Flying Probe Testing
Our flying probe testers can be programmed quickly from CAD data and unlike ICT, do not require the high cost of a fixture and the higher cost for programming. Flying probe testing is an excellent tool for measuring values of circuits and detecting shorts and opens. By measuring the value of circuits, the flying probe tester not only checks for manufacturing defects, but in many cases, validates the design by measuring the actual value of a circuit against the design values. The cost per test is higher, however the upfront cost is much less. For this reason, it is an ideal solution for supporting startup production when all that might be available is functional test.
Two 3070 ICT systems with high pin count
For complex board level products where even very good DPMO yields can still lead to a small number of defects, and these defects can be very difficult to troubleshoot. ICT is a perfect tool to validate continuity, localize the defect, and then validate the repair. Additionally, the ICT can provide levels of power on performance and jtag testing. Once the product has passed ICT it is ready for full functional testing.
Alpha has extensive functional test capabilities from simple go no go testing to sophisticated progressive “devices under test” DUT. Functional tests are designed to assure that circuitry functions within specifications. Testing is usually done “at speed” through DUT connectors and/or “bed of nails” BON fixtures.
Identification of PCA functional defects:
- Assessing functionality while applying marginal power supply voltage and/or current
- Appraising functionality of DUT while applying a range of input stimuli amplitudes or currents
- Determining DUT power consumption during operation
- Uncovering problems with analog circuitry such as:
- Wrong oscillator frequency
- Analog signal clipping/distortion
- Amplifier gain or bandwidth issues
- Drive currents of power output circuits
- Potentiometer adjustment issues
- Revealing issues with digital circuitry such as:
- Signal timing (design or component related)
- Communications problems (Ethernet, Device Net, Serial, etc.)
Defect Detection and Resolution
At Alpha, a great deal of effort goes into minimizing defects through process development, validation, and control. However, there are occasional issues that occur and Alpha has invested significantly in our ability to detect and resolve defects. We utilize new generation AOI, 3D X-ray and 5DX laminography for detection. Should the defect occur under a BGA or other complex device, we utilize VJ Electronix automated rework stations which include vision pick and place, along with temperature profiling reflow to facilitate the repair.
Thin pcba’s, or assemblies with parts close to the edge, are not good candidates for depanelization through breakaways such as mouse bites, scoring, or pizza cutters. A minute over flex, or small error in mishandling, could result in a broken or cut trace or a cracked solder joint, that could be undetectable and pass test, but could then quickly fail in the field. For that reason we have invested in tooling for automated depanelization. These systems provide perfect depanelization with the lowest risk to the product, and with reverse drill rotation and vacuum systems they allow us to maintain a completely dust and debris free environment.
Large environmental chambers for both static and dynamic burn-in.
Press Fit Connectors
Programmed and computer controlled pressure and speed for perfect repeatability and adherence to specifications.