JP2007158242A - Led light source device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an LED light source device having good heat radiation performance of heat generated in the LED itself, and capable of ensuring a conduction path for positively guiding an introduced applied voltage to an electrode of the LED. <P>SOLUTION: An LED mounting substrate 7 having an LED 6 mounted thereon is provided on a concave portion internal bottom surface 4 of a heat radiator 3 provided with a concave portion 2 having an opening 1 via an adhesive 5 having excellent thermal conductivity. A power feeding pattern 12 electrically conducting to both surfaces via a through hole 20 is formed on a top surface 11 of the heat radiator 3, and a power feeding circuit board 14 consisting of a double-sided through hole substrate having a through hole window 13 is fixed. In this way, conductors 16 are each sandwiched by power feeding pads 15 forming one part of the power feeding pattern 12 formed on the surface of the LED mounting substrate 7 side of the power feeding circuit board 14 and a conductor pattern 8 of the LED mounting substrate 7 to support the conductors 16 in a state of applying a compression force, and the power feeding pads 15 can electrically conduct with the conductor pattern 8 via the conductors 16. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an LED light source device, and more particularly, to an LED light source device that uses an LED in which an LED chip is sealed with a translucent resin containing a phosphor as a light source.

  Conventionally, LEDs have been employed as illumination or display light sources, information transmission media, sensor detection media, and the like. Among them, various methods have been proposed for increasing the brightness of LEDs used as light sources.

  For example, driving a LED with a large current is one method for achieving high brightness. However, in this case, since the light emission efficiency is lowered due to the temperature rise due to the self-heating of the LED, it is not always possible to ensure the brightness increase rate proportional to the current increase rate. Therefore, in this method, how to suppress the temperature rise due to the self-heating of the LED is an important decisive factor for realizing high brightness.

  In view of this, a light source unit has been proposed that is configured to promote heat dissipation of self-heating when driving a semiconductor light emitting device including an LED with a large current to suppress a temperature rise and to achieve high luminance by the large current driving. As shown in FIG. 3, it emits blue light on the upper end surface of a heat dissipating block 52 provided with a conductive sleeve 51 with an insulating film 50 sandwiched outside via a submount element 53 made of a Zener diode for electrostatic protection. The semiconductor light emitting element 54 is mounted, and the other end of the bonding wire 55 that connects one end to the submount element 53 is connected to the conductive sleeve 51. Thus, the heat dissipation block 52 is electrically connected to the p-side electrode of the semiconductor light emitting element 54 to become an anode electrode, and the conductive sleeve 51 is electrically connected to the n-side electrode of the semiconductor light emitting element 54 to become a cathode electrode. ing. Then, the semiconductor light emitting element 54 including the upper end portion of the heat dissipation block 52, the bonding wire 55, and the submount element 53 are sealed with a resin package 56 mixed with a fluorescent material, thereby reducing the light emission efficiency due to self-heating of the semiconductor light emitting element. A light source unit that emits white light and suppresses the above is realized. (For example, refer to Patent Document 1).

  In the case of the light source unit having such a configuration, since the heat radiation block 52 is disposed below the semiconductor light emitting element 54, self-heating when the semiconductor light emitting element 54 is turned on is externally (in the atmosphere) via the heat radiation block 52. Although there is a submount element 53 formed of a Zener diode having a high thermal resistance between the semiconductor light emitting element 54 and the heat dissipation block 52, there is a gap between the semiconductor light emitting element 54 and the heat dissipation block 52. It is difficult to ensure good thermal conductivity, and it is difficult to significantly suppress the temperature rise of the semiconductor light emitting element 54.

  In order to solve such a problem, an LED light source device having a configuration as shown in FIGS. 4 and 5 has been devised. 4 is a plan view, and FIG. 5 is a cross-sectional view taken along the line AA in FIG. It is provided with a power supply circuit board 63 having a power supply pattern 62 formed on the surface thereof on a radiator 60 via a heat conductive sheet 61 having excellent heat conductivity. On the power supply circuit board 63, an LED mounting board 65 on which an LED 64 in which an LED chip is sealed with a translucent resin containing a phosphor is mounted is disposed via a heat conductive adhesive 66. In addition, an external power supply lead 67 from one side surface side, an external power supply connector 69 that extends a contact terminal 68 from the other side surface facing each other, and a plate that penetrates between both side surfaces and extends in both directions. Two LED connection connectors 72 having spring-like contact terminals 70 and 71 are provided.

  Each of the pair of conductor patterns 73 formed on the LED mounting board 65 and electrically connected to the pair of electrodes of the LED 64 is formed on the power supply circuit board 63 via the contact terminals 70 and 71 of the LED connection connector 72. Connected to the feeding pattern 62. The power feeding pattern 62 is connected to the contact terminal 68 of the external power feeding connector 69 and is electrically connected to the external power feeding lead 67.

  When a voltage is applied to both ends of the external power feed lead 67, power is supplied to the LED electrode from the external power feed connector 69 through the power feed pattern 62, the LED connection connector 72, and the conductor pattern 73 of the LED mounting board 65 in sequence, and the LED 64 is lit.

  Also, an LED light source device having a configuration as shown in FIGS. 6 and 7 has been devised. 6 is a plan view, and FIG. 7 is a cross-sectional view taken along the line AA of FIG. It is provided with a power supply circuit board 83 having a power supply pattern 82 formed on the surface thereof on a radiator 80 via a heat conductive sheet 81 having excellent heat conductivity. On the power supply circuit board 83, an LED mounting board 85 composed of a double-sided through-hole board on which an LED 84 in which an LED chip is resin-sealed with a translucent resin containing a phosphor is placed is a through-hole of the LED mounting board 85. A power supply pad 87 provided via a hole 86 and a power supply pattern 82 of the power supply circuit board 83 are disposed by solder 88 bonding, and an external power supply lead 89 is connected from one side to the other side. External power supply connectors 91 each having contact terminals 90 extending from the side are disposed.

  Each of the pair of conductor patterns 92 formed on the LED mounting substrate 85 and electrically connected to the pair of electrodes of the LED 84 is connected to the power supply pattern 82 formed on the power supply circuit substrate 83 through the solder 88 joint. It is connected. The power supply pattern 82 is connected to the contact terminal 90 of the external power supply connector 91 and is electrically connected to the external power supply lead 89.

When a voltage is applied to both ends of the external power supply lead 89, power is supplied from the external power supply connector 91 to the LED electrode through the power supply pattern 82, the solder 88, the power supply pad 87 of the LED mounting board 85, the through hole 86, and the conductor pattern 92. LED84 lights up.
JP 2003-78174 A

  By the way, in the LED light source device having the configuration shown in FIGS. 4 and 5, the contact terminal 70 to be overhead is twisted and warped due to external stress, vibration, and impact, and is lifted at the contact portion and is in a non-contact state. Occurrence may result in an electrically open state, and the LED 64 may become unlit.

  Further, the LED light source device having the configuration shown in FIGS. 6 and 7 uses, for example, a ceramic substrate for the LED mounting substrate 85 and an aluminum substrate for the power supply circuit substrate 83. When the coefficients of thermal expansion are different, the LED mounting board 85 soldered to the power supply circuit board 83 is damaged due to self-heating when the LEDs are turned on or the ambient environment temperature to which the LED light source device is exposed. It may become unlit.

  Accordingly, the present invention was devised in view of the above problems, and the object of the present invention is that the heat dissipation of the LED self-heating is good and the introduced applied voltage is reliably guided to the LED electrode. It is providing the LED light source device which ensured the electric circuit.

  In order to solve the above-mentioned problem, an invention described in claim 1 of the present invention is an LED mounting in which an LED including an LED chip and a sealing resin for sealing the LED chip is mounted. A substrate is mounted on a heat sink via a thermally conductive adhesive, and the LED mounting substrate is electrically connected to the LED electrode, and the LED mounting substrate is connected to an external power source to supply power to the LED mounting substrate. A power supply pad that constitutes a part of the power supply pattern of the power supply circuit board on which the power supply pattern is formed, and supports the conductor pattern and the power supply pad with a compressive force sandwiched between conductors It is electrically connected through the conductor.

  Further, the invention described in claim 2 of the present invention is that in claim 1, the radiator is provided with a recess having an opening, and the LED mounting substrate is provided on the bottom surface of the recess with the thermally conductive adhesive. The feeder circuit board is mounted on the radiator and provided with a through window smaller than the opening.

  The invention described in claim 3 of the present invention is characterized in that, in claim 2, the feeder circuit board is screwed and fixed to the radiator.

  Moreover, the invention described in claim 4 of the present invention is characterized in that, in any one of claims 1 to 3, the sealing resin is made of a translucent resin containing at least one kind of phosphor. It is what.

  The LED light source device of the present invention uses an LED in which an LED chip is sealed with a translucent resin containing a phosphor as a light source, and a conductor pattern in which the LED is mounted and electrically connected to an electrode of the LED is provided. The formed LED mounting board is placed on a radiator via a heat conductive adhesive, and the power supply circuit board on which the power supply pattern for supplying power to the LED mounting board is connected to the conductor pattern and an external power source is formed. And a power supply pad constituting a part of the power supply pattern, and a conductor is interposed between the power supply pad and a compressive force is applied, and the conductor pattern and the power supply pad are electrically connected via the conductor. I did it.

  As a result, a Zener diode, a power feeding substrate, a heat conductive sheet, and the like are not required as in the conventional LED light emitting device. Therefore, the thermal resistance from the LED to the radiator is reduced, and the heat generated when the LED is turned on can be dissipated well to the outside. Therefore, the luminous efficiency of the LED chip due to the self-heating of the LED and the phosphor Reduction in wavelength conversion efficiency can be suppressed, and high luminance of the LED light source device can be ensured.

  Further, unlike conventional LED light-emitting devices, no attempt has been made to contact the LED mounting substrate and the power supply circuit substrate using contact terminals or a soldering method. For this reason, contact terminals that are wired overhead are twisted and warped due to external stress, vibration, and shock, and are lifted at the contact portion to generate a non-contact state, resulting in an electrically open state, and the LED is not lit. Such a problem does not occur. Even if each of the LED mounting board and the power supply circuit board is made of a member having a different thermal expansion coefficient, the LED mounting board is damaged due to self-heating when the LED is turned on or an ambient temperature to which the LED light source device is exposed. Therefore, a highly reliable LED light source device can be realized.

  Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIG. 1 and FIG. 2 (the same parts are denoted by the same reference numerals). The embodiments described below are preferable specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention particularly limits the present invention in the following description. Unless stated to the effect, the present invention is not limited to these embodiments.

  FIG. 1 is a plan view of an embodiment of the LED light source device of the present invention, and FIG. 2 is a cross-sectional view taken along line AA of FIG. An LED mounting substrate 7 on which an LED 6 is mounted via an adhesive 5 having a good thermal conductivity is placed on the bottom surface 4 in the recess of the radiator 3 provided with the recess 2 having the opening 1.

  The LED 6 includes an LED chip that serves as a light emitting source, and a translucent sealing resin that contains a phosphor that is a wavelength conversion member that covers the LED chip so as to cover the LED chip. In this case, the LED 6 emits light having a color tone different from that of the light emitted from the light emitting source (LED chip).

  For example, when the light emitted from the LED chip is blue light, a part of the blue light emitted from the LED chip is obtained by using a phosphor that converts the wavelength to yellow light that is excited by the blue light and becomes a complementary color of blue. Can produce white light by additive color mixing of yellow light wavelength-converted by exciting the phosphor and part of blue light emitted from the LED chip.

  Similarly, when the light emitted from the LED chip is blue light, it is emitted from the LED chip by using a mixture of two types of phosphors that are excited by the blue light and respectively convert the wavelength into green light and red light. It is also possible to produce white light by additive color mixture of green light and red light that have been wavelength-converted by exciting a phosphor with a part of the blue light and a part of the blue light emitted from the LED chip.

  In addition, when the light emitted from the LED chip is ultraviolet light, the LED chip is obtained by using a mixture of three kinds of phosphors that are excited by the ultraviolet light and respectively convert the wavelength into blue light, green light, and red light. It is also possible to produce white light by additive color mixture of blue light, green light and red light whose wavelengths are converted by exciting the phosphor with the ultraviolet light emitted from the light.

  Furthermore, light of various color tones other than white light can be created by appropriately combining the wavelength of light emitted from the LED chip and the type of phosphor.

  By the way, the LED chip and the phosphor have characteristics in which the light emission efficiency and the wavelength conversion efficiency are greatly reduced as the temperature rises. In order to ensure the high brightness of the LED light source device, the LED chip is turned on. It is an important requirement to reduce the influence of self-heating of as much as possible.

  The LED mounting substrate 7 is formed with a pair of conductor patterns 8 separated from each other on the surface opposite to the surface fixed to the inner bottom surface 4 of the concave portion of the radiator 3 via the adhesive 5. The LED 6 is mounted in a state where the pair of electrodes 9 of the LED 6 and the conductor pattern 8 are joined by a joining member 10 such as solder.

  On the upper surface 11 of the radiator 3, a power supply pattern 12 that is electrically connected to each other through a through hole 20 is formed on both surfaces, and a power supply circuit board 14 that is a double-sided through-hole substrate having a through window 13 is screwed. Has been.

  The through window 13 of the feeder circuit board 14 is located on the recess 2 opening 1 of the radiator 3 and is smaller than the recess 2 opening 1, and the ratio at which the light emitted from the LED 6 provided in the recess 2 becomes irradiation light. The size is set so as not to lower the image.

  The power supply pad 15 constituting part of the power supply pattern 12 formed on the surface of the power supply circuit board 14 on the LED mounting board 7 side and the conductor pattern 8 of the LED mounting board 7 are made of metal such as solder or gold, or conductive elastomer. Are electrically connected with a conductor 16 made of an elastic conductive member or the like interposed therebetween. That is, the conductor 16 is in compression contact with the sandwiched power supply pad 15 and the conductor pattern 8 by fixing the power supply circuit board 14 to the radiator 3 with screws.

  Further, a surface of the power supply circuit board 14 opposite to the surface in contact with the radiator 3 is electrically connected to a pair of contact terminals 17 extending from one facing surface and each of the contact terminals 17. An external external power supply connector 19 in which a pair of external power supply leads 18 for introducing an externally applied voltage is extended from the other surface side is disposed.

  The contact terminal 17 is made of a leaf spring-like elastic member, and the tip portion is abutted and supported by the power feeding pattern 12 so as to achieve electrical connection therebetween. Note that the contact terminal 17 and the power supply pattern 12 are not limited to contact support, and may be fixed by soldering.

  When a predetermined voltage is applied to the LED light source device having the above configuration via the external power supply lead 18, the contact terminal 17, the power supply pattern 12 of the power supply circuit board 14, the through hole 20, the power supply pad 15, the conductor 16, and the LED mounting board 7 are used. The conductive pattern 8 is sequentially applied to the electrode 9 of the LED, and the LED is turned on.

  As described above, the LED light source device of the present invention has only an LED mounting substrate and an adhesive with good thermal conductivity interposed between the LED and the radiator, and is a zener like a conventional LED light source device. A diode, a power supply circuit board, a heat conductive sheet, and the like are not required. Therefore, the thermal resistance from the LED to the radiator is reduced, and the heat generated when the LED is turned on can be dissipated well to the outside. Therefore, the luminous efficiency of the LED chip due to the self-heating of the LED and the phosphor Reduction in wavelength conversion efficiency can be suppressed, and high luminance of the LED light source device can be ensured.

  Furthermore, the electrical connection between the LED mounting board on which the LED is mounted and the power supply circuit board is realized by compressive contact between the LED mounting board and the power supply circuit board. No attempt was made to join by. For this reason, contact terminals that are wired overhead are twisted and warped due to external stress, vibration, and shock, and are lifted at the contact portion to generate a non-contact state, resulting in an electrically open state, and the LED is not lit. Such a problem does not occur. Even if each of the LED mounting board and the power supply circuit board is made of a member having a different thermal expansion coefficient, the LED mounting board is damaged due to self-heating when the LED is turned on or an ambient temperature to which the LED light source device is exposed. Therefore, a highly reliable LED light source device can be realized.

It is a top view which shows embodiment of this invention. It is AA sectional drawing of FIG. It is sectional drawing which shows a prior art example. It is a top view which shows another prior art example. It is AA sectional drawing of FIG. Similarly, it is a top view which shows another prior art example. It is AA sectional drawing of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Opening 2 Recessed part 3 Radiator 4 Bottom face in recessed part 5 Adhesive 6 LED
7 LED mounting substrate 8 Conductive pattern 9 Electrode 10 Joining member 11 Upper surface 12 Power supply pattern 13 Through window 14 Power supply circuit board 15 Power supply pad 16 Conductor 17 Contact terminal 18 External power supply lead 19 External power supply connector 20 Through hole

Claims (4)

  An LED mounting substrate having an LED chip and a sealing resin that seals the LED chip so as to cover the LED chip is mounted on a radiator via a heat conductive adhesive, and the LED electrode A part of the power supply pattern of the power supply circuit board formed with a conductive pattern of the LED mounting board electrically connected to the power supply pattern and a power supply pattern connected to an external power source to supply power to the LED mounting board. An LED light source device, characterized in that a conductor is sandwiched between and supported by a compressive force, and the conductive pattern and the power pad are electrically connected via the conductor. .   The power supply circuit in which the heat sink is provided with a recess having an opening, the LED mounting substrate is placed on the bottom surface of the recess through the heat conductive adhesive, and a through window smaller than the opening is provided. The LED light source device according to claim 1, wherein a substrate is attached to the radiator.   The LED light source device according to claim 2, wherein the power supply circuit board is screwed and fixed to the radiator.   The LED light source device according to claim 1, wherein the sealing resin is made of a translucent resin containing at least one kind of phosphor.

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