TWI435471B - Light-emitting diode chip and the manufacturing method thereof - Google Patents

Description

Light-emitting diode crystal grain and preparation method thereof

The present invention relates to a process for a light-emitting diode, and more particularly to a segmentation technique for a light-emitting diode wafer.

The light-emitting diode is epitaxially grown in the form of a wafer, and after the epitaxial growth is completed, a cutting process is required to form a chip.

The technology of dividing a conventional light-emitting diode wafer into a die is to form two sets of mutually perpendicular cutting lines on one surface of a self-luminous diode wafer, and then on the other side surface of the light-emitting diode wafer. The file is split at the same time by aligning the vertical lines in both directions, so that the wafer is split along the cutting line and separated into a plurality of grains.

The above-mentioned file must be accurately aligned with the position of the cutting line when the splitting is performed. However, the light-emitting diode wafer is translucent and not easily aligned from the other side, plus whether it is mechanical cutting or laser cutting. The cutting lines formed by the cutting are very narrow, so the file is not easy to accurately align each cutting line. Moreover, the size of the light-emitting diode wafer has evolved from the early 2吋 to 4吋, and in recent years it has evolved from 4吋 to 6吋, and when the size of the light-emitting diode wafer is larger, the file is more difficult to simultaneously Quasi-all cutting lines.

Furthermore, since the dicing line is formed on one side of the light-emitting diode wafer, and the boring tool is chopped from the other side, the side faces of the respective dies tend to be severely inclined after the separation, thereby damaging the light-emitting diode crystal grains. The area of the light. Although the problem of the side slope of the crystal grain can be solved by forming a deep cutting line, this will consume a lot of energy and affect the productivity, and more importantly, if the sintered surface formed by the cutting line touches the light. The epitaxial layer of the diode grains causes serious damage to the epitaxial layer and affects the luminous efficiency.

The invention provides a method for manufacturing a light-emitting diode die, the method comprising: providing a light-emitting diode wafer; forming a plurality of hidden cutting lines by using a Stealth Dicing laser in the light-emitting diode wafer; A rolling unit is rolled on one of the active surfaces of the LED wafer by the rolling unit, so that the LED wafer is separated into a plurality of LED dipoles along the plurality of cutting lines.

The invention also provides a light-emitting diode die comprising an upper surface; a lower surface; a plurality of sides; wherein each side surface comprises a crack initiation region between the upper surface and the lower surface; and the crack initiation region extends to the upper surface a first crack; and a second crack extending from the crack initiation region to the lower surface and separated from the first crack by the crack initiation region.

According to a first embodiment of the method for fabricating a light-emitting diode according to the present invention, as shown in FIG. 1, a light-emitting diode wafer 100 is first fixed on a carrying platform 202, wherein the light-emitting diode The wafer 100 includes a surface 100a away from the surface of the carrying platform 202. Optionally, a pad 201 is disposed between the LED wafer 100 and the carrier platform 202.

As shown in FIG. 2A, a Stealth Dicing laser unit 204 is provided to form a plurality of hidden cut lines 102 in the LED array 100 by concealing the cut laser unit 204. Referring to FIG. 2B, along the AA' section of FIG. 2A, the hidden cut line 102 includes a plurality of first cutting lines 104 that are parallel to each other and a plurality of second parallel to the first cutting line 104 and parallel to each other. Cutting line 106.

As shown in FIGS. 3A and 3B, a rolling unit 206 having a roller portion 206a and a pressing portion 206b is provided. The roller portion 206a is configured to be pressed against the active surface 100a of the LED wafer 100. The pressing portion 206b can press the roller portion 206a and drive the roller portion 206a to move, so that the roller portion 206a can be used for the LED wafer. The action surface 100a of 100 is rolled up, and pressure is generated during the rolling process so that the hidden cutting line inside the light-emitting diode wafer 100 is forced to generate cracks in the direction of the upper and lower surfaces. As shown in FIG. 3A, the direction of the LED wafer 100 is adjusted so that the rolling unit 206 drives the roller portion 206a to roll in a direction perpendicular to the first cutting line 104, as shown in FIG. 3B, and then adjusts the illumination. The direction of the diode wafer 100 is such that the rolling unit 206 drives the roller portion 206a to roll in a direction perpendicular to the second cutting line 106, so that the first cutting line 104 and the second cutting line 106 extend to the light emitting diode The upper surface of the bulk wafer 100 is thereby separated into a plurality of light emitting diode dies. The light-emitting diode wafer 100 can be separated into a plurality of light-emitting diode crystals by using the above-mentioned two-rolling method, and the roller of the rolling unit 206 can also be adjusted by adjusting the angle of the light-emitting diode wafer 100. The portion 206a is rolled or rolled back and forth in parallel with the diagonal direction of the square formed by the first cutting line 104 and the second cutting line 106. A metal foil 203 may be disposed on the active surface 100a of the LED wafer 100 to increase the moment when the rolling unit 206 is pressed against the LED wafer 100. In addition, a mechanism such as vibration or ultrasonic can be used in the rolling process to promote separation of the LED wafer 100 into LED dies. The LED wafer 100 can include a substrate 101 and a light emitting stack 103 formed on the substrate 101. The substrate 101 may be a sapphire substrate, a Silicone substrate, a tantalum carbide (SiC) substrate, a gallium nitride (GaN) substrate, or a gallium arsenide (GaAs) substrate, and the material of the light emitting layer 103 includes at least An element selected from the group consisting of aluminum (Al), gallium (Ga), indium (In), nitrogen (N), phosphorus (P), and arsenic (As), such as AlGaInP, AlN, GaN, AlGaN a semiconductor compound such as InGaN or AlInGaN. The light emitting diode wafer 100 may have a thickness of 90-250 μ 2 , and the positions of the first cutting line 104 and the second cutting line 106 are located in the substrate 101 , and the two ends of the cutting line are preferably respectively above and below the substrate 101 . The two surfaces are approximately equidistant. The two ends of the first dicing line 104 and the second dicing line 106 may be spaced apart from the upper and lower surfaces of the illuminating diode 100 by about 20 to 115 μm, respectively, depending on the thickness of the illuminating diode 100.

Referring to FIG. 4, the LED die 400 separated by the above process includes an upper surface 402, a lower surface 404, and a plurality of sides 406. Each side 406 can include a crack initiation zone 410 between the upper surface 402 and the lower surface 404, a first crack 412 extending from the crack initiation zone 410 to the upper surface 402, and a self-crack initiation zone 410 extending to the lower surface. One of the second cracks 414 of 404, wherein at least two of the crack initiation zone 410, the first crack 412, and the second crack 414 are not parallel. The crack initiation region 410 is formed by the aforementioned hidden cutting line in the light emitting diode wafer, and since the hidden cutting line is located in the light emitting diode wafer, the light emitting diode wafer is separated after being pressed The resulting LED die 400 forms a crack initiation region 410 on the side 406 and a first crack 412 and a second crack 414 separated by the crack initiation region 410 to reduce the slope of the side surface 406. .

The light emitting diode die 400 includes a substrate 401 and a light emitting laminate 403, wherein the substrate 401 can be a sapphire substrate, a Silicone substrate, a tantalum carbide (SiC) substrate, a gallium nitride (GaN) substrate, or a gallium arsenide (GaAs) substrate, and the material of the light-emitting layer 403 comprises at least one element selected from the group consisting of aluminum (Al), gallium (Ga), indium (In), nitrogen (N), phosphorus (P), and arsenic. The group formed by (As) is, for example, a semiconductor compound such as AlGaInP, AlN, GaN, AlGaN, InGaN, or AlInGaN. The thickness of the LED wafer 400 is approximately 90 to 250 μm. The side surface 406 can have a region of the substrate 401 and a region of a light-emitting layer 403. The crack initiation region 410 can be located in the region of the substrate 401 of the side surface 406, and the end points thereof are preferably substantially equal to the upper surface 402 and the lower surface 404. distance.

5A and 5B show a second embodiment of a method of fabricating a light-emitting diode of the present invention. First, a carrying platform 202 is provided to carry a light emitting diode wafer 500, a Stealth Dicing laser unit 204, and a rolling unit 206. The carrying platform 202 and the LED wafer 500 are A cushion 201 is selectively provided. In the vertical direction of the same position in the LED array 500 of the embodiment, the hidden cutting line can be formed by the hidden cutting laser unit 204, such as the first cutting line 504 of FIG. 5A and FIG. 5A. The second cut line 506 of FIG. 5B, which is perpendicular to the viewing angle, can determine the number of hidden cut lines required for the thickness of the light-emitting diode wafer 500. The rolling unit 206 has a roller portion 206a and a pressing portion 206b. The roller portion 206a is configured to be pressed against the active surface 500a of the LED wafer 500. The pressing portion 206b can press the roller portion 206a and drive the roller portion 206a to move, so that the roller portion 206a can be used for the LED wafer. The action surface 500a of 500 is rolled up, and pressure is generated during the rolling process so that the hidden cutting line inside the light-emitting diode wafer 500 is forced to generate cracks in the direction of the upper and lower surfaces. As shown in FIG. 5A, the direction of the LED array 500 can be adjusted to cause the rolling unit 206 to drive the roller portion 206a to roll in a direction perpendicular to the first cutting line 504, as shown in FIG. 3B. Adjusting the direction of the LED wafer 500 so that the rolling unit 206 drives the roller portion 206a to roll in a direction perpendicular to the second cutting line 506, so that the first cutting line 504 and the second cutting line 506 extend to emit light. The upper surface of the diode wafer 500 is above, thereby separating the light emitting diode wafer 500 into a plurality of light emitting diode crystal grains. The light-emitting diode wafer 500 can be separated into a plurality of light-emitting diode crystals by using the above-mentioned two-rolling method, and the roller of the rolling unit 206 can also be adjusted by adjusting the angle of the light-emitting diode wafer 500. The portion 206a is rolled or rolled back and forth in parallel with the diagonal direction of the square formed by the first cutting line 504 and the second cutting line 506. A metal foil 203 can be placed on the active surface 500a of the LED wafer 500 to increase the moment when the rolling unit 206 is pressed against the LED wafer 500. In addition, a mechanism such as vibration or ultrasonic wave may be used in the rolling process to facilitate separation of the light-emitting diode wafer 500 into light-emitting diode crystal grains. The LED wafer 500 can include a substrate 501 and a light emitting stack 503 formed on the substrate 501. The substrate 501 may be a sapphire substrate, a Silicone substrate, a cerium carbide (SiC) substrate, a gallium nitride (GaN) substrate, or a gallium arsenide (GaAs) substrate, and the material of the light emitting layer 503 includes at least An element selected from the group consisting of aluminum (Al), gallium (Ga), indium (In), nitrogen (N), phosphorus (P), and arsenic (As), such as AlGaInP, AlN, GaN, AlGaN a semiconductor compound such as InGaN or AlInGaN. The thickness of the light-emitting diode wafer 500 is approximately 90-250 μm, and the positions of the first cutting line 504 and the second cutting line 506 may be located in the substrate 501. The edges of the first row 504 or the second dicing line 506 of the plurality of columns which are formed in series with the end points of the upper and lower surfaces are preferably substantially equally spaced from the upper and lower surfaces of the LED wafer 500, respectively. Specifically, the first cutting line 504 or the second cutting line 506 of the plurality of columns may have a height of about 20 to 50 μm as a whole, and when formed in different thicknesses of the LED array 500, the two edges may be combined with the light emitting diode. The upper and lower surfaces of the polar wafer 500 are spaced apart by about 20 to 115 μm.

Referring to FIG. 6, the LED die 600 separated by the above process includes an upper surface 602, a lower surface 604, and a plurality of sides 606. Each side 606 includes a crack initiation region 610 and a self-crack start. The region 610 extends to a first crack 612 of the upper surface 602 and a second crack 614 extending from the crack initiation region 610 to the lower surface 604, wherein at least one of the crack initiation region 610, the first crack 612, and the second crack 614 The two are not parallel. Each crack initiation region 610 is formed in a concave-convex shape by a plurality of hidden cutting lines arranged in the above-mentioned light-emitting diode wafer, and since the hidden cutting line is located in the light-emitting diode wafer, The LED die 600 separated by the light-emitting diode wafer is pressed to generate a crack initiation region 610 on the side surface 606, and a first crack 612 separated by the crack initiation region 610 and The second crack 614 can reduce the inclination of the side 606.

The light emitting diode die 600 can have a substrate 601 and a light emitting stack 603, wherein the substrate 601 can be a sapphire substrate, a Silicone substrate, a lanthanum carbide (SiC) substrate, a gallium nitride (GaN) substrate, or a gallium arsenide (GaAs) substrate, and the material of the light-emitting layer 603 comprises at least one element selected from the group consisting of aluminum (Al), gallium (Ga), indium (In), nitrogen (N), phosphorus (P), and arsenic. The group formed by (As) is, for example, a semiconductor compound such as AlGaInP, AlN, GaN, AlGaN, InGaN, or AlInGaN. The thickness of the light emitting diode die 600 is approximately 90 to 250 μm. The side 606 can have a region of the substrate 601 and a region of the light-emitting layer 603. The crack initiation region 610 can be located in the region of the substrate 601 on the side, and the end points thereof are preferably substantially equidistant from the upper surface 602 and the lower surface 604. .

The examples of the invention are intended to be illustrative only and not to limit the scope of the invention. Any changes or modifications of the present invention to those skilled in the art will be made without departing from the spirit and scope of the invention.

100, 500. . . Light-emitting diode wafer

100a, 500a. . . Action surface

101, 501. . . Substrate

102. . . Hidden cutting line

103, 503‧‧‧Lighting laminate

104, 504‧‧‧ first cutting line

106, 506‧‧‧ second cutting line

200‧‧‧Dimensional separation system

201‧‧‧ cushion

202‧‧‧Loading platform

203‧‧‧metal foil

204‧‧‧Hidden cutting laser unit

206‧‧‧Rolling unit

206a‧‧‧Roller

206b‧‧‧Pressing

400, 600‧‧‧Light-emitting diode grains

401, 601‧‧‧ substrate

402, 602‧‧‧ upper surface

403, 603‧‧‧Lighting laminate

404, 604‧‧‧ lower surface

406, 606‧‧‧ side

410, 610‧‧‧ crack initiation zone

412, 612‧‧‧ first crack

414, 614‧‧‧ second crack

1 to 3B are diagrams showing a first embodiment of a method for fabricating a light-emitting diode of the present invention;

Figure 4 is a view showing a first embodiment of the light-emitting diode die of the present invention;

5A and 5B are views showing a second embodiment of the method for fabricating the light-emitting diode of the present invention;

Fig. 6 is a view showing a second embodiment of the light-emitting diode dies of the present invention.

100. . . Light-emitting diode wafer

100a. . . Action surface

101. . . Substrate

103. . . Light-emitting laminate

104. . . First cutting line

203. . . foil

206. . . Rolling unit

206a. . . Roller

206b. . . Pressure bar

Claims (16)

A method for fabricating a light-emitting diode die, the method comprising: providing a light-emitting diode wafer having an active surface; and utilizing a hidden cutting (Stealth Dicing) laser to the light-emitting diode Forming a plurality of hidden cut lines in the body wafer; providing a metal foil on the active surface; providing a rolling unit through which the rolling unit is rolled on the active surface of the light emitting diode wafer Pressing, the light-emitting diode wafer is separated into a plurality of light-emitting diode crystal grains along the plurality of cutting lines; wherein each of the light-emitting diode crystal grains comprises: an upper surface; a lower surface; and a plurality of sides; Each of the sides includes a crack initiation region between the upper surface and the lower surface, a first crack extending from the fracture initiation region to the upper surface, and extending from the fracture initiation region to the lower surface And the second crack is separated from the first crack by the crack initiation region, wherein at least two of the crack initiation region, the first crack and the second crack are not parallel. The method for manufacturing a light-emitting diode die according to claim 1, wherein the light-emitting diode wafer comprises a substrate, and a light-emitting stack formed on the substrate Floor. The method for fabricating a light-emitting diode according to claim 2, wherein the hidden cutting lines are formed in the substrate. The method of manufacturing the illuminating diode dies according to the second aspect of the invention, wherein the illuminating diode wafer has upper and lower surfaces, and the two ends of the hidden cutting lines are respectively equidistant from the upper and lower surfaces. . The method for manufacturing a light-emitting diode die according to claim 2, wherein the substrate is a sapphire substrate, a silicon oxide substrate, a silicon carbide (SiC) substrate, a gallium nitride (GaN) substrate or A gallium arsenide (GaAs) substrate. The method for fabricating a light-emitting diode according to claim 2, wherein the material of the light-emitting layer comprises at least one element selected from the group consisting of aluminum (Al), gallium (Ga), indium (In), and nitrogen. A group consisting of (N), phosphorus (P), and arsenic (As). The method for fabricating a light-emitting diode according to claim 1, wherein the hidden cutting lines are arranged in one or more columns. The method for fabricating a light-emitting diode according to claim 1 or 7, wherein the plurality of hidden cut lines comprise a plurality of first cuts parallel to each other a line and a plurality of second cutting lines that are vertically interlaced with the first direction cutting lines. The method for manufacturing a light-emitting diode die according to claim 8 , wherein the rolling unit is rolled once in a line perpendicular to the first direction cutting line and the second direction cutting line. The method for manufacturing a light-emitting diode die according to claim 8 , wherein the rolling unit is performed at least once in a diagonal direction parallel to a square formed by the first cutting line and the second cutting line. Rolling. A light-emitting diode die comprising: an upper surface; a lower surface; and a plurality of sides; wherein each of the sides includes a crack initiation region between the upper surface and the lower surface and extending from the fracture initiation region a first crack to one of the upper surfaces, and a second crack extending from the crack initiation region to the lower surface and the fracture initiation region and the first crack region, wherein the fracture initiation region, the At least two of the first crack and the second crack are not parallel. The illuminating diode dies according to claim 11, wherein the illuminating diode has a thickness of between 90 and 250 μm. The illuminating diode dies according to claim 11, wherein the two ends of the crack initiation region are substantially equidistant from the upper surface and the lower surface, respectively. The illuminating diode dies according to claim 11, wherein the illuminating diode dies include a substrate and a light emitting laminate formed on the substrate, and each of the sides has a substrate region And an area of the light-emitting laminate. The luminescent diode crystal according to claim 14, wherein the crack initiation region is located in a region of the substrate. The luminescent diode crystal grain according to claim 11, wherein the crack initiation region is concave and convex.