Fixtureless testing joins the ScanINSPECT family

Citation

(2007), "Fixtureless testing joins the ScanINSPECT family", Circuit World, Vol. 33 No. 2. https://doi.org/10.1108/cw.2007.21733bad.001

Fixtureless testing joins the ScanINSPECT family

Fixtureless testing joins the ScanINSPECT family

There are limited options available to manufacturers and repair centers with legacy products. Often the original schematics, design data and net lists have been misplaced, lost or destroyed. The method of choice for re- engineering these critical PCBs requires the total destruction of a known good board. Even then there are no guarantees that the re- engineered PCB will work. One of the most difficult tasks in the re- engineering process is accurately determining the hidden interconnects between layers. Validating the results of the reconstruction effort is difficult and imprecise, to say the least.

Traditional re-engineering techniques start with scanning the surface layer of the PCB with ScanFAB, a tool designed to generate Gerber data needed to re-build the board. Next, the outer layers are delaminated from the stack. Once again, ScanFAB is used to generate the necessary Gerber data for the newly exposed inner layers. This process continues until Gerber data is created for every layer resulting in a new net-list. All that's missing is to independently confirm the correctness of this new net-list using another board.

Now the ScanINSPECT FPT, a fixture-less flying probe tester, offers a way of reaching the final piece of the re- engineering puzzle.

ScanCAD FPT is a fixture-less flying probe electrical tester for bare boards. PCB's are held vertically in place with variable clamping system. The system can be used as a stand-alone tester or in conjunction with a more traditional Bed- of-Nail fixture. A flying probe system can test pads and vias that cannot be reached with a standard grid type fixture due to mechanical constraints.

ScanCAD FPT is capable of performing electrical continuity tests on bare boards used in prototype runs, as a statistical sampling tool during fabrication, selection of a true “golden” board, or in small volume product. Completing the re-engineering process with the ScanCAD FPT verifies board interconnects at each de-lamination phase, thereby increasing the opportunities for success future board fabrication.

ScanCAD FPT is available in four configurations designed to handle substrates from 0.8£0.8 in. up to 24.4£20 in. and 0.006 to 0.256 in. thick. Probes are capable of testing as small as 3mils on 5mil spacing.

The ScanCAD FPT accepts data in Gerber RS274D, RS274X, IPC-D-356A or Probot-HLS formats. When no data is available, ScanFAB can be used to scan the target board or artwork to generate the necessary information to verify the net-list.

ScanINSPECT FPT is one of a series of productivity enhancement tools that ScanCAD International, Inc. offers to the electronics fabrication and assembly industries. For more information about ScanINSPECT FPT or other ScanCAD products, contact ScanCAD International, Inc. 12779 W. Belleview Ave, Littleton CO 80127 USA, or 303-697-8888, by fax: 303-697-8580; e-mail: info@scancad.com or web site: www.scancad.com