JP2015207546A - Lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting device using LEDs showing a high distribution angle irrespective of its low cost and capable of effectively restricting a variation of light intensity.SOLUTION: A lighting device of this invention comprises: a light source module having a plurality of light-emitting diodes and a circuit board having the light-emitting diodes mounted thereon; a metallic base material on which the light source module is mounted; and a light diffusion cover of which outer shape is a partial body of rotation arranged at the metallic base material to cover the plurality of light-emitting diodes. The light diffusion cover has a base bottom part at the metallic base material side and a front head part at the extremity end side from an equator face, a flat ratio at the outer surface of the front head part is 1 or more and more than a flat ratio at the outer surface of the base bottom part, the light source module includes a salient of a right angle pyramid or a right angle truncated pyramid having a lateral face tilt angle of 55° or more and 85° or less with its central axis being substantially coincided with a rotating axis of the partial body of rotation of the light diffusion cover, the plurality of light-emitting diodes are substantially equally spaced apart only at the side surfaces of the salient and the centers of light-emitting surfaces of the plurality of light-emitting diodes are substantially coincided with the equator face of the light diffusion cover or positioned below it.

Description

  The present invention relates to a lighting device.

  In recent years, instead of conventional fluorescent lamps, LED lighting devices using light emitting diodes (LEDs) with low energy consumption and long life as a light source are becoming widespread.

  Since the light emitting diode has a small light emission amount per element, in the LED lighting device, a plurality of light emitting diodes are mounted on a printed wiring board. The plurality of light emitting diodes are generally juxtaposed in a plane on a printed wiring board as disclosed in, for example, Japanese Patent Application Laid-Open No. 2009-170114.

JP 2009-170114 A

  In the conventional LED lighting device described above, a plurality of light emitting diodes are arranged in a plane on a flat printed wiring board, and thus a light source formed by the plurality of light emitting diodes has directivity. That is, in the conventional LED lighting device, the light intensity on the front surface (normal direction) of the light emitting diode mounting surface is high, but the light intensity decreases as the angle with respect to the front surface of the light emitting diode mounting surface increases. Therefore, the conventional LED lighting device has a disadvantage that the light distribution angle is small due to the directivity of the light emitting diode, and it is difficult for light to reach the back side (back side) of the light emitting diode mounting surface. Further, when a plurality of light emitting diodes are mounted, there is a disadvantage that the brightness is not uniform due to the positional relationship with the LED lighting device, and the uniformity of the luminous intensity distribution is low.

  On the other hand, in order to improve this inconvenience, an LED lighting device has been devised in which a lens or a prism is laminated on the light output side of a light emitting diode and light from the light source is refracted in the lateral direction to improve the light distribution. However, when a lens or prism is used, unevenness in light intensity is likely to occur, and such an LED illumination device with a prism inevitably complicates the structure and increases the cost due to the attachment of the lens or prism.

  This invention is made | formed based on the above situations, and it aims at providing the illuminating device using LED which has a large light distribution angle and can suppress the fluctuation | variation of a luminous intensity effectively, though it is low-cost. To do.

  In response to the above problems, the present inventors have arranged the light emitting diode only on the side surface of the right-angled pyramid or the right-angled frustum and made the light diffusion cover (globe) covering the light-emitting diode into a certain shape, thereby illuminating. It has been found that the fluctuation of the luminous intensity of the apparatus can be remarkably improved and the light distribution angle can be remarkably improved by diffusing light to the back side.

  That is, an illumination device according to one embodiment of the present invention made to solve the above problems includes a light source module including a plurality of light emitting diodes and a substrate on which the plurality of light emitting diodes are mounted, and the light source module mounted thereon. And a light diffusion cover attached to the metal base so as to cover the plurality of light-emitting diodes and having a partially rotating body as an outer shape, wherein the light diffusion cover is an equatorial plane. The base portion on the metal base side and the frontal portion on the distal end side have a flatness ratio of the frontal head outer surface of 1 or more and a flatness ratio of the baseboard outer surface or more. A convex part of a right-angled pyramid or a right-angled frustum having a angle of not less than 85 ° and not more than 85 ° has a central axis substantially coincident with the rotation axis of the partial rotating body of the light diffusion cover, and the plurality of light emitting diodes are only on the side surface of the convex part. Almost evenly The center of the light emitting surface of the plurality of light emitting diodes is substantially coincident with or located below the equator surface of the light diffusion cover.

  The illuminating device of the present invention can realize an LED illuminating device that has a large light distribution angle and can effectively suppress fluctuations in luminous intensity at a low cost.

FIG. 1 is a schematic front view showing an illumination device according to an embodiment of the present invention. FIG. 2 is a schematic plan view of the illumination device of FIG. 1 as viewed from the front side of the flexible printed wiring board. FIG. 3A is a schematic plan view in which the light source module of the illumination device of FIG. 1 is developed on a plane. 3B is a schematic partial cross-sectional view taken along line AA in FIG. 3A. FIG. 3C is a schematic partial plan view of the flexible printed wiring board of the light source module of FIG. 3A viewed from the front side. 3D is a schematic partial plan view of the flexible printed wiring board of FIG. 3A viewed from the front side. FIG. 3E is a schematic partial cross-sectional view showing a light source module according to an embodiment different from FIG. 3B. FIG. 3F is a schematic partial cross-sectional view showing a light source module according to an embodiment different from those in FIGS. 3B and 3E. FIG. 4 is a graph (light distribution curve) showing the directivity of one light emitting diode. FIG. 5 is a schematic front view showing one step of the method for manufacturing the lighting device of FIG. 1. FIG. It is a graph (light distribution curve) which shows the directivity of 1 illuminating device. FIG. It is a graph (light distribution curve) which shows the directivity of 2 illuminating devices. FIG. It is a graph (light distribution curve) which shows the directivity of 3 illuminating devices. FIG. 4 is a graph (light distribution curve) showing the directivity of the illumination device 4. FIG. 5 is a graph (light distribution curve) showing the directivity of the illumination device of FIG. FIG. 6 is a graph (light distribution curve) showing the directivity of the illumination device of FIG. FIG. 7 is a graph (light distribution curve) showing the directivity of the illumination device of No. 7;

[Description of Embodiment of the Present Invention]
An illumination device according to one embodiment of the present invention includes a light source module including a plurality of light emitting diodes and a substrate on which the plurality of light emitting diodes are mounted, a metal base on which the light source module is mounted, and the metal base A light diffusing cover attached to cover the plurality of light emitting diodes and having a partially rotating body-shaped outer shape, wherein the light diffusing cover includes a base portion and a tip side on the metal base side from the equator plane. A right-angled pyramid or a right-angled pyramid having a flatness ratio of the frontal head outer surface of 1 or more and a flattening ratio of the outer surface of the base or more, and the light source module has a side inclination angle of 55 ° to 85 °. The convex portion of the base has a central axis substantially coincident with the rotational axis of the partial rotating body of the light diffusing cover, and the plurality of light emitting diodes are disposed substantially evenly only on the side surface of the convex portion, Light-emitting surface of light-emitting diode Is substantially coincident with or located below the equator plane of the light diffusion cover.

  Since the illuminating device includes a light diffusion cover having the base portion and the frontal portion as described above and having a certain positional relationship with the light emitting surface of the light emitting diode, the light emitted from the light emitting diode is transmitted to the back side ( The light distribution angle can be remarkably improved by effectively diffusing to the side opposite to the light emitting diode mounting surface. Moreover, since the said illuminating device has arrange | positioned the several light emitting diode substantially isotropically only to the side surface of the convex part of a right cone (right-sided pyramid or right-angled frustum) as mentioned above, it is mainly convex part. The variation in luminous intensity due to the relative position with the light source (light emitting diode group) on the apex side (illuminating device front side) can be reduced, and the uniformity of luminous intensity can be significantly improved. That is, the illuminating device can achieve improvement of the light distribution angle and suppression of variation in luminous intensity at low cost without providing a member such as a lens or a prism. The “partial rotating body” means a solid formed by rotating a tongue-like planar figure curved in one direction around its base side. “Equatorial plane” means a cut surface perpendicular to the short axis of the partial rotating body and having the largest area. The “flattening ratio” is a value obtained as a / b when the equator radius of the spheroid closest to the outer shape of the forehead or the base is a and the polar radius is b. The term “approximate spheroid” means a spheroid whose cut-out shape approximates its outer shape most closely. “The central axis substantially coincides with the rotational axis” means that the angle formed by the central axis and the rotational axis is within 5 °, and the minimum distance between the central axis and the rotational axis is within 1 mm. “Substantially evenly arranged” means that fluctuations in the distance between the centers of adjacent light emitting diodes are arranged within ± 5%. The “center of the light emitting surface of the light emitting diode” means the geometric gravity center of the light emitting surface of the plurality of light emitting diodes. “The center of the light emitting surface substantially coincides with the equator plane” means that the distance between the center of the light emitting surface and the equator plane is within 5 mm.

  It is preferable that the outer shape of the frontal part and the base part is a spheroid, the flatness ratio of the outer surface of the frontal part is preferably 1 to 5, and the flatness ratio of the outer surface of the base part is 0. 4 or more and 1.25 or less are preferable. In this way, by setting the flatness ratio of the outer surface of the frontal head and the base to be within the above ranges, the light emitted from the light emitting diode can be more effectively diffused and the improvement of the light distribution angle can be further promoted. . The “spheroid” means a part of the spheroid.

  The outer shape of the base is preferably spherical. Thus, by making a base part into a perfect spherical partial shape, the improvement of a light distribution angle can further be accelerated | stimulated, raising the luminous intensity of a front side. The “true sphere” means a part of a true sphere.

  The position where the normal line of the light emitting surface of the light emitting diode intersects the light diffusing cover is preferably within ± 20 ° in latitude relative to the center of the equator plane. By defining the relative position between the light emitting diode and the light diffusion cover in this way, it is possible to more effectively diffuse the light emitted from the light emitting diode and further promote the improvement of the light distribution angle. “Latitude” means an angle formed by a straight line connecting the center of the equator plane and a certain position with the equator plane.

  The substrate may be a flexible printed wiring board, and the metal base material may have the convex portion formed by press molding, die casting, cold forging, or cutting. Thus, by disposing the flexible printed wiring board on which the light emitting diode is mounted along the convex portion of the metal substrate, the light emitting diode can be easily and reliably disposed on the side surface of the straight cone. Moreover, the said illuminating device can be manufactured more easily by forming a convex part in a metal base material by press molding. As a result, the manufacturing cost can be further reduced. Furthermore, you may form a convex part in a metal base material by die-casting, cold forging, or cutting besides press molding. In these processing methods, the metal base material with which the inside was filled can be processed and the cost becomes high, but the heat dissipation by the metal base material can be improved.

  The flexible printed wiring board is laminated on the surface of the base film, a conductive pattern that is laminated on the surface side of the base film, and includes one or a plurality of land portions and a wiring portion that is connected to the land portion. A cover lay having an opening formed at a position corresponding to the one or more land portions, and one or more land portions on which the light emitting diode is mounted on the back surface of the flexible printed wiring board. It is preferable to further include a heat conductive adhesive that has a recess reaching the back surface of the conductive pattern in at least a part of the projection area and is filled in the recess. Since the conductive pattern and the metal substrate are connected via the heat conductive adhesive by filling the concave portion reaching the back surface of the conductive pattern in this way, the heat radiation effect of the light emitting diode is remarkably increased. Can be promoted.

  Here, the “land portion” refers to a portion in which the wiring is expanded to a size that allows solder connection in order to perform solder connection for mounting a chip component in the middle of the wiring circuit in the conductive pattern. Usually, an opening is formed at a position corresponding to this portion of the cover lay to expose the conductive portion for solder connection. When this opening is relatively small with respect to the size of the land portion, the entire surface of the opening becomes a circuit surface (conductive portion). Conversely, when the opening is relatively large with respect to the size of the land portion, a pad-shaped circuit surface corresponding to the land portion and a wiring portion connected thereto may exist in the opening.

  The base film may be left in a region including at least a part of the periphery of the one or more land portions in a plan view substantially perpendicular to the surface of the flexible printed wiring board. In this way, by leaving the base film in a region including at least a part of the periphery of the land portion, the conductive pattern is applied to the metal substrate when the flexible printed wiring board on which the light emitting diode is mounted is attached to the metal substrate. Generation | occurrence | production of the short circuit by contact can be prevented. Note that “substantially perpendicular” means that the angle formed with the plane is within 90 ± 5 °. The “connection edge with the wiring part” means a boundary line between the wiring part and the land part, and the “periphery opposite to the connection edge with the wiring part” means that on the connection edge of the peripheral part of the land part. It means a portion where a virtual straight line passing through the point and the geometric center of gravity of the land portion intersects.

  The recess may be formed in a region that covers at least the projection region of the opening of the coverlay. By forming the recess in the region covering the projection region of the cover lay opening as described above, the heat dissipation effect of the light emitting diode can be further promoted.

  The recess may be formed in a region covering at least the projection region of the light emitting diode, and a coverlay may exist between the plurality of land portions in a plan view substantially perpendicular to the surface of the flexible printed wiring board. Thus, by forming the recess in the region covering the projection region of the light emitting diode and having the coverlay between the plurality of land portions, the heat dissipation effect of the light emitting diode can be further promoted while maintaining the strength of the flexible printed wiring board. .

  The flexible printed wiring board has a through-hole for each projection region of the one or more land portions, and the thermally conductive adhesive is also filled in the through-hole and the upper portion thereof, and is in contact with the back surface of the light emitting diode. It is good to be. By forming the through hole in the flexible printed wiring board in this way, it is possible to prevent the heat conductive adhesive from leaking out of the projection area of the land portion when the heat conductive adhesive is filled. Moreover, the heat dissipation effect of a light emitting diode can further be accelerated | stimulated by making a heat conductive adhesive contact | abut to a light emitting diode through this through-hole.

  The metal substrate may be formed of aluminum, an aluminum alloy, magnesium, or a magnesium alloy. By forming the metal base material from these metals, heat conductivity, workability, light weight, low cost, and the like can be improved.

  It is preferable that the light diffusion cover has glass, ceramic or synthetic resin as a main component and a plurality of light diffusion particles. By configuring the light diffusion cover in this manner, it is possible to easily and reliably promote the improvement of the light distribution angle. The “main component” is a component that is contained in the most amount, for example, a component having a content of 50% by mass or more.

  Therefore, the said illuminating device can be used suitably as a light bulb.

[Details of the embodiment of the present invention]
Hereinafter, an illumination device according to an embodiment of the present invention will be described in detail with reference to the drawings. The “front and back” of the flexible printed wiring board means the direction in which the light emitting diode mounting side is the front and the side opposite to the light emitting diode mounting side is the back in the thickness direction of the base film. It does not mean the inside and outside of

  The lighting device shown in FIGS. 1 and 2 is a so-called LED bulb, and includes a light source module 3 having a plurality of light emitting diodes 1 and a flexible printed wiring board 2 on which the plurality of light emitting diodes 1 are mounted, and the light source module 3. Is attached to the metal substrate 4 so as to cover the plurality of light emitting diodes 1 and is connected to the light diffusion cover 5 having a partially rotating body and the metal substrate 4. It mainly includes a heat radiating body 6 for storing electronic devices and the like.

<Light source module>
The light source module 3 includes a flexible printed wiring board 2 and a plurality of light emitting diodes 1 mounted on the flexible printed wiring board 2, and has a right-angle frustum-shaped convex portion at the center.

(Flexible printed wiring board)
As shown in FIGS. 3A and 3B, the flexible printed wiring board 2 includes a base film 2a having flexibility and insulation, a conductive pattern 2b laminated on the surface side of the base film 2a, a base film 2a, and a conductive pattern. And a cover lay 2e laminated on the surface of 2b. The conductive pattern 2b has a plurality of land portions 2c and a wiring portion 2d connected to the land portions 2c, and the light emitting diode 1 is electrically connected to the land portions 2c through solder 1a. It is arranged (mounted) as follows. The cover lay 2e has openings at positions corresponding to the plurality of land portions 2c. Note that FIG. 3A shows a flat development view before the flexible printed wiring board 2 is laminated along the convex portion of the metal base 4 described later. For ease of viewing, the cover lay 2e is omitted in FIG. 3A.

  The base film 2a which comprises the said flexible printed wiring board 2 is comprised by the sheet-like member which has insulation and flexibility. Specifically, a resin film can be used as the sheet-like member constituting the base film 2a. As the main component of this resin film, for example, polyimide, polyethylene terephthalate or the like is preferably used. The base film 2a may include a filler, an additive, and the like. Here, “main component” means a component contained in an amount of 50% by mass or more.

  As shown in FIG. 3A, the base film 2a has a planar shape in which a plurality of trapezoids having the same shape are joined so that each side of the regular polygon is shared with the upper side, and only in the plurality of trapezoidal portions. A light emitting diode 1 is mounted. The base film 2a is bent at the connection sides of the regular polygon and each trapezoid so as to follow the convex portion of the metal base 4 described later, and the regular polygon portion is laminated on the upper surface of the convex portion of the metal base 4; Each trapezoidal part is laminated | stacked on the side surface of a convex part. Thereby, the convex part of the light source module 3 is formed.

  In addition, a rectangular region is further connected to the lower sides of the two trapezoidal portions facing each other on the base film 2a, and a connector 7 described later is mounted on the rectangular portion. When the base film 2 a is laminated on the metal base 4, the base film 2 a is also bent at the connection side between the trapezoid and the rectangle, and the rectangular portion is laminated on the flat surface around the convex portion of the metal base 4. In addition, the part which mounts the connector 7 is not limited to the position in the rectangular part shown to FIG. 2, 3A, It can form in arbitrary shape parts and positions, and is abbreviate | omitted when mounting the connector 7 in a trapezoid part. Is also possible.

  In addition, when the base film 2a is arrange | positioned along the convex part of the metal base material 4, it is preferable to have a shape where the hypotenuses of an adjacent trapezoid part contact | abut. Thus, by making the base film 2a into a shape in which the hypotenuses of the trapezoidal portions come into contact with each other, it is possible to prevent the surface of the metal base material 4 from appearing in the right-angled frustum portion A, and to adjust the luminous intensity of the lighting device. Uniformity and design can be improved.

  The lower limit of the average thickness of the base film 2a is preferably 9 μm, and more preferably 12 μm. On the other hand, the upper limit of the average thickness of the base film 2a is preferably 50 μm, and more preferably 38 μm. When the average thickness of the base film 2a is less than the above lower limit, the strength of the base film 2a may be insufficient. On the other hand, when the average thickness of the base film 2a exceeds the above upper limit, it may be difficult to bend the base film 2a into a straight cone shape along the convex portion.

  The conductive pattern 2b has a plurality of land portions 2c and wiring portions 2d connected to the land portions 2c, and a desired planar shape (pattern) is obtained by etching a metal layer laminated on the surface of the base film 2a. Is formed. One land portion 2c is provided in each trapezoidal portion of the base film 2a, and the light emitting diode 1 is mounted on each land portion 2c. The wiring part 2d is formed so as to connect the plurality of land parts 2c and the connector 7 in series.

  The conductive pattern 2b can be formed of a conductive material, but is generally formed of copper, for example.

  The lower limit of the average thickness of the conductive pattern 2b is preferably 5 μm, and more preferably 8 μm. On the other hand, the upper limit of the average thickness of the conductive pattern 2b is preferably 75 μm, and more preferably 50 μm. When the average thickness of the conductive pattern 2b is less than the above lower limit, the conductivity may be insufficient. Conversely, when the average thickness of the conductive pattern 2b exceeds the above upper limit, the flexibility of the flexible printed wiring board 2 may be impaired.

(Adhesive layer)
The flexible printed wiring board 2 further has an adhesive layer 2h laminated on the back surface of the base film 2a, and is bonded to the metal substrate 4 by the adhesive layer 2h. This adhesive layer 2 h is a layer mainly composed of an adhesive capable of bonding the base film 2 a to the metal substrate 4. The adhesive is not particularly limited, and for example, a thermosetting adhesive such as an epoxy adhesive, a silicone adhesive, and an acrylic adhesive can be used. The adhesive layer 2h can contain an additive as necessary. However, since the light source module 3 includes the heat conductive adhesive layers 11a and 11b described later, it is not necessary to impart thermal conductivity to the adhesive layer 2h.

  The lower limit of the average thickness of the adhesive layer 2h is preferably 5 μm and more preferably 10 μm. On the other hand, the upper limit of the average thickness of the adhesive layer 2h is preferably 50 μm, and more preferably 25 μm. When the average thickness of the adhesive layer 2h is less than the above lower limit, the adhesive strength between the flexible printed wiring board 2 and the metal substrate 4 may be insufficient. On the contrary, when the average thickness of the adhesive layer 2h exceeds the above upper limit, the light source module 3 may be unnecessarily thick, or the distance between the conductive pattern 2b and the metal substrate 4 becomes large, resulting in insufficient heat dissipation. There is a risk of becoming.

  In the adhesive layer 2h, an opening is formed that defines a back side portion of the recess 10 filled with thermally conductive adhesive layers 11a and 11b described later. The size of the opening of this back side portion, that is, the back side portion of the recess 10 in the adhesive layer 2h is larger than the size of the opening of the front side portion of the recess 10, that is, the base film 2a described later. Thus, the filling operation of the heat conductive adhesive layers 11a and 11b can be facilitated by increasing the opening of the recess 10 in the adhesive layer 2h. Further, when the adhesive layer 2h having an opening for defining the back side portion of the recess 10 is formed after the base film 2a is removed and the front side portion of the recess 10 is formed, these positions can be easily aligned.

(Concave)
The light source module 3 has a recess 10 that reaches the back surface of the conductive pattern 2b in at least a part of the projected area of the plurality of land portions 2c on which the one light emitting diode 1 is mounted among the back surface of the flexible printed wiring board 2. Further, as shown in FIG. 3C, a peripheral edge L2 facing the connection edge L1 of the plurality of land portions 2c with the wiring portion 2d in a plan view substantially perpendicular to the surface of the flexible printed wiring board 2 in the concave portion 10. The base film 2a remains in the remaining region P including This remaining region P is also a region between the pair of land portions 2c. By leaving the base film 2a in this manner, when the flexible printed wiring board 2 is attached to the metal substrate 4, the peripheral edge L2 of the land portion 2c facing the connection edge L1 with the wiring portion 2d is pressed to be flexible printed. Even if it falls to the back surface side of the wiring board 2, a short circuit between the land portion 2 c and the metal substrate 4 can be prevented by the base film 2 a in the remaining region P. In addition, illustration of the coverlay 2e is abbreviate | omitted in FIG. 3C. The “connection edge with the wiring part” means the boundary line between the wiring part and the land part, and the “periphery opposite to the connection edge with the wiring part” means the connection edge among the peripheral edges of the land part. It means a portion where an imaginary straight line passing through the upper point and the geometric center of gravity of the land portion intersects.

  The recess 10 is formed in a region overlapping with the projection region of the light emitting diode 1 mounted on the land portion 2c located on the bottom surface thereof. That is, the front side portion of the concave portion 10 is formed by removing the base film 2 a in the region covering the projection region of the light emitting diode 1 except for the remaining region P. Moreover, the back side part of the recessed part 10 is formed in the area | region which covers the projection area | region of a front side part. Thereby, as described above, the opening of the recess 10 is stepwise in the thickness direction so that it is large at the position of the back side adhesive layer 2h (back side part) and small at the position of the base film 2a (front side part). The diameter has been expanded.

  In the flexible printed wiring board 2 of FIGS. 3A and 3B, the projected areas of the plurality of land portions 2c all overlap with the opening area (including the front side portion and the remaining area P) of the recess 10 in the base film 2a in plan view. However, as long as the heat transfer promoting effect of the present invention is achieved, a part of the projected area of the land portion 2c may not overlap the opening area of the recess 10 in the base film 2a. The lower limit of the ratio of the overlapping area (excluding the remaining region P) of the recess 10 and the land 2c in the base film 2a to the total area of the land 2c is preferably 80%, more preferably 90%, and 95%. Further preferred. When the said area ratio is less than the said minimum, there exists a possibility that the heat transfer effect of the light source module 3 may become inadequate.

  In the flexible printed wiring board 2 of FIG. 3B, at least the front side portion of the recess 10 is formed in a region that covers at least the projection region of the opening of the cover lay 2e provided at a position corresponding to the plurality of land portions 2c. . Furthermore, at least the front side portion of the recess 10 is formed in a region covering at least the projection region of the light emitting diode 1, and a cover layout is provided between the plurality of land portions 2 c in a plan view substantially perpendicular to the surface of the flexible printed wiring board 2. 2e exists. 3B, the projection area of the opening H of the cover lay 2e of the flexible printed wiring board 2 is smaller than the projection area of the land portion 2c as shown in FIG. 3D, and exists in the projection area of the land portion 2c. That is, a part of the land portion 2 c is exposed by the opening H.

  The upper limit of the opening area of the recess 10 in the base film 2a is preferably twice the projected area of the light emitting diode 1, more preferably 1.8 times, and even more preferably 1.5 times. When the opening area of the recess 10 in the base film 2a exceeds the above upper limit, the removal region of the base film 2a becomes large, and there is a possibility that the insulation reliability becomes insufficient when the flexible printed wiring board 2 is bent. The “opening area of the recess” means the area of the bottom surface of the recess (the conductive pattern or the exposed back surface of the coverlay) and does not include the area of the remaining region P.

  The lower limit of the difference between the opening diameter of the recess 10 in the base film 2a (the diameter of the front side portion) and the opening diameter of the recess 10 in the adhesive layer 2h (the diameter of the back side portion) is preferably 2 μm, more preferably 40 μm, and more preferably 100 μm. Is more preferable. On the other hand, the upper limit of the difference between the opening diameter of the recess 10 in the base film 2a and the opening diameter of the recess 10 in the adhesive layer 2h is preferably 1000 μm, more preferably 600 μm, and even more preferably 200 μm. When the difference between the opening diameter of the recess 10 in the base film 2a and the opening diameter of the recess 10 in the adhesive layer 2h is less than the lower limit, the filling work of the heat conductive adhesive layers 11a and 11b is insufficiently facilitated. There is a risk. Conversely, when the difference between the opening diameter of the recess 10 in the base film 2a and the opening diameter of the recess 10 in the adhesive layer 2h exceeds the upper limit, the filling amount of the heat conductive adhesive layers 11a and 11b increases, There is a possibility that the cost of the module 3 may be unnecessarily increased and the adhesive strength to the metal substrate 4 may be reduced. The “opening diameter” means the diameter of a perfect circle having the same area as the opening.

  As a lower limit of the average overlap width w between the projection area (residual area P) of the remaining portion of the base film 2a and the projection area of the land portion 2c (one of the left or right land portion 2c in FIG. 3B), 10 μm is preferable, 30 μm is more preferable, and 50 μm is further preferable. On the other hand, the upper limit of the average overlap width w is preferably 500 μm, more preferably 300 μm, and even more preferably 100 μm. When the average overlap width w is less than the lower limit, the short-circuit preventing effect between the land portion 2c and the metal substrate 4 may be insufficient. On the contrary, when the average overlap width w exceeds the upper limit, the heat dissipation effect by the recess 10 and the heat conductive adhesive layers 11a and 11b may be insufficient. The “average overlapping width” means the area of the overlapping portion of the projection area between the land portion 2c and the remaining portion of the base film 2a, and the projection of the remaining portion of the base film 2a out of the peripheral edge in the projection area of the land portion 2c. It means the value divided by the length of the part that overlaps the area.

(Thermal conductive adhesive layer)
The light source module 3 includes thermally conductive adhesive layers 11a and 11b. The heat conductive adhesive layers 11 a and 11 b are filled in the recess 10 and adhere the conductive pattern 2 b and the metal substrate 4. Specifically, the heat conductive adhesive layer is laminated on the back surface of the conductive pattern 2b, and the first heat conductive adhesive layer 11a filled on the front surface side of the recess 10 and the first heat conductive adhesive layer. The second heat conductive adhesive layer 11b is laminated on the back surface of the agent layer 11a and is filled on the back surface side of the recess 10. By forming the thermally conductive adhesive layer in two layers in this way, after forming the first layer (first thermally conductive adhesive layer 11a), the presence or absence of voids is confirmed, and then the second layer ( Since the second thermally conductive adhesive layer 11b) can be formed, it is possible to prevent a decrease in thermal conductivity and adhesive force by ensuring the filling of the adhesive.

  The heat conductive adhesive layers 11a and 11b contain an adhesive resin component and a heat conductive filler, respectively.

  Examples of the adhesive resin component that can be used include polyimide, epoxy, alkyd resin, urethane resin, phenol resin, melamine resin, acrylic resin, polyamide, polyethylene, polystyrene, polypropylene, polyester, vinyl acetate resin, silicone resin, and rubber. If an adhesive mainly composed of an acrylic resin, silicone resin, urethane resin or the like is used as the adhesive resin component, the flexible printed wiring board 2 can be easily and reliably attached to the metal substrate 4.

  Examples of the heat conductive filler include metal oxides and metal nitrides. As the metal oxide, aluminum oxide, silicon oxide, beryllium oxide, magnesium oxide, or the like can be used. Among these, aluminum oxide is preferable from the viewpoint of electrical insulation, thermal conductivity, price, and the like. As the metal nitride, aluminum nitride, silicon nitride, boron nitride, or the like can be used. Among these, boron nitride is preferable from the viewpoint of electrical insulation, thermal conductivity, and low dielectric constant. In addition, the said metal oxide and metal nitride can be used in mixture of 2 or more types.

  As a minimum of content of a heat conductive filler in heat conductive adhesive layers 11a and 11b, 40 volume% is preferred and 45 volume% is more preferred. On the other hand, as an upper limit of content of a heat conductive filler, 85 volume% is preferable and 80 volume% is more preferable. When content of a heat conductive filler is less than the said minimum, there exists a possibility that the heat conductivity of heat conductive adhesive layer 11a, 11b may become inadequate. On the other hand, when the content of the heat conductive filler exceeds the above upper limit, bubbles are likely to enter during mixing of the adhesive resin component and the heat conductive filler, and the voltage resistance may be reduced. In addition, the heat conductive adhesive layers 11a and 11b may contain an additive such as a curing agent in addition to the heat conductive filler.

  As a minimum of thermal conductivity of heat conductive adhesive layers 11a and 11b, 1 W / mK is preferred and 2 W / mK is more preferred. On the other hand, the upper limit of the thermal conductivity of the heat conductive adhesive layers 11a and 11b is preferably 20 W / mK. When the thermal conductivity of the heat conductive adhesive layers 11a and 11b is less than the lower limit, the heat dissipation effect of the light source module 3 may be insufficient. On the contrary, when the thermal conductivity of the heat conductive adhesive layers 11a and 11b exceeds the upper limit, the content of the heat conductive filler is excessive, and bubbles are generated when the adhesive resin component and the heat conductive filler are mixed. There is a risk that the voltage resistance is lowered due to easy entry, and the cost may be excessive.

  The thermal conductivity of the second thermally conductive adhesive layer 11b is preferably smaller than the thermal conductivity of the first thermally conductive adhesive layer 11a. In other words, the content of the heat conductive filler in the second heat conductive adhesive layer 11b is preferably smaller than the content of the heat conductive filler in the first heat conductive adhesive layer 11a. Thus, while increasing the heat conductive filler content of the 1st heat conductive adhesive layer 11a, and reducing the heat conductive filler content of the 2nd heat conductive adhesive layer 11b, heat conductive adhesion The adhesive force with the metal substrate 4 can be increased while maintaining the heat dissipation effect in the entire agent layer.

  Moreover, it is preferable that the thixotropy (thixotropy) of the adhesive forming the first thermally conductive adhesive layer 11a is higher than the thixotropic property of the adhesive forming the second thermally conductive adhesive layer 11b. By increasing the thixotropy of the adhesive of the first heat conductive adhesive layer 11a as compared to the second heat conductive adhesive layer 11b, the filling property of the adhesive into the concave portion 10 can be improved, and the first can be more easily and reliably performed. One heat conductive adhesive layer 11a can be formed. The thixotropy is an index of the property that the viscosity decreases when a certain force is applied and recovers to the original viscosity when left standing, for example, the viscosity at a low shear rate is divided by the viscosity at a high shear rate. It is expressed as a ratio.

The heat conductive adhesive layers 11a and 11b are preferably highly insulating. Specifically, the lower limit of the volume resistivity of the heat conductive adhesive layers 11a and 11b is preferably 1 × 10 ⁸ Ωcm, and more preferably 1 × 10 ¹⁰ Ωcm. When the volume resistivity of the heat conductive adhesive layers 11a and 11b is less than the lower limit, the insulating properties of the heat conductive adhesive layers 11a and 11b are lowered, and the conductive pattern 2b is laminated on the back side of the base film 2a. There is a possibility that the metal substrate 4 is electrically connected. The volume resistivity is a value measured according to JIS-C2139 (2008).

  The average thickness of the entire heat conductive adhesive layers 11a and 11b (the average distance from the back surface of the second heat conductive adhesive layer 11b to the back surface of the conductive pattern 2b) is equal to the average thickness of the base film 2a and the adhesive layer 2h. It is preferable that it is larger than the sum of the average thicknesses. Specifically, the lower limit of the average thickness of the entire heat conductive adhesive layers 11a and 11b is preferably 5 μm, and more preferably 10 μm. On the other hand, the upper limit of the average thickness of the entire heat conductive adhesive layers 11a and 11b is preferably 100 μm, and more preferably 50 μm. When the average thickness of the entire heat conductive adhesive layers 11a and 11b is less than the lower limit, the heat conductive adhesive layers 11a and 11b are sufficiently in contact with the metal base material 4 laminated on the back side of the base film 2a. Otherwise, the heat transfer effect may be insufficient. On the contrary, when the average thickness of the whole heat conductive adhesive layers 11a and 11b exceeds the above upper limit, the filling amount of the heat conductive adhesive layers 11a and 11b may increase and the cost may increase, or the light source module 3 may not be used. May be thicker than necessary.

  The lower limit of the ratio of the average thickness of the second heat conductive adhesive layer 11b to the average thickness of the first heat conductive adhesive layer 11a is preferably 0.1, and more preferably 0.2. On the other hand, the upper limit of the ratio of the average thickness of the second heat conductive adhesive layer 11b to the average thickness of the first heat conductive adhesive layer 11a is preferably 2, and more preferably 1.5. If the ratio of the average thickness of the second heat conductive adhesive layer 11b to the average thickness of the first heat conductive adhesive layer 11a is less than the lower limit, the effect of improving the adhesiveness may be insufficient. Conversely, if the ratio of the average thickness of the second thermally conductive adhesive layer 11b to the average thickness of the first thermally conductive adhesive layer 11a exceeds the above upper limit, the heat dissipation effect may be insufficient.

  A cover lay 2e is laminated on a portion of the surface of the flexible printed wiring board 2 excluding a portion (land portion 2c) where the light emitting diode 1 is mounted. The cover lay 2e has an insulating function and an adhesive function, and is adhered to the surfaces of the base film 2a and the conductive pattern 2b. When the coverlay 2e has the insulating layer 2f and the adhesive layer 2g as shown in FIG. 3B, the insulating layer 2f can be made of the same material as the base film 2a, and the average thickness is the same as that of the base film 2a. be able to. Moreover, as an adhesive which comprises the adhesive layer 2g of the coverlay 2e, an epoxy-type adhesive agent etc. are used suitably, for example. The average thickness of the adhesive layer 2g is not particularly limited, but is preferably 12.5 μm or more and 25 μm or less.

  The surface of the coverlay 2e is preferably colored white. By forming a white layer on the surface of the coverlay 2e, the light emitted to the flexible printed wiring board 2 side of the light emitting diode 1 can be reflected, and the utilization efficiency of the light can be increased. Moreover, the design property of the said illuminating device can be improved. This white layer can be formed, for example, by applying a white pigment.

  Connectors 7 are connected to both ends of the conductive pattern 2b. The connector 7 is a member for electrically connecting the plurality of light emitting diodes 1 to a power supply circuit that supplies power to the lighting device, and is mounted on another land portion of the conductive pattern 2b. The connector 7 is connected to a lead wire penetrating the through hole 4 a of the metal base 4, and supplies lighting power to the light emitting diode 1.

(Light emitting diode)
The light emitting diode 1 is mounted on the land portion 2c of the flexible printed wiring board 2 via the solder 1a. As the light-emitting diode 1, a multi-color light-emitting type or a single-color light-emitting type and a surface-mounted light-emitting diode packaged with a chip type or a synthetic resin can be used. Moreover, it is preferable to use the light emitting diode which is not provided with the lens from a viewpoint of improving the effect of this invention. Further, the connection method of the light emitting diode 1 to the land portion 2c is not limited to solder, and for example, die bonding using a conductive paste, wire bonding using a metal wire, or the like can be used.

  In the lighting device, it is preferable to use a light emitting diode having a luminous intensity distribution as shown in FIG. In the graph of FIG. 4, one light emitting diode is arranged on one side surface of the right-angle frustum, and the circumference is 360 ° around the center axis of the right-angle frustum (in FIG. 4, the angle φ around the center axis is 0). The light intensity obtained by simulation of the light intensity in the range of from 0 ° to 360 ° is indicated by contour lines. Concentric circles in this graph are scales obtained by dividing θ (inclination angle with respect to the central axis direction) by 45 °, and the magnitude of the luminous intensity is indicated by contour lines dividing the relative intensity of luminous intensity by 10%.

<Metal base material>
The metal substrate 4 is a metal bulk or plate-like member, is formed in a circular shape in plan view, and has a right-angled frustum-shaped convex portion in the center. The flexible printed wiring board 2 is laminated along the convex portion, so that the right-angle frustum portion A is configured.

  As a metal that forms the metal substrate 4, for example, aluminum, aluminum alloy, magnesium, magnesium alloy, copper, iron, nickel, molybdenum, tungsten, or the like can be used. Among these, aluminum, aluminum alloy, magnesium, or magnesium alloy is particularly preferable from the viewpoints of heat conductivity, workability, lightness, cost, and the like.

  Although the formation method of the convex part of the metal base material 4 is not specifically limited, For example, it can form easily and reliably by press molding. Specifically, the metal substrate 4 having a convex portion can be formed by pressing a metal mold having a convex portion shape against a metal flat plate. By press-molding in this way, the convex portion and the casing end portion (connection portion with the light diffusion cover) can be formed at the same time, and the manufacturing cost can be reduced. Furthermore, you may form a convex part in a metal base material by die-casting, cold forging, or cutting besides press molding. In these processing methods, the metal base material with which the inside was filled can be processed, and although the cost and weight increase, the heat dissipation by the metal base material 4 can be improved.

  When press molding is used, the lower limit of the average thickness of the metal substrate 4 is preferably 0.3 mm, and more preferably 0.5 mm. On the other hand, the upper limit of the average thickness of the metal substrate 4 is preferably 4 mm, and more preferably 3 mm. When the average thickness of the metal substrate 4 is less than the above lower limit, the strength of the metal substrate 4 may be insufficient. Conversely, if the average thickness of the metal substrate 4 exceeds the above upper limit, it may be difficult to form convex portions by press molding or the like, and the weight and volume of the lighting device may become unnecessarily large. is there.

  The planar view shape of the metal substrate 4 can be appropriately designed according to the shape of the illumination device using the illumination device, and can be a polygonal shape in addition to the circle shown in FIGS. When the shape of the metal substrate 4 in plan view is a circle as shown in FIGS. 1 and 2, the diameter can be, for example, 10 mm or more and 200 mm or less.

  Further, the metal base 4 has a through hole 4a through which a lead wire for connecting a power supply circuit for supplying power to the lighting device and the conductive pattern 2b of the flexible printed wiring board 2 is inserted. In FIG. 2, a total of two through holes 4a are provided at positions facing each other across the right-angle frustum portion A. However, the formation positions of the through holes 4a are not limited to this, and a connector described later is provided. What is necessary is just to form the through-hole 4a in the position where the connection of 7 and a lead wire becomes easy.

  In addition, the metal base material 4 also has a function as a heat radiator that releases heat generated by the plurality of light emitting diodes 1.

<Right-angle frustum part>
The right-angle frustum part A is a right-angled frustum-shaped part whose bottom surface (a surface having a large area among the two surfaces facing the height direction of the right-angle frustum part A) is a regular polygon. The right-angle frustum portion A is formed such that its bottom surface is on the metal substrate 4 side, and its bottom surface and top surface (surface facing the bottom surface) are substantially parallel to the surface of the metal substrate 4. The plurality of light emitting diodes 1 are disposed in a region forming the side surface of the right-angle frustum portion A on the surface of the flexible printed wiring board 2. Note that “substantially parallel” means that the angle between the normal of one surface and the other surface is within 90 ± 5 °.

  The lower limit of the inclination angle with respect to the bottom surface of the side surface of the right-angle frustum portion A is 55 °, more preferably 60 °, and still more preferably 65 °. On the other hand, the upper limit of the inclination angle with respect to the bottom of the side surface of the right-angle frustum portion A is 85 °, more preferably 80 °, and more preferably 75 °. When the inclination angle is less than the lower limit, the luminous intensity in the direction in which the angle with the central axis of the right-angle frustum portion A is large is the right-angle frustum on the surface side of the flexible printed wiring board 2 (the protruding side of the right-angle frustum portion A). There is a possibility that the luminous intensity is greatly reduced with respect to the luminous intensity in the central axis direction (front) of the part A, and the luminous intensity variation (ratio of the maximum value to the minimum value of luminous intensity) is increased. In addition, the light distribution angle of the lighting device may be small. On the contrary, when the inclination angle exceeds the upper limit, the luminous intensity in the central axis direction of the right-angle frustum portion A is larger in the angle with the central axis of the right-angle frustum portion A on the surface side of the flexible printed wiring board 2. There is a risk that the uniformity of the luminous intensity distribution may be reduced.

  The bottom surface of the right-angle frustum portion A is a regular hexagon in FIGS. 1 and 2, but the shape of the bottom surface of the right-angle frustum portion A of the lighting device is not limited to a regular hexagon. For example, a truncated pyramid with a regular number of 9 angles, a regular 12 angles, a regular 15 angles, and more can be employed. If the number of light emitting diodes is large, a larger polygonal frustum may be used. The bottom surface of the right-angle frustum portion A is preferably a regular polygon, but may be a polygon having different lengths on each side.

  Further, as the shape of the bottom surface of the right-angle frustum portion A, it is possible to adopt a pentagon or the like in which each side has a different length. In order to effectively suppress fluctuations in luminous intensity, the shape of the bottom surface of the right-angle frustum portion A is preferably a regular polygon, but the effect can be obtained even with polygons having different lengths on each side.

  The dimension of the right-angle frustum part A is not particularly limited, and can be appropriately designed according to the illuminance, size, etc. of the lighting device using the lighting device. For example, in the case of a light bulb, the diameter of the circumscribed circle on the bottom surface of the right-angle frustum portion A can be set to, for example, 10 mm to 50 mm. The diameter of the circumscribed circle on the upper surface of the right-angle frustum portion A can be set to 1 mm or more and 45 mm or less, for example. The height of the right-angle frustum portion A can be set to, for example, 5 mm or more and 40 mm or less.

  The plurality of light emitting diodes 1 are substantially evenly disposed only on the side surface of the right-angle frustum portion A, and are not disposed on the upper surface of the right-angle frustum portion A. The plurality of light emitting diodes 1 are arranged such that the light emitting surface is substantially parallel to the side surface of the right-angle frustum portion A. Further, the angles formed by the projection lines on the bottom surface of the right-angle frustum portion A of the normal line of the light emitting surface of the adjacent light emitting diode 1 are all equal. This angle is preferably 72 ° or less. When a plurality of light emitting diodes 1 are arranged on one side surface of the right-angled frustum part A, the “normal line of the light emitting surface” means the geometry of the plurality of light emitting diodes 1 arranged on one side surface. It means the normal of the side surface of the right-angle frustum part A passing through the center of gravity.

  The number of light emitting diodes 1 disposed on each side surface of the right-angle frustum portion A is one in FIGS. 1 to 3A, but the number of light emitting diodes 1 disposed on each side surface is required by the size of the lighting device. It can be appropriately designed according to the illuminance and the like, and may be two or more, for example, three or four. In addition, it is preferable that the number of the light-emitting diodes 1 disposed on each side surface is the same so that the variation in luminous intensity depending on the direction can be suppressed.

  Moreover, it is preferable that the light emitting diode 1 is disposed at the same position on each side surface of the right-angle frustum portion A. By arranging the light emitting diodes 1 at the same positions on the side surfaces in this way, the light emitting diodes 1 can be arranged at equal intervals in the circumferential direction, so that fluctuations in luminous intensity can be more effectively suppressed.

<Light diffusion cover>
The light diffusion cover 5 has a so-called dome-like cover shape. Specifically, the light diffusing cover 5 has a partially rotating outer shape, and has a base portion 5b on the metal base 4 side and a frontal head portion 5a on the tip side from the equator plane E. The rotation axis of the partial rotating body of the light diffusion cover 5 substantially coincides with the central axis of the convex portion (right-angle frustum portion A) of the light source module 3. The light diffusion cover is a cover having a degree of dispersion (light receiving angle at which the relative transmittance with respect to the amount of transmitted light at a light receiving angle of 0 ° is 50%) of 10 ° or more.

  The outer shape of the forehead 5a is a spheroid, specifically, a hemisphere obtained by cutting a true sphere or oblate sphere along the equator plane. The flatness ratio of the outer surface of the frontal head 5a is 1 or more and is equal to or more than the flatness ratio of the outer surface of the base portion 5b described later.

  The lower limit of the flatness ratio of the outer surface of the forehead 5a is preferably 1, more preferably 1.2, and even more preferably 1.3. On the other hand, the upper limit of the flatness ratio of the outer surface of the forehead 5a is preferably 5, more preferably 4, and even more preferably 3. When the flatness ratio of the outer surface of the forehead 5a is less than the lower limit, the light distribution angle of the lighting device may not be sufficiently large. On the contrary, when the flatness ratio of the outer surface of the forehead 5a exceeds the upper limit, the luminous intensity on the front side of the lighting device may be reduced.

  The outer shape of the base part 5b is a spheroid like the frontal part 5a. Specifically, the outer shape of the base portion 5b is a shape obtained by cutting a true sphere or oblate sphere at a plane parallel to the equator plane and the equator and closer to the pole than the equator. The equatorial plane E of the base part 5b coincides with the equatorial plane E of the frontal head 5a. The base portion 5 b is connected to the metal substrate 4 at the bottom surface (cut surface opposite to the equator plane E), and the bottom surface of the base portion 5 b coincides with the surface of the metal substrate 4.

  As an upper limit of the flatness ratio of the outer surface of the base 5b, 1.25 is preferable, 1.2 is more preferable, and 1.1 is more preferable. On the other hand, the lower limit of the flatness ratio of the outer surface of the base portion 5b is preferably 0.4, more preferably 0.5, and even more preferably 0.8. When the flatness ratio of the outer surface of the base part 5b exceeds the said upper limit, there exists a possibility that the luminous intensity of the front side of the said illuminating device may fall. On the contrary, when the flatness ratio of the outer surface of the base part 5b is less than the said lower limit, there exists a possibility that the light distribution angle of the said illuminating device may not become large enough. Furthermore, the outer shape of the base portion 5b is preferably a perfect sphere, that is, a part of the true sphere.

  The centers of the light emitting surfaces of the plurality of light emitting diodes 1 are substantially coincident with or located below the equator plane E of the light diffusion cover 5. The lower limit of the vertical distance between the centers of the light emitting surfaces of the plurality of light emitting diodes 1 and the equator plane E of the light diffusion cover 5 is the height of the base portion 5b (the distance from the bottom surface of the base portion 5b to the equator plane E). On the other hand, 10% is preferable, 20% is more preferable, and 30% is more preferable. When the said distance is less than the said minimum, there exists a possibility that the light distribution angle improvement effect of the said illuminating device may become inadequate.

  The latitude with respect to the center of the equator plane E at the position where the normal of the light emitting surface of the light emitting diode 1 intersects the light diffusion cover 5 is preferably within ± 20 °, and more preferably within ± 10 °. If the latitude exceeds the above range, the effect of improving the light distribution angle of the lighting device may be insufficient.

  The light diffusing cover 5 includes a light transmissive plate and a plurality of light diffusing particles disposed on or inside the plate as components. As a material of the plate material, a known material used for a so-called bulb glove can be used, and for example, a transparent or translucent material mainly composed of glass, ceramic or synthetic resin can be used. Although the average thickness of a board | plate material is not specifically limited, For example, they are 0.1 mm or more and 5 mm or less.

  As said light-diffusion particle | grains, what has glass, a ceramic, a synthetic resin etc. as a main component can be used conveniently, for example.

<Heat radiator>
The radiator 6 supports the lighting device and functions to transmit heat of the light emitting diode 1 to the outside. As a material of the heat radiating body 6, aluminum or the like is preferably used. A base (not shown) is attached to the end of the radiator 6.

  Further, a power supply circuit (not shown) for supplying power to the light emitting diode 1 is housed in the radiator 6 and is electrically connected to the base. This power supply circuit is connected to the connector 7 of the light source module 3 via a lead wire, supplies power supplied from the base to the plurality of light emitting diodes 1 and lights them.

<Light distribution angle>
In a conventional lighting device in which a light emitting diode is installed on a plane, the light distribution angle is about 120 °, and a larger light distribution angle is required. Therefore, the lower limit of the light distribution angle of the lighting device is preferably 300 °. Of course, since there is a light source mounting portion, it is difficult to realize a light distribution angle of 360 °, but it is more preferable if a light distribution angle of 360 ° can be realized. The said illuminating device is suitably used as high light distribution type illumination because the light distribution angle is 300 ° or more. The “light distribution angle” is a value obtained by the following procedure. First, the center of the bottom surface of the right-angle frustum portion A is set as an origin, and one axis passing through this origin and parallel to the bottom surface of the right-angle frustum portion A is set as a reference axis. Next, in the direction in which the angle with respect to the central axis of the right-angle frustum portion A is θ (°), it is −90 ° to 90 ° left and right around the reference axis when viewed from the central axis direction of the right-angle frustum portion A. The average value of the luminous intensity of the range is calculated. This luminous intensity average value is calculated in the range of θ from 0 ° to 360 °, and the maximum value (maximum luminous intensity) of these luminous intensity average values is obtained. In the range of θ from 0 ° to 360 °, the size (angle width) of θ in which the ratio of the luminous intensity average value to the maximum luminous intensity is 50% or more is the light distribution angle. Here, “luminosity” is a value measured in accordance with JIS-C7801 (2009).

<Manufacturing method of lighting device>
For example, as shown in FIG. 5, the lighting device includes a step of laminating the flexible printed wiring board 2 along the convex portion on the surface side of the metal substrate 4, and a step of attaching the light diffusion cover 5 to the laminate. It can manufacture with a manufacturing method provided with.

  As a method for laminating the flexible printed wiring board 2 on the metal substrate 4, for example, a method having the following steps can be used. First, a hole defining the front side portion of the recess 10 is formed in the base film 2a, and an adhesive sheet having a hole defining the back side portion of the recess 10 is laminated on the back surface of the base film 2a. Next, the recess 10 is filled with a heat conductive adhesive. Then, the flexible printed wiring board 2 is laminated | stacked on the surface of the metal base material 4, and these are adhere | attached.

  Examples of a method of attaching the light diffusion cover 5 to the laminate composed of the flexible printed wiring board 2 and the metal base 4 include a method of fixing them with a mechanical element such as an adhesive or a screw.

<Advantages>
Since the lighting device includes the front head portion 5a and the base portion 5b having the above-described shape and includes the light diffusion cover 5 having a certain positional relationship with the light emitting surface of the light emitting diode 1, the light emitting device 1 emits light from the light emitting diode 1. The light distribution angle can be remarkably improved by effectively diffusing the light rays to the back side (the side opposite to the light emitting diode mounting surface). Moreover, since the said illuminating device has arrange | positioned the some light emitting diode 1 substantially equally isotropically only to the side surface of the right-angle frustum part A, mainly in the vertex side (illumination device front side) of the right-angle frustum part A The variation in luminous intensity due to the relative position with the light source (light emitting diode group) can be reduced, and the uniformity of luminous intensity can be significantly improved. That is, the illuminating device can achieve improvement of the light distribution angle and suppression of variation in luminous intensity at low cost without providing a member such as a prism.

  In addition, in the lighting device, since the right pyramid on which the light emitting diodes 1 are disposed is a right-angle frustum, the light emitting diodes 1 can be easily disposed at equal intervals.

  Furthermore, the lighting device is configured such that the flexible printed wiring board 2 on which the light-emitting diode 1 is mounted is disposed along the convex portion on the metal base 4 having the convex portion, so that the right-angle frustum portion A can be easily and reliably disposed. The light emitting diode 1 can be disposed on the side surface.

[Other Embodiments]
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is not limited to the configuration of the embodiment described above, but is defined by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims. The

  In the above embodiment, the lighting device includes a laminate of a metal substrate and a flexible printed wiring board, and the light emitting diode is mounted on the flexible printed wiring board. However, the present invention mounts the light emitting diode on the flexible printed wiring board. It is not limited to what you did. For example, a plurality of rigid printed wiring boards may be laminated on the side surfaces of the convex portions of the metal substrate, and the light emitting diodes may be mounted thereon. In addition, a hollow straight cone may be formed with a printed wiring board on a flat metal substrate having no protrusions, or a protrusion may be formed on the metal substrate with a resin or the like. A straight wiring body may be formed by arranging a printed wiring board so as to cover the convex portion.

  Moreover, it is also possible to use a right-angled pyramid instead of a right-angled frustum as the convex shape of the light source module.

  Further, the outer shape of the light diffusing cover may be a partial rotating body, and is not limited to the one in which the frontal portion and the base portion are configured by a part of a true sphere or a flat bulb as in the above embodiment. For example, the light diffusing cover may have an outer shape that is rotated with the opening (a straight line connecting the start point and the end point) of the U-shaped tongue-like planar figure as the base side (center axis).

  Moreover, the said illuminating device may be equipped with the heat sink laminated | stacked on the back surface side of a metal base material. As this heat sink, for example, a hollow or solid cylindrical body having a bottom surface similar to the planar shape of the metal substrate is used. The material of the heat sink is not particularly limited as long as it has high heat conductivity, but aluminum can be suitably used from the viewpoint of light weight and workability. Furthermore, the heat sink can be manufactured by machining a metal plate or a metal block, but it is preferable to use a metal plate from the viewpoint of cost. Moreover, you may integrate a heat sink and a metal base material.

  As a minimum of the average thickness of a heat sink, 0.3 mm is preferred and 0.5 mm is more preferred. On the other hand, the upper limit of the average thickness of the heat sink is preferably 10 mm, and more preferably 8 mm. When the average thickness of the heat sink is less than the above lower limit, the heat dissipation effect may be insufficient. Conversely, when the average thickness of the heat sink exceeds the upper limit, the weight and volume of the lighting device may be unnecessarily increased.

  Furthermore, in the said embodiment, although the recessed part was provided in the back surface side of the flexible printed wiring board, and it was set as the structure filled with a heat conductive adhesive layer, a recessed part is not an essential component of this invention, but a flexible printed wiring board. You may laminate | stack a normal adhesive bond layer or a heat conductive adhesive bond layer on the whole back surface of a base film.

  Moreover, when providing the said recessed part, you may provide a heat conductive adhesive layer by filling one type of heat conductive adhesive, without dividing a heat conductive adhesive layer into two layers. Further, the base film may be left in a region including the connection edge with the wiring portion in the land portion in plan view. Even if the remaining region is provided in this way, it is possible to suppress a short circuit with the metal base material due to the drop on the back surface side (metal base material side) of the land portion.

  Furthermore, an illumination device including a light source module that does not leave a base film when a recess is provided as shown in FIG. 3E is also within the intended scope of the present invention. In this light source module, at least the front side portion of the recess 10 is formed in a region covering at least the projection region of the opening of the cover lay 2e and the projection region of the light emitting diode 1 provided at positions corresponding to the plurality of land portions 2c. . Further, a cover lay 2e exists between the plurality of land portions 2c in a plan view substantially perpendicular to the surface of the flexible printed wiring board 2. The upper limit and the lower limit of the opening area of the recess 10 in the base film 2a of the light source module of FIG. 3E can be the same as those of the light source module of FIG. 3B.

  Moreover, the flexible printed wiring board 2 may have the through-hole 12 in the projection area | region of the several land part 2c like the light source module of FIG. 3F. The through hole 12 is formed in the projection region of the plurality of land portions 2c and penetrates the conductive pattern 2b and the cover lay 2e of the flexible printed wiring board 2. By filling the through hole 12 with the heat conductive adhesive also on the back side and the upper part thereof, the heat conductive adhesive abuts on the back surface of the light emitting diode 1 to further promote the heat dissipation effect of the light emitting diode 1. can do. Moreover, it can prevent that a heat conductive adhesive leaks out except the recessed part 10 at the time of thermal conductive adhesive filling.

The lower limit of the average area of the through hole 12 is preferably 0.005 mm ^2, 0.01 mm ² is more preferable. In contrast, the upper limit of the average area of the through-hole 12 is preferably 1 mm ^2, 0.5 mm ² is more preferable. When the average area of the through-holes 12 is less than the above lower limit, the effect of preventing the heat conductive adhesive from leaking and the promotion of the heat dissipation effect may be insufficient. Conversely, when the average area of the through holes 12 exceeds the upper limit, the strength of the flexible printed wiring board 2 may be reduced.

  The through-hole 12 can be formed before or after forming the recess 10 or simultaneously with the recess 10. As a method for forming the through hole 12, the same method as the method for forming the front side portion of the recess 10 can be used. A plurality of through holes 12 may be formed in one recess 10.

  In the above embodiment, the concave portion is formed so as to include the projected areas of the plurality of land portions to which one light emitting diode is connected. A recess may be formed so as to straddle between a plurality of light emitting diodes so as to include a projected area of one land portion to which the light emitting diodes are connected.

  Furthermore, in each of the above embodiments, the concave portion is formed in a region including the projected areas of a plurality of land portions, but the concave portion may be formed so as to include a projected area of one land portion. In addition, the formation region of the recess may include a region that does not overlap with the projection region of the light emitting diode and the land portion.

  In addition, the said illuminating device can also be applied to illuminating devices of forms other than an LED bulb.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

[No. 1-7]
In the illuminating device of FIG. 1, the bottom surface of the right-angle frustum portion A is a regular hexagon, the short axis radius (polar radius) r1 and equator radius r2 of the frontal portion of the light diffusing cover, the bottom surface diameter, height of the base portion, The minor axis radius (polar radius) R1 and the equator radius R2, the inclination angle with respect to the bottom surface of the side surface of the right-angle frustum portion A, the distance between the opposing side surfaces at the light emitting diode placement position, and the bottom surface bottom surface of the light emitting diode A model was formed in which the height from each was a value shown in Table 1. The light-emitting diode used for the model of the lighting device has a planar dimension of 1.5 mm wide × 3 mm long and does not have a lens. Each of the plurality of light emitting diodes is disposed at the center of the side surface of the right-angle frustum portion A. Further, in these models, no light emitting diode is arranged on the upper surface of the right-angle frustum portion A. No. 1-5 is an Example and the flat ratio (r2 / r1) of a frontal head outer surface is larger than the flat ratio (R2 / R1) of a base part outer surface. No. 6 and 7 are comparative examples, and the flatness ratio of the outer frontal surface is smaller than the flatness ratio of the outer base surface.

  No. above. For the lighting devices 1 to 7, the luminous intensity distribution was calculated according to the following procedure. First, the center of the bottom surface of the right-angle frustum portion is the origin, and one axis that passes through this origin and is parallel to the bottom surface of the right-angle frustum portion is the reference axis. Next, in the direction in which the angle with respect to the central axis of the right-angled frustum portion is θ (°), the angle is in the range of −90 ° to 90 ° to the left and right around the reference axis when viewed from the central axis direction of the right-angled frustum portion. The average value of luminosity is calculated. FIGS. 6A to 6G show the results of calculating this light intensity average value in the range of θ from 0 ° to 360 °. 6A to 6G, the direction of the back side of the bottom surface of the right-angle frustum portion on the central axis of the right-angle frustum portion (the side opposite to the light emitting surface of the light emitting diode) is θ = 0 °. This luminous intensity is based on the premise that the luminous intensity distribution of one light emitting diode is as shown in FIG. 4 and that the light incident on the light diffusing material has a Lambertian distribution. Using the analysis software “ZEMAX”, The number of rays is 100 million, and is calculated by performing illumination analysis using non-sequential and far fields. Note that light is scattered (reflected) on the bottom surface of the base of the light diffusion cover.

  No. Flatness ratio of outer frontal surface of 1 to 7 (ratio of equator radius r2 to minor axis radius r1, r2 / r1) Flatness ratio of outer surface of base part (ratio of equator radius R2 to minor axis radius R1, R2 / R1) The light distribution angle is shown in Table 1.

  As shown in Table 1 and FIGS. The light distribution angle of 1 to 7 is 200 ° or more, and the light distribution angle is improved while the light distribution angle of the conventional LED bulb is about 120 °. However, the light distribution angle of 300 ° or more can be realized because the center of the light emitting surface of the light emitting diode is located below the equator surface of the light diffusion cover, and the flatness ratio of the outer frontal surface is equal to that of the base outer surface. No. larger than flat ratio 1-5. Furthermore, the inclination angle of the side surface of the right-angled frustum portion is 66 ° or more and 69 ° or less. Nos. 2 to 5 can obtain a light distribution angle of 360 °. Nos. 4 and 5 are particularly excellent in uniformity of luminous intensity. As described above, the illumination device of the present invention can easily obtain a high light distribution type illumination.

  As described above, the lighting device of the present invention has a large light distribution angle while being low in cost, and can effectively suppress variation in luminous intensity.

DESCRIPTION OF SYMBOLS 1 Light emitting diode 1a Solder 2 Flexible printed wiring board 2a Base film 2b Conductive pattern 2c Land part 2d Wiring part 2e Cover lay 2f Insulating layer 2g Adhesive layer 2h Adhesive layer 3 Light source module 4 Metal base material 4a Through-hole 5 Light diffusion cover 5a Frontal head 5b Base 6 Heat sink 7 Connector 10 Recess 11a First thermally conductive adhesive layer 11b Second thermally conductive adhesive layer 12 Through hole P Residual region H Opening

Claims (13)

A light source module having a plurality of light emitting diodes and a substrate on which the plurality of light emitting diodes are mounted;
A metal substrate on which the light source module is placed;
A light diffusion cover attached to the metal base material so as to cover the plurality of light emitting diodes, and having a partially rotating body-shaped light diffusion cover,
The light diffusing cover has a base part on the metal substrate side and a frontal part on the tip side from the equator plane, and a flatness ratio of the frontal head outer surface is 1 or more and a flatness ratio of the basement outer surface or more,
The light source module has a right-angled pyramid or a right-angled pyramid convex portion having a side inclination angle of 55 ° or more and 85 ° or less so that its central axis substantially coincides with the rotation axis of the partial rotating body of the light diffusion cover, The light emitting diodes are disposed substantially evenly only on the side surfaces of the convex portions,
The illuminating device in which the centers of the light emitting surfaces of the plurality of light emitting diodes are substantially coincident with or located below the equator surface of the light diffusion cover.   The outer shape of the forehead and the base is a spheroid, the flat ratio of the outer surface of the forehead is 1 or more and 5 or less, and the flat ratio of the outer surface of the base is 0.4 or more and 1.25 or less. The lighting device according to claim 1.   The illumination device according to claim 1, wherein an outer shape of the base portion is a spherical shape.   The position at which the normal line of the light emitting surface of the light emitting diode intersects the light diffusion cover is within ± 20 ° in latitude relative to the center of the equator plane. Lighting device.   The said board | substrate is a flexible printed wiring board, The said metal base material has the said convex part formed by press molding, die-casting, cold forging, or a cutting process of any one of Claims 1-4. Lighting device. The flexible printed wiring board is laminated on the surface of the base film, a conductive pattern that is laminated on the surface side of the base film, and includes one or a plurality of land portions and a wiring portion that is connected to the land portion. And a coverlay having an opening formed at a position corresponding to the one or more land portions,
Of the back surface of the flexible printed wiring board, having a recess reaching the back surface of the conductive pattern in at least a part of the projected region of one or a plurality of land portions on which the light emitting diode is mounted,
The lighting device according to claim 5, further comprising a heat conductive adhesive filling the recess.   The lighting device according to claim 6, wherein the base film is left in a region including at least a part of a peripheral edge of the one or more land portions in a plan view substantially perpendicular to the surface of the flexible printed wiring board.   The lighting device according to claim 6, wherein the recess is formed in a region covering at least a projection region of the opening of the coverlay. The recess is formed in a region covering at least the projection region of the light emitting diode;
The lighting device according to claim 8, wherein a coverlay exists between the plurality of land portions in a plan view substantially perpendicular to the surface of the flexible printed wiring board.   The flexible printed wiring board has a through-hole for each projection region of the one or more land portions, and the thermally conductive adhesive is also filled in the through-hole and the upper portion thereof, and is in contact with the back surface of the light emitting diode. The lighting device according to claim 8 or 9.   The lighting device according to any one of claims 1 to 10, wherein the metal substrate is formed of aluminum, an aluminum alloy, magnesium, or a magnesium alloy.   The lighting device according to any one of claims 1 to 11, wherein the light diffusing cover has glass, ceramic, or synthetic resin as a main component and a plurality of light diffusing particles.   The illumination device according to any one of claims 1 to 12, which is used as a light bulb.

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