KR20050008259A - Light Emitting Diode Chip of High Absolute Maximum Ratings for High Brightness - Google Patents

Abstract

PURPOSE: A high absolute rated LED chip having high brightness is provided to maximize the optical output efficiency by increasing the size of the LED chip and installing a wire bonding electrode at an edge of the LED chip. CONSTITUTION: A size(1) of an LED chip is defined to increase an absolute rated current of an LED. The LED chip is formed with a shape of regular square or a shape of rectangle. Each side of the regular square or the rectangle has a length of 0.5 to 2.0mm. A bonding electrode(2) is formed at an edge within the LED chip. The bonding electrode is formed with a shape of circle or a shape of rectangle. An electrode area ratio belongs to a range of 20 to 30 percent in order to increase brightness of the LED.

Description

Light Emitting Diode Chip of High Absolute Maximum Ratings for High Brightness}

An object of the present invention is the chip size of a light emitting diode

Increase (Chip Size), shape of electrode and bonding electrode

(Bonding Electrode) location, electrode area ratio optimization design, and the epitaxial etch to make the current density of P / N junction of light emitting diode uniform and The purpose is to increase the maximum rated current to be saturated.

If the absolute rating is increased, the light emitting diode can be driven by applying a high current.

High brightness can be achieved.

Chip size of the conventional light emitting diode (Chip Size) is manufactured in 0.2 ~ 0.4mm, the absolute rating of the visible light emitting diode is 30 ~ 50mA, the infrared light emitting diode is 80 ~ 100mA.

In the light emitting diode of the present invention, the chip size is increased to 0.5 to 2.0 mm, the electrode area ratio is minimized, the current density is uniform, and the absolute rating is improved 3 to 6 times, and the light output is also improved. Increasing the brightness of the light emitting diode was achieved.

It can be used as a high brightness light emitting diode used as a light source for illumination.

In the conventional light emitting diode, a wire bonding electrode is disposed at the center, and the wiring is composed of 0 to 4 wires for distribution of current density.

In this case, the carrier concentration on the epi surface

If the carrier concentration is high, the current injected into the electrode is increased to the side by riding the surface, so that the current is saturated in the outer peripheral part of the chip.

In this case, if cracks and contamination of conductive materials generated during dicing occur, leakage current to the outer circumference is generated, which is a fatal abnormality factor for luminance deterioration and lifespan.

In the present invention, the wire bonding electrode is placed on the edge of the chip to obscure the factor of lowering the brightness due to the bonding wire, and the electrode is evenly arranged on the surface of the chip with 5-30 μm wiring. I was.

In addition, when the carrier concentration on the epi surface is high, chemicals other than the surface electrode may be removed after ohmic contact through metallization and alloy processes.

(Chemical) was removed by etching and the oxide film treatment (Passivation) to control the amount of current density that is strongly sent to the side on the surface.

As a result, the present invention aims to be able to be used as a light source for lighting by realizing high brightness of the light emitting diode by maximizing the light output while improving the absolute rating.

The technical problem to be achieved by the present invention is to increase the absolute rating of the light emitting diode and to achieve high brightness.

In order to carry out the technical problem of the present invention, the chip size of the light emitting diode was increased, and the wire bonding electrode was disposed at one edge of the chip, and the electrode area ratio was 20 to 30%, resulting in light output efficiency. The value was maximized.

In addition, for good ohmic contact, the carrier concentration of the epi surface such as GaAs, GaP, GaAsP, GaAlAs, InGaAlP, InP, GaN, etc. The current density of the P / N junction of the light emitting diode is uniformed and the maximum rated current at which the current density distribution is saturated is increased.

1 is a front view of a light emitting diode having a low surface carrier concentration according to the present invention.

2 is a front view of a light emitting diode having a high surface carrier concentration according to the present invention;

Figure 3 is a side view of the light emitting diode of the present invention

4 is a side view of a lamp assembled with the light emitting diode of the present invention.

The present invention will be described in detail with reference to the accompanying drawings.

1 is a front view of a light emitting diode having a low surface carrier concentration according to the present invention.

Chip Size (1) was 0.5mm to 2.0mm in consideration of absolute rating.

The wire bonding electrode portion 2 of the chip surface electrode has four corners of four corners for uniformity of current density distribution and to prevent the bonded Al and Au wire from covering the light emitting portion of the chip. It was arranged in one corner.

The wiring part 3 is configured with a wiring width of 5 to 30um to maintain low ohmic contact resistance between the semiconductor and metal and maximize the chip light emitting area ratio.

The position of the wiring part 3 is arranged in a radial shape from the circular electrode on the surface of the chip to the diagonal direction of the chip, and the pitch between the wirings has an area ratio of 20 ~ considering the area of the electrode and the whole chip. Placed to 30%.

2 is a front view of a light emitting diode having a high surface carrier concentration according to the present invention.

Chip size (4) was 0.5mm ~ 2.0mm in consideration of the absolute rating.

The wire bonding electrode portion 5 of the chip surface electrode is a quadrilateral of four corners for uniformity of current density distribution and to prevent the bonded Al and Au wire from covering the light emitting portion of the chip. It was arranged in one corner.

The wiring part 6 is configured to have a wiring width of 5 to 30 μm to maintain low ohmic contact resistance between the semiconductor and metal and to maximize the chip emitting area ratio.

The position of the wiring part 6 was arranged in a radial shape from the circular electrode on the surface of the chip to the diagonal direction of the chip, and the pitch between the wirings was 20 in consideration of the area of the electrode and the entire chip. Placed at ˜30%.

Chemical material after electrode formation of high Carrier Concentration Layer of Epi surface 7 such as GaAs, GaP, GaAsP, GaAlAs, InGaAlP, InP, GaN

(Chemical) and Dry Etch Equipment

Etch P / N junction of light emitting diode

The current density of the junction is made uniform and the maximum rated current at which the current density distribution is saturated is increased.

3 is a side view of the light emitting diode of the present invention.

The chip structure of the light emitting diode is briefly described as N or P substrate (8), N or P Epi layer (9), or P or N Epi layer (10). It is constructed.

P / N junction 11 is formed in the interface of Epi layer.

High Carrier Concentration Layers on the Epi Surface

(Chemical) and Dry Etch Equipment

Etch and the oxide film 11 is applied using a deposition process or a chemical treatment process.

It is possible to implement the current density (Current Density) formation of the P / N junction (12) of the light emitting diode uniformly (12) and to increase the maximum rated current at which the current density distribution is saturated.

4 is a side view of a lamp assembled with the light emitting diode of the present invention.

The lead frame 13 is positioned at the edge of the chip so that the respective directions of the bonding wires 15 connected to the lead frame 13 and the bonding electrode 14 do not cross the light emitting part of the chip.

This can reduce the light emitting area covered by the bonding wires, thereby improving the luminance.

As described above, the effect of the present invention can implement a chip having an absolute rating 3 to 6 times higher than that of a conventional light emitting diode, and thus it can be used for a high brightness light emitting diode such as lighting.

Claims (6)

Chip Size to Increase the Absolute Rated Current of Light-Emitting Diodes (1) Light-emitting diodes with square or rectangular chips and 0.5 mm to 2.0 mm Bonding Electrode in Chip 2 positions The round or square bonding electrodes of the four corners of the rectangle were arranged at one corner. Electrode area ratio (surface electrode / chip surface area) to increase the brightness of light emitting diodes: 20 ~ 30% Epi to increase the brightness of light emitting diodes (Epi) Surface Carrier Concentration Layer Etch Carrier Concen on the Epi Surface If the tration is 10 ¹⁸ cm ^-3 or more, the electrode is formed and then etched using chemical and dry etching equipment, and the oxide film 11 is deposited using a deposition process or a chemical treatment process. Lower to 10 ¹⁸ cm ^-3 . Wiring location in the chip The position of the wiring part 3 is in a radial shape from the circular electrode on the surface of the chip toward the square surface of the chip. arrangement Wiring section (3) (6) width length arranged in surface electrode: 5 ~ 30um wiring width for maintaining low ohmic contact resistance between semiconductor and metal and maximizing chip emitting area ratio