Selective chemical coarsening method for electroplated part

Abstract

The invention relates to the technical field of surface treatment, and particularly discloses a selective chemical coarsening method for an electroplated part. The selective chemical coarsening method for the electroplated part comprises the following steps: cleaning: cleaning the surface of the electroplated part by using 0.1-0.5 mol / L alkali liquor and clear water in sequence; shielding: shielding a non-coarsening area of the electroplated part by using a shielding part matched with the shape of the electroplated part; roughening is conducted, specifically, roughening liquid is horizontally sprayed to the electroplated part, roughening treatment is completed, and the spraying pressure ranges from 0.9 kg / cm < 2 > to 2.3 kg / cm < 2 >; cleaning: cleaning the shielding part and the electroplated part subjected to roughening treatment by using clear water; in addition, the preparation method disclosed by the invention has the advantage of selectively coarsening the electroplating area of the electroplated part.

Description

Technical Field

[0001] This application relates to the technical field of surface treatment, and more specifically, it relates to a selective chemical roughening method for electroplated parts. Background Art

[0002] Electroplating is a very common surface treatment method that can deposit a metal coating on various metal or non-metal surfaces through redox reactions. It has a relatively wide range of applications in industries such as aviation, semiconductors, automobiles, and household appliances. The coating can play various roles such as preventing metal oxidation, improving wear resistance, electrical conductivity, reflectivity, and corrosion resistance.

[0003] In the semiconductor industry, to improve the bonding effect between the coating and the electroplated part and the uniformity of the coating, the surface of the electroplated part is treated before electroplating to remove oil and impurities on the surface and perform a roughening treatment to increase the roughness of the surface of the electroplated part, thereby improving the bonding force between the coating and the electroplated part after electroplating. For example, tin is plated on the copper surface, etc. However, electroplated parts often do not require overall electroplating. Existing roughening often performs overall roughening on electroplated parts, causing the non-electroplated area and the electroplated area to be roughened synchronously, damaging the surface of the non-electroplated area, making it rough, increasing the consumption of the roughening solution, and at the same time affecting the subsequent processing of the non-electroplated area. Summary of the Invention

[0004] In order to selectively roughen the electroplated area of electroplated parts, this application provides a selective chemical roughening method for electroplated parts.

[0005] A selective chemical roughening method for electroplated parts includes the following steps: Cleaning: Use an alkali solution with a concentration of 0.1 - 0.5 mol / L and clean water to clean the surface of the electroplated part in sequence; Masking: Use a masking piece adapted to the shape of the electroplated part to cover the non-roughened area of the electroplated part; Roughening: Horizontally spray the roughening solution onto the electroplated part to complete the roughening treatment, and the spraying pressure is 0.9 - 2.3 kg / cm 2 ; Cleaning: Clean the masking piece and the electroplated part after roughening treatment with clean water.

[0006] By adopting the above technical solutions, cleaning enables the removal of oil and various impurities on the surface of the electroplated part, keeping the surface of the electroplated part clean. The masking piece can cover the electroplated part, exposing the roughened area of the electroplated part. After the non-roughened area of the electroplated part is covered by the masking piece, the roughening solution contacts the roughened area, enabling the roughened area of the electroplated part to complete the roughening treatment.

[0007] Preferably, a clamping member adapted to the electroplated member is detachably linked to the lower surface of the shielding member. Both the shielding member and the clamping member are coated with an organosilicon-modified acrylic hydrophobic layer, which is cross-linked from methyl methacrylate, 2-hydroxyethyl methacrylate, butyl acrylate, and a silane coupling agent as raw materials, and a modified silica sol is added as a curing agent for cross-linking and curing.

[0008] By adopting the above technical solution, the organosilicon-modified acrylic hydrophobic layer has good hydrophobicity, good chemical stability, good acid and alkali resistance, and the formed hydrophobic layer has good adhesion, which can protect the shielding member and the clamping member, reduce the corrosion of the shielding member and the clamping member during contact with the roughening solution, simultaneously shield the non-roughened area, reduce the contact between the non-roughened area and the roughening solution, and also reduce the impurity content in the roughening solution.

[0009] Preferably, the mass ratio of methyl methacrylate, 2-hydroxyethyl methacrylate, butyl acrylate, and the silane coupling agent is (7.54 - 7.91):(1.12 - 1.24):(2.58 - 2.81):(2.26 - 2.54).

[0010] By adopting the above technical solution, controlling the mass ratio of methyl methacrylate, 2-hydroxyethyl methacrylate, butyl acrylate, and the silane coupling agent enables the organosilicon-modified acrylic formed by cross-linking of the four to have good toughness and wear resistance, the cross-linking structure is relatively dense, the hydrophobicity is good, and the contact and erosion of the roughening solution with the shielding member are reduced.

[0011] Preferably, the preparation method of the modified silica sol includes the following steps: adding hydrochloric acid and sodium silicate to water, reacting at 4 - 6 °C for a period of time, then heating to room temperature, extracting with tetrahydrofuran to obtain a polysilicic acid solution, adding hexamethyldisilazane and reacting for 0.5 - 1 h to prepare the modified silica sol.

[0012] By adopting the above technical solution, the modified silica sol as a curing agent can improve the toughness of the organosilicon-modified acrylic hydrophobic layer, simultaneously increase the cross-linking degree of the coating, further reduce the corrosiveness of the roughening solution to the coating, and the addition of hexamethyldisilazane can effectively improve the hydrophobicity of the silica sol.

[0013] Preferably, the mass ratio of hexamethyldisilazane to sodium silicate is (0.56 - 0.87):(1.29 - 1.35).

[0014] By adopting the above technical solution, controlling the addition amount of hexamethyldisilazane can improve the hydrophobicity of the modified silica sol, and at the same time, the modified silica sol has more hydroxyl groups, which can cross-link with acrylic monomers to achieve curing.

[0015] Preferably, the roughening solution comprises 0.43 - 0.85 mol / L of divalent copper ions, 0.94 - 1.72 mol / L of chloride ions, 1.23 - 2.67 g / L of organic acid, 0.61 - 0.84 g / L of corrosion inhibitor and solvent water.

[0016] By adopting the above technical solution, the divalent copper ions in the roughening solution act as an oxidant to react with the copper on the surface of the electroplated part. The organic acid can provide an acidic environment, enabling the copper to dissolve in the roughening solution. The chloride ions can provide auxiliary assistance for the dissolution of copper, and the corrosion inhibitor can effectively regulate the roughening process and control the roughening degree of the surface of the electroplated part.

[0017] Preferably, the organic acid is selected from one or more of formic acid, acetic acid, citric acid, and maleic acid.

[0018] Preferably, the use temperature of the roughening solution is 25 - 40 °C, and the spraying time is 40 - 70 s.

[0019] By adopting the above technical solution, controlling the use temperature and spraying time of the roughening solution enables the roughening solution to achieve a better roughening effect, and makes the surface of the electroplated part have a suitable roughened surface.

[0020] In summary, the present application has the following beneficial effects: 1. In the present application, cleaning can remove the oil stains and various impurities on the surface of the electroplated part, keeping the surface of the electroplated part clean. The shielding part can shield the electroplated part, exposing the roughening area of the electroplated part to the outside. After the non-roughening area of the electroplated part is shielded by the shielding part, the roughening solution contacts the roughening area, enabling the roughening area of the electroplated part to complete the roughening treatment.

[0021] 2. In the present application, both the shielding part and the clamping part are coated with an organosilicon-modified acrylic hydrophobic layer. The organosilicon-modified acrylic hydrophobic layer has good hydrophobicity, good chemical stability, good acid and alkali resistance, and the formed hydrophobic layer has good adhesion. It can protect the shielding part and the clamping part, reducing the corrosion of the shielding part and the clamping part during contact with the roughening solution. At the same time, it shields the non-roughening area, reducing the contact between the non-roughening area and the roughening solution, and also reducing the impurity content in the roughening solution.

[0022] 3. In the present application, the divalent copper ions in the roughening solution act as an oxidant to react with the copper on the surface of the electroplated part. The organic acid can provide an acidic environment, enabling the copper to dissolve in the roughening solution. The chloride ions can provide auxiliary assistance for the dissolution of copper, and the corrosion inhibitor can effectively regulate the roughening process and control the roughening degree of the surface of the electroplated part. Detailed implementation manners

[0023] The following further elaborates on the present application with reference to examples.

[0024] Preparation Examples 1-4 of Modified Silica Sol Preparation Example 1 The preparation method of modified silica sol includes the following steps: Add hydrochloric acid and sodium silicate into water, react at 4°C for a period of time, then heat up to room temperature, extract with tetrahydrofuran to obtain polysilicic acid solution, add hexamethyldisilazane and react for 0.5 h to prepare modified silica sol, and the mass ratio of hexamethyldisilazane to sodium silicate is 0.56:1.29.

[0025] Preparation Example 2 The preparation method of modified silica sol includes the following steps: Add hydrochloric acid and sodium silicate into water, react at 6°C for a period of time, then heat up to room temperature, extract with tetrahydrofuran to obtain polysilicic acid solution, add hexamethyldisilazane and react for 1 h to prepare modified silica sol, and the mass ratio of hexamethyldisilazane to sodium silicate is 0.87:1.35.

[0026] Preparation Example 3 The difference between Preparation Example 3 and Preparation Example 1 is that the mass ratio of hexamethyldisilazane to sodium silicate is 0.56:0.87.

[0027] Preparation Example 4 The difference between Preparation Example 4 and Preparation Example 1 is that the mass ratio of hexamethyldisilazane to sodium silicate is 0.56:1.98.

[0028] Preparation Examples 5-12 of Organosilicon-Modified Acrylic Hydrophobic Layer Preparation Example 5 Mix methyl methacrylate, 2-hydroxyethyl methacrylate, butyl acrylate and silane coupling agent KH570 with a mass ratio of 7.54:1.12:2.58:2.26, add initiator and mix, add to solvent xylene at 85°C, the initiator accounts for 0.05 wt% of the total weight, and the mass ratio of solvent to solute is 5.2:1. After heat preservation for 4 h, obtain organosilicon-modified acrylic resin. Mix the organosilicon-modified acrylic resin, modified silica sol and dibutyltin dilaurate and coat to prepare the organosilicon-modified acrylic hydrophobic layer. The modified silica sol is the modified silica sol prepared in Preparation Example 1, and the addition amount of the modified silica sol is 0.92 wt% of the organosilicon-modified acrylic resin, and the addition amount of dibutyltin dilaurate is 0.5 wt% of the organosilicon-modified acrylic resin.

[0029] Preparation Example 6 Mix methyl methacrylate, 2-hydroxyethyl methacrylate, butyl acrylate, and silane coupling agent KH570 with a mass ratio of 7.91:1.24:2.81:2.54, add an initiator and mix. Then add the mixture to xylene solvent at 85°C. The initiator accounts for 0.06 wt% of the total weight, and the mass ratio of the solvent to the solute is 5.4:1. After heat preservation for 4 h, an organosilicon-modified acrylic resin is obtained. Mix the organosilicon-modified acrylic resin, modified silica sol, and dibutyltin dilaurate and coat to prepare an organosilicon-modified acrylic hydrophobic layer. The modified silica sol is the one prepared in Preparation Example 2, and the addition amount of the modified silica sol is 1.05 wt% of the organosilicon-modified acrylic resin. The addition amount of dibutyltin dilaurate is 0.6 wt% of the organosilicon-modified acrylic resin.

[0030] Preparation Example 7 The difference between Preparation Example 7 and Preparation Example 5 is that in Preparation Example 7, the modified silica sol is the one prepared in Preparation Example 3.

[0031] Preparation Example 8 The difference between Preparation Example 8 and Preparation Example 5 is that in Preparation Example 8, the modified silica sol is the one prepared in Preparation Example 4.

[0032] Preparation Example 9 The difference between Preparation Example 9 and Preparation Example 5 is that in Preparation Example 9, the mass ratio of methyl methacrylate, 2-hydroxyethyl methacrylate, butyl acrylate, and silane coupling agent is 7.54:1.12:1.54:2.26.

[0033] Preparation Example 10 The difference between Preparation Example 10 and Preparation Example 5 is that in Preparation Example 10, the mass ratio of methyl methacrylate, 2-hydroxyethyl methacrylate, butyl acrylate, and silane coupling agent is 7.54:1.12:3.26:2.26.

[0034] Preparation Example 11 The difference between Preparation Example 11 and Preparation Example 5 is that in Preparation Example 11, the addition amount of the modified silica sol is 0.56 wt% of the organosilicon-modified acrylic resin.

[0035] Preparation Example 12 The difference between Preparation Example 12 and Preparation Example 5 is that in Preparation Example 12, the addition amount of the modified silica sol is 1.68 wt% of the organosilicon-modified acrylic resin. Example

[0036] Example 1 A selective chemical roughening method for electroplated parts, comprising the following steps: Cleaning: Clean the surface of the electroplated part successively with 0.1 mol / L sodium hydroxide solution and clear water; Masking: Use a masking part adapted to the shape of the electroplated part to mask the non-roughened area of the electroplated part; Roughening: Horizontally spray the roughening solution onto the electroplated part to complete the roughening treatment. The roughening solution includes 0.43 mol / L divalent copper ions, 0.94 mol / L chloride ions, 1.23 g / L organic acid, 0.61 g / L corrosion inhibitor and solvent water. The organic acid is formic acid. The use temperature of the roughening solution is 25 °C, the spraying time is 70 s, and the spraying pressure is 2.3 kg / cm 2 , and the corrosion inhibitor is methylbenzotriazole; Cleaning: Clean the masking part and the electroplated part after roughening treatment with clear water.

[0037] Example 2 A selective chemical roughening method for electroplated parts, comprising the following steps: Cleaning: Clean the surface of the electroplated part successively with 0.5 mol / L sodium hydroxide solution and clear water; Masking: Use a masking part adapted to the shape of the electroplated part to mask the non-roughened area of the electroplated part; Roughening: Horizontally spray the roughening solution onto the electroplated part to complete the roughening treatment. The roughening solution includes 0.85 mol / L divalent copper ions, 1.72 mol / L chloride ions, 2.67 g / L organic acid, 0.84 g / L corrosion inhibitor and solvent water. The organic acid is citric acid. The use temperature of the roughening solution is 40 °C, the spraying time is 40 s, and the spraying pressure is 0.9 kg / cm 2 , and the corrosion inhibitor is sodium benzotriazole; Cleaning: Clean the masking part and the electroplated part after roughening treatment with clear water.

[0038] Example 3 The difference between Example 3 and Example 1 is that a clamping part adapted to the electroplated part is detachably connected to the lower surface of the masking part, and both the masking part and the clamping part are coated with an organosilicon-modified acrylic hydrophobic layer, and the organosilicon-modified acrylic hydrophobic layer is the organosilicon-modified acrylic hydrophobic layer prepared in Preparation Example 5.

[0039] Example 4 The difference between Example 4 and Example 1 is that a clamping part adapted to the electroplated part is detachably connected to the lower surface of the masking part, and both the masking part and the clamping part are coated with an organosilicon-modified acrylic hydrophobic layer, and the organosilicon-modified acrylic hydrophobic layer is the organosilicon-modified acrylic hydrophobic layer prepared in Preparation Example 6.

[0040] Example 5 The difference between Example 5 and Example 3 is that the organosilicon-modified acrylic hydrophobic layer is the organosilicon-modified acrylic hydrophobic layer prepared in Preparation Example 7.

[0041] Example 6 The difference between Example 6 and Example 3 is that the silicone-modified acrylic hydrophobic layer is the one prepared in Preparation Example 8.

[0042] Example 7 The difference between Example 7 and Example 3 is that the silicone-modified acrylic hydrophobic layer is the one prepared in Preparation Example 9.

[0043] Example 8 The difference between Example 8 and Example 3 is that the silicone-modified acrylic hydrophobic layer is the one prepared in Preparation Example 10.

[0044] Example 9 The difference between Example 9 and Example 3 is that the silicone-modified acrylic hydrophobic layer is the one prepared in Preparation Example 11.

[0045] Example 10 The difference between Example 10 and Example 3 is that the silicone-modified acrylic hydrophobic layer is the one prepared in Preparation Example 12.

[0046] Example 11 The difference between Example 11 and Example 1 is that the content of divalent copper ions in the roughening solution is 0.25 mol / L.

[0047] Example 12 The difference between Example 12 and Example 1 is that the content of divalent copper ions in the roughening solution is 1.65 mol / L.

[0048] Example 13 The difference between Example 13 and Example 1 is that the content of organic acid in the roughening solution is 0.52 g / L.

[0049] Example 14 The difference between Example 14 and Example 1 is that the content of organic acid in the roughening solution is 3.68 g / L.

[0050] Detection method The copper electroplated parts were roughened according to the methods of Examples 1 - 14, and the roughened electroplated parts were tested. The micro-etching amount and roughness were observed and recorded in Table 1; the acid and alkali resistance of the masking parts used in Examples 1 - 14 was tested. After continuously spraying the roughening solution prepared in Example 1 on the surface of the masking parts for 30 days, the mass retention rate before and after soaking was calculated and recorded in Table 1.

[0051] Table 1 Performance detection results Combined with Examples 1-2 and Table 1, it can be seen that the roughening methods in Examples 1-2 can cause micro-etching on the surface of the electroplated parts and increase their roughness. In Examples 1-2, the electroplated parts are clamped and shielded using a shielding member and a clamping member, and the horizontally sprayed roughening liquid falls on the roughening area of the electroplated parts, the surface of the shielding member and the clamping member, realizing selective roughening of a specific roughening area, and the roughening effect is good. The micro-etching amount and roughness on the surface of the roughening area of the electroplated parts both meet the standards.

[0052] Combined with Examples 3-4, Examples 1-2 and Table 1, it can be seen that the shielding member used in Examples 3-4 has better acid resistance. The surfaces of the shielding member and the clamping member used in Examples 3-4 are coated with an organosilicon-modified acrylic hydrophobic layer. After acrylic acid is modified by organosilicon, its chemical stability, acid and alkali resistance are both improved, and its adhesion is increased. After long-term contact with the roughening liquid, the corrosiveness of the roughening liquid to the shielding member and the clamping member is weakened, improving the service life of the shielding member and the clamping member. At the same time, due to the weakened erosion effect of the roughening liquid, the content of impurities accumulated due to erosion in the roughening liquid is reduced, which is conducive to the long-term use and recycling of the roughening liquid.

[0053] Combined with Examples 5-6, Examples 3-4 and Table 1, it can be seen that the acid resistance of the shielding member used in Examples 5-6 is inferior to that of Examples 3-4. When preparing the organosilicon-modified acrylic hydrophobic layer in Examples 5-6, the mass ratio of hexamethyldisilazane to sodium silicate is changed. The addition of hexamethyldisilazane can improve the hydrophobicity of the modified silica sol, making it difficult for the roughening liquid to accumulate and adhere to the surface of the shielding member. When the addition amount of hexamethyldisilazane is too much, the hydroxyl content in the modified silica sol decreases, weakening its curing effect as a curing agent, and the compactness of the cured organosilicon-modified acrylic hydrophobic layer decreases, resulting in a reduction in its acid resistance. When the addition amount of hexamethyldisilazane is too little, the hydroxyl content in the modified silica sol is too much, affecting its crosslinking degree and reducing its service life.

[0054] Combined with Examples 7-8, Examples 3-4 and Table 1, it can be seen that the acid resistance of the shielding member used in Examples 7-8 is inferior to that of Examples 3-4. When preparing the organosilicon-modified acrylic hydrophobic layer in Examples 7-8, the mass ratio of methyl methacrylate, 2-hydroxyethyl methacrylate, butyl acrylate and silane coupling agent in the raw materials is changed. Methyl methacrylate is used as a hard monomer, butyl acrylate is used as a soft monomer, 2-hydroxyethyl methacrylate is used as a polar monomer, and silane coupling agent is used as an organosilicon modifier. When the mass ratio among the four changes, the compactness of the crosslinked organosilicon-modified acrylic hydrophobic layer decreases, thereby reducing its acid resistance.

[0055] It can be seen from Examples 9-10, Examples 3-4 and Table 1 that the acid resistance of the shielding parts used in Examples 9-10 is inferior to that of Examples 3-4. When preparing the silicone-modified acrylic hydrophobic layer in Examples 9-10, the addition amount of the modified silica sol was changed. The modified silica sol was used as a curing agent, which could improve the crosslinking degree of the silicone-modified acrylic hydrophobic layer, provide its compactness, improve its toughness and wear resistance at the same time, reduce the physical wear of the hydrophobic layer, and have good acid resistance. Too much or too little addition amount of the modified silica sol was likely to affect the compactness of the silicone-modified acrylic hydrophobic layer, thereby affecting its acid resistance.

[0056] It can be seen from Examples 11-14, Examples 1-2 and Table 1 that the micro-etching amount and roughness in Examples 11-14 have changed. The content of divalent copper ions in the roughening solution was changed in Examples 11-12, and the content of organic acids in the roughening solution was changed in Examples 13-14, indicating that the content of divalent copper ions and organic acids in the roughening solution would affect the roughening effect of the roughening solution. Divalent copper ions in the roughening solution, as an oxidant, reacted with the copper on the surface of the electroplated part, and the organic acid provided an acidic environment, enabling the copper to dissolve in the roughening solution. The change in its addition amount caused a change in the roughening degree of the roughening solution, and the roughening effect did not meet the processing requirements.

[0057] This specific embodiment is only an interpretation of the present application and does not limit the present application. After reading this specification, those skilled in the art can make modifications to this embodiment without creative contributions as needed, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A selective chemical roughening method for electroplated parts, characterized in that: It includes the following steps: Cleaning: successively clean the surface of the electroplated part with 0.1 - 0.5 mol / L alkali solution and clear water; Masking: use a masking piece adapted to the shape of the electroplated part to mask the non-roughened area of the electroplated part; Roughening: Horizontally spray the roughening solution onto the electroplated part to complete the roughening process, and the spraying pressure is 0.9 - 2.3 kg / cm 2 ; Cleaning: clean the masking piece and the roughened electroplated part with clear water.

2. The selective chemical roughening method for an electroplated part according to claim 1, characterized in that: A clamping piece adapted to the electroplated part is detachably linked to the lower surface of the masking piece. Both the masking piece and the clamping piece are coated with an organosilicon-modified acrylic hydrophobic layer, which is crosslinked from methyl methacrylate, 2-hydroxyethyl methacrylate, butyl acrylate and a silane coupling agent as raw materials, and a modified silica sol is added as a curing agent for crosslinking and curing.

3. The selective chemical roughening method for an electroplated part according to claim 2, wherein: The mass ratio of methyl methacrylate, 2-hydroxyethyl methacrylate, butyl acrylate and the silane coupling agent is (7.54 - 7.91):(1.12 - 1.24):(2.58 - 2.81):(2.26 - 2.54).

4. A selective chemical roughening method for electroplated parts according to claim 2, characterized in that: The preparation method of the modified silica sol includes the following steps: add hydrochloric acid and sodium silicate into water, react at 4 - 6 °C for a period of time, then heat to room temperature, extract with tetrahydrofuran to obtain a polysilicic acid solution, add hexamethyldisilazane and react for 0.5 - 1 h to prepare the modified silica sol.

5. A selective chemical roughening method for electroplated parts according to claim 4, characterized in that: The mass ratio of hexamethyldisilazane to sodium silicate is (0.56 - 0.87):(1.29 - 1.35).

6. The selective chemical roughening method for an electroplated part according to claim 1, characterized in that: The roughening solution includes 0.43 - 0.85 mol / L divalent copper ions, 0.94 - 1.72 mol / L chloride ions, 1.23 - 2.67 g / L organic acid, 0.61 - 0.84 g / L corrosion inhibitor and solvent water.

7. A selective chemical roughening method for electroplated parts according to claim 6, characterized in that: The organic acid is selected from one or more of formic acid, acetic acid, citric acid and maleic acid.

8. A selective chemical roughening method for electroplated parts according to claim 1, characterized in that: The use temperature of the roughening solution is 25 - 40 °C, and the spraying time is 40 - 70 s.

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