JPH0595094U - Printed wiring board structure - Google Patents

Abstract

(57) [Abstract] [Purpose] It can be used as a common part without special processing such as notches in the shield case that covers each circuit, and only the printed board can be freely made to change the circuit after assembly and the pattern accompanying it. Improve freedom of change. [Structure] A plurality of circuits 2 (2A, 2
B, 2C) is formed, and each circuit 2 is covered with a shield case 3 (3A, 3B, 3C) from above and below the printed board 1 so that signals do not interfere with each other. On the printed circuit board 1 where the upper and lower peripheral wall end faces 3a, 3b of the shield cases 3A, 3C covering the circuits 2A, 2C to be wired are located, there are through holes 4 of a predetermined size extending into the respective shield cases 3A, 3C. Has been formed. The through holes 4 are inserted with their outer circumferences in contact with the upper and lower peripheral wall end surfaces 3a, 3b of the shield cases 3A, 3C, and the desired circuits 2A, 2C are wired.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a printed circuit board wiring structure for wiring between predetermined circuits in a plurality of circuits individually covered by a shield case so that signals of one printed circuit board do not interfere with each other.

[0002]

[Prior Art]

 For example, when multiple circuits are formed on a single printed circuit board and isolation (no interference of signals between the circuits) is required, as shown in Fig. 4, a rectangular metal plate is used. The shield case 21 (21A, 21B, 21C) covers the respective circuits 23 (23A, 23B, 23C) from above and below the print plate 22.

By the way, in the configuration in which each circuit 23 is covered with the shield case 21 as described above, a predetermined impedance (for example, 50Ω) is formed in the notch 24 formed in the peripheral wall 21a of the shield case 21 as shown in FIG. The circuits 23 are wired through a cable (for example, a coaxial cable) 25 having a cable, and signals are transmitted between the circuits 23. At this time, the outer peripheral surface 25a of the cable 25 is grounded by contacting the notch 24 of the shield case 21 and the ground pattern 22a of the printed board 22 to shield each shield case 21.

[0004]

[Problems to be solved by the device]

 However, in the above-described conventional wiring structure, the notch 24 formed in the peripheral wall 21a of the shield case 21 needs to be processed for each shield case 21 to be wired, and the position where the notch 24 is formed is different. Since not all shield cases 21 are the same, it was not possible to share parts.

When there are a large number of wirings between the circuits 23 adjacent to each other, as shown in FIG. 6, the notches 24 of the shield case 21 may communicate with each other to form a large hole, and wirings between the circuits 23 may be formed. A gap 26 is formed between the cable 25 and the cutout 24, and a signal leaks from the gap 26, so that each circuit 23 cannot be shielded sufficiently.

Further, when the cables are closely arranged and wired between different circuits, it is necessary to separate the cables when the signals guided by the cables interfere with each other. However, in the conventional structure, not only is it necessary to newly form a notch in the shield case 21, but there is a problem that a signal leaks from the original unnecessary notch and sufficient shielding cannot be performed. . Further, even if the desired characteristics cannot be obtained after assembly and a circuit needs to be added separately, and wiring for the signal line and the power supply line is required, it is necessary to form a new notch in the shield case 21. there were.

Therefore, in the conventional structure, when the pattern of the printed board or the wiring route is changed after the assembly, the notch 24 needs to be formed in the shield case 21 each time, and the circuit change after the assembly or There was a problem that the degree of freedom of changing the pattern was not effective.

Therefore, the present invention has been made in view of the above problems, and an object thereof is to be used as a common component without performing special processing such as notches in a shield case that covers each circuit, It is to provide a printed circuit board wiring structure in which only the printed circuit board can be freely made according to the pattern change after assembly.

[0009]

[Means for Solving the Problems]

 In order to achieve the above object, the printed circuit board wiring structure according to the present invention includes a printed circuit board 1 on which a plurality of circuits 2 are formed and a circuit board from above and below each circuit so that signals do not interfere with each other. The shield case 3 for covering and the printed board on which the peripheral wall end surfaces 3a, 3b of the shield case for covering the circuit to be wired are located are formed with a predetermined size so as to communicate from the inside of the shield case to the outside thereof. The wiring hole 4 (8) and the wire 6 having an outer diameter with which the end face of the peripheral wall of the shield case comes into contact and for wiring between the circuits to be wired through the wiring hole are characterized.

[0010]

[Action]

 A plurality of circuits 2 are formed on the printed board 1, and each circuit 2 is provided with a shield case 3 (3A, 3B, 3C) from above and below the printed board 1 to prevent signals from interfering with each other. ) Is covered by. The peripheral wall end faces 3a and 3b of the shield case 3 that covers the circuit 2 (for example, the circuit 2A and the circuit 2C) to be wired are located on the printed board 1. Through holes 4 (grooves 8) are formed as wiring holes of a predetermined size. Wires 6 are inserted through the through holes 4 (grooves 8) so that the outer circumferences thereof come into contact with the peripheral wall end surfaces 3a and 3b of the shield case 3, and the desired circuits 2 are wired.

[0011]

【Example】

 FIG. 1 is a diagram showing an embodiment of a printed circuit board wiring structure according to the present invention, and FIGS. 2 (a) and 2 (b) are sectional views showing a wiring portion of the same structure.

A circuit component is mounted on a predetermined circuit pattern (not shown) formed on one printed board 1 to form a plurality of circuits 2 (2A, 2B, 2C). Each of the circuits 2A, 2B, 2C is individually covered from above and below the printed board 1 by a metal shield case 3 (3A, 3B, 3C) which is molded, cut, or sheet metal into a rectangular shape.

Further, on the printed circuit board 1 where the upper and lower peripheral wall end surfaces 3a and 3b of the shield case 3 between the circuits to be wired (for example, between the circuit 2A and the circuit 2B) are located, the upper and lower peripheral wall end surfaces serve as boundaries. A through hole (wiring hole) 4 having a predetermined dimension L2 is formed to extend inside the shield case 3 and be longer than the thickness L1 of the peripheral wall end faces 3a and 3b. The extending portion of the through hole 4 will be described later. The wire 6 is designed to have a length necessary for routing.

The through holes 4 are collectively formed when the printed board 1 is cut and holes for through screws and through holes are processed. As a result, a gap 5 having substantially the same size L4 as the plate thickness L3 of the printed board 1 is formed between the upper and lower peripheral wall end surfaces 3a and 3b of each shield case 3, and the upper and lower peripheral wall end surfaces 3a and 3b of each shield case 3 are printed. It is flush with the board 1.

Further, a wire 6 such as a coaxial cable is inserted through the through hole 4. This wire 6 is wired between the circuits 2 so that signals can be mutually transmitted, and its outer diameter L5 is formed to be slightly larger than the gap 5 between the upper and lower peripheral wall end faces 3a and 3b of the shield case 3. . When the shield case 3 is fixed to the printed board 1, the upper and lower peripheral wall end surfaces 3a and 3b of the shield case 3 press the upper and lower outer peripheries 6a of the wire material 6 to ground them to shield each circuit 2.

Further, on the printed board 1, a plurality of through holes 7 for reducing high frequency impedance are formed around the through holes 4. As a result, signal leakage from the through holes 4 is reduced, and the shielding between the circuits 2 is sufficiently maintained.

Therefore, in the above-described embodiment, in order to cover each circuit 2 with the shield case 3 and shield each circuit 2, it is necessary to perform special processing such as a notch on the shield case 3 as in the conventional case. Since it is not provided, the cost can be reduced and the shield case 3 can be used as a common component of each circuit 2.

In addition, it is necessary to separate the wire rods 6 where signals interfere with each other after assembly, or it is necessary to add another circuit by adding another circuit because the desired characteristics cannot be obtained. Even in this case, the shield case 3 can be used as a common component, and only the print plate 1 can be freely created according to the changes, so it is possible to assemble the shield case in comparison with the conventional structure in which a notch is formed. It is possible to improve the degree of freedom in subsequent circuit changes and accompanying pattern changes.

By the way, in the above-described embodiment, when wiring between the predetermined circuits 2, the wiring hole into which the wire 6 is inserted is formed by the through hole 4, but the thickness L6 of the printed board 1 is As long as it is larger than the size L4 of the gap 5 between the upper and lower peripheral wall end faces 3a and 3b of the shield case 3, as shown in FIG. At this time, the outer circumference 6a of the wire 6 contacts only the end surface 3a of the upper peripheral wall of the shield case 3. Therefore, if an earth pattern is formed on the printed board 1 with which the lower side of the outer circumference 6a of the wire 6 comes into contact, the above-described embodiment can be used. Similarly to the above, sufficient shielding can be performed for each circuit 2.

Further, through holes 7 may be formed around the groove 8, and the number of through holes 7 and the above-mentioned ground pattern are freely selected according to the frequency of the signal transmitted between the circuits 2. be able to.

Further, in the above-described embodiment, the case where wiring is provided between the circuits 2 only on the front surface of the printed board 1 through the through holes 4 has been illustrated and described, but wiring is performed on the back surface of the printed board 1. Alternatively, wiring may be provided between the circuits 2 from one surface of the printed board 1 through the through hole 4 to the other surface.

Although the shield case 3 has been described as being covered from above and below the printed board 1 in the above-described embodiment, the flange 3 c is integrated as shown in FIGS. 4 (a) and 4 (b). The molded shield case 3 may be prepared, and the flange 3c may be fixed with the screw 9 while the printed board 1 is sandwiched between the upper and lower sides.

[0023]

[Effect of the device]

 As described above, according to the printed circuit board wiring structure of the present invention, it is not necessary to perform special processing such as a notch on the shield case covering each circuit as in the conventional case, so that the cost can be reduced and the shield can be achieved. The case can be used as a common component for each circuit. Also, even if the pattern changes after assembly, the shield case can be used as a common part and only the printed board can be freely created according to the changes, so compared to the conventional shield case that requires notches. The degree of freedom in changing the circuit after assembly and pattern change can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a printed circuit board wiring structure according to the present invention.

FIG. 2 (a) is a side sectional view showing a wiring portion of the same printed wiring board wiring structure, and (b) is a plane sectional view showing a wiring portion of the same printed wiring board wiring structure.

FIG. 3 is a diagram showing another embodiment of the same printed circuit board wiring structure.

FIG. 4 is a diagram showing a fixing structure of a shield case in the printed circuit board wiring structure.

FIG. 5 is a perspective view showing an example of a conventional printed circuit board wiring structure.

FIG. 6 is a side sectional view showing a wiring portion of a conventional printed circuit board wiring structure.

FIG. 7 is a cross-sectional view of a wiring portion in the case where there are many wirings close to each other in a conventional printed circuit board wiring structure.

[Explanation of symbols]

1 ... Printed board, 2 ... Circuit, 3 ... Shield case, 3
a, 3b ... Upper and lower peripheral wall end faces, 4 ... Through hole (wiring hole), 6 ...
Wire material, 8 ... Groove (wiring hole).

Claims (1)

[Scope of utility model registration request] 1. A printed circuit board (1) on which a plurality of circuits (2) are formed, and a shield case (3) for covering each circuit from above and below the printed circuit board so that signals do not interfere with each other. , A wiring hole (4) formed in a predetermined size so as to communicate from the inside of the shield case to the outside thereof in the printed board on which the peripheral wall end surfaces (3a, 3b) of the shield case that cover the circuit to be wired are located. , 8) and an outer diameter with which the peripheral wall end surface of the shield case comes into contact,
A printed circuit board wiring structure comprising: a wire (6) for wiring between the circuits to be wired through the wiring hole.