Titanium anode mesh for horizontal copper plating on PCB printed circuit board electroplating

Titanium anode mesh for horizontal copper plating on PCB Conventional data

PCB copper plating introduction

Acid electrolytic copper plating is an important link in hole metallization of printed circuit boards. With the rapid development of microelectronics technology, printed circuit board manufacturing to the direction of multilayer, layer, function and integration rapid development. Promote the printed circuit design using a large number of small holes, narrow spacing, fine wire circuit graphic design and design, making the printed circuit board manufacturing technology more difficult, especially the aspect ratio of the multilayer through hole more than 5:1 and a large number of deep blind holes used in the laminated board, so that the conventional vertical plating process can not meet the technical requirements of high quality, high reliability interconnection holes, So the horizontal electroplating technology.

Some conventional data for titanium anode mesh used in horizontal copper plating on PCB:

1. Mesh size: 60-80 openings per linear inch

2. Wire diameter: 0.15-0.20 mm

3. Coating: Platinum, iridium, or ruthenium

4. Size and shape: Matched to the size and shape of the PCB being plated

5. Purity: At least 99.5%

In terms of plating parameters, some conventional values for a typical copper plating solution used in PCB manufacturing might include:

1. Copper sulfate concentration: 180-200 g/L

2. Sulfuric acid concentration: 70-80 g/L

3. Temperature: 25-30°C

4. pH: 1.0-1.5

5. Current density: 1-3 A/dm²

It's worth noting that specific plating parameters will depend on a variety of factors, including the specific plating solution being used, the size and shape of the PCB, and the desired plating thickness and uniformity. These values should be used as a starting point, and may need to be adjusted through experimentation and optimization.

Electrochemical performance and life test (refer to HG/T2471-2007 Q/CLTN-2012)

1. Coating type: titanium based,Iridium-Tantalum coating

2. Compared the advantages of lead anode for conventional electroplating

    1) Low groove electricity, small energy consumption

    2) The rate of electrode loss is small and the size is stable

    3) The corrosion resistance of the electrode is good, and the insolubility does not pollute the solution, so that the coating performance is more reliable.

    4) Titanium anode using new materials and structure, greatly reduce its weight, convenient daily operation

    5) Long service life, and the matrix can be reused, saving cost

    6) Oxygen evolution overpotential is about 0.5V lower than that of lead alloy insoluble anode, which reduces the tank voltage and energy consumption.

1. PCB horizontal reverse pulse copper plating

Because the design requirements of the circuit board tend to be fine wire diameter, high density, fine aperture (high depth to diameter ratio, even micro-through holes), filling blind holes, traditional DC electroplating has become more and more unable to meet the requirements, especially in the through hole electroplating hole center coating, usually the copper layer at both ends of the aperture is too thick but the central copper layer is insufficient phenomenon. The uneven coating will affect the effect of current transmission and directly lead to poor product quality. To balance the thickness of the copper on the surface, especially in pores and micropores, the current density is forced to decrease, but this lengthens the plating time to an unacceptable extent. With the development of reverse pulse electroplating process and chemical additives suitable for electroplating process, it has become a reality to shorten electroplating time.

Typical electrolytic process:

Electrolyte: CuSO4/5H2O: 100-300g/L, H2SO4:50-150g/L

Forward current density: 500-1000A/m2

Reverse current density: 3 times of forward current density

Electroplating process: two-way pulse

Temperature: 20-70℃

Forward time: 19ms; Reverse time: 1ms

Life requirement: 50000kA   

Anode Type: Dedicated Iridium series titanium anode

2. PCB vertical continuous DC copper plating

In the process of vertical continuous DC copper plating on PCB, special organic additives are added to promote the uniform distribution of fine grain metal deposition layer and surface. These additives must be maintained in the best concentration to play their best function and obtain the best product quality.

This requires the anode not only to meet the life requirements, but also to reduce the consumption of organic additives, in order to reduce the cost of pharmaceutical consumption. Although the service life of traditional iridium titanium anode can meet the requirements, but the consumption of brightener is great. We improved the process and formula of the traditional Iridium titanium anode. The special PCB horizontal copper-plated titanium anode can reduce the consumption rate of organic additives, while the service life can meet the requirements.

Typical electrolytic process:

Electrolyte: Cu: 60-120g/L, H2SO4:50-100g/L, Cl- : 40-55ppm

Current density: 100-500A/m2

Temperature: 0-35℃

Life requirements: more than 1 year

Anode type: special iridium series titanium anode

Advantages: Good electroplating uniformity, long life, energy saving, high current density.

Titanium anode mesh for horizontal copper plating on PCB application case

Titanium anode mesh is often used in the electroplating industry due to its high corrosion resistance and electrical conductivity. In the case of horizontal copper plating on PCBs, titanium anode mesh can be used as the anode material in the plating bath.

During the copper plating process, the titanium anode mesh is immersed in the plating bath along with the PCB substrate, which acts as the cathode. When an electric current is applied to the system, copper ions from the plating solution are attracted to the surface of the PCB substrate and deposited onto it, forming a thin layer of copper.

The titanium anode mesh provides a stable source of positively charged ions to the plating bath, helping to maintain the electrochemical balance of the system. It also helps to prevent the formation of unwanted byproducts, such as oxygen gas, which can interfere with the plating process.

Overall, using titanium anode mesh in horizontal copper plating on PCBs can help to improve the quality and consistency of the plated copper layer, while also reducing the risk of defects and other issues that can arise during the plating process.