Electrolytic anode based on a non-aqueous electrolyte and method for its production and use

Abstract

The application discloses an electrolytic anode based on a degreasing fluid and a preparation method and application thereof, and belongs to the technical field of anodes for electrolysis and electroplating processes. The electrolytic anode comprises, from bottom to top, a titanium mesh substrate, a first coating film and a second coating film; the first coating film is a ruthenium oxide film; the weight of the first coating film accounts for 0.87% to 1.08% of the weight of the titanium mesh substrate; the second coating film is a mixed film of a rhodium oxide film and an iridium oxide film; the weight of the second coating film accounts for 1.47% to 1.98% of the weight of the titanium mesh substrate; the rhodium oxide film of the second coating film is in direct contact with the first coating film; and the first coating film and the second coating film are both formed through high-temperature treatment. The application solves the problem that the dust and impurity pollutants hidden in the scratch defects on the surface of a precision semiconductor element are sealed between the surface of the semiconductor device and the plating layer, thereby causing a major hidden danger of failure of the semiconductor electronic product; and the mesh-shaped electrolytic anode coated with the composite coating improves the degreasing and decontamination function of electrolysis.

Description

Technical Field

[0001] This invention relates to the field of electrolytic anodes and electroplating processes, and in particular to an electrolytic anode based on a degreasing fluid, its preparation method, and its application. Background Technology

[0002] With the continuous development of science and technology, in the field of precision semiconductor component surface treatment technology, the products inevitably develop nanoscale scratches on their surfaces during the processing and molding process. These scratches affect the flatness of the semiconductor component surface. In particular, the micro-dust impurities and contaminants hidden in these scratches, if not completely removed through pre-plating treatment methods, will be trapped between the semiconductor device surface and the plating layer during the electroplating process of semiconductor electronic products, becoming a major hidden danger for the failure of semiconductor electronic products.

[0003] Typically, before electroplating or coating the surface of precision semiconductor components, it is necessary to remove grease and any other contaminants from the surface. Existing electroplating surface treatment processes cannot completely eliminate nanoscale scratch defects. On the one hand, scratch defects can be observed during quality inspection of electroplated products, and copper exposure due to insufficient coating adhesion can occur during winding inspection. On the other hand, even if a coating with good adhesion can be formed around the scratches during electroplating, the micro-dust impurities hidden in the scratches can directly block the conduction of current, reducing the function of transmitting electronic signals. More seriously, the lifespan of the electronic product will be drastically reduced, resulting in a high product failure rate.

[0004] Regarding the scratch defects on the surface of the semiconductor device, the first chapter of the non-patent literature "Modern Electroplating Handbook" (Volume 1) on pre-plating treatment includes: chemical degreasing, ultrasonic degreasing, electrochemical degreasing, and surfactant degreasing. Furthermore, based on the electrolytic degreasing method and apparatus disclosed in patent CN 109415838 A, an attempt was made to employ the most conventional pre-plating treatment technology. However, regrettably, the results of single-strand and wrapped-wound inspections of the electroplated samples of the semiconductor device revealed that single-strand scratch defects were pits and long strips of indentation; the wrapped-wound inspection results showed pits, and in severe cases, exposed copper could be observed. Summary of the Invention

[0005] To address the challenges in quality inspection of electroplated samples obtained after pre-plating treatment of semiconductor device surfaces in existing technologies, such as single scratch defects (pits and long strips) and winding inspection results (pits and exposed copper), this invention provides an electrolytic anode based on degreasing fluid, its preparation method, and its application. This invention solves the problem that current conventional pre-plating treatment techniques cannot completely eliminate these scratch defects. On the one hand, winding inspection of electroplated samples reveals pits and exposed copper; on the other hand, this leads to impaired electronic signal transmission in semiconductor devices and reduced lifespan of electronic products, resulting in high product failure rates and difficulty in maintaining stable production.

[0006] The technical solution of the present invention is as follows:

[0007] The first objective of this invention is to provide an electrolytic anode based on a degreasing fluid for pretreatment before electroplating, comprising, from bottom to top, a titanium mesh substrate, a first coating film, and a second coating film;

[0008] The first coating film is a ruthenium oxide film; its weight is 0.87%~1.08% of the weight of the titanium mesh substrate.

[0009] The second coating film is a hybrid film of rhodium oxide film and iridium oxide film; its weight is 1.47%~1.98% of the weight of the titanium mesh substrate.

[0010] The rhodium oxide film of the second coating film is in direct contact with the first coating film.

[0011] Both the first and second coating films are formed through high-temperature processing.

[0012] In one embodiment of the present invention, the porosity of the first coating film is 0.00%.

[0013] In one embodiment of the present invention, the resistance of the second coating film is 188~190mΩ.

[0014] In one embodiment of the present invention, the weight of the second coating film is 157-207% of the weight of the first coating film.

[0015] In one embodiment of the present invention, the titanium mesh has an external dimension of 120mm in length and 50mm in width, and the length, width and height of its oblique mesh are 3mm × 3mm × 1.5mm.

[0016] A second objective of this invention is to provide a method for preparing the above-mentioned electrolytic anode based on degreasing fluid for pretreatment before electroplating, comprising the following steps:

[0017] (1) The surface of the titanium mesh is sandblasted, then immersed in degreasing solution and washed with water three times, then treated with citric acid solution, washed with water three times and dried to obtain a surface-pretreated titanium mesh.

[0018] (2) Spray the first layer of ruthenium chloride hydrate ethanol solution onto the surface of the pretreated titanium mesh, treat it at 500~550℃ for 3~5 min to form the first coating film, namely ruthenium oxide film, and then cool it to room temperature;

[0019] (3) Based on step (2), spray an ethanol solution of rhodium(III) chloride hydrate and an ethanol solution of iridium(IV) chloride hydrate, then treat at 500~550℃ for 3~10 min, cool to room temperature, and obtain the electrolytic anode based on degreasing fluid;

[0020] The specific steps for spraying the ethanol solution of rhodium(III) chloride hydrate and the ethanol solution of iridium(IV) chloride hydrate are as follows:

[0021] The first spraying of chloroiridium(IV) acid was completed by automatically spraying ethanol solution of rhodium(III) chloride hydrate evenly on both sides for 23 seconds, heating at 100°C for 10 minutes, and cooling to room temperature. Then, the first spraying of chloroiridium(IV) acid was completed by automatically spraying ethanol solution of chloroiridium(IV) acid hydrate evenly on both sides for 23 seconds, heating at 100°C for 10 minutes, and cooling to room temperature. Every ten sprayings of chloroiridium(IV) acid constituted one cycle. The above cycle was repeated 2 to 6 times.

[0022] The repeating decimal represents a number of times out of ten. For example, 4.1 means that after four whole cycles, one more coat will be applied.

[0023] In one embodiment of the present invention, in step (1), the sandblasting treatment is performed for 10 to 15 minutes.

[0024] In one embodiment of the present invention, in step (2), the mass concentration of the ethanol solution of ruthenium chloride hydrate is 5%, and the spraying time is 20 seconds.

[0025] In one embodiment of the present invention, the mass concentration of the ethanol solution of rhodium(III) chloride hydrate is 5%.

[0026] In one embodiment of the present invention, the mass concentration of the ethanol solution of chloroiridium(IV) acid hydrate is 5%.

[0027] The third objective of this invention is to provide a pre-plating treatment method for removing scratch defects on the surface of semiconductor elements using the above-mentioned electrolytic anode based on degreasing fluid, wherein the semiconductor element to be treated is placed in the electrolyte of an electrolytic degreasing device for electrolytic degreasing.

[0028] The pretreatment conditions for electroplating are: current density D阴极 The value is 6.7~10.0 A / dm. 2 The electrolytic power supply outputs a current of 6.2~26.7A; the current density of the titanium mesh anode... D 阳极 1.9~2.8A / dm 2 ;

[0029] The electrolyte is a degreasing solution, consisting of 60 g / L potassium hydroxide, 30 g / L sodium carbonate, and 10 g / L sodium dodecylbenzenesulfonate;

[0030] In the electrolytic degreasing device, the electrolytic anode based on the degreasing fluid serves as the left and right anodes, and the semiconductor element to be processed serves as the cathode.

[0031] In one embodiment of the present invention, the degreasing and decontamination effect is determined by the morphology and performance testing after electrolytic nickel plating;

[0032] The electrolyte used for electrolytic nickel plating is a nickel sulfamate solution, which includes nickel sulfamate with a concentration of 90 g / L (calculated as nickel), nickel chloride 10 g / L, boric acid 45 g / L, additives 1.5 mL / L, a solution pH of 4.0, and pure water as the solvent.

[0033] In one embodiment of the present invention, the additive is a tertiary alkyl polyol polyoxyethylene ether, and the additive concentration is 0.3 g / L.

[0034] In one embodiment of the present invention, the electrolytic current conditions for electrolytic nickel plating are 9.3~17.4A.

[0035] In one embodiment of the present invention, the precision semiconductor device after electrolytic degreasing treatment is accurately weighed using a precision balance to determine its weight before treatment. W 处理前 and the weight after processing W 处理后 By comparison, the amount of grease and dirt removed can be obtained, as shown in Formula 1; further, to confirm whether the grease on the surface of the precision semiconductor component has been completely removed, the following examples can be used. n+1 Weight of grease and dirt removed after treatment W 油污n+1 Compared with the examples n Weight of grease and dirt removed after treatment W 油污n The comparison is performed as shown in Formula 2;

[0036] W 处理前 -W 处理后 >0;Formula 1

[0037] W 油污n+1 -W 油污n≤ ±0.03 or = 0; Formula 2

[0038] The result of Formula 1 confirms the extent to which grease and dirt have been removed from the surface of the precision semiconductor component.

[0039] The results of Formula 2 confirm that, under the conditions of the embodiment, the grease and dirt on the surface of the precision semiconductor element are nearly completely removed or are completely removed.

[0040] For nickel-plated samples of precision semiconductor components, the adhesion of the metal plating was tested according to the national standard GB / T 5270-2005 "Review of Test Methods for Adhesion Strength of Electrodeposited and Chemically Deposited Metal Coatings on Metal Substrates". The test method was a bending and winding test, specifically based on Formula 3. The judgment criterion was based on the proportion of plating peel-off area.

[0041] Ni 镀层脱落面积 / Ni 镀层总面积 =0 Excellent

[0042] 0 < Ni 镀层脱落面积 / Ni 镀层总面积 ≤1% Good

[0043] 1% < Ni 镀层脱落面积 / Ni 镀层总面积 <5% qualified

[0044] 5% ≤ Ni 镀层脱落面积 / Ni 镀层总面积 Unqualified; Formula 3

[0045] In addition to testing the adhesion of the obtained nickel-plated samples, the appearance inspection of the nickel-plated surface of the precision semiconductor element is also an important factor in determining the performance of the electrolytic anode based on degreasing fluid of this invention, as shown in Formula 4:

[0046] Visual inspection revealed a smooth and flat surface, indicating excellent appearance.

[0047] Surface scratches are unacceptable.

[0048] Scratches and dents indicate the product is defective.

[0049] Exposed copper on the surface is unacceptable; Formula 4

[0050] Nickel-plated samples were obtained by testing various electrolysis conditions and were judged by formulas 2 and 3. If any one of them failed to meet the excellent standard, the result was deemed unqualified, as shown in formula 5.

[0051] Ni 镀层脱落面积 / Ni 镀层总面积 =0 Excellent

[0052] Excellent surface finish with no exposed copper, no scratches, and no dents; Formula 5

[0053] If the results of Formula 1 and Formula 2, which are used to determine whether the grease on the surface of the precision semiconductor component has been completely removed, are met, then further nickel plating is performed, and the result is determined according to Formula 5. The standard for judgment is that all test items are excellent.

[0054] The beneficial technical effects of this invention are as follows:

[0055] On the one hand, this invention solves the major hidden danger of micro-dust impurities and contaminants trapped on the surface of precision semiconductor components due to scratches and defects being sealed between the semiconductor device surface and the plating layer, leading to the failure of semiconductor electronic products; on the other hand, by using a mesh electrolytic anode with a preferred composite coating, the function of electrolytic degreasing and decontamination is greatly improved.

[0056] This invention uses the surface treatment area of ​​the mesh electrolytic anode and the precision semiconductor element as the basic conditions to calculate the current and electroplating time conditions of the electrolytic device. According to the national standard GB / T 5270-2005, the metal needles of the semiconductor device are subjected to a winding and bending test to screen the optimal process conditions for pre-plating treatment of surface scratch defects of the semiconductor device. After nickel plating of the precision semiconductor element, Formula 5 is used for comprehensive judgment to obtain the most suitable condition range for coating the titanium mesh electrolytic anode. Attached Figure Description

[0057] Figure 1 This is a schematic diagram of the electrolytic degreasing device system of the present invention.

[0058] Figure 2 This is a schematic diagram of the precision semiconductor element of the present invention.

[0059] Figure 3 This is a schematic diagram of the smallest unit of the precision semiconductor element of the present invention.

[0060] Figure 4 This is a schematic diagram of a single metal needle and a winding and bending detection method according to Embodiment 12 of the present invention.

[0061] Figure 5This is a schematic diagram of a single metal needle and a winding and bending detection method according to Embodiment 15 of the present invention.

[0062] Figure 6 This is a schematic diagram of a single metal needle and a winding and bending detection method according to Embodiment 18 of the present invention.

[0063] Figure 7 This is a schematic diagram of a single metal needle and a winding / bending detection method, which is Comparative Example 3 of the present invention.

[0064] Figure 8 This is an enlarged schematic diagram of the exposed copper area of ​​the nickel-plated winding in Comparative Example 3 of the present invention, enclosed in a box.

[0065] Figure 9 This is a schematic diagram of a single metal needle and a winding / bending detection method for Comparative Example 19 of the present invention.

[0066] In the figure, 400 is the degreasing solution electrolytic cell; 500a is the right-side composite-coated titanium mesh electrolytic anode; 500b is the left-side composite-coated titanium mesh electrolytic anode; 600 is a precision semiconductor element; 610 is the smallest component of a precision semiconductor element; and 700 is the electrolytic degreasing device. Detailed Implementation

[0067] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0068] First coating film for titanium mesh electrolytic anode: ruthenium oxide film

[0069] Examples 1 to 3

[0070] S1. Select a titanium mesh substrate for the electrolytic anode; its external dimensions are 120mm long × 50mm wide, and the length, width and height of its oblique mesh are 3mm × 3mm × 1.5mm. Sandblast its surface.

[0071] The titanium mesh substrate is 120mm x 50mm wide, with a 2mm gap between each mesh opening. Therefore, it has 23 mesh openings along its length and 9 mesh openings along its width, for a total of 207 mesh openings. Its single-sided surface area is 120 x 50 - (207 x 3 x 3) = 4137 mm². 2 The sum of the areas of the four sides of the 207 mesh is 207 × (4 × 3 × 1.5) = 3726 mm. 2 Therefore, the area of ​​both sides = 2 × 4137 mm² 2 +3726mm 2 =12000mm 2 ;

[0072] S2. The sandblasted titanium mesh substrate is immersed in a degreasing solution, washed with water three times, then treated with a citric acid solution, washed with water three times, and dried to obtain a surface-pretreated titanium mesh.

[0073] S3. The weight of the surface-pretreated titanium mesh is accurately weighed using a precision electronic platform scale; the right-side electrolytic anode titanium mesh in Example 1 consists of four minimum units, each with dimensions of 120mm in length and 50mm in width, and the weight of the four units is... W 右阳极 The electrolytic anode titanium mesh on the left is also composed of four pieces with the aforementioned dimensions of 120mm in length and 50mm in width, and its weight is marked as follows. W 左阳极 The weight (g) of the electrolytic anode titanium mesh from Examples 2 to 3 was measured using the same method, and the results are shown in Table 1.

[0074] Table 1

[0075]

[0076] The total surface area of ​​the right-side electrolytic anode titanium mesh, composed of four identical 120mm x 50mm meshes, is 4 x 12000mm. 2 =48000mm 2 Similarly, the total surface area of ​​the electrolytic anode titanium mesh on the left is also 12000 mm². 2 =48000mm 2 ;

[0077] like Figure 1 When configuring the right-side titanium mesh electrolytic anode and the left-side electrolytic anode, a single electrolytic power supply simultaneously provides current to both the right-side and left-side electrolytic anode titanium meshes, resulting in a total area of ​​2 × 48000 mm². 2 =96000mm 2 =9.6dm 2 ;

[0078] S4. The titanium mesh formed by spraying an ethanol solution (5% by mass concentration) of ruthenium(III) chloride hydrate onto the surface of a group of titanium meshes after weighing in step S3, and sintering at 535°C for 5 min, yields a ruthenium oxide thin film titanium mesh. W 涂层1+右阳极 A precision electronic platform scale was used to accurately weigh the samples; similarly, another set of titanium meshes underwent the same operation to obtain the desired results. W 涂层1+左阳极 The same operation was performed on Examples 2 and 3, and the weight (g) of the electrolytic anode titanium mesh + first coating film is shown in Table 2.

[0079] Table 2

[0080]

[0081] The weight of the first ruthenium oxide film can then be calculated using Formula 6;

[0082] W涂层1右阳极 = W 涂层1+右阳极 - W 右阳极

[0083] W 涂层1左阳极 = W 涂层1+左阳极 - W 左阳极 ;Formula 6

[0084] The weight (g) results of the first coating film are shown in Table 3;

[0085] Table 3

[0086]

[0087] The weight ratio of the first coating film to the electrolytic anode titanium mesh was calculated using Formula 7; the results are shown in Table 4.

[0088] η 涂层1右阳极 = W 涂层1右阳极 / W 右阳极

[0089] η 涂层1左阳极 = W 涂层1左阳极 / W 左阳极 ;Formula 7

[0090] Table 4

[0091]

[0092] Using the national standard GB / T17720, the porosity (%) of the first coating film on the right and left electrolytic anode titanium meshes was detected by applying voltage. The test results are shown in Table 5.

[0093] Table 5

[0094]

[0095] According to the national standard GB / T17720 for the porosity of the substrate coating for voltage application detection, the more pinholes on the surface of the conductive coating, i.e., the higher the porosity, the reduced electron transport function of the conductive coating due to the presence of pinholes, thereby reducing the electrolytic efficiency of the coated titanium mesh during the electroplating process. Conversely, the fewer pinholes on the surface of the conductive coating, up to a porosity of 0.00%, the optimal electron transport efficiency.

[0096] Therefore, Examples 1 to 3 can all be used as the conditions for the first coating, where the percentage of the first coating film (ruthenium oxide film) to the weight of the titanium mesh is 0.87% to 1.08%. In the actual test screening below, Example 2 was selected, where the average percentage of the ruthenium oxide film to the weight of the titanium mesh is 0.95%. These were used as the standard conditions for subsequent actual production.

[0097] Titanium mesh electrolytic anode coating second coating film: rhodium oxide and iridium oxide mixed film

[0098] Examples 4 to 7

[0099] S5. Using the same method as in Example 2 of S4, prepare a titanium mesh electrolytic anode coated with the first coating film, and accurately weigh it. W 钛网+涂层1 Then, a 5% (w / w) ethanol solution of rhodium(III) chloride hydrate was automatically sprayed uniformly on both sides for 23 seconds, heated at 100°C for 10 minutes, and cooled to room temperature. Next, a 5% (w / w) ethanol solution of iridium(IV) chloride hydrate was automatically sprayed uniformly on both sides for 23 seconds, heated at 100°C for 10 minutes, and cooled to room temperature, completing the first spraying of iridium(IV) chloride. Every ten sprays of iridium(IV) chloride constituted one cycle; the above cycle was repeated 3.5 to 4.1 times. The substrate was then treated in a high-temperature oven at 535°C for 8 minutes; Examples 4-7 were prepared, with the titanium mesh coated with a second coating film (a mixed film of rhodium oxide and iridium oxide). The weight (g) test data of the titanium mesh substrates in Examples 4-7 are shown in Table 6.

[0100] Table 6

[0101]

[0102] The test data of the weight (g) of the first coated ruthenium oxide thin film titanium mesh in Examples 4-7 are shown in Table 7;

[0103] Table 7

[0104]

[0105] The weight (g) test data of the first coated ruthenium oxide film in Examples 4-7 are shown in Table 8;

[0106] Table 8

[0107]

[0108] The test data of the weight (g) of the first coating + second coating + titanium mesh in Examples 4-7 are shown in Table 9;

[0109] Table 9

[0110]

[0111] As shown in Table 9, based on the first coating, the second coating is processed according to step S5, and after 3.5 to 4.1 cycles, the corresponding right-side composite coating titanium mesh anode and left-side composite coating titanium mesh anode are obtained.

[0112] The weight (g) test data of the second coating film in Examples 4-7 are shown in Table 10;

[0113] Table 10

[0114]

[0115] The weight percentage (%) of the second coating film and the titanium mesh in Examples 4-7 is shown in Table 11.

[0116] Table 11

[0117]

[0118] As shown in Table 11, the weight of the mixed film of rhodium oxide and iridium oxide in the second coating is 1.47% to 1.98% of the weight of the titanium mesh substrate.

[0119] The resistance values ​​of the second coating of the right composite coated titanium mesh electrolytic anode 500a and the left composite coated titanium mesh electrolytic anode 500b after weighing were tested using the four-terminal test method according to the national standard GB / T25485. The test results are shown in Table 12.

[0120] Table 12

[0121]

[0122] As can be seen from Table 12, the resistance values ​​of the resistors in Examples 4 to 7 tend to stabilize in the range of 188 to 190 mΩ.

[0123] According to the national standard GB / T25485 for testing the resistance of the composite coating at four terminals, the lower the resistance of the composite coating, that is, the thinner the second coating, the resistance gradually increases as the weight ratio of the second coating to the titanium mesh increases, as shown in Table 11, because the second coating does not completely cover the first coating. When the weight ratio of the second coating to the titanium mesh in Example 4 reaches greater than 1.47%~1.98%, the resistance values ​​of Examples 4~7 tend to stabilize, that is, the second coating of the composite coated titanium mesh electrode anode has uniformly covered the first coating.

[0124] The percentage of the weight of the second coating film in Examples 4-7 to the weight of the first coating film in Example 5 η 复合涂层 As shown in Table 13;

[0125] Table 13

[0126]

[0127] Table 13 shows the percentage of the average weight of the coating 2 film on the left and right anodes of the composite coated titanium mesh anodes in Examples 4-7 to the average weight of the coating 1 film on the left and right anodes in Example 5. η 复合涂层 The range is 167.3% to 220.6%;

[0128] Therefore, Examples 4 to 7 can all be considered as the optimal condition range for the second coating. In the following practical application, Example 5 is selected as the benchmark condition for subsequent practical application screening.

[0129] Practical application of composite coated titanium mesh electrolytic anodes: Electrolysis conditions in degreasing fluids

[0130] Examples 8 to 11

[0131] Select the right-side composite-coated titanium mesh electrolytic anode 500a and the left-side composite-coated titanium mesh electrolytic anode 500b prepared in Example 5, according to... Figure 1 The configured electrolysis apparatus performs electrolytic treatment on the precision semiconductor element 600. The total area of ​​the composite-coated titanium mesh electrolytic anode 500a on the right and the composite-coated titanium mesh electrolytic anode 500b on the left is 9.6 dm². 2 Its current conditions and current density D 阳极 The correspondence is shown in Table 14;

[0132] Table 14

[0133]

[0134] Based on the area calculation method for the titanium mesh anode, the total area of ​​the precision semiconductor element 600 can also be calculated to be 2.67 dm². 2 Therefore, the precision semiconductor element 600, as a cathode, requires specific current conditions and current densities to be applied. D 阴极 The correspondence is shown in Table 15;

[0135] Table 15

[0136]

[0137] Based on the current conditions in Tables 14 and 15, the electrolysis treatment time is set to 25 seconds; the weight of the precision semiconductor element 600 before electrolysis treatment is... W 处理前 and after processing W 处理后 Test results, i.e. W油污 = W 处理前 - W 处理后 The unit is g, and the results are shown in Table 16.

[0138] Table 16

[0139]

[0140] As shown in Table 16, the weight of the oily contaminants removed by the treatment in Examples 8 to 11 was in a stable state of 0.25 g to 0.27 g.

[0141] Furthermore, the precision semiconductor element 600 after electrolytic treatment can be derived from the embodiments in Table 17. n+1 Weight of grease and grime removed W 油污n+1 Compared with the examples n Weight of grease and grime removed W 油污n Comparisons were made, with the difference in g, to determine whether the grease and dirt on the surface of the precision semiconductor components were close to being completely removed or were in a state of being completely removed. The results are shown in Table 17.

[0142] Table 17

[0143]

[0144] As shown in Table 17, the embodiments n+1 Weight of grease and grime removed W 油污n+1 Compared with the examples n Weight of grease and grime removed W 油污n The difference W 油污n+1 - W 油污n As shown in Examples 9-8 to 11-10, -0.01, 0.02, and 0.00 satisfy the discrimination condition of ≤±0.03 or =0 in Formula 2; therefore, under the electroplating pretreatment conditions of Examples 8 to 11, it is confirmed that the grease and dirt on the surface of the precision semiconductor element have been nearly completely removed or are in a state of complete removal.

[0145] As can be seen from the confirmation results, Examples 8 to 11 can all be considered as the preferred range of electrolytic degreasing conditions before electroplating. In the following actual electroplating application, Example 9 is selected as the semiconductor device 600 obtained under the best electrolytic degreasing conditions before electroplating.

[0146] Nickel plating electrolysis conditions

[0147] Examples 12-18

[0148] The precision semiconductor element 600 obtained in Example 9 of the electroplating pretreatment was electroplated using the nickel sulfamate solution. The solvent in the electroplating solution was pure water, and it included nickel sulfamate with a concentration of 90 g / L (calculated as nickel), nickel chloride 10 g / L, boric acid 45 g / L, additives 1.5 mL / L, and pH 4.0.

[0149] Its nickel plating current, nickel plating current density D 镀镍 The nickel plating time is shown in Table 18, and the standard nickel plating film thickness is 3.5 μm.

[0150] Table 18

[0151]

[0152] The nickel plating current and plating time were used in accordance with Table 18 to test the nickel-plated precision semiconductor element 600. The results are shown in Table 19.

[0153] Table 19

[0154]

[0155] The ratio of the area of ​​coating peeling to the total area of ​​coating is: Ni 镀层脱落面积 / Ni 镀层总面积

[0156] As shown in Table 18, the electrolysis current conditions of the nickel plating electrolysis apparatus in Examples 12-18 were in the range of 9.3-17.4 A. Under the condition that the electroplating time was reduced from 77 seconds to 42 seconds, the obtained nickel plating samples maintained a stable film thickness of 3.63-3.70 μm. Table 19 shows the test results for the single needle and wound nickel plating samples obtained in Examples 12-18. It can be seen that their surfaces were smooth and flat with no exposed copper, and the ratio of the plating peeling area to its total area was... Ni 镀层脱落面积 / Ni 镀层总面积 The current density is 0.0%; therefore, its overall assessment result is excellent, specifically for the current density of the precision semiconductor device 600. D 镀镍 Using 3.5~6.5A / dm 2 The conditions are met to obtain qualified electroplated products that meet the product testing requirements.

[0157] Example 12 shows a single needle and a nickel-plated wound sample, such as... Figure 4 As shown; the single needle and the nickel-plated winding test sample of Example 15, as shown. Figure 5As shown; the single needle and the nickel-plated winding test sample of Example 18, as shown. Figure 6 As shown.

[0158] As can be seen from the comprehensive evaluation results of Examples 12-18, the composite coated titanium mesh electrolytic anode and electroplating method of the present invention, through the formation of a dense ruthenium oxide film with zero porosity by the first coating on the surface of the titanium mesh, and the second coating with excellent and stable resistance of rhodium oxide and iridium oxide films, effectively removes grease and dirt hidden in the surface of precision semiconductor components due to scratches, and achieves excellent results in the winding inspection of nickel-plated products without exposed copper. Compared with the comparative examples of the prior art, in the electrolytic degreasing process, the composite coated titanium mesh anode surface used is a rhodium oxide and iridium oxide film. By obtaining suitable catalytic activity and excellent stability of the metals rhodium and iridium with active catalytic properties in the form of oxide films, the composite coated titanium mesh electrolytic electrode of the present invention accelerates the generation of active hydrogen on the cathode surface of precision semiconductor components during electrolysis, thereby improving the removal intensity and excellent effect of grease and dirt on the surface of precision semiconductor components.

[0159] Comparative nickel plating electrolysis conditions

[0160] Comparative Examples 1-6

[0161] Similar to Examples 12-18, the precision semiconductor element 600 obtained in Example 9 was used for electrolytic treatment in the nickel plating electrolysis apparatus of Comparative Examples 1-6; the nickel plating current and nickel plating current density were as follows: D 镀镍 The nickel plating time is shown in Table 20, and the standard nickel plating film thickness is 3.5 μm.

[0162] Table 20

[0163]

[0164] The nickel plating current and plating time were used in accordance with Table 20 to test the nickel-plated precision semiconductor element 600. The results are shown in Table 21.

[0165] Table 21

[0166]

[0167] The ratio of the area of ​​coating peeling to the total area of ​​coating is: Ni 镀层脱落面积 / Ni 镀层总面积

[0168] As shown in Table 21, the nickel-plated single needles and wound nickel-plated samples of Comparative Examples 1 to 6, when magnified 140 times, exhibited scratches, pitted morphology, and exposed copper on their surfaces. The area ratios of Ni plating peel-off area / total Ni plating area were 3.6%, 2.8%, and 0.4%, respectively, with slight copper exposure at 0.1% and minimal copper exposure at 0.3%. Therefore, their overall judgment results were all unqualified. In other words, even if the optimal electrolytic degreasing process of this invention is used for pre-plating treatment, if the current density of nickel plating is too low or too high, it is impossible to obtain precision semiconductor component products with good adhesion and no exposed copper.

[0169] Comparative Example 3: Single needle and nickel-plated wound sample, such as Figure 7 As shown; the enlarged sample of Comparative Example 3, where the exposed copper area of ​​the nickel-plated winding was measured, is enclosed by a box, as shown. Figure 8 As shown.

[0170] Comparative electroplating pretreatment conditions

[0171] Comparative Examples 7-14

[0172] The most commonly used stainless steel 316 in existing technology is used, and its size and shape are the same as those of the right-side composite coated titanium mesh anode and the left-side composite electrolytic anode in Example 5. The surface of the stainless steel 316 is not coated and is directly applied to the pretreatment before electroplating. Figure 1 The apparatus shown;

[0173] Electrolytic treatment prior to nickel plating in Comparative Examples 7-14 was performed using the same precision semiconductor element 600 as in Example 9. The current conditions and current density were as follows. D 阳极 , D 镀件 The correspondence is shown in Tables 22 and 23;

[0174] Table 22

[0175]

[0176] Table 23

[0177]

[0178] Table 23 shows the current density of the precision semiconductor device 600 in Comparative Examples 7-14. D 镀件 Set a wider range of 1.0~13.5A / dm 2 To avoid omitting conditions suitable for electrolytic removal of grease contaminants; the current range corresponding to the current density is 2.7~36.0A; therefore, based on the current range, Table 22 shows the anodic current density of the most commonly used stainless steel 316 in the prior art.D 阳极 0.3~3.8A / dm 2 .

[0179] Based on the current conditions in Tables 22 and 23, the electrolysis treatment time was set to 25 seconds; the weight test results of the precision semiconductor element 600 before and after electrolysis treatment are shown in Table 24.

[0180] Table 24

[0181]

[0182] As shown in Table 24, the weight of grease contaminants removed during the pre-plating treatment of Comparative Examples 7-10 gradually increased from 0.03 g to 0.14 g. In subsequent Comparative Examples 11-14, the weight of grease contaminants removed remained between 0.15 g and 0.17 g, thus confirming the current density of the precision semiconductor device 600. D 镀件 Set to 7.5~13.5A / dm 2 Under the given conditions, the weight of the removed grease contaminants has reached a limit and stabilized, with no further room for increase.

[0183] Comparative nickel plating conditions

[0184] Comparative Examples 15-22

[0185] Precision semiconductor components 600, after being cleaned of grease contaminants according to Comparative Examples 11-14, were used as raw materials before nickel plating, and the nickel plating conditions of Examples 13, 14, 16, and 17 were combined as follows:

[0186] Comparative Example 15: The raw material before nickel plating was Comparative Example 11, and the nickel plating conditions were as described in Example 13;

[0187] Comparative Example 16: The raw material before nickel plating was Comparative Example 12, and the nickel plating conditions were those of Example 13;

[0188] Comparative Example 17: The raw material before nickel plating was Comparative Example 13, and the nickel plating conditions were as described in Example 14;

[0189] Comparative Example 18: The raw material before nickel plating was Comparative Example 14, and the nickel plating conditions were those of Example 14;

[0190] Comparative Example 19: The raw material before nickel plating was Comparative Example 11, and the nickel plating conditions were as described in Example 16;

[0191] Comparative Example 20: The raw material before nickel plating was Comparative Example 12, and the nickel plating conditions were as described in Example 16;

[0192] Comparative Example 21: The raw material before nickel plating was Comparative Example 13, and the nickel plating conditions were as described in Example 17;

[0193] Comparative Example 22: The raw material before nickel plating was Comparative Example 14, and the nickel plating conditions were those of Example 17.

[0194] The nickel plating time and nickel plating current of Examples 13, 14, 16 and 17 in Table 18 were operated, and the test results of the obtained nickel-plated precision semiconductor element 600 are shown in Table 25.

[0195] Table 25

[0196]

[0197] The ratio of the area of ​​coating peeling to the total area of ​​coating is: Ni 镀层脱落面积 / Ni 镀层总面积

[0198] As shown in Table 25, the single needles and nickel-plated winding samples obtained in Comparative Examples 15-22, when magnified 140 times, exhibit rough surfaces, scratches, pits, and exposed copper. The area ratios of Ni plating peeling area / total Ni plating area are 4.3%, 2.6%, and 0.2%; and 0.3%, 0.7%, 1.3%, 2.7%, and 0.9%, respectively. Therefore, Comparative Examples 15-22 are deemed unqualified based on their overall characteristics.

[0199] Comparative Example 19: Single needle and wound nickel-plated sample, such as Figure 9 As shown.

[0200] Comparative composite coating titanium mesh electrolytic anode coating

[0201] Comparative Example 23 is the same as Example 5, except that the process of spraying rhodium(III) chloride hydrate is omitted in step S5.

[0202] Comparative Example 24 is the same as Example 5, except that in step S5, the number of cycles of spraying chloroiridium(IV) acid is 2.

[0203] Comparative Example 25 is the same as Example 5, except that in step S5, chloroiridium(IV) acid is sprayed first, followed by rhodium(III) chloride hydrate, and the number of cycles for spraying rhodium(III) chloride hydrate is 4.

[0204] The weight (g) test data of the second coating film in Comparative Examples 23-25 ​​are shown in Table 26;

[0205] Table 26

[0206]

[0207] The weight percentage (%) of the second coating film and the titanium mesh in Comparative Examples 23-25 ​​is shown in Table 27.

[0208] Table 27

[0209]

[0210] The percentage of the weight of the second coating film in Comparative Examples 23-25 ​​to the weight of the first coating film in Example 5 η 复合涂层 As shown in Table 28;

[0211] Table 28

[0212]

[0213] The composite coated titanium mesh electrolytic anodes prepared in Comparative Examples 23-25 ​​were processed using the pre-plating conditions of Example 9 and the nickel plating electrolysis conditions of Example 12. The nickel-plated precision semiconductor element 600 was tested, and the results are shown in Table 29.

[0214] Table 29

[0215]

[0216] The ratio of the area of ​​coating peeling to the total area of ​​coating is: Ni 镀层脱落面积 / Ni 镀层总面积

[0217] In summary, the precision semiconductor element processing method and system of the mesh electrolytic anode electrolytic device created by the integration of degreasing fluid-based titanium mesh electrolytic anode and electroplating technology of the present invention is an effective and feasible preferred solution to replace existing electroplating pretreatment technologies.

[0218] The provided titanium mesh electrolytic anode and electroplating method based on degreasing fluid solves, on the one hand, the major hidden danger of micro-dust impurities and contaminants hidden by scratches on the surface of precision semiconductor components being sealed between the semiconductor device surface and the plating layer, leading to the failure of semiconductor electronic products; on the other hand, through the innovative function of the mesh electrolytic anode with optimized composite coating, the function of electrolytic degreasing and contamination removal is greatly improved.

[0219] An electrolytic anode and electroplating method based on degreasing fluid are provided. Using the surface treatment area of ​​the mesh electrolytic anode and the precision semiconductor element as the basic conditions, the current and electroplating time conditions of the electrolytic device are calculated. According to the national standard GB / T 5270-2005, the metal needles of the semiconductor device are subjected to a winding and bending test to screen the optimal process conditions for pretreatment of surface scratch defects of the semiconductor device before electroplating. After nickel plating of the precision semiconductor element, Formula 4 is used for comprehensive judgment to obtain the most suitable condition range for coating the titanium mesh electrolytic anode.

[0220] The embodiments provided above are not intended to limit the scope of the invention, nor are the described steps intended to limit the order of execution. Any obvious modifications made to the invention by those skilled in the art based on existing common knowledge also fall within the scope of protection defined by the claims.

Claims

1. An electrolytic anode based on degreasing fluid for pretreatment before electroplating, characterized in that, From bottom to top, it includes a titanium mesh substrate, a first coating film, and a second coating film; The first coating film is a ruthenium oxide film; its weight is 0.87%~1.08% of the weight of the titanium mesh substrate. The second coating film is a hybrid film of rhodium oxide film and iridium oxide film; its weight is 1.47%~1.98% of the weight of the titanium mesh substrate. The rhodium oxide film of the second coating film is in direct contact with the first coating film. Both the first and second coating films are formed through high-temperature processing.

2. The electrolytic anode according to claim 1, characterized in that, The weight of the second coating film is 157-207% of the weight of the first coating film.

3. The electrolytic anode according to claim 1, characterized in that, The titanium mesh has an external dimension of 120mm in length and 50mm in width, and its diagonal mesh has a length, width and height of 3mm × 3mm × 1.5mm.

4. A method for preparing an electrolytic anode based on degreasing fluid for pretreatment before electroplating, as described in any one of claims 1-3, characterized in that, Includes the following steps: (1) The surface of the titanium mesh is sandblasted, then immersed in degreasing solution and washed with water three times, then treated with citric acid solution, washed with water three times and dried to obtain a surface-pretreated titanium mesh. (2) Spray the first layer of ruthenium chloride hydrate ethanol solution onto the surface of the pretreated titanium mesh, treat it at 500~550 ℃ for 3~5 min to form the first coating film, namely ruthenium oxide film, and then cool it to room temperature; (3) Based on step (2), spray an ethanol solution of rhodium(III) chloride hydrate and an ethanol solution of iridium(IV) chloride hydrate, then treat at 500~550 °C for 3~10 min, cool to room temperature, and obtain the electrolytic anode based on degreasing fluid; The specific steps for spraying the ethanol solution of rhodium(III) chloride hydrate and the ethanol solution of iridium(IV) chloride hydrate are as follows: The first spraying of chloroiridium(IV) acid was completed by automatically spraying ethanol solution of rhodium(III) chloride hydrate evenly on both sides for 23 seconds, heating at 100°C for 10 minutes, and cooling to room temperature. Then, the first spraying of chloroiridium(IV) acid was completed by automatically spraying ethanol solution of chloroiridium(IV) acid hydrate evenly on both sides for 23 seconds, heating at 100°C for 10 minutes, and cooling to room temperature. Every ten sprayings of chloroiridium(IV) acid constituted one cycle. The above cycle was repeated 2 to 6 times.

5. The preparation method according to claim 4, characterized in that, In step (1), the sandblasting time is 10~15 minutes.

6. The preparation method according to claim 4, characterized in that, In step (2), the mass concentration of the ethanol solution of ruthenium chloride hydrate is 5%, and the spraying time is 20 seconds.

7. A pre-plating treatment method for removing scratch defects on the surface of semiconductor devices using the electrolytic anode described in claim 1, characterized in that, The semiconductor device to be processed is placed in the electrolyte of the electrolytic degreasing device for electrolytic degreasing. The pretreatment conditions for electroplating are: current density D 阴极 The value is 6.7~10.0 A / dm. 2 The electrolytic power supply outputs a current of 6.2~26.7A; the current density of the titanium mesh anode... D 阳极 1.9~2.8A / dm 2 ; The electrolyte is a degreasing solution, consisting of 60 g / L potassium hydroxide, 30 g / L sodium carbonate, and 10 g / L sodium dodecylbenzenesulfonate; In the electrolytic degreasing apparatus, the electrolytic anodes based on the degreasing fluid used for pretreatment before electroplating are used as left and right anodes, and the semiconductor element to be treated is used as the cathode.

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