WO2005104303A1

WO2005104303A1 - Wiring branch unit

Info

Publication number: WO2005104303A1
Application number: PCT/JP2004/004545
Authority: WO
Inventors: Yoshiaki Uematsu; Takahiro Nagamine; Masato Koyama
Original assignee: Mitsubishi Denki Kabushiki Kaisha
Priority date: 2004-03-30
Filing date: 2004-03-30
Publication date: 2005-11-03
Also published as: JP4129278B2; JPWO2005104303A1

Abstract

A wiring branch unit in which the region for mounting a matching resistor is reduced while suppressing reflection by branch wiring sufficiently. The wiring branch unit comprises a through hole (15) made in the middle of main wiring (14), i.e. a signal transmission line, formed on a mother board (2), a contact pin (12) contained in the through hole (15) and having an outside diameter smaller than the inside diameter of the through hole, an external circuit device (5) connected electrically with the contact pin (12), and resistive resin (18) filling the gap between the through hole (15) and the contact pin (12). The through hole (15) and the contact pin (12) are connected electrically through the resistive resin (18), and a signal on the main wiring (14) is transmitted while being branched to the external circuit device (5).

Description

Specification

Wiring branching device.

Technical field

The present invention relates to a wiring branching device, and more particularly to a device for suppressing reflection noise generated when a high-speed signal is branched.

Background art

Conventionally, there has been a communication base station apparatus which is configured to be capable of attaching an external circuit device as this type of wiring branching device. In such a communication base station device, a plurality of connectors (hereinafter, connectors on the backboard side are referred to as “plugs”) are mounted on a board (hereinafter, referred to as a “backboard”) provided on a rear surface of a housing constituting the device. ) Are installed side by side, and an external printed circuit board with a corresponding connector is attached to each of these plugs. (Hereinafter, the connector mounted on the external printed circuit board is called “receptacle”.)

In a device with such a configuration, the main wiring provided on the backboard is configured to branch toward each external printed circuit board, and when transmitting high-speed signals, reflection noise occurs at the branch point . In order to prevent this reflection, it is necessary to match the characteristic impedance of the main wiring with the impedance of each external printed circuit board. For this reason, it has been proposed to insert a series resistor between the branch point and the external printed circuit board and to match with the series resistor. For example, a series resistor described in Japanese Patent Application Laid-Open No. H10-302899 is mounted in contact with a main wiring provided on a motherboard, and the main wiring is connected to the mother wiring. This is to match the impedance with the memory module mounted on the board.

Generally, in a circuit provided with a series resistor, reflection noise is generated even by a branch wire having a short length between the branch point and the series resistor. The series resistor described in Japanese Patent Application Laid-Open No. 30-28999 has no wiring between the main wiring and the series resistor, so that the reflection noise can be effectively suppressed.

However, since the series resistor described in Japanese Patent Application Publication No. 10—302899 is provided on the motherboard, the area for mounting other circuit components on the motherboard decreases. Was something.

Disclosure of the invention

Therefore, an object of the present invention is to provide a wiring branching device that can reduce the mounting area of the matching resistor while sufficiently suppressing the reflection noise due to the branching wiring.

The present invention provides a through hole provided in the middle of a main wiring path as a signal transmission path wired on a mother board, a contact bin accommodated in the through hole, and having an outer diameter smaller than the inner diameter of the through hole, An external circuit device electrically connected to the contact pin, a resistive resin filled between the through hole and the contact bin, wherein the through hole and the contact pin are connected via the resistive resin; The wiring branching device is electrically connected and branches and transmits the signal of the main wiring to the external circuit device.

According to the present invention, since a resistive resin is filled between a contact hole and a through hole provided in the middle of the main wiring path, a matching resistor can be arranged at a branch point of a circuit. It is possible to prevent reflection noise generated from the branch wiring up to the use resistor.

Further, since the through holes for accommodating the contact bins electrically connected to the external circuit device are filled with the resistive resin, it is not necessary to secure an area for arranging the matching resistors on the mother board.

Brief Description of Drawings FIG. 1 is a perspective view showing a configuration of a wiring branching device according to Embodiment 1 of the present invention.

FIG. 2 is a perspective view showing a main part of the wiring branching device according to Embodiment 1 of the present invention.

FIG. 3 is a perspective view showing a main part of the wiring branching device according to Embodiment 1 of the present invention. '

FIG. 4 is a plan view showing a main part of the wiring branching device according to Embodiment 1 of the present invention.

FIG. 5 is a cross-sectional view showing a main part of the wiring branching device according to Embodiment 1 of the present invention.

FIG. 6 is a circuit diagram showing an operation of the wiring branching device according to Embodiment 1 of the present invention.

FIG. 7 is a sectional view showing a method of assembling the wiring branching device according to Embodiment 1 of the present invention.

FIG. 8 is a sectional view showing a wiring branching device according to Embodiment 2 of the present invention.

FIG. 9 is a sectional view showing a method of assembling the wiring branching device according to Embodiment 3 of the present invention.

FIG. 10 is a sectional view showing a wiring branching device according to Embodiment 5 of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1

The configuration of the wiring branching device according to the first embodiment will be described with reference to FIGS.

First, the overall configuration of the wiring branching device will be described with reference to FIG. For example, the wiring branching device 1, which is a communication base station device, A back board 2 which is a laminated printed wiring board having a signal transmission path is provided on the rear surface of the casing constituting the first component. A plurality of plugs 3 are fixed to the back board 2, and a signal output from a drive card 4 or a drive 4 for driving is mainly transmitted to each plug 3. A receiving device 5 is attached as an external circuit device for receiving the signal via the wiring printed on the back board 2. The configuration of the plug 3 and the receiving card 5 for receiving will be described with reference to FIG. 2 and FIG.

The receiving card 5 for reception has a plurality of through holes 7 on a printed wiring board 6, and a plurality of wirings formed in each through hole 7 so as to protrude from the surface of the receptacle 8. Terminals 9 are soldered or press-fitted after insertion. The receptacle 8 has a plurality of plug openings 10 electrically connected to the respective wiring terminals 9.

The plug 3 has a concave cross section so as to guide each card, and is fixed to the backboard 2. As shown in FIG. 5, the plug 3 has a contact pin 12 projecting therefrom. Also, one end of the contact pin 12 is inserted into the plug opening 10 of the receptacle 8 to electrically connect the contact bin 12 and the through hole 7 of the printed wiring board 6.

The fixed state of the backboard 2 and the plug 3 will be described with reference to FIG. 4 showing the surface of the backboard and FIG. 5 showing the state where the plug 3 is fixed to the backboard 2 shown in cross section.

In FIG. 4, the knock board 2 has a plurality of through-holes on its surface. Of the plurality of through-holes, a clock signal printed wiring (main wiring) 14 for which high-speed transmission is required. The clock signal through hole 15 provided in the middle of the path is formed so as to have a large inner diameter. In addition, by providing a matching circuit on the drive door card 4 or the receive door card 5, it is provided in the middle of the route of the data transmission printed wiring 16 that can match the impedance with each of these forces. The transmission through hole 17 is formed to have an inner diameter smaller than the inner diameter of the clock signal through hole 15.

In FIG. 5, the through hole 15 for the clock signal is formed to have a larger inner diameter than the outer shape of the 0-shaped portion 13 of the contact pin 12. Therefore, when the contact pin 12 is accommodated in the clock signal through-hole 15, it does not directly contact the clock signal through-hole 15. Further, between the contact pin 12 and the clock signal through-hole 15, for example, a paste-like conductive adhesive 18 having thermoplasticity made using carbon black is filled.

When a conductive adhesive having a volume resistivity of about 500 Ω / cm is used, the distance from the inner wall of the through hole 15 for the clock signal to the contact bin 12 is 0.075 due to an assembly error. Even if the distance fluctuates between 0.225 mm, the resistance value of the conductive adhesive 18 embedded between the inner wall of the clock signal through hole 15 and the contact pin 12 is 4 It is in the range of 0 Ω ± 20 Ω, and functions effectively as a matching circuit.

Hereinafter, the operation of the wiring branching device 1 according to the first embodiment will be described based on FIG. 6 showing a circuit diagram of the wiring branching device according to the first embodiment.

As shown in FIG. 6, the wiring branching device having the above-described configuration includes, as shown in FIG. Since the conductive adhesive 18 having t and the matching resistor 19 are connected, the clock signal output from the drive card 4 passes through the clock signal print wiring 14 and When branching to each receive doyu card 5, the reflection noise Does not occur.

Furthermore, since the resistor is directly attached to the branch point B, there is no reflection noise caused by the branch wiring from the branch point B to the resistor. Next, a method for manufacturing the wiring branching device 1 according to the first embodiment will be described with reference to FIG.

First, after the printed wiring is laminated to form the back board 2, the position of the clock signal through hole 15 is filled with a conductive adhesive 18 using a dispenser 1. In this state, contact pins 12 protruding from plug 3 are inserted into corresponding through holes 15 for clock signals or through holes 17 for data transmission. Since the through hole 17 for data transmission is formed to have an inner diameter enough to accommodate the contact bin 12 in a compressed state, the contact bin 12 corresponding to the through hole 17 for data transmission is formed. The contact pin 12 in the through-hole 15 for the click signal is fixed, and the contact pin 12 comes into contact with the inner wall of the through-hole 15 for the clock signal. Can be prevented.

Further, as shown in FIG. 4, the wiring branching device 1 according to the first embodiment has a through hole 17 for data transmission for press-fitting a contact pin 12 and a plug 3 on the back board 2. Since two or more are provided at the corresponding positions, the position of the corresponding contact pin 12 in the clock signal through hole 15 is accurately determined.

Then, with the contact pins 12 accommodated in the clock signal through holes 15, the backboard 2 and the plug 3 are placed in a heating furnace, the conductive adhesive 18 is cured, and the contact bins 12 and the clock are contacted. Fix the through hole 15 for signal.

As described above, according to the wiring branching device 1 according to the first embodiment, For example, a conductive adhesive (resistive resin) 18 is filled between the contact hole 12 and the clock signal through-hole 15 provided in the middle of the clock signal printed wiring (main wiring) 14. This makes it possible to directly arrange the matching resistor at the branch point of the circuit, thereby preventing reflection noise generated from the branch wiring from the branch point to the matching resistor.

In addition, a conductive adhesive (resistive resin) is filled in the through-holes 15 containing the contact bins 12 electrically connected to the receiving card 4 (external circuit device) for receiving, so that the backboard (Mother board) It is not necessary to secure a region for arranging matching resistors on the mother board.

Furthermore, since two or more of the through holes provided in the back board 2 contact the contact bin 12 with the inner wall and receive the contact bin 12, the corresponding contact bin 1 in the clock signal through hole 15 2 is arranged with high accuracy. Therefore, the conductive adhesive 18 disposed between the inner wall of the clock signal through hole 15 and the contact pin 12 provides a sufficiently accurate resistance value to function as a matching resistor. Furthermore, the through hole 17 for receiving the contact bin 12 in contact with the inner wall compresses and accepts the corresponding contact bin 12 so that the contact bin 12 accommodated in the clock signal through hole 15 can be positioned. Becomes more accurate.

Embodiment 2

The wiring branching device 1 according to the second embodiment will be described with reference to FIG. The wiring branching device 1 according to the first embodiment uses a dispenser to fill the clock signal through hole 15 with the conductive adhesive 18 in all parts. The wiring branching device 1 fills the conductive adhesive with a part of the clock signal through hole 15 by adjusting the amount of the conductive adhesive discharged from the capacitor. In this embodiment, since the resistance value can be changed depending on the amount of the conductive adhesive to be filled, it is possible to adjust the resistance value after the clock signal through hole 15 is formed in the backboard 2. it can.

Embodiment 3.

The wiring branching device 1 according to the first embodiment uses a dispenser to inject a conductive adhesive 18 into a through hole 15 for a click signal provided on a back board 2. Alternatively, masking may be performed with a film provided with an opening at a position corresponding to only the through hole 15 for the clock signal on the clock signal 2, and a conductive adhesive may be applied to the entire surface of the masked back board 2. Even with such a manufacturing method, since the existing soldering machine can be used, the manufacturing cost of the backboard 2 can be reduced.

Embodiment 4.

The wiring branching device 1 according to the third embodiment performs masking with a film having an opening only in a portion corresponding to the clock signal through-hole 15 out of the through-holes provided in the backboard 2. The wiring branching device 1 according to the fourth embodiment is characterized in that the back board 2 is masked with a film having openings at positions corresponding to all the through holes. As shown in FIGS. 9 (a) and 9 (b), the wiring branching device 1 according to the fourth embodiment is configured such that after the conductive adhesive is applied to the entire backboard 2, 12 is inserted into the corresponding through hole, and the conductive adhesive is cured.

In this way, not only the through-hole 15 for the clock signal but also the through-hole 17 for the data transmission is filled with the conductive adhesive 18. Since the inner wall of the through hole 17 is in direct contact, the conductive adhesive 18 4545

A state can be formed in which no resistance is interposed between the pin 12 and the transmission through hole 1 mm.

Therefore, according to the fourth embodiment, when providing an opening in the film for masking the backboard 2, if the opening is provided at a position corresponding to all of the plurality of through holes described in the board design drawing. good. That is, when forming a film for masking, it is possible to reduce the step of selecting through holes to be provided with openings at corresponding positions from the board design drawing.

Embodiment 5

The wiring branching device 1 according to the first to fourth embodiments is configured such that the clock signal through-hole 15 is filled with the conductive adhesive 18. However, the wiring branching device 1 according to the fourth embodiment The present invention is characterized in that a connector bin 12, which is covered with a resistive resin film 20, is compressed and accommodated in a through hole 15 for a clock signal.

According to the wiring branching device 1 formed in this way, the resistance value can be strictly adjusted by the resistive resin film 20. Therefore, the wiring branching device 1 with more accurate impedance matching is provided. be able to.

Embodiment 6.

In the wiring branching device 1 according to the first to fifth embodiments, an object configured to fill the conductive adhesive or the resistive resin film between the inner wall of the through hole and the connector pin transmits the clock signal. However, if the branch wiring device transmits high-speed signals, even if it is a short branch wiring, it can be used as a through hole for transmitting any kind of signal. Even if it is applied to contact pins, it has a sufficient effect. Embodiment 7

In the wiring branching device 1 according to the first to sixth embodiments, the contact bin 12 and the through hole for receiving the contact bin 12 by contacting the inner wall are provided. In FIG. 17, the printed wiring 16 for data transmission is branched, but the wiring branching device 1 according to the seventh embodiment receives the contact bin 12 and the contact bin 12 by contacting the inner wall. The through hole 17 is characterized in that a printed wiring for ground (main wiring for ground) or a printed wiring for power supply (main wiring for power supply) is branched.

If the contact bins 12 and the through holes 17 are provided in this manner, since high-speed data transmission is required, the contact pins 12 for overnight data transmission are placed inside the through holes 15 for the clock signal. Even if it cannot be used to position the corresponding contact bin 12, a contact pin for positioning can be secured.

Embodiment 8

The wiring branching device 1 according to the first embodiment inserts the contact pins 12 into the clock signal through holes 15 filled with the conductive adhesive 18, but the contact pins 12 are inserted. The conductive holes 18 may be filled in the through holes 15 for clock signals with a dispenser.

Claims

The scope of the claims

1. The main wiring as a signal transmission line wired on the motherboard.

A 3-pin outer bin that is housed in this through hole and has an outer diameter less than the inner diameter of the through hole;

An external circuit device electrically connected to this contact bin,

A resistive resin filled between the through hole and the contact bin;

A wiring branching device, wherein the through-hole and the contact pin are electrically connected via the resistive resin, and branch and transmit the signal of the main wiring to the external circuit device.

2. The route of the main wiring as the signal transmission line wired on the mother board The through hole provided in the middle,

A contact pin accommodated in the through hole and having an outer diameter smaller than the inner diameter of the through hole;

An external circuit device electrically connected to this contact bin,

A resistive resin film interposed between the through hole and the contact pin;

3. The mother board is provided with a plurality of through holes, and at least two of the plurality of through holes receive the corresponding contact pin by contacting the inner wall. The wiring branching device according to claim 1 or 2, wherein

4, at least two through-holes and corresponding contacts The pins are

4. The wiring branching device according to claim 3, wherein the main wiring for power supply or ground is branched to an external circuit device.

5. At least two through holes

The wiring branching device according to claim 3, wherein the corresponding contact pin is compressed and received.

6. The resistant resin is

2. The wiring branching device according to claim 1, wherein the thermoplastic paste resin is cured.