Difference into the vias of a PCB sega cartridge
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Difference into the vias of a PCB sega cartridge
I have been studying the operation and the connections of the sega sonic 3 PCB cartridge and I would like to know what is the difference into the vias, beyond the form and if it has the consequences into the operation of circuit, These two types of roads can be seen in the image marked with arrows.
- TmEE
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Re: Difference into the vias of a PCB sega cartridge
Only the green/blue kind are vias, rest are just drills. I am not completely sure how the boards are made but it seems to require all nets to be connected and probably for testing purposes and once done things are drilled or stamped out.
Re: Difference into the vias of a PCB sega cartridge
The punchouts are are plating things electrochemically - that required that everything needed to be shorted at some point. The punch happened afterwards because electrically they didn't want them shorted.
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Re: Difference into the vias of a PCB sega cartridge
Thank you very much for the information, you have really helped me.
- krzysiobal
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Re: Difference into the vias of a PCB sega cartridge
Most popular, metalized vias (with empty holes) are doable only on glass-fibre laminate (FR4).
This Sega cartridge uses cheaper paper laminate and for some reason, the above method does not work with it. So instead, they used some "blue" conducting substance that is filled into every hole and then somehow cemented. Drawback of this method is that legs of the elements can't be placedin this via, so elements are soldered only on one side. Just like you would do PCB in home and used wires for connecting both layers.
This Sega cartridge uses cheaper paper laminate and for some reason, the above method does not work with it. So instead, they used some "blue" conducting substance that is filled into every hole and then somehow cemented. Drawback of this method is that legs of the elements can't be placedin this via, so elements are soldered only on one side. Just like you would do PCB in home and used wires for connecting both layers.