A. Forward Voltage drop the dark light
A: A is the electrode and the light emitting data ohms touch, but touch the resistance, mainly by the data substrate low concentration or the electrode mutilated formed.
B: one kinds is the electrode and Data as non-ohm touch, first and foremost occurred in the the chip electrode preparation the process of transpiration first-layer electrode O’clock’s extrusion print or clip printed, spread azimuth.
Else wrapper process in can also be formed Forward pressure decreased, the primary reason there are silver adhesive curing is not sufficient, bracket, or chip electrodes pollute such as the formation touch resistance is large or touch resistance is unstable.
Forward pressure decreased of the chip in the fixed voltage quiz when, after the chip’s current is small, and then embodies dark spots, there is one kinds dark light representation is the chip self-luminous power is low, forward voltage drop to normal.
2. Difficult pressure welding: (foremost there are to fight non-stick, the electrode falling, punch through electrode)
A: to fight non-stick: The primary because the electrode appearance oxidation or there is glue
B: There are with the light emitting Data touch is not strong and thicker wire bonders layer is not strong, during which the in order to thickened layer of Drop-based.
C: punch through Electrode: usually associated with chip data relevant, data brittle and strength is not high’s Information Yi punch through electrode, usually GAALAS Data (such as high red, infrared chip) representing an GAP Data Yi punch through electrode,
D: pressure welding Debugging should Soldering Temperature, ultrasonic power, ultrasonic moments, pressure, golden goal big and small, stents positioning and other carry on adjustments.
3. Light-emitting Color distinction:
A: the same an chip light-emitting colors have a significant difference between the first and foremost is because the epitaxial wafers information doubt, ALGAINP four element data is selection of quantum layout of the is very thin, growth is the very difficult to ensure that the regional component jointly. (Component resolution band gap, the band gap of the resolution wavelength).
B: GAP yellow-green chip, light-emitting wavelength of will not have a large error, but the because the human eye right to this wave band color sensitive, is very simple find out yellowish, migraine greenish. Because the wavelength yes epitaxial wafers data resolutions of the, regional the smaller the, showing color error concept of the smaller the, so in the M / T job in the there are nearby Selecting Method Of.
C: GAP red chip and some light color is a partial orange, because its light emission mechanism is a direct leap. Affected by impurity concentration affected, the current density intensify when the, prone to impurity energy level offset and light-emitting plump, the light emitting yes beginning turns orange-yellow.
Four. Floodgate Fluid effects:
A: a light emitting diode in the normal voltage can not be turned on, when the voltage height to a certain extent, the current sudden change.
B: occurred floodgate fluid appearances reason is the light-emitting INFORMATION epitaxial wafers grow up O’clock presents a reverse mezzanine, have this presentational LED in the IF = 20MA O’clock quiz the forward drop of there are hiding Xing, in the use of process is the out of north and south pole Voltage will not do large, reflected off, the available test information instrument from transistor Tracer test curve, but also to go through a small current IF = 10UA lower forward voltage drop to find that a small current forward voltage drop significantly too large, then the be able to yes The doubt formed by the.
5. Reverse Earth Leakage:
A: reason: epitaxy information, the chip manufacturing, equipment, encapsulation, quizzes typically 5V under the reverse leakage current is 10UA, also be able to fixed reverse current under the quiz reverse voltage.
B: not the same type of LED reverse features big difference: P Green, Pu Huang chip reverse breakdown can reach over one hundred volts, while S & P chip in ten to twenty volts.
C: epitaxy the formation of’s Reverse Leakage @ foremost by the PN knot internal layout of the shortcomings formed by the, chip manufacturing the process of next to the surface was corroded will not do or there are silver glue silk buildup of In the measured noodles, strictly prohibited to use organic solution is dispensed silver glue. In order to avoid silver glue After a capillarity appearances climbed to the knot zone.