Embed Size (px)
Citation preview
This study has focused on the CUDA implementation to oblique-view CT(Computed Tomography) technique for non-destructive internal inspection of 3D IC chips. With 400 projected images from rotating phantom in an oblique direction, we executed 16 GUPS performance to reconstruct 5123 volume of phantom with NVIDIA Quadro K6000 GPU, showed that the GPU performed 100 times faster than the dual CPU processors in the CT reconstruction method.
I. Introduction of 3D IC Package
• 3D IC Package
Fig. 1. Multilayer chip
II. Chip-to-Chip Connection in 3D IC
• Chip-to-Chip Connection Techniques
(a) Conventional chip type (requirement: optical inspection)
(b) TSV packing chip type (requirement: 3D tomographic inspection)
TSV(Through Silicon Via) Packing
Fig. 2. Chip-to-Chip connection
- Long wire length- Pad area is needed
As advanced packing, offer size and performance.
Enable integration of several functional wafers
- Short wire length
- Packing size is smaller
III. 3D IC Inspection Method• CT Inspection System Based on X-ray
(d) close-to-focus(b) conventional (c) advanced(a) conical target detection scheme
Fig. 3. CT inspection system
! Characteristics - Sample on table with rotating/tilting - Similiar with CBCT - Thin and slim wafer inspection
Enable oblique views at highest magnifications
* [Ref] http://www.qualitymag.com/articles/print/89082-x-ray-powers-up-complex-parts
III. 3D IC Inspection Method
• Nano CT Inspection in Oblique-view Geometry
Fig. 4. Schematic of Nano CT System
Nano-focus X-ray generator
Detector
Rotation table
Object(sample)
- Open-type X-ray, FPD, rotational X-Y stage
- Acquisition step
(1) Sample rotate in X-Y state.
(2) X-ray projection images are obtained
from various directions.
(3) X-ray projection images are transferred to the
host memory via an image grabber board.
(4) 3D image is obtained using GPU.
! CT system : off-centered geometry
Tilt angle
III. 3D IC Inspection Method
Fig. 5. Off-centered geometry analysis
Fig. 6. Reconstructed image
Back-projection
IV. Experimental Results• Processing Hardware for 3D Volume Reconstruction
Fig. 7. Experimental hardware for image reconstruction
! OS : Linux 3.2.0, 64 bits.
! CPU : Intel Xeon X5520, 2.27GHz x 2
! Memory : 48 GB
! GPU : Quadro K6000
- CUDA core: 2880
- CUDA clock : 902Mhz
- Global memory size: 12288 MB
! CUDA : Capability: 3.5
- Runtime Driver: 6.5
GPU
CPU CPU
FPGA
IV. Experimental Results
• Simulation of Shepp-Logan Phantom
Fig. 8. Projection images generated by forward projection
512 pixels
512 pixels
! Input: 512x512, 400 projections, tilt angle: 0o
! Output : 512x512x512, tilt angle: 0o
Fig. 9. Output by back- projection
(a) CPU (b) GPU
IV. Experimental Results
• Performance Comparison for Back-projection Processing
! Correlation coefficient
Table 3. Correlation coefficient between reference and output
Table 1. Reconstruction performance by CPU
Input OutputRead/Write(s)
PreFilter(s)
RampFilter(s)
Back-projec=on(s)
TotalTime(s)
GUPS(BP)
256x256x400 256x256x256 0.15 0.19 1.58 51.21 53.13 0.13
512x512x400 512x512x512 4.88 0.69 5.85 426.38 437.80 0.13
Input OutputRead/Write(s)
PreFilter(s)
RampFilter(s)
Back-projec=on(s)
TotalTime(s)
GUPS(BP)
256x256x400 256x256x256 0.18 0.16 0.42 0.56 1.32 11.98
512x512x400 512x512x512 5.02 0.60 0.79 3.27 9.68 16.41
Table 2. Reconstruction performance by GPU
Reference(A) Output(B)Tiltangle
Correla=oncoefficient(r)
CPUprocessing
GPUprocessing
256x256x256 256x256x256
0o 0.982 0.977
10o 0.979 0.973
20o 0.969 0.963
30o 0.950 0.944
512x512x512 512x512x512
0o 0.984 0.979
10o 0.981 0.978
20o 0.970 0.964
30o 0.950 0.944
V. Conclusion
• Summary & Further Research! Planning scheme to inspect TSV defect using
off-centered geometry CT - GPU-based back-projection method to enhance the speed of reconstruction. ! In 512x512x512 volume, back-projection time
was measured. - CPU case : 426.38 sec - GPU case : 3.27 sec - GPU is faster than CPU over 100 times! In near future, the more adaptable filtering
scheme by missing wedge effect will be used in order to achieve wider adoption in inspection process.
Oblique-view Computed Tomography for 3D IC Package Inspection Using CUDA
Korea Institute of Industrial Technology1*, Korea Electronics and Telecommunication Research Institute2, SEC Co., LTD3Kyung-Chan Jin 1*, Yoon-Ho Song 2, Jung-Seok Yoon 3
• Reconstruction by Back-projection
Fig. 10. Reconstructed TSV image
ACKNOWLEDGEMENT:WewouldliketoacknowledgethefinancialsupportfromtheR&DConvergenceProgramofMSIP(MinistryofScience,ICTandFuturePlanning)andNST(NaHonalResearchCouncilofScience&Technology)ofRepublicofKorea(GrantB551179-12-04-00)andTSVphantomimageshavebeenkindlyprovidedcourtesybySECCo.,Ltd,SouthKorea. *Correspondingauthor:Kyung-ChanJin[E-mail:[email protected],TEL:+82-41-589-8439]
contact name
Kyung-Chan Jin: [email protected]
P6336
category: comPuter Vision & machine Vision - cVmV07
