Electrode chemical control system and method

Abstract

A method and system for controlling an electroless deposition process are provided. The system generally includes an electroless plating cell having a work piece to be plated positioned therein, the work piece also being positioned in communication with an electroless plating solution contained by the plating cell, and a voltage measurement device in communication with the work piece and the electroless plating solution, the voltage measurement device being configured to measure the electrical potential difference between the work piece and the plating solution. The system further includes a control voltage device in communication with the work piece and being configured to apply a determined control voltage to the work piece, and a system controller in communication with the voltage measurement device and the control voltage device, the system controller being configured to receive an input from the voltage measurement device and to generate a control voltage output corresponding to the determined control voltage, the output being sent to the control voltage device to cause the control voltage device to apply the determined control voltage to the work piece.

1 . A system for controlling an electroless deposition process, comprising:
 an electroless plating cell having a work piece to be plated positioned therein, the work piece also being positioned in communication with an electroless plating solution contained by the plating cell;   a voltage measurement device in communication with the work piece and the electroless plating solution, the voltage measurement device being configured to measure the electrical potential difference between the work piece and the plating solution;   a control voltage device in communication with the work piece and being configured to apply a determined control voltage to the work piece; and   a system controller in communication with the voltage measurement device and the control voltage device, the system controller being configured to receive an input from the voltage measurement device and to generate a control voltage output corresponding to the determined control voltage, the output being sent to the control voltage device to cause the control voltage device to apply the determined control voltage to the work piece.   
     
     
         2 . The system of  claim 1 , wherein the determined control voltage is calculated by the system controller to decrease a plating rate of the electroless deposition process. 
     
     
         3 . The system of  claim 1 , further comprising a temperature sensor in communication with the system controller; the temperature sensor being positioned to measure a temperature of the electroless plating solution in the plating cell. 
     
     
         4 . The system of  claim 3 , wherein the system controller is configured to generate a control voltage output calculated to stop the electroless deposition process when the temperature sensor senses that temperature of the electroless plating solution is outside of an optimal plating temperature range. 
     
     
         5 . The system of  claim 1 , wherein the voltage measurement device comprises a first inert electrode positioned in the plating cell in communication with the plating solution, and a second electrode positioned in communication with a plating surface of the work piece. 
     
     
         6 . The system of  claim 5 , wherein the first and second electrodes are in communication with a voltage measuring device configured to determine the electrical potential difference between the first and second electrodes. 
     
     
         7 . The system of  claim 4 , further comprising a heating unit positioned and configured to heat the electroless plating solution, the heating unit being in communication with the system controller. 
     
     
         8 . The system of  claim 7 , wherein the system controller is further configured to activate the heating unit in combination with generating the control voltage output calculated to stop the electroless deposition, the heating unit being activated until the temperature of the electroless plating solution is measured to be within the optimal plating temperature range. 
     
     
         9 . A method for controlling an electroless deposition process, comprising:
 measuring an electrical potential at a plating surface during an electroless deposition process;   comparing the measured electrical potential to desired electrical potential for the electroless deposition process; and   applying a control voltage to the plating surface to adjust the electrical potential at the plating surface to be closer to the desired electrical potential.   
     
     
         10 . The method of  claim 9 , wherein measuring the electrical potential at the plating surface comprises positioning a first electrical potential measuring electrode in communication with the plating surface and positioning a second electrical potential measuring electrode in communication with an electroless plating solution. 
     
     
         11 . The method of  claim 10 , wherein the second electrical potential measuring electrode is manufactured from an inert material that does not react with the electroless plating solution. 
     
     
         12 . The method of  claim 10 , wherein the first and second electrodes are in communication with a voltage measuring device. 
     
     
         13 . The method of  claim 10 , further comprising measuring a temperature of the electroless plating solution and stopping the electroless deposition process if the temperature of the electroless plating solution is not within a desired temperature range for the particular electroless deposition process. 
     
     
         14 . The method of  claim 13 , wherein stopping the electroless deposition process comprises applying a voltage to the plating surface that is equal in magnitude and opposite in polarity to the measured electrical potential at the plating surface. 
     
     
         15 . The method of  claim 14 , further comprising heating the electroless plating solution to a temperature within the desired temperature range while the electroless deposition is stopped. 
     
     
         16 . The method of  claim 15 , further comprising restarting the electroless deposition process by removing the voltage applied to the plating surface that is equal and opposite in magnitude to the measured electrical potential at the plating surface. 
     
     
         17 . The method of  claim 9 , wherein the measuring and applying are conducted independently at separate times. 
     
     
         18 . The method of  claim 9 , wherein the control voltage is calculated to decrease a deposition rate of the electroless deposition process. 
     
     
         19 . The method of  claim 9 , wherein the control voltage is calculated to stop an electroless deposition supporting chemical reaction taking place at the plating surface. 
     
     
         20 . A system for controlling an electroless deposition process, comprising:
 measuring means for measuring an electrical potential at a plating surface during an electroless deposition process;   control means for comparing the measured electrical potential to desired electrical potential for the electrical deposition process; and   voltage generating means for generating a control voltage that is communicated to the plating surface to adjust the electrical potential at the plating surface to be closer to the desired electrical potential.   
     
     
         21 . The system of  claim 20 , further comprising a temperature sensing means for measuring a temperature of an electroless plating solution. 
     
     
         22 . The system of  claim 21 , wherein the control means is configured to cooperatively operate with the voltage generating means to stop the electroless deposition process if the temperature of the electroless plating solution is outside of a desired temperature range. 
     
     
         23 . The system of  claim 22 , wherein the voltage generating means is configured to apply a voltage that is equal in magnitude and opposite in polarity to the measured electrical potential at a plating surface to stop the electroless deposition process. 
     
     
         24 . The system of  claim 20 , wherein the control voltage is calculated to decrease a deposition rate of the electroless deposition process.