Why use pure gold wire for SMD LED?
Small LED lamp beads, its main components are: bracket, chip, glue, phosphor, wire. It can be said that although the sparrow is small, it has all five internal organs. Pressure welding is a key link in the packaging technology of LED light-emitting diodes, and we will only introduce this link today. The wire connecting the LED lamp beads to the chip and the conductive pins at the 2 ends is called a wire. Basically, the wires are made of 0.999 pure gold wire, the diameter is divided into: 0.8mil, 1.0mil. There are also some manufacturers pursuing low prices with copper-doped alloy wires. But the quality will be worse, because the overcurrent and thermal conductivity of the gold wire is very high, and the heat can be conducted to the negative pin through the gold wire in time. In addition, the stretchability of the gold wire is stronger, and it is not easy to cause a dead light phenomenon due to the break of the gold wire.
At present, domestic packaging companies are mainly concentrated in Guangdong. There are many brands of LED lamp beads in the Guangdong market. Guangmai Technology was established in 2009 and the company is located in Shenzhen. Recently, Guangmai Technology launched 3535 high-power 9VLED lamp beads, the author went to visit. The above is the workshop of GMKJ LED automatic wire bonding machine. The purpose of pressure welding is to lead the electrode to the LED chip to complete the connection of the inner and outer leads of the product. The pressure welding process of LED has two types: gold wire ball bonding and aluminum wire bonding. The picture on the right is the process of aluminum wire bonding. First, press the first point on the LED chip electrode, then pull the aluminum wire to the top of the corresponding bracket, press the second point, and then tear the aluminum wire. The gold wire ball bonding process burns a ball before pressing the first point, and the rest of the process is similar. GMKJ LED 3535, 2525, 3030 lamp beads use imported 99.99% gold wire, good electrical conductivity, firm welding, good stability, non-dead lamp, high temperature resistance, strong light reflection ability. L
The characteristics of ED gold wire light-emitting diodes, gold wire performance is stable, but the price is high, and it is always the first in the field of high-end LED packaging. The main function of LED light-emitting diodes is to brighten, change color, etc., gold is generally used to prevent oxidation and ensure stable contact. Expanded LED introduction The number of gold wires (that is, LED chip electrodes) has little to do with the size of the chip. There are also double electrodes and single electrodes for 24mil. The number of gold wires for LEDs is mainly related to the process and characteristics of the chip. Generally, single electrode chips They are all vertical structures, the bottom can be directly energized, so there is one less electrode, and the electrode is directly made on the substrate. This kind of red and yellow LED chips are mostly used. And the double lines are mostly horizontal structures, and the positive and negative poles are made on the same plane. , The bottom substrate is insulated, and LED blue and green chips are generally the majority.
