JP4026439B2 - Terminal connection method of micro coaxial cable assembly - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a terminal connection method of a micro coaxial cable assembly used in a medical ultrasonic diagnostic apparatus or the like.
[0002]
[Prior art]
The micro coaxial cable assembly is composed of a plurality of micro coaxial cables. As an example, there is a probe cable 51 as shown in FIG. 6 that connects the main body of a medical ultrasonic diagnostic apparatus and a probe. .
[0003]
The probe cable 51 is composed of a plurality of micro coaxial cables 52 (16 in FIG. 6) to form a micro coaxial cable unit 53 and a plurality of micro coaxial cable units 53 (12 in FIG. 6). The outer periphery of the combined micro coaxial cable unit 53 is covered with a sheath 54, the outer periphery of the sheath 54 is covered with a shield conductor 55, and the outer periphery of the shield conductor 55 is covered with a jacket 56.
[0004]
Although the structure is slightly different depending on the cable specifications, the number of micro coaxial cables used for one probe cable is about 50 cores at least, and more than 2000 cores at most.
[0005]
As illustrated in FIG. 7, the micro coaxial cable 52 includes a plurality of conductors 61 (seven in FIG. 7) to form a central conductor 62, and the outer periphery of the central conductor 62 is covered with an insulator 63. The outer periphery is covered with a shield conductor 64, and the outer periphery of the shield conductor 64 is covered with a jacket 65. As for the center conductor 62, 44 AWG (seven strands having a strand diameter of 16 μm) to 46 AWG (seven strands having a strand diameter of 16 μm) has become mainstream in the American electric wire standard. The outer diameter a of the center conductor 62 is about 60 μm for 44 AWG and about 48 μm for 46 AWG.
[0006]
The terminal connection of the probe cable 51 includes connection to the board on the apparatus main body side and connection to the board on the probe side. As can be seen from the fact that the center conductor 62 is extremely thin, it is a very laborious operation. is there.
[0007]
The conventional terminal connection method of the micro coaxial cable assembly is a method in which all operations are performed manually. First, the jacket 56, the shield conductor 55, and the sheath 54 at the end of the probe cable 51 are peeled off to expose the micro coaxial cable unit 53. Thereafter, for the end of the micro coaxial cable 52 in the micro coaxial cable unit 53, the jacket 65, the shield conductor 64, and the insulator 63 are similarly peeled and removed, the center conductor 62 is exposed, and conduction is confirmed one by one, They were lined up according to the wiring pitch of the board on the diagnostic device body and the probe side, and soldered manually.
[0008]
[Problems to be solved by the invention]
However, in the conventional method, since there is no appropriate jig for aligning the ends of the plurality of micro coaxial cables 52 and connecting them to the substrate, the terminals of the center conductor 62 of the micro coaxial cable 52 are connected to the FPC ( When connecting to a flexible printed circuit board) or a printed circuit board, alignment between each line is also performed manually.
[0009]
At this time, if the center conductor 62 has a habit, it takes time to correct it and there is a problem that the connection workability is poor. Furthermore, since the wiring pitch is becoming narrower, the importance of center conductor alignment is increasing.
[0010]
SUMMARY OF THE INVENTION An object of the present invention is to provide a terminal connection method of a micro coaxial cable assembly that simplifies terminal connection of a central conductor of a micro coaxial cable and improves connection workability.
[0011]
[Means for Solving the Problems]
The present invention has been devised to achieve the above object, and the invention of claim 1 is directed to separating a plurality of micro coaxial cables to be connected to a wiring formed in a plurality of rows on a substrate. In the method of stacking and welding the central conductors, a batch connection pad formed integrally with the plurality of rows of wirings is provided on the substrate, and the plurality of micro coaxial cables preliminarily soldered on the pads are provided. The peeled center conductor is placed, and a jig for covering and transmitting the laser beam is overlapped and held on the pad and the center conductor, and the jig is irradiated with the laser beam. After the solder is melted by irradiating the laser beam that has passed through the jig to solder the pad and the center conductor, the connection between the center conductor and the fine coaxial cable assembly is cut. It is a method.
[0012]
According to a second aspect of the present invention, there is provided a method in which a plurality of fine coaxial cables to be connected to a wiring formed in a plurality of rows on a substrate are overlapped and welded and connected to each other on the substrate. A collective connection pad formed integrally with the wiring of the row is provided, and the peeled center conductors of the plurality of micro coaxial cables are placed on the pad, and these pads and the center conductor are covered with these pads. A jig for transmitting laser light is stacked and held in alignment, and the jig is irradiated with laser light, and the pad and the central conductor are irradiated with laser light transmitted through the jig to partially melt the pad. And a center conductor are welded, and then a pad between the center conductors is cut with a laser beam to connect the micro coaxial cable assembly.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings.
[0014]
First, a substrate suitable for terminal connection of the micro coaxial cable assembly will be described with reference to FIG. FIG. 1 is a plan view of an FPC as a connection board according to the present invention.
[0015]
As shown in FIG. 1, the substantially convex FPC 10 is provided on the diagnostic device main body side or the probe side, and is formed on the insulating film 11 having a substantially strip-like and flexible insulating film 11. Wiring pattern.
[0016]
The wiring pattern has one end facing the edge of the insulating film 11 to be connected to the outside so that the wiring pitch P1 is 0.15 mm (upper side in FIG. 1), and the other end faces the center of the insulating film 11. The signal line strip-shaped wirings 12a, 12b,... Formed in a plurality of rows with a wiring pitch P2 of 0.2 mm (lower side in FIG. 1), and the other ends of the wirings 12a, 12b,. A rectangular center conductor collective connection pad 13 connected together with the peeled center conductor of the micro coaxial cable, a ground strip-like wiring 14 formed along the wirings 12a, 12b,. A rectangular shield conductor collective connection pad 15 formed integrally with the other end of the wiring 14 along the central conductor collective connection pad 13 and collectively connected to the peeled shield conductors of a plurality of micro coaxial cables. Going on.
[0017]
The other end of each wiring 12a, 12b ... and the pad 13 are orthogonal to each other, and the whole wiring 12a, 12b ... and the pad 13 are formed in a substantially comb-like shape. The other end of the wiring 14 and the pad 15 are orthogonal to each other, and the entire wiring 14 and the pad 15 are formed in an approximately L shape.
[0018]
FIG. 2 is a perspective view of a jig for aligning and connecting the micro coaxial cable terminals. 3 is a cross-sectional view of the jig shown in FIG. 2 taken along line 3A-3A. FIG. 4 is a bottom view of the jig shown in FIG.
[0019]
As shown in FIGS. 2 to 4, the jig 1 for aligning and connecting the micro coaxial cable terminals according to the present invention is a probe mainly used in a medical ultrasonic diagnostic apparatus or the like as a micro coaxial cable assembly. A covering insulating material layer and the like of a plurality of micro coaxial cable terminals constituting the cable are overlaid on the separated central conductor.
[0020]
This jig 1 integrally covers and holds these central conductors, and the central conductors that are aligned and held are placed on a central conductor batch connection pad provided on a substrate on the main body side or the probe side of the diagnostic apparatus. It is used when connecting.
[0021]
The jig 1 has a substantially rectangular jig body 2 formed from quartz as a laser beam transmitting material capable of transmitting a laser beam and provided at the other end of the wiring formed in a plurality of rows on the substrate. The conductor collective connection pad and the separated central conductors of the plurality of micro coaxial cable terminals are welded and connected to each other by laser light.
[0022]
Also, on one side of the jig body 2, a cross section as a groove portion that is overlapped with the peeled central conductors of a plurality of ultrafine coaxial cable ends and integrally covers and holds these central conductors is substantially U-shaped. The U-shaped grooves 3a, 3b,... Are formed so that the U-shaped grooves 3a, 3b,... Extend along the short direction of the jig body 2, and the adjacent U-shaped grooves 3a, 3b,. It is formed to have a predetermined interval p along the longitudinal direction of the main body 2.
[0023]
The laser beam transmitting material is not limited to quartz, and any material may be used as long as it transmits the laser beam and the amount of attenuation of the transmitted laser beam is small.
[0024]
The dimensions of the U-shaped grooves 3a, 3b,... Are the outer diameter of the central conductor (a described in FIG. 7), the shape of the wiring pattern connected to the central conductor batch connection pad on the substrate, and the wiring pitch of the wiring pattern (FIG. 1). It may be determined according to P2) described in the above. For example, when considering the fillet shape when the center conductor is soldered to the substrate, the maximum width w is about twice the outer diameter a of the center conductor, and the depth h is 1.5-2 of the outer diameter a of the center conductor. The predetermined interval p is preferably the same as the wiring pitch of the wiring pattern connected to the central conductor collective connection pad on the substrate.
[0025]
The U-shaped grooves 3a, 3b... Are formed on one surface of the jig body 2 by etching after the rectangular jig body 2 is formed, for example. By utilizing etching, the predetermined interval p can be set to a narrow pitch of less than 0.5 mm, for example 0.3 mm or 0.2 mm, which is difficult in machining. The shape of the groove is not limited to the U-shaped grooves 3a, 3b..., For example, may be a V-shaped groove having a substantially V-shaped cross section or a rectangular groove.
[0026]
As for the wavelength of the laser beam, as will be described later with reference to FIG. 5, when soldering the central conductor and the central conductor batch connection pad on the substrate, for example, the fundamental wave of the YAG laser (wavelength 1064 nm) is preferable. The wavelength is not limited to the fundamental wave of the YAG laser as long as it can be melted.
[0027]
As the wavelength of the laser beam, as will be described later with reference to FIG. 5, when welding the central conductor and the central conductor batch connection pad, for example, the second harmonic of the YAG laser (wavelength 532 nm) is preferable. Any wavelength that can melt the central conductor is not limited to the second harmonic of the YAG laser.
[0028]
Further, as described later with reference to FIG. 5, the wavelength of the laser beam is YAG laser when the central conductor is connected to the central conductor collective connection pad and then the central conductor collective connection pad is cut between the central conductors. The fourth harmonic (wavelength 266 nm) is preferable, but is not limited to the fourth harmonic of the YAG laser or the like as long as the central conductor batch connection pad can be cut.
[0029]
Next, the terminal connection method of the micro coaxial cable assembly will be described.
[0030]
FIG. 5 is a view for explaining a terminal connection method of the micro coaxial cable assembly using the connection board according to the present invention and the jig 1 for aligning and connecting the micro coaxial cable terminals. As shown in FIG. 5, each of the fine coaxial cables 52a, 52b... Connected to the FPC 10 is the same as the fine coaxial cable 52 described in FIG.
[0031]
First, a connection method when soldering the terminals of the center conductors 62a, 62b... And the center conductor batch connection pad 13 will be described.
[0032]
Prior to connection with the FPC 10, the jackets 65a, 65b ..., shield conductors 64a, 64b ..., insulators 63a, 63b ... of the terminals of the micro coaxial cables 52a, 52b ... The shield conductors 64a, 64b,... Are exposed to form peeled central conductors 62a, 62b,... And peeled shield conductors 64a, 64b,.
[0033]
The pre-soldered center conductors 62a, 62b... Are placed on the central conductor collective connection pad 13 of the FPC 10, and these are placed on the pad 13 and the pre-soldered center conductors 62a, 62b. The jig 1 for aligning and connecting the micro coaxial cable terminals with the U-shaped grooves 3a, 3b,. The shield conductors 64a, 64b... Are positioned on the shield conductor collective connection pad 15.
[0034]
At this time, the central conductor collective connection pad 13 on the FPC 10 also plays a role of positioning when the jigs 1 are stacked, so that even if the wiring pitch of the wirings 12a, 12b. The central conductors 62a, 62b,... Can be easily aligned with the other ends of the wirings 12a, 12b,.
[0035]
.. And the pad 13 are irradiated with the fundamental wave L1 of the YAG laser from above the jig 1 to melt the solder, and the terminals of the center conductors 62a, 62b. Connect with solder.
[0036]
After that, the pad 13 between the lines of the center conductors 62a, 62b... Is irradiated with the fourth harmonic L4 of the YAG laser from above the jig 1 to cut the portion, and the center conductors 62a, 62b. To do. Finally, when the shield conductors 64a, 64b... And the pad 15 are soldered separately, the micro coaxial cables 52a, 52b.
[0037]
Next, a connection method in the case of welding the ends of the center conductors 62a, 62b... And the center conductor batch connection pad 13 will be described.
[0038]
In the same manner, the center conductors 62a, 62b,... Are exposed to be peeled center conductors 62a, 62b,..., Using the jig 1 without performing preliminary soldering on the peeled center conductors 62a, 62b,. The central conductors 62a, 62b... Are aligned and held on the central conductor collective connection pad 13 so as to coincide with the other ends of the wirings 12a, 12b.
[0039]
Here, the center conductors 62a, 62b,... And the pad 13 are irradiated with the second harmonic L2 of the YAG laser from above the jig 1 to melt the center conductors 62a, 62b, and the ends of the center conductors 62a, 62b,. The pads 13 are welded and connected together.
[0040]
In the FPC 10 according to the present invention, a central conductor collective connection pad 13 is formed. After the central conductors 62a, 62b,... Are connected to the pad 13, the pad 13 between the central conductors 62a, 62b,. Since the cutting is performed at the fourth harmonic L4, it is possible to simplify the alignment and terminal connection of the center conductors 62a, 62b.
[0041]
Further, since the jig 1 according to the present invention has the U-shaped grooves 3a, 3b,... Formed in the jig body 2, the center conductors 62a, 62b,. The predetermined interval p between the U-shaped grooves 3a, 3b,... Can be set to a narrow pitch of less than 0.5 mm, which is difficult in machining, so that a narrow pitch adjusting line such as a 0.3 mm pitch or a 0.2 mm pitch can be obtained. It becomes possible.
[0042]
Since the jig body 2 is formed of quartz, the center conductors 62a, 62b,... Can be easily aligned and held while the center conductors 62a, 62b,. Since the jig body 2 is transparent, visibility during work can be improved.
[0043]
As described above, by using the FPC 10 and the jig 1, the pre-soldered center conductors 62 a, 62 b... Are easily aligned and held, and these center conductors 62 a, 62 b. By irradiating the wave L1, the terminals of the center conductors 62a, 62b... And the center conductor batch connection pads 13 are collectively connected by soldering, and the pads 13 between the center conductors 62a, 62b. Since the lines of the center conductors 62a, 62b,... Are insulated by cutting with the wave L4, the terminal connection of the center conductors 62a, 62b,... Can be simplified and the connection workability can be improved.
[0044]
Therefore, the alignment and holding of the center conductors 62a, 62b... And the terminal connection can be automated.
[0045]
Further, the jigs 1 are used to align and hold the center conductors 62a, 62b... Not pre-soldered, and the center conductors 62a, 62b... Are irradiated with the second harmonic L2 of the YAG laser via the jig 1. The terminals of the central conductors 62a, 62b,... And the central conductor collective connection pad 13 are welded and collectively connected, and the pad 13 between the central conductors is cut by the fourth harmonic L4 of the YAG laser, whereby the central conductor 62a. , 62b... Are insulated from each other, so that it is not necessary to use solder for connecting the central conductors 62a, 62b..., The terminal connection of the central conductors 62a, 62b. be able to.
[0046]
Therefore, the alignment and holding of the center conductors 62a, 62b... And the terminal connection can be automated.
[0047]
In this case, since the ends of the center conductors 62a, 62b... Are melted and joined to the FPC 10, the mechanical / electrical reliability of the terminal connecting portion is improved as compared with the case of soldering.
[0048]
In the above embodiment, the center conductors 62a, 62b,... Are placed on the FPC 10, and the jig 1 is placed on the center conductors 62a, 62b, so that the U-shaped grooves 3a, 3b,. Although the conductors 62a, 62b,... Have been described as being aligned and held, the jig 1 is stacked on the FPC 10 so that the wirings 12a, 12b,... And the U-shaped grooves 3a, 3b,. The central conductors 62a, 62b,... May be inserted into the central conductors 62a, 62b,.
[0049]
Further, the jig 1 is arranged such that the U-shaped grooves 3a, 3b,... Are on the upper side, the center conductors 62a, 62b,... Are mounted on the U-shaped grooves 3a, 3b,. The FPC 10 may be mounted on the jig 1, and the center conductors 62a, 62b,. In this case, the central conductors 62a, 62b... And the central conductor collective connection pad 13 are irradiated with laser light from below the jig 1.
[0050]
【Example】
Example 1
The central conductor is exposed by peeling off the jacket, outer conductor, and inner insulator of the micro coaxial cable to expose the central conductor in advance, and the central conductor of the FPC 10 is collectively processed using the jig 1 according to the present invention. The center conductor is aligned and held on the connection pad, and the YAG laser fundamental wave is irradiated from above the jig 1 to solder the center conductor in a lump. 4 harmonics were irradiated and cut to insulate between the central conductors.
[0051]
(Example 2)
Similarly, the center conductor is exposed, the center conductor is aligned and held on the FPC 10 using the jig 1 according to the present invention, and the second harmonic of the YAG laser is irradiated from the top of the jig 1 to collect the center conductor. After the conductors were welded together, the pads between the central conductor lines were cut by irradiating the fourth harmonic of the YAG laser to insulate the central conductors.
[0052]
(Comparative example)
Similarly, the central conductor was exposed, and as described in the prior art, the conductors were arranged one by one in accordance with the wiring pitch of the substrate while confirming conduction one by one and soldered manually.
[0053]
The processing accuracy and working time of the terminal processed products manufactured based on Examples 1 and 2 and the comparative example were investigated. As a result, the processing accuracy of Example 1 and Example 2 was both equal to that of the comparative example, and the working time was shorter than that of the comparative example. Moreover, although the method of the comparative example was difficult unless it was a skilled worker, the method of Example 1 and Example 2 was possible even for beginners.
[0054]
【The invention's effect】
As is apparent from the above description, the present invention exhibits the following excellent effects.
[0055]
(1) The center conductor of the micro coaxial cable can be aligned and maintained, and the terminal connection can be mechanized and automated.
[0056]
(2) The terminal connection of the center conductor of the micro coaxial cable can be simplified, and the connection workability can be improved.
[0057]
(3) The central conductor can be connected to the substrate without using solder. In this case, since the terminal of the center conductor is melted and joined to the substrate, the mechanical and electrical reliability of the terminal connecting portion is improved.
[Brief description of the drawings]
FIG. 1 is a plan view of a substrate according to the present invention.
FIG. 2 is a perspective view of a jig according to the present invention.
FIG. 3 is a cross-sectional view of the jig shown in FIG. 2 taken along line 3A-3A.
4 is a bottom view of the jig shown in FIG. 2. FIG.
FIG. 5 is a diagram for explaining a terminal connection method of a micro coaxial cable assembly according to the present invention.
FIG. 6 is a cross-sectional view of a probe cable.
FIG. 7 is a cross-sectional view of a micro coaxial cable.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Jig 2 Jig body 3a, 3b ... U-shaped groove 10 FPC (board | substrate)
12a, 12b ... signal line wiring 13 central conductor lump pad L1 fundamental wave of YAG laser L2 second harmonic of YAG laser L4 fourth harmonic of YAG laser

Claims (2)

In a method in which a plurality of micro coaxial cables to be connected to a wiring formed in a plurality of rows on a substrate are overlapped and welded to each other, a plurality of wires are integrally formed on the substrate. A central connection pad for pre-soldering is placed on the pad, and the separated central conductors of the ultrafine coaxial cable are placed on the pads, and the pads and the central conductor are covered with the laser light. A jig that transmits light is stacked and held, and the jig is irradiated with laser light, and the center conductor is irradiated with laser light transmitted through the jig to melt the solder, and the pad and the central conductor After the solder connection, the pad between the center conductors is cut with a laser beam. In a method in which a plurality of micro coaxial cables to be connected to a wiring formed in a plurality of rows on a substrate are overlapped and welded to each other, a plurality of wires are integrally formed on the substrate. A jig for placing the central conductor from which the plurality of micro-coaxial cables have been peeled off and covering the pad and the central conductor so that the laser beam is transmitted through the pad. The jig is irradiated with laser light, the pad and the central conductor are irradiated with the laser light that has passed through the jig to partially melt, and the pad and the central conductor are welded and connected. Then, the method of connecting the micro coaxial cable assembly is characterized in that the pad between the central conductors is cut with a laser beam.

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