JP5928142B2 - Post-treatment agent for tin or tin alloy plating film, and method for treating tin or tin alloy plating film - Google Patents

Description

  The present invention relates to a post-treatment agent for tin or tin alloy plating film which prevents discoloration of tin or tin alloy plating film formed on a solder joint or the like, and deterioration of solder wettability over time, and tin using the same Or it is related with the processing method of a tin alloy plating film.

  Tin or tin alloy (tin-copper, tin-silver, tin-bismuth, etc.) plating films are widely used for electronic parts because of their excellent solder wettability. When exposed to high temperatures and high humidity (hereinafter referred to as “high humidity”) or high temperature drying (hereinafter referred to as “high temperature”) for a long period of time, the surface is oxidized, discoloration of the plating film, and solder wetting Degradation occurs.

  The tin or tin alloy plating film having deteriorated solder wettability lowers the performance and reliability of the product by repelling the solder paste during mounting. Moreover, if a reflow process is performed when the plating film is mounted, the tin or tin alloy plating film turns from yellow to purple. This is because tin melts and is oxidized and discolored when exposed to air at high temperatures.

  Conventionally, the following measures have been used to prevent discoloration of the tin or tin alloy plating film under high humidity conditions and high temperature conditions and to prevent deterioration of solder wettability, but each has problems.

  First, there is a method of immersing a tin or tin alloy plating film in a treatment agent containing a phosphate ester or a phosphonate ester. In this method, discoloration prevention (humidity resistance) under high humidity conditions and solder wettability are provided. Is effective in preventing deterioration, but is not effective in preventing discoloration under high temperature conditions, and discoloration tends to become more prominent.

  There is also a method of immersing a tin or tin alloy plating film in a treatment agent containing phosphoric acid, phosphonic acid or condensed phosphoric acid. This method is effective in preventing discoloration (heat resistance) under high temperature conditions. However, it is not effective in preventing discoloration under high humidity conditions and preventing deterioration of solder wettability.

Japanese Patent Laid-Open No. 2005-41989 JP 2005-240093 A

  As described above, conventionally, there is only a treatment agent effective for preventing discoloration and deterioration of solder wettability only for either high humidity conditions or high temperature conditions, and there is no treatment agent effective for both conditions. It was.

  For example, with a post-treatment agent that simply mixes a phosphoric acid ester effective for high-humidity conditions and phosphoric acid or condensed phosphoric acid effective for high-temperature conditions, the adsorption to tin or tin alloy plating film is uneven. There are variations in moisture resistance and heat resistance. In this case, after processing with a processing agent effective for high-humidity conditions after processing with a processing agent effective for high-temperature conditions, or after processing with a processing agent effective for high-humidity conditions, Although it is possible to perform treatment with an effective treatment agent for high temperature conditions, two tanks are required and the performance of either moisture resistance or heat resistance deteriorates for a single treatment There is. Therefore, if a treatment agent for tin or tin alloy plating film that is effective for both high humidity conditions and high temperature conditions is developed, the tin or tin alloy plating film can be processed efficiently, and the tin or tin alloy plating film can be effectively treated. It can be expected to greatly improve reliability.

  The present invention has been made in view of the above circumstances, and with one type of treatment agent, an effect excellent in preventing discoloration and deterioration of solder wettability can be obtained for both high humidity conditions and high temperature conditions. A post-treatment agent for tin or tin alloy plating film capable of simultaneously imparting moisture resistance and heat resistance to tin or tin alloy plating film, and a method for treating tin or tin alloy plating film using the same The purpose is to do.

  As a result of intensive studies to achieve the above object, the present inventors have made polyoxyalkylene alkyl ether phosphate ester, polyoxyalkylene alkyl phenyl ether phosphate ester, polyoxyalkylene phenyl ether phosphate ester, polyoxyalkylene. One or more anionic surfactants selected from naphthyl ether phosphates, polyoxyalkylene styrenated phenyl ether phosphates and salts thereof, phosphoric acid, condensed phosphoric acid, phosphorous acid, hypoxia If a post-treatment agent containing one or more phosphoric acid compounds selected from phosphoric acid and water-soluble salts thereof is used, and this is treated by contacting with a tin or tin alloy plating film, one type Discoloration and solder wetting under both high humidity and high temperature conditions Provides excellent effect to prevent deterioration of, with respect to tin or tin alloy plating film, it found that it is possible to provide moisture resistance and heat resistance simultaneously, the present invention has been accomplished.

Accordingly, the present invention provides the following post-treatment agent for tin or tin alloy plating film and a method for treating tin or tin alloy plating film.
Claim 1:
Polyoxyalkylene alkyl ether phosphate ester, polyoxyalkylene alkyl phenyl ether phosphate ester, polyoxyalkylene phenyl ether phosphate ester, polyoxyalkylene naphthyl ether phosphate ester, polyoxyalkylene styrenated phenyl ether phosphate ester and their One or more anionic surfactants selected from salts, and one or more phosphorus selected from phosphoric acid, condensed phosphoric acid, phosphorous acid, hypophosphorous acid and their water-soluble salts A post-treatment agent for a tin or tin alloy plating film, comprising an acid compound.
Claim 2:
The post-treatment agent for a tin or tin alloy plating film according to claim 1, further comprising a nonionic surfactant.
Claim 3:
The post-treatment agent for a tin or tin alloy plating film according to claim 1 or 2, further comprising an alkylphosphonic acid, an alkylphosphonic acid ester or a salt thereof.
Claim 4:
The post-treatment agent for a tin or tin alloy plating film according to any one of claims 1 to 3, wherein the pH is 1 to 4.
Claim 5:
A processing method for a tin or tin alloy plating film, wherein the post-treatment agent according to any one of claims 1 to 4 is brought into contact with the tin or tin alloy plating film.

  According to the present invention, it is possible to suppress discoloration under high humidity conditions and high temperature conditions of tin or tin alloy plating film, deterioration of solder wettability, and it is possible to suppress discoloration due to reflow oxidation. Reliability of soldering of electronic parts can be improved.

Hereinafter, the present invention will be described in detail.
The post-treatment agent of the present invention is a treatment agent for bringing into contact with the surface of a tin or tin alloy plating film, and is a post-treatment agent for a tin or tin alloy plating film formed by plating.

The post-treatment agent of the present invention is
(A) Polyoxyalkylene alkyl ether phosphate ester, polyoxyalkylene alkyl phenyl ether phosphate ester, polyoxyalkylene phenyl ether phosphate ester, polyoxyalkylene naphthyl ether phosphate ester, polyoxyalkylene styrenated phenyl ether phosphate ester And one or more anionic surfactants selected from the salts thereof, and (B) one type selected from phosphoric acid, condensed phosphoric acid, phosphorous acid, hypophosphorous acid, and water-soluble salts thereof. Or it contains 2 or more types of phosphoric acid compounds, and is normally prepared as aqueous solution.

  (A) Component anionic surfactant polyoxyalkylene alkyl ether phosphate ester, polyoxyalkylene alkyl phenyl ether phosphate ester, polyoxyalkylene phenyl ether phosphate ester, polyoxyalkylene naphthyl ether phosphate ester, and poly Specific examples of the oxyalkylene styrenated phenyl ether phosphate ester include the following.

  (A-1) The polyoxyalkylene alkyl ether phosphate ester is preferably an alkylene group having an ethylene group, a propylene group or the like, or an alkyl group having 2 to 20 carbon atoms, such as polyoxyethylene ethyl ether. Phosphate ester, polyoxyethylene propyl ether phosphate ester, polyoxyethylene butyl ether phosphate ester, polyoxyethylene amyl ether phosphate ester, polyoxyethylene hexyl ether phosphate ester, polyoxyethylene heptyl ether phosphate ester, polyoxy Ethylene octyl ether phosphate, polyoxyethylene nonyl ether phosphate, polyoxyethylene decyl ether phosphate, polyoxyethylene undecyl ether phosphate, Reoxyethylene dodecyl ether phosphate, polyoxyethylene tridecyl ether phosphate, polyoxyethylene tetradecyl ether phosphate, polyoxyethylene pentadecyl ether phosphate, polyoxyethylene cetyl ether phosphate, polyoxy Polyoxyethylene alkyl ether phosphates such as ethylene heptadecyl ether phosphate, polyoxyethylene octadecyl ether phosphate, polyoxyethylene nonadecyl ether phosphate, polyoxyethylene aralkyl ether phosphate, polyoxypropylene ethyl Ether phosphate, polyoxypropylene propyl ether phosphate, polyoxypropylene butyl ether phosphate Polyoxypropylene amyl ether phosphate ester, polyoxypropylene hexyl ether phosphate ester, polyoxypropylene heptyl ether phosphate ester, polyoxypropylene octyl ether phosphate ester, polyoxypropylene nonyl ether phosphate ester, polyoxypropylene Decyl ether phosphate, polyoxypropylene undecyl ether phosphate, polyoxypropylene dodecyl ether phosphate, polyoxypropylene tridecyl ether phosphate, polyoxypropylene tetradecyl ether phosphate, polyoxypropylene pentadecyl Ether phosphate, polyoxypropylene cetyl ether phosphate, polyoxypropylene heptadecyl ester And polyoxypropylene alkyl ether phosphates such as -terphosphate, polyoxypropylene octadecyl ether phosphate, polyoxypropylene nonadecyl ether phosphate and polyoxypropylene aralkyl ether phosphate.

  (A-2) As the polyoxyalkylene alkylphenyl ether phosphate ester, those having an alkylene group of ethylene group, propylene group or the like and those having an alkyl group of 2 to 20 carbon atoms are suitable. For example, polyoxyethylene ethyl Phenyl ether phosphate, polyoxyethylene propyl phenyl ether phosphate, polyoxyethylene butyl phenyl ether phosphate, polyoxyethylene amyl phenyl ether phosphate, polyoxyethylene hexyl phenyl ether phosphate, polyoxyethylene heptyl Phenyl ether phosphate, polyoxyethylene octyl phenyl ether phosphate, polyoxyethylene nonylphenyl ether phosphate, polyoxyethylene decyl Ether ether phosphate, polyoxyethylene undecyl phenyl ether phosphate, polyoxyethylene dodecyl phenyl ether phosphate, polyoxyethylene tridecyl phenyl ether phosphate, polyoxyethylene tetradecyl phenyl ether phosphate, polyoxy Ethylene pentadecyl phenyl ether phosphate, polyoxyethylene cetyl phenyl ether phosphate, polyoxyethylene heptadecyl phenyl ether phosphate, polyoxyethylene octadecyl phenyl ether phosphate, polyoxyethylene nonadecyl phenyl ether phosphate , Polyoxyethylene aralkyl phenyl ether phosphate, polyoxyethylene paracumyl phenyl ester Telluric acid ester, polyoxyethylene bisphenol A ether phosphoric acid ester, polyoxyethylene alkylphenyl ether phosphoric acid ester such as polyoxyethylene bisphenol F ether phosphoric acid ester, polyoxypropylene ethyl phenyl ether phosphoric acid ester, polyoxypropylene propylphenyl Ether phosphate ester, polyoxypropylene butylphenyl ether phosphate ester, polyoxypropylene amylphenyl ether phosphate ester, polyoxypropylene hexylphenyl ether phosphate ester, polyoxypropylene heptylphenyl ether phosphate ester, polyoxypropylene octylphenyl ester Ether phosphate, polyoxypropylene nonylphenyl ether phosphate , Polyoxypropylene decyl phenyl ether phosphate ester, polyoxypropylene undecyl phenyl ether phosphate ester, polyoxypropylene dodecyl phenyl ether phosphate ester, polyoxypropylene tridecyl phenyl ether phosphate ester, polyoxypropylene tetradecyl phenyl ether Phosphate ester, polyoxypropylene pentadecyl phenyl ether phosphate ester, polyoxypropylene cetyl phenyl ether phosphate ester, polyoxypropylene heptadecyl phenyl ether phosphate ester, polyoxypropylene octadecyl phenyl ether phosphate ester, polyoxypropylene nona Decyl phenyl ether phosphate, polyoxypropylene aralkyl phenyl ether Esters, polyoxypropylene para cumyl phenyl ether phosphate, polyoxypropylene bisphenol A ether phosphate, polyoxypropylene bisphenol F ether polyoxypropylene alkyl phenyl ether phosphoric acid esters and phosphoric acid esters.

  (A-3) Examples of the polyoxyalkylene phenyl ether phosphate ester include polyoxyethylene phenyl ether phosphate ester and polyoxypropylene phenyl ether phosphate ester.

  (A-4) As polyoxyalkylene naphthyl ether phosphate, polyoxyethylene naphthyl ether phosphate such as polyoxyethylene α-naphthyl ether phosphate, polyoxyethylene β-naphthyl ether phosphate, polyoxyethylene And polyoxypropylene naphthyl ether phosphates such as propylene α-naphthyl ether phosphate and polyoxypropylene β-naphthyl ether phosphate.

  Examples of (A-5) polyoxyalkylene styrenated phenyl ether phosphate esters include polyoxyethylene styrenated phenyl ether phosphate esters and polyoxypropylene styrenated phenyl ether phosphate esters.

  The polyoxyalkylene groups (polyoxyethylene group, polyoxypropylene group, etc.) of these phosphate esters are preferably those having 2-19 alkylene oxides (ethylene oxide, propylene oxide, etc.) added thereto. Examples of these phosphate esters include sodium salts, potassium salts, and ammonium salts.

  The concentration of the component (A) in the aftertreatment agent of the anionic surfactant is preferably 0.1 to 100 g / L, particularly preferably 0.5 to 10 g / L. If it is less than 0.1 g / L, sufficient moisture resistance may not be obtained in the treated tin or tin alloy plating film. In particular, it is preferably 0.5 g / L or more because high moisture resistance can be obtained. On the other hand, if it exceeds 100 g / L, moisture resistance is obtained, but it is too costly and uneconomical, and because of the high concentration, the viscosity of the post-treatment agent becomes high, and after treatment with the post-treatment agent There is a possibility that the excess components cannot be washed with water.

  As phosphoric acid, condensed phosphoric acid, phosphorous acid and hypophosphorous acid of the phosphoric acid compound of component (B), phosphoric acid (orthophosphoric acid), pyrophosphoric acid, polyphosphoric acid (metaphosphoric acid), phosphorous acid (phosphonic acid) ) And hypophosphorous acid (phosphinic acid). Examples of water-soluble salts of these phosphoric acid compounds include sodium salts, potassium salts, and ammonium salts.

  The concentration of the component (B) in the post-treatment agent of the phosphate compound is preferably 0.1 to 100 g / L, more preferably 0.5 to 10 g / L. If it is less than 0.1 g / L, sufficient heat resistance may not be obtained for the treated tin or tin alloy plating film. In particular, it is preferably 0.5 g / L or more because high heat resistance can be obtained. On the other hand, if it exceeds 100 g / L, heat resistance is obtained, but it is too costly and uneconomical, and depending on the plating film, the surface may be etched (roughened).

  The post-treatment agent of the present invention preferably further contains (C) a nonionic surfactant. The addition of these nonionic surfactants is used as a solvent for dissolving the anionic surfactant of the component (A), and when processing a tin or tin alloy plating film on a complex-shaped object to be plated. It is effective for improving the permeability of the post-treatment agent. Specific examples of the nonionic surfactant of component (C) include the following.

  (C-1) As the polyoxyalkylene alkyl ether, those having an alkylene group of ethylene group, propylene group or the like and those having an alkyl group of 2 to 20 carbon atoms are suitable. For example, polyoxyethylene ethyl ether, polyoxy Ethylenepropyl ether, polyoxyethylene butyl ether, polyoxyethylene amyl ether, polyoxyethylene hexyl ether, polyoxyethylene heptyl ether, polyoxyethylene octyl ether, polyoxyethylene nonyl ether, polyoxyethylene decyl ether, polyoxyethylene undecyl Ether, polyoxyethylene dodecyl ether, polyoxyethylene tridecyl ether, polyoxyethylene tetradecyl ether, polyoxyethylene pentadecyl ether, Polyoxyethylene alkyl ethers such as reoxyethylene cetyl ether, polyoxyethylene heptadecyl ether, polyoxyethylene octadecyl ether, polyoxyethylene nonadecyl ether, polyoxyethylene aralkyl ether, polyoxypropylene ethyl ether, polyoxypropylene propyl ether , Polyoxypropylene butyl ether, polyoxypropylene amyl ether, polyoxypropylene hexyl ether, polyoxypropylene heptyl ether, polyoxypropylene octyl ether, polyoxypropylene nonyl ether, polyoxypropylene decyl ether, polyoxypropylene undecyl ether, poly Oxypropylene dodecyl ether, polyoxypropylene tridecyl Poly, such as ether, polyoxypropylene tetradecyl ether, polyoxypropylene pentadecyl ether, polyoxypropylene cetyl ether, polyoxypropylene heptadecyl ether, polyoxypropylene octadecyl ether, polyoxypropylene nonadecyl ether, polyoxypropylene aralkyl ether Examples thereof include oxypropylene alkyl ether.

  (C-2) As polyoxyalkylene alkyl phenyl ethers, those having an alkylene group of ethylene group, propylene group, etc., and those having an alkyl group of 2 to 20 carbon atoms are suitable. For example, polyoxyethylene ethyl phenyl ether, Polyoxyethylene propyl phenyl ether, polyoxyethylene butyl phenyl ether, polyoxyethylene amyl phenyl ether, polyoxyethylene hexyl phenyl ether, polyoxyethylene heptyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether, poly Oxyethylene decyl phenyl ether, polyoxyethylene isodecyl phenyl ether, polyoxyethylene undecyl phenyl ether, polyoxyethylene Silphenyl ether, polyoxyethylene tridecyl phenyl ether, polyoxyethylene tetradecyl phenyl ether, polyoxyethylene pentadecyl phenyl ether, polyoxyethylene cetyl phenyl ether, polyoxyethylene heptadecyl phenyl ether, polyoxyethylene octadecyl phenyl ether, Polyoxyethylene alkyl phenyl ethers such as polyoxyethylene nonadecyl phenyl ether, polyoxyethylene aralkyl phenyl ether, polyoxyethylene paracumyl phenyl ether, polyoxyethylene bisphenol A ether, polyoxyethylene bisphenol F ether, polyoxypropylene ethyl Phenyl ether, polyoxypropylene propyl phenyl ether, poly Oxypropylene butyl phenyl ether, polyoxypropylene amyl phenyl ether, polyoxypropylene hexyl phenyl ether, polyoxypropylene heptyl phenyl ether, polyoxypropylene octyl phenyl ether, polyoxypropylene nonyl phenyl ether, polyoxypropylene decyl phenyl ether, polyoxy Propylene undecyl phenyl ether, polyoxypropylene dodecyl phenyl ether, polyoxypropylene tridecyl phenyl ether, polyoxypropylene tetradecyl phenyl ether, polyoxypropylene pentadecyl phenyl ether, polyoxypropylene cetyl phenyl ether, polyoxypropylene heptadecyl phenyl Ether, polyoxypropylene Polyoxypropylene alkyl phenyl ethers such as octadecyl phenyl ether, polyoxypropylene nonadecyl phenyl ether, polyoxypropylene aralkyl phenyl ether, polyoxypropylene paracumyl phenyl ether, polyoxypropylene bisphenol A ether, polyoxypropylene bisphenol F ether, etc. Is mentioned.

  Examples of (C-3) polyoxyalkylene phenyl ether include polyoxyethylene phenyl ether and polyoxypropylene phenyl ether.

  (C-4) As polyoxyalkylene naphthyl ether, polyoxyethylene α-naphthyl ether, polyoxyethylene naphthyl ether such as polyoxyethylene β-naphthyl ether, polyoxypropylene α-naphthyl ether, polyoxypropylene β-naphthyl Examples thereof include polyoxypropylene naphthyl ether such as ether.

Examples of (C-5) polyoxyalkylene styrenated phenyl ether include polyoxyethylene styrenated phenyl ether and polyoxypropylene styrenated phenyl ether.

  Also, polyoxyethylene oleyl ether, polyoxyethylene oleyl cetyl ether, polyoxyethylene stearyl ether, polyoxypropylene stearyl ether, polyoxyethylene polyoxypropylene glycol, polyoxyethylene-polyoxypropylene block copolymer, ethylenediamine type polyoxyethylene -Polyoxypropylene block copolymers can also be mentioned. A nonionic surfactant can be used individually by 1 type or in combination of 2 or more types. The polyoxyalkylene group (polyoxyethylene group, polyoxypropylene group, etc.) of these nonionic surfactants is preferably one having 2-30 alkylene oxides (ethylene oxide, propylene oxide, etc.) added thereto.

  The concentration of the component (C) in the post-treatment agent of the nonionic surfactant is preferably 0.1 to 200 g / L, particularly preferably 0.2 to 20 g / L. If it is less than 0.1 g / L, there exists a possibility that melt | dissolution of the anionic surfactant of (A) component cannot fully be promoted. On the other hand, if it exceeds 200 g / L, it is too costly and uneconomical, and because of the high concentration, the viscosity of the post-treatment agent becomes high, and excess components are removed by washing with water after treating with the post-treatment agent. There is a risk that it cannot be washed.

  The amount of the nonionic surfactant of component (C) is adjusted according to the amount of the anionic surfactant of component (A), and is 1 time (mass ratio) or more of the anionic surfactant of component (A). In particular, it is preferable to add twice or more (mass ratio). The upper limit of this ratio is not particularly limited, but is usually 10 times (mass ratio) or less.

  The post-treatment agent of the present invention preferably further contains (D) an alkylphosphonic acid, an alkylphosphonic acid ester, or a salt thereof. Addition of alkyl phosphonic acid, alkyl phosphonic acid ester or a salt thereof is effective in improving the moisture resistance to the tin or tin alloy plating film. The alkylphosphonic acid ester of component (D) includes alkylphosphonic acid monoalkyl esters and alkylphosphonic acid dialkyl esters, and each alkyl group of alkylphosphonic acid and alkylphosphonic acid ester has 1 to 20 carbon atoms, in particular 1-18 are preferred, and specifically, hexylphosphonic acid, heptylphosphonic acid, octylphosphonic acid, nonylphosphonic acid, decylphosphonic acid, undecylphosphonic acid, dodecylphosphonic acid, tridecylphosphonic acid, tetradecylphosphonic acid Examples thereof include acids, pentadecylphosphonic acid, dimethyloctadecylphosphonic acid ester, laurylphosphonic acid ester, and salts thereof. This salt is a water-soluble salt and includes sodium salt, potassium salt, ammonium salt and the like.

  The concentration of the component (D) in the post-treatment agent of alkylphosphonic acid, alkylphosphonic acid ester or salt thereof is preferably 0.01 to 50 g / L, particularly preferably 0.1 to 10 g / L. If it is less than 0.01 g / L, there is a possibility that the effect of improving moisture resistance due to the addition cannot be obtained. On the other hand, when it exceeds 50 g / L, heat resistance may be reduced. Moreover, there is a possibility that the viscosity of the post-treatment agent is increased and poor washing is caused.

  The pH of the post-treatment agent of the present invention is preferably 1 to 4, particularly 1.5 to 3. In particular, pH adjustment may be necessary in the case of using a salt for the anionic surfactant (A) or the phosphate compound (B). Examples of the pH adjuster include sulfuric acid, alkanesulfonic acid having 1 to 6 carbon atoms, sodium hydroxide, potassium hydroxide, ammonia, monoethanolamine, and triethanolamine.

  By treating the surface of the tin or tin alloy plating film formed by electroplating or electroless plating with the post-treatment agent of the present invention, high humidity conditions (typically 85 ° C.-85% RH, 105 ° C.-100% RH) or high temperature conditions (typically 175 ° C., 260 ° C., etc.), deterioration of solder wettability, discoloration due to reflow oxidation, and the like can be suppressed.

  In the tin or tin alloy plating film targeted by the post-treatment agent of the present invention, the tin alloy includes tin-copper, tin-silver, tin-bismuth, tin-lead, tin-nickel, tin-silver-copper, and the like. Can be mentioned. In the tin alloy, the content of metals other than tin is preferably 50% by mass or less, particularly 0.1 to 20% by mass.

  In the treatment of the tin or tin alloy plating film with the post-treatment agent of the present invention, for example, the tin or tin alloy plating film may be brought into contact with the post-treatment agent by a method such as immersion. The treatment temperature is preferably 10 to 50 ° C, particularly 20 to 40 ° C. The processing time is usually 1 to 120 seconds, and 5 to 30 seconds is particularly preferable.

The treatment of tin or tin alloy plating film using the post-treatment agent of the present invention has the following advantages.
-By simply changing the neutralization treatment with sodium phosphate, which is a conventional post-treatment of tin or tin alloy plating film, to the treatment with the post-treatment agent of the present invention, it is always necessary to increase the number of treatment steps and special equipment. There is no need to expand the system.
-The effect on the moisture resistance and heat resistance of the treatment temperature in the treatment with the post-treatment agent is small.
-Since the anionic surfactant of the component (A) and the phosphate compound of the component (B) have a pH buffering action, management is relatively easy even if the pH management range is narrow.
-By the treatment with the post-treatment agent of the present invention, surface oxidation of the tin or tin alloy plating film can be prevented, and solder mounting at a lower temperature becomes possible.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example.

[Examples 1 to 23, Comparative Examples 1 to 13]
For the following evaluation samples A and B on which a tin plating film was formed, the post-treatment agent shown in Tables 3 to 5 was used, and each tin plating film was processed under the processing conditions shown in Tables 3 to 5. The heat resistance and moisture resistance of the treated tin plating film were evaluated under the conditions of Tests 1 to 4.

The copper alloy material (C194) lead frame (surface area 0.245 dm ² ) is subjected to the following treatment (1) in order, and the evaluation sample A is subjected to the following treatment (2) in order, and the evaluation sample B is respectively performed. Got ready.
[Evaluation Sample A]
Treatment (1): Electrolytic degreasing → Washing → Pickling → Washing → Etching (dipping treatment) → Washing → Pickling → Tin plating → Washing → Treatment with post-treatment agents in Tables 3-5 (dipping treatment) → Washing → Ion exchange Water washing → drying [Evaluation sample B]
Treatment (2): Electrolytic degreasing → Washing → Pickling → Washing → Etching (dipping treatment) → Washing → Sulphamine nickel plating → Pickling → Tin plating → Washing → Treatment with a post-treatment agent in Tables 3 to 5 (dipping treatment) → Washing → Washing with ion exchange water → Drying

The tin plating bath used for the tin plating of the treatment (1) and the treatment (2) and the sulfamine nickel plating bath used for the sulfamine nickel plating of the treatment (2) are shown below. These plating conditions are shown in Table 1.
[Tin plating bath]
Tin (II) methanesulfonate 90g / L (50g / L as Sn)
70% methanesulfonic acid 135g / L
Nonionic surfactant (polyoxyethylene polyoxypropylene glycol) 5g / L
[Sulfamin nickel plating bath]
Nickel (II) amidosulfate tetrahydrate 300g / L
Nickel (II) chloride hexahydrate 15g / L
Boric acid 30g / L

Test 1: Evaluation sample A was treated with PCT8 in Examples 1-21 and Comparative Examples 1-13 (8 hours in a thermostatic bath held at 105 ° C.-100% RH), and Examples 22 and 23 were treated with PCT24 ( The temperature was kept in a thermostat kept at 105 ° C.-100% RH for 24 hours), and the degree of discoloration was visually confirmed.
Test 2: Evaluation sample A was subjected to PCT8 treatment (maintained in a thermostatic bath maintained at 105 ° C.-100% RH for 8 hours), and the solder wettability (zero cross time) was measured by a meniscograph method. For evaluation of solder wettability, lead-free solder (tin: silver: copper = 96.5: 3.0: 0.5 (mass ratio)) was used, the heating temperature was 235 ° C., and the flux was NA-200 ( Tamura Kaken, inert rosin type) was used.
Test 3: The evaluation sample B was heated twice on a 260 ° C. hot plate for 2 minutes, and the degree of discoloration due to heat was visually confirmed.
Test 4: Evaluation sample A was heated in an oven maintained at 175 ° C. for 48 hours, and the degree of discoloration due to heat was visually confirmed.
The evaluation results are shown in Tables 3 to 5 according to the criteria shown in Table 2.

Claims (5)

  Polyoxyalkylene alkyl ether phosphate ester, polyoxyalkylene alkyl phenyl ether phosphate ester, polyoxyalkylene phenyl ether phosphate ester, polyoxyalkylene naphthyl ether phosphate ester, polyoxyalkylene styrenated phenyl ether phosphate ester and their One or more anionic surfactants selected from salts, and one or more phosphorus selected from phosphoric acid, condensed phosphoric acid, phosphorous acid, hypophosphorous acid and their water-soluble salts A post-treatment agent for a tin or tin alloy plating film, comprising an acid compound.   The post-treatment agent for a tin or tin alloy plating film according to claim 1, further comprising a nonionic surfactant.   The post-treatment agent for a tin or tin alloy plating film according to claim 1 or 2, further comprising an alkylphosphonic acid, an alkylphosphonic acid ester or a salt thereof.   The post-treatment agent for a tin or tin alloy plating film according to any one of claims 1 to 3, wherein the pH is 1 to 4.   A processing method for a tin or tin alloy plating film, wherein the post-treatment agent according to any one of claims 1 to 4 is brought into contact with the tin or tin alloy plating film.