Gideon Analytical Laboratories received a TI TMS320F28335PGFA Digital Signal Processor for failure analysis. Digital Signal Processing applications include audio and speech processing,sonar,radar, and other sensor array processing,spectral density estimation,statistical signal processing,digital image processing, among many others. The TI TMS320F28335PGFA features high-performance static CMOS technology, a 32-bit CPU, 16 x 16 and 32 x 32 MAC operations, and Harvard bus architecture. It has up to 88 individually programmable, multiplexed GPIO pins with input filtering.
GideonAnalytical Laboratories received several Printed Circuit Boards (PCBs) that were experiencing delamination of the solder masks, specifically on the EMI filter card. A PCB mechanically supports and electrically connects electronic components using conductive tracks, pads and other features etched from copper sheets laminated onto a non-conductive substrate. Components (e.g. capacitors, resistors or active devices) are generally soldered on the PCB. Advanced PCBs may contain components embedded in the substrate. Electromagnetic interference (EMI), also called radio-frequency interference (RFI) when in the radio frequency spectrum, is a disturbance generated by an external source that affects an electrical circuit by electromagnetic induction, electrostatic coupling, or conduction.
Gideon Analytical Laboratories received four Printed Circuit Boards which had either opens or intermittent behavior on some of the P1 connector pins. A Printed Circuit Board (PCB)mechanically supports and electrically connects electronic components using conductive tracks, pads and other features etched from copper sheets laminated onto a non-conductive substrate. PCBs can be single sided,double sided,or multi-layered. An open circuit is an incomplete electrical circuit in which no current flows. Gideon Analytical Laboratories was asked specifically if the soldering on the PCBs was problematic.
Gideon Analytical Labs received three failed Kapton based flex circuits with opens in the trace lines. The origin of the open was not known. The opens in the trace lines were traced down on the Kapton to several eyelets where contact was supposed to be made.
No areas were distinguished and no anomalies were found suggesting a trace copper foil problem on any of the circuits received. A cross-section of the above trace line and eyelet demonstrates the trace line (the line in the middle) either has been dislodged from the barrel or was never connected.
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.
This is the same terminal where the EOS occurred. There are multiple cracks on the capacitor near the bottom. This is due to board flexing, however, the solder does not wet the terminal metal to form a continuous interface leaving a good connection.
The four arrows point toward cracks in the bottom margin area of the capacitor. The fourth arrow from the left, if one follows that crackdown, it ends where the solder first makes a continuous interface to the terminal metal and goes around the corner and ends at the first electrode, where the void is shown by the blue arrow.
This is a class 2 inspection of a printed circuit board (PCB) using the IPC-A-610 Rev E. There is a bubble between the two solder joints of the opposite polarity battery terminals.
These enclosed mini-environments are known repositories for ions which will conduct when a voltage is applied. The leakage current drain is often dependent on the amount of moisture present in the atmosphere since the inside bubble environment will equilibrate with the surrounding atmosphere.
Gideon Analytical Laboratories performed failure analysis on one Ansul IQ-396X, which was submitted for possible failure due to an electrical surge. These control units have two intelligent signaling line circuits (SLC), 396 intelligent device capacity (198 intelligent detectors and 198 monitors/control modules), four built-in output circuits, up to 64 internal output circuits/relays on optional modules in the unit, 99 programmable zone output relays, and manual sensitivity adjustment.
The CPU 400 unit was dissembled and the entire board and components were inspected under 40x to look for and evidence of EOS (electrical overstress) that may have affected the operation of the unit.