JP2014041863A - Semiconductor light-emitting device and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method in which chromaticity correction is facilitated on the blue side with respect to an LED device having LED dies covered with a translucent member containing a phosphor, and which has high productivity.SOLUTION: First, light emission color of an LED device 10 is measured to calculate a correction amount. Next, based on this correction amount, a flat recess 13 having a light outgoing surface is formed in a part of a translucent member 12. Since a phosphor is reduced by forming the recess 13 and the light outgoing surface of the recess 13 is flat, blue light radiated by the LED dies 21 is efficiently emitted to the outside of the LED device 10. As a result, the light emission color of the LED device 10 is shifted onto the blue side.

Description

  The present invention relates to a semiconductor light emitting device in which a semiconductor light emitting element is covered with a translucent member and a method for manufacturing the same.

  A semiconductor light emitting device (hereinafter referred to as an LED die unless otherwise specified) cut from a wafer is mounted on a lead frame or a circuit board and covered with a translucent member such as resin or glass and packaged (hereinafter referred to as a light emitting device). Unless otherwise specified, it is called an LED device). Among these, there is an LED device in which an LED die that emits blue light is covered with a translucent member containing a phosphor.

  In this LED device, the emission color varies depending on the emission spectrum of the LED die, the thickness of the translucent member, the phosphor concentration, and the like. Under such circumstances, if the chromaticity range / distribution with respect to the emission color is wide among LED devices, the product may not be established. Therefore, additional processing may be applied to the LED device to narrow the emission color distribution to a narrow range.

  For example, paragraph 0026 of Patent Document 1 describes that “the light scattering portion adjusts the pseudo-white chromaticity emitted from the LED light source (LED device) to be more yellow than that by being provided in a region within a critical angle”. ing. In other words, a scattering part is provided on the surface of the translucent member containing the phosphor, and part of the blue light to be emitted from the LED light source is returned to the translucent member by the scattering part, and this blue light is elongated by the phosphor. Wavelength conversion is performed on the wavelength side. In this way, the emission color of the LED light source can be shifted to the long wavelength side (from yellow).

  Further, paragraph 0027 of Patent Document 1 describes that “the light scattering portion is provided outside the region within the critical angle to adjust the chromaticity of the pseudo white emitted from the LED light source (LED device) to be blue”. ing. In other words, even if the surface of the translucent member containing the phosphor is provided with a scattering portion in a region where the blue light emitted from the LED die is totally reflected, a part of the blue light to be totally reflected is transmitted from the scattering portion. The light is emitted out of the optical member. In this way, the emission color of the LED light source can be shifted to the short wavelength side (from blue).

  In the correction to the yellow side shown in Patent Document 1, a scattering portion is provided in the vicinity of the upper portion of the LED die, and the intensity of the target blue light was strong, so that a sufficient correction amount was obtained. On the other hand, in the correction to the blue side shown in Patent Document 1, a sufficient amount of correction cannot be obtained because the blue light in the region where the total reflection occurs (the region away from the upper part of the LED die) is weak. Therefore, the method of Patent Document 2 has been proposed as a method of performing additional processing directly above the LED die and correcting it to the blue side.

  For example, in paragraph 0024 of Patent Document 2, “LED element is obtained by cutting a portion corresponding to a part of the optical path of light output from LED element 1 (LED die) and filling transparent resin 3 not containing phosphor. The ratio that the light output from 1 is converted into yellow light by the phosphor is reduced, and the chromaticity of the entire LED light source 10 (LED device) is shifted to the blue side. That is, in this method, the light emitting color of the LED light source 10 is shifted to the blue side by scraping the upper surface of the translucent member containing the phosphor and filling the shaved portion with the transparent resin 3.

JP 2009-283877 A (paragraphs 0026 and 0027) JP 2010-232525 (paragraph 0024)

  However, in the manufacturing method shown in Patent Document 2, a process of filling the transparent resin 3 is added as compared with the method shown in Patent Document 1 in which chromaticity is corrected only by a scattering surface formed by cutting. Is getting longer.

  Therefore, in order to solve this problem, the present invention provides a semiconductor light emitting device capable of easily realizing effective chromaticity correction to the blue side even when the semiconductor light emitting element is covered with a translucent member containing a phosphor, and the semiconductor light emitting device An object is to provide a manufacturing method.

In order to solve the above problems, a method for manufacturing a semiconductor light-emitting device according to the present invention is a method for manufacturing a semiconductor light-emitting device in which a semiconductor light-emitting element is covered with a translucent member containing a phosphor.
A correction amount calculating step of measuring a light emission color of the semiconductor light emitting device and calculating a correction amount;
A recess forming step of forming a recess having a flat light exit surface on a part of the translucent member based on the correction amount.

  In the method for manufacturing a semiconductor light emitting device of the present invention, first, the emission color of the semiconductor light emitting device is measured to calculate a correction amount. Next, based on the relationship between the correction amount and the shape and position of the recess, the recess is formed by cutting the translucent member covering the semiconductor light emitting element. Since the phosphor is reduced by cutting the light-transmitting member and the wavelength of blue light emitted from the semiconductor light emitting element is difficult to convert, the emission color of the semiconductor light emitting device is shifted to the blue side. Further, since the light exit surface of the recess formed by cutting is flat, there is no blue light scattering on the light exit surface. In other words, since there is no blue light that returns to the inside of the translucent member due to scattering and undergoes wavelength conversion, there is almost no shift component to the yellow side.

  The center position of the recess may be moved from the center position of the semiconductor light emitting element according to the correction amount.

  Generally, the region directly above the semiconductor light emitting element is the region with the strongest blue light. For this reason, as the center position of the concave portion is shifted from the portion directly above the semiconductor light emitting element, the blue light emitted from the concave portion becomes weak, so that the correction amount to the blue side with respect to the emission color of the semiconductor light emitting device becomes small.

  You may cut so that the said recessed part may become a V-shaped groove.

In order to solve the above problems, a semiconductor light-emitting device of the present invention is a semiconductor light-emitting device in which a semiconductor light-emitting element is covered with a translucent member containing a phosphor.
A part of the translucent member is provided with a recess having a flat light exit surface.

  The semiconductor light emitting device of the present invention includes a recess in a part of the translucent member. This recess is in the upper part of the semiconductor light emitting element, and the phosphor is reduced in the state where the recess is present compared to the state where there is no recess. Further, since the light exit surface of the recess is flat, the light exit surface is not scattered into the translucent member, and the blue light emitted from the semiconductor light emitting element is efficiently emitted from the light exit surface to the outside. As a result, in the semiconductor light emitting device, the emission color is shifted to the blue side when there is a recess as compared to the state without a recess.

  The center position of the recess may be shifted from the center position of the semiconductor light emitting element.

  The recess may be a V-shaped groove.

  As described above, the method for manufacturing a semiconductor light emitting device of the present invention merely measures the emission color of the semiconductor light emitting device before correction, and forms a recess in the translucent member based on the correction amount obtained from the measured value. Thus, it is possible to manufacture a semiconductor light emitting device in which the emission color is shifted to the blue side and the emission color is within a narrow chromaticity range.

  As described above, the semiconductor light-emitting device of the present invention has a concave portion formed by additional processing, so that the phosphor is reduced compared to the state without the concave portion, and the light emission surface of the concave portion is flat, so that the blue color is blue. Effective chromaticity correction to the side can be easily realized.

The external view of the LED device in 1st Embodiment of this invention. Sectional drawing of the LED apparatus of FIG. The flowchart which concerns on manufacture of the LED device of FIG. Sectional drawing of the other LED device manufactured at the manufacturing process of FIG. The characteristic view of the LED apparatus of FIG. Sectional drawing of the LED apparatus in 2nd Embodiment of this invention. The characteristic view of the LED device of FIG. Sectional drawing of the LED apparatus in 3rd Embodiment of this invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS. In the description of the drawings, the same or equivalent elements will be denoted by the same reference numerals, and redundant description will be omitted. For the sake of explanation, the scale of the members is changed as appropriate. Furthermore, the relationship with the invention specific matter described in the claims is described in parentheses.
(First embodiment)

  The manufacturing method of the LED device 10 (semiconductor light emitting device) and the LED device 10 according to the first embodiment of the present invention will be described with reference to FIGS. First, the outer shape of the LED device 10 will be described with reference to FIG. FIG. 1 is an outline view of the LED device 10, (a) is a plan view, (b) is a front view, and (c) is a bottom view. As shown in (a), when the LED device 10 is viewed from above, a translucent member 12 surrounded by a rectangular white reflecting frame 11 and two recesses 13 formed in a part of the translucent member 12 are shown. Can be seen. When the LED device 10 is viewed from the front as shown in (b), the circuit board 14 disposed under the white reflection frame 11 and the external connection electrodes 15 and 16 formed on the bottom surface of the circuit board 14 can be seen. When the LED device 10 is viewed from the bottom as shown in (c), the external connection electrodes 15 and 16 can be seen in the area inside the circuit board 14.

  The white reflective frame 11 is obtained by kneading and curing reflective fine particles such as titanium oxide and alumina in a silicone resin, and has a thickness of about 100 μm. The translucent member 12 is obtained by kneading and curing phosphor fine particles for converting blue light into a long wavelength side in a silicone resin. The recess 13 is formed by cutting the upper surface of the translucent member 12 with an end mill. The external connection electrodes 15 and 16 become the anode and cathode of the LED device 10.

Next, the internal structure of the LED device 10 shown in FIG. 1 will be described with reference to FIG. FIG. 2 is a cross-sectional view of the LED device 10 drawn along the line AA shown in FIG. Two LED dies 21 (semiconductor light emitting elements) are flip-chip mounted on the circuit board 14. A white reflective frame 11 is provided on the outer periphery of the circuit board 14, and the translucent member 12 is present inside the white reflective frame 11. The translucent member 12 covers the LED die 21 and has two concave portions 13 on the top. The concave portion 13 exists immediately above the LED die 21, has a flat bottom surface, and is adjusted in depth. In the drawing, the external connection electrodes 15 and 16 formed on the bottom surface of the circuit board 14 are shown, but the internal connection electrodes and wirings formed on the top surface of the circuit board 14 are not shown. Also, a through hole connecting the internal connection electrode and the external connection electrodes 15 and 16 is not shown.

  The LED die 21 is formed by laminating a semiconductor layer and a transparent insulating substrate on the protruding electrode 21a. The semiconductor layer includes a p-type GaN layer and an n-type GaN layer, and a boundary portion between the p-type GaN layer and the n-type GaN layer serves as a light emitting layer. The transparent insulating substrate is made of sapphire and has a thickness of 80 to 120 μm. The protruding electrode 21a is a bump electrode having Cu or Au as a core and is connected to the internal connection electrode described above. The LED die 21 is flip-chip mounted, but generally the LED die mounting method is not limited to flip-chip mounting. The LED die is die-bonded to a circuit board or a lead frame, and the LED die electrode is connected to an internal connection electrode or wire. It may be connected to a lead frame. Since flip-chip mounting has no wires, it is known that the mounting area can be reduced and there is no loss due to the shadow of the wires.

  Next, the flowchart concerning manufacture of the LED device 10 will be described with reference to FIG. In addition, the process shown by this flowchart includes the process of manufacturing the LED device 10 as a part. First, the outline of the flowchart will be described. An LED device before chromaticity correction is prepared as an initial state. In the LED device, the emission color is measured in the correction amount calculation step 32, and the correction amount is calculated. When chromaticity correction has to be performed on the short wavelength side, the LED device proceeds to a recess forming step 33 for forming a recess. When chromaticity correction has to be performed on the long wavelength side, the LED device proceeds to a scattering portion forming step 35 for forming a scattering portion. The LED device whose chromaticity has been corrected in these steps 33 and 35 is again measured for emission color in the re-measurement steps 34 and 36. The LED device determined to be unnecessary in the correction amount calculation step 32 and the LED device confirmed to be in the predetermined chromaticity range in the remeasurement steps 34 and 36 are mounted on the carrier tape in the taping step 37. The

  As shown in FIG. 3, in addition to the LED device 10 in which the chromaticity is corrected on the short wavelength side, the LED device in which the chromaticity is not corrected and the LED device in which the chromaticity is corrected on the long wavelength side gather in the taping process 37. Then, before explaining each process 32-37, the condition of the additional process in these LED devices is demonstrated with FIG. 4 is a cross-sectional view of an LED device other than the LED device 10 distributed in the manufacturing process of FIG. The LED device 41 shown in (a) has been determined that correction is unnecessary in the correction amount calculation step 32 of FIG. 3, and the upper surface of the translucent member 12 becomes flat because no additional processing is performed. Yes. The LED device 42 shown in (b) is determined to require correction to the long wavelength side in the correction amount calculation step 32, and is added to the upper surface of the translucent member 12 by additional processing in the scattering portion formation step 35. A scattering portion 43 is formed. Note that the LED device that is determined to require correction to the short wavelength side in the correction amount calculation step 32 is subjected to additional processing in the recess formation step 33 to become the LED device 10 in FIG.

  Returning to FIG. 3 again, steps 32 to 37 will be described. In the correction amount calculation step 32, the emission color is measured with a chromaticity meter for the LED device before the additional work, and the correction amount is calculated. Here, the correction amount is the difference between the chromaticity coordinates of the target emission color and the chromaticity coordinates of the emission color of the LED device. If the chromaticity coordinates of the LED device are within a predetermined range, it is determined that correction is unnecessary. Further, since the distribution of the luminescent color of the LED device often shows an upwardly rising distribution in the chromaticity coordinate system (x, y), the correction amount can be practically indicated only by x. In this case, when the chromaticity coordinate x of the LED device is larger than the target chromaticity coordinate x, it is determined that chromaticity correction to the short wavelength side is necessary. Similarly, when the chromaticity coordinate x of the LED device is smaller than the target chromaticity coordinate x, it is determined that chromaticity correction to the long wavelength side is necessary.

If it is determined that chromaticity correction to the short wavelength side is necessary, the LED device is advanced to the recess forming step 33 to form the recess 13 (see FIG. 2). In the recess forming step 33, a table showing the relationship between the correction amount and the depth of the recess 13 is prepared in advance. Using this table, a concave portion 13 having a flat light exit surface is formed in a part of the translucent member 12 based on the correction amount. The recess 13 is formed by cutting with an end mill. In addition, the diameter and position of the recessed part 13 take the same value in each LED device 10. FIG. When the concave portion 13 is formed, the amount of phosphor is reduced, so that it is difficult to convert the wavelength of blue light. As a result, the emission color of the LED device 10 (see FIGS. 1 and 2) is shifted to the short wavelength side (blue side).

  When the recess 13 is formed, the emission color of the LED device 10 is measured again (re-measurement step 34). When the chromaticity coordinates (x, y) of the emission color of the LED device 10 are within the standard, the LED device 10 is advanced to the taping step 37. If the emission color of the LED device 10 does not fall within the standard, the LED device 10 may be discarded or may be advanced to the recess forming step 33 or the scattering portion forming step 35 again. In the re-measurement step 34, the luminance as well as the chromaticity may be measured, and the LED devices 10 may be ranked based on the luminance.

  If it is determined that chromaticity correction to the long wavelength side is necessary, the LED device is advanced to the scattering portion forming step 35 to form the scattering portion 43 (see FIG. 4B). Also in the scattering portion forming step 35, a table showing the relationship between the correction amount and the scattering portion 43 is prepared in advance. In addition, an area and a position are given as a variable of a scattering part. Using this table, the scattering portion 43 is formed in a part of the translucent member 12 based on the correction amount. The scattering portion 43 is formed by a drill, and the area and position are adjusted according to the correction amount. Part of the blue light scattered by the scattering portion 43 returns to the inside of the translucent member 12 (see FIG. 4B), and is wavelength-converted to the long wavelength side (from yellow) by the phosphor. As a result, the emission color of the LED device 42 (see FIG. 4B) is shifted to the long wavelength side.

  When the scattering portion 43 is formed, the emission color of the LED device 42 is measured again (re-measurement step 36). When the chromaticity coordinates (x, y) of the emission color of the LED device 42 are within the standard, the LED device 42 is advanced to the taping step 37. If the emission color of the LED device 42 does not fall within the standard, the LED device 42 may be discarded or may be advanced to the recess forming step 33 or the scattering portion forming step 35 again. In the re-measurement step 36, the luminance as well as the chromaticity may be measured, and the LED devices 42 may be ranked based on the luminance.

  Finally, the LED devices 10, 41, and 42 (see FIGS. 2 and 4) that are within the standards in the taping step 37 are mounted on the carrier tape. The carrier tape may be classified by luminance rank, or the LED devices 10, 41, and 42 having different luminance ranks may be arranged so as to be dispersed on the carrier tape, and the luminance ranks may be averaged.

  Next, the relationship between the correction amount and the shape of the recess 13 in the LED device 10 (see FIGS. 1 and 2) will be described with reference to FIG. FIG. 5 is a characteristic diagram showing the relationship between the correction amount and the depth of the recess 13 in the LED device 10. The horizontal axis represents the depth of the recess 13 (see FIGS. 1 and 2), and the vertical axis represents the correction amount (chromaticity change Δx). The LED die 21 has a planar size of 290 μm × 500 μm and a thickness of 120 μm. The recess 13 is cylindrical and has a diameter of 600 μm. When the recess 13 is cut down to 100 μm, the chromaticity coordinate x can be moved up to about 1.5 / 100.

The concave portion forming step 33 and the scattering portion forming step 35 are common in that the chromaticity is adjusted only by cutting. For this reason, there are many elements that can be shared, such as a manufacturing apparatus.
(Second Embodiment)

The LED device 10 (see FIGS. 1 and 2) shown in the first embodiment adjusts the depth of the recess 13 in accordance with the correction amount. However, as described above, the correction amount can also be changed by changing the position of the recess. Can be adjusted. An LED device 60 in which the correction amount is adjusted by changing the position of the concave portion will be described as a second embodiment of the present invention with reference to FIGS. FIG. 6 is a cross-sectional view of the LED device 60. 6 differs from the cross-sectional view of the LED device 10 according to the first embodiment shown in FIG. 2 only in the position of the recess 63 in FIG. That is, the center position of the recess 63 is shifted from the center position of the LED die 21. The LED device 60 adjusts this movement amount (deviation amount) according to the correction amount.

  Since the radiant intensity of the blue light emitted from the LED die 21 is strongest in the upper part of the LED die 21, the chromaticity correction amount toward the blue side becomes the largest if the concave portion 63 is in the upper part of the LED die 21. Compared to this state, when the concave portion 63 is displaced from the position directly above the LED die 21 as shown in FIG.

Therefore, the relationship between the correction amount in the LED device 60 (see FIG. 6) and the position of the recess 63 (see FIG. 6) will be described with reference to FIG. FIG. 7 is a characteristic diagram showing the relationship between the correction amount and the position of the recess 63 in the LED device 60. The horizontal axis is the amount of movement of the recess 63 (the distance between the center position of the LED die 21 and the center position of the recess 63, and the vertical axis is the correction amount (chromaticity change Δx). The LED die 21 has a planar size of 290 μm × 500 μm. The thickness of the recess 63 is cylindrical, the diameter is 600 μm, and the depth is 100 μm.When the recess 63 is moved in the range of 0 to 600 μm, the chromaticity is about −1.5 / 100 to 0. The coordinate x can be changed.
(Third embodiment)

  The concave portions 13 and 63 of the LED device 10 (see FIGS. 1 and 2) shown in the first embodiment and the LED device 60 (see FIG. 6) shown in the second embodiment were cylindrical. However, the shape of the recess is not limited to a cylindrical shape. Accordingly, an LED device 80 in which the shape of the recess is a V-shaped groove will be described as a third embodiment with reference to FIG. FIG. 8 is a cross-sectional view of the LED device 80. Compared to the sectional view of the LED device 10 shown in FIG. 2, the position and shape of the recess 83 are different in FIG. 8. That is, the recess 83 has a center position that is offset from the center position of the LED die 21 and is a V-shaped groove. The LED device 80 adjusts this shift amount according to the correction amount. The recess 83 is formed by dicing only the upper surface of the translucent member 12, and the inclined surface is flat, so that the blue light is not scattered.

  When comparing the V-shaped groove (recessed portion 83) of the LED device 80 shown in FIG. 8 and the scattering portion 43 of the LED device 42 shown in FIG. 4B, the size and number of the V-shaped portions are different. Looks like. However, the V-shaped groove (recessed portion 83) is a single groove extending in the front and back direction of the paper surface, whereas the V-shaped portion of the scattering portion 43 is a cross section of a conical hole formed by a drill. Further, the width of the V-shaped groove (recessed portion 83) is several times the maximum diameter of the V-shaped portion of the scattering portion 43. As a result, the V-shaped portion of the scattering portion 43 has a high ability to scatter light, while the V-shaped groove (concave portion 83) does not scatter or hardly scatters light.

10, 41, 42, 60, 80 ... LED device (semiconductor light emitting device),
11 ... White reflective frame,
12 ... translucent member,
13, 63, 83 ... concave portion,
14 ... circuit board,
15, 16 ... external connection electrodes,
21 ... LED die (semiconductor light emitting element),
21a ... protruding electrode,
32 ... Correction amount calculation step,
33 ... concave portion forming step,
34, 36 ... re-measurement step,
35 ... scattering part forming step,
37 ... Taping process,
43: Scattering part.

Claims (6)

In a method for manufacturing a semiconductor light emitting device in which a semiconductor light emitting element is covered with a translucent member containing a phosphor,
A correction amount calculating step of measuring a light emission color of the semiconductor light emitting device and calculating a correction amount;
A method of manufacturing a semiconductor light emitting device, comprising: a recess forming step of forming a recess having a flat light exit surface in a part of the translucent member based on the correction amount.   2. The method of manufacturing a semiconductor light emitting device according to claim 1, wherein the center position of the recess is moved from the center position of the semiconductor light emitting element in accordance with the correction amount.   The method for manufacturing a semiconductor light emitting device according to claim 1, wherein the recess is cut into a V-shaped groove. In a semiconductor light emitting device in which a semiconductor light emitting element is covered with a translucent member containing a phosphor,
A semiconductor light-emitting device, wherein a part of the translucent member is provided with a recess having a flat light exit surface.   The semiconductor light emitting device according to claim 4, wherein a center position of the recess is shifted from a center position of the semiconductor light emitting element.   The semiconductor light emitting device according to claim 4, wherein the recess is a V-shaped groove.

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