|
Typical technical
information and properties of polyimide used in flexible printed circuitry
Property
|
Polyimide (Acrylic)
|
Polyimide (Adhesiveless)
|
Thickness
(mil)
|
½,1,2,3,5
|
1,2,3,5,6
|
Tensile
strength (Kg/mm²)
|
25.2
|
50
|
Elongation
(%)
|
85
|
50
|
Tensile
Modulus, PSI
|
430,000
|
70,000
|
Flammability
|
94VTM-0
|
94VTM-0
|
Moisture
Absorption, %
|
3.0
|
.8
|
Dielectric
Strength, V/mil
|
3800
|
6000
|
Dielectric
Constant
|
3.4
|
3.4
|
Dissipation
Factor
|
0.01
|
.003
|
Solder
ability
|
Pass
|
Pass
|
Chemical
Etching
|
Possible
|
Possible
|
Service
Temperature (min. /max.)°C
|
-200/+300
|
-200/+350
|
Operating Temperature |
150°C |
150°C |
|
GENERAL GUIDELINES FOR
CIRCUIT FEATURE SIZES AND TOLERANCES
Design Feature
|
Standard Product
|
Reduced Producibility
|
Normal Tolerance
|
Minimum Tolerance
|
Hole
size
|
0.020”(0.5mm)
|
< 0.020”(0.5mm)
|
± 0.003”(0.075mm)
|
± 0.001”(0.025mm)
|
Trace
width
|
0.010”(0.25mm)
|
< 0.010”(0.25mm)
|
± 0.002”(0.050mm)
|
± 0.001”(0.025mm)
|
Space
width
|
0.005”(0.125mm)
|
0.005”(0.125mm)
|
± 0.002”(0.050mm)
|
± 0.001”(0.025mm)
|
Trace
to edge of part
|
|
|
|
|
Steel
rule tool
|
0.020”(0.5mm)
|
< 0.010”(0.25mm)
|
± 0.010”(0.25mm)
|
± 0.005”(0.125mm)
|
Class
A die
|
0.005”(0.125mm)
|
< 0.002”(0.050mm)
|
± 0.005”(0.125mm)
|
± 0.002”(0.050mm)
|
|
|
|
|
|
Feature to Feature Location
(relative true position)
|
12.0”(≤ 300mm)
|
≤ 18.0” (≤ 450mm)
|
≤ 24.0” (≤ 600mm)
|
Preferred
(per MIL-STD-2118)
|
0.028 (.07mm)
|
0.034 (.85mm)
|
---*
|
Level
A (per IPC-D-249)
|
0.034 (.085mm)
|
0.040 (1.0mm)
|
0.046 (1.15mm)
|
Standard
(per MIL-STD-2118)
|
0.020 (.05mm)
|
0.024 (.60mm)
|
---*
|
Level
B (per IPC-D-249)
|
0.022 (.055mm)
|
0.024 (.60mm)
|
0.034 (0.85mm)
|
Reduced
Producibility (per MIL-STD-2118)
|
0.012 (.030mm)
|
0.016 (.40mm)
|
---*
|
Level
C (per IPC-D-249)
|
0.012 (.030mm)
|
0.018 (.45mm)
|
0.022 (0.55mm)
|
|
|
|
|
*Mil-Std-2118 offers the following
statement regarding tolerances: “Drawing tolerances must reflect bend and fold
allowances between component mounting rigid areas.”
Conductor Width
|
Maximum Current for 10°C rise
1 oz. copper
|
Conductor Resistance milliohms/ft
1 oz. copper
|
Maximum Current for 10°C rise
2 oz. copper
|
Conductor Resistance milliohms/ft
2 oz. copper
|
0.005
|
.25
|
1280
|
NA
|
NA
|
0.010
|
.6
|
640
|
1.0
|
320
|
0.015
|
1.1
|
400
|
1.8
|
200
|
0.020
|
1.3
|
320
|
20.
|
160
|
0.025
|
1.5
|
250
|
2.5
|
125
|
0.030
|
1.8
|
200
|
2.9
|
100
|
0.050
|
2.5
|
120
|
4.0
|
60
|
0.070
|
3.2
|
90
|
5.0
|
45
|
0.100
|
4.0
|
60
|
6.9
|
30
|
0.150
|
5.9
|
40
|
9.8
|
20
|
0.200
|
6.9
|
30
|
12.0
|
15
|
0.250
|
8.6
|
25
|
13.5
|
12.5
|
|
|
|
|
|
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