Laminated film, cured product, and electronic component

Abstract

The invention provides a laminated film, a cured product and an electronic component, and particularly relates to the technical field of circuit board protective films. The laminated film comprises a light-transmitting layer and a light-shielding layer which are sequentially laminated, the first glossiness of one surface of the light-transmitting layer away from the shading layer is less than or equal to 15; the light transmittance of the light transmitting layer is 70-90%, and the light transmittance of the light shielding layer is 20-60%. According to the laminated film provided by the invention, the first glossiness is controlled to be less than or equal to 15, and the surface glossiness (namely the second glossiness) after final curing is maintained at a relatively low level, so that an ideal matte appearance is obtained. Meanwhile, the light transmittance of the light-transmitting layer is controlled to be 70-90%, light can reach the bottom in the exposure process, curing of the shading layer is improved, and smaller and more complete windowing patterns are formed; the light transmittance of the light shielding layer is controlled to be 20-60%, the light transmittance is low, but the covering power is high, and enough covering power is provided for a finally formed cured product.

Description

Technical Field

[0001] This invention relates to the field of circuit board protective film technology, and in particular to a laminated film, a cured product, and an electronic component. Background Technology

[0002] With the rapid development of electronic components towards miniaturization and lightweighting, printed circuit boards (PCBs) are constantly evolving towards higher density and finer lines. Solder resist layers, as protective films for PCBs, require higher resolution, adhesion, heat resistance, resistance to electroless nickel-gold plating, and reliability. In particular, to cover the circuit patterns on wiring boards, the demand for black and white solder resist layers with high opacity is increasingly prominent. However, directly adding high-opacity pigments to the solder resist layer significantly reduces its deep curing ability, making it difficult to balance the degree of deep curing and the opacity to the substrate.

[0003] Existing technologies use small-molecule near-infrared absorbers to improve exposure resolution, but these small molecules are prone to precipitate during the subsequent electroless nickel-gold (ENIG) plating process, contaminating the nickel and gold baths and ultimately leading to plating defects. Therefore, this technology cannot simultaneously achieve high resolution and plating reliability.

[0004] Existing technologies also include adding an alkaline curing accelerator layer (A) containing N atoms and an alkaline curing accelerator layer (B) containing P atoms to the laminated film. The purpose is to improve the adhesion between the solder resist layer and the substrate and the reliability of insulation. However, it does not address the technical issues of insufficient deep curing of the black solder resist layer and high hiding power. Therefore, it is not suitable for application scenarios with high blackness requirements.

[0005] In view of this, the present invention is hereby proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a laminated film, a cured product, and an electronic component, aiming to solve the technical problem in the prior art that the solder resist layer is difficult to achieve both deep curing and insufficient masking.

[0007] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: A first aspect of the present invention provides a laminated film comprising a light-transmitting layer and a light-shielding layer sequentially stacked thereon; wherein the first gloss level of the light-transmitting layer is ≤15; The gloss of the surface of the light-transmitting layer away from the light-shielding layer after exposure and development but without heat curing is the first gloss. The light transmittance of the aforementioned light-transmitting layer is 70-90%, and the light transmittance of the aforementioned light-shielding layer is 20-60%.

[0008] Furthermore, the aforementioned light-transmitting layer includes a first alkali-soluble resin.

[0009] Furthermore, the aforementioned light-shielding layer includes a second alkali-soluble resin.

[0010] Furthermore, the luminance value in the Lab chromaticity system of the aforementioned light-transmitting layer is 35~50.

[0011] Furthermore, the luminance value in the Lab chromaticity system of the aforementioned light-shielding layer is ≤20.

[0012] Furthermore, the thickness of the above-mentioned laminated film is 20~50μm.

[0013] Furthermore, the thickness ratio of the light-transmitting layer to the light-shielding layer is 3 to 7.

[0014] Furthermore, the thickness of the aforementioned light-transmitting layer is 15~40μm.

[0015] Furthermore, the thickness of the aforementioned light-shielding layer is 5~15μm.

[0016] Furthermore, the gloss of the surface of the light-transmitting layer away from the light-shielding layer after exposure, development and heat curing is the second gloss, -0.1≤(the second gloss - the first gloss) / the first gloss≤0.1.

[0017] Furthermore, the above-mentioned heating and curing temperature is 140~160℃, and the time is 50~70min.

[0018] Preferably, the above-mentioned heating and curing temperature is 150°C and the time is 60 minutes.

[0019] Furthermore, according to parts by weight, the raw materials of the above-mentioned light-transmitting layer include 100-115 parts of the first alkali-soluble resin, 5-20 parts of the first photosensitive component, 10-30 parts of the first thermosetting component, and 0-10 parts of the first black colorant. Furthermore, by weight, the raw materials of the light-shielding layer include 100-115 parts of the second alkali-soluble resin, 5-20 parts of the second photosensitive component, 10-30 parts of the second thermosetting component, and 0-10 parts of the second black colorant.

[0020] Furthermore, the first alkali-soluble resin and the second alkali-soluble resin are each independently selected from at least one of acid-modified bisphenol A type epoxy acrylate resin, acid-modified bisphenol F type epoxy acrylate resin, acid-modified alicyclic epoxy acrylate resin, and acid-modified phenolic epoxy acrylate resin.

[0021] Furthermore, the first photosensitive component and the second photosensitive component each independently include a photosensitive monomer and a photoinitiator.

[0022] Furthermore, the photosensitive functional group in the above-mentioned photosensitive monomer is selected from at least one of diazo functional groups, azide functional groups, cinnamoyl functional groups, and acrylic functional groups; preferably, it contains an acrylic functional group.

[0023] Furthermore, the aforementioned photoinitiator is selected from free radical photoinitiators and / or cationic photoinitiators.

[0024] Furthermore, the first thermosetting component and the second thermosetting component each independently comprise epoxy resin and curing agent.

[0025] Furthermore, the curing agent mentioned above includes any one or more of the following: polyamine curing agents, imidazole curing agents, acid anhydride curing agents, boronamine curing agents, and boronamine salt curing agents.

[0026] Furthermore, the first black colorant and the second black colorant each independently include at least one of manganese iron black, copper chromium black, iron chromium black, cobalt black, aniline black, antimony sulfide and pigment carbon black, preferably pigment carbon black.

[0027] Furthermore, the weight ratio of the first black colorant in the light-transmitting layer to the second black colorant in the light-shielding layer is 0.3 to 0.7.

[0028] Furthermore, the aforementioned laminated film also includes a support layer; the support layer is disposed on the side of the light-transmitting layer away from the light-shielding layer.

[0029] Furthermore, the surface gloss of the support layer on the side closer to the light-transmitting layer is ≤20, and the surface gloss of the side farther from the light-transmitting layer is ≥80.

[0030] Furthermore, the ratio of the surface gloss of the support layer on the side closer to the light-transmitting layer to the surface gloss of the side farther from the light-transmitting layer is 5 to 9.

[0031] Furthermore, -0.1≤(the first gloss level - the surface gloss level of the support layer on the side near the light-transmitting layer) / the surface gloss level of the support layer on the side near the light-transmitting layer≤0.1.

[0032] Furthermore, the aforementioned support layer is selected from any one of polyester film, polyolefin film, polyethylene terephthalate film, or polyimide film, preferably polyethylene terephthalate film.

[0033] Furthermore, the aforementioned laminated film also includes a protective layer disposed on the side of the light-shielding layer away from the light-transmitting layer.

[0034] Furthermore, the protective layer is selected from either polyester film or polyolefin film, preferably polyolefin film.

[0035] A second aspect of the present invention provides a cured material, which is mainly formed by curing the laminated film described in the first aspect.

[0036] A third aspect of the present invention provides an electronic component having the cured material described in the second aspect.

[0037] Compared with the prior art, the present invention has at least the following beneficial effects: ① The laminated film provided by this invention controls the first gloss level to ≤15, ensuring that the final cured surface gloss level (i.e., the second gloss level) remains at a low level, thereby obtaining an ideal matte appearance. This matte effect not only improves the visual quality of the product but also effectively reduces light reflection, providing a uniform and interference-free background for automated optical inspection (AOI), significantly improving the accuracy and reliability of defect identification. During SMT placement, the matte surface helps reduce the interference of ambient light on the visual positioning system, improving the identification accuracy of reference points and pads, and thus improving the accuracy of solder paste printing and component placement. At the same time, the matte surface also has a masking effect, visually concealing minor scratches, fingerprints, and other defects generated during manufacturing or transportation, making the PCB board surface cleaner and more aesthetically pleasing. It is worth noting that the matte effect in this invention is achieved by a light-transmitting layer. Under the premise of maintaining its high light transmittance (70%~90%) to ensure sufficient curing of the underlying layer, it achieves a "transparent-matte" composite characteristic through structural design and transfer process, taking into account both functionality and appearance requirements.

[0038] ② The laminated film provided by the present invention controls the light transmittance of the light-transmitting layer to 70-90%, which enables light to reach the bottom during exposure, improves the curing of the light-shielding layer, and forms a smaller and more complete window pattern; the light transmittance of the light-shielding layer is controlled to 20-60%, which has a low light transmittance but high covering power, providing sufficient covering power for the final cured product.

[0039] ③ The laminated film provided by the present invention has a thickness ratio of light-transmitting layer to light-shielding layer that balances resolution while ensuring deep curing and covering power to the substrate, while giving the surface a stable matte effect, thus significantly optimizing its overall performance.

[0040] ④ The electronic components provided by this invention have the following characteristics due to the use of the aforementioned cured material: excellent surface appearance consistency, and significant improvements in aging resistance, acid and alkali resistance, solvent resistance and heat resistance. As a result, they maintain dimensional stability, do not crack or fade in subsequent processes such as high-temperature reflow soldering, electroless nickel-gold plating (ENIG), organic solder mask (OSP) and multiple lead-free tin spraying, and significantly reduce failure rate. Attached Figure Description

[0041] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0042] Figure 1 A schematic diagram of a laminated membrane provided by the present invention; Figure 2 A schematic diagram illustrating the use of a laminated film provided by the present invention; Figure 3 This is a schematic diagram of another layered membrane structure provided by the present invention.

[0043] Icons: 100 - Transparent layer; 200 - Light-shielding layer; 300 - Support layer; 400 - Protective layer; 500 - Substrate. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0045] In the following, the terms “comprising,” “having,” and their cognates, which may be used in various embodiments of the invention, are intended only to indicate a particular feature, number, step, operation, element, component, or combination thereof, and should not be construed as excluding, firstly, the presence of one or more other features, numbers, steps, operations, elements, components, or combinations thereof, or adding the possibility of one or more features, numbers, steps, operations, elements, components, or combinations thereof.

[0046] [Laminated film] like Figure 1 The laminated film shown employs a layered structure design, comprising a light-transmitting layer 100 and a light-shielding layer 200 stacked sequentially. The light-transmitting layer 100 and the light-shielding layer 200 have different light transmittances, satisfying the appearance and functional requirements of the laminated film.

[0047] In practical applications, this laminated film needs to be installed in a specific orientation. For example... Figure 2 As shown, the light-shielding layer 200 is bonded to the substrate 500 to ensure that the light-shielding layer 200 performs its optical shielding function; at the same time, the light-transmitting layer 100 is naturally located on the outer side away from the substrate 500. This arrangement ensures that incident light can reach deep into the laminated film while also achieving the function of covering the substrate 500.

[0048] The transmittance (T) of the present invention is measured by a UV-Vis spectrophotometer, selecting the transmittance at 385nm and 405nm, and the final transmittance is calculated by T=T(385)×70%+T(405)×30%.

[0049] The aforementioned light-transmitting layer 100 has a light transmittance of 70% to 90%, ensuring sufficient light to penetrate the layer and reach the bottom light-shielding layer 200 during exposure. This characteristic not only helps to promote the photocuring reaction of the light-shielding layer 200 but also significantly improves the forming accuracy of the pattern. Specifically, the high light transmittance allows for uniform light distribution, thereby forming smaller and more complete window patterns in the light-shielding layer 200, while ensuring the clarity and resolution of the pattern edges, meeting the requirements of high-precision micro-processing.

[0050] If the light transmittance is below 70%, insufficient light will penetrate the light-transmitting layer 100 during exposure, making it difficult for it to effectively reach the bottom of the light-shielding layer 200, thus affecting the photocuring reaction of the light-shielding layer 200. Insufficient photocuring will reduce the integrity of the pattern formation, leading to decreased windowing accuracy and blurred pattern edges, which in turn will severely affect the resolution and fail to meet the micro-processing precision requirements of high-density, high-fine-line printed circuit boards. Therefore, maintaining the light transmittance of the light-transmitting layer 100 within this range is a key condition for ensuring the full curing of the light-shielding layer 200 and achieving high-precision pattern transfer.

[0051] The light transmittance of the aforementioned light-shielding layer 200 is controlled within the range of 20% to 60%, providing high coverage while ensuring a certain degree of light penetration. The low light transmittance effectively blocks excess light, preventing overexposure. Simultaneously, the low light transmittance also reflects the excellent coverage of the light-shielding layer 200, providing a good optical shielding effect for the final cured product.

[0052] By adjusting the light transmittance, the light-transmitting layer 100 and the light-blocking layer 200 work together to achieve precise light control during exposure. This ensures sufficient light energy to penetrate and promotes photocuring to form patterns, while also controlling the light distribution to create a high-precision, high-contrast pattern structure.

[0053] Typically, but not limitingly, the light transmittance of the light-transmitting layer 100 can be, for example, 70%, 74%, 78%, 82%, 86%, or 90%, or any value within the range of 70% to 90%; the light transmittance of the light-blocking layer 200 can be, for example, 20%, 24%, 28%, 32%, 36%, 40%, 44%, 48%, 52%, 56%, or 60%, or any value within the range of 20% to 60%.

[0054] The method for measuring transmittance is as follows: The light-transmitting layer or the light-shielding layer is completely adhered to the transparent glass, and the transparent glass without the coating is used as a reference sample. The transmittance curve is measured in the 200nm to 800nm ​​wavelength range using a UV-Vis spectrophotometer. During the test, the transmittance values ​​at 385nm and 405nm are selected and recorded as T(385) and T(405). The final transmittance is calculated by weighting according to the formula T=T(385)×70%+T(405)×30% to obtain the transmittance of the layer.

[0055] The first gloss level of the light-transmitting layer 100 is ≤15; wherein, the gloss level of the surface of the light-transmitting layer 100 away from the light-shielding layer 200 after exposure, development and without heat curing is the first gloss level; the gloss level of the surface of the light-transmitting layer 100 away from the light-shielding layer 200 after exposure, development and heat curing is the second gloss level.

[0056] It should be noted that the first gloss of the light-transmitting layer 100 refers to the surface gloss of the layer after exposure and development without heat curing. Specifically, it is measured on the side that is in contact with the support layer 300 when it is not in use, or on the side that is exposed and in contact with air after the support layer 300 is peeled off during use.

[0057] In embodiments of the present invention, the development method includes alkaline dissolution.

[0058] After exposure and development, and before heat curing, the surface gloss of the side of the light-transmitting layer 100 away from the light-shielding layer 200 is ≤15. Within this gloss range, the final cured surface gloss (i.e., the second gloss) is maintained at a low level, thus achieving an ideal matte appearance. This matte effect not only enhances the visual quality of the product but also effectively reduces light reflection, providing a uniform and interference-free background for automated optical inspection (AOI), significantly improving the accuracy and reliability of defect identification. During SMT placement, the matte surface helps reduce the interference of ambient light on the visual positioning system, improving the identification accuracy of reference points and pads, thereby improving the accuracy of solder paste printing and component placement. At the same time, the matte surface also has a masking effect, visually concealing minor scratches, fingerprints, and other defects generated during manufacturing or transportation, making the PCB board surface cleaner and more aesthetically pleasing. It is worth noting that the matte effect in this invention is achieved by the light-transmitting layer 100. It is a "transparent-matte" composite property achieved through structural design and transfer process while maintaining its high light transmittance (70%~90%) to ensure that the underlying layer is fully cured. This takes into account both functionality and appearance requirements.

[0059] Typical, but not limiting, the first gloss level can be, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15.

[0060] In this invention, gloss is measured using a gloss meter according to ISO 2813 standard.

[0061] The gloss of the surface of the light-transmitting layer 100 away from the light-shielding layer 200 after exposure, development, and heat curing is the second gloss, which is the surface gloss of the air surface of the light-transmitting layer 100 in the resulting cured product. The heat curing process will cause changes in the surface morphology of the light-transmitting layer 100, and the gloss parameters will also change. This process will determine the surface morphology characteristics and optical appearance quality of the final cured product.

[0062] In some embodiments of the present invention, -0.1 ≤ (second gloss level - first gloss level) / first gloss level ≤ 0.1 means that the surface gloss change of the air surface of the light-transmitting layer 100 after heat curing does not exceed 10%, indicating that the heat curing process has little impact on the surface optical properties of the light-transmitting layer 100, and the gloss level remains highly stable before and after the process. This stability effectively reduces the appearance changes caused by fluctuations in curing conditions or batch differences, thereby ensuring good surface consistency of the product in actual use, avoiding obvious visual differences between different batches, and improving the appearance quality and production reliability of the product.

[0063] When the laminated film of the present invention is commercially sold as a final product, its structural composition is further optimized, and it also includes a support layer 300; the support layer 300 is disposed on the side of the light-transmitting layer 100 away from the light-shielding layer 200. The structure of the laminated film product at this time is that the support layer 300, the light-transmitting layer 100 and the light-shielding layer 200 are stacked sequentially from the bottom layer to the top layer.

[0064] In some embodiments of the present invention, the surface gloss of the support layer 300 near the light-transmitting layer 100 is ≤20, and the surface gloss of the side away from the light-transmitting layer 100 is ≥80. The side with lower gloss is in contact with the laminated film, providing a matte effect to the laminated film; while the side with higher gloss is in contact with air, so that light can reach the laminated film perpendicularly during exposure, providing better resolution.

[0065] For ease of description, the surface gloss of the support layer 300 on the side closer to the light-transmitting layer 100 is named the third gloss; the surface gloss of the support layer 300 on the side farther from the light-transmitting layer 100 is named the fourth gloss.

[0066] Typical, but not limiting, the third gloss level can be, for example, 2, 4, 6, 8, 10, 12, 14, 16, 18 or 20; the fourth gloss level can be, for example, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98 or 100.

[0067] In some embodiments of the present invention, the ratio of the fourth gloss level to the third gloss level is 5 to 9. When this ratio is too small, it will be detrimental to the vertical transmission of light during the exposure process, resulting in a decrease in the optical transmission efficiency of the support layer 300 material. This may cause non-target exposure areas to be affected by stray light and result in abnormal curing, thereby significantly degrading the windowing accuracy and graphic resolution of the product. Conversely, if this ratio is too large, it will cause the fourth gloss level index to exceed the design range, resulting in changes in the surface reflectivity of the material and ultimately destroying the matte visual effect required by the product.

[0068] Typically, but not restrictively, the ratio of the fourth gloss level to the third gloss level can be, for example, 5, 6, 7, 8, or 9, or any value within the range of 5 to 9.

[0069] In some embodiments of the present invention, -0.1 ≤ (first gloss level - third gloss level) / third gloss level ≤ 0.1 indicates that the values ​​of the first gloss level and the third gloss level are close, with a difference of no more than 10%. This indicates that the matte surface of the light-transmitting layer 100 is not formed by adding a matte agent, but is achieved through a physical transfer method: that is, utilizing the micro-uneven structure pre-formed on the surface of the support layer 300, the morphology is precisely transferred to the surface of the light-transmitting layer 100 during the bonding process by pressure or hot pressing, thereby giving it a stable matte effect. Therefore, this relationship is the key manifestation of obtaining a matte appearance through "mechanical transfer," which not only avoids the adverse effects of chemical additives on performance, but also ensures the consistency and repeatability of the surface matte effect.

[0070] In some embodiments of the present invention, when the laminated film of the present invention is commercially sold as a final product, the laminated film further includes a protective layer 400, which is disposed on the side of the light-shielding layer 200 away from the light-transmitting layer 100. The protective layer 400 is used to cover the laminated film during transportation and storage to ensure its functional integrity; in use, the protective layer 400 must first be peeled off before the laminated film is attached to the substrate 500 for subsequent processes.

[0071] In some embodiments of the present invention, the laminated film has Figure 3 The structure shown has a support layer 300, a light-transmitting layer 100, a light-shielding layer 200 and a protective layer 400 stacked sequentially from bottom to top.

[0072] Typically, but not limitingly, the support layer 300 can be a polyester film, a polyolefin film, a polyethylene terephthalate film, or a polyimide film, preferably a polyethylene terephthalate film, such as the YGD2, YGD3, YG5, YG0, and ZL-BT products of Foshan Mylar Hongji Film Co., Ltd.

[0073] Typically, but not limitingly, the protective layer 400 comprises a polyester film or a polyolefin film, preferably a polyolefin film. The polyolefin film may be a polyethylene film or a polypropylene film.

[0074] Furthermore, the luminance value in the Lab color system of the light-transmitting layer 100 is 35~50. If the luminance value is less than 35, the amount of light transmitted during exposure is insufficient, and the light is difficult to reach the bottom of the solder resist layer, resulting in a decrease in resolution; if the luminance value is greater than 50, although the resolution can be improved, the amount of light absorbed by the laminated film will decrease accordingly, the color will become lighter, and the preset black depth cannot be achieved.

[0075] Furthermore, the luminance value in the Lab chromaticity system of the light-shielding layer 200 is ≤20. If the luminance value is greater than 20, the absorption and scattering ability of the solder resist layer to visible light will be weakened, the covering power will decrease, and the base color of the substrate 500 will be revealed, failing to meet the appearance shielding requirements.

[0076] The brightness value of the aforementioned light-transmitting layer 100 or light-shielding layer 200 is measured at a standard thickness after the corresponding layer is individually laminated onto the substrate 500, exposed, developed, and completely thermoset. When measuring the brightness value of the light-transmitting layer 100 or light-shielding layer 200, consistent thickness is ensured.

[0077] Furthermore, the thickness of the laminated film is 20–50 μm. Typically, but not limitingly, the thickness of the laminated film can be, for example, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, or 50 μm, or any value within the range of 20–50 μm.

[0078] Furthermore, the thickness ratio of the light-transmitting layer 100 to the light-shielding layer 200 is 3 to 7. Typically, but not limitingly, the thickness ratio of the light-transmitting layer 100 to the light-shielding layer 200 can be, for example, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, 5.5:1, 6:1, 6.5:1, or 7:1, or any ratio within the range of 3–7.

[0079] If the thickness ratio of the light-transmitting layer 100 to the light-shielding layer 200 is less than 3 (i.e., the light-shielding layer 200 is too thick or the light-transmitting layer 100 is too thin), the incident light will be excessively absorbed and scattered when passing through the light-shielding layer 200, making it difficult to effectively reach the bottom of the light-shielding layer 200. This results in insufficient photocuring of the underlying layer, which in turn affects the windowing accuracy and resolution of the pattern. Simultaneously, incompletely cured areas are prone to lateral swelling or dissolution during development, leading to increased lateral etching and affecting the dimensional accuracy of the circuitry and the long-term reliability of the PCB. Furthermore, an excessively low thickness ratio may result in insufficient overall film coverage of the substrate 500, failing to effectively shield the substrate color or circuit patterns, thus affecting the final product's appearance quality. Therefore, maintaining an appropriate thickness ratio is crucial for achieving good deep curing, high-resolution imaging, and excellent masking performance.

[0080] Furthermore, the thickness of the light-transmitting layer 100 is 15–40 μm. Typically, but not limitingly, the thickness of the light-transmitting layer 100 can be, for example, 15 μm, 18 μm, 20 μm, 25 μm, 30 μm, 35 μm, 38 μm, or 40 μm, or any value within the range of 15–40 μm.

[0081] Furthermore, the thickness of the light-shielding layer 200 is 5–15 μm. Typically, but not limitingly, the thickness of the light-shielding layer 200 can be, for example, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, or 15 μm, or any value within the range of 5–15 μm.

[0082] Within the aforementioned thickness range, the laminated film can be guaranteed to have excellent resolution while providing good coverage of the substrate 500.

[0083] The light-transmitting layer 100 and the light-shielding layer 200 are formed by coating and drying the corresponding photosensitive resin compositions.

[0084] In some embodiments of the present invention, the light-transmitting layer 100 comprises a first alkali-soluble resin.

[0085] In other embodiments of the invention, the light-shielding layer 200 comprises a second alkali-soluble resin.

[0086] Furthermore, according to parts by weight, the raw materials of the light-transmitting layer include 100-115 parts of the first alkali-soluble resin, 5-20 parts of the first photosensitive component, 10-30 parts of the first thermosetting component, and 0-10 parts of the first black colorant; Furthermore, by weight, the raw materials of the light-shielding layer 200 include 100-115 parts of the second alkali-soluble resin, 5-20 parts of the second photosensitive component, 10-30 parts of the second thermosetting component, and 0-10 parts of the second black colorant.

[0087] Typically, but not limitingly, the first alkali-soluble resin and the second alkali-soluble resin can be adjusted independently, and their weight fractions can be selected independently, for example, 100 parts, 102 parts, 105 parts, 108 parts, 110 parts, 112 parts, or 115 parts, or any value within the range of 100–115 parts; the first photosensitive component and the second photosensitive component can be adjusted independently, and their weight fractions can be selected independently, for example, 5 parts, 7 parts, 9 parts, 12 parts, 15 parts, 18 parts, or 20 parts, or 5–20 parts. Any value within the range; the first thermosetting component and the second thermosetting component can be adjusted independently, and the weight fraction can be selected independently, for example, 10 parts, 12 parts, 15 parts, 18 parts, 20 parts, 25 parts, 28 parts or 30 parts, or any value within the range of 10-30 parts; the first black colorant and the second black colorant can be adjusted independently, and the weight fraction can be selected independently, for example, 0 parts, 1 part, 3 parts, 5 parts, 7 parts, 9 parts or 10 parts, or any value within the range of 0-10 parts.

[0088] Furthermore, the first alkali-soluble resin and the second alkali-soluble resin are each independently selected from at least one of acid-modified bisphenol A type epoxy acrylate resin, acid-modified bisphenol F type epoxy acrylate resin, acid-modified alicyclic epoxy acrylate resin, and acid-modified phenolic epoxy acrylate resin.

[0089] Furthermore, the first photosensitive component and the second photosensitive component each independently include a photosensitive monomer and a photoinitiator.

[0090] Furthermore, the photosensitive functional group in the above-mentioned photosensitive monomer is selected from at least one of diazo functional groups, azide functional groups, cinnamoyl functional groups, and acrylic functional groups; preferably, it contains an acrylic functional group.

[0091] Furthermore, the aforementioned photoinitiator is selected from free radical photoinitiators and / or cationic photoinitiators.

[0092] Typical, but not limiting, free radical photoinitiators may include, for example, IGM's Omnirad 1173, Omnirad 184, Omnirad 2959, Omnirad 389, Omnirad 907, Omnirad 819, Omnirad 410, Omnirad ITX, Omnirad DETX, Omnirad 784, and Omnirad 1312; cationic photoinitiators may include, for example, IGM's Omnicat 250, Omnicat 270, Omnicat 320, Omnicat 432, Omnicat 440, Omnicat 445, and Omnicat 550.

[0093] Furthermore, the first thermosetting component and the second thermosetting component each independently comprise epoxy resin and curing agent.

[0094] Furthermore, the aforementioned epoxy resin includes at least one of the following: bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, hydrogenated bisphenol A type epoxy resin, biphenol type epoxy resin, phenolic varnish type epoxy resin, epoxy resin having a dicyclopentadiene skeleton, bixylenol type epoxy resin, naphthyl-containing epoxy resin, glycidylamine type epoxy resin, hydantoin type epoxy resin, brominated epoxy resin, alicyclic epoxy resin, and trihydroxyphenylmethane type epoxy resin.

[0095] Furthermore, the aforementioned phenolic varnish-type epoxy resin includes bisphenol A phenolic varnish-type epoxy resin and / or biphenyl phenolic varnish-type epoxy resin.

[0096] Furthermore, the curing agent mentioned above includes any one or more of the following: polyamine curing agents, imidazole curing agents, acid anhydride curing agents, boronamine curing agents, and boronamine salt curing agents.

[0097] Typical, but not limiting, acid anhydride curing agents can include phthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, maleic anhydride, styrene-grafted maleic anhydride, etc.

[0098] Furthermore, the first black colorant and the second black colorant each independently include at least one of manganese iron black, copper chromium black, iron chromium black, cobalt black, aniline black, antimony sulfide, and pigment carbon black, preferably pigment carbon black, such as Raven 2000, Raven 1250, Raven 3500, Raven 1255, Raven 1185, Raven 1190 Ultra, Raven 1100, Raven 1170, Raven 1060, Raven 890, Raven 900, etc. from Birla Corporation.

[0099] And / or, the weight ratio of the first black colorant in the light-transmitting layer 100 to the second black colorant in the light-shielding layer 200 is 0.3 to 0.7.

[0100] Typically, but not limitingly, the weight ratio of the first black colorant in the light-transmitting layer 100 to the second black colorant in the light-shielding layer 200 can be, for example, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, or 0.70, or any ratio in the range of 0.3–0.7.

[0101] [cured material] The cured product described in this invention is formed by applying the aforementioned laminated film to a substrate 500, followed by exposure, development, and thermal curing. The cured product provided by this invention inherits the technical characteristics of the aforementioned laminated film: it ensures deep curing while maintaining resolution, enhances the opacity of the substrate, and imparts a stable matte finish, thus significantly optimizing its overall performance.

[0102] In some embodiments of the present invention, the bonding process is carried out using a vacuum laminating machine, which first completes the entire vacuum laminating process by vacuuming and maintaining vacuum, pressing and leveling.

[0103] In the specific operation, the light source wavelength used for exposure is one or more combinations of 365nm, 375nm, 385nm, and 405nm, and the exposure energy is 300 mJ / cm². 2 The line exposure scale is 8 grids.

[0104] In some embodiments of the present invention, the development is alkaline development.

[0105] Preferably, the developer used in the above-mentioned alkaline development includes an aqueous solution of sodium carbonate.

[0106] Preferably, the temperature for alkaline development is 25~35°C and the time is 45~55s.

[0107] Typical, but not limiting, the alkaline developing temperature can be, for example, 25°C, 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C, or 35°C, or any value within the range of 25–35°C; the developing time can be, for example, 45s, 46s, 47s, 48s, 49s, 50s, 51s, 52s, 53s, 54s, or 55s, or any duration within the range of 45–55s.

[0108] Preferably, the temperature for heating and curing is 140~160℃ and the time is 50~70min.

[0109] Typically, but not limitingly, the heat curing temperature can be, for example, 140°C, 142°C, 144°C, 146°C, 148°C, 150°C, 152°C, 154°C, 156°C, 158°C, or 160°C, or any value within the range of 140–160°C; the curing time can be, for example, 50 min, 52 min, 54 min, 56 min, 58 min, 60 min, 62 min, 64 min, 66 min, 68 min, or 70 min, or any duration within the range of 50–70 min.

[0110] More preferably, the above-mentioned heating and curing temperature is 150°C and the time is 60 minutes.

[0111] [Electronic Components] A third aspect of the present invention provides an electronic component having the cured material described in the second aspect.

[0112] The electronic components provided by this invention have the following characteristics due to the use of the aforementioned cured material: excellent surface appearance consistency, and significant improvements in aging resistance, acid and alkali resistance, solvent resistance and heat resistance. As a result, they maintain dimensional stability, do not crack or fade in subsequent processes such as high-temperature reflow soldering, electroless nickel-gold plating (ENIG), organic solder mask (OSP) and multiple lead-free tin spraying, and significantly reduce failure rate.

[0113] The present invention is further illustrated below with specific embodiments and comparative examples. However, it should be understood that these embodiments are merely for illustrative purposes and should not be construed as limiting the invention in any way. Unless otherwise specified, the raw materials used in the embodiments and comparative examples of the present invention were carried out under conventional conditions or conditions recommended by the manufacturer. Reagents or instruments used, unless otherwise specified, are all commercially available conventional products.

[0114] Example 1 This embodiment provides a laminated film in which, by weight, the first photosensitive resin composition used in the light-transmitting layer comprises: 100 parts of alkali-soluble resin anhydride-modified o-cresol formaldehyde epoxy acrylate resin (model PR3000, manufacturer: Shanghai Showa), 2 parts of photopolymerizable monomer 1,6-hexanediol diacrylate (manufacturer: Sartoma, trade name: SR238NS), 8 parts of photopolymerizable monomer pentaerythritol tetraacrylate (manufacturer: Sartoma, trade name: SR295NS), 2 parts of photoinitiator 2,4,6-trimethylbenzoyl diphenylphosphine oxide (manufacturer: Changzhou Qiangli, model: TR-TPO), and 1 part of photoinitiator 1-hydroxycyclohexylphenyl ketone. (Manufacturer: Changzhou Qiangli, Model: TR-184), 1 part photoinitiator 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone (manufacturer: Changzhou Qiangli, Model: TR-907), 15 parts bisphenol A type epoxy resin (manufacturer: Changchun Chemical, Model: BNE-186), 2 parts curing agent maleic anhydride (manufacturer: Aladdin), 20 parts inorganic filler barium sulfate (manufacturer: Sakai Chemicals, Japan, Model: BF-20), 4 parts carbon black (manufacturer: Bora Corporation, Model: Raven2500).

[0115] By weight, the composition of the second photosensitive resin composition used in the light-shielding layer is the same as that of the first photosensitive resin composition, the only difference being that the amount of carbon black used is 8 parts.

[0116] The preparation method of the laminated film is as follows: 1. Mix the first photosensitive resin composition evenly and grind it to a particle size of <5μm using a sand mill. Then, coat the first photosensitive resin composition evenly onto the PET support film using a coating machine and dry it at 85℃ for 30 minutes. The thickness of the light-transmitting layer is 25μm.

[0117] The support layer material is PET (manufacturer: Foshan Mylar Hongji Film, model: ZL-BT), with a fourth gloss level of 92 and a third gloss level of 15.

[0118] 2. Mix the second photosensitive resin composition evenly and grind it to a particle size of <5μm using a sand mill. Apply the second photosensitive resin composition to the light-transmitting layer using a horizontal coating machine and dry it at 85℃ for 10 minutes. The thickness of the light-shielding layer is 7μm.

[0119] The laminated film is obtained by covering the dried light-shielding layer surface with a protective BOPP film (manufacturer: Toray, model: KW-37).

[0120] Example 2 This embodiment provides a laminated film, which differs from Embodiment 1 in that the support layer material is PET (manufacturer: Foshan Mylar Hongji Film, model: YG5), wherein the fourth gloss is 80 and the third gloss is 16.

[0121] Example 3 This embodiment provides a laminated film, which differs from Embodiment 1 in that the support layer material is PET (manufacturer: Foshan Mylar Hongji Film, model: YGD3), wherein the fourth gloss is 90 and the third gloss is 10.

[0122] Example 4 This embodiment provides a laminated film, which differs from Embodiment 1 in that the carbon black in the first photosensitive resin composition is 3 parts and the carbon black in the second photosensitive resin composition is 10 parts.

[0123] Example 5 This embodiment provides a laminated film, which differs from Embodiment 1 in that the carbon black in the first photosensitive resin composition is 3 parts and the carbon black in the second photosensitive resin composition is 4.3 parts.

[0124] Example 6 This embodiment provides a laminated film, which differs from Embodiment 1 in that the thickness of the light-transmitting layer is 35 μm and the thickness of the light-shielding layer is 5 μm.

[0125] Example 7 This embodiment provides a laminated film, which differs from Embodiment 1 in that the thickness of the light-transmitting layer is 21 μm and the thickness of the light-shielding layer is 7 μm.

[0126] Example 8 This embodiment provides a laminated film, which differs from Embodiment 1 in that the thickness of the light-transmitting layer is 15 μm and the thickness of the light-shielding layer is 5 μm.

[0127] Example 9 This embodiment provides a laminated film, which differs from Embodiment 1 in that the thickness of the light-transmitting layer is 40 μm and the thickness of the light-shielding layer is 6 μm.

[0128] Example 10 This embodiment provides a laminated film, which differs from Embodiment 1 in that the thickness of the light-transmitting layer is 40 μm and the thickness of the light-shielding layer is 10 μm.

[0129] Comparative Example 1 This embodiment provides a laminated film, which differs from Embodiment 1 in that the support layer material is PET (manufacturer: Foshan Mylar Hongji Film, model: YG6), wherein the fourth gloss is 50 and the third gloss is 30.

[0130] Comparative Example 2 This embodiment provides a laminated film, which differs from Embodiment 1 in that the carbon black content in the first photosensitive resin composition is 6.4 parts, and the carbon black content in the second photosensitive resin composition is 8 parts.

[0131] Comparative Example 3 This embodiment provides a laminated film, which differs from Embodiment 1 in that the thickness of the light-transmitting layer is 20 μm and the thickness of the light-shielding layer is 10 μm.

[0132] Comparative Example 4 This embodiment provides a laminated film, which differs from Embodiment 1 in that the thickness of the light-transmitting layer is 30 μm and the thickness of the light-shielding layer is 3 μm.

[0133] Test case 1) Sensitivity test: The sensitivity test method is as follows: The laminated films of the examples and comparative examples are attached to a commercial copper-clad board using a vacuum laminator. The pressure of the vacuum section is 6 kgf, the vacuum time is 20 s, the pressing time is 30 s, and the temperature is 65 ℃; the pressure of the leveling section is 6 kgf, the leveling time is 50 s, and the temperature is 85 ℃.

[0134] After attachment, expose and develop on an ST21 exposure scale. The lowest energy at which the ST8 exposure scale is not developed and is fully exposed is the sensitivity energy of the formulation.

[0135] 2) L-value, gloss, and smoothness tests: L-value test method: The light-shielding layer and light-transmitting layer in the examples and comparative examples were attached using a vacuum laminator according to the attachment method in the sensitivity test. After attachment, the commercial copper-clad laminate with the laminated film was exposed under a high-pressure mercury lamp exposure machine. After exposure, it was placed at room temperature for 30 minutes, and then the PET support film was peeled off. It was developed at 30°C for 50 seconds with alkaline developer (1 wt% sodium carbonate aqueous solution). After development, it was rinsed with water for 50 seconds to remove the residual developer on the film surface. Then, the copper-clad laminate with the film was post-cured in an oven at 150°C for 1 hour. The luminance value in the Lab colorimetric system of the light-shielding layer and the light-transmitting layer was measured using a spectrophotometer.

[0136] The light transmittance test method is as follows: The light-transmitting layer and the light-blocking layer are respectively attached to the transparent glass using a vacuum laminating machine. The pressure of the vacuum section is 6 kgf, the vacuum time is 20 s, the pressing time is 30 s, and the temperature is 65 ℃; the pressure of the leveling section is 6 kgf, the leveling time is 50 s, and the temperature is 85 ℃.

[0137] Transmittance (T) was measured by a UV-Vis spectrophotometer. Transparent glass was placed at the reference and sample positions for baseline calibration. Glass with a light-transmitting layer and a light-shielding layer attached was placed at the sample position and transparent glass was placed at the reference position. The samples were scanned to obtain the transmittance curves of the light-transmitting layer and the light-shielding layer in the 200nm~800nm ​​wavelength range. The transmittance at 385nm and 405nm was selected. The final transmittance was calculated by T=T(385)×70%+T(405)×30%.

[0138] Under a microscope, observe whether the cured material on the copper-clad laminate exhibits cracking, wrinkling, or warping. The test results are graded as follows: Grade 1: Smooth surface, no wrinkling, cracking, or warping; Grade 2: Surface shows wrinkling, cracking, and warping.

[0139] The obtained data is recorded in Table 1.

[0140] Gloss change rate 1 = (second gloss - first gloss) / first gloss.

[0141] Gloss change rate 2 = (first gloss - third gloss) / third gloss.

[0142] Table 1

[0143] As shown in Table 1, the first gloss level of Examples 1–10 was controlled below 15 (10–15), and satisfied -0.1 ≤ (second gloss level - first gloss level) / first gloss level ≤ 0.1, indicating that the surface gloss change before and after thermosetting was small and the matte stability was good. Meanwhile, the difference between the third gloss level (at the contact surface of the support layer) and the first gloss level was small, consistent with the design principle of "transfer printing to form matte." It is worth noting that the third gloss level of Comparative Example 1 was 30, and the first gloss level was 28, which, although close, exceeded the range of ≤15 for the first gloss level, resulting in wrinkles and cracks (flatness level 2) in the final appearance, indicating that the high-gloss substrate disrupted the consistency of the matte structure. The brightness value of the light-shielding layer was generally ≤20, and the L value of the light-transmitting layer was between 35 and 50, which met the requirements of the claims. However, it is noteworthy that Comparative Example 4 could not effectively cover the substrate.

[0144] 3) Line width and spacing (L / S), lateral erosion, and minimum window opening tests: The laminated films of the examples and comparative examples were attached to commercial copper-clad laminates using the attachment method in the sensitivity test. After attachment, the films were exposed at a sensitivity energy of ST8 / 21 using a standard test mask. After thermal curing, the L / S and side etching were observed under a metallographic microscope by sectioning. The minimum opening window could be directly observed under a metallographic microscope.

[0145] The optimal L / S and minimum window size are achieved when the line width, line spacing, and window diameter are fully reproduced and the error between these values ​​and the standard mask film is within ±5%. At this point, the size of the lateral erosion is measured and recorded, and it is observed whether the lateral erosion is within ±5% of the standard mask film. The test results are graded as follows: Level 1: Error within ±5%; Level 2: Error between ±5% and ±10%; Level 3: Error beyond ±10%.

[0146] The obtained data is recorded in Table 2.

[0147] Table 2

[0148] As shown in Table 2, Examples 1-10 have an L / S ratio of 25–45 μm and a window diameter of 40–70 μm, with most achieving a Level 1 rating (error ≤ 5%), indicating high imaging accuracy. Examples 3 (L / S = 25 μm) and 6 (25 μm) perform even better, likely due to their thicker light-transmitting layer or optimized carbon black ratio, which facilitates light transmission. Comparative Examples 1–3 have an L / S ratio increased to 80–90 μm and a window diameter of 130–150 μm, achieving a Level 3 rating. This indicates that when the support layer exhibits abnormal gloss (Comparative Example 1) or an unbalanced thickness ratio (Comparative Examples 2–3), light scattering intensifies, and the underlying substrate is insufficiently cured, leading to overdevelopment and pattern deterioration. Although Comparative Example 4 has an L / S ratio of 20 μm (better than most examples), its light-shielding layer is only 3 μm thick, resulting in insufficient coverage (light-shielding layer brightness 23 > 20, transmittance 55% is too high), failing to effectively shield the substrate and limiting its practicality.

[0149] 4) Glass transition temperature (Tg) and coefficient of thermal expansion (CTE) tests: After testing the L value, gloss, and flatness of the material (2), the copper on the copper-clad laminate was removed using an etching solution, leaving only the cured material. Then, it was cut into pieces 5 mm wide and 25 mm long with a cutting tool to obtain the cured material for evaluating the coefficient of thermal expansion.

[0150] The coefficient of thermal expansion under tensile conditions was determined using a TMA apparatus (TMAQ400, Shenzhen SANTAK Technology). The tensile load was 0.1 N, the span (distance between clamps) was 15 mm, and the heating rate was 10 °C / min.

[0151] First, the sample was mounted on the apparatus and heated from room temperature (25°C) to 160°C, and left to stand for 15 minutes. Then, it was cooled to -60°C and measured again at a heating rate of 10°C / min from -60°C to 250°C. The inflection point observed in the range of 25°C to 200°C was marked as Tg, and the temperature at this point was recorded.

[0152] CTE uses the slope of the tangent line of the curve obtained at temperatures below Tg. The test results are graded as follows: Grade 1: less than 50 ppm / ℃; Grade 2: 50~60 ppm / ℃; Grade 3: 60~70 ppm / ℃; Grade 4: more than 70 ppm / ℃.

[0153] The obtained data is recorded in Table 3.

[0154] Table 3

[0155] As shown in Table 3, the Tg of Examples 1–10 is concentrated between 135–145℃, and the CTE is all below 60ppm / ℃ (except for a few at level 2), indicating high crosslinking density and good thermal dimensional stability. This is attributed to the alkali-soluble resin, epoxy system, and sufficient dual curing (light + heat). The Tg of Comparative Examples 1–3 decreased significantly (110–125℃), and the CTE rose to level 4 (>70ppm / ℃), indicating that incomplete photocuring was caused by mismatched support layers or improper thickness ratios, affecting the final crosslinking network formation. It is worth noting that the Tg of Comparative Example 4 reached 143℃, and the CTE was level 1, demonstrating excellent performance. However, combined with its excessively thin light-shielding layer (3μm) and high light transmittance (55%), although deep curing was good, the hiding ability was sacrificed, verifying the technical contradiction of "balancing curing and hiding".

[0156] 5) HAST test: According to the L value, gloss and flatness test in step 2), the resistivity of the cured film product before and after HAST treatment was tested using a resistivity meter. Then the sample was transferred to the HAST chamber (PC-422R8D, Hirayama Manufacturing Co., Ltd.) and placed at 121℃ and 100% humidity for 120 hours. The resistivity after HAST treatment was tested again, and it was observed whether there were phenomena such as bubble peeling. The change in resistivity before and after HAST was compared.

[0157] The test results were graded as follows: Grade 1: No bubbles or peeling, or resistivity change within ±10%; Grade 2: No bubbles or peeling, or resistivity change within ±30%; Grade 3: A small amount of blistering, peeling, or even detachment of the cured film; Grade 4: A large number of bubbles or detachment, or resistivity change >50%. The results are recorded in Table 4.

[0158] 6) Acid resistance test: Test samples were prepared using the HAST test preparation method described above. They were immersed in a 10 vol% H₂SO₄ aqueous solution at 30°C for 30 min, then rinsed with water and dried. A peel test was then performed using 3M tape. Acid resistance was evaluated according to the following standards. The test results were graded as follows: Grade 1: No blistering, peeling, or even detachment of the cured film; Grade 2: Minor blistering, no peeling, and no detachment of the cured film; Grade 3: Minor blistering, peeling, or even detachment of the cured film; Grade 4: Significant detachment of the cured film. The results are recorded in Table 4.

[0159] 7) Alkali resistance test: Test samples were prepared using the HAST test preparation method described above. They were immersed in a 10 vol% NaOH aqueous solution at 30°C for 30 minutes, then rinsed with water and dried. A peel test was then performed using 3M tape. Alkali resistance was evaluated according to the following standards. The test results were graded as follows: Grade 1: No blistering, peeling, or even detachment of the cured film; Grade 2: Minor blistering, no peeling, and no detachment of the cured film; Grade 3: Minor blistering, peeling, or even detachment of the cured film; Grade 4: Significant detachment of the cured film. The results are recorded in Table 4.

[0160] 8) Solvent resistance test: Test samples were prepared using the HAST test preparation method described above. They were immersed in propylene glycol methyl ether acetate solvent at 30°C for 30 minutes, dried, and then subjected to a peel test using 3M tape. Solvent resistance was evaluated according to the following standards. The test results were graded as follows: Grade 1: No blistering, peeling, or even detachment of the cured film; Grade 2: Minor blistering, no peeling, and no detachment of the cured film; Grade 3: Minor blistering, peeling, or even detachment of the cured film; Grade 4: Significant detachment of the cured film. The results are recorded in Table 4.

[0161] 9) Heat resistance test: Tests were conducted according to IPC-TM650.2.6.8 standard. The cured material was immersed in rosin flux for 30 seconds, then vertically immersed in a solder bath at 288°C for 10 seconds, repeated three times. Surface blistering, discoloration, and lifting were observed, and the cured film was peeled off using 3M tape to assess appearance changes. The following criteria were used to classify the test results as follows: Level 1: No blistering, peeling, or detachment of the cured film; Level 2: Minor blistering, no peeling, and no detachment of the cured film; Level 3: Minor blistering, peeling, or detachment of the cured film; Level 4: Significant detachment of the cured film. The results are recorded in Table 4.

[0162] Table 4

[0163] As shown in Table 4, Examples 1–10 achieved Level 1 or Level 2 in most tests, especially with small resistivity changes and no bubble peeling, indicating dense curing, good adhesion, and strong resistance to environmental stress. Examples 4, 6, 9, and 10 achieved Level 2 in some tests, possibly related to their proximity to parameter boundaries (e.g., the lower gloss ratio of the support layer in Example 4 and the larger total film thickness in Example 10), but still better than conventional levels. Comparative Examples 1–3 achieved Level 4 in all tests, exhibiting severe blistering, peeling, or a sharp increase in resistivity, reflecting poor initial curing leading to weak interfacial bonding and easy delamination after moisture absorption, further confirming the key role of the structural design of the present invention. Although Comparative Example 4 performed excellently in chemical resistance (Level 1), its insufficient hiding power still cannot meet the needs of practical applications.

[0164] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A laminated film, characterized in that, It includes a light-transmitting layer and a light-blocking layer stacked in sequence; The first gloss level of the light-transmitting layer is ≤15; The gloss of the surface of the light-transmitting layer away from the light-shielding layer after exposure and development but without heat curing is the first gloss. The light transmittance of the light-transmitting layer is 70-90%, and the light transmittance of the light-shielding layer is 20-60%.

2. The laminated film according to claim 1, characterized in that, The light-transmitting layer includes a first alkali-soluble resin; And / or, the light-shielding layer comprises a second alkali-soluble resin.

3. The laminated film according to claim 1, characterized in that, The brightness value of the light-transmitting layer in the Lab chromaticity system is 35~50; And / or, the luminance value in the Lab chromaticity system of the light-shielding layer is ≤20.

4. The laminated film according to claim 1, characterized in that, The thickness of the laminated film is 20~50μm; And / or, the thickness ratio of the light-transmitting layer to the light-shielding layer is 3 to 7; And / or, the thickness of the light-transmitting layer is 15~40μm; And / or, the thickness of the light-shielding layer is 5~15μm.

5. The laminated film according to claim 1, characterized in that, The gloss of the surface of the light-transmitting layer away from the light-shielding layer after exposure, development and heat curing is the second gloss, -0.1≤(second gloss - first gloss) / first gloss≤0.1; And / or, the heating and curing temperature is 140~160℃, and the time is 50~70min; Preferably, the heating and curing temperature is 150°C and the time is 60 minutes.

6. The laminated film according to claim 2, characterized in that, By weight parts The raw materials of the light-transmitting layer include 100-115 parts of a first alkali-soluble resin, 5-20 parts of a first photosensitive component, 10-30 parts of a first thermosetting component, and 0-10 parts of a first black colorant; And / or, the raw materials of the light-shielding layer include 100-115 parts of the second alkali-soluble resin, 5-20 parts of the second photosensitive component, 10-30 parts of the second thermosetting component, and 0-10 parts of the second black colorant.

7. The laminated film according to claim 6, characterized in that, The first alkali-soluble resin and the second alkali-soluble resin are each independently selected from at least one of acid-modified bisphenol A type epoxy acrylate resin, acid-modified bisphenol F type epoxy acrylate resin, acid-modified alicyclic epoxy acrylate resin and acid-modified phenolic epoxy acrylate resin. And / or, the first photosensitive component and the second photosensitive component each independently include a photosensitive monomer and a photoinitiator; And / or, the photosensitive functional group in the photosensitive monomer is selected from at least one of diazo functional groups, azide functional groups, cinnamoyl functional groups, and acrylic functional groups; preferably, it contains an acrylic functional group; And / or, the photoinitiator is selected from free radical photoinitiators and / or cationic photoinitiators; And / or, the first thermosetting component and the second thermosetting component each independently comprise an epoxy resin and a curing agent; And / or, the curing agent includes any one or more of polyamine curing agents, imidazole curing agents, acid anhydride curing agents, boronamine curing agents, and boronamine salt curing agents; And / or, the first black colorant and the second black colorant each independently include at least one of manganese iron black, copper chromium black, iron chromium black, cobalt black, aniline black, antimony sulfide and pigment carbon black, preferably pigment carbon black; And / or, the weight ratio of the first black colorant in the light-transmitting layer to the second black colorant in the light-shielding layer is 0.3 to 0.

7.

8. The laminated film according to claim 1, characterized in that, It also includes a support layer; the support layer is disposed on the side of the light-transmitting layer away from the light-shielding layer; And / or, the surface gloss of the support layer on the side closer to the light-transmitting layer is ≤20, and the surface gloss of the side farther from the light-transmitting layer is ≥80; And / or, the ratio of the surface gloss of the support layer on the side closer to the light-transmitting layer to the surface gloss of the side farther from the light-transmitting layer is 5 to 9; And / or, -0.1 ≤ (first glossiness - surface glossiness of the support layer near the light-transmitting layer) / surface glossiness of the support layer near the light-transmitting layer ≤ 0.1; And / or, the support layer is selected from any one of polyester film, polyolefin film, polyethylene terephthalate film or polyimide film, preferably polyethylene terephthalate film; And / or, the laminated film further includes a protective layer disposed on the side of the light-shielding layer away from the light-transmitting layer; And / or, the protective layer is selected from either polyester film or polyolefin film, preferably polyolefin film.

9. A cured product, characterized in that, It is mainly formed by curing the laminated film according to any one of claims 1 to 7.

10. An electronic component, characterized in that, It has the cured product as described in claim 9.

Images