Aluminum sheet back drilling base plate coated with UV resin coatings on two sides and machining method

Abstract

The invention relates to the technical field of PCB drilling base plates, and discloses an aluminum sheet back drilling base plate coated with UV resin coatings on both sides and a processing method.The aluminum sheet back drilling base plate comprises a base material aluminum sheet and the UV resin coatings coated on the upper surface and the lower surface of the aluminum sheet, the coating is prepared from the following components in parts by weight: 40 to 50 parts of polyurethane acrylic resin, 50 to 70 parts of active monomer, 7 to 12 parts of photoinitiator, 3.5 to 5.5 parts of enamine modified graphene oxide, 0.1 to 0.3 part of flatting agent, 1 to 3 parts of defoaming agent and 0.1 to 0.5 part of dispersing agent. The double-sided coating can protect the corrosion resistance and oxidation resistance of the aluminum sheet back drilling base plate, so that the service life of the aluminum sheet back drilling base plate is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of PCB drilling backing plates, and particularly relates to an aluminum back-drilling backing plate with a double-sided UV resin coating and a processing method therefor. Background Art

[0002] A backing plate is a material placed under a plate to be processed during the mechanical drilling of a printed circuit board (referred to as PCB) to meet the requirements of the processing technology. The use of the backing plate can effectively reduce the burrs at the drilling port of the base material, play a role in protecting the table surface of the drilling machine for the drilling process that penetrates the PCB board. In addition, it can also reduce the drill bit temperature, reduce drill bit wear, and clean part of the drilling dirt on the drill bit, and to a certain extent, play its positioning effect and improve the drilling accuracy.

[0003] The aluminum back-drilling backing plate is a commonly used backing plate for PCB drilling. If there are corrosion marks on the aluminum back-drilling backing plate, its surface hardness and smoothness will be greatly reduced, which will affect the flatness of the aluminum back-drilling backing plate during the drilling process, resulting in an increase in burrs at the drilling port of the base material, and further affecting the chip removal and drilling accuracy of the PCB. In this application, coatings are applied to both sides of the aluminum back-drilling backing plate to protect the anti-corrosion and anti-oxidation properties of the aluminum back-drilling backing plate, and the service life of the aluminum back-drilling backing plate can be extended. Summary of the Invention

[0004] The purpose of the present invention is to provide an aluminum back-drilling backing plate with a double-sided UV resin coating and a processing method therefor.

[0005] The purpose of the present invention can be achieved by the following technical solutions: An aluminum back-drilling backing plate with a double-sided UV resin coating, comprising a base aluminum sheet and UV resin coatings coated on the upper surface and the lower surface of the aluminum sheet. Among them, the UV resin coating comprises the following raw materials in parts by weight: 40 - 50 parts of acrylic resin, 40 - 50 parts of polyurethane acrylate resin, 50 - 70 parts of reactive monomer, 7 - 12 parts of photoinitiator, 3.5 - 5.5 parts of enamine-modified graphene oxide, 0.1 - 0.3 part of leveling agent, 1 - 3 parts of defoaming agent, 0.1 - 0.5 part of dispersing agent.

[0006] Further, the reactive monomer is one or a combination of more of pentaerythritol tetraacrylate, propoxylated trimethylolpropane triacrylate, and ethoxylated trimethylolpropane triacrylate.

[0007] Further, the photoinitiator is one of photoinitiator TPO, photoinitiator 819, and photoinitiator 184.

[0008] Further, the preparation method of the enamine-modified graphene oxide is as follows: S1. Acylation of graphene oxide Weigh 1.0 - 1.3 g of graphene oxide and 100 - 120 ml of N,N - dimethylformamide and add them to a reaction flask equipped with a reflux device. Start stirring, and slowly add 3.5 - 4.0 g of SOCl₂. After adding, start heating and keep stirring and reacting for 40 - 50 h. After the reaction is completed, naturally cool to room temperature, filter, wash with anhydrous ether, and dry to obtain acylated graphene oxide; S2. Preparation of enamine - modified graphene oxide Measure 400 - 450 ml of the solvent tetrahydrofuran and the acylated graphene oxide prepared in S1 and add them to a reaction flask. Then add 0.7 - 0.85 g of undec - 10 - en - 1 - amine. Start stirring and heating, and keep reacting for 48 - 72 h. After the reaction is completed, naturally cool to room temperature, filter, wash with anhydrous ether, and dry to obtain enamine - modified graphene oxide.

[0009] Graphene materials have excellent hydrophobic and oleophobic properties, high specific surface area, high aspect ratio, chemical inertness and impermeability. When applied to coatings, they can improve the impact resistance and wear resistance of the coatings. Their two - dimensional layered structure also has a certain barrier effect on corrosive media. However, graphene has poor dispersibility in coatings and is prone to aggregation, resulting in an uneven coating and unstable performance. Graphene oxide has a large number of oxygen - containing functional groups, which can graft some small - molecule compounds. The modified graphene oxide has good dispersibility in coatings and can effectively prevent aggregation. In this application, some carboxyl groups in graphite oxide can react with thionyl chloride to obtain acylated graphene oxide. The acylated graphene oxide reacts with undec - 10 - en - 1 - amine to undergo an acylation reaction to obtain enamine - modified graphene oxide. Enamine - modified graphene oxide contains olefins, and under a photoinitiator, it can react with the resin matrix in the coating, such as acrylic resin, polyurethane acrylate resin and active monomers, to cure together, further solving the problem of easy agglomeration of graphene, firmly fixing graphene in the coating, and grafting undec - 10 - en - 1 - amine in the form of covalent bonds. The formed aliphatic carbon chain further plays a role in blocking corrosive media, greatly enhancing the corrosion resistance of the coating.

[0010] Further, the temperature for heat preservation in step S1 is 65 - 75 °C.

[0011] Further, the temperature for heat preservation in step S2 is 65 - 70 °C.

[0012] Further, the leveling agent is butyl acrylate or propyl acrylate.

[0013] Further, the defoaming agent is polyoxyethylene polyoxypropylene pentaerythritol ether or polydimethylsiloxane.

[0014] Further, the dispersant is calcium stearate or zinc stearate.

[0015] A processing method for a back-drilled backing plate of an aluminum sheet with a double-sided UV resin coating, comprising the following steps: The first step: Add the formulated amounts of acrylic resin, polyurethane acrylate resin, reactive monomer, and enamine-modified graphene oxide to a stirring kettle. After stirring evenly, add the formulated amounts of photoinitiator, leveling agent, defoaming agent, and dispersant, and continue to stir for 1-2 h to mix evenly, thus obtaining the UV resin coating. The second step: Use a roll coater to coat one side of the base material aluminum sheet with the coating prepared in the first step, level it, and cure it by irradiating with a UV lamp. After curing, coat the other side of the base material aluminum sheet in the same way and cure it to obtain a back-drilled backing plate of an aluminum sheet with a double-sided UV resin coating; the thickness of the coating is 300-350 um.

[0016] Advantages of the present invention: The back-drilled backing plate of an aluminum sheet with a double-sided UV resin coating provided by the present invention uses an aluminum sheet as the base material, and UV resin coatings are coated on the upper surface and the lower surface of the aluminum sheet. The UV resin coating is mainly composed of acrylic resin, polyurethane acrylate resin, and reactive monomer. Under the action of a photoinitiator, it also polymerizes and cures with the enamine-modified graphene oxide in the formula, further solving the problem of easy agglomeration of graphene, firmly fixing graphene in the coating, and grafting undec-10-en-1-amine in the form of covalent bonds. The formed fatty carbon chain further plays a role in blocking corrosive media, greatly enhancing the corrosion resistance of the coating, and thus extending the service life of the back-drilled backing plate of the aluminum sheet.

[0017] Of course, it is not necessary for any product implementing the present invention to simultaneously achieve all the above-mentioned advantages. Description of the drawings

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 It is an infrared comparison diagram of graphite oxide and enamine-modified graphene oxide, where: a is the infrared spectrum of graphite oxide, and b is the infrared spectrum of enamine-modified graphene oxide; Figure 2 It is a TEM comparison diagram of graphite oxide and enamine-modified graphene oxide, where: A is the TEM image of graphene oxide; B is the TEM image of enamine-modified graphene oxide; Figure 3 It is the water contact angle drawing of Examples 1-3 and Comparative Examples 1-3. Detailed implementation mode

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0021] In the following embodiments, the preparation method of the enamine-modified graphene oxide is as follows: S1. Acylation of graphene oxide Weigh 1.0 g of graphene oxide and 100 ml of N,N-dimethylformamide and add them to a reaction flask equipped with a reflux device. Start stirring, slowly add 3.8 g of SOCl2. After the addition is complete, start heating, set the temperature to 70 °C, and keep stirring and reacting for 48 h. After the reaction is completed, naturally cool to room temperature, filter, wash with anhydrous ether, and dry to obtain acylated graphene oxide; S2. Preparation of enamine-modified graphene oxide Measure 400 ml of the solvent tetrahydrofuran and the acylated graphene oxide prepared in S1 and add them to the reaction flask. Then add 0.8 g of undec-10-en-1-amine, start stirring and heating, set the temperature to 65 °C, and keep reacting for 72 h. After the reaction is completed, naturally cool to room temperature, filter, wash with anhydrous ether, and dry to obtain enamine-modified graphene oxide; As Figure 1 shown, a is the infrared spectrum of graphite oxide, and b is the infrared spectrum of enamine-modified graphene oxide, Before the reaction, the absorption peak at 3430 cm-1 in Figure a of graphite oxide is the hydroxyl absorption peak in graphite oxide. After the reaction, the stretching vibration peak of amide N-H at 3226 cm-1 in b; before the reaction, the carboxyl stretching vibration peak at 1645 cm-1 in Figure a of graphite oxide. After the reaction, the stretching vibration peaks of carboxyl and carbonyl in amide at 1642 cm-1 and 1630 cm-1 in b respectively (part of the carboxyl participates in the reaction), and the characteristic absorption peak of N-H at 1478 cm-1.

[0022] Figure 2 In, A is the TEM image of graphene oxide; graphene oxide is a transparent sheet with a corrugated structure. B is the TEM image of enamine-modified graphene oxide; enamine-modified graphene oxide has an obvious black fog, which is due to the grafting of undec-10-en-1-amine on the edge of graphene oxide.

[0023] Example 1 A double-sided UV resin-coated aluminum back-drilling backing plate, comprising a base aluminum sheet and UV resin coatings applied to the upper and lower surfaces of the aluminum sheet, wherein the UV resin coating comprises the following raw materials in parts by weight: 40 parts of acrylic resin, 40 parts of polyurethane acrylate resin, 50 parts of reactive monomer, 8 parts of photoinitiator, 3.5 parts of enamine-modified graphene oxide, 0.1 part of leveling agent, 1 part of defoaming agent, 0.3 part of dispersant; The reactive monomer is pentaerythritol tetraacrylate; The photoinitiator is photoinitiator TPO; The leveling agent is polybutyl acrylate; The defoaming agent is polyoxyethylene polyoxypropylene pentaerythritol ether; The dispersant is calcium stearate; The processing method of the double-sided UV resin-coated aluminum back-drilling backing plate comprises the following steps: First step: Add the formulated amounts of acrylic resin, polyurethane acrylate resin, reactive monomer and enamine-modified graphene oxide into a stirring kettle. After stirring evenly, add the formulated amounts of photoinitiator, leveling agent, defoaming agent and dispersant, and continue to stir for 2 h to mix evenly to obtain the UV resin coating; Second step: Use a roll coater to coat one side of the base aluminum sheet with a layer of the coating prepared in the first step, level it, and irradiate and cure it with a UV lamp. After curing, coat the other side of the base aluminum sheet in the same way and cure it. The thickness of the coating is 300 μm.

[0024] Example 2 A double-sided UV resin-coated aluminum back-drilling backing plate, comprising a base aluminum sheet and UV resin coatings applied to the upper and lower surfaces of the aluminum sheet, wherein the UV resin coating comprises the following raw materials in parts by weight: 45 parts of acrylic resin, 46 parts of polyurethane acrylate resin, 55 parts of reactive monomer, 10 parts of photoinitiator, 4.5 parts of enamine-modified graphene oxide, 0.1 part of leveling agent, 1.5 parts of defoaming agent, 0.5 part of dispersant; The reactive monomer is a mixture of propoxylated trimethylolpropane triacrylate and ethoxylated trimethylolpropane triacrylate, and the mass ratio is 1:1; The photoinitiator is photoinitiator 819; The leveling agent is polybutyl acrylate; The defoaming agent is polydimethylsiloxane; The dispersant is calcium stearate; The processing method of the double-sided UV resin-coated aluminum back-drilling backing plate comprises the following steps: Step 1: Add the formulated amounts of acrylic resin, polyurethane acrylate resin, reactive monomer, and enamine-modified graphene oxide into a stirring kettle. After stirring evenly, add the formulated amounts of photoinitiator, leveling agent, defoaming agent, and dispersant, and continue stirring for 1.5 h to mix evenly, thus obtaining the UV resin coating; Step 2: Use a roller coater to coat one side of the substrate aluminum sheet with the coating prepared in the first step, level it, and cure it by irradiating with a UV lamp. After curing, coat the other side of the substrate aluminum sheet and cure it in the same way. The thickness of the coating is 300 μm.

[0025] Example 3 A double-sided UV resin-coated aluminum backdrill backing plate includes a substrate aluminum sheet and UV resin coatings coated on the upper and lower surfaces of the aluminum sheet. The UV resin coating includes the following raw materials in parts by weight: 50 parts of acrylic resin, 47 parts of polyurethane acrylate resin, 70 parts of reactive monomer, 12 parts of photoinitiator, 5.5 parts of enamine-modified graphene oxide, 0.2 part of leveling agent, 2.5 parts of defoaming agent, and 0.4 part of dispersant; The reactive monomer is ethoxylated trimethylolpropane triacrylate; The photoinitiator is photoinitiator 184; The leveling agent is polypropylacrylate; The defoaming agent is polyoxyethylene polyoxypropylene pentaerythritol ether; The dispersant is zinc stearate; The processing method of the double-sided UV resin-coated aluminum backdrill backing plate includes the following steps: Step 1: Add the formulated amounts of acrylic resin, polyurethane acrylate resin, reactive monomer, and enamine-modified graphene oxide into a stirring kettle. After stirring evenly, add the formulated amounts of photoinitiator, leveling agent, defoaming agent, and dispersant, and continue stirring for 2 h to mix evenly, thus obtaining the UV resin coating; Step 2: Use a roller coater to coat one side of the substrate aluminum sheet with the coating prepared in the first step, level it, and cure it by irradiating with a UV lamp. After curing, coat the other side of the substrate aluminum sheet and cure it in the same way. The thickness of the coating is 300 μm.

[0026] Comparative Example 1 A double-sided UV resin-coated aluminum backdrill backing plate includes a substrate aluminum sheet and UV resin coatings coated on the upper and lower surfaces of the aluminum sheet. The UV resin coating includes the following raw materials in parts by weight: 50 parts of acrylic resin, 47 parts of polyurethane acrylate resin, 70 parts of reactive monomer, 12 parts of photoinitiator, 5.5 parts of graphene oxide, 0.2 part of leveling agent, 2.5 parts of defoaming agent, and 0.4 part of dispersant; The active monomer described is ethoxylated trimethylolpropane triacrylate; The photoinitiator described is photoinitiator 184; The leveling agent described is polypropyl acrylate; The defoaming agent described is polyoxyethylene polyoxypropylene pentaerythritol ether; The dispersant described is zinc stearate; The processing method of the aluminum backdrilled backing plate with a double-sided UV resin coating described includes the following steps: The first step: Add the formulated amounts of acrylic resin, polyurethane acrylate resin, active monomer, and graphene oxide to a stirring kettle. After stirring evenly, add the formulated amounts of photoinitiator, leveling agent, defoaming agent, and dispersant, and continue stirring for 2 hours to mix evenly, thus obtaining the UV resin coating; The second step: Use a roller coater to coat one side of the base material aluminum sheet with a layer of the coating prepared in the first step, level it, and cure it by irradiating with a UV lamp. After curing, coat the other side of the base material aluminum sheet in the same way and cure it. The thickness of the coating is 300 μm.

[0027] Comparative Example 2 An aluminum backdrilled backing plate with a double-sided UV resin coating includes a base material aluminum sheet and UV resin coatings coated on the upper and lower surfaces of the aluminum sheet. Among them, the UV resin coating includes the following raw materials in parts by weight: 50 parts of acrylic resin, 47 parts of polyurethane acrylate resin, 70 parts of active monomer, 12 parts of photoinitiator, 5.5 parts of graphene, 0.2 part of leveling agent, 2.5 parts of defoaming agent, 0.4 part of dispersant; The active monomer described is ethoxylated trimethylolpropane triacrylate; The photoinitiator described is photoinitiator 184; The leveling agent described is polypropyl acrylate; The defoaming agent described is polyoxyethylene polyoxypropylene pentaerythritol ether; The dispersant described is zinc stearate; The processing method of the aluminum backdrilled backing plate with a double-sided UV resin coating described includes the following steps: The first step: Add the formulated amounts of acrylic resin, polyurethane acrylate resin, active monomer, and graphene to a stirring kettle. After stirring evenly, add the formulated amounts of photoinitiator, leveling agent, defoaming agent, and dispersant, and continue stirring for 2 hours to mix evenly, thus obtaining the UV resin coating; The second step: Use a roller coater to coat one side of the base material aluminum sheet with a layer of the coating prepared in the first step, level it, and cure it by irradiating with a UV lamp. After curing, coat the other side of the base material aluminum sheet in the same way and cure it. The thickness of the coating is 300 μm.

[0028] Comparative Example 3 A backdrilled backing plate for aluminum sheet with a double-sided UV resin coating, comprising a base aluminum sheet and UV resin coatings coated on the upper and lower surfaces of the aluminum sheet. Among them, the UV resin coating includes the following raw materials in parts by weight: 50 parts of acrylic resin, 47 parts of polyurethane acrylate resin, 70 parts of reactive monomer, 12 parts of photoinitiator, 0.2 part of leveling agent, 2.5 parts of defoaming agent, 0.4 part of dispersant; The reactive monomer is ethoxylated trimethylolpropane triacrylate; The photoinitiator is photoinitiator 184; The leveling agent is polypropyl acrylate; The defoaming agent is polyoxyethylene polyoxypropylene pentaerythritol ether; The dispersant is zinc stearate; The processing method of the backdrilled backing plate for aluminum sheet with a double-sided UV resin coating includes the following steps: First step: Add the formulated amounts of acrylic resin, polyurethane acrylate resin and reactive monomer into a stirring kettle. After stirring evenly, add the formulated amounts of photoinitiator, leveling agent, defoaming agent and dispersant, and continue stirring for 2 h to mix evenly to obtain the UV resin coating; Second step: Use a roll coater to coat one side of the base aluminum sheet with a layer of the coating prepared in the first step, level it, irradiate and cure it with a UV lamp. After curing, coat the other side of the base aluminum sheet in the same way and cure it. The thickness of the coating is 300 um.

[0029] Coating performance test Water contact angle test: Use a video optical contact angle measuring instrument ADSA-Realdrop®-C601 to measure the water contact angle of the coating surface; Neutral salt spray performance: Test according to ASTM-B117 standard; Adhesion of the coating film: Test according to GB / T9286-1998; The specific test results are shown in Table 1:

[0030] As can be seen from Table 1, the coatings on both sides of the backdrilled backing plates prepared in Examples 1-3 have good corrosion resistance. The corrosion resistance of Comparative Example 1 is inferior to that of Comparative Example 2. The possible reason is that graphene oxide contains a large number of hydrophilic groups such as hydroxyl and carboxyl groups. Compared with the blank coating of Comparative Example 3, the coating of Comparative Example 1 has stronger hydrophilicity, resulting in poor corrosion resistance. Although the coating of Comparative Example 2 shows certain corrosion-resistant and waterproof performance, due to the agglomeration problem of graphene, its corrosion resistance is relatively poor.

[0031] The above content is only an example and illustration of the concept of the present invention. Those skilled in the art of this technology can make various modifications, supplements or use similar methods of substitution to the described specific embodiments, as long as they do not deviate from the concept of the invention or exceed the scope defined by this claims, they should fall within the protection scope of the present invention.

Claims

1. A back-drilled backing plate of aluminum sheet with a double-sided UV resin coating, characterized in that: It includes a base material aluminum sheet and UV resin coatings coated on the upper and lower surfaces of the aluminum sheet. Among them, the UV resin coating includes raw materials in the following parts by weight: 40 - 50 parts of acrylic resin, 40 - 50 parts of polyurethane acrylate resin, 50 - 70 parts of reactive monomer, 7 - 12 parts of photoinitiator, 3.5 - 5.5 parts of enamine modified graphene oxide, 0.1 - 0.3 part of leveling agent, 1 - 3 parts of defoaming agent, 0.1 - 0.5 part of dispersant.

2. The aluminum back-drilled backing plate with a double-sided UV resin coating according to claim 1, wherein: The reactive monomer is one or a combination of more of pentaerythritol tetraacrylate, propoxylated trimethylolpropane triacrylate, and ethoxylated trimethylolpropane triacrylate.

3. The aluminum backdrilled backing plate with a double-sided UV resin coating according to claim 1, characterized in that: The photoinitiator is one of photoinitiator TPO, photoinitiator 819, and photoinitiator 184.

4. A back-drilled backing plate for aluminum sheet with a double-sided UV resin coating according to claim 1, characterized in that: The preparation method of the enamine modified graphene oxide is as follows: S1. Acylation of graphene oxide Weigh 1.0 - 1.3 g of graphene oxide and 100 - 120 ml of N,N - dimethylformamide and add them to a reaction flask equipped with a reflux device. Start stirring, slowly add 3.5 - 4.0 g of SOCl2. After adding, start heating, keep stirring and reacting for 40 - 50 h. After the reaction ends, naturally cool to room temperature, filter, wash with anhydrous ether, and dry to obtain acylated graphene oxide. S2. Preparation of enamine modified graphene oxide Measure 400 - 450 ml of the solvent tetrahydrofuran and the acylated graphene oxide prepared in S1 and add them to the reaction flask. Then add 0.7 - 0.85 g of undec - 10 - en - 1 - amine. Start stirring and heating, keep reacting for 48 - 72 h. After the reaction ends, naturally cool to room temperature, filter, wash with anhydrous ether, and dry to obtain enamine modified graphene oxide.

5. The aluminum backdrilled backing plate with a double-sided UV resin coating according to claim 4, wherein: The temperature for heat preservation in step S1 is 65 - 75 °C.

6. The aluminum back-drilled backing plate with a double-sided UV resin coating according to claim 4, characterized in that: The temperature for heat preservation in step S2 is 65 - 70 °C.

7. A back-drilled backing plate for aluminum sheet with a double-sided UV resin coating according to claim 1, characterized in that: The leveling agent is polybutyl acrylate or polypropyl acrylate.

8. A back-drilled backing plate for aluminum sheet with a double-sided UV resin coating according to claim 1, characterized in that: The defoaming agent is polyoxyethylene polyoxypropylene pentaerythritol ether or polydimethylsiloxane.

9. The aluminum backdrilled backing plate with a double-sided UV resin coating according to claim 1, wherein: The dispersant is calcium stearate or zinc stearate.

10. A processing method for a back-drilled backing plate of an aluminum sheet with a double-sided UV resin coating as described in claim 1, characterized in that: It includes the following steps: First step: Add the formulated amounts of acrylic resin, polyurethane acrylate resin, reactive monomer, and enamine modified graphene oxide to a stirring kettle. After stirring evenly, add the formulated amounts of photoinitiator, leveling agent, defoaming agent, and dispersant, and continue stirring for 1 - 2 h to mix evenly to obtain the UV resin coating. Second step: Use a roll coater to coat one side of the base material aluminum sheet with a layer of the coating prepared in the first step, level it, irradiate and cure it with a UV lamp. After curing, coat the other side of the base material aluminum sheet in the same way and cure it to obtain a double - sided coated aluminum sheet back - drilled backing plate with a coating thickness of 300 - 350 um.

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