1. European 3D TSV Summit 2015
Progress in TSV
Stacking Using
TCB Process
Dr. Hugo Pristauz
VP Thermocompression Bonding & Die Sorting

2. Solder Flip Chip Evolution
European 3D TSV Summit 2015
10µ@3
Mass Reflow Flip Chip Processes
*) C4: Controlled Collapse Chip Connect (IBM)
**) C2: Chip Connect (IBM)
TC Flip Chip
ultra fine pitch ≤40µ
Flip Chip on LF
coarse pitch ≥ 200µ
C2 Flip Chip **)
fine pitch ≥ 50µ
Cu-pillar
Flip Chip
C4 Flip Chip *)
standard pitch ≥ 130µ
low
Productivity
local reflow
mass reflow
high
Productivity
Jan-2015 2

3. Jan-2015
TSV Stacking – High Volume Production
3European 3D TSV Summit 2015
Current Driver: HMC

4. TC-Bonding
is Key to
TSV Stacking

5. TC-NCP Process
(pre-applied nonconductive paste)
TC-CUF Process
(capillary underfill,
or TC-MUF: molded underfill)
TC-NCF Process
(WL applied nonconductive film,
or TC-WLU: wafer level underfill)
Jan-2015
TC Bonding Processes
5European 3D TSV Summit 2015
T
F
T
F
T
F

6. Oct-2014
• Thermo compression bonder
• +200/-100 °C temperature
ramping
• 2µ @ 3 sigma accuracy
• 250 N bond force
• C2S / C2W
• TC/NCP, TC/NCF, TC/CUF
Datacon 8800 TC Thermo Compression Bonder
6Confidential
8800 TC
Launch: March 2014
Now 12 x 8800 TC installed base
Preparing for 5 bonder / month shipment

7. Jan-2015
TCB Bonding
7European 3D TSV Summit 2015

8. Challenges in
TCB / TSV
HV Production

9. Jan-2015
Challenge Level of TSV Stacks
9European 3D TSV Summit 2015
4-Stack HMC 1+4 HMC 1+8
initial
estimation
of challenges
current
understanding
of challenges
challenge level
from a view
of TC bonding
Challenges:
1) High Capabilities
2) Tool2Tool Repeatability
3) Monitoring & Alarming

10. Jan-2015
Bond Control for CUF Process
10European 3D TSV Summit 2015
z (position)
T (temperature)
F (force)
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5
-20
-10
0
10
20
30
40
50
-200
-100
0
100
200
300
400
500
Temperature[°C]
Bond Control for CUF Process
Force[N],Position[µm]
time [s]
high temperature
ramping rate
200°C/s
dynamic
z-control
during collapse
thermal
compensation
rapid cooling
-100°C/s
• Challenge 1: How do you teach the position control?
• Challenge 2: How do you move from one tool to another?
T (temperature)
F (force)
z (position)

11. Capabilities

12. Oct-2014
High Capabilities
12Confidential
8800 TC
7-axis
bond head
auto
tilt setupt
bond
control
(force/pos.)
dynamic
bond
control
2µ@3s
@
250 N
rapid
heater &
cooler
individual
bond profiles
per layer
temperature
sensing
In nozzle

13. Oct-2014
7-Axis / 250 N Bond Head
13Confidential
x/y micro
actors
force
actuator
(high dynamics)
theta
axis
main
z-axis
• 2 x actuators for bond control • 2 x actuators for auto tilt setup

14. Jan-2015
Enhanced Bond Control for CUF Process
14European 3D TSV Summit 2015
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5
-20
-10
0
10
20
30
40
50
-200
-100
0
100
200
300
400
500
Temperature[°C]
Enhanced Bond Control for CUF Process
Force[N],Position[µm]
time [s]
• By distributing bond control over two position axes
the complexity of the bond control is reduced
w (position)
T (temperature)
F (force)
z (position)
thermal
compensation
@ z-position-axis
w-position axis
used for
BLT control

15. Monitoring/Alarming
&
Tool-2-Tool
Repeatability

16. Jan-2015
• Setting up alarm windows for any process variable at chosen time
• Process variables are monitored against defined alarm windows
• Escaping an alarm window generates a machine stop and an alarm
Integrated Monitoring & Alarming
16European 3D TSV Summit 2015

17. Jan-2015
Key for Recipe Portability & Time to Yield
• machine parameters & recipe parameters must be strictly separated
• auto calibration procedures ensure consistently calibrated tools
Key for Monitoring & Alarming
• Portable alarm-windows are only working on repeatable tools
Tool-2-Tool Repeatability
17European 3D TSV Summit 2015

18. Jan-2015
• High repeatability due to sensor integration in bond tool
• Define a metrics which an automatic diagnostic can check
Thermal Repeatability
18European 3D TSV Summit 2015
0 2 4 6 8 10 12 14 16 18
-10
-5
0
5
10
15
20
25
30
35
Initial
3*sig = 0.05 °C
Cmk = 20.09
Warm-up
3*sig = 0.22 °C
Cmk = 4.5
Heating
3*sig = 0.35 °C
Cmk = 2.86
Cooling
3*sig = 0.59 °C
Cmk = 1.7
Residual Temperature Analysis: std = 0.12 °C, Cm = 2.86@+/-1°C (during heating)
$1 WH1 @ #2.42 (11:37)
-100
-50
0
50
100
150
200
250
300
350

19. 0 0.5 1 1.5 2 2.5 3 3.5 4
-10
0
10
20
30
40
50
-100
0
100
200
300
400
500
Temperature[°C]
Verification of Thermal Expansion Compensation
Force[N],Position[µm]
time [s]
Jan-2015
• Thermal expansion is automatically identified
• z-axis performs (feed-forward) thermal compensation movements
• Metrics for proper compensation: w-axis has to stay within +/- 1µ
Compensation Repeatability
19European 3D TSV Summit 2015
w (position)
z (position)
T (temperature)
F (force)

20. • TSV/TCB stacking is now in HV production, driven by
memory cube business
• 3 factors are crucial for TCB HV production: capabilities,
tool-2-tool repeatability and monitoring&alarming
• Reduction of complexity of the bond control can be
achieved by dual z-axis control, where the first one is
running thermal compensation, the other one does force
or bond line control
• Thermal repeatability leverages from sensor integration
in the bond tool
• Usage of proper metrics is helpful to verify Tool-2-Tool
repeatability (e.g. thermal-repeatability, compensation
repeatability)
• Integrated monitoring & alarming is mandatory for HV
TCB bonding. Tool-2-tool repeatability is mandatory for
integrated monitoring & alarming
Summary