http://rdf.ncbi.nlm.nih.gov/pubchem/patent/DE-2401313-A1
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_4ddcb273a108a5d8472b335280098e06 |
| classificationCPCAdditional | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/H05K3-07 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/H05K2203-1157 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/H05K3-385 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/H05K2203-161 |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/G01R31-2805 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/H05K1-0269 |
| classificationIPCAdditional | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/H05K3-38 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/H05K3-07 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/G01R31-28 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/H05K1-02 |
| filingDate | 1974-01-11-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| inventor | http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_e0e87eefe9658421bedd474fae6335a1 |
| publicationDate | 1975-07-24-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | DE-2401313-A1 |
| titleOfInvention | METHOD OF INSPECTING THE INTERIOR LAYERS OF MULTI-LAYER PCBs |
| abstract | The inner layer with conductive tracks separated by etching is tested for current passage between points of connection and/or for sufficiently high dielectric strength between conducting paths not to be connected. After the conducting paths are etched, the remaining copper surfaces are blackened by coating with a stable copper sulphide layer. Contacts are made with conducting paths to be tested, and the contact surfaces electrolytically reduced to that they can be visually recognised in contrast to the black remaining surfaces. Thus faulty points such as insufficiently insulated short circuit bridges and/or poor contacts can be easily apertained by visual checking. Preferably the degreased circuit boards are treated for copper surface blackening with an aqueous solution of 9 g/l of potassium sulphide and 1 g/l of 30% ammonia. The copper surface to be contacted may be first connected in a weak hydrochloric acid as a cathode, and after about two thirds of the total electrolytic treatment connected as an anode. The circuit board is then rinsed. |
| priorityDate | 1974-01-11-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 35.