temperature is 100-140°C, for example, it can be 105°C, 110°C, 115°C, 120°C, 125°C, 130°C or 135°C, as well as specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0066] In a preferred embodiment, the heating and drying time is 5-20 min, for example, 8 min, 10 min or 15 min, and specific values ​​between the above values ​​are not exhaustively listed in this invention for space limitations and for the sake of brevity.

[0067] In a preferred embodiment, the pressing is performed under a vacuum degree ≤ 3 torr, for example, the vacuum degree can be 0.1 torr, 0.5 torr, 1 torr, 2 torr, 3 torr, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0068] In a preferred embodiment, the temperature of the pressing film stage during the pressing process is 60-140°C, for example, it can be 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C or 135°C, as well as specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, but 70-130°C is preferred.

[0069] In a preferred embodiment, n is 3, that is, 3 pressings are performed. The pressure of the first pressing is less than the pressure of the second pressing and less than the pressure of the third pressing. The gradient pressure setting allows the dry film to gradually adhere to the substrate from the initial contact area. Combined with the vacuum adsorption environment, it can effectively remove the air between the dry film and the substrate and avoid the generation of air bubbles.

[0070] It should be noted that the pressing process is defined as "applying pressure - releasing pressure" as one pressing operation. That is, first, pressure is applied for the first pressing operation, and then the pressure is released; then pressure is applied for the second pressing operation, and then the pressure is released; finally, pressure is applied for the third pressing operation, and then the pressure is released.

[0071] In a preferred embodiment, the pressure of the first pressing is 0.2-0.4 MPa, for example 0.25 MPa, 0.3 MPa or 0.35 MPa, and specific values ​​between the above values ​​are not exhaustively listed here for space limitations and for the sake of brevity.

[0072] In a preferred embodiment, the time for the first pressing is 10-60 s, for example, it can be 15 s, 20 s, 25 s, 30 s, 35 s, 40 s, 45 s, 50 s or 55 s, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0073] In a preferred embodiment, the pressure of the second pressing is 0.3-0.5 MPa, for example 0.35 MPa, 0.4 MPa or 0.45 MPa, and specific values ​​between the above values ​​are not exhaustively listed here for space limitations and for the sake of brevity.

[0074] In a preferred embodiment, the time for the second pressing is 10-60 s, for example, it can be 15 s, 20 s, 25 s, 30 s, 35 s, 40 s, 45 s, 50 s or 55 s, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0075] In a preferred embodiment, the pressure of the third pressing is 0.4-0.6 MPa, for example 0.45 MPa, 0.5 MPa or 0.55 MPa, and specific values ​​between the above values ​​are not exhaustively listed here for space limitations and for the sake of brevity.

[0076] In a preferred embodiment, the time for the third pressing is 10-60 s, for example, it can be 15 s, 20 s, 25 s, 30 s, 35 s, 40 s, 45 s, 50 s or 55 s, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0077] In another preferred embodiment of the present invention, n is 2.

[0078] In a preferred embodiment, for a two-stage pressing process, the pressure of the first pressing is 0.3-0.6 MPa, for example, 0.35 MPa, 0.4 MPa, 0.45 MPa, 0.5 MPa, or 0.55 MPa; the time of the first pressing is 10-60 s, for example, 15 s, 20 s, 25 s, 30 s, 35 s, 40 s, 45 s, 50 s, or 55 s.

[0079] In a preferred embodiment, for a two-stage pressing process, the pressure of the second pressing is 0.5-0.8 MPa, for example, 0.55 MPa, 0.6 MPa, 0.65 MPa, 0.7 MPa, or 0.75 MPa; the time of the second pressing is 10-80 s, for example, 15 s, 20 s, 25 s, 30 s, 35 s, 40 s, 45 s, 50 s, 55 s, 60 s, 65 s, 70 s, or 75 s.

[0080] It should be noted that the pressing process (before curing and shaping) also includes optional photolithography and optional drilling steps to meet the needs of actual preparation.

[0081] In a preferred embodiment, the curing and shaping are carried out in an inert atmosphere.

[0082] For example, the inert atmosphere includes a nitrogen atmosphere, an argon atmosphere, and a helium atmosphere.

[0083] For example, the curing and shaping are carried out in a curing oven, where the oxygen content is ≤100 ppm, for example, 10 ppm, 20 ppm, 50 ppm, 60 ppm, 70 ppm, 80 ppm or 90 ppm, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, but preferably ≤20 ppm.

[0084] In a preferred embodiment, the curing and shaping includes a first stage of temperature holding, a second stage of temperature holding, and a third stage of temperature holding with the temperature increasing sequentially.

[0085] In a preferred embodiment of the present invention, during the curing and shaping step, the adhesive film layer is fully cured by stepwise heating and inert gas protection, which avoids the influence of oxidation reaction on the performance of the dry film, improves the bonding strength between the dry film and the substrate, and prevents the film from peeling off later.

[0086] In a preferred embodiment, the temperature range for holding the temperature is 60-120°C, for example, it can be 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C or 115°C, as well as specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0087] In a preferred embodiment, the holding time is 10-60 min, for example, it can be 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min or 55 min, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0088] In a preferred embodiment, the temperature of the two-stage holding temperature is 120-180℃, for example, it can be 125℃, 130℃, 135℃, 140℃, 145℃, 150℃, 155℃, 160℃, 165℃, 170℃ or 175℃, as well as specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0089] In a preferred embodiment, the holding time for the two stages is 10-60 min, for example, it can be 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min or 55 min, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0090] In a preferred embodiment, the temperature of the three temperature segments is 180-220°C, for example, it can be 185°C, 190°C, 195°C, 200°C, 205°C, 210°C or 215°C, as well as specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0091] In a preferred embodiment, the three holding times are 30-150 min, for example, 40 min, 50 min, 60 min, 70 min, 80 min, 90 min, 100 min, 110 min, 120 min, 130 min or 140 min, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0092] For example, the heating rate during the curing and shaping process is 1-5℃ / min, such as 1.5℃ / min, 2℃ / min, 2.5℃ / min, 3℃ / min, 3.5℃ / min, 4℃ / min, 4.5℃ / min, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, but preferably 1.5-3.5℃ / min.

[0093] In a preferred embodiment, the method includes the following steps: The dry film is left to stand in a constant temperature and humidity environment of 20-25℃ and 50-60% for 6-24 hours to eliminate internal stress and obtain a pretreated dry film. The substrate is placed in an alkaline solution and ultrasonically degreased at a frequency of 20-60 kHz for 5-10 min, then washed with water, dried with nitrogen, and heated at 100-140℃ for 5-20 min to obtain a pretreated substrate. After the adhesive layer of the pretreated dry film is bonded to the pretreated substrate, it is pressed in a vacuum pressing device. The pressing includes: first applying a pressure of 0.2-0.4 MPa for 10-60 s, releasing the pressure, then applying a pressure of 0.3-0.5 MPa for 10-60 s, releasing the pressure, and then applying a pressure of 0.4-0.6 MPa for 10-60 s, releasing the pressure, to obtain an intermediate. During the pressing process, the vacuum degree is controlled to be ≤3 torr, and the temperature of the film pressing stage is 60-140℃. The intermediate is cured and shaped in an inert atmosphere. The curing and shaped process includes: first, heating the temperature to 60-120°C at a rate of 1-5°C / min and holding it for 10-60 min; then heating the temperature to 120-180°C at a rate of 1-5°C / min and holding it for 10-60 min; then heating the temperature to 180-220°C at a rate of 1-5°C / min and holding it for 30-150 min; cooling is then performed to complete the dry film adhesion.

[0094] The method provided by this invention, through an optimized substrate pretreatment process, effectively removes surface oil and impurities, controls surface roughness, and lays a solid foundation for dry film lamination. Combined with gradient lamination and vacuum adsorption, it reduces the bubble formation rate to below 1%, significantly superior to existing technologies. The gradient lamination process avoids dry film wrinkles and uneven adhesive layer flow, improving the bonding strength between the dry film and the substrate and increasing the product yield. During the curing and setting stage, strict control of the oxygen content in the curing oven and the heating rate during the heating process ensures the adhesion of the dry film surface and the consistency of internal shrinkage, providing a guarantee for subsequent processing. The method has clear operation steps, easily controllable parameters, and is adaptable to different types of substrates and dry films, showing broad application prospects.

[0095] Another specific embodiment of the present invention provides an application of the dry film lamination method described in the foregoing specific embodiments in chip manufacturing, circuit board manufacturing or semiconductor processing.

[0096] The following describes the method of applying dry film according to the present invention in detail using several embodiments, but the method of applying dry film according to the present invention is not limited to these embodiments.

[0097] Example 1 A method for applying dry film includes the following steps: Dry film preparation: Select a photosensitive dry film with a thickness of 15 μm, place it in a constant temperature and humidity environment of 22℃ and 50% relative humidity for 6 h to obtain a pretreated dry film, and then manually remove the polyethylene protective film of the dry film to expose the adhesive film layer for later use. Substrate pretreatment: Select a ceramic substrate, place it in an alkaline composite solution, and perform ultrasonic degreasing at a frequency of 40 kHz for 5 min. Then take it out, rinse it with deionized water, blow it dry with a nitrogen gun, and finally bake it with a hot plate at 120℃ for 10 min to obtain the pretreated substrate. Gradient lamination: The adhesive layer of the pretreated dry film is applied to the surface of the pretreated substrate. The lamination equipment is started with an initial pressure of 0.3 MPa for 30 seconds. The pressure is released, and then 0.4 MPa is applied for 30 seconds. The pressure is released again, and then 0.5 MPa is applied for 30 seconds to obtain an intermediate. During the lamination process, the temperature of the lamination stage is controlled at 80°C, and the vacuum level in the cavity is maintained below 3 torr. Curing and shaping: The photolithographically completed intermediate is sent into the curing oven, and the oxygen content in the oven is controlled to be less than 20 ppm. The temperature is increased to 80°C at a rate of 3°C / min and held for 30 min; then the temperature is increased to 150°C at a rate of 3°C / min and held for 30 min; then the temperature is increased to 200°C at a rate of 3°C / min and held for 60 min; finally, the heating device is turned off and the mixture is allowed to cool naturally to room temperature to complete the dry film deposition.

[0098] AOI scanning and comparison was used for inspection. Multiple areas without defects such as bubbles or wrinkles were selected, and the equipment acquired images. These images were then composited to form a golden image. The defect detection dimensions were set to be ≥0.2 μm × 0.2 μm (length × width), and the defect detection area was set to be ≥0.1 μm. 2 Then, the substrate after lamination in Example 1 was tested, and the bubble occurrence rate was 0.4%, and there were no wrinkles in the dry film.

[0099] Example 2 A method for applying dry film includes the following steps: Dry film preparation: Select a photosensitive dry film with a thickness of 20 μm, place it in a constant temperature and humidity environment of 22℃ and 50% relative humidity for 6 h to obtain a pretreated dry film, and then manually remove the polyethylene protective film of the dry film to expose the adhesive film layer for later use. Substrate pretreatment: Select silicon-based wafers, place them in an alkaline composite solution, and perform ultrasonic degreasing at a frequency of 40 kHz for 5 min. Then remove them, rinse them with deionized water, dry them with a nitrogen gun, and finally bake them on a hot plate at 120℃ for 10 min to obtain the pretreated substrate. Gradient lamination: The adhesive layer of the pretreated dry film is applied to the surface of the pretreated substrate. The lamination equipment is started with an initial pressure of 0.3 MPa for 30 seconds. The pressure is released, and then 0.4 MPa is applied for another 30 seconds. The pressure is released again, and then 0.5 MPa is applied for another 60 seconds to obtain an intermediate. During the lamination process, the temperature of the lamination stage is controlled at 120°C, and the vacuum level in the cavity is maintained below 3 torr. Curing and shaping: The photolithographically completed intermediate is sent into the curing oven, and the oxygen content in the oven is controlled to be less than 20 ppm. The temperature is increased to 80°C at a rate of 3°C / min and held for 30 min; then the temperature is increased to 150°C at a rate of 3°C / min and held for 30 min; then the temperature is increased to 190°C at a rate of 3°C / min and held for 120 min; finally, the heating device is turned off and the mixture is allowed to cool naturally to room temperature to complete the dry film deposition.

[0100] The substrate after lamination in Example 2 was tested using the same method as in Example 1. The bubble occurrence rate was 0.2%, and there were no wrinkles in the dry film.

[0101] Example 3 A method for applying dry film includes the following steps: Dry film preparation: Select a non-photosensitive dry film with a thickness of 30 μm, place it in a constant temperature and humidity environment of 22℃ and 50% for 12 h to obtain a pretreated dry film, and then manually remove the polyethylene protective film of the dry film to expose the adhesive film layer for later use. Substrate pretreatment: Select glass-based wafers, place them in an alkaline composite solution, and perform ultrasonic degreasing at a frequency of 40 kHz for 5 min. Then remove them, rinse them with deionized water, dry them with a nitrogen gun, and finally bake them on a hot plate at 120℃ for 10 min to obtain the pretreated substrate. Gradient lamination: The adhesive layer of the pretreated dry film is applied to the surface of the pretreated substrate. The lamination equipment is started with an initial pressure of 0.5 MPa for 30 seconds. The pressure is released, and then 0.7 MPa is applied for 60 seconds to obtain the intermediate. During the lamination process, the temperature of the lamination stage is controlled at 120°C, and the vacuum degree in the cavity is maintained below 3 torr. Curing and shaping: The intermediate with holes completed is sent into the curing oven. The oxygen content in the oven is controlled to be less than 20 ppm. The temperature is increased to 100℃ at a rate of 3℃ / min and held for 30 min. Then the temperature is increased to 170℃ at a rate of 3℃ / min and held for 30 min. Then the temperature is increased to 200℃ at a rate of 3℃ / min and held for 90 min. Finally, the heating device is turned off and the mixture is allowed to cool naturally to room temperature to complete the dry film application.

[0102] The substrate after lamination in Example 3 was tested using the same method as in Example 1. The bubble occurrence rate was 0.3%, and there were no wrinkles in the dry film.

[0103] Comparative Example 1 A method for applying a dry film differs from Example 1 only in the pressing step, specifically including: covering the surface of the pretreated substrate with the adhesive layer of the pretreated dry film, starting the pressing equipment, applying a pressure of 0.5 MPa, operating for 120 seconds to obtain an intermediate; during the pressing operation, the temperature of the pressing stage is controlled at 120°C, and the vacuum degree in the cavity is maintained below 3 torr; other steps and parameters are the same as in Example 1.

[0104] The substrates of Comparative Example 1 after lamination were tested using the same method as in Example 1. The bubble occurrence rate was 3% and the wrinkle occurrence rate was 2%.

[0105] Comparative Example 2 A method for applying dry film differs from Example 1 only in that the dry film preparation step is omitted, i.e., the photosensitive dry film is not left to stand in a constant temperature and humidity environment, and the polyethylene protective film is directly removed to expose the adhesive film layer for gradient lamination; all other steps and parameters are the same as in Example 1.

[0106] The substrates of Comparative Example 2 were inspected using the same method as in Example 1. The bubble occurrence rate was 3% and the wrinkle occurrence rate was 2%.

[0107] The present invention has been illustrated through the above embodiments, but the present invention is not limited to the above process steps, that is, it does not mean that the present invention must rely on the above process steps to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials used in the present invention, additions of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for applying dry film, characterized in that, The method includes the following steps: The dry film is left to stand in a constant temperature and humidity environment to eliminate internal stress, thus obtaining a pretreated dry film. The substrate is cleaned and dried to obtain a pretreated substrate; The adhesive layer of the pretreated dry film is bonded to the pretreated substrate and then pressed under vacuum conditions n times to obtain an intermediate; wherein, n≥2, and the pressure of the nth pressing is greater than the pressure of the (n-1)th pressing. The intermediate is cured and shaped to complete the dry film application.

2. The method according to claim 1, characterized in that, The dry film includes a photosensitive dry film or a non-photosensitive dry film; And / or, the thickness of the dry film is 10-50 μm.

3. The method according to claim 1, characterized in that, The temperature of the constant temperature and humidity environment is 20-25℃; And / or, the relative humidity of the constant temperature and humidity environment is 50-60%; And / or, the settling time is 6-24 h.

4. The method according to claim 1, characterized in that, The substrate includes any one of ceramic substrate, silicon-based wafer, glass-based wafer, or circuit board.

5. The method according to claim 1, characterized in that, The cleaning process includes sequential ultrasonic degreasing and water washing. Preferably, the ultrasonic degreasing is performed in an alkaline solution; Preferably, the frequency of the ultrasonic degreasing is 20-60 kHz; Preferably, the ultrasonic degreasing time is 5-10 minutes.

6. The method according to claim 1, characterized in that, The drying process includes sequential steps of nitrogen blowing and heating drying. Preferably, the heating and drying temperature is 100-140℃; Preferably, the heating and drying time is 5-20 minutes.

7. The method according to claim 1, characterized in that, The pressing is performed under a vacuum degree ≤ 3 torr; And / or, the temperature of the pressing stage during the pressing process is 60-140°C; And / or, the n is 3; And / or, the pressure of the first pressing is 0.2-0.4 MPa, and the time is 10-60 s; And / or, the pressure of the second pressing is 0.3-0.5 MPa, and the time is 10-60 s; And / or, the pressure of the third pressing is 0.4-0.6 MPa, and the time is 10-60 s.

8. The method according to claim 1, characterized in that, The curing and shaping process is carried out in an inert atmosphere; Preferably, the curing and shaping includes a first stage of temperature holding, a second stage of temperature holding, and a third stage of temperature holding with the temperature increasing sequentially; Preferably, the temperature for holding the temperature for one stage is 60-120℃, and the time is 10-60 min; Preferably, the temperature for the two-stage temperature holding is 120-180℃, and the time is 10-60 min; Preferably, the temperature for the three temperature holding stages is 180-220℃, and the time is 30-150 min.

9. The method according to claim 1, characterized in that, The method includes the following steps: The dry film is left to stand in a constant temperature and humidity environment of 20-25℃ and 50-60% for 6-24 hours to eliminate internal stress and obtain a pretreated dry film. The substrate is placed in an alkaline solution and ultrasonically degreased at a frequency of 20-60 kHz for 5-10 min, then washed with water, dried with nitrogen, and heated at 100-140℃ for 5-20 min to obtain a pretreated substrate. After the adhesive layer of the pretreated dry film is bonded to the pretreated substrate, it is pressed in a vacuum pressing device. The pressing includes: first applying a pressure of 0.2-0.4 MPa for 10-60 s, releasing the pressure, then applying a pressure of 0.3-0.5 MPa for 10-60 s, releasing the pressure, and then applying a pressure of 0.4-0.6 MPa for 10-60 s, releasing the pressure, to obtain an intermediate. During the pressing process, the vacuum degree is controlled to be ≤3 torr, and the temperature of the film pressing stage is 60-140℃. The intermediate is cured and shaped in an inert atmosphere. The curing and shaped process includes: first, heating the temperature to 60-120°C at a rate of 1-5°C / min and holding it at that temperature for 10-60 min; then heating the temperature to 120-180°C at a rate of 1-5°C / min and holding it at that temperature for 10-60 min; then heating the temperature to 180-220°C at a rate of 1-5°C / min and holding it at that temperature for 30-150 min; cooling is then performed to complete the dry film adhesion.

10. The application of a dry film lamination method as described in any one of claims 1-9 in chip manufacturing, circuit board manufacturing, or semiconductor processing.