Combined stress agent onset auxiliary agent and application thereof

Abstract

The invention belongs to the technical field of additives for electroplating solutions, and particularly relates to a combined stress agent onset auxiliary agent and application thereof. The combined stress agent onset auxiliary agent is propane sulfonic acid pyridinium salt or a derivative thereof, and the propane sulfonic acid pyridinium salt derivative is characterized in that a pyridine ring contains at least one substituent group. The method is used for the palladium or palladium alloy bath-building electroplating liquid. According to the technical scheme provided by the invention, the stress of all samples produced after bath building of the plating solution can be always maintained within-20Mpa to 20Mpa by adding a small amount of the effective auxiliary agent, so that the process requirements are met; the palladium-cobalt ratio, the hardness, the modulus and the morphology of the plating layer are not changed; and the service life of the plating solution is not shortened and is still about 1.5 MTO, so that the plating solution is stable.

Description

Technical Field

[0001] This invention belongs to the technical field of additives for electroplating solutions, specifically relating to a combined stress-reducing agent and its application. Background Technology

[0002] Stress control has always been a challenge for palladium or palladium alloys due to severe lattice distortion. In Chinese patent CN119615310A, the applicant provides a combined stress agent that significantly improves the stress of palladium-cobalt alloys and achieves excellent overall stress control.

[0003] However, when using combined stress agents in a newly built electroplating bath, the initial electroplating samples often fail to meet stress standards and must be scrapped, resulting in low overall efficiency of electroplating production and unnecessary losses of both machine time and samples.

[0004] The inventors tried adjusting the amount of stress agent added and electroplating parameters, but failed to solve the problem of substandard stress in the initial samples. They speculated that this was because the stress agent in the newly prepared plating bath could not take effect immediately. Later, they tried adding some auxiliary agents, which perfectly solved the defect of the combined stress agent not taking effect in the early stages. Summary of the Invention

[0005] This invention provides an auxiliary agent for the activation of combined stress agents and a method of application, in order to solve the technical problem of combined stress agents not being effective in the early stage.

[0006] To solve the above-mentioned technical problems, the present invention provides a combined stress agent activation aid, wherein the combined stress agent includes component A as one or more of benzenesulfonic acid and benzenesulfonic acid derivatives, wherein the derivatives refer to aromatic rings containing at least one substituent and / or a corresponding salt;

[0007] Component B is selected from one or more compounds as shown in molecular formula I;

[0008] (I)

[0009] Wherein, R1 is selected from hydroxyl, alkyl substituted with at least one hydroxyl and / or amino, alkoxy substituted with at least one hydroxyl, amino, amino substituted with at least one alkyl, and amino substituted with at least one hydroxyl and one alkyl.

[0010] R2 is selected from hydrogen, alkyl, hydroxyl, or alkyl substituted with at least one hydroxyl group, or alkoxy substituted with at least one hydroxyl group;

[0011] The C component is selected from one or more of phosphites, hypophosphites, metaphosphites, nitrites, sulfites, and selenites;

[0012] The combined stress agent activation aid is pyridinium propane sulfonate or its derivative, wherein the pyridinium propane sulfonate derivative refers to a compound containing at least one substituent on the pyridine ring.

[0013] The pyridinium propane sulfonate or its derivatives contain both positively charged pyridinium cations and negatively charged sulfonate anions, resulting in a net charge of zero but a strong dipole moment. Due to its unique zwitterionic structure, it establishes a stable adsorption layer in the early stages of electroplating, effectively stabilizing the electric double layer and thus guiding the adsorption of stress-regulating agents on the cathode.

[0014] Optionally, the auxiliary agent is a compound of general formula (II).

[0015]

[0016] A1, A2, A3, A4 and A5 are each independently selected from alkyl or hydroxyl groups.

[0017] Optionally, the adjuvant is selected from... , , or .

[0018] Optionally, component A is selected from... or its salt, or its salt, or its salt, or its salt, or its salt, or its salt, or its salt, or Or its salt.

[0019] Optionally, the compound of formula I is selected from... , , , , , , , or .

[0020] The present invention also provides a palladium or palladium alloy electroplating bath, which includes palladium salt, a combined stress agent, an activating agent for the combined stress agent, and water.

[0021] Optionally, the palladium or palladium alloy plating bath further includes cobalt salts and complexing agents.

[0022] Optionally, the palladium or palladium alloy electroplating bath further includes conductive salts and surfactants.

[0023] Optionally, the total concentration of the combined stress agent is 2-12 g / L, and the concentration of the combined stress agent activation aid is 1 mg / L-1 g / L, preferably 0.05-0.5 g / L.

[0024] Optionally, in the combined stress agent, the ratio of component A, component B and component C by weight is (40-250):1:(4-200).

[0025] Optionally, the palladium or palladium alloy electroplating bath solution is prepared by first dissolving all components except the combined stress agent and the combined stress agent activation aid in water, then adding the combined stress agent, and finally adding the combined stress agent activation aid, mixing and adjusting the volume, and using the solution after it has become clear and stood for 12-24 hours.

[0026] Optionally, the palladium salt is first dissolved in an ammonia solution before being added to the plating solution.

[0027] Optionally, the cobalt salt is first dissolved in water with a complexing agent before being added to the plating solution.

[0028] The technical solution provided by this invention can maintain the stress of all samples produced after the plating bath is built up within -20Mpa to 20Mpa by adding a small amount of active additives, thus meeting the process requirements; the palladium-cobalt ratio, hardness, modulus and morphology of the coating do not change; and the life of the plating bath is not shortened, but is still around 1.5MTO, and the plating bath is stable. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0030] Example 1

[0031] A palladium-cobalt alloy electroplating bath contains the following components by weight-volume concentration:

[0032] Palladium salt: Palladium chloride 20 g / L;

[0033] Cobalt salt: Cobalt chloride 6 g / L;

[0034] Complexing agent: Ammonium glycine 20 g / L;

[0035] Conductive salt: Potassium sulfate 5 g / L;

[0036] Surfactant: Sodium dodecyl sulfate 0.02 g / L;

[0037] Component A: 4 g / L;

[0038] Component B: 0.03 g / L;

[0039] Component C: Sodium phosphite 0.5 g / L;

[0040] Combined stress-relieving agent activation aids: 0.2g / L;

[0041] PH: 7.

[0042] The preparation process of the palladium-cobalt alloy electroplating bath is as follows: Dissolve and stir the cobalt salt and complexing agent until they are uniformly mixed (to prevent cobalt salt hydrolysis). Then add the palladium salt ammonia solution (the palladium salt must first be dissolved in a weakly alkaline ammonia solution with pH=8 to prevent palladium salt hydrolysis). Next, add all components except the combined stress agent and the combined stress agent activation aid. Stir and sonicate until completely dissolved. Finally, add the combined stress agent and the combined stress agent activation aid in sequence, stirring and sonicating until completely dissolved. The solution should be clear and transparent. Let the plating bath stand at room temperature for one day before electroplating. During this time, all components in the plating bath will have reached a stable state, the metal complex will be stable, and the additives will be stable and dispersed.

[0043] Electroplating is performed using the following steps:

[0044] Step (1) Perform alkaline degreasing, Plasma cleaning and / or acid activation treatment on the plated parts;

[0045] Step (2) Place the workpiece and the anode plate facing each other in the plating solution. The area of ​​the anode plate is similar to that of the workpiece. The anode plate can be a platinum plate, platinum mesh, platinum titanium plate or platinum titanium mesh.

[0046] Step (3) Connect the power supply, set the current parameters according to the electroplating area of ​​the workpiece, set the electroplating time according to the required plating thickness, and carry out electroplating.

[0047] Step (4) After electroplating is completed, clean the plated parts with deionized water and check the quality of the plating layer.

[0048] The current density in this embodiment is 1A / dm². 2 The electroplating temperature is 45℃.

[0049] Performance testing:

[0050] Ten plates were electroplated, and the stress, palladium-cobalt ratio, hardness, and modulus of the 1st, 2nd, 3rd, 5th, and 10th samples were tested sequentially.

[0051] 1. Stress Testing: The anode was a platinum-titanium plate. Stress analysis of the plating was performed using a 1194UDF test piece manufactured by SPECIALTY TESTING & DEVELOPMENT COMPANY, and the stress value was calculated using a formula. Before use, the test piece was cleaned with a mild, non-alkaline detergent, rinsed with water, then immersed in a 10% sulfuric acid solution for 30 seconds, and finally rinsed with water again. The test piece was fixed so that its two legs were parallel to the anode and equidistant. Magnetic stirring was used during the electroplating process. The test results were 5 MPa, 0 MPa, 3 MPa, 10 MPa, and 8 MPa, respectively.

[0052] 2. Palladium-cobalt ratio test: The composition of the coating was characterized and analyzed by energy dispersive spectroscopy (EDS) of scanning electron microscope (SEM). The test results were 78:22, 81:19, 81:19, 80:20, and 78:22, respectively.

[0053] 3. Hardness test: The hardness of the sample was tested using a nano-indentation instrument. The test results were 581HV, 570HV, 603HV, 592HV, and 610HV, respectively.

[0054] 4. Modulus test: The modulus of the samples was tested using a nanoindentation instrument. The test results were 140 GPa, 135 GPa, 142 GPa, 150 GPa, and 145 GPa, respectively.

[0055] 5. Plating solution life: Failure criterion: Plating stress exceeding -20 MPa to 20 MPa; test result is 1.65 MTO.

[0056] Example 2

[0057] Palladium salt: Palladium chloride 30 g / L;

[0058] Conductive salt: Potassium sulfate 8 g / L;

[0059] Surfactant: Sodium dodecyl sulfate 0.02 g / L;

[0060] Component A: 4 g / L;

[0061] Component B: 0.03 g / L;

[0062] Component C: Sodium phosphite 0.5 g / L;

[0063] Combined stress-relieving agent activation aids: 0.2g / L;

[0064] PH: 7.

[0065] The preparation process of the palladium alloy electroplating bath is described in Example 1. The current density in this example is 1 A / dm²; the electroplating temperature is 45°C.

[0066] Performance testing: See Example 1 for testing methods.

[0067] Ten samples were electroplated, and the stress, hardness, modulus, and plating solution life of the 1st, 2nd, 3rd, 5th, and 10th samples were tested sequentially.

[0068] 1. The stress test results were 15 MPa, 19 MPa, 10 MPa, 12 MPa, and 5 MPa, respectively.

[0069] 2. The hardness test results were 610HV, 595HV, 639HV, 631HV, and 629HV, respectively.

[0070] 3. The modulus test results were 139 GPa, 142 GPa, 140 GPa, 136 GPa, and 144 GPa, respectively.

[0071] 4. Plating solution life: 1.61 MTO.

[0072] Example 3

[0073] A palladium-cobalt alloy electroplating bath contains the following components by weight-volume concentration:

[0074] Palladium salt: Palladium sulfate 30 g / L;

[0075] Cobalt salt: Cobalt sulfate 10 g / L;

[0076] Complexing agent: Ammonium acetate 100 g / L;

[0077] Conductive salt: Potassium sulfate 0.5 g / L;

[0078] Surfactant: Sodium hexadecyl sulfate, concentration 0.05 g / L;

[0079] Component A: 5 g / L

[0080] Component B: 0.05 g / L

[0081] Component C: Potassium hypophosphite 0.2 g / L;

[0082] Combined stress-relieving agent activation aids: 0.05g / L;

[0083] pH: 7.5.

[0084] The preparation process for the palladium-cobalt alloy electroplating bath is described in Example 1. The current density in this example is 0.5 A / dm³. 2The electroplating temperature is 30℃.

[0085] Performance testing: See Example 1 for testing methods.

[0086] Ten plates were electroplated, and the stress, palladium-cobalt ratio, hardness, and modulus of the 1st, 2nd, 3rd, 5th, and 10th samples were tested sequentially.

[0087] 1. The stress test results were 0 MPa, -3 MPa, -6 MPa, 3 MPa, and 10 MPa, respectively.

[0088] 2. The palladium-cobalt ratio test results were 73:27, 75:25, 78:22, 79:21, and 80:20, respectively;

[0089] 3. The hardness test results were 629HV, 591HV, 649HV, 627HV, and 601HV, respectively.

[0090] 4. The modulus test results were 143 GPa, 134 GPa, 138 GPa, 145 GPa, and 135 GPa, respectively.

[0091] 5. Plating solution life: 1.55 MTO.

[0092] Example 4

[0093] A palladium-cobalt alloy electroplating bath contains the following components by weight-volume concentration:

[0094] Palladium salt: Dichlorotetraamminepalladium 16 g / L;

[0095] Cobalt salt: Cobalt sulfate 6 g / L;

[0096] Complexing agent: Sodium citrate 30 g / L;

[0097] Conductive salt: Potassium propionate 6 g / L;

[0098] Surfactant: Dodecylphenol polyoxyethylene ether, concentration 0.1 g / L

[0099] Component A: 10 g / L

[0100] Component B: 0.1g / L;

[0101] Component C: Sodium sulfite 1g / L;

[0102] Combined stress-relieving agent activation aids: 0.5g / L;

[0103] PH: 8.

[0104] The preparation process for the palladium-cobalt alloy electroplating bath is described in Example 1. The current density in this example is 3 A / dm³. 2 The electroplating temperature is 60℃.

[0105] Performance testing: See Example 1 for testing methods.

[0106] Ten plates were electroplated, and the stress, palladium-cobalt ratio, hardness, modulus, and plating bath life of the 1st, 2nd, 3rd, 5th, and 10th samples were tested sequentially.

[0107] 1. The stress test results were 2 MPa, 12 MPa, 7 MPa, -1 MPa, and -8 MPa, respectively.

[0108] 2. The palladium-cobalt ratio test results were 73:27, 77:23, 82:18, 79:21, and 84:16, respectively;

[0109] 3. The hardness test results were 657HV, 602HV, 602HV, 561HV, and 606HV, respectively.

[0110] 4. The modulus test results were 157 GPa, 148 GPa, 149 GPa, 151 GPa, and 159 GPa, respectively.

[0111] Plating solution life: 1.53 MTO.

[0112] Comparative Example 1

[0113] The difference from Example 1 is that it does not contain the combined stress agent activation aid.

[0114] Performance testing: See Example 1 for testing methods.

[0115] Ten plates were electroplated, and the stress, palladium-cobalt ratio, hardness, modulus, and plating bath life of the 1st, 2nd, 3rd, 5th, and 10th samples were tested sequentially.

[0116] 1. The stress test results were 95 MPa, 63 MPa, 32 MPa, 21 MPa, and 11 MPa, respectively.

[0117] 2. The palladium-cobalt ratio test results were 73:27, 76:24, 84:16, 83:17, and 81:19, respectively;

[0118] 3. The hardness test results were 657HV, 602HV, 602HV, 561HV, and 606HV, respectively.

[0119] 4. The modulus test results were 157 GPa, 148 GPa, 149 GPa, 151 GPa, and 159 GPa, respectively.

[0120] 5. Plating solution life: 1.48 MTO.

[0121] Comparative Example 2

[0122] The difference from Example 2 is that it does not contain the combined stress agent activation aid.

[0123] Performance testing: See Example 1 for testing methods.

[0124] Ten plates were electroplated, and the stress, palladium-cobalt ratio, hardness, modulus, and plating bath life of the 1st, 2nd, 3rd, 5th, and 10th samples were tested sequentially.

[0125] 1. The stress test results were 152 MPa, 102 MPa, 62 MPa, 44 MPa, and 15 MPa, respectively.

[0126] 2. The palladium-cobalt ratio test results were 70:30, 76:24, 77:23, 76:24, and 77:23, respectively;

[0127] 3. The hardness test results were 607HV, 561HV, 615HV, 588HV, and 605HV, respectively.

[0128] 4. The modulus test results were 157 GPa, 148 GPa, 149 GPa, 151 GPa, and 159 GPa, respectively.

[0129] Plating solution life: 1.35 MTO.

[0130] Comparative Example 3

[0131] The difference from Example 1 is that the current density in this comparative example is 2 A / dm². 2 The electroplating temperature is 45℃.

[0132] Performance testing:

[0133] Ten electroplated pieces were tested, and the stress of the 1st, 2nd, 3rd, 5th and 10th samples was tested in sequence. The test results were 101 MPa, 79 MPa, 48 MPa, 41 MPa and 17 MPa, respectively.

[0134] Comparative Example 4

[0135] The difference from Example 1 is that the concentration of the combined stress agent activation aid is 0.01 g / L.

[0136] Performance testing

[0137] Ten electroplated pieces were tested, and the stress of the 1st, 2nd, 3rd, 5th and 10th samples was tested in sequence. The test results were 55 MPa, 48 MPa, 30 MPa, 18 MPa and 8 MPa, respectively.

[0138] Comparative Example 5

[0139] The difference from Example 1 is that the concentration of the combined stress agent activation aid is 0.8 g / L.

[0140] Performance testing

[0141] Ten electroplated pieces were tested, and the stress of the 1st, 2nd, 3rd, 5th and 10th samples was tested in sequence. The test results were 185 MPa, 143 MPa, 120 MPa, 88 MPa and 48 MPa, respectively.

[0142] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein, and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A combined stress agent activation aid, wherein the combined stress agent comprises component A being one or more of benzenesulfonic acid and benzenesulfonic acid derivatives, wherein the derivatives refer to aromatic rings containing at least one substituent and / or a corresponding salt; Component B is selected from one or more compounds as shown in molecular formula I; (I) in, R1 is selected from hydroxyl, alkyl group substituted with at least one hydroxyl and / or amino group, alkoxy group substituted with at least one hydroxyl, amino group, amino group substituted with at least one alkyl group, and amino group substituted with at least one hydroxyl and one alkyl group. R2 is selected from hydrogen, alkyl, hydroxyl, or alkyl substituted with at least one hydroxyl group, or alkoxy substituted with at least one hydroxyl group; The C component is selected from one or more of phosphites, hypophosphites, metaphosphites, nitrites, sulfites, and selenites; The characteristic feature is that the combined stress agent activation aid is pyridinium propane sulfonate or its derivative, wherein the pyridinium propane sulfonate derivative refers to having at least one substituent on the pyridine ring.

2. The combined stress-relieving agent activation aid according to claim 1, characterized in that, The auxiliary agent is a compound of general formula (II). A1, A2, A3, A4 and A5 are each independently selected from alkyl or hydroxyl groups.

3. The combined stress-relieving agent activation aid according to claim 2, characterized in that, The auxiliary agent is selected from , , or .

4. A palladium or palladium alloy electroplating bath, characterized in that, It includes palladium salt, combined stress agent, combined stress agent activation aid and water.

5. The palladium or palladium alloy plating bath according to claim 4, characterized in that, The palladium or palladium alloy electroplating bath also includes cobalt salts and complexing agents.

6. The palladium or palladium alloy plating bath according to claim 4, characterized in that, The total concentration of the combined stress agent is 2-12 g / L, and the concentration of the combined stress agent activation aid is 1 mg / L-1 g / L, preferably 0.05-0.5 g / L.

7. The palladium or palladium alloy plating bath according to claim 6, characterized in that, In the combined stress agent, the ratio of component A, component B and component C by weight is (40-250):1:(4-200).

8. The palladium or palladium alloy electroplating bath according to claim 4, characterized in that, The palladium or palladium alloy electroplating bath solution is prepared by first dissolving all components except the combined stress agent and the combined stress agent activation aid in water, then adding the combined stress agent, and finally adding the combined stress agent activation aid. The solution is then mixed and brought to a final volume. After the solution has clarified and been left to stand for 12-24 hours, it is ready for use.

9. The palladium or palladium alloy plating bath according to claim 4, characterized in that, The palladium salt is first dissolved in an ammonia solution and then added to the plating solution.

10. The palladium or palladium alloy plating bath according to claim 4, characterized in that, The palladium or palladium alloy electroplating bath also includes conductive salts and surfactants.

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