1.  the soft and hard combination board should consider the installation of electronic components, electrical conductivity and signal transmission performance after insertion, so the impedance will

be required as low as possible, and the resistivity should be lower than 1&TImes:10-6 per square centimeter.

2.  in the production process to go through the process of production, and the materials used in these links must ensure that the resistivity is low, in order to ensure that the overall impedance of the

soft and hard combined board to meet the product quality requirements, can operate normally.

3.  there will be a variety of signal transmission in the conductor of the soft and hard board, when to improve its transmission rate and must increase its frequency, the line itself if the etching,

laminated thickness, wire width and other factors are different, will cause the impedance change, so that the signal distortion, resulting in the use of the circuit board performance decline, so you

need to control the impedance value in a certain range.

The pad used for welding the external assembly components is not allowed to double as a test point, and a special test pad must be preset in addition to ensure that the solder joint inspection and

production debugging are carried out. The welding pad used for testing is arranged on the unified side of the soft and hard bonding plate as far as possible, which is conducive to reducing the cost of

testing even in testing.