JP4445436B2 - LED light source unit - Google Patents

Description

  The present invention relates to an LED light source unit used for a general illumination light source, an automobile headlight, and the like.

  LEDs (light emitting diodes) have advantages such as less heat generation and longer life compared to conventional illumination light sources such as incandescent light bulbs. It has been put to practical use in various fields as an illumination light source such as an automobile headlight. Conventionally, when an LED is used as a light source for general illumination, since the light flux per one is weak, a large amount of light is secured by mounting a plurality of LED elements in one package. Among these, a bulb-type LED light source in which a plurality of LED elements are mounted on a side surface of a cylindrical substrate is known (see, for example, Patent Document 1 and Patent Document 2). Further, the present applicant has applied for an LED light source unit that constitutes a bulb-type LED light source or the like as an improvement of these (see Patent Document 3).

  Improving the luminance of the light emitting unit is synonymous with increasing the luminous intensity without changing the size of the light emitting unit. In general, optical control by a reflector or the like becomes easier as the size of the light emitting portion is closer to a dot shape. Therefore, higher density mounting is essential as the number of light emitting elements to be used increases. In addition, in order to further increase the power of the LED light source, it is necessary to improve the light extraction efficiency. FIG. 15 is a perspective view showing an example of a conventional bulb type LED light source. FIG. 16 is a partially exploded perspective view of the LED light source unit constituting the bulb type LED light source. FIG. 17 is an exploded plan view of the main part showing a state where the sealing resin of FIG. 16 is removed.

  In FIG. 15, reference numeral 50 denotes a conventional bulb type LED light source. Reference numeral 51 denotes a hexagonal column-shaped or hexagonal cylindrical support member. Reference numeral 52 denotes an LED light source unit fixed to one of the side surfaces of the support member 51, which is a unit that constitutes a bulb-type LED light source by packaging a plurality of LED elements in a two-dimensional array. Is. Reference numeral 3 denotes a rectangular parallelepiped base made of metal such as copper having high thermal conductivity. Reference numeral 4 denotes a single-sided printed board having a long hole 4a at the center and wiring patterns 4b and 4c on both sides. Reference numeral 5 denotes an LED element. Reference numerals 6 and 7 denote wires connecting the electrodes of the LED element 5 and the wiring patterns 4b and 4c. Reference numeral 8 denotes a translucent sealing resin, which covers the printed circuit board 4 excluding the portions to be the two terminal electrodes 4d at both ends of the wiring patterns 4b and 4c, and covers the LED element 5 and the wires 6 and 7 with each other. Protect. As shown in FIG. 17, the LED elements 5 are arranged on the substrate 4 with an interval A around the periphery. The interval A is a distance that does not affect the light extraction efficiency by the adjacent wall surfaces.

Here, the details of an example of the LED element 5 will be described. FIG. 18 is a perspective view showing a light emitting element. In FIG. 18, 501 is a sapphire substrate, 502 is an n layer formed on the sapphire substrate 501, 503 is a p layer formed in an approximately L shape on the n layer 502, and 504 is on the n layer 502. The formed cathode electrode 505 is an anode electrode formed on the p layer 503. Light is emitted in all directions from the junction surface (junction surface) between the p layer 503 and the n layer 502, but since the LED element 5 is actually mounted on the base 3, the emitted light is emitted from the base 3 and adjacent Since the LED element 5 is affected by reflection or absorption, the light directivity does not become spherical when packaged, and the light extraction efficiency outside the package depends on the mounting density of the LED elements 5 and the surrounding conditions. Will fluctuate.
JP 2004-296245 A (FIG. 1, paragraph numbers 0014 to 0020) JP 2004-296249 A (FIGS. 1 to 3, paragraph numbers 0012 to 0019) Japanese Patent Application No. 2005-117616 (unpublished)

In the conventional LED light source unit, the luminance (cd / m ² ) increases as the LED elements are arranged at higher density. However, the light emitted from the side surface of the LED element 5 is blocked by the adjacent LED element 5, the printed circuit board 4 or the base 3, and the light extraction efficiency to the outside of the package becomes smaller as the arrangement interval of the LED elements 5 becomes smaller than A. Therefore, there is a trade-off relationship between high-density mounting (brightness improvement) of the LED elements 5 and improvement of light extraction efficiency at the package level. Therefore, when the LED elements 5 are arranged at a high density, there is a problem that the cost effectiveness is not improved in terms of light extraction efficiency.

  The above invention has been made to solve such a conventional problem, and an object of the invention is to provide an LED light source unit capable of satisfying both high-density mounting of LED elements and improvement of light extraction efficiency at the same time. Is to provide.

  The means of the present invention for solving the above problems includes a substantially rectangular parallelepiped base made of a metal having high thermal conductivity, a plurality of LED elements mounted on the upper surface of the base, and an upper surface of the base. The printed circuit board includes two terminal electrodes electrically connected to each electrode of the LED element via a wiring pattern of the printed circuit board, and the upper surface of the base except the terminal electrode portion is transparent. In the LED light source unit sealed with a light-sensitive resin, the side surfaces of the LED elements are arranged in parallel to the longitudinal direction of the base, and the adjacent LED elements are alternately staggered in the short direction of the base. The amount of deviation is not less than the width of the electrode of the LED element.

  Further, the amount of deviation of the LED element is equal to or greater than the width of the LED element.

  In addition, another means of the present invention for solving the above-described problems includes a substantially rectangular parallelepiped base made of a metal having high thermal conductivity, a plurality of LED elements mounted on the upper surface of the base, and the base. A printed circuit board disposed on the upper surface of the base plate, and two terminal electrodes electrically connected to each electrode of the LED element via a wiring pattern of the printed circuit board, and the base except for the terminal electrode portion In the LED light source unit in which the upper surface of the LED element is sealed with a translucent resin, a diagonal line on which the electrode of the LED element exists is arranged in parallel to the lateral direction of the base.

  Further, the adjacent LED elements are alternately shifted in a staggered pattern in the short direction of the base so that the overlapping amount of the adjacent side surfaces of the adjacent LED elements is equal to or more than the width of the electrode surface. It is characterized by that.

  Moreover, the overlapping amount of the opposing side surfaces of the adjacent LED elements is equal to or greater than the width of the LED elements.

  As described above, according to the present invention, a substantially rectangular parallelepiped base made of a metal having high thermal conductivity, a plurality of LED elements mounted on the top surface of the base, and disposed on the top surface of the base A printed circuit board having two terminal electrodes electrically connected to each electrode of the LED element via a wiring pattern of the printed circuit board, and transmitting the upper surface of the base except for the terminal electrode portion. In the LED light source unit sealed with the conductive resin, the side surfaces of the LED elements are arranged in parallel to the longitudinal direction of the base, and the adjacent LED elements are alternately staggered in the short direction of the base. Since the shift amount is set to be equal to or greater than the electrode element of the LED element, an LED light source unit that does not decrease the light extraction efficiency even if the brightness is improved by making the LED element mounting density as high as possible is realized. It could be.

  In addition, according to the present invention, since the diagonal line where the electrodes of the LED element are present is arranged in parallel to the short direction of the base, even if the mounting density of the LED elements is increased to improve the luminance, An LED light source unit in which the extraction efficiency does not decrease can be realized.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, the LED light source unit which comprises the valve | bulb type LED light source which is embodiment of this invention is demonstrated. FIG. 1 is an exploded plan view of an essential part of an LED light source unit constituting a bulb type LED light source according to a first embodiment of the present invention. FIG. 2 is a partially enlarged plan view showing the arrangement of the LED elements of FIG. 3, 4, and 5 are cross-sectional views showing the emitted light at the AA, BB, and CC sections of FIG. 2, respectively.

  In FIG. 1, reference numeral 1 denotes an LED light source unit. Adjacent LED elements 5 are alternately arranged in a staggered pattern in the lateral direction of the base 3 so that the side surfaces of the LED elements 5 are parallel to the longitudinal direction of the base 3. The width dimension of the LED light source unit 1 is wider than the conventional one by the amount shifted by this arrangement. An interval B between the LED elements 5 is the minimum mountable distance. The mutual displacement amount C of the adjacent LED elements 5 is equal to or larger than the electrode width of the cathode electrode 504 or the anode electrode 505 as shown in FIG. Since the other structure of the LED light source unit 1 is the same as that of the conventional LED light source unit 52, the same components are denoted by the same reference numerals and names, and detailed description thereof is omitted.

  Next, the effect of the LED light source unit according to the first embodiment of the present invention will be described. Since the interval B between the LED elements 5 is minimized, a larger number of the LED elements 5 can be mounted on the base 3 having the same length (the conventional 9 elements are 11 here), and the LED light source accordingly. The brightness of the unit 52 is improved. 3, 4, and 5 each show a reflection state of light emitted downward from the light emitting surface by 45 ° in each cross section. Since there is a deviation amount C between the adjacent LED elements 5, the light reflected on the base 3 is not affected by the adjacent LED elements 5. Since it becomes difficult to be influenced by adjacent elements, the light extraction efficiency is not adversely affected even if the element spacing B is minimized.

  FIG. 6 is an exploded plan view of an essential part of an LED light source unit constituting a bulb type LED light source according to a second embodiment of the present invention. In FIG. 6, reference numeral 11 denotes an LED light source unit. The arrangement in which the side surfaces of the adjacent LED elements 5 do not overlap each other, that is, the amount of deviation C is equal to or larger than the element width, so that the width of the LED light source unit 11 is increased correspondingly. The same constituent elements are given the same reference numerals and names, and detailed description thereof is omitted.

  Next, the effect of the LED light source unit according to the second embodiment of the present invention will be described. Since the LED elements 5 are not adjacent to each other, the light extraction efficiency is considerably improved as compared with the first embodiment even if the element interval is narrowed. Other effects are the same as those of the first embodiment.

  FIG. 7 is an exploded plan view of an essential part of an LED light source unit constituting a bulb type LED light source according to a third embodiment of the present invention. In FIG. 7, reference numeral 21 denotes an LED light source unit. The diagonal lines with the electrodes of the LED elements 5 are arranged so as to be parallel to the lateral direction of the LED light source unit 21. Accordingly, the width of the LED light source unit 21 is slightly widened. The gap A around the LED element 5 is the same as in the prior art, the side surfaces adjacent to each other do not overlap, and the interval B is minimal. Since the other structure of the LED light source unit 21 is the same as that of the conventional LED light source unit 52, the same components are denoted by the same reference numerals and names, and detailed description thereof is omitted.

  Next, the effect of the LED light source unit according to the third embodiment of the present invention will be described. FIG. 8 is a partially enlarged plan view showing the arrangement of the LED elements of FIG. 9, FIG. 10, FIG. 11 and FIG. 12 are sectional views showing the emitted light in the AA cross section, the BB cross section, the CC cross section and the DD cross section of FIG. As shown in FIGS. 9, 10, 11, and 12, the reflected light from the base 3 is not affected by the adjacent LED element 5 in any direction. In addition, since the diagonal lines of the LED elements 5 are arranged along the longitudinal direction of the base 3, the number of mounted elements is not different from the conventional one even if the interval B is minimum. In addition, since the closest part is a part without an electrode, the light extraction efficiency is not adversely affected and the brightness becomes brighter.

  FIG. 13 is an exploded plan view of an essential part of an LED light source unit constituting a bulb-type LED light source according to a fourth embodiment of the present invention. In FIG. 13, reference numeral 31 denotes an LED light source unit. The arrangement of the LED elements 5 is staggered, the gap between the side surfaces adjacent to each other is a distance B, and the amount of overlap D between the opposite side surfaces is equal to or greater than the width of the electrode surface. The width of the LED light source unit 31 is wide, and the number of mounted elements is eleven. Since the other structure of the LED light source unit 31 is the same as that of the LED light source unit 21 of the second embodiment, the same components are denoted by the same reference numerals and names, and detailed description thereof is omitted.

  Next, the effect of the LED light source unit which is the 4th Embodiment of this invention is demonstrated. Since there is an overlap amount D between the opposing side surfaces, the number of mounted elements is greater (11) than in the third embodiment (9), and the luminance of the LED light source unit 31 is improved. In addition, the light extraction efficiency is not affected.

  FIG. 14 is an exploded plan view of an essential part of an LED light source unit constituting a bulb-type LED light source according to a fifth embodiment of the present invention. In FIG. 14, reference numeral 41 denotes an LED light source unit. The gap between the side surfaces adjacent to each other of the LED element 5 is an interval A, and the overlapping amount D between the side surfaces facing each other is equal to or greater than the width dimension of the side surface. It is wider than the width of the LED light source unit 31 in the form. Since the other structure of the LED light source unit 41 is the same as that of the LED light source unit 31 of the third embodiment, the same components are denoted by the same reference numerals and names, and detailed description thereof is omitted.

  Next, the effect of the LED light source unit which is the 5th Embodiment of this invention is demonstrated. The side surfaces of the LED elements 5 are spaced A, the side surfaces are largely overlapped, and the degree of staggered feet is large. Therefore, the number of mounted elements is larger (13) than in the third embodiment (9), The brightness of the LED light source unit 41 is improved. Moreover, since the adjacent side surfaces of the LED elements 5 are spaced A, the same light extraction efficiency as before can be maintained even if the overlap amount D is large.

  The LED light source unit of the present invention can be widely applied to various directions by using various types of LED light sources including a bulb type LED light source by using them alone or in combination.

It is a principal part exploded front view of the LED light source unit which is the 1st Embodiment of this invention. It is a partial enlarged plan view which shows the arrangement | sequence of the LED element of the LED light source unit which is the 1st Embodiment of this invention. It is sectional drawing which shows the AA cross section of FIG. It is sectional drawing which shows the BB cross section of FIG. It is sectional drawing which shows CC cross section of FIG. It is a principal part exploded front view of the LED light source unit which is the 2nd Embodiment of this invention. It is a principal part exploded front view of the LED light source unit which is the 3rd Embodiment of this invention. It is the elements on larger scale which show the arrangement | sequence of the LED element of the LED light source unit which is the 3rd Embodiment of this invention. It is sectional drawing which shows the AA cross section of FIG. It is sectional drawing which shows the BB cross section of FIG. It is sectional drawing which shows CC cross section of FIG. It is sectional drawing which shows the DD cross section of FIG. It is a principal part exploded front view of the LED light source unit which is the 4th Embodiment of this invention. It is a principal part exploded front view of the LED light source unit which is the 5th Embodiment of this invention. It is a perspective view of the conventional bulb type LED light source. It is a partial exploded perspective view of the conventional LED light source unit. It is a principal part exploded front view of the conventional LED light source unit. It is a perspective view of an LED element.

Explanation of symbols

1, 11, 21, 31, 41 LED light source unit 3 base 4 printed circuit board 4b, 4c wiring pattern 5 LED element 8 translucent resin

Claims (5)

  A substantially rectangular parallelepiped base made of a metal having high thermal conductivity, a plurality of LED elements mounted on the upper surface of the base, and a printed circuit board disposed on the upper surface of the base, each of the LED elements In the LED light source unit having two terminal electrodes electrically connected to the electrodes via the wiring pattern of the printed circuit board, and sealing the upper surface of the base except the terminal electrode portion with a translucent resin, The side surfaces of the LED elements are arranged in parallel to the longitudinal direction of the base, and the adjacent LED elements are alternately shifted in a staggered pattern in the lateral direction of the base to shift the deviation amount of the electrodes of the LED elements. An LED light source unit characterized by having a width or more.   The LED light source unit according to claim 1, wherein a shift amount of the LED element is equal to or greater than a width of the LED element.   A substantially rectangular parallelepiped base made of a metal having high thermal conductivity, a plurality of LED elements mounted on the upper surface of the base, and a printed circuit board disposed on the upper surface of the base, each of the LED elements In the LED light source unit having two terminal electrodes electrically connected to the electrodes via the wiring pattern of the printed circuit board, and sealing the upper surface of the base except the terminal electrode portion with a translucent resin, An LED light source unit, characterized in that a diagonal line in which an electrode of an LED element exists is arranged in parallel to the short direction of the base.   The adjacent LED elements are alternately shifted in a staggered pattern in the short direction of the base so that the amount of overlap between the adjacent side surfaces of the adjacent LED elements is equal to or greater than the width of the electrode surface. The LED light source unit according to claim 3. The LED light source unit according to claim 3, wherein the amount of overlap between the side surfaces facing each other of the adjacent LED elements is equal to or greater than the width of the LED elements.

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