In recent years, LED electronic screen dead lights have been frequent, and not long ago, a large number of dead lights trend started. Chip, gold wire, bracket, process or glue, which link caused the dead light? What will often die lights?

   There may be more than 100 reasons for the LED electronic screen, which is limited by time. Today we only take the LED light source as an example. To start, introduce some of the reasons that may lead to dead lights.

  1. LED electronic screen copper wire, copper alloy, gold-clad silver alloy wire, silver alloy wire instead of gold wire and gold wire have the advantages of high electrical conductivity, good thermal conductivity, corrosion resistance, good toughness, excellent chemical stability, etc., but gold wire are expensive, resulting in high packaging costs. In the periodic table of elements, gold, silver, copper and aluminum among the transition metal elements have high electrical conductivity. Many LED manufacturers try to develop such as copper alloy, gold clad silver alloy wire, silver alloy wire to replace the expensive gold wire. While these alternatives are superior to gold wire in some properties, they are much worse in chemical stability, such as silver wire and gold-clad silver alloy wire susceptible to sulfur/chlorine/bromide corrosion, and copper wire susceptible to oxidation. In the case of encapsulated silica gel similar to water-absorbing and breathable sponge, these alternatives make the bonding wire susceptible to chemical corrosion, the reliability of the light source is reduced, and the LED lamp bead is easy to break and die after a long time of use.

  2. With a diameter deviation of 1 gram of gold, a gold wire with a length of 26.37m and a diameter of 50μm (2 mil) can be drawn, or a gold wire with a length of 105.49m and a diameter of 25μm (1 mil) can be drawn. If the length of the gold wire is fixed, and if the diameter of the incoming gold wire is half of the original diameter, then the measured resistance of the gold wire to be beaten is a quarter of the normal value.

  For suppliers, the thinner the diameter of the gold wire, the lower the cost, and the higher the profit when the selling price remains the same. For LED customers who use gold wires, purchasing gold wires that cut corners in diameter will increase the resistance of the gold wires and reduce the fuse current, which will greatly reduce the life of the LED light source. For example, the life of 1.0 mil gold wire must be shorter than that of 1.2 mil gold wire.

  3. Surface defects

  (1) The surface of the wire should be free from nicks, pits, scratches, cracks, bumps, folds and other defects that reduce the service life of the device that exceed 5% of the wire diameter. During the drawing process of the gold wire, the surface defects on the surface of the wire will lead to an increase in the current density, making the damaged part easy to be burned, and at the same time, the ability to resist mechanical stress is reduced, causing the inner lead to break at the damaged part.

  (2) The surface of the gold wire should be free of oil, rust, dust and other adhesions, which will reduce the bonding strength between the gold wire and the LED chip, and between the gold wire and the bracket.

  4. The breaking load and elongation of LED electronic screen are too low. A good gold wire that can withstand the impact generated by resin encapsulation must have the specified breaking load and elongation. At the same time, the breaking force and elongation of the gold wire play a key role in the quality of wire bonding, and the bonding wire with high breaking rate and elongation is more conducive to bonding. Too soft gold wire can cause the following problems:

 (1) The arch wire sags;

 (2) Spherical instability;

 (3) The ball neck is easy to shrink;

 (4) The gold wire is easy to break.

  Gold wire that is too hard can cause the following problems:

 (1) Punch holes in the chip electrodes or epitaxy;

 (2) The neck of the gold ball is broken;

 (3) Difficulty forming alloys;

 (4) It is difficult to control the arc of the arch wire.