IEC PAS 62207:2000
(Main)Hermeticity
Hermeticity
Aims at determining the effectiveness of the seal of hermetically sealed solid-state devices. The seal tests are considered nondestructive.
General Information
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Standards Content (Sample)
IEC/PAS 62207
Edition 1.0
2000-11
Hermeticity
PUBLI C LY AVAI LABLE SPECI F I CATI O N
IN TER N A TION AL Reference number
E L E C T R OT E CHNI CA L
IEC/PAS 62207
C O MMI S S I O N
Copyright © 1988, JEDEC; 2000, IEC
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HERMETICITY
FOREWORD
A PAS is a technical specification not fulfilling the requirements for a standard, but made available to the
public and established in an organization operating under given procedures.
IEC-PAS 62207 was submitted by JEDEC and has been processed by IEC technical committee 47: Semiconductor
devices.
The text of this PAS is based on the This PAS was approved for
following document: publication by the P-members of the
committee concerned as indicated in
the following document:
Draft PAS Report on voting
47/1515/PAS 47/1545/RVD
Following publication of this PAS, the technical committee or subcommittee concerned will investigate the
possibility of transforming the PAS into an International Standard.
An IEC-PAS licence of copyright and assignment of copyright has been signed by the IEC and JEDEC and is
recorded at the Central Office.
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising all
national electrotechnical committees (IEC National Committees). The object of the IEC is to promote international co-
operation on all questions concerning standardization in the electrical and electronic fields. To this end and in addition
to other activities, the IEC publishes International Standards. Their preparation is entrusted to technical committees;
any IEC National Committee interested in the subject dealt with may participate in this preparatory work. International,
governmental and non-governmental organizations liaising with the IEC also participate in this preparation. The IEC
collaborates closely with the International Organization for Standardization (ISO) in accordance with conditions
determined by agreement between the two organizations.
2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all interested
National Committees.
3) The documents produced have the form of recommendations for international use and are published in the fo rm of
standards, technical specifications, technical reports or guides and they are accepted by the National Committees in
that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International Standards
transparently to the maximum extent possible in their national and regional standards. Any divergence between the
IEC Standard and the corresponding national or regional standard shall be clearly indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this PAS may be the subject of patent rights. The
IEC shall not be held responsible for identifying any or all such patent rights.
Page i
Copyright © 1988, JEDEC; 2000, IEC
JESD22-A109
TEST METHOD A109
HERMETICITY
TABLE OF CONTENTS
Paragraph
1. PURPOSE 1
1.1 Definition
2. APPARATUS 1
2.1 Test Condition A - Helium Fine Leak Test 1
2.2 Test Condition B - Radioisotope Fine Leak Test 2
2.3 Test Condition C - Fluorocarbon Bubble Gross Leak 2
Test Condition D - Fluorocarbon Vapor Detection 3
2.4
Gross Leak
PROCEDURE 3
3.
3.1 Test Condition A - Helium Fine Leak
- Radioisotope Fine Leak Test
3.2 Test Condition B 7
Fluorocarbon Bubble Gross Leak
3.3 Test Condition C -
3.4 Fluorocarbon Vapor Detection Gross Leak
SUMMARY
4.
TABLE I: Fixed Conditions for Test Condition Al 5
TABLE II: 13
Purge Time
-ii-
Copyright © 1988, JEDEC; 2000, IEC
JESD22-A109
Page 1
TEST METHOD A109
HERMETICITY
(From JEDEC Council Ballot JCB-86-25A, formulated under the
cognizance of JC-14.1 Committee on Transportation/Automotive
Electronics.)
1. PURPOSE
The purpose of this test is to determine the effectiveness of
the seal of hermetically sealed solid-state devices.
The seal tests are considered nondestructive.
They are intended
to be used for 100% screen, lot acceptance, product monitoring
or for qualification testing as applicable. The seal tests may
also be employed as end points for other environmental
durability tests.
1.1 Definition
Measured Leak Rate
The measured leak rate is defined as the leak rate of a given
package as measured under specified conditions and employing a
specified test medium. Measured leak rate shall be expressed in
units of atmosphere cubic centimeters per second (atm-cm3/s).
2.
APPARATUS
2.1 Test Condition A - Helium Fine Leak Test
Apparatus required shall consist of suitable pressure and vacuum
chambers and a mass spectrometer-type leak detector, preset and
properly calibrated for a helium leak rate sensitivity to read
The
volume of the chamber used for leak measurement should be held
to the minimum practical, since this chamber volume has an
adverse effect on sensitivity limits.
The leak detector
indicator shall be calibrated using a diffusion-type calibrated
standard leak at least once during every working shift.
Test Method A109
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JESD22-A109
Page 2
2.2 Test Condition B - Radioisotope
Fine Leak Test
The apparatus for this shall consist of:
(1)
Radioactive tracer gas activation console.
(2)
Counting equipment consisting of a scintillation crystal,
photomultiplier tube, preamplifier, ratemeter, and
krypton-85 reference standards.
The counting station
shall be of sufficient sensitivity to determine the
radiation level of any krypton-85 tracer gas present
within the device. The counting station shall have a
atm-cm3/s of krypton-85 and shall be calibrated at least
once every working shift using krypton-85 reference
standards and following the equipment manufacturer’s
instruction.
A tracer gas consisting of a mixture of krypton-85 and dry
(3)
nitrogen. The concentration of krypton-85 in dry nitrogen
shall be no less than 100 microcuries per atmospheric
cubic centimeter. This value shall be determined at least
once per month.
2.3 Test Condition C - Fluorocarbon Bubble Gross Leak
The apparatus for this test shall consist of:
(1) A vacuum/pressure chamber for the evacuation and
subsequent pressure bombing of devices up to 75 psig for
up to 10 hours.
(2)
A suitable observation container with provisions to
maintain the indicator fluid at a temperature of 125°C and
a filtration system capable of removing particles greater
than 1 micron in size from the fluid.
A magnifier with a magnification in the range between 3X
(3)
and 30X for observation of bubbles emanating from devices
when immersed in the indicator fluid.
Sources of FC-72, FC-84 or D-80 fluorocarbon detector
(4)
fluids, and FC-40, FC-43 or DO-2 fluorocarbon indicator
fluids.
Test Method A109
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JESD22-A109
Page 3
A lighting source capable of producing at least 15
(5)
thousand foot candles in air at a distance equal to that
which the most distant device in the bath will be from the
source. The lighting source shall not require
calibration, but the light level at the point of
observation (i.e., where the device under test is located
during observation for bubbles) shall be verified.
(6) Suitable calibrated instruments to indicate that test
temperatures, pressures and times are as specified.
Suitable fixtures to hold the device(s) in the indicator
(7)
fluid.
2.4 Test Condition D - Fluorocarbon Vapor Detection
Gross Leak
The apparatus for this test shall consist of:
(1) A vacuum/pressure chamber for the evacuation and
subsequent pressure bombing of devices up to 75 psig for
up to 12.5 hours.
(2) Sources of FC-84 or D-80 fluorocarbon detector fluids.
Suitable calibrated instruments to indicate that test
(3)
temperatures, pressures and times are as specified.
A fluorocarbon vapor detection system capable of detecting
(4)
vapor quantities equivalent to 0.28 mg of FC-84.
The vapor
A calibration source for the vapor detector.
(5)
detector shall be calibrated at least once each working
shift per the manufacturer’s instructions.
PROCEDURE
3.
Fine and gross leak tests shall be conducted in accordance with
the requirements and procedures of the specified test condition.
Where
Testing order shall be fine leak, followed by gross leak.
bomb pressure specified exceeds the device package capability,
alternative pressure, exposure time and dwell time conditions
time
may be used provided they satisfy the leak rate, pressure,
relationships which apply, and provided no less than 30 psia
bomb pressure is applied in any case.
Test Method A109
Copyright © 1988, JEDEC; 2000, IEC
JESD22-A109
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3.1 Test Condition A - Helium Fine Leak
3.1.1 Test Condition Al, A2
Test condition Al is a “fixed” method with specified conditions
per Table I that will ensure the test sensitivity necessary to
detect the required measured leak rate (R1). Test condition A2
is a “flexible” method that allows the variance of test
conditions in accordance with the formula of 3.1.1.3 to detect
the specified equivalent standard leak rate (L) at a
predetermined leak rate (R1).
3.1.1.1 Test Conditions Al and A2
- Procedure Applicable
"Fixed" and "Flexible” Methods
to
The completed device(s) shall be placed in a sealed chamber,
which is then pressurized with a tracer gas of 100 +0/-5 percent
helium for the required time and pressure. The pressure shall
then be relieved and each specimen transferred to another
chamber(s) which are connected to the evacuating system and a
mass-spectrometer- type leak detector. When the chamber(s) is
evacuated, any tracer gas which was previously forced into the
specimen will thus be drawn out and indicated by the leak
detector as a measured leak rate (R1). (The number of devices
removed from pressurization for leak testing shall be limited to
such that the test of the last device can be completed within 60
minutes for test condition Al
or within the chosen value of
dwell time t2 for test condition A2).
3.1.1.2 Test Condition Al - Fixed Method
The device(s) shall be tested using the appropriate conditions
specified in Table I for the internal cavity volume of the
package under test. The time tl is the time under pressure and
time t2 is the maximum time allowed after release of pressure
before the device shall be read. The fixed method shall not be
used if the maximum equivalent standard leak rate limit given in
the procurement document is less than the limits specified
herein for the flexible method.
Test Method A109
Copyright © 1988, JEDEC; 2000, IEC
JESD22-A109
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TABLE I
Fixed Conditions for Test Condition Al
Bomb Condition
R 1
Volume of
psia Exposure time Maximum dwel l Reject limi t
package (c m )
+ hours hours
(atm-c m /He )
—
3.1.1.3 Test Condition A2 - Flexible Method
Values for bomb pressure exposure time, and dwell time shall be
chosen such that actual measured tracer gas leak rate (R1)
readings obtained for the devices under test (if defective) will
be greater than the minimum detection sensitivity capability of
the mass spectrometer. The devices shall be subjected to a
minimum of 2 atmospheres absolute of helium atmosphere. If the
chosen dwell time (t2) is greater than 60 minutes, graphs shall
R1 value which will assure overlap
be plotted to determine an
with the selected gross leak test condition. The chosen values,
in conjunction with the value of the internal volume of the
device package to be tested and the maximum equivalent standard
leak rate (L) limit (as shown below or as specified in the
applicable procurement document), shall be used to calculate the
measured leak rate (R1) limit using the following formula:
Test Method A109
Copyright © 1988, JEDEC; 2000, IEC
JESD22-A109
Page 6
Where:
R1 = The measured leak rate of tracer gas (He) through the
leak in atm cm3/s (He) .
=
L Equivalent standard leak rate in atm cm3/s(air) .
Pe = The pressure of exposure in atmospheres absolute.
Po = The atmospheric pressure in atmospheres absolute. (1)
(28.7)
M = The molecular weight in air in grams.
A
M = The molecular weight of the tracer gas (He) in grams.
(4)
tl = The time of exposure to Pe, in seconds.
t2 = The dwell time between release of pressure and leak
detection, in seconds.
v = The internal free volume of the device package cavity in
cubic centimeters.
3.1.1.3.1 Failure Criteria
devices with an internal cavity
Unless otherwise specified,
volume of 0.01 cm3 or less shall be rejected if the
-8
equivalent standard leak rate (L) exceeds 5 x 10 atm
cm3/s(air) .
Devices with an internal cavity volume greater
than 0.01 cm3 and equal to or less than 0.5 cm3 shall be
rejected if the equivalent standard leak rate (L) exceeds
-7
atm cm3/s(air).
lx10
Test Method A109
Copyright © 1988, JEDEC; 2000, IEC
JESD22-A109
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3.2 Test Condition B - Radioisotope Fine Leak Test
3.2.1 Activation Parameters
The activation pressure and soak time shall be determined in
accordance with the following equation:
Where:
QS = The maximum calculated leak rate allowable, in atm-cm/s
Kr, for the devices to be tested.
R = Counts per minute above the ambient background after
activation if the device leak rate were exactly equal to
QS. This is the reject count above the background of
both the counting equipment and the component, if it has
been through prior radioactive leak tests.
s = The specific activity, in microcuries per atmospheric
cubic centimeter, of the krypton-85 tracer gas in the
activation system.
k = The overall counting efficiency of the scintillation
crystal in counts per minute per microcurie of krypton-
85 in the internal void of the specific component being
evaluated. This factor depends upon component
configuration and dimensions of the scintillation
crystal. The counting efficiency shall be determined in
accordance with 3.2.2.
where Pe is the activation pressure in
atmospheres absolute, and Pi is the original internal
The
pressure of the device in atmospheres absolute.
activation pressure (Pe) may be established by
specification or i
...
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