Outgassing

What is outgassing test?

It is to determine the total concentration of volatile organic compounds that outgas from parts, assemblies, components, tapes, adhesives, etc. used inside hard drive assemblies. Volatile organic contamination inside the head/disk assembly (HDA) has the potential to cause head/disk interference including stiction. This method requires the use of a highly sophisticated microanalytical instrument.GC/MS.

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There are two sampling methods for outgassing test: Static Headspace Sampling and Dynamic Headspace Sampling.

After sample preparation, samples will be analyzed by GC-MS equipped with Hewlett Packard Headspace Sampler, Automatic Thermal Desorption System

Static Headspace Sampling GC-MS

Brief Procedure

Determine the number of pieces, surface area, and/or mass of the sample to be tested and place samples into a headspace sampler vial/chamber.

Using the digital 0.5 uL syringe, add 0.05 uL of neat decane internal standard solution to each sample vial/chamber. Touch the sides of the vial/chamber with the syringe needle to ensure total transfer of the internal standard.

Seal 20 ml each sample vial/chamber.

Bake samples at 85 °C for 16 hours.

Start run sequence.

After the run, integrate all of the peaks in each total ion chromatogram, and obtain the mass spectrum of each peak. Perform a computer spectral search and interpret each mass spectrum to identify each peak.

Analysis the results and Generate Report.

Typical Total Ion Chromatogram of GC-MS
Static Headspace Outgassing

For more details, please refer to IDEMA Reference Determination of Volatile Organic Compounds (VOC) by Static Headspace GC/MS.

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Dynamic Headspace Analysis by GC-MS

Brief Procedure

This method is applied to quantitatively and qualitatively measure the material purged from the space inside a chamber that contains disk drive piece parts and/or subassemblies.

Pack the adsorption tubes with the appropriate type and amount of sorbent (50 to 250 mg).

Condition the adsorption tubes by heating them 10 to 50 °C above the sample desorption temperature, while purging with a gas (i.e., nitrogen).

Prepare the samples and place sample in chamber.

Install the adsorption tube.

Use a calibrated flow meter and a flow controller to set the flow to 50 ml/min.

Heat chamber to 85 °C.

Remove the adsorption after three hours.

Analysis the results and Generate Report.

Typical Total Ion chromatogram of GC-MS
Dynamic Headspace Outgassing

For more details, please refer to IDEMA ReferenceGenaral Outgas Test Procedure by Dynamic Headspace Analysis.

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