JP2018113386A - Method for manufacturing light-emitting diode chip and light-emitting diode chip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a light-emitting diode chip capable of obtaining sufficient luminance, and the light-emitting diode chip.SOLUTION: A method for manufacturing a light-emitting diode chip comprises: a wafer preparing step of preparing a wafer which includes a laminate layer in which a plurality of semiconductor layers containing a light-emitting layer are formed on a transparent substrate for crystal growth, and in which an LED circuit is formed in each of the regions partitioned by a plurality of division schedule lines mutually crossing a surface of the laminate layer; a first transparent substrate sticking step of forming a first integrated wafer by sticking a surface of the first transparent substrate in which a plurality of air bubbles are formed inside to a rear surface of the wafer; a second transparent substrate sticking step of forming a second integrated wafer by sticking a surface of the second transparent substrate in which a plurality of air bubbles are formed inside to a rear surface of the first transparent substrate after performing the first transparent substrate sticking step; and a dividing step of dividing the second integrated wafer into individual light-emitting diode chips by cutting the wafer together with the first and second transparent substrates along the division schedule lines.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a light emitting diode chip manufacturing method and a light emitting diode chip.

  A stacked body layer in which a plurality of n-type semiconductor layers, light-emitting layers, and p-type semiconductor layers are stacked is formed on the surface of a crystal growth substrate such as a sapphire substrate, a GaN substrate, or a SiC substrate. A wafer in which a plurality of light emitting devices such as LEDs (Light Emitting Diodes) are formed in a region partitioned by the planned division line is cut along the planned division line and divided into individual light emitting device chips, and the divided light emission Device chips are widely used in various electric devices such as mobile phones, personal computers, and lighting devices.

  Since the light emitted from the light emitting layer of the light emitting device chip is isotropic, the light is emitted also to the inside of the crystal growth substrate, and the light is also emitted from the back and side surfaces of the substrate. However, of the light irradiated to the inside of the substrate, light whose incident angle at the interface with the air layer is greater than the critical angle is totally reflected at the interface and confined inside the substrate, and is not emitted outside from the substrate. Therefore, there is a problem that the luminance of the light emitting device chip is lowered.

  In order to solve this problem, a light emitting diode in which a transparent member is attached to the back surface of the substrate to improve the luminance in order to prevent light emitted from the light emitting layer from being confined inside the substrate. (LED) is described in Japanese Patent Application Laid-Open No. 2014-175354.

JP 2014-175354 A

  However, the light emitting diode disclosed in Patent Document 1 has a problem that sufficient luminance cannot be obtained although the luminance is slightly improved by sticking a transparent member to the back surface of the substrate.

  The present invention has been made in view of these points, and an object of the present invention is to provide a method of manufacturing a light-emitting diode chip and a light-emitting diode chip that can obtain sufficient luminance.

  According to invention of Claim 1, it is a manufacturing method of a light emitting diode chip | tip, Comprising: It has a laminated body layer in which the several semiconductor layer containing a light emitting layer was formed on the transparent substrate for crystal growth, This laminated body layer A wafer preparation step of preparing a wafer in which LED circuits are formed in each region partitioned by a plurality of division lines intersecting each other on the surface of the wafer, and a first in which a plurality of bubbles are formed inside the back surface of the wafer After performing the 1st transparent substrate sticking process which sticks the surface of a transparent substrate and forms the 1st integrated wafer, and the 1st transparent substrate sticking process, it is inside in the back of the 1st transparent substrate inside A second transparent substrate adhering step of adhering a surface of the second transparent substrate on which a plurality of bubbles are formed to form a second integrated wafer; and the first and second wafers along the division line. Cut with the second transparent substrate LED chip production method of which is characterized in that and a dividing step of dividing the integrated wafer into individual light emitting diode chips is provided.

  Preferably, the first and second transparent substrates are formed of any one of transparent ceramics, optical glass, sapphire, and transparent resin, and the first and second transparent substrate pasting steps use a transparent adhesive. Implemented.

  According to invention of Claim 4, it is a light emitting diode chip | tip, Comprising: The light emitting diode by which the LED circuit was formed in the surface, and the 1st which has a some bubble inside the surface stuck on the back surface of this light emitting diode There is provided a light-emitting diode chip comprising: a transparent member; and a second transparent member having a plurality of bubbles inside the surface of which is adhered to the back surface of the first transparent member.

  In the light-emitting diode chip of the present invention, the surface of the first transparent member having a plurality of bubbles inside is adhered to the back surface of the LED, and the second surface having a plurality of bubbles inside the back surface of the first transparent member. Since the surface of the transparent member is adhered, the light is refracted in a complicated manner in the first and second transparent members, and the light confined in the first and second transparent members is reduced. The amount of light emitted from the transparent member 2 is increased, and the luminance of the light emitting diode chip is improved.

It is a surface side perspective view of an optical device wafer. FIG. 2A is a perspective view showing a first transparent substrate adhering process in which the front surface of the first transparent substrate is attached to the back surface of the wafer and integrated, and FIG. 2B is a perspective view of the first integrated wafer. FIG. FIG. 3A is a perspective view showing a second transparent substrate attaching step for attaching and integrating the surface of the second transparent substrate to the back surface of the first transparent substrate of the first integrated wafer, FIG. B) is a perspective view of a second integrated wafer. It is a perspective view which shows the support process which supports a 2nd integrated wafer with an annular frame via a dicing tape. It is a perspective view which shows the division | segmentation process which divides | segments a 2nd integrated wafer into a light emitting diode chip. It is a perspective view of the 2nd integrated wafer after the end of a division process. 1 is a perspective view of a light emitting diode chip according to an embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Referring to FIG. 1, there is shown a front side perspective view of an optical device wafer 11 (hereinafter sometimes simply referred to as a wafer) 11.

  The optical device wafer 11 is configured by laminating an epitaxial layer (laminated body layer) 15 such as gallium nitride (GaN) on a sapphire substrate 13. The optical device wafer 11 has a front surface 11a on which an epitaxial layer 15 is stacked and a back surface 11b on which the sapphire substrate 13 is exposed.

  Here, in the optical device wafer 11 of the present embodiment, the sapphire substrate 13 is employed as the crystal growth substrate. However, a GaN substrate or a SiC substrate may be employed instead of the sapphire substrate 13.

  The stacked body layer (epitaxial layer) 15 includes an n-type semiconductor layer (for example, an n-type GaN layer) in which electrons are majority carriers, a semiconductor layer (for example, an InGaN layer) that is a light emitting layer, and a p in which holes are majority carriers. It is formed by epitaxially growing a type semiconductor layer (for example, a p-type GaN layer) in this order.

  The sapphire substrate 13 has a thickness of 100 μm, for example, and the laminate layer 15 has a thickness of 5 μm, for example. A plurality of LED circuits 19 are defined on the laminate layer 15 by a plurality of division lines 17 formed in a lattice pattern. The wafer 11 has a front surface 11a on which the LED circuit 19 is formed and a back surface 11b on which the sapphire substrate 13 is exposed.

  According to the light emitting diode chip manufacturing method of the embodiment of the present invention, first, a wafer preparation step for preparing an optical device wafer 11 as shown in FIG. 1 is performed. Furthermore, a transparent substrate preparation step is carried out for preparing first and second transparent substrates having a plurality of bubbles formed therein.

  After performing the transparent substrate preparation step, as shown in FIG. 2A, the first transparent substrate 21 is bonded to the back surface 11b of the wafer 11 with the surface 21a of the first transparent substrate 21 in which a plurality of bubbles are formed. A substrate sticking step is performed. FIG. 2B is a perspective view of the first integrated wafer 25.

  The first transparent substrate 21 is formed from any one of transparent resin, optical glass, sapphire, and transparent ceramics. In the present embodiment, the first and second transparent substrates are formed from a transparent resin such as polycarbonate and acrylic resin which is more durable than optical glass.

  After the first transparent substrate pasting step, the surface 21a of the second transparent substrate 21A in which a plurality of bubbles are formed is formed on the first surface of the first integrated wafer 25 as shown in FIG. Is attached to the back surface of the transparent substrate 21 (second transparent substrate attaching step) to form a second integrated wafer 25A as shown in FIG. The material of the second transparent substrate 21A is the same as the material of the first transparent substrate 21 described above.

  Instead of the first transparent substrate sticking step and the second transparent substrate sticking step described above, the first transparent substrate 21 is attached to the back surface of the second transparent substrate 21A and integrated, and then the first transparent substrate sticking step is integrated. The rear surface 11b of the wafer 11 may be adhered to the front surface 21a of the transparent substrate 21.

  After performing the second transparent substrate attaching step, as shown in FIG. 4, the second transparent substrate 21A of the second integrated wafer 25A is attached to the dicing tape T whose outer peripheral portion is attached to the annular frame F. Thus, a frame unit is formed, and a supporting step of supporting the second integrated wafer 25A with the annular frame F via the dicing tape T is performed.

  After carrying out the supporting step, the frame unit is put into a cutting device, and the dividing step of cutting the second integrated wafer 25A with the cutting device and dividing it into individual light emitting diode chips is carried out. This dividing step will be described with reference to FIG.

  This dividing step is performed using, for example, a well-known cutting device. As shown in FIG. 5, the cutting unit 10 of the cutting apparatus includes a spindle housing 12, a spindle (not shown) rotatably inserted into the spindle housing 12, and a cutting blade 14 attached to the tip of the spindle. Yes.

  The cutting blade of the cutting blade 14 is formed of, for example, an electroforming grindstone in which diamond abrasive grains are fixed by nickel plating, and the tip shape thereof is triangular, quadrangular, or semicircular.

  The upper half of the cutting blade 14 is covered with a blade cover (wheel cover) 16, and the blade cover 16 is a pair of cooler nozzles (only one is shown) extending horizontally toward the back side and the near side of the cutting blade 14. 18 is arranged.

  In the dividing step, the second integrated wafer 25A is sucked and held by the chuck table 20 of the cutting device via the dicing tape T of the frame unit, and the annular frame F is clamped and fixed by a clamp (not shown).

  Then, while rotating the cutting blade 14 in the direction of arrow R at high speed, the cutting blade 14 is cut into the division line 17 of the wafer 11 until the tip of the cutting blade 14 reaches the dicing tape T. From the cooler nozzle 18 to the processing point of the cutting blade 14 and the wafer 11. The second integrated wafer 25A is processed and fed in the direction of the arrow X1 while supplying the cutting fluid toward the wafer 11, and the wafer 11 and the first and second transparent substrates 21 and 21A along the scheduled division line 17 of the wafer 11. A cutting groove 27 for cutting is formed.

  While indexing and feeding the cutting unit 10 in the Y-axis direction, similar cutting grooves 27 are formed one after another along the planned dividing line 17 extending in the first direction. Next, after the chuck table 20 is rotated by 90 °, similar cutting grooves 27 are formed along all the planned dividing lines 17 extending in the second direction orthogonal to the first direction, as shown in FIG. In this state, the second integrated wafer 25A is divided into light emitting diode chips 31 as shown in FIG.

  In the embodiment described above, the cutting device is used to divide the second integrated wafer 25A into the individual light emitting diode chips 31, but the wavelength of the wavelength having transparency to the wafer 11 and the transparent substrates 21 and 21A. A laser beam is irradiated onto the wafer 11 along the division line 13 to form a plurality of modified layers in the thickness direction inside the wafer 11, the first transparent substrate 21 and the second transparent substrate 21A, and then Alternatively, an external force may be applied to the second integrated wafer 25 </ b> A, and the second integrated wafer 25 </ b> A may be divided into individual light emitting diode chips 31 using the modified layer as a division starting point.

  The light emitting diode chip 31 shown in FIG. 7 has a first transparent member 21 ′ having a plurality of bubbles 29 inside attached to the back surface of the LED 13A having the LED circuit 19 on the front surface. Further, a second transparent member 21A ′ having a plurality of bubbles 29 inside is attached to the back surface of the first transparent member 21 ′.

  Therefore, in the light emitting diode chip 31 shown in FIG. 7, in addition to increasing the surface areas of the first and second transparent members 21 ′ and 21A ′, the light is complicated in the first and second transparent members 21 ′ and 21A ′. The light that is refracted and confined in the transparent member decreases, the amount of light emitted from the transparent members 21 and 21A ′ increases, and the luminance of the light-emitting diode chip 31 is improved.

10 Cutting unit 11 Optical device wafer (wafer)
13 Sapphire substrate 14 Cutting blade 15 Laminate layer 17 Line to be divided 19 LED circuit 21 First transparent substrate 21A Second transparent substrate 25 First integrated wafer 25A Second integrated wafer 27 Cutting groove 29 Bubble 31 Light emitting diode chip

Claims (4)

A method of manufacturing a light emitting diode chip,
Each of the regions has a laminate layer in which a plurality of semiconductor layers including a light emitting layer are formed on a transparent substrate for crystal growth, and is divided into a plurality of division lines intersecting each other on the surface of the laminate layer. A wafer preparation step of preparing a wafer on which an LED circuit is formed;
A first transparent substrate adhering step for adhering the surface of the first transparent substrate having a plurality of bubbles formed therein on the back surface of the wafer to form a first integrated wafer;
After performing the first transparent substrate pasting step, the surface of the second transparent substrate having a plurality of bubbles formed therein is pasted on the back surface of the first transparent substrate to form a second integrated wafer. A second transparent substrate pasting step,
A dividing step of cutting the wafer together with the first and second transparent substrates along the division line to divide the second integrated wafer into individual light emitting diode chips;
A method for producing a light-emitting diode chip, comprising:   Instead of the first transparent substrate pasting step and the second transparent substrate pasting step, the surface of the second transparent substrate is pasted and integrated on the back surface of the first transparent substrate, The method for producing a light-emitting diode chip according to claim 1, wherein the back surface of the wafer is adhered to the surface of the transparent substrate.   The first and second transparent substrates are formed of any one of transparent ceramics, optical glass, sapphire, and transparent resin, and the first and second transparent substrate pasting steps are performed using a transparent adhesive. The method for producing a light-emitting diode chip according to claim 1. A light emitting diode chip,
A light emitting diode having an LED circuit formed on the surface;
A first transparent member having a plurality of bubbles inside the surface of which is adhered to the back surface of the light emitting diode;
A second transparent member having a plurality of bubbles inside the surface of which is adhered to the back surface of the first transparent member;
A light-emitting diode chip comprising: