Hitech Circuits is the most professional China PCB manufacturer, which is specialized in producing high quality and low cost High Density Interconnect PCB, Quick Turn PCB, Rigid-flex PCB, Flexible PCB, High Frequency PCB, Heavy Copper PCB and Metal Core PCB. Today Hitech Circuits is going to share the Common PCB board layout requirements with us.
In the common printed circuit board type, the layout design should pay attention to details are as follows:
1) single panel: In the case of low cost requirements typically use this type of panel. In the layout design, it is sometimes necessary to use components or wiring to skip across the circuit board traces. If too many, you should consider using double-sided.
2) Double panel: Two panels can be used may not use the PTH. PTH is expensive because the plate, when the circuit complexity and density to be used only when necessary.
In the layout design, component surface must be kept for at least the number of wires to ensure easy access to the necessary timber.
Plate in PTH, plated through holes for electrical connection only and not for the components to install. For economic and reliability considerations, the number of holes should be kept to a minimum.
To select a single-sided or double-sided, it is important to take into account the components of the surface area (C), printed circuit board with the total area (S) ratio is an appropriate constant ratio, which for the components The installation is useful. It is noteworthy that US “usually refers to the panel side of the area. Table 3-2 lists most commonly used printed circuit board S: C ratio range.
Listed in Table 3-2 can be the value as a design criterion, it just wire width, pad diameter, the smallest choice of the remaining space to provide a standard.
In general, choose single-sided or dual-panel must meet the cost of the most effective use. Experience with double-sided PTH PCB’s cost is a single panel of 5-10 times. Similarly, the cost of assembling components is also a need to consider the important aspects of a single-sided printed circuit board assembly components (manual) cost about 25% of board cost -50%, while assembling a band PTH The double-sided printed circuit board components, the cost is for the cost of -30% to 15%.
Printed circuit board not only provides mechanical support, but also on the components installed on it to play the role of the connection. Therefore, the designers of printed circuit board is necessary to know the physical size of the entire panel (frame size), the location of mounting holes, height restrictions and related details. The following is the mechanical design of printed circuit board to consider the main factors:
1) for the best production of printed circuit board panel size;
2) Panel mounting holes, brackets, plates, clamps, shielding box and the location of the radiator;
3) suitable for the heavier components of fixed installations;
4) Install the appropriate components aperture;
5) The assembled circuit board during transport to a compressive and shock resistance;
6) The circuit board assembly mode (vertically / horizontally);
8) components placed special demands, similar to the front panel operation of the components, such as: buttons, rheostat, etc..