Patent ID: 11742619

Abstract:
In this circuit board 30, first signal wiring portions 351 and second ground wiring portions 353 of a first wiring layer 34 are adjacent to each other in a pitch direction. Further, second signal wiring portions 381 and first ground wiring portions 383 of a second wiring layer 37 are adjacent to each other in the pitch direction. In the pitch direction, outer edges 405 of line portions 345 of two first signal wiring portions 351 are located more inward than both edges 435 of a line portion 375 of the first ground wiring portions 383. Outer edges 415 of line portions 375 of two second wiring portions 381 are located more inward than both edges 425 of the line portion 345 of the second ground wiring portion 353. This achieves good signal transmission characteristics without providing a ground layer separate from a signal layer.