Quality detection device and method of encapsulation LED solder joint

Abstract

The invention discloses a quality detection device and method of an encapsulation LED solder joint. The device comprises a current source, a sample holder, a current detection unit, a photoelectric detector, a data acquisition card and a computer; the current source drives the LED on the sample holder to work; the current detection unit obtains instantaneous current occurring by switching the LED and outputs the instantaneous current to the computer; the photoelectric detector is arranged in front of the sample holder to collect an optical signal sent by the LED and converts the optical signal into an electrical signal; the output end of the photoelectric detector is connected with the data acquisition card; the data acquisition card is connected with the computer; the data acquisition card obtains the electrical signal output by the photoelectric detector and outputs the electrical signal to the computer; and the computer processes and analyzes the measured photoelectrical data to evaluate the quality of the LED solder joint. The invention utilizes a new quality detection method of an encapsulation LED solder joint; and according to the instantaneous current occurring by switching the LED and response curve of light intensity, fall time and stable amplitude are obtained to be compared with preset thresholds, namely the soldering quality of an LED product can be identified so as to realize nondestructive testing of the quality of the solder joint.

Description

technical field [0001] The invention relates to the field of LED testing, in particular to a quality testing device and method for packaged LED solder joints. Background technique [0002] Light emitting diodes (Light emitting diodes, LEDs) are widely used in landscape lighting, backlighting, street lighting and indoor lighting due to their characteristics of energy saving, environmental protection, fast response speed, and cold light source, and are ideal alternative light sources. The LED lamp bead is composed of a chip, a gold wire, a bracket and an epoxy resin package. The chip is welded on the bracket by the gold wire to realize electrical connection. The quality of the welding is directly related to the life of the LED. In microelectronic packaging, about 1 / 4 to 1 / 3 of the failure of semiconductor devices is caused by chip interconnection, so the quality of LED welding must be inspected. Common LED solder joint quality problems are mainly manifested in defects such as...

AI Technical Summary

Problems solved by technology

In the packaging process, the packaging process itself may affect the welding quality, and factors such as the thermal effect during LED operation may also affect the welding quality, and even lead to product failure in severe cases.

Due to the packaging of the encapsulation layer, for the quality inspection of LED soldering after encapsulation, the common practice is to use chemical reagents to melt the outer encapsulation material and observe it with a microscope, which will inevitably cause irreversible damage to the sample.

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