AurumEX HG-01

1. Introduction

AurumEX HG-01 is a newly developed, specially formulated acidic gold plating solution designed for both barrel and rack plating processes, as well as hard gold electroplating. The deposited gold-cobalt alloy offers exceptional brightness, high hardness, superior wear resistance, and excellent corrosion resistance, making it ideal for:

● Connectors

● Lead frames

● IC card reel-to-reel plating

Key Advantages

● Suppresses gold displacement on nickel layers, minimizing unnecessary gold deposition.

● Significantly reduces gold consumption in non-target areas, plating tanks, and equipment.

● Extends bath life and lowers production costs.

Features

● Reduces gold usage effectively, cutting costs substantially.

● Wide operating window, ensuring ease of operation.

● Highly stable bath, prolonging solution lifespan.

● Uniform plating deposition, optimizing gold savings.

Coating Properties

● Appearance: Bright golden yellow;

● Brightener: Cobalt and organic compounds;

● Coating purity (%): 99.5 – 99.9

● Coating hardness (Hv): 150 – 200

● Coating weight (mg/μm·cm²): 1.62 – 1.72

● Deposition rate (sec/μm): Approx. 8 (at 50 ASD)

● Deposition efficiency (mg/A·min): 20 – 30 (at 50 ASD)

2. Materials

3. Operating Parameters

Reel-to-Reel Plating (Continuous Plating)

Barrel and Rack Plating

HG-01 PART A (Low-range inhibitor A): Not required

HG-01 Plus PART B (Anti-nickel displacement agent B): 1–3 mL/L

4. Equipment

Plating Tank: Polypropylene or polyethylene

Heater: Teflon or quartz immersion heater with thermostat control

Filter Pump: Polypropylene or PTFE (polytetrafluoroethylene)

Agitation Pump: Pump agitation must be used (air agitation is not allowed)

Filter: Continuous filtration with a 5-micron polypropylene filter cartridge is recommended

Exhaust System: A ventilation system is required

Anode: Platinum titanium mesh or platinum mesh

Rectifier: A rectifier with voltmeter and ammeter; an ampere-minute meter is recommended

Reel-to-Reel Plating

Tank Preparation Steps

Note:

●  The conductivity of pure water used for tank preparation must be below 10.

●  After cleaning the tank, the pure water conductivity should be below 10, and the pH should be neutral.

Example for preparing 100 liters:

① Continuous Plating:

1. Thoroughly clean the plating tank, then rinse at least twice with deionized water.

2. Add about 60 liters of deionized water to the tank and heat to 60°C.

3. While stirring, add 20 liters of HG-01 MU (5X) Tank Make-Up MU.

4. While stirring, add 9.0 kg of HG-01 Base Adjusting Salt and 4.6 kg of HG-01 Acid Adjusting Salt until fully dissolved.

5. If necessary, adjust the pH to 4.3–4.4 using analytical-grade potassium hydroxide.

6. Dissolve the required amount of gold salt in a small amount of hot deionized water and slowly add it to the solution.

7. Add 2–5 ml/L of HG-01 PLUS PART B (Anti-Nickel Displacement Agent B) and the required amount of HG-01 PART A (Low-Zone Suppressor A).

8. Top up with deionized water to the working level.

9. Mix well and heat to the operating temperature.

10. After checking and adjusting the pH and specific gravity of the solution, production can begin.

② Barrel Plating:

1. Thoroughly clean the plating tank, then rinse at least twice with deionized water.

2. Add about 60 liters of deionized water to the tank and heat to 45–50°C.

3. While stirring, add 20 liters of HG-01 MU (5X) Tank Make-Up MU.

4. While stirring, add 8.0 kg of HG-01 Base Adjusting Salt and 4.0 kg of HG-01 Acid Adjusting Salt until fully dissolved.

5. If necessary, adjust the pH to 4.3–4.4 using analytical-grade potassium hydroxide.

6. Dissolve the required amount of gold salt in a small amount of hot deionized water and slowly add it to the solution.

7. Add 3 ml/L of HG-01 PLUS PART B (Anti-Nickel Displacement Agent B).

8. Top up with deionized water to the working level.

9. Mix well and heat to the operating temperature.

10. The solution’s specific gravity should be 1.1–1.2.

11. After checking and adjusting the pH and specific gravity of the solution, production can begin.

5. Parameter Control

1. Gold Content: Replenish based on analysis results.

2. Cobalt Content: Normally, HG-01 REP Replenisher R can compensate for cobalt consumption, but regular analysis is required. If cobalt levels are too low, use HG-01 Co Additive (Co: 50 g/L) to replenish as needed.

3. For every 1 gram of pure gold consumed, add 2–4 mL of HG-01 REP Replenisher R. No additional replenishment is needed if only increasing gold concentration in the tank.

4. For every 1 gram of pure gold consumed, add 1 mL of HGC-01 PLUS PART B (Anti-Nickel Displacement Agent B). No additional replenishment is needed if only increasing gold concentration in the tank.

5. HG-01 PART A (Low-Zone Suppressor A): The initial tank concentration should be selected based on customer requirements. It is recommended to add 2–3 mL of HG-01 PART A per 1 gram of pure gold consumed. No additional replenishment is needed if only increasing gold concentration in the tank.

6. Bath pH:

● pH tends to rise slowly during plating and should be monitored and adjusted regularly.

● To lower pH: Use HG-01 Acid Adjusting Salt (adding 7–8 g/L reduces pH by ~0.1).

● To raise pH: Use HG-01 Base Adjusting Salt (adding 5–6 g/L increases pH by ~0.1).

7. Bath Specific Gravity:

● Due to drag-in/drag-out, specific gravity may decrease.

● Adjust by adding both HG-01 Acid Adjusting Salt and HG-01 Base Adjusting Salt.

● Adding 5 g/L of HG-01 Acid Adjusting Salt + 10 g/L of HG-01 Base Adjusting Salt increases specific gravity by ~0.007 g/cm³.

8. Regular Activated Carbon Treatment: Helps reduce organic contamination.

9. Metal Ion Control:

● Copper (Cu): ≤ 3 ppm

● Iron (Fe): ≤ 50 ppm

● Nickel (Ni): ≤ 1000 ppm

● For customers with strict requirements (e.g., reflow soldering, porosity), it is recommended to keep nickel ion concentration as low as possible.

6. Process Maintenance

1. Co²⁺ Concentration Control: 0.6–1.0 g/L

● If Co²⁺ < 0.6 g/L: Deposit hardness decreases, and appearance becomes hazy.

● If Co²⁺ > 1.0 g/L: Deposit hardness increases, but plating efficiency decreases.

2. pH Control (at 25°C): 4.2–4.6

● If pH < 4.2: Deposition rate decreases.

● If pH > 4.6: Gloss diminishes, and haziness occurs.

● To lower pH: Use HG-01 Acid Adjusting Salt (adding 7–8 g/L reduces pH by ~0.1 unit).

● To raise pH: Use HG-01 Base Adjusting Salt (adding 5–6 g/L increases pH by ~0.1 unit).

3. Specific Gravity (tested at 25°C): Baumé scale (12°–14°)

● If < 12°: Plating rate decreases, maximum current density drops, and deposit uniformity worsens.

● If > 14°: Plating selectivity deteriorates.

● Adjustment: Add 6.5 g/L HG-01 Acid Adjusting Salt + 8.5 g/L HG-01 Base Adjusting Salt to increase Baumé by 1°.

4. Temperature: 55–65°C (131–149°F)

● If < 55°C (131°F): Plating rate decreases.

● If > 65°C (149°F): Deposit gloss diminishes.

5. Agitation

● Vigorous agitation is critical. Weak agitation reduces plating rate and maximum current density.

6. Organic Contaminants

● Effects: Reduced deposition rate, lower maximum current density, poor gloss, uneven color, and weakened corrosion resistance.

● Solution: Regular activated carbon treatment is necessary to remove organic impurities.

7. Metal Impurities:

● Permissible Limits:

● Copper (Cu²⁺): ≤ 3 ppm

● Iron (Fe): ≤ 50 ppm

● Nickel (Ni): ≤ 1000 ppm

● Effects: Reduced plating rate, lower maximum current density, poor gloss, uneven deposit color, and degraded corrosion resistance.

● Special Note: Cu²⁺ impurities significantly reduce plating selectivity and require close attention.

7. Waste Disposal

Do not dispose of untreated plating solutions. Waste must be processed in accordance with local environmental regulations. It is the user's responsibility to verify that waste handling and disposal procedures comply with applicable local environmental laws.

8. Handling and Safety Precautions

When using AurumEX HG-01, appropriate personal protective equipment (PPE) must be worn, including:

● Protective clothing

● Safety goggles

● Face shield

● Respirator mask

● Chemical-resistant gloves

In case of exposure:

● Skin contact: Rinse immediately with clean water.

● Eye contact: Flush thoroughly with clean water for at least 15 minutes and seek medical attention promptly.

For additional handling and safety information, refer to the Material Safety Data Sheet (MSDS).

9. Storage

The storage area must be dry and well-ventilated.

10. Disclaimer

All proposals or suggestions regarding our company's products in this manual are based on experiments and data that our company trusts. Due to the inability to control the actual operations of other practitioners, our company cannot guarantee or be responsible for any adverse consequences.