ACCELERATED TEST

The Accelerated Testing offer aims at exposing a circuit to an accelerated radiation environment and collect the errors generated.

The value proposition is to run the fastest and cheapest accurate performance assessment on hardware reliability to radiations, impacting TTM as little as possible.

Compared to the real-time testing, this offer allows to:

  • Have a shorter test cycles (i.e. Reduced timing to get results)
  • Expose chips to particles which can not be considered in real-time test (e.g. Heavy ions)
  • Consider a larger set of test conditions (e.g. Different voltage values)
  • Deal with prototype chips (i.e. Less parts requested, ability to work around limitations)

Particles which can be considered in such test are:

  • White spectrum neutrons
  • Mono-Energy neutrons
  • Thermal neutrons
  • Heavy Ions
  • Protons
  • Alpha
  • Gamma rays
  • X rays (*)

Additional particle sources may be considered by iRoC based on customer demand.

Please check the different lab locations which iRoC works with for these various particles.

(*): iRoC offer on X rays is specific to DRAM devices.More

Note that test conditions can be either static or dynamic and are defined in a case-by-case mode.

The steps considered to implement such service are:

  • Define the test conditions to characterize the chip
  • Define reporting model to be considered for analysis
  • Define and build the hardware configuration needed to perform the tests
  • Develop the software needed to perform the tests
  • Execute the tests with accelerated source (in house alpha particle source or radiation labs for other particles)
  • Provide analysis report, based on agreed report items and formats

The hardware and software configuration are specific to a chip. Note that some irradiative environments may require particular chip packaging (e.g. Alpha test implies to have decapped chips).

iRoC's error detection algorithm (or test algorithm) are adapted to type of device and error mechanism. The customer is able to specify particular test condition in which the algorithm will be executed. More

For reporting, the iRoC accelerated test offers several report types differing in contents and formats. The customer will be able select which report type applies to his/her need, so iRoC results can be used the best way. More

Several options can be considered for this service, for both analysis and reporting:

Prototype chip support

Adapts to particular conditions of test chips (stuck bits, degraded functionalities). In that case, stuck bits for example will be managed by iRoC on a case by case.

Detailed analysis support

As a non-standard report, iRoC can provide a detailed analysis of errors that have been detected while running tests. In this case, the customer gets in addition to the selected formats a deep analysis report. See chapter 4 to have more details about contents.

Such kind of test applies to all type of chips.

Deliverables to the customer:

Deliverable Description
Test Plan Description of tests that will be performed
Report Files List of report types (as described in Test Plan) which reflect the test results
Detailed Report Detailed report proving an in-depth analysis of the chip SE characteristics

X ray test on DRAM

The X-Rays Testing offer is linked to DRAM chip family. It does not apply to other kind of chips.The value proposition is to bring evidence to improve assembly process and avoid DRAM failures in end products and systems.The objective here is to identify how the X-Ray exposition of DRAM chips during the manufacturing process (non destructive inspection (NDI) of solders) impacts the chip quality. This is related to the dose effect which affects the capacitance-based technology used for DRAM chips (i.e. Refresh-time TREF).

The service steps considered to achieve this objective are:

  • Get chips from the manufacturer BEFORE they've been exposed to X-Rays
  • Run tests on chips and analyze results [*]
  • Return chips to manufacturer for irradiation with the same dose and spectrum than NDI
  • Get chips from the manufacturer AFTER they've been exposed to X-Rays
  • Run tests on chips and analyze results [*]
  • Provide analysis report, comparing results from the two runs
  • Return chips to manufacturer

[*] Shmoo plot and TREF 1rst failing bits tests at high temperature (e.g. 85 degrees Celsius). More

Test conditions are fixed for X-Rays testing. As a consequence, no test plan is provided and test conditions are only reflected into the test report at the end of the service implementation. The test is performed on samples of 40 chips.

Note that - as an option - an additional test run may be considered after the second one. In that case, chips will be exposed to high temperature (e.g. 200 degrees Celsius during four days) to see how DRAM chips may recover from dose effect. The same tests already executed apply in this case and the analysis report issued to the manufacturer contains then three measurement points. Chips are returned afterwards.iRoC does not perform the X ray irradiation. The radiation flux and spectrum are defined by customer according to its inspection procedures. It is advised that irradiation of chips be performed on the same machine than NDI.