Products
In molecular physics, the van der Waals forces, named after Dutch scientist Johannes Diderik van der Waals, are distance-dependent interactions between atoms or molecules. Unlike ionic or covalent bonds, these attractions are not a result of any chemical electronic bond, and they are comparatively weak and more susceptible to being perturbed. Van der Waals forces quickly vanish at longer distances between interacting molecules.
Van der Waals forces play a fundamental role in fields as diverse as supramolecular chemistry, structural biology, polymer science, nanotechnology, surface science, and condensed matter physics. Van der Waals forces also define many properties of organic compounds and molecular solids, including their solubility in polar and non-polar media.
If no other forces are present, the point at which the force becomes repulsive rather than attractive as two atoms near one another is called the van der Waals contact distance. This results from the electron clouds of two atoms unfavorably coming into contact. It can be shown that van der Waals forces are of the same origin as that of the Casimir effect, arising from quantum interactions with the zero-point field. The resulting van der Waals forces can be attractive or repulsive.
The term "Van der Waals forces" is also sometimes used loosely as a synonym for the totality of intermolecular forces. The term always includes the force between instantaneously induced dipoles (London dispersion force), sometimes includes the force between a permanent dipole and a corresponding induced dipole (Debye force), and – less frequently – includes the force between permanent dipoles (Keesom force).
Contents.
Performance | Requested Specification | Solution |
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Clean room moving device |
300mm Prime Wafer (Polished Back side), THK 775 um, Weight 129g |
Tested by standard specification of pad (1mmm THK x 10mm D) (Depends on the handling products) |
Wafer Holding performance | Acceleration of horizontality : Tested till10,000mm/sec (No Miss alignment) |
Horizontal adhesion force(Friction): 1.3N/cm2 (1Point) 5.3 N/cm2 (3Point) (It’s available to control the holding performance) |
Placement | Vertical speed: Placed at 500 mm/sec (No Miss alignment) | Vertical adhesion force :1.7N=< (It’s available to control the holding performance) |
Responsibility |
Keep the pad’s performance above 99% after 150,000 cycle (200 cycle/hr)*(24 hr)*(365 days) |
On the marathon test at actual moving environment. |
Contamination |
Particle free (None particle material source), Cleaning SOP when the particle incoming. |
Simple cleaning method (IPA or N2 Blower), Anti-chemical (Ex: IPA, Acetone etc..: up to 48hrs soaked test) |
Using environment | Clean room class <1000 , ~250˚C | Tested on high temp(270℃) up to 5hrs. |
Standard | Changeable spec. | |
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Thickness | 1.0 mm THK | 0.2mm ~ 5.0mm < |
Diameter | 10mm Ø | 3mm Ø ~35mmØ (Available to change the shape into Square) |
Holding performance |
Horizontal Adhesion force: 1.3 N/㎡ (Per pad) Vertical adhesion force: 1.7 N/㎡ (Per pad) |
0.8 N/㎡ ~6.5N/㎡ (Horizontal) (Available to handle the 300mm Wafer to 90 to 180 degree) |
Using PAD’s Q’ty | 3 Pads on the EFEM (Based on 300mm wafer) |
Depends on customer requirement (Mixable to use with Vacuum device) |
Installation of the PADs | Molded on the EFEM | Screw (Installed the nuts in pad) or Adhesive tape (for clean room) |
Warranty | 1 year guaranty (Free charge to change If it damaged within 1 year) |
Weakness of current PAD | Strong point of GN-PAD |
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Urethane PAD (Composited Rubber) : Weak for high temp, chemical and Slipping issue during transportation of product |
100% clear the slipping issue and strong for high temp, chemical issue |
PEEK PAD (Super engineering plastic) : Slipping issue occurs and make some scratch during transportation of product when slipped |
100% clear the slipping issue and no scratch issue |
Vacuum PAD (High vacuum PAD) : Residue issue on surface of product(holding Mark) (Maintaining cost for utility and replacement) |
No residue issue on surface of product. (No maintaining cost during warranty) |
Viton (Composited rubber for anti chemical ) : Weak for high temp and residue issue |
Anti-chemical and high temp with no residue(Vacuum Chamber 300℃, 260℃ in stand-by) |
FKEM (Composited Fluor rubber) : Weak for high-temp and residue issue |
Strong for chemical and high temp, No out-gassing issue |
EFEM of Pocket design(Re-designed EFEM for current issues which are happened on current pad) :Chipping issue of product and low speed of robot |
No chipping and broken issue and keep the high speed of the robot |
EFEM of Gripper design (Re-designed EFEM for current issue and added device: Electronic solenoid) : Chipping and Broken issue. |
No chinpping and broken issue |
Weakness of current PAD |
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Urethane PAD (Composited Rubber) : Weak for high temp, chemical and Slipping issue during transportation of product |
PEEK PAD (Super engineering plastic) : Slipping issue occurs and make some scratch during transportation of product when slipped |
Vacuum PAD (High vacuum PAD) : Residue issue on surface of product(holding Mark) (Maintaining cost for utility and replacement) |
Viton (Composited rubber for anti chemical ) : Weak for high temp and residue issue |
FKEM (Composited Fluor rubber) : Weak for high-temp and residue issue |
EFEM of Pocket design(Re-designed EFEM for current issues which are happened on current pad) :Chipping issue of product and low speed of robot |
EFEM of Gripper design (Re-designed EFEM for current issue and added device: Electronic solenoid) : Chipping and Broken issue. |
Strong point of GN-PAD |
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100% clear the slipping issue and strong for high temp, chemical issue |
100% clear the slipping issue and no scratch issue |
No residue issue on surface of product. (No maintaining cost during warranty) |
Anti-chemical and high temp with no residue(Vacuum Chamber 300℃, 260℃ in stand-by) |
Strong for chemical and high temp, No out-gassing issue |
No chipping and broken issue and keep the high speed of the robot |
No chinpping and broken issue |
Present device |
Cost Save |
GN-PAD |
---|---|---|
Cost for Utility : Vacuum pump, supplying utilities |
No Utility cost | |
Cost for individual device (Purchase, installation) : Vacuum ejector, Solenoid and etc.. |
No device cost | |
Cost for maintenance : Labor cost for maintenance |
No maintenance coast during warranty |
Present device |
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Cost for Utility : Vacuum pump, supplying utilities |
Cost for individual device (Purchase, installation) : Vacuum ejector, Solenoid and etc.. |
Cost for maintenance : Labor cost for maintenance |
Cost Save |
GN-PAD |
No Utility cost |
No device cost |
No maintenance coast during warranty |
Improvement of Process |
Improvement of Process |
GN-PAD |
---|---|---|
Decrease the thru-put of transportation by current issues | Increase the thru-put of transportation (max speed) by cleared current issues | |
Decrease the thur-put and capability by additional cleaning process for residue | No additional cleaning process by residue. | |
Low capability by alignment issue of product | Improve the capability of production by clear the alignment of product |
Improvement of Process |
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Decrease the thru-put of transportation by current issues |
Decrease the thur-put and capability by additional cleaning process for residue |
Low capability by alignment issue of product |
Improvement of Process |
GN-PAD |
Increase the thru-put of transportation (max speed) by cleared current issues |
No additional cleaning process by residue. |
Improve the capability of production by clear the alignment of product |
Comparison Table for GN PAD and Others | ||||||
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Issues (symptom) | Products | O-rings | Edge Grip | Urethan PAD | Vcc PAD | GN-PAD |
#1 Slip Issue | Semiconductor(4' ~12'), FPD, Glass, OLED | O | X | O | X | X |
#2 Brocken Issue | Semiconductor(4' ~12'), FPD, Glass, OLED | X | O | X | X | X |
#3 Holding Marks | Semiconductor(4' ~12'), FPD, Glass, OLED | O | X | O | O | X |
#4 Maintenance Issue | Semiconductor(4' ~12'), FPD, Glass, OLED | X | X | X | O | X |
#5 Replacement Issue | Semiconductor(4' ~12'), FPD, Glass, OLED | O | X | O | O | X |
#6 Installation Issue | Semiconductor(4' ~12'), FPD, Glass, OLED | X | X | X | O | X |
#7 Cleaning Issue | Semiconductor(4' ~12'), FPD, Glass, OLED | O | X | O | O | X |