Printed circuit board
View Patent ↗A printed circuit board includes an insulation layer and a signal layer attached to the insulation layer. The signal layer includes a pair of differential transmission lines. Width W of each of the differential transmission lines is changed according to change of space S between the differential transmission lines, based on the following formula: W = C 1 × H × ( C 2 × H 0.8 W 0 + T ) C 3 × ⅇ C 4 × S 0 H - 1 1 - C 3 × ⅇ C 4 × S H - 1.25 T In above formula, C1=7.475, C2=5.98, C3=0.48, C4=−0.96, H is a thickness of the insulation layer, W 0 is an original width of each of the differential transmission lines, and S 0 is an original space between the differential transmission lines, and T is a thickness of each of the differential transmission lines.
1. A printed circuit board comprising:
an insulation layer; and
a signal layer attached to the insulation layer, the signal layer comprising a pair of differential transmission lines, wherein width W of each of the differential transmission lines is changed according to change of space S between the differential transmission lines, based on the following formula:
W
=
C
1
×
H
×
(
C
2
×
H
0.8
W
0
+
T
)
C
3
×
ⅇ
C
4
×
S
0
H
-
1
1
-
C
3
×
ⅇ
C
4
×
S
H
-
1.25
T
wherein C1=7.475, C2=5.98, C3=0.48, C4=−0.96, H is a thickness of the insulation layer, W 0 is an original width of each of the differential transmission lines, and S 0 is an original space between the differential transmission lines, and T is a thickness of each of the differential transmission lines.
2. The printed circuit board of claim 1 , wherein each of the differential transmission lines is a microstrip line.
3. The printed circuit board of claim 1 , wherein one of the differential transmission lines is set in serpentine routing in the signal layer.
4. A printed circuit board comprising:
a first insulation layer;
a second insulation layer; and
a signal layer sandwiched between the first insulation layer and the second insulation layer, the signal layer comprising a pair of differential transmission lines, wherein width W of each of the differential transmission lines is changed according to change of space S between the differential transmission lines, based on the following formula:
W
=
C
1
×
H
×
(
C
2
×
H
0.8
W
0
+
T
)
C
3
×
ⅇ
C
4
×
S
0
H
-
1
1
-
C
3
×
ⅇ
C
4
×
S
H
-
1.25
T
wherein C1 =2.375, C2 =1.9, C3=0.347, C4=−2.8, W 0 is an original width of each of the differential transmission lines, and S 0 is an original space between the differential transmission lines, T is a thickness of each of the differential transmission lines, and
H
=
T
+
3
H
1
+
H
2
2
,
wherein H 1 is a thickness of the first insulation layer, and H 2 is a thickness of the second insulation layer.
5. The printed circuit board of claim 4 , wherein each of the differential transmission lines is a stripline.
6. The printed circuit board of claim 4 , wherein one of the differential transmission lines is set in serpentine routing in the signal layer.