VE2TZT
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Re:low band antennas keyboard - 2011/01/31 21:05
As you can have seen I was not mush present on the CGQ site those last weeks. Following is a part of the reasons:
At last, during the transition between the two years, I have decided to allow some time to the learning and the setup of a complete electronic design and realisation process. It includes PCB design software, a modern personal PCB etching process and metal box making.
PROCESS
-For PCB design, I have chosen KIKAD because it is free and not too complex as for example ORCAD can be. With KIKAD, it is easy and fast to do add one’s own components for schematic as well as for routing. The rules for the size of vias and tracks are easy to modify.
It is the perfect tool for the needs of the average circuit designer that I am.
-For the etching process, I have chosen to try Pulsar tonner transfer system. At the very first beginning, I was somewhat disappointed by the result, I was not able to correctly transfer the tonner on the copper board. After 2 bad tries, I discovered that the quality of the tonner is very important and very variable from a brand or a printer make to another one. Another discovering was that the Pulsar Website is very optimistic on how fast you can manufacture a board they are claiming 7 minutes of total etching process from printing to etched board where I need around two hours... For example it is said on the site that we need only one pass through the laminator and a second by security where I need ten passes to have a good result.
I is true that this process is better designed for small boards and mine where middle sized.
After the learning phase, I must admit that it works well and that we can obtain very thin tracks.
The big default of this Pulsar process is the difficulty to have a good accuracy in the registration of two sided circuits. That default comes from the fact that we must put the printed picture one the copper board without seeing it. Then it is very difficult without industrial machine to position the second side in front of the first one with more than 0.5 mm (20 mils) of accuracy.
This lake of accuracy is combining with a certain amount of X,Y scale reproducibility distortion coming from the printer and from the laminator. I am suspecting the laminator to make some distortion by spreading not evenly the toner on the copper board while pressuring it against the board.
That fact must be taken into account when designing the PCB.
-It is very frustrating to see how poor is the choice of boxes on the market and how expensive they are compared to the cost of aluminum sheets, so I have invested in a multifunction machine which will be paid back at the tenth box. I have bought a 12’’ Metal machine 3 in 1 : Shear, brake and roll from Craftex. This machine was advised to me last year by a great electronics and radio amateur, Jacques VE2EMM who sadly disappeared in 2010 after a long illness.
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