Principles and Applications of Low-Light Microscopy EMMI/OBIRCH
Emission Microscope (EMMI) (wavelength range: 400nm to 1100nm) is a tool used to detect and locate fault points, search for bright spots and hot spots. By detecting the photons excited by electron hole binding and thermal carriers. In IC components, EHP (Electron Hole Pair) recombination emits photons. For example, when a bias voltage is applied at the pn junction, the electrons of n are easily diffused to p, and the holes of p are also easily diffused to n and then undergo EHP recombination with the holes at the p end (or the electrons at the n end).
Application scope:
Detecting leakage caused by various component defects, such as gate oxide defects, electrostatic discharge failure, latch up effect and leakage in circuit verification, junction leakage, forward bias, and transistors operating in saturation regions, can all be located by EMMI to detect the location of hot spots (Hot Spot or Bright Spot) in CMOS image sensing chips and LED flexible liquid crystal screen array areas, as well as uneven lateral current distribution and leakage in LED type chips.
Application scope:
1. Detect chip packaging wiring and internal circuit short circuits.
2. Short circuits and leakage of transistors and diodes.
3. Metal circuit defects and short circuits in TFT LCD panels, PCB/PCBA.
4. Partial failed components on PCB/PCBA.
5. Leakage of dielectric layer (oxide).
6. ESD lockout effect.
7.Depth estimation of failure points for 7.3D stacked die packaging.
8. Location detection of unopened failure points on chips (distinguishing packaging in Die)
9. The problem analysis of low impedance short circuit (<10 ohm) is commonly used to analyze some uncovered sample tests, as well as the failure location of metal lines and components on large PCBs. It is also used to analyze situations such as leakage and short circuits that cannot be detected by OBIRCH and INGAAS due to metal layer obstruction.
