KR101991157B1 - Method for direct bonding an printed circuit board with flexible flat cable, power supplying device bonded thereby and display apparatus comprising the same - Google Patents

Abstract

The present invention provides excellent direct connection between a flexible flat cable (FFC) and a printed circuit board, which is excellent in mechanical, thermal, and electrical properties even under high temperature and high humidity conditions. bonding), a connectorless power supply electrically connected by the above method, and a display device having the same.

Description

TECHNICAL FOR DIRECT BONDING AN PRINTED CIRCUIT BOARD WITH FLEXIBLE FLAT CABLE, POWER SUPPLYING DEVICE BONDED THEREBY AND DISPLAY APPARATUS COMPRISING THE SAME }

The present invention improves the connection structure between a flexible flat cable (FFC) and a printed circuit board having excellent mechanical, thermal, and electrical properties even under high temperature and high humidity conditions. A method (direct bonding), a power supply including a printed circuit board and an FFC electrically connected by the method, and a display device having the same.

In general, a display device, such as a liquid crystal display (LCD), is widely used as a flat panel display device because it can be driven using low power and has a vivid color reproduction ability. However, unlike CRTs and PDPs, LCDs are non-light emitting devices that do not emit light directly. Backlight units (BLUs) using fluorescent lamps are required separately to irradiate light from the back of the LCD panel. do.

The backlight used in the liquid crystal display device is classified into a front dimming type (or a direct type) and a side dimming type (or an edge type) according to a method of disposing a light emitting diode (LED) light source. Direct-lighting is to place the LED light source under the diffuser plate of the flat plate. Since the shape of the light source is shown on the liquid crystal panel, the space between the light source and the liquid crystal should be secured and maintained. Since the light scattering means must be separately installed for distribution, there is a limitation in thinning. In addition, edge-lighting is to distribute the light to the entire surface by using a light guide plate after installing the light source on the side of the light guide panel of the flat plate, there is a problem of low brightness but can improve the side thickness There is room.

On the other hand, most backlight devices are generally wired using the general wire cable shown in FIG. 1, in which case a connector is essentially required for the connection between the circuit board and the general wire cable. The use of the connector not only increases the cost, but also increases the thickness of the component, thereby limiting the thickness of the display device.

In addition, an anisotropic conductive film (AFC) may be used for thinning the product, but in this case, an increase in the cost due to the use of the anisotropic conductive film and an increase in the process cost due to the bonding process, and a decrease in thermal stability may cause 260 There was a limit to use it as it is in the existing high temperature solder joint process performed at ˜280 ° C.

An object of the present invention is to connect the structure of the flexible flat cable (FFC) and the printed circuit board excellent in the mechanical properties, thermal properties and electrical properties even under high temperature and high humidity conditions to be thinned through a structural design, which can be applied to high temperature solder joints To provide a new improved access method.

In addition, an object of the present invention is a connectorless power supply device which can be connected by the above method to realize a low cost while maintaining the connection stability and improved coupling structure between the flexible flat cable and the printed circuit board, and It is providing the display apparatus provided.

In order to achieve the above object, the present invention comprises the steps of (i) applying a solder cream on one side of the printed circuit board; (ii) stacking the flexible flat cable on the applied solder cream, exposing a portion of the conductor coated in the insulating film of the flexible flat cable and placing it on the solder cream; (iii) preparing a heat resistant reinforcement to which a thermosetting resin adhesive is applied on the first surface; (iv) stacking the first surface of the heat resistant reinforcement to which the thermosetting adhesive is applied so that an exposed conductor and a region of the flexible flat cable in contact with the conductor are covered; And (v) provides a direct bonding method of the printed circuit board and the flexible flat cable comprising the step of integrally bonding by performing a press (press) process on the upper surface of the heat resistant reinforcing material.

The present invention also provides a power supply comprising a printed circuit board and a flexible flat cable directly connected by the method described above.

More specifically, the power supply apparatus includes a printed circuit board having a circuit pattern layer formed on one side thereof; A solder layer formed on the circuit pattern layer of the printed circuit board; A flexible flat cable (FFC) disposed on the printed circuit board and bonded to the solder layer with a portion of the conductor coated in the insulating film exposed; A thermosetting adhesive layer formed to cover the exposed conductor and one region of the flexible flat cable contacting the conductor, and for enhancing adhesion to the heat resistant reinforcing material described below; And a heat resistant reinforcing member disposed on the thermosetting adhesive layer.

In addition, the present invention provides a display device having the above-described power supply.

In the present invention, the printed circuit board provided in the power supply device may be a component for controlling a light source of a backlight unit (BLU).

In the present invention, a flexible flat cable (FFC) and a printed circuit board (PCB) are bonded to each other under excellent temperature and humidity conditions, and have excellent mechanical and electrical properties and excellent heat resistance such as shrinkage and deformation due to heat. Through direct bonding, the connection structure can be improved to reduce the thickness of the final product, and the existing soldering process can be applied as it is to secure economic and mass production effects.

In addition, in the present invention, the connectorless power supply device having an improved coupling structure between the flexible flat cable and the circuit board is not only excellent in mechanical properties, heat resistance and electrical properties, but also maintains connection stability of the display device. Cost reduction and thinning can be realized.

1 is a view showing a conventional general electric wire cable coupled to the connector on one side.
FIG. 2 schematically illustrates a direct bonding structure of a printed circuit board and a flexible flat cable according to an exemplary embodiment of the present invention.
FIG. 3 schematically illustrates a manufacturing process in which a printed circuit board and a flexible flat cable are directly connected (direct bonding) according to an embodiment of the present invention.
4 is a photograph showing the connection structure of FIG. 1.
5 is Example 2 in Experimental Example 4 It is a graph which shows the change of contact resistance with time under severe conditions of the power supply apparatus of (solder junction) and the comparative example 7 (ACF bonding).

Hereinafter, preferred embodiments of the present invention will be described. However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. In addition, the embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art.

Recently, display devices such as LED TVs are required to continuously improve thickness and thinner.

Meanwhile, as shown in FIG. 1, the conventional general power cable has a form in which a connector is coupled to at least one end thereof. When combined with a printed circuit board through such a connector, not only there is a limit to reducing the thickness of the final display device but also a cost increase due to the use of the connector.

In addition, in order to reduce the thickness of the conventional final display device, an anisotropic conductive film (ACF) may be applied, but in this case, the use of a separate ACF film and the addition of a bonding process may cause economic and mass productivity degradation. In addition, since the bonding temperature of the ACF film is about 170-200 ° C., there was a limit to use it as it is for the high temperature solder bonding process performed at 260-280 ° C.

Therefore, in the present invention, by adopting a high heat-resistant flexible flat cable (FFC) that can be applied to high temperature solder bonding process and by bonding to a printed circuit board through soldering, physical and electrical direct connection (direct bonding) to them, a separate connector Innovative thickness reduction is possible without using a connector (see FIG. 2).

In the present invention, a high temperature resistant reinforcing material is used on the uppermost layer of the laminate in which the printed circuit board and the flexible flat cable (FFC) are laminated, and then a press process, for example, a hot-bar process by thermocompression bonding, is performed. . Since the laminate can be integrally joined by a single process by the heat generated from the hot bar equipment, it is possible to secure the simplicity, mass production, and economic efficiency of the manufacturing process.

In addition, the present invention can provide a connectorless type power supply device including a high heat resistant flexible flat cable and a printed circuit board having an improved connection structure through the above-described method, and thus, a low cost of a display device having the same. Thinning and thinning can be secured.

<Flexible Flat Cable>

The present invention provides a flexible flat cable (FFC) capable of continuously maintaining high mechanical properties, excellent heat resistance and electrical properties under severe conditions such as high temperature and high humidity.

According to one embodiment of the invention, the flexible flat cable is a conductor; And an insulating film in which an adhesive layer, an intermediate layer, and a resin layer are sequentially stacked on at least one surface of the conductor.

More specifically, it has a structure containing a plurality of flat plate-shaped conductors having a predetermined width and thickness; and at least one insulating film covering one or both sides of the conductor, for example, an adhesive layer is laminated on both sides of the conductor The intermediate layer is laminated on the other side of the adhesive layer, and the resin layer is laminated on the other back side of the intermediate layer.

In the flexible flat cable (FFC) according to the present invention, the type of the conductor is not particularly limited, but may be made of, for example, a conductive metal such as copper, tin plated copper, or nickel plated copper. As a conductor, a thin conductive metal is preferable.

In this case, the thickness or shape of the conductor is not particularly limited, and conventional conductors known in the art may be used without limitation. For example, in consideration of the sliding property of the flexible flat cable (FFC) 100, the thickness of the conductor may be in a range of 20 to 50 μm.

In the flexible flat cable (FFC) according to the present invention, the insulating film covering the conductor has a structure in which an adhesive layer, an intermediate layer, and a resin layer are sequentially stacked.

Here, the adhesive layer serves to bond and bond the insulating film to the conductor, and the intermediate layer is located between the adhesive layer and the resin layer to compensate for the insufficient bonding strength when the adhesive layer and the resin layer are directly bonded. The resin layer is located at the outermost side of the insulating film so that the conductor can be insulated from the outside.

In the flexible flat cable (FFC) according to the present invention, the ratio of the tensile stress (TR) at room temperature to the tensile stress (TH) after maintaining 1000hr under the condition of 85 ° C and 85% humidity of the insulating film (TH / TR) is 0.9 to 1.0, more preferably 0.93 to 1.0.

In the present invention, the ratio of the tensile stress (TR) at room temperature to the tensile stress (TH) after maintaining 1000hr under the severe conditions of the temperature of 85 ° C. and the humidity of 85% of the insulating film (TH / TR) is 0.9 or more in harsh conditions. Even at room temperature, the same and similar mechanical properties may be maintained. On the other hand, when the TH / TR ratio is less than 0.9, the cleavage of the crosslinked chain in the polymer resin included in the adhesive layer or the intermediate layer occurs, which may significantly reduce the mechanical strength and flexibility. Therefore, in the present invention, to control the ratio (TH / TR) of the tensile stress (TR) at room temperature to the tensile stress (TH) after maintaining 1000hr under 85 ℃, 85% conditions of the insulating film is 0.9 or more. Preferably, control is preferably at most 1.0 in view of feasibility and economic circumstances.

In addition, according to another embodiment of the present invention, after maintaining the temperature of the insulating film at a temperature of 85, humidity of 85% 1000hr, that is, under a harsh condition elongation (EH) has a high value of 85 ~ 105%.

In the present invention, the tensile stress (TR) at room temperature of the insulating film may have a high value of 130 ~ 140MPa.

In addition, in the present invention, the tensile stress (TH) of the insulating film after maintaining the insulating film 1000hr under severe conditions of 85 ° C. and 85% humidity may also have a very high value of 115 to 135 MPa.

In addition, in the present invention, the insulating film provided as described above has a shrinkage in the longitudinal direction (MD) of 0.20 to 0.35%, a shrinkage in the width direction (TD) of 0.08 to 0.13%, and a width direction relative to the shrinkage in the longitudinal direction. By controlling the ratio (MD / TD) of the shrinkage ratio to 2.5 to 3.0, the properties of the heat shrinkage ratio can be further improved.

In addition, in the insulating film of the present invention, the adhesive layer may include a polymer resin, wherein the polymer resin is a polyester resin, polyimide resin, polyethylene resin, polyurethane resin and polyphenylene sulfide resin One or more selected from the group consisting of may be used, but may preferably include a polyester resin.

As the polyester resin that can be used as the polymer resin in the present invention, preferably two or more polyester resins may be used, more preferably a first polyester resin having a molecular weight of 1,000 to 15,000, and a molecular weight of 20,000 to 35,000 second polyester (PE) resin or mixtures thereof may be used, more preferably two or more first polyester resins, two or more second polyester resins, or one or more first polyester resins And a mixture of at least one second polyester resin may be used, but most preferably, a mixture of at least one first polyester resin and at least one second polyester resin may be used.

However, the kind of the polyester resin that can be used in the present invention is not limited to the above-described kind, and may be selectively used depending on the characteristics of the product to be implemented.

In addition, in the insulating film of the present invention, the adhesive layer preferably comprises at least one curing agent.

In this case, the curing agent may be a compound including at least one functional group of an isocyanate group, a block isocyanate group, and a carbodiimide group. More specifically, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, diphenylmethane-4, 4'-diisocyanate, xylene diisocyanate, isophorone diisocyanate, polyethylene phenyl diisocyanate and hexamethylene Polyfunctional isocyanates such as diisocyanates, polyol modified products of these isocyanates, carbodiimide modified products, block type isocyanates obtained by masking these isocyanates with alcohols, phenols, lactams, amines, and the like, but are not limited thereto. no.

In the present invention, the curing agent is 6 to 60 parts by weight, preferably 6 to 26 parts by weight, more preferably 8 to 22 parts by weight, still more preferably 8 to 50 parts by weight of the polymer resin included in the adhesive layer. It is included in the amount of ~ 18 parts by weight can further improve mechanical properties and flexibility such as tensile strength, elongation and heat shrinkage. When the content of the polymer resin is 100 parts by weight, the content of the curing agent may increase twice.

In the present invention, at least 6 parts by weight of the curing agent is used in comparison to 50 parts by weight of the polymer resin to obtain the above effects, and more preferably, 8 parts by weight or more of the curing agent cross-linking between the polyester (Cross-Linking) It can fully exhibit excellent mechanical properties even under severe conditions. However, when the hardener is used in excess of 26 parts by weight, the adhesive layer is hardened, so that flexibility and flexibility are reduced, and elongation may be lowered.

In addition, the present invention may further include at least one flame retardant filler to impart flame retardancy to the adhesive layer.

The type of the flame retardant filler is not particularly limited, but due to the addition of the flame retardant filler, the flexible flat cable (FFC) according to the present invention provides flame retardancy that passes the UL standard vertical combustion test (VW-1 test). It is preferable.

More specifically, the flame retardant filler may be used at least one member selected from the group consisting of halogen flame retardant, phosphorus flame retardant, nitrogen-based flame retardant, metal-based flame retardant and antimony flame retardant, preferably at least one kind or a mixture of seven or less It can be used, More preferably, it can mix and use 3 or more types and 5 or less types of compounds suitably.

Specific examples of the flame retardant in the present invention include chlorine-based flame retardants such as chlorinated paraffin, chlorinated polyethylene, chlorinated polyphenyl, and perchloropentacyclodecane; Ethylenebispentabromobenzene, ethylenebispentabromodiphenyl, tetrabromoethane, tetrabromobisphenol A, hexabromobenzene, decabromobiphenyl ether, tetrabromophthalic anhydride, polydibromophenylene oxide, Brominated flame retardants such as hexabromocyclodecane and ammonium bromide; Triallyl phosphate, alkylallyl phosphate, alkyl phosphate, dimethyl phosphonate, phospholinate, halogenated phosphonate ester, trimethyl phosphate, tributyl phosphate, trioctyl phosphate, tributoxy ethyl phosphate, octyl diphenyl phosphate, tricre Diphosphate, credilphenylphosphate, triphenylphosphate, tris (chloroethyl) phosphate, tris (2-chloropropyl) phosphate, tris (2,3-dichloropropyl) phosphate, tris (2,3-dibromopropyl) Phosphate, tris (bromochloropropyl) phosphate, bis (2,3dibromopropyl) 2,3dichloropropylphosphate, bis (chloropropyl) monooctylphosphate, polyphosphonate, polyphosphate, aromatic polyphosphate, di Phosphate esters, such as bromoneopentyl glycol and tris (diethyl phosphinic acid) aluminum Is a compound; Polyols such as phosphonate polyols, phosphate polyols and halogen element-containing polyols; Aluminum hydroxide, magnesium hydroxide, magnesium carbonate, antimony trioxide, antimony trichloride, zinc borate, antimony borate, boric acid, molybdate antimony, molybdate oxide, phosphorus nitrogen compound, calcium aluminum silicate, titanium dioxide, zirconium compound, tin compound Metal powders or inorganic compounds such as dosonite, calcium aluminate hydrate, copper oxide, metal copper powder, calcium carbonate and barium metaborate; Nitrogen compounds such as melamine cyanurate, triazine, isocyanurate, urea and guanidine; And other compounds such as silicone-based polymers, ferrocene, fumaric acid and maleic acid. Especially, halogen flame retardants, such as a bromine flame retardant and a chlorine flame retardant, are preferable.

Although the content of the flame retardant filler in the present invention is not particularly limited, it is sufficient for the adhesive layer to include 5 parts by weight or more, preferably 10 parts by weight or more, and more preferably 15 parts by weight or more based on 50 parts by weight of the polymer resin. Flame retardancy can be imparted, and the upper limit thereof is 75 parts by weight, preferably 65 parts by weight, more preferably 60 parts by weight. If the content of the flame retardant filler exceeds the above upper limit, it may be economically problematic because the effect of improving the flame retardancy may not be seen in comparison with the increase in the amount added, and the filler may have low flexibility and low elongation due to the filler content.

In the present invention, flame retardant aids, pigments, antioxidants, masking agents, lubricants, processing stabilizers, plasticizers, foaming agent reinforcement to the adhesive layer within the range that does not impair the mechanical properties, flexibility and flame retardancy of the insulating film, if necessary Colorants, fillers, granules, metal inerts, silane coupling agents, and the like may further be included.

The present invention provides a method of manufacturing the above-described insulating film.

More specifically, for example, a method of preparing the insulating film may include: preparing a first solvent by combining and synthesizing one or more polyester resins, one or more curing agents, and one or more flame retardant fillers; Preparing a second solvent by combining and synthesizing one or more polyester resins, one or more curing agents, and an inorganic filler; Coating the second solvent on a resin layer to form an intermediate layer; And coating and drying the first solvent on the intermediate layer to form an adhesive layer.

In the method of manufacturing the insulating film, the polyester resin, the curing agent and the flame retardant filler are overlapped with those described in the insulating film described above, and the detailed description thereof is omitted.

In addition, although the type of the inorganic filler used in the preparation of the second solvent is not particularly limited, for example, silica (SiO ₂ ) may be used.

In addition, the present invention provides a method for manufacturing a flexible flat cable (FFC) comprising the above-described insulation film.

More specifically, for the preferred embodiment of manufacturing the flexible flat cable (FFC), preparing two insulating films; And laminating a conductor after the conductor is interposed between the adhesive layers of the two insulating films.

In the present invention, prior to attaching the insulating film to the conductor, the step of cutting the insulating film to a desired size may be further performed.

The thickness of the flexible flat cable including the above-described configuration is not particularly limited, and may be, for example, in the range of 100 to 300 μm, preferably in the range of 100 to 150 μm.

<Direct bonding method of printed circuit board and flexible flat cable>

In addition, the present invention provides a method for direct bonding with a printed circuit board (PCB) through soldering using a flexible flat cable (FFC) having high heat resistance, mechanical properties, and excellent electrical properties.

Hereinafter, a direct connection method between the printed circuit board and the flexible flat cable according to the present invention will be described. However, the present invention is not limited only to the following methods, and the steps of each process may be modified or selectively mixed as necessary.

For one preferred embodiment of the connection method, (i) applying a solder cream on one side of the printed circuit board ('S10 step'); (ii) stacking the flexible flat cable on the applied solder cream, and placing the flexible flat cable on the solder cream while exposing a part of the conductor coated in the insulating film of the flexible flat cable ('S20 step'); (iii) preparing a heat resistant reinforcing material to which a thermosetting resin adhesive is applied on the first surface ('S30 step'); (iv) stacking the first surface of the heat resistant reinforcement to which the thermosetting adhesive is applied so that an exposed conductor and a region of the flexible flat cable in contact with the conductor are covered ('S40'); And (v) performing a hot-bar process by a press process, for example, hot pressing (heat fusion), on the second surface of the heat resistant reinforcing member ('S50 step'). It can be configured to include.

2 and 3 are schematic views illustrating a direct bonding structure of a printed circuit board and a flexible flat cable (FFC) and a connection process thereof according to an embodiment of the present invention.

Hereinafter, referring to FIGS. 2 to 3, the process steps will be described below.

(1) Solder cream application step (hereinafter referred to as 'S10 step')

In step S10, the solder cream 20 is coated on one side of the printed circuit board 10.

In the present invention, the printed circuit board (PCB) 10 can use any conventional circuit board known in the art without limitation. For example, the printed circuit board 10 may include a plurality of chips associated with a light source, a backlight driving circuit, a camera driving circuit, a power driving circuit, and the like.

The printed circuit board 10 may be a printed circuit board 10 electrically connected to a light source for generating light and functioning to supply power to the light source. A circuit pattern (terminal) having a predetermined shape is formed on at least one surface of the printed circuit board 10, and in particular, a copper circuit pattern layer (not shown) and a photo solder resist (PSR) layer for insulating the circuit layer are formed. It is preferably a metal printed circuit board (MPCB).

Here, the shape, thickness, position, etc. of the circuit pattern layer are not particularly limited and may be freely deformed according to the needs of the user. For example, the circuit pattern layer may be formed on one side or both sides of the printed circuit board 10, and may be formed in a predetermined shape according to the length direction or the thickness direction of the printed circuit board 10.

The solder cream 20 applied on one side of the printed circuit board 10 may use a conventional one known in the art, and the component and the coating amount thereof are not particularly limited as long as it can be electrically connected with other electrical and electronic components. . For example, Sn-Pb-based, Sn-Ag-based, or Sn-Bi-based solders may be used.

In the step S10, the solder cream 20 is preferably applied to cover the circuit pattern layer of the printed circuit board 10.

(2) Stacking of flexible flat cable (hereinafter referred to as 'S20 step')

In this step, in order to electrically connect the printed circuit board 10 and the flexible flat cable 30, the flexible flex cable 30 is laminated on the solder cream 20, and the flexible flat cable 30 A portion of the conductor 31 coated in the insulating film (not shown) is exposed and disposed on the solder cream 20.

Here, the flexible flat cable 30 is the same as the above-described configuration, for example (i) a cross-sectional insulating film in which a plurality of conductors, an adhesive layer and a resin layer are sequentially stacked, or (ii) a plurality of It may be a double-sided insulating film in which an adhesive layer and a resin layer are sequentially stacked on the upper and lower surfaces, respectively, based on the conductor.

The flexible flat cable 30 is a cross-sectional type in which the conductive film is exposed on one side of the flexible flat cable 30 so as to be connected to a connection terminal formed at a lower portion of the printed circuit board 10 or other electrical and electronic components. The insulating film on one side is removed from the double-sided insulating film by using a flat surface, or a part of the conductor 31 is used to be exposed to the outside.

In step S20, the flexible flat cable 30 may be freely disposed in consideration of the circuit pattern layer of the printed circuit board 10. For example, when the circuit pattern layer is formed at one end in the longitudinal direction of the printed circuit board, the flexible flat cable 30 may be disposed in the direction in which the longitudinal direction of the printed circuit board 10 crosses. However, this is not particularly limited.

(3) Heat-resistant reinforcement preparation step (hereinafter referred to as 'S30 step')

In this step, the heat resistant reinforcing material 50 to be arranged on the upper portion of the flexible flat cable 30 is prepared.

In the present invention, the heat resistant stiffener 50 can be used without limitation to conventional stiffeners known in the art.

In detail, the heat resistant reinforcing member 50 may use a high heat resistant resin or an engineering plastic that can withstand changes in physical properties under high temperature / high pressure conditions of a press process, preferably a hot-bar process, described later. Preferably it is a polyimide polyimide film or sheet having an extrusion processing temperature of at least 350 ° C. or higher, preferably 350 to 380 ° C.

On the other hand, since the heat resistant reinforcing material 50 should exhibit excellent adhesive strength with the flexible flat cable 30 disposed below it, it is preferable to use the one coated with the thermosetting resin adhesive 40 on the first surface.

Thereby, the thermosetting resin adhesive 40 can be apply | coated and used on the 1st surface of the said heat resistant reinforcement material 50. FIG. At this time, the coating method and the coating amount are not particularly limited and may be appropriately adjusted within the conventional range known in the art. In addition, a commercially available reinforcing material 50 may be used as it is while the adhesive 40 is applied to the first surface. In this case, the adhesive film may be used after removing the release film of the surface to which the adhesive is applied.

The thermosetting resin adhesive 40 applied on the first surface of the heat resistant reinforcement serves to strengthen the physical bond with another substrate, such as the flexible flat cable 30, which is in physical contact with the heat resistant reinforcement 50. do. In addition, the thermosetting resin adhesive 40 has to have excellent adhesive properties continuously while fast curing within a short time by heat generated by a hot-bar process.

The thermosetting resin adhesive 40 includes a main component of a conventional epoxy resin and a curing agent known in the art, and may further include other thermosetting resins, thermoplastic resins, curing accelerators, or the like in the art.

According to a preferred embodiment of the present invention, the thermosetting resin adhesive 40 includes an epoxy resin and a curing agent, and is a fast curing type epoxy adhesive having a curing degree of 90% or more within 30 minutes at a temperature of 260 ° C or higher, for example, 260 to 380 ° C. It is preferable that it is a high heat resistant adhesive whose glass transition temperature (Tg) is 70-100 degreeC.

The epoxy resin can be used without limitation to conventional epoxy resins known in the art, it is preferred that two or more epoxy groups are present while containing a halogen element in one molecule. Non-limiting examples of the epoxy resins that can be used include bisphenol A / F / S resins, novolak type epoxy resins, alkylphenol novolak type epoxy, biphenyl type, aralkyl type and naphthol ( Naphthol) type, dicyclopentadiene type, or a mixed form thereof.

More specific examples include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, naphthalene type epoxy resins, anthracene epoxy resins, biphenyl type epoxy resins, tetramethyl biphenyl type epoxy resins, and phenol novolacs. Epoxy resin, cresol novolac epoxy resin, bisphenol A novolac epoxy resin, bisphenol S novolac epoxy resin, biphenyl novolac epoxy resin, naphthol novolac epoxy resin, naphthol phenol coaxial novolac epoxy resin , Naphthol corresol coaxial novolac epoxy resin, aromatic hydrocarbon formaldehyde resin modified phenol resin epoxy resin, triphenyl methane epoxy resin, tetraphenylethane epoxy resin, dicyclopentadiene phenol addition reaction epoxy resin, phenol aral Kill type epoxy resin, polyfunctional phenol resin, naphthol aralkyl type epoxy resin There is. At this time, the above-mentioned epoxy resins may be used alone or in combination of two or more thereof. Preferably, a bisphenol-A epoxy resin and a cresol novolak-type epoxy resin are mixed.

In the present invention, conventional curing agents known in the art may be used without limitation, and may be appropriately selected and used depending on the type of epoxy resin to be used. Non-limiting examples of curing agents that can be used include phenolic, anhydride, dicyanamide, and aromatic polyamine curing agents. Non-limiting examples of hardeners that can be used include phenolic hardeners such as phenol novolak, cresol novolak, bisphenol A novolak, naphthalene type; And polyamine curing agents such as metaphenylenediamine, diaminodiphenylmethane (DDM) and diaminodiphenylsulfone (DDS), and the like, and these may be used alone or in combination of two or more thereof. It is preferably a diaminodiphenyl sulfone (DDS) curing agent. At this time, the content of the curing agent is not particularly limited, and may be, for example, in the range of 5 to 10 parts by weight based on 100 parts by weight of the entire thermosetting resin adhesive.

As a preferable example of the present invention, the thermosetting resin adhesive 40 is 20 to 70 parts by weight of bisphenol A epoxy resin, 1 to 30 parts by weight of cresol novolac epoxy resin, and 1 to 15 parts by weight of diaminodisphenyl sulfone-based curing agent. It can be configured to include.

The thermosetting resin adhesive 40 of the present invention configured as described above may have a peel strength of 1.5 to 1.7 kgf / cm with the substrate at a thickness of 20 to 25 μm. In addition, the resin flow (resin flow) may be 70 ~ 80 ㎛, the glass transition temperature may be 70 ~ 100 ℃, preferably 70 ~ 80 ℃. In addition, it may be to pass the solder floating (@ 300 ℃, 10sec) test.

(4) lamination step of heat resistant reinforcing material (hereinafter referred to as 'S40 step')

In the step S40, the heat resistant reinforcing material 50 is laminated on the exposed conductor 31 of the flexible flat cable 30, the first surface on which the thermosetting adhesive 40 is applied, the exposed conductor 31 and Lay out and arrange so that one area of the flexible flat cable 30 in contact with the conductor is covered.

The structure of the laminate laminated as described above is as shown in FIG.

(5) Joining step using the press process (hereinafter referred to as 'S50 step')

In the step S50, the upper surface of the laminated body laminated in the previous step S40, that is, the upper surface of the second surface of the heat resistant reinforcing material 50 is subjected to a press (press) process to integrally bond the laminate.

Here, the press process may use any conventional press equipment known for sugar distribution without limitation, and for example, a hot-bar process may be performed. This hot bar process is a thermocompression bonding by applying heat and pressure through hot-bar equipment that is a heating and pressing member. In this case, since the equipment is simple, the process speed is fast, and mass production is possible, it is eco-friendly and economical by other conventional methods.

Press process conditions of the step S50 can be appropriately adjusted within the conventional range known in the art, for example, using a hot bar equipment for 10 seconds to 5 minutes under a temperature of 260 ~ 380 ℃ and pressure conditions of 0.1 ~ 10 MPa Thermocompression may be performed, and preferably, thermocompression bonding is performed for 10 seconds to 5 minutes under a temperature of 260 to 360 ° C. and a pressure of 0.1 to 5 MPa.

When thermal compression is performed through the hot bar device as described above, the generated heat is conducted from the heat resistant reinforcement 50 that is the uppermost part of the laminate to the lowermost printed circuit board 10. Curing of the thermosetting resin adhesive 40 in accordance with this heat conduction; And since the soldering process of the solder cream 20 is made at the same time, the laminate is integrally bonded in a short time by a single process. For example, when the hot bar process is performed at 350 to 380 ° C., the generated heat is transferred to the heat resistant reinforcement 50 as the uppermost part, and the flexible flat cable 30 at the lower part is 280 to 300 ° C., and the solder cream 20 is It is about 260 ~ 280 ℃.

The structure of the printed circuit board 10 and the flexible flat cable 30 connected through the above-described method is as shown in FIG. 2.

<Power supply>

In addition, the present invention provides a power supply, preferably a power supply of a light source for a display device, including a printed circuit board and a flexible flat cable that are directly bonded by the above-described method.

More specifically, the power supply apparatus includes a printed circuit board 10 having a circuit pattern layer formed on one side thereof; A solder layer 20 formed on the circuit pattern layer of the printed circuit board 10; A flexible flat cable (FFC) 30 disposed on the printed circuit board 10 and bonded to the solder layer 20 with a portion of the conductor 31 coated in the insulating film exposed; A thermosetting adhesive layer 40 formed to cover up to one region of the exposed conductor 31 and the flexible flat cable 30 in contact with the conductor, and to enhance adhesion to the heat resistant reinforcing member 50 described below; And a heat resistant reinforcing member 50 disposed on the thermosetting adhesive layer 40.

In the present invention, the power supply device is a connectorless connection structure in which a printed circuit board, a flexible flat cable, and a heat resistant reinforcement are integrally bonded to each other. Accordingly, by directly connecting a high heat resistant flexible flat cable (FFC) and a printed circuit board by the conventional solder joint without using a connector, innovative thickness and volume reduction are possible.

The power supply device of the present invention may include a plurality of printed circuit boards different in structure and / or function thereof. At this time, each printed circuit board may have a structure that is connected in series through both ends of the flexible flat cable.

In addition, the power supply may include a plurality of flexible flat cables, wherein both ends of the printed circuit board may be directly connected to each flexible flat cable.

More specifically, the power supply apparatus of the present invention includes a first printed circuit board including a terminal and mounted with a plurality of light sources (eg, LED chips); A second printed circuit board including a terminal and providing power to the first printed circuit board; And a flexible flat cable, wherein both ends of the flexible flat cable have a structure in which terminals of the first printed circuit board and the second printed circuit board are connected in series, and both ends of the printed circuit board are each flexible. Direct bonding with a flat cable allows electrical connection.

The power supply device of the present invention not only has an improved connection structure with other electric and electronic components through structural design modifications, but also uses a high heat resistant FFC, a high heat resistant adhesive, and a high heat resistant reinforcement as essential, A test for evaluating the reliability of an electronic component package, for example, under high temperature and high humidity conditions, is characterized by exhibiting mechanical, thermal and electrical properties that are almost the same as or similar to room temperature conditions.

According to one embodiment of the present invention, the flexible flat cable provided in the power supply, the tensile stress (TR) at room temperature to the tensile stress (TH) after maintaining 1000hr under a condition of temperature 85 ℃, 85% humidity The ratio (TH / TR) may be 0.9 to 1.0. Preferably it is 0.93-1.0.

According to another embodiment of the present invention, the flexible flat cable provided in the power supply device may have a contact resistance (Ω _HTHH ) value of 10 mΩ or less after maintaining 500hrs under a condition of 85 ° C. and 85% humidity. Preferably it may be 6.0 mΩ or less.

According to another embodiment of the present invention, the peel strength value of the flexible flat cable for the printed circuit board after maintaining 500hrs under the condition of 85 ° C. and 85% humidity in the power supply is 1.00 to 5.00. It may range from kgf / cm. Preferably from 1.20 to 5.00 kgf / cm.

<Display device>

Furthermore, the present invention provides a display device having the above-described power supply.

Here, the display device may be applied to any conventional flat panel display device known in the art without limitation, for example, a liquid crystal display (LCD), a light emitting diode (LED), a touch panel, A field emission display (FED), a PDA, a plasma display panel (PDP), a backlight unit (BLU), a light source component, and the like.

The display apparatus according to an embodiment of the present invention includes a light source and a power supply device electrically connected to the light source and supplying power to the light source.

More specifically, a flat panel for displaying an image; A light source for outputting light to the flat panel; And a power supply for supplying power to the light source. Here, the metal printed circuit board provided in the power supply device may be a component for controlling a light source, preferably a light source of a backlight unit (BLU).

In this case, the light source and the power supply device may be provided separately, or the light source may be already mounted on the metal printed circuit board of the power supply device. As such, the light source mounted on the metal printed circuit board may have a structure electrically connected to the flexible flat cable.

The power supply device not only has flexibility and flatness, but also does not include a connector, thus occupying a remarkably small volume, thereby contributing to thinning of a display device having the same. The display device of the present invention having such a power supply is applicable to both a conventional front dimming type (direct type) or side dimming type (edge type), and in particular, the side dimming type (or edge type) that can improve side thickness. desirable.

Hereinafter, the present invention will be described in more detail with reference to specific examples. The following examples are merely examples to help understanding of the present invention, but the scope of the present invention is not limited thereto.

 [Examples 1 to 6 and Comparative Examples 1 to 6]

<1-1. Insulation Film Manufacturing>

25 parts by weight of the reactive polyester resin (molecular weight 8,000 / glass transition temperature 61 ℃) and the reactive polyester resin (molecular weight 30,000 / glass transition temperature 80 ℃) are dissolved in a solvent composed of 80 toluene 80 and 90 parts by weight of methyl ethyl ketone. After preparing a resin solution and mixing by adding 50 parts by weight of a flame retardant filler for improving the flame retardant properties, an isocyanate curing agent was added to the content shown in Table 1 below to prepare a first solvent for an adhesive layer of 2,000 cps or more. Isocyanate curing agent was added just before coating with a factor affecting the aging of the resin composition to prepare a mixture.

Further, 20 parts by weight of silica was added to 80 parts by weight of the mixed resin of the polyester resin (molecular weight 5,000 / glass transition temperature 51 ° C.) and the reactive polyester resin (molecular weight 20,000 / glass transition temperature 35 ° C.) to add a second solvent for the intermediate layer. Was prepared. One surface of the stretched polyethylene film was coated with a coating amount of 10 g / m ² in a comma coat method and then dried to form an intermediate layer, followed by coating the first solvent with a coating amount of 100 g / m ² on the intermediate layer. And dried to form an adhesive layer having a thickness of 20 μm to prepare an insulating film.

<1-2. Flexible Flat Cable Manufacturing>

As described above, the flexible flat of Preparation Examples 1 to 6 and Comparative Examples 1 to 6 by interposing a conductor having a thickness of 35 μm between two adhesive layers prepared in 1-1 and laminating at a speed of 0.8 m / min. Each cable (FFC) was prepared.

<1-3. Power Supply Manufacturing>

After applying the solder cream on the circuit pattern of the metal printed circuit board, the flexible flat cable of Preparation Example 1-6 and Comparative Example 1-6 with a conductor exposed on the coated solder cream was laminated respectively. Then, a polyimide reinforcing material coated with an epoxy thermosetting adhesive (glass transition temperature: 72 ° C.) having a composition of 70 parts by weight of a bisphenol A epoxy resin, 25 parts by weight of a cresol novolac epoxy resin, and 5 parts by weight of a diaminodisphenyl sulfone-based curing agent. After laminating on the conductor and the flexible flat cable, the laminate was placed in a hot bar equipment and pressed for 15 seconds under a temperature of 350 ° C. and 0.2 MPa condition to power the Examples 1-6 and Comparative Examples 1-6. Each supply device was prepared.

Comparative Example 7

An anisotropic conductive film (CP7652K, Dec. Cereals, Inc.) and a flexible flat cable with exposed conductors were sequentially stacked on the circuit pattern of the metal printed circuit board, and then pressed for 20 seconds under a temperature of 180 ° C. and 0.2 MPa. The power supply of Comparative Example 7 was manufactured.

An anisotropic conductive film (CP7652K, Dec. Cereals, Inc.) and a flexible flat cable with exposed conductors were sequentially stacked on the circuit pattern of the metal printed circuit board, and then pressed for 20 seconds under a temperature of 180 ° C. and 0.2 MPa. The power supply of Comparative Example 7 was manufactured.

division Composition (parts by weight) 1st polyester
(Molecular weight 1,000-15,000) 2nd polyester
(Molecular weight 20,000-35,000) Hardener Flame retardant filler Preparation Example 1 25 25 8 50 Preparation Example 2 25 25 10 50 Preparation Example 3 25 25 14 50 Preparation Example 4 25 25 18 50 Preparation Example 5 25 25 22 50 Preparation Example 6 25 25 26 50 Comparative Example 1 25 25 One 50 Comparative Example 2 25 25 3 50 Comparative Example 3 25 25 5 50 Comparative Example 4 25 25 - 50 Comparative Example 5 50 - 14 50 Comparative Example 6 - 50 14 50

Experimental Example 1

Tensile tester of the insulation film of each sample was maintained for 1000hr under the normal temperature condition (TR), 85 ° C, 85% humidity (TH) with respect to the insulating film prepared in Preparation Examples 1 to 6 and Comparative Examples 1 to 6 Tensile stress was evaluated as shown in Table 2 below. The curing agent content is based on 50 parts by weight of polyester.

Hardener content Room temperature tensile stress
(TR) High temperature, high humidity tensile stress
(TH) Hardener content and tensile stress ratio
(TH / TR) Preparation Example 1 8 134 128 0.96 Preparation Example 2 10 138 131 0.95 Preparation Example 3 14 139 129 0.93 Preparation Example 4 18 135 125 0.93 Preparation Example 5 22 131 118 0.90 Preparation Example 6 26 130 117 0.90 Comparative Example 1 One 115 88 0.77 Comparative Example 2 3 119 94 0.79 Comparative Example 3 5 128 108 0.84 Comparative Example 4 - 112 75 0.67 Comparative Example 5 14 89 72 0.81

As shown in Table 2, the insulating film of Preparation Examples 1 to 6 according to the present invention can be seen that the TH / TR is in the range of 0.90 ~ 0.96 in the harsh conditions compared to the normal temperature conditions. However, Comparative Examples 1 to 6 can be seen that the mechanical properties in the harsh conditions compared to the room temperature conditions are very reduced.

Experimental Example 2

For the insulating films prepared in Preparation Examples 1 to 6 and Comparative Examples 1 to 6, the elongation rate (ER) at room temperature and the elongation rate (EH) after maintaining 1000hr at 85 ° C and 85% humidity were evaluated. Table 3 shows. The curing agent content is based on 50 parts by weight of polyester.

Hardener content Room temperature elongation
(ER) High temperature and high humidity elongation
(EH) Preparation Example 1 8 120 92 Preparation Example 2 10 123 97 Preparation Example 3 14 125 103 Preparation Example 4 18 121 105 Preparation Example 5 22 104 89 Preparation Example 6 26 109 85 Comparative Example 1 One 104 77 Comparative Example 2 3 109 78 Comparative Example 3 5 117 82 Comparative Example 4 - 98 75 Comparative Example 5 14 85 75

As shown in Table 3, the insulating film of Preparation Examples 1 to 6 according to the present invention can be seen that the elongation (EH) after maintaining 1000hr at a temperature of 85 ℃, humidity 85% has a high value of 85 ~ 105%. have. On the other hand, in the insulating films of Comparative Examples 1 to 6 it can be seen that the elongation (EH) under harsh conditions after maintaining 1000hr at a temperature of 85 ° C and a humidity of 85% is only about 75 to 82%.

Experimental Example 3

The insulation films prepared in Production Examples 1 to 6 and Comparative Examples 1 to 6 were maintained at 1000 hr under conditions of heat shrinkage, temperature of 85 ° C., and humidity of 95%, and 1000 hr under conditions of 85 ° C. and 85% of humidity The external appearance was evaluated and the results are shown in Table 4 below.

However, specific evaluation criteria of the flexibility and appearance are as follows.

1. Flexibility Assessment

Under the condition of 85 ° C and 95% humidity, the number of times the insulation film was slid was measured until the conductor resistance increased more than 10%.

◎: More than 100,000 times, ○: 7-100,000 times, △: 50,000-70,000 times, X: 50,000 times or less

2. Appearance Evaluation

It was evaluated whether or not delamination occurred under the conditions of a temperature of 85 ° C. and a humidity of 85%.

◎: Delamination occurs more than 2,000 hours, ○: Delamination occurs 1,500 to 2,000 hours, △: Delamination occurs 1,000 to 1,500 hours, X: Delamination occurs less than 1,000 hours

Hardener content MD TD MD / TD flexibility Appearance Example 1 8 0.30 0.10 3 ◎ ◎ Example 2 10 0.20 0.08 2.5 ◎ ◎ Example 3 14 0.20 0.08 2.5 ◎ ◎ Example 4 18 0.20 0.08 2.5 ○ ○ Example 5 22 0.20 0.08 2.5 ○ ○ Example 6 26 0.20 0.08 2.5 ○ ○ Comparative Example 1 One 0.75 0.25 3 △ △ Comparative Example 2 3 0.60 0.20 3 ○ ○ Comparative Example 3 5 0.40 0.15 2.67 ○ ○ Comparative Example 4 - 0.80 0.30 2.67 △ △ Comparative Example 5 14 0.35 0.13 2.69 △ △

As shown in Table 4, the insulating film of Preparation Examples 1 to 6 according to the present invention is a level of 0.2 to 0.3% MD, TD of 0.08 to 0.10% level than the insulating film of Comparative Examples 1 to 6 It can be seen that the heat shrinkage rate has a significantly low value, and the properties of flexibility and appearance are also very good.

Experimental Example 4. Evaluation of Physical Properties of Power Supply Device

Using a power supply device manufactured in Example 2 and Comparative Example 7 was carried out as follows (High Temp. High Humidity Test, HTHH).

After measuring the flexible flat cable manufactured in Example 2 and Comparative Example 7 at a temperature of 85 ° C. and a humidity of 85% for 500hrs, the contact resistance and the peel strength (P / S) of the printed circuit board were respectively measured. The results are shown in Table 5 and FIG. 5.

At this time, the evaluation method and evaluation criteria of Experimental Example 4 are as follows.

1) The contact resistance of the flexible flat cable was measured using the Keysight B2901A Source Meter.

2) The adhesive strength of the flexible flat cable was measured at 90 degrees (vertical) and 180 degrees (horizontal) adhesion force (kgf / cm) with respect to the printed circuit board at a tensile speed of 300 mm / min. Instron 8942 UTM was used. .

division Example 2 Comparative Example 7 FPCB FFC Joining method Solder joint Anisotropic Conductive Bonding (ACF Bonding) Adhesive strength
(kgf / cm) 90 degrees 1.35 1.38 180 degrees 1.28 1.25 Contact resistance
(mΩ) Initial resistance 2.9 3.5 HTHH 4.6 5.9

As shown in Table 5, Comparative Example 7 bonded using a conventional anisotropic conductive film, compared with Example 2 directly connected by soldering, the contact resistance was continuously high from the beginning under severe conditions, 400 hours Over time, the contact resistance tended to be significantly higher (see Table 5 and FIG. 5). In addition, it was found that Example 2 and Comparative Example 7 exhibited comparable characteristics in terms of adhesive strength.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and changes can be made without departing from the technical spirit of the present invention described in the claims. It will be obvious to those of ordinary skill in the field.

10: printed circuit board, 20: solder layer
30: flexible flat cable, 31: conductor
40: heat resistant adhesive layer, 50: heat resistant reinforcing material

Claims (21)

(i) applying solder cream to one side of the printed circuit board;
(ii) stacking the flexible flat cable on the applied solder cream, exposing a portion of the conductor coated in the insulating film of the flexible flat cable and placing it on the solder cream;
(iii) preparing a heat resistant reinforcement to which a thermosetting resin adhesive is applied on the first surface;
(iv) stacking the first surface of the heat resistant reinforcement to which the thermosetting resin adhesive is applied so that an exposed conductor and a region of the flexible flat cable in contact with the conductor are covered; And
(v) A direct bonding method of a printed circuit board and a flexible flat cable, comprising a step of integrally bonding a press process to an upper portion of a second surface of the heat resistant reinforcing member,
The thermosetting resin adhesive is an epoxy resin and a curing agent, a high heat resistance adhesive having a curing degree of 90% or more within 30 minutes at a temperature of 260 ° C. or higher and a glass transition temperature (Tg) of 70 to 100 ° C.,
The flexible flat cable is a conductor; And an insulating film having an adhesive layer and a resin layer laminated on at least one surface of the conductor,
The adhesive layer includes two or more polyester polymer resins and curing agents,
The polyester polymer resin includes at least one first polyester resin having a number average molecular weight of 1,000-15,000 and at least one second polyester resin having a number average molecular weight of 20,000-35,000, wherein the curing agent is applied to the adhesive layer. A direct connection method of a printed circuit board and a flexible flat cable, which is included in an amount of 8 to 26 parts by weight based on 50 parts by weight of the polymer resin included. The method of claim 1,
The printed circuit board of step (i) is a circuit pattern layer; and a metal printed circuit board (MPCB) on which a photosolder resist (PSR) layer is formed to insulate the circuit pattern layer. How to connect. The method of claim 2,
The step (i) is a method of directly connecting a printed circuit board and a flexible flat cable to apply a solder cream on the circuit pattern layer. The method of claim 1,
The flexible flat cable of step (ii)
(i) a cross-sectional insulating film in which a plurality of conductors, adhesive layers and resin layers are sequentially stacked; or
(ii) A direct connection method of a printed circuit board and a flexible flat cable, each of which is a double-sided insulating film in which an adhesive layer and a resin layer are sequentially stacked on upper and lower surfaces of a plurality of conductors, respectively. delete delete The method of claim 1,
Wherein the curing agent is a compound comprising at least one functional group of an isocyanate group, a block isocyanate group, and a carbodiimide group direct connection method of the printed circuit board and the flexible flat cable. The method of claim 1,
The adhesive layer further comprises at least one flame retardant filler,
The flame retardant filler is one or more selected from the group consisting of halogen flame retardant, phosphorus flame retardant, nitrogen flame retardant, metal flame retardant and antimony flame retardant direct connection method of a printed circuit board and a flexible flat cable. The method of claim 1,
The heat-resistant reinforcing member of the step (iii) is a direct connection method of the printed circuit board and the flexible flat cable is a polyimide film having an extrusion processing temperature of at least 350 ℃. delete delete The method of claim 1,
The press process of step (iv) is a direct connection method of the printed circuit board and the flexible flat cable is subjected to thermal compression for 10 seconds to 5 minutes at a temperature of 260 ~ 380 ℃ and pressure conditions of 0.1 ~ 10 MPa. The method of claim 1,
Step (iv) is a step of curing the thermosetting resin adhesive heat is transferred by the press process from the heat resistant reinforcement to the printed circuit board; And a direct connection method of the printed circuit board and the flexible flat cable, wherein the soldering cream soldering process is performed at the same time. A printed circuit board having a circuit pattern layer formed on one side thereof;
A solder layer formed on the circuit pattern layer of the printed circuit board;
A flexible flat cable (FFC) disposed on the printed circuit board and bonded to the solder layer with a portion of the conductor coated in the insulating film exposed;
A thermosetting resin adhesive layer formed to cover up to one region of the exposed conductor and the flexible flat cable contacting the conductor, and to enhance adhesion with the following heat resistant reinforcing material; And
Heat resistant reinforcing material disposed on the thermosetting resin adhesive layer
As a power supply comprising a,
The thermosetting resin adhesive layer is an epoxy resin and a curing agent, a high heat resistance adhesive having a curing degree of 90% or more within 30 minutes at a temperature of 260 ° C. or higher and a glass transition temperature (Tg) of 70 to 100 ° C.,
The flexible flat cable is a conductor; And an insulating film having an adhesive layer and a resin layer laminated on at least one surface of the conductor,
The adhesive layer includes two or more polyester polymer resins and curing agents,
The polyester polymer resin includes at least one first polyester resin having a number average molecular weight of 1,000-15,000 and at least one second polyester resin having a number average molecular weight of 20,000-35,000, wherein the curing agent is applied to the adhesive layer. Power supply device, which comprises 8 to 26 parts by weight based on 50 parts by weight of the polymer resin included. The method of claim 14,
And the printed circuit board, the flexible flat cable, and the heat resistant reinforcement are integrally connected to each other and connected to each other. The method of claim 14,
The printed circuit board is a power supply device which is electrically connected to a light source for generating light, and a component for a display device for supplying power to the light source. The method of claim 14,
The flexible flat cable is characterized in that the ratio (TH / TR) of the tensile stress (TR) at room temperature to the tensile stress (TH) after maintaining 1000hrs under the conditions of 85 ° C temperature, 85% humidity is 0.9 ~ 1.0 Power supply. The method of claim 14,
The flexible flat cable has a contact resistance (Ω _HTHH ) value of 10 mΩ or less after 500hrs of holding at a temperature of 85 ° C. and a humidity of 85%. The method of claim 14,
And a peel strength value of the flexible flat cable is 1.00 to 5.00 kgf / cm to the printed circuit board after maintaining 500 hrs under a temperature of 85 ° C. and a humidity of 85%. Display device comprising the power supply of claim 14. The method of claim 20,
The display device includes a liquid crystal display (LCD), a light emitting diode (LED), a touch panel, a field emission display (FED), a PDA, and a plasma display panel (PDP). ), A display unit (BLU) and a light source component.

Images