JP5698808B2 - Semiconductor light emitting device - Google Patents

Description

  The present invention relates to a semiconductor light-emitting device in which a plurality of semiconductor light-emitting elements are arranged, and in particular, a color obtained by mixing light emission of a semiconductor element and light emission color-converted by a fluorescent material or the like using this light emission as excitation light. The present invention relates to a semiconductor light emitting device using a conversion semiconductor element.

  Semiconductor light-emitting devices using semiconductor light-emitting elements (hereinafter also referred to as LED chips or simply chips) are used in various light-emitting devices such as headlamps, street lamps, backlights, displays, and general lighting. In semiconductor light emitting devices, in order to obtain light of a desired color such as white light, a combination of a light emitting element and a phosphor as a wavelength conversion material is often used. In a semiconductor light emitting device using such a color conversion semiconductor element, there are the following methods as a method of arranging a phosphor layer in a light emitting device in which a plurality of LED chips are arranged.

  First, as shown in FIG. 13A, a suspension containing a phosphor is applied to and dried on an LED chip 122 and a contact electrode (not shown) formed on a substrate 121. In this method, the phosphor layer 123 having a uniform film thickness is formed around the periphery. This method is described in Patent Document 1, for example. Another method is a method of forming a phosphor layer by a screen printing method using a metal mask matched to a chip shape, and is described in Patent Document 2. In this method, as shown in FIG. 13B, the phosphor layer 123 is provided not only on the upper surface of the chip 122 but also between the chips. Further, as shown in FIG. 13C, another method is to form a phosphor layer 123 only on the upper surface of the chip by applying a resin dispersion containing phosphor on the upper surface of each LED chip 122. is there.

  In addition to the three methods described above, a method of arranging a phosphor layer at a position away from a plurality of arranged LED chips has also been proposed (Patent Document 3).

Special table 2003-526212 gazette JP 2006-313886 A JP 2004-288760 A

  In the conventional method of directly forming the phosphor layer on the LED chip described above, when a plurality of chips are arranged and used, chromaticity unevenness and brightness unevenness are particularly observed between the chips, within the light emitting surface viewed from above. There was a problem that caused.

  Specifically, when each of the chips is covered with a phosphor layer, light emission is repeatedly reflected between the chips, and the color conversion by the phosphor is performed in a multiple manner, so that the yellow light component increases. For this reason, when viewed from the top surface of the chip, the distance between the chips appears yellower than the chromaticity immediately above the chips. Further, since there is no light emitting portion between the chips, when viewed from the top surface of the chip, dark non-light emitting portions appear between the chips as a line.

  In addition, when the entire chip is covered with a phosphor layer, the phosphor existing between the chips, particularly the phosphor located on the lower side (substrate side), the phosphor present in the other part Compared to the portion directly above the chip with a large amount of excitation light, the phosphor concentration is relatively high because the amount of excitation light that reaches is relatively small. Since the color of the light emitting device is a mixture of the color emitted by the chip (excitation light) and the color emitted by the phosphor, when viewed from the top surface of the chip, the distance between the chips appears more yellow than the color immediately above the chip. End up.

  If only the upper surface of the chip is coated, a uniform color mixture is obtained on the upper surface of the chip, but since there is no light emitting component between the chips, when viewed from the upper surface of the chip, dark non-light emission between the white chips The part looks linear.

  When such a light emitting device (LED package) is used as a light source of an optical system in which a convex lens and a reflecting mirror are combined, color unevenness and luminance unevenness appear remarkably in a projected image. In order to reduce these unevenness, a layer containing a light diffusing material such as silica fine particles with a light diffusing / scattering effect is provided on the top of the light emitting part, but it is still sufficient to eliminate chromaticity unevenness and brightness unevenness However, the light diffusion layer causes a new problem such as a decrease in luminous flux.

  On the other hand, when the phosphor layers are arranged at intervals from the upper surface of the plurality of LED chips, the above-described color unevenness and luminance unevenness are considerably reduced. However, it is difficult to reduce the light source size of the light emitting device having such a structure. In order to facilitate optical design, it is desired to reduce the light source size.

  Accordingly, an object of the present invention is to provide a light-emitting device in which a phosphor layer is directly provided on an LED chip, and in addition, a light-emitting device that greatly reduces color unevenness and luminance unevenness.

  In order to solve the above problems, the semiconductor light emitting device of the present invention is characterized in that one continuous phosphor layer is formed on the upper surfaces of a plurality of LED chips. Specifically, the semiconductor light-emitting device of the present invention includes a plurality of semiconductor light-emitting elements each having an upper surface and a side surface, with the side surfaces disposed with a gap, and at least a part of light emitted from the semiconductor light-emitting element. And a phosphor layer containing a phosphor that converts the wavelength of the light. The phosphor layer is formed by cross-linking the upper surfaces of the plurality of semiconductor light emitting elements.

  By forming the phosphor layer so as to connect the upper surfaces (substantially light emitting portions) of the plurality of LED chips, light emission with less luminance unevenness and chromaticity unevenness in the light emitting surface can be obtained.

The figure which shows 1st Embodiment of the semiconductor light-emitting device of this invention. The figure which shows the semiconductor element used for the semiconductor light-emitting device of this invention FIG. 3 is a view for explaining a method of manufacturing the semiconductor light emitting device of FIG. The figure which shows 2nd Embodiment of the semiconductor light-emitting device of this invention. The figure which shows 3rd Embodiment of the semiconductor light-emitting device of this invention. The figure which shows 4th Embodiment of the semiconductor light-emitting device of this invention. The figure which shows 5th Embodiment of the semiconductor light-emitting device of this invention. The figure which shows other embodiment of the semiconductor light-emitting device of this invention. The figure which shows the luminance distribution of the LED apparatus of Example 1 and a comparative example. The figure which shows chromaticity distribution of the LED apparatus of Example 1 and a comparative example The figure which shows the luminance distribution and chromaticity distribution of the LED device of Example 2. The figure which shows the luminance distribution and chromaticity distribution of the LED device of Example 3. The figure which shows the conventional semiconductor light-emitting device

Embodiments of the light emitting device of the present invention will be described below.
In the following embodiments, as an example, a blue light emitting LED device and a YAG-based phosphor that emits blue light as excitation light and emits yellow-orange fluorescent light are combined to obtain a white color by mixing colors in a complementary color relationship. A configuration in which a plurality of LED chips are arranged on one substrate (package) using the apparatus will be described. However, the present invention is not limited to a white LED device as long as it is a color conversion light emitting element that obtains arbitrary light emission by combining an LED element and a wavelength conversion material.

<First Embodiment>
1A and 1B are diagrams showing a first embodiment, in which FIG. 1A is a side sectional view of a white LED device in which four LED chips 102 are arranged on one substrate 101, and FIG. 1B is a white LED device. It is the figure which looked at from the upper surface. In FIG. (B), a part of the LED chip hidden under the phosphor layer is illustrated, but actually, the phosphor layer covers the upper surface of all the LED chips. In the following description, each LED chip is called an LED chip or a chip, and an array of four chips is called a chip row.

  The LED chip 102 has, for example, a structure in which one or a plurality of conductive semiconductor layers (n-type or p-type) are stacked on an element substrate. Depending on the type of the element substrate and the arrangement of the semiconductor layers, the LED chip 102 is shown in FIG. There are three types. In type 1, the semiconductor layer 1021 is disposed on an opaque element substrate 1022, and the semiconductor layer side is the light emitting side. This type of chip has almost Lambertian alignment characteristics, the thickness of the semiconductor layer 1021 is very thin compared to the thickness of the element substrate, and the side emission area is smaller than the emission area on the top surface. The output from is very small compared to the output from the top surface. In type 2, a semiconductor layer 1021 is disposed on a transparent element substrate 1022, and the element substrate side is a light emitting side. In type 3, a semiconductor layer 1021 is disposed on a transparent element substrate 1022, and the semiconductor layer side is a light emitting side. In the type 2 and type 3 chips, light is emitted also from the side surface of the transparent element substrate, so that the output from the side surface is the same as the output from the upper surface. Although each embodiment of the present invention can be applied to any of these types of LED chips 102, the first embodiment is particularly suitable for a type 1 LED chip that does not leak light from the element substrate 1022. .

  On the upper surface of the LED chip 102, a pad portion 102a necessary for wire bonding the semiconductor layer 1021 is formed. In the LED chip 102 shown in FIG. 1, the pad portion 102a is formed only at one place, but may be formed at two or more places. In some cases, no electrode is formed on the upper surface of the LED chip 102, that is, conduction is obtained only from the lower surface.

  In the white LED device 100 of the present embodiment, as shown in the figure, four LED chips 102 are arranged on the substrate 101 with a predetermined interval, and the upper surface of the LED chip 102 and between the chips (interval portion). A phosphor layer 103 is continuously formed on the upper part of the substrate. That is, the phosphor layer 103 is formed by cross-linking between the chips. On the upper surface of the LED chip 102, the phosphor layer 103 is not formed on the pad portion 102a necessary for wire bonding.

  The arrangement interval L (μm) of the LED chips 102 has an optimum range depending on the directivity of the LED light emitted from the LED chips, but is usually 30 to 250 μm, preferably 50 to 120 μm. When the arrangement interval L is long, light emission from the phosphor particles from this portion increases, and it looks yellow.

  Although the thickness T (μm) of the phosphor layer 103 is related to the LED chip arrangement interval L, it is usually 50 to 400 μm, preferably 50 to 250 μm. When the thickness of the phosphor layer is increased, the component that increases the optical path length that propagates through the phosphor layer increases, resulting in more yellow fluorescent components mainly in the end face direction, resulting in chromaticity unevenness and brightness unevenness. It becomes easy.

  The phosphor layer 103 is made of a material in which a phosphor such as a YAG phosphor is dispersed in a resin such as a silicone resin, an epoxy resin, or an acrylic resin, and can be formed into a film by stencil printing using a mask, screen printing, or the like. it can. Alternatively, a thin sheet made of a material in which a phosphor is dispersed in a resin may be produced, and this phosphor sheet may be attached to the upper surface of the LED chip 102 using an adhesive or the like. In the former case, in order to improve the printability of the phosphor layer material (coating solution) and the ease of crosslinking, a thickener such as fumed silica is added to the coating solution to increase the viscosity of the coating solution and thixotropy. Is desirable.

  The white LED device 100 of the present embodiment is manufactured by the following method, for example. First, four LED chips 102 are die-bonded on a substrate 101, and then a spacer mask 301 having a thickness substantially the same as or slightly thinner than the thickness of the chip 102, as shown in FIG. A metal mask 302 having the same thickness as the phosphor layer 103 on the upper surface and provided with an opening so as to cover the pad portion 102a, and a stencil printing method using a squeegee 303 is used. Then, the phosphor layer coating solution is applied and cured to form the phosphor layer 103. Finally, the pad portion 102a of each LED chip 102 is wire-bonded.

In the cross section shown in FIG. 3, the spacer mask 301 has an opening wider than the size of the chip, but the opening covers the wire bonding pad on the upper surface of the chip in the other cross section. It has a shape. Therefore, at the time of printing, a metal mask is placed on the wire bonding pad so that the phosphor layer is not formed on the wire bonding pad.
By using the spacer mask in this manner, it is possible to solve the problem that the squeegee gets caught on the metal mask when the metal mask is flexibly printed. Moreover, it is possible to prevent the phosphor layer from being formed thinner than the design thickness by bending the metal mask.

  As another manufacturing method of the present embodiment, when using a phosphor sheet, for example, a phosphor layer material is stencil-printed on the heat-resistant film having releasability using the metal mask 302 described above, Curing is performed to obtain a phosphor sheet. On the other hand, four LED chips 102 are die-bonded on the substrate 101, and the pad portion 102a of each LED chip 102 is wire-bonded. A phosphor sheet is attached to the upper surface of a chip to which an adhesive such as a silicone-based adhesive has been applied in advance, thereby obtaining a white LED device in which a uniform phosphor layer is formed on the upper surface of the chip and the upper portion of the gap between the chips.

  In the method using the phosphor sheet, since the phosphor sheet is disposed after wire bonding is performed on the pad portion 102a, contamination of the wire bonding pad can be avoided. In addition, even if the chip height varies, the phosphor layer thickness does not vary even when the chip height varies compared to the manufacturing method based on stencil printing, and the case where there is a difference in height can be accommodated. Furthermore, when the phosphor sheet is arranged on the chip, the chip end face and the phosphor sheet end face can be aligned by the self-alignment function based on the surface tension of the adhesive, so that the phosphor sheet can be arranged with high accuracy.

  In the present embodiment, the phosphor layer 103 is formed so as to bridge between the chips, and the phosphor is not present between the chips, particularly on the substrate side, so that the bridging portions of the phosphor layer 103 are on both sides. Since light is emitted by the excitation light from the chip, it is possible to reduce the occurrence of dark linear non-light emitting portions between the chips, and to prevent an excessive amount of phosphor with respect to the amount of excitation light to be emitted. Can be reduced.

  Further, in the present embodiment, since an air layer is formed between the LED chip and the LED chip, light from the phosphor layer is reflected, and a reduction in luminance between the chips can be more effectively prevented. . When the space between the LED chips is filled with a transparent resin or the like, the light from the phosphor layer incident on the transparent resin portion between the chips is absorbed by the side surface of the chip or the upper surface of the substrate. This is to cause a decrease. Therefore, it is preferable that an air layer or a reflection layer and a scattering layer as described later are formed between the LED chips. And when sealing the LED device of this invention, it is preferable not to be filled with the transparent resin to which the reflecting material and the scattering material are not added at least between LED chips.

<Second Embodiment>
FIG. 4 shows a white LED device according to the second embodiment. The present embodiment is the same as the first embodiment in that the phosphor layer 103 is formed by crosslinking between the chips, but the semiconductor layer 1021 of the LED chip 102 is smaller than the element substrate 1022, and the phosphor layer This is different from the first embodiment in that 103 is formed so as to cover not only the upper surface of the semiconductor layer 1021 but also the side surfaces. Since the structure of the LED chip 102 and the material of the phosphor layer other than those described above are the same as those in the first embodiment, description thereof is omitted.

  In the white LED device of the present embodiment, for example, when a phosphor layer is manufactured by a method of applying a phosphor layer coating solution, a spacer mask 301 having a thickness similar to the thickness of the element substrate 1022 is used. The metal mask 302 having a total thickness of the semiconductor layer 1021 and the phosphor layer formed on the upper surface thereof is used. As a result, as shown in FIG. 4A, the phosphor layer 103 is formed which covers the entire semiconductor layer 1021 and bridges the chips.

  The white LED device of the present embodiment can be applied to any of the three types of LED chips shown in FIG. 2, but in particular, in a type 1 LED chip in which the output from the side surface is extremely small compared to the output from the top surface. Is preferred. The phosphor layer 103 may have a protruding shape so as to completely cover the end portion as indicated by an arrow in FIG.

  Also in the white LED device of the present embodiment, by providing the phosphor layer 103 by bridging the chips, it is possible to reduce dark linear non-light-emitting portions generated between the chips, chromaticity unevenness, luminance Unevenness can be reduced. In this embodiment, since the phosphor layer covers the entire semiconductor layer that is a light emitting portion, light generated from the semiconductor layer can be used effectively, and compared with the LED device shown in FIG. Since the thickness of the phosphor layer 103 existing between the chips can be reduced, the difference in color tone, that is, the chromaticity unevenness due to the relative phosphor concentration difference with respect to the respective excitation light amounts between the chip upper surface and the chips is reduced. be able to.

<Third Embodiment>
5A and 5B are diagrams showing an LED device according to a third embodiment, in which FIG. 5A is a side cross-sectional view, and FIG. 5B is a cross-sectional view taken along line AA ′ in FIG.

  The LED device according to the present embodiment is different from the first embodiment in that a phosphor layer is formed on both side surfaces in the vertical and horizontal directions of the arranged LED chip rows. Other configurations are the same as those of the first embodiment. The LED device according to the present embodiment is a type 2 or type 3 LED chip that is composed of a transparent element substrate and a semiconductor layer among the three types shown in FIG. Is preferred. By covering the side surface of the chip row with the phosphor layer 103, the phosphor layer provided on the side surface side can emit light using the output from the side surface as excitation light, and the output of the entire LED device can be increased.

  It is also possible to provide a reflective layer made of a resin containing a white pigment or a reflective material instead of the phosphor layers formed on both side surfaces of the LED chip array. For example, before forming the upper phosphor layer, the phosphor layer or the reflective layer provided on the side surface is inserted with a spacer mask in the gap between the chips, and stencil printing is performed a plurality of times, or the phosphor sheet or the reflective sheet is chipped. It can be formed by a method such as sticking around a row.

<Fourth embodiment>
An example of the LED device of the present embodiment is shown in FIG. As shown in the drawing, in this embodiment, before forming the phosphor layer 103, a filler is filled between the chips 102 to form the ribs 104. In the present embodiment, by adjusting the height of the rib 104, the thickness of the phosphor layer 103 on the top surface of the chip and the thickness of the phosphor layer located in the gap between the chips can be made different, and the rib material By using a material having a high reflectivity, it is possible to reduce a decrease in luminance between chips.

The height of the rib 104 is preferably higher than the thickness of the chip 102. Specifically, the height exceeding the upper surface of the chip is preferably higher than 1/4 of the thickness of the phosphor layer on the chip. That is, it is preferable that the thickness of the phosphor layer at a portion where the chips are cross-linked is 3/4 or less of the thickness of the phosphor layer on the top surface of the chip. The filler is not particularly limited, but a resin can be used. In particular, a resin containing a reflective material such as a white pigment or reflective particles or a resin containing a scattering material is suitable, and fine particles such as TiO ₂ and ZrO ₂ can be added. By using a reflective filler and using a resin containing a scattering material, the amount of light absorbed by the inter-chip portion is reduced, and the light is reflected and extracted to the top surface, preventing a decrease in luminance at the inter-chip portion. can do.

  Similarly to the first to third embodiments, the LED device of the present embodiment also has a phosphor layer formed on a chip arranged on a substrate by a stencil printing method using a metal mask or the like. It can be manufactured by wire bonding to the pad portion of the chip.

  In the figure, the LED device is shown in which the phosphor layer is provided only on the upper side of the chip row, but the phosphor layer may be provided on both sides of the chip row as in the third embodiment. In this case, in the figure, the filler on both sides in the longitudinal direction may be left as it is, and the phosphor layer may be provided only on both sides in the direction perpendicular to it (the front and back direction of the paper), or the filler on both sides in the longitudinal direction. Instead of this, a phosphor layer may be provided. It can be appropriately selected depending on the type of chip.

  The LED device of the present embodiment requires a manufacturing process in which a filler is provided between the chips, but the phosphor layer can be easily formed by coating as compared with the case where the gaps are between the chips. Further, by adjusting the height of the rib, that is, the thickness of the phosphor layer located between the chips, it is possible to adjust the color tone and obtain an LED device with less chromaticity unevenness.

<Fifth embodiment>
The LED device of the fifth embodiment is different in that the thickness of the phosphor layer existing between the chips is made thinner than the thickness of the phosphor layer existing on the upper surface of the chip. In the first to third embodiments described above, the thickness of the phosphor layer is uniform, or the thickness of the phosphor layer existing between the chips is thicker. The light emission color of the LED device is a color mixture of the color emitted by the chip and the color emitted by the phosphor. The color from the phosphor becomes dominant and the yellowish fluorescence becomes stronger. On the other hand, in the present embodiment, the thickness of the phosphor layer existing between the chips is made thinner than the thickness of the phosphor layer on the upper surface, so that unevenness in color can be reduced.

  The LED device of the fifth embodiment uses a phosphor sheet having portions with different thicknesses in order to vary the thickness of the phosphor layer. 7A and 7B are side sectional views of the LED device according to the present embodiment.

  As shown in the figure, the phosphor sheet 1031 used in the present embodiment has concave portions 103a formed on the surface thereof having the same pitch as the chip arrangement pitch and having substantially the same diameter as the gap between the chips. Such a phosphor sheet 1031 is subjected to an embossing process before curing a phosphor film produced by stencil printing on a releasable film as in the first embodiment using injection molding using a mold. Alternatively, it can be produced by a method such as stencil printing on a releasable film on which convex portions are formed. In the figure, the concave portion 103a has a semicircular cross section, but may have an arbitrary shape such as a V shape or a U shape. From the viewpoint of releasability and strength when producing the sheet, a semicircular shape is preferable.

  In the LED device shown in FIG. 7A, such a phosphor sheet 1031 is bonded to a chip row with an adhesive 105 or the like so that the surface on which the concave portion 103a is formed is the upper surface (light emission side). It is a body layer. The LED device shown in FIG. 7B is obtained by bonding the phosphor sheet 1031 to the chip row with an adhesive 105 or the like so that the surface on which the concave portion 103a is not formed becomes the upper surface (light emission side). In either case, the phosphor sheet 1031 is disposed so that the recess 103a and the gap between the chips coincide.

  In the present embodiment, as in the fourth embodiment, the thickness of the phosphor layer existing between the chips is made thinner than the thickness of the phosphor layer on the upper surface, thereby reducing the unevenness of the color. be able to. The LED device shown in FIGS. 7A and 7B has the same effect in that the thickness of the phosphor layer existing between the chips is reduced. However, the adhesive 105 has few protrusions and sticks out. The LED device shown in FIG. 7B is more preferable in that light leakage from the agent portion is prevented. Further, in this embodiment, by using the phosphor sheet, contamination of the wire bonding pad can be avoided, and a phosphor layer having a desired thickness can be formed even if the chip height varies.

<Other embodiments>
The first to fifth embodiments of the light-emitting device of the present invention have been described above. However, the light-emitting device of the present invention can be combined with these embodiments as appropriate, or other elements can be combined. It is also possible to change the shape of the body layer.
For example, as the shape of the phosphor layer, a plate-like shape and a shape having a concave portion corresponding to the chip gap have been exemplified. For example, as shown in FIGS. It is also possible to form a mold shape.
In addition, a layer that does not contain phosphor particles, such as a resin layer with a higher refractive index or a resin layer that contains a light scattering material such as silica particles for the purpose of light scattering, is laminated on the plate-like phosphor layer. It is possible to create different shapes.
Further, ribs can be formed even when a phosphor sheet is used.

[Example 1]
Four LED chips each having a length of 980 μm were arranged on a ceramic package (substrate) with a chip interval L = 200 μm. A phosphor layer having a thickness of 200 μm was formed on the LED chip using a stencil printing (metal mask printing) method.

  The phosphor layer is formed by using a phosphor dispersion liquid in which 27 wt% of YAG phosphor with respect to silicone thermosetting resin and 13 wt% of fumed silica are mixed for the purpose of viscosity adjustment. Printing was performed using a stencil (metal mask). After printing the phosphor layer, it was heated at 150 ° C. for 2 hours to cure the silicone resin, thereby forming a phosphor layer having substantially the same thickness as the metal mask. Thereafter, a gold wire was wire-bonded to the pad portion on the upper surface of the LED chip to produce an LED device having the structure shown in FIG. An air layer is formed at the portion between the chips below the phosphor layer.

[Comparative Example 1]
Using the LED device in which the same LED chips as in Example 1 were arranged, phosphor particles were attached by electrophoretic electrodeposition, and each chip was covered, and then the surface was coated with a silicone-based thermosetting resin, An LED device having the structure shown in FIG. The thickness of the phosphor layer was about 30 μm.

[Comparative Example 2]
Using the LED device in which the same LED chips as in Example 1 are arranged, the chip array and the chip are covered with a phosphor dispersion liquid containing 27 wt% YAG phosphor with respect to the silicone thermosetting resin. An LED device having the structure shown in (b) was manufactured. The thickness of the phosphor layer was about 200 μm.

For the LED devices manufactured in Example 1 and Comparative Examples 1 and 2, the luminance distribution and chromaticity distribution were measured. The results of the luminance distribution measurement are shown in FIGS. (A) is the result of Comparative Example 1, (b) is the result of Comparative Example 2, and (c) is the result of Example 1. The figure shows a plot of the luminance distribution in the light emitting surface measured from directly above the package in the longitudinal section, and is normalized with the maximum luminance being 100%. The horizontal axis is the relative position of the LED chip on the package (the center is zero).
From the result of the figure, it can be seen that in the LED device of Example 1, there is little luminance unevenness between the chips (ratio of luminance reduction with respect to the maximum luminance, a portion that can be seen in the valley in the figure).

The results of the chromaticity distribution measurement are shown in FIGS. (A) is the result of Comparative Example 1, (b) is the result of Comparative Example 2, and (c) is the result of Example 1. The figure shows a plot of the chromaticity distribution in the light emitting surface measured from directly above the package in the longitudinal section, and the chromaticity change based on the chromaticity on the chip (x and y values of CIE1931) Minutes were plotted. The horizontal axis is the relative position of the LED chip on the package (the center is zero).
From the result of the figure, it can be seen that in the LED device of Example 1, the difference in chromaticity appearing between the chips (solid line is x value, dotted line is y value) is small. In particular, the change width of the y value (dotted line) is small. This means that it is hard to look yellow.

[Example 2]
Four LED chips each having a length of 980 μm and a height of 100 μm were arranged on a ceramic package (substrate) with a chip interval L = 100 μm via a conductive adhesive made of AuSn having a thickness of about 30 μm. One-component heat-curable adhesive liquid silicone resin (white) containing 30 to 40% titanium oxide was injected and filled between the three chips, and then heat-cured to fill the space between the chips. The height of the silicone resin to which titanium oxide is added is about 120 μm, which is lower than the upper surface of the chip disposed on the substrate via the conductive adhesive. On this LED chip, a phosphor layer having a thickness of 200 μm was formed using the stencil printing (metal mask printing) method as in Example 1. Thereafter, a gold wire was wire-bonded to the pad portion on the upper surface of the LED chip to produce an LED device having a structure shown in FIG.

  For the LED device of Example 2, as in Example 1, the luminance distribution and chromaticity distribution in the light emitting surface were measured from directly above the package. The results are shown in FIGS. 11 (a) and 11 (b). (A) is a luminance distribution, and (b) is a chromaticity distribution. In the LED device of Example 2, the light emission by the phosphor between the chips is reflected by the white filler and taken out to the upper surface, so that the luminance unevenness in the surface can be reduced by preventing the luminance decrease between the chips, It can also be seen that the chromaticity unevenness is reduced.

  In this embodiment, the height of the resin (rib) filled between the chips is lower than the upper surface of the chip, but it may be formed higher than the chip as shown in FIG. When forming a rib having a height higher than the upper surface of the chip, it can be formed by a printing method using a mask.

[Example 3]
Four LED chips each having a length of 980 μm and a height of 100 μm were arranged on a ceramic package (substrate) with a chip interval L = 100 μm via a conductive adhesive made of AuSn having a thickness of about 30 μm.
The average particle diameter D _{50 (before} dispersion) is 23 wt% titanium oxide 21 nm, using a 9 wt% dispersed silicone resin thickener consisting of fumed silica, after printing using a metal mask, and heat curing, the chip A rib having a height of 200 μm was formed therebetween. Thereafter, a phosphor layer having a flat top surface with a thickness of 200 μm on the chip and about 130 μm on the rib was formed by using a metal mask printing method on the top surface and rib of the LED chip. Thereafter, a gold wire was wire-bonded to the pad portion on the upper surface of the LED chip to produce an LED device having a structure without ribs at both ends of the LED device shown in FIG.

  For the LED device of Example 3, as in Example 1, the luminance distribution and chromaticity distribution in the light emitting surface were measured from directly above the package. The results are shown in FIGS. 12 (a) and 12 (b). (A) is a luminance distribution, and (b) is a chromaticity distribution. In the LED element of Example 3, the light emitted by the phosphor between the chips is reflected by the ribs and taken out to the upper surface, so that the luminance unevenness in the surface can be reduced by preventing the luminance decrease between the chips, and the chromaticity unevenness. Became smaller.

  The present invention can be used for white LEDs, LED headlamps, LED street lamps, backlights, displays, and general lighting. In particular, chromaticity unevenness and luminance unevenness of the light emitting surface such as LED, headlamp package, street light package, etc. using an optical system that projects (projects) the light emitting surface as a light source image using a convex lens or a reflecting mirror. Is useful for a light-emitting device in which is projected as it is.

101 ... substrate (package), 102 ... semiconductor light emitting device (LED chip), 102a ... pad portion, 1021 ... device substrate, 1022 ... semiconductor laminate, 103 ... phosphor layer , 1031 ... phosphor sheet, 1032 ... recess, 105 ... adhesive

Claims (5)

A chip array in which a plurality of semiconductor light emitting devices each having an upper surface and a side surface are arranged so that each side surface has a gap, and a phosphor that converts the wavelength of at least part of light emitted from the semiconductor light emitting device And a phosphor layer that
In the gap, a rib using a resin containing a reflecting material is formed in contact with the side surface forming the gap,
The phosphor layer, the is formed by crosslinking between the upper surface to the plurality of semiconductor light emitting elements of the chip sequence, the thickness of the phosphor layer on the plurality of semiconductor light emitting elements positioned over said ribs A semiconductor light emitting device having a thickness different from that of the phosphor layer . The semiconductor light emitting device according to claim 1,
  2. A semiconductor light emitting device according to claim 1, wherein a phosphor layer or a reflective layer is also formed on side surfaces in two vertical and horizontal directions of the chip row. The semiconductor light-emitting device according to claim 1 or 2,
  The rib is higher than the height of the side surface of the semiconductor light emitting element. The semiconductor light-emitting device according to claim 1 or 2,
  The rib is lower than the height of the side surface of the semiconductor light emitting element. The semiconductor light-emitting device according to claim 1,
  The semiconductor light-emitting device, wherein the rib is a white resin.

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