Compared to testing IC’s, testing MEMS introduces various peculiarities. In addition to the electrical test, they require a specific type of stimulus, to properly test their capability to transduce a physical input to an electrical output, under their actual working conditions. They also require to be handled with specialized equipment, able to provide high throughput without shocking the micromechanical internal structures. And, last but not least, tests often need to be performed at temperature.
SPEA demonstrated to be the most qualified supplier of test equipment for MEMS devices: SPEA MEMS test cells combine fast and gentle pick&place handling, reliable contacting and complete final test capabilities, including electrical test, physical stimulus for functional test and calibration, and tri-temp thermal conditioning. Everything is controlled by a single software interface, to offer an easy-to-use environment along the whole process, from equipment programming to production control.
Single-manufacturer complete solution
All MEMS Test Cell elements are designed and manufactured directly by SPEA, so that the test cell works as a single, best-performance machine.
This guarantees best technical performance, equipment cost optimization, one-shot factory integration.
Cost of test results greatly reduced, thanks to the high throughput, lower investment, short application development time and rapid accommodation of different applications.
Complete testing with MEMS stimulus
Test under actual working conditions
Reliable functional test and calibration of MEMS and sensors is not limited to the electrical characteristics of the devices. They also require to determine and analyse the device mechanical functions, by measuring their non-electrical behaviour.
For this reason, SPEA MEMS Test Cells are able to perfectly replicate the real working conditions of a wide variety of devices, applying the same physical stimulus the device must sense and answer to. The constant connection to the test resources during the stimulus application makes the equipment able to accurately verify the correct device working.
Test resources can be embedded into the stimulus unit, or housed into a compact, test-head-only tester.
Full Final Test Concept
SPEA test cells perform the complete parametric and functional test on the fully packaged devices – for either standard packages or WLCSP die-level packages – at the end of the production process.
After testing, the devices can be directly shipped to the customer, without needing any further work or re-test.
Multiple stimuli can be combined in a single test unit, to test combo MEMS, such as environmental sensors (pressure + humidity + gas + temperature) or navigation sensors (accelerometer + gyroscope + compass). The test area can be easily reconfigured on field with different test units.
- Low g accelerometers
- High G sensors
- 6-DOF sonsors
- Barometric sensors
- Humidity sensors
- Temperature sensors
- Gas sensors
- Absolute & Differential pressure sensors
- Force sensors
- Medium & high pressure sensors
- Proximity sensors
- Time-of-flight sensors
- Ranging sensors
- UV sensors
- IR sensors
- Gesture sensors
- Hall effect sensors
- Angular sensors
High-throughput MEMS handling
High-throughput pick and place test handlers (able to move up to 33,000 units per hour) are specifically designed to perform gentle, fully automated handling of MEMS devices, without applying extra-force to the components. The handler architecture gives the best flexibility, so that the configuration can fit with every process: devices are picked up from trays or bowl feeder, wafer or strip on blue/UV tape, transferred to the test area and, at the end of the test, are placed on trays, reel or box.
Nitrogenless temperature conditioning
Thermal conditioning is applied to the devices which need to be tested at temperature (temperature sensors, but also devices that are called to work under extreme conditions, such as automotive sensors), with an innovative nitrogen-less system ranging from -65 to 200°C.
A fast temperature change mechanism allows for a single-insertion test at different temperatures: the device can remain in the same pocket while it is tested at the required temperature values, in sequence. This lowers the overall costs, reducing in number the handling operations required, while guaranteeing higher calibration precision and easier device traceability.
- Temperature range: -65 to +200°C
- temperature accuracy ± 1°C
- temperature stability ± 0.5 °C
- No defrost needed for intervention on the sockets
- 24 hours/day working without interruption
- Accurate temperature control at full temperature range
- Controlled ambient temperature
- Precise tracking of thermal performance parameters
- Temperature monitoring per site
Reliable, gentle contacting
SPEA provides the test cells complete of all the tools required to interface and contact the devices under test with the test instrumentation.
Sockets and contacting units are developed in-house by SPEA, for the most common IC packages (with or without leads) as well as for custom packages, to provide the best performance in MEMS testing:
- Low-Force Contacting
- High-efficiency thermal transfer with DUT
- Dead-bug or live-bug contacting units
- Customizable DUT presser tip shape
- Device Aligner
- Temperature sensors on contactors