JP2009032479A - Linear light source device and flexible board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a linear light source device and a flexible board capable of lessening a space for installation, in installation at one side face of a light guide plate. <P>SOLUTION: The linear light source device 100 is provided with a linear light source part 110 equipped with a long-size wiring board 1110 and a plurality of light-emitting elements arrayed along a length direction of the wiring board 1110, and a flexible board 140 equipped with a board main body 1410 with wirings for supplying the light-emitting elements with a power source formed in an insulating film. The wiring board 1110 has a wiring pattern electrically conducted with the light-emitting elements provided on a mounting face as well as a power source terminal 1114 connected with the wiring pattern provided on a rear face contrary to the mounting face. The flexible board 140 has a connecting pad 1443 provided having the wirings exposed from the insulating film, and a rear-face side of the wiring board 1110 and one face of the board main body 1410 are made face to face to have the connecting pad 1443 connected to the power source terminal 1114. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a linear light source device having a long substrate on which a wiring pattern is formed and a light emitting element that is conductively mounted on the substrate, and a flexible substrate that supplies power to the light emitting element.

  As a light source of a backlight that irradiates a liquid crystal display panel from the back, a linear light source device disposed on one side of a light guide plate is known. For example, in the linear light source device described in Patent Document 1, a plurality of light emitting elements are arranged on a long wiring board along the longitudinal direction of the wiring board, and a power supply terminal that is electrically connected to the light emitting element is provided on the board. It is provided at each end.

  By the way, in the linear light source device described in Patent Document 1, the power supply terminal is provided on the mounting surface side where the light emitting elements at both ends of the wiring board are mounted. In order to connect the power supply terminal and the power supply. The wiring is easier when the power supply terminal is provided on the back side of the wiring board.

In particular, a conventional linear light source device in which a plurality of linear light source portions 510 each having a light emitting element mounted on a wiring substrate as shown in FIG. In the case of 500, since the connection to the individual power pins 511 by the elongated conventional flexible substrate 530 is performed on the back side of the wiring substrate 512, wiring from the light emitting element can be performed without obstructing. In addition, since the wiring is arranged linearly along the arrangement of the wiring boards 512, it is possible to reduce the occupied space for wiring rather than connecting the flexible boards each branched like an octopus to each power supply pin 511. Can do.
JP 2004-235139 A

  However, when the conventional linear light source device 500 shown in FIG. 8 is arranged on the side surface of the light guide plate 540 shown in FIG. 9 to form a backlight, the power pins 511 protrude from the back surface of the wiring board 512. It is necessary to secure a wide space on the back side of the wiring board 512. Since the power supply pin 511 is for supplying power from the conventional flexible substrate 530 to the light emitting element, in order to avoid a short circuit between the power supply pin and the metal case if the case for storing the backlight is made of metal. It is necessary to secure a wider installation space.

  In addition, as shown in FIG. 10, the other conventional flexible board 560 is soldered so that the end face of the wiring board 570 abuts on the back side of the wiring board 570 provided with the power supply terminals. Although the substrate 560 is not an octopus, it is necessary to secure a space on the back side of the substrate as much as the width of another conventional flexible substrate 560.

  Therefore, an object of the present invention is to provide a linear light source device and a flexible substrate that can reduce the space for arrangement when arranged on one side of a light guide plate.

  In the linear light source device of the present invention, a long wiring board, a plurality of light emitting elements arranged along the longitudinal direction of the wiring board, and a wiring for supplying power to the light emitting elements are formed in an insulating film. A linear light source device comprising a flexible substrate having a printed circuit board body, wherein the wiring substrate is provided with a wiring pattern that is electrically connected to the light emitting element, and a power supply terminal that is connected to the wiring pattern. Is provided on the back surface opposite to the mounting surface, and the flexible substrate is provided with a connection pad exposing the wiring from the insulating film, and the back surface side of the wiring substrate and one surface side of the substrate body are connected to each other. The connection pads are connected to the power supply terminals so as to face each other.

  Further, the flexible substrate of the present invention is a flexible substrate having a substrate body in which wiring is formed in an insulating film, and a connection pad that is separated from the substrate body in a band shape leaving a base and exposes the wiring from the insulating film. A belt-like part located at the tip part is provided.

  In the linear light source device of the present invention, it is not necessary to secure a space on the wiring substrate as wide as the width of the flexible substrate on the back side of the wiring substrate or to provide a connection pin on the flexible wiring substrate. There is no need to secure space on the back side of the. Therefore, when it arrange | positions to one side of a light-guide plate, the space to arrange | position can be decreased.

  The first invention of the present application is a substrate in which an elongated wiring substrate, a plurality of light emitting elements arranged along the longitudinal direction of the wiring substrate, and wiring for supplying power to the light emitting elements are formed in an insulating film. A linear light source device including a flexible substrate having a main body, wherein the wiring substrate is provided with a wiring pattern electrically connected to the light emitting element, and a power supply terminal connected to the wiring pattern is opposite to the mounting surface. The flexible substrate is provided with a connection pad in which the wiring is exposed from the insulating film, the back side of the wiring substrate and one side of the substrate body are facing each other, and the connection pad is provided on the power supply terminal. It is characterized by being connected.

  On the flexible substrate, a connection pad is formed by exposing a wiring for supplying power to the power supply terminal from the insulating film. Then, the width of the flexible board is set on the back side of the wiring board by connecting one side of the board body of the flexible board to the back side of the wiring board and connecting the connection pad of the flexible board to the power supply terminal of the wiring board. There is no need to secure such a space or to provide connection pins on the flexible wiring board. Therefore, it is not necessary to secure a wide space on the back side of the linear light source device of the present invention.

  According to a second invention of the present application, the wiring board is held by a holding frame having a U-shaped cross section, the holding frame is provided with an opening for exposing the power supply terminal, and the flexible board is provided on the board body. A band-shaped portion is provided, which is connected and a connection pad is provided at the tip portion, and the band-shaped portion is connected to the power supply terminal of the wiring board through the opening.

  The connection pad of the band-shaped part passes through the opening of the holding frame and connects to the power supply terminal of the wiring board, so even if a holding frame for holding the wiring board is provided, it is flexible without securing a large space on the back side The board can be connected to the wiring board.

  The third invention of the present application is characterized in that the belt-like portion is formed by separating the belt-like portion from the substrate body leaving the base portion.

  Since the band-shaped portion is formed by separating the band-shaped portion from the substrate main body leaving the base portion, it can be easily manufactured from one flexible substrate.

  According to a fourth invention of the present application, in a flexible substrate having a substrate body in which wiring is formed in an insulating film, a connection pad that is separated from the substrate body in a band shape leaving a base portion and exposes the wiring from the insulating film is a tip portion. It is characterized in that a belt-like portion located at is provided.

  The flexible substrate of the present invention is cut into a strip shape leaving a base portion from the substrate body, and a power strip is provided on the back side by providing a strip portion with a connection pad where the wiring is exposed from the insulating film at the tip. Can be reliably connected to the wiring board provided with the. Therefore, when the linear light source device is arranged on one side surface of the light guide plate, the arrangement space can be reduced.

(Embodiment)
The configuration of the linear light source device according to the embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an exploded perspective view of the linear light source device as viewed from the flexible substrate side. FIG. 2 is an enlarged view of a main part of the linear light source device shown in FIG. FIG. 3 is a cross-sectional view showing a linear light source unit. 4A and 4B are enlarged views of a part A shown in FIG. 1, in which FIG. 4A is a perspective view and FIG. 4B is an exploded perspective view. 5 is an enlarged view of a portion B shown in FIG. 1, in which (A) is a perspective view and (B) is an exploded perspective view. 6 is an enlarged view of a portion C shown in FIG. 1, in which (A) is a perspective view and (B) is an exploded perspective view.

  As shown in FIG. 1, a linear light source device 100 is a light source that irradiates one side of a light guide plate with linear light, and is a 9-inch (228.6 mm) liquid crystal used in a car navigation device or a vehicle-mounted television. It is used as a light source for a backlight of a display panel. The linear light source device 100 includes a plurality of linear light source units 110, a holding frame 120 that houses the plurality of linear light source units 110, and a heat transfer sheet that is disposed between the linear light source unit 110 and the holding frame 120. 130 and a flexible substrate 140 that supplies power to the linear light source unit 110.

  As shown in FIGS. 2 and 3, the linear light source unit 110 includes a plurality of light emitting elements 1120 mounted on a long wiring board 1110, and a reflecting unit 1130 that reflects light from the light emitting element 1120 includes a light emitting element. It is arranged on both sides of 1120. A resin sealing portion 1140 that seals the light emitting element 1120 is formed.

  On the wiring substrate 1110, a wiring pattern 1111 on which the light emitting element 1120 is die-bonded and a wiring pattern 1112 on which wire bonding is performed are formed on the mounting surface S1 on which each light emitting element 1120 is mounted. Power supply terminals 1114 for supplying power to the wiring patterns 1111 and 1112 through the through-hole electrodes 1113 are provided on the back surface S2 opposite to the mounting surface S1.

  As the light emitting element 1120, for example, a blue light emitting element using a GaN compound semiconductor can be used. In this embodiment mode, the reflective portion 1130 is provided for each light emitting element 1120; however, the reflective portion 1130 may be provided for every two or more light emitting elements 1120.

  The reflecting portion 1130 is formed of PPA (Polyphthalamide) resin, and an inclined surface 1131 is formed so as to reflect the light emitted from the light emitting element 1120 in the longitudinal direction in the main light emitting direction F of the linear light source portion 110. Yes.

  The resin sealing portion 1140 seals the light emitting element 1120 by filling the concave portion with the wiring substrate 1110 as the bottom surface and the reflection portions 1130 located on both sides as the wall surfaces with an epoxy resin. The resin sealing portion 1140 contains a phosphor (not shown). The phosphor emits a complementary color by converting the wavelength of light from the light emitting element 1120. In this embodiment, since a light emitting element 1120 that emits blue light is used, a phosphor that converts the wavelength to yellow is used. Therefore, the surface of the resin sealing portion 1140 becomes white by mixing the blue color from the light emitting element 1120 and the wavelength-converted yellow color.

  As shown in FIG. 1 to FIG. 2 and FIG. 4 to FIG. 6, the holding frame 120 is formed in a U-shaped cross section and accommodates each of the plurality of linear light source portions 110 along the side surface of the light guide plate 200. They are arranged in a straight line and can be formed of stainless steel or aluminum. A reflection layer 1201 formed of silver plating or white paint is provided on the entire inner surface of the holding frame 120. The holding frame 120 is provided with an opening 1202 through which the power terminal 1114 of the linear light source unit 110 can be seen. The opening 1202 is formed in a substantially U shape at both ends of the holding frame 120, and is formed in a substantially rectangular shape in other cases.

  As shown in FIG. 1, the heat transfer sheet 130 is an elongated sheet-like member disposed between the linear light source units 110 in the holding frame 120. As the heat transfer sheet 130, a heat conductive silicon sheet, a graphite sheet, a heat conductive gel sheet, or the like can be used, but the graphite sheet is 600 to 800 W / (m · K), twice that of copper, 3 of aluminum. This is desirable because it has twice the thermal conductivity. In the present embodiment, a heat transfer sheet 130 is used in which a graphite sheet is used as a base material and a silicone rubber layer, which is an elastic layer having slight adhesiveness, is formed on both front and back surfaces.

  As shown in FIG. 1, the flexible substrate 140 is a substrate that connects a power source supplied from the outside and each linear light source unit 110. The flexible substrate 140 is formed such that the wiring is sandwiched between a base film that is an insulating film and a cover film. The flexible substrate 140 includes a substrate main body 1410 disposed along the outer surface of the holding frame 120, a connection portion 1420 in which the wiring 1401 is exposed for connection to a power connector (not shown), and the connection portion 1420 and the substrate. In order to connect the main body 1410, a wiring portion 1430 that is gradually widened toward the connection portion 1420 is provided.

  As shown in FIGS. 4 to 6, the substrate body 1410 is provided with a band-like portion 1440 for conducting connection to a power supply terminal 1114 provided in the linear light source portion 110. The band-shaped portion 1440 is formed by cutting the substrate main body 1410 into a band shape leaving the base portion 1441. A connection pad 1443 that exposes the wiring 1401 is formed at the distal end 1442 of the strip 1440. The connection pad 1443 is formed in a substantially U shape by forming a substantially semicircular cutout 1444. The band-shaped portion 1440 located at the end of the holding frame 120 is formed so that the tip end portion 1442 faces outward, and is otherwise formed so as to face each other. The strip 1440 passes through the opening 1202 of the holding frame 120 and is soldered to the power supply terminal 1114 of the wiring board 1110.

  Next, a state in which the linear light source device according to the embodiment of the present invention is disposed on one side surface of the light guide plate will be described with reference to FIG. FIG. 7 is a cross-sectional view showing a surface light emitting device using the linear light source device shown in FIG.

  As shown in FIGS. 4 to 7, in the surface light emitting device 300 including the linear light source device 100 and the light guide plate 200, the linear light source device 100 directs the main light emission direction F toward the side surface S <b> 3 of the light guide plate 200. It is arranged on the lower case 301 made of metal. In the light guide plate 200, a reflection sheet 201 is disposed on the lower surface, and a light control sheet 202 such as a diffusion sheet, a first prism sheet, and a second prism sheet is disposed on the upper surface. A liquid crystal display panel 220 is disposed on the light control sheet 202. The linear light source device 100 is mounted on a base portion 302 that is aligned with the height of the side surface S3 of the light guide plate 200. And it accommodates in the upper case 304 so that the liquid crystal display panel 220 and the resin holder 303 may be pressed down.

  In this way, the connection pad 1443 of the flexible substrate 140 is connected to the power supply terminal 1114 of the wiring substrate 1110 so that the one surface of the substrate body 1410 of the flexible substrate 140 faces the back surface of the wiring substrate 1110, thereby There is no need to secure a space as wide as the flexible substrate 140 on the back side or to provide connection pins on the flexible substrate 140. Accordingly, since it is not necessary to secure a space on the back side of the linear light source device 100, the space to be disposed can be reduced when the light source plate 200 is disposed on the side surface S3.

  Further, since the connection pad 1443 of the belt-like portion 1440 passes through the opening 1202 of the holding frame 120 and is connected to the power supply terminal 1114 of the wiring board 1110, even if the holding frame 120 holding the wiring board 1110 is provided, the back side The flexible substrate 140 can be connected to the wiring substrate 1110 without securing a large space.

  Further, the band-shaped portion 1440 can be easily manufactured from a single flexible substrate by forming the band-shaped portion 1440 by separating it from the substrate body 1410 in a band shape leaving the base portion 1441.

  According to the present invention, when the light guide plate is disposed on one side surface, it is possible to reduce the space for the disposition. Therefore, a long substrate on which a wiring pattern is formed and a light emitting element that is conductively mounted on the substrate are provided. It is suitable for the linear light source device and the flexible substrate that supplies power to the light emitting element.

The exploded perspective view which looked at the linear light source device from the flexible substrate side FIG. 1 is an enlarged view of a main part of the linear light source device shown in FIG. Sectional view showing a linear light source It is the A section enlarged view shown in FIG. 1, (A) is a perspective view, (B) is an exploded perspective view. It is the B section enlarged view shown in FIG. 1, (A) is a perspective view, (B) is an exploded perspective view. It is the C section enlarged view shown in FIG. 1, (A) is a perspective view, (B) is an exploded perspective view. Sectional drawing which shows the surface light-emitting device using the linear light source device shown in FIG. An exploded perspective view showing a conventional linear light source device Sectional drawing which shows the state which has arrange | positioned the conventional linear light source device to one side of a light-guide plate The figure which shows another conventional linear light source device

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Linear light source device 110 Linear light source part 120 Holding frame 130 Heat transfer sheet 140 Flexible substrate 200 Light guide plate 201 Reflective sheet 202 Light control sheet 300 Surface light-emitting device 301 Lower case 302 Base part 303 Resin holder 304 Upper case 500 Conventional Linear light source device 510 Linear light source unit 511 Power supply pin 512 Wiring board 520 Holding frame 530 Conventional flexible board 540 Light guide plate 560 Other conventional flexible board 570 Wiring board 1110 Wiring board 1111, 1112 Wiring pattern 1113 Through-hole electrode 1114 Power supply Terminal 1120 Light emitting element 1130 Reflection part 1131 Inclined surface 1140 Resin sealing part 1201 Reflection layer 1202 Opening 1401 Wiring 1410 Substrate body 1420 Connection part 1430 Wiring part 1440 Band-like part 14 1 base 1442 tip 1443 connection pad 1444 cutout portions S1 mounting surface S2 rear S3 side

Claims (4)

A long wiring board;
A plurality of light emitting elements arranged along the longitudinal direction of the wiring board;
A linear light source device comprising a flexible substrate having a substrate body in which a wiring for supplying power to the light emitting element is formed in an insulating film,
In the wiring board, a wiring pattern that is electrically connected to the light emitting element is provided on the mounting surface, and a power supply terminal that is connected to the wiring pattern is provided on the back surface opposite to the mounting surface,
The flexible substrate is provided with a connection pad that exposes the wiring from the insulating film,
The linear light source device, wherein the connection pad is connected to the power supply terminal with the back side of the wiring board facing one side of the board body. The wiring board is held by a holding frame formed in a U-shaped cross section,
The holding frame is provided with an opening for exposing the power supply terminal,
The flexible substrate is connected to the substrate body, and is provided with a belt-like portion where the connection pad is provided at the tip portion.
2. The linear light source device according to claim 1, wherein the belt-like portion is connected to a power supply terminal of the wiring board through the opening. The linear light source device according to claim 2, wherein the belt-like portion is formed in a belt-like shape leaving a base portion from the substrate body. In a flexible substrate having a substrate body in which wiring is formed in an insulating film,
A flexible substrate characterized in that a strip-like portion is provided in which a connection pad that is separated from the substrate main body leaving a base portion and exposes wiring from an insulating film is located at a tip portion.

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