JP6743866B2 - Semiconductor light emitting device - Google Patents

Description

The present invention relates to a semiconductor light emitting device using a light emitting diode (LED) and a manufacturing method thereof. In particular, the present invention relates to a semiconductor light emitting device that is preferably used in a light source device that requires light distribution characteristics and a method for manufacturing the same.

BACKGROUND ART Light emitting diodes (hereinafter abbreviated as “LEDs”) are used in various application products such as lighting devices, optical communication devices, printers and scanners from the viewpoint of high luminous efficiency, low power consumption and long life. It is used as a light source. The white LED currently in the mainstream is a single LED element (single chip) based on a combination of a blue LED with a wavelength peak of around 450 nm and a yellow phosphor that converts the blue light into a wavelength of around 550 nm. Only the white light is realized. Further, by widening or arbitrarily selecting the wavelength conversion band of the phosphor or adding an LED element not coated with the phosphor, it is possible to obtain high-quality illumination light with excellent color rendering properties.

In an LED element of the type that is surface-mounted on a circuit board of a light source device, p-type and n-type semiconductor layers are epitaxially grown on a growth substrate such as sapphire, and then p-electrodes and n-electrodes made of a conductor are formed on each semiconductor layer. It has a basic structure of being laminated on. Face down (FD) mounting is one method of surface-mounting LED elements on a substrate of a chip package or a circuit board of a light source device (collectively referred to as "mounting board" in this specification). Face down is a method of mounting an LED element in a direction in which the stacking direction of semiconductor layers and the light extraction direction are reversed. A mounting method in which the stacking direction of the semiconductor layers and the light extraction direction are the same is called face-up (FU).

For example, Patent Document 1 discloses a structure in which LEDs are mounted face down on a carrier substrate (corresponding to a mounting substrate). According to the mounting method of Patent Document 1, after the LED is flip-chip mounted on the carrier substrate, an underfill is injected between the bump-shaped electrodes. The underfill extends to the side surface of the epitaxial structure (semiconductor layer in this specification) of the LED and is cured, so that the support rigidity of the LED mounted on the carrier substrate is enhanced.

JP 2006-344971 A

By the way, in an illuminator that controls the light distribution characteristics such as the direction of light spread and the direction using an optical lens, the light emitting area is small, the front brightness is high, and the light distribution color temperature difference is small. A so-called point light source light emitting device is said to be preferable. Therefore, in a conventional semiconductor light emitting device using an LED, a light emitting element provided with a lens is used. By installing a lens in the light emitting element, the light extraction efficiency is increased and the front brightness is increased. However, since the lens is required, the step of forming the lens is required.

The present invention has been made in view of the above conventional problems, and can be realized with a simple structure, which suppresses light leakage in the edge direction of the light emitting element and improves the light distribution characteristics of the light source. And its manufacturing method.

The present invention is a semiconductor layer, an electrode formed on a lower surface side of the semiconductor layer, and a frame-shaped portion surrounding an outer edge of the semiconductor layer, the frame portion being perpendicular to the upper surface of the semiconductor layer with respect to the upper surface. A frame-shaped portion having a constant height and a constant width at its upper end portion in a direction along the upper surface, at least a portion of which is formed in contact with the outer edge of the semiconductor layer. And a semiconductor light emitting device.

Further, the present invention, a step of disposing a plurality of light emitting elements having a semiconductor layer on a growth substrate and an electrode on the semiconductor layer, one surface of the growth substrate is in contact with a sheet at a predetermined interval, Arranging an insulating member so as to fill a gap between the growth substrates of the plurality of light emitting devices; forming a groove in the gap between the growth substrates while leaving a part of the insulating member; And a step of peeling the semiconductor light emitting device.

Further, the present invention provides a step of preparing a semiconductor wafer in which semiconductor layers are stacked on a growth substrate and a plurality of light emitting elements are arranged at predetermined intervals, and a step between the adjacent semiconductor layers. A step of processing a groove in the growth substrate, a step of arranging an insulating member so as to fill the groove of the growth substrate, a step of peeling the growth substrate, and a step of leaving the insulating member in part to leave the groove. And a step of cutting out each of the light emitting elements at the position.

According to the semiconductor light emitting device of the present invention, it can be realized with a simple structure, light leakage in the edge direction can be suppressed, and the light distribution characteristics of the light source can be improved. Further, according to the method for manufacturing a semiconductor light emitting device of the present invention, it is possible to obtain a high quality semiconductor light emitting device with a small number of steps and excellent mass productivity.

1 is a diagram schematically showing a cross-sectional structure of a semiconductor light emitting device according to a first embodiment of the present invention. FIG. 2 is a plan view of the semiconductor light emitting device according to the first embodiment shown in FIG. 1 viewed from the light extraction surface side. FIG. 5 is a diagram for explaining the operation of the semiconductor light emitting device according to the first embodiment. FIG. 6 is a manufacturing process diagram for illustrating the method for manufacturing the semiconductor light emitting device according to the first embodiment. It is a figure which shows typically the cross-section of the semiconductor light-emitting device by the 2nd Embodiment of this invention. FIG. 8 is a diagram for explaining the operation of the semiconductor light emitting device according to the second embodiment. FIG. 9 is a manufacturing process diagram for describing the method for manufacturing the semiconductor light emitting device according to the second embodiment. FIG. 11 is a manufacturing process diagram for describing a method for manufacturing the semiconductor light emitting device according to the third embodiment. It is a figure which shows the cross section of the light source device typically by 4th Embodiment. It is a figure which shows typically the cross-section of the semiconductor light-emitting device by 5th Embodiment. It is a figure which shows typically the cross-section of the semiconductor light-emitting device by the modification of 5th Embodiment. It is a figure which shows typically the cross-section of the semiconductor light-emitting device by the other modification of 5th Embodiment. It is a figure which shows typically the cross-section of the semiconductor light-emitting device by 6th Embodiment.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. Throughout the referenced drawings, the same reference numerals are given to the same constituent elements and the corresponding constituent elements that have different forms but have a corresponding relationship. Further, the embodiments described below are merely examples, and the invention is not limited to these specific modes.

(First embodiment)
FIG. 1 is a diagram schematically showing a cross-sectional structure of a semiconductor light emitting device 10 according to the first embodiment of the present invention. The semiconductor light emitting device 10 includes a semiconductor layer 11 that constitutes an LED that is a light emitting element, and a p electrode 12 and an n electrode 13 that are respectively formed on the lower surface side of the semiconductor layer 11. The wavelength conversion unit 15 may be arranged in contact with the upper surface of the semiconductor layer 11.

Note that the expressions “upper surface” and “lower surface” of the semiconductor layer 11 are used in a relative meaning when the light extraction surface side is defined as up and the bottom surface side where an electrode is formed is defined as down in this specification. Nothing more than. That is, "upper" and "lower" are not intended to be interpreted in the absolute upper and lower senses.

As shown in detail in FIG. 1, the semiconductor layer 11 has a pn double hetero structure in which an n-type semiconductor layer 111, an active layer 112, and a p-type semiconductor layer 113 are sequentially stacked. The semiconductor layer 11 is, for example nitride compound semiconductor (general formula _{In x Al y Ga 1-xy} N (0 ≦ x, 0 ≦ y, x + y ≦ 1)) consisting of a is for example GaN based blue LED of. The semiconductor layer 11 forming the LED may be made of another compound semiconductor such as ZnSe-based, InGaAs-based, or AlInGaP-based. The semiconductor layer 11 can be formed by sequentially stacking it on a growth substrate (not shown) such as sapphire by, for example, a metal organic chemical vapor deposition (MOCVD) method. Alternatively, the semiconductor layer 11 may be formed by using another vapor phase or liquid phase growth method.

The p-electrode 12 electrically connected to the anode of the LED is provided so as to be electrically joined to the p-type semiconductor layer 113. On the other hand, the n-electrode 13 electrically connected to the cathode is provided so as to be electrically joined to the n-type semiconductor layer 111. The p electrode 12 and the n electrode 13 are formed as bumps protruding toward a mounting substrate (not shown). For example, an under barrier metal (UBM) is deposited on each predetermined position of the p-type and n-type semiconductor layers 113 and 111 by sputtering or the like, and a conductive metal having good wettability is formed on the deposited UBM. By plating Au, the bump-shaped p electrode 12 and n electrode 13 are obtained.

In the semiconductor light emitting device 10, when a forward current is supplied to the semiconductor layer 11, carriers move and are confined in the active layer 112, where recombination of carriers occurs efficiently and light is emitted. Therefore, the active layer 112 is also called a light emitting layer.

Further, a light reflection layer 114 may be provided on the lower surface of the p-type semiconductor layer 113 in order to realize a high brightness LED. For the light reflection layer 114, for example, a DBR (Distributed Bragg Reflector) formed as a part of a p-type semiconductor can be used. The DBR is a diffraction grating with a spatial period of λ/2n (where λ is the wavelength of light in vacuum and n is the refractive index of the medium (specifically, p-type semiconductor layer)). That is, the light reflecting layer 114 made of DBR diffracts the light having the wavelength λ emitted from the active layer 112 to the mounting substrate side to the light extraction surface side which is the upper surface on the opposite side, while driving the forward drive current. It can be supplied to the active layer 112 and the n-type semiconductor layer 111. As a result, the light distribution characteristics can be improved and the light extraction efficiency can be improved.

According to the embodiment of the present invention, the semiconductor light emitting device 10 is characterized by including a frame-shaped portion 14 a formed so as to surround the outer edge of the semiconductor layer 11. The frame-shaped portion 14 a is formed on the outer edge of the semiconductor layer 11 as a part of the insulating member 14 arranged so as to fill the space between the p electrode 12 and the n electrode 13.

Specifically, as shown in FIG. 1, the frame-shaped portion 14a has a constant height H with respect to the upper surface 11a of the semiconductor layer 11 in a direction perpendicular to the upper surface 11a, and extends along the upper surface 11a. It has a constant width W at the upper end portion of the frame-shaped portion 14a in the horizontal direction. The inner side surface of the frame-shaped portion 14a located above the position in contact with the semiconductor layer 11 is formed as a surface perpendicular to the upper surface 11a of the semiconductor layer 11. Further, the outer wall surface 14b of the frame-shaped portion 14a is orthogonal to or perpendicular to a mounting substrate (not shown) on which the semiconductor light emitting device 10 is mounted, or a surface (mounting surface) mounted on the mounting substrate. It is preferably formed as a surface.

The insulating member 14 including the frame-shaped portion 14a is formed of an insulating material having light reflectivity. Specifically, the main component of the insulating member 14 is preferably a thermosetting resin such as a silicone resin. The insulating material of the insulating member 14 is a thermosetting resin, which is one kind of oxide selected from the group consisting of Ti, Zr, Nb, Al and Si, or at least one kind of AlN and MgF. It is preferable to mix at least one selected from the group consisting of TiO ₂ , ZrO ₂ , Nb ₂ O ₅ , Al ₂ O ₃ , MgF, AlN, and SiO ₂ . Thereby, in addition to the electrical insulation and mechanical strength suitable for the insulating member 14, light reflectivity can be provided.

FIG. 2 is a plan view of the semiconductor light emitting device 10 shown in FIG. 1 viewed from the light extraction surface (semiconductor layer upper surface 11a) side. As shown in FIG. 2, the semiconductor light emitting device 10 has a quadrangle in a plan view, and the frame-shaped portion 14a has a quadrangle so as to surround the edge (outer edge) of the light extraction surface of the LED (the upper surface 11a of the semiconductor layer). It is formed in a frame shape.

The wavelength conversion unit 15 is preferably made of a resin containing a phosphor material. The wavelength conversion unit 15 does not necessarily need to contain the phosphor material, and may be a resin containing a diffusing material (such as a filler) or a coloring material (such as a pigment). The wavelength converter 15 has a constant thickness H'. As is easily understood from FIG. 1, the height from the mounting surface, which is the bottom surface, to the upper surface of the wavelength conversion portion 15 is higher than that of the frame-shaped portion 14a (that is, H'>H). As described above, the frame-shaped portion 14a is formed of an insulating material having light reflectivity. Therefore, a part of the light emitted from the semiconductor layer 11 in the edge direction is reflected on the inner side surface of the frame-shaped portion 14a (see FIG. 3). As a result, the spread of light emitted from the semiconductor light emitting device 10 can be suppressed, light leakage in the edge direction can be suppressed, and the light distribution characteristics of the light source can be improved.

Further, the insulating member 14 filling the space between the p-electrode 12 and the n-electrode 13 packages the entire LED light-emitting element, so that there is no need for underfilling, which is conventionally required at the time of mounting on a substrate or after mounting on a substrate. Further, since the frame-shaped portion 14a forming a part of the insulating member 14 has a constant height H and width W and surrounds the outer edge of the semiconductor layer 11, the external force applied from the lateral side is smaller than that of the conventional one even though the structure is simple. The rigidity against stress and stress is improved. Further, since the frame-shaped portion 14a having a constant height extends to and supports the side surface of the wavelength conversion portion 15, peeling and damage of the wavelength conversion portion 15 can be prevented.

Next, a method of manufacturing the semiconductor light emitting device 10 according to the first embodiment described above will be described with reference to FIG.

First, a semiconductor in which the semiconductor layer 11 is stacked on the growth substrate 31, a plurality of light emitting elements 32, 32,... Are arranged at predetermined intervals, and a predetermined electrode, a protective film, or the like is formed on each light emitting element 32. A wafer 30 is prepared (see FIG. 4a). When the semiconductor layer 11 is a nitride-based compound semiconductor, for example, a GaN-based blue LED, a sapphire single crystal wafer is preferably used as the growth substrate 31.

The semiconductor layer 11 already shown in FIG. 1 can be formed of the n-type semiconductor layer 111 from GaN using Si as a dopant, and the p-type semiconductor layer 113 from GaN using Mg or Zn as a dopant. Layer 112 may be formed of GaN or InGaN, for example. Further, the semiconductor layer 11 can be formed of an InAlGaN-based compound to form a blue LED.

The semiconductor layer 11 can be formed by sequentially epitaxially growing the n-type semiconductor layer 111, the active layer 112, and the p-type semiconductor layer 113 on the growth substrate 31 by, for example, the MOCVD method or another vapor phase growth method.

After forming the semiconductor layer 11, the p electrode 12 and the n electrode 13 are formed. The p-electrode 12 and the n-electrode 13 may have a bump shape protruding from a predetermined position of the semiconductor layer 11. That is, a UBM film is formed at a predetermined position on each of the p-type and n-type semiconductor layers 113 and 111 by sputtering or the like, and Au is plated on the formed UBM to form bump-shaped p-electrodes 12 and n-electrodes. 13 is formed. Alternatively, the bumps may be formed by wire bonding.

Next, the grooves 31a, 31a,... Which separate the respective light emitting elements 32 are processed at positions between the adjacent semiconductor layers 11 (see FIG. 4b). The method of processing the groove 31a is not particularly limited, but the groove 31a can be formed on the growth substrate 31 by dicing, diamond cutting, or the like with a blade having a rectangular cross section, for example.

Then, the insulating member 14 is arranged so as to fill the grooves 31a, 31a,... Between the electrodes of the semiconductor layer 11 and between the plurality of light emitting elements 32, 32,. The insulating member 14 is, for example, a thermosetting resin such as a silicone resin and one oxide selected from the group consisting of Ti, Zr, Nb, Al, and Si, or at least one of AlN and MgF. _May be formed of an insulating material having light reflectivity, which is a mixture of at least one selected from the group consisting of TiO ₂ , ZrO ₂ , Nb ₂ O ₅ , Al ₂ O ₃ , MgF, AlN, and SiO _2. it can.
As a method of forming the insulating member 14, a general molding method such as a compression molding method, a transfer molding method, or an injection molding method can be adopted. Alternatively, the insulating member 14 may be molded by a method of printing or applying a resin, a method of using a gel-like sheet, or the like, and then cured. Alternatively, the insulating member 14 may be formed (cured) so as to cover the p-electrode 12 and the n-electrode 13 and then cut to expose the electrode to obtain the state of FIG. 4c.

The growth substrates 31, 31,... Are placed on another pressure-sensitive adhesive sheet 41 so that the electrode sides of the light emitting elements 32, 32,... Contact each other (see FIG. 4D).

Next, the growth substrates 31, 31,... Are separated from the semiconductor layers 11, 11,... By, for example, the LLO (Laser Lift Off) method (see FIG. 4e). Then, the wavelength conversion unit 15 is arranged on the semiconductor layers 11, 11,... As needed (see FIG. 4f). The wavelength conversion section 14 can be formed using a general molding method such as a compression molding method, a transfer molding method, or an injection molding method.
Further, it may be arranged on the semiconductor layer 11 by using an appropriate method such as potting of material (mainly phosphor), screen printing, electrodeposition, application by spraying, and sheet attachment.

As the material of the wavelength conversion unit 15, for example, a nitride-based phosphor or an oxynitride-based phosphor activated by a lanthanoid-based element such as Ce or Eu can be used.
Specifically, as the phosphor material, for example, a rare earth aluminate activated by a lanthanoid element such as Ce can be used, and among them, the YAG phosphor material is preferably used. Further, a part or all of Y of the YAG-based phosphor material may be replaced with Tb or Lu. Moreover, a rare earth silicate or the like activated by Ce can be used as the phosphor material.
Further, alkaline earth halogen apatites, alkaline earth metal borate halogens, alkaline earth metal aluminates, alkaline earth metal sulfides, alkaline earth metal sulfur thiogallates, alkalis, which are activated by lanthanoid elements such as Eu. An organic metal or organic complex activated by an earth metal silicon nitride or germanate, or a lanthanoid-based element such as Eu can be used as the phosphor material. Examples of red phosphors include SCASN-based phosphors such as (Sr,Ca)AlSiN ₃ :Eu, CASN-based phosphors such as CaAlSiN ₃ :Eu, and SrAlSiN ₃ :Eu. Besides, it is possible to use, for example, a chlorosilicate phosphor or a β-sialon phosphor that absorbs blue light of the light emitting element and emits green light.

Then, the light emitting elements 32, 32,... Are cut out at a position of the groove 31a shown in FIG. 7b by using an appropriate cutting means such as dicing, leaving a part of the insulating member 14 (see FIG. 4g). Through these steps, a plurality of semiconductor light emitting devices 10 can be simultaneously obtained from one semiconductor wafer 30. In addition, the insulating member 14 that insulates the p-electrode 12 and the n-electrode 13 from each other and packages the entire light-emitting element, and the frame-shaped portion 14a that prevents light leakage in the edge direction are formed of the same material in the same step. Since it can be formed, it is possible to provide a method for manufacturing a high-quality semiconductor light emitting device with a small number of steps and excellent mass productivity.

(Second embodiment)
Next, a second embodiment of the present invention will be described. Here, FIG. 5 is a diagram schematically showing a cross-sectional structure of the semiconductor light emitting device 10 according to the second embodiment of the present invention. Similar to the first embodiment, the semiconductor light emitting device 10 includes the semiconductor layer 11, and the p electrode 12 and the n electrode 13 formed on the lower surface side of the semiconductor layer 11. Further, it is preferable that the wavelength conversion unit 15 is arranged in contact with the upper surface of the semiconductor layer 11.

The semiconductor layer 11 has a pn double hetero structure in which an n-type semiconductor layer 111, an active layer 112, and a p-type semiconductor layer 113 are sequentially stacked. The semiconductor layer 11 is, for example nitride compound semiconductor (general formula _{In x Al y Ga 1-xy} N (0 ≦ x, 0 ≦ y, x + y ≦ 1)) consisting of a is for example GaN based blue LED of. The semiconductor layer 11 forming the LED may be made of another compound semiconductor such as ZnSe-based, InGaAs-based, or AlInGaP-based. The semiconductor layer 11 is formed, for example, by MOCVD, by sequentially stacking it on a growth substrate (not shown) such as sapphire. The semiconductor layer 11 may be formed by using another vapor phase or liquid phase growth method.

The p-electrode 12 electrically connected to the anode of the LED is provided so as to be electrically joined to the p-type semiconductor layer 113. On the other hand, the n-electrode 13 electrically connected to the cathode is provided so as to be electrically joined to the n-type semiconductor layer 111. The p electrode 12 and the n electrode 13 are formed as bumps protruding toward a mounting substrate (not shown).

Further, a light reflection layer 114 may be provided on the lower surface of the p-type semiconductor layer 113 in order to realize a high brightness LED. For the light reflection layer 114, for example, DBR formed as a part of p-type semiconductor can be used. As a result, the light distribution characteristics can be improved and the light extraction efficiency can be improved.

The semiconductor light emitting device 10 is characterized by including a frame-shaped portion 14 a formed so as to surround the outer edge of the semiconductor layer 11. The frame-shaped portion 14 a is formed on the outer edge of the semiconductor layer 11 as a part of the insulating member 14 having light reflectivity and arranged so as to fill the space between the p electrode 12 and the n electrode 13.

The frame-shaped portion 14a has a quadrangular outer edge shape in a plan view, has a constant height with respect to the upper surface 11a of the semiconductor layer 11 in a direction perpendicular to the upper surface 11a, and extends in a direction along the upper surface 11a. It has a constant width at its upper end. In more detail, in the semiconductor light emitting device 10 of the second embodiment, the inner side surface 14t of the frame-shaped portion 14a in contact with the semiconductor layer 11 is formed as an inclined surface that spreads upward with respect to the upper surface 11a. That is, the rectangular opening side of the frame-shaped portion 14 a is wider than the light extraction surface of the semiconductor layer 11. On the other hand, the outer wall surface 14b of the frame-shaped portion 14a is formed as a surface orthogonal to or perpendicular to the mounting surface of the semiconductor light emitting device 10.

The insulating member 14 including the frame-shaped portion 14a is formed of an insulating material having light reflectivity. Specifically, the main component of the insulating member 14 is preferably a thermosetting resin such as a silicone resin. The insulating material of the insulating member 14 is a thermosetting resin, which is one kind of oxide selected from the group consisting of Ti, Zr, Nb, Al and Si, or at least one kind of AlN and MgF. It is preferable to mix at least one selected from the group consisting of TiO ₂ , ZrO ₂ , Nb ₂ O ₅ , Al ₂ O ₃ , MgF, AlN, and SiO ₂ . Thereby, in addition to the electrical insulation and mechanical strength suitable for the insulating member 14, light reflectivity can be provided. When the wavelength conversion portion 15 is arranged in contact with the upper surface of the semiconductor layer 11, the height from the mounting surface, which is the bottom surface, to the upper surface of the wavelength conversion portion 15 is as shown in FIG. Higher than that.

FIG. 6 is a diagram showing the operation of the semiconductor light emitting device 10 of the second embodiment. As described above, the frame-shaped portion 14a is formed of an insulating material having light reflectivity. Therefore, part of the light emitted from the semiconductor layer 11 in the edge direction is reflected by the inclined inner side surface 14t of the frame-shaped portion 14a. This suppresses the spread of light emitted from the semiconductor light emitting device 10 and suppresses light leakage in the edge direction. Further, since the direction of light reflected by the inner surface 14t of the frame-shaped portion 14a is substantially orthogonal to the surface of the wavelength conversion portion 15, refraction in an undesired direction at the boundary surface between the wavelength conversion portion 15 and air is suppressed. be able to. Thereby, the light distribution characteristics of the light source can be further improved.

Further, the structure in which the insulating member 14 filling the space between the p electrode 12 and the n electrode 13 packages the entire semiconductor layer 11 eliminates the need for underfilling, which is conventionally required at the time of mounting the substrate or after mounting the substrate. In addition, since the frame-shaped portion 14a forming a part of the insulating member 14 has a constant height and width and surrounds the outer edge of the semiconductor layer 11, external force and stress from the side can be obtained as compared with the conventional structure, although the structure is simple. The rigidity against is increased. Further, the frame-shaped portion 14a having a certain height extends to and supports the side surface of the wavelength conversion portion 15, so that the wavelength conversion portion 15 can be prevented from being peeled off or damaged.

Next, a method of manufacturing the semiconductor light emitting device 10 according to the second embodiment described above will be described with reference to FIG. 7.

First, a semiconductor in which the semiconductor layer 11 is stacked on the growth substrate 31, a plurality of light emitting elements 32, 32,... Are arranged at predetermined intervals, and a predetermined electrode, a protective film, or the like is formed on each light emitting element 32. A wafer 30 is prepared (see FIG. 7a). When the semiconductor layer 11 is a nitride-based compound semiconductor, for example, a GaN-based blue LED, sapphire is preferably used as the growth substrate 31.

The semiconductor layer 11 already shown in FIG. 5 can be formed of the n-type semiconductor layer 111 from GaN using Si as a dopant, and the p-type semiconductor layer 113 from GaN using Mg or Zn as a dopant. Layer 112 may be formed of GaN or InGaN, for example. Further, the semiconductor layer 11 can be formed of an InAlGaN-based compound to form a blue LED.

The semiconductor layer 11 can be formed by sequentially epitaxially growing the n-type semiconductor layer 111, the active layer 112, and the p-type semiconductor layer 113 on the growth substrate 31 by, for example, the MOCVD method or another vapor phase growth method.

After forming the semiconductor layer 11, the p electrode 12 and the n electrode 13 are formed. The p-electrode 12 and the n-electrode 13 may have a bump shape protruding from a predetermined position of the semiconductor layer 11. That is, a UBM film is formed at a predetermined position on each of the p-type and n-type semiconductor layers 113 and 111 by sputtering or the like, and Au is plated on the formed UBM to form bump-shaped p-electrodes 12 and n-electrodes. 13 is formed.

Next, at the position between the adjacent semiconductor layers 11, the grooves 31b, 31b,... With the side surfaces being inclined and the bottom surfaces being flat or substantially flat are processed (see FIG. 7b). The method of processing the groove 31b is not particularly limited, but the groove 31b can be formed on the growth substrate 31 by dicing, diamond cutting, or the like with a blade having a trapezoidal cross section, for example. Then, the insulating member 14 is arranged so as to fill the grooves 31b, 31b,... Between the electrodes of the semiconductor layer 11 and between the plurality of light emitting elements 32, 32,. The insulating member 14 is, for example, a thermosetting resin such as a silicone resin and one oxide selected from the group consisting of Ti, Zr, Nb, Al, and Si, or at least one of AlN and MgF. _May be formed of an insulating material having light reflectivity, which is a mixture of at least one selected from the group consisting of TiO ₂ , ZrO ₂ , Nb ₂ O ₅ , Al ₂ O ₃ , MgF, AlN, and SiO _2. it can.

The growth substrates 31, 31,... Are placed on the adhesive sheet 41 so that the electrode sides of the light emitting elements 32, 32,.

Next, the growth substrate 31 is separated from the semiconductor layers 11, 11,... By, for example, the LLO method (see FIG. 7e). Then, the wavelength conversion unit 15 is arranged on the semiconductor layers 11, 11,... As necessary (see FIG. 7f). Before disposing the wavelength conversion section 15, plasma cleaning or primer treatment may be performed in order to improve the adhesion between the semiconductor layer 11 and the wavelength conversion section 15.

Next, each light emitting element 32, 32,... Is cut out at the position of the groove 31b shown in FIG. 7b, leaving a part of the insulating member 14 (see FIG. 7g). Appropriate cutting means such as dicing can be used to cut out each light emitting element. Through these steps, a plurality of semiconductor light emitting devices 10 can be simultaneously obtained from one semiconductor wafer 30. In addition, the insulating member 14 that insulates the p-electrode 12 and the n-electrode 13 from each other and packages the entire light-emitting element, and the frame-shaped portion 14a that prevents light leakage in the edge direction are formed of the same material in the same step. Since it can be formed, it is possible to provide a method for manufacturing a high-quality semiconductor light emitting device with a small number of steps and excellent mass productivity.

(Third Embodiment)
Next, a third embodiment which is another method for manufacturing the semiconductor light emitting device 10 having the structure shown in FIG. 1 will be described with reference to the manufacturing process chart of FIG.

First, a plurality of light emitting elements 32, 32,... Having a semiconductor layer 11, a predetermined electrode and a protective film formed on a growth substrate 31, are prepared. Similar to the first and second embodiments, the semiconductor layer 11 can be formed of the n-type semiconductor layer 111 from GaN using Si as a dopant, for example, by a MOCVD method or another vapor deposition method, and a p-type semiconductor can be formed. Layer 113 can be formed, for example, of GaN with Mg or Zn as a dopant, and active layer 112 can be formed of, for example, GaN or InGaN. Further, the semiconductor layer 11 can be formed of an InAlGaN-based compound to form a blue LED.

The p-electrode 12 and the n-electrode 13 are formed into bumps by depositing UBM on the predetermined positions of the p-type and n-type semiconductor layers 113 and 111 by sputtering or the like, and plating the deposited UBM with Au, for example. It is formed.

Each light emitting element 32 is arranged on the adhesive sheet 40 at a predetermined interval so that one surface of the growth substrate 31 contacts the adhesive sheet 40 (see FIG. 8a). It is to be noted that after a wafer having a plurality of light emitting elements 32, 32,... Adhered to the adhesive sheet 40, grooves are formed at the boundaries of the light emitting elements 32, 32,. Alternatively, the light emitting element 32 may be separated on the adhesive sheet 40.

Next, the insulating member 14 is arranged so as to fill the spaces between the electrodes of the semiconductor layer 11 and the spaces between the plurality of light emitting devices 32, 32,... (See FIG. 8B). The insulating member 14 is, for example, a thermosetting resin such as a silicone resin and one oxide selected from the group consisting of Ti, Zr, Nb, Al, and Si, or at least one of AlN and MgF. _May be formed of an insulating material having light reflectivity, which is a mixture of at least one selected from the group consisting of TiO ₂ , ZrO ₂ , Nb ₂ O ₅ , Al ₂ O ₃ , MgF, AlN, and SiO _2. it can.

The growth substrates 31, 31,... Are placed on another pressure-sensitive adhesive sheet 41 so that the electrode sides of the light-emitting elements 32, 32,... Contact each other (see FIG. 8C). Then, after the insulating member 14 is thermoset, each light emitting element 32 is left in the boundary between the light emitting elements 32, 32,..., That is, in the gap between the growth substrates 31, 31,. Grooves 14c, 14c,... Which separate 32,... Are formed (see FIG. 4d). A cutting means such as dicing is used to form the grooves 14c and 14c, but the grooves 14c and 14c may be formed by a dry etching method. The frame-shaped portion 14a is formed by forming the groove 14c while leaving a part of the insulating member 14.

Note that the frame-shaped portion 14a may be formed in a step of cutting out the light emitting elements 32, 32,..., Which will be described later, by omitting the above step of forming the grooves 14c, 14c in the insulating member 14.

Next, the growth substrates 31, 31,... Are separated from the semiconductor layers 11, 11,..., For example, by the LLO method (see FIG. 8e). The wavelength conversion unit 15 may be arranged on the semiconductor layers 11, 11,... As necessary (see FIG. 8f).

Next, the light emitting elements 32, 32,... Are cut out on the adhesive sheet 41 by using an appropriate cutting means such as dicing (see FIG. 8g).

According to the manufacturing method of the third embodiment, since only the light emitting element 32 whose color tone has been selected in advance can be arranged on the adhesive sheet 40, it is possible to reduce variations in color tone after whitening.

(Fourth Embodiment)
FIG. 9 is a diagram schematically showing a cross section of a light source device according to a fourth embodiment of the present invention. Here, FIG. 9A shows a state in which the semiconductor light emitting device 10 of the first embodiment shown in FIG. 1 is mounted on a mounting substrate 20 which is a circuit board of the light source device. FIG. 9B shows the semiconductor light emitting device 10 of the second embodiment shown in FIG. 5 mounted on the mounting substrate 20.

The mounting board 20 is made of a glass-epoxy resin or a plate-shaped material having an insulating property such as ceramics such as alumina, and a conductive pattern made of, for example, copper on the surface thereof is formed by a well-known printing technique such as an electrolytic plating method or an etching method. Has been formed. The surface of the conductive pattern is preferably plated with a metal having a high reflectance such as Ag, Au, Al. In the fourth embodiment, the plurality of semiconductor light emitting devices 10 are provided in a state of being flip-chip mounted on the conductive pattern of the mounting substrate 20 of the light source device.

According to the fourth embodiment, since the amount of light emitted from each semiconductor light emitting device 10 in the lateral direction is reduced, the light absorbed by the adjacent light emitting device is also reduced, and the semiconductor light emitting device 10 is mounted on the mounting substrate 20. Even when a plurality of them are arranged in a row, a decrease in light extraction efficiency can be suppressed.

(Fifth Embodiment)
FIG. 10 is a diagram schematically showing a cross section of a semiconductor light emitting device 10 according to a fifth embodiment of the present invention. The semiconductor light emitting device 10 includes the semiconductor layer 11, and the p electrode 12 and the n electrode 13 respectively formed on the lower surface side of the semiconductor layer 11 as in the above-described embodiment. The semiconductor light emitting device 10 also includes a frame-shaped portion 14 a having light reflectivity, which is formed so as to surround the outer edge of the semiconductor layer 11. The frame-shaped portion 14 a is formed on the outer edge of the semiconductor layer 11 as a part of the insulating member 14 arranged so as to fill the space between the p electrode 12 and the n electrode 13.

Furthermore, in the semiconductor light emitting device 10 according to the present embodiment, the wavelength conversion unit 15 ′ having a step is arranged in contact with the upper surface of the semiconductor layer 11. The wavelength conversion unit 15′ is preferably made of a resin containing a phosphor material, but may be a resin containing a diffusing material and/or a coloring material or a resin mixed with the diffusing material and the coloring material. Good.

In the wavelength conversion portion 15′, the thickness of the portion covering the vicinity of the frame-shaped portion 14a and the thickness of the central portion covering the upper surface of the semiconductor layer 11 are substantially the same, but the height of the frame-shaped portion 14a is H (see FIG. 1). ), a step as shown in FIG. 10 is formed. The semiconductor light emitting device 10 according to the fifth embodiment may have a rectangular outer shape or a circular outer shape in a plan view. In the case of the semiconductor light emitting device 10 having a quadrangular shape in plan view, the step of the wavelength conversion portion 15 ′ is formed in a quadrangle along the outer edge of the semiconductor layer 11, and in the case of the circular semiconductor light emitting device 10, the step of the wavelength conversion portion 15 ′ is formed. It is formed in a circular shape along the outer edge of the semiconductor layer 11.

The semiconductor light emitting device 10 of the fifth embodiment as described above includes a step of peeling the growth substrate from the semiconductor layer 11 and then applying the resin material of the wavelength conversion unit 15 ′ to the upper surface of the semiconductor layer 11 by, for example, spraying. Can be manufactured by.

FIG. 11 shows a cross section of a semiconductor light emitting device 10 according to a modification of the fifth embodiment. In this modification, the resin material of the wavelength conversion portion 15 ′ is thinly laminated on the upper surface of the semiconductor layer 11 by, for example, electrodeposition or spray coating. That is, as shown in FIG. 11, the wavelength conversion portion 15′ is formed so that the height to the upper surface thereof is lower than that of the frame-shaped portion 14a. Here, when the wavelength conversion part 15′ is formed by electrodeposition, the wavelength conversion material can be disposed only on the upper surface of the semiconductor layer 11 that is conductive. When using a spray, the wavelength conversion material can be thinly applied only to the upper surface of the semiconductor layer 11 by masking the frame-shaped portion 14a.
Note that, as shown in FIG. 12, a transparent layer 16 for protecting the wavelength conversion portion 15 ′ which is electrodeposited or spray coated and laminated may be formed over the entire surface of the wavelength conversion portion 15 ′.

(Sixth Embodiment)
FIG. 13 is a diagram schematically showing a cross section of the semiconductor light emitting device 10 according to the sixth embodiment of the present invention. The semiconductor light emitting device 10 of this embodiment also includes the semiconductor layer 11, and the p-electrode 12 and the n-electrode 13 respectively formed on the lower surface side of the semiconductor layer 11, similarly to the above-described embodiments. The semiconductor light emitting device 10 also includes a frame-shaped portion 14 a having light reflectivity, which is formed so as to surround the outer edge of the semiconductor layer 11. The frame-shaped portion 14 a is formed on the outer edge of the semiconductor layer 11 as a part of the insulating member 14 arranged so as to fill the space between the p electrode 12 and the n electrode 13.

Further, in the semiconductor light emitting device 10 according to the sixth embodiment, a dome-shaped wavelength conversion portion 15″ is arranged in contact with the upper surface of the semiconductor layer 11. The wavelength conversion portion 15″ is made of a resin containing a phosphor material. However, a resin containing a diffusing material and/or a coloring material or a resin obtained by mixing the diffusing material and the coloring material with a phosphor may be used.

The semiconductor light emitting device 10 according to the sixth embodiment preferably has a circular outer shape in a plan view. In this case, the peripheral end portion of the wavelength converting portion 15″ is formed in a circular shape along the outer edge of the semiconductor layer 11. Further, the peripheral end portion of the wavelength converting portion 15″ covers the frame-shaped portion 14a. It may be.

Such a semiconductor light emitting device 10 of the sixth embodiment is manufactured by including a step of, for example, potting the resin material of the wavelength conversion portion 15″ on the upper surface of the semiconductor layer 11 after peeling the growth substrate from the semiconductor layer 11. can do.

10 semiconductor light emitting device 11 semiconductor layer 11a upper surface 12 p electrode 13 n electrode 14 insulating member 14a frame portion 14b outer wall surface 14c groove 14t inner side surface 15 wavelength conversion portion 20 mounting substrate 30 semiconductor wafer 31 growth substrate 31a, 31b groove 32 light emitting element

Claims (4)

A semiconductor layer,
An electrode formed on the lower surface side of the semiconductor layer,
A frame shape that surrounds the outer edge of the semiconductor layer, has a constant height with respect to the upper surface in a direction perpendicular to the upper surface of the semiconductor layer, and has a constant width at its upper end portion in the direction along the upper surface. A frame-shaped portion formed at least in contact with the outer edge of the semiconductor layer,
A wavelength conversion unit arranged on the upper surface side of the semiconductor layer and having an upper surface lower than the frame-shaped portion,
A semiconductor light emitting device comprising :
An upper surface of the semiconductor light emitting device has a shape in which a peripheral region is higher than an inner region,
A semiconductor light emitting device, wherein the peripheral region is the upper surface of the frame-shaped portion .
The semiconductor light emitting device according to claim 1, wherein an outer wall surface of the frame-shaped portion is a surface perpendicular to a mounting surface of the semiconductor light emitting device.
The inner surface of a portion of the frame-shaped portion in contact with the semiconductor layer above the upper surface of the semiconductor layer is an inclined surface that spreads upward with respect to the upper surface of the semiconductor layer. Semiconductor light emitting device.
The semiconductor light emitting device according to claim 1, wherein an outer edge shape of the frame-shaped portion is a quadrangle in a plan view.

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