Download - C-SAM-Sonix_Seminar_1
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What is Ultrasonics ?What is Ultrasonics ?
• Sound waves which have
a frequency over 20kHz.
(Audible frequency: 16Hz - 20kHz)
• The sound waves which can not be heard by the human ear.
16Hz - 20,000Hz
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Types of Ultrasonic WavesTypes of Ultrasonic Waves
1. Shear Wave1) The vibration direction and propagation direction are
perpendicular.
2) Transmission in liquid or air is impossible.
Vibration
Propagation
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Types of Ultrasonic Waves Types of Ultrasonic Waves
2. Longitude Wave 1) The vibration direction and propagation direction are same.
2) Transmission in liquid is possible.
PropagationVibration
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Characteristics of UltrasonicsCharacteristics of Ultrasonics
1. 100% reflection when it meets air(delamination)
2. Reflects at interfaces
3. Travels straight as light because of the very short wavelength.
AirDie
EMC
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Advantages of UltrasonicsAdvantages of Ultrasonics
1. High resolution :Detectable minimum gap thickness of Sonix : 0.13 micro meter
2. High sensitivity : The measuring of size, location, shape of fine defects is possible.
3. Real time inspection is possible.
4. Safe : Harmless to human body.
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Weak Points of UltrasonicsWeak Points of Ultrasonics
1. Difficult to inspect samples that have a rough surface or bubbles.
2. Liquid is required to transmit ultrasonic
3. Needs expertise(Solution:TAMI)
rough surface bubbles
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Uses for UltrasonicsUses for Ultrasonics
1. Nondestructive test equipment.(S.A.M.)
2. Sonar to find submarine, fish-finder
3. Medical examination equipment
4. Cleaner(15~50KHz)
5. Humidifier
6. Welding(15~40KHz)
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Reasons for Use of UltrasonicsReasons for Use of Ultrasonics
1. Evaluation of semiconductor reliabilityÅExisting the only estimation method of semiconductor reliability
2. Nondestructive inspection of internal defectsÅKeep fine defects which can be lost by destructive inspection
ÇReuse of good samples after inspection
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Structure of QFPStructure of QFP
EMC
EpoxyCu Lead Frame
Cu L/FCu L/FSilicon Chip
Gold Wire
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Detectable Defects Detectable Defects
1. Delamination2. Package Crack3. Die Crack4. Void5. Tilt6. Foreign Materials
DelaminationPKG CrackVoid
PKG Crack
Chip Crack
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Inspection using UltrasonicInspection using Ultrasonic
Signals in Digital Oscilloscope
PackageSurface
DieSurface
DieBottom
Inspect defects using reflected signalin each interface
Die Attach Adhesive
DieEMC Die Surface
Die Bottom
Package Surface
Ultrasonic
Transducer
GateGate
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Inspection MethodsInspection Methods
1. Pulse Echo Methods1) A-scan : Inspection with waveform displayed on oscilloscope.
2) B-scan : Inspection with vertically x-sectioned 2-d image.
3) C-scan : Inspection with horizontally x-sectioned 2-d image..4) TAMI : C-Scan with multiple(2~999) gate
2. Thru-Transmission Method
1) T-scan : Inspection with transmitted signal.
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Pulse Echo & Thru-TransmissionPulse Echo & Thru-Transmission
Pulse Echo Thru-Transmission
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Structure of a Scanner Which uses both Pulse Echo and Thru-Transmission
Structure of a Scanner Which uses both Pulse Echo and Thru-Transmission
Water
Transducer for Pulse Generationand Receiver for Pulse Echo
Transducer for Thru-Transmission
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A-ScanA-Scan
1. Inspect defects with the phase and the magnitude of reflected waves on oscilloscope.
2. Merit : The most accurate inspection method.
3. Weak Point : Only one point analysis is available not plane.
4. Used to confirm the inspection results.
PKG Surface Die Surface Die Bottom PKG Surface
Die Surface
Die Bottom
Ultrasonic
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B-ScanB-Scan
1. Show the x-sectional image from each interface.
2. Detectable defects : Crack, Tilt and Void.
3. Merit : Analysis of the level of defects are possible.
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Void Size MeasuringVoid Size Measuring
Void
Void
Void
No Void
Void
PKG Surface
Die Surface
VoidSize
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Die Crack Direction InspDie Crack Direction Insp
PKG Surface
Die SurfaceDie Bottom
Die Surface
Die Bottom
Die Crack
Die Crack Direction
B-Scan Image
B-Scan
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C-ScanC-Scan
1. Shows the horizontally x-sectioned images after focus at an interface.
2. Detectable defects : Delamination, Die crack.
3. Merit : The most precise inspection method.
4. Weak point : Needs expertise(Solution : TAMI).