Abstract: To suppress occurrence of a difference in transmission time due to a difference in length between signal lines, there is provided a printed wiring board having: an insulating substrate (10); a first signal line (L31) formed on the insulating substrate (10); a second signal line (L32) having a shorter length than that of the first signal line (L31); and a ground layer (30) formed for the first signal line (L31) and the second signal line (L31) via an insulating material (10). The ground layer (30) includes a first ground layer (G31) corresponding to a first region (D1) and a second ground layer (G32) corresponding to a second region (D2). The first region (D1) is defined based on the first signal line (L31) and has a first predetermined width (W31). The second region (D2) is defined based on the second signal line (L32) and has a second predetermined width (W32). The first ground layer (G31) has a remaining ratio lower than a remaining ratio of the second ground layer (G32).

Abstract: To suppress occurrence of a difference in transmission time due to a difference in length between signal lines, there is provided a printed wiring board having: an insulating substrate (10); a first signal line (L31A) that constitutes differential signal lines formed on the insulating substrate (10) and includes a curved portion; a second signal line (L31B) provided along the first signal line (L31A) and side by side inside the curved portion; and a ground layer (30) formed for the first signal line (L31A) and the second signal line (L31B) via an insulating material (10). The ground layer (30) includes a first ground layer (G31A) corresponding to a first region (D1) and a second ground layer (G31B) corresponding to a second region (D2). The first region (D1) is defined based on the first signal line (L31A) and has a first predetermined width (W31A). The second region (D2) is defined based on the second signal line (L31B) and has a second predetermined width (W31B).

Abstract: To suppress occurrence of a difference in transmission time due to a difference in length between signal lines, there is provided a printed wiring board having: an insulating substrate (10); a first signal line (L31A) that constitutes differential signal lines formed on the insulating substrate (10) and includes a curved portion; a second signal line (L31B) provided along the first signal line (L31A) and side by side inside the curved portion; and a ground layer (30) formed for the first signal line (L31A) and the second signal line (L31B) via an insulating material (10). The ground layer (30) includes a first ground layer (G31A) corresponding to a first region (D1) and a second ground layer (G31B) corresponding to a second region (D2). The first region (D1) is defined based on the first signal line (L31A) and has a first predetermined width (W31A). The second region (D2) is defined based on the second signal line (L31B) and has a second predetermined width (W31B).

Abstract: To suppress occurrence of a difference in transmission time due to a difference in length between signal lines, there is provided a printed wiring board having: an insulating substrate (10); a first signal line (L31) formed on the insulating substrate (10); a second signal line (L32) having a shorter length than that of the first signal line (L31); and a ground layer (30) formed for the first signal line (L31) and the second signal line (L31) via an insulating material (10). The ground layer (30) includes a first ground layer (G31) corresponding to a first region (D1) and a second ground layer (G32) corresponding to a second region (D2). The first region (D1) is defined based on the first signal line (L31) and has a first predetermined width (W31). The second region (D2) is defined based on the second signal line (L32) and has a second predetermined width (W32). The first ground layer (G31) has a remaining ratio lower than a remaining ratio of the second ground layer (G32).

Abstract: The printed wiring board has a conductor of signal line 41 and two conductive lines 42 on one face of the first insulating layer 10 covered by a second insulating layer 20, while having a ground layer of the ground 30 potential on the opposite face thereof, when the dielectric tangent A of the second insulating layer (insulating layer A) 20 is larger than the dielectric tangent B of the first insulating layer (insulating layer B) 10, Relational Expression 1: (relative permittivity B)·(width (W41) of signal line(s) 41)/(thickness (T10) of first insulating layer (insulating layer B) 10)>(relative permittivity A)·{(thickness (T41) of signal line(s) 41)/(distance (S1) between signal line(s) 41 and one conductive line 42a)+(thickness (T41) of signal line(s) 41)/(distance (S2) between signal line(s) 41 and other conductive line 42b)+(thickness (T41) of signal lines 41)/(distance (S3) between pair of signal lines (41a and 41b)·2} is satisfied.

Abstract: Quickly making changes to etching conditions suppresses the production yield of printed wiring boards from being deteriorated. Disclosed is a method comprising: an etching step that comprises: preparing a conductor-clad base material continuous in a certain direction, the conductor-clad base material (1) having an insulating layer and one or more conductive layers formed on main surfaces of the insulating layer; and subjecting a predetermined region of a conductor layer of one main surface of the conductor-clad base material (1) to an etching process thereby to form a wiring pattern (1a) to be of a product and an inspection pattern (1b) to be used for inspection; a measuring step that measures a line width of the inspection pattern after the etching step; and a control step that controls an etching condition in the etching step based on the measured line width.

Abstract: Quickly making changes to etching conditions suppresses the production yield of printed wiring boards from being deteriorated. Disclosed is a method comprising: an etching step that comprises: preparing a conductor-clad base material continuous in a certain direction, the conductor-clad base material (1) having an insulating layer and one or more conductive layers formed on main surfaces of the insulating layer; and subjecting a predetermined region of a conductor layer of one main surface of the conductor-clad base material (1) to an etching process thereby to form a wiring pattern (1a) to be of a product and an inspection pattern (1b) to be used for inspection; a measuring step that measures a line width of the inspection pattern after the etching step; and a control step that controls an etching condition in the etching step based on the measured line width.

Abstract: The printed wiring board has a conductor of signal line 41 and two conductive lines 42 on one face of the first insulating layer 10 covered by a second insulating layer 20, while having a ground layer of the ground 30 potential on the opposite face thereof, when the dielectric tangent A of the second insulating layer (insulating layer A) 20 is larger than the dielectric tangent B of the first insulating layer (insulating layer B) 10, Relational Expression 1: (relative permittivity B)·(width (W41) of signal line(s) 41)/(thickness (T10) of first insulating layer (insulating layer B) 10)>(relative permittivity A)·{(thickness (T41) of signal line(s) 41)/(distance (S1) between signal line(s) 41 and one conductive line 42a)+(thickness (T41) of signal line(s) 41)/(distance (S2) between signal line(s) 41 and other conductive line 42b)+(thickness (T41) of signal lines 41)/(distance (S3) between pair of signal lines (41a and 41b)·2} is satisfied.

Abstract: A circuit board 1 comprises: an insulating substrate 10; and electric circuit patterns 20 formed on the insulating substrate 10. Each electric circuit pattern 20 has: a mounting pad section 30; and a wiring section 40 extending from the mounting pad section 30. The mounting pad section 30 has a first nonparallel surface 32a inclined to or substantially orthogonally intersecting a main surface 41 of the wiring section 40.