A dry film photoresist for high-temperature-resistant ceramic substrates and a preparation method thereof

Abstract

This application relates to the field of photoresist materials technology, and discloses a dry film photoresist for high-temperature resistant ceramic substrates and its preparation method. The dry film photoresist includes an interface layer and an imaging layer laminated on a PET carrier film; the interface layer contains OSiER-L, BIC-DMP, and ZrMA, with a G' of 0.20–0.50 MPa at 25°C, and a G' that jumps to over 50 MPa at 160–170°C; the imaging layer contains OSiER, ZrMA, and a photoinitiator, with a weight loss rate of <3% at 350°C. This application improves the pattern integrity retention capability of the dry film photoresist throughout the entire temperature range of ceramic co-firing and the adhesion reliability to alumina substrates.

Description

Technical Field

[0001] This application relates to the field of photoresist materials technology, and in particular to a dry film photoresist for high-temperature resistant ceramic substrates and its preparation method. Background Technology

[0002] In the manufacturing of high-density interconnects for industrial electronic devices, low-temperature co-fired ceramic (LTCC) technology is widely used in 5G communications, aerospace, and semiconductor packaging due to its excellent high-frequency characteristics and multilayer integration capabilities. Currently, the fabrication of conductive patterns on LTCC substrates primarily relies on screen printing, where metal pastes (silver paste, gold paste, etc.) are printed onto the surface of a green ceramic tape through a metal screen. After drying and curing, a conductive layer is formed. This process is widely used in the industry due to its low cost and ease of operation. For applications requiring slightly higher precision, the industry has begun to introduce photolithography based on liquid photoresist. Liquid photosensitive resin is spin-coated onto a ceramic substrate, followed by pre-baking, UV exposure, development, and post-baking steps to form a patterned mask. Metal paste is then filled in, and the photoresist is removed, thus overcoming the resolution limitations of screen printing. Building upon this, to address the surface roughness issue of ceramic substrates, some research has laminated dry-film polymer dielectric materials that can withstand soldering temperatures onto the ceramic substrate surface as a smoothing layer, and then coated with photosensitive resist, improving the resolution of the photolithographic pattern.

[0003] However, the existing solutions mentioned above still have significant shortcomings when applied to the fabrication of fine patterns on high-temperature ceramic substrates. First, the resolution limit of traditional screen printing is usually above 50μm, which cannot meet the requirements of high-density interconnection scenarios such as 5G millimeter-wave communication for fine conductor patterns at the 10μm level. Second, ordinary commercial liquid or dry film photoresists use acrylate, phenolic resin, etc. as the matrix, and their glass transition temperature and thermal decomposition temperature are usually below 300℃. During the LTCC sintering process (850-900℃) or the high-temperature ceramic co-firing stage, they cannot maintain the integrity of the pattern structure, and are prone to defects such as warping, cracking, and even carbonization residue, resulting in excessive deviation of line resistance after sintering. Third, there is a significant difference in the coefficient of thermal expansion between the ceramic substrate (thermal expansion coefficient of about 6-8ppm / ℃) and the organic photoresist material. The thermal stress generated during sintering and cooling can easily lead to interface delamination. Existing research mostly adjusts the resin skeleton at the material formulation level to improve heat resistance. Essentially, this is a passive way of bearing thermal stress rather than actively eliminating it, and a systematic solution for the entire temperature range of ceramic co-firing has not yet been formed.

[0004] The core contradiction in ceramic substrate photoresist lies in the inherent conflict between two performance requirements: on the one hand, to ensure room-temperature photolithography accuracy (10μm linewidth), the imaging layer needs a high cross-linking density to maintain pattern dimensional stability; on the other hand, a high cross-linking density means high material modulus and poor flexibility, making it unable to absorb interfacial thermal stress through deformation during sintering and heating, thus exacerbating the risk of interfacial delamination. While simply improving the resin's heat resistance through formulation can delay thermal decomposition, it cannot fundamentally solve the problem of thermal stress accumulation in high-modulus materials during the heating stage; conversely, reducing the cross-linking density to improve interfacial flexibility will inevitably compromise pattern accuracy. A deeper problem is that even if a flexible interfacial layer is introduced to release thermal stress, if this interfacial layer maintains a low modulus state during the high-temperature sintering and holding stage, the pattern will drift under high-temperature creep, and the line resistance deviation will still fail to meet design requirements. Therefore, the real technical problem that needs to be solved is: how to make the same dry film photoresist material exhibit three completely different mechanical response states of precision maintenance, stress release, and structural locking in the three process stages of room temperature exposure and development, sintering heating, and sintering heat preservation. No single-layer or double-layer dry film photoresist system in the current technology can achieve the above-mentioned time-series dynamic response function. Summary of the Invention

[0005] This application provides a dry film photoresist for high-temperature resistant ceramic substrates and its preparation method, which solves the problems of excessive line resistance deviation and pattern warping and cracking caused by the inability to actively release interfacial thermal stress and pattern drift due to high-temperature creep during the high-temperature sintering of ceramic substrates. It improves the ability of dry film photoresist to maintain pattern integrity and the adhesion reliability to alumina substrates throughout the entire temperature range of ceramic co-firing.

[0006] In a first aspect, this application provides a dry film photoresist for high-temperature resistant ceramic substrates, the dry film photoresist for high-temperature resistant ceramic substrates comprising: an interface layer and an imaging layer sequentially laminated onto a polyethylene terephthalate carrier film.

[0007] The interface layer is prepared by casting and drying an interface layer coating solution, which comprises the following components by mass percentage: low crosslinking density silicone-modified epoxy resin OSiER-L 55wt%~68wt%, blocked isocyanate BIC-DMP 12wt%~20wt%, zirconium methacrylate chelate ZrMA 5wt%~9wt%, dibutyltin dilaurate 0.3wt%~0.7wt%, and the balance being a mixed solvent of ethyl acetate and propylene glycol methyl ether acetate in a mass ratio of 7:3;

[0008] The imaging layer is prepared by casting and drying an imaging layer coating solution, which comprises the following components by mass percentage: silicone-modified epoxy resin OSiER 52wt%–63wt%, zirconium methacrylate chelate ZrMA 10wt%–14wt%, diphenyliodonium hexafluorophosphate 2wt%–5wt%, trimethylolpropane triacrylate 8wt%–13wt%, 9-anthracene methanol 1wt%–3wt%, and the balance being propylene glycol methyl ether acetate;

[0009] After the interface layer is cast and dried to form a film, the energy storage modulus G' is 0.20-0.50 MPa at 25°C, and G' jumps to more than 50 MPa when the temperature rises to 160-170°C; after the imaging layer is cured, the weight loss rate is <3% under a nitrogen atmosphere at 350°C.

[0010] Secondly, this application provides a method for preparing a dry film photoresist for a high-temperature resistant ceramic substrate, the method comprising:

[0011] Step 1: Preparation of OSiER, an organosilicon-modified epoxy resin for the imaging layer: 100 parts by weight of bisphenol A type epoxy resin and 30-40 parts by weight of methoxy-terminated polydimethylsiloxane intermediate are polycondensed at 170°C with a stirring rate of 200-300 rpm under nitrogen atmosphere and catalysis of 0.10-0.20 parts by weight of p-toluenesulfonic acid. The temperature is increased to 170°C at a stirring rate of 2°C / min until the melt viscosity reaches 2500-3500 mPa·s at 175°C. The process is then terminated by cooling the temperature to below 140°C to obtain OSiER.

[0012] Step 2: Preparation of low crosslinking density organosilicon modified epoxy resin OSiER-L for the interface layer: 100 parts by weight of bisphenol A type epoxy resin and 18-22 parts by weight of methoxy-terminated polydimethylsiloxane intermediate were polycondensed at 170°C with a stirring rate of 2°C / min under nitrogen atmosphere protection and stirring rate of 200-300 rpm. Polycondensation was terminated when the melt viscosity reached 800-1200 mPa·s at 175°C and the temperature was lowered to below 140°C to obtain OSiER-L.

[0013] Step 3, preparation of zirconium methacrylate (ZrMA): 100 parts by mass of zirconium n-propoxide were dissolved in 150 parts by mass of anhydrous ethanol. Under nitrogen protection, 79-81 parts by mass of methacrylic acid were added dropwise at a dropping rate of 0.8-1.2 mL / min. The system temperature was controlled at 20-25℃ using an external ice-water bath. The reaction was stirred for 4 hours. Ethanol and n-propanol were removed by vacuum distillation at 50℃ and 0.08 MPa to obtain the bulk ZrMA. The bulk ZrMA was dissolved in propylene glycol methyl ether acetate to prepare a 30 wt% stock solution for later use.

[0014] Step 4, Preparation of Blocked Isocyanate BIC-DMP: Dissolve 100 parts by weight of hexamethylene diisocyanate trimer in 80 parts by weight of N-methylpyrrolidone, and add 52-55 parts by weight of 3,5-dimethylpyrazole dropwise at a dropping rate of 0.5-0.7 mL / min under nitrogen protection at 60°C. React at 60°C for 3 hours. When the area of ​​the -NCO characteristic peak is less than 2% of the initial value, BIC-DMP is obtained.

[0015] Step 5, prepare the imaging layer coating solution: Weigh the OSiER obtained in Step 1, the ZrMA stock solution obtained in Step 3 (based on the dry weight of ZrMA), diphenyliodonium hexafluorophosphate, trimethylolpropane triacrylate and 9-anthracene methanol according to the mass percentage of each solid component of the imaging layer. Dissolve OSiER in propylene glycol methyl ether acetate to prepare a solution with a solid content of 40 wt%. Then add the remaining solid components in sequence, stirring for no less than 10 min after each addition. After stirring evenly in the dark, filter through a 0.2 μm polytetrafluoroethylene membrane to obtain the imaging layer coating solution.

[0016] Step 6, prepare the interface coating solution: Weigh the OSiER-L obtained in Step 2, the BIC-DMP obtained in Step 4, the ZrMA stock solution obtained in Step 3 (based on the dry weight of ZrMA), and dibutyltin dilaurate according to the mass percentage of each solid component of the interface layer. Dissolve OSiER-L in a mixed solvent of ethyl acetate and propylene glycol methyl ether acetate in a mass ratio of 7:3 to prepare a solution with a solid content of 35wt%. Then add the remaining solid components in sequence, stirring for no less than 10 minutes after each addition. After stirring in the dark for 30 minutes, filter through a 0.45μm polytetrafluoroethylene membrane to obtain the interface coating solution.

[0017] Step 7, Double-layer co-casting film formation: The interface layer coating liquid obtained in Step 6 is cast onto a polyethylene terephthalate carrier film with a surface tension ≥52mN / m and a thickness of 25μm after corona treatment, with a die lip gap of 110-130μm and a casting rate of 2.0m / min. After drying in three stages at 60℃ / 2min, 80℃ / 3min, and 100℃ / 2min, an interface layer with a thickness of 8.0±0.5μm is obtained. The imaging layer coating liquid obtained in Step 5 is cast onto the surface of the interface layer with a die lip gap of 190-210μm and the same casting rate. The wet contact time between the two layers is controlled to be 5-10s. After drying in three stages at 70℃ / 2min, 90℃ / 3min, and 110℃ / 3min, an imaging layer with a thickness of 20.0±1.0μm is obtained. A polyethylene protective film is then attached to the surface of the imaging layer and wound into a roller.

[0018] The technical solution provided in this application fundamentally overcomes the performance bottleneck of existing single-layer homogeneous photoresist systems in high-temperature ceramic substrate applications by designing the dry film photoresist as a two-layer composite structure consisting of an interface layer and an imaging layer, supported by a polyethylene terephthalate carrier film. The blocked isocyanate BIC-DMP introduced into the interface layer endows the layer with unique temperature response characteristics. Under normal temperature conditions, BIC-DMP is in a capped state, and the interface layer, with low crosslinking density silicone-modified epoxy resin OSiER-L as the matrix, maintains a flexible and low-modulus state. It can actively absorb and release the interfacial thermal stress caused by the difference in thermal expansion coefficients between the ceramic substrate and the photoresist through elastic creep during the sintering heating stage, rather than passively bearing it. When the temperature rises to the decapping temperature range of BIC-DMP, the capped groups automatically deprotect, triggering secondary crosslinking and curing of the interface layer, and the modulus rapidly increases, completing the temporal transition from flexible to rigid, firmly locking the pattern structure after the thermal stress has been released, thereby preventing the pattern from drifting due to high-temperature creep during the sintering heat preservation and cooling stages. Meanwhile, the zirconium methacrylate (ZrMA) introduced into the interface layer forms a coordination covalent bond between zirconium atoms and aluminum hydroxyl groups on the surface of the alumina substrate, establishing a strong chemical anchor between the photoresist and the ceramic substrate at the molecular level. This elevates the interface adhesion from physical adhesion to chemical bonding, fundamentally solving the hidden danger of interface delamination after high-temperature sintering.

[0019] The imaging layer uses OSiER, a silicone-modified epoxy resin with a high siloxane content, as its matrix. The high proportion of Si-O-Si bonds in the framework endows the cured film with excellent thermal stability under a high-temperature nitrogen atmosphere, ensuring that the imaging layer maintains its structural integrity without carbonization or decomposition at ceramic co-firing temperatures. The ZrMA component also introduced into the imaging layer further strengthens the interfacial bonding between the imaging layer and the interface layer, as well as between the imaging layer and the silver paste conductive pattern. Combined with the highly efficient photocuring system composed of trimethylolpropane triacrylate crosslinking monomer and diphenyliodonium hexafluorophosphate photoinitiator, it ensures the formation of fine patterns with vertical sidewalls and precise dimensions after exposure and development. It is particularly worth emphasizing that the gradient transition zone naturally formed between the interface layer and the imaging layer during wet co-casting eliminates the abrupt physical interface between the two layers, avoiding the risk of interlayer stress concentration and delamination. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments 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 based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the process flow for preparing the double-layer dry film photoresist in this application;

[0022] Figure 2 This is a schematic diagram showing the change of the interface layer energy storage modulus G' with temperature in an embodiment of this application;

[0023] Figure 3 This is a schematic diagram illustrating the effect of the amount of ZrMA used in the imaging layer on the adhesion of the alumina substrate and the deviation of the line resistance after sintering in the embodiments of this application. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. Unless otherwise specified, the pharmaceuticals used in the embodiments are commercially available products, and the methods used are conventional methods in the art. The methoxy content of the methoxy-terminated polydimethylsiloxane intermediate used is 7.5wt%–8.5wt%, and the viscosity at 25°C is 50–80 mPa·s; the NCO content of the hexamethylene diisocyanate trimer used is 21.5wt%–22.5wt%; the purity of the zirconium propoxide used is ≥97%; and the epoxy equivalent of the bisphenol A type epoxy resin used is 185–195 g / eq, and the number-average molecular weight is 370–390 g / mol.

[0025] Figure 1 This is a schematic diagram of the process flow for preparing the double-layer dry film photoresist in this application. Figure 1 The flowchart clearly demonstrates the parallel progress of the interface layer coating preparation route and the imaging layer coating preparation route of this invention: the left route sequentially completes the synthesis of OSiER-L, BIC-DMP, ZrMA, and the preparation of the interface layer coating; the right route sequentially completes the synthesis of OSiER, the preparation of ZrMA stock solution, the addition of photoinitiator and crosslinking monomer, and the preparation of the imaging layer coating; after the two coatings are combined, they undergo a double-layer co-casting film formation process, with the interface layer cast first, followed by the imaging layer cast after 5-10 seconds of wet contact, forming a gradient transition region of 0.5-1.2 μm, and then undergoes three stages of drying and curing, lamination with a polyethylene protective film, and winding into a roller to obtain the double-layer dry film photoresist product.

[0026] Example 1

[0027] This embodiment provides a dry film photoresist for high-temperature resistant ceramic substrates, comprising an interface layer and an imaging layer sequentially laminated onto a polyethylene terephthalate carrier film, using the median ratio of each component, to verify the basic performance of the dual-layer time-response dry film photoresist system of the present invention.

[0028] I. Formula

[0029] The mass percentages of each component in the interface coating solution are as follows: OSiER-L 62wt%, BIC-DMP 16wt%, ZrMA 8wt%, dibutyltin dilaurate 0.5wt%, and the balance is a mixed solvent of ethyl acetate and propylene glycol methyl ether acetate in a mass ratio of 7:3.

[0030] The mass percentages of each component in the imaging layer coating are as follows: OSiER 58wt%, ZrMA 12wt%, diphenyliodonium hexafluorophosphate 3.5wt%, trimethylolpropane triacrylate 10wt%, 9-anthracene methanol 2wt%, and the balance being propylene glycol methyl ether acetate.

[0031] II. Preparation of each component

[0032] Preparation of OSiER: 100 parts by weight of bisphenol A type epoxy resin and 35 parts by weight of methoxy-terminated polydimethylsiloxane intermediate were polycondensed at 170°C under nitrogen atmosphere and stirring at 250 rpm, with the temperature increased at a rate of 2°C / min. The melt viscosity at 175°C was measured every 60 min. The reaction was terminated when the melt viscosity reached 3000 mPa·s and the temperature was lowered to below 140°C to obtain OSiER. FTIR analysis showed that I(SiOSi) / I(Ph) = 1.42, meeting the requirement of ≥1.35; the epoxy equivalent was 1185 g / eq, meeting the requirement of 1100~1300 g / eq. OSiER was dissolved in propylene glycol methyl ether acetate to prepare a solution with a solid content of 40 wt%.

[0033] Preparation of OSiER-L: 100 parts by weight of bisphenol A type epoxy resin and 20 parts by weight of methoxy-terminated polydimethylsiloxane intermediate were polycondensed at 170°C under nitrogen atmosphere and stirring at 250 rpm, with a heating rate of 2°C / min. The reaction was terminated when the melt viscosity reached 1000 mPa·s at 175°C and the temperature was lowered to below 140°C to obtain OSiER-L. OSiER-L was dissolved in a mixed solvent of ethyl acetate and propylene glycol methyl ether acetate in a mass ratio of 7:3 to prepare a solution with a solid content of 35 wt%.

[0034] Preparation of ZrMA: 100 parts by mass of zirconium n-propoxide were dissolved in 150 parts by mass of anhydrous ethanol. Under nitrogen protection, 80 parts by mass of methacrylic acid were added dropwise at a dropping rate of 1.0 mL / min. The system temperature was controlled at 22 °C using an external ice-water bath. The reaction was stirred for 4 h. Ethanol and n-propanol were removed by vacuum distillation at 50 °C and 0.08 MPa to obtain the ZrMA bulk. ICP-OES analysis showed that the zirconium content in the ZrMA bulk was 25.8 wt%, meeting the requirement of 24.0–27.0 wt%. DLS analysis showed that the hydrodynamic radius of ZrMA in propylene glycol methyl ether acetate was 1.8 nm, meeting the requirement of 1.2–2.5 nm. A 30 wt% stock solution of ZrMA bulk was prepared by dissolving it in propylene glycol methyl ether acetate for later use.

[0035] Preparation of BIC-DMP: 100 parts by weight of hexamethylene diisocyanate trimer were dissolved in 80 parts by weight of N-methylpyrrolidone. 53 parts by weight of 3,5-dimethylpyrazole were added dropwise at a rate of 0.6 mL / min under nitrogen protection at 60 °C. The reaction was carried out at 60 °C for 3 h, and the reaction was detected by FTIR. When the area of ​​the -NCO characteristic peak is 1.3% of the initial value, the sealing is considered complete, and BIC-DMP is obtained. DSC analysis shows that the desealing temperature of BIC-DMP is 155℃, meeting the requirement of 150~160℃.

[0036] III. Preparation of Coating Solution and Film Formation

[0037] Preparation of imaging layer coating solution: Place the 40wt% propylene glycol methyl ether acetate solution of OSiER in a light-proof container, and add ZrMA stock solution (40 parts of stock solution based on 12 parts of dry weight of ZrMA), 3.5 parts of diphenyliodonium hexafluorophosphate, 10 parts of trimethylolpropane triacrylate, and 2 parts of 9-anthracene methanol in sequence. Stir for at least 10 min under light-proof conditions after each addition. After all the solution has been added, continue stirring under light-proof conditions for 30 min. Filter through a 0.2 μm polytetrafluoroethylene membrane to obtain the imaging layer coating solution.

[0038] Preparation of interfacial coating solution: Place the 35wt% mixed solvent solution of OSiER-L in a container, and add 16 parts of BIC-DMP, ZrMA stock solution (27 parts of stock solution based on 8 parts of dry weight of ZrMA) and 0.5 parts of dibutyltin dilaurate in sequence. Stir for at least 10 minutes after each addition, stir for 30 minutes in the dark, and then filter through a 0.45μm polytetrafluoroethylene membrane to obtain the interfacial coating solution.

[0039] Double-layer co-casting film formation: The interface layer coating solution was cast onto a polyethylene terephthalate (PET) carrier film with a surface tension of 54 mN / m and a thickness of 25 μm after corona treatment, with a die lip gap of 120 μm and a casting rate of 2.0 m / min. The film was dried in three stages at 60℃ / 2 min, 80℃ / 3 min, and 100℃ / 2 min to obtain an interface layer with a thickness of 8.0 μm. An imaging layer coating solution was then cast onto the interface layer surface with a die lip gap of 200 μm and the same casting rate. The wet contact time between the two layers was 7 s. The film was dried in three stages at 70℃ / 2 min, 90℃ / 3 min, and 110℃ / 3 min to obtain an imaging layer with a thickness of 20.0 μm. A polyethylene protective film was then laminated onto the imaging layer surface and the film was wound into a roll to obtain the dry film photoresist of this embodiment.

[0040] IV. Performance Testing

[0041] The double-layer dry film photoresist obtained in this embodiment was used. The polyethylene terephthalate (PET) carrier film was removed, and the interface layer was aligned with an alumina substrate containing 96% Al₂O₃. Hot roll lamination was performed at 110°C, 0.3 MPa, and a speed of 0.5 m / min. The polyethylene protective film was then removed, and the image was exposed through a chrome photomask (pattern linewidth 10 μm, line spacing 10 μm) using a 365 nm line light source (exposure dose 175 mJ / cm²). 2 ), developed with 0.26 mol / L tetramethylammonium hydroxide aqueous solution for 70 s, rinsed with deionized water and dried.

[0042] Adhesion test: The adhesion grade was determined to be 5B and the peel strength was 3.5 N / cm by the cross-cut adhesion test method according to ASTM D3359.

[0043] Graphic accuracy test: The line width after development was 10.1 μm, which meets the requirement of 10 ± 0.5 μm, as measured by scanning electron microscopy; the line edge roughness was 0.6 μm, which meets the requirement of ≤ 0.8 μm.

[0044] Timing response performance test: The interfacial layer energy storage modulus G' as a function of temperature was measured using a dynamic thermomechanical analyzer (DMA, heating rate 5℃ / min, frequency 1Hz): at 25℃, G'=0.38MPa, meeting the requirement of 0.20~0.50MPa; at 155℃, G'=0.40MPa (BIC-DMP begins to decapsulate, and the modulus basically maintains a flexible state); at 165℃, G' jumps to 62MPa; at 170℃, G'=68MPa, meeting the requirement that G' jumps to more than 50MPa at 160~170℃, confirming that the timing response characteristics meet the design.

[0045] Thermal stability test: The image layer cured film was tested by TGA (nitrogen atmosphere, heating rate of 10℃ / min, 25℃ to 600℃). The weight loss rate at 350℃ was 2.4%, which meets the requirement of <3%.

[0046] Gradient transition region characterization: SAXS analysis was performed on the cross-section of the bilayer film, and the full width at half maximum (FWHM) of the characteristic scattering peak Δ was obtained. Satisfying less than The requirements were met, and the thickness of the gradient transition zone was confirmed to be uniform. The actual thickness was 0.9 μm, which meets the requirement of 0.5–1.2 μm.

[0047] Post-sintering pattern integrity test: The alumina substrate sample after film coating and development was placed in a sintering furnace and sintered according to the LTCC standard sintering curve (heating rate 3℃ / min, peak temperature 875℃, holding time 30min, cooling rate 5℃ / min). After sintering, the linewidth retention rate was 98.1%, the line resistance deviation of the silver paste conductive pattern was 2.8%, meeting the requirement of <5%, and the pattern showed no warping or cracking.

[0048] Figure 2 This is a schematic diagram illustrating the variation of the interface layer energy storage modulus G' with temperature in an embodiment of this application. Figure 2 The figure contains three curves: the solid dot represents the interface layer G' of the present invention (left axis), the dashed square dot represents the single-layer homogeneous film G' of Comparative Example 1 (right axis), and the dotted triangle represents the interface layer G' without BIC-DMP in Comparative Example 2 (left axis). As can be seen from the figure, the interface layer of the present invention has a G' of only 0.38 MPa at 25°C, which is in the flexible creep range. After BIC-DMP begins to de-encapsulate at 155°C and completes de-encapsulation at 160°C, G' rapidly jumps to 68 MPa in the 160-170°C range, achieving rigid locking. In contrast, the single-layer homogeneous film of Comparative Example 1 maintains a high modulus (57-85 MPa) throughout the process, resulting in the inability to release interfacial thermal stress. Although the interface layer of Comparative Example 2 without BIC-DMP has initial flexibility, G' does not exceed 0.23 MPa throughout the process and cannot achieve rigid locking. The two comparative experiments jointly verify the necessity and effectiveness of the time-response bilayer structure of the present invention.

[0049] Example 2

[0050] This embodiment provides a dry film photoresist for high-temperature resistant ceramic substrates and verifies its performance under the lower limit ratio of each component in the interface layer.

[0051] I. Formula

[0052] The mass percentages of each component in the interface coating solution are as follows: OSiER-L 68wt%, BIC-DMP 12wt%, ZrMA 5wt%, dibutyltin dilaurate 0.3wt%, and the balance is a mixed solvent of ethyl acetate and propylene glycol methyl ether acetate in a mass ratio of 7:3.

[0053] The formulation of the imaging layer coating solution is the same as that in Example 1.

[0054] II. Preparation of each component

[0055] The OSiER preparation method is the same as in Example 1, yielding OSiER with I(SiOSi) / I(Ph) = 1.42 and an epoxy equivalent of 1185 g / eq.

[0056] Preparation of OSiER-L: 100 parts by weight of bisphenol A type epoxy resin and 18 parts by weight of methoxy-terminated polydimethylsiloxane intermediate were polycondensed at 170°C under nitrogen protection and stirring at 200 rpm, with the temperature increased at 2°C / min, catalyzed by 0.10 parts by weight of p-toluenesulfonic acid. The polymerization was terminated when the melt viscosity reached 820 mPa·s at 175°C and then cooled to below 140°C to obtain OSiER-L. This is the lower limit ratio of siloxane intermediate usage, corresponding to the minimum crosslinking density.

[0057] The preparation methods for ZrMA and BIC-DMP are the same as in Example 1, with ZrMA containing 25.8 wt% zirconium and BIC-DMP unsealing temperature of 155°C.

[0058] III. Preparation of Coating Solution and Film Formation

[0059] The preparation method was the same as in Example 1, and the film formation parameters were consistent, resulting in a double-layer dry film photoresist with an interface layer thickness of 8.0 μm and an imaging layer thickness of 20.0 μm.

[0060] IV. Performance Testing

[0061] The adhesion grade is 5B, and the peel strength is 3.1 N / cm (the ZrMA content is the lower limit of 5wt%, the number of zirconium-aluminum coordination bonds is relatively reduced, the peel strength is slightly lower than that of Example 1, but the adhesion grade still reaches 5B).

[0062] After development, the line width is 10.2 μm and the line edge roughness is 0.7 μm, which meets the design requirements.

[0063] DMA time response: at 25℃, G' = 0.22MPa (OSiER-L crosslinking density is the lowest, G' is near the lower limit of the range of 0.20-0.50MPa); at 158℃, G' begins to jump (BIC-DMP dosage is the lower limit of 12wt%, unblocking triggers secondary crosslinking); at 168℃, G' = 51MPa, which meets the requirement that G' jumps to above 50MPa at 160-170℃.

[0064] The TGA test showed a weight loss rate of 2.4% at 350℃, which meets the requirement of <3%.

[0065] After sintering, the linewidth retention rate is 97.5%, the line resistance deviation is 3.6%, which meets the design requirement of <5%, and the pattern is free from warping and cracking.

[0066] This embodiment demonstrates that when the components of the interface layer are used in the lower limit ratio, the timing response mechanism and graphic accuracy both meet the design requirements, and the rationality of the lower limit range is verified.

[0067] Example 3

[0068] This embodiment provides a dry film photoresist for high-temperature resistant ceramic substrates and verifies its performance under the upper limit ratio of each component in the interface layer.

[0069] I. Formula

[0070] The mass percentages of each component in the interface coating solution are as follows: OSiER-L 55wt%, BIC-DMP 20wt%, ZrMA 9wt%, dibutyltin dilaurate 0.7wt%, and the balance is a mixed solvent of ethyl acetate and propylene glycol methyl ether acetate in a mass ratio of 7:3.

[0071] The formulation of the imaging layer coating solution is the same as that in Example 1.

[0072] II. Preparation of each component

[0073] The preparation method of OSiER is the same as in Example 1.

[0074] Preparation of OSiER-L: 100 parts by weight of bisphenol A type epoxy resin and 22 parts by weight of methoxy-terminated polydimethylsiloxane intermediate were polycondensed at 170°C under nitrogen protection and stirring at 300 rpm, with the temperature increased at 2°C / min, catalyzed by 0.20 parts by weight of p-toluenesulfonic acid. The polymerization was terminated when the melt viscosity reached 1180 mPa·s at 175°C and then cooled to below 140°C to obtain OSiER-L. This is the upper limit ratio of siloxane intermediate usage.

[0075] The preparation methods for ZrMA and BIC-DMP are the same as in Example 1, and the unpacking temperature for BIC-DMP is 155°C.

[0076] III. Preparation of Coating Solution and Film Formation

[0077] The preparation method is the same as in Example 1, resulting in a double-layer dry film photoresist with an interface layer thickness of 8.0 μm and an imaging layer thickness of 20.0 μm.

[0078] IV. Performance Testing

[0079] Adhesion rating 5B, peel strength 3.8 N / cm (ZrMA dosage is up to 9 wt%, the number of zirconium-aluminum coordination bonds increases, resulting in the strongest adhesion).

[0080] After development, the line width is 10.1 μm and the line edge roughness is 0.6 μm, which meets the design requirements.

[0081] DMA timing response: At 25°C, G' = 0.48 MPa (BIC-DMP dosage is the upper limit of 20 wt%, the crosslinking precursor content is relatively high, but BIC-DMP is in the end-capped state at room temperature and does not participate in crosslinking, so G' is still in the flexible range of 0.20~0.50 MPa); G' begins to jump at 162°C; at 170°C, G' = 78 MPa, which meets the requirement that G' jumps to more than 50 MPa at 160~170°C, and the jump amplitude is greater than that of Example 1 (78 MPa vs 68 MPa), and the pattern locking is more stable.

[0082] The TGA test showed a weight loss rate of 2.4% at 350℃, which meets the requirement of <3%.

[0083] After sintering, the linewidth retention rate is 98.5%, the line resistance deviation is 2.3% (the secondary cross-linking is more complete under the upper limit ratio of BIC-DMP, and the pattern locking is more stable), which meets the design requirement of <5%, and the pattern is free from warping and cracking.

[0084] This embodiment demonstrates that when the components of the interface layer are used in the upper limit ratio, the G' jump is larger, the pattern locking is more stable, the line resistance deviation is smaller, the upper limit range is reasonable, and the performance is better than the median ratio.

[0085] Example 4

[0086] This embodiment verifies the effect of siloxane content in the OSiER imaging layer on its thermal stability at 350°C through univariate comparison. In this embodiment, only the amount of siloxane intermediate used in OSiER synthesis is changed; all other components and process parameters are exactly the same as in Example 1.

[0087] Example 4-A (Siloxane intermediate usage 30%, lower limit)

[0088] Preparation of OSiER-A: 100 parts by mass of bisphenol A type epoxy resin and 30 parts by mass of methoxy-terminated polydimethylsiloxane intermediate were synthesized under the catalysis of 0.15 parts by mass of p-toluenesulfonic acid. The final viscosity was 2520 mPa·s. FTIR analysis showed that I(SiOSi) / I(Ph) = 1.36, meeting the requirement of ≥1.35; the epoxy equivalent was 1108 g / eq, meeting the requirement of 1100~1300 g / eq.

[0089] In the imaging layer coating solution, OSiER was replaced with OSiER-A, while the remaining components of the formulation remained unchanged. The formulation of the interface layer coating solution was the same as in Example 1.

[0090] Performance testing: The TGA imaging layer cured film showed a weight loss rate of 2.9% at 350℃, meeting the requirement of <3%. After sintering, the linewidth retention rate was 97.2%, and the line resistance deviation was 4.1%, meeting the design requirement of <5%. The pattern showed no warping or cracking.

[0091] Example 4-B (Siloxane intermediate usage 40%, upper limit)

[0092] Preparation of OSiER-B: 100 parts by weight of bisphenol A type epoxy resin and 40 parts by weight of methoxy-terminated polydimethylsiloxane intermediate were synthesized under the catalysis of 0.15 parts by weight of p-toluenesulfonic acid. The final viscosity was 3480 mPa·s. FTIR analysis showed I(SiOSi) / I(Ph) = 1.58, and the epoxy equivalent was 1290 g / eq.

[0093] In the imaging layer coating, OSiER was replaced with OSiER-B, while the remaining components of the formulation remained unchanged. The formulation of the interface layer coating was the same as in Example 1.

[0094] Performance testing: TGA testing showed that the weight loss of the cured film in the imaging layer at 350℃ was 1.8% (higher Si-O-Si content, better thermal stability). After sintering, the linewidth retention rate was 98.8%, the line resistance deviation was 2.0%, meeting the design requirement of <5%, and the pattern showed no warping or cracking.

[0095] Summary of comparison results between Examples 4-A and 4-B:

[0096]

[0097] The comparison shows that within the range of 30% to 40% of siloxane intermediate, as the Si-O-Si content increases, the weight loss rate at 350℃ decreases from 2.9% to 1.8%, and the thermal stability increases monotonically. The ratios at both ends meet the design requirement of <3%, and the rationality of the 30% to 40% range is fully verified.

[0098] Example 5

[0099] This embodiment verifies the effect of BIC-DMP dosage on the timing response mechanism through univariate comparison. In this embodiment, only the BIC-DMP dosage in the interface layer coating solution is changed, and the OSiER-L dosage is adjusted accordingly to maintain a consistent residual solvent ratio. ZrMA 8wt% and dibutyltin dilaurate 0.5wt% remain unchanged, and the imaging layer coating solution formulation is exactly the same as in Example 1.

[0100] Example 5-A (BIC-DMP 12wt%)

[0101] Interface coating solution: OSiER-L 66wt%, BIC-DMP 12wt%, ZrMA 8wt%, dibutyltin dilaurate 0.5wt%, balance being a mixed solvent. Other preparation parameters were the same as in Example 1.

[0102] DMA measurement: G'=0.24MPa at 25℃; G'=53MPa at 170℃, meeting the requirement of above 50MPa. The linear resistance deviation after sintering is 3.9%, meeting the requirement of <5%.

[0103] Example 5-B (BIC-DMP 16wt%, i.e. Example 1)

[0104] DMA measurements: G' = 0.38 MPa at 25℃; G' = 68 MPa at 170℃. The linear resistance deviation after sintering was 2.8%.

[0105] Example 5-C (BIC-DMP 20wt%)

[0106] Interface coating solution: OSiER-L 58wt%, BIC-DMP 20wt%, ZrMA 8wt%, dibutyltin dilaurate 0.5wt%, balance being a mixed solvent. Other preparation parameters were the same as in Example 1.

[0107] DMA measurement: G'=0.48MPa at 25℃; G'=78MPa at 170℃, meeting the requirement of above 50MPa. The linear resistance deviation after sintering is 2.3%, meeting the requirement of <5%.

[0108] Summary of the three sets of comparison results:

[0109]

[0110] Three sets of data show that when the BIC-DMP dosage is within the range of 12wt% to 20wt%, the resistance G' at 25℃ remains within a flexible range of 0.20 to 0.50 MPa, while at 170℃, G' jumps to over 50 MPa. After sintering, the linear resistance deviation is consistently <5%, fully validating the rationality of the 12wt% to 20wt% range. With increasing BIC-DMP dosage, the G' value at 170℃ increases, and the linear resistance deviation further decreases, showing a monotonic improvement trend in performance.

[0111] Example 6

[0112] This embodiment verifies the effect of ZrMA dosage in the imaging layer on the adhesion of the alumina substrate through univariate comparison. In this embodiment, only the ZrMA dosage in the imaging layer coating is changed, and the OSiER dosage is adjusted accordingly, while the other components remain unchanged. The formulation of the interface layer coating is exactly the same as in Example 1.

[0113] Example 6-A (Imaging layer ZrMA 10wt%)

[0114] Imaging layer coating: OSiER 60wt%, ZrMA 10wt%, diphenyliodonium hexafluorophosphate 3.5wt%, trimethylolpropane triacrylate 10wt%, 9-anthracene methanol 2wt%, balance propylene glycol methyl ether acetate. Other preparation parameters are the same as in Example 1.

[0115] Performance testing: Adhesion grade 5B, peel strength 3.0 N / cm. Linear resistance deviation after sintering is 3.2%, meeting the requirement of <5%.

[0116] Example 6-B (Imaging layer ZrMA12wt%, i.e. Example 1)

[0117] Adhesion grade 5B, peel strength 3.5 N / cm. Linear resistivity deviation after sintering 2.8%.

[0118] Example 6-C (Imaging layer ZrMA14wt%)

[0119] Imaging layer coating: OSiER 56wt%, ZrMA 14wt%, diphenyliodonium hexafluorophosphate 3.5wt%, trimethylolpropane triacrylate 10wt%, 9-anthracite methanol 2wt%, balance propylene glycol methyl ether acetate. Other preparation parameters were the same as in Example 1.

[0120] Performance testing: Adhesion grade 5B, peel strength 3.9 N / cm. Linear resistance deviation after sintering is 2.5%, meeting the requirement of <5%.

[0121] Summary of the three sets of comparison results:

[0122]

[0123] Three sets of data show that when the ZrMA dosage in the imaging layer is within the range of 10wt% to 14wt%, the adhesion grade to alumina substrates with Al2O3 content ≥96% reaches 5B, meeting the design requirements. With increasing ZrMA dosage, the peel strength monotonically increases from 3.0 N / cm to 3.9 N / cm, fully validating the rationality of the 10wt% to 14wt% range.

[0124] Comparative Example 1

[0125] This comparative example provides a single-layer homogeneous dry film photoresist for comparison with the dual-layer time-response dry film photoresist of the present invention, directly verifying the core technical advantages of the dual-layer structure of the present invention compared with the single-layer structure of the prior art.

[0126] The comparative example used the exact same formulation as the imaging layer coating solution in Example 1: OSiER 58wt%, ZrMA 12wt%, diphenyliodonium hexafluorophosphate 3.5wt%, trimethylolpropane triacrylate 10wt%, 9-anthracite methanol 2wt%, with the balance being propylene glycol methyl ether acetate. A single-layer dry film photoresist with a thickness of 28μm was prepared (similar to the total functional film thickness of the bilayer of this invention, excluding polyethylene terephthalate carrier film), without an interface layer, and directly laminated onto the same... On an alumina substrate with a content of 96%, the remaining lamination, exposure, development, and sintering conditions were exactly the same as in Example 1.

[0127] The performance test results are as follows:

[0128] Adhesion rating: Comparative Example 1 is 2B, and Example 1 of the present invention is 5B. Comparative Example 1 has a single-layer homogeneous structure without a low-crosslink density flexible interface layer, and the thermal stress at the interface with the ceramic substrate cannot be effectively released, resulting in a significant decrease in the adhesion rating.

[0129] At 25°C, G': Comparative Example 1 homogeneous membrane G'=85MPa (high cross-linking density homogeneous membrane, rigid at room temperature), and Example 1 of the present invention interface layer G'=0.38MPa.

[0130] Calculation of interfacial thermal stress when sintering temperature is raised to 120℃: Comparative Example 1 The stress exceeding 38 kPa, which causes the bonding failure between the single-layer photoresist and the ceramic interface, leads to interface peeling; in Embodiment 1 of this invention The stress is far below the interfacial bonding failure stress of 45 kPa, and the interface remains intact.

[0131] Line width after development: Comparative Example 1 is 10.2 μm, which is similar to Example 1 of the present invention (10.1 μm), indicating that the pattern accuracy of the imaging layer formulation itself is quite similar, and the difference comes from the subsequent sintering stage.

[0132] Line width deviation after sintering: Comparative Example 1 ΔCD = 4.2 μm (interface peeling caused pattern deformation), Example 1 of the present invention ΔCD = 0.3 μm.

[0133] Line resistance deviation: Comparative Example 1 has a deviation of 12.3%, which does not meet the design requirement of <5%; Example 1 of the present invention has a deviation of 2.8%, which meets the design requirement.

[0134] Graphic integrity: Comparative Example 1 shows local warping and line width widening, while Embodiment 1 of the present invention has no warping or cracking.

[0135] Summary of comparison results:

[0136]

[0137] This comparative example directly proves that the dual-layer time-response dry film photoresist of the present invention releases thermal stress through the flexible creep mechanism of the interface layer, which solves the fundamental technical defects of the existing single-layer homogeneous photoresist in the high-temperature sintering process of ceramic substrates, such as interface peeling, pattern deformation, and large deviation of line resistance. The technical contribution of the core invention point has been fully verified.

[0138] Comparative Example 2

[0139] This comparative example is used to verify the necessity of the thermal response secondary crosslinking mechanism of BIC-DMP, and to rule out whether the design requirements can be met by relying solely on a low crosslinking density interface layer without the need for secondary crosslinking locking.

[0140] The interface coating formulation for Comparative Example 2 was: OSiER-L 78wt%, ZrMA 8wt%, dibutyltin dilaurate 0.5wt%, with the balance being a mixed solvent of ethyl acetate and propylene glycol methyl ether acetate in a 7:3 mass ratio. It did not contain BIC-DMP, and the amount of OSiER-L was increased accordingly to maintain overall formulation balance. The imaging layer coating formulation was the same as in Example 1, and all other preparation parameters were identical to those in Example 1.

[0141] The performance test results are as follows:

[0142] Adhesion rating: 5B, peel strength 3.4 N / cm (similar to Example 1, indicating that the ZrMA anchoring effect is not affected by the presence or absence of BIC-DMP).

[0143] At 25°C, G': The interface layer G' of Comparative Example 2 is 0.21 MPa, which is in the same flexibility range as that of Example 1 of the present invention (0.38 MPa), and its normal flexibility is comparable.

[0144] At 170℃, G': The interface layer G' of Comparative Example 2 is only 0.23MPa (without BIC-DMP, without secondary crosslinking, the interface layer always maintains a low modulus and flexible state, and cannot complete rigid locking during the sintering and heat preservation stage), while G' of Example 1 of this invention is 68MPa.

[0145] Line width deviation after sintering: Comparative Example 2 ΔCD=2.8μm (the interface layer undergoes creep displacement due to lack of locking during the sintering cooling shrinkage stage, resulting in pattern drift), Example 1 of the present invention ΔCD=0.3μm.

[0146] Line resistance deviation: Comparative Example 2 has a deviation of 8.7%, which does not meet the design requirement of <5%; Example 1 of the present invention has a deviation of 2.8%, which meets the design requirement.

[0147] Graphic integrity: Comparative Example 2 shows obvious line width drift, while Embodiment 1 of the present invention has no warping or cracking.

[0148] Summary of comparison results:

[0149]

[0150] This comparative example demonstrates that the thermally responsive secondary crosslinking mechanism of BIC-DMP is a core and essential technical feature of the time-response design of this invention. While the interface layer lacking BIC-DMP can release thermal stress during the heating stage (adhesion still reaches 5B), it cannot achieve rigid locking during the sintering and holding stage, leading to pattern drift under high-temperature creep, excessive line resistance deviation, and failure to meet design requirements. BIC-DMP is indispensable.

[0151] Figure 3This is a schematic diagram illustrating the effect of the amount of ZrMA used in the imaging layer on the adhesion of the alumina substrate and the deviation of the line resistance after sintering in the embodiments of this application. Figure 3 The data consists of two sub-figures. The left figure shows the peel strength of ZrMA on the alumina substrate when the ZrMA dosage is 10wt% (lower limit), 12wt% (median), and 14wt% (upper limit). All three groups achieve an adhesion rating of 5B. The peel strength increases monotonically from 3.0 N / cm to 3.9 N / cm with increasing ZrMA dosage. The right figure shows the corresponding post-sintering line resistance deviation. The three values ​​are 3.2%, 2.8%, and 2.5%, respectively, all below the design upper limit of 5%, and showing a monotonically decreasing trend with increasing ZrMA dosage. The above data verify the rationality of the ZrMA range of 10wt% to 14wt% in the imaging layer, and the positive contribution of ZrMA to the final pattern accuracy by strengthening the interface anchorage through zirconium-aluminum coordination bonds.

[0152] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications 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.

Claims

1. A dry film photoresist for high-temperature resistant ceramic substrates, characterized in that: This includes an interface layer and an imaging layer sequentially composited onto a polyethylene terephthalate (PET) carrier film; The interface layer is prepared by casting and drying an interface layer coating solution, which comprises the following components by mass percentage: low crosslinking density silicone-modified epoxy resin OSiER-L 55wt%–68wt%, blocked isocyanate BIC-DMP 12wt%–20wt%, zirconium methacrylate chelate ZrMA 5wt%–9wt%, dibutyltin dilaurate 0.3wt%–0.7wt%, and the balance being a mixed solvent of ethyl acetate and propylene glycol methyl ether acetate in a mass ratio of 7:3; wherein the silicone-modified epoxy resin OSiER is obtained by reacting bisphenol A type epoxy resin with methoxy-terminated polydimethylsiloxane intermediate. The epoxy resin is prepared by polycondensation, wherein the amount of the methoxy-terminated polydimethylsiloxane intermediate is 30%–40% of the mass of the bisphenol A epoxy resin; the low crosslinking density organosilicon modified epoxy resin OSiER-L is prepared by polycondensation of bisphenol A epoxy resin and the methoxy-terminated polydimethylsiloxane intermediate, wherein the amount of the methoxy-terminated polydimethylsiloxane intermediate is 18%–22% of the mass of the bisphenol A epoxy resin; the blocked isocyanate BIC-DMP is prepared by end-capping hexamethylene diisocyanate trimer with 3,5-dimethylpyrazole; and the zirconium methacrylate chelate ZrMA is prepared by reacting zirconium n-propoxide with methacrylic acid. The imaging layer is prepared by casting and drying an imaging layer coating solution, which comprises the following components by mass percentage: silicone-modified epoxy resin OSiER 52wt%–63wt%, zirconium methacrylate chelate ZrMA 10wt%–14wt%, diphenyliodonium hexafluorophosphate 2wt%–5wt%, trimethylolpropane triacrylate 8wt%–13wt%, 9-anthracene methanol 1wt%–3wt%, and the balance being propylene glycol methyl ether acetate; After the interface layer is cast and dried to form a film, the energy storage modulus G' is 0.20-0.50 MPa at 25°C, and G' jumps to more than 50 MPa when the temperature rises to 160-170°C; after the imaging layer is cured, the weight loss rate is <3% under a nitrogen atmosphere at 350°C.

2. The dry film photoresist as described in claim 1, characterized in that: The peak intensity ratio of the Si-O-Si characteristic absorption peak to the benzene ring skeleton characteristic absorption peak of the obtained OSiER is I(Si-O-Si) / I(Ph)≥1.35, and the epoxy equivalent is 1100~1300g / eq.

3. The dry film photoresist as described in claim 1, characterized in that: The obtained OSiER-L has a melt viscosity of 800–1200 mPa·s at 175 °C.

4. The dry film photoresist as described in claim 1, characterized in that: The molar ratio of 3,5-dimethylpyrazole to isocyanate groups is 1.03:1.0 to 1.07:1.0, and the reaction proceeds until... When the area of ​​the -NCO characteristic peak is less than 2% of the initial value, the sealing is considered complete. The unsealing temperature determined by differential scanning calorimetry using BIC-DMP is 150℃~160℃.

5. The dry film photoresist as described in claim 1, characterized in that: The molar ratio of methacrylic acid to zirconium is 2.8:1.0 to 3.2:1.0, and the zirconium content in the resulting ZrMA bulk is 24.0 wt% to 27.0 wt%. The hydrodynamic radius of ZrMA in propylene glycol methyl ether acetate is 1.2 to 2.5 nm.

6. The dry film photoresist as described in claim 1, characterized in that: The purity of the diphenyliodonium hexafluorophosphate is ≥98%; the functionality of the trimethylolpropane triacrylate is 3 and the molecular weight is 296 g / mol.

7. The dry film photoresist as described in claim 1, characterized in that: A gradient transition region with a thickness of 0.5–1.2 μm exists between the interface layer and the imaging layer. This gradient transition region is formed by the mutual penetration of the interface layer coating and the imaging layer coating during the wet contact stage. The small-angle X-ray scattering characteristic scattering peak half-width of the gradient transition region is... The interface layer dry film thickness is 7.5–8.5 μm, and the imaging layer dry film thickness is 19.0–21.0 μm.

8. The dry film photoresist as described in claim 7, characterized in that: The dry film photoresist is exposed to a 365nm line light source. After exposure and development with a 0.26 mol / L tetramethylammonium hydroxide aqueous solution, in The linewidth of the pattern formed on the alumina substrate with a content of ≥96% is 10±0.5μm, and the line edge roughness measured by scanning electron microscopy is ≤0.8μm; the adhesion grade of the dry film photoresist to the alumina substrate is 5B as determined by the cross-cut adhesion test method ASTM D3359.

9. A method for preparing a dry film photoresist for a high-temperature resistant ceramic substrate as described in any one of claims 1-8, characterized in that, Includes the following steps: Step 1: Preparation of OSiER, an organosilicon-modified epoxy resin for the imaging layer: 100 parts by weight of bisphenol A type epoxy resin and 30-40 parts by weight of methoxy-terminated polydimethylsiloxane intermediate are polycondensed at 170°C with a stirring rate of 200-300 rpm under nitrogen atmosphere and catalysis of 0.10-0.20 parts by weight of p-toluenesulfonic acid. The temperature is increased to 170°C at a stirring rate of 2°C / min until the melt viscosity reaches 2500-3500 mPa·s at 175°C. The process is then terminated by cooling the temperature to below 140°C to obtain OSiER. Step 2: Preparation of low crosslinking density organosilicon modified epoxy resin OSiER-L for the interface layer: 100 parts by weight of bisphenol A type epoxy resin and 18-22 parts by weight of methoxy-terminated polydimethylsiloxane intermediate were polycondensed at 170°C with a stirring rate of 2°C / min under nitrogen atmosphere protection and stirring rate of 200-300 rpm. Polycondensation was terminated when the melt viscosity reached 800-1200 mPa·s at 175°C and the temperature was lowered to below 140°C to obtain OSiER-L. Step 3, preparation of zirconium methacrylate (ZrMA): 100 parts by mass of zirconium n-propoxide were dissolved in 150 parts by mass of anhydrous ethanol. Under nitrogen protection, 79-81 parts by mass of methacrylic acid were added dropwise at a dropping rate of 0.8-1.2 mL / min. The system temperature was controlled at 20-25℃ using an external ice-water bath. The reaction was stirred for 4 hours. Ethanol and n-propanol were removed by vacuum distillation at 50℃ and 0.08 MPa to obtain the bulk ZrMA. The bulk ZrMA was dissolved in propylene glycol methyl ether acetate to prepare a 30 wt% stock solution for later use. Step 4, Preparation of Blocked Isocyanate BIC-DMP: Dissolve 100 parts by weight of hexamethylene diisocyanate trimer in 80 parts by weight of N-methylpyrrolidone, and add 52-55 parts by weight of 3,5-dimethylpyrazole dropwise at a dropping rate of 0.5-0.7 mL / min under nitrogen protection at 60°C. React at 60°C for 3 hours. When the area of ​​the -NCO characteristic peak is less than 2% of the initial value, BIC-DMP is obtained. Step 5, prepare the imaging layer coating solution: Weigh the OSiER obtained in Step 1, the ZrMA stock solution obtained in Step 3, diphenyliodonium hexafluorophosphate, trimethylolpropane triacrylate and 9-anthracene methanol according to the mass percentage of each solid component of the imaging layer. Dissolve OSiER in propylene glycol methyl ether acetate to prepare a solution with a solid content of 40 wt%. Then add the remaining solid components in sequence, stirring for no less than 10 min after each addition. After stirring evenly in the dark, filter through a 0.2 μm polytetrafluoroethylene membrane to obtain the imaging layer coating solution. Step 6, prepare the interface coating solution: Weigh the OSiER-L obtained in Step 2, the BIC-DMP obtained in Step 4, the ZrMA stock solution obtained in Step 3, and dibutyltin dilaurate according to the mass percentage of each solid component of the interface layer. Dissolve OSiER-L in a mixed solvent of ethyl acetate and propylene glycol methyl ether acetate in a mass ratio of 7:3 to prepare a solution with a solid content of 35wt%. Then add the remaining solid components in sequence, stirring for no less than 10 minutes after each addition. After stirring in the dark for 30 minutes, filter through a 0.45μm polytetrafluoroethylene membrane to obtain the interface coating solution. Step 7, Double-layer co-casting film formation: The interface layer coating liquid obtained in Step 6 is cast onto a polyethylene terephthalate carrier film with a surface tension ≥52mN / m and a thickness of 25μm after corona treatment, with a die lip gap of 110-130μm and a casting rate of 2.0m / min. After drying in three stages at 60℃ / 2min, 80℃ / 3min, and 100℃ / 2min, an interface layer with a thickness of 8.0±0.5μm is obtained. The imaging layer coating liquid obtained in Step 5 is cast onto the surface of the interface layer with a die lip gap of 190-210μm and the same casting rate. The wet contact time between the two layers is controlled to be 5-10s. After drying in three stages at 70℃ / 2min, 90℃ / 3min, and 110℃ / 3min, an imaging layer with a thickness of 20.0±1.0μm is obtained. A polyethylene protective film is then attached to the surface of the imaging layer and wound into a roller.

10. The preparation method according to claim 9, characterized in that: The surface tension of the polyethylene terephthalate carrier film described in step seven, after corona treatment, is confirmed by a wetting tension tester to be ≥52mN / m; the imaging layer coating solution obtained in step five is stored at 4℃ under light-proof and sealed conditions, with a shelf life of 90 days; the interface layer coating solution obtained in step six is ​​stored at 20℃ under light-proof and sealed conditions, with a shelf life of 60 days; the dry film photoresist product is stored at 20℃ and 40% relative humidity under sealed conditions, with a shelf life of 180 days.

Images