Optical Leak Testing

The next generation of hermetic package testing

NorCom Systems Inc Norristown, PA

www.NorcomSystemsInc.com

Company History

• Established in 1982• World Leader in NDT, Engineering and Services

with Holography and Shearography• Delivered over 200 systems to 14 countries• Approved by Pratt & Whitney, Boeing Aircraft,

Northrop-Grumman, NASA, Lockheed Martin, Raytheon Aircraft Co.

• FAA Approved Repair Station LT6R187J

NDT Instruments, Systems and Services

Aerospace Vehicles & Engines

Naval Structures

Electronics

Tires

Established in 2000 to:

• Focus on 4 main areas:

fiber optic industry

quartz crystal oscillators

frequency control devices

display devices• Develop future products and applications

• Concentrate on the Micro- and Opto- electronics industry for leak testing hermetically sealed packages.

Hermetic Leak Test Methods

• Helium Mass Spectrometry ( Fine)

• Radioisotope testing (Fine)

• Bubble Leak testing (Gross)

• Dye Penetrant (Gross) (Destructive)

• Residual Gas Analysis (Destructive)

• Optical Leak testing (Gross & Fine)

Range of Leak Sensitivity (Component Level)

Bubble

Helium

Krypton

OpticalLeak Test

True Leak Rate (deceasing )

Max. Required Sensitivity:2x10E-8 cc-atm/sec. Mil Std. 883F TM 1014

Gross Leak -6 Fine Leak

Only Optical Leak Testing covers thefull required test range in one method.

Optical Leak TestingOptical Leak Testing is the most accurate,repeatable leak test technology availabletoday for the Semiconductor, Hybrid andOpto-electronics industries.

Optical Leak testing provides:1. Automated, In-line, full matrix leak testing to dramatically improve productivity.2. Ability to leak test SMC soldered to PCBs.3. Full range leak test: Gross & Fine Leak

Package Pressure

Pp

Prior to Chamber pressurization internal and external chamber pressure are

essentially equal

Chamber Pressure

Pc

Package lid is flat

Chamber Pressure

Pc

Package Pressure

Pp

As Chamber Pressure (Pc) is applied the package lid is deflected due to the higher

relative external package pressure

Package lid is deformed and out of plane

Chamber Pressure

Pc

Package Pressure

Pp

With constant chamber pressure appliedto a none leaking package the lid

will remain out of plane

Package lid is deformed and out of plane

Package Pressure

Pp

With constant chamber pressure appliedA gross leaking package will return to the

Pre-pressurized plane

Chamber Pressure

Pc

Package lid is flat

The NorCom 2020Optical Leak Test System

Hermetic devices areLeak Tested on the sameBoat all the way throughManufacturing.

Above: parts in boat

Right: loaded into Test Cell

Lids of leakingdevices move.

Lids of non-leakingdevices do notmove during hold-time. With chamberat constant pressure.

Digital Holography Lid Deformation Measurement

True Leak Rate Measurement Achieved by:

1. Differentiating between lid deflection due to changes in chamber pressure Pc(t) and lid deflection due to change in internal package pressure Pp(t).

2. Modulating the Helium pressure sinusoidally around the working pressure causes Pc(t) and Pp(t) to be linearly independent.

Example:

Mini-DIL OE packageLeak rate of 5.6 x 10e-7 cc-atm/sec. measuredwith Helium Mass spectroscopy , pig tail removed.(Average of 4 runs with an order of magnitude variation in results)

Optical leak Test parameters: Chamber working Pressure, Pw = 3.86 atm Test Time, t = 556 seconds Package Volume, V= 0.1cc

During the 556 sec test time, the observed lid wasexactly that predicted by the model.

Internal Package Pressure change, Pp

was determined to be 3.76 x 10e-2 atm.

Using eq. 4, yields a Measured Leak Rateof 2.53x 10e-6 atm-cc/sec, which is then converted to the True Leak Rate by dividing by the Chamber Working Pressure of 3.68 atm. resulting in a leak rate for this Mini-DIL of:

6.88 x 10e-7 cc-atm/sec

This compares very favorably with the average leak rate of 5.6 x 10e-7 cc-atm/sec leak rate determined with helium Mass. Spec.

Leak Test Applications for the Optical Leak Test

Method

• Board Mounted Components• Vacuum Packaged MEMS Devices• Helium Absorbing Materials• Fiber Optic Pig Tails• Optical Surfaces • OLED Devices

Testing a full matrix of pig tailed butterfly packages.

Tray with 10 Hermetic Fiber Optic Devices

• 0.015 in. Welded Lids• Metal Package

Automatic Test Analysis with a set Accept/Rejectthreshold shows 6 leaking and 4 hermetic packages.

Test Results

Board Level Leak Testing

Discrete hermetic devices that passMIL STD 883Emay failure during or after board assembly.

These devices, onassembled circuitcards can not be leaktested, except withOptical Leak Testing.

Missile circuit module.

Launch of Atlas AV-001August 21, 2002

Booster Remote Control Unit (BRCU) manufactured by for Lockheed Martin Astronautics by BAE SYSTEMS Controls.

Hermetic SMC components cracked during solder operation.

NorCom 2020 was modified to allow leak testing of the circuit card assemblies.

Flight hardware tested, repaired and reverified with NorCom 2020

Why is Optical Leak Testing Important?

• Simultaneous Gross and Fine leak test.• Real-time Data provides Process Control for lid sealing. • Test Devices intolerant of temperatures above 90ºC.• Leak test packages with helium absorbing/emitting materials and features: fiber optic pigtails, ceramics• Leak test board mounted and even conformal coated components.• Automate leak test operations, reduce cost and improve product reliability.

Optical Leak Testing dramatically increasesmanufacturing productivity and quality by providing in-line, full matrix product testing.

NorCom 2020Optical Leak Testing

Applications

• Optoelectronic Devices• Semiconductor• Microwave• Automotive• Hi Rel Hybrids• MEMS• OLED Displays• Board Mounted Surface Mount Devices

For More Information Contact:

NorCom Systems Inc.1055 W. Germantown Pike

Norristown, PA 19403

Tel. (610) 592-0167

www.NorComSystemsInc.com