JP3989518B2 - LED display substrate and LED display - Google Patents

Description

  The present invention relates to an LED display substrate and an LED display in which a large number of LED portions are directly formed on the substrate.

When LEDs are used for displaying characters and symbols, conventionally, off-the-shelf LEDs are used, and these are arranged in a matrix on a substrate to constitute a display (Patent Document 1, etc.). However, since an off-the-shelf LED is used, its assembling workability is poor, and the light emission direction tends to be uneven, and stable display cannot be performed. Therefore, recently, a display device has been developed in which the LED portion is directly formed on a substrate to solve the above problems.
Japanese Patent Laid-Open No. 1-194479

  When the LED part is directly formed on the substrate as described above, there are the following problems to be solved. First, a large number of electrode parts for LEDs composed of electrode groups of a predetermined shape for arranging and connecting light emitting diode elements are formed on the substrate surface, and wiring for connecting them is also formed on the substrate surface. The periphery of the electrode part tends to be uneven due to the presence of the wiring. Although this unevenness is as small as about several tens of μm, it is considerably larger than the size of the light emitting diode element disposed on the electrode (about 300 μm square), so that the light of the light emitting diode element is scattered along the unevenness. It is easy to disperse, and it is easy to cause insufficient light quantity and poor outline for display. Furthermore, when the resin for covering the light emitting diode element is molded on the LED electrode portion, the resin flows out to the periphery along the unevenness, so that the shape of the resin is not stable, and unevenness in the light emitting direction is likely to occur. Furthermore, when the reflection frame is provided on the substrate surface so as to cover the LED portions, the adjacent LED portions communicate with each other on the back side portion of the reflection frame via the irregularities, and the adjacent LED portions are connected via the connection portions. Of light leaks out. In addition, a circuit board for driving is disposed on the back side of the board, but a countermeasure for shielding unnecessary radio waves generated from these circuits is not sufficiently provided. In addition, the surrounding color of the LED electrode portion is uneven due to the wiring and the insulating resist, and the lighting outline of the LED portion tends to be unclear.

  Then, this invention makes it a subject to prevent that the light of an adjacent LED part leaks out.

The LED display substrate of the present invention, as described in claim 1, is an LED display substrate in which LED electrode portions composed of a plurality of electrodes are arranged in a matrix on the surface of an insulating substrate, The LED electrode portions are independent from each other on the surface side of the insulating base material, and a metal foil having a thickness substantially the same as the LED electrode portion and a resist film provided on the metal foil. It is characterized by being surrounded by a ring .

As described in claim 2, the LED display substrate of the present invention is characterized in that the resist film is black and thicker than the thickness of the metal foil .

The LED display device according to the present invention includes a light emitting diode element attached to an LED electrode portion arranged in a matrix on a substrate, a wire bonding wiring connected to the element, and the wire. An LED display in which an LED portion is directly formed on the substrate by providing a translucent resin that covers a wire bonding portion by bonding wiring , wherein the LED display substrate described above is used as the substrate. To do.
It is characterized by.

  It can prevent that the light of the adjacent LED part leaks out.

  Embodiments of the present invention will be described below with reference to the drawings. The substrate 1 is composed of an insulating base material 2 such as a glass epoxy resin colored in black, and a plurality of LED electrode portions 3 are formed on its surface independently of each other as shown in FIGS. (24 rows and 24 columns), on the back surface thereof, as shown in a perspective view in FIG. 3, a wiring pattern 4 made of copper foil constituting a wiring portion for performing electrical connection wiring of the LED electrode portions 3. Is provided. As shown in FIG. 5, the connection between each LED electrode portion 3 and the wiring pattern 4 is performed inside the base material 2 through a through hole 5 penetrating the base material 2, and the wiring pattern 4 on the back surface is black. It is covered with an insulating film.

  Each electrode portion 3 for LED is a group of electrodes made of conductive metal foil having a predetermined shape, that is, as shown in FIGS. 1B and 2B, three copper foil lead electrodes 3a having a circular shape as a whole. , 3b, 3c. Each lead electrode 3a, 3b, 3c is formed with the through-hole 5 penetrating the base material 2, and through the wiring copper foils 5a, 5b, 5c provided in the through-hole 5, as shown in FIG. Then, wiring to the wiring pattern 4 on the back surface is performed. Each LED electrode portion 3 is electrically connected by the wiring copper foils 5a, 5b, 5c penetrating the base material 2 and the wiring pattern 4 on the back surface of the base material 2 in this way. Are not connected to each other, and are independent of each other on the surface side of the base material 2. When the LED unit 10 shown in FIGS. 4 and 5 is configured, as shown by a dotted line in FIG. 1B, one to a plurality of light-emitting diode elements 11 are electrically connected to the central lead electrode 3b. The light emitting diode element 11 is attached via an adhesive, and is electrically connected to the other lead electrodes 3a and 3c by wire-bonding wiring.

  A common electrode portion 6 is formed on the surface of the substrate 1 so as to fill in the space between the adjacent LED electrode portions 3 as shown in FIG. The common electrode portion 6 is formed by etching a copper foil that is the same material as the lead electrodes 3a, 3b, and 3c constituting the LED electrode portion 3, and therefore has substantially the same thickness as the LED electrode portion 3. . Between the common electrode part 6 and each LED electrode part 3, an annular insulating region 7 for maintaining electrical insulation is provided by etching a copper foil. In this way, the periphery of the LED electrode portion 3 can be formed as a flat surface without irregularities since the common electrode portion 6 having a single thickness surrounds the ring, and the edge of the common electrode portion 6 has the same height as the ring. Therefore, when the LED unit 10 is configured, the translucent resin 12 can be formed more uniformly when the translucent resin 12 is poured into the LED electrode unit 3 and molded. Further, since the common electrode portion 6 is formed in a wide range on the substrate 1 so as to fill the space between the electrode portions 3 for LED, a shield that absorbs unnecessary radio waves generated from the substrate 1 or a drive substrate separately attached to the substrate 1. It can function effectively as a layer.

  On the common electrode portion 6, as shown in FIG. 1 (particularly hatched in FIG. 1 (b)), a black resist film 8 having an electrical insulating property is provided so as to cover substantially the entire area of the common electrode portion 6. It is provided with a uniform thickness (set to be about 2 to 3 times thicker than the thickness of the common electrode portion 6). The black resist film 8 is provided with a slight distance from the annular insulating region 7 so that the common electrode portion 6 surrounding the annular insulating region 7 is slightly exposed in an annular shape. There is also an object to prevent the black resist film 8 from entering the annular insulating region 7 and thereby causing the LED electrode portion 3 to be uneven. Thus, by providing the black resist film 8, the periphery of the LED electrode portion 3 can be flattened, and the heights of the edges of the common electrode portion 6 and the black resist film 8 as shown in FIG. That is, the height of the portion functioning as a wall 9 surrounding the LED electrode portion 3 annularly through the annular insulating region 7 is increased to effectively prevent the translucent resin from flowing out, and the light emitting diode element 11 light leakage paths can be blocked. In addition, by providing the black resist film 8 on the common electrode portion 6, it is possible to enhance the absorption effect of unnecessary reflected light, and it is possible to make the color tone when the LED portion 10 is turned on clear.

  And after attaching the light emitting diode element 11 to each electrode part 3 for LED of the said board | substrate 1 with a conductive adhesive as mentioned above, it wired by bonding and, for example, circular shape corresponding to FIG. 4, for example A reflective frame having a matrix of windows is arranged on the substrate 1 or a resin mold is formed by pouring a translucent resin 12 so as to cover the bonding portion, and the LED portion 10 is directly formed on the substrate 1. By forming, the LED display which has the matrix-shaped LED part 10 can be comprised. In the arrangement of the reflection frame (not shown), the periphery of each LED electrode portion 3 is flattened, so that the adhesion between the substrate 1 and the reflection frame is good and no light leakage path is formed. Further, when molding the translucent resin 12, the periphery of each LED electrode portion 3 is flattened, so that the workability is good, and the periphery of each LED electrode portion 3 is as shown in FIG. As shown in FIG. 3, the wall 9 is surrounded by an annular wall 9 constituted by the edge of the common electrode portion 6 and the black resist film 8, so that the wall 9 functions as a dam that prevents the resin from flowing out during the translucent resin molding. And the shape when the translucent resin 12 hardens | cures can be made into a fixed shape, and the quality of the LED part 10 can be equalized uniformly.

  As described above, according to the present invention, the periphery of the LED electrode portion is flattened by the presence of the common electrode portion arranged so as to be filled between the adjacent LED electrode portions, and at a constant height. Since it is surrounded, there is no light leakage path, and the resin can be stably molded when the LED mold resin is placed and molded. In addition, the common electrode portion can effectively function as a shield layer that absorbs unnecessary radio waves.

  Further, the LED electrode portion and the common electrode portion are formed of a conductive layer having the same thickness, and substantially the entire surface of the common electrode portion is covered with an insulating film, so that the periphery of the LED electrode portion is predetermined by the common electrode portion and the insulating film. The resin leakage is not caused by the common electrode portion and the insulating film when the mold resin is disposed in the LED electrode portion.

  The present invention can be applied to a dot matrix type LED display.

BRIEF DESCRIPTION OF THE DRAWINGS It is a top view of the board | substrate concerning one Example of this invention, (a) is a whole top view, (b) is a partial enlarged plan view. BRIEF DESCRIPTION OF THE DRAWINGS It is a top view of the board | substrate (without an insulating film) concerning one Example of this invention, (a) is a whole top view, (b) is a partial enlarged plan view. It is the top view which saw through the wiring pattern given to the back surface of the board | substrate concerning one Example of this invention. It is a top view of the indicator concerning one example of the present invention. It is a fragmentary sectional view of the indicator concerning one example of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Base material 3 LED electrode part 6 Common electrode part 7 Annular insulating region 8 Black resist film (insulating film)
DESCRIPTION OF SYMBOLS 10 LED part 11 Light emitting diode element 12 Translucent resin

Claims (3)

  An LED display substrate in which an LED electrode portion composed of a plurality of electrodes is arranged in a matrix on the surface of an insulating substrate, wherein the LED electrode portions are independent from each other on the surface side of the insulating substrate. An LED display substrate characterized in that the periphery thereof is annularly surrounded by a metal foil having substantially the same thickness as the LED electrode portion and a resist film provided on the metal foil.   The LED display substrate according to claim 1, wherein the resist film is black and thicker than the metal foil. By comprising a light emitting diode element attached to an electrode part for LED arranged in a matrix on a substrate, a wire bonding wiring connected to the element, and a translucent resin covering a wire bonding portion by the wire bonding wiring An LED display in which an LED unit is directly formed on the substrate, wherein the LED display substrate according to claim 1 or 2 is used as the substrate.

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