Vaidyanathan Ramalingam_Agile QA_SOFTEC_2_July2011_Silicon India Conf_Bangalore
Bits2010jemison
1. BiTS 2010
Test Flow and Handling of WLCSP Devices
Have Significant Impact on Cost
Bob Jemison, RJI Technical Sales
2010 BiTS Workshop
March 7-10, 2010
2. Our Challenge Today
“ What can I do to lower the
cost of testing my company’s
WLCSP product? “
WLCSP is here!
March 10, 2010 Cost Impact of WLCSP Test & Handling 2
3. Our Employers Demand
• Meet increasing production volumes
• Limit capital purchases
• Lower the cost of test
• Do more with less
March 10, 2010 Cost Impact of WLCSP Test & Handling 3
4. This Presentation
Will examine a possible transition that
can be made in today’s test flow to
increase effectiveness while
lowering the cost of test
Will compare the “traditional” test flow
with this new flow for WLCSP
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5. WLCSP Growth
WLCSP + WLP Forecast
14000
12000
2008
10000
8000 2009
6000 2010
Millions of units
4000 2011
2000 2012
0
2008 2009 2010 2011 2012
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6. Restating Our Challenge
Consider the cost of test
• Management needs to lower costs
• Test is a complex combination of things
• Costs are made up of many factors
• Some are built on tradition
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7. Tradition Plays a Role
Simplified test flow for packaged product
Finished Goods
Wafers-Material
Wafer
Assembly Final Test
Probe
• ATE • Wafer Saw • ATE
• Device Interface • Sort • Test Boards
• Probe Cards • Die attach • Test Sockets
• Probe Stations • Wire Bond • Device Handlers
• Encapsulation
• Trim & Form • Marking
• Inspection
March 10, 2010 Cost Impact of WLCSP Test & Handling 7
8. Cost of Test
Is made up of many components
Capital Operating Device
Expense Expense Throughput
• Equipment • Labor • Effective
• Upgrades • Floor space UPH
• Options • Factory • Downtime
• Economic integration • Utilization
Life • Service &
support
March 10, 2010 Cost Impact of WLCSP Test & Handling 8
9. Cost of Test
Some items are big contributors
Capital Operating Device
Expense Expense Throughput
• Equipment • Labor • Effective
• Upgrades • Floor space UPH
• Options • Factory • Downtime
• Economic integration • Utilization
Life • Service &
support
March 10, 2010 Cost Impact of WLCSP Test & Handling 9
10. WLCSP Changes Things
Revised test flow for WLCSP product
Finished Goods
Wafers-Material
Wafer
Assembly Final Test
Probe
• ATE • Wafer Saw • ATE
• Device Interface • Sort • Test Boards
• Probe Cards • Test Sockets
• Probe Stations • Die attach • Device Handlers
• Wire Bond
• Encapsulation • Marking
• Trim & Form • Inspection
March 10, 2010 Cost Impact of WLCSP Test & Handling 10
11. Returns Complicate Matters
Return flow for traditional product
Finished Goods
Wafer
Assembly Final Test
Probe
• ATE • Wafer Saw • ATE
• Device Interface • Sort • Test Boards
Returned Product
• Probe Cards • Die attach • Test Sockets
• Probe Stations • Wire Bond • Device Handlers
• Encapsulation
• Trim & Form • Inspection
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12. WLCSP Returns
Flow for WLCSP product returns … oops!
Finished Goods
Wafer
Assembly Final Test
Probe
• ATE • Wafer Saw • ATE
• Device Interface • Sort • Test Boards
Returned Product
• Probe Cards • Test Sockets
• Probe Stations • Die attach • Device Handlers
• Wire Bond
• Encapsulation • Marking
• Trim & Form • Inspection
Typical returned product has no final test infrastructure
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13. What Have We Learned
If we want to cut costs we need to …
• Reduce the equipment needed for test
• Shrink the size to save floor space
• Reduce the number of operators needed
• Accommodate the parts flows that are
required for these new WLCSP products
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14. WLCSP Approach
Redefine the equipment
Input Tester & Output
Inspection
Options Interface Options
• Trays • Direct dock to • 6-way vision • Trays
• Tubes tester inspection • Tubes
• Wafer Frame platforms • Tape & Reel
• De-tape • Allow probe • Marking
card use or
test
contactors
Combine all of these functions into one single platform
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15. Financial Justification
Consideration Traditional New Process
Capital Equip 3 – 6 Machines 1 machine
Work Flow 3 - 6 Steps 1 combined step
JIT Benefits Multi-step process Simplified process
Long cycle time Shorter cycle time
High cost of inventory Low cost of inventory
Traceability burden Single station
Staffing Multi-machines to train Single machine to train
Returns Processing Complicated non-std Simple de-tape to tape
Qual/Engineering Complicated non-std Simple tray to tray
Development Tasks Non-correlated Correlates to production
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16. WLCSP Handler
Wafer
Frame
Input Vision
Inspection
De-tape
Tape & Reel
Test
Contactor
Test head
Manipulator
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17. Typical Multipurpose
WLCSP Handler
An example of a multipurpose WLCSP test handler
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18. Cost of Test
So, based on this information …
New equipment
Effective use of space =
Fewer staff
Effective UPH
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19. In Conclusion
New methods result in viable manufacturing
New equipment is available in the marketplace
Processes can be revamped today
Improvements will result in cost savings
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20. Acknowledgements
Our contributors include:
Bob Jemison, GM, RJI Technical Sales
bjemison@rjisales.com
Afshin Nouri, President, Contech Solutions
Werner Foltz, President, Peak Automation
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