LED device with protective circuit of diode

Abstract

The LED device includes following parts: a LED for converting electrical energy to electromagnetic wave; a set of lead wire frames in use for connecting LED to external electrical source; a group containing multiple Zener diodes, and at least one set being as back to back coupling or face to face coupling. Through gold wire or aluminum wire being connected to a lead wire frame, the set of Zener diode is connected to LED in parallel. Besides function of electrostatic protection, the invention can carry out test of reverse voltage in order to screen out products with potential problems. The invention also makes LED device possess overvoltage protection so as to be possible to maintain service life and quality in severe condition.

Description

technical field [0001] The invention relates to a light emitting diode device, in particular to a light emitting diode device with a diode protection circuit. Background technique [0002] Conventional light-emitting diode devices such as figure 1 As shown, the light-emitting diode chip 100 is placed on a metal lead frame, and it is electrically connected to the positive electrode 131 and the negative electrode 132 of the metal lead frame by using gold wire or aluminum wire to form an electrical path. The metal lead frame part A die-bonding area and a reflective plate 110 are formed by being covered by a plastic shell, and the reflective plate is covered with an epoxy resin 150 with good light transmission. Sometimes in order to provide better LED chip protection or optical functions, the LED is first covered with silicone (Silicone), or even mixed with phosphor powder in the silicone or epoxy resin to match the blue LED chip to produce white light. This device Has been wi...

AI Technical Summary

Problems solved by technology

[0006] Although this kind of electrostatic protection device using a zener diode chip connected in parallel with the light emitting diode chip can provide the electrostatic protection effect of the device, its disadvantage is that it is impossible to perform a reverse voltage test on the protected light emitting diode chip

Since the reverse voltage test of LED chips has always been a standard test item for LED devices, the purpose is to use this test to screen out defective LED chips. The chip may have potential defects, which will greatly reduce the life of the chip. Eliminating products with too high reverse current can effectively improve the reliability of the product

The execution of this device will cause the Zener diode to be turned on when the reverse voltage test is carried out on the LED device, so that the reverse current of the LED chip cannot be measured, so that the LED chip with potential problems cannot be effectively screened. , so that the reliability of the product is greatly reduced

[0007] There are also other prior art ESD protection devices using more than one zener diode, such as U.S. Patent No. 6,642,550, which designs two back-to-back zener diodes on the carrier of the light-emitting diode chip. However, the purpose of this patent is to reduce one welding line and Did not consider how to select the Zener diode to meet the reverse current test of the LED chip, nor did it consider the selection of the Zener diode as an overvoltage protection for the LED chip, because some circuit designs may have an instantaneous power switch. The possibility of surge, so when the instantaneous surge voltage of the line is higher than the limit of the LED chip, it may damage the LED chip

In addition, designing the Zener diode on the carrier of the LED chip can only be used for the LED chip with a flip-chip design, and cannot be used for the LED chip whose electrodes are located on the front of the chip, and the carrier will also increase additional costs.

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