| Photoimageable
Polyimide Resins
------Three series of photoimageable
polyimides are available. ZKPI-510 series are standard polyimides,
which could be photo-patterned by wet or dry etching pathways
aided by using negative resist. ZKPI-520 series are ester-based
photosensitive polyimides with negative mode and ZKPI-530 series
are inherent negative photosensitive polyimide resins.
------The photoimageable polyimide
resins have merits of easy processing, excellent thermal and thermo-oxidative
stability, high mechanical performance, excellent electrical insulating
and dielectric properties, and good adhesion to common electronic
devices and circuit substrates with superior moisture resistance
and other atmosphere contaminates.
Advantageous Features
1. Easy processing
2. High purity, low impurity: Na+ <
1 ppm, K+ < 1ppm, Cl-
< 1 ppm
3. Good adhesion to substrates such as Si, GaAS, SiO2,
Si2N3, Cu,
Al, Ni,···
4. Excellent thermal and thermo-oxidative stability with thermal
decomposition temperature of 450 ℃,
5. Excellent chemical stability. Resistant to the attack of
almost of organic solvents
6. Shields against a-particle
radiation and is free of a-particle
generator
7. Low stress to the chip and bonding wires
8. Better planarization than inorganic dielectrics such as SiO2
and Si3N4.
Typical Applications:
1. Primary and Secondary Passivation Layers
2. Stress buffer coatings and protect layers
3. a-particle
Barriers
4. Interlayer dielectrics of multiplayer structure and MCM-D,
BGA and CSP
5. Liquid crystal Alignment layers for TN-LCD, STN-LCD and TFT-LCD
Typical Photo-pattern process:
The basic photo patterns process include 6 steps(Figure
1):
1. Spin coating of the photo-imageable polyimide resins on
wafer
2. Prebaking using hot plates or a convection oven at 120-150
℃
3. Masking and Exposuring with standard I or G line lithograpghy
with negative tone photo mask.
4. Develop and rinse
5. Remove the mask
6. Final curing the polyimide layers
Table 1 Properties of ZKPI Photoimageable
Polyimide Resins
| Property\Products |
ZKPI-510 |
ZKPI-520 |
ZKPI-530 |
| Appearance |
Pale-yellow Liquid |
Pale-yellow Liquid |
Pale-yellow Liquid |
| Solid, w/w % |
12-15 |
15-25 |
15-25 |
| Absolutely viscosity at 25 ℃, mPa.s |
500-2000 |
3000-5000 |
3000-5000 |
| InherentViscosity, 35 ℃, |
0.8-1.1 |
0.9-1.2 |
1.0-1.2 |
| Solvents |
Hydrocarbons |
Hydrocarbons |
Hydrocarbons |
| Density, 25 ℃ |
1.01-1.04 |
1.01-1.04 |
1.01-1.04 |
| Photosensitivity, mJ/cm2 |
-- |
150-250 |
100-250 |
| Cured Temperature, ℃ |
250-300 |
250-300 |
180-200 |
| Film Thickness Shrinkage |
<25% |
<50% |
<50% |
Stability:
25℃
4℃ |
>6 weeks
>12 months |
> 6weeks
> 3months |
> 6weeks
> 6 months |
Impurity: Na+
K+
Fe
Cl-
Cu |
< 1.0 ppm
< 1.0 ppm
< 1.0 ppm
<
1.0ppm
< 1.0 ppm |
< 1.0 ppm
< 1.0 ppm
< 1.0 ppm
<
1.0ppm
< 1.0 ppm |
< 1.0 ppm
< 1.0 ppm
< 1.0 ppm
<
1.0ppm
< 1.0 ppm |
* Solid content and viscosity of the coatings could be depended
on custom requirements
Table 2 Properties of the Cured PI Coating
Films
| Features\Products |
ZKPI-510 |
ZKPI-520 |
ZKPI-530 |
| Mechanical Property |
|
|
|
Tensile strength, MPa
Elongation, %
Density, g/cm3
Moisture uptake, %
Hardness |
80-100
10-25
1.10-1.12
<0.50
H |
90-120
10-25
1.10-1.12
<0.40
H |
90-120
10-25
1.10-1.12
<0.40
H |
| Thermal Property |
|
|
|
Tg , ℃
Tin, ℃
T5, ℃
T10, ℃
CTE, .10 -6/ ℃ |
230
>400
>450
>500
42-44 |
243
>450
>490
>530
38-40 |
243
>450
>490
>530
38-40 |
| Electric Property |
|
|
|
Dielectric Constant1 MHz; 0-50% RH
Dissipation factor1 MHz; 0-50% RH
Dielectric strength, V/µmR.T.; 0-50% RH
Volume resistivity, W.cm
Surface resistivity, W |
3.0-3.2
2-6 x 10-3
250-350
>1016
>1015 |
3.0-3.2
2-6 x 10-3
250-350
>1016
>1015 |
3.0-3.2
2-6 x 10-3
250-350
>1016
>1015 |
|
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