orslabs's Space http://orslabs.posterous.com Most recent posts at orslabs's Space posterous.com Wed, 29 Aug 2012 23:22:00 -0700 Why you should understand the Test Method & Specification of Krypton 85? http://orslabs.posterous.com/why-you-should-understand-the-test-method-spe http://orslabs.posterous.com/why-you-should-understand-the-test-method-spe

The Krypton-85 Leak Testing method is a highly sensitive technique used to measure fine and gross leak rates in high reliability devices. It is the preferred method to characterize small leak rates in critical military components.

The technique was developed in the 1950’s and is still in use today for evaluating military hybrids, commercial sensors, medical implants, silicon based MEMS packaging applications and many others.

The advantages of Krypton 85 over other methods include extremely fast test times, lower overall testing cost, lower leak rate detection (<10-12 atm cc/sec Air limits), minimal absorption to glasses, leak site(s) identification and the ability to test in ambient conditions.

Description of Test Procedure:
The device is placed into a specialized test chamber and pressurized with a gas mixture of air and small amounts of Krypton-85 gas. The mixture will then enter the package cavity if a leak is present. The Krypton-85 leak rate equation determines the pressure and duration of the test based on a reject leak rate value. The client only needs to determine the reject leak rate (Qs) value for the package under test.

The Krypton-85 equation is defined as:
Qs =           R          
        (S)(K)(P)(T)(t)

Where:
Qs = reject leak rate (atm cc/ sec Kr)
R = detector reject level (cpm)
S = specific activity (uCi/atm cc)
K = counting efficiency (cpm/uCi)
P = (Pe2 – Pi2)
       Pe2 = external bomb pressure (atm)
         Pi2 = internal pressure of part (atm)
T = bomb time (hours)
t = 3600 (sec/hr)

After the pressurization cycle, the packages are typically screened using an X-ray scintillation crystal. The crystal is capable of detecting up to 15,000 cpm/uCi of residual Krypton-85. This type of ultra-sensitive detection capability allows for the measurement of extremely small quantities of Krypton-85 gas that may have entered the package.

Various crystal geometries are available but two types are the most common. A flat crystal and/or a well type crystal are commonly utilized depending on the package size and quantity being tested.

The net X-ray count rate measured is proportional to the total Krypton-85 content within the package. The count rate measured is the actual detection of the disintegration rate of Krypton-85 molecules. Each Krypton-85 molecule emits a 0.51 MeV Gamma ray. The total number of molecules that entered the package can also be calculated and hence the total leak rate of the package. In addition, the detection process is performed at ambient conditions and thus the packages are not exposed to vacuum. Testing at ambient conditions mitigates or eliminates the problems encountered with helium based leak testing.

Gross leaks can also be measured using a small directional counter (Geiger Müller tube) that detects the 0.69 MeV Beta particles. This system can be used to pin point the exit site of the gas from the package.

Test Methods:
° Mil-Std 750 method 1071 condition G1, G2
° Mil-Std 883 method 1014 condition B1, B2

Specifications:
° Radioisotope: Krypton-85 gas
° Pressurization range. 30-120 psia
° Minimum detection limit: <1X10-12 atm cc/sec Air
° Accuracy: +/- 10% of value.
° Measurement method: Batch Testing or Read and Record

About us:

Oneida Research Services® (ORS) offers specialized laboratory testing services to support the microelectronics, tele-communications, aerospace, medical, and defense industries. Our services focus on research, development and quality control of our client's products exclusively for our client. ORS strives to develop long term relationships with our clients through unwavering professionalism, flexibility and attention to detail.

Address:

8282 Halsey Road
Whitesboro, NY 13492
Phone:   (315) 736-5480      
Fax: (315) 736-9321

For further information
please contact:
Deborah Delluomo
Phone :( 315) 736-5480       ext. 2202

http://www.orslabs.com

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Tue, 07 Aug 2012 02:16:00 -0700 Why does u need Analytical Testing Services? http://orslabs.posterous.com/why-does-u-need-analytical-testing-services http://orslabs.posterous.com/why-does-u-need-analytical-testing-services home

MATERIALS AND COMPONENT SERVICES OVERVIEW

ORS offers a variety of analytical services to assist you in the Quality Control, Process Monitoring, Failure Investigation or Research & Development of your products. Our goal is to provide you with analytical tools to aid in maintaining and improving the quality of your products.

Testing Services for the Microelectronic Industry
A comprehensive suite of tests evaluating the quality and integrity of microelectronic components and manufacturing practices.

Internal Vapor Analysis (IVA™)
Internal Vapor Analysis (IVA™) is a versatile and precise test procedure developed at ORS for the Residual Gas Analysis (RGA) of hermetic packages. The IVA™ method utilizes advanced Mass Spectrometry techniques to accurately determine the relative concentrations of gas or vapor content in hermetic devices, modules, packages, and inclusions.

Internal Vapor Analysis (IVA™) may now be performed by Gas Chromatography with Mass Spectrometry (GC/MS) to identify unknown volatile and semi-volatile organics in hermetic devices, modules, and packages. ORS has developed a procedure to determine relative concentrations of gases in these packages using a modified GC sample inlet designed at ORS. The GC/MS procedure allows positive identification of unknown organics not traditionally identified during RGA analysis. This procedure is an excellent complement to RGA for a “complete picture” of internal vapors.

Hermeticity Testing
ORS offers two types of non-destructive hermeticity testing. Test methods are designed to determine the quality of a hermetic seal. Fine leak rates are quantified using a helium mass spectrometer or a Kr85 Scintillation Detector. Gross leak rates are characterized by perflourocarbons, dye pentrants or devices failing the initial Kr85 gross leak pressurization. Specialized testing capabilities to measure the leak rate of various other gases or compounds (i.e. Argon, Acetic Acid, etc.) are also available.

Materials Outgassing Studies
The Material Outgassing Characterization test, developed at ORS, is a qualitative and quantitative analysis of the off-gassed gaseous substances desorbed from bulk materials. Outgassing studies may be useful in determining hydrogen desorption rates, adhesive outgassing species (pre and post cure), and to characterize other organic bulk materials used in high reliability components, including polymers, coatings, and epoxies. This method can even be modified to identify organic contamination on materials.

Organic Mass Spectrometry
Numerous techniques are available to identify volatile and semi-volatile organic compounds, and impurities from a variety of sample matrices. Sensitivity in the ppb range is commonly obtained. A useful technique to identify low level "unknown" organic compounds in IVA™ data.

Construction Analysis
Typically performed on microelectronic devices to determine or evaluate the inherent design and robustness of a component by examining its physical characteristics and quality of workmanship.

Destructive Physical Analysis
Disassembly, testing and inspection of microelectronic devices to determine conformance with applicable design, process and procurement requirements.

Failure Analysis
A comprehensive examination of failed devices or components to verify a reported failure mode, identify the failure mechanism, and recommend corrective actions.

About Us:

Oneida Research Services® (ORS) offers specialized laboratory testing services to support the microelectronics, Tele-communications, aerospace, medical, and defense industries. Our services focus on research, development and quality control of our client's products exclusively for our client. ORS strives to develop long term relationships with our clients through unwavering professionalism, flexibility and attention to detail.

Address:

8282 Halsey Road
Whitesboro, NY 13492
Phone:  (315) 736-5480 ext. 2202   (Deborah Delluomo) 

Fax: (315) 736-9321
http://www.orslabs.com

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