A cationic free radical polymerization composition for LDI dry film and LDI dry film

Abstract

This invention relates to a cationic radical polymerization composition for preparing LDI dry films and the LDI dry film itself. According to the present invention, the cationic radical polymerization composition for preparing LDI dry films comprises an alkali-soluble polymer, a radical polymerizable compound, and an initiator; wherein the side chains of the alkali-soluble polymer have oxetane groups, and the initiator includes both a cationic initiator and a radical initiator. Direct exposure of the LDI dry film containing the cationic radical polymerization composition of the present invention to a laser results in a cross-linking reaction due to the oxetane groups on the side chains of the alkali-soluble polymer and the cationic initiator, forming a network structure within and between the polymer chains. This improves the hardness and adhesion strength of the LDI dry film, thereby enhancing its photosensitivity, resolution, adhesion, and porosity, and also improving the resist shape.

Description

Technical Field

[0001] This invention relates to the field of PCBs, and more particularly to a cationic free radical polymerization composition for LDI dry film and the LDI dry film. Background Technology

[0002] PCB stands for Printed Circuit Board; LDI stands for Laser Direct Imaging Dry Film, an important material used in laser direct imaging processes in the PCB field.

[0003] According to the "2019-2024 In-depth Market Research and Investment Prospect Forecast Analysis Report on Photosensitive Dry Film Industry", since 2014 to 2018, with technological innovation, the PCB industry has developed rapidly. The domestic demand for PCB dry film has increased exponentially year by year. With the expansion of the market, various PCB-related companies have also emerged.

[0004] In 2014, the demand for photosensitive dry film in China was 3.084 billion yuan; experts predict that by 2024, the demand for photosensitive dry film in my country will increase to 10.095 billion yuan.

[0005] With the continuous advancement of technology, driven by the trend towards lighter and more compact electronic devices with higher circuit density, LDI dry film technology has emerged.

[0006] However, existing LDI dry films have problems such as low photosensitivity, resolution, adhesion, porosity, and poor resist shape when used for direct laser imaging.

[0007] Therefore, there is a need to provide a composition and an LDI dry film that simultaneously improve the aforementioned properties of LDI dry film. Summary of the Invention

[0008] This invention provides a cationic free radical polymerization composition for preparing LDI dry films and the LDI dry film itself. Using the cationic free radical polymerization composition of this invention, after the LDI dry film is prepared, during direct laser exposure, the alkali-soluble polymer, in conjunction with a cationic initiator, undergoes a cationic polymerization reaction within and between the alkali-soluble polymer chains, forming a cross-linked network. This improves the hardness and adhesion of the LDI dry film, thereby solving the technical problems of low photosensitivity, resolution, adhesion, and porosity of LDI dry films, as well as poor resist shape.

[0009] According to one aspect of the present invention, a cationic radical polymerization composition for preparing LDI dry films is provided, comprising: an alkali-soluble polymer; a radical polymerizable compound; and an initiator; wherein,

[0010] The side chains of the alkali-soluble polymers have oxocyclic butyl groups; and the initiators include cationic initiators and free radical initiators.

[0011] According to one embodiment of the composition of the present invention, the polymeric unit containing an oxygen-containing heterocyclic butyl group accounts for 1 to 65% by mass percentage in the alkali-soluble polymer.

[0012] According to one embodiment of the composition of the present invention, the polymeric monomers constituting the polymeric unit containing the oxygen-containing heterocyclic butyl group are as shown in Formula I and / or Formula II:

[0013]

[0014] Preferably, n is a natural number from 1 to 3.

[0015] According to one embodiment of the composition of the present invention, the alkali-soluble polymer further includes polyacrylic acid units;

[0016] Preferably, the polymeric monomers constituting the polyacrylic acid units are selected from at least one of the following: acrylic acid, methacrylic acid, fumaric acid, cinnamic acid, crotonic acid, itaconic acid, maleic anhydride, and maleic half ester.

[0017] According to one embodiment of the composition of the present invention, the alkali-soluble polymer further includes alkyl polyacrylate units;

[0018] Preferably, the polymeric monomer constituting the polyalkyl acrylate unit is selected from at least one of the following: methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, and butyl methacrylate.

[0019] According to one embodiment of the composition of the present invention, the alkali-soluble polymer further includes a benzene-ring-containing polymeric unit; preferably, the polymeric monomer constituting the benzene-ring-containing polymeric unit is selected from at least one of the following: benzyl acrylate and its derivatives, benzyl methacrylate and its derivatives, styrene and its derivatives.

[0020] According to one embodiment of the composition of the present invention, the weight-average molecular weight of the alkali-soluble polymer is 10,000 to 200,000 Da.

[0021] Preferably, the glass transition temperature of the alkali-soluble polymer is 100–150°C;

[0022] Preferably, the acid value of the alkali-soluble polymer is 100–250 mg KOH / g;

[0023] Preferably, the dispersion of the alkali-soluble polymer is 1.0 to 8.0.

[0024] According to one embodiment of the composition of the present invention, the polymeric units constituting the alkali-soluble polymer include: polymethacrylate units, polybenzyl methacrylate units, polymethyl methacrylate units, and poly(3-ethyloxetane-3-yl)methyl methacrylate units;

[0025] Preferably, based on the total mass of the alkali-soluble polymer, the polymethacrylic acid unit accounts for 5%-50% by mass percentage; the polybenzyl methacrylate unit accounts for 1%-50%; the polymethyl methacrylate unit accounts for 1-80%; and the polymethyl methacrylate (3-ethyloxetane-3-yl) methyl methacrylate accounts for 1-65%.

[0026] According to one embodiment of the composition of the present invention, the cationic initiator is selected from at least one of the following:

[0027] Iodonium salts, thioonium salts, and triazine compounds.

[0028] According to one embodiment of the composition of the present invention, the alkali-soluble polymer comprises 30 to 70 parts by weight, the free radical polymeric compound comprises 10 to 50 parts by weight, the cationic initiator comprises 0.1 to 1 part by weight, and the free radical initiator comprises 0.1 to 20 parts by weight.

[0029] According to another aspect of the present invention, an LDI dry film is provided, comprising:

[0030] Support layer;

[0031] Protective layer; and

[0032] A cationic free radical polymer composition layer is disposed between the support layer and the protective layer; and...

[0033] The cationic radical polymer layer comprises the cationic radical polymer composition of the present invention.

[0034] Compared with the prior art, the beneficial effects of using the technical solution of the present invention are as follows:

[0035] In the cationic radical polymerization composition of the present invention, when used for LDI dry film, an alkali-soluble polymer and a cationic initiator are used in combination.

[0036] Because the side chains of alkali-soluble polymers have oxocyclic butyl groups, when lasers are directly exposed, on the one hand, under the initiation of cationic initiators, the oxocyclic butyl groups of the side chains of alkali-soluble polymers can be opened, and cationic crosslinking reactions can occur inside the polymer chains and between the alkali-soluble polymer chains; on the other hand, compared with free radical polymerization, cationic polymerization does not have problems such as oxygen inhibition, and the dry film shrinkage rate of LDI is small.

[0037] The photosensitivity of the LDI dry film is improved by the cationic polymerization reaction occurring within the alkali-soluble polymer. Based on the above two aspects, the hardness and adhesion strength of the exposed areas of the LDI dry film are improved, thereby enhancing the alkali resistance of the exposed cross-linked areas. This results in improved porosity, adhesion, and resolution of the LDI dry film, and improved resist shape.

[0038] This invention introduces an oxocyclic butyl group into the alkali-soluble polymer contained in the cationic radical polymerization composition. Compared with the scheme that does not introduce an oxocyclic butyl group into the alkali-soluble polymer, but instead introduces an oxocyclic butyl group into the radical monomer during the LDI dry film preparation process, this invention allows for further cationic crosslinking reactions within and between the alkali-soluble polymer chains. The comparative scheme does not involve any reaction within the alkali-soluble polymer, but only radical polymerization occurs between the radical monomers. The reason for choosing a compound containing an oxocyclic butyl group is simply as a conventional choice for radical polymerization.

[0039] The LDI dry film according to the present invention, due to the use of the cationic free radical polymer composition of the present invention, has good porosity, photosensitivity, resolution and adhesion; and also has good resist shape. Attached Figure Description

[0040] Figure 1 This is a diagram illustrating the reaction mechanism of the LDI dry film of the present invention during direct laser exposure.

[0041] Figure 2 A diagram illustrating the reaction mechanism of an existing LDI dry film under direct laser exposure.

[0042] Figure 3 This invention provides an illustrative reaction equation for an LDI dry film during direct laser exposure.

[0043] Figure 4 The NMR spectrum of the alkali-soluble polymer prepared according to Example 1 is shown.

[0044] Figure 5 This is a comparison chart of the hardness of LDI dry films prepared according to Comparative Example 1 and Examples 1-3 of the present invention before and after exposure. Detailed Implementation

[0045] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] According to one aspect of the present invention, a cationic radical polymerization composition for preparing LDI dry films is provided, comprising: an alkali-soluble polymer; a radical polymerizable compound; and an initiator; wherein,

[0047] The side chains of the alkali-soluble polymers have oxocyclic butyl groups; and the initiators include cationic initiators and free radical initiators.

[0048] The LDI dry film containing the cationic free radical polymerization composition of the present invention is used in combination with an alkali-soluble polymer and a cationic initiator.

[0049] Because the side chains of alkali-soluble polymers have oxocyclic butyl groups, when lasers are directly exposed, on the one hand, under the initiation of cationic initiators, the oxocyclic butyl groups on the side chains of alkali-soluble polymers can be opened, and cationic crosslinking reactions can occur inside and between polymer chains; on the other hand, compared with free radical polymerization, cationic polymerization does not have the problem of oxygen inhibition, and the dry film shrinkage of LDI is small.

[0050] The photosensitivity of the LDI dry film is improved by the cationic polymerization reaction occurring within the alkali-soluble polymer. Based on these two aspects, the hardness and adhesion strength of the exposed area of ​​the LDI dry film are improved, thereby enhancing the alkali resistance of the exposed crosslinked area, and ultimately improving the porosity, adhesion, resolution, and resist shape of the LDI dry film. The cationic free radical polymerization composition of this invention comprises an alkali-soluble polymer having an oxetane group and a cationic initiator. During direct laser exposure, the oxetane group in the side chain of the alkali-soluble polymer undergoes cationic polymerization in conjunction with the cationic initiator. Within the exposed area B, due to the ring-opening of the oxetane group, cationic polymerization occurs within and between the polymer chains, forming a crosslinked network structure. The reaction mechanism is as follows: Figure 1 As shown, a is a monofunctional radical polymerizing monomer and / or a difunctional radical polymerizing monomer, b is the alkali-soluble polymer of this application, c is a polyfunctional radical polymerizing monomer, and d is a radical initiator and a cationic initiator; A is the unexposed soluble region; and B is the photo-crosslinked insoluble region after exposure.

[0051] In the prior art, neither an alkali-soluble polymer with an oxetane group nor a cationic initiator is introduced into the composition. Instead, the oxetane group is introduced into the free radical monomers during the LDI dry film preparation process. This invention allows for further cationic crosslinking reactions within and between the alkali-soluble polymer chains. The prior art does not involve any reaction within the alkali-soluble polymer; free radical polymerization occurs only between the free radical monomers. The choice of compounds containing oxetane groups is merely a conventional option for free radical polymers.

[0052] Reaction mechanism such as Figure 2 As shown, a is a monofunctional radical polymerizable monomer and / or a difunctional radical polymerizable monomer, b is a prior art alkali-soluble polymer, c is a polyfunctional radical polymerizable monomer, d is a radical initiator, A is an unexposed soluble region, and B is a photocrosslinked insoluble region after exposure. According to one embodiment of the composition of the present invention, the mass percentage of the oxy-heterocyclic butyl group polymeric unit in the alkali-soluble polymer is preferably 1-65%.

[0053] If the ratio is less than 1%, the number of oxobutyryl groups undergoing cationic polymerization is small, which cannot form sufficient crosslinking within the alkali-soluble polymer, and thus cannot better enhance the hardness and adhesion of the LDI dry film.

[0054] If the content is higher than 65%, although it can increase the number of oxobutyryl groups in cationic polymerization, it will at the same time reduce the amount of other polymerization units (such as polymer monomers containing carboxyl groups, which will reduce other properties of LDI dry film, such as developability and flexibility), thereby reducing the photosensitivity, resolution, porosity and adhesion of LDI dry film, as well as affecting the shape of the resist.

[0055] According to the alkali-soluble polymer of the present invention, the mass percentage of the polymerization unit containing the oxygen-containing heterocyclic butyl group in the alkali-soluble polymer is further preferably 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, and 65%.

[0056] According to one embodiment of the composition of the present invention, the polymerizable monomers of the oxy-heterocyclic butyl group polymerizable unit are as shown in Formula I and / or Formula II:

[0057]

[0058] Preferably, n is a natural number from 1 to 3; more preferably, it is 1 or 2.

[0059] Formulas I and II contain double bonds at one end, allowing them to copolymerize with other polymeric monomers; the other end contains a four-membered ring, enabling them to undergo ring-opening polymerization.

[0060] When n is preferably 1 or 2, the peelability of the LDI dry film prepared using the composition of the present invention can be improved.

[0061] That is, the polymerizable monomer containing an oxygen-containing heterocyclic butyl group is selected from at least one of the following:

[0062] Methyl (3-ethyloxetane-3-yl) acrylate (the compound corresponding to the one in formula I when n is 1), methyl (3-ethyloxetane-3-yl) methacrylate (the compound corresponding to the one in formula II when n is 1);

[0063] 2-(3-ethyloxetane-3-yl)ethyl acrylate (the compound corresponding to the compound of formula I when n is 2), 2-(3-ethyloxetane-3-yl)ethyl methacrylate (the compound corresponding to the compound of formula II when n is 2);

[0064] 3-(3-ethyloxetane-3-yl)propyl acrylate (the compound corresponding to n=3 in Formula I) and 3-(3-ethyloxetane-3-yl)propyl methacrylate (the compound corresponding to n=3 in Formula II).

[0065] According to one embodiment of the composition of the present invention, the alkali-soluble polymer further includes polyacrylic acid units; the polymeric monomers constituting the polyacrylic acid units are selected from at least one of the following: acrylic acid, methacrylic acid, fumaric acid, cinnamic acid, crotonic acid, itaconic acid, maleic anhydride, and maleic half ester.

[0066] Among them, acrylic acid and methacrylic acid are preferred.

[0067] Preferably, based on the total mass of the alkali-soluble polymer, the polyacrylic acid units account for 1 to 50% of the total mass of the alkali-soluble polymer.

[0068] If the acid value is less than 1%, the acid value is too low, and the development performance of the LDI dry film is poor; if it is greater than 50%, the resist shape is poor, and the exposed area may also be washed away.

[0069] Based on the above considerations, 1-35% is further preferred; 1-30% is even more preferred; 1-25% is even more preferred; and 1-20% is even more preferred.

[0070] Specifically, the percentage of polyacrylic acid units in the total mass of the alkali-soluble polymer is preferably 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50%.

[0071] According to one embodiment of the composition of the present invention, the alkali-soluble polymer further includes alkyl polyacrylate units;

[0072] The polymeric monomers constituting the polyacrylate units are selected from at least one of the following: methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, and butyl methacrylate.

[0073] According to the composition of the present invention, the acrylate monomers preferably alkyl acrylate and alkyl methacrylate as alkyl acrylates, which can be represented by chemical formula III, wherein R1 represents a hydrogen atom or a methyl group, and R2 represents an alkyl group having 1 to 12 carbon atoms.

[0074]

[0075] In Formula III, R1 can be a methyl group or a hydrogen atom; R2 represents an alkyl group with 1 to 12 carbon atoms, selected from any of the following groups: methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, and their structural isomers; preferably methyl, ethyl, propyl, and butyl. The alkyl group is preferably an alkyl group with 4 or fewer carbon atoms (i.e., methyl, ethyl, propyl, and butyl), which can improve the peelability of the LDI dry film.

[0076] That is, in this invention, the compounds shown in Formula III above may be selected from at least one of the following compounds: methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, and butyl methacrylate.

[0077] It may also be selected from the following compounds: pentyl acrylate, pentyl methacrylate, hexyl acrylate, hexyl methacrylate, heptyl acrylate, heptyl methacrylate, octyl acrylate, octyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, nonyl acrylate, nonyl methacrylate, decyl acrylate, decyl methacrylate, undecyl acrylate, undecyl methacrylate, dodecyl acrylate and dodecyl methacrylate.

[0078] When using alkyl acrylates and / or alkyl methacrylates as the base, preferably, the base accounts for 1 to 80% of the total mass of the alkali-soluble polymer, within which the peelability and adhesion of the LDI film can be improved.

[0079] If the percentage is less than 1%, the peelability of the LDI dry film is poor; if it is greater than 80%, the adhesion, resolution, and resist shape of the LDI dry film are poor; when it is between 1% and 80%, the peelability, adhesion, resolution, and resist shape of the dry film are all good.

[0080] Based on the above considerations, a further preferred ratio is 2-70%, and an even more preferred ratio is 3-60%.

[0081] Specifically, the preferred percentages are: 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 60%, 70%, and 80%.

[0082] According to one embodiment of the composition of the present invention, the alkali-soluble polymer further includes benzene-ring-containing polymeric units; preferably, the polymeric monomers constituting the benzene-ring-containing polymeric units are selected from at least one of the following: benzyl acrylate and its derivatives, benzyl methacrylate and its derivatives, styrene and its derivatives. Preferably, the benzene-ring-containing polymeric units account for 1 to 50% of the alkali-soluble polymer by mass percentage. If it is less than 1%, sufficient resolution is not easily obtained; if it is greater than 50%, the release slab becomes larger and the release time becomes longer. Specifically, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, and 50% are preferred.

[0083] In this application, in addition to the acrylic polymer monomers, acrylate polymer monomers, and polymer monomers containing benzene rings as specifically described above, the following polymer monomers may also be selected: (1) polymerizable styrene derivatives such as vinyltoluene and α-methylstyrene with substituted α-positions or aromatic rings; (2) acrylamides such as diacetone acrylamide; (3) cycloalkyl methacrylates, furfuryl methacrylates, tetrahydrodiethyl methacrylates, adamantyl methacrylates, dicyclopentyl methacrylates, etc. (4) α-bromo(meth)acrylic acid, α-chloro(meth)acrylic acid, β-methyl(meth)acrylic acid, β-styryl(meth)acrylic acid, etc. (5) monomethyl maleate, maleic acid, propynic acid, etc. (6) acrylonitrile. It is worth noting that the presence of (methyl) in parentheses in (1) to (6) above indicates that the compound is divided into two cases: containing methyl and not containing methyl; and this is also true in the following text. According to one embodiment of the composition of the present invention, the weight average molecular weight of the alkali-soluble polymer is 10,000 to 200,000 Da; preferably, the glass transition temperature of the alkali-soluble polymer is 100 to 150 °C;

[0084] Preferably, the acid value of the alkali-soluble polymer is 100-250 mg KOH / g; preferably, the dispersity of the alkali-soluble polymer is 1.0-8.0.

[0085] Among them, alkali-soluble polymers are one of the main components of LDI dry film. If the weight average molecular weight of the alkali-soluble polymer is less than 10,000 Da, the LDI dry film will be too easy to wash off, and even the exposed areas will be washed off. If the weight average molecular weight of the alkali-soluble polymer is greater than 200,000 Da, the LDI dry film will be too difficult to wash off and will leave residue. Therefore, within this range, the best effect is achieved when the LDI dry film in the exposed areas is not easy to wash off, while the non-exposed areas are easy to remove.

[0086] The preferred weight-average molecular weights of the alkali-soluble polymers are 10,000 Da, 20,000 Da, 30,000 Da, 40,000 Da, 50,000 Da, 80,000 Da, 100,000 Da, 150,000 Da, and 200,000 Da.

[0087] In this process, the alkali-soluble polymer is the main component of the LDI dry film. The LDI dry film needs to maintain a glass transition temperature above 100°C, significantly higher than the storage and / or transportation environment temperature. This gives the LDI dry film good stability and prevents uneven thickness caused by localized flow, i.e., prevents cold flow. Specifically, the preferred glass transition temperatures of the alkali-soluble polymer are: 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, and 150°C.

[0088] According to the composition of the present invention, the acid value of the alkali-soluble polymer is preferably 100-250 mg KOH / g.

[0089] When the acid value is below 100 mg KOH / g, the non-exposed areas are not easily washed away by the alkaline solution; when the acid value is above 250 mg KOH / g, the exposed areas will also be washed away by the alkaline solution.

[0090] According to the compositions of the present invention, the preferred acid values ​​of the alkali-soluble polymers are: 100 mg KOH / g, 110 mg KOH / g, 120 mg KOH / g, 130 mg KOH / g, 140 mg KOH / g, 150 mg KOH / g, 160 mg KOH / g, 170 mg KOH / g, 180 mg KOH / g, 190 mg KOH / g, 200 mg KOH / g, 210 mg KOH / g, 220 mg KOH / g, 230 mg KOH / g, and 250 mg KOH / g.

[0091] According to the alkali-soluble polymer of the present invention, the dispersion of the alkali-soluble polymer is preferably 1.0 to 8.0. Further preferred dispersions are 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0 and 8.0.

[0092] According to one embodiment of the composition of the present invention, the polymeric monomers constituting the alkali-soluble polymer include: methacrylic acid, benzyl methacrylate, methyl methacrylate, and (3-ethyloxetane-3-yl)methyl methacrylate.

[0093] According to the composition of the present invention, the alkali-soluble polymer is selected from the four specific polymeric monomers mentioned above. Due to their similar structures, they have a high reactivity ratio and a high polymerization rate. Furthermore, the alkali-soluble polymer prepared is used to prepare LDI dry films, which exhibit high photosensitivity, resolution, adhesion, porosity, and good resist shape. Preferably, based on the total mass of the alkali-soluble polymer, the following percentages are expressed by weight: polymethacrylic acid units account for 5%-50%; polybenzyl methacrylate units account for 1%-50%; polymethyl methacrylate units account for 1-80%; and poly(3-ethyloxetane-3-yl)methyl methacrylate accounts for 1-65%.

[0094] The polymethacrylic acid unit is further preferably 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, and 50%. The polybenzyl methacrylate unit is further preferably 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, and 50%. The polymethyl methacrylate unit is further preferably 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 60%, 70%, and 80%. The polymethyl methacrylate (3-ethyloxetane-3-yl) methyl methacrylate is further preferably 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, and 65%.

[0095] Alkali-soluble polymers within the above range are used to prepare LDI dry films, which have high photosensitivity, resolution, adhesion and porosity, and good resist shape.

[0096] According to the above-described composition of the present invention, after preparing the LDI dry film, a cationic initiator is used to induce cationic polymerization of the alkali-soluble polymer with the cationic initiator during direct laser exposure. An illustrative reaction equation is as follows: Figure 3 As shown.

[0097] According to one embodiment of the composition of the present invention, the cationic initiator is selected from at least one of the following: iodonium salt compounds, thiodonium salt compounds, and triazine compounds.

[0098] The iodonium salt compound is selected from at least one of the following: 4-isobutyl-4'-methyliodonium hexafluorophosphate, bis(4-dodecylphenyl)iodonium hexafluoroantimonate, bis(4-tert-butylphenyl)iodonium hexafluorophosphate, and 4,4′-xylyliodonium hexafluorophosphate.

[0099] The thioonium salt compound is selected from at least one of the following: triphenylthioonium hexafluorophosphate, 4-phenylthiophenyl diphenylthioonium hexafluorophosphate, and bis(4-(diphenylsulfonium)phenyl)sulfide-bis(hexafluorophosphate).

[0100] The triazine compound is selected from at least one of the following: 2-(3,4-dimethoxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-S-triazine, and 2-(1,3-benzodioxolane-5-yl)-4,6-bis(trichloromethyl)-1,3,5-triazine.

[0101] Using the above-mentioned cationic initiator, under direct laser exposure, cationic cross-linking polymerization can occur within and between alkali-soluble polymer chains in the exposed area, forming a cross-linked network.

[0102] It should be further noted that, in addition to the preferred cationic initiators mentioned above, other cationic initiators that can produce cationic polymerization of the initiator under light irradiation may also be selected in this application.

[0103] In the cationic radical polymer composition of the present invention, the initiator further includes a radical initiator. The radical initiator may be selected from hexaaryldiimidazole compounds, quinone compounds, aromatic ketone compounds, acetophenone compounds, acylphosphine oxide compounds, benzoin compounds, benzoin ether compounds, dialkyl ketals, thioxanone compounds, oxime ester compounds, and acridine compounds.

[0104] Hexaaryl diimidazole compounds can be selected from 2-(o-chlorophenyl)-4,5-diphenyldiimidazole, 2,2,5-tris-(o-chlorophenyl)-4-(3,4-dimethoxyphenyl)-4',5'-diphenyldiimidazole, 2,4-bis-(o-chlorophenyl)-5-(3,4-dimethoxyphenyl)-diphenyldiimidazole, 2,4,5-tris-(o-chlorophenyl)-diphenyldiimidazole, 2-(o-chlorophenyl)-bis-4,5-(3,4-dimethoxyphenyl)-diimidazole, 2,2'-bis-(2-fluorophenyl)-4,4',5,5'-tetra-(3-methoxyphenyl)-diimidazole, 2,2'-bis-(2,3-difluoromethylphenyl)-4,4',5,5'-tetra-(3-methoxyphenyl)-diimidazole, 2,2'-bis-(2,4-difluorophenyl)-diimidazole, and 2,2'-bis-(2,4-difluorophenyl)-diimidazole.

[0105] 2,2'-bis(2,5-difluorobenzene)-4,4',5,5'-tetra-(3-methoxyphenyl)-diimidazole, 2,2'-bis(2,5-difluorobenzene)

[0106] 2,2'-bis(2,6-difluorobenzene)-4,4',5,5'-tetra-(3-methoxyphenyl)-diimidazole, 2,2'-bis(2,6-difluorobenzene)

[0107] 2,2'-bis-(2,3,4-trifluorophenyl)-4,4',5,5'-tetra-(3-methoxyphenyl)-diimidazole, 2,2'-bis-(2,3,6-trifluorophenyl)-4,4',5,5'-tetra-(3-methoxyphenyl)-diimidazole, 2,2'-bis-(2,3,5-trifluorophenyl)-0135.4,4',5,5'-tetra-(3-methoxyphenyl)-diimidazole, 2,2'-bis-(2,3,6-trifluorophenyl)-4,4',5,5'-tetra-(3-methoxyphenyl)-diimidazole, 2,2'-bis-(2,4,5-trifluorophenyl)-4,4',5,5'-tetra-(3-methoxyphenyl)-diimidazole, 2,2'-bis-(2,4,5-trifluorophenyl)-4,4',5,5'-tetra-(3-methoxyphenyl)-diimidazole 2,2'-(2,4,6-trifluorophenyl)-4,4',5,5'-tetra-(3-methoxyphenyl)-diimidazole, 2,2'-bis-(2,3,4,5-tetrafluorophenyl)-4,4',5,5'-tetra-(3-methoxyphenyl)-diimidazole, 2,2'-bis-(2,3,4,5-tetrafluorophenyl)-4,4',5,5'-tetra-(3-methoxyphenyl)-diimidazole, and 2,2'-bis-(2,3,4,5,6-pentafluorophenyl)-4,4',5,5'-tetra-(3-methoxyphenyl)-diimidazole, etc. Further preferred are 2-(o-chlorophenyl)-4,5-diphenylimidazole dimers.

[0108] Aromatic ketone compounds, such as benzophenone and 4,4'-diethylaminobenzophenone, can be selected.

[0109] The acetophenone compound can be selected from 2-hydroxy-2-methyl-1-phenylpropane-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-one, 1-(4-dodecylphenyl)-2-hydroxy-2-methylpropane-1-one, 4-(2-hydroxyethoxy)-phenyl(2-hydroxy-2-propyl)one, 1-hydroxycyclohexylphenylone, 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butanone-1, and 2-methyl-1-[4-(methylthio)phenyl]-2-morpholin-acetone-1.

[0110] Acylphosphine oxide compounds can be selected from 2,4,6-trimethylbenzyl diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phosphine oxide, and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide. Thioxanone compounds can be selected from 2,4-diethylthioxanone, 2,4-diisopropylthioxanone, and 2-chlorothioxanone. Oxime ester compounds can be selected from 1-phenyl-1,2-propanedione-2-O-benzoyl oxime and 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl) oxime.

[0111] According to one embodiment of the composition of the present invention, the alkali-soluble polymer comprises 30 to 70 parts by weight, the free radical polymeric compound comprises 10 to 50 parts by weight, the cationic initiator comprises 0.1 to 1 part by weight, and the free radical initiator comprises 0.1 to 20 parts by weight.

[0112] When the total amount of the composition for preparing LDI dry film by cationic free radical polymerization is 100 parts by mass, the alkali-soluble polymer is preferably 30 to 70 parts.

[0113] The 30-70 parts of alkali-soluble polymer refer to the solid solution in the solution.

[0114] When the content is less than 30 parts, the unexposed areas are not easily washed away, resulting in poor developability. When the content is greater than 70 parts, the amount of free radical polymerizable compounds is relatively reduced, leading to poor adhesion and porosity of the exposed areas after laser exposure when preparing LDI dry film. However, within the range of 30 to 70 parts, the developability, adhesion, and porosity are all good.

[0115] Based on the comprehensive consideration of the above-mentioned developability, sealing and pore-covering properties, 30 to 65 parts are further preferred; 40 to 60 parts are even more preferred.

[0116] Specifically, 30, 35, 40, 45, 50, 55, 60, and 65 portions are preferred.

[0117] When the total amount of the composition for preparing LDI dry film by cationic free radical polymerization is 100 parts by mass, the amount of cationic initiator is preferably 0.1 to 1 part.

[0118] Further preferred amounts are 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, and 1.0 parts.

[0119] When the amount of cationic initiator is within the above range, it is sufficient to initiate a cationic polymerization reaction of the alkali-soluble polymer in the exposed area.

[0120] In this invention, when the total amount of the free radical initiator is 100 parts by mass relative to the total amount of the composition for preparing LDI dry film cationic free radical polymerization, the total amount of the free radical initiator is preferably 0.1 to 20 parts.

[0121] The free radical initiator is preferably a hexaaryl diimidazole compound, preferably used in amounts of 0.1 to 10 parts, more preferably 0.5 to 5 parts.

[0122] free radical polymerizable monomers

[0123] According to one embodiment of the present invention, the free radical polymerizable compound is a free radical polymerizable compound containing olefinically unsaturated groups, and the free radical polymerizable compound can be in the form of monomers or resins (including oligomers and prepolymers).

[0124] According to one embodiment of the present invention, based on 100 parts of a cationic free radical polymerizable composition, the total amount of free radical polymerizable compound is preferably 10 to 50 parts.

[0125] Further preferred amounts are 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, and 50 parts. The free radical polymerizable compound includes monofunctional compounds, difunctional compounds, trifunctional compounds, or compounds with more than one functional group that can be polymerized by free radicals, and mixtures thereof; preferably, mixtures of monofunctional compounds, difunctional compounds, and trifunctional compounds, or mixtures of two or more difunctional compounds.

[0126] Free radical polymerizable monofunctional compounds have low viscosity and can be used as photoreactive diluents. Examples include acrylate compounds, methacrylate compounds, acryloyl compounds, methacryloyl compounds, ethylene derivatives, styrene compounds, acid anhydrides containing olefinic unsaturated double bonds (such as maleic anhydride), N-vinylpyrrolidone, and N-vinylformamide.

[0127] Preferred acrylate and methacrylate compounds include: C1-C18 alkyl acrylate and C1-C18 alkyl methacrylate; further preferred are C1-C6 alkyl acrylate and C1-C6 alkyl methacrylate; even more preferred are methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, lauryl acrylate, lauryl methacrylate, stearyl acrylate, stearyl methacrylate, and 2-isobutylenoyl ethoxyphthalate.

[0128] Alternatively, hydroxyl-functionalized (meth)acrylates can be selected, such as hydroxy C1-C6 alkyl (meth)acrylates, specifically 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, glycidyl methacrylate, etc.

[0129] Alternatively, methacrylates with a cyclic skeleton can be selected, such as isobornyl methacrylate, tetrahydrofurfuryl methacrylate, glycidyl methacrylate, γ-butyrolactone methacrylate, γ-butyrolactone methacrylate, and tricyclodecyl methacrylate.

[0130] Alternatively, (meth)acrylates containing alkoxy groups such as EO and PO (e.g., having 1-10, such as 2, 4, 6, 6, or 8, preferably 1-5 EO and / or PO units) can be selected, such as methoxydiethylene glycol (meth)acrylate, methoxytriethylene glycol (meth)acrylate, and phenoxyethyl (meth)acrylate. Among these, (meth)acryloyl groups can be selected from acryloylmorpholine, 2-methacryloylethoxysuccinate, N,N-dimethylacrylamide, N,N-diethylacrylamide, and N,N-dipropylacrylamide.

[0131] Chloromethylstyrene and α-methylstyrene can be selected as styrene compounds.

[0132] For acid anhydrides containing olefinic unsaturated double bonds, maleic anhydride, etc., can be selected.

[0133] Vinyl esters can be selected as ethylene derivatives, preferably vinyl esters of C2-C6 monocarboxylic acids, such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl valerate, vinyl hexanoate, or mixtures thereof.

[0134] When the total amount of the composition for preparing LDI dry film by cationic free radical polymerization is 100 parts by mass, 5 to 35 parts by mass of free radical polymerizable monofunctional compound can be selected.

[0135] The reactivity of free-radical polymerizable difunctional compounds is higher than that of monofunctional compounds, which can improve the surface curing properties of LDI dry films. Their viscosity is lower than that of free-radical polymerizable trifunctional compounds. By combining them with monofunctional compounds, they can serve as effective diluents for trifunctional and more functional compounds, thereby reducing the viscosity and increasing the reactivity of LDI dry films containing the cationic free-radical polymerizable composition of this invention.

[0136] Free radical polymerizable bifunctional compounds, such as di(meth)acrylates of diols or triols having 2-12 carbon atoms, such as 2, 4, 6, 8, or 10, with a number average molecular weight not exceeding 1,500, such as di(meth)acrylates of polyethylene glycol or polypropylene glycol not exceeding 1,200. These compounds are optionally modified with EO or PO, such as by 5-15 EOs and / or PO. Specifically, the following can be selected: 2-hydroxy-3-acryloyloxypropyl (meth)acrylate, neopentyl glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 2-methyl-1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, ethoxylated 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, propoxylated neopentyl glycol di(meth)acrylate, polyethylene glycol 400 di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol 400 di(meth)acrylate, polypropylene glycol 400 di(meth)acrylate, etc. Diol 700 di(meth)acrylate, neopentyl glycol di(meth)acrylate, glycerol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol 200 di(meth)acrylate, polyethylene glycol 600 di(meth)acrylate, polyethylene glycol 1000 di(meth)acrylate, ethoxylated polypropylene glycol 700 di(meth)acrylate, polypropylene glycol 400 di(meth)acrylate, bisphenol A type di(meth)acrylate (may contain different EO, PO, etc. alkoxy segments), hydrogenated bisphenol A type di(meth)acrylate (may contain different EO, PO, etc. alkoxy segments), dicyclopentadiene, 2,2-bis(4-(methacryloyloxypolyethoxy)phenyl)propane (average number of EO units is 5-15 per molecule). One or more of the above compounds may be selected.

[0137] Preferred are di(meth)acrylates of polyethylene glycol with a number average molecular weight not exceeding 1,200 (e.g., not exceeding 800) and 2,2-bis(4-(methacryloyloxypolyethoxy)phenyl)propane (with an average number of EO units of 5-15 per molecule and mixtures thereof).

[0138] When the total amount of the composition for preparing LDI dry film by cationic free radical polymerization is 100 parts by mass, 5 to 40 parts by mass of the free radical polymerizable bifunctional compound can be selected.

[0139] Free radical polymerizable compounds with three or more functional groups can be selected from compounds having three or more (meth)acrylate groups.

[0140] Specifically, the following can be selected: trimethylolpropane triacrylate, trimethylolmethane triacrylate, ethylene oxide-modified trimethylolpropane triacrylate, propylene oxide-modified trimethylolpropane triacrylate, epichlorohydrin-modified trimethylolpropane triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetra(meth)acrylate, tetramethylolmethane tetraacrylate, ethylene oxide-modified phosphate triacrylate, propylene oxide-modified phosphate triacrylate, epichlorohydrin-modified glycerol triacrylate, dipentaerythritol hexaacrylate, di(trimethylolpropane)tetraacrylate, or their sesquioxane-modified polyfunctional acrylates, or their corresponding methacrylate monomers, ε-caprolactone-modified triacryloyloxyethyl isocyanurate, etc.

[0141] When the total amount of the composition for preparing LDI dry film by cationic free radical polymerization is 100 parts by mass, 5 to 40 parts by mass of free radical polymerizable trifunctional compound or more functional compound can be selected.

[0142] In one embodiment of the invention, the free radical polymerizable compound is in the form of a resin (containing oligomers or prepolymers).

[0143] The preferred free radical polymerizable resins are epoxy (meth)acrylate resins, polyester (meth)acrylate resins, polyurethane (meth)acrylate resins, olefin unsaturated polyesters, amino (meth)acrylate resins, and alkali-soluble resins for optical imaging.

[0144] The present invention preferably uses epoxy (meth)acrylate resin, polyester (meth)acrylate, polyurethane (meth)acrylate or a combination thereof.

[0145] The preferred epoxy (meth)acrylate resins are bisphenol A epoxy (meth)acrylate, bisphenol A epoxy acrylate diluted with tripropylene glycol dimethacrylate, or combinations thereof, such as bisphenol A epoxy acrylate WSR-U125 from Wuxi Resin Factory, bisphenol A epoxy acrylate 621A-80 diluted with 20% tripropylene glycol diacrylate from Chang Hsing Chemical Co., Ltd. in Taiwan, modified bisphenol A epoxy acrylate 623-100 from Chang Hsing Chemical Co., Ltd. in Taiwan, and modified bisphenol A epoxy acrylate 6231A-80 diluted with 20% tripropylene glycol diacrylate from Chang Hsing Chemical Co., Ltd. in Taiwan.

[0146] For polyester (meth)acrylates, highly functional hyperbranched polyester acrylate resins are preferred, especially those with a functionality of 5-30, such as hyperbranched polyester acrylate prepolymers with a functionality of 6-20. Examples of suitable prepolymers include Wuxi Knox's hyperbranched polyester acrylate prepolymer 932-100 (6 functionality), and Sartoma's hyperbranched polyester acrylate prepolymers CN2300 (8 functionality), CN2301 (9 functionality), and CN2302 (16 functionality). Polyester (meth)acrylates can also be polyester polyol acrylate resins diluted with 20% ethoxytrimethylolpropane triacrylate.

[0147] The preferred polyurethane (meth)acrylate is an aliphatic polyurethane acrylate. For this purpose, aliphatic polyurethane hexaacrylates 6145-100 and 6161-100, and aliphatic polyurethane diacrylates 611B-85 and 6141H-80 diluted with 15% 1,6-hexanediol diacrylate (HDDA) from Chang Hsing Chemical Co., Ltd. (Taiwan) can be selected; aliphatic polyurethane acrylate CN9013 (9 functionalities) from Sartoma Chemical Co., Ltd. (USA), aliphatic polyurethane acrylate CN966B85 (2 functionalities) diluted with 15% 1,6-hexanediol diacrylate (HDDA) from Sartoma Chemical Co., Ltd. (USA), and aliphatic polyurethane acrylate CN962 (2 functionalities) from Sartoma Chemical Co., Ltd.

[0148] The cationic radical polymerization composition of the present invention may contain only the above-mentioned components, or it may contain other components in addition to the above-mentioned components.

[0149] Other components may include sensitizers, hydrogen donors, colorless dyes, base dyes, and polymerization inhibitors.

[0150] The sensitizer may be selected from at least one of the following: pyrazoline compounds, anthracene compounds, acridine, triarylamine compounds, and oxazole compounds.

[0151] The hydrogen donor may be selected from at least one of the following: N-aryl amino acid compounds and thiol compounds, such as N-phenylglycine and mercaptobenzoxazole.

[0152] The colorless dye is selected from one of the following: colorless crystal violet (tris[4-(dimethylamino)phenyl]methane), 3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide; preferably colorless crystal violet.

[0153] The preferred base dyes are Basic Green 1, Malachite Green Oxalate, and Basic Blue 7.

[0154] The free radical polymerization inhibitor is selected from at least one of the following: p-methoxyphenol, hydroquinone, pyrogallol, naphthylamine, tert-butylcatechol, cuprous chloride, 2,6-di-tert-butyl-p-cresol, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], aluminum salt of nitrosophenylhydroxylamine (e.g., aluminum salt obtained by adding 3 moles of nitrosophenylhydroxylamine), diphenylnitrosamine, etc. Among these, triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate] and aluminum salt obtained by adding 3 moles of nitrosophenylhydroxylamine are preferred.

[0155] According to another aspect of the present invention, an LDI dry film is provided, comprising:

[0156] Support layer;

[0157] Protective layer; and

[0158] A cationic free radical polymer composition layer is disposed between the support layer and the protective layer; and...

[0159] The cationic radical polymer layer comprises the cationic radical polymer composition of the present invention.

[0160] The support can be made of polyester such as polyethylene terephthalate, or it can be made of polymer films such as polypropylene and polyethylene that have heat resistance and solvent resistance.

[0161] The protective layer can be made of polymer films such as polyethylene and polypropylene.

[0162] The LDI dry film according to the present invention has good photosensitivity, adhesion, resolution and pore-covering properties, as well as good resist shape.

[0163] In this embodiment, a cationic radical polymerization composition conditioning solution can be prepared by adding a solvent to the above-mentioned cationic radical polymerization composition.

[0164] The preferred solvents are methyl ethyl ketone (MEK), methanol, ethanol, and isopropanol.

[0165] The viscosity of the prepared liquid is 500 mPa·s to 4000 mPa·s at 25°C.

[0166] The preparation liquid of the cationic free radical polymer composition of the present invention is used as a coating liquid and coated on the surface of the support. After drying, a cationic free radical polymer composition layer is formed. A protective layer is then applied to the surface of the cationic free radical polymer layer to obtain an LDI dry film.

Claims

1. A cationic free radical polymerization composition for preparing LDI dry films, characterized in that, include: Alkali-soluble polymers, including monomers of polyacrylic acid units or monomers of polyalkyl acrylate units; Free radical polymerizable compounds; Initiator; among which, The side chains of the alkali-soluble polymer have oxoheterobutyl groups; and the initiator includes cationic initiators and free radical initiators; the oxoheterobutyl group-containing polymeric units account for 1 to 65% by mass percentage in the alkali-soluble polymer; the polymeric monomers constituting the oxoheterobutyl group-containing polymeric units are shown in Formula I and / or Formula II: ； n is a natural number from 1 to 3; The polymer monomers of the polyacrylic acid unit are selected from at least one of the following: acrylic acid, methacrylic acid, fumaric acid, cinnamic acid, crotonic acid, itaconic acid, maleic anhydride, and maleic half ester. The monomers for the polyalkyl acrylate units are selected from at least one of the following: methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, and butyl methacrylate.

2. The composition according to claim 1, characterized in that, The weight-average molecular weight of the alkali-soluble polymer is 10,000 to 200,000 Da; the glass transition temperature of the alkali-soluble polymer is 100 to 150 °C; the acid value of the alkali-soluble polymer is 100 to 250 mg KOH / g; and the dispersity of the alkali-soluble polymer is 1.0 to 8.

0.

3. The composition according to claim 1, characterized in that, The polymeric units constituting the alkali-soluble polymer include: polymethacrylic acid units, polybenzyl methacrylate units, polymethyl methacrylate units, and poly(3-ethyloxetane-3-yl)methyl methacrylate units; based on the total mass of the alkali-soluble polymer, the polymethacrylic acid units account for 5%-50% by mass percentage. The polymethyl methacrylate unit accounts for 1%-50%, the polymethyl methacrylate unit accounts for 1-80%, and the polymethyl methacrylate accounts for 1-65%.

4. The composition according to claim 3, characterized in that, The cationic initiator is selected from at least one of the following: iodonium salt compounds, thiodonium salt compounds, and triazine compounds.

5. The composition according to claim 1, characterized in that, The alkali-soluble polymer comprises 30-70 parts by weight, the free radical polymerizable compound comprises 10-50 parts by weight, the cationic initiator comprises 0.1-1 parts by weight, and the free radical initiator comprises 0.1-20 parts by weight.

6. An LDI dry film, characterized in that, include: Support layer; Protective layer; and a cationic radical polymeric composition layer disposed between the support layer and the protective layer; and, The cationic radical polymer layer comprises the cationic radical polymer composition according to any one of claims 1 to 5.

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