JP2008257969A - Electronic device and harness for electronic device wiring - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic device that can incorporate an ultrafine coaxial cable into a slide mobile terminal device and has excellent resistance to slide-bending, and a harness for the electronic device's wiring. <P>SOLUTION: The electronic device is configured to have a plurality of circuit-holding housings slidably adjoined to each other, with the circuits within these housings being electrically connected to each other by a harness for electronic device wiring. The harness for electronic device wiring causes a multitude of electric wires to be arranged in parallel and has a cable layered portion in which a plurality of flat cables collectively covered with a jacket material having a Young's modulus of 300-2,700 MPa in the form of a tape are stacked, and the cable layered portion is arranged in U-shape on a slide surface of the housing. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electronic device formed by joining a plurality of casings having circuits in a slidable manner, and electrically connecting the circuits in these casings by an electric wire such as a micro coaxial cable. The present invention relates to a mobile terminal device such as Personal Digital Assistants) and a harness used for wiring between housings of the electronic device.

  In recent years, electronic devices typified by mobile phones have been rapidly reduced in size, weight and functionality. Therefore, a large number of IC chips are mounted, the transmission capacity is increased, the transmission speed is increased, and the transmission frequency is particularly in a high frequency band. Along with this, the electrical signal noise in the device also increases, so that an electrical signal transmission medium is required to have excellent electromagnetic wave shielding characteristics. For this reason, instead of an FPC (Flexible Printed Circuit), an assembly of ultra-fine coaxial cables excellent in electromagnetic wave shielding (shielding) characteristics has been introduced as an internal wiring material in equipment. In small electronic devices, particularly mobile terminal devices such as mobile phones, the clamshell type shown in FIG. 5A, the jack knife type shown in FIG. 5B, and the two-axis type shown in FIG. An assembly of extra fine coaxial cables has been introduced.

  However, with respect to the slide-type mobile terminal device shown in FIG. 5 (d), the FPC is still used, and an assembly of micro coaxial cables has not been introduced. This is due to the slide-type mechanical structure, and conventionally, it has been difficult to use the micro coaxial cable. FIG. 6 is a diagram illustrating a case where the FPC 4 is applied as the inter-casing wiring member of the slide type electronic device 1. The electronic device 1 has a structure in which respective circuits of the first housing 2 and the second housing 3 slidably joined to the first housing 2 are electrically connected by the FPC 4. It has become.

  Therefore, in order to increase the functionality and multifunction of the slide-type mobile terminal device, it is essential to introduce a micro-coaxial cable assembled like other structures. In short, it has been desired to introduce a slide type mobile terminal device assembled with a micro coaxial cable. For example, the techniques disclosed in Patent Documents 1 and 2 have been proposed as an example of introducing a micro coaxial cable into a mobile terminal device.

  That is, it is known to use a micro coaxial cable for a mobile terminal device, and it is also known that such a device is already on the market. However, as described in Patent Documents 1 and 2, ultra-fine coaxial cables are used for folding (clamshell type), opening and closing + twisting (biaxial type), etc. No case has been seen. On the other hand, it is known that an FPC is used as a connection means between cases of a slide type mobile terminal device. For example, techniques disclosed in Patent Documents 3 to 5 have been proposed.

A typical shape, structure, and mechanical operation of a mobile terminal device, particularly a mobile phone, is illustrated in FIG. Clamshell type with open / close structure (see FIG. 5 (a)), jackknife type with rotary structure (see FIG. 5 (b)), and biaxial structure that can be opened / closed and rotated called twist type (FIG. 5 (c)) And a slide type having a horizontal movement structure (see FIG. 5D).
A characteristic required for a slide-type structure is horizontal bending in a space with a height restriction. Typically, it is necessary to be able to handle repeated slides in a 3 mm space. Conventionally, as shown in FIG. 6, only FPC which is a thin and flexible printed wiring board can cope with this structure. This is also described in Patent Documents 3 to 5.
Conventionally, it has been considered that the micro coaxial cable is not suitable for a slide type structure. That is, when several dozens of micro coaxial cables are bundled, as a characteristic required for a slide-type structure, it is insufficient as a bending space within a height limit (for example, 3 mm) and satisfies repeated bending characteristics. This is because they cannot.
On the other hand, the structure (clamshell type or jackknife type) in which the bending space is ensured even in the method of grouping the cables into bundles has been put to practical use because sufficient characteristics are ensured. This is shown in Patent Documents 1 and 2.
JP 2006-286299 A JP 2006-202641 A JP 2006-128808 A JP 2006-216908 A Japanese Patent No. 3723539

In general, a micro coaxial cable used in a mobile electronic device typified by a mobile phone is a type called AWG 46 to AWG 42 in a model number, and the outer diameter of the cable is about 0.2 mm to 0.3 mm. . Furthermore, the bending space used in a general slide type structure has a height of about 3 mm, and the number of times of sliding (number of bending resistances) of 100,000 times or more is required.
However, there is a problem that if the above-mentioned micro coaxial cable is used to bend into a space with a height of 3 mm without any particular measures, the cable will be bent and the number of repeated slides will be the target. It will not reach the value.
Further, as a result of the study by the present inventors, when the ultrafine cables are bundled, the bending radius for satisfying a large number of times (for example, 100,000 times or more) and the number of times of sliding (number of bending resistances) is required to be R = 5 mm or more. In a required space (height 3 mm), it is difficult to satisfy the bending characteristics.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electronic device that can introduce an extra fine coaxial cable into a slide-type mobile terminal device and has excellent resistance to slide bending, and a wiring harness for the electronic device. And

In order to achieve the above object, the present invention is an electronic device in which a plurality of housings having circuits are slidably joined and the circuits in these housings are electrically connected by an electronic device wiring harness. And
The electronic device wiring harness is a flat type in which a large number of electric wires are arranged in parallel and covered with a cylindrical jacket material made of fluororesin, and the average surface roughness (Ra) is 0.8 μm or less. There is provided an electronic apparatus having a cable lamination portion in which a plurality of cables are laminated, and the cable lamination portion is wired in a U shape on a slide surface of a housing.

  In the electronic device of the present invention, it is preferable that at least one of the electric wires is a micro coaxial cable.

  In the present invention, a plurality of flat cables having a plurality of electric wires arranged in parallel and collectively covered with a cylindrical jacket material made of fluororesin and having an average surface roughness (Ra) of 0.8 μm or less. Provided is a wiring harness for electronic equipment, which has a laminated cable section and is used as a wiring material in the electronic equipment according to the present invention.

  In the electronic device wiring harness according to the present invention, it is preferable that at least one of the electric wires is a micro coaxial cable.

The electronic device according to the present invention is a flat cable in which a large number of electric wires are arranged in parallel and are collectively covered with a cylindrical jacket material made of fluororesin, and the average surface roughness (Ra) is 0.8 μm or less. Since the wiring harness is an electronic device wiring harness having a plurality of laminated cable layers as a wiring material, and the cable laminated portion is wired in a U shape on the slide surface of the housing, It is possible to provide an electronic apparatus that enables an ultrafine coaxial cable assembly in a space of 3 mm or less in height.
By using the method of the present invention, a micro coaxial cable assembly is possible in a slide-type electronic device, so that transmission characteristics and noise resistance characteristics are improved as compared with those using a conventional FPC as a wiring material between cases. be able to.
The wiring harness for electronic equipment according to the present invention comprises a large number of electric wires arranged in parallel and collectively covered with a cylindrical jacket material made of a fluororesin, and its average surface roughness (Ra) is 0.8 μm or less. By having a cable lamination part in which a plurality of flat type cables are laminated, the flat cable has good bending resistance, and satisfies the bending resistance number of 100,000 times or more required for slide-type electronic devices. Can do.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating an embodiment of an electronic device of the present invention. In the present embodiment, a case where the present invention is applied to a mobile terminal device such as a mobile phone is illustrated as an electronic device. FIG. 1 (a) shows a state when stored, and FIG. 1 (b) shows a state when pulled out.

  In the electronic device 11 of this embodiment, a first housing 12 and a second housing 13 having circuits are slidably joined, and the circuits in these housings 12 and 13 are connected to an electronic device wiring harness 14. (Hereinafter referred to as a harness), and this harness 14 is formed by arranging a large number of electric wires in parallel and collectively covering with a cylindrical jacket material made of a fluororesin. A cable laminating portion 15 in which a plurality of flat cables having a roughness (Ra) of 0.8 μm or less are laminated, and the cable laminating portion 15 is wired in a U-shape on the slide surface of the housing; It is a feature.

  Here, the U-shaped wiring is not bent in a space of a predetermined height (for example, 3 mm in height) as in the FPC 4 shown in FIG. 6, but in the lateral direction as in the harness 14 shown in FIG. This is a wiring structure in which R is taken. By adopting such a wiring structure, in the electronic device 11 of the present embodiment, the bending caused by the sliding operation of the casings 12 and 13 is bending in a space of a predetermined height (see FIG. 6). Compared to the above, the bending operation can be performed with a larger radius of curvature.

Since the electronic device 11 of the present embodiment is formed by wiring the cable stacking portion 15 on the slide surface of the housing in a U shape, in the slide type electronic device 11, the micro coaxial cable assembly is formed in a space of 3 mm or less in height. Is possible.
In addition, since the electronic device 11 of the present embodiment can be an ultra-fine coaxial cable assembly, the transmission characteristics and noise resistance can be improved as compared with an electronic device using a conventional FPC as a wiring material between cases. .

  The harness 14 used in the present invention is a flat type in which a large number of electric wires are arranged in parallel and collectively covered with a cylindrical jacket material made of fluororesin, and the average surface roughness (Ra) is 0.8 μm or less. It is only necessary to have a cable lamination portion 15 in which a plurality of cables are laminated, and the other components are not particularly limited. Usually, however, each flat cable has a structure in which connectors for connection are provided at both ends. It has become. Each housing 12 and 13 is configured to have a connection portion that can be connected to the connector of the harness 14 at an appropriate position.

  FIG. 2 is a cross-sectional view showing an example of the structure of a flat cable constituting the harness 14. The flat cable 16 of this example is formed by arranging four micro coaxial cables 17 in parallel and collectively covering with a cylindrical jacket material 18 made of fluororesin, and its average surface roughness (Ra) is 0.8 μm. The configuration is as follows. Here, the flat type is obtained by arranging a plurality of micro coaxial cables 17 in parallel and wrapping them in a cylindrical jacket material 18. Therefore, unlike the “tape type” in which the jacket material is filled in all the gaps between the micro coaxial cables, there is a space between the micro coaxial cable 17 and the jacket material 18, as shown in FIG.

  The micro coaxial cable 17 used in this example includes a central conductor, an inner insulating layer that covers the central conductor, an outer conductor that is wound around the inner insulating layer, and a skin that covers the outer conductor. The structure of the flat cable 16 is not limited to this example, and any structure may be used as long as two or more micro coaxial cables 17 or wires other than the micro coaxial cables are collectively covered with the jacket material 18. Various types of flat cables having different combinations can be stacked and used.

  The flat cable 16 is manufactured by arranging four micro coaxial cables 17 in parallel and applying a collective jacket by an extrusion method.

  3 and 4 show a state in which a cable laminated portion 15 formed by stacking a plurality of flat cables 16 is bent at a predetermined radius of curvature R. FIG. The thickness a, the width b, and the radius of curvature R of the cable laminated portion 15 can be appropriately set according to the size of the accommodation space in the electronic device to be used.

  The flat cable 16 used in the harness 14 of the present invention is made of a fluororesin, for example, a copolymer of tetrafluoroethylene and perfluoroalkoxyethylene (PFA), polytetrafluoroethylene (PTFE), polyvinylidene fluoride as a jacket material 18. Resin such as (PVDF) is used. The outer surface of the jacket material 18 of the flat cable 16 has an average surface roughness (Ra) of 0.8 μm or less. If the average surface roughness (Ra) of the jacket material 18 exceeds 0.8 μm, when the slide is repeatedly applied to the cable laminated portion 15, the surface can be scraped or caught, and smooth repeated operation cannot be performed. When the excessive stress is instantaneously applied, the center conductor of the micro coaxial cable is broken, and the target number of bendings cannot be achieved 100,000 times.

The harness 14 of the present invention is a flat cable in which a large number of electric wires are arranged in parallel and covered in a lump with a cylindrical jacket material made of fluororesin, and the average surface roughness (Ra) is 0.8 μm or less. Is configured to have a cable laminated portion 15 in which a plurality of sheets are laminated, so that the flat cable 16 has good bending resistance and satisfies the bending resistance number of 100,000 times or more required for slide-type electronic devices. Can do.
Hereinafter, the effects of the present invention will be demonstrated by examples.

<Example 1>
-Ultrafine coaxial cable; Model number: AWG46, outer diameter: 0.24 mm.
AWG is an abbreviation for American Wire Gauge, and is a standard widely used in the coaxial cable industry. It produced in the way shown below.
The micro coaxial cable is made by twisting three copper alloy wires with a diameter of 25μm to be the central conductor, covering the outer surface with a fluororesin to form an insulating layer, and winding the outer periphery with a 25μm copper alloy wire by lateral winding. It was made so that the outer diameter was about 240 μm with a fluororesin outer skin.

Jacket material: manufactured by 3M, trade name: Dinion PFA (composition: thermoplastic fluororesin composed of a copolymer of tetrafluoroethylene and purple chloroalkoxyethylene). Young's modulus: 500 MPa grade is used.
The above-mentioned ultrafine coaxial cable was flattened using 4 cores and a jacket material, and a flat cable (flat 4 core ultrafine coaxial cable) shown in FIG. 2 was produced. The dimensions after fabrication are: width: 1.2 mm, thickness: 0.3 mm.
The flattening here is different from tape. Flattening is a state in which several fine coaxial cables having a circular cross section are arranged in parallel and wrapped in a cylindrical jacket material. Therefore, unlike the tape filled in all the places, there is a space between the micro coaxial cable having a circular cross section and the jacket material.

In the 40-core harness in which the flat cable is vertically arranged at the bent portion of the cable and 10 flat cables are laminated, the cable lamination portion can be bundled to a width of 3 mm. And as a bending space used for a general slide type structure, the height is 3 mm. In the harness of the present embodiment, this corresponds to the cable width (b in FIG. 3) when flattened. Since the thickness is 1.2 mm, there is sufficient clearance and bending characteristics can be exhibited.

As described above, the micro coaxial cable needs a bending radius of about R = 5 mm. This is almost the same even when flattened. For this reason, in the harness of this example, the cable stack portion was wired in a U shape on the slide surface of the housing as shown in FIGS. 3 and 4.
As a result, wiring with a height of 3 mm and a refraction radius R = 5 mm was made possible.

<Bending test>
7A and 7B are diagrams for explaining an example of a bending test method for measuring the number of bending resistances of the manufactured harness, FIG. 7A is a plan view of the bending test apparatus, and FIG. 7B is a side view of the same apparatus. It is. In FIG. 7, reference numeral 20 denotes a first test stand, 21 denotes a second test stand, 22 denotes a test harness, 23 denotes a cable lamination portion, and 24 and 25 denote connectors.

  In this bending test, the terminal is first processed, and the central conductor and shield are connected to the whole core series. Next, as shown in FIG. 7, the test harness is arranged at a predetermined position of the bending test apparatus so that a part of the cable laminated portion is U-shaped. Next, in order to perform the bending operation, the test harness is fixed to the sliding sample stage. Connect both ends (not shown) of the conductors connected to the series to a measuring terminal (not shown) for checking conduction, and confirm that there is conduction. The test condition was a stroke amount of 40 mm and 30 reciprocations per minute.

About the harness of Example 1, ten 4 core types were laminated | stacked and it used for the test as 40 cores.
The test conditions described above were carried out while the continuity was maintained, the number of times until the continuity could not be obtained was measured, and the number of bending resistances was examined. The number of samples was N = 50, and an average value, a maximum value, and a minimum value were obtained. However, if continuity is obtained without breaking even if the number of slides is 100,000 times or more, the number of times of bending resistance is 100,000 times or more, or> 100,000 times.

  As a result of intensive studies, the present inventors have found that the surface characteristics of the jacket material, particularly the average surface roughness (Ra), are related to the repeated bending characteristics of the harness. Specifically, by setting the average surface roughness (Ra) of the jacket material to 0.8 μm or less, a target bending resistance of 100,000 times or more is achieved. This point will be described in detail in the following examples.

<Example 2>
Example 1 was the same as Example 1 except that the surface property of the jacket material was changed depending on the type of jacket material and the presence or absence of sandblasting.
Three types of resin A, B, and C were used. Both are general-purpose products on the market.
In the sandblasting process, the surface property of the jacket material was modified using a sandblasting apparatus manufactured by Fuji Seisakusho. However, it was devised to change the surface properties (surface roughness) by changing the conditions such as sand type and spraying speed.
As for the surface roughness, the average surface roughness (Ra) of the sample is set as the average value of the number of samples N = 20 using a surface roughness measuring machine manufactured by Mitutoyo Corporation, trade name: foam tracer, model number: SV-C4100. Calculated.

-Resin type: A; copolymer of tetrafluoroethylene and perfluoroalkoxyethylene (PFA).
B: Polytetrafluoroethylene (PTFE).
C: Polyvinylidene fluoride (PVDF).

  The sample of Example 2 was subjected to a bending test under the same conditions and the same number of samples as the above <Bending test>. The results are shown in Table 1.

From the results described in Table 1, it can be seen that in the slide type bending test, the number of bending resistances of the harness depends on the surface property of the jacket material. When a jacket material with a large average surface roughness (Ra) is used, the surface can be scraped or caught due to repeated slides, making it impossible to perform smooth repeated operations, and momentarily stress is applied. It was found that the center conductor of the ultrafine coaxial cable was broken. Therefore, it is necessary that the surface of the jacket material of the flat cable constituting the cable lamination portion of the harness has as little as possible unevenness and can smoothly perform the sliding operation.
As a result of the test, it was found that a material having an average surface roughness of 0.8 μm or less needs to be used as the jacket material in order to achieve the bending resistance of 100,000 times or more.

In the present invention, the lower limit of the average surface roughness (Ra) of the jacket material is not particularly mentioned. This is because it is obvious that a jacket material with superior surface properties can perform a smoother sliding motion and is more resistant to repeated bending.
Further, it is known that if a higher-precision surface roughness measuring device is used, for example, it has a resolution of about 1 nm, but even if it is stepped into such a fine area, it is directly related to the effect of the present invention. do not do.
Further, in the above-described embodiment, a four-core flat cable is used. However, since it is possible to make a flat cable with two or more cables, the number of cores of the micro coaxial cable is not particularly limited.

It is a figure which shows one Embodiment of the electronic device of this invention, (a) is a top view which shows the state of the cable lamination | stacking part at the time of accommodation, (b) at the time of drawer | drawing-out. It is sectional drawing which shows an example of the flat cable used for the harness of this invention. It is a perspective view which shows an example of the cable lamination | stacking part of the harness of this invention. It is a top view which shows an example of the cable lamination | stacking part of the harness of this invention. It is a perspective view which illustrates the various mobile phones from which an opening / closing method differs as an example of an electronic device. It is sectional drawing which shows the prior art example which used FPC as a wiring material between housing | casings. In the Example of this invention, the outline | summary of the testing apparatus used for the measurement of the number of times of bending resistance is shown, (a) is a top view of a testing apparatus, (b) is a side view.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Electronic device, 12 ... 1st housing | casing, 13 ... 2nd housing | casing, 14 ... Harness (harness for electronic device wiring), 15 ... Cable lamination | stacking part, 16 ... Flat cable, 17 ... Micro coaxial cable, 18 ... jacket material.

Claims (4)

A plurality of housings having circuits are slidably joined, and the electronic devices in which the circuits in these housings are electrically connected by an electronic device wiring harness,
The electronic device wiring harness is a flat type in which a large number of electric wires are arranged in parallel and covered with a cylindrical jacket material made of fluororesin, and the average surface roughness (Ra) is 0.8 μm or less. An electronic apparatus comprising a cable lamination portion in which a plurality of cables are laminated, and the cable lamination portion is wired in a U shape on a slide surface of a housing.   The electronic device according to claim 1, wherein at least one of the electric wires is a micro coaxial cable.   A cable in which a plurality of flat cables with an average surface roughness (Ra) of 0.8 μm or less are laminated, with a large number of wires arranged in parallel and collectively covered with a cylindrical jacket material made of fluororesin An electronic device wiring harness comprising a laminated portion and being used as a wiring material in the electronic device according to claim 1.   The electronic device wiring harness according to claim 3, wherein at least one of the electric wires is a micro coaxial cable.

Images