Gideon Analytical Labs examined the extrusion marks on the tungsten IC probes wires versus a Monel K500 IC probes via SEM. MONEL K500 is a nickel-copper alloy, precipitation hardenable through additions of aluminum and titanium. MONEL K500 retains the excellent corrosion resistant characteristics of 400 and has enhanced strength and hardness after precipitation hardening when compared with 400. Alloy K500 has approximately three (3) times the yield strength and double the tensile strength when compared with 400.
Gideon Analytical Labs received several Fairchild QTC H11N1s, a high-speed logic optocoupler, in 6-pin plastic DIPs. The devices were reported as some good, some intermittent and some not working in the application.
The main function of an opto-isolator is to block high voltages and voltage transients, so that a surge in one part of the system will not disrupt or destroy another part of the circuit. Opto-couplers allow a signal to be sent in digital (some analog) between circuits.
Gideon Analytical Labs received a failed IR FR22ON MOSFET within DC-DC converter. All the MOSFETs were shorted on all terminals. The MOSFETs were tested by lifting the gate and source wires from the circuitry. The Idss leakage for a good IR MOSFET is typically around less than 1 nano-amp. All the good MOSFETs tested were around .8 nano-amps, BVdss 220V, Vgsth 3.6, Igss <100nA. This IR FR220N has thermal damage. This typically overwhelms the junctions with current (heat) and the weakest hex cells are destroyed first.
Gideon Analytical Labs received pulse width modulators PWM failing in a MuRata Ps DC-DC converter. The PWM was removed from the encapsulation and tested. Several I/O pins were either open or showed no connection to the circuitry of the IC. The PWM CS51022AG is a fixed frequency current mode controller family provides the necessary features for DC−DC primary side control. In addition to low startup current (75A) and high frequency operation capability, the CS51022A includes over-voltage and under-voltage monitoring, externally programmable dual threshold over-current protection, current sense leading edge blanking, current slope compensation, accurate duty cycle control and an externally available 5.
Relays are very susceptible to contamination because the leads are made of copper and vulnerable to corrosion and leakage current if not protected from the environment.
The liquid shown here was thought to have come from the flux residue and, therefore, an organic analysis FTIR was required as opposed to inorganic XRF. However, the liquid was acidic in nature and XRF was employed. The material was a filled, glass fiber reinforced material containing a phosphorus species along with an antimony/bromine fire retardant package.
Gideon Analytical Labs received four tantalum capacitors identified as failing from two vendors, Kemet (T491B225K035AT) and AVX TAJB225K035RNJ. A tantalum capacitor is a type of electrolytic capacitor. It is constructed of a pellet of tantalum metal as anode, covered by an insulating oxide layer that forms the dielectric (manganese dioxide), surrounded by conductive material as a cathode (carbon with a silver epoxy interface). Tantalum electrolytic capacitors exploit the tendency of tantalum to form a non-conductive protective oxide surface layer.
Gideon Analytical Labs received several VCSELs (vertical-cavity surface-emitting laser) with diminished light capacity were submitted for failure analysis. A VCSEL is a type of semiconductor laser diode with laser beam emission perpendicular from the top surface, contrary to conventional edge-emitting semiconductor lasers which emit from surfaces formed by cleaving the individual chip out of a wafer. Thus, all the light is emitted from one spot, the laser aperture. The devices were tested on a curve tracer to determine whether any junction problems (junction inversion, leakage current, facet oxidation, etc.
Gideon Analytical Labs received two linear adjustable monolithic silicon 5962-89981 adjustable positive regulators both with no measurable output for failure analysis. A third device was sent with a questionable output. This is a three terminal positive adjustable voltage regulator designed to provide 1.5A with higher efficiency than conventional voltage regulators. The device is designed to operate to 1 Volt input to output differential and the dropout voltage is specified as a function of load current.
Gideon Analytical Labs received several failed AS169 PHEMT DC 2676 transistors on several PCBs (pseudomorphic high electron mobility transistor) is a field-effect transistor incorporating a junction between two materials (GaAs and AlGaAs) with different valence and conduction bands (bandgap is the difference between the two bands for the two materials) as opposed to a doped region where a MOSFET structure would be formed. The thickness of the one material is stretched such that the bandgap opens more than it normally would which allows better performance because the lattice does not bunch up when the two materials are forced together.
X-Ray Radiography Inspection This report contains images taken of the BGAs on the two boards provided. There are no significant defects present, however, significant voiding is present throughout the two parts. The last image shows a BGA analysis performed on one of the worst areas of voiding. The analysis shows voiding greater than 15%, but less than 20%.
When run, this feature shows voiding in the solder joints as well as background features such as traces and vias, all within the same image.
