Advancement of SPI Tools to Support Industry 4.0 and Package Scaling
August 6, 2019 | A. Prasad, L. Pymento, S.R. Aravamudhan, and C. Periasamy, Intel Corp.Estimated reading time: 13 minutes
Another point to be noted is that the majority of these tools (except A+ and B) employ Z-height threshold >10 um to estimate. They ignore the height and volume of the metal pad in the solder paste deposit calculation. For large volume deposits, metal pad volume contribution will be small and may not affect accuracy bias as much. Software algorithms and implementations can vastly vary from vendor to vendor. It is clearly evident that threshold-free measurements, along with correct hardware, is more accurate for low-volume solder paste deposits.
Figures 7a and b: Variability chart for bias % for Phase 3 volume range.
Conclusions and Recommendations
The results of the study showed increased sensitivities to low solder deposits of less than 250 cubic mils across SPI equipment employing threshold algorithm values >10 µm and spatial resolution ≥7 µm. Evaluations on a 5-µm resolution system (A+ tool) employing 0-µm threshold algorithms were found to have acceptable accuracy deviations of less than ±20%.
To improve inline SPI accuracy for low solder paste volume deposits, SPI vendors must consider calibration of SPI tools with lower-volume (below 200 cubic mils) NIST or equivalent standards. For fine-pitch applications, as well as lines configured for Industry 4.0, accuracy should be a consideration for SPI tool selection.
Acknowledgments
The authors would like to acknowledge the Intel internal team and the engineering teams at various SPI vendors for their help in completing the SPI measurements and answering inquiries about the tool capabilities.
References
- C. Shea, and R. Farrell, “Stencil and Solder Paste Inspection Evaluation or Miniaturized SMT Components,” Proceedings of SMTA International, 2013.
- J. M. Peallat, “New Opportunities for 3D-SPI,” www.circuitnet.com, 2008.
- CyberOptics, “‘True’ Heights Measurement in Solder Paste Inspection (SPI),” www.cyberoptics.com, 2013.
- H. Biemans, “5D Solder Paste Inspection: Merits Beyond 3D Technology,” Global SMT & Packaging, 2011.
- C. Periasamy, and S. Walwadkar, “A Scanning Chromatic Confocal Microscope for Accurate Off-Line Solder Paste Volume Measurement,” Proceedings of SMTA International, 2017.
- Intel internal survey report.
This paper was originally presented at the Technical Proceedings of SMTA International 2018.
Authors
Abhishek Prasad is a process engineer at Intel Corporation.
Larry Pymento is a senior process/technology development program manager at Intel Corporation.
Srinivasa R. Aravamudhan is a process technology development engineer at Intel Corporation.
Chandru Periasamy is a packaging R&D engineer, metrology and mechanics, at Intel Corporation.
Page 3 of 3Suggested Items
BEST Inc. Presents StencilQuik for Simplifying BGA Rework Challenges
04/02/2025 | BEST Inc.BEST Inc., a leader in electronic component rework services, training, and rework tools is thrilled to announce StencilQuik™ rework stencils. This innovative product is specifically designed for placing Ball Grid Arrays (BGAs) or Chip Scale Packages (CSPs) during the rework process.
Real Time with... IPC APEX EXPO 2025: Nordson's Expansion of Intelligent Technologies
04/02/2025 | Real Time with...IPC APEX EXPOJonathia Ang-Mueller gives an update on Nordson's latest selective soldering system which features a small footprint, offering cost savings and increased production capacity. Advanced software allows for pre-sales simulations, enhancing customer engagement.
Knocking Down the Bone Pile: Basics of Component Lead Tinning
04/02/2025 | Nash Bell -- Column: Knocking Down the Bone PileThe component lead tinning process serves several critical functions, including removing gold plating, mitigation of tin whiskers, reconditioning of component solderability issues, and alloy conversion from lead-free (Pb-free) to tin-lead or from tin-lead to lead-free for RoHS compliance. We will cover each of these topics in more detail in upcoming columns.
Real Time with... IPC APEX EXPO 2025: Innovations at Indium Corporation—A Look into the Future
04/02/2025 | Real Time with...IPC APEX EXPOIndium Corporation, led by CEO Ross Berntson, is making strides in automotive applications with innovative solder paste technologies. The company prioritizes sustainability and energy efficiency in manufacturing while developing its workforce through partnerships with local universities.
KYZEN to Highlight Stencil and Cleaning Solutions at SMTA Monterrey
03/27/2025 | KYZEN'KYZEN, the global leader in innovative environmentally friendly cleaning chemistries, will exhibit at the SMTA Monterrey Expo & Tech Forum scheduled to take place on Thursday, April 10 at the Cintermex Convention Center in Monterrey, Nuevo León. KYZEN cleaning experts will be on-site highlighting stencil cleaning chemistries KYZEN E5631J and CYBERSOLV C8882.