Copper sheet pretreatment method for avoiding poor insulation between DCB islands

Abstract

The invention relates to the technical field of copper sheet pretreatment, and particularly discloses a copper sheet pretreatment method for avoiding poor insulation between DCB islands. The method comprises the following steps of: sequentially deoiling and cleaning the surface of a copper substrate, printing micro-etching glue on the surface of the copper substrate, standing for 30 + / -5 minutes after photocuring, and stripping the micro-etching glue to obtain a surface-roughened copper sheet; the surface-roughened copper sheet is sequentially subjected to acid pickling, ultrasonic cleaning, drying and oxidation treatment, and a prefabricated copper sheet is obtained; and the prefabricated copper sheet is cleaned and dried, the oxidation layer face of the prefabricated copper sheet is attached to the ceramic, sintering is conducted for 1-2 hours at the temperature of 1065-1083 DEG C, and a DCB product is obtained.

Description

Technical Field

[0001] The invention relates to the technical field of copper sheet pretreatment, in particular to a copper sheet pretreatment method for avoiding poor insulation between DCB islands. Background Art

[0002] ZTA, the full name of which is Zirconia Toughened Alumina, is a toughened alumina ceramic doped with zirconium oxide. Due to its excellent bending strength and hot and cold cycle performance, it is used in most automotive components. But everything has its two sides. On the one hand, doping with zirconium oxide can change the lattice arrangement of alumina ceramics, thereby greatly improving its toughness. But at the same time, since the introduced zirconium element itself is a conductor, the inter-island leakage current value of its product is larger than that of conventional alumina, which is also one of the main indicators that consumers pay attention to. Therefore, it is necessary to invent a special oxidation method that can completely avoid the occurrence of inter-island leakage current, so that the ZTA ceramic can be widely promoted and used.

[0003] The basic principle of ZTA sintering is similar to that of conventional Al2O3. The DCB process is used to introduce an appropriate amount of oxygen between copper and ceramic (alumina) before or during the bonding process. Within a certain temperature range, copper and oxygen form a Cu-O eutectic liquid. The eutectic liquid can wet both the metal copper foil and the Al2O3 ceramic substrate well. After cooling to room temperature and solidifying, a strong bond can be formed between the two.

[0004] In summary, it is of great significance to invent a copper sheet pretreatment method for avoiding poor insulation between DCB islands. Summary of the invention

[0005] The object of the present invention is to provide a copper sheet pretreatment method for avoiding poor insulation between DCB islands, so as to solve the problems raised in the above background technology.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] A copper sheet pretreatment method for avoiding poor insulation between DCB islands includes the following steps:

[0008] S1: Degreasing and cleaning the surface of the copper substrate in sequence, printing micro-etching glue on the surface, standing for 30±5 minutes after light curing, and stripping off the micro-etching glue to obtain a surface roughened copper sheet;

[0009] S2: The surface roughened copper sheet is pickled, ultrasonically cleaned, and dried in sequence, and then an alkaline oxidizing solution is evenly sprayed on the surface at a liquid feed rate of 2 mL / min to 6 mL / min by high-pressure atomization spraying at 70°C to 90°C, and then the alkaline oxidizing solution is removed by cold wind at 0°C to 10°C to preform the copper sheet;

[0010] S3: The prefabricated copper sheet is cleaned and dried, and the oxide layer thereof is bonded to the ceramic, and sintered at 1065° C. to 1083° C. for 1 to 2 hours to obtain a DCB product.

[0011] More optimally, the raw materials of the alkaline oxidizing solution include the following components: in terms of concentration percentage, 20% to 30% of NaClO2, 7.5% to 12.5% ​​of NaOH, and the rest is water.

[0012] More optimally, the raw materials of the micro-etching glue include the following components: by weight percentage, 62% to 70% of basic colloid, 16% to 18% of tetrahydrofuran acrylate, 10% to 12% of micro-etching solution, 1% to 3% of polyamide wax, 1% to 2% of silane coupling agent, and 2% to 3% of 2-hydroxy-methylphenylpropane-1-one.

[0013] More optimally, the micro-etching solution is a sulfuric acid solution of Na2S2O8; the concentration of the Na2S2O8 is 50g / L to 60g / L, and the concentration of the sulfuric acid is 2wt% to 4wt%.

[0014] In a more optimized embodiment, the base colloid comprises one or more of polyurethane acrylate and waterborne polyurethane acrylate; the preparation method of the waterborne polyurethane acrylate is as follows: (1) adding hydroxyethyl acrylate, ethylene glycol bis(thioglycolate) and azobisisobutyronitrile to DMF and mixing them uniformly, irradiating them under ultraviolet light of 350nm-365nm and 100W for 2 hours, purifying and drying to obtain an intermediate; (2) adding dibutyltin dilaurate to isophorone diisocyanate and mixing them uniformly to obtain a mixture A; mixing polyethylene glycol and bis(hydroxymethyl)propionic acid uniformly, heating them to 60°C-70°C, adding the mixture A to react for 0.8-2 hours, heating them to 80°C-90°C and continuing to react for 30-45 minutes to obtain a top polymer; (3) adding the intermediate, N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid and deionized water to the top polymer in sequence and mixing them uniformly, reacting them at 30°C-35°C for 1-2 hours to obtain a waterborne polyurethane acrylate.

[0015] More optimally, the raw materials of the intermediate include the following components: by weight, 1 to 1.2 parts of hydroxyethyl acrylate, 4 to 4.5 parts of ethylene glycol bis(thioglycolate), 0.002 to 0.003 parts of azobisisobutyronitrile, and 30 to 40 parts of DMF; the molecular weight of the polyethylene glycol is 200 to 1200.

[0016] More optimally, the raw materials of the top polymer include the following components: by weight, 0.02-0.024 parts of dibutyltin dilaurate, 10-15 parts of isophorone diisocyanate, 9-10 parts of polyethylene glycol, and 1-3 parts of dihydroxymethylpropionic acid; the raw materials of the water-based polyurethane acrylate include the following components: by weight, 4.2-12.5 parts of the top polymer, 3-3.5 parts of the intermediate, 4-6 parts of N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid, and 20-40 parts of deionized water.

[0017] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0018] The oxidizing solution will make Cu or Cu + Oxides will be generated, and some suspended particles will be generated in the oxidizing solution. Due to the presence of the filter, these particles will be removed by the filter under normal circumstances, but it is inevitable that a small amount of particles will exist. At about 1065℃~1083℃, these oxides, cuprous oxide and copper will form a multi-element eutectic liquid. During the solidification of the eutectic liquid, some composite oxides will precipitate, which are small semi-spherical. During the cooling process, the precipitated Cu2O will gradually decompose into Cu and O2, and then form many interlayer pores. Some precipitates will adhere to the surface of the porcelain piece and generate spinel-like substances (CuAl2O4) at high temperatures. These substances are difficult to be completely removed in the subsequent etching process. CuAl2O4 has a cubic crystal structure and an optical band gap of 4eV. On the one hand, when the CuAl2O4 content in the precipitated phase increases, the band gap energy will increase, that is, the resistivity between the islands will increase. On the other hand, the staggered existence of CuAlO2 and CuAl2O4 in the precipitated phase will limit the conductivity of CuAlO2 to a smaller range, and it will not be completely turned on to cause insulation failure.

[0019] In terms of technology, micro-etching glue is used to slightly roughen the copper sheet. The purpose is to roughen the copper surface and increase the surface area of ​​the copper surface. The advantage is that the micro-etching glue can be applied on one side to make the copper sheet slightly roughened, while the other side maintains the original smaller roughness.

[0020] The invention initiates polymerization of hydroxyethyl acrylate and ethylene glycol bisthioglycolate under UV light irradiation through free radicals generated by azobisisobutyronitrile to form an intermediate containing acrylate and thiol; the intermediate is used as a chain extender to prepare waterborne polyurethane acrylate, thereby improving water resistance to a certain extent; polyethylene glycol is introduced into the waterborne polyurethane acrylate to improve the viscosity of the waterborne polyurethane acrylate, and N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid is introduced to increase the cross-linking structure, while further improving water resistance and stability.

[0021] The waterborne polyurethane acrylate provided by the present invention has good adhesion, flexibility and durability, and can provide a uniform coating and a better micro-etching effect due to its good dispersibility and uniform coating properties; it is beneficial to prolong the roughening reaction time, making it easier to control the roughening degree of the copper sheet, making the surface of the copper sheet more uniform, and after the roughening is completed, it is easier to remove and not easy to break.

[0022] In order to reduce the content of CuAlO2 between islands, the present invention oxidizes the copper surface by spraying an oxidizing liquid through high-pressure atomization. The purpose is to oxidize the roughened copper surface to form an oxygen-containing layer with a larger surface area. The advantages are: more uniform oxidation, faster oxidation speed and thinner oxidation layer. Under the premise of ensuring the sintering effect, the precipitated phase is more inclined to CuAl2O4, thereby ensuring insulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0024] Figure 1 It is a schematic diagram of the structure of CuAlO2;

[0025] Figure 2 This is the XRD diagram of the interface product with poor insulation and qualified insulation;

[0026] Figure 3 This is the XRD pattern of the interface product of Comparative Example 1;

[0027] Figure 4 This is the XRD diagram of the interface product of Example 4. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] In the following specific embodiments, parts are parts by weight. In this embodiment, it should be noted that the purchase manufacturers of all raw materials involved in the present invention are not subject to any special restrictions and exemplarily include: polyurethane acrylate with a brand of 230A2; tetrahydrofuran acrylate with a product number of 0002, 2-hydroxy-methylphenylpropane-1-one with a CAS number of 7473-98-5, polyamide wax with a model of Ceridust3910, and hydroxyethyl acrylate with a CAS number of 8 18-61-1, ethylene glycol bisthioglycolate has a CAS number of 123-81-9, azobisisobutyronitrile has a CAS number of 78-67-1, dibutyltin dilaurate has a CAS number of 77-58-7, isophorone diisocyanate has a CAS number of 4098-71-9, bis(hydroxymethyl)propionic acid has a CAS number of 4767-03-7, and N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid has a CAS number of 10191-18-1.

[0030] The specific embodiments of the present invention are as follows:

[0031] Embodiment 1: A copper sheet pretreatment method for avoiding poor insulation between DCB islands, comprising the following steps:

[0032] S1: The copper sheet is degreased and cleaned by a spray-type horizontal transmission device, and immersed in a micro-etching solution for 30 minutes to obtain a surface roughened copper sheet;

[0033] The micro-etching solution is a sulfuric acid solution of Na2S2O8 (the concentration of Na2S2O8 is 60 g / L and the concentration of sulfuric acid is 4 wt%);

[0034] S2: The surface roughened copper sheet is passed through a vertical gantry device, pickled in sequence, cleaned under 50kHz ultrasonic waves for 15 minutes, and dried with hot air; then vertically immersed in 38°C deionized water for ultrasonic cleaning for 5 minutes, cooled to 20°C for ultrasonic cleaning for 12 minutes, then cleaned under 0.86MHz megasonic waves for 12 minutes, and dried with hot air; then, at 85°C, high-pressure atomization spraying is performed at a liquid feed rate of 6mL / min, and an alkaline oxidizing solution is evenly sprayed on its surface, and then the alkaline oxidizing solution is removed by 4°C cold air to obtain a prefabricated copper sheet;

[0035] S3: cleaning and drying the prefabricated copper sheet, laminating the oxidized surface of the copper sheet with the ceramic, and sintering the copper sheet at 1070° C. for 1 hour to obtain a DCB product;

[0036] The raw materials of the alkaline oxidizing solution include the following components: 30% NaClO2, 12.5% ​​NaOH, and the rest water, in terms of concentration percentage.

[0037] Example 2 Based on Example 1, micro-etching solution is mixed with polyurethane acrylate and other substances to prepare micro-etching glue, which is placed on the surface of the copper sheet:

[0038] S1: Degreasing and cleaning the copper sheet through a spray-type horizontal transmission device; covering the surface of the cleaned copper sheet with micro-etching glue by screen printing; then photocuring the micro-etching glue by exposure; after standing for 30 minutes, peeling off the micro-etching glue to obtain a surface roughened copper sheet;

[0039] The raw materials of the micro-etching glue include the following components: by weight percentage, 67% of polyurethane acrylate, 16% of tetrahydrofuran acrylate, 2% of 2-hydroxy-methylphenylpropane-1-one, 1.5% of polyamide wax, 1.5% of silane coupling agent, and 12% of micro-etching solution; the micro-etching solution is a sulfuric acid solution of Na2S2O8 (the concentration of Na2S2O8 is 60g / L, and the concentration of sulfuric acid is 4wt%);

[0040] S2: The surface roughened copper sheet is passed through a vertical gantry device, pickled in sequence, cleaned under 50kHz ultrasonic waves for 15 minutes, and dried with hot air; then vertically immersed in 38°C deionized water for ultrasonic cleaning for 5 minutes, cooled to 20°C for ultrasonic cleaning for 12 minutes, then cleaned under 0.86MHz megasonic waves for 12 minutes, and dried with hot air; then, at 85°C, high-pressure atomization spraying is performed at a liquid feed rate of 6mL / min, and an alkaline oxidizing solution is evenly sprayed on its surface, and then the alkaline oxidizing solution is removed by 4°C cold air to obtain a prefabricated copper sheet;

[0041] S3: cleaning and drying the prefabricated copper sheet, laminating the oxidized surface of the copper sheet with the ceramic, and sintering the copper sheet at 1070° C. for 1 hour to obtain a DCB product;

[0042] The raw materials of the alkaline oxidizing solution include the following components: 30% NaClO2, 12.5% ​​NaOH, and the rest water, in terms of concentration percentage.

[0043] Example 3 is based on Example 2, except that the polyurethane acrylate is replaced with waterborne polyurethane acrylate;

[0044] S1: The preparation method of waterborne polyurethane acrylate is as follows: (1) 1.2 parts of hydroxyethyl acrylate, 4.3 parts of ethylene glycol bisthioglycolate, and 0.002 parts of azobisisobutyronitrile are added to 30 parts of DMF and mixed uniformly, and then irradiated under 365 nm, 100 W ultraviolet light for 2 hours, purified, and dried to obtain an intermediate; (2) 0.02 parts of dibutyltin dilaurate are added to 14 parts of isophorone diisocyanate and the mixture is uniformly mixed to obtain an intermediate. Mixture A; 9.3 parts of polyethylene glycol-600 and 2.8 parts of dihydroxymethyl propionic acid were mixed evenly, heated to 60°C, added to mixture A and reacted for 1 hour, and then heated to 85°C and continued to react for 35 minutes to obtain a top polymer; (3) 8.2 parts of the top polymer were successively added with the intermediate, 5.3 parts of N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid, and 30 parts of deionized water, mixed evenly, and reacted at 30°C for 1 hour to obtain waterborne polyurethane acrylate;

[0045] S2: Degreasing and cleaning the copper sheet through a spray-type horizontal transmission device; covering the surface of the cleaned copper sheet with micro-etching glue by screen printing; then photocuring the micro-etching glue by exposure; after standing for 30 minutes, peeling off the micro-etching glue to obtain a surface roughened copper sheet;

[0046] The micro-etching solution is a sulfuric acid solution of Na2S2O8 (the concentration of Na2S2O8 is 60 g / L and the concentration of sulfuric acid is 4 wt%);

[0047] S3: The surface roughened copper sheet is passed through a vertical gantry device, and then pickled, cleaned under 50kHz ultrasonic waves for 15 minutes, and dried with hot air in sequence; then vertically immersed in 38°C deionized water for ultrasonic cleaning for 5 minutes, cooled to 20°C for ultrasonic cleaning for 12 minutes, then cleaned under 0.86MHz megasonic waves for 12 minutes, and dried with hot air; then, at 85°C, high-pressure atomization spraying is performed at a liquid feed rate of 6mL / min, and an alkaline oxidizing solution is evenly sprayed on its surface, and then the alkaline oxidizing solution is removed by 4°C cold air to obtain a prefabricated copper sheet;

[0048] S4: cleaning and drying the prefabricated copper sheet, laminating the oxidized surface of the copper sheet with the ceramic, and sintering the copper sheet at 1070° C. for 1 hour to obtain a DCB product;

[0049] The raw materials of the alkaline oxidizing solution include the following components: 25% NaClO2, 8% NaOH, and the rest water, in terms of concentration percentage.

[0050] Example 4 is based on Example 3, and the raw material content of the micro-etching glue is adjusted;

[0051] S1: The preparation method of waterborne polyurethane acrylate is as follows: (1) 1.2 parts of hydroxyethyl acrylate, 4.3 parts of ethylene glycol bisthioglycolate, and 0.002 parts of azobisisobutyronitrile are added to 30 parts of DMF and mixed uniformly, and then irradiated under 365 nm, 100 W ultraviolet light for 2 hours, purified, and dried to obtain an intermediate; (2) 0.02 parts of dibutyltin dilaurate are added to 14 parts of isophorone diisocyanate and the mixture is uniformly mixed to obtain an intermediate. Mixture A; 9.3 parts of polyethylene glycol-600 and 2.8 parts of dihydroxymethyl propionic acid were mixed evenly, heated to 60°C, added to mixture A and reacted for 1 hour, and then heated to 85°C and continued to react for 35 minutes to obtain a top polymer; (3) 8.2 parts of the top polymer were successively added with the intermediate, 5.3 parts of N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid, and 30 parts of deionized water, mixed evenly, and reacted at 30°C for 1 hour to obtain waterborne polyurethane acrylate;

[0052] S2: Degreasing and cleaning the copper sheet through a spray-type horizontal transmission device; covering the surface of the cleaned copper sheet with micro-etching glue by screen printing; then photocuring the micro-etching glue by exposure; after standing for 30 minutes, peeling off the micro-etching glue to obtain a surface roughened copper sheet;

[0053] The raw materials of the micro-etching glue include the following components: by weight percentage, 67% of polyurethane acrylate, 18% of tetrahydrofuran acrylate, 2% of 2-hydroxy-methylphenylpropane-1-one, 1.5% of polyamide wax, 1.5% of silane coupling agent, and 10% of micro-etching solution; the micro-etching solution is a sulfuric acid solution of Na2S2O8 (the concentration of Na2S2O8 is 60g / L, and the concentration of sulfuric acid is 3wt%);

[0054] S3: The surface roughened copper sheet is passed through a vertical gantry device, and then pickled, cleaned under 50kHz ultrasonic waves for 15 minutes, and dried with hot air in sequence; then vertically immersed in 38°C deionized water for ultrasonic cleaning for 5 minutes, cooled to 20°C for ultrasonic cleaning for 12 minutes, then cleaned under 0.86MHz megasonic waves for 12 minutes, and dried with hot air; then, at 85°C, high-pressure atomization spraying is performed at a liquid feed rate of 6mL / min, and an alkaline oxidizing solution is evenly sprayed on its surface, and then the alkaline oxidizing solution is removed by 4°C cold air to obtain a prefabricated copper sheet;

[0055] S4: cleaning and drying the prefabricated copper sheet, laminating the oxidized surface of the copper sheet with the ceramic, and sintering the copper sheet at 1070° C. for 1 hour to obtain a DCB product;

[0056] The raw materials of the alkaline oxidizing solution include the following components: 25% NaClO2, 8% NaOH, and the rest water, in terms of concentration percentage.

[0057] Comparative Example 1, directly oxidizing the copper sheet;

[0058] S1: Degreasing and cleaning the copper sheet through a spray-type horizontal transmission device;

[0059] S2: oxidation by oxygen-containing tunnel furnace;

[0060] S3: The oxide layer is bonded to the ceramic and sintered at 1070°C for 1 hour to obtain a DCB product.

[0061] Testing experiment: 100 products were prepared according to the methods of Examples 1 to 4, and their yields were calculated;

[0062]

[0063]

[0064] Table 1

[0065] Conclusion: From Table 1, it can be found that in Example 1, the micro-etching solution is used to directly immerse the copper sheet, which corrodes quickly and causes uneven coarsening of the copper sheet, thereby reducing the yield rate. Therefore, the present invention designs another copper sheet coarsening treatment, that is, the micro-etching solution is mixed with substances such as polyurethane acrylate to form a viscous coating, which is applied to the surface of the copper sheet. This not only prolongs the coarsening reaction time, but also makes the coarsening degree of the copper sheet easier to control. In order to improve its adhesion, flexibility and durability, the present invention prepares a water-based polyurethane acrylate for micro-etching glue, which can provide a uniform coating and better micro-etching effect due to its good dispersibility and uniform coating properties, thereby benefiting to improving the yield rate.

[0066] Detection and analysis: From Figure 2 and Figure 3 By comparison, it can be seen that the interface phase produced by Comparative Example 1 is CuAlO2; CuAlO2 has a hexagonal crystal structure and is a transparent p-type semiconductor with a band gap range of 2.7 to 3.5 eV and a low resistivity (1.4 to 74 kΩ.cm), so it will cause the inter-island insulation of the DCB product pattern to be greatly reduced.

[0067] The present invention has found in experiments that a large number of spinel structures are generated during the sintering process of the prefabricated copper sheet and the ceramic. These spinel structure materials are difficult to be completely removed during etching, so light yellow circular marks are left on the surface of the ceramic sheet. When the band gap width of the spinel structure is large enough, the copper islands of the DCB product pattern have sufficient insulation, avoiding excessive leakage current when a high voltage is applied between the islands. Figure 3 and Figure 4 Comparative studies have shown that the product produced by the new method of Example 4 has some more CuAl2O4 on its surface, which confirms the previous theoretical analysis and verifies the effectiveness of the method.

[0068] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0069] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A copper sheet pretreatment method for avoiding poor insulation between DCB islands, characterized in that: The steps include: S1: Degreasing and cleaning the surface of the copper substrate in sequence, printing micro-etching glue on the surface, standing for 30±5 minutes after light curing, and stripping off the micro-etching glue to obtain a surface roughened copper sheet; S2: The surface roughened copper sheet is pickled, ultrasonically cleaned, and dried in sequence, and then an alkaline oxidizing solution is evenly sprayed on the surface at a liquid feed rate of 2 mL / min to 6 mL / min by high-pressure atomization spraying at 70°C to 90°C, and then the alkaline oxidizing solution is removed by cold wind at 0°C to 10°C to preform the copper sheet; S3: The prefabricated copper sheet is cleaned and dried, and the oxide layer thereof is bonded to the ceramic, and sintered at 1065° C. to 1083° C. for 1 to 2 hours to obtain a DCB product.

2. A copper sheet pretreatment method for avoiding poor insulation between DCB islands according to claim 1, characterized in that: The raw materials of the alkaline oxidizing solution include the following components: in terms of concentration percentage, 20% to 30% of NaClO2, 7.5% to 12.5% ​​of NaOH, and the rest is water.

3. A copper sheet pretreatment method for avoiding poor insulation between DCB islands according to claim 1, characterized in that: The raw materials of the micro-etching glue include the following components: by weight percentage, 62% to 70% of basic colloid, 16% to 18% of tetrahydrofuran acrylate, 10% to 12% of micro-etching solution, 1% to 3% of polyamide wax, 1% to 2% of silane coupling agent, and 2% to 3% of 2-hydroxy-methylphenylpropane-1-one.

4. A copper sheet pretreatment method for avoiding poor insulation between DCB islands according to claim 3, characterized in that: The micro-etching solution is a sulfuric acid solution of Na2S2O8; the concentration of the Na2S2O8 is 50g / L to 60g / L, and the concentration of the sulfuric acid is 2wt% to 4wt%.

5. A copper sheet pretreatment method for avoiding poor insulation between DCB islands according to claim 3, characterized in that: The base colloid comprises one or more of polyurethane acrylate and waterborne polyurethane acrylate; the preparation method of the waterborne polyurethane acrylate is as follows: (1) adding hydroxyethyl acrylate, ethylene glycol bisthioglycolate and azobisisobutyronitrile to DMF and mixing them uniformly, irradiating them under ultraviolet light of 350nm-365nm and 100W for 2 hours, purifying and drying to obtain an intermediate; (2) adding dibutyltin dilaurate to isophorone diisocyanate and mixing them uniformly to obtain a mixture A; mixing polyethylene glycol and bishydroxymethyl propionic acid uniformly, heating them to 60°C-70°C, adding the mixture A to react for 0.8-2 hours, heating them to 80°C-90°C and continuing to react for 30-45 minutes to obtain a top polymer; (3) sequentially adding the intermediate, N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid and deionized water to the top polymer and mixing them uniformly, reacting them at 30°C-35°C for 1-2 hours to obtain a waterborne polyurethane acrylate.

6. A copper sheet pretreatment method for avoiding poor insulation between DCB islands according to claim 5, characterized in that: The raw materials of the intermediate include the following components: by weight, 1-1.2 parts of hydroxyethyl acrylate, 4-4.5 parts of ethylene glycol bisthioglycolate, 0.002-0.003 parts of azobisisobutyronitrile, and 30-40 parts of DMF; the molecular weight of the polyethylene glycol is 200-1200.

7. A copper sheet pretreatment method for avoiding poor insulation between DCB islands according to claim 5, characterized in that: The raw materials of the top polymer include the following components: by weight, 0.02-0.024 parts of dibutyltin dilaurate, 10-15 parts of isophorone diisocyanate, 9-10 parts of polyethylene glycol, and 1-3 parts of dihydroxymethyl propionic acid; the raw materials of the water-based polyurethane acrylate include the following components: by weight, 4.2-12.5 parts of the top polymer, 3-3.5 parts of the intermediate, 4-6 parts of N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid, and 20-40 parts of deionized water.

8. A DCB product is prepared according to a copper sheet pretreatment method for avoiding poor insulation between DCB islands according to any one of claims 1 to 7.

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