JP2003309339A - Connecting circuit board and connecting method of extra- fine cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a connecting circuit board and a connecting method for extra-fine cable, in which the connection for the end part of a probe cable is simplified and wiring pitch of the probe cable is narrowed. <P>SOLUTION: The connecting circuit board and connecting method of extra- fine coaxial cable comprises an insulating circuit board 32, in which a plurality of extra-fine coaxial cables are arranged like flat cables, in a manner that the end portions are ordered in the line, wires 34 formed on the extension line of each extra-fine coaxial cable arranged on this insulating circuit board 32, and a pad for simultaneous connection, which is integrally formed with the wires 34, facing the end portion of the extra-fine coaxial cable. After the pad 31 for simultaneous connection is connected to the end portion of the center conductor of each extra-fine coaxial cable, the portion between the end portions of the center conductors of the extra-fine coaxial cables are separated with each other. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection board and connection method for an ultrafine cable, and more particularly to a connection board and connection method for an ultrafine coaxial cable assembly used in a medical ultrasonic diagnostic apparatus or the like.

[0002]

2. Description of the Related Art FIG. 3 shows a cross-sectional view of a probe cable connecting a main body of a medical ultrasonic diagnostic apparatus and a probe.

As shown in FIG. 3, the probe cable is
A plurality of micro-coaxial cable units 11 formed by twisting 16 micro-coaxial cables are twisted together, and a sheath 12, a shield conductor 13, and a jacket 14 are sequentially covered on the outer periphery thereof.

Although the structure varies slightly depending on the cable specifications, the number of micro coaxial cables used for one probe cable is small, about 50 cores, and many are 200 cores.
Over 0 hearts.

FIG. 4 shows a cross sectional view of a micro coaxial cable.

As shown in FIG. 4, the micro coaxial cable is
An insulator 22, a shield conductor 23, and a jacket 24 are sequentially coated on the outer periphery of the central conductor 21.

The central conductor 21 is a 44 AWG (wire diameter 20
From 7 stranded conductors of μm conductor to 46 AWG (strand diameter 16μ)
7 conductors of m conductors) are becoming mainstream.

[0008] The terminal connection of the probe cable is a very troublesome work since it has a connection to the substrate on the main body side and a connection to the substrate on the probe side.

First, the jacket 14, the shield conductor 13 and the sheath 12 of the probe cable end are removed to expose the micro coaxial cable unit 11. After that, the micro coaxial cables in the micro coaxial cable unit 11 are arranged one by one according to the wiring pitch of the board while confirming the continuity one by one, and the center conductor of the micro coaxial cable and the wiring of the board are manually soldered.

[0010]

However, when connecting a micro coaxial cable terminal to an FPC or a printed circuit board, a wire spacing of 0.3 mm is currently the mainstream, but a narrower pitch of 0.25 mm pitch. , 0.2 m
There is also a demand for m-pitch ones, and the limit of manual soldering is approaching.

It is therefore an object of the present invention to provide an ultrafine cable connecting board and a connecting method which can simplify the terminal connection of a probe cable and can also narrow the wiring pitch of the probe cable.

[0012]

In order to solve the above-mentioned problems, the invention of claim 1 is an insulation in which a plurality of ultrafine cables are placed in a flat cable shape so that the tips are aligned in a line. In a connection board of an ultrafine cable having a flexible substrate and wiring formed on an extension line of each ultrafine cable placed on the insulating board, the pad for collective connection faces the tip portion of the ultrafine cable It is formed integrally with the wiring.

According to a second aspect of the present invention, the insulating substrate is an insulating film, and the insulating film on the back surface of the collective connection pad is removed.

According to a third aspect of the present invention, an insulating substrate on which a plurality of ultrafine cables are arranged and mounted in a flat cable shape so that the tips are aligned in a row, and the insulating substrate is mounted on the insulating substrate. A method for connecting an ultrafine cable to a connection board having wiring formed on an extension of each ultrafine cable and a collective connection pad integrally formed with the wiring facing the tip of the ultrafine cable. , Connecting the pad for collective connection and the tip of the center conductor of each extra-fine cable,
This is a method in which the tips of the central conductors of this ultrafine cable are cut off and insulated by a non-contact cutting method such as laser processing.

According to a fourth aspect of the present invention, an insulating substrate on which a plurality of ultrafine cables are arranged and mounted in a flat cable shape so that the tips are aligned in a line, and the insulating substrate is mounted on the insulating substrate. A method for connecting an ultrafine cable to a connection board having wiring formed on an extension line of each ultrafine cable and a collective connection pad integrally formed with the wiring facing the tip of the ultrafine cable. , Connecting the pad for collective connection and the tip of the center conductor of each extra-fine cable,
This is a method in which the tips of the central conductors of this ultrafine cable are separated by a contact-type cutting method such as press working for insulation.

That is, the gist of the present invention is not to connect the ultrafine cable to the connection board in which the wiring circuit is formed in advance at the connection portion with the ultrafine cable on the insulating board.
The purpose is to form a circuit by connecting an ultrafine cable to a connection board having a collective connection pad at the connection portion and cutting the lines.

According to the structure of the first aspect, after connecting the ultrafine cables in a lump by a method such as soldering, resistance welding, or an anisotropic conductive adhesive, the lines are cut.

According to the second aspect of the present invention, the tip of the cutting means is released into the hole formed in the insulating film when the line is cut, so that the insulating film is less likely to be scratched or soiled.

According to the structure of claim 3, 0.2 mm
The lines are cut at the following narrow pitches.

According to the structure of the above-mentioned claim 4, when the lines are cut at a pitch of 0.5 mm, which has a relatively coarse wiring pitch, the wires are cut in a short time.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a connection board according to the present invention, which is F
The top view of PC is shown.

As shown in FIG. 1, the FPC is composed of a substantially band-shaped and flexible insulating film 32 and a wiring pattern formed on the insulating film 32.

The wiring pattern has a plurality of wirings 34 arranged at 0.15 mm pitch (upper side of the drawing) facing the edge of the insulating film 32 so that one end is connected to the outside, and the other end of these wirings 34. Of the central conductor of the micro coaxial cable, which is formed in a central portion of the micro coaxial cable and is collectively connected to the central conductor of the micro coaxial cable. The external conductor (shield conductor) of the coaxial cable is collectively connected to the external conductor collective connection pad 33. On the other end side (lower side in the drawing) of the wiring 34, a wiring pattern is formed with a pitch of 0.2 mm.

Next, a method of connecting a micro coaxial cable using this FPC will be described together with its operation.

When connecting the microfine coaxial cables to the connection board of FIG. 1, a plurality of microfine coaxial cables are arranged in a flat cable so that the tips are aligned in a line, and the shield conductor of each microfine coaxial cable is used as an external conductor. While connecting to the collective connection pad 33 by a method such as soldering, resistance welding, or an anisotropic conductive adhesive, the tip end of the central conductor is similarly soldered to the central conductor collective connection pad 31.
Connect by resistance welding or anisotropic conductive adhesive.
Then, the connecting portions are separated and insulated by a non-contact cutting method such as laser processing so that each wiring 34 is connected to the center conductor of each micro coaxial cable.

As a result, a micro coaxial cable can be connected to the wiring having a pitch of 0.2 mm. Therefore, the connection board can be downsized.

Furthermore, since the central conductor of the micro coaxial cable is connected to the central conductor collective connection pad 31 and then separated, there is a variation in the distance between the tip ends of the central conductors of the micro coaxial cables arranged in a flat cable shape. Even if this is allowed, the connection can be made, and the connection becomes easy.

Next, another embodiment of the present invention will be described.

FIG. 2 shows a plan view of another FPC as another embodiment of the present invention.

As shown in FIG. 2, this FPC is composed of a substantially band-shaped and flexible insulating film 42 and a wiring pattern formed on this insulating film 42.

The wiring pattern has a plurality of wirings 44 arranged at 0.15 mm pitch (upper side of the drawing) facing the edge of the insulating film 42 so that one end is connected to the outside, and the other ends of these wirings 44. And a central conductor collective connection pad 41 that is collectively connected to the central conductor of the micro coaxial cable, and is formed at an appropriate interval in the longitudinal direction of the wiring 44 from the central conductor collective connection pad 41. The external conductor collectively connecting pad 43 is connected to the external conductor (shield conductor) of the cable. On the other end side (lower side in the drawing) of the wiring 44, a wiring pattern is formed with a pitch of 0.2 mm.

The insulating film 42 has a hole 42 slightly larger than the central conductor batch connection pad 41 on the back side of the central conductor batch connection pad 41 for collectively connecting the central conductors.
While h is formed, the wiring 44 is formed so as to extend across the central conductor collective connection pad 41 so that the central conductor collective connection pad 41 is supported from both edges.

When connecting the micro coaxial cables to this connection board, a plurality of micro coaxial cables are arranged in a flat cable shape so that the tips are aligned in a line, and the shield conductors of the micro coaxial cables are collectively connected to the outer conductor. To the pad 43 for soldering by soldering, resistance welding, anisotropic conductive adhesive, or the like, and the tip of the center conductor is similarly connected to the pad 41 for collectively connecting the center conductors by soldering, resistance welding, or The connection is made by a method such as a conductive adhesive. Then, the connecting portions are separated and insulated by a non-contact cutting method such as laser processing so that each wiring 44 is connected to the center conductor of each micro coaxial cable.

At this time, since the cutting laser is allowed to escape into the hole 42h formed in the insulating film 42, the insulating film 42 and the like are less likely to be scratched or soiled.

Even with this structure, as in the case of the present embodiment, since it is possible to connect the micro coaxial cable to the wiring having a pitch of 0.2 mm, the connection board can be downsized.

Further, since the central conductor of the micro coaxial cable is connected to the central conductor collective connection pad 41 and then separated, there is variation in the distance between the tip ends of the center conductors of the micro coaxial cables arranged in a flat cable shape. Even if this is allowed, the connection can be made, and the connection becomes easy.

Further, as a modification of this embodiment, the cutting after connecting the central conductor of the micro coaxial cable and the collective connection pad 31 may be separated by a contact type cutting method such as press working. . Thereby, the cutting time can be shortened as compared with the non-contact cutting method.

Next, the microscopic coaxial cable and the connection board are connected by the present invention and the prior art, and the processing accuracy and working time are compared.

(Embodiment 1) 16-core micro coaxial cables are arranged in a flat cable shape, and the outer conductor and the inner conductor are connected to a pad for collective connection of an insulating substrate, and the pad to which the inner conductor is connected is a wire. Excimer laser (K
It was cut into 0.2 mm pitch with rF: 248 nm).

(Embodiment 2) 16-core micro coaxial cables are arranged in a flat cable shape, and the outer conductor and the inner conductor are connected to the collective connection pads of the insulating substrate, and the pad to which the inner conductor is connected is a wire. 2nd YAG laser between
It was cut at a pitch of 0.3 mm with a harmonic wave (532 nm).

(Embodiment 3) 16-core micro coaxial cables are arranged in a flat cable form, and the outer conductor and the inner conductor are connected to the collective connection pads of the insulating substrate, and the pads to which the inner conductor is connected are lined. 0.5 between press
It was cut into mm pitch.

(Comparative Example) A center conductor and an outer conductor were manually soldered to a connection substrate having a wiring pitch of 0.3 mm, one core at a time.

As a result, the working accuracy of Examples 1 to 3 was the same as that of the comparative example, and the working time was slightly shorter than that of the comparative example.

Although the method of the comparative example was difficult for a skilled worker to perform, in Examples 1 to 3, even a beginner could work.

The second harmonic of the excimer laser or the YAG laser is used as the laser light used in the present embodiment, but the laser light is not limited to this and can be selected according to the material of the circuit board or the insulating film. It is possible. As far as cutting the pads for collective connection is concerned, the wavelength is preferably in the range of 200 nm to 600 nm.

Further, even if the holes 42h are not formed in the insulating film 42 on the back surface of the central conductor collective connection pad 41 as in the other embodiments, the insulating film is transparent and the metal is used as a cutting laser. By using the laser light having the absorbing wavelength, the central conductor collective connection pads 31 and 41 can be cut without damaging the insulating film.

The present invention can of course be applied to a printed circuit board in addition to the FPC described in this embodiment.

Further, the same effect can be expected by applying the present invention to the case of connecting an electric wire other than the micro coaxial cable.

[0050]

In summary, according to the present invention, the pitch of the ultrafine cables arranged in a flat cable shape is conventionally required to be accurate, but since a certain degree of variation can be allowed, the connection becomes easy.

Further, since the pitch between lines can be narrowed, the connection board can be downsized.

[Brief description of drawings]

FIG. 1 is a plan view of a connection board showing an embodiment of the present invention.

FIG. 2 is a plan view of a connection board according to another embodiment of the present invention.

FIG. 3 is a cross-sectional view of a probe cable.

4 is a cross-sectional view of a micro coaxial cable that constitutes the probe cable of FIG.

[Explanation of symbols]

31 Central conductor batch connection pad 32 Insulating film (insulating substrate) 33 Pads for collectively connecting external conductors 34 wiring

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hitoshi Ueno             1-6-1, Otemachi, Chiyoda-ku, Tokyo             Standing Wire Co., Ltd. (72) Inventor Daisuke Kimoto             4-10-1, Kawajiri-cho, Hitachi-shi, Ibaraki Hitachi             Electric Wire Fine Tech Co., Ltd. F-term (reference) 5E051 GA03 GA08 GB10                 5E077 BB07 BB08 BB09 BB32 BB33                       HH07 HH08 JJ05 JJ11 JJ21                       JJ23                 5E317 AA04 AA07 BB12 CD34 GG14

Claims (4)

[Claims] 1. An insulative substrate on which a plurality of ultrafine cables are arranged and mounted in a flat cable shape so that the tips are aligned in a line, and each of the ultrafine cables placed on the insulative substrate. In a connection board of an ultrafine cable having a wiring formed on an extension line, a connection board for an ultrafine cable, wherein a collective connection pad is formed integrally with the wiring so as to face a tip portion of the ultrafine cable. . 2. The insulating substrate is an insulating film,
The connection board for an ultrafine cable according to claim 1, wherein the insulating film on the back surface of the collective connection pad is removed. 3. An insulating substrate on which a plurality of microfine cables are arranged and mounted in a flat cable shape so that their tip portions are aligned in a line, and the respective microfine cables mounted on the insulating substrate. A method for connecting an ultrafine cable to a connection board having wiring formed on an extension line and a collective connection pad integrally formed with the wiring facing the tip of the ultrafine cable. A pad and a tip of the center conductor of each extra-fine cable are connected, and the tip of the center conductor of the extra-fine cable is separated by a non-contact cutting method such as laser processing to insulate the extra-fine cable. How to connect. 4. An insulative substrate on which a plurality of ultrafine cables are arranged and placed in a flat cable shape so that the tips are aligned in a line, and each of the ultrafine cables placed on the insulative substrate. A method for connecting an ultrafine cable to a connection board having wiring formed on an extension line and a collective connection pad integrally formed with the wiring facing the tip of the ultrafine cable. Connecting a pad and the tip of the center conductor of each extra-fine cable, and separating the tip of the center conductor of the extra-fine cable by a contact-type cutting method such as press working for insulation Method.