Upload
others
View
2
Download
0
Embed Size (px)
Citation preview
Rapid Diagnostics Using a Prober Based PCA
Sammy MokVeraConnex, LLC
June 7-10, 2009San Diego, CA
Tools for Verifying Connections
June 7 to 10, 2009June 7 to 10, 2009 IEEE SW Test WorkshopIEEE SW Test Workshop 22
Motivation• Experienced the challenges of building advanced
memory probe cards • How do you ensure your probe card works in
production?– Cards in production deflect differently than PCAs– Testing at multiple temperatures is required– Intermittent connections can not be detected– Life testing with relays does not work
• Test solutions get expensive– Probe counts - 60K+, embedded ICs, card sizes - >480 mm– Need convoluted test flow with custom developed tools
• Need real time and comprehensive diagnostic tools• There has to be a simpler solution
June 7 to 10, 2009June 7 to 10, 2009 IEEE SW Test WorkshopIEEE SW Test Workshop 33
Challenges• Probe cards can generate >200Kg force &
every test cell can deflect differently– Deflection contributors
• Prober chuck and head plate• Probe cards and their attachment to head plates• ATE test head weight• Temperature distortion (-45 to +200C)
• Significantly reduce the cost of test• How do you test for Cres and electrical
planarity with ICs in the way?
June 7 to 10, 2009June 7 to 10, 2009 IEEE SW Test WorkshopIEEE SW Test Workshop 44
Objectives / Implementation• Minimize deflection differences of test cells
– Mount switch electronics on probe card in target prober– Use ATE suppliers interface kits to attach to head plate – Use manipulator to support electronics & replicate load– Perform tests at all required temperatures – Measure tip positions using scrub marks on blank wafer
• Reduce cost of test– Faster parallel bussed pin testing– Streamline the test flow – keep on one tool– Minimal cabling and connectors– Scrub mark damage to replace force measurement
• Test through embedded ICS– Any channel can be a logic control channel
June 7 to 10, 2009June 7 to 10, 2009 IEEE SW Test WorkshopIEEE SW Test Workshop 55
Approach• First target: ATE with large installed base
– Advantest T5375: 96 ZIF connectors, 440 mm • Criteria
– True 4 - point measurements– Control digital ICs– High performance: intermittent & life time testing
• Hot switching & stable solid state switches– Measure passives and relays– Scalable architecture: start at 65,536 channels– Thorough self-test: configuration and communication– Confocal microscope: location & damage = force
June 7 to 10, 2009June 7 to 10, 2009 IEEE SW Test WorkshopIEEE SW Test Workshop 66
Electronics Hardware• Manipulator to
support pin electronics and match load
• Prototype: Shown directly mounted on head plate of EG prober
Prototype on EG Prober
Probe CardConnectors
ATE Connectors
Probe Card
VeraConnexElectronics
Board
Probe Card Top ViewSide View
Probe CardConnectors
ATE Connectors
Probe Card
VeraConnexElectronics
Board
Side View
``
June 7 to 10, 2009June 7 to 10, 2009 IEEE SW Test WorkshopIEEE SW Test Workshop 77
Cres Testing: Signal Probes• 4-wire resistance measurement of each probe using probe card
– Use prober to raise blank metalized wafer in contact with all probes– Connect force F+ and sense S+ rails from measurement unit to selected probe– Connect force F- and sense S- from measurement unit to several near by probes– Voltage across F+ to F- limited to < 50mv to not burn through interface layers
Performance Verification• Use system to analyze a 64 site LM4 probe card
to evaluate tool effectiveness in diagnosing problems– Electrical Planarity (on Au and Al wafers)– Cres on 100 touchdowns to Au and Al wafer– Leakage
• Verify measurement speed– More than 300 Cres tests per second
(Data+Reports for presentation in minutes)– Immediate data analysis and capture of images from
electrical results
June 7 to 10, 2009June 7 to 10, 2009 IEEE SW Test WorkshopIEEE SW Test Workshop 88
June 7 to 10, 2009June 7 to 10, 2009 IEEE SW Test WorkshopIEEE SW Test Workshop 99
Resistance Repeatability• Pin Card Measurements with shorting board
– 100 Measurements are consistent to within 16 mohms– Values include: Shorting resistance +Traces + Connector
0
0.002
0.004
0.006
0.008
0.01
0.012
0.014
0.016
0.018
0
0.001
0.002
0.003
0.004
0.005
0.006
0.007
0.008
0.009
0.01
37.5
7 67
G2
37.6
2 19
G2
37.6
5 16
G2
37.7
0 68
G2
37.8
3 12
G2
37.9
6 11
3G1
37.1
06 2
4G2
38.3
PPS
170F
38.9
6 11
5G1
38.1
06 2
5G2
40.3
PPS
234F
40.4
1 10
9G1
40.4
8 11
2G1
40.1
01 2
3G2
40.1
09 6
5G2
45.6
0 15
G4
45.6
3 17
G4
45.6
7 18
G4
45.7
1 14
G4
45.8
4 13
G4
45.1
01 2
0G4
45.1
09 2
8G4
47.3
7 10
6G3
47.4
4 10
7G3
47.9
6 11
4G3
47.1
06 2
6G4
48.3
PPS
236F
48.4
1 10
9G3
48.4
8 11
2G3
48.1
01 2
3G4
48.1
09 6
5G4
74.4
1 10
1H5
74.7
0 68
H6
74.7
4 3H
674
.76
5H6
74.7
8 7H
674
.80
8H6
77.9
6 49
H5
77.1
06 2
4H5
79.9
6 50
H5
79.1
06 2
6H5
80.3
7 46
H5
80.4
8 48
H5
80.1
01 2
3H5
169.
3 …16
9.62
19F
616
9.65
16F
616
9.71
14F
616
9.81
9F6
169.
83 1
2F6
169.
96 1
13F5
169.
106
24F6
170.
3 PP
S54F
170.
48 1
04F5
170.
101
21F6
170.
109
29F6
171.
37 1
06F5
171.
44 1
07F5
171.
96 1
14F5
171.
106
26F6
172.
37 1
10F5
172.
44 1
11F5
172.
96 1
16F5
172.
106
27F6
225.
37 3
4A1
225.
44 3
5A1
225.
57 6
7A1
225.
62 1
9A1
225.
65 1
6A1
225.
70 6
8A1
225.
72 1
A122
5.74
3A1
225.
76 5
A122
5.78
7A1
225.
80 8
A122
5.82
10A
122
5.84
13A
1 Del
ta R
esis
tanc
e (M
ax-M
in) (
ohm
s)
Stan
dard
Dev
iatio
n
Test Channels
100X Shorted Cres Repeatability Results - Shorting BoardStdDev
delta Cres
June 7 to 10, 2009June 7 to 10, 2009 IEEE SW Test WorkshopIEEE SW Test Workshop 1010
3X Planarity Results on Au Wafer
0
10
20
30
40
50
60
70
80
90
100
110
Test Channel
Con
tact
Res
ista
nce
(ohm
s)
Au PT4 P2 Au PT5 P2 Au PT6 P2 #N/A API Loaded Planarity
Stepping Cres on Au Wafer (100um OD from 1st touch)
June 7 to 10, 2009June 7 to 10, 2009 IEEE SW Test WorkshopIEEE SW Test Workshop 1111
0
10
20
30
40
50
60
70
80
90
100
110
Test Channel
Con
tact
Res
ista
nce
(ohm
s)
Au SS1 P3 PTres @ Z=26786 Au SS2 P 4 PTres @ Z=26786 Au SS3 P5 PTres @ Z=26786 Au SS4 P6 PTres @ Z=26786 Al SS5 P9 PTres @ Z=26812
Positions withFluctuating Cres
CorrespondingScrub Marks
After 50 steps on Probe Clean™ @ 50um OD
Cres during cleaning on WC wafer
June 7 to 10, 2009June 7 to 10, 2009 IEEE SW Test WorkshopIEEE SW Test Workshop 1212
Die.Pin = 225.74 3A1 / Test Pass = WC Rough StepClean
0
10
20
30
40
50
60
70
80
90
100
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49
Touchdown Number
Con
tact
Res
ista
nce
(ohm
s)
Die.Pin = 45.109 28G4 / Test Pass = WC Rough StepClean
0
10
20
30
40
50
60
70
80
90
100
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49
Touchdown Number
Con
tact
Res
ista
nce
(ohm
s)
Die.Pin = 45.96 113G3 / Test Pass = WC Rough StepClean
0
10
20
30
40
50
60
70
80
90
100
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49
Touchdown Number
Con
tact
Res
ista
nce
(ohm
s)
Die.Pin = 79.96 50H5 / Test Pass = WC Rough StepClean
0
10
20
30
40
50
60
70
80
90
100
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49
Touchdown Number
Con
tact
Res
ista
nce
(ohm
s)
After Probe Clean™ + 50 Steps on WC + Probe Clean™
3X Planarity on Au Wafer after clean
June 7 to 10, 2009June 7 to 10, 2009 IEEE SW Test WorkshopIEEE SW Test Workshop 1313
0
10
20
30
40
50
60
70
80
90
100
110
Test Channel
Plan
arity
(1st
Z @
10 o
hms)
(um
)
Au PTa P14 Au PTc P14 Au PTd P14 #N/A API Loaded Planarity
Fewer Fluctuating pins
Insert Chart Animation Video HERE
Animation of Contact Resistance During Planarity TestBefore Cleaning After Cleaning
154 Test Channels
Individual Pin Cres During Planarity Test (Au Wafer @ 75um OD after 1st touch) (Post clean)
June 7 to 10, 2009June 7 to 10, 2009 IEEE SW Test WorkshopIEEE SW Test Workshop 1515
Die.Pin = 40.109 65G2 / Test Pass = Au PTa P14
0
10
20
30
40
50
60
70
80
90
100
-129 -29
-29 21 9 3 0 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 74
Touchdown Number
Con
tact
Res
ista
nce
(ohm
s)
Die.Pin = 79.106 26H5 / Test Pass = Au PTa P14
0
10
20
30
40
50
60
70
80
90
100
-129 -29
-29 21 9 3 0 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 74
Touchdown Number
Con
tact
Res
ista
nce
(ohm
s)
Die.Pin = 169.84 13F6 / Test Pass = Au PTa P14
0
10
20
30
40
50
60
70
80
90
100
-129 -29
-29 21 9 3 0 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 74
Touchdown Number
Con
tact
Res
ista
nce
(ohm
s)
Die.Pin = 40.37 110G1 / Test Pass = Au PTa P14
0
10
20
30
40
50
60
70
80
90
100
-129 -29
-29 21 9 3 0 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 74
Touchdown Number
Con
tact
Res
ista
nce
(ohm
s)
June 7 to 10, 2009June 7 to 10, 2009 IEEE SW Test WorkshopIEEE SW Test Workshop 1616
Cres Results100 Step Repeatability Results - No stepping (Pos 1) (50um OD on Au6)
0.1
1
10
100
100037
.57
67G
237
.62
19G
237
.65
16G
237
.70
68G
237
.83
12G
237
.96
113G
137
.106
24G
238
.3 P
PS
170F
38.9
6 11
5G1
38.1
06 2
5G2
40.3
PP
S23
4F40
.41
109G
140
.48
112G
140
.101
23G
240
.109
65G
245
.60
15G
445
.63
17G
445
.67
18G
445
.71
14G
445
.84
13G
445
.101
20G
445
.109
28G
447
.37
106G
347
.44
107G
347
.96
114G
347
.106
26G
448
.3 P
PS
236F
48.4
1 10
9G3
48.4
8 11
2G3
48.1
01 2
3G4
48.1
09 6
5G4
74.4
1 10
1H5
74.7
0 68
H6
74.7
4 3H
674
.76
5H6
74.7
8 7H
674
.80
8H6
77.9
6 49
H5
77.1
06 2
4H5
79.9
6 50
H5
79.1
06 2
6H5
80.3
7 46
H5
80.4
8 48
H5
80.1
01 2
3H5
169.
3 P
PS
182F
169.
62 1
9F6
169.
65 1
6F6
169.
71 1
4F6
169.
81 9
F616
9.83
12F
616
9.96
113
F516
9.10
6 24
F617
0.3
PP
S54
F17
0.48
104
F517
0.10
1 21
F617
0.10
9 29
F617
1.37
106
F517
1.44
107
F517
1.96
114
F517
1.10
6 26
F617
2.37
110
F517
2.44
111
F517
2.96
116
F517
2.10
6 27
F622
5.37
34A
122
5.44
35A
122
5.57
67A
122
5.62
19A
122
5.65
16A
122
5.70
68A
122
5.72
1A
122
5.74
3A
122
5.76
5A
122
5.78
7A
122
5.80
8A
122
5.82
10A
122
5.84
13A
1
Test Channels
Cre
s (o
hms)
0
2
4
6
8
10
12
14
16
18
Stan
dard
Dev
iatio
n
MaxMinMedianStdDev
Fluctuation in Cres over repeated steps identifies problem pins
Per Pin Cres Signature over 100 Steps on Au
June 7 to 10, 2009June 7 to 10, 2009 IEEE SW Test WorkshopIEEE SW Test Workshop 1717
45.109 28G4 Max = 7.181 Min = 5.013 Stdev = .7189
0.1
1
10
100
1 11 21 31 41 51 61 71 81 91Step Number
Cre
s (o
hms)
77.106 24H5 Max = 19.133 Min = 3.752 Stdev = 3.6937
0.1
1
10
100
1 11 21 31 41 51 61 71 81 91Step Number
Cre
s (o
hms)
79.106 26H5 Max = 19.225 Min = 7.928 Stdev = 2.6221
0.1
1
10
100
1 11 21 31 41 51 61 71 81 91Step Number
Cre
s (o
hms)
38.109 29G2 Max = 2.717 Min = 2.689 Stdev = .0065
0.1
1
10
100
1 11 21 31 41 51 61 71 81 91Step Number
Cre
s (o
hms)
Ideal Pin Passing Pin
Intermittent Pin Intermittent Pin
10 Ohm passing limit
Per Pin Cres signature over 100 Steps on Al
June 7 to 10, 2009June 7 to 10, 2009 IEEE SW Test WorkshopIEEE SW Test Workshop 1818
38.109 29G2 Max = 2.647 Min = 2.362 Stdev = .0489
0.1
1
10
100
1 11 21 31 41 51 61 71 81 91Step Number
Cre
s (o
hms)
45.109 28G4 Max = 99.9 Min = 5.245 Stdev = 15.8795
0.1
1
10
100
1 11 21 31 41 51 61 71 81 91Step Number
Cre
s (o
hms)
77.106 24H5 Max = 99.9 Min = 2.727 Stdev = 10.0404
0.1
1
10
100
1 11 21 31 41 51 61 71 81 91Step Number
Cre
s (o
hms)
79.106 26H5 Max = 99.9 Min = 4.243 Stdev = 19.3432
0.1
1
10
100
1 11 21 31 41 51 61 71 81 91Step Number
Cre
s (o
hms)
First Touch Z Sampled During 1 hr Soak
June 7 to 10, 2009June 7 to 10, 2009 IEEE SW Test WorkshopIEEE SW Test Workshop 1919
Initial Probe card temp = 25°CChuck temp = 85°C
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10
20
0
300
600
900
1200
1500
1800
2100
2400
2700
3000
3300
3600
3900
Time (secs)
Del
ta Z
from
Roo
m te
mp
Posi
tion
(um
)
Soaking with chuck tracking at 0 um ODSoaking with chuck tracking at 50um OD
Soaking at 200um below tip median plane(@25°C)Reference with Chuck and Probe card @25°C
Dynamic First-Touch Z Profiling
June 7 to 10, 2009June 7 to 10, 2009 IEEE SW Test WorkshopIEEE SW Test Workshop 2020
Chuck temp = 85C
‐90
‐80
‐70
‐60
‐50
‐40
‐30
‐20
‐10
0
10
20
30
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115
Time (mins)
First T
ouch Z (u
m)
10 min Tracking@ 75umabove1stTouch
10 min Tracking@ 75umabove1stTouch
10 min Tracking@ 75umabove1stTouch
10 min Tracking@ 75umabove1stTouch
90 sec interval with chuckmoved under lookdown camera
60 min Soak @ 200 um below mean 25C tip plane
First Touch @ 25C
June 7 to 10, 2009June 7 to 10, 2009 IEEE SW Test WorkshopIEEE SW Test Workshop 2121
Results• Demonstrated that the system can collect data
in minutes and provide immediate analysis• Fast electronics integrated into prober opens up
new methods in diagnosing problems– Fast Cres measurements enable collection of individual
pin signatures • Can identify unique problems despite passing Cres• Intermittent Cres can be identified
– Dynamic planarity behavior of probe card can be observed
– Integrated real time data analysis help correlate measurements to problem pins
June 7 to 10, 2009June 7 to 10, 2009 IEEE SW Test WorkshopIEEE SW Test Workshop 2222
Follow-On Work• Investigate other signatures
– Scrub• Correlation of pin signature to
– Probe card life– Product die test yield
June 7 to 10, 2009June 7 to 10, 2009 IEEE SW Test WorkshopIEEE SW Test Workshop 2323
Acknowledgements• Co-Authors: VeraConnex, LLC
– Frank Swiatowiec– Fariborz Agahdel– Bruce Pettyjohn
• Hyphenated Systems, LLC– Edward Robinson
• Electroglas, Inc.– Steve Martinez– Jonathan Halderman
• Aehr Test– Chris Buckholtz