Transcript Hermetic Leak Test Methods

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
Tires
Electronics
Established in 2000 to:
• Concentrate on the Micro- and Opto- electronics
industry for leak testing hermetically sealed
packages.
• Focus on 4 main areas:
fiber optic industry
quartz crystal oscillators
frequency control devices
display devices
• Develop future products and applications
Hermetic Leak Test Methods
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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)
Gross Leak
-6
Fine Leak
Bubble
Max. Required
Sensitivity:
2x10E-8 cc-atm/sec.
Mil Std. 883F TM
1014
Helium
Krypton
Optical
Leak Test
True Leak Rate (deceasing
)
Only Optical Leak Testing covers the
full required test range in one method.
Optical Leak Testing
Optical Leak Testing is the most accurate,
repeatable leak test technology available
today for the Semiconductor, Hybrid and
Opto-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
Prior to Chamber pressurization internal
and external chamber pressure are
essentially equal
Chamber
Pressure
Pc
Package lid is
flat
Package
Pressure
Pp
As Chamber Pressure (Pc) is applied the
package lid is deflected due to the higher
relative external package pressure
Chamber
Pressure
Pc
Package lid is
deformed and
out of plane
Package
Pressure
Pp
With constant chamber pressure applied
to a none leaking package the lid
will remain out of plane
Chamber
Pressure
Pc
Package lid is
deformed and
out of plane
Package
Pressure
Pp
With constant chamber pressure applied
A gross leaking package will return to the
Pre-pressurized plane
Chamber
Pressure
Pc
Package lid is
flat
Package
Pressure
Pp
The NorCom 2020
Optical Leak Test System
Hermetic devices are
Leak Tested on the same
Boat all the way through
Manufacturing.
Above: parts in boat
Right: loaded into Test Cell
Digital Holography Lid
Deformation Measurement
Lids of non-leaking
devices do not
move during holdtime. With chamber
at constant pressure.
Lids of leaking
devices move.
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 package
Leak rate of 5.6 x 10e-7 cc-atm/sec. measured
with 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 was
exactly 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 Rate
of 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
Test Results
Automatic Test Analysis
with a set Accept/Reject
threshold shows 6 leaking
and 4 hermetic packages.
Board Level Leak Testing
Discrete hermetic
devices that pass
MIL STD 883E
may failure during or
after board assembly.
These devices, on
assembled circuit
cards can not be leak
tested, except with
Optical Leak Testing.
Missile circuit module.
Launch of Atlas AV-001
August 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?
Optical Leak Testing dramatically increases
manufacturing productivity and quality
by providing in-line, full matrix product testing.
• 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.
NorCom 2020
Optical 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