Evaporation driven counterflow rinse system and method

Claim 1

An electroplating apparatus comprising: a plating tank for receiving a plating solution including plating chemicals and water to a predetermined fluid level in which a selected number of workpieces on a supporting structure are submersed and plated, the plating solution level being diminished by evaporation; a first rinse tank for receiving rinsing solution to said predetermined level, the first rinse tank being disposed sufficiently adjacent the plating tank to enable plated workpieces to be submersed in the first rinse tank solution to rinse the plating solution from the plated workpieces, whereby the rinsing solution in the first rinse tank includes water and the plating chemicals rinsed from preceding workpieces; a first elongated fluid path interconnecting the plating tank and the first rinsing tank, the first fluid path being disposed at or below said predetermined level such that solution flows by gravity from the first rinsing tank to the plating tank to replace evaporated plating solution, whereby plating chemicals are returned to the plating tank, with said first fluid path including a plurality of baffles therein to prevent fluid from flowing directly therethrough; a final rinse tank for receiving rinsing solution to said predetermined level, the final rinse tank being disposed sufficiently adjacent the first rinse tank to enable the rinsed workpieces to be submersed in the final rinse tank solution to rinse the plated workpieces further, whereby the rinsing solution in the final rinse tank includes water and the plating chemicals rinsed from preceding workpieces; a second elongated fluid path in fluid connection with the first and final rinse tanks, the second fluid path being disposed at or below said predetermined level such that solution flows by gravity from the final rinse tank to the first rinse tank with said second fluid path including a plurality of baffles therein to prevent fluid from flowing directly therethrough; and level maintaining means operatively connected with the final rinse tank for maintaining the rinsing solution in the final rinse tank at said predetermined level, whereby the solutions in the first rinse tank, final rinse tank and the plating tank are maintained at said predetermined level and plating chemicals are returned from the final rinse tank to the first rinse tank and from the first rinse tank to the plating tank.

Claim 14

A method of electroplating with an electroplating apparatus which includes a plating tank filled to a predetermined level with a plating solution including plating chemicals and water, a first rinse tank filled to said predetermined level with a rinsing solution including water and a dilute concentration of plating chemicals, a first elongated fluid path interconnecting the plating and first rinse tank below the predetermined level, a final rinse tank filled to said predetermined level with a rinsing solution including water and a more dilute concentration of plating chemicals, a second elongated fluid path in fluid communication with the first and final rinse tanks below the predetermined level, an overflow outlet disposed in the final rinse tank substantially at said predetermined level, and a water inlet for supplying water to the final rinse tank, the method comprising: selecting a workpiece to be plated and the supporting structure therefor so that when said workpiece and said supporting structure are submerged in said plating tank the volume of fluid displaced is less than the volume of said first elongated fluid path; running water from the water inlet into the final rinse tank at a rate greater than the rate of evaporation of water from the plating tank and allowing any excess water to flow through the overflow outlet, whereby the level of fluid in the tanks is maintained substantially at said predetermined level; submersing said workpiece in the plating tank and electroplating the same; withdrawing the workpiece from the plating tank and submersing it in the first rinse tank; withdrawing the workpiece from the first rinse tank and submersing it in the final rinse tank; and withdrawing the workpiece from the final rinse tank.

Claim 15

A method of electroplating with an electroplating apparatus which includes a plating tank filled to a predetermined level with a plating solution including plating chemicals and water, a first rinse tank filled to said predetermined level with a rinsing solution including water and a dilute concentration of plating chemicals, a first elongated fluid path interconnecting the plating and first rinse tank below the predetermined level, a final rinse tank filled to said predetermined level with a rinsing solution including water and a more dilute concentration of plating chemicals, a second elongated fluid path in fluid communication with the first and final rinse tanks below the predetermined level, an overflow outlet disposed in the final rinse tank substantially at said predetermined level, and a water inlet for supplying water to the final rinse tank, the method comprising: selecting a workpiece to be plated and the supporting structure therefor so that when said workpiece and said supporting structure are submerged in said plating tank the volume of fluid displaced is less than the volume of said first elongated fluid path; running water from the water inlet into the final rinse tank at a rate greater than the rate of evaporation of water from the plating tank and allowing any excess water to flow through the overflow outlet, whereby the level of fluid in the tanks is maintained substantially at said predetermined level; submersing said workpiece in the plating tank and electroplating the same; withdrawing the workpiece from the plating tank and submersing it in the first rinse tank; withdrawing the workpiece from the first rinse tank and submersing it in the final rinse tank; and withdrawing the workpiece from the final rinse tank.