JP2015099640A - LED lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an LED lamp which can emit light equally in all directions, and in which heat dissipation can be improved to prevent a reduction in the quantity of light of an LED chip and a deterioration in the durability life thereof.SOLUTION: The LED lamp includes: an LED module 2 including a base member 6 formed into a hollow triangular frustum shape, a plurality of LED chips 8 directly mounted on the upper and side surfaces of the base member 6, a flexible substrate 9 adhered to the outer surface of the base member 6, in which a wiring pattern 10 formed on the flexible substrate 9 and each of the LED chips 8 are electrically connected to each other by wire bonding; an optical lens 3 covering the circumference of the LED module 2; and a rigid substrate 4 which penetrates the bottom face of the base member 6 of the LED module 2 and a part of which is inserted into the base member 6. A wiring pattern 11 of the rigid substrate 4 and the wiring pattern 10 of the flexible substrate 9 are connected to each other, and the interior of the base member 6 is filled with a heat-conductive resin 5.

Description

  The present invention relates to a wedge-based LED lamp using an LED (light emitting diode) as a light source.

  For example, incandescent bulbs that emit light from filaments have been exclusively used for vehicles, but in recent years, LED lamps that use LEDs with low power consumption, high brightness, and long life as light sources have been used. In particular, for vehicle LED lamps, wedge-based small lamps are frequently used as substitutes for incandescent bulbs, and their installation is commercialized as interchangeable products that can be exchanged with incandescent bulbs.

  By the way, although LED has the said characteristic, since the light radiate | emitted from this has strong directivity, there exists a problem that it cannot illuminate uniformly over a wide area | region.

  Therefore, in Patent Document 1, as shown in the side sectional view of FIG. 8, two substrates 21 are arranged back to back, and a plurality of (two in the illustrated example) LEDs 22 are mounted on each substrate 21. A lamp 20 has been proposed.

  However, the LED lamp 20 has a problem that the irradiation direction of the emitted light from each LED 22 is limited to two directions and the light does not reach in other directions, so that all directions cannot be illuminated uniformly. .

  Therefore, in Patent Document 2, as shown in the longitudinal sectional view of FIG. 9, a substrate 32 is attached to the outer surface of a support body 31 having a polygonal pyramid shape, and a plurality of light emitting modules 33 are mounted on the substrate 32 and supported. There has been proposed a lighting device 30 in which a heat insulating material 34 is filled in a body 31.

  Further, in Patent Document 3, as shown in a longitudinal sectional view of FIG. 10, an LED lamp in which a plurality of LEDs 42 are directly mounted on the upper surface and the peripheral surface of a support portion 41 made of a metal such as aluminum having high thermal conductivity. 40 have been proposed.

  Thus, according to the illumination device 30 and the LED lamp 40 proposed in Patent Documents 2 and 3, since light is irradiated in almost all directions, it is possible to uniformly illuminate all directions.

JP 2009-277479 A JP 2011-134442 A JP 2010-135309 A

However, in the lighting device 30 proposed in Patent Document 2, since the LED module 33 is mounted on the substrate 32, heat generated in the LED module 33 is conducted to the support 31 through the substrate 32. For this reason, the thermal conductivity is poor, and the support 31 is made of a material having low thermal conductivity such as polybutylene terephthalate (PBT) resin, and the support 31 is filled with a heat insulating material 34. Therefore, there is a problem that heat dissipation is poor, the light emitting module 33 can be efficiently cooled and the temperature rise cannot be kept low,
In the LED lamp 40 proposed in Patent Document 3, since the LED 42 is directly mounted on the outer surface of the support portion 41 made of a metal having high thermal conductivity, the heat generated by the LED 42 is transferred to the support portion 41. Although the heat conductivity is good, the inside of the support portion 41 is hollow, and the inside is filled with air with low heat conductivity, so the heat dissipation is poor, the temperature of the LED 42 rises, and the light emission time In addition to the decrease in the light amount with the progress, there is a problem that the durability life of the LED 42 itself is decreased.

  The present invention has been made in view of the above-mentioned problems, and the intended process is to irradiate light uniformly in all directions and to improve heat dissipation to prevent a reduction in the light quantity and durable life of the LED chip. It is to provide an LED lamp that can be used.

In order to achieve the above object, the LED lamp according to claim 1 comprises:
A base member formed into a hollow frustum shape with a metal having high thermal conductivity, a plurality of LED chips mounted directly on the top and side surfaces of the base member, and a flexible substrate bonded to the outer surface of the base member; An LED module formed by electrically connecting a wiring pattern formed on the flexible substrate and each of the LED chips;
An optical lens covering the periphery of the LD module;
A rigid board that penetrates the bottom surface of the base member of the LED module and is partially inserted into the base member;
The wiring pattern formed on the rigid board and the wiring pattern of the flexible board are connected, and the base member is filled with a heat conductive resin.

  According to a second aspect of the present invention, in the first aspect of the present invention, the length of the extended portion of the flexible substrate that extends from the base member and is connected to the rigid substrate is set to the length of the rigid substrate relative to the base member. It is set to the value to position.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, a through hole into which the rigid board is fitted is formed on the bottom surface of the base member.

According to the first aspect of the present invention, light is emitted in all directions from the plurality of LED chips mounted on the upper surface and side surfaces of the hollow frustum-shaped base member, so that light is uniformly irradiated in all directions. be able to. In addition, the LED chip is mounted directly on the upper and side surfaces of the base member made of a metal having high thermal conductivity without interposing a substrate, and the base member is filled with the heat conductive resin, so that the heat generated in each LED chip. Is efficiently conducted to the rigid substrate through the base member and the heat conductive resin, and is efficiently radiated from the rigid substrate to the surroundings. For this reason, each LED chip is efficiently cooled, the temperature rise is suppressed low, and the fall of the light quantity and durable life of each LED chip is prevented. ,
According to the second aspect of the present invention, the rigid substrate can be accurately positioned with respect to the base member by the extension portion of the flexible substrate extending from the base member and connected to the rigid substrate.

  According to the third aspect of the present invention, the rigid substrate can be reliably prevented from rotating with respect to the base member by fitting the rigid substrate into the through hole formed in the bottom surface of the base member.

It is a top view of the LED lamp which concerns on this invention. It is the sectional view on the AA line of FIG. It is a perspective view which shows the state which removed the optical lens of the LED lamp which concerns on this invention. It is an expanded view of the LED module of the LED lamp which concerns on this invention. It is a side view of the LED module of the LED lamp which concerns on this invention. FIG. 6 is an enlarged sectional view taken along line BB in FIG. 5. It is a wiring diagram of the LED chip in the LED lamp which concerns on this invention. It is a sectional side view of the LED lamp proposed in patent document 1. FIG. It is a longitudinal cross-sectional view of the illuminating device proposed in patent document 2. It is a longitudinal cross-sectional view of the LED lamp proposed in patent document 3.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  1 is a plan view of an LED lamp according to the present invention, FIG. 2 is a cross-sectional view taken along line AA of FIG. 1, FIG. 3 is a perspective view showing a state in which the optical lens of the LED lamp is removed, and FIG. 5 is a development view of the LED module, FIG. 5 is a side view of the LED module, FIG. 6 is an enlarged sectional view taken along line BB of FIG. 5, and FIG. 7 is a wiring diagram of the LED chip.

  The LED lamp 1 according to the present invention is a wedge-based small lamp having no base, and as shown in FIGS. 1 and 2, an LED module and an optical lens 3 covering the periphery of the LED module 2, The LED module 2 includes a rigid substrate 4 that penetrates a bottom surface of a base member 6 (described later) and is partially inserted into the base member, and a heat conductive resin 5 (see FIG. 2) inside the base member 6. ).

  The LED module 2 includes a base member 6 formed into a hollow triangular frustum shape by a metal such as copper having high thermal conductivity, and a conductive filler 7 (on the upper surface of the base member 6 and three inclined side surfaces). LED chip 8 directly mounted using each of the LED chip 8 and a flexible substrate 9 bonded to the outer surface of the base member 6. The wiring pattern 10 formed on the flexible substrate 9 and each LED As shown in FIG. 6, the chip 8 is electrically connected by wire bonding. Here, wiring patterns 10 and 11 are respectively formed on the flexible substrate 9 and the rigid substrate 4 by printing copper foil or the like. As shown in FIG. 6, the wiring patterns 10 and LEDs formed on the flexible substrate 9 are formed. By connecting the electrode (P, N) 8a of the chip 8 using the wire 12 (wire bonding), the wiring pattern 10 and the LED chip 8 are electrically connected as described above.

  Here, in the state before the base member 6 is folded and assembled, a copper plate having a thickness of 0.5 mm is punched into the shape shown in FIG. 4, and the punched copper plate is bent so as to be hollow as shown in FIG. Molded into a triangular frustum shape. The copper plate punched here is formed with one small triangular portion 6A that becomes the upper surface of the base member 6 after assembly and three trapezoidal portions 6B that become the side surfaces of the base member 6, and these triangular portions 6A. Apart from the trapezoidal portion 6B, the large triangular portion 6C that becomes the bottom surface of the base member 6 after assembly is formed independently in a state where the small triangular portion 6A and the trapezoidal portion 6B are separated. A plurality of slits 6a are formed at the boundary between the triangular portion 6A and the trapezoidal portion 6B that are continuous with each other so as to be bent at the boundary portion. Further, the rigid substrate 4 is fitted in the center of a large triangular portion (a portion that becomes the bottom surface of the base member 6 after assembly) 6C that is formed independently by separating the triangular portion 6A and the trapezoidal portion 6B. A rectangular through-hole 6b is formed. The triangular portion 6C may be connected via a plurality of slits similarly to the relationship between the triangular portion 6A and the trapezoidal portion 6B.

  Then, as shown in FIG. 4, the wiring pattern 10 is previously formed on the surfaces of the triangular portion 6A and the trapezoidal portion 6B that are continuous with each other of the punched planar copper plate (the surface that becomes the outer surface of the assembled base member 6). The formed flexible substrate 9 is adhered, and each LED chip 8 is directly mounted by the heat conductive filler 7 (see FIG. 6). Thereafter, each LED chip 8 and the wiring pattern 10 of the flexible substrate 9 are electrically connected by wire bonding as described above (see FIG. 6). Thus, when each LED chip 8 and the wiring pattern 1 of the flexible substrate 9 are electrically connected, each two LED chips 8 connected in series are parallel to each other as shown in FIG. A connected electrical circuit is formed. In this case, the electrical connection by wire bonding between each LED chip 8 and the wiring pattern 10 of the flexible substrate 9 is a work on a plane, so that workability is good and high work efficiency is obtained.

  Next, as shown in FIG. 4, a copper plate that is continuous with each other to form a planar shape is bonded to the surface (the portion where the slit 6 a is formed) between the triangular portion 6 </ b> A and the trapezoidal portion 6 </ b> B, and the surface (the flexible substrate 9 is bonded) As shown in FIGS. 3 and 5, the base member 6 having a triangular truncated pyramid shape whose bottom surface is open is obtained. When the triangular part 6C is connected to the trapezoidal part 6B, the process proceeds to the next step without bending the connecting part of the triangular part 6C and the trapezoidal part 6B so that the lower surface is opened. Here, as shown in FIG. 4, a part of the flexible substrate 9 extends to the outside of the base member 6 to form an extension portion 9a, and the extension portion 9a and the rigid substrate 4 are connected. The wiring pattern 10 of the flexible substrate 9 and the wiring pattern 11 of the rigid substrate 4 are electrically connected.

  Then, from this state, as shown in FIG. 2, a heat conductive resin 5 such as polyethylene terephthalate (PET) resin is filled from the lower surface opening of the base member 6 by low pressure sealing, and the lower surface opening of the base member 6 is filled with a copper plate. Is covered with the triangular portion 6C (see FIG. 4), and the heat conductive resin 5 is confined inside the base member 6, a triangular frustum-shaped LED module 2 as shown in FIG. 3 is obtained. When the triangular portion 6C and the trapezoidal portion 6B are connected, after filling the heat conductive resin 5, the triangular portion 6C and the trapezoidal portion 6B are bent to close the bottom surface.

  Thereafter, as shown in FIG. 2, the upper end of the rigid substrate 4 is fitted into a rectangular through hole 6b (see FIG. 4) formed in the bottom surface of the base member 6 and pushed into the base member 6, When the thermally conductive resin 5 is cooled and solidified, the upper end portion inserted into the base member 6 of the rigid substrate 4 is fixed vertically to the base member 6 via the thermally conductive resin 5 (see FIG. 2). ). In this case, if the rigid board 4 is inserted into the base member 6, the extension 9a of the flexible board 9 connected to the rigid board 4 is tensioned as shown in FIG. The length is set to such a length that the rigid substrate 4 is positioned at a predetermined position with respect to the base member 6 in a state where the rigid substrate 4 is tensioned without slack. Therefore, if the rigid substrate 4 is pushed into the base member 6 until the extension 9 a of the flexible substrate 9 is tensioned without slack, the rigid substrate 4 is accurately positioned with respect to the base member 6. In the present embodiment, the rigid substrate 4 is formed in an elongated rectangular plate shape having a thickness of 2 mm, and an end portion extending from the base member 6 is connected to a 12V power source via a socket (not shown). Has been.

  In the LED module 2 configured as described above, the LED chips 8 are respectively disposed on the upper surface and the three side surfaces of the base member 6 having a triangular frustum shape. As shown in FIGS. 2 is covered with the hemispherical optical lens 3. As shown in FIG. 2, the light emitted from the LED chip 8 mounted on the upper surface of the base member 6 is spread on the top surface of the inner surface of the optical lens 3 and irradiated forward (upward in FIG. 2). A concave spherical surface 3a is formed, and a concave lens is formed on the top of the optical lens 3 by the concave spherical surface 3a. In addition, the light emitted from each LED chip 8 is spread on the side facing the LED chip 8 mounted on the side surface of the base member 6 on the inner surface of the optical lens 3 and directed to the side (angle range of 120 °). A concave spherical surface 3b for irradiating is formed, and a concave lens is formed on the side of the optical lens 3 by the concave spherical surface 3b. A reflection film 3c for reflecting the light returning to the LED chip 8 side by internal reflection and irradiating it forward is formed at the boundary between the concave spherical surface 3a and the concave spherical surface 3b on the inner surface of the optical lens 3. It is formed by white painting or two-color molding. In FIG. 1, one circle c <b> 1 and three ellipses c <b> 2 indicated by broken lines are lines indicating the shapes of the concave spherical surfaces 3 a and 3 b in accordance with the diffusion angles of the LED chips 8 of the optical lens 3.

  Thus, in the LED lamp 1 configured as described above, when a current is supplied to the LED lamp 1 from a power source (not shown), the wiring pattern 11 of the rigid board 4 passes through the wiring pattern 10 of the flexible board 9. Current is supplied to a total of four LED chips 8, and each LED chip 8 is driven to emit light. In this case, light traveling forward (upward in FIG. 2) from the LED chip 8 mounted on the upper surface of the triangular pyramidal base member 6 passes through a concave lens constituted by the concave spherical surface 3 a of the optical lens 3. Light that is emitted while being diffused and directed laterally from the LED chip 8 mounted on each of the three inclined side surfaces of the base member 6 is diffused by passing through a concave lens constituted by the concave curved surface 3 b of the optical lens 3. However, a part of the light that exits from the surrounding 120 ° angle range and returns to the LED chip 8 side by internal reflection is reflected by the reflective film 3c formed on the inner surface of the optical lens 3 and forwards. Exit.

  Therefore, in the LED lamp 1 according to the present invention, light is directed from all four LED chips 8 mounted on the top and side surfaces of the hollow triangular frustum-shaped base member 6 in all directions including the upper side and the side. Therefore, light can be irradiated uniformly in all directions, and light distribution characteristics equivalent to those of conventional incandescent bulbs can be obtained.

  Further, in the LED lamp 1 according to the present invention, the LED chip 8 is directly mounted on the upper and side surfaces of the triangular pyramidal base member 6 made of a metal having high heat conductivity without using a substrate, and the base member 6 is also mounted. Since the heat conductive resin 5 is filled inside, the heat generated in each LED chip 8 is efficiently conducted to the rigid substrate 4 through the base member 6 and the heat conductive resin 5, and is efficiently radiated from the rigid substrate 4 to the surroundings. The For this reason, each LED chip 8 is cooled efficiently, the temperature rise is suppressed low, and the fall of the light quantity and durable life of each LED chip 8 is prevented. As a result, even if the LED lamp 1 is small and has a small volume, high heat dissipation is ensured, and a large amount of light can be obtained by increasing the current supplied to each LED chip 8.

  Furthermore, in the LED lamp 1 according to the present invention, the length of the extension 9 a of the flexible substrate 9 that extends from the base member 6 and is connected to the rigid substrate 4 is positioned with respect to the base member 6. Since the extension portion 9a is not loosened and the extension portion 9a is in a tensioned state, the rigid substrate 4 is inserted into the base member 6 so that the rigid substrate 4 is moved relative to the base member 6. Can be positioned accurately.

  Further, according to the LED lamp 1 according to the present invention, the rigid substrate 4 is fitted into the through hole 6b formed in the bottom surface of the base member 6 so that the rigid substrate 4 is inserted into the base member 6. The rigid substrate 4 can be reliably prevented from rotating with respect to the base member 6.

  In the above embodiment, the base member 6 is formed in a hollow triangular frustum shape. However, a base member having a polygonal frustum shape or a truncated cone shape that is not less than a square frustum shape may be used. Further, in the above embodiment, the method of fixing the rigid substrate 4 to the base member 6 with the heat conductive resin 5 is adopted, but the rigid substrate 4 is fixed to the base member 6 by a metal stack and screwing or the like. You may adopt the method to do. Furthermore, the electrical conduction between the LED chip 8 and the flexible substrate 9 is not limited to wire bonding, and connection means such as application of a conductive paste may be used.

DESCRIPTION OF SYMBOLS 1 LED lamp 2 LED module 3 Optical lens 3a, 3b Concave spherical surface of optical lens 3c Reflective film of optical lens 4 Rigid substrate 5 Thermal conductive resin 6 Base member 6A, 6C Triangular part of base member 6B Trapezoid part 6a of base member Member slit 6b Base member through hole 7 Conductive filler 8 LED chip 8a LED chip electrode 9 Flexible substrate 9a Flexible substrate extension 10, 11 Wiring pattern 12 Wire

Claims (3)

A base member formed into a hollow frustum shape with a metal having high thermal conductivity, a plurality of LED chips mounted directly on the top and side surfaces of the base member, and a flexible substrate bonded to the outer surface of the base member; An LED module formed by electrically connecting a wiring pattern formed on the flexible substrate and each of the LED chips;
An optical lens covering the periphery of the LD module;
A rigid board that penetrates the bottom surface of the base member of the LED module and is partially inserted into the base member;
The LED lamp is characterized in that a wiring pattern formed on the rigid board and a wiring pattern on the flexible board are connected, and the inside of the base member is filled with a heat conductive resin.   The length of the extension part of the flexible substrate extending from the base member and connected to the rigid substrate is set to a value for positioning the rigid substrate with respect to the base member. LED lamp. The LED lamp according to claim 1, wherein a through hole into which the rigid board is fitted is formed on a bottom surface of the base member.

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