TW201742236A - LED element substrate and LED display device for reducing cost of bending damage caused by flexibility of the resin substrate and difference between bending flexible coefficients of the resin substrate and metal wiring portion - Google Patents

Abstract

The subject of the present invention is to reduce risk of bending damage to a flexible substrate type LED element substrate. The bending damage is caused by flexibility of the resin substrate and difference between bending flexible coefficients of the resin substrate and metal wiring portion. The present invention provides an LED element substrate 1 having a resin substrate 11 composed of a resin thin film with flexibility; and a metal wire portion 13 that is formed as conductible LED elements 2 on the resin substrate 11. The LED elements 2 are configured into a matrix shape. Moreover, the metal wire portion 13 is composed of a plurality of conductive plate portions 131, each having a circle shape or a polygon shape, configured on the resin substrate 11. A non-conducting portion between two adjacent conductive plate portions 131, that is an insulating slit potion 132, is not at the same straight line with adjacent another insulating slit portion 132.

Description

LED element substrate and LED display device

The present invention relates to a substrate for an LED element and an LED display device using the substrate for the LED element. More specifically, the present invention relates to a substrate for an LED element and an LED display device using the substrate for the LED element, wherein the LED element substrate can be configured by a light emitting diode (LED) element. The element is used as a backlight of the LED display device, and can contribute to the improvement of the productivity of the LED display device.

In recent years, as a screen for replacing a conventional cathode ray tube type, it is an LED display device such as a liquid crystal television or a liquid crystal display that uses LED elements as backlights in response to demands for low power consumption, large size and thinness of equipment. The popularity is rapidly progressing.

In order to mount an LED element as a light source in these display devices, various substrates for LED elements composed of a support substrate and a line portion are generally used. In addition, a laminated body in which an LED element is formed on these substrates (hereinafter, such a laminated body member is referred to as an "LED package module") can be used as a light source of various display devices such as the above-described liquid crystal television. It is widely used as an LED backlight.

In these display devices, in order to achieve high image quality, an increase in brightness of the light source is required. However, an increase in the amount of heat generated from the LED elements accompanying the increase in brightness also leads to an increase in power consumption and a decrease in the light-emitting capability of the LED elements. Therefore, in terms of the LED package module, together with the improvement of the brightness, it is also strongly required to improve the heat dissipation. This demand for improved heat dissipation has become a particularly urgent problem in displays such as liquid crystal televisions as the size of recent years has progressed.

For example, a method of directly mounting an LED element on a metal surface of a metal base substrate has been proposed as a configuration of an LED element for improving heat dissipation (see Patent Document 1). However, this method lacks design freedom because the metal substrate is a plate shape, and productivity is also low because it is a batch production of one substrate at a time.

In view of this, there is also proposed a circuit board which is a substrate in which a metal circuit is formed on a flexible resin substrate (hereinafter referred to as a "flexible substrate"), and is provided only for exhibiting heat dissipation. A metal layer which is provided separately from the conduction circuit (Patent Document 2) or a portion which is separately formed to be separated from the circuit for conduction is a thermal connection portion (Patent Document 3).

However, in any of these flexible substrates, in any step up to assembly into a final product such as an LED display device, there are occasional cases of fatal damage to an LED display device or the like, which is a cause of fatal damage. The flexibility of the resin substrate and the difference in bending elastic modulus between the resin substrate and the metal wiring portion, and the unrecoverable substrate bending and LED components Damage to the structure, etc. Moreover, this has become one of the important reasons hindering the productivity improvement of LED display devices.

[Previous Technical Literature] (Patent Literature)

Patent Document 1: Japanese Laid-Open Patent Publication No. 2009-81194

Patent Document 2: Japanese Laid-Open Patent Publication No. 2012-59867

Patent Document 3: Japanese Patent Publication No. 2013-522893

The present invention has been made in view of the above circumstances, and an object thereof is to reduce the risk of bending damage in a substrate for a flexible substrate type LED element, which is caused by flexibility of a resin substrate, and a resin substrate. Produced by the difference in the bending elastic coefficient of the metal wiring portion.

As a result of the intensive study by the present inventors, the arrangement of the insulating slit portions between the metal wiring portions was found for the substrate for a flexible substrate type LED element in which a metal wiring portion was formed on a flexible resin film. The present invention can be solved by forming a metal wiring portion in a specific configuration unique to the present application. Specifically, the present invention provides the invention as described below.

(1) A substrate for an LED element, comprising: a resin substrate comprising a flexible resin film; and a metal wiring portion formed on the resin substrate to electrically connect the LED elements, the LEDs The elements are arranged in a matrix shape; and the metal line portion is formed by a plurality of circular or polygonal conductive plate portions disposed on the resin substrate, and non-conducting between the adjacent two conductive plate portions Part of it is an insulating slit portion which is not in line with another adjacent insulating slit portion.

(2) The substrate for an LED element according to the above aspect, wherein the conductive plate portion is a conductive plate portion having a regular hexagonal shape.

(3) The LED element substrate according to the above aspect, wherein the metal line portion is formed by a plurality of right circular or elliptical conductive plate portions which are alternately arranged on the resin substrate.

The substrate for LED elements according to any one of the above aspects, wherein the metal line portion covers a range of 70% or more of one surface of the resin substrate.

(5) The substrate for LED elements according to the above aspect, wherein the metal wiring portion covers a range of 95% or more of one surface of the resin substrate.

The substrate for LED elements according to any one of the aspects of the present invention, wherein the resin substrate has a diagonal length of 32 Å or more and a single flexible resin film. Composition.

(7) A LED display device which is a substrate for a LED element according to any one of (1) to (3). It is made up of LED components.

According to the present invention, it is possible to provide a substrate for an LED element which is a substrate for a flexible substrate type LED element, which has a reduced risk of bending damage, which is caused by the flexibility of the resin substrate. And the difference between the bending elastic modulus of the resin substrate and the metal wiring portion.

1, 1A‧‧‧ substrate for LED components

2‧‧‧LED components

3‧‧‧ screen

4‧‧‧ Heat dissipation structure

10‧‧‧LED Assembly Module

11‧‧‧Resin substrate

12‧‧‧Adhesive layer

13‧‧‧Metal Lines Department

131, 131A, 131B, 131C, 131D, 131E, 131F, 131G, 131H, 131I, 131J‧‧‧ conductive plate

132, 132A, 132B, 132C, 132D, 132E, 132F, 132DF, 132DI, 132EJ, 132GH‧‧‧ insulated slit

133‧‧‧Connector line

134‧‧‧ terminals

14‧‧‧ solder layer

15‧‧‧Insulating protective film

16‧‧‧reflective layer

100‧‧‧LED display device

X, Y‧‧ direction

D‧‧‧ diagonal

Fig. 1 is a plan view schematically showing the overall configuration of a metal wiring portion of a substrate for an LED element of the present invention.

Fig. 2 is a plan view schematically showing the overall configuration of a metal wiring portion of another embodiment of the LED element substrate of the present invention.

Fig. 3 is a partial cross-sectional view showing an LED module in which an LED element is mounted on a substrate for an LED element of the present invention.

Fig. 4 is a plan view schematically showing an LED module in which an LED element is mounted on a substrate for an LED element of the present invention.

Fig. 5 is a plan view showing the shape of the conductive plate portion and the insulating slit portion in the metal wiring portion of the first embodiment of the LED element substrate of the present invention, and the positional relationship therebetween.

Fig. 6 is a plan view showing the shape of the conductive plate portion and the insulating slit portion in the metal wiring portion and the positional relationship among the second embodiment of the LED element substrate of the present invention.

Fig. 7 is a plan view showing the shape of the conductive plate portion and the insulating slit portion in the metal wiring portion and the positional relationship among the third embodiment of the LED element substrate of the present invention.

Fig. 8 is a plan view showing the shape of the conductive plate portion and the insulating slit portion in the metal wiring portion and the positional relationship among the fourth embodiment of the LED element substrate of the present invention.

Fig. 9 is a perspective view schematically showing an outline of a layer configuration of an LED display device using the LED module of the present invention.

Hereinafter, each embodiment of the LED element substrate, the LED package module, and the LED display device of the present invention will be described. The present invention is not limited to the following embodiments, and can be appropriately modified and implemented within the scope of the object of the present invention.

Hereinafter, an embodiment of the LED element substrate and the LED display device of the present invention will be described. The present invention is not limited to the following embodiments, and can be appropriately modified and implemented within the scope of the object of the present invention.

<Substrate for LED components>

As shown in FIGS. 1 to 3, the LED element substrate 1 is formed of a metal foil laminated on the surface of a resin substrate 11 made of a flexible resin film via an adhesive layer 12. Conductive metal line portion 13. The metal line portion 13 is formed on the resin substrate 11 in such a manner that the LED element 2 can be electrically connected, and the LED elements 2 are arranged in a matrix. The details of the shape and arrangement of the metal wiring portion 13 for the characteristic portion of the present invention will be described later.

Further, as shown in FIG. 3, the LED element substrate 1 is formed with an insulating protective film 15 made of a thermosetting ink or the like on the resin substrate 11 and the metal wiring portion 13. In order to improve the migration resistance of the substrate 1 for an LED element, the insulating protective film 15 is formed by covering the entire surface of the surface of the metal wiring portion 13 except for the connection portion for arranging the LED element 2, and The approximately entire surface of the portion of the surface of the resin substrate 11 where the metal wiring portion 13 is not formed.

Further, as shown in FIG. 3, the LED element substrate 1 is preferably further provided with a reflective layer 16 made of a white resin or the like on the insulating substrate 15 on the resin substrate 11 and the metal wiring portion 13. . In particular, when the LED package module 10 in which the LED element 2 is mounted on the LED element substrate 1 is used as the backlight of the LED display device 100 shown in FIG. 9, it is generally required. The reflective layer 16 is disposed on the outermost surface of the LED package module. However, by providing the insulating protective film 15 with a reflection function, the desired reflection function can be ensured by the insulating protective film without providing the reflective layer.

As shown in FIG. 3, the LED component substrate 1 will become the LED component module 10, and the LED component module 10 is an LED component 2 that is electrically connected to the metal line via the solder layer 14. The part 13 is formed. Moreover, the LED package module 10 can preferably use a backlight as an LED display device such as an LED liquid crystal television.

The size of the substrate 1 for LED elements is not particularly limited. For example, in the large-sized LED package module shown in FIG. 4, the substrate 1 for LED elements of the present invention can also be preferably used. The group has a length of the diagonal d of 32 Å or more and 100 or more LED elements 2 are arranged in a matrix. Fig. 4 is a view showing an example of the configuration of the LED element 2 to the substrate 1 for LED elements, and shows an example in which 40 LED elements 2 are integrated in the X direction and 30 in the Y direction. In addition, the planar shape of the substrate for LED elements of the present invention is not necessarily limited to a rectangular shape. In the present specification, the "diagonal length is 32 吋 or more" means the length of the long diameter of the LED element substrate, for example, when the substrate is elliptical.

[Resin substrate]

As a material of the resin substrate 11, a resin film which is formed into a sheet shape by a thermoplastic resin and has flexibility can be used. Here, the flaky shape means a concept including a film shape, and as long as it is any one having flexibility, there is no difference between the two in the present invention.

The thermoplastic resin used as the material of the resin substrate 11 is required to have high heat resistance and insulation properties. As such a resin, a polyimide resin (PI) can be used, which is excellent in heat resistance, dimensional stability during heating, mechanical strength, and durability. Further, it is also possible to use various other thermoplastic resins which have improved heat resistance and dimensional stability by performing heat resistance enhancement treatment such as annealing treatment. For example, polyethylene naphthalate (PEN) or the like which is required to have sufficient heat resistance and dimensional stability is provided by annealing treatment. In addition, PET (polyethylene terephthalate) or the like which is improved in flame retardancy by addition of a flame retardant inorganic filler or the like can be selected as a raw material resin of the resin substrate.

The thermoplastic resin forming the resin substrate 11 is preferably one having improved heat resistance in the following manner: heat shrinkage by the above annealing treatment The initial temperature is equal to or higher than the heat curing temperature of the thermosetting ink for forming the insulating protective film 15. For example, in the case where the insulating protective film 15 is formed by a thermosetting ink having a thermosetting temperature of about 80 ° C, the heat shrinkage initiation temperature of PEN, which is usually about 80 ° C, is raised by annealing treatment. It can be up to 100 °C. Thereby, it is possible to prevent the fine thermal damage of the resin substrate 11 and form an insulating protective film 15 which has sufficient heat resistance, strength, and insulation properties.

Further, the "heat shrinkage initiation temperature" in the present specification means that a sample sheet composed of a thermoplastic resin is attached to a TMA (thermo-mechanical analyzer) device, and a load of 1 g is applied and the temperature is raised at a rate of 2 When the temperature is raised to 120 °C at °C/min, the amount of shrinkage at that time (in %) is measured, and this data is output and a graph of the temperature and the shrinkage is recorded to read the deviation from the 0% reference line due to shrinkage. The temperature, which is the temperature at which the heat shrinks the onset temperature. In the present specification, the term "thermosetting temperature" means measuring and calculating the temperature at the position immediately after the heat curing reaction when the object to be measured is heated, that is, the thermosetting resin, and the temperature is taken as the heat curing temperature.

The insulating property of the resin substrate 11 is required to be, for example, a resin having a volume specific resistivity which is displayed as an LED when the LED element substrate 1 is used as a backlight of an LED display device. When the device is integrated, the insulation required for the substrate 1 for LED elements can be imparted. In general, the volume specific resistivity of the resin substrate 11 is preferably 10 ¹⁴ Ω. More than cm, further preferably 10 ¹⁸ Ω. More than cm.

The thickness of the resin substrate 11 is not particularly limited, but is preferably about 10 μm or more and 100 μm or less from the viewpoint of balance between heat resistance and insulation properties and production cost. Moreover, it is preferable that the said thickness range is the viewpoint of the favorable maintenance of the manufacture by the roll-to-roll type manufacture.

The size of the resin substrate 11 is not particularly limited. However, the substrate for an LED element can be formed, for example, by a single resin film having a diagonal length of 32 Å or more. In the present specification, the "single resin film" means that the resin film is not an aggregate of a plurality of resin films or a bonded body formed by the physical bonding, but a resin film composed of a single sheet-shaped film. Such a single large film can be manufactured by a special extrusion forming apparatus that can manufacture a film outside the conventional specification range.

[adhesive layer]

The bonding of the metal wiring portion 13 to the surface of the LED element substrate 1 is preferably performed by a dry lamination method via the adhesive layer 12. The adhesive for forming the adhesive layer 12 may have a heat resistance at a heat curing temperature of the thermosetting ink forming the insulating protective film 15, that is, a known resin-based adhesive can be suitably used. Among these resin binders, a urethane type, a polycarbonate type, or an epoxy resin type adhesive agent can be particularly preferably used.

[Metal line part]

The substrate for an LED element of the present invention is mainly characterized in that the shape and arrangement of the metal wiring portion are limited to a unique state. The risk of bending damage described above. Hereinafter, details of the shape and arrangement of the metal wiring portion will be described.

The metal wiring portion 13 is a wiring pattern composed of a polygonal or circular conductive plate portion 131 on the surface of the LED element substrate 1, and the conductive plate portion 131 is formed of a conductive substrate. The shape of the plan view of the conductive plate portion 131 may be a polygonal shape or a circular shape that can electrically connect the LED elements 2 arranged in a matrix.

When the shape of the plan view of the conductive plate portion 131 is a polygonal shape, the shape may be a convex polygon such as a regular polygon or a concave polygon as shown in FIG. 5.

When the shape of the plan view of the conductive plate portion 131 is a circular shape, the shape may be a perfect circular shape or an elliptical shape as shown in Fig. 8. Moreover, as long as it is such a circular shape, the ratio of the long diameter to the short diameter and the ellipse having a different size or a perfect circle having a different size may be mixed.

Preferably, the arrangement of the metal line portion 13 is such that the joint portion of the LED element 2 to the metal line portion 13 is the basic unit of the structure, as shown in Figs. 1 and 2, etc., so that the LED element 2 can be turned on. The pattern repeats in the matrix in the XY two directions. The basic unit of the package means a portion formed by the adjacent one of the conductive plate portions 131 in the substrate 1 for LED elements, that is, the insulating slit portion 132, as shown in Fig. 3.

The insulating slit portion 132 is, in detail, an unformed portion of the metal wiring portion 13 in the LED element substrate 1 (that is, a portion where the metal wiring portion is not formed), and is an adjacent one of the above-mentioned conductive groups. Board A non-conducting portion between 131. When the shape of the plan view of the conductive plate portion 131 is a polygonal shape, the insulating slit portions 132A to 132D and the like in FIGS. 5 and 6 correspond to the insulating slit portion. When the shape of the plan view of the conductive plate portion 131 is a circular shape, the insulating slit portions 132DF, 132GH, 132DI, 132EJ and the like in Fig. 8 correspond to the insulating slit portion.

Further, as shown in Fig. 1, the metal line portion 13 includes, in addition to the portion which is the basic unit of the above-described configuration, a connector line 133 which is disposed in a matrix arrangement. The rows and columns of the conductive plate portions 131 are connected to each other; and the terminals 134 are used for electrically connecting the LED package module 10 to an external power source or the like at the end portions of the rows or columns. In the LED element substrate 1, the degree of freedom in designing the arrangement of the conductive plate portion 131, the connector line 133, and the terminal 134 constituting the metal wiring portion 13 and the combination thereof is high, and the conduction pattern of the plurality of LED elements 2 is Any one of series connection and parallel connection is possible, and the two connection modes can be made into the most suitable combination line depending on the characteristics required for the assembled LED display device.

In the metal line portion 13 of the substrate 1 for an LED device of the present invention, the arrangement of the insulating slit portion 132 is such that the arrangement condition of the insulating slit portion peculiar to the present invention which satisfies the following detailed description is satisfied in order to reduce the risk of the above-described bending damage. In the manner of limiting the shape and arrangement of the conductive plate portion 131 to a specific shape and arrangement.

The "conditions for arranging the insulating slit portion peculiar to the present invention" means that "an insulating slit portion is not in line with the adjacent another insulating slit portion". "Adjacent insulating slit portion" means another insulating slit portion, and the other An insulating slit portion is formed such that an outer edge thereof is constituted by one conductive plate portion constituting an outer edge of an insulating slit portion and an adjacent another conductive plate portion, and the other insulating slit portion is other than the aforementioned one of the insulating slit portions . In other words, in the substrate for a flexible substrate type LED element, the insulating slit portion which is likely to be a starting point of the bending damage does not cross the plurality of structures. The basic unit of the installation is not connected to a straight line. Therefore, the LED element substrate 1 can be made to reduce the risk of bending damage.

Further, as shown in FIG. 8 , when the shape of the plan view of the conductive plate portion 131 is a circular shape, the circular conductive plate portion 131 can be disposed "staggered" on the resin substrate 11 The arrangement is such that "an insulating slit portion is not in line with another adjacent insulating slit portion". Here, the arrangement is a staggered shape, which means that the arrangement may be other than a completely lattice-like arrangement, and it is preferable that the centers of the conductive plate portions disposed in adjacent rows are in the matrix formed by the metal wiring portion 13 In the mutually parallel rows, they are in different coordinate positions, and are arranged in a zigzag manner with a fixed amplitude in the column direction. Thereby, in the matrix of the metal line portion 13, the insulating slit portion is formed "on the same straight line", that is, in the "same direction" or "continuous", across the rows or columns. Therefore, as shown in FIG. 2, in the LED element substrate 1A having a circular shape in the plan view of the conductive plate portion 131, the risk of bending damage can be reduced similarly to the LED element substrate 1 of Fig. 1 . In the case where the plan view shape of the conductive plate portion 131 is a circular shape, the direction of the insulating slit portion 132 (for example, the insulating slit portion 132EJ) means that a pair of adjacent conductive plates forming the insulating slit portion are formed. The point on the circumference of each outer edge of the portion 131 (for example, the conductive plate portion 131E and the conductive plate portion 131J) is a tangential direction of a point at which the distance between the two points is the smallest, and the tangential direction is approximately the same direction. As a specific example, in FIG. 8, the direction of the insulating slit portion 132EJ is the Y direction in the drawing.

Various embodiments can be implemented as the embodiment of the metal wiring portion for realizing the above-described "specific configuration conditions of the present invention", and a specific example of the shape and arrangement of the metal wiring portion will be described with reference to FIG. However, the substrate for an LED element of the present invention is not limited to the following embodiments as long as the conductive plate portion satisfies the conditions of the "specific arrangement of the present invention", and various applications are possible within a range that satisfies the above conditions. The present invention includes all of these.

Various embodiments can be implemented as the embodiment of the metal wiring portion for realizing the above-described "arrangement of the insulating slit portion peculiar to the present invention". Hereinafter, the shape of the metal wiring portion in the representative four embodiments will be described. The specific example of the arrangement will be described with reference to the drawings from Fig. 5 to Fig. 8 respectively. However, the substrate for an LED element of the present invention is not limited to the following four embodiments as long as it satisfies the above-described "arrangement of the insulating slit portion peculiar to the present invention", and may be within the range satisfying the above conditions. There are various application forms, and the present invention includes all of these application types.

(first embodiment)

In the first embodiment of the LED element substrate 1 of the present invention, the shape and arrangement of the metal wiring portion 13 are as shown in Fig. 5. As shown in Fig. 5, an insulating slit formed between the concave polygonal shaped conductive plate portions 131A Any of the portions 132A to 132D satisfies the condition of "the arrangement of the insulating slit portion peculiar to the present invention". Specifically, none of the insulating slit portions 132A to 132D are arranged in the same straight line. Thereby, an insulating slit portion which is likely to be a starting point of the bending damage and another insulating slit portion which is formed by the adjacent conductive plate portion 131 are not connected to the basic unit of the plural configuration and are not connected in a straight line. Further, the risk of bending damage of the substrate 1 for LED elements can be reduced.

(Second embodiment)

In the second embodiment of the LED element substrate 1 of the present invention, the shape and arrangement of the metal wiring portion 13 are as shown in Fig. 6. As shown in Fig. 6, the insulating slit portions 132A to 132D formed between the concave polygonal conductive plate portions 131B satisfy the "insert insulating slit portion unique to the present invention as in the first embodiment. The condition of the configuration. Since the insulating slit portion which is likely to be the starting point of the bending damage does not cross the basic unit of the plural configuration and does not communicate in a straight line, the risk of bending damage can be reduced. Moreover, by adjusting the arrangement angle of the conductive plate portions as in the second embodiment, the LED elements 2 can be arranged in a completely lattice shape as needed, while satisfying the conditions of "the arrangement of the insulating slit portions peculiar to the present invention".

(third embodiment)

In the third embodiment of the LED element substrate 1 of the present invention, the shape and arrangement of the metal wiring portion 13 are as shown in FIG. As shown in Fig. 7, the insulating slit portions 132A to 132F formed between the regular hexagonal conductive plate portions 131C satisfy the "insert insulating slit portion unique to the present invention as in the first and second embodiments. The condition of the configuration. Because of tolerance The insulating slit portion which easily becomes the starting point of the bending damage does not cross the basic unit of the plural configuration and does not communicate in a straight line, so that the risk of bending damage can be reduced. Further, in the third embodiment, the bending strength of the substrate 1 for LED elements can be remarkably improved by forming a so-called honeycomb structure.

Further, in the first to third embodiments described above, the width of the insulating slit portion 132 is preferably 0.1 mm or more and 1.0 mm or less, and more preferably 0.15 mm or more and 0.5 mm or less. Further, by the width of the insulating slit portion 132 being 0.5 mm or less, it is possible to achieve better heat transfer between the conductive plate portions 131. For example, in a large-sized LED backlight of a local dimming method, in the case of local heat generation, the heat is caused by the conductive plate portion 131 which has become a relatively high temperature portion, which is still relatively low temperature. The movement of the conductive plate portion 131. Thereby, it is possible to dissipate a part of the high temperature in the large-sized LED backlight to the entire substrate for the LED element, and to prevent the function of each LED element from being lowered or malfunction due to the local temperature rise.

(Fourth embodiment)

In the fourth embodiment of the LED element substrate 1 of the present invention, the shape of the conductive plate portion 131 in a plan view is a circular shape, and the shape and arrangement of the metal wiring portion 13 are as shown in Fig. 8. In the fourth embodiment, the insulating slit portion 132EJ formed between the circular conductive plate portion 131D and the conductive plate portion 131J which are arranged in a staggered manner, and the conductive plate portion which is adjacent to the conductive plate portion 131D Any of the insulating slit portions 132DF and 132DI formed by the 131F or the conductive plate portion 131I is disposed so as not to be aligned with each other in a straight line. Thus, in the fourth embodiment, In the same manner as the first to third embodiments, the "insulation of the insulating slit portion peculiar to the present invention" can be satisfied, and an insulating slit portion which is likely to be a starting point of the bending damage and another adjacent conductive plate portion 131 are formed. The insulating slit portion does not cross the basic unit of the plurality of packages and does not communicate in a straight line, and the risk of bending damage of the LED element substrate 1 can be reduced.

Further, in the fourth embodiment, the minimum width of the insulating slit portion 132 (the shortest distance between the circumferences of the adjacent conductive plate portions 131) is preferably 0.1 mm or more and 1.0 mm or less, and further preferably 0.15. Above mm and below 0.5 mm. Moreover, by the width of the insulating slit portion 132 being 0.5 mm or less, heat transfer between the conductive plate portions 131 is possible. For example, in the large-sized LED backlight of the area dimming method, in the case where local heat generation occurs, the heat is caused by the conductive plate portion 131 which has become a relatively high temperature portion, and the conductive plate portion which is still relatively low temperature. The movement of 131. Thereby, it is possible to dissipate a part of the high temperature in the large-sized LED backlight to the entire substrate for the LED element, and to prevent the function of each LED element from being lowered or malfunction due to the local temperature rise.

Fig. 8 illustrates a case where all of the conductive plate portions 131 are of a perfect circle and have the same size. However, for example, an ellipse having a different size may be mixed or an ellipse having a different ratio of a long diameter to a short diameter may be arbitrarily mixed. The circuit configuration of various forms is formed, and the coverage by the metal wiring portion can be improved to further improve heat dissipation.

Further, in any of the above embodiments, the arrangement of the metal wiring portion 13 is not limited as long as it can arrange the LED elements. For specific configurations, etc. However, in the LED element substrate 1, it is preferable that the surface of one side of the resin substrate 11 is at least 70% or more, and more preferably 75% or more, and is covered by the metal wiring portion 13.

In particular, in the first to third embodiments, that is, in the case where the conductive plate portion 131 has a polygonal shape, it is preferable that at least 95% or more and preferably 98% or more of one surface of the resin substrate 11 is provided. The range is covered by the metal line portion 13. Thereby, the LED display device using the LED element substrate 1 can provide better heat dissipation.

In any of the above embodiments, the heat transfer coefficient λ of the metal constituting the metal wiring portion 13 is preferably 200 W/(m.K) or more and 500 W/(m.K) or less, and further preferably 300 W/(m). .K) or more and 500 W/(m.K) or less. The specific resistance R of the metal constituting the metal wiring portion 13 is preferably 3.00 × 10 ^-8 Ωm or less, and more preferably 2.50 × 10 ^-8 Ωm or less. Here, for the measurement of the heat transfer coefficient λ, for example, a thermal conductivity coefficient meter QTM-500 manufactured by Kyoto Electronics Industry Co., Ltd. can be used, and for the measurement of the specific resistance R, for example, a 6517B type electrometer manufactured by Keithley Co., Ltd. can be used. Thereby, for example, in the case of copper, the heat transfer coefficient λ is 403 W/(m.K), and the specific resistance R becomes 1.55×10 ^-8 Ωm. Thereby, it is possible to achieve both heat dissipation and electrical conductivity. More specifically, since the heat dissipation from the LED element is stabilized and the increase in resistance is prevented, the variation in luminescence between the LEDs becomes small, stable light emission of the LED becomes possible, and the life of the LED is prolonged. Further, since deterioration of peripheral members such as a substrate due to heat can be prevented, it is possible to extend the product life of the image display device itself in which the LED element substrate is assembled as a backlight.

Further, in any of the above embodiments, the surface resistance value of the metal wiring portion 13 is preferably 500 Ω/□ or less, further preferably 300 Ω/□ or less, more preferably 100 Ω/□ or less, and particularly preferably 50 Ω/ □The following. The lower limit is about 0.005 Ω / □.

As the metal forming the metal wiring portion 13, a metal foil such as aluminum, gold, silver or copper can be exemplified. The thickness of the metal line portion 13 is not particularly limited as long as it is appropriately set depending on the magnitude of the current resistance required for the LED element substrate 1, and the like, and examples thereof include a thickness of 10 μm to 50 μm. The thickness of the metal wiring portion 13 is preferably 10 μm or more from the viewpoint of improving heat dissipation. In addition, when the thickness of the metal layer is less than the above lower limit, the influence of heat shrinkage of the resin substrate 11 is large, and the warpage after the treatment is likely to increase during the reflow processing of the solder. In other words, the thickness of the metal wiring portion 13 is also preferably 10 μm or more. On the other hand, when the thickness is 50 μm or less, it is possible to maintain sufficient flexibility of the substrate for an LED element, and it is possible to prevent deterioration in handleability due to an increase in weight.

[solder layer]

In the LED element substrate 1, the bonding of the metal wiring portion 13 and the LED element 2 is performed by bonding via the solder layer 14. The details of the bonding method performed by the solder will be described later, but in general, it can be performed by either of the reflow method or the laser method.

[Insulation Protective Film]

The insulating protective film 15 is formed on the surface of the metal wiring portion 13 and the resin substrate 11 by a thermosetting ink as described above except for electrical connection. The synthesis is a part other than the necessity, and it is mainly for improving the migration resistance of the substrate 1 for LED elements.

As the thermosetting ink, as long as the heat curing temperature is 100 ° C or lower, a known ink can be suitably and preferably used. Specifically, a representative example of the ink which can be preferably used is exemplified by a polyester resin, an epoxy resin, an epoxy resin, a phenol resin, an epoxy acrylate resin, and a polyfluorene. An oxygen-based resin or the like is used as an insulating ink for the base resin. Among these, as the material of the insulating protective film 15 for forming the LED element substrate 1, a polyester-based thermosetting insulating ink excellent in flexibility can be preferably used.

Further, the thermosetting ink forming the insulating protective film 15 may be, for example, a white ink, and further contains an inorganic white pigment such as titanium dioxide. By whitening the insulating protective film 15, it is possible to improve the design.

In addition, the formation of the insulating protective film 15 by the above-described insulating thermosetting ink can be carried out by a known method such as screen printing.

[reflective layer]

In the LED package module 10, the reflective layer 16 is intended to improve the light-emitting capability, and in the present embodiment, the LED element 2 is mounted on the outermost surface of the light-emitting surface side of the LED element substrate. Part outside the part. As long as it is a member having a reflecting surface for reflecting light emitted from the LED element and guiding it to a predetermined direction, that is, there is no particular limitation, but depending on the use of the final product and its required specifications, etc., A white polyester foamed white polyester, a white polyethylene resin, a silver vapor-deposited polyester, or the like is used.

<Method for Manufacturing LED Element Substrate>

The LED element substrate 1 can be manufactured by one of the conventionally known electronic substrate manufacturing methods, that is, a manufacturing method including an etching step. Further, depending on the selected raw material resin, it is preferred to subject the resin to a heat resistance enhancement treatment which is carried out by annealing treatment.

[annealing treatment]

Although it is not essential in the present invention, a conventionally known heat treatment means can be used for the annealing treatment. As an example of the annealing treatment temperature, in the case where the thermoplastic resin forming the resin substrate 11 is PEN, it is a range from glass transition temperature to melting point, more specifically, 160 ° C to 260 ° C and further preferably 180 ° C. To the range of 230 °C. The annealing treatment time can be exemplified by the range of 10 seconds to 5 minutes. According to such heat treatment conditions, the heat shrinkage initiation temperature of PEN, which is generally about 80 ° C, can be increased to about 100 ° C.

[etching step]

A layered body which is a raw material of the substrate 1 for LED elements is obtained by laminating a copper foil or the like which is a raw material of the metal wiring portion 13 on the surface of the annealed resin substrate 11 as needed. The lamination method may be a method of bonding a metal foil to the surface of the resin substrate 11 by an adhesive, or a method of directly forming a surface of the resin substrate 11 by a plating method or a vapor phase deposition method (sputtering, ion) A method of depositing the metal wiring portion 13 by plating, electron beam evaporation, vacuum vapor deposition, chemical vapor deposition, or the like. By cost and productivity aspects In other words, a method of bonding a metal foil to the surface of the resin substrate 11 by a urethane-based adhesive is advantageous.

Next, an etching mask patterned into a shape of the metal wiring portion 13 is formed on the surface of the metal foil of the laminated body. The etching mask is provided in order to prevent the etching of the wiring pattern forming portion of the metal foil of the metal wiring portion 13 from the etching liquid. The method of forming the etching mask is not particularly limited. For example, an etching mask can be formed on the surface of the laminated board by light-resisting or developing a dry film by a light-transmissive mask, or by inkjet. An etching mask is formed on the surface of the laminated board by a printing technique such as a printer.

Next, the metal foil which is not covered by the etching mask is removed by the immersion liquid. Thereby, a portion other than the portion where the metal wiring portion 13 is formed in the metal foil is removed.

Finally, an alkaline stripper is used to remove the etch mask. Thereby, the etching mask is removed by the surface of the metal wiring portion 13.

[Insulating protective film and reflective layer forming step]

After the metal wiring portion is formed, the insulating protective film 15 and the reflective layer 16 are further laminated as necessary. These laminates can be carried out by a known method. Depending on the material to be used, various lamination methods such as a screen printing method or a dry lamination method or a thermal lamination method can be used.

<LED Assembly Module>

The LED component 2 is directly mounted on the metal wiring portion 13 of the LED element substrate 1 to obtain the LED package module 10.

The LED element 2 is a light-emitting element that emits light in a PN junction portion, and the PN junction portion is formed by bonding a P-type semiconductor and an N-type semiconductor. A structure in which a P-type electrode and an N-type electrode are provided on the top surface and the bottom surface of the element, and a structure in which both the P-type and N-type electrodes are provided on one surface of the element has been proposed. The LED element 2 of any of the structures can be used in the LED package module 10 of the present invention. However, in the above, it is possible to particularly preferably use a configuration in which both P-type and N-type electrodes are provided on one surface of the element. LED components.

As described above, the LED package module 10 is formed by directly mounting the LED element 2 to the metal wiring portion 13 capable of exhibiting high heat dissipation. Thereby, the heat generated by the LED element 2 at the time of lighting is quickly diffused to the entire metal line portion 13, and the heat dissipation of the LED package module 10 is greatly enhanced.

The LED package module 10 of the present invention can mount at least 100 or more LED elements 2. It is also possible to use it in a large-sized LED display device in which the screen size conversion of the LED display device is approximately 32 吋 or more. In addition, in the manufacture of a large-sized display device of approximately 32 inches or more, the circuit design of the substrate 1 for a large-sized flexible substrate type LED element composed of a single resin is used in comparison with a conventional small-sized substrate having a plurality of fixed sizes. Since the degree of freedom is high, the arrangement interval of the LED elements 2 to be mounted can be arbitrarily adjusted, and the physical properties required for various large-sized LED display devices can be matched at a lower cost than ever.

<Manufacturing method of LED package module>

A method of manufacturing the LED package module 10 using the substrate 1 for LED elements will be described. LED element 2, connection to metal line portion 13 The combination can be preferably performed by solder processing. This solder joint can be by means of reflow or laser. In the reflow method, the LED element 2 is mounted on the metal line portion 13 via solder, and thereafter, the LED element substrate 1 is transported into the reflow furnace, and a hot air of a predetermined temperature is blown to the metal line portion 13 in the reflow furnace. A method of melting the solder paste to solder the LED element 2 to the metal wiring portion 13. Further, the laser mode means a method of soldering the LED element 2 to the metal wiring portion 13 by locally heating the solder by the laser.

When the LED element 2 is soldered to the metal wiring portion 13, it is preferably a method of performing solder reflow by laser irradiation from the back side of the resin substrate 11. Thereby, it is possible to more reliably suppress the ignition of the solder organic component caused by the heating and the damage of the substrate accompanying the solder.

<LED display device>

FIG. 9 is a perspective view schematically showing an outline of a layer configuration of the LED display device 100 using the LED package module 10. The LED display device 100 displays information (images) such as characters and images on the screen 3 by driving (light-emitting) the plurality of LED elements 2 arranged in a matrix at predetermined intervals. The LED element 2 is mounted on the metal line portion 13 of the LED element substrate 1. Moreover, it is more preferable that the heat dissipation structure 4 is provided on the back side of the resin substrate 11, and the heat dissipation structure 4 is for efficiently radiating heat from the LED package module 10 to the outside. By using the LED module module 10 of the present invention, for example, it is possible to manufacture a large-sized LED display device having a screen size (diagonal length) of 32 Å or more at a lower cost than conventional ones and improved quality stability.

According to the LED element substrate, the LED package module, and the like of the present invention described above, and the LED display device using the same, the following effects are exhibited.

(1) In the present invention, in the substrate 1 for a flexible substrate type LED element in which the bending damage is reduced, the shape and arrangement of the metal wiring portion 13 are made of a polygonal shape or a circular shape. The plate portion 131 is configured to satisfy the non-conduction portion between the adjacent two conductive plate portions 131, that is, the insulating slit portion 132 is not in line with the adjacent other insulating slit portion 132. Thereby, it is possible to reduce the risk of bending damage due to the flexibility of the base resin and the difference in the bending elastic modulus between the base resin and the metal wiring portion in the substrate for a flexible substrate type LED element.

(2) The shape of the conductive plate portion in (1) is a regular hexagon. Thereby, the strength of the LED element substrate 1 against bending can be further improved, and the effect of reducing the risk of bending damage in the invention of (1) can be exhibited more stably.

(3) When the shape of the conductive plate portion in (1) is a circular shape, the circular conductive plate portions 131 are arranged in a staggered manner in the arrangement of the metal wiring portions. Thereby, the reliability of the strength of the bending resistance of the substrate 1 for LED elements can be further improved, and the effect of reducing the risk of bending damage in the invention of (1) can be exhibited more stably.

(4) In the present invention, the metal wiring portion 13 covers a range of 70% or more of the surface of one side of the resin substrate 11. Thereby, can It is sufficient to maintain the efficiency of the inventions of (1) to (3) while improving heat dissipation.

(5) In the present invention, the metal line portion 13 covers a range of 95% or more of the surface of one side of the resin substrate 11. Thereby, it is possible to further improve heat dissipation while maintaining the effect of the invention of (1) or (2).

(6) The LED element substrate 1 has a diagonal length of 32 Å or more and is composed of a single resin film. Therefore, since the large-sized LED display device which can be formed only by the bonding of the plurality of LED module modules can be formed by the single LED element substrate 1, the productivity and quality stability of the LED display device can be remarkably improved. .

(7) The LED display device 100 in which the LED element substrate 1 described in (6) and the display area are formed. Thereby, the large-sized LED display device 100 having a screen size of 32 Å or more can be provided with high productivity, and it has excellent quality stability.

According to the present invention, it is possible to provide a substrate for an LED element which is a substrate for a flexible substrate type LED element, wherein the risk of bending damage is reduced, and the bending damage is caused by the flexibility of the resin substrate. And the difference between the bending elastic modulus of the resin substrate and the metal wiring portion.

2‧‧‧LED components

13‧‧‧Metal Lines Department

131A‧‧‧conductive plate

132A, 132B, 132C, 132D‧‧‧ insulated slits

X, Y‧‧ direction

Claims (7)

A substrate for an LED element, comprising: a resin substrate comprising a flexible resin film; and a metal wiring portion formed on the resin substrate to electrically connect the LED elements, wherein the LED elements are arranged in a matrix And the metal wiring portion is composed of a plurality of circular or polygonal conductive plate portions disposed on the resin substrate, and the non-conductive portion between the adjacent two conductive plate portions is also a The insulating slit portion is not in line with the adjacent another insulating slit portion. The substrate for LED elements according to claim 1, wherein the conductive plate portion is a conductive plate portion having a regular hexagonal shape. The substrate for LED elements according to claim 1, wherein the metal wiring portion is formed of a plurality of right circular or elliptical conductive plate portions which are alternately arranged on the resin substrate. The substrate for LED elements according to any one of claims 1 to 3, wherein the metal wiring portion covers a range of 70% or more of one surface of the resin substrate. The substrate for LED elements according to claim 1 or 2, wherein the metal wiring portion covers a range of 95% or more of one surface of the resin substrate. The LED element according to any one of claims 1 to 3 In the substrate, the resin substrate has a diagonal length of 32 Å or more and is composed of a single flexible resin film. An LED display device in which a LED device is mounted on a substrate for an LED element according to any one of claims 1 to 3, which is a laminated LED package module and a display screen. Made.