JP2008257970A - 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 tape-type cables having a tape form as a whole using a jacket material made of ultraviolet curable resin having a gel fraction of 88% or more 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 when the above-mentioned micro coaxial cable is used to bend into a space of 3 mm in height without any special measures, there is a problem that the cable bends and the number of repeated slides is 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, a bending radius for satisfying a large number of times (for example, 100,000 times or more) and the number of sliding times (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 cable in which a plurality of tape-type cables formed by arranging a large number of electric wires in parallel and collectively taped with a jacket material made of an ultraviolet curable resin having a gel fraction of 88% or more are laminated. Provided is an electronic device having a laminated portion, wherein the cable laminated portion is wired in a U shape on a sliding 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.

  Further, the present invention provides a cable laminated portion in which a plurality of tape-type cables are laminated by arranging a large number of electric wires in parallel and forming a tape at once with a jacket material made of an ultraviolet curable resin having a gel fraction of 88% or more. And an electronic device wiring harness characterized by being used as a wiring material in the electronic device of 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 an electronic device having a cable laminated portion in which a plurality of tape-type cables obtained by forming a plurality of electric wires into a single tape with a jacket material made of an ultraviolet curable resin having a gel fraction of 88% or more are laminated. Since the equipment wiring harness is used as the wiring material and the cable stack is wired in a U-shape on the slide surface of the housing, in a slide-type electronic device, an ultrafine coaxial cable assembly can be used in a space of 3 mm or less in height. It is possible to provide a possible electronic device.
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 electronic device wiring harness according to the present invention includes a cable laminated portion obtained by laminating a plurality of tape type cables obtained by forming a tape of a large number of electric wires with a jacket material made of an ultraviolet curable resin having a gel fraction of 88% or more. By having the structure, the bending resistance of the flat cable becomes good, and the bending resistance number of 100,000 times or more required in the slide type electronic device can be satisfied.

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 the harness 14 includes a plurality of tape-type cables that are taped together with a jacket material made of an ultraviolet curable resin having a gel fraction of 88% or more. It is characterized by having a laminated cable section 15, which is wired in a U-shape on the slide surface of the housing.

  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 cable in which a plurality of tape type cables formed by arranging a large number of electric wires in parallel and collectively taped with a jacket material made of an ultraviolet curable resin having a gel fraction of 88% or more are laminated. The other components are not particularly limited as long as the laminated portion 15 is provided, but normally, a connection connector is provided at each end of each flat cable. Moreover, it is preferable that each housing 12 and 13 has 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 tape-type cable constituting the harness 14. The tape type cable 16 of this example has a configuration in which four micro coaxial cables 17 are arranged in parallel and are collectively taped with a jacket material made of an ultraviolet curable resin having a gel fraction of 88% or more. Here, the tape type is one in which a plurality of micro coaxial cables 17 are arranged in parallel and overcoated with a jacket material 18. Therefore, in the tape type cable, as shown in FIG. 2, the jacket material 18 is filled in all the gaps between the micro coaxial cables 17, and there is a “flat” space between the micro coaxial cable 17 and the jacket material 18. Different from "type".

  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 tape-type cable 16 is not limited to this example, 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, and the cables and wires Various types of tape-type cables having different combinations can be laminated and used.

  The tape type 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 tape-type cables 16 is bent with a predetermined radius of curvature. 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 tape type cable 16 used for the harness 14 of the present invention uses an ultraviolet curable resin having a gel fraction of 88% or more as the jacket material 18. If the gel fraction of the jacket material 18 is less than 88%, the rigidity of the tape-type cable 16 becomes low, and stress due to bending is applied to the central conductor of the micro-coaxial cable. It breaks, and the target number of flexing times of 100,000 cannot be achieved.

The harness of the present invention is configured to have a cable laminated portion 15 in which a plurality of tape-type cables formed by batch tape formation with a jacket material made of an ultraviolet curable resin having a gel fraction of 88% or more are laminated. The bending resistance of the flat cable becomes good, and the bending resistance number of 100,000 times or more required in the slide type electronic device can be satisfied.
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: Urethane / acrylate ultraviolet curable resin (hereinafter referred to as UV resin), manufactured by JSR Corporation, trade name: Desolite, model number R3059. The gel fraction after curing was 95%.
The above-described ultrafine coaxial cable was taped using 4 cores and a jacket material to produce a tape-type cable (tape-type 4-core ultrafine coaxial cable) shown in FIG. The dimensions after fabrication are: width: 1.2 mm, thickness: 0.3 mm.
Here, the tape formation means that several ultra-fine coaxial cables having a circular cross section are arranged in parallel and overcoated with a jacket material. Therefore, this is different from so-called “flattening” in which the jacket material is filled in all portions, the micro coaxial cable is wrapped with a cylindrical jacket material, and a space exists between the jacket material and the micro coaxial cable.

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 gel fraction of the jacket material is related to the repeated bending characteristics of the harness. Specifically, by setting the gel fraction of the jacket material in the range of 88 to 98%, the target number of bending resistances of 100,000 or more is achieved. This point will be described in detail based on the results of Examples 2, 3, and 4 below.

<Example 2>
It was the same as Example 1 except that the UV resin as the jacket material of Example 1 was changed to a different gelation rate by changing the UV irradiation rate.

<Example 3>
As a jacket material, urethane acrylate UV resin, manufactured by JSR Corporation, trade name: Desolite, model number R3061 was used, and the UV irradiation rate was changed to have different gelation rates. Otherwise, it was the same as Example 1.

<Example 4>
As a jacket material, urethane acrylate UV resin, manufactured by JSR Corporation, trade name: Desolite, model number R3041, was used, and the UV irradiation rate was changed to have different gelation rates. Otherwise, it was the same as Example 1.

  About each test harness produced in Examples 2-4, the bending test was done on the same conditions and the number of samples as the said <bending test>, and the frequency | count of a fracture | rupture was investigated. In Examples 1 and 2, the relationship between the gel fraction of the jacket material and the number of breaks is shown in FIG. In Example 3, the relationship between the gel fraction of the jacket material and the number of breaks is shown in FIG. In Example 4, the relationship between the gel fraction of the jacket material and the number of breaks is shown in FIG. However, all the bending times of 100,000 times or more were displayed at the 100,000 times.

In general, it is known that a UV resin has different crosslink density and curing degree depending on the amount of ultraviolet rays (UV light) irradiated. The index is a gel fraction. In this method, uncured components are extracted with an organic solvent (for example, methyl ethyl ketone (MEK, IUPAC name: 2-butanone)), and the ratio of the remaining weight to the initial weight is displayed as a percentage. Widely used. For example, a gel fraction of 95% means that the cured component is 95% and the uncured component is 5%. That is, 95% is polymerized by a crosslinking reaction, and 5% means that the crosslinking reaction is insufficient or unreacted and not polymerized, and is a low molecular weight substance.
Therefore, it is self-evident that a certain level of crosslink density or polymer network formation is necessary for UV resin to act effectively as a jacket material. As a result, it is necessary to have a gel fraction above a certain level. is there.

  Generally, it is known that the upper limit of the gel fraction of a UV resin used as a jacket material is about 98%, although it varies depending on the material type. Most of the curing reaction is due to the main reaction as in the material design, but in fact, a side reaction occurs in the curing reaction and an intermediate main component that is not polymerized also occurs. Furthermore, there is an intermediate component at the end of the curing reaction in which there is no other partner for the curing reaction. Therefore, it is known that a certain amount of uncured components and low molecular weight components remain, and it is difficult to produce a gel having a gel fraction of 100%.

It is known that a phenomenon called “over cure” occurs when UV light is irradiated more than necessary. This is a phenomenon in which UV resin is cured by UV light irradiation in a normal range, but when it is irradiated more than necessary, molecules are cut and the formed polymer network is destroyed. Eventually, the UV resin will carbonize. In short, it is obvious that the UV resin in the overcured state cannot maintain the quality as material characteristics. Therefore, these products are not commercially provided as industrial products.
From the above, even if the upper limit of the gel fraction of the UV resin used as the jacket material is specified, there is not much meaning.

From the results of FIGS. 8 to 10, it is understood that the number of breaks (= number of bending resistances) depends on the gel fraction of the jacket material in the slide type bending test. When a material having a low gel fraction was used as the jacket material, the tape-type cable had low rigidity, so stress in the bending test was applied to the central conductor, and it broke about tens of thousands of times.
That is, for the resistance to repeated bending in the slide type bending test, it is necessary to use a material having a gel fraction of at least 88% as a jacket material.

  The resin used in Examples 1 and 2 (R3059), the resin used in Example 3 (R3061), and the resin used in Example 4 (R3041) are all urethane / acrylate UV resins. , Monomer species, photoinitiator species, and their blending ratios are different. As a result, mechanical properties such as elasticity and rigidity after curing differ depending on the curing speed and the crosslinking density. In general, Young's modulus is used as an index representing the mechanical properties of the UV resin after curing. The Young's modulus when cured by sufficiently irradiating with UV light is 860 MPa for R3059, 700 MPa for R3061, and 450 MPa for R3041. Even with such materials having different Young's moduli, it was found that if the gel fraction was not 88% or more, the number of flexing times in the slide type flexing test was not satisfied. In particular, it was found that the number of bendings can be clearly divided into more than 100,000 and less than 88%.

  In this embodiment, a four-core flat cable is used. However, the number of cores of the ultrafine coaxial cable is not particularly limited because it is possible to flatten the cable if there are two or more cables.

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. It is a graph which shows the result of Example 1,2. 10 is a graph showing the results of Example 3. 10 is a graph showing the results of Example 3.

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 cable in which a plurality of tape-type cables formed by arranging a large number of electric wires in parallel and collectively taped with a jacket material made of an ultraviolet curable resin having a gel fraction of 88% or more are laminated. An electronic apparatus having a laminated portion, wherein the cable laminated portion is wired in a U shape on a sliding 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 laminating unit in which a plurality of tape-type cables are arranged in which a large number of electric wires are arranged in parallel and are collectively taped by a jacket material made of an ultraviolet curable resin having a gel fraction of 88% or more, An electronic device wiring harness, which is used as a wiring material for the electronic device according to 1.   The electronic device wiring harness according to claim 3, wherein at least one of the electric wires is a micro coaxial cable.

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