Datasheet

8
Introduction
Design
Guide
Polyimide
Heaters
Silicone
Rubber
Heaters (foil)
Standard
Polyimide
& Rubber
Rubber
Heaters
(wire-wound)
Mica Heaters
Thermal-Clear
Heaters
All-Polyimide
Heaters
Sensors,
Controllers &
Accessories
Reference
|
Flexible Heaters Design Guide | www.minco.com
Maximum Watt Density
The watt density tables on this page show the maximum allow-
able power for each heater type, expressed in watts per square
inch, or centimeter, of effective area. The rating depends upon
the heater’s insulation/internal adhesive, heat sink control tem-
perature, and the mounting method.
If watt density exceeds the maximum rating, the heater is in
danger of overheating and premature failure. To obtain more
power:
• Select a larger size heater
• Consider other heater materials, e.g. mica
• Change the mounting method
• Use proportional control to reduce power as the heat sink
temperature rises
• Contact Minco for product and design assistance
In addition to wattage, you should calculate the current (I)
through the heater leadwires to keep it within the maximum
rating for the AWG wire size used.
Using watt density charts
1. Look up the effective area for the heater model in question.
This is total heater area minus borders and lead attachment
space (calculated by Minco).
2. Divide the power requirement in watts by this area to obtain
watt density.
3. Draw a line from the heat sink temperature (at the bottom of
the chart) to the line labeled with the mounting method
and/or insulation you have chosen.
4. The maximum watt density is indicated by the value on the
left or right axis that corresponds with that intersection.
0
10
20
30
40
50
60
-25°C 0°C 25°C 50°C 75°C 100°C 125°C 150°C 175°C 200°C 225°C
Maximum Allowable Power:
Watts/square inch of effective area
0.00
3.10
6.20
9.30
-13°F 32°F 77°F 122°F 167°F 212°F 257°F 302°F 347°F 392°F 437°F
Watts/square cm
Acrylic PSA
#15 Epoxy
12 PSA w/
Aluminum
Acrylic
PSA w/
Aluminum
BM3 Shrink Band
Stretch tape or
Clamped
MOUNTING METHOD
HEATER:
0.002” POLYIMIDE (0.05mm)
0.001” ADHESIVE (0.03mm)
0
5
10
15
20
25
30
35
40
45
50
55
60
65
-100°C -50°C 0°C 50°C 100°C 150°C 200°C 250°C
Heat Sink Temperature
Maximum allowable power:
Watts/square inch of effective area
0.0
0.8
1.6
2.3
3.1
3.9
4.7
5.4
6.2
7.0
7.8
8.5
9.3
10.1
-148°F -58°F 32°F 122°F 212°F 302°F 392°F 482°F
Watts/square cm
#6 RTV
#12 PSA
#20 Stretch
Tape
Vulcanized
MOUNTING METHOD
HEATER:
0.008” SILICONE RUBBER (0.2mm)
0
10
20
30
40
50
60
70
80
90
100
110
120
-200°C
-100°C 0°C 100°C 200°C 300°C 400°C 500°C 600°C
Maximum allowable power:
Watts/square inch of effective area
0.0
1.6
3.1
4.7
6.2
7.8
9.3
10.9
12.4
14.0
15.5
17.1
18.6
-328°F -148°F 32°F 212°F 392°F 572°F 752°F 932°F 1112°F
Watts/square cm
0.020“ (0.5mm) Mica
0.010” (0.3mm) Mica
MOUNTING METHOD:
Clamped
HEATER:
0
5
10
15
20
25
-60°C -30°C 0°C 30°C 60°C 90°C 120°C 150°C
Maximum allowable power:
Watts/square inch of effective area
0.00
0.78
1.55
2.33
3.10
3.88
-76°F -22°F 32°F 86°F 140°F 194°F 248°F 302°F
Watts/square cm
MOUNTING METHOD:
Acrylic PSA
HEATER:
0.002” POLYESTER (0.05mm)
0.002” ADHESIVE (0.05 mm)
Silicone Rubber Heaters (foil)
Note: Find the silicone rubber heaters (wire-wound)
watt density chart on page 32
Mica Heaters
Note: Find the All-Polyimide heaters watt density chart on page 41
Polyimide/FEP Heaters
Thermal-Clear
™ Polyimide Heaters