JP2002198326A - Method for dividing semiconductor substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for dividing a semiconductor substrate by which light-emitting elements, which have an excellent optical-property and reliability and can be closely arranged, are obtained. SOLUTION: To divide the semiconductor substrate 1, on which a plurality of light-emitting junctions 21 are scattered like a matrix in a wafer 2, into the light-emitting elements 20 of a predetermined size, a process for forming a dicing notch 6, which does not reach a depth of the light-emitting junctions 21, on a surface S2 of a side opposite to a light-emitting surface S2, a process for forming a scriber line 7 on a bottom of the dicing notch 6, and a process for cleaving the semiconductor 1 at a position of the scriber line 7 and dividing in into each of the light-emitting elements 20 are carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a light emitting element used for an optical printer head or the like by dividing a semiconductor substrate.

[0002]

2. Description of the Related Art When a compound semiconductor substrate in which a plurality of light emitting junctions are scattered in a matrix in a wafer is divided and a light emitting device having a predetermined size is manufactured, the substrate is divided by a scribing method or a dicing method. Is common. In the scribe method, a scribe line is formed on the surface of a semiconductor substrate and pressurized, and the substrate is divided using a cleavage phenomenon. In the dicing method, the substrate is cut by a dicing cutter. However, both the scribe method and the dicing method have inherent problems. This will be described below.

First, a scribing method is used. A cleavage perpendicular to the substrate surface is surely caused by a cleavage phenomenon when the substrate thickness is up to about 150 μm. . Also, the probability of occurrence of “burrs” and “chips” increases. For example, in the case of a GaAsP substrate having a thickness of about 300 μm, assuming that a cleavage plane 103 runs obliquely from the scribe line 102 formed on the substrate 101 as shown in FIG.
2 between the position 2 and the exit corner of the cleavage plane 103
1 reaches 5 to 52 μm. On the other hand, the following considerations are required for the arrangement of the light emitting elements obtained by dividing the substrate 101.
FIG. 13 schematically shows the arrangement of the light emitting elements 110. In the figure, P1 indicates the alignment pitch of the light emitting regions 111 formed on the surface of the light emitting element 110, and P2 indicates the gap width between the adjacent light emitting elements 110. Represent. The light emitting region 111 occupies a ratio of か ら to の of the alignment pitch P1, so that the value of P2 is limited to about 1/10 of P1. Light emitting element 1
If a position shift G1 as shown in FIG. 12 occurs on the cleavage surface of FIG.
0 and the cleavage planes interfere with each other, and a correct alignment pitch P1 cannot be secured at this location.

When the substrate 101 having a thickness of about 300 μm, which is generally used, is divided by the scribe method, the edge of the substrate 101 has “chips” as shown in FIG.
120 or “burr” 121 as shown in FIG.
May occur. As shown in FIG. 16, “unari” 122 in which the step pattern is regularly repeated may occur on the cleavage surface. "Lack" 120, "Burr" 121,
When the “unari” 122 or the like is present, stress distortion occurs at or near the light-emitting junction in the substrate, and the light-emitting efficiency is reduced, the life is shortened, and the optical characteristics and reliability are deteriorated.
The closer the light emitting junction is to the split, the more likely it is to be adversely affected by this stress strain.

Next, the dicing method, which is also applied to the substrate 1
"Chip" and "burr" tend to occur at the edge of 01. Another problem inherent to the dicing method is wear of the dicing cutter. That is, as shown in FIG. 17, the dicing cutter 130 used for a long time is worn and thinner toward the cutting edge. Due to such a shape difference between the cutting edge and the cutting edge, a position shift G2 occurs between the cutting position on one surface and the cutting position on the other surface in the cut surface of the substrate 101, and the value is as large as 18 to 43 μm. Reach. This displacement G2 also becomes a major obstacle in securing a correct alignment pitch.

[0006] In order to improve the problem of the alignment pitch of the light emitting elements 110, a division method using both the scribe method and the dicing method has been developed. That is, the dicing groove is cut into the surface opposite to the light emitting surface of the substrate to a depth that does not reach the light emitting junction. In other words, in this portion, the thickness of the substrate becomes thin, and the condition for reliably generating a crack perpendicular to the substrate surface due to the cleavage phenomenon is established. A scribe line is formed on the light emitting surface of the substrate at a position facing the dicing groove with the thickness of the substrate therebetween. Thereafter, pressure is applied to cleave at the location of the scribe line for division.

[0007] The above combined method is somewhat advantageous in terms of optical characteristics and reliability as compared with only the scribe method or the dicing method alone, but the following inherent problems arise due to the combined use.

When cleaving is performed at the scribe line, irregularities on the inner surface of the dicing groove become seeds, and distortion (wrinkles / faults) easily occurs on the cleaved surface. In the case of a light-emitting element used in an optical printer head, since the light-emitting junction exists near the division, the strain approaches the vicinity of the light-emitting junction, and light is emitted from a light-emitting element surface other than a predetermined light-emitting area. Light leakage will occur. This is a fatal problem for light-emitting elements for optical printer heads, where individual light spots must be clear and clear.

Although not limited to light emitting elements manufactured by the combined use method, when assembling an optical printer head, if the distance between the light emitting elements is short, the adhesive for fixing the light emitting elements to the mounting base is formed by capillary action. Crawling up the gap between the light emitting elements and oozing to the surface of the light emitting region. Since the light emitting element whose light emitting area is contaminated by the adhesive is useless, the entire optical printer head is eventually defective. In order to prevent this, it is necessary to increase the distance between the light emitting elements to some extent, and the resolution (dp
i) was hindered.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to divide a semiconductor substrate which is excellent in optical characteristics and reliability and can manufacture a light emitting element which can be arranged close to each other. The aim is to provide a method.

[0011]

In order to solve the above problems, the present invention provides a method for dividing a semiconductor substrate, in which a plurality of light emitting junctions are scattered in a matrix in a wafer, into light emitting elements of a predetermined size. Forming a dicing groove on the surface opposite to the light emitting surface to a depth that does not reach the light emitting junction; forming a scribe line at the bottom of the dicing groove; and cleaving the semiconductor substrate at the location of the scribe line And performing a dividing step.

In the semiconductor substrate on which the light emitting junction is formed, the vicinity of the light emitting junction is more fragile than other portions. Therefore, in the conventional method in which the scribe line is formed on the light emitting surface, the strain and stress generated by the scribe line propagate to the light emitting junction and lead to deterioration. Further, a load at the time of forming the scribe line causes cracks or cracks on the light emitting surface, and light is reflected at the cracks or cracks, resulting in an abnormal light emitting pattern when viewed from the surface of the light emitting element. On the other hand, in the method of the present invention, since the dicing groove is formed from the far side of the light emitting junction and the scribe line is formed at the bottom of the dicing groove, strain and stress are not easily transmitted to the light emitting junction. Also, even if cracks or cracks occur, they are located on the back side of the light emitting junction when viewed from the surface of the light emitting element, so that it is unlikely that the light emitting pattern is abnormal. Furthermore, when the light emitting element is fixed to the mounting base with an adhesive, the dicing groove located on the side opposite to the light emitting surface serves as an adhesive pool and stops the adhesive here, and does not allow the adhesive to climb up to the light emitting surface. Therefore, the light emitting elements can be arranged very close to each other.

According to the present invention, a scribe line is formed on a surface opposite to a light-emitting surface when a semiconductor substrate having a plurality of light-emitting junctions scattered in a matrix in a wafer is divided into light-emitting elements having predetermined dimensions. And a step of cleaving and dividing the semiconductor substrate at the location of the scribe line, and forming a dicing groove having a depth that does not reach the light emitting junction on the surface on which the scribe line is formed, in a shape following the scribe line. And performing the steps of:

Also in this method, since the scribe line is formed on the side far from the light emitting junction, distortion and stress are not easily transmitted to the light emitting junction. Further, even if cracks, cracks, chips, or burrs occur due to scribing, the area is removed by dicing, so that the performance of the light emitting element is not adversely affected. Chips and burrs generated by dicing are located on the back side of the light emitting junction when viewed from the surface of the light emitting element, and do not constitute an abnormal light emitting pattern. Furthermore, when the light emitting element is fixed to the mounting base with an adhesive, the dicing groove located on the side opposite to the light emitting surface serves as an adhesive pool and stops the adhesive here, and does not allow the adhesive to climb up to the light emitting surface. Therefore, the light emitting elements can be arranged very close to each other.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS.

FIG. 5 shows a part of the surface of the semiconductor substrate 1 from which the light emitting element is cut out. The semiconductor substrate 1 has a light emitting junction 21 and an electrode 22 formed in a wafer 2, and a pair of one light emitting junction 10 and one electrode 22 is scattered in a matrix. The light emitting junctions 21 are arranged closely and narrowly in the X direction indicated by the arrow in FIG. 5, but are arranged with a margin between the adjacent pair of electrodes 22 in the Y direction. Therefore, the light emitting junction 21 and the electrode 2
The ordinary dicing method is applied to insert the X-direction dividing line 3 between the two pairs, and the present invention is applied to insert the Y-directional dividing line 4 between the pair of the light emitting junction 21 and the electrode 22. Apply the method. Each light emitting element 20 divided by the X direction dividing line 3 and the Y direction dividing line 4 has a shape as shown in FIG.

The division of the semiconductor substrate 1 is performed in the following procedure. First, an X-direction dividing line 4 is inserted into the semiconductor substrate 1 by a dicing cutter, and cut into a plurality of band-shaped substrates 1a. Here, the surface on the side from which the light emitting junction 21 emits light is defined as “light emitting surface”, and the surface on the opposite side is defined as “back surface”.
This definition includes the semiconductor substrate 1, the strip-shaped substrate 1a, the light emitting element 20
Used commonly for. Also, in the figure, S
The reference numeral 1 is assigned, and the “back surface” is assigned the reference numeral S2. The cut strip-shaped substrate 1a is attached to a sheet 5 having a surface coated with an adhesive, with the light emitting surface S1 facing down. This is the state of FIG. As shown in FIG. 2, dicing grooves 6 are formed on the rear surface S2 of the strip-shaped substrate 1a. The position where the dicing groove 6 is formed is between the adjacent light emitting junctions 21. Further, the depth of the dicing groove 6 does not reach the light emitting junction 21.

Subsequently, as shown in FIG. 3, a scribe line 7 is formed at the bottom of the dicing groove 6 by a diamond cutter or the like. The position of the scribe line 7 is set exactly in the middle between the light emitting junctions 21. When the band-shaped substrate 1a is pressurized by a metal roller or the like in this state, a cleavage phenomenon occurs from the scribe line 7, and the band-shaped substrate 1a is converted into a plurality of light emitting elements 20 by the cleavage surface 8 as shown in FIG. Divided. Thereafter, the sheet 5 is stretched to increase the distance between the light emitting elements 20 and to be transported to the assembling apparatus.

The light emitting element 20 carried to the assembling apparatus is separated from the sheet 5. The posture in which the light emitting surface S1 is upward as shown in FIG. When the light emitting element 20 is placed on a mounting base (not shown) in this steady posture, the adhesive 9 applied to the mounting base enters the dicing groove 6 as shown in FIG. Since the adhesive 9 accumulates in the dicing groove 6 as described above, the adhesive 9 does not creep up in the gap between the light emitting elements 20, and the light emitting elements 20 are arranged in a state of being very close to each other. It becomes possible.

Next, a second embodiment of the present invention will be described with reference to FIGS. X-direction dividing line 3
Is cut into a plurality of band-shaped substrates 1a, and the band-shaped substrates 1a are illuminated on a sheet 5 having a surface coated with an adhesive.
The process is the same as that of the first embodiment up to the point of sticking with 1 down. The scribe line 11 is formed on the back surface S2 of the band-shaped substrate 1a by a diamond cutter or the like as shown in FIG. The position of the scribe line 11 is exactly halfway between the light emitting junctions 21. When the band-shaped substrate 1a is pressed with a metal roller or the like in this state, a cleaving phenomenon occurs from the scribe line 11, and the band-shaped substrate 1a is converted into a plurality of light emitting elements 20 by the cleavage surface 12 as shown in FIG. Divided.

Subsequently, the dicing groove 1 is formed on the back surface S2.
Form 3 The dicing groove 13 is cut along the scribe line 11 to a depth that does not reach the light emitting junction 21. Thereafter, as in the first embodiment, the sheet 5 is stretched to increase the distance between the light emitting elements 20, and is conveyed to the assembling apparatus. The light emitting element 20 carried to the assembling apparatus is separated from the sheet 5 and mounted on a mounting base (not shown) with the light emitting surface S1 facing upward as shown in FIG. As in the first embodiment, the dicing groove 13 functions as an adhesive reservoir, and the light emitting elements 20 can be arranged in a very close state.

Although various embodiments of the present invention have been described, other various modifications can be made without departing from the gist of the present invention.

[0023]

The present invention has the following effects. In a semiconductor substrate dividing method in which a semiconductor substrate in which a plurality of light emitting joints are scattered in a matrix in a wafer is divided into light emitting elements having a predetermined size, the light emitting surface does not reach the light emitting joint. Forming a dicing groove having a depth, forming a scribe line at the bottom of the dicing groove, and cleaving and dividing the semiconductor substrate at the scribe line. Since a dicing groove is formed from the side farther from the substrate and a scribe line is formed at the bottom of the dicing groove, distortion and stress are less likely to propagate to the light emitting junction, and are less likely to deteriorate the light emitting junction. Also, even if cracks or cracks occur during the formation of the scribe line, they are located on the back side of the light-emitting junction when viewed from the surface of the light-emitting element, so that the light-emitting pattern is unlikely to be abnormal. Furthermore, when the light emitting element is fixed to the mounting base with an adhesive, the dicing groove located on the side opposite to the light emitting surface serves as an adhesive pool and stops the adhesive here,
Since the adhesive is not allowed to crawl up to the light emitting surface, the light emitting elements can be arranged very close to each other, and the resolution of the optical print head or the like can be improved. Further, according to the present invention, in a method of dividing a semiconductor substrate in which a plurality of light emitting junctions are scattered in a matrix in a wafer into light emitting elements of a predetermined size, a scribe line is formed on a surface opposite to a light emitting surface. Forming a semiconductor substrate at the location of the scribe line, dividing the semiconductor substrate, and tracing a dicing groove having a depth that does not reach the light emitting junction on the surface on which the scribe line is formed. And forming a scribe line on the side far from the light emitting junction, so that distortion and stress are not easily transmitted to the light emitting junction. Further, even if cracks, cracks, chips, or burrs occur due to scribing, the area is removed by dicing, so that the performance of the light emitting element is not adversely affected. Chips and burrs generated by dicing are located behind the light emitting junction when viewed from the surface of the light emitting element,
Does not constitute an emission pattern abnormality. Furthermore, when the light emitting element is fixed to the mounting base with an adhesive, the dicing groove located on the side opposite to the light emitting surface serves as an adhesive pool and stops the adhesive here, and does not allow the adhesive to climb up to the light emitting surface. Therefore, the light emitting elements can be arranged very close to each other, and the resolution of the optical print head or the like can be improved.

[Brief description of the drawings]

FIG. 1 is a first explanatory view of a first embodiment of the present invention.

FIG. 2 is a second explanatory view of the first embodiment of the present invention.

FIG. 3 is a third explanatory view of the first embodiment of the present invention.

FIG. 4 is a fourth explanatory view of the first embodiment of the present invention.

FIG. 5 is a partial plan view of a semiconductor substrate.

FIG. 6 is a plan view of a light emitting element.

FIG. 7 is a side view of a light emitting element.

FIG. 8 is a side view showing a mounting state of the light emitting element.

FIG. 9 is a first explanatory view of a second embodiment of the present invention.

FIG. 10 is a second explanatory view of the second embodiment of the present invention.

FIG. 11 is a third explanatory view of the second embodiment of the present invention.

FIG. 12 is an explanatory diagram showing a problem in the case of division by the scribe method.

FIG. 13 is an explanatory diagram showing points to be noted in light emitting element arrangement.

FIG. 14 is a partial perspective view showing a situation where “chips” have occurred due to the division of the substrate;

FIG. 15 is a partial perspective view showing a state in which “burrs” have occurred due to substrate division.

FIG. 16 is a partial perspective view showing a situation in which “unari” has occurred due to substrate division.

FIG. 17 is a diagram illustrating the effect of the shape of a dicing cutter on a cut surface of a substrate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor substrate 1a Strip substrate 2 Wafer 3 X direction dividing line 4 Y direction dividing line 5 Sheet 6 Dicing groove 7 Scribe line 8 Cleaved surface 9 Adhesive 11 Scribe line 12 Cleaved surface 13 Dicing groove 20 Light emitting element 21 Light emitting junction 22 Electrode S1 Light-emitting surface S2 Back surface (surface opposite to light-emitting surface)

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Shoji Inaba 3-201 Minamiyoshikata, Tottori City, Tottori Prefecture F-term in Tottori Sanyo Electric Co., Ltd.

Claims (2)

[Claims] 1. A method of dividing a semiconductor substrate into a plurality of light emitting elements of a predetermined size in which a plurality of light emitting junctions are scattered in a matrix in a wafer. Forming a dicing groove having a depth that does not reach the bonding portion; forming a scribe line at the bottom of the dicing groove; and cleaving and dividing the semiconductor substrate at the location of the scribe line. A method for dividing a semiconductor substrate. 2. A method for dividing a semiconductor substrate into a plurality of light emitting elements of a predetermined size in which a plurality of light emitting junctions are scattered in a matrix in a wafer, wherein a scribe line is provided on a surface opposite to the light emitting surface. Forming a semiconductor substrate at the location of the scribe line, dividing the semiconductor substrate, and tracing a dicing groove having a depth not reaching the light emitting junction on the surface on which the scribe line is formed. A method of dividing a semiconductor substrate.