JP2013069912A - Lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the flexure of a light emitting panel and a wiring board which is caused by a thermal expansion difference and adequately conducts wire joining to the wiring board in a lighting device where the light emitting panel and the wiring board are joined through a wire.SOLUTION: A lighting device 1 comprises: a light emitting panel 4; a wiring board 5; and a fixing part 8 disposed between the members 4, 5 and bonding and fixing the members 4, 5. The light emitting panel 4 and the wiring board 5 are electrically connected with each other by connecting an electrode pad 42d of the light emitting panel 4 with an electrode pad 5c of the wiring board 5 through a wire 7. The fixing part 8 is disposed at a position corresponding to the electrode pad 5c of the wiring board 5. Since the light emitting panel 4 and the wiring board 5 are partially bonded and fixed to each other, thermal expansion of one member does not easily affect the other member and the flexure of the members 4, 5 due to a thermal expansion difference is reduced. Further, the bonding between the light emitting panel 4 and the wiring board 5 is enhanced at an area near the electrode pad 5c, and ultrasonic joining is effectively performed to adequately conduct joining between the electrode pad 5c and the wire 7.

Description

  The present invention relates to an illumination device using a solid light emitting element such as an organic EL element as a light source.

  The organic EL element can emit light with high luminance at a low voltage, and various emission colors can be obtained depending on the kind of the organic compound contained, and can be easily manufactured as a flat light-emitting panel. For this reason, in recent years, it has been attracting attention as a light source for lighting devices.

  As shown in FIG. 8, this type of lighting device includes a light emitting panel 100, a wiring board 200 for supplying power to the light emitting panel 100, and a fixing unit 300 for bonding and fixing the light emitting panel 100 and the wiring board 200. Provided (see, for example, Patent Document 1). The light emitting panel 100 includes a translucent substrate 101, a light emitting unit 102 provided on the substrate 101, and a sealing can 103 that seals the light emitting unit 102. The light emitting unit 102 is configured by stacking, in order from the substrate 101 side, a positive electrode 102a made of a transparent conductive film, a light emitting layer 102b containing a light emitting organic material, and a negative electrode 102c having light reflectivity. . A portion of the positive electrode 102a is led out to the outside of the sealing can 103, and an electrode pad 102d is provided in the lead-out portion. One end of a wire 400 is bonded to the electrode pad 102d by ultrasonic bonding, and the other end of the wire 400 is bonded to a positive electrode pad 200a provided on the wiring board 200. Similar to the positive electrode 102 a, the negative electrode 102 c also has an electrode pad (not shown), and this electrode pad and a negative electrode pad (not shown) on the wiring substrate 200 are connected by a wire 400. Thereby, the light emitting panel 100 and the wiring board 200 are electrically connected.

JP 2006-100071 A

  However, in the lighting device as described above, the mutually facing surfaces of the sealing can 103 and the wiring board 200 of the light emitting panel 100 are bonded and fixed by the fixing portion 300 over the entire surface. Therefore, when the sealing can 103 and the wiring board 200 are thermally expanded at different rates due to the light emission heat of the light emitting panel 100, the members 103 and 200 may be bent. If the sealing can 103 and the wiring substrate 200 are not sufficiently fixed, when the wire 400 is bonded to the electrode pad of the wiring substrate 200, ultrasonic vibration is not effectively transmitted to the bonding portion, Bonding with the wire 400 may be insufficient.

  The present invention solves the above-described problem, and in an illumination device using a solid light-emitting element such as an organic EL element as a light source, illumination capable of reducing the curvature of a light-emitting panel and a wiring board caused by a difference in thermal expansion An object is to provide an apparatus. Another object of the present invention is to enable sufficient bonding between an electrode pad of a wiring board and a wire.

  The lighting device of the present invention includes a flat light-emitting panel, a wiring board provided on one side of the light-emitting panel for supplying power to the light-emitting panel, and interposed between the light-emitting panel and the wiring board. A fixing portion for adhering and fixing the panel and the wiring board, and the light-emitting panel has an electrode pad formed outside the wiring board on a surface on which the wiring board is provided, and the wiring board Has electrode pads formed at positions close to the electrode pads of the light-emitting panel on the surface opposite to the surface facing the light-emitting panel, and these electrode pads are electrically connected to each other by wires, The fixing portion is arranged at a position corresponding to the electrode pad of the wiring board.

  It is preferable that a plurality of electrode pads of the light emitting panel and a plurality of electrode pads of the wiring board are provided.

  It is preferable that the fixing portion is arranged in a line shape or a dot shape.

  When the illumination device is viewed from the side of the wiring board, the wiring board preferably has a frame shape with an opening at the center.

  When the illumination device is viewed from the side of the wiring board, the wiring board is preferably open from the center to a part of the peripheral edge.

  According to the present invention, since the light emitting panel and the wiring board are only partially bonded and fixed, even if one member is thermally expanded, it is difficult to affect the other member, and light emission caused by the difference in thermal expansion is caused. The curvature of the panel and wiring board is reduced. In addition, since the fixing portion is arranged at a position corresponding to the electrode pad of the wiring board, the adhesion between the wiring board and the light emitting panel in the vicinity of the electrode pad is strengthened, and ultrasonic bonding is effectively performed to Bonding with a wire can be sufficiently performed.

The disassembled perspective view when the illuminating device which concerns on embodiment of this invention is seen from the attachment surface side. The exploded perspective view when the said illuminating device is seen from the light emission surface side. The disassembled perspective view of the light source part which comprises the said illuminating device. FIG. 4 is an enlarged perspective view of a region surrounded by a dotted line in FIG. 3. The sectional side view which shows arrangement | positioning of the light emission panel which comprises the said light source part, a wiring board, and a fixing | fixed part. The top view which shows arrangement | positioning of the light emission panel, wiring board, and fixing | fixed part in the said illuminating device. The top view which shows arrangement | positioning of the light emission panel, wiring board, and fixing | fixed part in the illuminating device which concerns on the modification of the said embodiment. The sectional side view of the conventional illuminating device.

  An illumination device according to an embodiment of the present invention will be described with reference to FIGS. As illustrated in FIGS. 1 and 2, the lighting device 1 includes a flat plate-shaped mounting portion 2 and a flat plate-shaped light source unit 3 that is detachably mounted on the mounting portion 2. The mounting portion 2 is attached to the ceiling or wall via the attachment surface 2A, and the light source portion 3 irradiates the living space or the like from the light emitting surface 3A.

  The mounting portion 2 has a rectangular shape when viewed from the mounting surface 2 </ b> A side, and has an engaged portion 21 and a held portion 22 for holding the light source portion 3 on a surface facing the light source portion 3. The engaged portion 21 and the held portion 22 are both hook-shaped, the engaged portion 21 is provided near the center of one side of the mounting portion 2, and the held portion 22 is a side facing the one side. It is provided in the vicinity of the center. The mounting unit 2 further includes a circuit board 23 that controls the lighting operation of the light source unit 3 at the center of the surface facing the light source unit 3. The circuit board 23 leads out terminal receiving parts 24 a and 24 b related to electrical connection between the mounting part 2 and the light source part 3.

  The light source unit 3 has a rectangular shape when viewed from the light emitting surface 3A side, and includes a light emitting panel 4 having a rectangular flat plate shape. A wiring board 5 for supplying power to the light emitting panel 4 is provided on the mounting portion 2 side of the light emitting panel 4. The light emitting panel 4 and the wiring substrate 5 are accommodated in the package 6 in a state where they are bonded to each other by a fixing portion (see FIGS. 4 to 6 described later). The package 6 includes a case 61 that covers the mounting unit 2 side of the light source unit 3 and a cover 62 that covers the light emitting surface 3A side of the light source unit 3. The case 61 has an engaging portion 61 a that engages with the engaged portion 21 of the mounting portion 2 and a holding portion 61 b that engages with the held portion 22 of the mounting portion 2 on the surface on the mounting portion 2 side. The light source section 3 is detachably mounted on the mounting section 2 by the engaged section 21 and the engaging section 61a and the held section 22 and the holding section 61b engaging with each other.

  The case 61 is made of, for example, a plastic material such as ABS resin, acrylic resin, or polystyrene resin, or a metal material such as aluminum whose surface is subjected to insulation treatment. As shown in FIG. 3, the case 61 has a frame shape with an opening at the center thereof, and is inserted through terminal portions 5 a and 5 b (see FIGS. 4 to 6 described later) standing on the wiring board 5. Groove portion 61c. The case 61 has a plurality of engaging grooves 61d for holding the cover 62 on the inner peripheral side surface thereof. The cover 62 is provided so as to engage with a rectangular flat plate-shaped transparent protective member 62a provided on the surface facing the light-emitting panel 4, and an engaging groove 61d of the case 61 at the peripheral edge of the transparent protective member 62a. A plurality of engaging claws 62b. The case 61 and the cover 62 are integrated with the light emitting panel 4 and the wiring board 5 included by engaging the engaging grooves 61d and the engaging claws 62b with each other.

  As shown in FIGS. 4 to 6, the light-emitting panel 4 includes a rectangular flat plate-shaped translucent substrate 41, a light-emitting unit 42, and a sealing can 43 that seals the light-emitting unit 42 in order from the light-emitting surface side. Have. The light emitting section 42 is composed of an organic EL element in which a positive electrode 42a made of a transparent conductive film, a light emitting layer 42b containing a light emitting organic material, and a negative electrode 42c having light reflectivity are stacked in this order from the substrate 41 side. Is done. A plurality of portions of the positive electrode 42 a are led out to the outside of the sealing can 43, and electrode pads 42 d used for electrical connection with the wiring board 5 are provided in each of the lead-out portions. Similarly, a plurality of portions of the negative electrode 42c are led out of the sealing can 43, and electrode pads 42e used for electrical connection with the wiring board 5 are provided in each of the lead-out portions. . These electrode pads 42d and 42e are arranged outside the wiring board 5 on the surface on which the wiring board 5 of the light emitting panel 4 is provided, and specifically, one side of the substrate 41 and a side facing the one side. Are alternately arranged along each of the. The sealing can 43 is made of, for example, glass, metal, ceramic, or plastic, and prevents the light emitting unit 42 from being deteriorated by isolating the light emitting unit 42 from outside air, particularly moisture and oxygen.

  The wiring board 5 is composed of a glass fiber board cured by impregnating an epoxy resin or the like into a glass fiber cloth, for example, a base material that achieves both flame retardancy and low electrical conductivity, such as FR-4. When the lighting device 1 is viewed from the side of the wiring board 5, the wiring board 5 has a rectangular flat frame shape having an opening having the same size as the opening of the case 61 at the center thereof. The opening accommodates the circuit board 23 of the mounting portion 2. In addition, the wiring substrate 5 is provided on a surface opposite to the surface facing the light emitting panel 4, with terminal portions 5 a and 5 b used for electrical connection with the mounting portion 2, and the terminal portions 5 a and 5 b and the wiring substrate 5. And a plurality of electrode pads 5c and 5d connected to each other by wiring embedded therein. These electrode pads 5c and 5d are disposed at positions close to the electrode pads 42d and 42e of the light emitting section 42, respectively, and are electrically connected to the electrode pads 42d and 42e by the wire 7. The joint portions between the electrode pads 42d, 42e, 5c, and 5d and the wire 7 are sealed with a sealing resin 7a made of silicone resin, epoxy resin, or the like (see FIG. 5). As a result, the light emitting part 42 is electrically connected to the terminal parts 5a and 5b through the wirings embedded in the electrode pads 42d, 42e-wires 7-electrode pads 5c, 5d-wiring substrate 5. The terminal portions 5a and 5b protrude through the groove portion 61c of the case 61 to the mounting portion 2 side of the light source unit 3 and are inserted into the terminal receiving portions 24a and 24b of the circuit board 24 of the mounting portion 2, respectively. Thereby, the mounting part 2 and the light source part 3 are electrically connected.

  A plurality of wires 7 (three in the illustrated example) are connected between the electrode pads 42d, 42e, 5c, and 5d. Thereby, even if any of the wires 7 is disconnected, the electrical connection between the electrode pads 42d, 42e, 5c, and 5d is maintained unless the other wires 7 are disconnected. The wire 7 is composed of a pure aluminum wire. The pure aluminum wire is bonded to the electrode pads 42d, 42e, 5c, and 5d by ultrasonic bonding at room temperature in a short time. The diameter of the wire 7 is determined in consideration of the current consumption of the light emitting panel 4, the constituent material, and the like. For example, when the current consumption of the light emitting panel 4 is 1A, the fusing current is considered in consideration of a safety factor of 50%. Is a diameter of 100 μm of 2A. In addition, the wire 7 is not limited to an aluminum wire, You may be comprised from a gold wire and a copper wire.

  The fixing portion 8 is composed of an acrylic double-sided tape containing a core material excellent in heat resistance, moisture resistance, and stress relaxation, a thermosetting adhesive, or an ultraviolet curable adhesive. The fixing portion 8 is interposed between the light emitting panel 4 and the wiring substrate 5 and is linearly disposed along the side of the wiring substrate 5 where the electrode pads 5c and 5d are provided. Thereby, the wiring board 5 is bonded and fixed to the sealing can 43 of the light emitting panel 4 on the two sides of the rectangle. Since there is no fixing portion 8 at the side where the electrode pads 5 c and 5 d of the wiring substrate 5 are not provided and at the central portion of the wiring substrate 5, a clearance C is formed between the wiring substrate 5 and the light emitting panel 4.

  According to the lighting device 1 of the present embodiment, since the light emitting panel 4 and the wiring board 5 are partially bonded and fixed by the fixing portion 8, even if one of these members 4 and 5 is thermally expanded, the fixing portion 8 is used. Reduces the displacement in the shear direction and hardly affects the other member. As a result, the bending of the members 4 and 5 due to the difference in thermal expansion is reduced. For example, the members 4 and 5 are prevented from peeling off, and the light emitting panel 4 is prevented from being damaged to prevent moisture from entering the light emitting panel 4. Thus, the reliability of the lighting device 1 can be improved. In addition, since the fixing portion 8 is disposed at a position corresponding to the electrode pads 5c and 5d, adhesion between the light-emitting panel 4 and the wiring board 5 in the vicinity of the electrode pads 5c and 5d becomes strong, and ultrasonic bonding is effective. Thus, the electrode pads 5c and 5d and the wire 7 can be sufficiently bonded.

  In addition, since a plurality of electrode pads 42d and 42e are provided in the light emitting unit 42, a voltage drop in the light emitting unit 42 can be prevented as compared with a case where only a pair of electrode pads is provided. Thereby, the light emission part 42 can be light-emitted more uniformly, and a brightness variation can be reduced. Such a configuration is effective when, for example, ITO (Indium Tin Oxide) having a relatively low electrical conductivity is used as the positive electrode 42a of the light emitting unit 42 as the conductive material.

  In addition, since the fixing portion 8 is linearly arranged in a part between the light emitting panel 4 and the wiring board 5, compared with the conventional lighting device in which the light emitting panel and the wiring board are solidly attached by the fixing portion. Thus, the consumption of the fixed part 8 can be reduced.

  Furthermore, since the wiring board 5 has a frame shape having an opening at the center thereof, the convex parts such as the circuit board 23 in the mounting part 2 and the light source part 3 are less likely to interfere with each other, so The thickness can be reduced.

  Next, an illumination device according to a modification of the present embodiment will be described with reference to FIG. In the present illuminating device, the fixing portion 8 is arranged in a dot shape immediately below the electrode pads 5 c and 5 d of the wiring substrate 5. Therefore, the consumption of the fixing unit 8 can be further reduced as compared with the above-described lighting device 1. Further, since the wiring board 5 has an opening shape from the center portion to a part of the peripheral edge portion, the effective space in the lighting device is increased as compared with the lighting device 1, and the total thickness of the device is further reduced. More members can be mounted in the lighting device.

  In addition, the illuminating device according to the present invention is not limited to the above-described embodiment and its modifications, and various modifications are possible. For example, the solid state light emitting elements that constitute the light emitting panel are not limited to organic EL elements, and may be composed of inorganic EL elements, LEDs (Light emitting diodes), or the like. Further, the light emitting panel may be directly bonded to the circuit board by wire bonding without going through the wiring board. Furthermore, the electrical bonding between the light-emitting panel and the wiring board or circuit board is not limited to wire bonding bonding, and may be performed by, for example, ribbon bonding bonding.

DESCRIPTION OF SYMBOLS 1 Illuminating device 4 Light emission panel 42d, 42e Electrode pad 5 (light emission panel) 5 Wiring board 5c, 5d Electrode pad 7 (wiring board) 7 Wire 8 Fixing part

Claims (5)

A flat light emitting panel, a wiring board provided on one side of the light emitting panel for supplying power to the light emitting panel, and the light emitting panel and the wiring board interposed between the light emitting panel and the wiring board In a lighting device provided with a fixing part for bonding and fixing,
The light-emitting panel has an electrode pad formed outside the wiring board on the surface on which the wiring board is provided,
The wiring board has an electrode pad formed at a position close to the electrode pad of the light emitting panel on the surface opposite to the surface facing the light emitting panel;
These electrode pads are electrically connected to each other by wires,
The lighting device according to claim 1, wherein the fixing portion is disposed at a position corresponding to an electrode pad of the wiring board.   The lighting device according to claim 1, wherein a plurality of electrode pads of the light emitting panel and a plurality of electrode pads of the wiring board are provided.   The lighting device according to claim 1, wherein the fixing portion is arranged in a line shape or a dot shape.   4. The illumination according to claim 1, wherein when the illumination device is viewed from the side of the wiring board, the wiring board has a frame shape with an opening at the center thereof. 5. apparatus.   4. The device according to claim 1, wherein when the illumination device is viewed from the side of the wiring board, the wiring board has an opening shape from a center part to a part of the peripheral part. The lighting device according to item.

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