CN119800461B - Tin-silver alloy electroplating solution, preparation method and application thereof, and electroplating method - Google Patents
Tin-silver alloy electroplating solution, preparation method and application thereof, and electroplating method Download PDFInfo
- Publication number
- CN119800461B CN119800461B CN202510288630.1A CN202510288630A CN119800461B CN 119800461 B CN119800461 B CN 119800461B CN 202510288630 A CN202510288630 A CN 202510288630A CN 119800461 B CN119800461 B CN 119800461B
- Authority
- CN
- China
- Prior art keywords
- surfactant
- tin
- electroplating solution
- electroplating
- silver
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Electroplating And Plating Baths Therefor (AREA)
Abstract
The invention relates to the field of electroplating, and discloses tin-silver alloy electroplating solution, a preparation method and application thereof, and an electroplating method. The available current density of the electroplating solution can reach 25ASD, the electroplating efficiency is high, the tin-silver alloy bumps obtained by electroplating are uniform, the void ratio after the bumps reflow is small, and collapse is not generated.
Description
Technical Field
The invention relates to the field of electroplating, in particular to tin-silver alloy electroplating solution, and a preparation method, application and an electroplating method thereof.
Background
Through flip chip bump interconnection technology, the chips can be stacked layer by layer, high density is achieved, and high-density three-dimensional packaging of the chips is achieved. Tin and tin alloy have the characteristics of good weldability, good electric conductivity, good thermal conductivity, good chemical stability and the like due to the characteristics of low melting point, high boiling point, good wettability and the like, and are very suitable for being used as chip bumps and used as welding materials. There are various methods for producing tin and tin alloy bumps, such as stencil printing, evaporation/sputtering, electroplating, etc. The electroplating method has low cost, and the size, the size and the height of the salient points are uniform and controllable. Therefore, developing tin and tin alloy electroplating solutions suitable for wafer electroplating and improving the electroplating performance thereof are key to manufacturing tin and tin alloy bumps.
However, in actual production, the pure tin plating layer is easy to cause short circuit in the high-density fine-pitch bump flip product due to tin whisker problem, so that the device is invalid. The lead-tin alloy is replaced by lead pollution to the environment, and the gold-tin alloy has the defects of high gold price, low plating speed and the like. The tin-copper alloy and the tin-bismuth alloy are easy to generate holes after reflow, and have poor reliability. The tin-silver alloy is excellent in environmental protection, reliability and use cost, and is an ideal bump interconnection material.
CN116529428a provides a tin alloy plating solution for producing bumps as bump electrodes of tin alloy on a circuit board when a semiconductor integrated circuit chip is mounted on the circuit board, the plating solution comprising (a) a soluble salt containing at least a stannous salt, (B) a soluble salt of a metal which is more inactive than tin, (C) an alkanesulfonic acid having 9 to 18 carbon atoms or a salt thereof in a molecule, (D) a nonionic surfactant having 1 or more phenyl groups in a molecule, and (E) a leveling agent. The plating solution is composed of a leveling agent composed of an alkanesulfonic acid having 9 to 18 carbon atoms in the molecule or a salt thereof, and does not use an aromatic carbonyl compound (such as benzalacetone, cinnamic acid, cinnamaldehyde, benzaldehyde, etc.) as the leveling agent, and does not supplement the leveling agent for a long time during plating, thereby forming a plated film uniformly and densely and smoothing the plated film. In actual operation, the solubility of the alkane sulfonic acid or the salt thereof containing 9-18 carbon atoms is often poor, and additional cosolvent is needed to be added for dissolution, so that the complexity of the plating solution is increased. And the alkane sulfonic acid or the salt thereof has too rich foam during working and is easy to form holes during electroplating. Also, in the examples and comparative examples, the current density used was only 4ASD.
CN108474127a mentions that a tin-silver alloy plating solution is a Sn-Ag alloy plating solution containing a water-soluble tin compound and a water-soluble silver compound, and contains a specific thioether compound in a range of 0.25 mol to 10 mol inclusive with respect to 1mol of silver in the water-soluble silver compound. In order to stably dissolve the silver compound in the sn—ag alloy plating solution, a sulfur-containing compound such as a heterocyclic compound having a mercapto group or a thioether compound is added as a complexing agent to form a silver complex. The Sn-Ag alloy plating solution is less likely to precipitate as a metal or insoluble salt in the plating solution and is capable of stably forming a Sn-Ag alloy plating film even when the plating solution is used or stored for a long period of time. But the current density mentioned in the examples and comparative examples is only 5ASD.
JP2022063889A provides a tin or tin alloy plating solution for suppressing generation of voids in bumps under a wide range of current densities of 2ASD-14ASD and a bump forming method using the solution. The inventors have conducted intensive studies and found that by incorporating polypropylene glycol having a specific mass average molecular weight into a plating solution at a specific mass ratio, the generation of voids in the bump can be suppressed in a wide current density range. The first aspect includes a soluble salt (a) containing at least a stannous salt, an acid or a salt thereof (B) selected from an organic acid and an inorganic acid, and a surfactant (C). A plating solution comprising a polypropylene glycol in an amount of 0.05g/L to 5g/L, the polypropylene glycol having a mass average molecular weight of 610 to 740. The second aspect is the invention according to the first aspect, wherein the surfactant (C) is a nonionic surfactant of polyoxyethylene (EO) and Polyoxypropylene (PO) condensation, and is a tin or tin alloy plating solution. A third aspect is to form a tin or tin alloy plating deposit layer to be a plurality of bump precursors on a substrate using the tin or tin alloy plating solution of the first or second aspects.
CN104032337a provides a tin alloy plating bath with high continuous stability, with little variation in co-deposition ratio of tin and alloy metal due to variation in current density and substantially no cyanide. The inventors' series of test results show that by incorporating a peptide having a cysteine residue into a plating solution, the plating solution can be used stably for a long period of time even if a metal ion more inert than tin is present in the plating solution, and the plating solution can obtain a substantially unchanged co-deposition ratio of tin and metal ion with respect to an increase or decrease in current density. The current used in the tin alloy plating solution may be a direct current or a pulsed current. The current density is preferably in the range of 0.5 to 10A/dm 2, more preferably 1 to 8A/dm 2.
JP11256390a relates to a tin-silver alloy plating solution for tin-silver alloy plating. The plating solution is used for joining electronic parts, solder joining parts at the time of mounting, surface treatment of lead frame printed circuit boards, and the like, and it is considered that the composition of plated products varies greatly with current density in all conventional tin-silver alloy plating solutions. For example, at higher current densities, 2ASD has a silver content of 3-5 wt.%, but at lower current densities, the silver content increases rapidly to 15-25 wt.%, more than a few times. In this patent application, a silver compound is dissolved in a tin plating solution to form fine metallic silver particles having a particle diameter of about 5nm, and the fine metallic silver particles are stably dispersed in the plating bath without aggregation or sedimentation. And then the mixed tin and silver alloy plating layer is formed in the tin plating layer during the subsequent electroplating. The temperature of the plating bath of the invention ranges from 20 ℃ to 70 ℃, preferably from 30 ℃ to 60 ℃, and the cathodic current density is 0.1-10ASD, more preferably 0.1-5.0ASD.
US20070037377A1 provides a tin-silver alloy plating solution useful for solder wafer bumps that is added with additives to enhance silver stability, an N-allylthiourea compound and a quaternary surfactant, allowing Sn-Ag wafer bumps to be plated at high current densities of 1-20ASD, thereby greatly reducing or completely eliminating voids between the bumps and Cu and UBM. However, the maximum current density used in all of the examples and comparative examples was only 12ASD.
JP2006265572a provides a cyanide-free electroplated tin-silver alloy plating solution, and a tin-silver alloy film obtained from the plating solution has excellent solder wettability and appearance. The inventors added an aliphatic sulfide and an aliphatic thiol as stabilizers for silver ions to the plating solution, and added an aliphatic amino acid such as glycine and a nitrogen-containing aromatic carboxylic acid such as picolinic acid to the plating solution. The film obtained from the plating solution can effectively improve solderability and appearance. However, the tin-silver alloy plating solutions obtained in examples 1 to 10 and comparative examples 1 to 5 were used with a current density of 5 to 15ASD for the cathode.
CN106757212A discloses an electroplating tin-silver alloy solution for wafer level packaging, which comprises the following concentration components of 50-450 g/L of methylsulfonic acid, 20-60 g/L of tin ions, 0.1-1.0g/L of silver ions, 10-50 g/L of silver ion chelating agents and 0.52-5.08 g/L of organic additives, wherein the current density is between 1 and 10ASD and the temperature is between 15 and 35 ℃ during electroplating of the tin-silver alloy solution. The solution comprises methylsulfonic acid, tin ions, silver ions, a silver ion chelating agent and an organic additive, wherein the current density is between 1 and 10ASD during electroplating, the temperature is between 15 and 35 ℃, the components are electroplated to form a tin-silver alloy solution, the electroplated tin-silver plating solution is used for replacing the traditional electroplated pure tin solution, the problem that the tin whisker is easy to generate in the existing pure tin bump is solved, the defects of tin whisker and the like generated by a pure tin plating layer can be effectively prevented, and the reliability of an electronic product is further improved.
CN118639288a provides a tin-silver alloy electroplating solution and a preparation method thereof, and electroplated tin-silver alloy bumps. The electroplating solution for preparing the tin-silver alloy contains sulfhydryl-containing compound, amino acid, nonylphenol polyoxyethylene ether and fluorine-containing surfactant, can obviously improve coplanarity of tin-silver alloy bumps and uniformity of silver content in the alloy, and can be used with current density of 1-10ASD.
It can be seen that the current density of the tin-silver alloy electroplating solution disclosed in the prior art is low and cannot reach more than 20 ASD.
Disclosure of Invention
In order to solve the problem of low electroplating current density in the prior art, the invention provides a tin-silver alloy electroplating solution, a preparation method and application thereof, and an electroplating method.
In order to achieve the above object, a first aspect of the present invention provides a tin-silver alloy plating solution comprising a soluble stannous salt, a soluble silver salt, a complex surfactant, a free acid, an antioxidant, a complexing agent, and a solvent, the complex surfactant comprising a first surfactant, a second surfactant, a third surfactant, and a fourth surfactant;
The first surfactant is at least one selected from linear alkylphenol polyether, linear alkylphenol polyether ester and salts thereof, aromatic phenol polyether ester, styrylphenol polyether and EO-PO-EO block copolymer with weight average molecular weight of 2000-4000 Da;
the second surfactant is a polyol;
the third surfactant is a cationic surfactant and/or an amphoteric surfactant;
The fourth surfactant is thio-polyoxyethylene ether;
The mass ratio of the first surfactant to the second surfactant to the third surfactant to the fourth surfactant is 1:1-12:0.05-2:0.25-8;
the content of the composite surfactant in the electroplating solution is 30-180 g/L.
In a second aspect, the invention provides a method for preparing the tin-silver alloy electroplating solution provided in the first aspect, which comprises the steps of mixing a soluble stannous salt, a soluble silver salt, a composite surfactant, a free acid, an antioxidant, a complexing agent and an optional brightening agent in the presence of a solvent to obtain the tin-silver alloy electroplating solution.
The third aspect of the invention provides an application of the tin-silver alloy electroplating solution provided by the first aspect of the invention in electroplating.
In a fourth aspect, the invention provides a method for electroplating using the tin-silver alloy electroplating solution provided in the first aspect, wherein the electroplating current density is 1-25 ASD.
The invention has the beneficial effects that:
the available current density of the electroplating solution can reach 25ASD, the electroplating efficiency is high, the tin-silver alloy bumps obtained by electroplating are uniform, the void ratio after the bumps reflow is small, and collapse is not generated.
Drawings
FIG. 1 is a photograph of appearance of a coating, wherein (a) is a photograph of appearance of a coating obtained in example 1, (b) is a photograph of appearance of a coating obtained in comparative example 1, (c) is a photograph of appearance of a coating obtained in comparative example 2, (d) is a photograph of appearance of a coating obtained in comparative example 3, (e) is a photograph of appearance of a coating obtained in comparative example 4, (f) is a photograph of appearance of a coating obtained in comparative example 5, and (g) is a photograph of appearance of a coating obtained in comparative example 6;
FIG. 2 is a scanning electron microscope image before reflow of the bumps obtained from the plating solution of example 2;
FIG. 3 is a scanning electron microscope image of a front cut surface of a bump reflow obtained from the plating solution of example 2;
FIG. 4 is a scanning electron microscope image of the bump reflow obtained by the electroplating solution of example 2;
FIG. 5 is a scanning electron microscope image of a cross section of a bump obtained by the plating solution of example 2 after reflow;
FIG. 6 is an X-Ray CT image of the bump reflow obtained from the plating solution of example 1;
FIG. 7 is an X-Ray CT image of the bump reflow obtained from the electroplating solution of comparative example 3;
FIG. 8 is an X-Ray CT image of the bump reflow obtained from the electroplating solution of comparative example 4;
FIG. 9 is an X-Ray CT image of the bump reflow obtained from the plating solution of comparative example 6.
Detailed Description
The endpoints and any values of the ranges disclosed herein are not limited to the precise range or value, and are understood to encompass values approaching those ranges or values. For numerical ranges, one or more new numerical ranges may be found between the endpoints of each range, between the endpoint of each range and the individual point value, and between the individual point value, in combination with each other, and are to be considered as specifically disclosed herein.
In the present invention, ASD means ampere/square decimeter, namely A/dm 2.
The first aspect of the invention provides a tin-silver alloy electroplating solution, which comprises a soluble stannous salt, a soluble silver salt, a compound surfactant, free acid, an antioxidant, a complexing agent and a solvent, wherein the compound surfactant comprises a first surfactant, a second surfactant, a third surfactant and a fourth surfactant;
The first surfactant is at least one selected from linear alkylphenol polyether, linear alkylphenol polyether ester and salts thereof, aromatic phenol polyether ester, styrylphenol polyether and EO-PO-EO block copolymer with weight average molecular weight of 2000-4000 Da;
the second surfactant is a polyol;
the third surfactant is a cationic surfactant and/or an amphoteric surfactant;
The fourth surfactant is thio-polyoxyethylene ether;
The mass ratio of the first surfactant to the second surfactant to the third surfactant to the fourth surfactant is 1:1-12:0.05-2:0.25-8;
the content of the composite surfactant in the electroplating solution is 30-180 g/L.
In the invention, the first surfactant can promote tin to be precipitated in a low current density interval (0.1-2 ASD), the second surfactant can inhibit silver from being precipitated in a low current density interval (0.1-2 ASD), the third surfactant can promote tin to be normally precipitated in an ultrahigh current density interval (12-25 ASD), and the fourth surfactant can refine tin silver grains.
The four surfactants cooperate to improve the available current density of the electroplating solution during electroplating, improve the electroplating efficiency, and the tin-silver alloy bumps obtained by electroplating are uniform, the hollow space ratio is small after the bumps reflow, and collapse is not generated.
In the present invention, EO values have the meaning customary in the art, i.e. the molar amount of-CH 2CH2 O-fragment contained per mole of polymer molecule.
For the first surfactant:
According to the present invention, preferably, the first surfactant is selected from at least one of cardanol polyoxyethylene ether, cardanol polyoxyethylene ether sulfate and salts thereof, phenol polyoxyethylene ether, distyrylphenol polyoxyethylene ether, and tristyrylphenol polyoxyethylene ether.
Preferably, the EO value of the first surfactant is from 5 to 25.
For the second surfactant:
according to the present invention, preferably, the polyhydric alcohol is at least one of polyethylene glycol (PEG), polypropylene glycol (PPG), and EO-PO-EO block copolymer.
Preferably, the weight average molecular weight of the second surfactant is 200-2000 Da.
More preferably, the PEG is at least one selected from PEG 200-2000, and can be, for example, PEG 200, PEG 400, PEG 600, PEG 1000, PEG 1500, or PEG 2000.
More preferably, the PPG is selected from at least one of PPG 400-1000, and may be, for example, PPG 400, PPG 600, PPG 800, PPG 1000.
More preferably, the EO-PO-EO block copolymer is selected from at least one of polyethylene oxide-polypropylene oxide, polyethylene glycol-polypropylene ether, and polyvinyl alcohol-polypropylene oxide.
For the third surfactant:
According to the present invention, preferably, the third surfactant is selected from at least one of C 12-C18 alkyl trimethyl ammonium chloride, C 12-C18 alkyl dimethyl benzyl ammonium chloride, C 12-C18 alkyl trimethyl ammonium bromide, C 12-C18 alkyl dimethyl benzyl ammonium bromide, C 12-C18 alkyl trimethyl para-toluene sulfonic acid ammonium, month Gui Er methyl amine oxide, citric acid betaine, and 3-sulfopropyl tetradecyl dimethyl betaine.
For the fourth surfactant:
Preferably, according to the present invention, the fourth surfactant is a C 12-C18 alkyl thiol polyoxyethylene ether and/or thiodiglycol ethoxylate;
preferably, the EO value of the fourth surfactant is from 5 to 25.
According to a particularly preferred embodiment of the present invention, the first surfactant is cardanol polyoxyethylene ether BGF-10, the second surfactant is PEG 1000, the third surfactant is dodecyldimethylbenzyl ammonium bromide, and the fourth surfactant is thiodiglycol ethoxylate (eo=10).
According to a preferred embodiment of the present invention, the mass ratio of the first surfactant, the second surfactant, the third surfactant and the fourth surfactant is 1:3-6:0.2-1:3-5.
According to a preferred embodiment of the present invention, the content of the complex surfactant in the plating solution is 50 to 150 g/L.
The specific type of the soluble stannous salt is not particularly limited in the present invention, and may be routinely selected by those skilled in the art. According to one embodiment of the invention, the soluble stannous salt is selected from at least one of stannous sulfonate, stannous sulfate and stannous fluoroborate.
According to a preferred embodiment of the present invention, the soluble stannous salt is present in the plating solution in an amount of from 30 to 150 g/L, calculated as metal ions.
In the invention, when the content of the soluble stannous salt in the electroplating solution is within the range, the precipitation of tin can be further promoted, and meanwhile, the electroplating solution keeps moderate viscosity, so that the occurrence of voids in a plating layer is avoided.
More preferably, the soluble stannous salt is present in the plating solution in an amount of 50 to 120 g/L, calculated as metal ions.
The specific type of the soluble silver salt is not particularly limited in the present invention, and may be soluble in an acid, and may be selected by those skilled in the art as usual. According to one embodiment of the present invention, the soluble silver salt is selected from at least one of silver sulfonate, silver acetate, silver sulfate.
According to the present invention, the plating solution preferably contains 0.01 to 5g/L of the soluble silver salt in terms of metal ions.
In the present invention, when the content of the soluble silver salt in the plating solution is within the above range, a tin-silver alloy plating layer having a more suitable melting point can be obtained.
More preferably, the soluble silver salt content in the plating solution is 0.5 to 3 g/L, still more preferably 1.5 to 2.5 g/L, in terms of metal ions.
The specific type of the free acid is not particularly limited in the present invention, and may be routinely selected by those skilled in the art. For example, the free acid may be at least one of sulfuric acid, hydrochloric acid, alkyl sulfonic acid, sulfamic acid, aryl sulfonic acid, and other soluble strong acids.
The specific type and content of the antioxidant is not particularly limited in the present invention, and may be routinely selected by those skilled in the art.
According to one embodiment of the invention, the antioxidant may be a phenolic compound and its derivatives, such as phenol, benzenediol, benzenetriol, naphthol, may be hydroxybenzoic acid and its derivatives, such as parahydroxybenzoic acid, orthohydroxybenzoic acid, 3, 4-dihydroxybenzoic acid, 2, 4-dihydroxybenzoic acid, gallic acid, may be hydroxybenzenesulfonic acid, naphtholsulfonic acid and its derivatives, such as cresol sulfonic acid, naphtholsulfonic acid, 1-amino-2-naphthol-4-sulfonic acid, 4-hydroxy-1-naphthalenesulfonic acid monosalt, may be a flavonoid compound, such as flavones, flavonols and flavonols, chalcones, dihydrochalcones, orange, anthocyanidins and flavanols.
According to the invention, the antioxidant content in the electroplating solution is 0.5-5 g/L.
The specific type and content of the complexing agent is not particularly limited in the present invention, and may be routinely selected by one skilled in the art.
According to one embodiment of the present invention, the complexing agent may be selected from at least one of hydroxyethylidene diphosphonic acid, gluconic acid, N-hydroxyethylethylenediamine triacetic acid, malic acid, N-acetyl-L histidine; the complexing agent may also be selected from at least one of a thioether compound, a thiol compound and a mercapto compound, for example 4, 4-dihydroxydiphenyl sulfide, 4-diaminodiphenyl sulfide, 2-hydroxyethyl ethyl sulfide, methylthioethanol, methylthioacetic acid, 3-methylthiopropanol, 3-methylthiopropionic acid, methylthiopyridine, methylthiopyrazine, methylthiopyrimidine, thiodiglycol, 1- (2-dimethylaminoethyl) -1H-tetrazole-5-thiol, 3, 6-dithio-1, 8-octanediol, 3, 6-dioxa-1, 8-octanedithiol, 1-thioglycerol, thioglycolic acid, mercaptopropionic acid, mercaptoimidazole, thioauxiliary amino acid, dithiocompounds such as 2,2' -dithiodipyridine, dithiophene disulfide, bis (thiobenzoyl) disulfide, 4-amino-4H-1, 2, 4-triazole-3, 5-dithiol, dithiodiacetic acid.
According to the invention, in particular, the molar ratio of complexing agent to soluble silver salt calculated as silver ion is 2-10:1.
According to the present invention, preferably, the plating solution further contains a brightening agent.
The specific type and content of the brightening agent is not particularly limited in the present invention, and may be routinely selected by those skilled in the art. According to one embodiment of the present invention, the brightening agent is at least one selected from the group consisting of polyquaternium, polyvinylpyrrolidone, polyethylenimine, benzalacetone, 2',3,4',5, 7-pentahydroxyflavone, 2- (3, 4-dihydroxyphenyl) -3,5, 7-trihydroxy-4H-1-benzopyran-4-one, glutaraldehyde, cinnamaldehyde, anisaldehyde, vanillin.
According to the invention, the content of the brightening agent in the electroplating solution is 0.01-1 g/L.
In a second aspect, the invention provides a method for preparing the tin-silver alloy electroplating solution provided in the first aspect, which comprises the steps of mixing a soluble stannous salt, a soluble silver salt, a composite surfactant, a free acid, an antioxidant, a complexing agent and an optional brightening agent in the presence of a solvent to obtain the tin-silver alloy electroplating solution.
The third aspect of the invention provides an application of the tin-silver alloy electroplating solution provided by the first aspect of the invention in electroplating.
In a fourth aspect, the invention provides a method for electroplating using the tin-silver alloy electroplating solution provided in the first aspect, wherein the electroplating current density is 1-25 ASD.
Preferably, according to the present invention, the method comprises sequentially energizing 30-90 s at 1-2 ASD, 300-480 s at 3-5 ASD, 120-240 s at 20-25 ASD.
The present invention will be described in detail by examples. In the following examples, the silver content in the bump was determined by X-ray fluorescence spectroscopy (XRF);
The void ratio after bump reflow is measured by X-Ray computed tomography (X-Ray CT);
measuring roughness Ra of the surface of the plating layer by using a Keyence laser microscope, wherein the definition of Ra is referred to GB/T3505-2009;
the content of each substance in the electroplating solution is calculated by the feeding amount.
Unless otherwise indicated, all reagents, starting materials were obtained from commercial sources.
Examples 1 to 15 and comparative examples 1 to 6
Adding stannous methanesulfonate, silver methanesulfonate, methanesulfonic acid, catechol, hydroquinone, gluconic acid, 3, 6-dithio-1, 8-octanediol, 2' -dithiodipyridine and benzalacetone into water, stirring and mixing, and then adding a first surfactant, a second surfactant, a third surfactant and a fourth surfactant, and stirring and mixing to obtain the tin-silver alloy electroplating solution.
The plating solution contains 85g/L stannous, 2g/L silver, 1g/L catechol, 1g/L hydroquinone, 15g/L gluconic acid, 5 g/L3, 6-dithio-1, 8-octanediol, 1 g/L2, 2' -dithiodipyridine, 0.1g/L benzalacetone and 0 pH value.
The mass ratio of the four surfactants and the total content of the surfactants in the plating solution are shown in Table 1.
TABLE 1
Table 1 (subsequent)
Table 1 (subsequent)
Test example 1
The titanium-based platinum-coated coating is used as an anode, and a copper sheet with the thickness of 100mm multiplied by 65mm is used as a cathode. The copper sheet is sequentially subjected to electrolytic degreasing, cleaning, acid activation and cleaning. The anode and the cathode were placed in a helter tank, 250mL of the plating solutions obtained in the above examples and comparative examples were added, respectively, a direct current of 5A was applied for 5 minutes, the appearance of the plating layer in the range of 1 to 25 ASD was observed, and the roughness Ra of the surface of the plating layer was measured, and the results are shown in table 2.
TABLE 2
FIG. 1 is a photograph of appearance of a coating, wherein (a) is a photograph of appearance of a coating obtained in example 1, (b) is a photograph of appearance of a coating obtained in comparative example 1, (c) is a photograph of appearance of a coating obtained in comparative example 2, (d) is a photograph of appearance of a coating obtained in comparative example 3, (e) is a photograph of appearance of a coating obtained in comparative example 4, (f) is a photograph of appearance of a coating obtained in comparative example 5, and (g) is a photograph of appearance of a coating obtained in comparative example 6.
It can be seen that the plating layer obtained by the plating solution of example 1 has uniform and fine appearance and no abnormality;
the plating solution of comparative example 1 resulted in high potential and large area scorch, and poor low potential coverage;
The plating layer obtained by the electroplating solution in comparative example 2 is slightly blackened in color and has higher silver content;
the low potential region of the plating layer obtained by the electroplating solution in comparative example 3 can not deposit tin-silver alloy and is seriously missed to be plated;
the color of the coating test piece obtained by the electroplating solution in comparative example 4 is entirely blackish;
high-potential scorch of the plating layer obtained by the plating solution of comparative example 5;
The plating layer obtained by the plating solution of comparative example 6 was rough.
Application example
The titanium-based platinum-coated coating is used as an anode, and the wafer pattern piece is used as a cathode. The wafer pattern piece is silicon-based coated with copper and coated with photoresist with the thickness of 80 mu m, the size of the wafer pattern piece is about 23mm multiplied by 23mm, and the wafer pattern piece is totally 9 single chip units (DIEs), and each DIE contains 1351 small holes with the diameter of 85 mu m and the depth of 80 mu m. The anode and the cathode are placed in a cube small groove with the volume of 500mL, 500mL of the electroplating solution obtained in the example and the comparative example are respectively added, 60 s is electrified by 1 ASD, 360 s is electrified by 4 ASD, 180 s is electrified by 25 ASD, 50 mu m tin-silver alloy bumps are plated in the small holes, and then the photoresist is removed.
And (3) heating the wafer pattern sheet with the photoresist removed to 100 ℃ at the rate of 2 ℃ per second, maintaining for 60 seconds, heating to 200 ℃ at the rate of 2 ℃ per second, maintaining for 100 seconds, heating to 240 ℃ at the rate of 2 ℃ per second, maintaining for 120 seconds, and naturally cooling to room temperature to obtain the reflowed salient point.
Test example 2
And observing the forms before and after the bump reflow by using a scanning electron microscope.
FIG. 2 is a scanning electron microscope image before reflow of the bump obtained by the electroplating solution in example 2, wherein the accelerating voltage is 10 kV, the focal length is 10.9 mm, the multiplying power is 200 times, and the receiving signal probe is a secondary electron detector;
FIG. 3 is a scanning electron microscope image of the front cut surface of the bump reflow obtained by the electroplating solution of example 2, wherein the accelerating voltage is 5 kV, the focal length is 5.6 mm, the multiplying power is 1000 times, and the receiving signal probe is a secondary electron detector;
FIG. 4 is a scanning electron microscope image of the electroplating solution of example 2 after bump reflow, the accelerating voltage is 5 kV, the focal length is 8.5 mm, the multiplying power is 200 times, and the receiving signal probe is a secondary electron detector;
Fig. 5 is a scanning electron microscope image of a section of a bump after reflow obtained from the plating solution of example 2, the accelerating voltage is 5 kV, the focal length is 5.8 mm, the magnification is 1000 times, and the receiving signal probe is a secondary electron detector.
It can be seen that the qualified tin-silver alloy bumps can be obtained on the silicon chip by selecting proper surfactant types, proportion and addition amount.
Silver content in the bump after photoresist removal and before reflow was measured by XRF, and the bump void ratio after reflow was observed by using an X-Ray CT detection apparatus, and the results are shown in table 3.
TABLE 3 Table 3
NA expression does not apply, or has no data.
FIG. 6 is an X-Ray CT image of the bump reflow obtained from the plating solution of example 1;
FIG. 7 is an X-Ray CT image of the bump reflow obtained from the electroplating solution of comparative example 3;
FIG. 8 is an X-Ray CT image of the bump reflow obtained from the electroplating solution of comparative example 4;
FIG. 9 is an X-Ray CT image of the bump reflow obtained from the plating solution of comparative example 6.
It can be seen that the bumps obtained from the plating solution of example 1 were normally free of voids, the bumps obtained from the plating solutions of comparative examples 3 and 6 were more void, and the bumps obtained from the plating solution of comparative example 4 were completely collapsed.
The results of tables 2 and 3 show that the available current density of the electroplating solution provided by the invention can reach 25ASD, the electroplating efficiency is high, the tin-silver alloy plating layer obtained by electroplating is uniform and fine, the roughness is low, the silver content is proper, the void ratio is small after bump reflow, and collapse is not generated.
The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, a number of simple variants of the technical solution of the invention are possible, including combinations of the individual technical features in any other suitable way, which simple variants and combinations should likewise be regarded as being disclosed by the invention, all falling within the scope of protection of the invention.
Claims (9)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202510288630.1A CN119800461B (en) | 2025-03-12 | 2025-03-12 | Tin-silver alloy electroplating solution, preparation method and application thereof, and electroplating method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202510288630.1A CN119800461B (en) | 2025-03-12 | 2025-03-12 | Tin-silver alloy electroplating solution, preparation method and application thereof, and electroplating method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN119800461A CN119800461A (en) | 2025-04-11 |
| CN119800461B true CN119800461B (en) | 2025-06-13 |
Family
ID=95277056
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202510288630.1A Active CN119800461B (en) | 2025-03-12 | 2025-03-12 | Tin-silver alloy electroplating solution, preparation method and application thereof, and electroplating method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN119800461B (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2016152986A1 (en) * | 2015-03-26 | 2016-09-29 | 三菱マテリアル株式会社 | Plating solution using ammonium salt |
| WO2019234088A1 (en) * | 2018-06-08 | 2019-12-12 | Atotech Deutschland Gmbh | Aqueous composition for depositing a tin silver alloy and method for electrolytically depositing such an alloy |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109594108B (en) * | 2018-12-21 | 2021-03-02 | 上海集成电路研发中心有限公司 | Method for forming tin alloy electroplating bath and method for preparing solder bump coating |
| CN118639288B (en) * | 2024-08-12 | 2024-11-15 | 江苏中科智芯集成科技有限公司 | Tin-silver alloy bump and preparation method thereof |
-
2025
- 2025-03-12 CN CN202510288630.1A patent/CN119800461B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2016152986A1 (en) * | 2015-03-26 | 2016-09-29 | 三菱マテリアル株式会社 | Plating solution using ammonium salt |
| WO2019234088A1 (en) * | 2018-06-08 | 2019-12-12 | Atotech Deutschland Gmbh | Aqueous composition for depositing a tin silver alloy and method for electrolytically depositing such an alloy |
Also Published As
| Publication number | Publication date |
|---|---|
| CN119800461A (en) | 2025-04-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4603812B2 (en) | Improved tin plating method | |
| JP6482822B2 (en) | Plating bath and method | |
| KR101361555B1 (en) | Tin electroplating bath, tin-plated coating film, tin electroplating method, and electronic device component | |
| US20150267310A1 (en) | Tin or tin alloy electroplating bath and process for producing bumps using same | |
| EP1754805B1 (en) | Tin electroplating solution and tin electroplating method | |
| JP3871013B2 (en) | Tin-copper alloy electroplating bath and plating method using the same | |
| CN111356789B (en) | Tin or tin alloy electroplating solution | |
| CN108603300B (en) | Aqueous indium or indium alloy plating bath and method for depositing indium or indium alloy | |
| JP2004263291A (en) | Tin plating method | |
| US8277630B2 (en) | Tin electroplating solution and a method for tin electroplating | |
| JP3632499B2 (en) | Tin-silver alloy electroplating bath | |
| WO2013046731A1 (en) | Acidic aqueous composition for tin plating | |
| KR20200133330A (en) | Tin or tin alloy plating solution, bump formation method, circuit board manufacturing method | |
| TWI754135B (en) | Plating solution of tin or tin alloy, method for forming bump, and method for manufacturing circuit board | |
| CN119800461B (en) | Tin-silver alloy electroplating solution, preparation method and application thereof, and electroplating method | |
| JP2004183091A (en) | Plating solution containing, tin-silver-copper electrolytic plating method, plating film containing tin-silver-copper and soldering method using this plating film | |
| JP2019077949A (en) | Tin or tin alloy plating liquid | |
| JP4461295B2 (en) | Neutral bright tin-zinc alloy plating bath | |
| KR20230130618A (en) | tin alloy plating solution | |
| JP7140176B2 (en) | Tin alloy plating solution | |
| JP2009019226A (en) | Tin-silver-copper-nickel-containing plating solution and tin-silver-copper-nickel-containing plating film formed using the same | |
| TW201704546A (en) | Plating solution including sulfonium salt | |
| TW202136587A (en) | Tin or tin alloy electroplating solution, method for forming bumps, and method for producing circuit board | |
| WO2019082885A1 (en) | Tin or tin-alloy plating liquid |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |