Wire Bonding

pad
lead
Free air ball is captured in the chamfer
pad
lead
Free air ball is captured in the chamfer
pad
lead
Formation of a first bond
pad
lead
Formation of a first bond
pad
lead
Formation of a first bond
PRESSURE
Ultra
Sonic
Vibration
pad
heat
lead
Formation of a first bond
PRESSURE
Ultra
Sonic
Vibration
pad
heat
lead
Capillary rises to loop height position
pad
lead
Formation of a loop
pad
lead
Formation of a loop
pad
lead
pad
lead
pad
lead
pad
lead
pad
lead
pad
lead
pad
lead
pad
lead
pad
lead
pad
lead
pad
lead
pad
lead
pad
shows higher tensile strength and shorter heat affected zone length.
E. Gold Wire Property (Grain size)
1.4WD 1.6WD 1.8WD 2.0WD
160
Wire diameter (1.0mil)
•
•
B. Gold Wire Property (B/L and E/L)
C. Wire Diameter Property - R,L,C
D. Gold Wire Property (Recrystallization Temp.)
Each wire type has each recrystallization temperature. Wire with higher recrystallization temperature
0.7mil, 0.8mil, 0.9mil, 1.0mil, 1.1mil, 1.2mil,1.3mil,2.0mil
•VENDER :
HERAEUS, SUMITOMO, MKE, TANAKA AMERICAN FINE WIRE(AFW)
•TOLERANCE:
+/-0.05MIL
Manufacturing Process of Gold Wire
MCM
D. M/C BASIC DATA
• M/C TYPE:
• Kulicke & Soffa
– 1484XQ, 1488, 8020, 8028/S/PPS,NewTek/Elite, Maxum/Plus/Ultra
• ASM
– Eagle100/200/400/700…
• Shinkawa
ASSEMBLY WIRE BOND PROCESS INTRODUCTION
Semiconductor Packaging Process
WAFER
WAFER MOUNT
Back Grinding & Die Saw
DIE ATTACH
MODING
WIRE BOND
EPOXY CURE
TRIM / FORM
Wire Diameter 20 um 23 um 25 um Criteria 8g min 8g min. 12g min.
2.
Wire pull test
1. 2. 3.
3.
Ball shear test
1. 2.
IMC COVERAGE
IMC =59.15%
IMC=59.15%
IMC=63.6%
Capillary
Workholder Heat Block Clamp
Shinkawa UTC1000 Super
GOLD WIRE
K&S Ultra
Electronic Flame-Off
WIRE PULL TEST
Wire Failure 4 Stitch Failure 5
Lifted 1st Bond 2
10 Final products
9 Rewinding
8 Final products
A. Stress-Strain Characteristics of bonding wire
• • Typical stress v.s. strain curves for bonding wire in two states of hardness. Wire A is typical of large-diameter bonding wire; Wire B is typical of small-diameter bonding wire. 1 is the elastic region;2 is the elastic limit ;3 is the region of plastic deformation;4 is the breaking load of the wire Different diameter and hardness could affect the stress-strain characteristics. How to combine different diameter and hardness is a very important factor for a good gold wire.
HAZ Length(um)
140
HAZ Length
HAZ Length
120
100 80 2.0WD 1.8WD 1.6WD 1.4WD
Free Air Ball Size Fig. 1 HAZ Length Variation of grain size at HAZ according to FAB size 1.4 WD Grain size(um) 2.2 ~ 3.3 1.6 WD 2.5 ~ 3.6 1.8 WD 2.8 ~ 3.9 2.0 WD 3.3 ~ 4.4 Fig. 2 HAZ length according to FAB size
A.PURPOSE
Ball Bond
( 1st Bond ) Stitch Bond/Wedge Bond ( 2nd Bond )
Gold wire
pad
lead
B.PRINCIPLE
• HARD WELDING:
– PRESSURE – AMPLIFY & FREQUENCY – WELDING TIME – WELDING TEMPATURE
lead
pad
lead
pad
lead
pad
lead
pad
lead
Formation of a second bond
pad
heat
lead
Formation of a second bond
pad
heat
lead
pad
heat
lead
pad
heat
lead
pad
lead
pad
lead
(1). Mitsubishi :
1 4N gold (99.99%)
2 Refining
3 Melting & casting
4 Caliber rolling
5 Drawing
6 Annealing
7 Winding
8 Packing & Shipping
(2).
Sumitomo :
＋
1 5N gold (99.999%) Dopant 2 Ingot making 3 Roll press 4 Single dies drawing 5 Heavy drawing 6 Intermediate annealing 7 Fine drawing
pad
lead
Capillary rises to loop height position
pad
lead
Capillary rises to loop height position
pad
lead
Capillary rises to loop height position
pad
lead
Capillary rises to loop height position
SOP/SSOP
QFP/LQFP/TQFP
• STACK DIE • SIDE BY SIDE
MCP/FBGA
SPSN
TM2633 B92283.1 #6 9852Z
RBC
2ND BOND
FILM BGA
CSP (With Spacer)
Function Die Spacer Function Die
– UTC400, UTC1000(Super)
• ESEC, Kaijo (FB780).
WIRE BOND MACHINE
K&S 8028
K&S Maxum
Wire
Air guide
Tensioner
Wire clamp
Tensioner
EFO Wand
Wire clamp Ultra Sonic Transducer
ห้องสมุดไป่ตู้
1st bond Cross-section
T0
T24
T48
T72
T96
T120
T144
T168
E. MATERIAL
Wire Tool Bonder
Bonded Wire
Bonding Surface
Work Holder
GOLD WIRE
•DIAMETER(1mil=0.001inch) :
pad
lead
pad
lead
pad
lead
pad
lead
Disconnection of the tail
pad
lead
Disconnection of the tail
pad
lead
Formation of a new free air ball
pad
lead
D. PACKAGE INTRODUCE PDIP
A.PURPOSE
• FORMING A STRONG AND RELIABLE INTERTALLIC BOND BETWWEEN THE WIRE AND THE PAD , AS WELL AS BETWEEN THE WIRE AND THE LEAD
DICE GOLD WIRE
LEADFRAME
• THERMOSONIC BONDING:
– THERMAL COMPRESSURE – ULTRASONIC ENERGY(1.2MHZ)
B.PRINCIPLE
PRESSURE
VIBRATION
AL2O3
CONTAMINATION
GOLD BALL GLASS Al SiO2, TiN, TiW
MOISTURE
Si
C. WIREBOND PROCESS
Free air ball is captured in the chamfer
GOLD BALL
pad
lead
Free air ball is captured in the chamfer
pad
lead
Free air ball is captured in the chamfer
Neck Failure 3
Lifted 2nd Bond 6
Cratering 1
WIRE PULL TEST
BALL SHEAR TEST
BALL SHEAR TEST
POST BAKE UNDER PITCH 60 um
1. IMC coverage inspection
1. 2. Sample size: 3 balls/4side/unit Criteria: Average > 70% Wire pull position: Close to 1st bond Sample size: 40 wires/unit At W/B Post Bake verification run, ball lift and metal peel defect mode is not allowed at T0 readout only Sample size: 20 Balls/unit Criteria:
Saw Singulation
Integrated Circuit (IC)
CONTENTS
• • • • • • • • • A. PURPOSE B. PRINCIPLE C. PROCESS D. PACKAGE INTODUCE E. M/C BASIC DATA F. MATERIAL G. PARAMETER H. DEFECTS I. VARIOUS LOOPING PROFILE