View
37
Download
0
Category
Tags:
Preview:
DESCRIPTION
Evitherm September 15, 2003. Transient Plane Source Techniques for measuring Thermal Conductivity of Various Materials. Dr. Lars H älldahl Hot Disk AB. Hot Disk … or Transient Plane Source, TPS… or Gustafsson Probe… or G-Probe. The technique is based around :. -A unique sensor. - PowerPoint PPT Presentation
Citation preview
Transient Plane Source Techniques for measuring Thermal Conductivity of Various MaterialsEvitherm
September 15, 2003
Dr. Lars HlldahlHot Disk AB
Hot Disk
or
Transient Plane Source, TPS
or
Gustafsson Probe
or
G-Probe
The technique is based around:-A unique sensorA new mathematical model for thermal conductivityA Transient Plane Source in infinite material- Special electronics to collect dataDesigned for accuracy and precision
The SensorA double spiral made of Nickel metal foil, cladded by Kapton or Mica to provide electrical insulation from the sample. The diameter varies from 1 mm up to 60 mm. It connects to the electronics, which sends out a current during a selected time, while the voltage drop is recordedSee in the following four slides the historical development of Hot Diskfrom Hot Wire Hot Strip !
Hot Wire
About 1960-tiesMetal wire in contact with the sampleOK for liquids, but not for solids contact resistance problems
Hot Strip
Development of Hot Wire the wire.flattened outbetter contact on sample
From a Strip..to a spiralcovers larger area on smaller sample
So.the story is
from
Hot Wire
to
Hot strip
and next stepTransient Plane SourceThis is Hot Disk
Sensor embedded in the sample. Heat can spread in all directions
A transient recordingPowerTimeTimeVoltage=resistance=temperatureSend in power...and measure at the same timeFor good conductors:high power, short timeFor good insulators: low power, long time
Ideally, the sensor is surrounded by infinite sample in all direction. Cant see the edge, the temperature increase doesnt reach the edges.Both Conductivity and Diffusivity are measured, and from them Heat Capacity is calculatedHeat dissipation in infinite sample
Sample
Parameters of importance: POWER, TIME SENSOR SIZE The relation between Diffusivity, Time for measurement and radius of sensor is called Total to Characteristic Timex tr x r
SampleSensor=1This value between 0.3 1.0 satisfies the basic assumption done for the Heat Conductivity equation: A Plane Source in Infinite Material
Variants of the TPS methodBy varying sensor size, power and time in the basic method, thermal conductivity over morethan 4 orders of magnitude can be covered.To cover more applications, some variants have been developed
Thin Film MethodSamples like paper, textile, cloth, polymer films, etc.Background material
Sample Sensor Sample
Background materialThickness from ~ 10m ~ 500m Conductivity from ~ 0.01W/mK ~ 10W/mKBackground material is good conductor, experiment parameters as if this is the sample: high power, short time
Thin Film often uses a square, naked Ni-sensorwhich is most sensitive, but also cladded sensors can be used
Slab MethodInsulator
SampleSensorSample
InsulatorFor good conductors, >10 W/mK- Ceramic, metals, Si-wafer, SiC. Etc.Relation between Sample Thickness/Sensor radius 0.03 < t/R < 0.75 - Different radii to match different samples
Developing Slab Method-Air is very insulating
Anisotropic samplesRadial directionConductvityDiffusivity
Axial directionConductivityDiffusivityTo solve the heat conductivity equation in this case: Heat Capacity Cp must be known!
Anisotropic sampelsTensile testing bars, polymer matrix with fiber reinforcement in the plan. Thickness2 mm.
radial W/mK axial W/mK radial mm2/s axial mm2/s mm2/s W/mK
Diagr1
0.1060505330.08107838910.23005423070.1758824394
0.09393397590.06523192770.3021892040.2098536139
0.10433047190.07235122880.35020875380.2428632134
laxial [W/mK]
kaxial [mm2/s]
lradial [W/mK]
kradial [mm2/s]
% Fiber
l [W/mK] k [mm2/s]
Results
Results :Dragprov5%Number of Rows:9
File:(Points)TemperatureAx.Th.ConductivityAx.Th.DiffusivityRad.Th.ConductivityRad.Th.DiffusivityAx.Pr.DepthRad.Pr.DepthTemp.Incr.Temp.DriftTotal/Char.TimeTime Corr.Mean Dev.Disk Res.
Dragprov_1procent. 1.ani( 13- 200,tc)Rumstemp 23 deg. C0.10671190880.08158402820.2277899990.17415137541.8029458632.63416859942.00744473260 (No corr.)0.32396674790.06818926980.00100373132.4391883427
Dragprov_1procent. 2.ani( 11- 200,tc)Rumstemp 23 deg. C0.10605698050.08108331840.23029433350.17606600421.79740469322.64860910782.09159920410 (No corr.)0.32752845430.06493702220.00097298832.4395240383
Dragprov_1procent. 3.ani( 12- 200,tc)Rumstemp 23 deg. C0.10538270970.08056782080.23207835960.17742993851.79168196752.6588483352.05306347030 (No corr.)0.33006572620.05998533730.00091250942.4396604686
Average0.10610.08110.2300.176
Stdev0.00070.00050.0020.002
Stdev %0.60.60.90.9
Dragprov_2p5procent. 3. 1.ani( 17- 200,tc)Rumstemp 23 deg. C0.09324416070.06475288940.30342819120.21071402171.60623723812.89752260081.80809214650 (No corr.)0.39198275750.05979339940.00101941492.438608362
Dragprov_2p5procent. 3. 2.ani( 12- 200,tc)Rumstemp 23 deg. C0.09404777620.06531095570.30220465070.20986434081.61314398682.89167473071.98973895020 (No corr.)0.39040213060.06888370750.00101089392.4393531958
Dragprov_2p5procent. 3. 3.ani( 13- 200,tc)Rumstemp 23 deg. C0.09450999090.06563193810.30093476990.20898247911.6171031712.88559284541.94656121280 (No corr.)0.38876163910.07376207880.00079178132.4392357993
Average0.09390.06520.3020.2099
Stdev0.00060.00040.0010.0009
Stdev %0.70.70.40.4
Dragprov_5procent. 1.ani( 10- 200,tc)Rumstemp 23 deg. C0.1045385730.0724955430.34973895670.2425374181.69955712943.10863325781.86091427340 (No corr.)0.45118253230.0498447190.00100174862.4372097143
Dragprov_5procent. 2.ani( 10- 200,tc)Rumstemp 23 deg. C0.10415165130.072227220.3506127290.24314336271.69640898463.11251407131.8625816620 (No corr.)0.45230974680.05003665690.00086337312.4375126291
Dragprov_5procent. 3.ani( 12- 200,tc)Rumstemp 23 deg. C0.10430119130.07233092330.35027457560.24290885961.69762639233.1110127551.78420769760 (No corr.)0.45187351020.0498447190.00085680182.4377487672
Average0.10430.07240.35020.2429
Stdev0.00020.00010.00040.0003
Stdev %0.20.20.10.1
Outp.power.Meas.timeSp.heat SampleRadius
Dragprov_1procent. 1.ani0.02101.3082.001
Dragprov_1procent. 2.ani0.02101.3082.001
Dragprov_1procent. 3.ani0.02101.3082.001
Dragprov_2p5procent. 3. 1.ani0.02101.442.001
Dragprov_2p5procent. 3. 2.ani0.02101.442.001
Dragprov_2p5procent. 3. 3.ani0.02101.442.001
Dragprov_5procent. 1.ani0.02101.4422.001
Dragprov_5procent. 2.ani0.02101.4422.001
Dragprov_5procent. 3.ani0.02101.4422.001
laxial [W/mK]kaxial [mm2/s]lradial [W/mK]kradial [mm2/s]Cp [MJ/m3K]
1Sample 1%Average0.10610.08110.2300.1761.308
2.5Sample 2.5%Average0.09390.06520.3020.20991.44
5Sample 5%Average0.10430.07240.35020.24291.442
&A
Page &P
Results
0000
0000
0000
laxial [W/mK]
kaxial [mm2/s]
lradial [W/mK]
kradial [mm2/s]
% Fiber
l [W/mK] k[mm2/s]
Parameters
Parameters :Dragprov5%Number of Rows:9
File:TemperatureOutp.power.Meas.timeSp.heat SampleRadiusTCRDisk TypeTemp.drift rec.
Dragprov_1procent. 1.aniRumstemp 23 deg. C0.02101.3082.0010.004693KaptonYes
Dragprov_1procent. 2.aniRumstemp 23 deg. C0.02101.3082.0010.004693KaptonYes
Dragprov_1procent. 3.aniRumstemp 23 deg. C0.02101.3082.0010.004693KaptonYes
Dragprov_2p5procent. 3. 1.aniRumstemp 23 deg. C0.02101.442.0010.004693KaptonYes
Dragprov_2p5procent. 3. 2.aniRumstemp 23 deg. C0.02101.442.0010.004693KaptonYes
Dragprov_2p5procent. 3. 3.aniRumstemp 23 deg. C0.02101.442.0010.004693KaptonYes
Dragprov_5procent. 1.aniRumstemp 23 deg. C0.02101.4422.0010.004693KaptonYes
Dragprov_5procent. 2.aniRumstemp 23 deg. C0.02101.4422.0010.004693KaptonYes
Dragprov_5procent. 3.aniRumstemp 23 deg. C0.02101.4422.0010.004693KaptonYes
&A
Page &P
T-t
Temperature-time graph :Number of Columns:0
Point nr.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
&A
Page &P
T(drift)
Temperature drift graph :Number of Columns:0
Point nr.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
&A
Page &P
T-f(Tau)
Temperature-f(Tau) graph :Number of Columns:0
Point nr.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
&A
Page &P
Diff
Difference graph :Number of Columns:0
Point nr.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
&A
Page &P
Single sided methodIf you do not want to cut your precious sampleput the sensor on the surface..and back it up with a known sample. Tell the software the properties of the known, and run the analysis as before.In principal, the more similar, the better
In Transient Methods, like Hot Disk, the contact resistance does not cause any problem.
This is not the case with Steady State Methods, wherethis is a limitation for the use.
The following slides explains how Contact resistanceis dealt with, and gives an illustrative example.
Ideally, the sensor is surrounded by infinite sample in all direction. Contact areaTemp CTime sCut off here!
Ideally, the sensor is surrounded by infinite sample in all direction.
If this should occur, the later part of the raw data are removedCut off here!Temp CTime s
Measuring coated and uncoated ceramicsVaristors made of ZnO ceramicsuncoated surfacesurface coated by Al-metal, 60m thickMeasuring with same conditions sensor, time, power,temperature
It seems like the Al-metal coating was insulating?A metal like Al ?In this case the sprayed metal was very porous. The conductivity was about 0.5 W/mK60m of porous metal added to the kapton coating increases the temperture about 4 times!
Some resultsGreen Metal Coated W/mK std % W/mk std% 23 C 24.70 (0.2) 24.69 (0.8) 300 C 12.67 (2.2) 13.36 (0.8) Sensor radius 6.675 mmSensor radius 14.65 mm23 C 24.71 (0.8) 24.88 (1.0) 300 C 12.19 (1.3) 13.08 (0.4) Mica sensorKapton sensorMica sensorMica sensor
Constant T after initial period
Thin film making use of contact resistance
Temp. vs time without sample
Temp. vs time with sample
Temp
Time
Measuring liquids-vertical sensor-low power-short timeto avoid convectionPut it in a heating/cooling bath, and run at different temperatures- liquids with a viscosity as low as water and methanol can be measured
Sheet1
-350.3007
-200.33110.2515
00.37230.5379
00.5271
250.6191
250.6366
400.44310.711
800.51880.90440.3127
1000.3605
Sheet1
Mix Gly/Water
Water
Pure Glycol
Temp C
W/mK
Conductivity
Sheet2
-350.11442.6208
-200.10982.2910.12322.6894
00.13092.8490.15123.5572
00.14553.64
250.16743.7058
250.17953.5487
400.13763.2220.20653.445
800.08933.5040.14993.46940.27983.2392
1000.11243.207
Sheet2
000
000
000
000
000
000
000
000
000
Glycol
Mixture
Water
Temp C
mm2/s
Diffusivity
Sheet3
Sheet3
-352.6208-35
2.2912.6894-20
02.8493.5572
003.64
25253.7058
25253.5487
403.2223.445
3.5043.46943.2392
3.207100100
Cp Glycol
Cp Mixture
Cp Water
Temp C
MJ/m3K
Heat Capacity
Pure water:
Temperature Time Conductivity std Diffusivity std Heat Capacity std C s W/mK % mm2/s % MJ/m3K % 0 5 0.538 0.4 0.151 1.7 3.56 1.3 0 2.5 0.530 0.8 0.146 1.9 3.64 1 25 see A 2.5 0.619 2.4 0.167 6.5 3.71 3.9 25 see B 2.5 0.637 1.5 0.180 3. 7 3.55 2.3 40 2.5 0.711 0.7 0.207 1.6 3.45 0.9 80 1 0.904 2.9 0.280 6.8 3.24 4.1
Measuring at high temperaturesSampleMuffle furnace from RTto 700 CMica cladded sensor
How accurate is Hot Disk ?An article by professor Torbjorn Log*compares results from 5 different materials, measured with different techniques, with Hot Disk measurements.*T.Log, S.E.Gustafsson, Transient Plane Source (TPS) Technique for Measuring Thermal Transport Properties of Building Materials, Fire and Materials 19, 43-49 (1995)
Layer Thickness : The thickness of the copper layers and intermediate insulating glass epoxy layers is specified in Table 1 using millimeters (mm).
Table 1 Cross sectional details of the Test PCB #4's construction.
PCB #
Thickness of each Copper
Layer (micrometers)
Representation of Construction
(Red=Copper and Black = FR-4)
Thickness of each FR-4
Layer (millimeters)
PCB #4
4-Layer
Outer Signal Layer - 70 (m
Top Plane Layer - 35 (m
Bottom Plane Lyr - 35 (m
Outer Signal Layer - 70 (m
0,30 mm (2 Prepreg Layers)
0,22 mm (core)
0,30 mm (2 Prepreg Layers)
0,40 mm (core)
0,30 mm (2 Prepreg Layers)
Notes: the Core and Prepreg layers are both considerd to have the same thermal conductivity values as FR-4.
ITHERM 2000: Seventh Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems,
May 23-26, 2000, Las Vegas, NE, USA.
Using Experimental Analysis to Evaluate the Influence of Printed Circuit Board
Construction on the Thermal Performance of Four Package Types
in both Natural and Forced Convection
John Lohan1, Pekka Tiilikka2, Peter Rodgers3, Carl-Magnus Fager2, Jukka Rantala2
1 Mechanical & Industrial Engineering Department, Galway-Mayo Institute of Technology, Galway, Ireland
2 Nokia Research Center, P.O. Box 407, FIN-00045 NOKIA GROUP, Finland
3 Mechanical & Aeronautical Engineering Department, University of Limerick, Limerick, Ireland
john.lohan@merlin.gmit.ie
ITHERM 2000: Seventh Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems,
May 23-26, 2000, Las Vegas, NE, USA.
Using Experimental Analysis to Evaluate the Influence of Printed Circuit Board Construction on the Thermal Performance of Four Package Typesin both Natural and Forced Convection
John Lohan1, Pekka Tiilikka2, Peter Rodgers3, Carl-Magnus Fager2, Jukka Rantala2
1 Mechanical & Industrial Engineering Department, Galway-Mayo Institute of Technology, Galway, Ireland
2 Nokia Research Center, P.O. Box 407, FIN-00045 NOKIA GROUP, Finland
3 Mechanical & Aeronautical Engineering Department, University of Limerick, Limerick, Ireland
john.lohan@merlin.gmit.ie
These are the samples..with properties found with different techniques.Almost 4 orders of magnitude
Results for diffusivity. Small deviations but who is right?
Results on Conductivity almost perfect agreement
Measuring on a NIST StandardExtruded Polystyrene, cert. No 1453Values given for a range of density and temperatures for a thickness of 13.4mmDensity from 38 kg/m3 to 46 kg/m3at 295 K, the given Thermal Resistance (m2K/W),converted to Thermal Conductivity by using the thicknessgives a range 0.0328-0.0338 W/mK
13.4 mm100 mmDensity 43.8 kg/m3
40.4 kg/m34 possible combinations to place the sensorSide combinations Results (W/mK) Std % 1-2 0.03394 0.12 2-1 0.03379 0.042-2 0.03451 0.081-1 0.03346 0.23
So.what Hot Disk can do in Evitherm..
measure most materials from 0.005 to 500 W/mK..
develop new applications
provide consultancy, measurements and equipment,
as well as training, courses, seminarsIn Uppsala development electronics, manufacturing, applications, testingservice
In Gteborg development sensors/software applications, testing
Thats all folks !
Thank you for your attention.
Metal insertVacuum feed throughSample holder and sensor
Outer lid with vacuum connection, gas valves, pressure valveand cables
Recommended