JP2018029015A - White LED lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a white LED lighting device which inhibits its form from undesirably becoming large while realizing white emission light which is uniform and stable.SOLUTION: A white LED lighting device 100 includes: a white LED element 102 mounted on a surface of a base substrate 101; and a mounting type ceramic electronic component 10 mounted on the surface of the base substrate 101 and placed near the white LED element 102. The mounting type ceramic electronic component 10 includes: an element assembly 20 formed by a white ceramic; and input/output terminal conductors 51, 52 which are formed only on the rear surface side of the element assembly and mounted on the surface of the base substrate 101.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a white LED illumination device using a white LED element.

  Currently, many lighting devices using LED (light emitting diode) elements have been put into practical use. In a lighting device using LEDs (LED lighting device), a thermistor element may be used for the purpose of monitoring a change in temperature of the LED element, reducing the amount of light accompanying a rise in temperature of the LED element, and protecting it from voltage fluctuations.

  For example, the light emitting device disclosed in Patent Document 1 includes a configuration in which a thermistor element and an LED element are connected in series. The thermistor element realizes overcurrent protection for the LED element.

  In general, it is preferable to dispose ceramic electronic components related to driving of LED elements such as thermistor elements that perform current control according to the state of the LED elements in the vicinity of the LED elements.

  When the ceramic electronic component is disposed near the LED element, part of the light emitted from the LED element propagates to the ceramic electronic component and is reflected by the surface of the ceramic electronic component. This reflected light becomes part of the emitted light as the illumination device.

JP 2002-151741 A

  However, ceramic electronic parts such as the thermistor element described above are black for ferrite parts or resistors, and brown for multilayer ceramic capacitors. That is, each functional element reflects a color derived from the material.

  For this reason, when these functional elements are arrange | positioned near the LED element, the emitted light as an illuminating device will be influenced by the color of these functional elements. In particular, a white LED illumination device using a white LED element requires white emitted light, but it may not be possible to obtain uniform and stable white emitted light due to the influence of these functional elements.

  In order to solve this problem, a configuration in which the functional element is covered with a white material (white coating) can be considered. However, the outer shape of the functional element is increased by the amount of the white coating, and light may not be reflected uniformly depending on the accuracy of the coating.

  Accordingly, an object of the present invention is to provide a white LED illumination device capable of suppressing an unnecessarily large shape while realizing uniform and stable white outgoing light.

  The white LED lighting device of the present invention includes a white LED element mounted on the surface of a base substrate, and a mountable ceramic electronic component mounted on the surface of the base substrate. The mountable ceramic electronic component includes an element body made of white ceramics, and an input / output terminal conductor formed only on the back surface side of the element body and mounted on the surface of the base substrate.

  In this configuration, the surface of the mounting type ceramic electronic component that reflects the light of the white LED element is white. Therefore, the mounting ceramic electronic component realizes uniform and stable white reflected light without becoming an unnecessarily large shape.

  Moreover, in the white LED illuminating device of this invention, it is preferable that it is the following structure. The white LED lighting device includes a cover member that is at least partially transparent. The cover member covers the white LED element and the mounting ceramic electronic component on the surface side of the base substrate.

  In this configuration, the environmental resistance between the white LED element and the mounting ceramic electronic component is enhanced. In addition, the light emitted from the cover member to the outside becomes a uniform and stable white color. In addition, since the mountable ceramic electronic component is small (not unnecessarily large), the cover member is small and the white LED lighting device is small.

  In the white LED lighting device of the present invention, the mounting ceramic electronic component is a thermistor connected to the white LED element.

  In this configuration, the overcurrent protection of the white LED element is realized, and a highly reliable white LED illumination device is realized. In addition, since the configuration is simple and space-saving, a highly reliable white LED lighting device is realized in a small size.

  In the white LED illumination device of the present invention, the height of the mounting ceramic electronic component is preferably lower than the height of the white LED element.

  In this configuration, the light emitted from the white LED element is efficiently propagated to the illumination target area.

  In the white LED lighting device of the present invention, the mountable ceramic electronic component includes a resist film formed on the back surface of the element body and having a hole through which the input / output terminal conductor is exposed, and the resist film may be white. preferable.

  In this configuration, even if the conductor is formed on the back side of the element body, insulation protection for a necessary portion of the conductor and uniform and stable reflection of the white light described above are realized.

  Moreover, in the white LED illuminating device of this invention, it is preferable that it is the following structure. The mountable ceramic electronic component includes a functional member formed on the back surface of the element body, and an insulating layer that covers substantially the entire surface of the functional member excluding a hole that connects the functional member to the input / output terminal conductor. The insulating layer is white.

  In this configuration, even when the functional member is formed on the back surface of the element body, insulation protection of the functional member and uniform and stable reflection of the white light described above are realized.

  In the white LED lighting device of the present invention, the element body is preferably alumina.

  In this configuration, a white mounting ceramic electronic component is realized with an easily available material. Further, a mounting ceramic electronic component having high heat resistance and high thermal conductivity is realized.

  Moreover, in the white LED illuminating device of this invention, it is preferable that the surface of the base substrate is white at least.

  In this configuration, the reflected light from the surface of the base substrate is also uniform and stable.

  In the white LED lighting device of the present invention, it is preferable that at least a portion of the base substrate forming the surface is alumina.

  In this configuration, a base substrate with uniform and stable surface reflection is realized with an easily available material. In addition, a base substrate having excellent heat resistance is realized.

  In the white LED lighting device of the present invention, the configuration of the present invention works particularly effectively when the mounting ceramic electronic component is disposed near the white LED element.

  In the white LED lighting device of the present invention, the configuration of the present invention works particularly effectively when the mounting ceramic electronic component is disposed adjacent to the white LED element.

  According to the present invention, it is possible to prevent the shape from becoming unnecessarily large while realizing uniform and stable white emitted light.

It is side surface sectional drawing which shows the main structures of the white LED illuminating device which concerns on embodiment of this invention. (A) is a surface view of the mounting ceramic electronic component according to the embodiment of the present invention, (B) is a side sectional view of the mounting ceramic electronic component, and (C) is a mounting ceramic electronic component. FIG. (A) is the external appearance perspective view of the surface side of the mounting ceramic electronic component which concerns on embodiment of this invention, (B) is the external appearance perspective view of the back surface side of the mounting ceramic electronic component which concerns on embodiment of this invention. FIG.

  A white LED illumination device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a side sectional view showing a main configuration of a white LED illumination device according to an embodiment of the present invention. 2A is a surface view of the mounting ceramic electronic component according to the embodiment of the present invention, FIG. 2B is a side sectional view of the mounting ceramic electronic component, and FIG. It is a reverse view of a mounting type ceramic electronic component. FIG. 2B shows an AA cross section shown in FIG. 3A is an external perspective view of the front surface side of the mounting ceramic electronic component according to the embodiment of the present invention, and FIG. 3B is the back surface of the mounting ceramic electronic component according to the embodiment of the present invention. FIG.

  As shown in FIG. 1, the white LED lighting device 100 includes a base substrate 101, a white LED element 102, a cover member 103, and a mountable ceramic electronic component 10. In FIG. 1, the number of the white LED elements 102 and the mountable ceramic electronic component 10 is one, but a plurality of them may be used.

  The base substrate 101 has a predetermined conductor pattern (not shown) formed on the insulating substrate. A land conductor 201 for the white LED element 102 and a land conductor 202 for the mountable ceramic electronic component 10 are formed on the surface of the base substrate 101. The land conductor 201 and the land conductor 202 are connected by a predetermined conductor pattern (not shown).

  The base substrate 101 preferably has at least a white surface layer. Specifically, when the base substrate 101 is formed of one insulating substrate, the insulating substrate is made of white alumina. When the base substrate 101 is formed of a plurality of insulating layers, the surface insulating layer is made of white alumina.

  The white LED element 102 includes a housing 121 and a terminal conductor 122. The housing 121 has a substantially rectangular parallelepiped shape in plan view. The light exit surface of the white LED element 102 is the surface of the housing 121. The terminal conductor 122 is formed on the back surface of the housing 121. The terminal conductor 122 is joined to the land conductor 201 formed on the surface of the base substrate 101. Thus, the white LED element 102 is mounted on the surface of the base substrate 101, and the side opposite to the base substrate 101 side is used as a light exit surface.

  The specific structure of the mountable ceramic electronic component 10 will be described later with reference to FIGS. 2 and 3. The mountable ceramic electronic component 10 has a substantially rectangular parallelepiped shape in plan view. The surface and all the side surfaces of the mountable ceramic electronic component 10 are white. In other words, the entire surface of the mounting ceramic electronic component 10 excluding the back surface is white.

  The mountable ceramic electronic component 10 includes an input / output terminal conductor 51 on the back surface. The input / output terminal conductor 51 is joined to a land conductor 202 formed on the surface of the base substrate 101. Thereby, the mountable ceramic electronic component 10 is mounted on the surface of the base substrate 101. Since the back surface of the mountable ceramic electronic component 10 faces the surface of the base substrate 101, the exposed surface of the mountable ceramic electronic component 10 is all white.

  The mounting ceramic electronic component 10 is disposed adjacent to the white LED element 102. More specifically, the mounting ceramic electronic component 10 is disposed adjacent to the white LED element 102 and in the vicinity of the white LED element 102. Thereby, the connection distance of the mounting type ceramic electronic component 10 and the white LED element 102 can be shortened. Further, when the mountable ceramic electronic component 10 is an element (for example, a thermistor element if the temperature is exceeded) that controls the operation of the white LED element 102 depending on the state (for example, temperature) of the white LED element 102, The state of the LED element 102 can be accurately acquired, and accurate operation control can be performed.

  The cover member 103 includes a main surface part 131 and a side wall part 132. The main surface portion 131 has a flat plate shape and has translucency. The main surface portion 131 may be a lens. The side wall part 132 supports the main surface part 131. The cover member 103 covers the surface side of the base substrate 101. More specifically, an end portion of the side wall portion 132 of the cover member 103 opposite to the end portion communicating with the main surface portion 131 is in contact with the surface of the base substrate 101. Accordingly, the main surface portion 131 of the cover member 103 is disposed at a position spaced apart from the surface of the base substrate 101 by a predetermined distance. With this configuration, a space 110 surrounded by the cover member 103 and the surface of the base substrate 101 is formed.

  The white LED element 102 and the mountable ceramic electronic component 10 are disposed in the space 110. In other words, the cover member 103 is disposed so as to cover the white LED element 102 and the mountable ceramic electronic component 10 on the surface side of the base substrate 101. The space 110 may be a sealed space or may partially communicate with the outside. When the space 110 is a sealed space, the white LED element 102 and the mounted ceramic electronic component 10 can be protected from the external environment, and the environmental resistance of the white LED element 102 and the mounted ceramic electronic component 10 is improved.

  The height of the mounted ceramic electronic component 10 in the mounted state is preferably equal to or lower than the height of the white LED element 102 in the mounted state. Thereby, it is suppressed that the light from the white LED element 102 to the main surface part 131 side is shielded and refracted by the mounting ceramic electronic component 10, and the irradiation efficiency to the outside is improved.

  The light emitted from the white LED element 102 is emitted to the outside through the main surface portion 131. At this time, a part of the light emitted from the white LED element 102 propagates in the space 110 and is reflected by the mounting ceramic electronic component 10 disposed near the white LED element 102, and passes through the main surface portion 131. It is emitted to the outside.

  As for “the mounted ceramic electronic component 10 is disposed near the white LED element 102”, “near” means “the light of the white LED element 102 is reflected by the surface of the mounted ceramic electronic component 10. It means that the white LED element 102 and the mounting ceramic electronic component 10 are close to each other. " When the white LED element 102 and the mounting ceramic electronic component 10 are arranged on the same base substrate 101 and arranged in the same space 110, the light of the white LED element 102 is surely obtained. Is reflected by the surface of the mountable ceramic electronic component 10, it can be said that “the white LED element 102 and the mountable ceramic electronic component 10 are close to each other”.

  As described above, since the exposed surface of the mountable ceramic electronic component 10 is white, the light emitted from the white LED element 102 is reflected as it is. Thereby, the light emitted from the white LED element 102 and the light reflected by the mounting ceramic electronic component 10 have substantially the same color, and the emitted light as the white LED illumination device 100 becomes a uniform and stable white color. This is particularly effective when the mounted ceramic electronic component 10 and the white LED element 102 are close to each other. Furthermore, when the mountable ceramic electronic component 10 and the white LED element 102 are adjacent to each other, the light of the white LED element 102 is reflected by the surface of the mountable ceramic electronic component 10. There is a problem similar to the case where the white LED element 102 is disposed in the vicinity, and this problem can be similarly solved by the configuration of the present embodiment.

  In the present invention, white means translucent or opaque, and its surface color is cloudy, light yellow, milky white, cream, or an intermediate color thereof. Alternatively, it means that the hue is in the range from 5R to 5Y through 5YR, the lightness is V8.5 or more, and the saturation is C6 or less.

  Next, a specific structure of the mounting ceramic electronic component 10 will be described with reference to FIGS. In the following, a case where a thermistor element is configured as the mounting ceramic electronic component 10 is shown.

  As shown in FIG. 2, the mountable ceramic electronic component 10 includes an element body 20, an insulating layer 30, a resist film 40, input / output terminal conductors 51 and 52, and a thermistor material layer 60.

  The element body 20 has a rectangular parallelepiped shape and is made of white ceramics. Examples of the white ceramic include alumina, zirconia, and YSZ (yttria-added zirconia).

  The thermistor material layer 60 is formed on the back surface of the element body 20. The thermistor material layer 60 is formed substantially at the center of the back surface of the element body 20. The thermistor material layer 60 corresponds to the “functional member” of the present invention.

The insulating layer 30 is formed on substantially the entire back surface of the element body 20 except for portions overlapping the both end portions of the thermistor material layer 60. In other words, the insulating layer 30 has the through hole P in a portion overlapping with both end portions of the thermistor material layer 60. The insulating layer 30 is made of SiO ₂ or the like and is white.

  The input / output terminal conductors 51 and 52 are formed on the surface of the insulating layer 30 opposite to the element body 20. The input / output terminal conductor 51 is connected to the thermistor material layer 60 through a through hole P that overlaps one end of the thermistor material layer 60 in the insulating layer 30. The input / output terminal conductor 52 is connected to the thermistor material layer 60 through a through hole P that overlaps the other end of the thermistor material layer 60 in the insulating layer 30. The input / output terminal conductors 51 and 52 are made of a material having high workability and conductivity such as copper.

  The resist film 40 is formed on substantially the entire surface of the insulating layer 30 opposite to the element body 20. The resist film 40 has a through hole Q that partially opens the input / output terminal conductors 51 and 52. The resist film 40 is preferably made of a material that can be easily formed, such as coating properties and labeling properties, and is white.

  With this configuration, the mounting ceramic electronic component 10 exposes the non-white input / output terminal conductors 51 and 52 only on the back surface side. Therefore, if the insulating layer 30 and the resist film 40 are white, the entire surface other than the back surface can be white. Even when the insulating layer 30 and the resist film 40 are not white, most of the portions other than the back surface (the portions on the front surface and the side surface excluding the portion where the insulating layer 30 and the resist film 40 are disposed) can be white. The thermistor material layer 60 is usually black, but the thermistor material layer 60 is covered with the element body 20, the insulating layer 30, the resist film 40, and the opaque input / output terminal conductors 51 and 52. Does not affect the reflected color. Thereby, the mounting ceramic electronic component 10 can realize white reflected light.

  Further, since the mounting ceramic electronic component 10 is white except for the back surface, it is not necessary to separately coat the outer surface of the element body with white. Further, since the element body 20 can achieve high flatness, the flatness of the white surface can be increased. Thereby, uniform white reflected light can be realized.

  Further, the mountable ceramic electronic component 10 need not be separately covered with a white mold resin or the like. Thereby, the space required to obtain white reflected light can be reduced. In other words, the structure for obtaining white reflected light is not unnecessarily large. Thereby, it can suppress that the white LED lighting apparatus 100 becomes unnecessarily large.

  Further, the mounting ceramic electronic component 10 can be arranged closer to the white LED element 102. For example, when the mountable ceramic electronic component 10 is a thermistor element, the resistance value corresponds to a temperature closer to the actual temperature of the white LED element 102. Thereby, the control with respect to the light quantity fall and voltage fluctuation by the heat | fever of the white LED element 102 can be implement | achieved correctly, and overcurrent protection can also be implement | achieved more reliably. That is, the highly reliable white LED lighting device 100 can be realized.

  Note that the insulating layer 30 and the resist film 40 are thin with respect to the element body 20 and on the back side of the element body 20, and therefore do not have to be completely the same color as the element body 20. However, the insulating layer 30 and the resist film 40 are preferably white or highly translucent, and more preferably white.

  Further, when the mountable ceramic electronic component 10 is a thermistor element, it may be a positive characteristic thermistor or a negative characteristic thermistor. The mounted ceramic electronic component 10 may be connected to the white LED element 102 by a circuit configuration that matches the characteristics of the thermistor.

  Further, the mountable ceramic electronic component 10 may be other than the thermistor element, and may be, for example, a resistor or a capacitor. Also in this case, the input / output terminal conductors are arranged only on the back side of the white element body forming the resistor or capacitor. A portion that generates resistance in the resistor (such as a conductor pattern having a predetermined resistivity) and a portion that generates capacitance in the capacitor (such as a laminate of a conductor pattern and a dielectric) are the “functional members” of the present invention. Correspond.

  Moreover, when alumina is used for the element body 20 of the mountable ceramic electronic component 10, the mountable ceramic electronic component 10 having high heat resistance and high thermal conductivity can be realized. Then, due to the high thermal conductivity, when the mounted ceramic electronic component 10 is a thermistor element, the resistance value changes at a temperature closer to the temperature of the white LED element 102. Thereby, more accurate operation control can be realized.

  Moreover, the irradiation efficiency as the white LED illuminating device 100 can be improved by making the surface of the base substrate 101 white. Although not shown in detail above, when forming a conductor pattern exposed on the surface of the base substrate 101, a white resist film is formed on the surface, and this resist film is used as a surface layer of the base substrate 101. Good.

  Further, by using alumina for the base substrate 101, the white LED lighting device 100 having excellent heat resistance and high heat dissipation effect can be realized.

  Further, in the above description, the mounting ceramic electronic component 10 has a mode in which one circuit element is formed in the element body, but a plurality of circuit elements may be formed.

10: Mounting ceramic electronic component 20: Element body 30: Insulating layer 40: Resist film 51, 52: Input / output terminal conductor 60: Thermistor material layer 100: LED lighting device 101: Base substrate 102: LED element 103: Cover member 110 : Space 121: Housing 122: Terminal conductor 131: Main surface portion 132: Side wall portion 201, 202: Land conductor P, Q: Through hole

Claims (11)

A white LED element mounted on the surface of the base substrate;
A mounting-type ceramic electronic component mounted on the surface of the base substrate,
The mounting ceramic electronic component is
An element made of white ceramics,
An input / output terminal conductor formed only on the back side of the element body and mounted on the surface of the base substrate,
White LED lighting device. A cover member having at least a part of translucency,
The cover member covers the white LED element and the mounting ceramic electronic component on the surface side of the base substrate.
The white LED illumination device according to claim 1. The mounting ceramic electronic component is a thermistor connected to the white LED element.
The white LED lighting device according to claim 1 or 2. The height of the mounting ceramic electronic component is lower than the height of the white LED element,
The white LED illuminating device in any one of Claims 1 thru | or 3. The mounting ceramic electronic component is
A resist film formed on the back surface of the element body and having a hole through which the input / output terminal conductor is exposed;
The resist film is white.
The white LED illuminating device in any one of Claims 1 thru | or 4. The mounting ceramic electronic component is
A functional member formed on the back surface of the element body;
An insulating layer covering substantially the entire surface of the functional member excluding a hole connecting the functional member to the input / output terminal conductor;
The insulating layer is white;
The white LED illuminating device in any one of Claims 1 thru | or 5. The element body is alumina;
The white LED illuminating device in any one of Claims 1 thru | or 6. The base substrate has at least a white surface.
The white LED illuminating device in any one of Claim 1 thru | or 7. The portion forming at least the surface of the base substrate is alumina.
The white LED lighting device according to claim 8. The mounting ceramic electronic component is disposed near the white LED element.
The white LED illuminating device in any one of Claims 1 thru | or 9. The mounting ceramic electronic component is disposed adjacent to the white LED element.
The white LED illuminating device in any one of Claims 1 thru | or 10.

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