Advances in X-Ray Technology for Semicon Applications Keith Bryant - PowerPoint PPT Presentation

Advances in X-Ray Technology for Semicon Applications Keith Bryant and Thorsten Rother X-Ray Champions, Telspec, Yxlon International

Agenda  The x-ray tube, the heart of the system  Advances in digital detectors  Enhancing the image and automation  Advances in computed tomography  Challenges of microelectronics applications

Introduction  X-Ray Technology has been around for over 100 years mostly in the Medical industry  Traditionally Electronics used components from Medical Systems  FeinFocus was the first X-Ray company in the Electronics industry in the 1980s. Most companies came from here

The x-ray tube, the heart of any system  Most systems for electronics applications use Open transmission tubes , this technology is 55 years old  Open tube technology has improved dramatically in all key areas over the last 10 years

Recent Advances in Open Tube Technology  Pre-vacuum pumps are maintenance free  Vacuum inside the tube is much higher improving feature recognition  Filament lifetime has been extended some 4 times  Replacement of the filament can now be done in a few minutes, as a pre-adjusted quick change unit can be clicked into place, fast and easy

Recent Advances in Open Tube Technology Modern high end x-ray systems include the following features and settings:  Multifocus x-ray capability for more flexibility  New types of targets, for demanding applications  True X-ray Intensity (TXI) control for stable and repeatable imaging results

Multifocus x-ray capability Nanofocus High Power Microfocus Semi-conductor High Density & Assembly Applications Optoelectronics Applications < 0.3µm Feature < 3µm Feature < 1µm Feature Recognition Recognition Recognition

New types of targets  Open tube design allows the use of dedicated targets, developed specifically for demanding applications  High Power target (diamond based)  High Resolution Power target (diamond based)  High Magnification target  Conical target

True X-ray Intensity (TXI) control  Target current is measured continuously  Emission current is adjusted automatically Without TXI Benefits include:  Consistent results over time  Accurate void measurements  Better image quality of CT scans With TXI

Nanofocus Mode with HPR target X-ray Image of a solder crack in X-ray Image of a polymer 50μm Cu pillar, Sample size: material, voids and orientation of 300mm wafer fibers are easily visible

TXI + High Power Resolution target CT scan of a failed Multi-Layer Ceramic Capacitor TXI technology secures extremely stable image quality for each projection High Power Resolution target allows the use of a high target power without decreasing the resolution

The Detector, the art of the image  Early technology was Analogue using lens’s and a camera  Image Intensifiers then improved using software and better camera technology  The Digital Flat Panel was a huge leap forwards, from 0.3 MPixels to 1 MPixels  Now DFP’s are available, designed and purpose built for our industry

High End Flat Panel Detector Technology  Real-time Imaging  Distortion-free Image  High-contrast and highly detailed image  16 Bit Image processing for great greyscale (65000 shades) UHD flat-panel detector image of µBGA

Recent Advances of Flat Panel Technology  Panels are now less sensitive to radiation so their lifetime is extended  Frame capture rate is faster so good images are on screen sooner  Pixel size is reduced to make it easier to see smaller features at high magnification

High Quality Real Time Digital Imaging

Enhancing the image chain The biggest recent improvement has been in special filters which dramatically improve the on-screen image Benefits:  Faster inspection  Easier to see faults  Less operator stress μHDR live filter

Automation has to be accurate and repeatable 17 micron gold wires

Automated wire sweep measurement red indicates failure

Computed Tomography Advances  Advanced x-ray systems provide fast scanning  QuickScan delivers almost as good result but much faster, in 3 to 5 minutes versus more than 30 minutes Conventional µCT (left) and QuickScan (right) of a BGA with volume views (top) and views of a slice (bottom)

QuickScan Plus  HPR x-ray tube target  TXI (True Intensity Control)  10-15W target power  Real Time Flat Panel Detector  64bit CT High Speed reconstruction software QuickScan Plus - volume view and virtual cross-sections of micro-BGA with micro-vias, wedge bonding

Cracked Passive caused by interfacial voiding

Challenges of Microelectronics As component engineers escalate from 2D single die designs to 3D multiple die package solutions, it sets high demands for inspection tools.

Challenges of Microelectronics Thinned die cracking  Stacked packages must be able to maintain the Z-height of a Die cracking standard package, requiring thinned die down to 50μm  Thinned dies make stacked components susceptible to brittle fracture failures Cracked die  Die cracking is a significant concern with stacked packages

Challenges of Microelectronics Flip chip connections  In most current 3D packages, the stacked chips are connected along their edges with wire bonds  Also flip chip bumps are used to create an interconnection between stacked dies  Potential defects of flip-chip bumping – opens and solder voiding Flip-chip pin grid array, FCPGA Flip chip bump area voiding

Challenges of Microelectronics Thru Silicon Via (TSV) connections  TSV replaces edge wiring by creating vertical connections through the body of the chips  A TSV is a via hole in a silicon wafer, which is insulated and filled with a conductive fill, usually copper Micro void in 30 μ m diameter TSV

Head on Pillow, 30µm µBGA balls chip structure easily visible

35µm µBGA ball with voiding and open circuit (HoP)

25µm diameter copper pillars 50µm long, 2D angled view

2D angled view of 20µm TSV µbumps

Voiding measurement of 15µm copper pillar

3D image of 6µm diameter TSV’s

25µm Copper Pillars and 6µm TSV µBump connections

Automated measurement of blind and buried µvias

Thanks for your Attention Any Questions?