JP2013038020A - Fluorescent lamp type led lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorescent lamp type LED lamp capable of improving heat dissipating efficiency of an LED chip.SOLUTION: When each LED chip 7C of a plurality of LED packages 7 mounted on a package board 5 is lighted up, heat generated by that lighting-up is efficiently transmitted and dissipated to a heat dissipation cover member 4 through a thermal via 5A of the package board 5 from each LED package 7. As a result, high temperature of each LED chip 7C is suppressed and the lifetime is prolonged.

Description

  The present invention relates to an LED lamp using a plurality of LEDs (light emitting diodes) as a light source, and more particularly to a straight tube type or an annular fluorescent lamp type LED lamp.

  2. Description of the Related Art As an LED lamp using an LED chip as a light source, a fluorescent lamp type LED lamp having both ends of a base that is detachably attached to a socket on an appliance side is generally known (see, for example, Patent Document 1). Further, as this type of fluorescent lamp type LED illumination lamp, one having a sectional structure as shown in FIG. 8 is generally known.

  Here, Patent Document 1 discloses a transparent cylindrical pipe (2), a support plate (3) provided inside the pipe (2), and both ends of the support plate (3). A terminal (4) fitted in the socket part (14) of (11), an AC / DC converter (7) provided on the upper surface of the support plate (3) connected to the terminal (4), and And a fluorescent lamp type LED lighting device including a voltage control unit (8) for adjusting a voltage supplied to each of the plurality of LEDs (9) provided on the bottom surface of the support plate (3). .

  On the other hand, the conventional fluorescent lamp type LED lamp shown in FIG. 8 includes an LED package B having an LED chip A, a package substrate C on which the LED package B is mounted on one surface, and the other surface of the package substrate C. The heat sink D is stacked, the heat sink E has a semicircular cross section that covers the side of the heat sink D while sandwiching both side edges of the heat sink D, and the semicircular cross section that covers the LED package B side. The light transmitting cover F is connected to both side edges of the heat dissipation cover E.

JP 2001-351402 A

  By the way, since the fluorescent lamp type LED lamp described in Patent Document 1 does not include means for dissipating heat generated by lighting of the plurality of LEDs (9), each LED (9) is heated to a high temperature. There is a great risk of shortening the service life.

  On the other hand, the conventional fluorescent lamp type LED lamp shown in FIG. 8 includes a heat radiating plate D and a heat radiating cover E for radiating heat generated by the lighting of the LED chip A, but the LED package B having the LED chip A is The heat sink D is mounted on one surface of the package substrate C, and the heat sink D is overlaid on the other surface of the package substrate C. For this reason, heat dissipation from the LED chip A to the heat sink D is performed through the LED package B and the package substrate C, and the heat dissipation efficiency is as low as about 25%, for example.

  The present invention has been made in response to such problems of the prior art, and an object thereof is to provide a fluorescent lamp type LED lamp capable of improving the heat dissipation efficiency of the LED chip.

  In order to solve such problems, the fluorescent lamp type LED lamp according to the present invention is a straight tube type or annular type fluorescent lamp type LED lamp having a base at both ends, and has a tubular shape to which the base is mounted. A translucent cover having a slit-like opening in a part of its peripheral surface, a heat-dissipating cover member attached to the slit-like opening of the translucent cover, a package substrate joined to the inner surface of the heat-dissipating cover member, And a plurality of LED packages mounted on the package substrate, wherein the package substrate is provided with thermal vias that transfer heat generated by the LED packages to the heat dissipation cover member.

  In the fluorescent lamp type LED lamp according to the present invention, when each LED chip of the plurality of LED packages mounted on the package substrate is lit, heat generated by the lighting is transferred from the LED package to the heat dissipation cover member via the thermal via of the package substrate. The heat is efficiently transferred and dissipated.

  In the fluorescent lamp type LED lamp of the present invention, the thermal via provided in the package substrate may be a through via not filled with a heat transfer material, but if it is a blind via filled with a heat transfer material, the heat dissipation efficiency is improved. Since it improves further, it is preferable.

  In the fluorescent lamp type LED lamp according to the present invention, when each LED chip of the plurality of LED packages mounted on the package substrate is lit, heat generated by the lighting is transferred from the LED package to the heat dissipation cover member via the thermal via of the package substrate. The heat is efficiently transferred and dissipated. Therefore, according to the present invention, the heat dissipation efficiency of each LED chip can be improved.

It is a perspective view of the fluorescent lamp type LED lamp which concerns on one Embodiment of this invention. It is a typical cross-sectional view orthogonal to the longitudinal direction of the fluorescent lamp type LED lamp shown in FIG. It is a typical longitudinal cross-sectional view along the longitudinal direction of the fluorescent lamp type LED lamp shown in FIG. It is an expanded sectional view of the package substrate shown in FIG. It is a cross-sectional view corresponding to FIG. 2 which shows typically the 1st modification of the fluorescent lamp type LED lamp which concerns on one Embodiment. It is a cross-sectional view corresponding to FIG. 2 which shows typically the 2nd modification of the fluorescent lamp type LED lamp which concerns on one Embodiment. It is a top view of the fluorescent lamp type LED lamp which concerns on other embodiment of this invention. It is a typical cross-sectional view corresponding to FIG. 2 which shows a prior art example.

  Embodiments of a fluorescent LED lamp according to the present invention will be described below with reference to the accompanying drawings. As shown in FIG. 1, the fluorescent lamp type LED lamp of one embodiment is a straight tube type fluorescent lamp type LED illuminating lamp having a standard length in a range of 600 to 2400 mm. A base 2, 2 having two terminals 1, 1 that can be connected to a fluorescent lamp socket (not shown) is provided.

  The caps 2 and 2 are attached to both ends of a straight tubular translucent cover 3 having a slit-like opening on a part of its peripheral surface. A groove-type heat radiation cover member 4 extending along the longitudinal direction of the cover 3 is mounted.

  The translucent cover 3 is formed by mixing an appropriate light diffusing agent in a transparent resin such as polycarbonate (PC) or acrylic resin, and exhibits a so-called ground glass-like appearance. The translucent cover 3 may have a transparent appearance in which a light diffusing agent is not mixed, or may have a translucent appearance such as milky white, or may be made of frosted glass, milky white, or transparent glass. There may be.

  As shown in FIG. 2, a lenticular lens 3 </ b> A is formed on the inner surface of the translucent cover 3 to diffuse the lighting light of the LED package 7 described later in the circumferential direction of the translucent cover 3. The translucent cover 3 has a diameter of, for example, 32 mm and a maximum thickness of, for example, about 0.8 to 1.0 mm. Then, on the slit-like opening edge of the translucent cover 3, engagement convex portions 3B and 3B having a substantially circular cross section for mounting the groove-shaped heat radiation cover member 4 are formed so as to face each other. Yes.

  The heat radiating cover member 4 is formed into a groove-shaped cross-sectional shape by extrusion molding of an aluminum alloy, and an engagement protrusion formed at a slit-like opening edge of the translucent cover 3 is formed at an end of the opening. Clamping parts 4A and 4A for detachably sandwiching the parts 3B and 3B are formed.

  The radiating cover member 4 is detachably attached to the slit-like opening of the translucent cover 3 by engaging the sandwiching portions 4A and 4A with the engaging convex portions 3B and 3B of the translucent cover 3, In this mounted state, the heat radiating cover member 4 protrudes inside the translucent cover 3.

  As shown in FIG. 3, a long plate-like package substrate extending along the longitudinal direction of the heat dissipation cover member 4 is provided on the inner surface of the heat dissipation cover member 4 protruding inside the translucent cover 3, that is, on the flat protruding top surface 4 </ b> B. 5 is fixed by a plurality of set screws 6 as fastening means. A plurality of LED packages 7 are mounted on the package substrate 5 at predetermined intervals along the longitudinal direction.

  As shown in FIG. 4 in an enlarged manner, the LED package 7 has an LED chip 7C disposed at the bottom of the reflector recess 7B of the cavity base 7A with a thickness of about 0.15 to 0.20 mm via wires 7D and 7D. The LED chip 7C has a structure connected to the lead frames 7E and 7E, and is encapsulated by an encapsulating resin 7F filled in the reflector recess 7B.

  The LED chip 7C emits blue light to cause the LED package 7 to emit white light, for example. The encapsulating resin 7F is made of an epoxy resin or a silicon resin. In the encapsulating resin 7F, a phosphor that emits the complementary yellow light by the blue light of the LED chip 7C is dispersed.

  Such an LED package 7 is arranged such that the base end surface opposite to the light projecting direction of the LED chip 7 </ b> C directed downward in FIG. 2 faces the protruding top surface 4 </ b> B that is the inner surface of the heat dissipation cover member 4. The position where the LED package 7 is disposed is a position that is closer to the slit-shaped opening from the center of the cross section of the translucent cover 3.

  Here, as shown in an enlarged view in FIG. 4, the upper surface of the package substrate 5 is joined in close contact with the projecting top surface 4 </ b> B of the heat dissipation cover member 4 via the adhesive layer 8, and the lower surface of the package substrate 5 is the same. The base end surfaces of the LED packages 7 are bonded in close contact via the adhesive layer 8. The adhesive layer 8 may be a thin adhesive sheet having a thickness of about 0.20 mm.

  In such a package substrate 5, a plurality of thermal vias 5 </ b> A for transferring heat generated from each LED package 7 to the heat radiating cover member 4 are provided to face the base end face of each LED package 7. The thermal via 5A may be a through via in which a copper plating layer 5B is formed in the shape of a pigeon on the wall surface of a hole penetrating the package substrate 5, but in the illustrated example, the inside of the copper plating layer 5B in the shape of a pigeon The blind via is filled with a heat transfer material 5C such as copper (Cu).

  In the fluorescent lamp type LED lamp of one embodiment, the power source unit 9 connected to each terminal 1 and 1 of the base plate 2 and 2 shown in FIG. It is arranged in the inside.

  In the fluorescent lamp type LED lamp configured as described above, a lighting switch (not shown) is turned on in a state where the terminals 1 and 1 of the caps 2 and 2 at both ends are connected to the existing fluorescent lamp socket. Then, as shown in FIG. 3, each LED chip 7 </ b> C of the plurality of LED packages 7 arranged along the longitudinal direction of the package substrate 5 is turned on, and the white light is emitted through the translucent cover 3. .

  Here, since each LED package 7 is disposed at a position near the slit-shaped opening from the center of the cross section of the translucent cover 3, the lighting light of each LED chip 7 </ b> C is below the translucent cover 3. Irradiated from a wide area of the half.

  At that time, the LED chips 7C of the plurality of LED packages 7 generate heat when they are turned on, and the heat generation is performed by the plurality of thermal vias 5A of the package substrate 5 provided at a portion facing the base end surface of each LED package 7. The heat is efficiently transferred to the heat radiating cover member 4 through the heat and radiated. The heat radiation efficiency reaches about 30% or more compared to about 25% in the conventional fluorescent LED lamp having the cross-sectional structure shown in FIG. As a result, the temperature of each LED chip 7C can be maintained at about 60 ° C.

  Therefore, according to the fluorescent lamp type LED lamp of one embodiment, it is possible to improve the heat dissipation efficiency of each LED chip 7C of the plurality of LED packages 7 and to achieve the long life thereof. In addition, the lighting light of each LED chip 7C of each LED package 7 can be diffused in the circumferential direction of the translucent cover 3 and irradiated over a wide range by the lenticular lens 3A of the translucent cover 3.

  The fluorescent LED lamp of the present invention is not limited to the above-described embodiment. For example, the heat dissipation cover member 4 may be an extruded product of a copper alloy or a press-formed product of a stainless plate. In addition, each LED package 7 that emits white light may have a configuration in which three LED chips that emit light of three primary colors of red (R), green (G), and blue (B) are incorporated.

  Moreover, the cross-sectional shape of the thermal radiation cover member 4 shown in FIG. 2 can be changed into the vertical cross-sectional shape shown in FIG. The heat radiating cover member 4 is formed in a shallow groove shape in which sandwiching portions 4A, 4A are continuous on both sides of the bottom portion 4B, and left and right side wall portions 4C, 4C rise from the sandwiching portions 4A, 4A. Each LED package 7 is installed, and partition walls 4D and 4D having substantially the same height as the left and right side wall portions 4C and 4C are integrally formed on the outer surface of the bottom portion 4B.

  In the first modification shown in FIG. 5, each LED package 7 installed on the inner surface of the bottom portion 4B of the heat dissipation cover member 4 is located in the vicinity of the slit-like opening of the translucent cover 3, and thus each LED chip 7C In the circumferential direction of the translucent cover 3, the irradiation range of the lighting light is expanded to the range indicated by α in FIG.

  Moreover, the cross-sectional shape of the heat radiation cover member 4 shown in FIG. 5 in the fluorescent lamp type LED lamp of the first modification can be changed to the cross-sectional shape shown in FIG. The heat radiating cover member 4 is formed in a reverse groove shape in which a bottom portion 4B is located radially outward from the slit-like opening of the translucent cover 3, and each LED package 7 is installed on the inner surface of the bottom portion 4B. A plurality of radiating fins 4E and 4E are integrally formed on the outer surface of the bottom portion 4B.

  In the second modification shown in FIG. 6, each LED package 7 installed on the inner surface of the bottom portion 4 </ b> B of the heat dissipation cover member 4 is located radially outward from the slit-like opening of the translucent cover 3. The illumination range of each LED chip 7 </ b> C greatly expands to the range indicated by β in FIG. 6 in the circumferential direction of the translucent cover 3.

  In the second modification shown in FIGS. 5 and 6, the lenticular lens 3A formed on the inner surface of the translucent cover 3 is not essential and may be omitted.

  Here, the fluorescent lamp type LED lamp of the present invention can be configured as an annular fluorescent lamp type LED lamp as shown in FIG. This circular fluorescent LED lamp has an annular light-transmitting cover 23 having both ends continuous via a single base 22 having four terminals 21, 21..., And a periphery of the light-transmitting cover 23. And a heat dissipating cover member 24 having an annular shape in plan view, which is attached to a slit-like opening formed in a part of the surface, and the cross-sectional structure thereof is shown in FIG. 2, FIG. 5 and FIG. Various cross-sectional structures can be used.

1: Terminal 2: Base 3: Translucent cover 4: Radiation cover member 5: Package substrate 6: Set screw 7: LED package 7A: Cavity base 7B: Reflector recess 7C: LED chip 7D: Wire 7E: Lead frame 7F: Encapsulation Resin 8: Adhesive layer 9: Power supply unit

Claims (3)

A straight tube type or an annular type fluorescent lamp type LED lamp having a base at both ends,
Presenting a tubular shape to which the base is mounted, a translucent cover having a slit-like opening on a part of its peripheral surface;
A heat dissipating cover member attached to the slit-like opening of the translucent cover;
A package substrate joined to the inner surface of the heat dissipation cover member;
A plurality of LED packages mounted on the package substrate,
The fluorescent lamp type LED lamp, wherein the package substrate is provided with a thermal via for transferring heat generated by the LED packages to the heat radiating cover member.   The fluorescent lamp type LED lamp according to claim 1, wherein the thermal via is a blind via filled with a heat transfer material.   The fluorescent lamp type LED lamp according to claim 2, wherein the heat transfer material is copper oxide that emits far infrared rays.