connector reliability test recommendations: phase ii...
TRANSCRIPT
Connector Reliability Test Recommendations: Phase II Project
End of Project Webinar Sessions:
Session 1: November 14, 2018 at 11:00 am ESTSession 2: November 14, 2018 at 09:00 pm EST
Project Chair: Holly Rubin, Nokia
Project Co-Chair: Jyoti Gupta, Keysight
Agenda
• Background
• Project Description
• Recommended Test Protocol
• Identified Gaps
• Conclusions and Future Work
2
Project Participants
3
Company Name* Member Role
Amphenol ICC Jeffrey Toran, Bob Druckenmiller Team Members
Dell Phil Conde, Vasu Vasudevan Team Members
DOW Michael Lipschutz Team Member
Keysight Jyoti Gupta Co-Chair
Keysight Yen-Han Oon Team Member
Nokia Holly-Dee Rubin Co-Chair
TE Connectivity Vince Pascucci Team Member
Wistron Cindy Han, Seven Cheng Team Members
Keysight Shane Kirkbride Former Chair
CALCE Carlos Morillo Former Co-Chair
Keysight Li-Siah Tai Former team member
*company that member was associated with at time of participation
Members
4
BACKGROUND
• The iNEMI Connector Reliability Test Recommendations Project Phase I addressed the need for a standardized reliability evaluation method for connectors
• The project team reviewed current standards pertaining to connector reliability and also conducted an industry-wide connector reliability survey to determine common metrics for connector reliability evaluation guidelines across the industry
• Results presented in the publication iNEMI Connector Reliability Test Recommendations Project Report white paper at SMTAI 2016
5
Definitions
• Application Class/Product Sector: broadly
defined as categories based on the types and levels
of stress expected in the application; can be based
on type of use (e.g., consumer, office, server,
telecom, portable, etc.)
• Stress Level: relates to the values that quantify
environmental parameters expected to be seen by
the connector in the use environment
• Interconnect Level: for connectors, interconnect
levels 2 through 7 are applicable (as defined in
phase 1, see slide 8)
6
Phase I Conclusions & Recommendations
• The existing connector reliability testing standards do not address the full range of connector applications nor have the necessary detailed, defined test conditions and sequences.
• There is sufficient agreement on definition of levels of interconnect to create a common set and thus use it as needed as one factor in defining connector reliability testing standards (see next slide).
• For assessment of connector reliability a physics-of-failure approach is needed.
• If the actual application is known, then customized testing based on specific knowledge of the application conditions and connector design is optimal
• If the specific application is not known, then an application class based testing standard is required.
• An industry need exists for development of standard reliability testing protocols.
• The Project team recommends additional work to define specific test conditions to be used to evaluate the expected degradation of connectors used under different stress levels in the defined application classes.
7
Levels of Interconnect
• Level 1: On-Chip
• Level 2: Chip-to-Package
• Level 3: Package-to-Board / PCB Mount
• Level 4: Board-to-Board/Board-
Subassembly/Subassembly-to-Subassembly
• Level 5: Input-Output / Chassis-to-Chassis
• Level 6: Intersystem Cabling
• Level 7: Long Haul Telecom/Datacom
8
Connector Reliability Test Recommendations: Phase II Project
Detailed Description and Results
Purpose of Project
1. Scope/drive opportunity for industry level standard
reliability test conditions and equipment capabilities,
failure analysis capability and criteria
2. Drive common database / data formats of test results
for suppliers/OEM's to use by defining recommended
test result attributes
3. Primarily documenting the current state for a
knowledge based connector reliability evaluation
4. Set foundation for a test vehicle in Phase III
10
Scope of Work
1. Signal contacts of Level 4 separable connectors used in the following iNEMI
product sectors: office/consumer, high-end systems, and portable &
wireless
2. Define stress levels and map to Level 4 connectors
3. Review existing specification test sequences and propose updates/changes
to stress testing for each group of tests to allow parts to experience the
interaction of the resulting degradation mechanisms as they do in the real
world.
4. Test recommendations for non-noble vs noble plating systems
5. Alignment of critical elements that will be included in the connector
reliability report
6. Better alignment of connector reliability requirements between suppliers and
OEMs
Exclusions
1. Non-metallic optical connectors used for mating of fiber optics, connectors
intended for power supplies or ac/dc power applications, and RF connectors
11
Interconnect Level 4 Examples
Level 4: Board-to-Board / Board-Subassembly / Subassembly-to-
Subassembly
• Connector-to-Connector or Connector-to-Edge of PCB
• Connections may be made directly or via cable assembly
• Mix of interconnections
– Permanent (soldered, crimped, IDC, IPC)
• Connector-to-Board
• Connector-to-Cable
– Semi-permanent (press-fit) for Connector-to-Board
– Separable
• Connector-to-Connector
• Connector-to-Edge of PCB
• Typically minimal mate/unmate cycles
The basic interconnection issues are the same in that there is use of some
form of connector or connector pair(s) to ease assembly and disassembly
and the number of mate/unmate cycles is usually low
12
Degradation Mechanisms Considered
• For this work, main response variable is limited to contact resistance
• Failure/degradation mechanisms directly affecting contact resistance stability and the main
tests used to evaluate them:
13
Failure Mechanism Relevant Test
Wear Durability, vibration
Corrosion
Primarily Mixed Flowing Gas. Salt spray also used but not addressed here. Salt
spray is usually performed to determine the ability of the connector seals to protect
the contacts from salt spray ingress.
Oxidation Cyclic temperature/humidity
Other Contaminants (films, dust, etc.) Dust, vibration
Fretting Vibration, thermal cycling
Loss of Normal Force Temperature Life
Diffusion Temperature Life
Mechanical Damage
Vibration, mechanical shock, durability cycling (for damage potentially caused by
these tests). Other extrinsic sources of damage not addressed.
Organic polymer buildup (mainly for Pd or
other Pt group metals) Vibration, thermal cycling
Fatigue failure of surface mount solder joints
Thermal cycling of connectors assembled to PCB; Not specifically addressed here
other than referencing IPC 9701 as relevant requirement.
Deposition of outgassed materials on contacts Temperature life, vibration, endurance after environmental tests.
Thermal expansion failure mechanisms Thermal cycling
Delamination Temp cycling with humidity can evaluate delamination of poorly plated contacts.
Contact bending Durability
Some failure mechanisms not addressed include arcing, dendrite and other electrochemical mechanisms, mechanical damage
beyond that experienced in mechanical shock, surface mount solder joint failures
Associating Stress Levels with Interconnect Level 4
• Recommended stress levels defined independent of
Level of Interconnect
• Level 4 interconnects could potentially be subject to
any defined stress levels with the following
exceptions:
– Highest level dust if enclosure offers sufficient protection
– Highest durability level is only encountered in limited
cases, some examples include:
• Graphics cards used by gamers
• Some limited PCI & hot swappable internal HDD connectors
14
• EIA-364-1000 provides recommended tests/test sequences to
assess the performance of Electrical Connectors and Sockets used
in Controlled Environment Applications.
• These sequences and test methods should also be applicable for
uncontrolled environments and thus form the basis for the project
team’s recommendations.
• To assess the connectors for application conditions broader than
controlled environments, the project team recommends some
additions to the test sequences recommended by EIA 364-1000.
• Suggested test methods are limited to those in current standards
(new methods were beyond the scope of this project).
indicates gap has been identified and noted on slide 37.
Background on Tests & Test Sequence Recommendations
15
Test Sequence Recommendations
Recommended additions are highlighted
Test Order
Tests Required for All Connectors
Tests for Connectors
w/Noble Metal Finish
Tests for Connectors with
Tin Plate (optional for
<0.38 um Gold plate)
Tests for Connectors with surface
treatment or short wipe length (<0.127mm)
Tests for Connectors with more than 50
mate/unmate cycles
1 2 3 4 5 6 7
1Contact Resistance Contact Resistance Contact Resistance Contact Resistance
Contact Resistance Contact Resistance
Dielectric Withstanding Voltage
2
Mate/Unmate Cycles (preconditioning)
Mate/Unmate Cycles (preconditioning)
Mate/Unmate Cycles (preconditioning)
Mate/Unmate Cycles (preconditioning)
Mate/Unmate Cycles (preconditioning)
Mate/Unmate Cycles (preconditioning) Contact Resistance
3
Temperature LifeDust (preconditioning)
Temperature Life (preconditioning)
Thermal Shock (preconditioning)
Thermal Shock (preconditioning) Dust Mate/Unmate Cycles
4Contact Resistance Thermal Shock
Dust (preconditioning)
Temperature Life (preconditioning)
Temperature Life (preconditioning) Contact Resistance Contact Resistance
5 Reseating (mate/unmate) Contact Resistance Vibration Contact Resistance
Contact Resistance
Thermal Cycling (disturbance)
Dielectric Withstanding Voltage
6Contact Resistance
Temp/Humidity Cycling Mechanical Shock Mixed Flowing Gas Thermal Cycling Contact Resistance
7Contact Resistance Contact Resistance Contact Resistance
Contact Resistance
Reseating (mate/unmate)
8Reseating (mate/unmate)
Thermal Cycling (disturbance)
Reseating (mate/unmate) Contact Resistance
9Contact Resistance Contact Resistance
Contact Resistance
10Reseating (mate/unmate)
11 Contact Resistance16
Test Sequence Recommendations
• Addition of dust as precondition to Sequence 2 and 3
– The impact of dust is likely to be increased when a connector is exposed to
humidity or vibration.
• Addition of Thermal Shock test as precondition to test sequence 4
and 5
– Thermal shock can affect how a connector is seated and the normal force on
the contacts and because many connectors can be expected to experience
thermal shock during transportation/shipping if not during use.
• Inclusion of Mechanical Shock in test sequence 3
– Mechanical shock during operation can be applicable although it often is not a
concern in the application classes currently covered in EIA-364-1000.
17
General Guidance
• Recommended parameters/test schedules apply to
majority of connectors used in the market. There
will always be those with special needs to be agreed
between customer/supplier.
• The stress level that most closely matches the
application use condition should be selected. If the
expected stresses exceed those in one level, the
next higher level should be used.
18
• Test temperatures and durations are based on stress relaxation properties of typical
connector brass and phosphor-bronze alloys
• In critical applications, conditions appropriate for other alloys should be determined
• Five application levels are defined by ranges of maximum operating temperature
• Two lifetimes are defined based on expected operating hours at operating
temperature
• Stress relaxation is highly sensitive to minor temperature changes
• Testing all connectors at the extreme case for a specified application level may
– excessively degrade the parts relative to most applications
– result in test durations impractical for routine testing
Therefore two Application Categories, Typical and Critical, are provided
– In Typical Applications the maximum contact temperature will be in the bottom 67% of the
level range
– In Critical Applications the maximum contact temperature will be in the top 33% of the level
range
– Because stress relaxation is most rapid early in the test exposure the typical application test
durations achieve approximately 80% to 95% of the stress relaxation achieved using the
longer critical application test durations
Temperature Life Guidance
19
Temperature Life
20
• Example: • Application lifetime 10,000 operating hours, Level 3 operating temperature range
• Typical application (i.e. contact temperature in lower 67% of level range) test conditions 90 C / 1115 hrs or 100 C / 269 hrs
• Critical application (i.e. contact temperature in upper 33% of level range) test conditions 90 C / 3767 hrs or 100 C / 879 hrs
• Operating temperature is expected temperature of the contact in the application when carrying rated current• Test times for Level 1 are equivalent for both typical and critical applications due to minimal expected stress
relaxation below 30 C
Typical Application Test Times (hrs)
Operating Temp. (C)
(Level 1)≤30
(Level 2)31 to 55
(Level 3)56 to 80
(Level 4)81 to 105
(Level 5)106 to 130
Operating Time (hr)
Test Temperature (C)
60 70 80 90 100 115 120 140 150
≤8760 61 220 51 577 142 687 352 802 231
>8760 115 421 96 1115 269 1331 676 1556 440
Critical Application Test Times (hrs)
Operating Temp. (C)
(Level 1)≤30
(Level 2)31 to 55
(Level 3)56 to 80
(Level 4)81 to 105
(Level 5)106 to 130
Operating Time (hr)
Test Temperature (C)
60 70 80 90 100 115 120 140 150
≤8760 61 787 177 1920 456 2117 1069 2307 647
>8760 115 1527 337 3767 879 4159 2082 4537 1252
Dust
a) Note that several
current standards only
require benign dust
composition
b) Benign dust per EIA
364-91, A.1
c) Corrosive dust per EIA
364-91, A.2
Optional: perform testing
dependent on user
requirements
Recommended: project
team recommends testing
Dust Type anticipated (select types anticipated in
environmentLevel (a) Benign(b) Corrosive (c)
Pre Condition Dust Test Pre Condition Dust Test
Example applicationsBusiness Office,
Data Center
Warehouse,
Industrial environmentLevel 1 Weather protected,
with precautions to minimize
dust; not close to coarse
dust/sand sources, some
temperature and humidity
control. (humidity maintained
below 65%)
optional optional
Example applicationsGround-Based, Portable Electronics,
Transportation vehicles - cabin
Level 2 Locations without
precautions to minimize dust,
close to dust/sand sources, and
relative humidity expected to
exceed 65%
recommend recommend
Example applications
Level 3 Locations w/processes
producing sand/dust or in
places w/ high proportion of
wind-driven sand or dust in the
air, condensing environment
recommend recommend
21
Dust Guidance
• Recommend selection of benign or corrosive
dust per expected use environment
– Corrosive dust may be present in certain geographic
regions or when equipment is known to be located
near sources of corrosive dust
– Indoor locations can contain dust of either type
22
Thermal Shock (pg 1 of 2)
Stress Levels: Stress levels 1, 2 and 3 are ranges expected inclusive of shipping and normal
operation. See next slide for associated recommended test levels
The thermal shock experienced by a connector may be influenced by the system/equipment mass.
Testing per this method is expected to be more severe (typically) than the end-use equipment.
Recommended Tests: Duration at temperature according to specimen mass (excerpted from
EIA 364-32)
Stress
Level
Temperatures Use Case
1 -55 C to +85 C Portable equipment; equipment mounted in weather protected
& movable enclosure; equipment mounted near a
door/window or other that when opened, would expose the
equipment to air of significantly different temperature.
Equipment mounted in non-weather protected environment.
2 -65 C to +105 C3 -65 C to +125 C
4 More severe environments requiring harsher testing than those
above.
Mass of specimen Minimum time for steps 1 and 3, time in cold
zone and hot zone, (hours)
28 g (1 oz) and below 1/2 ; (or ¼ (when specified)
>28 g (1 oz) to 136 g (0.3 lb) inclusive ½
136 g (0.3 lb) to 1.36 kg (3 lb) inclusive 1
1.36 kg (3 lb) to 13.6 kg (30 lb) inclusive 2
13.6 kg (30 lb) to 136 kg (300 lb) inclusive 4
23
Thermal Shock (pg 2 of 2)
Recommended Test conditions (Testing per requirements of EIA 364-32)
i. Recommended test conditions for Test Group 2 reflecting shipping, storage
and normal operation temperature extremes.
If thermal shock is expected to occur during operation:
• Appropriate test condition recommendations still need to be developed
• In the interim, recommend test conditions in ii below
ii. Recommended test conditions for Test Groups 4 and 5 (preconditioning
intended to reflect shipping and storage only)
Stress
Level
Test
condition
Comment
1 I -55 C to + 85 C temperature range, minimum 5 cycles
2 II -65 C to +105 C temperature range, minimum 5 cycles
3 III -65 C to + 125 C temperature range, minimum 5 cycles
4 To be defined in the referenced connector specification, customer
specification or industry association specification.
24
Temperature-Humidity Cycling (pg 1 of 2)
Level and Description Recommended Test
Level 1: Equipment located in an indoor
environment with temp/humidity control. Typical
office environment where there are good controls
on the overall environment. Equipment located in
noncondensing environments with <65%RH.
EIA-364-1000 (soon to be EIA-364-
31, Method VIII)
Level 2: Equipment located in an indoor/outdoor
environment with little temp/humidity control.
More of an industrial environment where there
maybe some environmental controls but not tightly
maintained. Probably not direct exposure to
moisture. Equipment located in noncondensing
environments with >=65%RH.
EIA-364-31, Method VII, Test
Condition G (500 hours)
Level 3: Equipment located in an outdoor
environment with no temp/humidity controls.
Wide swing in temperatures and humidity. Possible
direct exposure to condensation moisture.
Equipment located in condensing environments.
EIA-364-34, Test Condition C (504
hours)
25
Temperature-Humidity Cycling (pg 2 of 2)
Level 1: EIA 364-1000 Method VIII Level 2: EIA 364-31 Method VII
Level3: EIA 364-34 Test Condition C
0
10
20
30
40
50
60
70
80
90
0
10
20
30
40
50
60
70
80
90
0.0 0.5 1.0 1.5 2.0 2.5 3.0
Hu
mid
ity
(% R
H)
Tem
p (
De
g. C
)
Time (Hours)
Cyclic Temp & Humidity 3 hour Profile
Temp. (Deg C) Rel. Hum. (%)
26
Test Guidance
Profile the chamber to determine the exact times needed
• Once an hour, lower the chamber temperature to no less than 20C and introduce warm
humid air in order to induce heavy condensation
• Continue the influx of warm humid air for at least 10 minutes
• Once the flow of warm humid air has stopped, the chamber shall not be controlled until
the next hour’s exposure.
• Total test time 504 hours
Mixed Flowing Gas (pg1 of 3)Stress levels derived from Battelle classes
Level 1: Benign, non-industrial business-office and equipment environment, with good
atmospheric control, such as by continuous air-conditioning and filtered air re-
circulation.
Level 2: Typical conditions in business offices, control rooms, and telephone exchanges
that are associated with light industrial areas, or where air-conditioning and other
environmental controls are not operating in an efficient or continuous manner, or where
high humidity levels are anticipated within the electronic equipment enclosure.
Level 3: Industrial and related locations, including many storage areas, where moderate
amounts of pollutants and particulates are present in poorly controlled, uncontrolled,
natural outside air cooled environments, environments with evaporative cooling
systems, or within equipment enclosures such as washing machines where high
humidity levels and corrosive environments may be anticipated.
Level 4: Extremely corrosive heavy-industrial and/or highly polluted locations (for
example paper mills, bleaching plants, and high-sulfur chemical and sewage treatment
facilities), where the combined effects of combinations of environmental corrodents - as
well as high humidity - can rapidly destroy the integrity of precious metal finishes, and
produce extremely heavy tarnish films on some base metal surfaces.
27
Click on green arrow for more details
Mixed Flowing Gas (pg 2 of 3)
Stress Level Test Comment1 Not
applicable
No test needed because no corrosive degradation from
gaseous contaminants such as H2S, SO2, NO2 is expected
2 EIA 364-65
Class 2a
MFG testing required for the following finishes:
• Gold, Pd, PdNi finishes irrespective of the
underplate
• Ag: EIA test conditions are derived from those
developed by Battelle Columbus Laboratories to
replicate corrosion processes of contacts with
gold plating systems. No correlation has been
demonstrated between the corrosion of Ag
plating systems in these MFG tests and the
corrosion expected in typical application
environments.
3 EIA 364-65
Class 3a
4 Protective measures required; depending on the
measures selected, test recommendations include
contaminant monitoring and/or MFG testing
28
Mixed Flowing Gas (pg 3 of 3)
• Recommended Test Conditions
29
EIA Class 2A EIA Class 3A
NO2, ppb 200 200
CL2, ppb 10 20
H2S, ppb 10 100
SO2, ppb 100 200
RH (%) 70 70
Temp (C) 30 30
Field Life 5 yr 10 yr
Class 2A test time (hr) (From EIA 364-1000)
168 336
Class 3A test time (hr) (From IEC 60068-2-60)
240 480
Mechanical Shock
• Mechanical shock testing is usually defined at the system level.
• The shock experienced by a connector is very dependent on system design and
may be more or less than the acceleration at the equipment level.
• The shock levels provided here are starting points, loosely based on IEC 60068-
2-27, that can be used to determine initial suitability for use. Ultimately a system
test is required.
Level Acceleration Example Use Case
1 10-30g Stationary Computer and
Communications Equipment in
Office,
Data Equipment Closet2 >30-50g General Purpose Industrial, General
Purpose Land Transport and Land-
Based Equipment; portable
computers and communications
equipment3 >50-100g Heavy Industrial, Harsh
Transportation, Other Harsh
Environment4 >100g More severe environments requiring
harsher testing than those
above
Stress
Level
Test
condition
Comment
1 H Test condition H = 30 g acceleration
maximum; 11 m-sec pulse;
18 shocks total (3 positive & negative in
each of 3 perpendicular axis).2 A Test Condition A = 50 g acceleration; 11
m-sec pulse; 18 shocks total, (3 positive &
negative in each of 3 perpendicular axis).
3 C Test condition C = 100 g acceleration; 11
m-sec pulse; 18 shocks total, (3 positive &
negative in each of 3 perpendicular axis).
4 To be defined in the referenced connector
specification, customer specification or
industry association specification.
30
Vibration (pg 1 of 2)
Levels and Recommended Tests
• Table below provides guidance for vibration testing of connectors. Use classes
are based on a combination of amplitude and frequency range, e.g. light
amplitude / mid-frequency
• Knowledge of the actual amplitude and frequency range expected at the intended
location connector mounting should guide the selection of the appropriate use
class. Vibration Test Conditions
Stress Level
(Amplitude
Category)
Frequency / Type
Low Frequency
Sine
Mid Frequency
Random
High Frequency
Random
Level 1
(Light)
Example
Application
Industrial Rotating Machinery -
Light Vibration
or
Equipment Mounted Adjacent
to Heavy Rotating Machinery
Business Office, Data Center -
Light Vibration
Transportation Vehicles -
Passenger Cabin
Test
Condition
IEC 60068-2-6
10-55 Hz, 0.015-inch DA, 2 h /
axis
EIA-364-28 TC VII, Letter B
1.6 g, 15 min / axis
20 Hz 0.005 G2/Hz500 Hz 0.005 G2/Hz
EIA-364-28 TC V, Letter A
5.4 g, 3 h / axis
50 Hz .005 G2/Hz100 Hz 0.02 G2/Hz1000 Hz 0.02 G2/Hz2000 Hz 0.005 G2/Hz
31
Vibration (pg 2 of 2)
Stress Level
(Amplitude
Category)
Frequency / Type
Low Frequency
Sine
Mid Frequency
Random
High Frequency
Random
Level 2
(Moderate)
Example
Application
Industrial Rotating Machinery -
Moderate VibrationBusiness Office, Data Center
Transportation Vehicles -
Moderate Vibration
Test
Condition
IEC 60068-2-6
10-55 Hz, 0.03-inch DA, 2 h / axis
EIA-364-28 TC VII, Letter D
3.1 g, 15 min / axis
20 Hz 0.02 G2/Hz500 Hz 0.02 G2/Hz
EIA-364-28 TC V, Letter C
9.3 g, 3 h / axis
50 Hz 0.015 G2/Hz100 Hz 0.06 G2/Hz1000 Hz 0.06 G2/Hz2000 Hz 0.015 G2/Hz
Level 3
(Severe)
Example
Application
Industrial Rotating Machinery -
Severe Vibration
Ground-Based, Portable Electronics,
Rough Service - Commercial
Transportation Vehicles -
Engine Compartment
Test
Condition
IEC 60068-2-6
10-55 Hz, 0.06-inch DA, 2 h / axis
EIA-364-28 TC VII, Letter E
4.9 g, 1 h / axis
20 Hz 0.05 G2/Hz500 Hz 0.05 G2/Hz
EIA-364-28 TC V, Letter G
23.9 g, 4 h / axis
50 Hz 0.1 G2/Hz100 Hz 0.4 G2/Hz1000 Hz 0.4 G2/Hz2000 Hz 0.1 G2/Hz
Level 4
(Extremely
Severe)
Example
ApplicationUnbalanced Rotating Machinery
Ground-Based, Portable Electronics,
Rough Service - MilitaryHigh Performance Military Aircraft
Test
Condition
IEC 60068-2-6
10-55 Hz, 0.12-inch DA or 10 g's,
whichever is less, 2 h / axis
EIA-364-28 TC VII. Letter F
6.9 g, 2 h / axis
20 Hz 0.1 G2/Hz500 Hz 0.1 G2/Hz
EIA-364-28 TC VI, Letter J
43.9 g, 8 h / axis
50 Hz 0.25 G2/Hz100 Hz 1.0 G2/Hz2000 Hz 1.0 G2/Hz
32
Durability
Stress Levels: Derived from EIA-364-09 and Telcordia-1217
Recommended Tests: As per EIA-364-09
• The number of mate/unmate cycles should be commensurate with the number of
cycles the connector and/or socket is expected to experience during its useful life.
• When required as a precondition, preconditioning and subsequent reseat
requirements should be per EIA 364-1000.
– For preconditioning: 5 cycles should be used for level 1, 20 cycles for level 2,
and 50 cycles for level 3. Reseating should use 3 cycles for all levels.
• Additional details about the test procedure, equipment, sample preparation and
test fixtures can be found in EIA documents.
Level Number of Mate/Un-mate cycles
Level 1 25
Level 2 200
Level 3 >1000
33
Thermal Cycling (pg 1 of 2)
• Level 1: Equipment located in an indoor environment with
temperature control. Typical office environment where there
are good controls on the overall environment.
• Level 2: Equipment located in an indoor/outdoor environment
with little temperature control. More of an industrial
environment where there may be some environmental
controls but not tightly maintained.
• Level 3: Equipment located in an outdoor environment with
no temperature controls. Wide swing in temperatures.
• Level 4: Equipment located in an outdoor environment with
no temperature controls. Wide swing in temperatures and
lower negative temperature extremes below -40C.
34
Thermal Cycling (pg 2 of 2)
Temp Cycle Test Stress levelNo. mate/unmate
cycles prior to cyclingComments
Temperature (°C) Level 1 Level 2 Level 3 Level 4 0500 cycles minimum,
1000 cycles preferredHigh Temp 85 85 105 125 5Low Temp 15 -15 -40 -20 5
T 70 100 145 145 5
• Stress Level/Application conditions
Stress Level Segment Operational Temperature
Range (°C)
ΔT, °C (nominal)
Comments
Level 1 Controlled 15 to 45 20 Temperatures are derived from EIA 364 but with a thermal adder; if subzero
temperatures are only expected in shipping, use appropriate thermal shock precondition
& do not include subzero temperatures in the full Thermal Cycling test.
ΔT is a nominal operational ΔT (within the full op. temp range)
Level 2Weather protected from extreme cold
5 to 105 40
Level 3 Uncontrolled -40 to 100 60
Level 4 Industrial -55 to 130 80
• Test conditions
35
Test temperatures should be limited/adjusted to the rated connector range
The temperature cycle test recommendation is not intended to cover connector body attachment to PCB. Refer
to IPC 9701 for testing connector to PCB surface mount solder joint interconnections.
Test Report Recommendations
EIA-364-1000 includes a comprehensive list of required
elements of a test report. In addition we recommend to
include:
• The connector interconnect level and stress levels should be
noted.
• A note that additional test data may be requested by users
and should be made available on request.
36
Summary of Gaps
• Temp Life Recommendations for contact alloys other than brass and phosphor-bronze
• Guidance for use of in-situ low-level contact resistance measurements during thermal
shock: appropriate to consider for operation simulation. Also need guidance/comments
re consideration of TCR when defining the resistance requirement/failure criteria
• Operational thermal shock test conditions and guidance
• Dust testing and dust preconditioning are areas that require more study
– Impact of fine particles(<2.5um) and/or additional types of fiber on intermittent connections
– Inclusion of recommendations in standards on when to use corrosive dust
– Inclusion of dust compositions representative of those found in the field
• MFG tests and correlations to field conditions were done before electronics were widely
deployed in developing sections of the world where corrosion can be a significant
source of failures. Conditions & test times may need to be modified to reflect actual
corrosion rates observed in the field. Work is ongoing to modify test conditions to more
accurately reflect these use environments. Additionally, acceleration factors for Ag
finishes on connectors are not well developed
• A set of recommendations for when to perform specialty tests for specific concerns,
especially when developing new technology. Examples include fretting, salt spray,
solder joint reliability, etc.
37
Conclusions
• With some modifications, the test sequences
and report elements recommended in EIA 364-
1000 can be extended to connectors intended
for use in uncontrolled environments.
• Recommendations for stress levels and
associated test conditions were made based on
existing test standards.
• Identified gaps provide opportunity for
additional activities.
38
Potential Future Work
• Define a test vehicle on which to apply the defined
methodology
• Extend to other connector interconnect levels
• Additional research needed on corrosive dust impacts
on connector reliability
• A literature review to understand currently known
interaction effects of dust concentration, particle size,
temperature, and humidity on connector contact
resistance
• Develop recommended test conditions to reflect
operational thermal shock
• Develop a list of specialty tests and guidance for their
use39
Back-Up
40
Mixed Flowing Gas -complete description
• Level 1: Benign, non-industrial business-office and equipment environment, with
good atmospheric control, such as by continuous air-conditioning and filtered air
re-circulation. The only significant chemical stresses are oxidation of the surfaces
of copper, nickel, and other base metals from moderate humidity levels typically
in the range of 40% to 55%RH
• Level 2: Typical conditions in business offices, control rooms, and telephone
exchanges that are associated with light industrial areas, or where air-
conditioning and other environmental controls are not operating in an efficient or
continuous manner, or where high humidity levels are anticipated within the
electronic equipment enclosure. Level 2 (as well as Level 3) conditions can also
be found inside electronic cabinets or other enclosures that have poor air
circulation, thus allowing the build-up of small amounts of volatile compounds as
well as the accumulation of trapped moisture. Level 2 humidity levels are
typically in the range of 55% to 80%RH. Potential failure mechanisms involve
mild pore corrosion of plating, with slow tarnish creepage from the pores, and
significant oxidation and tarnishing of base metals, as well as possible attack on
other material surfaces.
(Pg 1 of 2)
41
Mixed Flowing Gas (HDR)
• Level 3: Industrial and related locations, including many storage areas, where moderate
amounts of pollutants and particulates are present in poorly controlled, uncontrolled, natural
outside air cooled environments, environments with evaporative cooling systems, or within
equipment enclosures such as washing machines where high humidity levels and corrosive
environments may be anticipated. All of these environments can create conditions with
elevated and fluctuating humidity. Humidity levels inside a Class 3 facility can vary widely
from low humidity in winter (below Class 1 ranges) to high humidity (>80%RH). In the case
of evaporative cooling systems, facility humidity levels can reach 93%RH. Potential failure
mechanisms include enhanced pore corrosion and corrosion-product films, and tarnish
migration from pores - as well as tarnish creepage from base-metal edges adjoining the
gold finish. Heavy tarnish film growth on base metals and accelerated attack on other
susceptible materials (such as plastics) are also possible.
• Level 4: Extremely corrosive heavy-industrial and/or highly polluted locations (for example
paper mills, bleaching plants, and high-sulfur chemical and sewage treatment facilities),
where the combined effects of combinations of environmental corrodents - as well as high
humidity - can rapidly destroy the integrity of precious metal finishes, and produce
extremely heavy tarnish films on some base metal surfaces. Accelerated attack on
susceptible plastic materials might also be expected. Materials selection alone may not be
sufficient to protect the reliability of contact surfaces and other ways of altering the
component's micro-environment must be considered.
(Pg 2 of 2)
42
Abbreviations
Ag Silver
DA Displacement Amplitude
HDD Hard Disk Drive
H2S Hydrogen Sulphide
IDC Insulation Displacing Connector
IPC Insulation Piercing Connector
MFG Mixed Flowing Gas
NO2 Nitrogen Dioxide
OEM Original Equipment Manufacturer
PCB Printed Circuit Board
PCI Peripheral Component Interconnect
Pd Palladium
PdNi Palladium Nickel
RF Radio Frequency
RH Relative Humidity
SO2 Sulphur Dioxide
TC Test Condition
TCR Temperature Coefficient of Resistance43