JP2863979B2 - Method for manufacturing semiconductor light emitting device - Google Patents

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 semiconductor light emitting device having an LED array used as a light source for exposing a photosensitive drum of a page printer.

[0002]

2. Description of the Related Art When manufacturing a semiconductor light emitting device including an LED array composed of a plurality of LEDs arranged in a row and individual electrodes provided for each LED, a plurality of the semiconductor light emitting devices are formed on a wafer. After that, the semiconductor light emitting devices are separated from each other by dividing the wafer.

[0003]

In order to connect the electrodes of the above-described semiconductor light emitting device to the wiring of the control circuit board via bumps by a micro-bump bonding method or the like, bumps are formed on the electrodes by electroplating. It has been proposed. Therefore, before cutting the wafer and separating the semiconductor light emitting devices from each other, short-circuit wires connected to all the individual electrodes of each LED are formed on the wafer, and the short-circuit wires are connected to the plating electrodes to form bumps. It may be formed on the electrode.

In addition, each LED is connected via such a short-circuit wiring.
It is conceivable to inspect the presence or absence of light emission by energizing the LED and prevent electrostatic breakdown of each LED.

[0005] In order to control the light emission of each LED individually, it is necessary to finally cut the short-circuit wiring as described above between the individual electrodes. However, if the short-circuit wiring is cut by photoetching, the number of steps increases, and the productivity decreases.

An object of the present invention is to provide a method for manufacturing a semiconductor light emitting device which can solve the above-mentioned problems of the prior art.

[0007]

According to the present invention, a plurality of semiconductor light emitting devices each including an LED array constituted by a plurality of LEDs arranged in a line and individual electrodes provided for each LED are formed on a wafer. When the semiconductor light-emitting devices are separated from each other by dividing the wafer along the dividing line, a short-circuiting line connected to all of the individual electrodes is divided between the individual electrodes before dividing the wafer. It is formed on a wafer so as to straddle the dividing line.

[0008]

According to the present invention, the individual electrodes of a plurality of LEDs formed on a wafer are all connected to each other by short-circuit wiring before the wafer is divided. Since the short-circuit wiring is formed so as to straddle the cutting line of the wafer between the individual electrodes, the wafer is cut along the dividing line and simultaneously cut between the individual electrodes. Each individual electrode is insulated from each other.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

The semiconductor light emitting device 1 shown in FIGS. 3 and 4 has a plurality of LEDs arranged in a row on one main surface of a silicon substrate 2.
LED array constituted by ED3 and its substrate 2
An anode electrode (individual electrode) 4 provided for each LED 3 formed on one main surface of the substrate 2 and a cathode electrode (common electrode) 5 formed on the other main surface of the substrate 2 are provided.

The semiconductor light emitting device 1 is one of a large number formed on a silicon wafer 6 as shown in FIG. That is, the semiconductor light emitting device 1 is formed in each of a plurality of regions surrounded by a dividing line L indicated by a two-dot chain line in FIG. 2, and the semiconductor light emitting device 1 is divided by dividing the wafer 6 along the dividing line L. Separated from each other.

In each LED 3, a semiconductor crystal is formed on one main surface of a wafer 6 by metal-organic vapor phase epitaxy (MOCVD).
And molecular beam epitaxy (MBE) and the like, and the grown layer is formed by etching while leaving a portion to be LED3. For example, as shown in FIG. Layer 3, which is a growth layer of gallium phosphide (GaP) or the like
a, and an n-type semiconductor layer 3b, a p-type semiconductor layer 3c, and a p ^{+ -type} semiconductor layer 3d, which are growth layers of Al _x Ga ₁ -x As. Further, silicon nitride (SiN _x ), silicon oxide ( The protective film 7 such as SiO ₂ ) can be formed by plasma CVD or the like. The individual electrode 4 for each LED 3 is connected to the p ⁺ -type semiconductor layer 3 d which is exposed by removing a part of the protective film 7 covering the light emitting surface of each LED 3 by etching, and the common electrode 5 is connected to the other side of the wafer 6. Connected to the entire main surface.

As shown in FIG. 1, before the wafer 6 is divided, the short-circuit wires 8 connected to all the individual electrodes 4 of each LED 3 cross the division line L between the individual electrodes 4. Formed. The short-circuit wires 8 can be formed simultaneously with the individual electrodes 4. For example, the short-circuit wires 8 can be formed by growing a metal film and then removing the portions to be the individual electrodes 4 and the portions to be the short-circuit wires 8 by etching.

Each individual electrode 4 is drawn out from each LED 3 in a direction (vertical direction in FIG. 1) perpendicular to the parallel direction (left-right direction in FIG. 1) of the LED array, and is drawn to one side and the other side. Are alternately arranged in parallel, and oppose the individual electrodes 4 of the adjacent LED arrays with the dividing line L interposed therebetween, except for those located at the periphery of the LED array formation region on the wafer 6.

The short-circuit line 8 has a first portion 8a along a direction perpendicular to the parallel direction of the LED arrays, a second portion 8b along a direction inclined with respect to the parallel direction of the LED arrays,
It comprises an annular third portion 8c surrounding the ED array formation region, and a fourth portion 8d straddling the dividing line L between the third portion 8c and the LED array formation region. The first portion 8a of the short-circuit line 8 connects the individual electrodes 4 facing each other across the division line L and straddles the division line L. The second portion 8b of the short-circuit line 8 connects one of the individual electrodes 4 opposed to each other across the dividing line L to the other of the opposed individual electrodes 4 adjacent to the opposed individual electrode 4, It straddles the dividing line L. The fourth portion 8d of the short-circuit wire 8 connects the third portion 8c to the individual electrode 4 located at the periphery of the LED array formation region.

According to the above configuration, the individual electrodes 4 of the respective LEDs 3 formed on the wafer 6 are all connected to each other by the short-circuit wiring 8 before the wafer 6 is divided, so that the short-circuit wiring 8 is used as the plating electrode. 5 to form a gold bump 10 as shown by a phantom line in FIG. 5. The LED 3 is energized through the short-circuit wiring 8 to check for light emission omission. Electric breakdown can be prevented. Since the short-circuit wiring 8 is cut at the same time as the wafer 6 is cut along the cutting line L, the individual electrodes 4 can be insulated from each other without separately performing photoetching or the like.

The present invention is not limited to the above embodiment. For example, as in the modification shown in FIG. 6, each individual electrode 4 is pulled out from each LED 3 only to one side, and the common electrode 5 is formed on one main surface of the wafer 6 like the individual electrode. May be formed on the wafer 6 so as to straddle the dividing line L between the electrodes 4 and 5 as well as to the common electrode 5.
In this case, the fifth short-circuit wiring portion 8e connecting the common electrodes 5 facing each other with the dividing line L interposed therebetween, the third portion 8c of the short-circuit wiring 8 and the common electrode 5 located at the peripheral edge of the LED array forming region. The sixth short-circuit wiring portion 8f to be connected may be newly formed in addition to the above embodiment, and other portions are the same as those in the above embodiment, and the same portions are denoted by the same reference numerals. In addition,
In the case of this modified example, it is not possible to inspect for light emission omission by supplying current to each LED via the short-circuit wiring, but bumps can be formed on the common electrode by electroplating.

[0018]

According to the present invention, since the individual electrodes of each LED formed on the wafer are all connected to each other by the short-circuit wiring before the wafer is divided, the short-circuit wiring is connected to the plating electrode. It becomes possible to form a bump on each electrode, or to apply an electric current to each LED via its short-circuit wiring to inspect for the presence or absence of light emission, and to prevent electrostatic breakdown of each LED. Since the short-circuiting line is cut at the same time as the wafer is divided to separate the LED arrays from each other, the individual electrodes can be insulated from each other without separately performing photoetching or the like.

[Brief description of the drawings]

FIG. 1 is a plan view showing a short-circuit wiring pattern according to an embodiment of the present invention.

FIG. 2 is an explanatory view of an arrangement of a semiconductor light emitting device according to an embodiment of the present invention on a wafer.

FIG. 3 is a plan view of a semiconductor light emitting device according to an embodiment of the present invention.

FIG. 4 is a perspective view of a semiconductor light emitting device according to an embodiment of the present invention.

FIG. 5 is a sectional view of a semiconductor light emitting device according to an embodiment of the present invention.

FIG. 6 is a plan view showing a short-circuit wiring pattern according to a modification of the present invention.

[Explanation of symbols]

 3 LED 4 Individual electrode 6 Wafer 8 Short circuit wiring L Dividing line

Claims (1)

(57) [Claims] 1. A plurality of semiconductor light emitting devices each including an LED array composed of a plurality of LEDs arranged in a line and individual electrodes provided for each LED are formed on a wafer, and then the wafer is cut along a cutting line. When the semiconductor light emitting devices are separated from each other by dividing them, before dividing the wafer, the short-circuit wiring connected to all of the individual electrodes is placed on the wafer so as to straddle the dividing line between the individual electrodes. A method for manufacturing a semiconductor light emitting device, comprising: