Electroplating Bath Analyzer

Inline plating solution measurements

optek’s electroplating analyzers are inline devices designed to measure plating solution’s metal concentration in real time. These analyzers can be designed to accommodate virtually any concentration range. Operationally, the analyzer passes a white light beam through the plating solution to be monitored. Then, light absorbance is measured at two distinct wavelengths, and the difference in light absorbance between the two wavelengths is equated to a plating solution concentration.

Measuring at two wavelengths is better than one

A distinct advantage of optek’s electroplating analyzer is its ability to simultaneously monitor light absorbance at two different wavelengths. The measuring wavelength is set to focus on or near the peak of the plating solution’s absorbance curve, while the secondary wavelength is chosen to compensate for any influence due to light scattering, caused by:

• window fouling
• particulate / suspended solids
• gas bubbles

Together, the analyzer yields very repeatable and extremely reliable plating solution concentration values under process conditions - in real time.

Copper Sulfate Electroplating Bath solution being measured in real time, 221.1 G/L

Monitoring Electroplating Solution

Electroplating is a process by which current is passed through a metal salt solution, with the purpose of depositing a layer of metal on a substrate immersed in the solution. The thickness of metal deposited on the substrate will then be a function of three variables:

• Time
• Electric Current Strength
• Solution Concentration

Therefore, for a given amount of electric current, knowing the real time plating solution’s metal concentration allows the electroplating operator to determine how long it will take to achieve a desired plated thickness. Further, monitoring the plating solution in real time allows for automated control of metal salt feeder systems designed to achieve a plating solution concentration set point.

Chema Technology uses optek’s Electroplating Bath Analyzer to monitor copper sulfate concentration to control their DisCoP feeder system

What makes optek’s electroplating analyzer systems better?

A complete optek plating solution analyzer utilizes a C4000 series converter, an AF26-VB sensor and a stainless steel or TFMC (Teflon) process connection. Together, this package offers the following advantages:

• Plating solution concentration measurements in real-time
• Plating solution measurements independent of flow rate or flow velocity
• Can accommodate two independent measurement points on one C4422 transmitter
• According to ATEX: Can be installed in Zone 1 (EPL, "Gb") or in Zone 2 (EPL, "Gc"). Conform to IECEx.
  According to FM: Can be installed in Class 1, Division 1 or Class 1, Division 2 areas
• Independent monitoring of the reference wavelength, giving a real-time indication of window fouling or bath contamination
• System comes with a NIST traceable validation filter allowing for an online check of sensor performance
• Utilizes a tungsten filament lamp ensuring long lamp life and consistent emissivity

optek AF26-VB dual channel sensor with a TFMC sensor body

Typical electroplating metals (metal salt solutions) monitored include:

• Copper
• Nickel
• Chromium
• Zinc
• Cadmium
• Gold
• Silver
• Tin