IEC 62047-37-2020 pdf free download – Semiconductor devices – Micro-electromechanical devices – Part 37: Environmental test methods of MEMS piezoelectric thin films for sensor application.
This part of IEC 62047 specifies test methods forevaluating the durability of MEMSpiezoelectric thin film materials under the environmentalstress of temperature and humidityand under mechanical stress and strain, and test conditions for appropriate qualityassessment. Specifically， this document specifies test methods and test conditions formeasuring the durability of a DUT under temperature and humidity conditions and appliedvoltages. it further applies to evaluations of direct piezoelectric properties in piezoelectric thin
films formed primarily on silicon substrates,i.e. piezoeiectric thin films used as acousticsensors, or as cantilever-type sensors.
This document does not cover reliabilityassessments，such as methods of predicting thelifetime of a piezoelectric thin film based on a Weibull distribution.
2Normative references
The following documents are referred to in the text in such a way that some or all of theircontent constitutes requirements of this document. For dated references,only the editioncited applies.For undated references, the latest edition of the referenced document (inciuding
any amendments) applies.
IEC 62047-30, Semiconductor devices – Micro-electromechanical devices – Part 30:Measurement methods of electro-mechanicalconversion characteristicsofMEMSpiezoelectric thin film
3 Terms and definitions
No terms and definitions are listed in this document.
ISo and lEc maintain terminological databases for use in standardization at the followingaddresses:
. IEC Electropedia: available at http://www.electropedia.orgl
. Iso Online browsing platform: available at http://www.iso.orglobp
4Testing procedure
4.1 General
The degree of degradation in a device under test (DUT) is evaluated by measuring thepiezoelectric properties of the DUT before and after applying the environmental stress oftemperature and humidity.Figure 1 shows the general flow of the testing procedure.
4.2Initial measurements
The methods of measurement used in the environmental tests shall conform to the methodsdescribed in IEC 62047-30. The ambient conditions for measurements shallinclude anambient temperature of 25 C± 3 °C, a relative humidity of 45 % to 75 %, and an atmospheric
pressure of 86 kPa to 106 kPa.
4.3Tests
4.3.1 DUT setup and environmental conditions
For tests requiring continuous operation of the DUT, the DUT is placed in a test bedthat canbe adjusted to the prescribed temperature and humidity to conditions. The test conditions are
monitored to verify that no abnormalities occur when the chamber environment reaches theprescribed conditions. For tests that do not require continuous operations of the DUT,theDUT may be placed in the test bed and the test bed may be deposited in the chamber, but the
test bed need not be put in the chamber. When depositing and removing the DUT and testbed for either test, the operator shall ensure that:
. water does not drip onto the DUT;
.the DUT is not directly immersed in water.4.3.2Test duration
Test duration is described in 5.1.1 to 5.1.7.
4.3.3Number of tests and number of DUTs
Specifications for the number of tests and the number of DUTs shal take the failuremechanism, failure distribution，and other factors anticipated in each test into account. Whenintermediate measurements are required, such measurements may be performed inaccordance with the following timetable:
• 24 h (+8 h，-O h);
• 48 h (+8 h，-0 h);
• 96 h (+24 h, -0 h);
• 168 h (+48 h,-O h);
• 480 h (+72 h, −0 h).
Here, the time spent removing the DUT and conducting the intermediate measurements shall be omitted from the test duration.IEC 62047-37 pdf download.