A flash etching solution, a preparation method thereof and a flash etching method

Abstract

This invention discloses a flash etching solution, its preparation method, and the flash etching method. The flash etching solution comprises 15-25 g / L of divalent copper ions, 105-140 g / L of chloride ions, 100-180 g / L of inorganic acid, 0.02-0.1 g / L of pterin derivative, 3-10 g / L of multi-arm polyethylene glycol derivative, and water. Compared with existing technologies, the flash etching solution of this invention uses a sulfuric acid / chloride system. Compared with sulfuric acid / hydrogen peroxide system solutions, this solution contains a large amount of chloride ions and is not affected by small amounts of external chloride ions. Compared with traditional acidic chloride etching solutions, it uses oxygen from the air as a circulating regeneration oxidant for divalent copper, which does not oxidize the side etching inhibitor, resulting in good solution stability. The use of multi-arm polyethylene glycol derivative as the side etching inhibitor results in minimal side etching at the bottom of the etched circuit and good line shape preservation.

Description

Technical Field

[0001] This invention relates to the field of packaging substrate manufacturing technology, and more particularly to a flash etching solution, its preparation method, and the flash etching method. Background Technology

[0002] Semi-Additive Process (SAP) is a key technology in the field of integrated circuit (IC) substrate manufacturing. This method involves the following steps: First, a base copper layer is deposited on the substrate as a seed layer for subsequent electroplating; next, the desired pattern is formed through processes such as dry film lamination, exposure, and development; subsequently, electroplating is performed to increase the circuit thickness; finally, a flash etching process is used to remove the base copper between the circuits, thereby forming a finely patterned circuit.

[0003] In the flash etching process for removing the base copper, the flash etching solution simultaneously etches both the electroplated copper forming the circuitry and the base copper serving as the seed layer. Due to differences in the fabrication processes of the base copper and electroplated copper, such as grain size, crystal structure, and density, the etch rate of the flash etching solution differs between them. This difference can lead to excessive undercut etching at the interface between the base copper and electroplated copper, thereby affecting the adhesion between the substrate and the copper layer and causing problems such as flywires and open circuits. Therefore, the etch rate stability and undercut control of the flash etching solution are key performance indicators.

[0004] Currently, most flash etching solutions on the market are based on a sulfuric acid / hydrogen peroxide system, using a protective agent (lateral corrosion inhibitor) to reduce undercut. These protective agents are typically small molecule compounds containing N, O, and P atoms, which adsorb onto the copper surface via lone pairs of electrons. Combined with appropriate spray pressure, they can effectively reduce undercut. However, sulfuric acid / hydrogen peroxide flash etching solutions have some drawbacks: they are sensitive to changes in chloride ion and hydrogen peroxide concentrations, leading to unstable etching rates and poor stability during continuous production; under the catalytic action of metal ions, the protective agent can be oxidized by hydrogen peroxide, thus affecting its protective effect.

[0005] In contrast, the acidic copper chloride etchant used in traditional subtractive etching is not affected by chloride ions, but its etching rate is too fast (exceeding 10 μm / min), making it unsuitable for etching the bottom copper (less than 3 μm) in flash etching processes. Furthermore, the acidic copper chloride etchant contains strong oxidants, such as sodium chlorate, which causes the side etching inhibitor to be quickly oxidized after addition, reducing its effectiveness. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a sulfuric acid / chloride system flash etching solution that is unaffected by external chloride ions, exhibits a stable etching rate, and is easy to manage on-site.

[0007] The technical solution of this invention is:

[0008] The present invention provides a flash etching solution comprising 15-25 g / L of divalent copper ions, 105-140 g / L of chloride ions, 100 g / L-180 g / L of inorganic acid, 0.02-0.1 g / L of pterin derivative, 3 g / L-10 g / L of multi-arm polyethylene glycol derivative, and water.

[0009] Furthermore, the divalent copper ions are derived from at least one of copper chloride, copper sulfate, and copper formate.

[0010] Furthermore, the chloride ions are derived from at least one of sodium chloride, potassium chloride, and copper chloride or their hydrochloride salts.

[0011] Furthermore, the pterin derivative is at least one of 6-biopterin, 7,8-dihydrobiopterin, and pterin-6-carboxylic acid.

[0012] Furthermore, the multi-arm polyethylene glycol derivative is at least one of multi-arm polyethylene glycol amine, multi-arm polyethylene glycol maleimide, and multi-arm polyethylene glycol thiol.

[0013] Furthermore, the multi-arm polyethylene glycolamine is one of four-arm polyethylene glycolamine, six-arm polyethylene glycolamine, or eight-arm polyethylene glycolamine.

[0014] Furthermore, the molecular weight of the 6-arm polyethylene glycolamine is 2K to 10K.

[0015] Furthermore, the concentration of the 6-arm polyethylene glycolamine is 3 g / L to 10 g / L.

[0016] The present invention also provides a method for preparing flash etching solution, which includes the following steps: dissolving divalent copper ions, chloride ions, inorganic acid, pterin derivative, and multi-arm polyethylene glycol derivative in water in a certain proportion to form an aqueous solution, and stirring evenly to form flash etching solution.

[0017] This invention also provides a flash etching method using a flash etching solution, wherein the aforementioned flash etching solution is used to flash etch an integrated circuit substrate, and the spraying pressure is 1.2–1.8 kg / cm². 2 10. The etching temperature is 25℃~35°C, and the etching time is 90~150s.

[0018] The beneficial technical effects of this invention are:

[0019] The flash etching solution of this invention uses a sulfuric acid / chloride system. Compared with sulfuric acid / hydrogen peroxide systems, this solution contains a large amount of chloride ions and is unaffected by small amounts of external chloride ions. Compared with traditional acidic chloride etching solutions, it uses oxygen from the air as a circulating regeneration oxidant for divalent copper, thus avoiding oxidation of the undercut inhibitor and exhibiting good solution stability. Through the synergistic effect of its components, excellent etching results are achieved, effectively flash etching away the underlying copper while minimizing undercut, ensuring adhesion between the circuitry and the substrate. A small amount of pterin derivative can form a small anode and large cathode corrosion cell effect on the copper surface, promoting the etching of the underlying copper. The use of a multi-arm polyethylene glycol derivative as an undercut inhibitor results in minimal undercut at the bottom of the etched circuitry and good line shape retention. Attached Figure Description

[0020] Figure 1 This is a metallographic micrograph of an integrated circuit substrate after flash etching with the flash etching solution of Example 1.

[0021] Figure 2 This is a metallographic micrograph of an integrated circuit substrate after flash etching with the flash etching solution of Example 2.

[0022] Figure 3 This is a metallographic micrograph of an integrated circuit substrate after flash etching with the flash etching solution of Example 3.

[0023] Figure 4 This is a metallographic micrograph of an integrated circuit substrate after flash etching with the flash etching solution of Example 4.

[0024] Figure 5 This is a metallographic micrograph of an integrated circuit substrate after flash etching with the flash etching solution of Example 5.

[0025] Figure 6 This is a metallographic micrograph of an integrated circuit substrate after flash etching with the flash etching solution of Example 6.

[0026] Figure 7 This is a metallographic micrograph of an integrated circuit substrate after flash etching with the flash etching solution of Example 7.

[0027] Figure 8 This is a metallographic micrograph of an integrated circuit substrate after flash etching with the flash etching solution of Example 8.

[0028] Figure 9 The image shows a metallographic cross-section of an integrated circuit substrate after flash etching with the flash etching solution used in Comparative Example 3.

[0029] Figure 10 The image shows a metallographic cross-section of an integrated circuit substrate after flash etching with the same etching solution used in Comparative Example 4. Detailed Implementation

[0030] In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0031] This invention discloses a flash etching solution for use on integrated circuit substrates. The flash etching solution comprises 15-25 g / L divalent copper ions, 105-140 g / L chloride ions, 100-180 g / L inorganic acid, 0.02-0.1 g / L pterin derivative, 3-10 g / L multi-arm polyethylene glycol derivative, and water. The flash etching solution of this invention uses a sulfuric acid / chloride system. Compared with sulfuric acid / hydrogen peroxide systems, this solution contains a large amount of chloride ions and is unaffected by small amounts of external chloride ions. Compared with traditional acidic chloride etching solutions, it uses oxygen from the air as a circulating regeneration oxidant for divalent copper, thus avoiding oxidation of the undercut corrosion inhibitor and exhibiting good solution stability. Through the synergistic effect of the components, a good etching effect can be achieved, effectively flash etching away the underlying copper while minimizing undercut corrosion, ensuring adhesion between the circuitry and the substrate. A small amount of pterin derivative can form a small anode and large cathode corrosion cell effect on the copper surface, promoting the etching of the underlying copper. Using a multi-arm polyethylene glycol derivative as a side etching inhibitor results in minimal side etching at the bottom of the etched circuit and good preservation of the line shape.

[0032] Furthermore, the divalent copper ions in the flash etching solution originate from at least one of copper chloride, copper sulfate, and copper formate. Copper chloride, copper sulfate, or copper formate, when dissolved in water, can provide divalent copper ions. These divalent copper ions act as an oxidant, reacting with copper to form monovalent copper ions. The monovalent copper ions are then oxidized back to divalent copper ions by oxygen in the air, achieving a cycle of regeneration. This results in a stable etching rate and simple on-site management. Compared to traditional acidic chloride etching solutions, the flash etching solution of this invention utilizes oxygen in the air as a circulating oxidant for divalent copper, preventing the oxidation of side-etching inhibitors and exhibiting good solution stability.

[0033] Preferably, the divalent copper ions are derived from copper chloride. The concentration of divalent copper ions provided by copper chloride is 15 g / L to 25 g / L.

[0034] Furthermore, the chloride ions originate from at least one of sodium chloride, potassium chloride, and copper chloride or their hydrochloride salts. Dissolving sodium chloride, potassium chloride, or copper chloride or their hydrochloride salts in water provides chloride ions. The chloride ions and cuprous chloride form a soluble chloride, promoting the copper etching reaction. Because the flash etching solution of the present invention uses a sulfuric acid / chloride system, compared with the sulfuric acid / hydrogen peroxide system solution, the flash etching solution contains a large amount of chloride ions and is not affected by a small amount of external chloride ions.

[0035] Preferably, the chloride ions are derived from sodium chloride, and the concentration of chloride ions provided is 105 g / L to 140 g / L.

[0036] Preferably, the inorganic acid is sulfuric acid with a concentration of 100 g / L to 180 g / L. The inorganic acid provides an acidic environment, which is conducive to the dissolution of copper.

[0037] Furthermore, the pterin derivative is at least one of 6-biopterin, 7,8-dihydrobiopterin, and pterin-6-carboxylic acid. A small amount of the pterin derivative can form a corrosion cell effect with a small anode and a large cathode on the copper surface, promoting the etching of the underlying copper.

[0038] Preferably, the pterin derivative is pterin-6-carboxylic acid.

[0039] Further, the concentration of the pterin derivative is 0.02-0.1 g / L, preferably 0.04-0.06 g / L.

[0040] Furthermore, the multi-arm polyethylene glycol derivative is a polymer compound. Using a polymer compound as a side etching inhibitor results in minimal side etching at the bottom of the etched circuit, maintaining good line shape.

[0041] Furthermore, the multi-arm polyethylene glycol derivative is at least one of multi-arm polyethylene glycol amine, multi-arm polyethylene glycol maleimide, and multi-arm polyethylene glycol thiol.

[0042] Preferably, the multi-arm polyethylene glycol derivative is a multi-arm polyethylene glycolamine. By using multi-arm polyethylene glycolamine as a side-etching inhibitor, its molecule has multiple structures such as N and O atoms that can provide lone pairs of electrons, possessing multiple potential active adsorption centers, allowing it to be firmly adsorbed onto the metal surface. Simultaneously, the star-shaped branched structure of the multi-arm polyethylene glycolamine ensures sufficient contact area during adsorption with the copper surface, and its molecular structure's flexibility allows for maximum bonding with the copper surface, forming a dense protective film. Through the synergistic effect of the components, the bottom copper can be rapidly etched to form the circuit, while effectively preventing bottom side-etching. Furthermore, the multi-arm polyethylene glycolamine can adsorb onto the copper surface to form an isolation film. With appropriate spray pressure, the flash etching solution can break through the isolation film on the front of the circuit, but the isolation films on both sides of the circuit are maintained due to insufficient pressure, thus reducing side-etching.

[0043] Furthermore, the multi-arm polyethylene glycolamine is one of four-arm polyethylene glycolamine, six-arm polyethylene glycolamine, or eight-arm polyethylene glycolamine.

[0044] Furthermore, the molecular weight of the 6-arm polyethylene glycolamine is 2K to 10K, preferably 4K.

[0045] Furthermore, the concentration of the 6-arm polyethylene glycolamine is 3 g / L to 10 g / L, preferably 4 g / L to 6 g / L.

[0046] The present invention also provides a method for preparing flash etching solution, which includes the following steps: dissolving divalent copper ions, chloride ions, inorganic acid, pterin derivative, and multi-arm polyethylene glycol derivative in water in a certain proportion to form an aqueous solution, and stirring evenly to form flash etching solution.

[0047] This invention also provides a flash etching method using a flash etching solution, wherein the aforementioned flash etching solution is used to flash etch an integrated circuit substrate, and the spraying pressure is 1.2–1.8 kg / cm². 2 10. The etching temperature is 25℃~35°C, and the etching time is 90~150s.

[0048] To clearly illustrate the flash etching solution, its preparation method, and the flash etching method of the present invention, the following description provides a detailed explanation using specific examples and comparative examples.

[0049] Example 1:

[0050] The divalent copper ions are derived from copper sulfate at a concentration of 20 g / L.

[0051] Chloride ions are derived from sodium chloride at a concentration of 120 g / L.

[0052] The inorganic acid is sulfuric acid with a concentration of 150 g / L.

[0053] The pterin derivative is pterin-6-carboxylic acid, with a concentration of 0.05 g / L.

[0054] The multi-arm polyethylene glycol derivative is a 6-arm polyethylene glycol amine with a molecular weight of 4K and a concentration of 5 g / L.

[0055] Dissolve the above components in water according to the proportions to form an aqueous solution, and stir evenly to form a flash corrosion solution.

[0056] Example 2:

[0057] The divalent copper ions are derived from copper sulfate at a concentration of 15 g / L.

[0058] Chloride ions are derived from sodium chloride, with a concentration of 105 g / L.

[0059] The inorganic acid is sulfuric acid with a concentration of 100 g / L.

[0060] The pterin derivative is pterin-6-carboxylic acid, with a concentration of 0.02 g / L.

[0061] The multi-arm polyethylene glycol derivative is a 6-arm polyethylene glycol amine with a molecular weight of 4K and a concentration of 3 g / L. The above components are dissolved in water according to the specified proportions to form an aqueous solution, which is then stirred until homogeneous to form a flash etching solution.

[0062] Example 3:

[0063] The divalent copper ions are derived from copper chloride at a concentration of 25 g / L.

[0064] Chloride ions are derived from sodium chloride and copper chloride, with a concentration of 140 g / L.

[0065] The inorganic acid is sulfuric acid with a concentration of 180 g / L.

[0066] The pterin derivative is pterin-6-carboxylic acid, with a concentration of 1 g / L.

[0067] The multi-arm polyethylene glycol derivative is a 6-arm polyethylene glycol amine with a molecular weight of 2K and a concentration of 10 g / L. The above components are dissolved in water according to the specified proportions to form an aqueous solution, which is then stirred until homogeneous to form a flash etching solution.

[0068] Example 4:

[0069] The divalent copper ions are derived from copper formate at a concentration of 20 g / L.

[0070] Chloride ions are derived from sodium chloride at a concentration of 120 g / L.

[0071] The inorganic acid is sulfuric acid with a concentration of 150 g / L.

[0072] The pterin derivative is pterin-6-carboxylic acid, with a concentration of 0.05 g / L.

[0073] The multi-arm polyethylene glycol derivative is a 6-arm polyethylene glycol amine with a molecular weight of 10K and a concentration of 3 g / L. The above components are dissolved in water according to the specified proportions to form an aqueous solution, which is then stirred until homogeneous to form a flash etching solution.

[0074] Example 5:

[0075] Divalent copper ions are derived from copper chloride at a concentration of 20 g / L.

[0076] Chloride ions are derived from potassium chloride at a concentration of 120 g / L.

[0077] The inorganic acid is sulfuric acid with a concentration of 150 g / L.

[0078] The pterin derivative is pterin-6-carboxylic acid, with a concentration of 0.05 g / L.

[0079] The multi-arm polyethylene glycol derivative is a 4-arm polyethylene glycol amine with a molecular weight of 10K and a concentration of 5 g / L. The above components are dissolved in water according to the specified proportions to form an aqueous solution, which is then stirred until homogeneous to form a flash etching solution.

[0080] Example 6:

[0081] The divalent copper ions are derived from copper chloride at a concentration of 25 g / L.

[0082] Chloride ions are derived from sodium chloride and copper chloride, with a concentration of 120 g / L.

[0083] The inorganic acid is sulfuric acid with a concentration of 120 g / L.

[0084] The pterin derivative is 6-biopterin, with a concentration of 0.1 g / L.

[0085] The multi-arm polyethylene glycol derivative is an 8-arm polyethylene glycol amine with a molecular weight of 2K and a concentration of 3 g / L.

[0086] Dissolve the above components in water according to the proportions to form an aqueous solution, and stir evenly to form a flash corrosion solution.

[0087] Example 7:

[0088] The divalent copper ions are derived from copper sulfate at a concentration of 15 g / L.

[0089] Chloride ions are derived from sodium chloride and potassium chloride, with a concentration of 100 g / L.

[0090] The inorganic acid is sulfuric acid with a concentration of 100 g / L.

[0091] The pterin derivative is 7,8-dihydrobiopterin, with a concentration of 0.02 g / L.

[0092] The multi-arm polyethylene glycol derivative is a 2K molecular weight multi-arm polyethylene glycol maleimide with a concentration of 3 g / L.

[0093] Dissolve the above components in water according to the proportions to form an aqueous solution, and stir evenly to form a flash corrosion solution.

[0094] Example 8:

[0095] The divalent copper ions are derived from copper formate at a concentration of 20 g / L.

[0096] Chloride ions are derived from sodium chloride at a concentration of 120 g / L.

[0097] The inorganic acid is sulfuric acid with a concentration of 150 g / L.

[0098] The pterin derivative is pterin-6-carboxylic acid, with a concentration of 0.05 g / L.

[0099] The multi-arm polyethylene glycol derivative is a multi-arm polyethylene glycol thiol with a molecular weight of 4K and a concentration of 5 g / L.

[0100] Dissolve the above components in water according to the proportions to form an aqueous solution, and stir evenly to form a flash corrosion solution.

[0101] Comparative Example 1:

[0102] The divalent copper ions are derived from copper sulfate at a concentration of 20 g / L.

[0103] Chloride ions are derived from sodium chloride at a concentration of 120 g / L.

[0104] The inorganic acid is sulfuric acid with a concentration of 150 g / L.

[0105] Dissolve the above components in water according to the proportions to form an aqueous solution, and stir evenly to form a flash corrosion solution.

[0106] Comparative Example 2:

[0107] The divalent copper ions are derived from copper sulfate at a concentration of 20 g / L.

[0108] Chloride ions are derived from sodium chloride at a concentration of 120 g / L.

[0109] The inorganic acid is sulfuric acid with a concentration of 150 g / L.

[0110] The pterin derivative is pterin-6-carboxylic acid, with a concentration of 0.01 g / L.

[0111] The multi-arm polyethylene glycol derivative is a 6-arm polyethylene glycol amine with a molecular weight of 4K and a concentration of 5 g / L.

[0112] Dissolve the above components in water according to the proportions to form an aqueous solution, and stir evenly to form a flash corrosion solution.

[0113] Comparative Example 3:

[0114] The divalent copper ions are derived from copper sulfate at a concentration of 20 g / L.

[0115] Chloride ions are derived from sodium chloride at a concentration of 120 g / L.

[0116] The inorganic acid is sulfuric acid with a concentration of 150 g / L.

[0117] The pterin derivative is pterin-6-carboxylic acid, with a concentration of 0.2 g / L.

[0118] The multi-arm polyethylene glycol derivative is a 6-arm polyethylene glycol amine with a molecular weight of 4K and a concentration of 5 g / L.

[0119] Dissolve the above components in water according to the proportions to form an aqueous solution, and stir evenly to form a flash corrosion solution.

[0120] Comparative Example 4:

[0121] The divalent copper ions are derived from copper sulfate at a concentration of 15 g / L.

[0122] Chloride ions are derived from sodium chloride, with a concentration of 105 g / L.

[0123] The inorganic acid is sulfuric acid with a concentration of 100 g / L.

[0124] The pterin derivative is pterin-6-carboxylic acid, with a concentration of 0.02 g / L.

[0125] The multi-arm polyethylene glycol derivative is a 6-arm polyethylene glycol amine with a molecular weight of 4K and a concentration of 0.5 g / L. The above components are dissolved in water according to the specified proportions to form an aqueous solution, which is then stirred until homogeneous to form a flash etching solution.

[0126] Comparative Example 5:

[0127] The divalent copper ions are derived from copper sulfate at a concentration of 15 g / L.

[0128] Chloride ions are derived from sodium chloride, with a concentration of 105 g / L.

[0129] The inorganic acid is sulfuric acid with a concentration of 100 g / L.

[0130] The pterin derivative is pterin-6-carboxylic acid, with a concentration of 0.02 g / L.

[0131] The multi-arm polyethylene glycol derivative is a 6-arm polyethylene glycol amine with a molecular weight of 4K and a concentration of 15 g / L. The above components were dissolved in water according to the specified proportions to form an aqueous solution, which was then stirred until homogeneous to form a flash etching solution. Furthermore, the performance of the flash etching solutions from the above examples and comparative examples was tested.

[0132] Test board: Uses Mitsui H-series copper foil as the base, Rz = 3μm. Production board process: film application – exposure – development – ​​pattern electroplating – film removal – washing and drying, ready for use.

[0133] Spraying equipment: Etching test tank, with nozzles 5cm away from the board surface. The nozzles are fan-shaped. During the etching process, the board surface automatically swings back and forth to ensure uniformity.

[0134] Test procedure: Fix the test board in the etching test tank, start the swing etching and start the timer. After the time is up, take it out, wash it with water and blow it dry. The spray pressure is 1.5±0.1kg / cm2, the etching temperature is 30±2℃, and the etching time is 120±30s.

[0135] Determination of performance indicators:

[0136] Circuit appearance: No residual copper on the circuit board is acceptable; residual copper is unacceptable.

[0137] Undercut etching: The cleaned test piece with no residual copper is sliced, coated with adhesive, polished, and then observed and measured under a microscope. A single-sided undercut etching depth of less than 1 μm is considered acceptable.

[0138] The performance test results of the flashover chemicals in the above embodiments and comparative examples are shown in Table 1 and... Figures 1 to 10 As shown.

[0139] Table 1 Performance results of each embodiment and comparative example

[0140] Examples / Comparative Examples Line appearance Metallographic sections Left lateral erosion μm Right lateral erosion μm Example 1 No residual copper, qualified. Figure 1 0.4466 0.4094 Example 2 No residual copper, qualified. Figure 2 0.2977 0.521 Example 3 No residual copper, qualified. Figure 3 0.3683 0.2947 Example 4 No residual copper, qualified. Figure 4 0.5955 0.4466 Example 5 No residual copper, qualified. Figure 5 0.7815 0.6327 Example 6 No residual copper, qualified. Figure 6 0.6327 0 Example 7 No residual copper, qualified. Figure 7 0.8188 0.3722 Example 8 No residual copper, qualified. Figure 8 0.6327 0.2977 Comparative Example 1 There is residual copper, which is unacceptable. / / / Comparative Example 2 There is residual copper, which is unacceptable. / / / Comparative Example 3 No residual copper, qualified. Figure 9 1.079 1.154 Comparative Example 4 No residual copper, qualified. Figure 10 1.489 0.6699 Comparative Example 5 There is residual copper, which is unacceptable. / / /

[0141] As demonstrated in Examples 1 to 8, after flash etching experiments using the flash etching solution of the present invention, the bottom copper on the substrate between the circuit lines after copper etching was completely etched away, with no residual copper, and the appearance of the circuit was qualified. Furthermore, the lateral etching depth on each undercut side was less than 1 μm, which was considered acceptable.

[0142] Comparing Example 1 and Comparative Example 1, it can be seen that the flash etching solution in Comparative Example 1 does not contain pterin derivatives or multi-arm polyethylene glycol derivatives. Therefore, in Comparative Example 1, residual copper remains on the substrate between the circuits, resulting in an unacceptable appearance of the circuits. This indicates that when using a sulfuric acid chloride etching solution directly, the residual copper between the circuits will not be completely etched away.

[0143] Comparing Example 1 and Comparative Example 2, it can be seen that the amount of pterin derivative used in Comparative Example 2 was reduced. Therefore, in Comparative Example 2, residual copper remained on the substrate between the circuit lines, resulting in an unsatisfactory circuit appearance. This indicates that insufficient use of pterin derivative leads to incomplete etching.

[0144] Comparing Example 1 and Comparative Example 3, it can be seen that the amount of pterin derivative used in Comparative Example 3 was increased. Therefore, there was no residual copper on the substrate between the circuits in Comparative Example 3, and the appearance of the circuits was acceptable. However, the side etching depth on both the left and right sides was greater than 1 μm, which is considered excessive and unacceptable. This indicates that when the amount of pterin derivative is excessive, the etching is too fast and the side etching is too large.

[0145] Comparing Example 2 and Comparative Example 4, it can be seen that the amount of multi-arm polyethylene glycol derivative used in Comparative Example 4 was reduced. Therefore, there was no residual copper on the substrate between the circuits in Comparative Example 4, and the appearance of the circuits was acceptable. However, the side etching depth on both the left and right sides was greater than 1 μm, which is considered excessive and unacceptable. This indicates that reducing the amount of multi-arm polyethylene glycol derivative used reduces the protective effect and increases the side etching depth.

[0146] Comparing Example 2 and Comparative Example 5, it can be seen that Comparative Example 4 used an increased amount of multi-arm polyethylene glycol derivative. Therefore, in Comparative Example 2, residual copper remained on the substrate between circuits, resulting in an unsatisfactory circuit appearance. This indicates that when the amount of multi-arm polyethylene glycol derivative used is too large, the copper etching is incomplete.

[0147] In summary, this invention provides a flash etching solution, its preparation method, and the flash etching method thereof. This flash etching solution uses a sulfuric acid / chloride system. Compared to sulfuric acid / hydrogen peroxide systems, this solution contains a large amount of chloride ions and is unaffected by small amounts of external chloride ions. Compared to traditional acidic chloride etching solutions, it uses oxygen from the air as a circulating regeneration oxidant for divalent copper, thus avoiding oxidation of the undercut inhibitor and exhibiting good solution stability. Through the synergistic effect of its components, excellent etching results are achieved, effectively removing the underlying copper while minimizing undercut corrosion, ensuring adhesion between the circuitry and the substrate. A small amount of pterin derivative can form a small anode, large cathode corrosion cell effect on the copper surface, promoting the etching of the underlying copper. Using a multi-arm polyethylene glycol derivative as an undercut inhibitor results in minimal undercut corrosion at the bottom of the etched circuitry and good line shape retention.

[0148] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A flash photoprotein solution, characterized by, The mixture includes 15-25 g / L of divalent copper ions, 105-140 g / L of chloride ions, 100 g / L-180 g / L of sulfuric acid, 0.02-0.1 g / L of pterin derivative, 3 g / L-10 g / L of multi-arm polyethylene glycol derivative, and water; wherein the pterin derivative is at least one of 6-biopterin, 7,8-dihydrobiopterin, and pterin-6-carboxylic acid; and wherein the multi-arm polyethylene glycol derivative is at least one of multi-arm polyethylene glycol amine, multi-arm polyethylene glycol maleimide, and multi-arm polyethylene glycol thiol.

2. The flash photoprotein according to claim 1, wherein The divalent copper ions are derived from at least one of copper chloride, copper sulfate, and copper formate.

3. The flash photodynamic water of claim 1, wherein, The chloride ions are derived from at least one of sodium chloride, potassium chloride, and copper chloride.

4. The flash photodynamic water of claim 1, wherein, The multi-arm polyethylene glycolamine is one of four-arm polyethylene glycolamine, six-arm polyethylene glycolamine, or eight-arm polyethylene glycolamine.

5. The flash photolysis water of claim 4, wherein, The molecular weight of the 6-arm polyethylene glycolamine is 2K~10K.

6. The flash photolysis water of claim 4, wherein, The concentration of the 6-arm polyethylene glycolamine is 3 g / L to 10 g / L.

7. A method of preparing a flash-etching drug solution, characterized by, The preparation of the flash etching solution as described in any one of claims 1 to 6 comprises the following steps: dissolving divalent copper ions, chloride ions, sulfuric acid, pterin derivatives, and multi-arm polyethylene glycol derivatives in water in a certain proportion to form an aqueous solution, and stirring evenly to form the flash etching solution.

8. A flash etching method of flash etching drug water, characterized by, The integrated circuit substrate is flash-etched using the flash-etching solution as described in any one of claims 1 to 6, wherein the spraying pressure is 1.2 to 1.8 kg / cm². 2 The etching temperature is 25°C to 35°C, and the etching time is 90 to 150 seconds.

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