First, you want to have a complete understanding of the components and a variety of socket specifications, dimensions and area of choice; arrangement of the components of the position of a reasonable, careful consideration, mainly from electromagnetic compatibility, interference angle traces short cross less power, ground and decoupling path and other considerations. After the location of the components set is the online components, in accordance with the relevant circuit diagram connecting pins, there are several ways to complete printed circuit diagram design and computer-aided design manual design two ways. Next, determine the size of the printed circuit board required, press schematics, initially identified the location of the various components down, and then through constant adjustments to make more rational layout, wiring arrangement between the components of the printed circuit board as follows:
(1) are not allowed in the printed circuit cross circuit, may cross the line, you can use the "drill", "around" two kinds of solutions. That is, let a lead from the gap at the other resistors, capacitors, transistors at the foot of the "drill" in the past, or from one end of a cross section may lead "around" in the past, in exceptional circumstances if the circuit is very complicated, to simplify design allows the jumper wire, cross-circuit problem solving.
(2) resistors, diodes, capacitors and other components are tubular, "vertical", "horizontal" two installation methods. Vertical refers to the component perpendicular to a circuit board mounting, solder, the advantage of saving space, the horizontal refers to the component parallel to and close to the body of the circuit board mounting, solder, the advantage of better mechanical strength of the components installed. These two different installation components, printed circuit board assembly pitch is not the same.
(3) the same level circuits should be as close to the ground, and power supply filter capacitor circuits at this level should also be connected on the level ground. In particular, the level of the transistor base and emitter of the ground is not too far away, otherwise it would be too long because of the copper foil between the two ground causing interference with the self-excited, the use of such a "point ground method" circuit, working over the stability, not the self-excited.
(4) The total ground must be strictly in accordance with the high-frequency - IF - low frequency level by level to weak to strong electric order principle, must not just repetitious random access, inter-stage and grade can be rather long connection point, To comply with this requirement. In particular frequency head, the playback head, the head of the grounding wire FM arrangements more stringent requirements, if any, will arise from improper excited that does not work. Prime FM frequency circuit is often used large wraparound ground, in order to ensure a good shielding effect.
(5) a strong current lead (common ground, amplifier power lead, etc.) should be as wide as those to reduce wiring resistance and voltage drop can be reduced parasitic coupling arising from shock.
(6) high impedance traces short, low impedance traces can be longer because of the high impedance traces prone flute and absorption signals, causing circuit instability. Power lines, ground, no feedback component base alignment, the emitter lead, etc. are low-impedance traces emitter follower base alignment, ground recorders of both channels must be separated into their own way until the end of efficacy together again, even if the two-way to connect the ground wire to easily generate crosstalk, the separation decreased.
