CN115404471B - Electroless tin plating solution and application - Google Patents

Electroless tin plating solution and application Download PDF

Info

Publication number
CN115404471B
CN115404471B CN202211047065.2A CN202211047065A CN115404471B CN 115404471 B CN115404471 B CN 115404471B CN 202211047065 A CN202211047065 A CN 202211047065A CN 115404471 B CN115404471 B CN 115404471B
Authority
CN
China
Prior art keywords
plating solution
tin plating
electroless tin
electroless
tin
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
Application number
CN202211047065.2A
Other languages
Chinese (zh)
Other versions
CN115404471A (en
Inventor
尹勇
高翔
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Jiangxi Zhujing New Materials Co ltd
Original Assignee
Jiangxi Zhujing New Materials Co ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Jiangxi Zhujing New Materials Co ltd filed Critical Jiangxi Zhujing New Materials Co ltd
Priority to CN202211047065.2A priority Critical patent/CN115404471B/en
Publication of CN115404471A publication Critical patent/CN115404471A/en
Application granted granted Critical
Publication of CN115404471B publication Critical patent/CN115404471B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
    • C23C18/16—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by reduction or substitution, e.g. electroless plating
    • C23C18/52—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by reduction or substitution, e.g. electroless plating using reducing agents for coating with metallic material not provided for in a single one of groups C23C18/32 - C23C18/50
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/20—Recycling

Landscapes

  • Chemical & Material Sciences (AREA)
  • General Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Chemically Coating (AREA)

Abstract

The invention discloses an electroless tin plating solution and application thereof. The electroless tin plating solution includes, in addition to a solvent: (a) a tin source that generates tin (II) ions; (b) at least one of an inorganic acid and an organic acid; (c) a compound having a thiourea skeleton; (d) AntioxidantA chemical agent; (e) A gloss agent selected from HO-R having a structure 1 ‑S‑R 2 ‑S‑R 3 Disulfide of-OH and/or HO-R having the structure 4 ‑S‑R 5 -monosulfide of OH; HO-R in said structure 1 ‑S‑R 2 ‑S‑R 3 in-OH, R 1 And R is 3 Independently selected from straight or branched alkyl groups having 1 to 8 carbon atoms, R 2 Selected from hydrogen atoms, linear or branched alkyl groups having 1 to 8 carbon atoms, wherein R 1 And R is 3 May be the same or different; HO-R in said structure 4 ‑S‑R 5 in-OH, R 4 And R is 5 Independently selected from straight or branched alkyl groups having 1 to 8 carbon atoms, wherein R 4 And R is 5 May be the same or different.

Description

Electroless tin plating solution and application
Technical Field
The invention relates to the field of electronics, in particular to an electroless tin plating solution and application thereof.
Background
With the expansion of smart phone screens, chip On Film (COF) is used to connect the display and the circuit of the substrate. COF is a product in which a driver Integrated Circuit (IC) is mounted on a copper (loop) wiring formed on a PI (Polyimide) film. As for connection of the drive integrated circuit and the copper wiring, a general method is to ultrasonically connect a gold bump (IC side) and a Sn plating layer formed on the copper wiring. Tin plating on copper wiring is generally performed by immersing copper wiring in a tin plating solution, and tin is deposited on copper wiring by substitution of copper and tin, so that neither electricity nor electrolytic tin (immersion tin) is required. However, the existing tin plating solution has the defect of poor solder wettability due to the roughness of formed particles.
Disclosure of Invention
In order to solve the problems, the invention provides the electroless tin plating solution and the application thereof, wherein the electroless tin plating solution can realize stable tin plating precipitation by introducing the luster agent with a special structure and regulating and controlling the composition of the electroless tin plating solution, and can remarkably improve the wettability of solder and avoid the particle roughness defect caused by poor wettability of the solder.
In a first aspect, the present invention provides an electroless tin plating solution. The electroless tin plating solution includes, in addition to a solvent: (a) a tin source that generates tin (II) ions; (b) at least one of an inorganic acid and an organic acid; (c) a compound having a thiourea skeleton; (d) an antioxidant; (e) A gloss agent selected from HO-R having a structure 1 -S-R 2 -S-R 3 Disulfide of-OH and/or HO-R having the structure 4 -S-R 5 -monosulfide of OH; HO-R in said structure 1 -S-R 2 -S-R 3 in-OH, R 1 And R is 3 Independently selected from straight or branched alkyl groups having 1 to 8 carbon atoms, R 2 Selected from hydrogen atoms, linear or branched alkyl groups having 1 to 8 carbon atoms, wherein R 1 And R is 3 May be the same or different; HO-R in said structure 4 -S-R 5 in-OH, R 4 And R is 5 Independently selected from straight or branched alkyl groups having 1 to 8 carbon atoms, wherein R 4 And R is 5 May be the same or different.
Preferably, the electroless tin plating solution further comprises, in addition to the solvent: (a) 5-80g/L of a tin source that produces tin (II) ions; (b) 5-450g/L of at least one of an inorganic acid and an organic acid; (c) 10-350g/L of a compound having a thiourea skeleton; (d) 10-300g/L of an antioxidant; (e) 101-300g/L of a gloss agent selected from the group consisting of HO-R having the structure 1 -S-R 2 -S-R 3 Disulfide of-OH and/or HO-R having the structure 4 -S-R 5 -monosulfide of OH; HO-R in said structure 1 -S-R 2 -S-R 3 in-OH, R 1 And R is 3 Independently selected from straight or branched alkyl groups having 1 to 8 carbon atoms, R 2 Selected from hydrogen atoms, linear or branched alkyl groups having 1 to 8 carbon atoms, wherein R 1 And R is 3 May be the same or different; HO-R in said structure 4 -S-R 5 in-OH, R 4 And R is 5 Independently selected from straight or branched alkyl groups having 1 to 8 carbon atoms, wherein R 4 And R is 5 May be the same or different.
PreferablyThe electroless tin plating solution includes, in addition to a solvent: (a) 5-80g/L of a tin source that produces tin (II) ions; (b) 5-450g/L of at least one of an inorganic acid and an organic acid; (c) 10-350g/L of a compound having a thiourea skeleton; (d) 10-300g/L of an antioxidant; (e) A gloss agent selected from HO-R having a structure 1 -S-R 2 -S-R 3 Disulfide of-OH and/or HO-R having the structure 4 -S-R 5 -monosulfide of OH; HO-R in said structure 1 -S-R 2 -S-R 3 in-OH, R 1 And R is 3 Independently selected from straight or branched alkyl groups having 1 to 8 carbon atoms, R 2 Selected from hydrogen atoms, linear or branched alkyl groups having 1 to 8 carbon atoms, wherein R 1 And R is 3 May be the same or different; HO-R in said structure 4 -S-R 5 in-OH, R 4 And R is 5 Independently selected from straight or branched alkyl groups having 1 to 8 carbon atoms, wherein R 4 And R is 5 May be the same or different; (f) 1-50g/L of surfactant.
Preferably, the compound having a thiourea skeleton has a sulfur atom on the thiourea skeleton unsubstituted, a nitrogen atom on the thiourea skeleton unsubstituted or at least one nitrogen atom substituted with an alkane, an alkene, or two nitrogen atoms linked in a carbon chain to form a ring.
Preferably, the compound having a thiourea skeleton has the structure
Figure BDA0003822776170000021
Wherein R is 4 Selected from alkanes or alkenes, preferably R 4 Selected from methyl, ethyl or allyl; r is R 5 Selected from alkyl or hydrogen atoms, preferably R 5 Selected from methyl or hydrogen atoms; r is R 6 Selected from alkyl or hydrogen atoms, preferably R 6 Selected from methyl, ethyl or hydrogen atoms.
Preferably, the compound having a thiourea skeleton has the structure
Figure BDA0003822776170000022
Wherein n is any natural number from 1 to 10; preferablyN is 1.
Preferably, the antioxidant contains at least hypophosphorous acid and/or hypophosphite.
Preferably, the organic acid has the same anion as the soluble tin salt as the tin source.
Preferably, the surfactant includes at least one of a nonionic surfactant and an amphoteric surfactant.
In a second aspect, the invention also provides the use of an electroless tin plating solution as described in any of the preceding claims for copper tin plating.
Drawings
Fig. 1 is an SEM image of the tin-plated film layer of comparative example 1;
FIG. 2 is an SEM image of a tin-plated film layer of comparative example 3;
fig. 3 is an SEM image of the tin plating film layer of example 1.
Detailed Description
The invention is further illustrated by the following embodiments, which are to be understood as merely illustrative of the invention and not limiting thereof.
The electroless tin plating solution provided by the invention comprises, in addition to a solvent, the following components: (a) a tin source that generates tin (II) ions; (b) at least one of an inorganic acid and an organic acid; (c) A compound having a thiourea skeleton (thiourea compound); (d) an antioxidant; (e) A gloss agent selected from HO-R having a structure 1 -S-R 2 -S-R 3 Disulfide of-OH and/or HO-R having the structure 4 -S-R 5 -monosulfide of OH; HO-R in said structure 1 -S-R 2 -S-R 3 in-OH, R 1 And R is 3 Independently selected from straight or branched alkyl groups having 1 to 8 carbon atoms, R 2 Selected from hydrogen atoms, linear or branched alkyl groups having 1 to 8 carbon atoms, wherein R 1 And R is 3 May be the same or different; HO-R in said structure 4 -S-R 5 in-OH, R 4 And R is 5 Independently selected from straight or branched alkyl groups having 1 to 8 carbon atoms, wherein R 4 And R is 5 May be the same or different. The invention proposes to make the tin plating electroless byThe solution incorporates the gloss agent of the above structure to improve the solder wettability of the tin plating layer. The smooth Sn particles are precipitated, which contributes to obtaining a tin plating film having a smooth surface state, which contributes to improving wettability of the solder. Conversely, a rough Sn particle shape may result in poor solder wettability.
The concentration of the gloss agent is controlled within the range of 101-300g/L to stabilize the smooth (tin) particle deposition shape. If the concentration of the gloss agent is less than 101g/L, particles may be caused to be uneven without the solder wettability improving effect. If the concentration of the gloss agent is higher than 300g/L, the Sn deposition rate is lowered, and the productivity is deteriorated. Preferably, the concentration of gloss agent is between 101-250g/L, most preferably between 105-200 g/L.
In some technical schemes, the structural general formula of the gloss agent is HO (CH) 2 ) n S(CH 2 ) m S(CH 2 ) n OH, wherein m is any natural number from 0 to 8, and n is any natural number from 1 to 8. It should be noted that the above values should not be taken as limiting the inventive aspects of the present invention. As an example, the gloss agent is selected from at least one of 2, 5-dithio-1, 6-hexanediol, 3, 6-dithio-1, 8-octanediol, 4, 7-dithio-1, 10-decanediol, dithiodimethanol, dithio-diethanol, and dithio-dipropanol. At this time, m=0, 2; n=1, 2,3.
TABLE 1
Figure BDA0003822776170000031
In other technical schemes, the structural general formula of the gloss agent is HO (CH) 2 ) p S(CH 2 ) p OH, wherein p is any natural number from 1 to 8. It should be noted that the above values should not be taken as limiting the inventive aspects of the present invention. As an example, the gloss agent is selected from at least one of 2-2 '-thiodiethanol, 3' -thiodipropanol.
TABLE 2
Figure BDA0003822776170000041
Tin (II) ions are stannous ions from a variety of tin compounds (tin salts) capable of generating such ions in solution. In some embodiments, the tin salt is a soluble stannous salt. The composition of the tin salt is not limited as long as it satisfies the provision of divalent tin ions. Preferably, the tin salt is an organic acid salt of tin (II), including but not limited to one or more of tin methane sulfonate, tin citrate, tin malate, tin tartrate. The tin salt may also be an inorganic acid salt of tin (II), including but not limited to tin sulfate, tin acetate, and the like. In the specific embodiment, the tin methane sulfonate has Lewis acid ions, shows weak acidity and has good solubility in a solvent. The concentration of the tin source that generates tin (II) ions in the electroless tin plating solution may be in the range of 5 to 80g/L. When the content exceeds the above range, the Sn deposition rate is lowered, excessive oxidation of Sn is promoted, and the life of the plating solution is reduced. The concentration of the tin salt is preferably 20 to 50g/L.
The thiourea compound acts as a complex with copper to cause a potential shift. The sulfur atoms on the thiourea skeleton of the thiourea compound are not substituted, the nitrogen atoms in the thiourea skeleton are not substituted or at least one nitrogen atom is substituted by alkane or alkene, or two nitrogen atoms are connected into a ring through a carbon chain.
When the nitrogen atom in the thiourea skeleton is not substituted or at least one N atom is substituted by alkane or alkene, the thiourea compound has the structure
Figure BDA0003822776170000042
Wherein R is 4 Selected from alkanes or alkenes, preferably R 4 Selected from methyl, ethyl or allyl; r is R 5 Selected from alkyl or hydrogen atoms, preferably R 5 Selected from methyl or hydrogen atoms; r is R 6 Selected from alkyl or hydrogen atoms, preferably R 6 Selected from methyl, ethyl or hydrogen atoms.
When two nitrogen atoms of the thiourea skeleton are connected into a ring by a carbon chain, the structure of the thiourea compound is that
Figure BDA0003822776170000043
Wherein n is any natural number from 1 to 10; preferably, n is 1.
In some embodiments, the thiourea compound comprises at least one of thiourea, dimethylthiourea, diethylthiourea, trimethylthiourea, diethylthiourea, allylthiourea, and ethylenethiourea.
The concentration of the thiourea compound in the electroless tin plating solution is 10 to 350g/L. Preferably 100-300g/L. The concentration of the thiourea compound exceeding the above range may decrease the Sn deposition rate or may cause abnormal deposition of Sn due to an excessive deposition rate. If the thiourea compound is omitted from the electroless tin plating solution, a tin plating layer formed by the electroless tin plating solution is not formed.
Chinese patent CN1549875a uses organic brighteners, such as aldehyde analogues (aldehyde analogs) or amine-based brighteners, such as ammonium salts, etc., to form a fine and firm deposited film with improved solder wettability immediately after electroplating. Tin plating includes both electroplating and electroless plating, wherein electroless plating includes reduction and displacement. The electroless tin plating solution of the present invention is a precipitation method that is quite different from electroplated tin. The present invention thus has a completely different mechanism of action than chinese patent CN1549875a for improving solder wettability. Specifically, the substitution type electroless tin plating solution of the present invention uses a sulfur compound typified by a thiourea compound as a complexing agent, and the specific behavior of the sulfur complexing agent causes tin to precipitate on copper. Tin has a higher ionization tendency than copper, that is, is a base metal, and therefore, precipitation reaction due to substitution does not occur on the surface of copper. However, copper has a tendency to be more easily moved in oxidation-reduction potential in the presence of a sulfur-based compound complexing agent such as a thiourea compound, and in fact, has a higher ionization tendency than tin and acts as a base metal. Therefore, copper remains in the circuit and dissolves in the liquid, and tin ions (valence 2) obtain the electrons, which are deposited as metal on the copper circuit.
Each standard redox potential E0 (V) and reaction is represented by the following formula:
oxidation-reduction potential (25 ℃ C.)
Cu + +e - →Cu O E＝+0.522(v)
Sn 2+ +2e - → Sn O E＝-0.140(v)
The reversal of the potential of the coordination of the chalcogenide complexing agent and copper occurs as follows:
Cu 2 S+2e - →2Cu O +S 2- E＝-0.560(v)
precipitation reaction of replacement electroless tin plating:
Sn 2+ +2Cu O →Sn o +2Cu +
the invention is to prevent turbidity of the plating solution caused by the conversion of tin (II) to tin (IV) by introducing an antioxidant into the electroless tin plating solution. Preferably, an antioxidant containing hypophosphite ions is used. The antioxidant containing hypophosphite ions is preferably hypophosphorous acid and/or hypophosphite. The hypophosphite includes, but is not limited to, sodium hypophosphite, potassium hypophosphite, and the like. The concentration of the antioxidant in the electroless tin plating solution is 10-300g/L. The concentration of the antioxidant exceeding the above range may cause promotion of Sn due to the reduced amount of the antioxidant 2+ Oxidation causes deterioration of the lifetime of the plating solution, or an excessive amount of antioxidant causes an excessive Sn precipitation rate, which causes Sn precipitation anomalies. Preferably, the concentration of antioxidant in the electroless tin plating solution is 50-160g/L. If the antioxidant is omitted from the electroless tin plating solution, the tin plating layer formed by the electroless tin plating solution becomes roughened.
The electroless tin plating solution includes at least one of an inorganic acid and an organic acid. Preferably, the electroless tin plating solution has a pH <1. By having the pH as described above, it is possible to avoid a decrease in Sn precipitation rate due to an excess or deficiency of acid, which is advantageous in obtaining an excellent tin plating film. Both organic and inorganic acids commonly used in the art may be suitable for use in the present invention. In some embodiments, the organic acid includes, but is not limited to, methanesulfonic acid, gluconic acid, citric acid, malic acid, tartaric acid, and the like. Preferably, an organic acid having the same anion as the tin source is used. For example, the tin source is tin methane sulfonate, and the acid is methane sulfonic acid accordingly. In other technical schemes, the technical purpose of the invention can be achieved by adopting inorganic acid. The inorganic acid includes, but is not limited to, one or more of sulfuric acid, hydrochloric acid and pyrophosphoric acid. Preferably, the concentration of at least one of the inorganic acid and the organic acid is 5 to 450g/L.
The electroless tin plating solution also includes a solvent. Can be one or more selected from pure water, methanol and ethanol. The concentration of the above solvent in the electroless tin plating solution may be 300 to 600g/L.
In some embodiments, a surfactant may also be introduced into the electroless tin plating solution. The surfactant includes, but is not limited to, at least one of a nonionic surfactant, an anionic surfactant, a cationic surfactant, and an amphoteric surfactant. Preferably, the surfactant is at least one of a nonionic surfactant and an amphoteric surfactant. More preferably, the surfactant is a nonionic surfactant. The above surfactants may be used alone or in combination of two or more. As an example, the surfactant may be polyoxyethylene dodecyl phenyl ether.
An electroless tin plating solution was prepared. And (3) preparing raw materials of the electroless tin plating solution, and uniformly stirring. The stirring mode, stirring temperature, stirring rotation speed and stirring time can be changed according to actual requirements. In some embodiments, stirring is performed at 50-60℃for 1-2 hours.
The copper material is kept in the electroless tin plating solution at 50-80 ℃ for 10-60 minutes until a tin plating film layer with the required thickness is formed. For example, hold at 65℃for 30 minutes. As an example, the thickness of the tin plating film layer formed on the surface of the copper wire by the above electroless tin plating solution is 0.8 to 1.5 μm.
The present invention will be further illustrated by the following examples. It is also to be understood that the following examples are given solely for the purpose of illustration and are not to be construed as limitations upon the scope of the invention, since numerous insubstantial modifications and variations will now occur to those skilled in the art in light of the foregoing disclosure. The specific process parameters and the like described below are also merely examples of suitable ranges, i.e., one skilled in the art can make a suitable selection from the description herein and are not intended to be limited to the specific values described below.
Comparative examples 1 to 3 and examples 1 to 18
Raw materials for electroless tin plating solutions were prepared in accordance with the compositions of tables 3, 4 and 5, and stirred at 50℃for 2 hours to obtain electroless tin plating solutions.
Preparing a tinning layer sample: and rolling the copper material to form a copper plate. The copper plate has a size of 25X 25mm and a thickness of 0.2mm. Copper plates were immersed in an acidic degreasing solution (commercially available commercial acidic degreasing solution) at room temperature for 30 seconds to degrease. The degreased copper plate was rinsed with pure water. The soaking was continued with 10% by volume sulfuric acid at room temperature for 30 seconds. The acid-washed copper plate was rinsed with pure water. The copper plate was kept in an electroless tin plating solution at 65 ℃ for 30 minutes to form a tin plating film layer. After the completion of tin plating, the plating was rinsed with pure water and washed with hot water at 70℃and then dried.
TABLE 3 Table 3
Figure BDA0003822776170000071
Figure BDA0003822776170000081
TABLE 4 Table 4
Figure BDA0003822776170000082
TABLE 5
Figure BDA0003822776170000091
The solderability tester is a test instrument for evaluating solder wettability, and the solder wettability of a tin-plated layer is measured by measuring zero-crossing time (zero-crossing time) using a test method called a wetting balance method (meiscograh). Specifically, the test piece was immersed in the solder bath until the time at which the wetting stress became 0. Showing the rate at which the solder is wetted. The faster the wetting speed, the shorter the zero crossing time and the better the solder wettability.
TABLE 6 zero crossing time measurement conditions
Figure BDA0003822776170000092
Figure BDA0003822776170000101
The surface roughness of the tin-plated film layer is characterized by microscopic morphology and apparent gloss. The apparent gloss was evaluated by using a gloss meter model M396RF-20SN manufactured by Shiro industries, inc. Fig. 1 shows the microstructure of comparative example 1, and it can be seen that Sn particles are precipitated in a protruding form as a whole and have a rough surface. The tinned film layer of comparative example 1 had a gray appearance tone and poor solder wettability. The tin plated film layer of comparative example 2 was apparent similar to comparative example 1. Fig. 2 shows the microstructure of comparative example 3, and it can be seen that a part of Sn particles are precipitated in a protruding form and the surface state is slightly rough. The tinned film layer of comparative example 3 had an off-white color in appearance and poor solder wettability. Fig. 3 shows the surface microstructure of example 1, and it can be seen that Sn particles smoothly precipitate and the surface state is smooth. The tin-plated film layer of example 1 was excellent in solder wettability with a half-gloss tone. The tin plated film layers of examples 2-18 were apparent similar to example 1.
The electroless tin plating solution of the present invention causes tin particles to precipitate in a smooth shape, thereby improving solder wettability. The zero crossing time of the tin-plated film layers of the respective examples was 3 seconds or less. In contrast, the solder wettability of the tin plating layer formed by the electroless tin plating solution of the comparative example was increased to 5 seconds or more.
In summary, the electroless tin plating solution of the present invention was not energized, and a displacement plating film having smooth Sn precipitation was obtained under electroless conditions.

Claims (10)

1. An electroless tin plating solution characterized in that it comprisesThe tin plating solution includes, in addition to the solvent: (a) 5-80g/L of a tin source that produces tin (II) ions; (b) 5-450g/L of at least one of an inorganic acid and an organic acid; (c) 10-350g/L of a compound having a thiourea skeleton; (d) 10-300g/L of an antioxidant; (e) 101-300g/L of a gloss agent selected from the group consisting of HO-R having the structure 1 -S-R 2 -S-R 3 Disulfide of-OH and/or HO-R having the structure 4 -S-R 5 -monosulfide of OH; HO-R in said structure 1 -S-R 2 -S-R 3 in-OH, R 1 And R is 3 Independently selected from straight or branched alkyl groups having 1 to 8 carbon atoms, R 2 Is empty or is selected from linear alkyl or branched alkyl with 1 to 8 carbon atoms; HO-R in said structure 4 -S-R 5 in-OH, R 4 And R is 5 Independently selected from straight chain alkyl or branched alkyl groups having 1 to 8 carbon atoms.
2. The electroless tin plating solution according to claim 1, wherein said electroless tin plating solution further comprises: (f) 1-50g/L of surfactant.
3. Electroless tin plating solution according to claim 1, characterized in that said compound having a thiourea skeleton has a sulfur atom on the thiourea skeleton unsubstituted, a nitrogen atom on the thiourea skeleton unsubstituted or at least one nitrogen atom substituted with an alkane, an alkene, or two nitrogen atoms linked in a cyclic shape with a carbon chain.
4. An electroless tin plating solution according to claim 3, characterized in that the structure of the compound having thiourea skeleton is
Figure FDA0004220190150000011
Wherein R is 4 Selected from alkanes or alkenes; r is R 5 Selected from alkyl groups or hydrogen atoms; r is R 6 Selected from alkyl groups or hydrogen atoms.
5. Electroless tin plating solution according to claim 4, characterized in thatWhere R is 4 Selected from methyl, ethyl or allyl; r is R 5 Selected from methyl or hydrogen atoms; r is R 6 Selected from methyl, ethyl or hydrogen atoms.
6. An electroless tin plating solution according to claim 3, characterized in that the structure of the compound having thiourea skeleton is
Figure FDA0004220190150000012
Wherein n is any natural number from 1 to 10.
7. Electroless tin plating solution according to any of the claims 1 to 6, characterized in that said antioxidant contains at least hypophosphorous acid and/or hypophosphite.
8. Electroless tin plating solution according to any of the claims 1 to 6, characterized in that said organic acid has the same anions as the soluble tin salt as the tin source.
9. Electroless tin plating solution according to claim 2, characterized in that said surfactant comprises at least one of a nonionic surfactant and an amphoteric surfactant.
10. Use of the electroless tin plating solution according to any of claims 1 to 9 for copper tin plating.
CN202211047065.2A 2022-08-30 2022-08-30 Electroless tin plating solution and application Active CN115404471B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202211047065.2A CN115404471B (en) 2022-08-30 2022-08-30 Electroless tin plating solution and application

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202211047065.2A CN115404471B (en) 2022-08-30 2022-08-30 Electroless tin plating solution and application

Publications (2)

Publication Number Publication Date
CN115404471A CN115404471A (en) 2022-11-29
CN115404471B true CN115404471B (en) 2023-07-04

Family

ID=84162595

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202211047065.2A Active CN115404471B (en) 2022-08-30 2022-08-30 Electroless tin plating solution and application

Country Status (1)

Country Link
CN (1) CN115404471B (en)

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4016326B2 (en) * 2002-08-02 2007-12-05 石原薬品株式会社 Electroless tin plating bath
CN100351428C (en) * 2003-07-15 2007-11-28 天津英诺泰克科技发展有限公司 Chemical tin solution for flexible printed circuit board
CN100370062C (en) * 2005-03-24 2008-02-20 广东风华高新科技集团有限公司 Composition for plating pure tin and electronic component employing the same
KR100973007B1 (en) * 2008-01-29 2010-07-30 삼성전기주식회사 Electroless Sn reduction plating solution for metal product and electroless plating method using the same
WO2009157334A1 (en) * 2008-06-26 2009-12-30 日本高純度化学株式会社 Reduction-type electroless tin plating solution and tin coats formed by using the same
CN106939417B (en) * 2017-04-28 2018-01-09 深圳市创智成功科技有限公司 The chemical plating stannum solution of printed wiring board

Also Published As

Publication number Publication date
CN115404471A (en) 2022-11-29

Similar Documents

Publication Publication Date Title
CN100543195C (en) The plating of composite substrate
JP3871013B2 (en) Tin-copper alloy electroplating bath and plating method using the same
JP4812365B2 (en) Tin electroplating solution and tin electroplating method
TW211044B (en)
TW200303938A (en) Electroplating solution containing organic acid complexing agent
JP6432667B2 (en) Tin alloy plating solution
TW201700797A (en) Plating solution including ammonium salt
JP2017179515A (en) Plating solution
JP2017197788A (en) Manufacturing method of electronic component contact member and electronic component contact member
CN115404471B (en) Electroless tin plating solution and application
US6982030B2 (en) Reduction of surface oxidation during electroplating
TWI689629B (en) Plating solution including phosphonium salt
KR102591174B1 (en) Electroplating solution for iron-nickel alloy with low thermal expansion coefficient and electroplating method using the same
JP5025815B1 (en) Hard gold plating solution
JP7316250B2 (en) Electroless gold plating bath and electroless gold plating method
JP6607106B2 (en) Plating solution using sulfonium salt
JP2000309876A (en) Substitution type electroless tin-silver alloy plating solution
Gamburg et al. Technologies for the electrodeposition of metals and alloys: electrolytes and processes
JP2018123402A (en) Plating solution using ammonium salt
TWI835422B (en) Plating solutions containing ether compounds containing sulfur groups
US11280014B2 (en) Silver/tin electroplating bath and method of using the same
JPH0565659A (en) Electroless copper-nickel alloy plating method
KR20240155294A (en) Plating solution containing a sulfonium group-containing ether compound
CN116157555A (en) Cyanide electrolytic silver alloy plating solution
JP2013144835A (en) ELECTROLESS Ni-P-Sn PLATING SOLUTION

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