Title: Process control circuit for metal-depositing baths

Do you think this is a good invention? Vote now:

Votes so far: For:(0) Against:(0)
Claims: We claim as our invention:

1. A process control circuit adapted for the simultaneous and repeated control and monitoring of a plurality of parameters in at least one metal-depositing bath, comprising:

a. an independent parameter control circuit block for each of said plurality of parameters, each block having

i. measuring means for producing a measured value for one of said parameters;

ii. calibrator means connected to the measuring means for calibrating said measuring means;

iii. comparator means connected to said measuring means for comparing said measured value to a nominal value stored in said comparator means and creating a comparison signal;

iv. a dosing means connected to said comparator means for dosing said metal-depositing bath in response to said comparison signal;

b. a program generator means connected to each of the parameter control circuit blocks for controlling the operation of each in a simultaneous fashion so as to simultaneously control and monitor the bath parameters, said program generator means including at least

i. first switch means in each parameter circuit block for activating the calibrator means, and

ii. second switch means in each parameter circuit block for activating the measuring, comparator and dosing means to maintain tight control over the value of each parameter in the bath.

2. The circuit of claim 1 in which a temperature compensation means is connected to said measuring means for adjusting the measured value in response to temperature.

3. The circuit of claim 1 in which said calibrator means has a motor for driving a calibration control in said measuring means.

4. The circuit of claim 1 in which a program control means is connected to said measuring stage calibrator means and dosing means for controlling automatic callibration prior to filling said metal-depositing bath and for controlling measurement and dosing of said metal-depositing bath.

5. The circuit of claim 1 in which the measuring means in each of said parameter control circuit blocks has a measured value storage means connected thereto; and a boundary level monitor means being connected to each of said storage means for shutting off said dosing circuit when a boundary level is violated by the measured value.

6. The circuit of claim 5 in which a plurality of metal-depositing baths are provided, and an interrogation means having indicators is connected to each storage means associated with each of said baths and circuit blocks.

7. The process control circuit of claim 1 in which at least one parameter control circuit block is connected to monitor and regulate bath fluid metal concentration, and at least one other parameter control circuit block is connected to monitor and regulate bath fluid pH value.

8. The process control circuit of claim 7 in which the parameter control circuit block connected to monitor and regulate metal concentration of the bath fluid has in its measuring stage a measuring photoconductive resistor and a comparison photoconductive resistor to form a two beam colorimeter, an amplifier, an automatically operating potentiometer having a center tap connected at the input of said amplifier, the measuring photoconductive resistor being arranged in a feedback line of the amplifier and also being connected to the potentiometer, the other end of the potentiometer being connected to the comparison photoconductive resistance.

9. The process control circuit of claim 1, characterized in that the calibrating device has a program switch connected to a servomotor, said servomotor driving an automatic calibrating control in said measuring circuit.

10. The circuit of claim 1 in which the program control generator automatically repeats calibration and dosing in each of the parameter control circuits.

11. The circuit of claim 1 in which measured value storage means are connected to each of the parameter control circuits, interrogation means also being provided for simultaneously interrogating measured values in each of the storage means.

Other info:

Inventors: De Steur, Hubert (Drongen, BE)
Pernegger, Wolfgang (Erlangen, DT)
Bussmann, Egon (Munich, DT)

Application Number: 688784
Filing Date: 1976-05-21
Publication_date: 1978-01-17
Assignee: Siemens Aktiengesellschaft (Berlin & Munich, DT)
Primary Class(es): 137/93 204/228.6
Other Classes:
US Patent Ref:

3361150	Jan, 1968	Horner	137/93.
3532102	Oct, 1970	Glassey	137/93.
3607549	Sep, 1971	Bielefel, Jr.	137/93.
3650196	Mar, 1972	Hosoe et al.	137/93.
3674672	Jul, 1972	Whitesell	137/93.

Other Refs:
Primary Examiner: Cline, William R.
Assistant Examiner:
Attorney: Hill, Gross, Simpson, Van Santen, Chiara & Simpson