A resin composition and use thereof

Abstract

The application provides a resin composition and application thereof. The composition comprises a photosensitive resin, polycarbodiimide and a photoinitiator, wherein the photosensitive resin contains carboxyl and carbon-carbon double bond in the molecular structure, the polycarbodiimide is a polymer containing carbodiimide groups, and the resin composition has an exothermic peak temperature greater than 90 DEG C measured by differential scanning calorimetry. At a temperature not higher than 90 DEG C, the reactivity of the polycarbodiimide in the composition is low, and the polycarbodiimide hardly reacts with the photosensitive resin to crosslink, so that the photosensitive dry film formed by baking the composition can have good developability, and the cured product has good heat resistance and reflow soldering resistance, low dielectricity, and is suitable for manufacturing a high-reliability patterned coating through a negative patterning process.

Description

Technical Field

[0001] This application relates to the field of photosensitive materials technology, specifically to a resin composition and its application. Background Technology

[0002] In the field of electronic packaging, patterned solder resist ink layers are typically fabricated on the packaging substrate to selectively mask the surface copper layer, thereby protecting non-soldered areas and improving electrical insulation reliability. With the increasing trend towards thinner and higher-performance electronic devices in recent years, the requirements for patterned solder resist ink layers have become increasingly stringent, such as requiring low dielectric properties and a good film appearance.

[0003] Patterned solder resist ink layers are typically formed using a negative patterning process. Therefore, it is necessary to provide a photosensitive resin composition suitable for fabricating patterned solder resist ink layers using a negative patterning process, ensuring that the cured product exhibits characteristics such as low dielectric properties and high quality reliability. Summary of the Invention

[0004] Therefore, embodiments of this application provide a resin composition suitable for negative patterning processes, and ensure that the patterned film layer produced by it has characteristics such as low dielectric properties and excellent appearance.

[0005] The first aspect of this application provides a resin composition comprising a photosensitive resin, polycarbodiimide, and a photoinitiator, wherein the molecular structure of the photosensitive resin contains carboxyl groups and carbon-carbon double bonds, the polycarbodiimide is a polymer having carbodiimide groups, and the peak temperature of the exothermic peak of the resin composition, as measured by differential scanning calorimetry, is greater than 90°C.

[0006] The above-mentioned resin composition contains a carboxyl-containing photosensitive resin suitable for negative patterning systems, and also introduces polycarbodiimide with carbodiimide groups. This ensures that the photosensitive dry film formed by the resin composition has a good appearance and few surface defects. The cured photosensitive dry film has low dielectric properties and high electrical insulation reliability. At the same time, the exothermic peak temperature of the overall composition is controlled to be higher than 90°C. This indicates that the introduced polycarbodiimide has low reactivity below 90°C, and the carbodiimide groups therein do not react with the carboxyl groups in the photosensitive resin at temperatures below 90°C. This ensures that the resin composition and the photosensitive film formed by drying at temperatures below 90°C both have excellent developability and room temperature storage stability, which can meet the requirements for producing patterned solder resist ink layers based on negative patterning processes.

[0007] In this embodiment, the peak temperature of the exothermic peak of the resin composition, measured by differential scanning calorimetry, is within the range of 100-150°C. This ensures that during the low-temperature baking process of the resin composition, the polycarbodiimide does not react with the photosensitive resin, guaranteeing good subsequent developability. Furthermore, during the thermosetting process of the composition, the two can undergo a sufficient cross-linking reaction, thereby increasing the cross-linking density and heat resistance of the cured product.

[0008] In this embodiment, the content of carbodiimide groups in the polycarbodiimide per mol of molecular structure is 4-30 mol. This ensures that the reaction between the polycarbodiimide and the acid-sensitive photosensitive resin is sufficiently suppressed below 90°C, guaranteeing good subsequent exposure and developability. It also ensures that the cured product formed by the complete curing of the resin composition at higher temperatures has sufficient crosslinking density and heat resistance.

[0009] In this embodiment, the weight-average molecular weight of the polycarbodiimide is 800-9000. By controlling the molecular weight of the polycarbodiimide, the reactivity between components in the resin composition containing it can be kept low below 90°C, while the cured product exhibits good heat resistance, reflow soldering resistance, and flexibility.

[0010] In this embodiment of the application, the polycarbodiimide includes the structure shown in formula (I):

[0011] Formula (I)

[0012] In formula (I), A and D are independently selected from one or more of substituted or unsubstituted alkylene, substituted or unsubstituted cycloalkylene, and substituted or unsubstituted arylene, and p is in the range of 2-15; Q represents the end-capping group that closes the NCO group.

[0013] The degree of polymerization of the repeating unit containing two carbodiimide groups in the above-mentioned polycarbodiimide is in the range of 2-15, which can ensure that the carbodiimide groups in the polymer have low reactivity below 90°C. This makes it suitable for use in resin compositions for negative patterning systems with carboxyl-containing photosensitive resins, ensuring its low-temperature stability and developability after exposure to light.

[0014] In this embodiment, when p is in the range of 2-4, Q contains an aromatic ring structure; when p is in the range of 5-15, Q contains one or more of an aromatic ring structure, an aliphatic ring structure, and an aliphatic chain structure. This control of the end-capping groups based on the degree of polymerization of the polycarbodiimide better ensures that the carbodiimide groups in the polycarbodiimide have low low-temperature reactivity below 90°C, resulting in good developability of the above composition, and also good heat resistance and solderability of its cured product.

[0015] In this embodiment, the photosensitive resin has a weight-average molecular weight of 3000-20000 and an acid value of 50-120 mgKOH / g. Using a photosensitive resin with these properties in the above resin composition ensures high photopolymerization activity, while also ensuring a suitable dissolution rate of the unexposed portion of the dried film in the alkaline developer.

[0016] In this embodiment, the molar amount of carbodiimide groups in the polycarbodiimide is 0.2-1.5 times the molar amount of carboxyl groups in the photosensitive resin. This ensures high storage stability of the resin composition while also providing excellent flexibility and heat resistance in the cured product.

[0017] In some embodiments of this application, the resin composition further includes an epoxy resin. During the thermosetting process of the composition (typically around 150°C), the epoxy resin can undergo a crosslinking reaction with the carboxyl groups in the photosensitive resin and the carbodiimide groups in the polycarbodiimide, thereby increasing the crosslinking density of the cured composition, which in turn improves its heat resistance and solderability, and also helps to reduce the dielectric constant and dielectric loss factor.

[0018] In some embodiments of this application, the resin composition further includes a colorant; wherein the colorant includes one or more pigments and dyes. The polycarbodiimide contained in the resin composition can improve the compatibility of the colorant in the composition system, ensuring that the photosensitive dry film and cured product formed by the resin composition have a smooth appearance with few defects.

[0019] A second aspect of this application provides a film material, including a photosensitive film, which is formed by drying a resin composition as described in the first aspect of this application.

[0020] In some embodiments of this application, the film material may further include a support and a protective film, with the photosensitive film and the protective film sequentially stacked on the support. That is, the film material is typically a three-layer film structure. In use, the protective film generally needs to be removed first, and only the cured photosensitive film remains in the final product.

[0021] The third aspect of this application provides the application of the resin composition as described in the first aspect of this application, or the film material as described in the first aspect of this application, in the preparation of printed circuit boards and the packaging of electronic components.

[0022] In some embodiments of this application, the application may specifically be a patterned solder resist ink layer on a substrate for manufacturing printed circuit boards or packaging electronic components. This patterned solder resist ink layer may possess good heat resistance, reflow soldering resistance, acid and alkali resistance, low dielectric constant, and high adhesion to conductor layers such as copper layers, resulting in high reliability of the printed circuit board or packaging structure.

[0023] A fourth aspect of this application provides a packaging carrier board, which includes a substrate with a conductor layer on its surface. A patterned solder resist ink layer is disposed on the conductor layer. The patterned solder resist ink layer includes a cured product of the resin composition described in the first aspect of this application. The cured product of this resin composition has good heat resistance, reflow soldering resistance, acid and alkali resistance, flexibility, high copper adhesion, and low dielectric properties. It can provide good solder resist and insulation effects on the substrate with the conductor layer, resulting in high reliability and thus improving the packaging effect of the packaging carrier board.

[0024] A fifth aspect of this application provides a sealed package comprising a cured resin composition as described in the first aspect of this application, or a packaging carrier as described in the fourth aspect of this application.

[0025] In this embodiment, the sealed packaging includes the packaging substrate and electronic components disposed on the packaging substrate, wherein the electronic components are disposed on a patterned solder resist layer in the packaging substrate. These electronic components can be one or more of the following: chips, transistors, resistive, capacitive, and inductive components.

[0026] A sixth aspect of this application provides an electronic device including a circuit board and a sealed package as described in the fifth aspect of this application, disposed on the circuit board. This electronic device includes the aforementioned highly reliable sealed package, which improves the stability of the electronic device in use. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of a structure of a sealed package 100 provided in an embodiment of this application.

[0028] Figure 2 This is a schematic diagram of the structure of the membrane material 200 provided in the embodiments of this application.

[0029] Figure 3 for Figure 1 A schematic diagram of the structure after the sealed package 100 is connected to the circuit board.

[0030] Figure 4 This is a schematic diagram of the structure of the electronic device 300 provided in an embodiment of this application.

[0031] Figure 5 This is a DSC curve of the photosensitive resin composition of Example 3 of this application.

[0032] Figure 6 This is a DSC curve of the photosensitive resin composition of Example 6 of this application. Detailed Implementation

[0033] The technical solution of this application will be described below with reference to the accompanying drawings in the embodiments of this application.

[0034] Please see Figure 1 , Figure 1 This is a schematic diagram of a sealed package 100 provided in an embodiment of this application. The sealed package 100 includes a package carrier 10 and electronic components 20 disposed on the package carrier 10. The side of the package carrier 10 facing the electronic components 20 may have multiple solder bumps 13 (e.g., gold bumps), and the electronic components 20 can be attached to the package carrier 10 by remelting the solder bumps 13. The electronic components 20 may be one or more of the following: chips, transistors (such as diodes, triodes), LEDs (Light Emitting Diodes), and resistive-capacitive-inductive components (such as resistors, capacitors, inductors). In some embodiments, the side of the package carrier 10 away from the electronic components 20 may have multiple solder balls 14 (such as solder balls) arranged in an array. The solder balls 14 are used to achieve subsequent electrical connections between the package carrier 10 and the circuit board (e.g.,...). Figure 3 (As shown). It can be... Figure 1 The sealed package 100 in the package is called a DGA (Dall Grid Array) package.

[0035] A patterned solder resist ink layer 12 is formed on the packaging substrate 10. Figure 1 The example shown uses a packaging carrier 10 with patterned solder resist ink layers 12 on both opposite surfaces. The packaging carrier 10 includes a substrate 11 with a conductor layer on its surface. Figure 1 The example illustrates that both opposite surfaces of substrate 11 are provided with conductor layers (specifically copper layers, designated 101 and 102, respectively) bearing circuit patterns, and patterned solder resist layers 12 are specifically disposed on conductor layers 101 and 102. In some embodiments, Figure 1 The substrate 11 with a conductor layer on its middle surface can specifically be a copper-clad laminate with a circuit pattern. The patterned solder resist layer 12 does not completely cover the conductor layer; generally, the areas on the substrate 11 with the conductor layer that are to be electrically connected to other conductive components are not covered. Figure 1 In the middle, the solder bumps 13 and solder balls 14 are exposed from the patterned solder resist ink layer 12 to enable subsequent electrical connection with electronic components 20 and the circuit board. The patterned solder resist ink layer 12 can be a cured product of the resin composition provided in the embodiments of this application.

[0036] Specifically, the resin composition provided in this application includes: a photosensitive resin, polycarbodiimide, and a photoinitiator. The photosensitive resin contains a carboxyl group (-COOH) and a carbon-carbon double bond in its molecular structure. The polycarbodiimide is a polymer with unprotected carbodiimide groups (i.e., -N=C=N-). The exothermic peak temperature of the resin composition, measured by differential scanning calorimetry (DSC), is greater than 90°C. It should be noted that because the resin composition of this application contains a photosensitive resin, it can be referred to as a "photosensitive resin composition."

[0037] The above-mentioned resin composition contains a carboxyl-containing photosensitive resin for negative patterning systems, and also introduces polycarbodiimide with carbodiimide groups. This ensures that the photosensitive dry film formed by the resin composition has a good appearance and few surface defects. The cured photosensitive dry film has low dielectric properties, as well as good heat resistance, reflow soldering resistance, and acid and alkali resistance. Furthermore, based on the strong interaction between the carbodiimide groups and conductor layers such as copper layers, the reliability of the above-mentioned resin composition in the field of electronic packaging is also guaranteed. More importantly, the exothermic peak temperature of the DSC curve of the above resin composition is greater than 90°C, which indicates that the introduced polycarbodiimide has low reactivity below 90°C (the baking temperature commonly used to bake the resin composition into a dry film is generally 60-80°C). The carbodiimide groups hardly react with the carboxyl groups in the photosensitive resin. Therefore, the above resin composition has excellent room temperature storage stability. Even if the composition is baked into a photosensitive dry film at the above baking temperature, the photosensitive dry film also has good storage stability. The reaction between polycarbodiimide and carboxyl groups is also suppressed, ensuring that the dry film has high development resolution, which can meet the needs of producing patterned solder resist ink layers based on negative patterning processes.

[0038] In this application, the DSC curve of the above-mentioned resin composition can be a DSC curve obtained under atmospheric conditions at a heating rate of 10°C / min. The peak temperature of its exothermic peak can be obtained based on this DSC curve. The horizontal axis of the DSC curve represents temperature in °C, and the vertical axis represents heat flux in mW / mg. The DSC curve of the above-mentioned resin composition may have more than one exothermic peak, but the peak temperature of the first exothermic peak with the lowest peak temperature is greater than 90°C.

[0039] In this application, the exothermic peak intensity of the resin composition is greater than 0.1 mW / mg. This peak intensity is also the absolute value of the difference between the heat flux value corresponding to the peak temperature of the exothermic peak and the baseline of the DSC curve of the resin composition (i.e., the heat flux corresponding to the lowest point). This eliminates small exothermic peaks generated by small molecules or water vapor evaporation during DSC testing. That is, this application has an exothermic peak with a peak temperature greater than 90°C and a peak intensity greater than 0.1 mW / mg. Below 90°C, no exothermic peaks with a peak intensity greater than 0.1 mW / mg are observed in the DSC curve of the above-mentioned resin composition.

[0040] Polymers with unprotected carbodiimide groups have been reported for use in resin compositions for positive patterning systems, but they are rarely used directly in negative patterning systems. This is mainly because compositions used in negative patterning systems often contain unsaturated photosensitive resins with carboxyl groups, which readily undergo cross-linking reactions with carbodiimide groups at room temperature and below common baking temperatures, significantly affecting the storage stability and subsequent developability of the composition. In the embodiments of this application, the content of unprotected carbodiimide groups in the polycarbodiimide with controlled unit mol (i.e., 1 mol) molecular structure is 4-30 mol. This approach ensures that the reaction between polycarbodiimide and carboxyl groups is sufficiently suppressed during the storage of the resin composition at room temperature or during its drying process to form a photosensitive dry film, guaranteeing that the exothermic peak temperature of the resin composition is greater than 90°C. This prevents subsequent exposure and developability from being affected. Furthermore, it ensures that when the photosensitive dry film is fully cured at higher temperatures, sufficient carbodiimide groups can undergo cross-linking reactions with the carboxyl groups in the photosensitive resin, increasing the cross-linking density of the cured product. This significantly improves the heat resistance and mechanical properties of the cured product (the polymer chains formed after the reaction of carbodiimide and carboxyl groups exhibit good flexibility) and guarantees excellent low dielectric properties. Moreover, based on the strong interaction between carbodiimide groups and conductor layers such as copper layers, and by controlling the content of carbodiimide groups in polycarbodiimide within the aforementioned range, the bonding force between the cured resin composition and the conductor layer is strong, thus ensuring the reliability of the composition in electronic packaging applications. Therefore, the above-mentioned condition control solves the problems of carbodiimide-containing substances being unsuitable for photosensitive resin compositions used in negative lithography systems and the difficulty in guaranteeing the development resolution of the composition.

[0041] Specifically, the content of carbodiimide groups in a unit mol of polycarbodiimide can be 4 mol, 5 mol, 6 mol, 8 mol, 10 mol, 12 mol, 15 mol, 16 mol, 18 mol, 20 mol, 22 mol, 25 mol, 26 mol, 28 mol, 30 mol, etc. In some embodiments of this application, the content of carbodiimide groups in a unit mol of polycarbodiimide is 6-20 mol, and more specifically, 8-16 mol. This better ensures that polycarbodiimide has essentially no reactivity below 90°C, resulting in better storability and subsequent developability of the above resin composition. Regarding the "content of carbodiimide groups in 1 mol of polycarbodiimide," the molar number of polycarbodiimide molecules can be obtained by the ratio of its mass to its weight-average molecular weight. The molar number of carbodiimide groups can be obtained by reverse monitoring of the groups that react with it, thus determining the molar amount of carbodiimide groups in a unit mol of polycarbodiimide.

[0042] Furthermore, regarding the aforementioned "the content of carbodiimide groups in 1 mol of polycarbodiimide is 4-30 mol", in other words, the degree of polymerization of the carbodiimide groups in the polycarbodiimide is 4-30. In the embodiments of this application, when the polycarbodiimide has a repeating unit containing one carbodiimide group (-N=C=N-), the degree of polymerization of the repeating unit is 4-30, and can further be 6-20, 8-16, etc.; when the repeating unit of the polycarbodiimide contains two carbodiimide groups (-N=C=N-), the degree of polymerization of the repeating unit is in the range of 2-15, for example, specifically 2.5, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 14.5, etc., and can further be in the range of 3-10, or in the range of 4-8. Controlling the degree of polymerization of the carbodiimide group within this range is beneficial for reducing the reactivity of the carbodiimide group in polycarbodiimide below 90°C, thereby ensuring its stability below common baking temperatures.

[0043] In some embodiments of this application, the peak temperature of the exothermic peak of the above-mentioned resin composition, measured by DSC, is greater than or equal to 95°C, and may further be greater than or equal to 100°C. This indicates that at temperatures below 95°C or even below 100°C, the polycarbodiimide does not react with the carboxyl groups in the photosensitive resin to generate heat. When the above-mentioned resin composition is baked to form a dry film, the reaction of polycarbodiimide is sufficiently suppressed. This facilitates the subsequent exposure treatment of the dry film, resulting in high solubility of the unexposed area in the alkaline developer and good developer resistance of the exposed area, thereby obtaining the desired pattern with high developing resolution.

[0044] In some embodiments of this application, to balance the good developability of the unexposed area of ​​the dry film of the resin composition with the crosslinking density of the fully cured resin composition, the peak temperature of the exothermic peak of the resin composition, measured by DSC, is in the range of 100-200°C, for example, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, etc. This ensures that the polycarbodiimide does not react with the photosensitive resin during the low-temperature baking process of the resin composition, resulting in good developability. However, during the thermal curing process of the composition, the two can undergo sufficient crosslinking reaction, thereby increasing the crosslinking density and heat resistance of the cured product. In some embodiments, the peak temperature of the exothermic peak of the resin composition is between 110-160°C.

[0045] In this application, the peak temperature of the DSC exothermic peak of the above-mentioned resin composition is greater than 90°C, greater than or equal to 95°C, etc., which can be achieved by controlling parameters including "the content of carbodiimide groups in polycarbodiimide with a molecular structure of 4-30 mol". For example, only "the content of carbodiimide groups in polycarbodiimide with a molecular structure of 4-30 mol" can be controlled, or it can be achieved based on the content of carbodiimide groups in polycarbodiimide with a molecular structure of 4-30 mol and the control of the end capping groups of the polycarbodiimide.

[0046] In the embodiments of this application, the starting temperature of each exothermic peak in the DSC curve of the above-mentioned resin composition is greater than or equal to 85°C, greater than or equal to 90°C, greater than or equal to 95°C, or even greater than or equal to 100°C. This results in higher peak temperatures for each exothermic peak, necessarily greater than 90°C, to better ensure the storage stability and good developability of the resin composition.

[0047] In this embodiment, the weight-average molecular weight (Mw) of the polycarbodiimide is 800-9000. This helps ensure that the reactivity between components in the negative resin composition containing the polycarbodiimide is low below common baking temperatures, and also ensures that the cured composition has both good flexibility and heat resistance, especially enhancing the reflow solderability of the copper layer it covers, making it less prone to softening and deformation. In some embodiments, the weight-average molecular weight (Mw) of the polycarbodiimide is 1000-4000, and more specifically, 1500-3500, or 1800-3500, etc. Here, the weight-average molecular weight refers to the value converted from polystyrene by gel permeation chromatography (GPC).

[0048] In this embodiment of the application, the polycarbodiimide includes the structure shown in formula (I):

[0049] Formula (I)

[0050] In formula (I), A and D are independently selected from one or more of substituted or unsubstituted alkylene groups, substituted or unsubstituted cycloalkylene groups, and substituted or unsubstituted arylene groups, with p in the range of 2-15; Q represents the end-capping group blocking the NCO group. Polycarbodiimide is prepared by the polycondensation reaction of diisocyanate.

[0051] The substituted or unsubstituted alkylene groups have 1-20 carbon atoms, more preferably 1-10, such as 1-6 or 1-4, and can be straight-chain or branched. For example, unsubstituted alkylene groups can be methylene (-CH2-), ethylene (-CH2CH2-), propylene (-CH2CH2CH2-), n-butylene (-(CH2)4-), n-pentylene (-(CH2)5-), n-hexylene (-(CH2)6-, also known as hexamethylene), etc. The substituted or unsubstituted cycloalkylene groups have 4-20 carbon atoms, more preferably 6-20, 4-15, etc. For example, unsubstituted cycloalkylene groups can be cyclobutylene, cyclobutylene, cyclopentylene, cyclohexylene, etc. The substituted or unsubstituted arylene groups have 6-20 carbon atoms, such as 6-15, 6-10, etc. For example, the unsubstituted arylene can be phenylene, naphthylene, etc. The substituents in the substituted alkylene can be one or more of a halogen atom, a substituted or unsubstituted aryl group, an alkoxy group, etc. The substituents in the substituted cycloalkylene and substituted arylene can be independently selected from one or more of a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, and a substituted or unsubstituted aryl group.

[0052] In some embodiments of this application, A and D are independently selected from one or more of substituted or unsubstituted cycloalkylene groups and substituted or unsubstituted arylene groups. In this case, the structure of A and D has greater rigidity, which is more conducive to improving the heat resistance of the aforementioned polycarbodiimide. Furthermore, when A and D are selected from two or more of substituted or unsubstituted alkylene groups, substituted or unsubstituted cycloalkylene groups, and substituted or unsubstituted arylene groups, they can be linked by chemical bonds (such as connecting single bonds). In some embodiments, A and D are alkylene groups containing at least one of substituted or unsubstituted cycloalkylene groups and substituted or unsubstituted arylene groups.

[0053] In formula (I) of this application, p represents the degree of polymerization of the aforementioned polycarbodiimide, specifically the degree of polymerization of the repeating units containing two carbodiimide groups. p is in the range of 2-15, specifically 2, 2.5, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15. In some embodiments, p is 3-10, further 4-8. This is more conducive to the lower reactivity of the aforementioned polycarbodiimide below common baking temperatures (e.g., 60-80°C, 80°C being a common upper limit for baking temperatures), avoiding its reaction with carboxyl-containing photosensitive resins in the system during room temperature storage and before baking to form a film, thus affecting storage stability and subsequent developability. Based on the range of p, it can be known that the number of carbodiimide groups (-N=C=N-) contained in one molecule of polycarbodiimide is 4-30, further 6-20 or 8-16, etc.

[0054] In this application, Q is a residue generated after a substance capable of reacting with an isocyanate group (-NCO) (i.e., a capping agent) reacts with the -NCO terminal of a polycarbodiimide. In some embodiments of this application, when p is in the range of 2-4, the capping group Q contains an aromatic ring structure. In this case, Q has greater steric hindrance (i.e., a sterically hindrance-prone capping agent is used for sealing), which can better reduce the low-temperature reactivity of the polycarbodiimide with lower p, ensuring good developability of the above resin composition. The aromatic ring structure can be one or more of substituted or unsubstituted benzene rings, naphthyl rings, anthracene rings, binatidine rings, biphenyls, etc. In this case, the capping agent corresponding to Q can be one or more of phenols (such as phenol, naphthol, etc.), monobasic aromatic alcohols, monobasic aromatic amines, aromatic monoisocyanates, acids containing aromatic ring structures, etc. Exemplarily, phenols can include one or more of phenol, naphthol, anthraquinone, binatol, p-fluorobiphenyl, p-cyanotriphenylphenol, etc. Aromatic monoisocyanates can be one or more of phenyl isocyanates, toluene isocyanates, dimethyl phenyl isocyanates, 2,6-diisopropyl phenyl isocyanates, etc.

[0055] In other embodiments of this application, when p is an integer from 5 to 15, the end-capping group Q may contain one or more of an aromatic ring structure, an aliphatic ring structure, and an aliphatic chain structure. When p is within this range, the end-capping group Q of the polycarbodiimide does not necessarily need to contain a sterically hindered aromatic ring structure; the low reactivity of the polycarbodiimide below 90°C can be ensured simply by controlling p. In this case, the end-capping agent corresponding to Q may include, but is not limited to, phenols (such as phenol and naphthol), monohydric alcohols (such as monohydric fatty alcohols and monohydric aromatic alcohols), monoamines (monohydric fatty amines or monohydric aromatic amines, which may be primary or secondary amines), monoisocyanates (alicyclic monoisocyanates, alkyl monoisocyanates, aromatic monoisocyanates), acids, acid anhydrides, and silane coupling agents containing at least one of -OH, -NH2, -COOH, and epoxy groups.

[0056] The -Q mentioned above can be represented by -k-Q', where Q' represents the parent compound of the end-capping agent after removing one group that can react with -NCO, and k represents the group or chemical bond formed by the reaction of the end-capping agent's group that can react with -NCO. Taking isooctanol as the end-capping agent as an example, Q' is CH3CH2CH2CH2-CH(CH2CH3)(CH2-), and -k- is -NHCOO-. ★ , ★ The end is connected to Q'. Where p is in the range of 2-4, Q' comprises an aromatic ring structure. Where p is in the range of 5-15, Q' comprises one or more of the following: an aromatic ring structure, an aliphatic ring structure, and an aliphatic chain structure.

[0057] In this embodiment of the application, when the capping agent is a phenol, a monohydric alcohol, or a silane coupling agent with -OH, -k- is -NHCOO-. ★ When the end-capping agent is a monoamine or a silane coupling agent with -NH2, -k- is a urea group (-NH-CO-NH-). When the end-capping agent is a monoisocyanate, -k- is -N=C=N-. When the end-capping agent is an acid or a silane coupling agent with -COOH, k is an amide bond (i.e., -NH-CO-). ★ When the capping agent is an acid anhydride, -k- is -CO-NH-CO-.

[0058] In some embodiments of this application, when p is in the range of 2-15, the end-capping group Q contains an aromatic ring structure. This results in lower low-temperature reactivity of the carbodiimide group in the aforementioned polycarbodiimide, better storage stability and developability of the resin composition, and better heat resistance of its cured product.

[0059] In this embodiment, the polycarbodiimide contains no more than 5 wt% NCO groups. That is, the polycarbodiimide contains NCO groups with a mass percentage less than or equal to 5 wt% that are not Q-terminated. For ease of understanding, the structure of the polycarbodiimide can also be described as follows: the polycarbodiimide comprises the repeating unit shown in formula (i):

[0060] Formula (i)

[0061] Wherein, A and D are independently selected from one or more of substituted or unsubstituted alkylene, substituted or unsubstituted cycloalkylene, and substituted or unsubstituted aryl, and the degree of polymerization of the repeating unit shown in formula (i) is in the range of 2-15; at least some of the polymer segments shown in formula (i) are capped by the capping group Q. As mentioned above, when the degree of polymerization p of the repeating unit shown in formula (i) is an integer from 2 to 4, Q contains an aromatic ring structure; when p is an integer from 5 to 15, Q contains one or more of an aromatic ring structure, an aliphatic ring structure, and an aliphatic chain structure.

[0062] In the polycarbodiimide, at least some of the polymer segments shown in Formula (i) have the terminal group Q as described above. In some embodiments, some of the polymer segments shown in Formula (i) have the terminal group Q as described above, and some polymer segments have the terminal group -NCO group. In other embodiments of this application, all polymer segments shown in Formula (i) have the terminal group Q as described above, that is, the polycarbodiimide does not contain uncapped NCO groups. The mass percentage of uncapped NCO groups in the polycarbodiimide is less than or equal to 5 wt%. This avoids excessive residual active -NCO groups in the polycarbodiimide, which could crosslink with hydroxyl groups in the photosensitive resin below 90°C, resulting in lower solubility of the dry film of the unexposed photosensitive resin composition in the alkaline developer.

[0063] In this application, the preparation of the above-mentioned polycarbodiimide may include the following steps:

[0064] At least one diisocyanate was polymerized in the presence of a catalyst at a stirring temperature of 130°C-200°C for a period of time. Then, a capping agent was added to cap the resulting polymer product, yielding a polycarbodiimide with the structure shown in formula (I).

[0065] Formula (I)

[0066] In formula (I), A and D are independently selected from one or more of substituted or unsubstituted alkylene, substituted or unsubstituted cycloalkylene, and substituted or unsubstituted arylene; x and y are independently integers from 1 to 5; p is an integer from 2 to 15; and Q represents a capping group used to block the NCO group; wherein the capping agent is a substance that can react with the -NCO group.

[0067] The selection of the capping agent can be found in the preceding description of this application. The diisocyanate substance can be selected from one or more of the following: diphenylmethane diisocyanate (MDI), naphthalene diisocyanate (NDI), toluene diisocyanate (TDI), isophthalic dimethyl isocyanate (XDI), terephthalic diisocyanate (PPDI), tetramethyl isophthalimide diisocyanate (TMXDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 1,4-cyclohexane diisocyanate (CHDI), methylcyclohexyl diisocyanate (HTDI), and 4,4-dicyclohexylmethane diisocyanate (HMDI). When A and D in formula (I) are the same, only one diisocyanate substance may be used.

[0068] The catalyst can be selected from one or more of alkali metal or alkaline earth metal compounds, organophosphorus compounds (e.g., 3-methyl-1-phenyl-2-phosphacyclopentene-1-oxide), tertiary amines (e.g., triethylamine, tri-n-butylamine, N,N-dimethylaniline, triethylenediamine, triisopropylamine), and non-alkaline organometallic compounds (e.g., dibutyltin dilaurate). The alkali metal or alkaline earth metal compounds can include one or more of alkali metal or alkaline earth metal hydroxides (e.g., magnesium hydroxide, sodium hydroxide), inorganic salts (e.g., sodium carbonate, potassium bicarbonate), and organic salts (e.g., phenolic salts, sodium methoxide). The catalyst can enhance the polycondensation reactivity of the diisocyanate. The mass of the catalyst can account for 0.01%-2% of the total mass of the reactants.

[0069] In some embodiments, an organic solvent (such as toluene, cyclohexanone, etc.) may be added during the polymerization reaction based on changes in the system viscosity. The degree of polymerization of the polymerized product can be determined by collecting CO2 mass and titrating with dibutylamine.

[0070] In this application, the photosensitive resin is a photosensitive prepolymer containing carbon-carbon double bonds and carboxyl groups in its molecular structure, and still possesses polymerization reactivity. Under irradiation with light of a certain wavelength, and initiated by a photoinitiator, the photosensitive resin undergoes photopolymerization via its carbon-carbon double bonds, and physically intertwines with polycarbodiimide, etc., to obtain a cross-linked product with a certain network structure. Subsequently, at a temperature above 90°C, the carboxyl groups in the photosensitive resin undergo a cross-linking reaction with the aforementioned polycarbodiimide to obtain a cured product with a certain network structure.

[0071] In this embodiment, the weight-average molecular weight (Mw) of the photosensitive resin is 3000-20000. Photosensitive resins with Mw within this range ensure both high photopolymerization activity and a suitable solubility rate in alkaline developing solution, as well as good developability of their photopolymerization products. In this embodiment, the acid value of the photosensitive resin is 50-120 mgKOH / g. This further ensures suitable solubility of the unexposed dry film of the above-mentioned resin composition in alkaline developing solution, thereby guaranteeing high developing resolution.

[0072] In this embodiment, the resin composition may include the following components in parts by weight: 30-40 parts of photosensitive resin, 1-20 parts of polycarbodiimide, and 0.5-6 parts of photoinitiator. By using a reasonable ratio of photosensitive resin, the aforementioned polycarbodiimide, and photoinitiator, the resin composition can be guaranteed to have good storage stability, a suitable viscosity at room temperature for good coating performance, and its photocured product can be guaranteed to have good developability, good adhesion (especially adhesion to copper layers), and heat resistance, etc.

[0073] The resin composition may contain one or more photosensitive resins; it may also contain one or more photoinitiators and one or more polycarbodiimides. All the weight parts mentioned above refer to their total weight parts. Specifically, the total weight parts of the photosensitive resin in the resin composition may be 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, or 40 parts, etc. The total weight parts of the polycarbodiimide in the resin composition may be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 15, 16, 18, or 19 parts, etc.; in some embodiments, the weight parts of the polycarbodiimide may be 2-10 parts. The total weight parts of the photoinitiator in the above resin composition may be 0.6 parts, 0.8 parts, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 5.5 parts or 6 parts, etc.; in some embodiments, the weight parts of the photoinitiator may be 1-5 parts.

[0074] In this embodiment of the application, the molar amount of carbodiimide groups in the polycarbodiimide of the resin composition is 0.2-1.5 times the molar amount of carboxyl groups in the photosensitive resin. This ensures high storage stability of the resin composition while also providing excellent flexibility and heat resistance of the cured product. In some embodiments, the molar amount of carbodiimide groups is 0.5-1.5 times that of carboxyl groups, and more specifically, it can be 0.6-1.2 times.

[0075] In this application, the photoinitiator can be a free radical photoinitiator. Free radical photoinitiators generate free radicals upon irradiation with light of a certain wavelength, and through the transfer of these free radicals, they can initiate the polymerization reaction of the photosensitive resin or the photopolymerizable monomers described below. In the embodiments of this application, the maximum absorption wavelength of the photoinitiator is in the range of 270-400 nm. That is, the photoinitiator generates free radicals under ultraviolet light irradiation, initiating the polymerization reaction.

[0076] The photoinitiator may include one or more of the following: acetophenones, α-aminoalkyl acetophenones, benzophenones, benzoin, thioxanthones, etc., but is not limited to these. Specifically, for acetophenones, examples include 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone (907), 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-acetophenone, 2,2-dibutoxyacetophenone, 1-hydroxy-cyclohexyl-phenyl ketone (184), 2-hydroxy-2-methyl-1-phenyl-1-propanone (1173), 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholino)-1-propanone, etc. Examples of α-aminoalkyl benzophenones include 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-1-butanone (369), 2-dimethylamino-2-(4-methyl)benzyl-1-[4-(4-morpholinyl)phenyl]-1-butanone (379), and 2-(dimethylamino)ethylbenzoate. Examples of benzophenones include benzophenone, methyl benzophenone, hydroxybenzophenone, 4,4-dimethylaminobenzophenone, and 4-bromobenzophenone. Examples of benzoins include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether. Examples of thioxanones include thioxanone, 2-chlorothioxanone, 2-ethylthioxanone, 2-isopropylthioxanone, 2,4-dimethylthioxanone, and 2,4-diisopropylthioxanone.

[0077] In some embodiments of this application, the resin composition further includes epoxy resin. The epoxy resin can also act as a thermosetting agent for the photosensitive resin. At a certain temperature (e.g., above 90°C), it can undergo a crosslinking reaction with the carboxyl groups in the photosensitive resin, increasing the crosslinking density of the cured product, thereby improving mechanical properties, heat resistance, solderability, and adhesion of the cured product to substrates such as copper layers. Furthermore, the epoxy resin can also undergo a crosslinking reaction with the carbodiimide groups in the aforementioned polycarbodiimide at temperatures above 150°C, which also contributes to improving the heat resistance of the cured resin composition and reducing the dielectric constant and dielectric loss factor.

[0078] In this embodiment, the epoxy resin includes one or more of bisphenol A type epoxy resin, bisphenol F type epoxy resin, naphthalene-based epoxy resin, biphenyl type epoxy resin, dicyclopentadiene type epoxy resin, and phenolic epoxy resin. These epoxy resins have good heat resistance, and their use in the above resin composition helps to increase the glass transition temperature and improve the heat resistance of the cured product. The epoxy equivalent of the epoxy resin can be 100-500 g / eq.

[0079] To further improve the heat resistance, mechanical properties, and adhesion of the cured resin composition, in this embodiment, the molar amount of epoxy groups in the epoxy resin is controlled to be 0.8-1.5 times the molar amount of carboxyl groups in the photosensitive resin, specifically 0.9 times, 1.0 times, 1.1 times, 1.2 times, 1.3 times, or 1.4 times. This also indicates that introducing too much epoxy resin would result in excessive rigidity of the cured resin composition.

[0080] In this embodiment, the epoxy resin in the above resin composition can be 5-20 parts by weight, for example, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 15 parts, 16 parts, 18 parts, or 19 parts. Introducing an appropriate amount of epoxy resin can improve the heat resistance and adhesion of the cured resin composition.

[0081] In some embodiments of this application, the resin composition further includes a photopolymerizable monomer. The photopolymerizable monomer is a substance containing one or more unsaturated carbon-carbon double bonds in its molecular structure. The photopolymerizable monomer can also undergo its own polymerization and crosslinking reaction under certain light irradiation and the action of a photoinitiator, or it can undergo a polymerization and crosslinking reaction with the photosensitive resin to increase the crosslinking density of the system, thereby improving heat resistance and mechanical properties.

[0082] In this embodiment, the photopolymerizable monomer can be in the resin composition in the amount of 5-20 parts by weight, for example, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 15 parts, 16 parts, 18 parts, or 19 parts. Introducing an appropriate amount of photopolymerizable monomer can appropriately improve the photoreactivity of the resin composition and increase the crosslinking density of the photoreactant.

[0083] In some embodiments of this application, the photopolymerization monomer includes one or more of monofunctional acrylate monomers and polyfunctional acrylate monomers. Polyfunctional acrylate monomers refer to substances containing two or more acrylate groups in their molecular structure. Monofunctional acrylate monomers have better dilution ability for photosensitive resins. Polyfunctional acrylate monomers have higher photoreactivity. Exemplarily, polyfunctional acrylates may include one or more of dipentaerythritol hexaacrylate (DPHA), pentaerythritol triacrylate (PETA), pentaerythritol trimethacrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol pentaacrylate, trimethylolpropane triacrylate (TMPTA), tetraethylene glycol dimethacrylate, etc. Monofunctional acrylates may include one or more of isobornyl acrylate, glycidyl methacrylate, hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxymethyl methacrylate, etc.

[0084] In some embodiments of this application, the resin composition may further include a colorant. The colorant can impart a certain color to the resin composition. The colorant may include one or more pigments, dyes, etc. The pigment may be an organic pigment, an inorganic pigment, etc. When the resin composition contains a colorant, the polycarbodiimide contained in the resin composition can improve the compatibility of the colorant in the composition system, ensuring that the photosensitive dry film and cured product formed by the resin composition have a smooth appearance with few defects, thereby ensuring servo reliability when used as a patterned solder resist ink layer. Exemplarily, organic pigments may be phthalocyanine-based, anthraquinone-based, quinacridone-based, benzimidazolone-based, perylene-based, azo-based, quinoline phthalone-based, aniline-based, anthocyanin-based, etc. Inorganic pigments may be carbon black, titanium black, Prussian blue, chrome yellow, zinc yellow, red lead, iron oxide red, zinc white, zinc barium white, titanium dioxide, etc.

[0085] In some embodiments of this application, the resin composition may further include fillers. The addition of fillers can improve the viscosity of the resin composition, its resistance to high-temperature molding, and reduce the coefficient of thermal expansion of its cured product. Fillers may include, but are not limited to, one or more of silica, alumina, barium sulfate, talc, mica powder, glass powder, etc. The polycarbodiimide contained in the resin composition also helps to improve the compatibility of the fillers in the composition.

[0086] In this embodiment, the resin composition may further contain additives, which may include one or more of toughening agents, leveling agents, dispersants, coupling agents, stress modifiers, and ion trapping agents. These additives have different functions, and in actual production, one or more of these additives can be added to the resin composition as needed to improve its performance and meet practical requirements.

[0087] In this embodiment, the resin composition contains a solvent. This makes the resin composition a mixture, and because it is a viscous, colloidal fluid with a certain degree of fluidity, it can also be called a photosensitive ink. The solvent is selected to ensure that the photosensitive resin, polycarbodiimide, photoinitiator, and other optional components are dissolved therein. In some embodiments, the solvent may be selected from one or more of diethylene glycol ethyl ether acetate (DGMEA), propylene glycol methyl ether acetate (PMA), cyclohexanone, butanone (MEK), and solvent oil.

[0088] In this embodiment, the resin composition described above can be obtained by mixing various components. The resin composition is typically a mixture. The resin composition can be coated and dried into a photosensitive film, and then exposed, developed, and fully cured to obtain a patterned coating containing the cured resin composition.

[0089] This application also provides a film material, which includes a photosensitive film, and the photosensitive film is dried using the resin composition described in this application.

[0090] See Figure 2 This application provides a film material 200, which includes a photosensitive film 220. The photosensitive film 220 is a solid dry film, obtained by coating the aforementioned resin composition and then baking. In some embodiments, the film material 200 is the same as the photosensitive film 220. In other embodiments, such as... Figure 2 As shown, the photosensitive film 220 is usually attached to the surface of the support 210. The surface of the photosensitive film 220 facing away from the support 210 is generally also provided with a protective film 230 for protection, forming a three-layer film structure. That is, the film material 200 usually includes the support 210, and the photosensitive film 220 and the protective film 230 are sequentially stacked on one side of the support 210.

[0091] The support 210 can be a polymer film with heat and solvent resistance, such as polyethylene terephthalate (PET), polypropylene, or polyethylene. The coating process can include one or more methods such as blade coating, spin coating, spray coating, and spool coating. The coating thickness of the photosensitive film 220 can be determined based on its thickness after complete curing in practical applications. During the baking process, the polycarbodiimide and photosensitive resin in the resin composition of this embodiment do not undergo a crosslinking reaction. The baking temperature generally does not exceed 80°C, for example, 50-80°C.

[0092] The protective film 230 and the support 210 can be made of the same or different film materials, and it is preferable that the adhesion between the protective film 230 and the photosensitive film 220 is less than that between the support 210 and the photosensitive film 220. The protective film 230 can be pressed onto the surface of the photosensitive film 220 under certain temperature and pressure. Within the pressing temperature range, no cross-linking reaction will occur within the photosensitive film 220, which makes the photosensitive film 220 more stable and has better room temperature storage properties. The pressing temperature can be 50-80℃, and more specifically 55-75℃.

[0093] When using the aforementioned film material 200, the protective film 230 on the photosensitive film 220 is generally removed first. Then, the photosensitive film 220 is brought into contact with the target substrate and hot-pressed. Following this, the photosensitive film 220 undergoes patterning processes (such as exposure and development). During the hot-pressing process, no cross-linking reaction occurs within the photosensitive film 220. The hot-pressing temperature generally does not exceed 80°C, for example, 50-80°C or 55-75°C. Additionally, the support 210 is generally removed before development. Therefore, in practical applications, only the cured product of the photosensitive film 220 remains in the final product structure.

[0094] This application provides the application of the above-described resin composition and the above-described film material 200 in the preparation of printed circuit boards and the packaging of electronic components.

[0095] The applications in the fabrication of printed circuit boards include, but are not limited to, the fabrication of patterned solder resist ink layers and insulating layers on printed circuit boards. The resin composition and film material 200 of this application embodiment can be used to encapsulate various electronic components, such as chips, transistors (e.g., diodes, triodes), LED devices, and resistive-capacitive-inductive components (e.g., resistors, capacitors, inductors), forming electronic packaging structures, or sealed packages. The applications in the fabrication of electronic packaging structures include, but are not limited to, the fabrication of packaging carriers (specifically, the fabrication of patterned solder resist ink layers on the packaging carrier), electrical insulating layers, protective layers, molding layers, and adhesive layers for fixing electronic components (e.g., bottom filler layers). All of the above film layers include cured products of the resin composition of this application embodiment. The above resin composition is specifically designed for electronic packaging structures requiring low dielectric constant, low dielectric loss tangent, high-density wiring, and high-frequency signal processing.

[0096] The following describes the preparation Figure 1 Taking the encapsulation carrier 10 as an example, an application method of the above-mentioned resin composition of this application is introduced. Specifically, the application method includes:

[0097] Step (1): Coat the above-described resin composition of the present application onto the substrate and bake to form a photosensitive film.

[0098] The substrate used has good high-temperature resistance and is not easily deformed at the curing temperature of the aforementioned resin composition. In this embodiment, the substrate is a substrate with a circuit pattern formed on its surface, which may include an insulating layer and a conductor layer disposed on the surface of the insulating layer. The insulating layer is typically formed by laminating multiple insulating films. The conductor layer can be transformed into a conductor layer with a circuit pattern by patterning an initial metal foil layer covering the dielectric layer. The conductor layer may be copper, aluminum, nickel, silver, or their alloys, with copper or its alloys being more common. Specifically, the substrate with the circuit pattern can be a pre-patterned printed circuit board, a flexible printed circuit board, a copper-clad laminate for high-frequency circuits, etc. Figure 1 Reference numeral 11 refers to a copper-clad laminate with a copper circuit pattern, the copper layers on its surface being indicated by reference numerals 101 and 102, respectively. Furthermore, the coating process parameters can be found in the preceding description of this application.

[0099] Step (2): Expose a predetermined area of ​​the substrate with the above-mentioned photosensitive film.

[0100] During exposure, the photosensitive film is irradiated by an exposure light source through a patterned photomask to achieve selective exposure. The light provided by the exposure light source typically includes ultraviolet light, which induces cross-linking of the photosensitive film by generating free radicals through common photoinitiators. Generally, the exposure light source can be a mercury lamp, ultraviolet light-emitting diode, etc. The exposure dose can be selected as needed, typically ranging from 50-200 mJ / cm². 2 Within the range.

[0101] Step (3): The exposed photosensitive film is developed using a developing solution. This removes the unexposed areas, resulting in a patterned film.

[0102] For the negative resin composition used in this application, the unexposed areas of the photosensitive film are soluble in the developing solution, while the exposed areas are relatively insoluble. Therefore, the shape of the patterned film remaining after development corresponds to the cutout area of ​​the photomask. The portion of the substrate not covered by the patterned film is generally the electrical connection point between the substrate and other conductive components. Figure 1 On the side of the substrate closest to the electronic component 20, the solder bumps 13 are not covered by the patterned film. The developing solution used is typically an alkaline solution; for example, a solution containing inorganic bases such as sodium hydroxide, potassium hydroxide, sodium carbonate, or sodium bicarbonate can be used, or an organic base such as tetramethylammonium hydroxide (TMAH), trimethylamine, or triethanolamine can be used.

[0103] Step (4): Complete curing: The patterned film is heated and cured to transform it into a hardened film.

[0104] Through a heat curing process, the carbodiimide groups of the polycarbodiimide in the patterned film can undergo a cross-linking reaction with the carboxyl groups in the photosensitive resin. When the resin composition contains epoxy resin, a cross-linking reaction between epoxy groups and carboxyl groups can also occur during this heat curing process. The resulting hardened film is the cured product of the above resin composition, and this hardened film can be referred to as... Figure 1 Patterned solder resist ink layer on the intermediate packaging substrate 10.

[0105] Generally, the heat curing temperature can be set according to the properties of the polycarbodiimide described above and in combination with actual needs. Understandably, the heat curing temperature should be higher than the peak temperature of the exothermic reaction measured by DSC of the resin composition, and lower than the temperature tolerance of the substrate. In some embodiments of this application, the heat curing temperature is 100-180°C, or it can be 120-170°C.

[0106] In some embodiments of this application, photocuring can be performed before heating and curing the patterned film. This allows the photosensitive resin and photopolymerizable monomers that have not completed the free radical polymerization reaction in the system to continue the polymerization reaction before the corresponding heat curing, thereby ensuring that the crosslinkable components in the system are fully crosslinked, and ensuring that the resulting cured product has a high crosslinking density and high heat resistance. The photocuring can be performed under the exposure light source described above, and the exposure dose used can be larger than that in step (2), for example, the exposure dose can be 1000-2000 mJ / cm. 2 .

[0107] It should be noted that the main difference between using the above-mentioned film material 200 to prepare the above-mentioned patterned solder resist ink layer and directly using the above-mentioned resin composition is that: in step (1), the protective film 230 on the photosensitive film 220 is removed first, and then the photosensitive film 220 is hot-pressed onto the substrate; before exposure in step (2) or before development in step (3), the support 210 of the film material 200 is removed first. In this way, only the cured product of the photosensitive film 220 is retained in the final product structure.

[0108] This application also provides a packaging carrier plate containing a cured product of the resin composition described above in this application.

[0109] See Figure 1The packaging substrate 10 provided in Embodiment 1 of this application includes a substrate 11 with a conductor layer on its surface. A patterned solder resist ink layer 12 is disposed on the conductor layer, and the patterned solder resist ink layer 12 includes a cured product of the above-mentioned resin composition. As described above, the substrate 11 with a conductor layer on its surface includes an insulating layer and a conductor layer disposed on at least one surface of the insulating layer. The insulating layer may be a laminate of multiple insulating films, and the conductor layer may be a conductor layer with a wiring pattern. Its material includes, but is not limited to, copper, aluminum, nickel, silver, or alloys thereof, with copper and copper alloys being more common.

[0110] This application also provides a sealed packaging component, which may include a cured product of the resin composition described in this application embodiment, or a packaging carrier plate described in this application embodiment. Because this sealed packaging component contains a cured product of the resin composition provided in this application embodiment, it has high reliability.

[0111] Please continue reading Figure 1 The sealed package 100 provided in some embodiments of this application includes a packaging carrier 10 and electronic components 20 disposed on the packaging carrier 10. The electronic components 20 may be disposed on a patterned solder resist layer 12 in the packaging carrier 10 (specifically, disposed on the side of the patterned solder resist layer 12 facing away from the substrate 11), and the electrical connection points between the packaging carrier 10 and the electronic components 20 (e.g., ...) Figure 1 The welding bumps 13 in the package are not covered by the patterned solder resist ink layer 12. For further structural details of the sealed package 100, please refer to the description above in this application. Figure 1 The medium structure usually uses electronic components, with chips being the most common.

[0112] The sealed package 100 can be electrically connected to a circuit board. See also Figure 3 The side of the packaging substrate 10 furthest from the electronic component 20 (also referred to as the "bottom of the packaging substrate 10") may have an array of solder balls 14 (such as solder balls). These solder balls 14 enable electrical connection between the packaging substrate 10 and the circuit board 30 within the sealed package 100, thus achieving the connection between the electronic component 20 and the circuit board 30 via the packaging substrate 10. The circuit board 30 and the electronic component 20 within the sealed package 100 are located on opposite sides of the packaging substrate 10.

[0113] In addition, as described above, in addition to the patterned solder resist ink layer 12 containing the cured resin composition described in the embodiments of this application, the sealed package 100 may also contain the cured material in the insulating layer of the encapsulation carrier 10, the bottom filler adhesive layer between the solder bumps 13, and the encapsulation body covering the electronic components 20.

[0114] It should be noted that, Figure 3 The example shown is a sealed package 100 specifically a BGA package, illustrating its structure after connection with a circuit board. However, it is understood that the sealed package described in this application embodiment can also be a sealed package using FC-CSP (Flip Chip-Chip Scale Package), SiP (System in Package), QFP (Quad Flat Package), or SOP (Small Outline Package) technology, etc.

[0115] This application also provides an electronic device that includes the sealed packaging described in this application.

[0116] In some embodiments of this application, such as Figure 4 As shown, the electronic device 300 includes a housing 301 and a circuit board and a sealed package 100 disposed within the housing 301. The sealed package 100, located inside the electronic device 300, can be as follows: Figure 3 The device shown is mounted on and electrically connected to circuit board 30. This electronic device can be a mobile phone, tablet computer, laptop computer, wearable device (such as a smartwatch or smart bracelet), television, video recorder, camcorder, home smart device, in-vehicle device, or other terminal product.

[0117] In other embodiments of this application, the electronic device may also be various wired or wireless communication devices such as antennas, radars, routers, gateways, walkie-talkies, switches, surge arresters, etc.; or a communication base station. The aforementioned sealed packaging is electrically connected to the circuit boards of these communication devices or communication base stations.

[0118] In this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. In this application, "at least one" means one or more, and "more" means two or more. When this application mentions that the content of a substance does not exceed a certain value, such as not exceeding 10%, it means "less than or equal to 10%".

[0119] The technical solutions of the embodiments of this application will be further described below through multiple examples.

[0120] First, let's introduce the synthesis of each polycarbodiimide.

[0121] Synthesis of polycarbodiimides P1 to P3: Tetramethyl-methylene diisocyanate (TMXDI) was used as a monomer for polycondensation to prepare the target polycarbodiimides. 200 parts by mass of the monomer TMXDI were added to a three-necked flask and heated to 90°C under stirring. Then, 0.15 parts by mass of 3-methyl-1-phenyl-2-phosphacyclopentene-1-oxide was added as a catalyst. The polycondensation reaction was then carried out at 178°C and 350 rpm. The change in -NCO concentration in the system was monitored using di-n-butylamine titration. The degree of polymerization of the polymer was controlled by the reaction time. After reaching the predetermined degrees of polymerization (2, 4, and 8, respectively), the system temperature was lowered to 100°C, and then a certain amount of isooctanol was added as a capping agent to completely consume the unreacted NCO, yielding polycarbodiimides, named P1, P2, and P3, respectively.

[0122] The general reaction formula for preparing polycarbodiimides P1-P3 is as follows:

[0123]

[0124] In the structural formula of polycarbodiimide P1, the degree of polymerization of the repeating unit is p=2, meaning that in 1 mol of P1 molecules, the content of carbodiimide groups is 4 mol. The weight-average molecular weight Mw of this P1 is 905.

[0125] The degree of polymerization of the repeating unit in polycarbodiimide P2 is p=4, meaning that in 1 mol of P1 molecular structure, the content of carbodiimide groups is 8 mol. The weight-average molecular weight Mw of P2 is 1306.

[0126] The degree of polymerization of the repeating unit in polycarbodiimide P3 is p=8, meaning that in 1 mol of P1 molecular structure, the content of carbodiimide groups is 16 mol. The weight-average molecular weight Mw of P3 is 2107.

[0127] Synthesis of polycarbodiimide P4: 200 parts by mass of TMXDI as a monomer were added to a three-necked flask and heated to 90°C with stirring. Then, 0.15 parts by mass of 3-methyl-1-phenyl-2-phosphacyclopentene-1-oxide were added as a catalyst. Polycondensation was then carried out at 178°C and 350 rpm. The change in -NCO concentration in the system was monitored by di-n-butylamine titration, and the degree of polymerization of the polymer was controlled by the reaction time. After reaching the predetermined degree of polymerization (4 in this example), 0.1 parts by mass of dibutyltin dilaurate and 50 parts by mass of toluene were added and stirred thoroughly to dissolve, obtaining mixed solution A. 30 parts by mass of the end-capping agent phenol were dissolved in 100 parts by mass of anhydrous toluene and added to a three-necked flask, heated to 60°C, and then mixed solution A was added dropwise to a three-necked flask containing the phenol and toluene solution over 1 hour. After the addition was complete, the reaction was carried out at 60°C for 3 hours. After the reaction was completed, the unreacted phenol and toluene were removed by distillation under reduced pressure of 150°C and 2 mmHg to obtain phenol-terminated polycarbodiimide, named P4.

[0128] Polycarbodiimide P4 includes the structure shown below:

[0129]

[0130] Where p=4. The weight-average molecular weight Mw of the repeating unit in P4 was measured to be 1234.

[0131] Synthesis of polycarbodiimide P5: The difference between this synthesis and that of polycarbodiimide P4 is as follows: When the predetermined degree of polymerization (degree 4) is reached, 0.1 parts by mass of dibutyltin dilaurate and 100 parts by mass of toluene are added to the system and stirred thoroughly to dissolve, yielding a mixed solution B. 43 parts by mass of the end-capping agent 1-naphthol and 200 parts by mass of anhydrous toluene are added to a three-necked flask and heated to 70°C to dissolve completely. Then, the above mixed solution B is added dropwise over 1 hour to a three-necked flask containing a solution of phenol and toluene. After the addition is complete, the reaction is carried out at 70°C for 4 hours. After the reaction is complete, unreacted 1-naphthol and toluene are removed by distillation under reduced pressure of 200°C and 2 mmHg to obtain naphthol-terminated polycarbodiimide, named P5.

[0132] Polycarbodiimide P5 includes the structure shown below:

[0133]

[0134] Where p=4. The weight-average molecular weight Mw of the repeating unit in P5 was measured to be 1335.

[0135] Synthesis of polycarbodiimides P6 and P7: Isophorone diisocyanate (IPDI) was used as a monomer for polycondensation to prepare the target polycarbodiimides. 200 parts by mass of IPDI monomer were added to a three-necked flask and heated to 80°C under stirring. Then, 0.15 parts by mass of 3-methyl-1-phenyl-2-phosphacyclopentene-1-oxide was added as a catalyst. The polycondensation reaction was then carried out at 155°C and 370 rpm. The concentration of -NCO in the system was monitored by di-n-butylamine titration. The degree of polymerization of the polymer was controlled by the reaction time. During the reaction, the stirring speed was adjusted according to the viscosity of the system, and toluene solvent was added. After reaching the predetermined degrees of polymerization (2 and 4, respectively), the system temperature was lowered to 90°C, and a certain amount of isooctanol was added as a capping agent to consume the unreacted NCO, yielding isooctanol-capped polycarbodiimide P6 with a degree of polymerization of 2 and isooctanol-capped polycarbodiimide P7 with a degree of polymerization of 4.

[0136] Both polycarbodiimides P6 and P7 have the following structures:

[0137]

[0138] The degree of polymerization of the repeating unit in polycarbodiimide P6 is p=2, and the degree of polymerization of the repeating unit in polycarbodiimide P7 is p=4. Furthermore, the weight-average molecular weight (Mw) of P6 was measured to be 839, and that of P7 was 1196.

[0139] Synthesis of polycarbodiimide P8: 200 parts by mass of the monomer IPDI were added to a three-necked flask and heated to 80°C under stirring. Then, 0.15 parts by mass of 3-methyl-1-phenyl-2-phosphacyclopentene-1-oxide were added as a catalyst. The polycondensation reaction was then carried out at 155°C and 370 rpm. The change in the -NCO concentration in the system was monitored by di-n-butylamine titration. The degree of polymerization of the polymer was controlled by the reaction time. During the reaction, the rotation speed was adjusted according to the change in the viscosity of the system and toluene solvent was added.

[0140] After reaching the predetermined degree of polymerization of 10, 0.1 parts by mass of dibutyltin dilaurate and an appropriate amount of toluene were added to the system and stirred thoroughly to dissolve, yielding a mixed solution C. 30 parts by mass of glycidyl ether end-capping agent and 200 parts by mass of anhydrous toluene were added to a three-necked flask and heated to 60°C to dissolve completely. Then, the above mixed solution C was added dropwise to the same three-necked flask containing glycidyl ether over 1 hour. After the addition was complete, the reaction was carried out at 60°C for 3 hours. After the reaction was completed, unreacted glycidyl ether and toluene were removed by distillation under reduced pressure of 120°C and 2 mmHg to obtain glycidyl ether-terminated polycarbodiimide, named P8.

[0141] Polycarbodiimide P8 includes the structure shown below:

[0142]

[0143] Where p=10. The weight-average molecular weight Mw of the repeating unit in P8 was measured to be 2154.

[0144] Synthetic polycarbodiimide P9: The difference between it and synthetic polycarbodiimide P8 is that after the polymerization product of the polycondensation reaction reaches the predetermined degree of polymerization 4, a certain amount of end-capping agent 1-naphthol is used for end-capping.

[0145] Polycarbodiimide P9 includes the structure shown below:

[0146]

[0147] In P9, the degree of polymerization of the repeating unit is p=4. The weight-average molecular weight Mw of P9 was measured to be 1224.

[0148] Synthetic polycarbodiimide P10: The difference between it and synthetic polycarbodiimide P8 is that after the polymerization product of the polycondensation reaction reaches the predetermined degree of polymerization 10, a certain amount of end-capping agent 1-naphthol is used for end-capping.

[0149] Polycarbodiimide P10 includes the structure shown below:

[0150]

[0151] In P10, the degree of polymerization of the repeating unit is p=10. The weight-average molecular weight Mw of P10 was measured to be 2149.

[0152] Example 1

[0153] Preparation of a photosensitive resin composition:

[0154] Two parts by weight of the above-mentioned polycarbodiimide P4, 16 parts by weight of photosensitive resin 1 (specifically, acid-modified phenolic epoxy acrylate with a Mw of 10,000 and an acid value of 49.27 mgKOH / g), and 16 parts by weight of photosensitive resin 2 (specifically, acid-modified bisphenol F epoxy acrylate with a Mw of 2,000 and an acid value of 50) were mixed. The following ingredients were added to a certain amount of organic solvent: mgKOH / g, 2 parts by weight of photoinitiator 907, 10 parts by weight of epoxy resin (specifically, biphenyl-type epoxy resin NC3000H with an epoxy equivalent of 285 g / eq), 6 parts by weight of photopolymerizable monomer DPHA, 20 parts by weight of inorganic filler (specifically, 10 parts by weight of silica and 10 parts by weight of barium sulfate), and 0.4 parts by weight of colorant (specifically, 0.25 parts by weight of copper phthalocyanine pigment and 0.15 parts by weight of pigment yellow 147 (also known as 1,1'-[(6-phenyl-1,3,5-triazine-2,4-diimino]bisanthraquinone)). After stirring evenly, a photosensitive resin composition slurry was obtained.

[0155] The composition and weight percentages of each non-volatile component in the photosensitive resin compositions of other examples and comparative examples are listed in Table 1, and their preparation process can be referred to Example 1. In addition, Table 1 also summarizes the peak exothermic temperatures of each photosensitive resin composition measured by DSC.

[0156] Table 1

[0157]

[0158] The DSC curve of the photosensitive resin composition in Example 3 is shown below. Figure 5 As shown, the DSC curve of the photosensitive resin composition in Example 6 is as follows. Figure 6 As shown. From Figure 5 , Figure 6 It can be seen more intuitively that the photosensitive resin composition of the present application embodiment has no exothermic peak before 90°C, reflecting that the composition system of the photosensitive resin composition is stable and that no reaction occurs between the components in the system at common baking temperatures, thus ensuring its good exposure and developability.

[0159] Preparation of the photosensitive film and its cured film: The photosensitive resin composition slurries of the above examples and comparative examples were coated onto a PET release film using a 100-mesh rod. After baking in an 80°C forced-air oven for 30 min, a photosensitive dry film with a thickness between 30-40 μm was obtained. Then, the photosensitive dry film was first photocured under a mercury lamp with an exposure of 3000 mJ, followed by thermal curing in a 150°C forced-air oven for 60 min to ensure complete curing, resulting in a cured film. After cooling to room temperature, the cured film with a thickness of 30-40 μm was peeled off from the PET release film for subsequent heat resistance, flexibility, and dielectric tests.

[0160] Appearance evaluation of each photosensitive dry film: The appearance of each photosensitive dry film was visually observed and evaluated. The main observations included color uniformity, pits, orange peel texture, etc. The judgment criteria are as follows: ○: Uniform color, smooth surface, no defects; △: Uneven color dispersion, pits, a few orange peel marks; ×: Uneven color dispersion, numerous pits or orange peel marks, and other appearance defects.

[0161] Heat resistance test of each cured film: The above cured films were cut into strips 5mm wide and 30mm long using a stamping die, and tested on a dynamic thermomechanical analyzer (DMA) under the following conditions to measure their glass transition temperature (Tg) value.

[0162] The testing instrument was a Mettler DMA1, the testing mode was tensile mode, the testing temperature was 30℃~260℃, the heating rate was 5℃ / min, and the testing frequency was 1Hz. The judgment criteria were as follows: if Tg ≥ 160℃, the heat resistance was marked ◎; if 150℃ ≤ Tg < 160℃, the heat resistance was marked 〇; if 140℃ ≤ Tg < 150℃, the heat resistance was marked △; and if Tg < 140℃, the heat resistance was marked ×.

[0163] Flexibility testing of each cured film: Each cured film was cut into strips 3mm wide and 30mm long using a stamping die. These strips were then tested on a dynamic thermomechanical analyzer (DMA) at a stress rate of 3 N / min. The average elongation of the eight strips was measured and used as a quantitative indicator of flexibility. The judgment criteria were as follows: if the elongation was ≥5%, flexibility was marked as ◎; if 4% ≤ elongation < 5%, flexibility was marked as 〇; if 3% ≤ elongation < 4%, flexibility was marked as △; and if the elongation was < 3%, flexibility was marked as ×.

[0164] Dielectric property testing of each cured film: The cured films peeled from the PET release film were used as test samples. Using an SPDR dielectric resonator and network analyzer, the dielectric constant and dielectric loss tangent were measured at 10 GHz, and evaluated according to the following criteria: The evaluation criteria for dielectric constant Dk are: ∠Dk: less than 3.3; ΔDk: greater than 3.3 and less than 3.5; ×Dk: greater than 3.5. The evaluation criteria for dielectric loss tangent Df are: ∠Dk: less than 0.020; ΔDk: greater than 0.020 and less than 0.025; ×Dk: greater than 0.025.

[0165] The pattern-forming properties of the photosensitive resin compositions in the above examples and comparative examples were evaluated. Specifically, each photosensitive resin composition was coated onto a copper plate using screen printing to achieve a dried film thickness of 20 μm, and then baked at 80°C for 30 min to obtain a photosensitive dry film with a thickness of 20 μm. Subsequently, a mercury lamp at 200 mJ / cm² was used for further processing. 2The photosensitive dry film was subjected to full-surface ultraviolet exposure at a certain exposure level. Afterwards, the copper plate with the exposed photosensitive dry film was immersed in a 1% sodium carbonate aqueous solution at 30°C for 1 minute for development. The developability of the dry film was evaluated according to the following visual criteria: ◎: no residue; 〇: residue less than 1 μm thick; △: residue more than 1 μm but less than 3 μm thick; ×: residue more than 3 μm thick.

[0166] Storage stability test: Test samples were prepared according to the method described above for evaluating developability—a photosensitive dry film with a thickness of 20 μm was formed on a copper plate. This photosensitive dry film was then stored in a dark room at room temperature (23°C) for a certain period of time. Afterwards, it was subjected to a mercury lamp at 200 mJ / cm². 2 The photosensitive dry film was subjected to full-surface ultraviolet exposure at a certain exposure level, and then immersed in a 1% sodium carbonate aqueous solution at 30°C for 1 minute for development.

[0167] The evaluation criteria for storage stability are as follows: ◎: After storage at room temperature for 2 weeks, it can still be developed without residue; 〇: After storage at room temperature for 2 weeks, it develops with residue with a film thickness of less than 1μm; △: After storage at room temperature for 2 weeks, it has residue with a film thickness of more than 1μm but less than 3μm; ×: After storage at room temperature for 2 weeks, it has residue with a film thickness of more than 3μm.

[0168] Copper adhesion test: Various photosensitive resin compositions were screen-printed onto a copper plate to achieve a dried film thickness of 20 μm. The film was then dried in a hot air circulating drying oven at 80°C for 30 minutes to obtain a photosensitive dry film with a thickness of 20 μm. Then, a mercury lamp was used at 2 J / cm²... 2 Expose the film, and then heat the exposed dry film at 150°C for 1 hour to completely cure the dry film into a cured film sample.

[0169] Subsequently, according to the cross-cut adhesion test standard (size 1mm x 1mm), a peel test was conducted on the cured film sample using 3M tape, and the following quantitative evaluations were performed: ◎: No residue of any components on the 3M tape; 〇: Peeling area of ​​the cured film is less than 10%; △: More than 10% but less than 20% of the cured film area was peeled off; ×: More than 20% of the cured film area was peeled off.

[0170] Reflow resistance test: Various photosensitive resin compositions were screen-printed onto a copper plate to achieve a dried film thickness of 20 μm. The film was then dried in a hot air circulating drying oven at 80°C for 30 minutes to obtain a photosensitive dry film with a thickness of 20 μm. Then, a mercury lamp was used at 2 J / cm²... 2The exposed dry film was then heated at 150°C for 1 hour to completely cure it into a cured film sample, thus obtaining the evaluation substrate. The copper plate with the cured film was then subjected to reflow soldering according to a standard thermal reflow profile (peak temperature 260°C). This process was repeated 10 times. Following the cross-cut adhesion test standard (size 1mm x 1mm), a peel test was performed on the cured film sample using 3M tape, and the following quantitative evaluations were made: ◎: No residue on the 3M tape; 〇: Peeled area of ​​the cured film is less than 10%; △: 10% to 20% of the cured film area was peeled off; ×: More than 20% of the cured film area was peeled off.

[0171] Acid Resistance Test: Evaluation substrates were prepared using the same method as the Reflow resistance test. Each substrate was then immersed in a 20wt% sulfuric acid aqueous solution for 30 minutes, followed by drying. The dried substrates were then subjected to a peel test using 3M tape to evaluate the expansion, peeling, and discoloration of the solder mask. The evaluation criteria were as follows: ◎: No change in appearance, no peeling; 〇: Slight change in appearance, peeled area less than 10%; △: Slight change in appearance, peeled area between 10% and 20%; ×: Significant change in appearance, expansion, peeled area greater than 20%.

[0172] Alkali resistance test: Evaluation substrates were prepared using the same method as the Reflow resistance test. Each evaluation substrate was then immersed in a 20wt% sodium hydroxide aqueous solution for 30 minutes, followed by drying. The dried evaluation substrates were then subjected to a peel test using 3M tape to evaluate the expansion, peeling, and discoloration of the solder mask. The evaluation criteria were as follows: ◎: No change in appearance, no peeling; 〇: Slight change in appearance, peeled area less than 10%; △: Slight change in appearance, peeled area between 10% and 20%; ×: Significant change in appearance, expansion, peeled area greater than 20%.

[0173] Table 2 below summarizes the evaluation results of the above embodiments and comparative examples.

[0174] Table 2

[0175]

[0176] As shown in Table 2, when the negative photosensitive resin composition does not contain polycarbodiimide (Comparative Example 1), although the developability and retention stability of the composition are acceptable, the appearance of the photosensitive dry film is poor. Furthermore, the dielectric properties of the cured product are poor, and its weather resistance (such as acid and alkali resistance, solderability), copper adhesion, etc., are also unsatisfactory. Therefore, its reliability as a patterned solder resist ink layer on a packaging substrate is poor. However, after introducing polycarbodiimide (as in the examples and Comparative Examples 2-5), the appearance of the photosensitive dry film is improved, indicating that polycarbodiimide has good compatibility with other components in the composition. At the same time, the acid and alkali resistance and solderability of the cured product are also improved to some extent. However, the developability and storage stability of the compositions in Comparative Examples 2-5 are significantly worse.

[0177] A comparison of Examples 1-3 and Comparative Examples 2-3 reveals that when the degree of polymerization p of the polycarbodiimide used is less than or equal to 4, if the terminal NCO of the polycarbodiimide is capped with a sterically hindered end-capping agent (phenol, naphthol), the reactivity of -N=C=N- in the polycarbodiimide is low. The DSC exothermic peak temperature of the above-mentioned photosensitive resin composition containing this agent is greater than 90°C (generally between 110-140°C), indicating low reactivity and good developability and storage stability. In particular, when the monomers of the polycarbodiimide are the same, and the degree of polymerization p is equal and all are 4, the end-capping groups of the polycarbodiimide in Examples 2-3 contain aromatic ring structures. The developability and storage stability of their compositions are significantly improved compared to Comparative Example 3, while the heat resistance and reflow soldering resistance of the cured products are also improved to a certain extent. Simultaneously, their flexibility, dielectric properties, and copper adhesion do not decrease.

[0178] Similarly, a comparison of Examples 4-6 and Comparative Examples 4-5 shows that when the degree of polymerization p of the polycarbodiimide used is greater than 4, even without end-capping with an aromatic ring-containing end-capping agent (i.e., polycarbodiimide P8), the DSC exothermic peak temperature of the above-mentioned photosensitive resin composition containing it can still be greater than 90°C, thereby making its developability and storage stability of the photosensitive dry film superior, while other properties of its cured product do not deteriorate significantly.

Claims

1. A resin composition, characterized in that, The composition includes a photosensitive resin, polycarbodiimide, and a photoinitiator. The photosensitive resin contains carboxyl groups and carbon-carbon double bonds in its molecular structure. The polycarbodiimide is a polymer containing carbodiimide groups. The peak temperature of the exothermic peak, measured by differential scanning calorimetry, is greater than 90°C. The polycarbodiimide comprises the structure shown in formula (I). Equation (I) In formula (I), A and D are independently selected from one or more of substituted or unsubstituted alkylene, substituted or unsubstituted cycloalkylene, and substituted or unsubstituted arylene, Q represents the capping group of the NCO group, and p is in the range of 2-15. Wherein, when p is in the range of 2-4, Q contains an aromatic ring structure; when p is in the range of 5-15, Q contains one or more of an aromatic ring structure, an aliphatic ring structure, and an aliphatic chain structure.

2. The resin composition according to claim 1, characterized in that, The exothermic peak intensity of the resin composition is greater than 0.1 mW / mg.

3. The resin composition according to claim 1, characterized in that, The peak temperature of the exothermic peak of the resin composition, as measured by differential scanning calorimetry, is in the range of 100-200℃.

4. The resin composition according to claim 1, characterized in that, In the polycarbodiimide with a unit mol molecular structure, the content of the carbodiimide group is 4-30 mol.

5. The resin composition according to claim 1, characterized in that, The weight-average molecular weight of the polycarbodiimide is 800-9000.

6. The resin composition according to claim 1, characterized in that, The unsubstituted alkylene group has 1-20 carbon atoms, the unsubstituted cycloalkylene group has 4-20 carbon atoms, and the unsubstituted arylene group has 6-20 carbon atoms.

7. The resin composition according to claim 1, characterized in that, The polycarbodiimide contains no more than 5 wt% uncapped NCO groups.

8. The resin composition according to claim 1, characterized in that, The photosensitive resin has a weight-average molecular weight of 3000-20000 and an acid value of 50-120 mgKOH / g.

9. The resin composition according to claim 1, characterized in that, In the resin composition, the molar amount of carbodiimide groups in the polycarbodiimide is 0.2-1.5 times the molar amount of carboxyl groups in the photosensitive resin.

10. The resin composition according to claim 1, characterized in that, The resin composition comprises the following components in parts by weight: 30-40 parts by weight of the photosensitive resin, 1-20 parts by weight of the polycarbodiimide, and 0.5-6 parts by weight of the photoinitiator.

11. The resin composition according to any one of claims 1-10, characterized in that, The resin composition also includes epoxy resin.

12. The resin composition according to claim 11, characterized in that, The epoxy resin includes one or more of the following: bisphenol A type epoxy resin, bisphenol F type epoxy resin, naphthalene-based epoxy resin, biphenyl type epoxy resin, dicyclopentadiene type epoxy resin, and phenolic epoxy resin.

13. The resin composition according to claim 11, characterized in that, The molar amount of epoxy groups in the epoxy resin is 0.8-1.5 times the molar amount of carboxyl groups in the photosensitive resin.

14. The resin composition according to claim 11, characterized in that, The epoxy resin is present in 5-20 parts by weight in the resin composition.

15. The resin composition according to any one of claims 1-10, characterized in that, The resin composition also includes photopolymerizable monomers.

16. The resin composition according to claim 15, characterized in that, The photopolymerizable monomer is present in 5-20 parts by weight in the resin composition.

17. The resin composition according to claim 15, characterized in that, The resin composition also includes epoxy resin.

18. The resin composition according to any one of claims 1-10, characterized in that, The resin composition further includes a colorant; wherein the colorant includes one or more pigments and dyes.

19. The resin composition according to claim 18, characterized in that, The resin composition also includes one or more of epoxy resin and photopolymerizable monomers.

20. A membrane material, characterized in that, Includes a photosensitive film, which is formed by drying the resin composition as described in any one of claims 1-19.

21. The membrane material as described in claim 20, characterized in that, The film material also includes a support and a protective film, with the photosensitive film and the protective film stacked sequentially on the support.

22. The use of the resin composition according to any one of claims 1-19, or the film material according to any one of claims 20-21, in the preparation of printed circuit boards and the packaging of electronic components.

23. The application as described in claim 22, characterized in that, The application in packaged electronic components includes the use of patterned solder resist ink layers on packaged substrates.

24. A packaging carrier board, characterized in that, The encapsulation carrier includes a substrate having a conductor layer on its surface, wherein a patterned solder resist ink layer is disposed on the conductor layer, and the patterned solder resist ink layer comprises a cured product of the resin composition as described in any one of claims 1-19.

25. A sealed package, characterized in that, It includes the packaging substrate as described in claim 24, and electronic components disposed on the packaging substrate.

26. The sealed package as claimed in claim 25, characterized in that, The electronic components are disposed on the patterned solder resist ink layer.

27. An electronic device, characterized in that, The electronic device includes a circuit board and a sealed package as described in any one of claims 25-26 disposed on the circuit board.

28. The electronic device as claimed in claim 27, characterized in that, The circuit board and the electronic components are located on opposite sides of the packaging carrier.

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