hot-spot: high temperature probing...w15x17 /j750 on uf3000 prober 0 10 20 30 40 50 60 70 80 90 100...

June 2009 FEINMETALL GmbH, Dr. W. Schaefer / G. Boehm 1

Hot-Spot: High Temperature ProbingChallenges of wafer probing beyond 150°C

Dr. Wolfgang SchaeferGunther BoehmFeinmetall GmbH

F E I N M E T A L LContact technologies for electronics

June 7-10, 2009San Diego, CA USA


IEEE SW Test WorkshopIEEE SW Test Workshop

Demand on High Temperature Probe Cards

- ITRS-Roadmap max. test temperature demand: -55°C +175°C

- automotive industrie requests higher test temperatures: -40°C +180°C

- trend to large footprint multi DUT testing at high temperatures

ITRS

automotive



Wired Connector

wired card:

PCB

connector

connector plate

head

back stiffener

front stiffener



2. temperature of electronics1. temperature

distribution

3. dimensionalstability

4. alignment

5. contact performance

Probing Challenges at 180°C wafer temperature



1. Temperature Measurements within the Probecard

temperature sensor locations:

connector housing

connector platehead

back stiffener

front stiffener

PCB top

PCB bottom



1. Temperature Measurements within the Probecard

component temperature vs. wafer temperature

-25

0

25

50

75

100

125

150

-40 0 40 80 120

160

200

wafer temperature (°C)

com

pone

nt te

mpe

ratu

re (°

C)

headconnector platefront stiffenerPCB bottomconnector housing back stiffenerPCB top



1. Temperature Rise within the Probecardprobecard warmup: 180°C wafer temperature

W15x17 /J750 on UF3000 prober

0102030405060708090

100110120130140

0 25 50 75 100 125 150 175 200time (minutes)

com

pone

nt te

mpe

ratu

re (

°C)

connector platePCB-bottomheadfront-stiffenerPCB-topback-stiffenerconnector housing

insert probecard

wafer in contact

end of test

alignment and test

com

pone

nt te

mpe

ratu

re (°

C)

the setup-time can be kept very shortif immediate wafer contact is used



component temperature vs. wafer temperature

0

25

50

75

100

125

100 120 140 160 180wafer temperature (°C)

com

pone

nt te

mpe

ratu

re (°

C)

PCB bottomPCB top

2. Probecard Electronics Temperature Limit

selection and location of electronic components on the probecard with respect to their max. temperature limit

125°Csemi conductorresistor

max. temp.component type



3. Dimensional Changes of Wafer and Probecard

dimensional change of probecard material

0 100 200 300 400 500 600

Vespel®

aluminum

PCB

stainless steel

MLC

Al2O3

Si3N4

wafer

position change in µm for given temperature range

from +22°C to +90°Cfrom -40°C to +180°C

50mm distance

Many traditional probecard materials are unsufficient forhigh temperature probing.

Alignment?Cracks?

position change in µm



3. Needle – Connector Alignment

needle

wire

old styleheat expansion

new designheat expansion

Vespel – ceramicnon symmetric

ceramic – ceramicsymmetricwire

needle



needle to connector wire alignment accuracyW30x35 head

-50

-40

-30

-20

-10

0

10

20

30

40

50

-50 -40 -30 -20 -10 0 10 20 30 40 50

X-position error in µm

Y-po

sitio

n er

ror i

n µm

old style -40°C

new design -40°C

old style +140°C

new design +185°C

new connector wire

spec. limit

connector wire diameter

3. Needle – Connector Alignment



probecard scaling35mm footprint, relative to wafer

1

1

1

1

1

1

1

1

-40 +25 +150 +180wafer temperature [°C]

rela

tive

scal

ing

erro

r [µm

]

X scaling errorY scaling error

0

+2

-2

-4

-8

-6

4. Tip Alignment Accuracy at Wide Temperature Range

optimized material selectionfor small scaling error required



-30

-20

-10

0

10

20

30

-30 -20 -10 0 10 20 30

padsize X [µm]pa

dsiz

e Y

[µm

] +150°Cpadsize

4. Tip Alignment Accuracy at Wide Temperature Range

-30

-20

-10

0

10

20

30

-30 -20 -10 0 10 20 30

padsize X [µm]

pads

ize

Y [µ

m] -40°C

padsize

-30

-20

-10

0

10

20

30

-30 -20 -10 0 10 20 30

padsize X [µm]

pads

ize

Y [µ

m] +25°C

padsize

CTE matchedguide plates

-30

-20

-10

0

10

20

30

-30 -20 -10 0 10 20 30

padsize X [µm]

pads

ize

Y [µ

m] +180°C

padsize

probemarkinspection data



5. Contact Resistance MeasurementTypical test result from the prober:

100 200 300 400 500

1

2

3

4

5

Cre

s[O

hm]

Touchdown

15.01.2009Contact HT-1@-40°C 500TDs500 needles, 75µm pitch @ -40°C

on AlCu0,5%100 200 300 400 500

5

4

3

2

1



5. Contact Resistance MeasurementRatio of measurements greater than specified CRes in ppm

1

10

100

1000

10000

100000

1000000

1.00 1.25 1.50 1.75 2.00 2.25 2.50 2.75 3.00 3.50 4.00 4.50 5.00 6.00 7.00

CRes[]

ppm

ratio of contacts above a specific Cres

data from 250.000 contacts

discontinuing X-scale



5. Contact Resistance MeasurementRatio of measurements greater than specified CRes in ppm

1

10

100

1000

10000

100000

1000000

1.00 1.25 1.50 1.75 2.00 2.25 2.50 2.75 3.00 3.50 4.00 4.50 5.00 6.00 7.00

CRes[]

ppm

probecard with 100 needles, 3 Ohm Cres limit, 1% yieldloss

the required performance depends on application:

- required max. Cres

- needles per DUT

probecard with 1000 needles, 3 Ohm Cres limit,

1% yieldloss



5. Contact Resistance at High Temperature RangeRatio of measurements greater than specified CRes in ppm

1

10

100

1000

10000

100000

1000000

1.00 1.25 1.50 1.75 2.00 2.25 2.50 2.75 3.00 3.50 4.00 4.50 5.00 6.00 7.00

CRes[]

ppm

-40°C75µm pitchon AlCu0.5no online Cleaning

Ratio of measurements greater than specified CRes in ppm

1

10

100

1000

10000

100000

1000000

1.00 1.25 1.50 1.75 2.00 2.25 2.50 2.75 3.00 3.50 4.00 4.50 5.00 6.00 7.00

CRes[]

ppm

-40°CRT75µm pitch

on AlCu0.5no online Cleaning


1

10

100

1000

10000

100000

1000000

1.00 1.25 1.50 1.75 2.00 2.25 2.50 2.75 3.00 3.50 4.00 4.50 5.00 6.00 7.00

CRes[]

ppm

-40°CRT125°C75µm pitchon AlCu0.5

no online Cleaning


1

10

100

1000

10000

100000

1000000

1.00 1.25 1.50 1.75 2.00 2.25 2.50 2.75 3.00 3.50 4.00 4.50 5.00 6.00 7.00

CRes[]

ppm

-40°CRT125°C150°C

75µm pitchon AlCu0.5no online Cleaning


1

10

100

1000

10000

100000

1000000

1.00 1.25 1.50 1.75 2.00 2.25 2.50 2.75 3.00 3.50 4.00 4.50 5.00 6.00 7.00

CRes[]

ppm

-40°CRT125°C150°C180°C



1

10

100

1000

10000

100000

1000000

1.00 1.25 1.50 1.75 2.00 2.25 2.50 2.75 3.00 3.50 4.00 4.50 5.00 6.00 7.00

CRes[]

ppm

-40°CRT125°C150°C180°CAll


75µm pitchon AlCu0.5%

no online cleaning



Cleaning Frequency vs. Wafer Temperature

-40 -20 0 20 40 60 80 100 120 140 160 180

100

200

300

500

1000

>1000

onlin

e cl

eani

ng in

terv

all

wafer temperature in °C

5. Online Cleaning at Elevated Temperatures

each bullet: one test with 500 needles/

500 touchdowns

75µm pitch ViProbeon AlCu0.5%



5. Contact Resistance MeasurementTypical testresult from the prober: online cleaning not required

100 200 300 400 500

1

2

3

4

5

Cre

s[O

hm]

Touchdown

V42Z @ 180°C, 100µm OTW30x35, 75µm pitch, no online cleaning @ 180°C

500 needleson AlCu0,5%

100 200 300 400 500

5

4

3

2

1



5. Scrubmarks at Elevated Wafer Temperatures25°C-40°C 125°C 150°C 180°C

Total_Scrub :

Length 20µm 22µm 25µm 29µm 29µm

Width 12µm 14µm 15µm 16µm 16µm(Average, count : 90)

length

width



scrub size vs. wafer temperature

0

5

10

15

20

25

30

-40 -20 0 20 40 60 80 100 120 140 160 180 200wafer temperature (°C)

size

[µm

]

on AlCu0.5

5. Scrubmarks at Elevated Wafer Temperatures

scrub length

scrub width

on AlCu0.5%

adjusted scrublength for optimized performance



High Temperature Probing Recommendations

- adjusted scrub length

- adjusted online cleaning

5. contact performance

CTE matched guide plates4. alignment

- CTE matched materials

- design to consider temperature gradients

3. dimensional stability

selection and location of electronic components on the probecard with respect to their max. temperature limit

2. temperature of electronics

adequate warmup setting with the needles in contact with the wafer

1. temperature distribution

solutionchallenge



Summary

- probing from -40°C to +180°C with one probecard is ready for industrial applications

- space transformer or wired probecardsare both possible

- application specific optimizationcan reduce cleaning frequency



Thank You.

Feinmetall GmbHHerrenberg, Germanywww.feinmetall.de

hot-spot: high temperature probing...w15x17 /j750 on uf3000 prober 0 10 20 30 40 50 60 70 80 90 100...

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