Materials and Processes related to Space Electronic.
Perugia 14-9-2004
Materials and Processes related to Space Electronic
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
INTRODUCTION
One question frequently asked is “Why does ESA, NASA etc not have a preferred
materials list whereas such a list does exist for electronic components?”
The reason for this is best summarised by the relationship:
In other words a material can only be considered together with the associated
process and the final application. To complicate matters further the effects of the
environment (manned or unmanned, LEO or GEO etc.) have to be considered since
these can significantly affect the suitability of the application
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
Example 1
For example:
This combination is widely used in spacecraft application.
However for manned space applications this cannot be used since solithane,
in common with most polyurethanes, is flammable
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
Example 2
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
The following section presents the requirements for PMP. However the actual
requirements for a particular project depend on several factors, e.g.
1.
Type of spacecraft (manned or unmanned)
2.
Spacecraft orbit (LEO, GEO, polar etc.)
3.
Complexity (satellite, payload, etc.)
4.
Duration of space exposure (x years, y days, etc.)
The requirements will therefore be specified as part of the contract either in the
statement of work or in the PA plan.
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
ECSS Specifications Related to PMP
(http://www.ecss.nl)
ECSS-Q-70A-April 96
Space Product Assurance - Materials, Mechanical Parts and
Processes.
The purpose of this standard is to define the requirements and statements applicable to
Materials, Mechanical Parts and Processes to satisfy the mission performance requir.
This standard also provides details concerning the documentation requirements and the
procedures relevant to obtaining approval for the use of PMP in the fabrication of Space
Systems and associated equipment.
This documentation is currently under revision and issue B will include the
documentation Requirements presently given in PSS-01-700.
In addition many of the lower level PSS Specification (PSS-01-7XXX series) are being
replaced by ECCS Specification (ECSS-Q-70-XX series).
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
European Co-operation for Space
Standardisation (ECSS) (1)
For materials and processes the situation is presently as follows:
1.
2.
ESA PSS-01-70 has been replaced by ECSS Specification ECCS-Q-70A
An additional 26 specifications, based on the PSS-01-7xx Series, have been issued as
ECSS Specifications
• ECSS-Q-70-01A Contamination and cleanliness control
• ECSS-Q-70-02 Outgassing Testing of Materials
• ECSS-Q-70-04A Thermal Cycling test for the Screening of space materials and processes
• ECSS-Q-70-07A Automatic machine wave soldering
• ECSS-Q-70-08A The manual soldering of high reliability electrical connections
• ECSS-Q-70-09A Measurements of thermo-optical properties of thermal control materials
• ECSS-Q-70-10A Qualification of printed circuit boards
• ECSS-Q-70-11A Procurement of printed circuit boards
• ECSS-Q-70-13A The Peel and Pull Off Strength of Adhesives
• ECSS-Q-70-18A Preparation, assembly and mounting of RF coaxial cables
• ECSS-Q-70-21A Flammability testing for the screening of space materials Francesco Petroni
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Materials and Processes related to Space Electronic.
Perugia 14-9-2004
European Co-operation for Space
Standardisation (ECSS) (2)
• ECSS-Q-70-20A Determination of the susceptibility of silver-plated copper wire and cable
to .red-plague. corrosion
• ECSS-Q-70-22A The control of limited shelf-life materials
• ECSS-Q-70-25A The Application of Aeroglaze Z306
• ECSS-Q-70-26A Crimping of high-reliability electrical connections
• ECSS-Q-70-28A The repair and modification of printed circuit board assemblies
• ECSS-Q-70-29A Offgassing Testing of Materials
• ECSS-Q-70-30A Wire-wrapping of high reliability electrical connections
• ECSS-Q-70-33A The Application of Thermal Coating PSG120FD
• ECSS-Q-70-34A The Application of Aeroglaze H322
• ECSS-Q-70-35A The Application of Aeroglaze L300
• ECSS-Q-70-36A Materials selection for controlling stress corrosion
• ECSS-Q-70-37A Test method for stress corrosion cracking
• ECSS-Q-70-38A High reliability soldering for surface mount and mixed technology PCBs
• ECSS-Q-70-45A Standard methods for mechanical testing of metallic materials
• ECSS-Q-70-46A Requirements for manufacturing and procurement of threaded fasteners
• ECSS-Q-70-71A Data for selection of space materials and processes
Francesco Petroni
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Materials and Processes related to Space Electronic.
Perugia 14-9-2004
The Requirements
PMP which cannot be considered either space proven or standard/established shall be
subjected to an evaluation programme in order to assess their suitability for the intended
application. This programme and subsequently its result shall be submitted to ESA.
1. Thermal Vacuum Products considered for use in space systems shall have their
outgassing properties assessed by thermal vacuum tests according to
PSS-01-702 (to be superceded by ECSS-Q-70-02).
2. Thermal Cycling Products which are likely to be subjected to thermal stresses shall have
their thermal cycling properties assessed as per ECSS-Q-70-04A.
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
The Requirements (Continued)
3. Radiation
Products which will be exposed to particle/UV radiation shall be assessed
to determine their ability to withstand the type and degree of radiation
dosage expected during the mission. Tests are specified in PSS-01-706.
4. Stress Corrosion Products intended for structural applications and likely to be exposed to
long term terrestial storage, or flown on the STS, or used in launchers
shall possess a high resistance to SCC. Structural products of a metallic
nature shall be selected from the preferred list in Table 1 of
ECSS-Q-70-36A.
Where no data exists testing shall be performed as per ECCS-Q-70-37A.
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
The Requirements (Continued)
5. Flammability Products considered for use in unmanned spacecraft to be launched by
the STS and manned spacecraft (including those of the spacecraft itself,
stored equipment or payload/experiments) shall be evaluated for
flammability resistance in the most hazardous environment.
Flammability testing is described in PSS-01-721 (to be superceded by
ECSS-Q-70-21A).
6. Offgassing and Toxic analysis
All products considered for use in the crew compartment of manned
spacecraft shall be evaluated for offgassing and odour. Samples of each
product shall be tested according to ECSS-Q-70-29A.
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
The Exception
ECSS-Q-70-71A Data for selection of space materials and processes
Annex C (informative) Material data sheets
C.1 Aluminium and Al-alloys
C.2 Copper and Cu-alloys
C.3 Nickel and Ni-alloys
C.4 Titanium and Ti-alloys
C.5 Steels
C.11 Adhesive tapes and films
C.12 Paints and inks
C.13 Lubricants
C.14 Potting compounds, sealants and foams
C.15 Reinforced plastics
C.6 Stainless steels
C.7 Filler materials: welding, brazing and soldering
C.8 Miscellaneous metallic materials
C.9 Optical materials
C.10 Adhesives, coatings and varnishes
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C.16 Rubbers and elastomers
C.17 Thermoplastics
C.18 Thermoset plastics
C.19 Miscellaneous non-metallic materials
Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
• specifications
• pcb’s manufacturing
• soldering processes
• crimping
• wire wrapping
• Repair and modification of PCB assemblies
• cleaning
• quality evaluations
• good solderjoints
• failure modes
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
• ECSS -Q-70-28
• ECSS -Q-70-08A
– Space product assurance - manual soldering of
high-reliability electrical connections
• ECSS -Q-70-10
– Space product assurance - qualification and
procurement of multilayer printed circuit boards
(gold plated or tin-lead finish)
• ESA PSS -01-718
– the preparation, assembly and mounting of RF
coaxial cables
– Space product assurance - repair and modification
of printed circuit board assemblies
• ECSS -Q-70-30A
– Space product assurance - wire-wrapping of high reliability
electrical connections
• ECSS -Q-70-38
– Space product assurance - high-reliability soldering
for surface mount and mixed technology printed
circuit boards
• ECSS -Q-70-26
– Space product assurance - the crimping of high reliability
electrical connections
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
• BOSCH Telecom GmbH, Germany
• CIT (ALCATEL), France
• LABTECH Ltd, England
• PRINTCA AS , Denmark
• SEXTANT Avionique, France
• SPEMCO Group Ltd, England
• STRASCHU Leiterplatten GmbH, Germany
• SYSTRONIC S.A.L, France
• VIASYSTEMS , div. CSI, Italy
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
• Soldering processes
• Solder flux
• solder alloys
• cleaning
• accept/reject criteria
• conformal coatings
• thermal cycling
• operator training and certification
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
• Hand soldering
• qualification
• machine wave soldering
• verification and approval
• surface mounting
• verification and approval
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
• solder flux
– rosin-based
• pretinning: mildly activated (fully activated in cases of poor solderability)
• assembly: pure rosin flux
– water-soluble acid flux
• only for pretinning when rosin-based fluxes are inadequate. (immediate cleaning after
use is required)
• solder alloy
– 63 tin solder (63 Sn, 37 Pb)
– 62 tin silver-loaded solder (62 Sn, 2 Ag, 36 Pb)
– 60 tin solder (60 Sn, 40 Pb)
– 96 tin silver solder (96 Sn, 4 Ag)
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
• Cleaning
– solvents shall be non-corrosive and non-conductive and shall not degrade parts or
materials .
• Acceptable solvents are:
– ethyl alcohol (99.5% or 95% pure by volume)
– isopropyl alcohol (best commercial grade, 99% pure)
– deionized water at 40 °C maximum for certain fluxes (dry after use)
– any mixture of the above
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
• Reliable soldered connections result from proper
design, control of tools , materials and work
environments , and careful workmanship
• basic deign concepts :
– stress relief shall be inherent in the design
– where adequate stress relief is not possible, solder-joint reinforcement is necessary
– materials shall be so selected that the mismatch of thermal expansion coefficient is minimal
– materials and processes which the formation of brittle intermetallic shall be avoided
– the design shall permit inspection of the soldered joints
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
• Clean, smooth, bright undisturbed surface
• solder fillets between conductor and termination
areas as illustrated
• contour of wire sufficiently visible to determine
presence of wire
• complete wetting as evidenced by a low contact
angle
• proper amount and distribution of solder
• absence of defects as mentioned in the next sheet
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
– Charred, burned, or melted insulation of
– fractured or cracked solder connections
– cut, nicked, gouged, or scraped
parts
– conductor pattern separation for board
conductors or conductor pattern
– improper conductor length or direction of
– burns on base material
– discoloration which is continuous between
clinch and lap termination
– repaired or damaged conductor
two conductors
– excessive solder (peaks , bridging)
– flux residue, solder spatter, or other
pattern(rework if applicable)
– bare copper or base metal (except end of
cut wire or leads )
foreign matter
– soldered joints made directly to goldplated
– dewetting
terminals and conductors
– insufficient solder
– pits, holes or voids , or exposed base metal
– cold solder joints
– component moulding with solder fillet
in the solder connection
– granular or disturbed solder joints
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
• Order of merit of conformal coating tested evaluated by:
• Cost, Process , Repair, Solvent resistance, humidity, life test, resistance to thermal cycling,
outgassing, micro-vcm, flammability, offgassing, toxicity
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
• Trained and competent personnel shall be employed for all
soldering operations and inspections
• Trained personnel performing soldering operations and
inspection shall be certified at a soldering school
– ZVE , Oberpfaffenhofen, Germany
– Highbury College, Portsmouth, England
– Italian Institute of welding (IIS ), Genova, Italy
– IFE , Oberpfaffenhofen, Germany
– Hytek, Aalborg, Denmark
– Institute de soudure, Paris , France
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
• Hand soldering to ESA PSS -01-708
• inspection of solder joints
• repair and modification of pcb’s to ESA PSS-01-728
• RF cable assembly to ESA PSS-01-718
• crimping and wire wrapping to ESA PSS-01-726/730
• surface mounting techn. Ass. To ESA PSS-01-738
• Instructor cat 1 to ESA PSS-01-748
• fiber optic terminations to ESA-draft/NASA-std-8739.5
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
ESA PS S -01-738
• Request for verification
• technology sample
• process identification document and process control sheet
• audit of assembly line
• verification programme
• smd assembly approval
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
• Request for verification
– The verification of any SMD assembly line will be restricted to those companies which have
been selected for the fabrication of ESA sponsored projects.
• Technology sample
– the contractor will supply one sample from his SMD assembly process to ESTEC. This sample
will be examined at ESTEC or a recognised test house
• no conformal coating
• workmanship
• cleanliness
• metallography of soldered interconnections
• Audit of assembly process line
– following acceptance of the technology sample the manufacturing facility will be audited by ESA
– findings of the audit remain as confidential to ESA
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
• Verification programme
– Details of verification programme will be discussed at the time of the audit
• acc. To ESA PSS-01-738
• thermal cycling (500: -55 to +100 oC)
• vibration
• visual, electrical test, cleanlines s test, microsection control
– the verification programme shall be established and approved by E S A
– the verification programme shall be funded and performed by the contractor or one or more
independent test houses (test house require approval by ESA)
– summary table for SMD verified to ESA PSS-01-738 shall be compiled
• SMD assembly approval
– following the successful completion of the verification programme a letter of approval will be is sued by
ESA. ESA project approval by means of Project Declared Process List
– The summary table for SMD’s will be attached to this letter
– The validation period is indefinite until change to PID
– history of supply, manufacturing defects and unauthorised change of materials and or manufacturing
methods will require new verification
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
• ECSS-Q-70-07A
• verification tests to establish confidence in all
automatic machine soldering lines
• technology samples
– technology samples , cleanliness , documentation
– examination by recognised test house
• line audit
• verification testing
– testing according to ECSS-Q-70-70A: visual inspection, electrical tes ts , thermal cycling,
vibration when design deviates from ECSS-Q-70-08
– microsectioning
– pull testing of leads on board surface
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
• CRIMPING
– Forms of crimps
– Crimping optimisation
– Workmanship examples
• WIRE WRAPPING
– wire types
– recommended insulations
– terminal posts
– examples
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
• Wire used for wrapped connections shall conform to ESA/SCC No. 3903 or other
approved national wire specification intended for wire wrapping
– the wire shall be a single solid round conductor. Stranded conductors shall not be used
– Conductor size shall be between AWG 24 and AWG 30
• soft annealed high-conductivity copper for AWG 28 and AWG 30
• high strength high-conductivity copper for wire gauges AWG 28 and AWG 30
– copper shall be silver plated (>2 micron)
• Recommended wire insulations
– outgassing according to ECSS-Q-70-02
– ETFE (Tefzel), PFA (Perfluoroalkoxy), PVDF (Kynar), and Kapton poluimide over extruded PTFE
• Terminal post
– suitable grades of copper or nickel alloys (Copper-Z inc, Phosphor-bronze, copper-nickel-zinc, beryllium-copper,
nickel-copper(Monel) and nickel-cclad copper(Kulgrid)
– 1 to 3 microns of Gold over min. 1 micron of copper or nickel (barrier plating). No Silver undeplating
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
• Good quality solderjoints
• Good quality SMT solderjoints
• Cross section of smd devices
• Soldering to gold
• No pretinning
• After thermal cycling
• Whisker growth on Tin-plated brass
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
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Francesco Petroni
Materials and Processes related to Space Electronic.
Perugia 14-9-2004
Fine
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Francesco Petroni