ABF membrane curing method

Abstract

The present application relates to a kind of circuit board processing method, especially a kind of ABF film curing method, comprising: according to initial first constant temperature stage, initial second constant temperature stage, set multiple baking temperature and / or baking time different contrast first constant temperature stage, contrast second constant temperature stage, one of contrast first constant temperature stage and one of contrast second constant temperature stage are combined to form multiple different experimental groups, and baking is carried out according to each experimental group respectively, then the roughness of ABF film after baking of multiple experimental groups is compared after etching by drug water, select a group of experimental groups with roughness closest to preset roughness, and the corresponding contrast first constant temperature stage and contrast second constant temperature stage are set in the baking of ABF film for mass production and applied.By the structure of the present application, the optimal contrast first constant temperature stage and contrast second constant temperature stage can be screened by setting multiple experimental groups, so that the ABF film after curing has better roughness.

Description

Technical Field

[0001] The present invention relates to a circuit board processing method, in particular to an ABF film curing method. Background Art

[0002] The description in this section merely provides background information related to the present disclosure and may not constitute prior art.

[0003] In the packaging technology of PCB manufacturing, ABF (Ajinomoto Build-up Film) substrates refer to circuit boards made using ABF film and a substrate. They are widely used in advanced packaging. The build-up process of ABF substrates is a crucial step in the electronic packaging manufacturing process, directly affecting the electrical performance and reliability of the final product.

[0004] In the ABF lamination process, the surface roughness of the ABF film, generally referred to as the arithmetic mean roughness (Ra), is a key physical parameter. Controlling the surface roughness of the ABF film not only improves the material's physical properties and adhesion, but also effectively balances product yield. Excessive surface roughness can cause chemical copper to deposit deep into the pits, making it impossible to completely remove the chemical copper deep in the subsequent etching process. This leads to unclean etching, which can cause short circuits during electrical testing of the substrate, seriously affecting the product's electrical performance and reliability. However, excessively low surface roughness leads to insufficient adhesion between the ABF film and the substrate, seriously affecting the product's material strength.

[0005] Therefore, it is worth noting that the thermal process significantly affects the degree of curing of polymer materials. After the desmearing process in the ABF lamination process, the surface roughness of the ABF film will change. In order to control the roughness of the ABF film within an appropriate range during production and ensure the quality stability of the ABF lamination process, it is necessary to find the optimal ABF film lamination production conditions.

[0006] Currently, there is no ABF film curing method that can solve the above problems. Summary of the Invention

[0007] The purpose of the present invention is to provide an ABF film curing method, which is based on the original initial first constant temperature stage and the initial second constant temperature stage. By setting up multiple experimental groups, the optimal comparative first constant temperature stage and the comparative second constant temperature stage can be screened out, so that the cured ABF film has better roughness.

[0008] To achieve the above-mentioned object, the present invention discloses the following ABF film curing method; the method comprises providing an ABF film, disposing the ABF film on a substrate, and baking the ABF film in an oven, wherein the baking step comprises an initial first constant temperature stage and an initial second constant temperature stage; wherein the ABF film curing method further comprises:

[0009] According to the initial first constant temperature stage, a plurality of comparative first constant temperature stages having different baking temperatures and / or baking times are set, wherein the absolute value of the difference between each comparative first constant temperature stage and the initial first constant temperature stage is within a first preset range; according to the initial second constant temperature stage, a plurality of comparative second constant temperature stages having different baking temperatures and / or baking times are set, wherein the absolute value of the difference between each comparative second constant temperature stage and the initial second constant temperature stage is within a second preset range;

[0010] One of the comparative first constant temperature stages is combined with one of the comparative second constant temperature stages to form a plurality of different experimental groups, and baking is performed separately according to each of the experimental groups. Then, the roughness of the ABF films after baking in the plurality of experimental groups after being etched by chemical solution is compared, and a group of the experimental groups whose roughness is closest to the preset roughness is selected, and the corresponding comparative first constant temperature stage and the comparative second constant temperature stage are set and applied in the baking of the ABF films in mass production.

[0011] Furthermore, after the step of "combining one of the comparative first constant temperature stages with one of the comparative second constant temperature stages to form a plurality of different experimental groups, and baking each of the experimental groups separately, and then comparing the roughness of the baked ABF films of the plurality of experimental groups after being etched by chemical solution, and selecting a group of the experimental groups whose roughness is closest to the preset roughness", it also includes performing a reflow test on the basis of the ABF film of the experimental group whose roughness is closest to the preset roughness. If there is no explosion after the reflow test, then the step of "and setting the corresponding comparative first constant temperature stage and the comparative second constant temperature stage in the baking of the ABF film in mass production" is performed.

[0012] Furthermore, the reflow test is set to 10 times, and the highest temperature during the reflow test is 260°C.

[0013] Furthermore, after each mass production bake is completed in the step of "and setting the corresponding comparative first constant temperature stage and the comparative second constant temperature stage for application in the mass production bake of the ABF film", the substrate on which the ABF film is cured is drilled, and then the substrate on which the ABF film is cured is desmeared after drilling, and then chemical copper deposition is performed on the substrate on which the ABF film is cured after desmearing.

[0014] Furthermore, in the step of "de-smearing the substrate on which the ABF film is cured", the substrate on which the ABF film is cured is immersed in a desmearing liquid for ten minutes, and the temperature of the desmearing liquid is maintained at 70°C-90°C.

[0015] Furthermore, after the step of “then performing chemical copper deposition on the substrate having the ABF film cured thereon after desmearing”, a uniform copper layer with a thickness of 0.5±0.3 μm is formed.

[0016] Furthermore, in the step of "selecting a group of experimental groups whose roughness is closest to the preset roughness", the preset roughness is set to 0.1-0.4µm.

[0017] Furthermore, in the step of "combining one of the comparative first constant temperature stages with one of the comparative second constant temperature stages to form a plurality of different experimental groups, and performing baking separately according to each of the experimental groups", five points at the four corners and the center of each of the ABF films are selected as temperature detection locations.

[0018] Furthermore, in the step of "combining one of the comparative first constant temperature stages with one of the comparative second constant temperature stages to form a plurality of different experimental groups, and baking each of the experimental groups separately, and then comparing the roughness of the baked ABF films of the plurality of experimental groups after being etched by chemical solution, and selecting a group of the experimental groups whose roughness is closest to the preset roughness", the comparison of the roughness is performed by visual inspection through a scanning electron microscope and corrosion degree detection by weighing.

[0019] Furthermore, in the step of "selecting a group of experimental groups whose roughness is closest to the preset roughness, and setting the corresponding comparative first constant temperature stage and the comparative second constant temperature stage for application in the baking of the ABF film in mass production", the heating slope from room temperature to the temperature of the comparative first constant temperature stage needs to be 7°C-9°C / min, and the heating slope from the temperature of the comparative first constant temperature stage to the temperature of the comparative second constant temperature stage needs to be 3°C-5°C / min, and the total baking time of the ABF film in the oven is 85min-95min.

[0020] By means of the above technical solution, the beneficial effects of the present invention are as follows:

[0021] The ABF film curing method of the present invention is based on the original initial first constant temperature stage and the initial second constant temperature stage. By setting up multiple experimental groups and conducting baking experiments separately, after the experiment, the roughness results of the baked ABF films of each group are analyzed, and an experimental group that best meets the preset roughness is screened out. The optimal comparative first constant temperature stage and comparative second constant temperature stage of the experimental group are extracted and put into mass production operations, thereby improving the overall production quality of the ABF carrier board. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0023] Figure 1 This is a schematic diagram of multi-point baking and heating in the third experimental group of an ABF film curing method provided in the embodiments of this specification;

[0024] Figure 2 This is a temperature acquisition schematic diagram of an ABF film curing method provided in an embodiment of this specification;

[0025] Figure 3 This is a roughness detection schematic diagram of an ABF film curing method provided in an embodiment of this specification;

[0026] Figure 4 Schematic diagram of the results of six experimental groups of an ABF film curing method provided in the examples of this specification;

[0027] Figure 5 This is a schematic diagram of the surface morphology after desmearing of the first experimental group of an ABF film curing method provided in an embodiment of this specification;

[0028] Figure 6 This is a schematic diagram of the surface morphology after desmearing in the second experimental group of an ABF film curing method provided in an embodiment of this specification;

[0029] Figure 7 This is a schematic diagram of the surface morphology after desmearing of the third experimental group of an ABF film curing method provided in an embodiment of this specification;

[0030] Figure 8 This is a schematic diagram of the surface morphology after desmearing of the fourth experimental group of an ABF film curing method provided in the embodiments of this specification;

[0031] Figure 9This is a schematic diagram of the surface morphology of the chemical copper rear surface of the second experimental group of an ABF film curing method provided in an embodiment of this specification;

[0032] Figure 10 This is a schematic diagram of the surface morphology of the chemical copper rear surface of the third experimental group of an ABF film curing method provided in the embodiments of this specification;

[0033] Figure 11 This is a schematic diagram of the surface morphology of the fourth experimental group of chemical copper in an ABF film curing method provided in an embodiment of this specification. DETAILED DESCRIPTION

[0034] To help those skilled in the art better understand the technical solutions in this specification, the following will provide a clear and complete description of the technical solutions in the embodiments of this specification, in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of this specification, not all of them. All other embodiments derived by those skilled in the art based on the embodiments in this specification without creative effort shall fall within the scope of protection of this specification.

[0035] In the description of the present invention, it should be noted that the terms "upper", "middle", "lower", "inside", "outside", "front", "back" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention. The terms "first", "second" and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The following describes an implementation method of the present invention based on its overall structure.

[0036] An ABF film curing method according to this embodiment includes providing an ABF film, placing the ABF film on a substrate, and baking the ABF film in an oven, wherein the baking step includes an initial first constant temperature stage and an initial second constant temperature stage. The ABF film curing method further includes:

[0037] Setting a plurality of comparative first constant temperature stages with different baking temperatures and / or baking times according to the initial first constant temperature stage, wherein the absolute value of the difference between each comparative first constant temperature stage and the initial first constant temperature stage is within a first preset range; setting a plurality of comparative second constant temperature stages with different baking temperatures and / or baking times according to the initial second constant temperature stage, wherein the absolute value of the difference between each comparative second constant temperature stage and the initial second constant temperature stage is within a second preset range;

[0038] One of the comparative first constant temperature stages is combined with one of the comparative second constant temperature stages to form multiple different experimental groups, and baking is performed separately according to each experimental group. Then, the roughness of the baked ABF films of the multiple experimental groups after being etched by chemical solution is compared, and a group of experimental groups with roughness closest to the preset roughness is selected. The corresponding comparative first constant temperature stage and comparative second constant temperature stage are set and applied in the baking of ABF films in mass production.

[0039] In the existing ABF substrate production process, production is typically based on the lamination parameters recommended by the raw material manufacturer. Some manufacturers fine-tune these lamination parameters, but fail to optimize quality by integrating them with the preceding and subsequent processes, often resulting in batch scrapping of ABF substrates during manufacturing. To address this issue, the initial first and second constant temperature stages, which contain the specific baking times and temperatures for the ABF film as recommended by the raw material manufacturer, were extracted. Using these initial first and second constant temperature stages as a basis, adjustments were made to adjacent temperature and time values, generating multiple comparative first and second constant temperature stages. Notably, the comparative first constant temperature stages are all set within a first preset range, which is a reasonable set of times or temperatures that includes the specific baking times or temperatures recommended by the manufacturer. The comparative first constant temperature stages are composed of a uniformly selected set of representative time and temperature values ​​within this set. Similarly, the second constant temperature comparison stage is set within the second preset range. This second preset range is a reasonable set of time or temperature values ​​that includes the specific baking time or temperature of the ABF film as part of the lamination parameters recommended by the raw material manufacturer. The second constant temperature comparison stage is a combination of several representative time and temperature values ​​evenly selected from several segments within this set. Finally, one of the first constant temperature comparison stages is combined with the second constant temperature comparison stage to form a test group. Similarly, this process is repeated several times to select a sufficient number of test groups to increase the coverage of the experiment.

[0040] In the above embodiment, baking needs to follow the following principles. First, compared with the first constant temperature stage, considering the control of reaction kinetics, it is necessary to control at a lower temperature to achieve a slower reaction rate, which helps to prevent uneven curing caused by rapid exothermic reactions and avoid the formation of pores or microcracks. At the same time, in the early stage of curing, residual solvents or volatile by-products need to be discharged from the resin matrix. Low-temperature heating can gradually release these substances to avoid blistering or excessive expansion of the ABF film. On the basis of the comparison of the first constant temperature stage, semi-curing is achieved, so that the ABF film maintains a certain plasticity, which is convenient for subsequent processing. Then, in comparison with the second constant temperature stage, complete curing is achieved at a higher temperature. By setting a two-stage heating method, the risks of cracks caused by a single rapid heating are avoided.

[0041] Specifically, according to the glass transition temperature (Tg) of the ABF film and the oven temperature range recommended by the manufacturer, the control temperature of the first constant temperature stage for preheating needs to be between 70°C and 130°C, and the baking time needs to be between 15 and 30 minutes. The control temperature of the second constant temperature stage for complete curing needs to be between 130°C and 200°C, and the baking time needs to be between 15 and 30 minutes.

[0042] wherein, as shown in Figure 4 , in this embodiment, the number of experimental groups is six, which are respectively the first experimental group (the baking temperature of the first constant temperature stage is 130°C, the baking time is 30 minutes, the baking temperature of the second constant temperature stage is 160°C, and the baking time is 30 minutes), the second experimental group (the baking temperature of the first constant temperature stage is 130°C, the baking time is 30 minutes, the baking temperature of the second constant temperature stage is 165°C, and the baking time is 30 minutes), the third experimental group (the baking temperature of the first constant temperature stage is 130°C, the baking time is 30 minutes, the baking temperature of the second constant temperature stage is 170°C, and the baking time is 30 minutes), the fourth experimental group (the baking temperature of the first constant temperature stage is 130°C, the baking time is 30 minutes, the baking temperature of the second constant temperature stage is 175°C, and the baking time is 30 minutes), the fifth experimental group (the baking temperature of the first constant temperature stage is 130°C, the baking time is 30 minutes, the baking temperature of the second constant temperature stage is 180°C, and the baking time is 30 minutes), and the sixth experimental group (the baking temperature of the first constant temperature stage is 130°C, the baking time is 30 minutes, the baking temperature of the second constant temperature stage is 190°C, and the baking time is 30 minutes). After baking the above six experimental groups under the condition of controlling the temperature floating interval of the oven within 5°C, the ABF film surface is sprayed with medicinal water, so that the ABF film surface is etched by the medicinal water and roughness is generated. The amount of medicinal water sprayed for each experimental group and the observation time are the same, and the etched ABF film surface is detected by visual detection by a scanning electron microscope (SEM), and the detection results are sampled and analyzed. Specifically, the output sample is observed under the scanning electron microscope at a magnification of 5000 times to analyze the roughness level.

[0043] Specifically, in the experimental results shown in Figure 4 , the roughness, reliability and other characteristics of the ABF film under different conditions of different experimental groups after the experiment are shown. Please refer to Figure 5-8 , which are respectively the surface morphology schematic diagram of the first experimental group, the second experimental group, the third experimental group, and the fourth experimental group after the residue is removed. It can be seen that the above four groups basically meet the production requirements, and there is no fracture and the like; please refer to Figure 9-11, respectively, are the surface morphology diagrams of the second, third, and fourth experimental groups after chemical copper treatment. It can be seen that the above three groups basically meet the production requirements and have no cracks, etc., while the first experimental group, although it has passed the desmear step, has obvious cracks after chemical copper treatment. Therefore, the first experimental group with cracks is discarded. The above desmear and chemical copper treatment environment for each experimental group is referenced Figure 4 , keep the experimental variables uniform, the temperature of the high-temperature manganese bath in the desmearing process is kept at 82±2℃, and the deposition thickness of the chemical copper is kept at 0.5±0.3um. At the same time, the ABF film of each experimental group after being corroded is weighed and the degree of corrosion of the ABF carrier is judged by the weight change of the ABF carrier. Finally, combining the above visual inspection and weighing test results, as shown Figure 4 As shown, the arithmetic mean roughness (Ra) value of the third experimental group is closest to the preset roughness of 0.1~0.4µm. Although the fourth experimental group is also within the preset roughness range of 0.1~0.4µm, according to the observation effect and weighing results, Figure 3 As shown, the third experimental group achieved superior data aggregation. Specifically, the roughness area within the 0.1-0.4µm range was the largest. This means that the ABF substrates in the third experimental group exhibited a more uniform roughness compared to the other experimental groups. This prevented excessive roughness from causing copper to deposit deep into pits during electroless copper deposition, leading to incomplete etching during the subsequent etching process and resulting in poor etching. Furthermore, this group also avoided excessive roughness from causing insufficient bonding between the ABF film and the substrate, seriously impacting the product's material strength. Consequently, the substrates were suitable for mass production and exhibited optimal quality.

[0044] The scanning electron microscope used to detect the arithmetic mean roughness value of the ABF substrate uses Bruker's Wyko series optical machine. Its principle is to use white light interferometry technology to regress the actual 3D graphics / contour conditions of the ABF substrate surface, which can directly generate the arithmetic mean roughness value. Of course, other regular optical instruments on the market can also be used as substitutes to detect the arithmetic mean roughness.

[0045] Please continue reading Figure 4In the aforementioned experiment, after desmearing and electroless copper treatment, the reliability testing phase included two steps: multiple reflow soldering and hot plate testing. The multiple reflow soldering step was designed to test the aging of the ABF substrate after multiple thermal shocks, confirming any abnormalities under specific conditions and timeframes. The procedure involved heating the solder-coated ABF substrate to 260°C (a temperature high enough to melt the solder paste) for 10 cycles, allowing the solder paste to melt and form a solder connection. The hot plate test was then observed for cracks. The hot plate test evaluated the performance and stability of the ABF substrate at high temperatures, helping to determine whether the substrate would fail under extreme temperature conditions. In this embodiment, the ABF substrate was placed on a heatable hot plate set to 280°C (a temperature significantly higher than the normal operating temperature of the circuit board) for 5 minutes. After heating, the substrate was allowed to cool naturally, and then observed for cracks. After any of the above-mentioned multiple reflow tests and hot plate tests, if no cracks or the like occur on the ABF carrier board, the ABF carrier board of the corresponding experimental group is deemed qualified.

[0046] Of course, it is worth noting that the baking temperature of the second constant temperature stage of the third experimental group selected from the six experimental groups mentioned above is between 165°C and 175°C. If the temperature fluctuates within a reasonable range and is close to 170°C from the equipment perspective, the substrate can still maintain a good roughness. Therefore, this embodiment also introduces a high-precision oven, such as a Taiwanese upright nitrogen oven with better precision, so that the baking temperature of the second constant temperature stage in the subsequent mass production process is as close to 170°C as possible to achieve the best production quality.

[0047] Furthermore, in this embodiment, after the step of "combining one of the comparative first constant temperature stages with one of the comparative second constant temperature stages to form multiple different experimental groups, and baking each experimental group separately, then comparing the roughness of the baked ABF films from the multiple experimental groups after erosion by chemical etching, and selecting the experimental group with a roughness closest to the preset roughness," a reflow test is also performed on the ABF films from the experimental group with a roughness closest to the preset roughness. If no cracking occurs after the reflow test, the step of "incorporating the corresponding comparative first constant temperature stage and comparative second constant temperature stage into the mass production baking of the ABF film" is performed. Specifically, the reflow test was performed 10 times, with the highest temperature during the reflow test being 260°C. After multiple high-temperature reflow tests, the ABF carrier boards in the third experimental group did not crack, demonstrating that the structure and bonding strength of the carrier boards remained stable under high-temperature cycling conditions, and that the substrates did not delaminate or crack during multiple heating and cooling cycles, thus avoiding potential risks in mass production.

[0048] Furthermore, after each mass production bake is completed in the step "and the corresponding comparative first constant temperature stage and comparative second constant temperature stage are set for application in the mass production bake of the ABF film," the substrate with the cured ABF film is drilled, and then the substrate with the cured ABF film is desmeared after drilling. After desmearing, the substrate with the cured ABF film is subjected to chemical copper deposition. Simultaneously, the substrate with the cured ABF film is immersed in a desmearing solution for ten minutes, and the desmearing solution temperature is maintained at 70°C-90°C, specifically, the high-temperature manganese bath temperature is maintained at 82±2°C, and chemical copper deposition is performed to form a uniform copper layer with a thickness of 0.5±0.3µm. Through the above method, the cured ABF carrier treated in the corresponding comparative first constant temperature stage and comparative second constant temperature stage has a good desmear removal effect under the above-mentioned desmearing solution temperature and immersion time. In existing processes, the desmear process is influenced by the interactions of temperature, pressure, chemical concentration, and line speed. Even slight variations can impact quality, and even minor changes can cause stability issues. Therefore, while maintaining the aforementioned desmear temperature and duration, the ABF film bake time was varied to find the optimal match between the first and second constant-temperature stages. Specifically, in comparing the roughness of the curing and chemical etch tests in the aforementioned experimental groups, the chemical type, duration, and hold temperature used in the chemical etch test were consistent with those used in the subsequent mass production desmear process, ensuring optimal coordination between the bake and desmear processes. Similarly, during the mass production electroless copper deposition process, a consistent copper layer thickness of 0.5±0.3µm was maintained to achieve optimal coordination between all steps, resulting in optimal conductivity and mechanical strength for the ABF substrate.

[0049] It's worth noting that the combination of a fixed desmear process and an electroless copper deposition process must be consistent and coordinated. Any residue left on the hole wall during desmearing will affect the subsequent copper layer's adhesion, further impacting conductivity and reliability. Overall, the present invention achieves optimal coordination between the desmear and electroless copper deposition processes by fine-tuning the baking process.

[0050] Furthermore, if Figure 2As shown, in the step of "combining one of the first constant temperature stages for comparison with one of the second constant temperature stages to form a plurality of different experimental groups, and baking each experimental group separately", the four corners and five points in the center of each ABF film are selected as the temperature detection positions. Specifically, the cured ABF carrier to be tested is set as a regular rectangular geometric plate structure. In the oven, three identical ABF carriers are set for each experimental group and placed on the test plates at the corresponding positions in the front / middle / rear of the tin frame (rack) in the oven. A temperature sensor is placed at each of the four corners and five positions in the center of each plate in the front / middle / rear. That is, each experimental group can obtain 15 temperature data. If the 15 temperature data are equivalent and float within the controllable range, the data is valid, as shown in FIG. Figure 1 The temperature curves of the 15 data in the baking curve diagram of the third experimental group shown remain consistent, and the data is valid, making the coverage of the temperature data more accurate and eliminating sporadic errors.

[0051] Furthermore, in the third experimental group of this embodiment, during the baking process of the ABF film, while maintaining a baking temperature of 130°C and a baking time of 30 minutes in the first constant temperature stage and a baking temperature of 170°C and a baking time of 30 minutes in the second constant temperature stage, the baking time was controlled to 90 minutes. The heating slope from room temperature to the temperature of the first constant temperature stage was controlled to be 7°C-9°C / min, and the heating slope from the temperature of the first constant temperature stage to the temperature of the second constant temperature stage was controlled to be 3°C-5°C / min. By controlling the heating slope, the accumulation of thermal stress between the ABF film and the substrate caused by excessively rapid heating was avoided, eliminating the risks of delamination and cracking, while ensuring a relatively uniform curing effect and improving process stability. Of course, while a slow heating slope can make the heating more uniform and avoid internal stress and defects, it is still necessary to control the baking time to 85-95 minutes to achieve a certain balance in processing efficiency.

[0052] It is worth noting that in this embodiment, the oven is set as a Taiwan-made nitrogen baking device, the temperature accuracy of which is controlled within ±5°C, and the ABF membrane is a Japanese-made Ajinomoto GL type membrane (please refer to Figure 4 ), through precise temperature control and matching of corresponding membrane types to improve actual production capacity.

[0053] Although different specific embodiments are mentioned in this application, this application is not limited to the situations described in industry standards or embodiments. Some industry standards or slightly modified implementations based on customized methods or implementations described in the embodiments can also achieve the same, equivalent, or similar implementation effects as the above embodiments, or predictable implementation effects after modification. Examples that apply these modified or modified data acquisition, processing, output, judgment methods, etc. can still fall within the scope of optional implementation schemes of this application.

[0054] Although the present application has been described through embodiments, those skilled in the art will appreciate that there are many modifications and variations to the present application without departing from the spirit of the present application. It is intended that the appended embodiments include these modifications and variations without departing from the present application.

Claims

1. A method for curing an ABF film, comprising providing an ABF film, placing the ABF film on a substrate, and baking the ABF film in an oven, wherein: The baking step includes an initial first constant temperature stage and an initial second constant temperature stage; characterized in that the ABF film curing method further includes: According to the initial first constant temperature stage, a plurality of comparative first constant temperature stages having different baking temperatures and / or baking times are set, wherein the absolute value of the difference between each comparative first constant temperature stage and the initial first constant temperature stage is within a first preset range; according to the initial second constant temperature stage, a plurality of comparative second constant temperature stages having different baking temperatures and / or baking times are set, wherein the absolute value of the difference between each comparative second constant temperature stage and the initial second constant temperature stage is within a second preset range; One of the comparative first constant temperature stages is combined with one of the comparative second constant temperature stages to form multiple different experimental groups, and baking is performed separately according to each of the experimental groups. Then, the roughness of the ABF films of the multiple experimental groups after baking and etching by chemical solution is compared, and a group of the experimental groups with a roughness closest to a preset roughness is selected, and the preset roughness is set to 0.1-0.4µm. A reflow test is performed on the ABF films of the experimental group with a roughness closest to the preset roughness. If no board explodes after the reflow test, the corresponding comparative first constant temperature stage and the comparative second constant temperature stage are set in the baking of the ABF films in mass production; Among them, the first constant temperature stage for preheating needs to control the temperature between 70℃~130℃, and the baking time is between 15~30min. The second constant temperature stage for complete curing needs to control the temperature between 130℃~200℃, and the baking time is between 15~30min.

2. The ABF film curing method according to claim 1, characterized in that: The reflow test was performed 10 times, and the highest temperature during the reflow test was 260° C.

3. The ABF film curing method according to claim 1, wherein: After each mass production bake in the step of "and setting the corresponding comparative first constant temperature stage and the comparative second constant temperature stage for application in the mass production bake of the ABF film" is completed, the substrate on which the ABF film is cured is drilled, and then the substrate on which the ABF film is cured is desmeared after drilling, and then chemical copper deposition is performed on the substrate on which the ABF film is cured after desmearing.

4. The ABF film curing method according to claim 3, wherein: In the step of "de-smearing the substrate on which the ABF film is cured", the substrate on which the ABF film is cured is immersed in a desmearing liquid for ten minutes, and the temperature of the desmearing liquid is maintained at 70°C-90°C.

5. The ABF film curing method according to claim 3, wherein: After the step of "then performing chemical copper deposition on the substrate having the ABF film cured thereon after desmearing", a uniform copper layer with a thickness of 0.5±0.3 μm is formed.

6. The ABF film curing method according to claim 1, wherein: In the step of "combining one of the comparative first constant temperature stages with one of the comparative second constant temperature stages to form a plurality of different experimental groups, and performing baking separately according to each of the experimental groups", five points at the four corners and the center of each of the ABF films are selected as temperature detection locations.

7. The ABF film curing method according to claim 1, characterized in that: In the step of "combining one of the comparative first constant temperature stages with one of the comparative second constant temperature stages to form a plurality of different experimental groups, and performing baking respectively according to each of the experimental groups, and then comparing the roughness of the baked ABF films of the plurality of experimental groups after being etched by chemical solution, and selecting a group of experimental groups whose roughness is closest to the preset roughness", the comparison of the roughness is performed by visual inspection using a scanning electron microscope and corrosion degree detection by weighing.

8. The ABF film curing method according to claim 1, wherein: In the step of "selecting a group of experimental groups whose roughness is closest to the preset roughness, and setting the corresponding comparative first constant temperature stage and the comparative second constant temperature stage for application in the baking of the ABF film in mass production", the heating slope from room temperature to the temperature of the comparative first constant temperature stage needs to be 7°C-9°C / min, and the heating slope from the temperature of the comparative first constant temperature stage to the temperature of the comparative second constant temperature stage needs to be 3°C-5°C / min, and the total baking time of the ABF film in the oven is 85min-95min.

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