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

Microfocus Assembly Applications < 1µm Feature Recognition Nanofocus Semi-conductor Applications < 0.3µm Feature Recognition High Power High Density & Optoelectronics < 3µm Feature 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 Benefits include:

• Consistent results over time
• Accurate void measurements
• Better image quality of CT scans

Without TXI With TXI

Nanofocus Mode with HPR target

X-ray Image of a solder crack in 50μm Cu pillar, Sample size: 300mm wafer X-ray Image of a polymer material, voids and orientation of 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

QuickScan Plus - volume view and virtual cross-sections of micro-BGA with micro-vias, wedge bonding

 HPR x-ray tube target  TXI (True Intensity Control)  10-15W target power  Real Time Flat Panel Detector  64bit CT High Speed reconstruction software

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 standard package, requiring thinned die down to 50μm

• Thinned dies make stacked

components susceptible to brittle fracture failures

• Die cracking is a significant

concern with stacked packages

Cracked die

Die cracking

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 30μm 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?