| Predicate |
Object |
| assignee |
http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_315ae544538aaeac6d1f4eed6754e4bb |
| classificationCPCInventive |
http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/H05K3-067
http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C23F1-34 |
| classificationIPCInventive |
http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C23F1-34
http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/H05K3-06 |
| filingDate |
1972-10-30-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| grantDate |
1974-10-29-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| inventor |
http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_234fc129446c523272517a44c64a1378 |
| publicationDate |
1974-10-29-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber |
US-3844857-A |
| titleOfInvention |
Automatic process of etching copper circuits with an aqueous ammoniacal solution containing a salt of a chloroxy acid |
| abstract |
Copper circuits are etched with an ammoniacal aqueous solution of from about 0.4 mole/liter to limit of solubility of cupric amine chloride maintained at a pH of 8-12 with ammonia, buffered with an ammonium salt and activated by a soluble salt of a chloroxy acid such as sodium chlorite whose concentration does not exceed about 0.1 mole/liter wherein automatic feed valves maintain the pH and sodium chlorite concentration. The feed valves are operated by voltage sensitive relays. The output from a pH meter activates the relay for controlling ammonia feed while the EMF developed between a platinum and reference electrode immersed in the etchant, activates the relay for controlling sodium chlorite feed. The etchant composition exhibits low undercutting thereby rendering it especially suitable for fine line circuits and circuits resisted with noble metals such as gold/nickel. |
| isCitedBy |
http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-3951711-A
http://rdf.ncbi.nlm.nih.gov/pubchem/patent/CN-103842553-A
http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-4233106-A
http://rdf.ncbi.nlm.nih.gov/pubchem/patent/EP-0424845-A2
http://rdf.ncbi.nlm.nih.gov/pubchem/patent/EP-0424845-A3
http://rdf.ncbi.nlm.nih.gov/pubchem/patent/CN-103842553-B
http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-9301397-B2
http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-4083758-A
http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-5431734-A
http://rdf.ncbi.nlm.nih.gov/pubchem/patent/KR-20140074364-A
http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-5919379-A
http://rdf.ncbi.nlm.nih.gov/pubchem/patent/WO-2013048834-A1 |
| priorityDate |
1972-10-30-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type |
http://data.epo.org/linked-data/def/patent/Publication |