Hasan2016 wrote:".But, dont you feel this cause rest of ratlines?."Ratlines are only an indication of unrouted nets. Pay close attention to the traces that are in close proximity to each other and make decisions on placement, spacing and shielding that are best for every signal type.
You may still need to do some manual clean-up afterwards. Hasan2016 wrote:".placing component manually in board and then auto-routing is not a good way?."Autorouting is fine for non-critical circuitry, but it is not infallible. See this link for a voltage vs spacing calculator. Hasan2016 wrote:".Isnt useful for large size circuit with bundle of components ? What about insulation ?."If you are not dealing with high voltage, large signal levels or high frequencies then spacing can be kept to a minimum. * When more shielding from other circuits is needed. * When it is necessary to design and control RF signal line impedances. * When it is necessary to lower the power supply line impedance to reduce the possibility of the supply line being modulated by high-frequency current demands and nearby high-frequency/amplitude signal lines.
Hasan2016 wrote:".Kindly explain, whats are the necessity for making 4 layers, GND, TOP.BOT,PWR?."* When more traces are needed in a very small area. When space is at a premium, small bypass chip capacitors are sometimes installed on the circuit side ( Bottom) of the PCB.
10nF) as close to the power supply inputs of ICs as you can get them, especially if there will be a lot of high-frequency digital "thrashing" going on.
Try to install small bypass capacitors (e.g. low-level analog, sense, and low-current supply lines) the best you can. Try to separate noisy digital circuitry from other more sensitive circuitry (e.g. Hasan2016 wrote:".If it does cross-talk, how things could be minimized?."By placing ground planes around and between signal lines. See this link for some help in researching board houses. Typically, a low-cost board house should easily be capable of going down to 0.008" (~20mm) without problems. See this link for a trace size calculator. Hasan2016 wrote:".What the minimum distance I should keep?."I don't know what the minimum trace size and spacing should be for a home project, but I would think that you would want those numbers as large as you can make them without affecting your design since most home-brew manufacturing is probably not as precise as the commercial offerings. Hasan2016 wrote:".Dont you think, if two track with minimal distances conduct current, there would not be any effect of getting short ?."Short traces minimize impedances and reduce the possibility of crosstalk. Hasan2016 wrote:".Do you mean when I want to place my components where copper plane is exists?."Yes.