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Services: Cleanliness Analysis
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Analysis Methods Used In Standard Investigative Projects
Cleanliness analysis projects focus on the identification of any
ionic residues that may be present on product. The investigation
addresses the impact on reliability and compliance to specifications.
The effort requires characterization of the residues that pose an
elevated risk of electromechanical failure. Typical analysis investigations
can be done on bare printed circuit boards, components, process
materials, and finished assemblies. Foresite has extensive experience
in relating process residues that impact product electrical performance
and maintains cleanliness guidelines to establish process control
parameters.
Foresite engages in consultation with each customer prior to any activity
to identify project goals, design an applicable test matrix, and
provide technical information derived from our experience and knowledge
of contamination effects on product reliability.
Foresite Final Report Deliverables
- Specific Project Goal — defined at time of quote
- Description of customer specifications — cleanliness levels
- Description of Foresite test protocol to accomplish project goal
- Process Sequence Flowchart — as defined by customer
- Material matrix indicating fluxes and chemistries used in process
- Residue analysis data —
identification and amount of residues present
- Education regarding the general sources of the specific ionic residues found
- Foresite cleanliness limit recommendation for each ionic species identified
- Foresite limits derived through over 13 years of Failure Analysis and Process Qualification experience
- Foresite interpretation of data and conclusions from our technical team
- Foresite recommendations for any process optimizations
- Formal project report electronically sent to customer project contact (fax or
e-mail)
- Original hard copy report mailed upon completion of project
- Telephone support included for discussion of report
Project Completion Timing Options
- IC Testing
- Standard — Final Report completion in ten working days after project start
- Fast Turn — Analytical results (verbal discussion) in 48 hours after project start — analysis of up to 100 samples
- Analytical results (verbal discussion) in 72 hours after project start — analysis of 100-250 samples
- Final Report completion in three working days after project start
Project Start Requirement –- Receipt of Approved Purchase Order via fax or mail
Foresite Inc. Cleanliness Analysis Service
To provide the customer with the deliverables mentioned, a process
profile must be established. This process profile is used to acquire all of
the pertinent facts required to make a valid assessment of the assembly process
and resulting cleanliness condition of the final assemblies produced. The
information collected will become a basis for the final report analysis and
recommendations. The accuracy and completeness of the requested information
is imperative to the success of the project.
To analyze process performance, the materials and process options must be identified:
- Laminate specifications — base laminate material, surface finishes, solder resist
- Solder resist vendor and formulation nomenclature
- Flux types used — OA (water-soluble), NC (no-clean/low-residue), other
- Flux vendor and formulation nomenclature
- Flux application method (spray or foam)
- Cleaning technology used — tap water, DI water, solvent
- Cleaner type — vendor, batch or in-line
- Stage(s) at which assembly will cleaned (post reflow, post wave, hand, rework)
- Assembly equipment to be used (automated and hand)
- Types of components to be assembled (through-hole, surface mount, COB, BGA, HDI)
- Thermal profiles for all heat excursions product will see (reflow, wave, hand, rework)
- Atmosphere to be used during reflow and wave process — (oxygen or nitrogen)
- Solder pot temperature
- Other assembly materials (adhesives, temporary masks)
- Conformal coating material (if used) — manufacturer, formulation, solvent, application
- All hand operations and materials (post-wave, irons used, cleaning methods)
- Procedure and instrument used to measure and record ionic cleanliness levels
Process samples will be required at specific stages (as applicable)
- bare boards (all suppliers)
- after wave soldering
- after hand soldering (rework, repair, hand placement)
- after conformal coat (if used)
- after Surface Mount
- after cleaning (all occurrences)
- finished product ready to ship
- assembly drawings
- process sequence flow charts
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