Visual Fault Analyzer (VFAT) speeds PCB fault Diagnostics and Repair
San Jose, CA. February 21, 2000. Intellitech Corporation, the technology leader in scan-based debug and test, announced today the availability of the Visual Fault Analyzer (VFAT) for viewing and identifying PCB (printed circuit board) assembly faults. VFA is a new generation application that works with Intellitech's PCB ATE (Automatic Test Equipment) that speeds diagnostics and repair by visually showing where the faults are located. Previously, when performing PCB assembly tests, interconnect faults such as stuck-at faults, shorts and opens were diagnosed with text messages, displaying net connectivity information. VFA augments text based diagnostics by visually displaying the diagnostic information onto an image of the Unit-Under-Test (UUT).
The VFA user interface integrates an advanced graphical viewing capability of the UUT with the text diagnostic message output. It provides design and test engineers with the ability to visually analyze fault diagnostic data on a display of the physical UUT. Users now have failure information available that is based on the physical placement, etch routing and layout of components, interconnects and VIAs (a VIA is a small hole used to connect copper etch from one layer of the PCB to another layer). Viewing the fault information in this way allows isolation and diagnosis of faults to be made quickly and easily. Plain text output doesn't include information about the PCB's VIA's which contribute to the faults in a large number of cases. Users can readily see the relationship between the logical fault diagnosis and the real manufacturing defects of the physical design.
"You can diagnose faults much faster and easier with VFA", said Mike Ricchetti, Chief Technology Officer of Intellitech Corporation. "The VFA enables users to pinpoint difficult to find VIA-to-VIA solder bridges and pin-to-VIA shorts, that plain text based diagnostics can't solve. It really excels with SMT (Surface Mount Technology) as this technology requires VIA's to connect the surface mount pads with the other PCB layers. We've found that VIA's contribute to a large number of the faults.
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Some devices, particularly BGA's (Ball Grid Arrays), typically don't allow access to the VIA's underneath. In this case, the VFA performs diagnostics without resorting to X-rays of the PCB. When a single stuck at fault or open exists between two large BGA devices, the 'shot-gun' approach doesn't have to be used. VFA will show which BGA device to remove, saving hundreds, maybe thousands of dollars of PCB re-work costs", Mr. Ricchetti added. VFA is the direct result of several years of development, Intellitech's engineer's ingenuity and its continuing effort to build technology-leading solutions for its customers.
The viewing and fault analysis features of VFA coupled with Intellitech's scan-based ATE, offers companies a unique solution to efficiently resolve manufacturing defects with today's high density, surface mount PCBs. This method can be used during all phases of PCB debug and test, from prototype bring-up through production manufacturing test. VFA fault viewing and analysis features include:
- Listing of failures by fault types of STUCK AT 1, STUCK AT 0, OPEN and SHORT.
- Allows user to select which failures to display, from a single net fault to all failures. Selections can be made using the fault type and/or net name.
- Selectable highlighting of each pin and VIA on failing nets, and potentially shorted pin-to-VIA and VIA-to-VIA locations.
- Ability to turn on/off viewing of all power and ground pins to allow easy detection of shorts to power or ground for stuck-at faults.
- Optionally displays physical X-Y coordinates of failures.
- Zoom the display in and out; Pan through the UUT image.
- Display full Diagnostic text with selected VFA failure(s) on display.
- Toggle the VFA view to display the backside of the PCB, or to select layers within a layout database.
By combining both the connectivity failure data and knowledge of the physical board topology, from PCB CAD layout tools, VFA provides a comprehensive diagnostic solution.
The Visual Fault Analyzer provides an easy-to-use interface that allows even the most novice users to readily determine the physical location of manufacturing defects and determine the course of action for repair. This is especially true in ambiguous situations, where determining the cause of a fault is impossible with traditional text based diagnostics. The faults don't have to be visible to the naked eye or even by X-RAY as locating "hidden" faults, such as pin-to-VIA or VIA-to-VIA shorts is provided by VFA. Also, because VFA enables users to display a combination of failures, it can provide more pertinent information in such cases, allowing quick and easy diagnosis of nets or entire devices.
VFA accepts a variety of image file formats for the viewer, including .GIF. It also supports the industries leading PCB layout formats, including Viewlogic Workview and Cadence Allegro.
The VFA option is free with the purchase of any of Intellitech's Eclipse family of scan-based test and debug tools. For pricing of the Eclipse products, contact Intellitech at:
East Coast: (603) 868-7116 press (2 for Sales)
West Coast: (408) 437-7737
Intellitech Corporation is the technology leader in scan-based debug and test tools for SoC, ICs, PCBs and Systems. Intellitech markets its products to the electronics and semiconductor industries including some of the leading manufacturers of computers, telecommunications equipment, and consumer electronics. They provide a wide range of inexpensive test and debug solutions that enable their customers to deliver the highest quality products to market faster. Intellitech has sales and support offices located in Durham, NH and San Jose, CA