Post on 19-Jul-2015
SMT Assemblies
Why Solder Paste Inspection?
The majority of SMT defects occurs during the solder paste printing process.
According to data from SMTA (The Surface Mount Technology Association),
74% of defects in PCB manufacturing process are related to solder paste.
Assembly Process Defect Chart
Why??Is Printing so Important
1. Production must be more
FLEXIBLE.
2. Mixed technologies, on the same
board.
3. Limited space, Assembly density 4. Budget reductions
5. Quality demand
6. No rework permitted
Stainless SteelFG/PHD
Nickel
1. Láser Cut
2. Local support
3. Rapid Deliveries
1. Laser Cut
2. Local support
3. Rapid Deliveries
4. Improved “Paste
Release”*
Stencil Options
Both have Laser Cuts but “Ni” is famed for the improved “Paste Release” element.
Electroformed, EF, EFAB
1. Production process
2. Superior “Paste
Release”* properties
3. Delivery issues
4. Product Revision
5. NO re-work
6. Mechanical seal
Stencil Options
The Mechanical seal is different EF vs SS/Ni Laser cut
EFABLaser Cut
The trends indicate that the “Normal” is:
EF produces more “Bridging”
“SS/Ni” produce more insufficiencies
Concept of the “NANO” Stencil
1.Laser cut, SS
2.Additional Processing “NANO”
3. Improved Paste deposit definition.
4.Reduction in consumables
5. Improved Aspect Ratio performance
NOTE: We went back to “Laser Cuts”
2 concepts exist
“Onsite” Towellette
1) Vendor application
2) No Rework
3) Limited durability
4) Delivery constraints
5) Extra sensative to Customer
process
6) Stencil wash methods limit
“NANO” effectivity.
7) Maintenance Costs
1) Applied locally by
customer
1) Process is subjective
to customer
application process.
2) “Nano” Maintenance
3) Additional expenses
4) Lifecycle…Subjective
5) Another factor in
Production fails
Topical “Coating”
The real world of Manufacturing Limits the
Enhancements /BenefitsOf the “Nano “Processed Stencils
THE CONCEPT.. “Nano Stencil” Improves the “Paste Release” ……The Paste release is
critical to support the challenges which compromises the ASPECT RATIO Calcs for
our Mfg world/marketplace. …….But….
2 concepts exist
“Onsite” Towellette
1) Vendor application
2) No Rework
3) Limited durability
4) Delivery constraints
5) Extra sensative to Customer
process
6) Stencil wash methods limit
“NANO” effectivity.
7) Maintenance Costs
1) Applied locally by
customer
1) Process is subjective
to customer
application process.
2) “Nano” Maintenance
3) Additional expenses
4) Lifecycle…Subjective
5) Another factor in
Production fails
Topical “Coating”
The real world of Manufacturing Limits the
Enhancements /BenefitsOf the “Nano “Processed Stencils
2 concepts exist
“Onsite” Towellette
1) Vendor application
2) No Rework
3) Limited durability
4) Delivery constraints
5) Extra sensative to Customer
process
6) Stencil wash methods limit
“NANO” effectivity.
7) Maintenance Costs
1) Applied locally by
customer
1) Process is subjective
to customer
application process.
2) “Nano” Maintenance
3) Additional expenses
4) Lifecycle…Subjective
5) Another factor in
Production fails
Topical “Coating”
2013 Q1Proprietary documents for
Mexico/EU Generated
2013 Q1Proprietary documents in USA
Generated
2010 Q4ProJect formalized
2012 Q1Cobra Launched
2012 Q2Sales Began
2012 Q3Revised New process to improve Adherance
2013 Q1Cobra “TX” CreatedLower Cost COBRA
2013 Q2The 2 New Cobra’s were
introduced to Market
2011 Q2Trademark established
2013 Q1InterLatin Received recognition
CONACYT- Stimulation for Innovation
Since Q32013 Sales Started
• ALL TopLINE Nanos (Coatings and Towllette) vs “COBRA 3.0 & TX”
– Sensative to stencil wash
– Wearing of the “COATING”
– Aplication type “Coating”
– On time Delivery
– Componentes
– “Nano” waste management
– Outperforms any Nano, Eform, Ni stencil
– ECO-Friendly
Product ComparisonAsked customers, “What issues do you encounter with current SMT print
solutions”
• ALL TopLINE Nanos vs “COBRA 3.0 y TX”
– Sensative to stencil wash
– Wearing of the “COATING”
– Aplication type “Coating”
– On time Delivery
– Componentes
– “Nano” waste management
– Outperforms any Nano, Eform, Ni stencil
– ECO-Friendly
Product ComparisonWhen we compared the 3.0 and TX to customer
needs….
• ALL TopLINE Nanos, “Cobra HD” vs “COBRA 3.0 y TX”
– Sensative to stencil wash
– Wearing of the “COATING”
– Aplication type “Coating”
– On time Delivery
– Componentes
– “Nano” waste management
– Outperforms any Nano, Eform, Ni stencil
– ECO-Friendly
– Cobra…Lasts the Life of the Stencil !!!!
Product Comparison
REX Customer
“COBRA, BGA “.35”, AR .49, Paste
type 3 mesh,
Over 17000 assemblies, zero fail.
Mechanical or Electrical.”
GDL Site
Increased ICT Yield 60% to 75%. Excellent paste release
GDL Site
We compared COBRA with E-Fab stencil. COBRA had a
better release of solder paste,
we reduced problems in our printing process
SPC data reflects the same stencil print, volume, without and with COBRA process
Automotive Customer Requirement: Use Eform Std as minimum requirmentsThey had 3D SPI inline
Volume MeasurementsCpK >/= 1.6
Std Dev </= 816 mil pitch QFP
ANY SPC sine wave is representative only
The customer was using an Efab Stencil:(Customer Actual results) 65% of designed aperture deposition.
Efab 100% of established SPI volumeCpk: 1.56
Std Dev= 11
Automotive Customer Requirement: Use Eform Std as minimum requirmentsThey had 3D SPI inline
Volume MeasurementsCpK >/= 1.6
Std Dev </= 816 mil pitch QFP
EFab
This denotes an effect caused by the USC while using EF but did not affect COBRA print quality
ANY SPC sine wave is representative only
The common concern…..
EFab
COBRA 3.0
This denotes an effect caused by the USC while using EF but did not affect COBRA print quality
ANY SPC sine wave is representative only
InterLatin produced a COBRA 3.0Simply taking the Paste from the Efab Stencil and loading it onto the COBRA
Restarted the production process….The results….
Automotive Customer Requirement: Use Eform Std as minimum requirmentsThey had 3D SPI inline
Volume MeasurementsCpK >/= 1.6
Std Dev </= 816 mil pitch QFP
EFab
COBRA 3.0
This denotes an effect caused by the USC while using EF but did not affect COBRA print quality
The SPC sine wave is representative only
Final Comparison: (Customer Actual results) 65% of designed aperture deposition.
Efab 100% of established SPI volumeCpk: 1.56
Std Dev= 11
COBRA 115% Volume compared to EfabCpK: 2
Std Dev= 6
Note: NOT even the underscreen cleaners elements interfered with the COBRA print quality
10 months LATER
Automotive Customer Requirement: Use Eform Std as minimum requirmentsThey had 3D SPI inline
Volume MeasurementsCpK >/= 1.6
Std Dev </= 816 mil pitch QFP
EFab
COBRA 3.0
This denotes an effect caused by the USC while using EF but did not affect COBRA print quality
The SPC sine wave is representative only
Final results: (Customer Actual results) 65% of designed apeture deposition.Efab 100% of established SPI volume
Cpk: 1.56Std Dev= 11
COBRA 115% Volume compared to EfabCpK: 2
Std Dev= 6
Note: NOT even the underscreen cleaners elements interfered with the COBRA print quality
I only changed the Stencil
What we Did, June 2014
• Created a test vehicle, representing current assembly challenges, for our customers
• Setup an SMT printer, Fully automated
• Programmed Solder Paste Inspection system, fully automated
• Made one common stencil design, IAW industry standards…..NO special designs
• 5 mils material used
• ONLY changed the Stencil