A packaging substrate solder resist dry film and preparation method thereof

Abstract

The present invention relates to a package substrate solder resist dry film and a preparation method thereof, wherein the package substrate solder resist dry film comprises the following components by mass: 10-20 parts of acrylic resin, 1-10 parts of active monomer, 5-15 parts of modified polyacrylate, 10-20 parts of epoxy resin, 5-15 parts of filler, 1-10 parts of auxiliary agent, and 20-60 parts of solvent; wherein the modified polyacrylate is obtained by reacting polysaccharide, acrylic anhydride, and phenyl acrylate. The present invention adopts modified polyacrylate to compound with epoxy resin, acrylic resin, filler and other components, thereby improving the strength, adhesion and stability of the dry film, being able to be stably used for a long time under various conditions, providing a protection function for the circuit, and having good application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of solder resist dry films, and in particular to a packaging substrate solder resist dry film and a preparation method thereof. Background Art

[0002] There are a large number of precision circuits on the surface of the packaging substrate, so a protective layer needs to be coated to prevent problems such as circuit oxidation, corrosion, and short circuits, thereby maintaining long-term and stable operation of the circuit board.

[0003] The current conventional treatment method is to apply solder mask ink on the surface of the package substrate and then cure it. Although solder mask ink has been widely used, this type of treatment method has many steps and the process is cumbersome. There is also a technical solution that uses solder mask dry film. After the resin is dried and cured into a film layer, it is directly pressed on the surface of the package substrate. Not only is the process simpler, but it can also avoid defects such as bubbles and unevenness.

[0004] However, the existing solder mask dry film still has some shortcomings, such as: weak adhesion effect, insufficient dry film adhesion; low dry film strength, and unsatisfactory protection effect on the packaging substrate; and poor dry film stability. After long-term storage under high and low temperature or acid, alkali, salt spray and other conditions, it will be corroded and damaged, resulting in circuit damage.

[0005] In summary, it is urgent to develop a new technical solution to improve the performance of the solder mask dry film to solve the deficiencies in the existing technology and meet the needs of the market and industry. Summary of the invention

[0006] Based on this, the present invention provides a package substrate solder resist dry film and a preparation method thereof. The present invention uses modified polyacrylate compounded with epoxy resin, acrylic resin, filler and other components to improve the strength, adhesion and stability of the dry film, can be used stably for a long time under various conditions, provides protection for the circuit, and has good application prospects.

[0007] One object of the present invention is to provide a package substrate solder resist dry film, wherein the package substrate solder resist dry film comprises the following components in parts by mass:

[0008]

[0009] in,

[0010] The modified polyacrylate is obtained by the reaction of polysaccharide, acrylic anhydride and phenyl acrylate.

[0011] Furthermore, the mass ratio of the polysaccharide, acrylic anhydride and phenyl acrylate is 1:(0.5-2):(0.1-2).

[0012] Furthermore, the polysaccharide is gum arabic.

[0013] Furthermore, the filler is surface-modified with polyvinyl pyrrolidone.

[0014] Furthermore, the active monomer is a monomer having a monofunctional or multifunctional acrylate unit.

[0015] Furthermore, the auxiliary agent is selected from one or more of an initiator, a photoinitiator, a crosslinking agent, a color powder, a leveling agent, a defoaming agent, a UV absorber, a dispersant, an antioxidant, and a toughening agent.

[0016] Another object of the present invention is to provide a method for preparing the above-mentioned package substrate solder resist dry film, the method for preparing the package substrate solder resist dry film comprising the following steps:

[0017] S1, mixing polysaccharide and acrylic anhydride, reacting at low temperature, mixing with phenyl acrylate and initiator, and heating to react, thereby obtaining modified polyacrylate;

[0018] S2, mixing the modified polyacrylate, acrylic resin, active monomer, epoxy resin, filler, additive, and solvent to obtain a solder resist dry film mixed liquid;

[0019] S3, applying the solder resist dry film mixture to a substrate, and covering it with a protective film after drying to obtain the packaging substrate solder resist dry film.

[0020] Furthermore, in step S1, the temperature of the low-temperature reaction is 0-30°C and the time is 1-12h.

[0021] Furthermore, in step S1, the heating reaction temperature is 40-80°C and the time is 1-10h.

[0022] Furthermore, the filler is surface-modified with polyvinyl pyrrolidone, comprising the following steps:

[0023] The filler is subjected to hydroxylation treatment, then mixed with polyvinyl pyrrolidone, and subjected to ultrasonic heating reaction to obtain a product.

[0024] Furthermore, the temperature of the ultrasonic heating reaction is 40-80°C and the time is 1-4h.

[0025] The present invention has the following beneficial effects:

[0026] The package substrate solder resist dry film provided by the present invention uses acrylic resin, modified polyacrylate, epoxy resin and other ingredients as raw materials, which improves multiple properties of the solder resist dry film. Gum arabic has good viscosity, and using it as a component is beneficial to improving the adhesion of the film layer. However, due to the large number of polar groups in gum arabic, it has strong hydrophilicity, which will also lead to reduced water resistance and stability of the film. Therefore, the present invention first mixes gum arabic with methacrylic anhydride to introduce unsaturated double bonds, and then continues to polymerize with phenyl acrylate, thereby introducing a hydrophobic benzene ring structure, while ensuring adhesion, improving the hardness and stability of the film layer, and enhancing compatibility with epoxy resin. The double bonds therein can also be further cross-linked with acrylic resin and active monomers to form a more stable network structure, thereby improving the strength of the film layer.

[0027] The present invention also uses polyvinyl pyrrolidone to perform surface treatment on the hydroxylated filler, and forms adsorption and bonding through electrostatic force and hydrogen bonding between polar groups, thereby improving the dispersion effect of the filler and enhancing the affinity with the organic resin, thereby promoting the filling and film-forming effect. In summary, the package substrate solder resist dry film of the present invention solves the problems existing in the prior art and is of great significance to the development of products in this field. DETAILED DESCRIPTION

[0028] In order to more clearly illustrate the technical solution of the present invention, the following examples are listed. Unless otherwise stated, the raw materials, reactions and post-treatment methods shown in the examples are common raw materials on the market and technical methods well known to those skilled in the art.

[0029] The words "preferred", "preferably", "more preferably", etc. in the present invention refer to embodiments of the present invention that can provide certain beneficial effects in certain circumstances. However, other embodiments may also be preferred under the same circumstances or other circumstances. In addition, the description of one or more preferred embodiments does not imply that other embodiments are not applicable, nor is it intended to exclude other embodiments from the scope of the present invention.

[0030] It should be understood that, except in any operating examples, or where otherwise indicated, all numbers indicating, for example, the amounts of ingredients used in the specification and claims should be understood to be modified in all cases by the term "about". Therefore, unless indicated to the contrary, the numerical parameters set forth in the following specification and the appended claims are approximate values ​​that vary depending on the desired properties to be obtained by the present invention.

[0031] The acrylic resin in the embodiment of the present invention is Sartomer SB520A20, and the acid value is 200 mgKOH / g (content 80%).

[0032] The active monomers in the embodiment of the present invention are trimethylolpropane triacrylate (TMPTA) and polydipentaerythritol hexaacrylate (DPHA) in a mass ratio of 1:1.

[0033] The epoxy resin in the embodiment of the present invention is E44 bisphenol A epoxy resin.

[0034] The auxiliary agents in the embodiment of the present invention are initiator BPO, photoinitiator 819, leveling agent isopropyl alcohol and dispersant sodium dodecyl sulfate in a mass ratio of 1:1:1:1.

[0035] The solvent in the embodiment of the present invention is dibasic acid ester (DBE).

[0036] The gum arabic in the examples of the present invention was purchased from Shandong Yousuo Chemical Technology Co., Ltd.

[0037] The polyvinyl pyrrolidone in the embodiment of the present invention is PVP-K30.

[0038] The filler in the embodiment of the present invention is surface-modified with polyvinyl pyrrolidone, comprising the following steps:

[0039] L1. Immerse hexagonal boron nitride in 5 mol / L sodium hydroxide solution, ultrasonically treat for 6 hours, then place in a high pressure reactor at 180°C for 24 hours, wash and dry to obtain a surface hydroxylated filler;

[0040] L2. Add the surface hydroxylated filler into a 3 wt % polyvinyl pyrrolidone-water solution (surface hydroxylated filler: polyvinyl pyrrolidone=1:5, m / m), ultrasonically heat at 60° C. for 4 h, and obtain the product after filtration and drying.

[0041] The "parts" in the embodiments of the present invention refer to parts by mass.

[0042] Example 1

[0043] A package substrate solder resist dry film, comprising the following components in parts by mass:

[0044] Acrylic resin 10 parts

[0045]

[0046] The method for preparing the package substrate solder resist dry film comprises the following steps:

[0047] S1. Using water as solvent, add gum arabic and stir for 1 hour, adjust the pH to 7.4 with 1 mol / L NaOH solution, then add methacrylic anhydride (gum arabic: methacrylic anhydride = 1:1, m / m), react at 30°C for 5 hours, dialyze for 3 days (KDa = 10000), and freeze-dry to obtain acrylate-based gum arabic;

[0048] Using water as solvent, acrylate-based gum arabic, 2-phenyl ethyl acrylate and potassium persulfate in a mass ratio of 2:1:0.03 are mixed, reacted at 65°C for 3 hours, and after removing the solvent, washed and dried to obtain modified polyacrylate;

[0049] S2. Mix the modified polyacrylate, acrylic resin, active monomer, epoxy resin, filler, additive, and solvent according to the above mass fractions, stir evenly, and obtain a solder resist dry film mixed solution;

[0050] S3, coating the solder resist dry film mixture on a PET film, drying at 80° C., and covering with a PE protective film to form a sandwich structure, thereby obtaining the package substrate solder resist dry film (the thickness of the solder resist dry film middle layer is 20 μm).

[0051] Example 2

[0052] A package substrate solder resist dry film, comprising the following components in parts by mass:

[0053]

[0054] The method for preparing the package substrate solder resist dry film comprises the following steps:

[0055] S1. Using water as solvent, add gum arabic and stir for 1 hour, adjust the pH to 7.4 with 1 mol / L NaOH solution, then add methacrylic anhydride (gum arabic: methacrylic anhydride = 1:1, m / m), react at 30°C for 5 hours, dialyze for 3 days (KDa = 10000), and freeze-dry to obtain acrylate-based gum arabic;

[0056] Using water as solvent, acrylate-based gum arabic, 2-phenyl ethyl acrylate and potassium persulfate in a mass ratio of 2:1:0.03 are mixed, reacted at 65°C for 3 hours, and after removing the solvent, washed and dried to obtain modified polyacrylate;

[0057] S2. Mix the modified polyacrylate, acrylic resin, active monomer, epoxy resin, filler, additive and solvent according to the above mass fractions, stir evenly, and obtain a solder resist dry film mixed solution;

[0058] S3, coating the solder resist dry film mixture on a PET film, drying at 80° C., and covering with a PE protective film to form a sandwich structure, thereby obtaining the package substrate solder resist dry film (the thickness of the solder resist dry film middle layer is 20 μm).

[0059] Example 3

[0060] A package substrate solder resist dry film, comprising the following components in parts by mass:

[0061]

[0062] The method for preparing the package substrate solder resist dry film comprises the following steps:

[0063] S1. Using water as solvent, add gum arabic and stir for 1 hour, adjust the pH to 7.4 with 1 mol / L NaOH solution, then add methacrylic anhydride (gum arabic: methacrylic anhydride = 1:1, m / m), react at 30°C for 5 hours, dialyze for 3 days (KDa = 10000), and freeze-dry to obtain acrylate-based gum arabic;

[0064] Using water as solvent, acrylate-based gum arabic, 2-phenyl ethyl acrylate and potassium persulfate in a mass ratio of 2:1:0.03 are mixed, reacted at 65°C for 3 hours, and after removing the solvent, washed and dried to obtain modified polyacrylate;

[0065] S2. Mix the modified polyacrylate, acrylic resin, active monomer, epoxy resin, filler, additive, and solvent according to the above mass fractions, stir evenly, and obtain a solder resist dry film mixed solution;

[0066] S3, coating the solder resist dry film mixture on a PET film, drying at 80° C., and covering with a PE protective film to form a sandwich structure, thereby obtaining the package substrate solder resist dry film (the thickness of the solder resist dry film middle layer is 20 μm).

[0067] Comparative Example 1

[0068] A solder resist dry film, the difference between this comparative example and Example 1 is that in step S1, only acrylate-based gum arabic is prepared, in step S2, acrylate-based gum arabic is used to replace modified polyacrylate, and other ingredients and preparation methods are the same as those in Example 1.

[0069] Comparative Example 2

[0070] A solder resist dry film. The difference between this comparative example and Example 1 is that in the surface modification method of the filler, only step L1 is retained, and then in the preparation method of the solder resist dry film, 0.5 parts of polyvinyl pyrrolidone is added in step S2, and the other ingredients and preparation method are the same as those in Example 1.

[0071] Test Case

[0072] The performance of the solder resist dry films prepared in Examples 1-3 and Comparative Examples 1-2 was tested.

[0073] The test method is as follows:

[0074] The solder resist dry films prepared in the examples and comparative examples were pressed onto the surface of the copper clad laminate at 400 mJ / cm 2 Exposure, followed by thermal curing at 150°C for 1 hour.

[0075] Pencil hardness: measured in accordance with JIS K5400.

[0076] Adhesion: Use a needle tip to make an "X" on the film, then stick a cellophane tape on the cut and pull it. The evaluation criteria are as follows:

[0077] Qualified: not torn off or only a small amount torn off;

[0078] Failure: Extensive tearing off.

[0079] Acid resistance / alkali resistance: At 20°C, immerse the sample in a 10wt% sulfuric acid solution or a 10wt% sodium hydroxide solution, take it out after 30 minutes, and evaluate the state and adhesion of the coating. The evaluation criteria are as follows:

[0080] Pass: No change or slight change was found;

[0081] Unqualified: There is swelling or shedding on the coating film.

[0082] Heat resistance: Thermal shock performance test is carried out according to the method in IPC-SM-840E, and the evaluation criteria are as follows:

[0083] Qualified: no bubbles or cracks;

[0084] Unqualified: bubbles and cracks appear.

[0085] The test results are shown in Table 1.

[0086] Table 1 Performance test results

[0087] project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Pencil hardness 3H 3H 3H 2H 3H Adhesion qualified qualified qualified qualified qualified Acid resistance qualified qualified qualified Failure Failure Alkali resistance qualified qualified qualified qualified Failure Heat resistance qualified qualified qualified Failure Failure

[0088] According to Table 1, it can be concluded that the package substrate solder resist dry film prepared in the embodiment of the present invention has excellent mechanical properties and stability; in Comparative Example 1, only double bonds are introduced into gum arabic, and no reaction is performed with phenyl acrylate, and the hardness and stability are reduced, while the filler in Comparative Example 2 is only hydroxylated, and although polyvinyl pyrrolidone is subsequently added, the filler is still easy to agglomerate, and the compatibility with the resin is insufficient, resulting in uneven dispersion and reduced stability of the film layer.

[0089] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0090] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A package substrate solder resist dry film, characterized in that: The package substrate solder resist dry film comprises the following components in parts by mass: Acrylic resin 10-20 parts Active monomer 1-10 parts Modified polyacrylate 5-15 parts Epoxy resin 10-20 parts Filler 5-15 parts 1-10 parts of additives 20-60 parts of solvent; in, The modified polyacrylate is obtained by reacting polysaccharide, acrylic anhydride and phenyl acrylate; The filler is obtained by hydroxylation and surface modification with polyvinyl pyrrolidone.

2. The package substrate solder resist dry film according to claim 1, characterized in that: The mass ratio of the polysaccharide, acrylic anhydride and phenyl acrylate is 1:(0.5-2):(0.1-2).

3. The package substrate solder resist dry film according to claim 1, characterized in that: The reactive monomer is a monomer having a monofunctional or multifunctional acrylate unit.

4. The package substrate solder resist dry film according to claim 1, characterized in that: The auxiliary agent is selected from one or more of an initiator, a cross-linking agent, a color powder, a leveling agent, a defoaming agent, a UV absorber, a dispersant, an antioxidant, and a toughening agent.

5. The method for preparing a package substrate solder resist dry film according to any one of claims 1 to 4, characterized in that: The method for preparing the package substrate solder resist dry film comprises the following steps: S1, mixing polysaccharide and acrylic anhydride, reacting at low temperature, mixing with phenyl acrylate and initiator, and heating to react, thereby obtaining modified polyacrylate; S2, mixing the modified polyacrylate, acrylic resin, active monomer, epoxy resin, filler, additive, and solvent to obtain a solder resist dry film mixed liquid; S3, applying the solder resist dry film mixture to a substrate, and covering it with a protective film after drying to obtain the packaging substrate solder resist dry film.

6. The method for preparing a solder resist dry film for a packaging substrate according to claim 5, characterized in that: In step S1, the low temperature reaction is carried out at a temperature of 0-30°C and for a time of 1-12 h.

7. The method for preparing a solder resist dry film for a packaging substrate according to claim 5, characterized in that: In step S1, the heating reaction temperature is 40-80°C and the time is 1-10 h.

8. The method for preparing a solder resist dry film for a packaging substrate according to claim 5, characterized in that: The filler is surface-modified with polyvinyl pyrrolidone, comprising the following steps: The filler is subjected to hydroxylation treatment, then mixed with polyvinyl pyrrolidone, and subjected to ultrasonic heating reaction to obtain a product.

9. The method for preparing a solder resist dry film for a packaging substrate according to claim 8, characterized in that: The temperature of the ultrasonic heating reaction is 40-80° C. and the time is 1-4 h.

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