Advances in X-Ray Technology

for Semicon ApplicationsKeith Bryant and Thorsten RotherX-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 moreflexibility

New types of targets, for demandingapplications

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 targetCT 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 MicroelectronicsAs 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

voidingFlip-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 AttentionAny Questions?