KR100981942B1 - Flexible printed circuit board and slide type mobile phone terminal using the same - Google Patents

Abstract

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a flexible printed wiring board capable of maintaining a desired number of sliding times, especially when applied to a slide-type portable electronic device, and a slide-type mobile phone terminal using the same.

(Solution means) The present invention is a flexible printed wiring board in which a coverlay made of at least an adhesive layer and an electrical insulation layer is provided through the adhesive layer on a conductor layer of a substrate made of at least an electrical insulation layer and a conductor layer, wherein the adhesive layer is used. Silver storage modulus (E ') is 1-4 GPa, loss elastic modulus (E ") is 0.03-0.1 GPa, and the recovery rate after extending | stretching consists of resin of 90% or more, and the thickness of the electrical insulation layer in the said board | substrate is It is 7.5-20 micrometers, The thickness of the electrical insulation layer in the said coverlay is 7.5-40 micrometers, The flexible printed wiring board is provided.

Flexible printed wiring board

Description

FLEXIBLE PRINTED CIRCUIT BOARD AND SLIDE TYPE MOBILE PHONE TERMINAL USING THE SAME}

The present invention relates to a flexible printed wiring board and a slide-type mobile phone terminal using the flexible printed wiring board.

In recent years, the spread of portable telephone terminals (hereinafter also referred to as cellular telephones) has been rapidly progressing. Accordingly, there is a demand for various types of mobile phones, such as stick type, rotary type, and folding type, which have no hinge for the purpose of compacting the mobile phone. In recent years, the popularity of slide-type mobile phones aimed at more compactness is remarkable.

By the way, since flexible printed wiring board (henceforth FPC board | substrate) has the outstanding flexibility and flexibility, it is widely used for portable electronic devices, especially a mobile telephone.

In addition, the FPC board | substrate here can be broadly divided into the following two types. For example, after forming an adhesive layer on one side or both sides of electrical insulation layers, such as a polyimide film, after forming the conductor layer of the three-layer board | substrate which laminated the metal foils, such as copper foil, and formed the conductor layer, a polyimide film The conductor of the two-layer board | substrate which hardened | cured after apply | coating the coverlay which consists of electrical insulation layers, such as these, and an adhesive bond layer, on the circuit-formed conductor layer, and applied electrical insulation layers, such as polyimide, to conductor layers, such as copper foil. There is a type in which a layer is formed in a circuit and a coverlay is laminated on the circuit formed conductor layer.

In order to apply to a compact portable electronic device, the development of the FPC board also becomes thin. As a flexible wiring board for the purpose of thinning, for example, in Unexamined-Japanese-Patent No. 2005-209913, it is a very thin flexible wiring board which has the part which at least the base film and the very thin copper foil laminated | stacked through the hardened | cured material of an adhesive composition, The said The very thin flexible wiring board of 20 micrometers or less in thickness of the laminated part which consists of a base film, the hardened | cured material of an adhesive composition, and very thin copper foil is proposed (patent document 1).

Further, in Japanese Unexamined Patent Publication No. 2005-235948, a very thin cover used for protecting a flexible wiring board having an adhesive layer containing a filler having an average particle diameter of 10 μm or less on one surface of an aramid resin film having a thickness of 3 to 10 μm. Flexible wiring boards using a ray and the coverlay have been proposed (Patent Document 2). However, the technique in these publications is, for example, a technique for improving the bending resistance and bending characteristics having a cutout radius of 2 mm or a cutout radius of 0.1 mm or 0.38 mm. This is different from the technique of improving sliding characteristics with a very small radius.

On the other hand, portable telephones that can be thin and easy to use have been proposed.

For example, Japanese Patent Laid-Open No. 2003-298695 discloses that an upper case body and a lower case body are movably connected to each other in a substantially parallel direction, and the upper case body and the lower case body are developed according to the development and storage of the upper case body. A slide type mobile telephone is disclosed in which an antenna is extended from a case body or the lower case body and accommodated therein (Patent Document 3). This slide-type mobile phone enables thinning of the mobile phone because the antenna is extended and stored in accordance with the opening and closing of the mobile phone, so that the hand does not take much and there is no need to form a protruding portion.

Although the FPC board used in such a thin-sliding mobile phone slides while maintaining a predetermined sliding radius at the time of slide, the sliding radius at that time needs to be considerably smaller (hereinafter, also referred to as narrowing of the slide sliding portion). R is the sliding radius.). Moreover, when the conventional FPC board | substrate is used, there exists a problem that it will short-circuit thousands of times-tens of thousands of times.

[Patent Document 1] Japanese Patent Application Laid-Open No. 2005-209913

[Patent Document 2] Japanese Unexamined Patent Publication No. 2005-235948

[Patent Document 3] Japanese Patent Publication No. 2003-298695

Accordingly, an object of the present invention is to provide a flexible printed wiring board that is particularly applicable to narrower sliding portions of a slide sliding part in a slide-type portable electronic device and that does not short-circuit even when repeated sliding of several hundred thousand times under such conditions. have.

Another object of the present invention is to provide a slide-type mobile telephone terminal using the flexible printed wiring board.

This invention achieves the said objective by providing the following invention.

1. A coverlay composed of at least an adhesive layer and an electrical insulating layer on a conductor layer of a substrate made of at least an electrical insulation layer and a conductor layer is a flexible printed wiring board provided through the adhesive layer.

The adhesive layer is made of a resin having a storage modulus (E ') of 1 to 4 GPa, a loss modulus (E ") of 0.03 to 0.1 GPa, and a recovery rate after stretching of 90% or more,

The thickness of the electrical insulation layer in the said board | substrate is 7.5-20 micrometers,

The thickness of the electrical insulation layer in the said coverlay is 7.5-40 micrometers, The flexible printed wiring board characterized by the above-mentioned.

2. Resin which comprises the said adhesive bond layer contains high molecular weight epoxy resin, The said flexible printed wiring board of 1 characterized by the above-mentioned.

3. The molecular weight of the said high molecular weight epoxy resin is 20,000-70,000, The flexible printed wiring board of said 2 characterized by the above-mentioned.

4. The thickness of the said adhesive bond layer is 5-20 micrometers, The flexible printed wiring board in any one of said 1-3 characterized by the above-mentioned.

5. Conductor layer in said board | substrate consists of rolled metal foil or special electrolytic metal foil, The flexible printed wiring board in any one of said 1-4 characterized by the above-mentioned.

6. At least one of the electrical insulation layers in each of the said board | substrate and a coverlay consists of polyimide, The flexible printed wiring board in any one of said 1-5 characterized by the above-mentioned.

7. A first case body having a display screen and a second case body, wherein the display case overlaps the first case body and the second case body toward a surface side, and the first case body is the first case body. As a slide-type mobile telephone terminal connected to move substantially parallel to 2 case bodies,

The flexible printed wiring board according to any one of the above 1 to 6 is slidably accommodated in the first case body and the second case body, and the wiring board housed in the first case body when the first case body moves is A sliding portable telephone terminal, which slides substantially parallel to the wiring board accommodated in the second case body, and the sliding radius is maintained at 0.4 to 1 mmR.

8. The coverlay used for the flexible printed wiring board as described in any one of said 1-6, or the slide type mobile telephone terminal as described in Claim 7, Comprising: It consists of at least an adhesive bond layer and an electrical insulation layer,

The adhesive layer is made of a resin having a storage modulus (E ') of 1 to 4 GPa, a loss modulus (E ") of 0.03 to 0.1 GPa, and a recovery rate after stretching of 90% or more,

The cover layer, characterized in that the thickness of the electrical insulation layer is 7.5 ~ 40㎛.

(Effects of the Invention)

Advantageous Effects of Invention According to the present invention, it is particularly applicable to narrower sliding portions of a slide sliding part in a slide-type portable electronic device. Moreover, under such conditions that were not obtained with a conventional FPC board, even if the sliding of hundreds of thousands of times or more is repeated, a short circuit does not occur. A flexible printed wiring board and a slide type mobile telephone terminal using the flexible printed wiring board can be provided.

EMBODIMENT OF THE INVENTION Hereinafter, although this invention is demonstrated through embodiment of invention, the following embodiment does not limit invention according to a claim, and all combinations of the features described in embodiment are essential for the solution of this invention. Can not.

(Flexible printed wiring board)

Preferred embodiment of the flexible printed wiring board of this invention is described in detail using drawing. 1 shows a perspective view of a flexible printed wiring board of a first embodiment.

As shown in FIG. 1, the flexible printed wiring board 100 of 1st Embodiment is the conductor layer 12 of the board | substrate 101 which consists of the conductor layer 12 in which the electrical insulation layer 11 and the circuit pattern are formed. The coverlay 102 which consists of the adhesive bond layer 13 and the electrical insulation layer 14 is formed on the said adhesive bond layer 13 on the surface. In addition, in FIG. 1, the board | substrate 101 and the coverlay 102 are shown separately, for easy understanding.

The adhesive layer 13 in the coverlay 102 has a storage modulus (E ') of 1 to 4 GPa, a loss modulus (E ") of 0.03 to 0.1 GPa, and a recovery ratio of 90% or more after stretching. Is made of.

In the present invention, the storage modulus (E ') and the loss modulus (E ") are values measured by a dynamic viscoelasticity measuring device manufactured by Rheometric Scientific. Incidentally, the recovery rate after stretching is obtained by the test method in Examples described later. Value.

Although the storage elastic modulus (E ') of resin which comprises the adhesive bond layer 13 is 1-4 GPa, it is preferable that it is 1-3 GPa especially in the point which expresses flexibility.

Moreover, although the loss elastic modulus (E ") of this resin is 0.03-0.1 GPa, it is preferable that it is 0.04-0.1 GPa especially in the point which improves the recoverability after extending | stretching and raises a viscosity.

Moreover, although the recovery rate after extending | stretching of copper resin is 90% or more, it is preferable that it is 99% or more, and it is more preferable that it is 99.5% or more especially from the point which maintains the shape of copper resin and is difficult to collect residual stress.

It is preferable that the thickness of the adhesive bond layer 13 exists in the range of 5-20 micrometers, More preferably, it is 5-15 micrometers.

The resin constituting the adhesive layer 13 is not particularly limited as long as a high molecular weight epoxy resin is added to the epoxy resin-based adhesive resin used in the field of flexible printed wiring boards. In this embodiment, phenoxy resin is used as a high molecular weight epoxy resin. As said phenoxy resin, the skeleton of a principal chain consists of bisphenol A, bisphenol F, bisphenol S, biphenyl, etc., or the thing containing the several skeleton which consists of bisphenol A and bisphenol F, for example can be used. In addition, a phenoxy resin containing halogen or phosphorus may be used to impart flame retardancy required in FPC.

As the epoxy resin, for example, bisphenol epoxy resins (bisphenol S, bisphenol F, etc.), novolac epoxy resins (phenol novolac, cresol novolac, etc.), biphenyl epoxy resins and the like can be used.

Especially, it is preferable that the resin of the adhesive bond layer 13 is a high molecular weight epoxy resin whose molecular chain like phenoxy resin is linear (linear). In the case of a resin having linear molecular chains compared to a resin having a three-dimensional mesh structure, since the molecular chains are linear, it is easy to store a stress when an external stress is applied, and it is possible to prematurely store a stress when opened from the stress. This is because it is preferable from the point of releasing to (excellent restorative property).

It is preferable that content of a phenoxy resin is 20 to 90% in the whole resin. This improves the resilience of the resin itself.

It is preferable that the weight average molecular weights of resin which can be used as resin which comprises the adhesive bond layer 13 are 20,000-70,000, and it is preferable that it is 25,000-50,000. When the molecular weight is in this range, it is preferable in view of excellent restorability and improvement in workability such as coating described later.

As the resin constituting the adhesive layer 13, a curing agent such as a novolak phenol-based curing agent, diaminodiphenylmethane, diaminodiphenylsulfone, diaminodiphenyl ether, imidazole, hexamethylenediamine, and dicyandiamide as necessary. Can be used.

The thickness of the electrical insulation layer 14 in the coverlay 102 is 7.5-40 micrometers. In particular, since the flexibility of the whole board | substrate improves and a compressive stress is reduced, it is preferable that the thickness of the electrical insulation layer 14 is 7.5-25 micrometers. Here, the reason why the compressive stress is reduced when the electrical insulation layer 14 of this embodiment whose thickness is in such a predetermined range is demonstrated, referring FIG. FIG. 9A shows a state of compressive stress when the electrical insulation layer 14 in the coverlay 102 is thin, and FIG. 9B shows a case where the electrical insulation layer 14 is thick. Shows the state of compressive stress. 9 (a) and 9 (b) compare states when the sliding radius is the same.

As shown in Figs. 9A and 9B, when the sliding radius is the same, when the electrical insulation layer of the coverlay becomes thick, the inner diameter (inner diameter) of the wiring board becomes small (narrows) {Fig. 9 ( b)}. As a result, the compressive stress acts more toward the inner side, so that the slide sliding characteristics in the narrow R decrease. In addition, the structure shown in FIG.9 (a) (the structure which provided the shield layer on both surfaces) is a structure performed by the sliding test in the Example mentioned later.

As the electrical insulation layer 14, electrical insulation films, such as a polyimide film, a polyamide film, a polyamideimide film, and a polyether ether ketone film, are employ | adopted, for example. In particular, polyimides having sufficient heat resistance and flexibility are preferable.

The method of forming the coverlay 102 is obtained by appropriately applying the resin for the adhesive layer 13 to the surface of the electrical insulating layer 14, heating and drying it to a semi-cured state (hereinafter also referred to as B stage). The coverlay 102 is formed on the conductor layer 12 from which the circuit pattern in the board | substrate 101 was obtained, and it heat-hardens, and 1st Embodiment flexible printed wiring board is formed.

As a coating method at the time of apply | coating resin for the adhesive bond layer 13, a comma coater, a die coater, a gravure coater, etc. are mentioned, It can employ | adopt suitably according to the desired thickness etc. of each layer.

The thickness of the electrical insulation layer 11 in the board | substrate 101 is 7.5-20 micrometers. In particular, since the flexibility of the whole board | substrate improves and a compressive stress is reduced, it is preferable that the thickness of the electrical insulation layer 11 is 7.5-15 micrometers. In addition, the principle that the compressive stress is reduced is as described above.

As the electrical insulation layer 11, what consists of resin which has insulation, such as a polyimide, polyamide, polyamideimide, etc. is employ | adopted, for example, polyimide is especially preferable at the point of heat resistance. The electrical insulation layer 11 may be a single layer or a multilayer.

Moreover, you may add various additives, for example, a leveling agent, a coupling agent, an antifoamer, etc. to resin which comprises the electrical insulation layer 11 as needed in the range which does not reduce all the characteristics.

As the conductor layer 12 in the board | substrate 101, metal foil, such as copper and SUS, is used, for example. There is no restriction | limiting in particular if the thickness of metal foil etc. exists in the range of the thickness used in this field. In addition, in order to express antirust property and adhesiveness, you may give an alloy process, an organic process, etc. to the said metal foil surface.

In the present invention, the copper foil can be used for the conductor layer 12 in the board | substrate 101, Especially, it is preferable that it consists of a rolled copper foil or a special electrolytic copper foil. When the conductor layer 12 consists of a rolled copper foil, it is preferable at the point which a crack hardly progresses and disconnection does not occur easily. In addition, the special electrolytic copper foil is preferable in view of obtaining an effect equivalent to that of the rolled copper foil, because the crystal grains are larger than the normal electrolytic copper foil and have a structure similar to the rolled copper foil.

In the present invention, at least one of the electrical insulating layers 11 and 14 in each of the substrate 101 and the coverlay 102 is preferably made of polyimide from the viewpoint of excellent insulation reliability and heat resistance and high elasticity. In particular, it is more preferable that both consist of polyimides.

The manufacturing method of the board | substrate 101 can employ | adopt the manufacturing method of a two-layer single-sided board | substrate, etc. by the casting method, for example.

When an example of the manufacturing method of a two-layer single-sided substrate is shown, after apply | coating and drying a polyimide precursor resin liquid to support bodies, such as copper foil, there exists a method of imidating the said resin by a thermal imidation method or a chemical imidation method, and manufacturing it. . In addition, the thermal imidation method is a method of advancing the imidation reaction by heating, and the chemical imidation method is a method of imidizing by adding a dehydrating agent and a catalyst to a polyimide precursor resin liquid.

As a polyimide precursor resin liquid, polyamic acid etc. can be used, For example, diamine containing paraphenylenediamine or its derivative (s), 3,3 ', 4,4'-biphenyl tetracarboxylic anhydride, etc. The thing obtained by making tetracarboxylic acids react is mentioned.

In addition, if the specific example is shown, after apply | coating so that the thickness after hardening a polyimide precursor resin liquid to the rough surface of copper foil as a support body may become desired thickness, 1, while heating up stepwise in the temperature range of 80-150 degreeC, Dry for 30 minutes. Subsequently, in a nitrogen atmosphere, it heats up gradually to 180-about 400 degreeC for 3 hours, the imidation reaction of the said resin is advanced, and a two-layer single-sided substrate (FIG. 3) is obtained.

In addition, it is preferable to perform reaction temperature at more than the glass transition point temperature of the said resin, and below the thermal decomposition temperature.

And a board | substrate can be obtained by removing and drying the copper foil layer of the two-layer single-sided substrate which consists of a polyimide layer (PI) and copper foil layer (Cu) shown by FIG. 3 by etching so that a desired circuit pattern may be formed.

In the first embodiment, a two-layer single-sided substrate is used as the substrate, but in the present invention, a two-layered double-sided substrate can also be used. An example of the lamination method is shown below as a manufacturing method of such a two-layer double-sided board | substrate. Specifically, after forming a thermoplastic polyimide (TPI) layer on the surface of the polyimide layer (PI) of the two-layer single-sided plate produced by the casting method (1), copper foil layer (Cu) is heat-compression-bonded and produced Or (2) A method in which a copper foil layer is heat-compressed and produced by coating and drying TPI on both surfaces of a polyimide film (PI) (see FIG. 4).

As TPI, for example, diamines containing 4,4'-diaminodiphenyl ether or derivatives thereof and tetracarboxylic acids such as 3,3 ', 4,4'-benzophenone tetracarboxylic anhydride are reacted. The polyamic acid etc. which are obtained by making it make it possible to use can be used. Lamination temperature is more than the glass transition point temperature of TPI, below a pyrolysis temperature, More preferably, it exists in the range of 250-400 degreeC.

And as shown in FIG. 4, the single-sided copper foil layer (upper side of drawing) of a two-layered double-sided board | substrate {(a) of FIG. 4) is removed and dried by etching so that a desired circuit pattern may be formed. Subsequently, the substrate {FIG. 4 (b)} is obtained by further removing and drying the entire one-side copper foil layer (lower side of the drawing) on the opposite side to the circuit pattern of the two-layer double-sided substrate {(a) of FIG. 4 by etching. .

Next, a second embodiment of the flexible printed wiring board of the present invention will be described in detail. 2 shows a perspective view of the flexible printed wiring board of the second embodiment.

As shown in FIG. 2, the flexible printed wiring board 200 of 2nd Embodiment is further provided with the electrical insulation layer 21 and the metal on the board | substrate 101 and coverlay 102 in 1st Embodiment mentioned above. The shield layer 201 including the deposition layer 22 and the adhesive layer 23 is formed through the adhesive layer 23. In addition, although only the form which formed the shield layer 201 in the single side | surface is shown in this figure, you may form and use on both surfaces.

In addition, the shield layer 201 is provided to provide functions such as earth and electromagnetic shield.

The board | substrate 101 which consists of the layer below the coverlay 102 in the flexible printed wiring board 200 of the 2nd embodiment, ie, the conductor layer 12 in which the electrical insulation layer 11 and the circuit pattern are formed, and The coverlay 102 composed of the adhesive layer 13 and the electrical insulating layer 14 is the same as the layer in the first embodiment described above, and therefore, the details described in the first embodiment are appropriately applied.

The shield layer 201 is not particularly limited as long as it exhibits sliding characteristics in the present invention. However, in the present embodiment, the shield layer 201 is composed of an electrical insulating layer 21, a metal deposition layer 22, and an adhesive layer 23. . Although the electrical insulation layer 21 can be suitably selected according to conditions of use, For example, plastic films, such as a polyester film, can be used. In addition, the metal vapor deposition layer 22 is a vapor deposition layer which consists of silver etc., for example. In addition, the adhesive layer 23 is not particularly limited as long as it is an adhesive used as a shielding material in the art. In addition, the thickness of each layer can be suitably selected according to a use structure. Moreover, it is also possible to apply | coat and harden paste-like resin which disperse | distributed metal microparticles | fine-particles, such as silver, to the coverlay surface and to use it as a shield layer other than the said structure.

(Slide type mobile phone terminal)

The slide-type mobile phone terminal of the present invention can provide the slide-type mobile phone terminal shown in FIG. 5 as one embodiment.

As shown in FIG. 5, the slide-type mobile telephone terminal 500 is equipped with the 1st case body 51 provided with the display screen, and the 2nd case body 52, and the 1st display body facing the surface side is shown. A slide type mobile phone terminal in which a case body 51 and a second case body 52 overlap each other, and the first case body 51 is connected so as to move substantially parallel to the second case body 52. The flexible printed wiring board 100 of 1st Embodiment is slidably accommodated in the case body 51 and the 2nd case body 52, and when the 1st case body 51 moves, the 1st case body 51 is moved. The wiring board 100 accommodated in) is slid almost parallel to the wiring board 100 housed in the second case body 52, and the sliding radius thereof is maintained at 0.4 to 1 mmR.

The slide-type mobile phone terminal 500 is used by sliding the first case body 51 appropriately from the state (at the time of use) of FIG. 5A to the state (at the time of storage) of FIG. 5B.

And the flexible printed wiring board 100 of 1st Embodiment in the sliding portable telephone terminal 500 is provided so that it may slide, maintaining the sliding radius R at 0.4-1 mmR at the time of use. Thus, since the slide type portable telephone terminal 500 uses the flexible printed wiring board of this invention mentioned above, it can maintain the desired sliding frequency, and it is equipped with the characteristic which was excellent in use tolerance.

In addition, there are generally types of sliding sliding type that slides while maintaining a constant sliding radius and a sliding type that slides while the sliding radius is varied within a predetermined range (for example, sliding in a range of 0.65 to 1 mmR). The present invention can exhibit excellent sliding characteristics in any type.

As shown in Figs. 6 (a) and 6 (b), conventionally, there is no necessity of thinning as a demand characteristic of a mobile phone terminal. I needed to be angry. The slide-type mobile telephone terminal of the present invention satisfies this narrowing requirement.

Moreover, in this invention, it is a coverlay used for the flexible printed wiring board mentioned above or the slide-type mobile telephone terminal mentioned above, Comprising: It consists of at least an adhesive bond layer and an electrical insulation layer, The adhesive bond layer has a storage modulus (E ') of 1-. A coverlay having a thickness of 4 GPa, a loss modulus (E ″) of 0.03 to 0.1 GPa, a recovery ratio of 90% or more after stretching, and a thickness of 7.5 to 40 µm is provided.

Hereinafter, the present invention will be described in more detail with reference to Examples and Test Examples of the present invention, but the present invention is not limited by these Examples.

(1) Production of coverlay

The resin for coverlay shown in Table 1 was prepared, and it apply | coated using the bar coater to the single side | surface of Apical (registered trademark) NPI (made by Kaneka Co., Ltd.) so that the said resin may become the predetermined thickness shown in Table 2, and it was 150 degreeC It dried for 5 minutes (preferred condition range: 100 degreeC-180 degreeC, 1 to 10 minutes), and obtained the coverlay film whose said resin is B stage (semicuring). In addition, the resin surface was protected by the separator film which performed the mold release process, and it peeled and used at the time of use.

The sample for measuring the physical property of each resin shown in Table 1 was produced by the following procedures. First, after adding each material so that it may become the mixing | blending ratio shown in Table 1, and stirring well, the said resin was heat-hardened at 180 degreeC x 30 minutes, and it produced so that it might become a predetermined sample shape.

The elastic modulus (E ', E ") of each resin shown in Table 1 is a value in 23 degreeC, and is the value measured by the dynamic viscoelasticity measuring apparatus by Rheometric Scientific. The measurement of dynamic viscoelasticity was performed on condition of the following.

Sample size: 40 mm x 10 mm x thickness 0.1 mm,

Temperature range: -30 ~ 150 ℃

In addition, breaking elongation is the value measured based on JISC2318. In this example, the breaking elongation was measured under the following conditions.

Sample size: 200 mm x 13 mm x thickness 0.1 mm

Distance between fixing jig: 100 mm

Tensile Speed: 50mm / min

When the sample is stretched under the above conditions and the sample elongation when the sample is broken is L, it can be obtained by the following equation.

Elongation at Break (%) = (L / Interline Distance) × 100

In addition, the expansion-contraction test method of resin was performed on condition of the following based on the weighting profile shown in FIG.

Sample size: 11 mm x 5 mm x thickness 0.1 mm

Device: TMA-60 made by Shimadzu Seisakusho

Measuring temperature: 30 ℃

Weighting Speed: 50g / min

Derating Speed: -50g / min

Max weighting: 100g

The calculation formula of elongation rate is as follows based on LO, L1, and L3 of FIG.

<1st cycle>

{(L1-L0) / L0} × 100

<2nd cycle>

{(L3-L0) / L0} × 100

The formula for restoring rate is as follows based on LO, L2 and L4 of FIG.

<1st cycle>

(L0 / L2) * 100

<2nd cycle>

(L0 / L4) × 100

In addition, elongation rate means the numerical value which divided | segmented the deformation | transformation amount at the time of maximum deformation of a sample in an extension test by the initial sample length. In addition, a restoration rate means the numerical value which divided | diluted the initial sample length by the sample length after a stretch test (quantifying the degree of restoration of the sample after a test, and 100% represents complete restoration).

(2) substrate

As for the board | substrate used by the present Example, the board | substrate which consists of a lamination method used the PKFW series by Arisa and Seisakusho, and the board | substrate which consists of the cast method used PNS H series by Arisa and Seisakusho.

(3) shield material

As the shielding material used in this example, SFPC 5000 manufactured by Tatsuta Electronics Co., Ltd. was used.

(4) Fabrication of Flexible Printed Wiring Boards

180 degreeC * 2.94 MPa * 30 minutes (preferable conditions range) affixing the board | substrate (two-layer board | substrate which formed the copper foil circuit on the polyimide), and the adhesive surface (resin side) of the coverlay which peeled the separate film shown in Table 2. : Press molding under the conditions of 140 ° C. to 200 ° C. and a pressure of 2 to 5 MPa for 10 to 60 minutes), and then attach the adhesive surface of the shield material from which the separate film was peeled off to both the coverlay and the PI surface of the substrate to be 160 ° C. After molding for 30 minutes, a flexible printed wiring board was obtained. As copper foil in a board | substrate, the thing made by Nikko Kinzoku Co., Ltd. about the rolled copper foil, and the thing by the Nippon Denkai Co., Ltd. were used about the special electrolytic copper foil.

About the flexible printed wiring board which consists of a structure of each Example and comparative example shown in Table 2, sliding evaluation was performed according to the following measuring methods and apparatus. In addition, the structure 1-17 of Table 2 shows an Example, and the structure of the comparative 1-3 shows a comparative example.

<Measuring method of sliding>

Sliding method: The measurement was performed in accordance with IPF-FC-241A 2.4.3.

Apparatus: Low Speed Narrow Sliding Testing Machine {See Figs. 7 (a) and (b)}.

Measurement condition: Stroke {distance traveled during sliding (one way)}: 50 mm

           Speed (1 minute sliding count): 100 cpm

Sliding radius: 1 mm

Measuring temperature: room temperature

(Device used for sliding evaluation)

The schematic sectional drawing of the apparatus used for sliding evaluation in a present Example is shown to FIG. 7 (a). The sliding evaluation method here is based on IPC-FC-241A 2.4.3.

As shown in Fig. 7A, the sample is fixed between the lower plate and the upper plate connected to the cam so as to be U-shaped, and the sample is slid by using the rotation of the cam while keeping the stroke 50 mm and the sliding radius 1.0 mm. Evaluate.

Here, the sliding radius is the gap ÷ 2 of the plate on which the sample is fixed (not the inner diameter of the sample: see FIG. 7A).

As shown in Fig. 7B, the pattern of the conductor layer in the elongated substrate is L / S (line width / space width) = 75/75 占 퐉 and length 15 mm in the form of the sample used for evaluation. The thing which consists of 20 copper lines was used.

In addition, at the time of a measurement, it tested after forming a shield layer on both surfaces of the polyimide surface as a coverlay, and the polyimide surface at the board | substrate side.

The result of sliding evaluation is shown in Table 2 with the coverlay and board | substrate which were used for the Example and the comparative example (thickness of each layer, resin type, copper foil type, a manufacturing method).

When the number of sliding reaches 1 million times, the result is shown in 1 million times and no further measurement is performed. Rank division of the sliding count is as follows.

◎: 800,000 or more times, ○: 200,000 or more times, △: 100,000 or more times, ×: less than 100,000 times

Industrial Applicability The present invention has industrial applicability as a flexible printed wiring board capable of maintaining a desired number of sliding times when applied to a slide-type portable electronic device, a slide-type mobile phone terminal using the same, and a coverlay used therein.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which isolates a board | substrate and a coverlay of the flexible printed wiring board of 1st Embodiment.

It is a perspective view which shows the flexible printed wiring board of 2nd Embodiment separately from a board | substrate, a coverlay, and a shield layer.

It is a schematic perspective view which shows one process of the casting method which is an example of the manufacturing method of a board | substrate.

It is a schematic perspective view which shows one process of the laminating method which is an example of the manufacturing method of a board | substrate.

5 is a schematic cross-sectional view showing one embodiment of a sliding portable telephone terminal.

Fig. 6 is a schematic explanatory diagram showing the necessity of narrowing the wiring board in the mobile phone terminal.

FIG. 7A is a schematic cross-sectional view showing a device used for sliding evaluation in the present embodiment, and FIG. 7B is a schematic plan view showing a partial layer of a sample used for the evaluation.

It is a schematic diagram of the measurement of the stretch test of resin used for the Example and the comparative example.

FIG. 9A is a schematic cross-sectional view showing a state of compressive stress when the electrical insulation layer of the coverlay in Embodiment 1 is thin, and (b) shows a state of compressive stress when the electrical insulation layer is thick. It is a schematic sectional drawing which shows.

Claims (9)

A flexible printed wiring board having at least a coverlay composed of an adhesive layer and an electrical insulating layer provided on a conductor layer of a substrate composed of at least an electrical insulating layer and a conductor layer through the adhesive layer; The adhesive layer is made of a resin having a storage modulus (E ') of 1 to 4 GPa, a loss modulus (E ") of 0.03 to 0.1 GPa, and a recovery rate after stretching of 90% or more, The thickness of the electrical insulation layer in the said board | substrate is 7.5-20 micrometers, The thickness of the electrical insulation layer in the said coverlay is 7.5-40 micrometers, The resin which comprises the said adhesive bond layer contains the high molecular weight epoxy resin whose molecular weight is 20,000-70,000. The flexible printed wiring board characterized by the above-mentioned. delete delete The flexible printed wiring board according to claim 1, wherein the adhesive layer has a thickness of 5 to 20 µm. The flexible printed wiring board according to claim 1, wherein the conductor layer in the substrate is made of a rolled metal foil or a special electrolytic metal foil. The flexible printed wiring board according to claim 1, wherein at least one of the electrical insulating layers in each of the substrate and the coverlay is made of polyimide. A first case body having a display screen and a second case body, wherein the first case body and the second case body overlap the display screen toward the surface side, and the first case body is the second case. A slide type mobile phone terminal connected to move in parallel with a sieve; The flexible printed wiring board according to any one of claims 1 or 4 to 6 is slidably accommodated in the first case body and the second case body, and the first case body is moved when the first case body moves. The said wiring board accommodated in the 1st case body slides in parallel with the said wiring board accommodated in the said 2nd case body, and the sliding radius is hold | maintained at 0.4-1 mmR. As a coverlay used for the flexible printed wiring board according to any one of claims 1 to 4, wherein: At least an adhesive layer and an electrical insulating layer, wherein the adhesive layer is a resin having a storage modulus (E ') of 1 to 4 GPa, a loss modulus (E ") of 0.03 to 0.1 GPa, and a recovery rate of 90% or more after stretching. Done; The cover layer, characterized in that the thickness of the electrical insulation layer is 7.5 ~ 40㎛. As a coverlay used for the slide-type mobile phone terminal according to claim 7, At least an adhesive layer and an electrical insulating layer, wherein the adhesive layer is a resin having a storage modulus (E ') of 1 to 4 GPa, a loss modulus (E ") of 0.03 to 0.1 GPa, and a recovery rate of 90% or more after stretching. Done; The cover layer, characterized in that the thickness of the electrical insulation layer is 7.5 ~ 40㎛.

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