PCB design relevant skills

Set skills 
All point design in different stage requires different Settings,
In the layout phase a large lattice can be used in device layout;For big components such as IC, connectors which are not located, we can choose 50 ~ 100 mil lattice accuracy to device layout .While for passive components such as resistance capacitance and inductance,we can choose 25mil.he precision of the large lattice is advantageous to the alignment of the device and the layout beautiful.
PCB layout rules:
1, Normally all components shall be arranged on the the same circuit board side.Only top-level components is too close, some device height is limited and small calorific value device be set up on the bottom ,Such as SMD resistor, SMD capacitors, SMD IC.
2, on the premise of guarantee the electrical performance,elements should be placed on the grid in parallel or vertical alignment in order to be neat, beautiful.In general we don't allow components overlap,but to compact arranged components .Components in the page layout should be uniform distribution, the density is consistent .
3,Different components on printed circuit boards, neighboring,and the minimum distance between solder graphics should be more than 1 mm .
4,The distance from Components to the circuit board edge is generally not less than 2 mm.The best shape for the circuit board is rectangular and aspect ratio is 3:2 or 4:3. When Circuit board face 'is greater than 200 mm by 150 mm, we should consider mechanical strength which circuit board can withstand .
Layout skills
In the layout of the PCB design to we should analyze circuit unit according to the function.Layout all the components of the circuit , we need to comply with the following principles:
1, Arrangement of each functional circuit unit according to the process of the circuit to facilitate signal flow and ss far as possible to maintain the signal consistent direction.
2,Centered on the core of each function unit components, we layout around it .The arrangement of components should be uniform, compact, on the PCB and we should as far as possible reduce and shorten the lead and the connection between each components.
3,For the circuit which works under high frequency , we need to consider the components distribution parameters.Generally components should be as far as possible made parallel arrangement ,which are beautiful, and easy fabrication, easy to mass production .