Printed wiring board

Abstract

To obtain a printed wiring board that can reduce power consumption.SOLUTION: A high-speed data transmission wiring pattern satisfies relations, W12>1.5×W11 and W13>1.5×W11 where: W11 is a width of each data transmission wire; W12 is a distance between a first data transmission wire and a second data transmission wire; and W13 is a distance between the second data transmission wire and a third data transmission wire. A low-speed data transmission wiring pattern satisfies relations, W22≤1.5×W21 and W23≤1.5×W21 where: W21 is a width of each data transmission wire; W22 is a distance between a first data transmission wire and a second data transmission wire; and W23 is a distance between the second data transmission wire and a third data transmission wire. Surface roughness R1 of the high-speed data transmission wiring pattern is less than surface roughness R2 of the low-speed data transmission wiring pattern.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a printed wiring board including a low-speed data transmission path and a high-speed data transmission path. [Background technology]

[0002] A printed wiring board including a low-speed data transmission path and a high-speed data transmission path is known that transmits low-speed data as an electrical signal and high-speed data as an optical signal (see Patent Document 1).

[0003] In the technology disclosed in Patent Document 1, for high-speed data, an electrical signal is first converted into an optical signal, the converted optical signal is transmitted through an optical waveguide, and the optical signal is converted back into an electrical signal after transmission is complete. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2010-504663 Summary of the Invention [Problem to be solved by the invention]

[0005] The technology disclosed in Patent Document 1 involves converting an electrical signal into an optical signal and converting an optical signal into an electrical signal, which results in a large amount of power consumption for the conversion. [Means for solving the problem]

[0006] A printed wiring board according to the present invention is a printed wiring board including a substrate, and a wiring pattern for high-speed data transmission and a wiring pattern for low-speed data transmission formed on the substrate, wherein the wiring pattern for high-speed data transmission satisfies the relationship W12>1.5×W11 and W13>1.5×W11 in adjacent first, second and third data transmission wirings, where W11 is the width of each data transmission wiring, W12 is the distance between the first data transmission wiring and the second data transmission wiring, and W13 is the distance between the second data transmission wiring and the third data transmission wiring. and wherein, in adjacent first, second and third data transmission wires, the low-speed data transmission wiring pattern satisfies the relationship W22≦1.5×W21 and W23≦1.5×W21, where W21 is the width of each data transmission wire, W22 is the distance between the first data transmission wire and the second data transmission wire, and W23 is the distance between the second data transmission wire and the third data transmission wire, and the high-speed data transmission wiring pattern has a surface roughness R1 that is less than the surface roughness R2 of each data transmission wire of the low-speed data transmission wiring pattern. [Brief description of the drawings]

[0007] [Figure 1] 1 is a diagram for explaining an embodiment of a printed wiring board according to the present invention; [Figure 2A] 1 is a diagram for explaining an embodiment of surface roughening of wiring in a printed wiring board according to the present invention. FIG. [Figure 2B] 1 is a diagram for explaining an embodiment of surface roughening of wiring in a printed wiring board according to the present invention. FIG. [Figure 2C] 1 is a diagram for explaining an embodiment of surface roughening of wiring in a printed wiring board according to the present invention. FIG. [Figure 2D] 1 is a diagram for explaining an embodiment of surface roughening of wiring in a printed wiring board according to the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] <About the printed wiring board of the present invention> An embodiment of a printed wiring board of the present invention will be described with reference to the drawings. In the example shown in Figures 1 and 2, the dimensions of each member, particularly the height dimension, are shown in dimensions different from the actual dimensions in order to make the features of the present invention easier to understand.

[0009] Fig. 1 is a cross-sectional view for explaining one embodiment of a printed wiring board according to the present invention. In Fig. 1, the printed wiring board 1 includes a substrate 2, and a wiring pattern 10 for high-speed data transmission and a wiring pattern 20 for low-speed data transmission formed on the substrate 2. In addition, the wiring pattern 10 for high-speed data transmission and the wiring pattern 20 for low-speed data transmission are covered and protected by a resin insulating layer 3 on the substrate 2.

[0010] The printed wiring board 1 may be a cored board formed by alternately laminating conductor layers and resin insulating layers having a predetermined circuit pattern on one or both sides of a core board (not shown). When conductor layers are formed on both sides of the core board, the conductor layers facing each other through the core board may be connected via through-hole conductors (not shown). Alternatively, the printed wiring board 1 may be a coreless board formed by alternately laminating conductor layers and resin insulating layers on a support board (not shown) instead of a core board, and then removing the support board. In any case, as shown in FIG. 1, the printed wiring board 1 includes a board 2 which is the outermost of at least one resin insulating layer, and a high-speed data transmission wiring pattern 10 and a low-speed data transmission wiring pattern 20 formed on the board 2. In many cases, other conductor layers and resin insulating layers are alternately provided under the board 2, but these are omitted in the figure.

[0011] In the printed wiring board 1 according to the present invention shown in FIG. 1, the high-speed data transmission wiring pattern 10 has first, second and third adjacent data transmission wirings 11-1 to 11-3. When the width of each data transmission wiring is W11, the distance between the first data transmission wiring 11-1 and the second data transmission wiring 11-2 is W12, and the distance between the second data transmission wiring 11-2 and the third data transmission wiring 11-3 is W13, the relationship W12>1.5×W11 and W13>1.5×W11 is satisfied.

[0012] Furthermore, in the printed wiring board 1 according to the present invention shown in FIG. 1, the wiring pattern 20 for low-speed data transmission satisfies the relationship W22≦1.5×W21 and W23≦1.5×W21 in which, in the adjacent first, second and third data transmission wirings 21-1 to 21-3, the width of each data transmission wiring is W21, the distance between the first data transmission wiring 21-1 and the second data transmission wiring 21-2 is W22, and the distance between the second data transmission wiring 21-2 and the third data transmission wiring 21-3 is W23.

[0013] 1, the surface roughness R1 of each of the data transmission wires 11-1 to 11-3 of the high-speed data transmission wiring pattern 10 is less than the surface roughness R2 of each of the data transmission wires 21-1 to 21-3 of the low-speed data transmission wiring pattern 20. In the high-speed data transmission wiring pattern 10, the root-mean-square roughness Rq of the surface roughness R1 of each of the data transmission wires 11-1 to 11-3 is preferably 0.23 μm or less, more preferably 0.1 μm or less. In the low-speed data transmission wiring pattern 20, the root-mean-square roughness Rq of the surface roughness R2 of each of the data transmission wires 21-1 to 21-3 is preferably 0.4 μm or more, more preferably 0.5 μm or more.

[0014] 1, the embodiment of the printed wiring board according to the present invention uses a high-speed data transmission wiring pattern 10 for transmitting high-speed data. Therefore, the conversion between electrical signals and optical signals that was conventionally required is no longer necessary, and power consumption can be reduced compared to the case where an optical waveguide is used for transmitting high-speed data.

[0015] 1, in the embodiment of the printed wiring board according to the present invention, in the high-speed data transmission wiring pattern 10, the intervals W12 and W13 arranged on both sides of the second data transmission wiring 11-2 are greater than 1.5 times the width W11 of the wiring pattern 10, so that high-speed data is less likely to be degraded. Also, since the surface roughness R1 of each of the data transmission wirings 11-1 to 11-3 of the high-speed data transmission wiring pattern 10 is less than the surface roughness R2 of each of the data transmission wirings 21-1 to 21-3 of the low-speed data transmission wiring pattern 20, the widths W12 and W13 are wide in the high-speed data transmission wiring pattern 10 portion, and the surface roughness of each of the data transmission wirings 21-1 to 21-3 in the low-speed data transmission wiring pattern 20 portion is rough, so that the high-speed data transmission wiring pattern 10 and the low-speed data transmission wiring pattern 20 are less likely to peel off from the resin insulating layer 3.

[0016] The reason why data degradation during high-speed data transmission is less likely in the high-speed data transmission wiring pattern 10 is believed to be due to the following. In this embodiment, the width W2 between the first data transmission wiring 11-1 and the second data transmission wiring 11-2 and the width W3 between the second data transmission wiring 11-2 and the third data transmission wiring 11-3 are formed wide. Therefore, the capacitance of the capacitor in the portions of the widths W2 and W3 between the adjacent data transmission wirings can be reduced, and data degradation is believed to be less likely even during high-speed data transmission.

[0017] <Surface roughening of wiring in printed wiring board according to the present invention> 2A to 2D are diagrams for explaining one embodiment of surface roughening of wiring in a printed wiring board according to the present invention. Hereinafter, the surface roughening of wiring in a printed wiring board according to the present invention will be described with reference to FIGS. 2A to 2D.

[0018] First, as shown in FIG. 2A, a wiring pattern 10 for high-speed data transmission and a wiring pattern 20 for low-speed data transmission are formed on a substrate 2.

[0019] In this embodiment, the high-speed data transmission wiring pattern 10 is composed of adjacent first, second and third data transmission wirings 11-1 to 11-3, and when the width of each data transmission wiring is W11, the distance between the first data transmission wiring 11-1 and the second data transmission wiring 11-2 is W12, and the distance between the second data transmission wiring 11-2 and the third data transmission wiring 11-3 is W13, the relationships W12>1.5×W11 and W13>1.5×W11 are satisfied.

[0020] In addition, in this embodiment, the low-speed data transmission wiring pattern 20 is composed of adjacent first, second and third data transmission wirings 21-1 to 21-3, and when the width of each data transmission wiring is W21, the distance between the first data transmission wiring 21-1 and the second data transmission wiring 21-2 is W22, and the distance between the second data transmission wiring 21-2 and the third data transmission wiring 21-3 is W23, the relationships W22≦1.5×W21 and W23≦1.5×W21 are satisfied.

[0021] Next, a first conductor roughening is performed uniformly on the surface of each data transmission wiring in the high-speed data transmission wiring pattern 10 and the low-speed data transmission wiring pattern 20 formed as shown in Fig. 2A. Then, data transmission wirings 11-1 to 11-3 and data transmission wirings 21-1 to 21-3, each of whose surfaces is uniformly roughened, are obtained as shown in Fig. 2B.

[0022] Next, as shown in Fig. 2C, a mask 31 is formed on the portion of the wiring pattern 10 for high-speed data transmission. Next, a second conductor roughening is uniformly performed on the intermediate body formed as shown in Fig. 2C in which the portion of the wiring pattern 10 for high-speed data transmission is covered with the mask 31. In this second roughening, the portion of the wiring pattern 10 for high-speed data transmission is not roughened due to the presence of the mask 31, and only the portion of the wiring pattern 20 for low-speed data transmission is roughened.

[0023] Thereafter, the mask 31 is removed from the intermediate body that has been subjected to the second roughening. As a result, as shown in Fig. 2D, the printed wiring board 1 according to the present invention can be formed in which the surface roughness R1 of each of the data transmission wires 11-1 to 11-3 of the high-speed data transmission wiring pattern 10 is less than the surface roughness R2 of each of the data transmission wires 21-1 to 21-3 of the low-speed data transmission wiring pattern 20. Finally, the resin insulating layer 3 covers and protects the entire surface of the printed wiring board 1 in the state shown in Fig. 2D.

[0024] In the high-speed data transmission wiring pattern 10, the root-mean-square roughness Rq of the surface roughness R1 of each of the data transmission wires 11-1 to 11-3 is preferably 0.23 μm or less, more preferably 0.1 μm or less. In the low-speed data transmission wiring pattern 20, the root-mean-square roughness Rq of the surface roughness R2 of each of the data transmission wires 21-1 to 21-3 is preferably 0.4 μm or more, more preferably 0.5 μm or more.

[0025] In addition, in the above-described embodiment, the conductor roughening was performed twice, that is, the first conductor roughening and the second conductor roughening. However, if the surface roughness R1 of the surface of each of the data transmission wirings 11-1 to 11-3 of the high-speed data transmission wiring pattern 10 satisfies the above-mentioned preferred conditions at the time of formation, the first conductor roughening can be omitted and only the second conductor roughening can be performed. [Explanation of symbols]

[0026] 1 Printed wiring board 2. Board 3 Resin insulation layer 10. Wiring patterns for high-speed data transmission 11-1 First data transmission wiring 11-2 Second data transmission wiring 11-3 Third data transmission wiring 20 Wiring patterns for low-speed data transmission 21-1 First data transmission wiring 21-2 Second data transmission wiring 21-3 Third data transmission wiring 31 Mask

Claims

1. A substrate; A printed wiring board including a wiring pattern for high-speed data transmission and a wiring pattern for low-speed data transmission formed on the substrate, in the high-speed data transmission wiring pattern, in adjacent first, second and third data transmission wirings, when the width of each data transmission wiring is W11, the distance between the first data transmission wiring and the second data transmission wiring is W12, and the distance between the second data transmission wiring and the third data transmission wiring is W13, the relationships W12>1.5×W11 and W13>1.5×W11 are satisfied, the low-speed data transmission wiring pattern, in adjacent first, second and third data transmission wirings, satisfies the relationships W22≦1.5×W21 and W23≦1.5×W21, where W21 is the width of each data transmission wiring, W22 is the distance between the first data transmission wiring and the second data transmission wiring, and W23 is the distance between the second data transmission wiring and the third data transmission wiring; a surface roughness R1 of each data transmission wire of the high-speed data transmission wiring pattern is less than a surface roughness R2 of each data transmission wire of the low-speed data transmission wiring pattern; A printed wiring board comprising:

2. 2. The printed wiring board according to claim 1, A printed wiring board, characterized in that, in the wiring pattern for high-speed data transmission, the root mean square roughness Rq of the surface roughness R1 of each data transmission wiring is 0.23 μm or less, and in the wiring pattern for low-speed data transmission, the root mean square roughness Rq of the surface roughness R2 of each data transmission wiring is 0.4 μm or more.

3. 2. The printed wiring board according to claim 1, A printed wiring board, characterized in that, in the wiring pattern for high-speed data transmission, the root mean square roughness Rq of the surface roughness R1 of each data transmission wiring is 0.10 μm or less, and in the wiring pattern for low-speed data transmission, the root mean square roughness Rq of the surface roughness R2 of each data transmission wiring is 0.5 μm or more.

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