H4-HH-8B ilt within weeks using the Fast Track designator Helical gearbox H4

Flender/Flender Gear Units/Helical gearbox H4

hemically reductive metallising, except that externally electroless copper deposition is replaced by electrolytic cop- per-plating. The method, initial1 applied in laboratory-scale studies in connection with the use of catalyst system, included txe following process steps: 1. Drilling 2. Deburring 3. Oxidising pickl.ing 4. Reduction 5. Conditioning 6. Pickling 7. Redipping 8. Catalysing 9. Activation 1. Electroplating The PCBs metallised on laboratory scale using the processin yequence described were sub- jected to numerous tests, in order thoroughly to confirm reliability of the electrolytic ' method. At the same time, the individual process steps were tested and optimised using vari- ous chemicals. The influence of all the parameters mentioned on the quality of the PCBs was examined on more than 1,0 sample boards in each case, on the basis of the following criteria: - Adapter test, - Test of solderina behaviour. - Plating test, - Test of the holes in reflected and transmitted liaht. - Crack test, - Climate test, - Ageing test. Based on the test results, which were ultimately all positive, the decision was taken to consider the use of this electrolytic method on an industrial scale, articularly because initial cost calcu.la- tions had shown that this environmentally-friendly metiod also represented an economically attractive alternative to chemically reductive copper through-plating. However, the risk involved in directly converting the rocess to an industrial scale (scale-up of over ap eared to be too great, in view of tle dependence of the results on mass exchange prollems, .. geometric factors - particularly as some of the observations described had indicated this type of problem. For this reason, the project was expanded, in order to con- struct pilot plant and then convert this process step-by-step from the laboratory scale to industrial dimensions. ., . 8 3. Results 8,9 PCBs had been successfully metallised electroly