| 摘要 |
The invention discloses a characteristic impedance accuracy control structure of a signal transmission circuit board. A plurality of extended first signal transmission paths are formed on a base plate, a first covering insulating layer is formed on the first surface of the base plate, and the surface of each first signal transmission path and spacers among the first signal transmission paths are covered. The signal transmitted by each first signal transmission path is a different-mode signal or a common-mode signal. At least one first planarization insulating layer is formed between the surface of the covering insulating layer and the first conductive shielding layer, and the first planarization insulating layer fills altitude difference between the surface of each first signal transmission path and interval among each first signal transmission path, thus fixed distance between the signal transmission path and the conductive shielding layer can be guaranteed, and the aim of controlling characteristic impedance accuracy of the signal transmission circuit board is achieved. |
