Definition of up-screening
It’s an automatic assumption that OEM devices will operate in accordance with their manufacturer specified datasheet. However these same devices could potentially outperform their original specifications by varying degrees.
Up-screening describes the assessment process of a homogenous batch of components in order to derive quality assurance for operation over an extended temperature range or higher electrical performance. Each assessment is tailored to suit the reliability needs of the end application, usually the product of environmental, electrical and life requirements.
Typical factors assessed are:
- Capability of a device operate with ambient temperature (TA) extended beyond the OEM spec
- Capability of active semiconductor material to operate with junction temperature (TJ) extended beyond the OEM spec
- Long term degradation at a given performance or environmental exposure
- Specific performance parameters with tightened min / max measurements e.g. VOS for amplifiers
- Speed, frequency, timing performance
- Higher maximum ratings with respect to voltage and current handling
- Operational supply voltage limits and/or input/output voltage thresholds.
- Parameter drift tolerances,
- Initial accuracy figures and PPM figures over temperature
Why would you need to up-screen components?
The 3 main drivers are below.
Leading-edge – A technology or product exists but is not commercially released by the OEM with your desired specification but might materially be capable. This is often described as COTS (Commercial Off The Shelf) up-screening, seeking assurance to suit higher performance industrial, medical or military needs.
Trailing-edge – Legacy or long term applications suffer from commercial obsolescence of the original device grade during their lifetime. An up-screened part provides a potential means to avoid a board re-design and associated re-qualification or system change.
Production enhancement – To remove any marginal performance or electrical outliers from a batch and as a result increase the overall reliability and yield within the larger build.
What we do
1 – Bespoke customer specification
Engineering assessment of application:
- Environmental, electrical, mechanical – overall reliability
- Timescale requirements
- Material leadtimes, inclusive of project consumables and raw material
- Budget requirements.
Produce a test plan which accommodates all of the above can migrate from sampling to production and that (subject to device performance) will provide the end assurance needed.
2 – In accordance with recognized industry standards
- MIL-STD-883 M5004
- MIL-PRF-38534-Class H
- MIL-PRF-38534-Class J
- MIL-PRF-123 (ceramic caps)
- MIL-PRF-39007 (resistors fixed, wirewound)
- MIL-PRF-49465 (resistors)
- MIL-PRF-55310 (crystal oscillators)
- MIL-PRF-55342 (chip resistors)
- MIL-PRF- 55365 (capacitors, tant, electrolytic)
- NASA EE-INST-002
We are located in the UK and operate within a purpose-built engineering facility. The majority of testing is performed using in-house resources and equipment. Where a project requires additional resources we fully manage the process using our network of authorised manufacturing partners. The product to the customer is a complete solution for high-reliability component test and screening.
View our parametric electrical test capability.
In house equipment
Unimet Testers & other various ATE
Screening of unencapsulated component
In addition to encapsulated components and passives we can also screen components at the bare die level via wafer probing or lot acceptance testing. This may be to enable future die assembly or to give assurance for un-encapsulated bare die use in an MCM or hybrid circuit scenario.
Sales & Support
We offer a selection of in-house environmental tests, such as centrifuge acceleration, life burn-in, stabilization bake and thermal shock temperature cycling.
We offer a comprehensive selection of mechanical tests, from ball shear, die shear, wire bond pull to SEM inspection.