The initial key of pcb design - overall layout of pcb

Pcb design, if you want to make the pcb board achieve the desired appearance, the overall layout and placement of components are the primary considerations, they play a key role in the design of pcb board.

To make a good design, as a designer, the first thing to do is to have a general overall layout, so as to make a specific design scheme. The same is true for the pcb design. If you want to make the pcb board look like you want, the overall layout and placement of components are the primary considerations. They play a key role in the design of the pcb board. They directly affect the installation, reliability, ventilation and heat dissipation, and wiring straightness of the entire printed circuit board.

a. Outer dimension. When the size is too large, the printed line is long, the impedance increases, the anti noise ability decreases, and the cost increases; Too small, poor heat dissipation, and adjacent lines are vulnerable to interference. Therefore, we should first make a reasonable positioning for the size and shape of PCB.

PCB board

b. Location of special components and unit circuits, etc. The whole circuit shall be divided into several unit circuits or modules according to the circuit flow, and the core components of each unit circuit shall be taken as the center. The other components shall be evenly, neatly and compactly arranged on the PCB board in a certain order. Can't get too close

c. Large components, especially some relatively large and high components, should have a certain distance to facilitate welding and repair.

d. Color heat sink shall be considered for integrated circuits with large power. Sufficient space shall be reserved and placed in a well ventilated and heat dissipating position. At the same time, they should not be too concentrated, they should be at a certain distance, and they should be in the direction of 45 corners.

e. Smaller integrated circuits shall be arranged along the axial direction, while resistance and capacitance components shall be arranged vertically and axially. All these directions are relative to the transmission direction of PCB production process. The regular arrangement of components will reduce the defects in welding.

f. The LED used for display is used for observation in the application process and can be placed at the edge of the printed circuit board.

g. Switches, trim elements, etc. shall be placed at places where they are easy to operate.

h. In the same frequency circuit, the distribution parameters between components should be considered. In general high-frequency circuit, the distribution parameters between components should be considered. In general circuit, the components should be arranged in parallel as far as possible, which is not only beautiful, but also easy to assemble and weld, and also easy to batch production. The i. component at the edge of the circuit board must be 3-5 cm away from the edge.

j. At the same time, the thermal expansion coefficient, thermal conductivity, heat resistance, bending strength and other properties of PCB shall be comprehensively considered to avoid adverse effects on components or PCB in production.

After the above considerations are completed, you can proceed to the next step. You can't underestimate this step. This is the beginning of a pcb board. It determines what kind of board it will be and what functions it will have. It is all in this step, so it is necessary to do this step well. Circuit board assembly, circuit board design, and circuit board processing manufacturers explain the initial key of pcb design - overall layout of pcb.