JPH0413873B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to high-frequency connection lines for printed wiring boards, and particularly to conductor patterns and through-hole plating for connecting high-frequency components on printed wiring boards without using coaxial cords. It relates to a high frequency connection line consisting of.

BACKGROUND ART With the advancement of the information society, the demand for miniaturization of electronic devices is increasing, and technology for mounting various components on printed wiring boards has been widely adopted as a means of miniaturization. In computer and communication line circuits, components are mounted on printed wiring boards even for high frequencies of several MHz or higher, but in this case coaxial cords are used to suppress high frequency crosstalk.

Connections using conventional coaxial cords require time and effort to pre-treat the ends of the coating before connection, soldering is required and requires highly skilled soldering work, and paste cleaning after soldering is required. It had drawbacks such as time-consuming processing and low reliability.

Further, recently, printed wiring boards are being automatically designed, their assembly is being automated, and inspection is also being mechanized, but the use of coaxial cords has problems that impede automation and mechanization.

Problems to be solved by the invention Therefore, the problems to be solved by the invention are as follows:
An object of the present invention is to provide a high frequency connection line for connecting high frequency electronic components on a printed wiring board without using a coaxial cord.

Means for Solving the Problems Referring to FIGS. 1, 2, and 3, in the printed wiring board 1 according to the present invention, a front copper foil 3 and a back copper foil 4 are provided on both sides of an insulating substrate 2. stretched,
Both copper foils 3 and 4 are grounded. The insulating substrate 2 may be a plate made of a suitable insulating material, but preferably,
Constructed of glass cloth-based epoxy resin laminates, paper-based epoxy resin laminates, etc. Grounding is accomplished by connecting a suitable ground wire (not shown) to the copper foils 3,4.

Linear conductor pattern 5 formed on grounded copper foil 3
has lands 6 at both ends, and a pair of through-hole platings 7 are formed in parallel to the conductor pattern on the grounded copper foils 3 and 4 facing on both sides thereof. Each through-hole plating 7 has a plating layer 8 and short-circuits both copper foils 3 and 4. Linear conductor pattern 5
can be formed by a subtractive method in which the copper foils 3 or 4 are etched, or an additive method in which they are deposited on the insulating substrate 2 together with the copper foils 3 and 4.

In FIG. 2, each linear conductor pattern 5 has a row of through-hole plating 7, but the present invention is not limited to this, and as shown in FIG. A row of through-hole plating 7 may be provided on both sides of a group of a plurality of linear conductor patterns 5. The through-hole plating 7 only needs to be a means for short-circuiting both the copper foils 3 and 4, and may be a solid conductor, for example. Further, the copper foils 3 and 4 are conductive thin layers, and may be foils or thin films of gold, silver, aluminum, etc., for example.

Function The function of the high frequency connection line according to the present invention will be explained by an experimental example with reference to FIG. Two linear conductor patterns 5 each having a length of about 150 mm are placed on a printed wiring board (not shown) in the arrangement shown in the diagram on the right side of the figure.
formed on top. That is, the central portion of each strip (100 mm) was parallel to each other with a spacing of 6 mm, and the remaining strips were arranged so that the spacing between the two strip ends gradually increased toward the end. A signal source 9 was connected to one end of one linear conductor pattern 5, and the other end was grounded at 75Ω, and one end of the other conductor pattern 5 was grounded at 75Ω, and a level meter 9a was connected to the other end.

As an example of a high frequency connection line according to the present invention, through-hole plating 7 is provided in parallel to each linear conductor pattern 5.
The amount of crosstalk attenuation between the two linear conductor patterns 5 was measured for the case where a row of through-hole plating 7 was provided as a comparative example and the case where a row of through-hole plating 7 was not provided. The results are shown in the graph of FIG.

FIG. 3 shows a schematic cross-sectional view of a high-frequency connection line consisting of a linear conductor pattern 5 of the above-mentioned example of the present invention and a row of parallel through-hole plating 7 on both sides, and FIG. 4 shows a conductor pattern of the above-mentioned comparative example. A schematic cross-sectional view is shown.

In this example, the conductor width of the conductor pattern 5 was 0.8 mm, the nominal conductor thickness was 35 μm, the through hole diameter was 0.8 mm, and the through hole plating interval was 2.5 mm.

As is clear from the above graph, in the case of the high frequency connection line provided with the row of through-hole plating 7 according to the present invention, the crosstalk is 10 dB to 30 dB lower than the comparative example.
is decreasing. The frequency that gives the maximum crosstalk attenuation reaching 30 dB can be determined experimentally.

Thus, according to the invention, for example, a length of 100 mm
A high-frequency connection line that combines a linear conductor pattern 5 and a row of parallel through-hole plating 7 on both sides, rather than a coaxial cord,
It is possible to provide high frequency signals substantially without leakage.

The reason why a large amount of crosstalk attenuation can be obtained by providing rows of parallel through-hole plating 7 on both sides of the linear conductor pattern 5 is that, as can be seen from a comparison between FIGS. This is thought to be due to the fact that the row of through-hole plating 7 has the effect of shielding the linear conductor pattern 5.

Embodiment FIG. 6 shows, as an embodiment of the present invention, a coaxial connector 10 and a high-frequency relay installed on a wiring board 1a for actual equipment having high-frequency connection lines similar to the printed wiring board 1 shown in FIGS. 1 and 2. 11 is a perspective view of a high frequency relay device formed by mounting. Figure 7 shows
Actual measured values of the operating characteristics of this example are shown. Terminals A, B, C, D, E, and F in the connection diagram on the right side of Fig.
Of the coaxial connectors 6 in the figure, symbols A, B, C, D,
Corresponds to those marked E and F. As shown in the figure, using the high-frequency connection line according to the present invention, the crosstalk attenuation was 80 dB, which exceeded the target standard value at the frequency 140 MHz specified in the target standard, and the target standard value.
25dB mismatch attenuation and below target standard value
We were able to secure an insertion loss of 0.2dB.

In the above explanation, the printed wiring board is assumed to have a single layer of insulating board, but as is clear from a comparison between FIGS. 3 and 4, the high frequency connection line according to the present invention The same applies to

Effects of the Invention As explained above, the high-frequency connection line of the wiring board according to the present invention uses a combination of a conductor pattern and through-hole plated rows formed on both sides of the conductor pattern, and therefore has the following effects.

(b) By removing the coaxial cord from the connection wires on the wiring board, the man-hours required for coaxial cord pre-treatment, soldering, post-treatment, etc. can be saved.

(b) The quality of wiring boards becomes uniform.

(c) Reliability is improved because there is no soldering.

(d) Automatic design is possible because it consists only of a conductor pattern and through-hole plating.

(e) Easier automatic assembly since coaxial cords are omitted.

[Brief explanation of drawings]

FIG. 1 is a front view of a wiring board provided with a connection line according to the present invention, FIG. 2 is a back view thereof, FIG. 3 is a schematic sectional view of a connection line according to the present invention, and FIG. 4 is a schematic diagram of a conductor pattern. 5 is an explanatory diagram of an experimental example, FIG. 6 is a perspective view of an embodiment, and FIG. 7 is an explanatory diagram of operational characteristics of the embodiment. 1...Printed wiring board, 2...Insulating board, 3...
...Surface copper foil, 4...Back surface copper foil, 5...Conductor pattern, 6...Land, 7...Through hole plating,
8...Plating layer, 9...Signal source, 9a...Level meter, 10...Coaxial connector, 11...High frequency relay.

Claims (1)

[Claims] 1. In a wiring board in which grounded copper foil is pasted on both sides of an insulating substrate, a pair of through holes are plated in the grounded copper foil in areas facing both sides of a linear conductive pattern formed on the copper foil in parallel with the conductive pattern. High-frequency connection wires on printed wiring boards formed in rows.