Printed circuit board

[0014] See figure 1 and figure 2 , Is the printed circuit board 100 of the first embodiment of the present invention. The printed circuit board 100 includes a first signal layer 10, a first reference layer 20, a second signal layer 30, a third signal layer 40, a second reference layer 50, and a bottom layer that are sequentially stacked from top to bottom. 60.

[0015] Please combine image 3 and Figure 4 The first signal layer 10 includes a wiring layer 12 and a connection layer 14 opposite to the wiring layer 12. A first differential pair 16 is arranged on the wiring layer 12 in an edge coupling manner. The first differential pair 16 includes a first differential transmission line 162 and a second differential transmission line 164. The first differential transmission line 162 and the second differential transmission line 164 are adjacent in parallel and coupled to each other. The first differential transmission line 162 includes a first connection end 162a. The second differential transmission line 164 includes a second connecting end 164a. Electronic components (not shown), such as capacitors, resistors, and inductors, are also arranged on the first wiring layer 12.

[0016] The first reference layer 20 and the second reference layer 50 are used to ensure signal transmission quality, and the first reference layer 20 and the second reference layer 50 may be ground layers or power layers. The first reference layer 20 is closely attached to the first connection layer 14 and the second signal layer 30 respectively. The second reference layer 50 is closely attached to the third signal layer 40 and the bottom layer 60 respectively. The bottom layer 60 is closely attached to the second reference layer 50. Electronic components (not shown), such as capacitors, resistors, and inductors, can also be arranged on the bottom layer 60.

[0017] A second differential pair 30a is arranged on the second signal layer 30 and the third signal layer 40 in a broadside coupling manner. The second differential pair 30 a includes a third differential transmission line 32 arranged in the second signal layer 30 and a fourth differential transmission line 42 arranged in the third signal layer 40. The third differential transmission line 32 includes a third connecting end 322. The fourth differential transmission line 42 includes a fourth connection end 422. The third differential transmission line 32 and the fourth differential transmission line 42 are coupled to each other.

[0018] The printed circuit board 100 is further provided with a first inclined via 102 and a second inclined via 104. The spatial positional relationship between the first inclined via hole 102 and the second inclined via hole 104 is different, that is, they do not intersect or are parallel to each other. The first inclined via 102 penetrates the first signal layer 10 and the first reference layer 20. One end of the first inclined via hole 102 is electrically connected to the first connecting terminal 162a, and the other end is electrically connected to the third connecting terminal 322, so that the first differential transmission line 162 and the third differential transmission line 32 are electrically connected. The second inclined via hole 104 penetrates the first signal layer 10, the first reference layer 20 and the second signal layer 30. One end of the second inclined via hole 104 is electrically connected to the second connecting terminal 164a, and the other end is electrically connected to the fourth connecting terminal 422, so as to realize the electrical connection between the second differential transmission line 164 and the fourth differential transmission line 42.

[0019] The first differential pair 16 in the first signal layer 10 only uses the first reference layer 20 as the reference layer. At this time, the electric field of the first differential pair 16 is mostly distributed between the first reference layer 20 and the first differential pair 16 Between the first differential transmission line 162 and the second differential transmission line 164, there is less crosstalk to the second differential pair 30a of the second signal layer 30 and the third signal layer 40. The second differential pair 30a uses the first reference layer 20 and the second reference layer 50 as reference layers. At this time, the electric field of the second differential pair 30a is mostly distributed between the third differential transmission line 32 and the third differential transmission line 32 and the second differential pair 30a. Between the fourth differential transmission lines 42, there is less crosstalk to the first signal layer 10. In this embodiment, the second differential pair 30a is located on the vertical bisector connecting the centers of the first differential transmission line 162 and the second differential transmission line 164 (please download from image 3 Can also be seen from the X direction figure 2 It can be seen), therefore, the less noise crosstalk from the first differential pair 16 to the second differential pair 30a will be due to the first differential transmission line 162 and the second differential transmission line 164 being transmitted as signals of equal magnitude and opposite directions. The crosstalk on the second differential pair 30a cancels each other out to be very small or even zero.

[0020] It can be understood that the second differential pair 30a may also vertically correspond to the first differential transmission line 162 ( Figure 5 Show), or the second differential pair 30a may be vertically corresponding to the second differential transmission line 164, or other positional relationship, as long as the space between the first inclined via 102 and the second inclined via 104 is ensured The positional relationship does not need to intersect each other.

[0021] The printed circuit board 100 provided by the present invention directly electrically connects the first differential transmission line 162 with the third differential transmission line 32 by using the first inclined via 102, and uses the second inclined via 104 to connect the second differential transmission line 164 with the fourth differential transmission line 42 Direct electrical connection to shorten the length of the uncoupled line segment added in each transmission line, and to keep the differential signal impedance between the differential pairs as consistent as possible, so as to ensure the signal transmission quality.

[0022] It is understandable that for those of ordinary skill in the art, various other corresponding changes and modifications can be made according to the technical concept of the present invention, and all these changes and modifications should fall within the protection scope of the claims of the present invention.