A functional coordination type photosensitive polyimide film, a preparation method and application thereof

Abstract

The application discloses a functional coordination type photosensitive polyimide film and a preparation method and application thereof, and belongs to the technical field of polymer functional materials. The functional coordination type photosensitive polyimide film is prepared by polymerization and imidization of aromatic diamine monomers, dianhydride monomers, tertiary amine acrylate compounds and thioether compounds. The application grafts the photosensitive tertiary amine acrylate with double reactive sites as a side group on the polyamide acid skeleton, and then covalently bonds the thioether bond chelating element to the polyamide acid skeleton, and through the topological reconstruction of the photo-crosslinking reaction and the thioether group, the density of the surface accessible sulfur-containing sites is significantly improved, the spatial distribution of the nucleation sites in the initial stage of electroless plating is homogenized, the copper deposition mode is driven to change from island growth to layer growth, and finally a continuous and dense copper layer is formed, and the bonding performance with the interface is greatly improved, and the application has a wide application prospect in flexible circuits, high-frequency circuits and IC packaging substrates.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high polymer functional materials, and particularly relates to a functional coordination type photosensitive polyimide film and a preparation method and application thereof. BACKGROUND

[0002] Photosensitive polyimide (PSPI) is a kind of functional polymer material with excellent intrinsic performance and photosensitive properties of polyimide (PI), and is widely used in high-end fields such as microelectronics, aerospace, flexible electronics and optoelectronics. As a device insulating structure layer, the long-term interface bonding capacity of PSPI with a metal substrate has become one of the core performance indicators. The interface bonding performance not only determines whether the insulating layer can effectively insulate current and protect internal components, but also is directly related to the environmental interference resistance and overall service life of the device. Therefore, it is of great significance to develop an insulating layer with excellent bonding performance.

[0003] The prior art with the application publication number CN 101575414 A discloses a polyimide containing a sulfide structure, which is obtained by co-polymerizing a diamine monomer containing a sulfide structure, other structure diamine and various dianhydride monomers. The polyimide has excellent size stability, high thermal stability, excellent film forming property and low thermal expansion coefficient, and has good bonding performance with copper.

[0004] However, the polyimide described above has the following problems: first, the molecular chain of the prepared polyimide is mainly rigid aromatic ring, the surface energy is low, the interface polarity difference with copper is large, resulting in poor bonding performance; second, the introduced sulfide structure is a static permanent group, which does not have the ability of selective photoetching pattern, and cannot be directly used as a high-density electronic packaging material. SUMMARY

[0005] The application discloses a functional coordination type photosensitive polyimide film and a preparation method and application thereof, and aims to solve the technical problems of poor bonding performance of the existing polyimide containing a sulfide structure with a substrate and lack of pattern metallization integration.

[0006] In order to achieve the above-mentioned purpose, the technical scheme of the application is as follows:

[0007] The first aspect of the application provides a functional coordination type photosensitive polyimide film, which is prepared by polymerization and imidization of aromatic diamine monomers, dianhydride monomers, tertiary amine acrylate compounds and sulfide compounds;

[0008] The sulfide compound is prepared by reaction of an olefin compound and a mercapto compound;

[0009] The olefin compound is one or more of L-carvyl lactone, methyl vinyl ether, 5-norbornene-2-methyl carboxylate;

[0010] The mercapto compound is one or more of 3-mercaptopropionic acid methyl ester, mercaptoacetic acid methyl ester, 3-mercaptopropionic acid glycidyl ester, 11-mercaptoundecanoic acid.

[0011] In combination with the first aspect, preferably, the aromatic diamine monomer is one or more of 4,4'-diaminodiphenyl ether, p-phenylenediamine, 2,2-bis[4-(4-aminophenoxy)phenyl]propane.

[0012] In combination with the first aspect, preferably, the dianhydride monomer is one or more of 3,3',4,4'-diphenyltetracarboxylic dianhydride, pyromellitic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, or hexafluoro dianhydride.

[0013] In combination with the first aspect, preferably, the tertiary amine acrylate compound is one or more of dimethylaminoethyl methacrylate, dimethylaminoethyl acrylate, morpholinoethyl methacrylate.

[0014] The molar mass of the thioether unit in the thioether compound is (0.05-1.5):1 of the aromatic diamine monomer.

[0015] The second aspect of the present application provides a preparation method of the functional coordination type photosensitive polyimide film of the first aspect, and the preparation method comprises:

[0016] The aromatic diamine monomer is dissolved in a first organic solvent to obtain solution A, and the dianhydride monomer is dissolved in a second organic solvent to obtain solution B, which are mixed for reaction to obtain a polyamic acid solution;

[0017] The tertiary amine acrylate compound is added to the polyamic acid solution for reaction under light shielding conditions to obtain a photosensitive polyimide acid solution;

[0018] The olefin compound, the mercapto compound, and the photoinitiator are added to the photosensitive polyimide acid solution for reaction to obtain a functional coordination type photosensitive polyimide acid solution;

[0019] After the functional coordination type photosensitive polyimide acid solution is coated into a film, photoetching, development, activation, and imidization are performed to obtain the functional coordination type photosensitive polyimide film;

[0020] The first organic solvent and the second organic solvent are the same or different.

[0021] Preferably in combination with the second aspect, the first organic solvent is one or several of N-vinyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, cyclopentanone, benzene or butyrolactone.

[0022] The second organic solvent is one or several of N-vinyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, cyclopentanone, benzene or butyrolactone.

[0023] Preferably in combination with the second aspect, the photoinitiator is 2,4,6-trimethylbenzoyl phenyl phosphinate, phenyl bis(2,4,6-trimethylbenzoyl) phosphine oxide or derivatives thereof.

[0024] The exposure wavelength range of the photoinitiator is 365-405 nm.

[0025] The third aspect of the present application provides a metal plating layer comprising the functional coordination type photosensitive polyimide film prepared by the preparation method of the second aspect.

[0026] The fourth aspect of the present application provides the application of the metal plating layer of the third aspect in flexible circuits, high-frequency circuits and IC packaging substrates.

[0027] Compared with the prior art, the advantages or beneficial effects of the embodiments of the present application at least include:

[0028] The functional coordination type photosensitive polyimide film provided by the present application is prepared by polymerization and imidization of aromatic diamine monomers, dianhydride monomers, tertiary amine acrylate compounds and thioether compounds. On one hand, the photosensitive tertiary amine acrylate with double reactive sites is grafted as a side group on the polyamide acid skeleton, and then the thioether chelating group is covalently bonded to the polyamide acid skeleton. Through the topological reconstruction of the photo-crosslinking reaction and the thioether group, the density of the surface accessible sulfur-containing sites is significantly improved, which promotes the spatial distribution uniformization of the nucleation sites in the initial stage of electroless plating, drives the copper deposition mode to change from island growth to layer growth, and finally forms a continuous and dense copper layer, which greatly improves the adhesion performance with the interface. On the other hand, through the synergistic effect of the metal-sulfur coordination bond and the physical interlocking of the crosslinking network, the interface bonding strength is greatly improved, and the thermal cycle reliability is also increased. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments described in the present application, and those skilled in the art can also obtain other drawings according to these drawings without creating any creative labor.

[0030] Figure 1Optical microscope image of a metal plating prepared for an embodiment of the present application;

[0031] Figure 2 Scanning electron microscope image of a metal plating prepared for an embodiment of the present application;

[0032] Figure 3 Atomic force microscope image of a metal plating prepared for an embodiment of the present application. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0034] In the following description of the embodiments of the present application, the term "and / or" is used to describe the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the cases of A alone, B alone and A and B existing at the same time. Wherein A and B can be singular or plural. The character " / " generally represents an "or" relationship between the front and rear associated objects.

[0035] In the following description of the embodiments of the present application, the term "at least one" means one or more, and "multiple" means two or more. "At least one of the following" or similar expressions means any combination of these items, including any combination of single item or multiple items. For example, "at least one of a, b or c", or "at least one of a, b and c", can represent a, b, c, a-b (i.e. a and b), a-c, b-c, or a-b-c, wherein a, b and c can be single or multiple.

[0036] Those skilled in the art should understand that in the following description of the embodiments of the present application, the order of the serial numbers does not mean the order of execution, and some or all steps can be executed in parallel or in sequence, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0037] The terms used in the embodiments of the present application are only for the purpose of describing the specific embodiments, and are not intended to limit the present application. The singular forms "a" and "the" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0038] It should be noted that all raw materials and / or reagents in the embodiments of the present application are purchased in the market or prepared according to conventional methods well known to those skilled in the art.

[0039] In a first aspect, the embodiments of the present application provide a functional coordination type photosensitive polyimide film, which is made by polymerization and imidization of aromatic diamine monomers, dianhydride monomers, tertiary amine acrylate compounds and thioether compounds;

[0040] The thioether compound is made by reaction of an olefin compound and a mercapto compound;

[0041] The olefin compound is one or more of L-carvone, methyl vinyl ether and 5-norbornene-2-methyl formate;

[0042] The mercapto compound is one or more of 3-mercapto propionic acid methyl ester, mercapto acetic acid methyl ester, 3-mercapto propionic acid glycidyl ester and 11-mercapto undecanoic acid.

[0043] In one aspect, the photosensitive tertiary amine acrylate with double reactive sites is grafted on the polyamide acid skeleton, and then the thioether chelating element is covalently bonded to the negative photosensitive polyimide main chain, and through the topological reconstruction of the thioether group by photo-crosslinking reaction, the surface accessible sulfur site density is significantly improved, the spatial distribution of the nucleation site in the initial stage of electroless plating is homogenized, the copper deposition mode is changed from island growth to layer growth, and finally a continuous and dense copper layer is formed, which greatly improves the adhesion performance with the interface. In another aspect, through the synergistic effect of the metal-sulfur coordination bond and the physical interlocking of the crosslinking network, the interface bonding strength is greatly improved, and the thermal cycle reliability is also increased.

[0044] It should be noted that the 3,3',4,4'-biphenyl tetracarboxylic dianhydride (BPDA) / 4,4'-oxydianiline (ODA) copolymer is used as the skeleton, dimethylaminoethyl methacrylate (DMAMA) is used as the photo-crosslinking side group, and the thioether chelating element is covalently bonded in the molecular structure. The ultraviolet exposure synchronously triggers the crosslinking and curing and the photo-induced topological reconstruction of the thioether group, so that the surface of the exposed area exposes a high-density metal coordination cavity, which can selectively anchor the palladium catalytic active site. After development and gradient imidization, without surface roughening treatment and physical vapor deposition seed layer, micro-area selective electroless copper plating can be realized, and an ultra-smooth copper layer with high density and high interface bonding force can be obtained. Experiments have proved that the content of the thioether element in the range of 0.1-1.2 mmol / g is linearly positively correlated with the density of the plated layer, and SEM shows that the copper deposition mode is changed from island growth to layer continuous structure; the photoetching resolution reaches 40μm line width / 40μm pitch, which meets the requirements of high-speed signal integrity.

[0045] It needs to be explained that the application reduces copper consumption, reduces process, adapts full addition and modified semi-addition process, and is suitable for high-frequency and high-density packaging scenes such as glue-free flexible copper-clad plate, wafer-level redistribution layer and 5G millimeter wave antenna feed network.

[0046] In the embodiment of the application, the aromatic diamine monomer is preferably one or more of 4,4'-diamino diphenyl ether, p-phenylenediamine, and 2,2-bis[4-(4-aminophenoxy)phenyl]propane. The dianhydride monomer is preferably one or more of 3,3',4,4'-diphenyl tetracarboxylic dianhydride, pyromellitic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, or hexafluoro dianhydride. The tertiary amine acrylate compound is preferably one or more of dimethylaminoethyl methacrylate, dimethylaminoethyl acrylate, and morpholinoethyl methacrylate, and more preferably dimethylaminoethyl methacrylate. The thioether unit in the thioether compound has a molar mass of (0.05-1.5):1 of the aromatic diamine monomer. The mass ratio of the aromatic diamine monomer and the dianhydride monomer is 1:1-3:1; the solid content of the polyamic acid solution is 10%-30%; and the mass ratio of dimethylaminoethyl methacrylate to 4,4'-diamino diphenyl ether is 2:1-4:1; the molar mass of the thioether unit relative to the diamine is 0.05-1.5 mmol, preferably 0.2-0.8 mmol.

[0047] It needs to be explained that the solution B is added to the solution A in multiple times, which is 2-4 times, and each time interval is 10-30 min; the mixing temperature is 0℃-15℃, and the mixing time is 10-16 h; the dimethylaminoethyl methacrylate is added to the polyamic acid solution, the mixing temperature is 25-40℃, and the mixing time is 2-4 h; the thioether compound is added, the mixing temperature is 25-40℃, and the mixing time is 20-40 min.

[0048] In a second aspect, the application provides a preparation method of the functional coordination type photosensitive polyimide film of the first aspect, and the preparation method comprises:

[0049] In an inert atmosphere, the solution A obtained by dissolving the aromatic diamine monomer in a first organic solvent and the solution B obtained by dissolving the dianhydride monomer in a second organic solvent are mixed for reaction to obtain a polyamic acid solution;

[0050] In a light-proof condition, the tertiary amine acrylate compound is added to the polyamic acid solution for reaction to obtain a photosensitive polyimide acid solution;

[0051] The olefin compound, the mercapto compound, and the photoinitiator are added to the photosensitive polyimide acid solution for reaction to obtain a functional coordination type photosensitive polyimide acid solution;

[0052] After the functional coordination type photosensitive polyimide acid solution is coated and formed into a film, photoetching, development, activation and imidization are performed, and the functional coordination type photosensitive polyimide film is obtained.

[0053] The first organic solvent and the second organic solvent are the same or different.

[0054] It should be noted that the application provides a method for coating and forming a film from the functional coordination type photosensitive polyimide acid solution.

[0055] S1, uniformly coating the functional coordination type photosensitive polyimide acid solution on the surface of a 2.5*2.5 cm glass sheet by a doctor blade method, the coating thickness is 100-300 um, and the coating amount is 100-300 μL / cm. 2 ;

[0056] S2, moving the polyimide film of S1 to a hot stage, and performing preliminary drying at 50-80℃ for 10-20 min;

[0057] S3, after the preliminary drying of the polyimide film, performing photoetching, development and activation, and then transferring to a rubber baking machine to perform thermal ring formation, in an inert atmosphere, at 50-60℃ for 60-80 min, at 120-160℃ for 60-80 min, at 160-200℃ for 60-80 min, at 200-250℃ for 60-80 min, and at 250-300℃ for 60-80 min, and performing imidization by stepwise heating; the imidization conditions are as follows: increasing the temperature to 100, 150, 200, 250 and 300℃ at a temperature increasing rate of 2-5℃ / min, and maintaining at each temperature for 60-80 min.

[0058] In a third aspect, the application provides a metal plating layer comprising the functional coordination type photosensitive polyimide film prepared by the preparation method of the second aspect.

[0059] It should be noted that the application provides a method for preparing a metal plating layer, comprising the following steps:

[0060] S1, exposing the preliminarily dried polyimide film material to ultraviolet light with a wavelength of 100-400 nm for 10-6000 s;

[0061] S2, after the photoetching, developing at 25-40℃ using an organic solvent for 5-80 s, and then rinsing and blowing dry with cold air;

[0062] S3, after the development, activating by immersing in an active liquid palladium solution containing a chemical active agent at 25-40℃ for 5-20 s;

[0063] S4, after the activation treatment, the polyimide film with the catalytic site carrier thioether bond introduced is directly contacted with the electroless copper plating solution and dried to obtain a photosensitive polyimide film with surface immobilized conductive copper metal.

[0064] The developing organic solvent is selected from N,N'-dimethylacetamide (DMAc); the electroless copper plating solution comprises a copper salt, a complexing agent, a stabilizer, a promoter, an anti-nucleation agent, a pH adjuster and a reducing agent. The copper salt in the electroless copper plating solution is selected from copper sulfate pentahydrate, the complexing agent is selected from ethylenediaminetetraacetic acid and potassium sodium tartrate, the stabilizer is selected from 2,2-bipyridine, the promoter is selected from polyethylene glycol (20000), the anti-nucleation agent is selected from potassium ferrocyanide, the pH adjuster is selected from NaOH solution, the reducing agent is selected from an aqueous formaldehyde solution, and the solvent is selected from deionized water. The content of each component in the electroless copper plating solution is as follows: copper sulfate pentahydrate 24 g / L, ethylenediaminetetraacetic acid 21 g / L, potassium sodium tartrate 10 g / L, 2,2-bipyridine 8 mg / L, polyethylene glycol (20000) 1 g / L, potassium ferrocyanide 70 mg / L, NaOH solution 16 g / L, aqueous formaldehyde solution 10 ml / L, and deionized water 1 L. The temperature of the developing is 25-40℃, and the developing time is 5-80 s; the temperature of the Pd bubbling solution is 25-40℃, and the Pd bubbling time is 5-20 s; the temperature of the electroless copper plating solution is 40-55℃, and the copper plating time is 60-300 s.

[0065] It should be noted that the four dimensions of material design, process path, interface reliability and system cost realize collaborative innovation: at the material level, by covalently bonding the thioether chelating unit to the negative photosensitive polyimide skeleton, the ultraviolet exposure synchronously triggers the photocrosslinking reaction and the topological reconstruction of the thioether group, which significantly improves the density of surface accessible sulfur-containing sites. This design promotes the spatial distribution of nucleation sites to be uniform in the initial stage of electroless plating, drives the copper deposition mode to change from island growth to layer growth, and finally forms a continuous and dense copper layer. At the process level, after exposure and development, no traditional roughening treatment and metal seed layer is needed to realize high-selectivity area electroless plating, completely avoiding the risk of side etching and over etching of the subtractive process, providing a basis for high-precision wiring and impedance consistency control, and being seamlessly compatible with the modified semi-additive or full-additive manufacturing process. At the interface reliability level, the synergistic effect of the palladium-sulfur coordination bond (Pd-S) and the physical interlocking of the crosslinked network improves the copper / medium interface bonding strength and thermal cycle reliability. At the electrical performance and cost level, the ultra-low roughness copper surface effectively suppresses high-frequency skin effect loss and crosstalk; at the same time, the omission of the roughening / secondary processing process can reduce copper consumption, energy consumption and waste liquid treatment cost. In summary, the present application breaks through the bottleneck of the collaborative optimization of fine wiring, low loss and high reliability, and has significant industrialization value in high-end application fields such as glue-free copper-clad plate, wafer-level redistribution layer and 5G millimeter wave antenna.

[0066] In a fourth aspect, the embodiments of the present application further provide the application of the metal plating layer in the flexible circuit, high-frequency circuit, IC packaging substrate.

[0067] The technical solutions of the present application will be further described below in combination with specific embodiments.

[0068] Embodiment 1

[0069] The embodiment provides a preparation method of an A1-functional coordination type photosensitive polyimide film, and specifically comprises the following steps:

[0070] S101: 625.74 mg of 4,4'-diamino diphenyl ether (ODA) is added into a 25 ml round-bottom flask, and then N,N'-dimethylacetamide (DMAc) is added, and stirring is performed at room temperature until complete dissolution. After stirring and dissolving, stirring is performed at a speed of 200 rpm in an ice water bath at 5-8°C for 20 minutes, so that the ODA is fully dissolved. Then, 3,3',4,4'-biphenyl tetracarboxylic dianhydride (BPDA) in an equal molar amount of ODA is added in three times, and each addition is separated by no less than 10 minutes, so as to avoid excessive reaction and cause explosive polymerization. During the whole process, the ice water bath environment and the stirring speed of 200 rpm are maintained. Stirring is continuously performed in the ice water bath for 12 hours, so as to stabilize the reaction system.

[0071] S102: 1105.12 mg of dimethylaminoethyl methacrylate (DMAMA) is added, the ice water bath is removed, and stirring is continuously performed at room temperature for 2 hours, so as to obtain a photosensitive polyimide acid solution;

[0072] S103: Then, methyl 3-mercaptopropionate is added into the L-carvyl ketone and uniformly mixed, so as to obtain a thioether compound methyl 3-((2-(4-methyl-5-oxocyclohex-3-en-1-yl)propyl)thio)propanoate; 0.1 mmol (23.9 mg) of the thioether compound methyl 3-((2-(4-methyl-5-oxocyclohex-3-en-1-yl)propyl)thio)propanoate and 12.1 mg of a photoinitiator 2,4,6-trimethylbenzoyl phenyl phosphonic acid ethyl ester are stirred at room temperature in dark for 30 minutes, and finally a functional coordination type photosensitive polyimide acid solution is prepared;

[0073] S104: The 100 μL PAA dilute solution was filtered using an oil filter membrane with a pore size of 0.22 μm to remove impurities. Thin film preparation was performed using a doctor blade method. Specifically, a 2.5 cm * 2.5 cm glass sheet was first treated with ultraviolet light (UV) for 30 minutes to enhance its surface properties. Then, 100 μL of the filtered photosensitive polyamic acid (PS-PAA) dilute solution was uniformly applied to the surface of the 2.5 cm * 2.5 cm glass sheet using a doctor blade method, with a controlled thickness of 200 μm, and the substrate temperature was maintained at 60°C to ensure uniform distribution of the solution and the formation of a uniform thin film. Subsequently, the coated glass sheet was placed on a hot plate and dried at 80°C for 4 to 6 minutes to allow the photosensitive polyamic acid (PS-PAA) thin film to be initially formed.

[0074] After the initial formation of the thin film, it was placed in a high-precision exposure machine for photolithography. A mask plate was placed on the thin film, and the circuit layout of the selected mask plate had a line width / line spacing referred to as L / S. The L / S value for the formed circuit was 40 μm / 40 μm or 40 μm / 80 μm, 40 μm / 120 μm, which could achieve high-resolution patterned exposure. Among them, 40 μm is the exposure area. During exposure, the exposure intensity was set to 80 mW / cm 2 , to ensure that enough energy penetrates the thin film and initiates the cross-linking reaction of the photosensitive monomer. The exposure time was precisely controlled to 10 minutes to ensure that the thin film uniformly and sufficiently completes the photochemical reaction during the photolithography process, thereby achieving precise patterning.

[0075] After photo-crosslinking, the thin film was placed in a developer N,N'-dimethylacetamide (DMAc) at room temperature, and the development time was controlled to 10-60 seconds (different samples correspond to different development times), and then deionized water was used for cleaning, and finally dried at 80°C for 5 minutes. The developed thin film was immersed in a PdCI2 / EtOH solution (0.1 mol / L) for 10 seconds, then washed with absolute ethanol and compressed air to dry. For the conversion process from PAA to polyimide (PI), a baking machine was used for thermal cyclization treatment. The specific steps were: sequentially maintaining at 60°C for 30 minutes, 150°C for 30 minutes, 200°C for 30 minutes, 250°C for 30 minutes, and 300°C for 30 minutes, gradually increasing the temperature and completing the thermal cyclization reaction, and finally obtaining a photosensitive polyimide thin film. Finally, surface metallization treatment was performed, 1 ml of NaOH was added to the bubbling 40°C copper plating solution, and the pH test paper was observed to be purple red with pH = 14, then the photosensitive polyimide thin film was placed in the copper plating solution, and an appropriate amount of formaldehyde was slowly added twice, and about 5 minutes after the copper plating solution was immersed, a photosensitive polyimide thin film material containing a specific conductive metal copper pattern on the surface was obtained, which was an A1-functional coordination type photosensitive polyimide thin film.

[0076] Example 2

[0077] The embodiment provides a material preparation method, and the component allocation ratio and preparation operation and process parameters are basically same to those of the embodiment 1, and the difference is that the content of the thioether compound methyl 3-((2-(4-methyl-5-oxocyclohex-3-en-1-yl)propyl)thio)propanoate added in the embodiment is 71.1 mg (0.3 mmol), and A2-functional coordination type photosensitive polyimide film is obtained.

[0078] Embodiment 3

[0079] The embodiment provides a material preparation method, and the component allocation ratio and preparation operation and process parameters are basically same to those of the embodiment 1, and the difference is that the content of the thioether compound methyl 3-((2-(4-methyl-5-oxocyclohex-3-en-1-yl)propyl)thio)propanoate added in the embodiment is 119.5 mg (0.5 mmol), and A3-functional coordination type photosensitive polyimide film is obtained.

[0080] Embodiment 4

[0081] The embodiment provides a material preparation method, and the component allocation ratio and preparation operation and process parameters are basically same to those of the embodiment 1, and the difference is that the content of the thioether compound methyl 3-((2-(4-methyl-5-oxocyclohex-3-en-1-yl)propyl)thio)propanoate added in the embodiment is 143.3 mg (0.6 mmol), and A4-functional coordination type photosensitive polyimide film is obtained.

[0082] Embodiment 5

[0083] The embodiment provides a material preparation method, and the component allocation ratio and preparation operation and process parameters are basically same to those of the embodiment 1, and the difference is that the content of the thioether compound methyl 3-((2-(4-methyl-5-oxocyclohex-3-en-1-yl)propyl)thio)propanoate added in the embodiment is 286.8 mg (1.2 mmol), and A5-functional coordination type photosensitive polyimide film is obtained.

[0084] Meanwhile, in order to verify the electrochemical performance of the functional coordination type photosensitive polyimide film prepared in the above embodiments, the following comparative examples are provided for detailed description.

[0085] Comparative Example 1

[0086] The comparative example provides a material preparation method, and the component allocation ratio and preparation operation and process parameters are basically same to those of the embodiment 1, and the difference is that the thioether compound is not added in the comparative example, and B1-polyimide film is recorded.

[0087] In order to verify the topography structure of the photosensitive polyimide film material with specific conductive metal copper pattern on the surface prepared by the embodiment of the application, the polyimide film prepared by the embodiment is characterized, and the result is Figures 1-2

[0088] According to Figure 1 It can be seen that the metallization effect of the photosensitive polyimide film material with the conductive metal copper circuit board pattern on the surface is observed under the polarizing microscope. The introduction of sulfide compounds can realize the plating of copper on the photosensitive polyimide film material, and with the increase of the content of sulfide bond (from 0.1 mmol to 1.2 mmol), the metallization effect of the surface of the photosensitive polyimide film material will be better. Because the coordination ability of -S- bond is strong, it can enhance the adsorption of palladium activator, form high-density palladium catalytic sites, increase the nucleation points of electroless copper plating, accelerate the reduction of copper, strengthen the interface bonding and improve the copper plating effect. Therefore, with the increase of -S- content, the copper plating effect will be better.

[0089] According to Figure 2 It can be seen that the SEM topography of the photosensitive polyimide film material with specific conductive metal copper pattern on the surface is observed under the laser confocal microscope. With the increase of the content of sulfide bond, the copper layer topography gradually transitions from sparse island structure, obvious gap to semi-continuous network structure, grain refinement and local fusion, and then to continuous dense layer, and the crystal grains are uniform. Again, it is proved that by introducing sulfide bond, S atom forms Pd-S coordination bond with Pd, the adsorption density of palladium is improved, and the number of copper particles in high sulfide compound increases. This effect is crucial in flexible circuit, high-frequency substrate and other scenarios. The dense copper plating layer can reduce signal damage, improve current carrying capacity and block environmental corrosion medium penetration.

[0090] According to Figure 3 It can be seen that the roughness test of the photosensitive polyimide film material with specific conductive metal copper pattern on the surface. The roughness of the copper layer on the surface of the photosensitive polyimide film material is observed under the atomic force microscope. The surface of the copper layer is relatively smooth and flat, and the surface roughness Rq is 15.2 nm, which is basically suitable for most scenarios such as ordinary high-frequency circuit, IC packaging substrate, etc.

[0091] And the peel strength of the photosensitive polyimide film with specific conductive metal copper pattern on the surface is tested according to the IPC-TM-650 2.4.9 method.

[0092] Table 1 Comprehensive performance test results of photosensitive polyimide film

[0093] ​

[0094]

[0095] Therefore, the application provides a functional coordination type photosensitive polyimide film, which is prepared by polymerization and imidization of aromatic diamine monomers, dianhydride monomers, tertiary amine acrylate compounds and sulfide compounds; the sulfide compounds are prepared by reaction of olefin compounds and mercapto compounds; the olefin compounds are one or more of L-carvone, methyl vinyl ether and 5-norbornene-2-methyl formate; and the mercapto compounds are one or more of 3-mercapto propionic acid methyl ester, mercapto acetic acid methyl ester, 3-mercapto propionic acid glycidyl ester and 11-mercapto undecanoic acid. By grafting photosensitive tertiary amine acrylate with double reactive sites on the polyamide acid skeleton, and then covalently bonding the chelating unit through the sulfide bond to the negative photosensitive polyimide main chain, and through the topological reconstruction of the photo-crosslinking reaction and the sulfide group, the density of the surface accessible sulfur-containing sites is significantly improved, the spatial distribution of the nucleation sites in the initial stage of electroless plating is homogenized, the copper deposition mode is driven to change from island growth to layer growth, and finally a continuous and dense copper layer is formed, and the adhesion performance with the interface is greatly improved.

[0096] The various embodiments in the specification are described in a progressive manner, and the same or similar parts between the various embodiments can be mutually referred to, and each embodiment focuses on the difference from other embodiments.

[0097] The above examples are only used to illustrate the technical solutions of the application, and are not limited to the application; although the application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the application.

Claims

1. A functional coordination type photosensitive polyimide film, characterized by comprising a polyimide film having a functional group on the surface thereof. The aromatic diamine monomer, the dianhydride monomer, the tertiary amine acrylate compound and the sulfide compound are polymerized and imidized to form the functional coordination type photosensitive polyimide film. The sulfide compound is prepared by reacting an olefin compound and a mercapto compound. The olefin compound is one or more of L-carvyl ketone, methyl vinyl ether and 5-norbornene-2-methyl formate. The mercapto compound is one or more of 3-mercapto propionic acid methyl ester, mercapto acetic acid methyl ester, 3-mercapto propionic acid glycidyl ester and 11-mercapto undecanoic acid.

2. The functional coordination type photosensitive polyimide film according to claim 1, wherein The aromatic diamine monomer is one or more of 4,4'-diamino diphenyl ether, p-phenylenediamine and 2,2-bis[4-(4-aminophenoxy)phenyl]propane.

3. The functional coordination type photosensitive polyimide film according to claim 1, wherein The dianhydride monomer is one or more of 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, pyromellitic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride and hexafluoro dianhydride.

4. The functional coordination type photosensitive polyimide film according to claim 1, wherein The tertiary amine acrylate compound is one or more of dimethylaminoethyl methacrylate, dimethylaminoethyl acrylate and morpholinoethyl methacrylate.

5. The functional coordination type photosensitive polyimide film according to claim 1, wherein The sulfide unit in the sulfide compound has a molar ratio of (0.05-1.5):1 relative to the aromatic diamine monomer.

6. A method for producing the functional coordination type photosensitive polyimide film according to any one of claims 1 to 5, characterized by, The preparation method comprises the following steps: under an inert atmosphere, mixing a solution A obtained by dissolving the aromatic diamine monomer in a first organic solvent and a solution B obtained by dissolving the dianhydride monomer in a second organic solvent to form a polyamic acid solution; under light shielding conditions, adding the tertiary amine acrylate compound to the polyamic acid solution to form a photosensitive polyimide acid solution; adding the olefin compound, the mercapto compound and a photoinitiator to the photosensitive polyimide acid solution to form a functional coordination type photosensitive polyimide acid solution; coating the functional coordination type photosensitive polyimide acid solution to form a film, and then performing photoetching, development, activation and imidization to form the functional coordination type photosensitive polyimide film. The first organic solvent and the second organic solvent are the same or different.

7. The method for preparing the functional coordination-type photosensitive polyimide film according to claim 6, characterized in that, The first organic solvent is one or more of N-vinyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, cyclopentanone, benzene and butyrolactone. The second organic solvent is one or more of N-vinyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, cyclopentanone, benzene and butyrolactone.

8. The method for preparing the functional coordination-type photosensitive polyimide film according to claim 6, characterized in that, The photoinitiator is 2,4,6-trimethylbenzoyl phenyl phosphinic acid ethyl ester, phenyl bis(2,4,6-trimethylbenzoyl) phosphine oxide or a derivative thereof. The exposure wavelength range of the photoinitiator is 365-405 nm.

9. A metal plating layer, characterized by, The functional coordination type photosensitive polyimide film prepared by the preparation method of any one of claims 6-8.

10. Application of the metal plating layer of claim 9 to a flexible circuit, a high-frequency circuit and an IC packaging substrate.

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