JP3885644B2 - Super fine cable connection board and connection method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a connection board and a connection method for an ultrafine cable, and more particularly to a connection board and a connection method for an ultrafine coaxial cable assembly used in a medical ultrasonic diagnostic apparatus and the like.
[0002]
[Prior art]
FIG. 3 shows a cross-sectional view of a probe cable connecting the main body of the medical ultrasonic diagnostic apparatus and the probe.
[0003]
As shown in FIG. 3, the probe cable is formed by twisting a plurality of micro coaxial cable units 11 formed by twisting 16 micro coaxial cables, and a sheath 12, a shield conductor 13 and a jacket 14 are provided on the outer periphery thereof. Sequentially covered.
[0004]
Although the structure differs slightly depending on the cable specifications, the number of micro coaxial cables used for a single probe cable is about 50 cores with a small number and over 2000 cores with a large number.
[0005]
FIG. 4 shows a cross sectional view of the micro coaxial cable.
[0006]
As shown in FIG. 4, the micro coaxial cable is configured such that the outer periphery of the center conductor 21 is sequentially covered with an insulator 22, a shield conductor 23, and a jacket 24.
[0007]
The central conductor 21 has become mainstream from 44 AWG (seven strands of conductor with a wire diameter of 20 μm) to 46 AWG (seven strands of conductor with a diameter of 16 μm).
[0008]
The terminal connection of the probe cable includes a connection with the substrate on the main body side and a connection with the substrate on the probe side, which is a very laborious operation.
[0009]
First, the jacket 14, shield conductor 13 and sheath 12 of the probe cable end are removed, and the micro coaxial cable unit 11 is exposed. Thereafter, the micro coaxial cables in the micro coaxial cable unit 11 are arranged in accordance with the wiring pitch of the substrate while confirming conduction one by one, and the central conductor of the micro coaxial cable and the wiring of the substrate are soldered manually.
[0010]
[Problems to be solved by the invention]
However, when connecting an ultra-fine coaxial cable terminal to an FPC or printed circuit board, the current wiring spacing is mainly 0.3 mm pitch, but the narrower pitch 0.25 mm pitch and 0.2 mm pitch are the mainstream. Due to demand, the limit of manual soldering is approaching.
[0011]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a connection board and a connection method for an ultrafine cable that can simplify the terminal connection of the probe cable and can narrow the wiring pitch of the probe cable.
[0012]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, an invention according to claim 1 is directed to an insulating substrate on which a plurality of extra-fine cables are arranged and placed in a flat cable shape so that the end portions are aligned in a line, and the insulating substrate Connection of the ultrafine cable to a connection board having wiring formed on an extension line of each ultrafine cable placed on the wire and a batch connection pad formed integrally with the wiring facing the tip of the ultrafine cable Connecting the above-mentioned batch connection pad and the tip of the center conductor of each ultrafine cable, and isolating the tip of the center conductor of this ultrafine cable by a non-contact cutting method such as laser processing. It is a method to make it.
[0013]
According to the invention of claim 2, an insulating substrate on which a plurality of extra fine cables are arranged and placed in a flat cable shape so that the tip portions are aligned in a row, and each extra fine wire placed on the insulating substrate. A method of connecting an ultra-thin cable to a connection board having a wiring formed on an extension line of the cable and a collective connection pad formed integrally with the wiring facing the tip of the ultra-fine cable, In this method, the connection pad and the tip of the center conductor of each ultrafine cable are connected, and the tip of the center conductor of the ultrafine cable is separated and insulated by a contact-type cutting method such as press working .
[0014]
That is, the main point of the present invention is not to connect the ultrafine cable to the connection substrate in which the wiring circuit is formed in advance at the connection portion with the ultrafine cable on the insulating substrate, but to connect the connection portion having the batch connection pad at the connection portion. The purpose is to connect a very fine cable to the substrate and cut the line to form a circuit.
[0015]
According to the above Ki構 formation, soldering, resistance welding, by a method such as anisotropic conductive adhesive, after the ultrafine cables are connected together, between lines is disconnected.
[0016]
According to the configuration of the first aspect , the line is cut at a narrow pitch of 0.2 mm or less.
[0017]
According to the configuration of the second aspect , when a line is cut at a relatively coarse pitch of 0.5 mm, the line is cut in a short time.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Next, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.
[0019]
FIG. 1 shows a plan view of an FPC as a connection board according to the present invention.
[0020]
As shown in FIG. 1, this FPC is composed of a substantially strip-like flexible insulating film 32 and a wiring pattern formed on the insulating film 32.
[0022]
The wiring pattern is formed at the other end of the wiring 34 and a plurality of wirings 34 arranged at a pitch of 0.15 mm (upper side in the drawing) facing one end of the insulating film 32 to be connected to the outside. The central conductor collective connection pad 31 that is connected to the central conductor of the micro coaxial cable and the central conductor collective connection pad 31 in the longitudinal direction of the wiring 34 and spaced from the central conductor collective connection pad 31 as appropriate. It comprises an external conductor collective connection pad 33 that is collectively connected to an external conductor (shield conductor). On the other end side (lower side of the drawing) of the wiring 34, a wiring pattern is formed at a pitch of 0.2 mm.
[0022]
Next, the connection method of the micro coaxial cable using this FPC will be described together with the operation.
[0023]
When connecting a micro coaxial cable to the connection board of FIG. 1, arrange a plurality of micro coaxial cables in a flat cable shape so that the tips are aligned in a row, and connect the shield conductors of each micro coaxial cable to the outer conductor batch connection The pad 33 is connected to the pad 33 by soldering, resistance welding, anisotropic conductive adhesive or the like, and the tip of the central conductor is connected to the central conductor batch connection pad 31 in the same manner. The connection is made by a method such as 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 the respective micro coaxial cable.
[0024]
As a result, it is possible to connect the ultra-fine coaxial cable to the 0.2 mm pitch wiring. For this reason, a connection board | substrate can be reduced in size.
[0025]
Further, since the center conductor of the micro-coaxial cable is connected to the center conductor batch connection pad 31 and then disconnected, even if there is a variation in the distance between the ends of the center conductors of the micro-coaxial cable arranged in a flat cable shape, Can be connected with ease, and the connection becomes easy.
[0026]
Next, another embodiment of the present invention will be described.
[0027]
FIG. 2 shows a plan view of another FPC as another embodiment of the present invention.
[0028]
As shown in FIG. 2, the FPC is composed of a substantially strip-like flexible insulating film 42 and a wiring pattern formed on the insulating film 42.
[0029]
The wiring pattern is formed on a plurality of wirings 44 arranged at a pitch of 0.15 mm (upper side in the drawing) with one end facing the edge of the insulating film 42 so as to be connected to the outside, and the other ends of these wirings 44. The central conductor collective connection pad 41 that is collectively connected to the central conductor of the micro coaxial cable and the central conductor collective connection pad 41 in the longitudinal direction of the wiring 44 and spaced from the central conductor collective connection pad 41 as appropriate. It comprises an external conductor collective connection pad 43 that is collectively connected to a conductor (shield conductor). A wiring pattern is formed on the other end side (the lower side in the drawing) of the wiring 44 at a pitch of 0.2 mm.
[0030]
The insulating film 42 is formed with a hole 42h slightly larger than the central conductor collective connection pad 41 on the back side of the central conductor collective connection pad 41 for connecting the central conductors collectively, and the central conductor collective connection. The wiring 44 is formed to extend so as to sandwich the central conductor collective connection pad 41 so that the pad 41 is supported from both edge sides.
[0031]
When connecting the micro coaxial cable to the connection board, a plurality of micro coaxial cables are arranged in a flat cable shape so that the tip portions are aligned in a line, and the shield conductor of each micro coaxial cable is connected to the external conductor batch connection pad 43. Are connected by soldering, resistance welding, anisotropic conductive adhesive, and the like, and the tip of the central conductor is similarly connected to the central conductor batch connection pad 41 by soldering, resistance welding, anisotropic conductivity. Connect with adhesive or other method. Then, the connecting portions are separated and insulated by a non-contact type cutting method such as laser processing so that each wiring 44 is connected to the center conductor of each micro coaxial cable.
[0032]
At this time, since the cutting laser escapes into the hole 42h formed in the insulating film 42, the insulating film 42 and the like are hardly damaged or stained.
[0033]
Even if configured in this manner, the micro coaxial cable can be connected to the wiring with a pitch of 0.2 mm as in the present embodiment, so that the connection board can be reduced in size.
[0034]
Further, since the center conductor of the micro-coaxial cable is connected to the center conductor collective connection pad 41 and then separated, even if there is a variation in the distance between the ends of the center conductors of the micro-coaxial cable arranged in a flat cable shape, Can be connected with ease, and the connection becomes easy.
[0035]
As a modification of the present 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 pressing. Thereby, cutting time can be shortened rather than the non-contact-type cutting method.
[0036]
Next, the micro coaxial cable and the connection substrate are connected by the present invention and the prior art, and the processing accuracy and working time are compared.
[0037]
Example 1
A 16-core micro coaxial cable is arranged in a flat cable shape, and the outer conductor and the inner conductor are connected to a batch connection pad on the insulating substrate, and an excimer laser (KrF: 248 nm) between the lines of the pad to which the inner conductor is connected. ) Was cut to a pitch of 0.2 mm.
[0038]
(Example 2)
A 16-core micro coaxial cable is arranged in a flat cable shape, the outer conductor and the inner conductor are connected to a batch connection pad on the insulating substrate, and the second harmonic of the YAG laser is connected between the lines of the pads to which the inner conductor is connected. It cut | disconnected by 0.3 mm pitch with the wave (532 nm).
[0039]
(Example 3)
16 core micro coaxial cables are arranged in a flat cable shape, the outer conductor and the inner conductor are connected to the batch connection pad of the insulating substrate, and the pad to which the inner conductor is connected is pressed by 0.5 mm between the lines. Cut into pitches.
[0040]
(Comparative example)
The center conductor and the outer conductor were soldered manually by one by one to the connection substrate having a wiring pitch of 0.3 mm.
[0041]
As a result, the processing accuracy of Examples 1 to 3 was the same as that of the comparative example, and the working time was slightly shortened from that of the comparative example.
[0042]
Moreover, although the method of the comparative example was difficult to work unless it was a skilled worker, Examples 1 to 3 were able to be performed even by beginners.
[0043]
The laser beam used in this embodiment is the second harmonic of an excimer laser or a YAG laser, but is not limited to this, and can be selected according to the material of the circuit board or insulating film. . The wavelength is preferably in the range of 200 nm to 600 nm as long as the collective connection pad is cut.
[0044]
Further, as in other embodiments, even if the hole 42h is not formed in the insulating film 42 on the back surface portion of the central conductor collective connection pad 41, the insulating film transmits and the metal absorbs the wavelength as a cutting laser. By using this laser beam, the central conductor collective connection pads 31 and 41 can be cut without damaging the insulating film.
[0045]
Of course, the present invention can be applied to a printed circuit board in addition to the FPC described in this embodiment.
[0046]
Furthermore, the same effect can be expected by applying the present invention to connecting wires other than micro coaxial cables.
[0047]
【The invention's effect】
In short, according to the present invention, conventionally, accuracy has been required for the pitch of the ultra-thin cable aligned in the form of a flat cable. However, since a certain degree of variation can be allowed, connection is facilitated.
[0048]
Moreover, since the pitch between lines can be narrowed, the connection board can be reduced in size.
[Brief description of the drawings]
FIG. 1 is a plan view of a connection substrate showing an embodiment of the present invention.
FIG. 2 is a plan view of a connection board showing 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 constituting the probe cable of FIG. 3;
[Explanation of symbols]
31 Pad for central conductor batch connection 32 Insulation film (insulating substrate)
33 Pads for external conductor batch connection 34 Wiring

Claims (2)

  An insulating substrate on which a plurality of extra-fine cables are arranged and placed in a flat cable shape so that the end portions are aligned in a row, and an extension line of each extra-fine cable placed on the insulating substrate is formed. A connection method for connecting an ultrafine cable to a connection board having a wiring and a batch connection pad formed integrally with the wiring facing the leading end of the ultrafine cable, wherein the batch connection pad and each ultrafine cable A method for connecting an ultrafine cable, comprising: connecting a tip end portion of a center conductor of the wire to a tip portion of the center conductor of the ultrafine cable and isolating the tip portion by a non-contact type cutting method such as laser processing.   An insulating substrate on which a plurality of extra-fine cables are arranged and placed in a flat cable shape so that the end portions are aligned in a row, and an extension line of each extra-fine cable placed on the insulating substrate is formed. A connection method for connecting an ultrafine cable to a connection board having a wiring and a batch connection pad formed integrally with the wiring facing the leading end of the ultrafine cable, wherein the batch connection pad and each ultrafine cable A method for connecting an extra fine cable, comprising: connecting a tip end portion of the center conductor of the lead wire and isolating the tip portions of the center conductor of the extra fine cable by a contact type cutting method such as press working.

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