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Measurements of true leak rates of MEMS packages.

Han B - Sensors (Basel) (2012)

Bottom Line: Gas transport mechanisms that characterize the hermetic behavior of MEMS packages are fundamentally different depending upon which sealing materials are used in the packages.In metallic seals, gas transport occurs through a few nanoscale leak channels (gas conduction) that are produced randomly during the solder reflow process, while gas transport in polymeric seals occurs through the bulk material (gas diffusion).In this review article, the techniques to measure true leak rates of MEMS packages with the two sealing materials are described and discussed: a Helium mass spectrometer based technique for metallic sealing and a gas diffusion based model for polymeric sealing.

View Article: PubMed Central - PubMed

Affiliation: CALCE Electronic Products and Systems Center, Department of Mechanical Engineering, University of Maryland, College Park, MD 20742, USA. bthan@umd.edu

ABSTRACT
Gas transport mechanisms that characterize the hermetic behavior of MEMS packages are fundamentally different depending upon which sealing materials are used in the packages. In metallic seals, gas transport occurs through a few nanoscale leak channels (gas conduction) that are produced randomly during the solder reflow process, while gas transport in polymeric seals occurs through the bulk material (gas diffusion). In this review article, the techniques to measure true leak rates of MEMS packages with the two sealing materials are described and discussed: a Helium mass spectrometer based technique for metallic sealing and a gas diffusion based model for polymeric sealing.

No MeSH data available.


Helium leak test signals for (a) polymer-sealed packages (Vcavity = 3.1 × 10−4 cm3) and (b) metal-sealed packages (Vcavity = 2.156 × 10−4 cm3). Test parameters include a bombing pressure of 4 atm (gage), a bombing time of 6 h and a dwell time of 10 min.
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f2-sensors-12-03082: Helium leak test signals for (a) polymer-sealed packages (Vcavity = 3.1 × 10−4 cm3) and (b) metal-sealed packages (Vcavity = 2.156 × 10−4 cm3). Test parameters include a bombing pressure of 4 atm (gage), a bombing time of 6 h and a dwell time of 10 min.

Mentions: Figure 2 shows helium fine leak test results obtained from two separate tests with polymer-sealed packages (Vcavity = 3.1 × 10−4 cm3) and metal-sealed packages (Vcavity = 2.16 × 10−4 cm3). The test conditions include a bombing time of 6 hours at 4 atm (gauge) and a dwell time of 10 minutes. In the experiment, individual packages as well as batches containing multiple identical packages were tested; in the batch tests 20 polymer-sealed packages and 54 metal-sealed were used. The signals obtained from the batch tests and single package tests are shown in Figure 2(a,b) for polymer-sealed and metal-sealed packages, respectively. The batch test signals normalized by the number of packages in the batches are also plotted for comparison.


Measurements of true leak rates of MEMS packages.

Han B - Sensors (Basel) (2012)

Helium leak test signals for (a) polymer-sealed packages (Vcavity = 3.1 × 10−4 cm3) and (b) metal-sealed packages (Vcavity = 2.156 × 10−4 cm3). Test parameters include a bombing pressure of 4 atm (gage), a bombing time of 6 h and a dwell time of 10 min.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3376579&req=5

f2-sensors-12-03082: Helium leak test signals for (a) polymer-sealed packages (Vcavity = 3.1 × 10−4 cm3) and (b) metal-sealed packages (Vcavity = 2.156 × 10−4 cm3). Test parameters include a bombing pressure of 4 atm (gage), a bombing time of 6 h and a dwell time of 10 min.
Mentions: Figure 2 shows helium fine leak test results obtained from two separate tests with polymer-sealed packages (Vcavity = 3.1 × 10−4 cm3) and metal-sealed packages (Vcavity = 2.16 × 10−4 cm3). The test conditions include a bombing time of 6 hours at 4 atm (gauge) and a dwell time of 10 minutes. In the experiment, individual packages as well as batches containing multiple identical packages were tested; in the batch tests 20 polymer-sealed packages and 54 metal-sealed were used. The signals obtained from the batch tests and single package tests are shown in Figure 2(a,b) for polymer-sealed and metal-sealed packages, respectively. The batch test signals normalized by the number of packages in the batches are also plotted for comparison.

Bottom Line: Gas transport mechanisms that characterize the hermetic behavior of MEMS packages are fundamentally different depending upon which sealing materials are used in the packages.In metallic seals, gas transport occurs through a few nanoscale leak channels (gas conduction) that are produced randomly during the solder reflow process, while gas transport in polymeric seals occurs through the bulk material (gas diffusion).In this review article, the techniques to measure true leak rates of MEMS packages with the two sealing materials are described and discussed: a Helium mass spectrometer based technique for metallic sealing and a gas diffusion based model for polymeric sealing.

View Article: PubMed Central - PubMed

Affiliation: CALCE Electronic Products and Systems Center, Department of Mechanical Engineering, University of Maryland, College Park, MD 20742, USA. bthan@umd.edu

ABSTRACT
Gas transport mechanisms that characterize the hermetic behavior of MEMS packages are fundamentally different depending upon which sealing materials are used in the packages. In metallic seals, gas transport occurs through a few nanoscale leak channels (gas conduction) that are produced randomly during the solder reflow process, while gas transport in polymeric seals occurs through the bulk material (gas diffusion). In this review article, the techniques to measure true leak rates of MEMS packages with the two sealing materials are described and discussed: a Helium mass spectrometer based technique for metallic sealing and a gas diffusion based model for polymeric sealing.

No MeSH data available.