| 3704806 | DEHUMIDIFYING COMPOSITION AND A METHOD FOR PREPARING THE SAME | December, 1972 | Plachenov et al. | 206/204 |
| 3813265 | May, 1974 | Marks | ||
| 3900440 | Adhesive composition | August, 1975 | Ohara et al. | 523/410 |
| 3955880 | Infrared radiation modulator | May, 1976 | Lierke | |
| 4036360 | Package having dessicant composition | July, 1977 | Deffeyes | 206/204 |
| 4074480 | Kit for converting single-glazed window to double-glazed window | February, 1978 | Burton | 52/127.1 |
| 4099854 | Optical notch filter utilizing electric dipole resonance absorption | July, 1978 | Decker et al. | |
| 4228437 | Wideband polarization-transforming electromagnetic mirror | October, 1980 | Shelton | |
| 4377324 | Graded index Fabry-Perot optical filter device | March, 1983 | Durand et al. | |
| 4389096 | Image display apparatus of liquid crystal valve projection type | June, 1983 | Hori et al. | |
| 4403248 | Display device with deformable reflective medium | September, 1983 | Te Velde | |
| 4431691 | Dimensionally stable sealant and spacer strip and composite structures comprising the same | February, 1984 | Greenlee | 428/34 |
| 4441791 | Deformable mirror light modulator | April, 1984 | Hornbeck | |
| 4445050 | Device for conversion of light power to electric power | April, 1984 | Marks | |
| 4482213 | Perimeter seal reinforcement holes for plastic LCDs | November, 1984 | Piliavin et al. | |
| 4500171 | Process for plastic LCD fill hole sealing | February, 1985 | Penz et al. | |
| 4519676 | Passive display device | May, 1985 | te Velde | |
| 4531126 | Method and device for analyzing a very high frequency radiation beam of electromagnetic waves | July, 1985 | Sadones | |
| 4552806 | Cellular glass coated with a heat insulator | November, 1985 | Hayashi et al. | 428/312.6 |
| 4566935 | Spatial light modulator and method | January, 1986 | Hornbeck | |
| 4571603 | Deformable mirror electrostatic printer | February, 1986 | Hornbeck et al. | |
| 4596992 | Linear spatial light modulator and printer | June, 1986 | Hornbeck | |
| 4615595 | Frame addressed spatial light modulator | October, 1986 | Hornbeck | |
| 4662746 | Spatial light modulator and method | May, 1987 | Hornbeck | |
| 4663083 | Electro-optical dipole suspension with reflective-absorptive-transmissive characteristics | May, 1987 | Marks | |
| 4681403 | Display device with micromechanical leaf spring switches | July, 1987 | te Velde et al. | |
| 4710732 | Spatial light modulator and method | December, 1987 | Hornbeck | |
| 4748366 | Novel uses of piezoelectric materials for creating optical effects | May, 1988 | Taylor | |
| 4786128 | Device for modulating and reflecting electromagnetic radiation employing electro-optic layer having a variable index of refraction | November, 1988 | Birnbach | |
| 4790635 | Electro-optical device | December, 1988 | Apsley | |
| 4856863 | Optical fiber interconnection network including spatial light modulator | August, 1989 | Sampsell et al. | |
| 4950344 | Method of manufacturing multiple-pane sealed glazing units | August, 1990 | Glover et al. | 156/109 |
| 4954789 | Spatial light modulator | September, 1990 | Sampsell | |
| 4956619 | Spatial light modulator | September, 1990 | Hornbeck | |
| 4977009 | Composite polymer/desiccant coatings for IC encapsulation | December, 1990 | Anderson et al. | 428/76 |
| 4982184 | Electrocrystallochromic display and element | January, 1991 | Kirkwood | |
| 5018256 | Architecture and process for integrating DMD with control circuit substrates | May, 1991 | Hornbeck | |
| 5018258 | Support system for a variable-crown roll | May, 1991 | Hornbeck | |
| 5022745 | Electrostatically deformable single crystal dielectrically coated mirror | June, 1991 | Zayhowski et al. | |
| 5028939 | Spatial light modulator system | July, 1991 | Hornbeck et al. | |
| 5037173 | Optical interconnection network | August, 1991 | Sampsell et al. | |
| 5044736 | Configurable optical filter or display | September, 1991 | Jaskie et al. | |
| 5061049 | Spatial light modulator and method | October, 1991 | Hornbeck | |
| 5075796 | Optical article for multicolor imaging | December, 1991 | Schildkraut et al. | |
| 5078479 | Light modulation device with matrix addressing | January, 1992 | Vuilleumier | |
| 5079544 | Standard independent digitized video system | January, 1992 | DeMond et al. | |
| 5083857 | Multi-level deformable mirror device | January, 1992 | Hornbeck | |
| 5095375 | Holographic combiner edge seal design and composition | March, 1992 | Bolt | 359/1 |
| 5096279 | Spatial light modulator and method | March, 1992 | Hornbeck et al. | |
| 5099353 | Architecture and process for integrating DMD with control circuit substrates | March, 1992 | Hornbeck | |
| 5124834 | Transferrable, self-supporting pellicle for elastomer light valve displays and method for making the same | June, 1992 | Cusano et al. | |
| 5142405 | Bistable DMD addressing circuit and method | August, 1992 | Hornbeck | |
| 5153771 | Coherent light modulation and detector | October, 1992 | Link et al. | |
| 5162787 | Apparatus and method for digitized video system utilizing a moving display surface | November, 1992 | Thompson et al. | |
| 5168406 | Color deformable mirror device and method for manufacture | December, 1992 | Nelson | |
| 5170156 | Multi-frequency two dimensional display system | December, 1992 | DeMond et al. | |
| 5172262 | Spatial light modulator and method | December, 1992 | Hornbeck | |
| 5179274 | Method for controlling operation of optical systems and devices | January, 1993 | Sampsell | |
| 5192395 | Method of making a digital flexure beam accelerometer | March, 1993 | Boysel et al. | |
| 5192946 | Digitized color video display system | March, 1993 | Thompson et al. | |
| 5206629 | Spatial light modulator and memory for digitized video display | April, 1993 | DeMond et al. | |
| 5212582 | Electrostatically controlled beam steering device and method | May, 1993 | Nelson | |
| 5214419 | Planarized true three dimensional display | May, 1993 | DeMond et al. | |
| 5214420 | Spatial light modulator projection system with random polarity light | May, 1993 | Thompson et al. | |
| 5216537 | Architecture and process for integrating DMD with control circuit substrates | June, 1993 | Hornbeck | |
| 5226099 | Digital micromirror shutter device | July, 1993 | Mignardi et al. | |
| 5231532 | Switchable resonant filter for optical radiation | July, 1993 | Magel et al. | |
| 5233385 | White light enhanced color field sequential projection | August, 1993 | Sampsell | |
| 5233456 | Resonant mirror and method of manufacture | August, 1993 | Nelson | |
| 5233459 | Electric display device | August, 1993 | Bozler et al. | |
| 5244707 | Enclosure for electronic devices | September, 1993 | Shores | 428/76 |
| 5254980 | DMD display system controller | October, 1993 | Hendrix et al. | |
| 5272473 | Reduced-speckle display system | December, 1993 | Thompson et al. | |
| 5278652 | DMD architecture and timing for use in a pulse width modulated display system | January, 1994 | Urbanus et al. | |
| 5280277 | Field updated deformable mirror device | January, 1994 | Hornbeck | |
| 5287096 | Variable luminosity display system | February, 1994 | Thompson et al. | |
| 5296950 | Optical signal free-space conversion board | March, 1994 | Lin et al. | |
| 5304419 | Moisture and particle getter for enclosures | April, 1994 | Shores | 428/355R |
| 5305640 | Digital flexure beam accelerometer | April, 1994 | Boysel et al. | |
| 5311360 | Method and apparatus for modulating a light beam | May, 1994 | Bloom et al. | |
| 5312513 | Methods of forming multiple phase light modulators | May, 1994 | Florence et al. | |
| 5323002 | Spatial light modulator based optical calibration system | June, 1994 | Sampsell et al. | |
| 5325116 | Device for writing to and reading from optical storage media | June, 1994 | Sampsell | |
| 5327286 | Real time optical correlation system | July, 1994 | Sampsell et al. | |
| 5331454 | Low reset voltage process for DMD | July, 1994 | Hornbeck | |
| 5339116 | DMD architecture and timing for use in a pulse-width modulated display system | August, 1994 | Urbanus et al. | |
| 5365283 | Color phase control for projection display using spatial light modulator | November, 1994 | Doherty et al. | |
| 5381253 | Chiral smectic liquid crystal optical modulators having variable retardation | January, 1995 | Sharp et al. | |
| 5401983 | Processes for lift-off of thin film materials or devices for fabricating three dimensional integrated circuits, optical detectors, and micromechanical devices | March, 1995 | Jokerst et al. | |
| 5411769 | Method of producing micromechanical devices | May, 1995 | Hornbeck | |
| 5444566 | Optimized electronic operation of digital micromirror devices | August, 1995 | Gale et al. | |
| 5446479 | Multi-dimensional array video processor system | August, 1995 | Thompson et al. | |
| 5448314 | Method and apparatus for sequential color imaging | September, 1995 | Heimbuch et al. | |
| 5452024 | DMD display system | September, 1995 | Sampsell | |
| 5454906 | Method of providing sacrificial spacer for micro-mechanical devices | October, 1995 | Baker et al. | |
| 5457493 | Digital micro-mirror based image simulation system | October, 1995 | Leddy et al. | |
| 5457566 | DMD scanner | October, 1995 | Sampsell et al. | |
| 5459602 | Micro-mechanical optical shutter | October, 1995 | Sampsell | |
| 5459610 | Deformable grating apparatus for modulating a light beam and including means for obviating stiction between grating elements and underlying substrate | October, 1995 | Bloom et al. | |
| 5461411 | Process and architecture for digital micromirror printer | October, 1995 | Florence et al. | |
| 5489952 | Method and device for multi-format television | February, 1996 | Gove et al. | |
| 5497172 | Pulse width modulation for spatial light modulator with split reset addressing | March, 1996 | Doherty et al. | |
| 5497197 | System and method for packaging data into video processor | March, 1996 | Gove et al. | |
| 5499062 | Multiplexed memory timing with block reset and secondary memory | March, 1996 | Urbanus | |
| 5500635 | Products incorporating piezoelectric material | March, 1996 | Mott | |
| 5500761 | Micromechanical modulator | March, 1996 | Goossen et al. | |
| 5506597 | Apparatus and method for image projection | April, 1996 | Thompson et al. | |
| 5515076 | Multi-dimensional array video processor system | May, 1996 | Thompson et al. | |
| 5517347 | Direct view deformable mirror device | May, 1996 | Sampsell | |
| 5523803 | DMD architecture and timing for use in a pulse-width modulated display system | June, 1996 | Urbanus et al. | |
| 5526051 | Digital television system | June, 1996 | Gove et al. | |
| 5526172 | Microminiature, monolithic, variable electrical signal processor and apparatus including same | June, 1996 | Kanack | |
| 5526688 | Digital flexure beam accelerometer and method | June, 1996 | Boysel et al. | |
| 5535047 | Active yoke hidden hinge digital micromirror device | July, 1996 | Hornbeck | |
| 5547823 | Photocatalyst composite and process for producing the same | August, 1996 | Murasawa et al. | 430/531 |
| 5548301 | Pixel control circuitry for spatial light modulator | August, 1996 | Kornher et al. | |
| 5550373 | Fabry-Perot micro filter-detector | August, 1996 | Cole et al. | |
| 5551293 | Micro-machined accelerometer array with shield plane | September, 1996 | Boysel et al. | |
| 5552924 | Micromechanical device having an improved beam | September, 1996 | Tregilgas | |
| 5553440 | Multi-sheet glazing unit and method of making same | September, 1996 | Bulger et al. | 52/786.13 |
| 5559358 | Opto-electro-mechanical device or filter, process for making, and sensors made therefrom | September, 1996 | Burns et al. | |
| 5563398 | Spatial light modulator scanning system | October, 1996 | Sampsell | |
| 5567334 | Method for creating a digital micromirror device using an aluminum hard mask | October, 1996 | Baker et al. | |
| 5570135 | Method and device for multi-format television | October, 1996 | Gove et al. | |
| 5579149 | Miniature network of light obturators | November, 1996 | Moret et al. | |
| 5581272 | Signal generator for controlling a spatial light modulator | December, 1996 | Conner et al. | |
| 5583688 | Multi-level digital micromirror device | December, 1996 | Hornbeck | |
| 5589852 | Apparatus and method for image projection with pixel intensity control | December, 1996 | Thompson et al. | |
| 5591379 | Moisture getting composition for hermetic microelectronic devices | January, 1997 | Shores | 252/194 |
| 5597736 | High-yield spatial light modulator with light blocking layer | January, 1997 | Sampsell | |
| 5600383 | Multi-level deformable mirror device with torsion hinges placed in a layer different from the torsion beam layer | February, 1997 | Hornbeck | |
| 5602671 | Low surface energy passivation layer for micromechanical devices | February, 1997 | Hornbeck | |
| 5606441 | Multiple phase light modulation using binary addressing | February, 1997 | Florence et al. | |
| 5608468 | Method and device for multi-format television | March, 1997 | Gove et al. | |
| 5610438 | Micro-mechanical device with non-evaporable getter | March, 1997 | Wallace et al. | |
| 5610624 | Spatial light modulator with reduced possibility of an on state defect | March, 1997 | Bhuva | |
| 5610625 | Monolithic spatial light modulator and memory package | March, 1997 | Sampsell | |
| 5619059 | Color deformable mirror device having optical thin film interference color coatings | April, 1997 | Li et al. | |
| 5619365 | Elecronically tunable optical periodic surface filters with an alterable resonant frequency | April, 1997 | Rhoades et al. | |
| 5619366 | Controllable surface filter | April, 1997 | Rhoades et al. | |
| 5636052 | Direct view display based on a micromechanical modulation | June, 1997 | Arney et al. | |
| 5646768 | Support posts for micro-mechanical devices | July, 1997 | Kaeiyama | |
| 5650881 | Support post architecture for micromechanical devices | July, 1997 | Hornbeck | |
| 5654741 | Spatial light modulator display pointing device | August, 1997 | Sampsell et al. | |
| 5657099 | Color phase control for projection display using spatial light modulator | August, 1997 | Doherty et al. | |
| 5659374 | Method of repairing defective pixels | August, 1997 | Gale, Jr. et al. | |
| 5665997 | Grated landing area to eliminate sticking of micro-mechanical devices | September, 1997 | Weaver et al. | |
| 5703710 | Method for manipulating optical energy using poled structure | December, 1997 | Brinkman et al. | |
| 5710656 | Micromechanical optical modulator having a reduced-mass composite membrane | January, 1998 | Goossen | |
| 5739945 | Electrically tunable optical filter utilizing a deformable multi-layer mirror | April, 1998 | Tayebati | |
| 5745193 | DMD architecture and timing for use in a pulse-width modulated display system | April, 1998 | Urbanus et al. | |
| 5745281 | Electrostatically-driven light modulator and display | April, 1998 | Yi et al. | |
| 5771116 | Multiple bias level reset waveform for enhanced DMD control | June, 1998 | Miller et al. | |
| 5784190 | Electro-micro-mechanical shutters on transparent substrates | July, 1998 | Worley | |
| 5784212 | Method of making a support post for a micromechanical device | July, 1998 | Hornbeck | |
| 5815141 | Resistive touchscreen having multiple selectable regions for pressure discrimination | September, 1998 | Phares | 345/173 |
| 5818095 | High-yield spatial light modulator with light blocking layer | October, 1998 | Sampsell | |
| 5825528 | Phase-mismatched fabry-perot cavity micromechanical modulator | October, 1998 | Goosen | |
| 5835255 | Visible spectrum modulator arrays | November, 1998 | Miles | 359/291 |
| 5842088 | Method of calibrating a spatial light modulator printing system | November, 1998 | Thompson | |
| 5853662 | Method for preserving polished inorganic glass and method for preserving article obtained by using the same | December, 1998 | Watanabe | 422/40 |
| 5912758 | Bipolar reset for spatial light modulators | June, 1999 | Knipe et al. | |
| 5939785 | Micromechanical device including time-release passivant | August, 1999 | Klonis et al. | |
| 5986796 | Visible spectrum modulator arrays | November, 1999 | Miles | 359/260 |
| 6028690 | Reduced micromirror mirror gaps for improved contrast ratio | February, 2000 | Carter et al. | |
| 6038056 | Spatial light modulator having improved contrast ratio | March, 2000 | Florence et al. | |
| 6040937 | Interferometric modulation | March, 2000 | Miles | 359/291 |
| 6049317 | System for imaging of light-sensitive media | April, 2000 | Thompson | |
| 6055090 | Interferometric modulation | April, 2000 | Miles | 359/291 |
| 6061075 | Non-systolic time delay and integration printing | May, 2000 | Nelson et al. | |
| 6099132 | Manufacture method for micromechanical devices | August, 2000 | Kaeriyama | |
| 6113239 | Projection display system for reflective light valves | September, 2000 | Sampsell et al. | |
| 6147790 | Spring-ring micromechanical device | November, 2000 | Meier et al. | |
| 6160833 | Blue vertical cavity surface emitting laser | December, 2000 | Floyd et al. | |
| 6180428 | Monolithic scanning light emitting devices using micromachining | January, 2001 | Peeters et al. | |
| 6201633 | Micro-electromechanical based bistable color display sheets | March, 2001 | Peeters et al. | |
| 6232936 | DMD Architecture to improve horizontal resolution | May, 2001 | Gove et al. | |
| 6238755 | Insulating glass units | May, 2001 | Harvey et al. | 428/334 |
| 6282010 | Anti-reflective coatings for spatial light modulators | August, 2001 | Sulzbach et al. | |
| 6295154 | Optical switching apparatus | September, 2001 | Laor et al. | |
| 6323982 | Yield superstructure for digital micromirror device | November, 2001 | Hornbeck | |
| 6355328 | Preformed flexible laminate | March, 2002 | Baratuci et al. | 428/68 |
| 6447126 | Support post architecture for micromechanical devices | September, 2002 | Hornbeck | |
| 6455927 | Micromirror device package | September, 2002 | Glenn et al. | |
| 6465355 | Method of fabricating suspended microstructures | October, 2002 | Horsley | |
| 6466358 | Analog pulse width modulation cell for digital micromechanical device | October, 2002 | Tew | |
| 6473274 | Symmetrical microactuator structure for use in mass data storage devices, or the like | October, 2002 | Maimone et al. | |
| 6480177 | Blocked stepped address voltage for micromechanical devices | November, 2002 | Doherty et al. | |
| 6496122 | Image display and remote control system capable of displaying two distinct images | December, 2002 | Sampsell | |
| 6545335 | Structure and method for electrical isolation of optoelectronic integrated circuits | April, 2003 | Chua et al. | |
| 6548908 | Structure and method for planar lateral oxidation in passive devices | April, 2003 | Chua et al. | |
| 6549338 | Bandpass filter to reduce thermal impact of dichroic light shift | April, 2003 | Wolverton et al. | |
| 6552840 | Electrostatic efficiency of micromechanical devices | April, 2003 | Knipe | |
| 6582789 | Surface protective film and laminate formed therefrom | June, 2003 | Sumi | 428/40.1 |
| 6600201 | Systems with high density packing of micromachines | July, 2003 | Hartwell et al. | |
| 6606175 | Multi-segment light-emitting diode | August, 2003 | Sampsell et al. | |
| 6625047 | Micromechanical memory element | September, 2003 | Coleman, Jr. | |
| 6630786 | Light-emitting device having light-reflective layer formed with, or/and adjacent to, material that enhances device performance | October, 2003 | Cummings et al. | |
| 6643069 | SLM-base color projection display having multiple SLM's and multiple projection lenses | November, 2003 | Dewald | |
| 6650455 | Photonic mems and structures | November, 2003 | Miles | |
| 6674090 | Structure and method for planar lateral oxidation in active | January, 2004 | Chua et al. | |
| 6674562 | Interferometric modulation of radiation | January, 2004 | Miles | |
| 6680792 | Interferometric modulation of radiation | January, 2004 | Miles | |
| 6709750 | Hot-melt adhesive for sealing the edge of laminated glass | March, 2004 | Pohlmann et al. | 428/441 |
| 6710908 | Controlling micro-electro-mechanical cavities | March, 2004 | Miles et al. | |
| 6775174 | Memory architecture for micromirror cell | August, 2004 | Huffman et al. | |
| 6778155 | Display operation with inserted block clears | August, 2004 | Doherty et al. | |
| 6822628 | Methods and systems for compensating row-to-row brightness variations of a field emission display | November, 2004 | Dunphy et al. | |
| 6859218 | Electronic display devices and methods | February, 2005 | Luman et al. | |
| 6862022 | Method and system for automatically selecting a vertical refresh rate for a video display monitor | March, 2005 | Slupe | |
| 6862029 | Color display system | March, 2005 | D'Souza et al. | |
| 6867896 | Interferometric modulation of radiation | March, 2005 | Miles | |
| 7012726 | MEMS devices with unreleased thin film components | March, 2006 | Miles | |
| 7012732 | Method and device for modulating light with a time-varying signal | March, 2006 | Miles | |
| 7042643 | Interferometric modulation of radiation | May, 2006 | Miles | |
| 7119945 | Altering temporal response of microelectromechanical elements | October, 2006 | Kothari et al. | |
| 7123216 | Photonic MEMS and structures | October, 2006 | Miles | |
| 7130104 | Methods and devices for inhibiting tilting of a mirror in an interferometric modulator | October, 2006 | Cummings | |
| 7136213 | Interferometric modulators having charge persistence | November, 2006 | Chui | |
| 7138984 | Directly laminated touch sensitive screen | November, 2006 | Miles | |
| 7142346 | System and method for addressing a MEMS display | November, 2006 | Chui et al. | |
| 20010003487 | VISIBLE SPECTRUM MODULATOR ARRAYS | June, 2001 | Miles | |
| 20020015215 | Interferometric modulation of radiation | February, 2002 | Miles | |
| 20020056898 | Package with environmental control material carrier | May, 2002 | Lopes et al. | |
| 20020075555 | Interferometric modulation of radiation | June, 2002 | Miles | |
| 20020126364 | Interferometric modulation of radiation | September, 2002 | Miles | |
| 20020187254 | Ultrasonically sealing the cover plate to provide a hermetic enclosure for OLED displays | December, 2002 | Ghosh | |
| 20030043157 | Photonic MEMS and structures | March, 2003 | Miles | |
| 20030072070 | Visible spectrum modulator arrays | April, 2003 | Miles | |
| 20030202266 | Micro-mirror device with light angle amplification | October, 2003 | Ring et al. | |
| 20040051929 | Separable modulator | March, 2004 | Sampsell et al. | |
| 20040240032 | Interferometric modulation of radiation | December, 2004 | Miles | |
| 20050254155 | ND filter and aperture diaphragm apparatus | November, 2005 | Plamateer et al. | |
| 20060066935 | Process for modifying offset voltage characteristics of an interferometric modulator | March, 2006 | Cummings et al. | |
| 20070097477 | Visible spectrum modulator arrays | May, 2007 | Miles |
| EP0667548 | August, 1995 | Micromechanical modulator. | ||
| JP02068513 | March, 1990 | |||
| JP03199920 | August, 1991 | |||
| WO/1997/017628 | May, 1997 | INTERFEROMETRIC MODULATION | ||
| WO/1995/030924 | November, 1997 | VISIBLE SPECTRUM MODULATOR ARRAYS | ||
| WO/1999/052006 | October, 1999 | INTERFEROMETRIC MODULATION OF RADIATION | ||
| WO/2003/007049 | January, 2003 | PHOTONIC MEMS AND STRUCTURES |
The present invention relates to a hermetic seal and methods to create the same. Specifically, a functional hermetic seal is disclosed that includes an adhesive mixed with an active component that can act as an absorbing filter on a molecular level.
To create an electronic display screen, a micro-electromechanical systems (MEMS) based device such as a mirror is sandwiched between two glass plates: the back plate glass stand the substrate glass. The mirror is typically processed on the substrate glass. The back plate glass is then placed on top of the substrate glass to form the sandwich. The purpose of the back plate glass is to act as a viewing surface and to provide mechanical and environmental protection to the mirror. The sandwich is also referred to as the package.
The MEMS based device that is packaged in this manner is susceptible to problems associated with moisture and other harmful contaminants. The presence of moisture can cause stiction (static friction). The stiction can result because of the physical hydrogen bonding between the two glass surfaces in contact or because of the surface tension forces that result when the moisture between the two glass surfaces undergoes capillary condensation during the actuation of the MEMS based device. The presence of moisture can also cause electrochemical corrosion; for example, if the mirror includes an aluminum mirror.
The presence of harmful contaminants and moisture can pose a danger to the functioning of MEMS based device. For example, chlorine and moisture can combine to form an acidic environment that can be harmful to the MEMS based device. It is important that the package is moisture and contaminant free for the life of the device.
There are various channels by which water vapor or the contaminant can find its way inside the package. The moisture can enter the package from the environment in which the MEMS device is packaged. The moisture can permeate into the package from outside. The contaminant can be formed as a result of the outgassing of package components such as glass and polymers, especially at elevated temperatures.
In the prior art, to prevent the moisture and the contaminant from entering the package, the back plate glass and the substrate glass of the package are sealed to each other by using techniques such as welding and soldering, and by using o-rings. These prior art techniques are lacking in at least two respects. One, welding and soldering materials and o-rings occupy space. Real estate in MEMS based device packages is tight and there is a growing need for smaller form factors. Two, these prior art techniques do not eliminate the moisture and contaminants that are formed inside the package as a result of, for example, outgassing.
A simple technique to effectively seal two surfaces to each other that does not occupy additional real estate is desirable.
The present invention is illustrated by way of example and not limitation in the figure of the accompanying drawing, in which:
FIG. 1 illustrates an exemplary embodiment of package components that can be sealed with the hermetic seal of the present invention.
The hermetic seal including an adhesive mixed with an active component that can act as an absorbing filter on a molecular level is disclosed. The material can include a zeolite.
Additional features and advantages of the present invention will be apparent from the accompanying drawing and the detailed description that follows.
In the following descriptions for the purposes of explanation, numerous details are set forth such as examples of specific materials and methods in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that these specific details are not required in order to practice the present invention. In other instances, well known materials and methods have not been described in detail in order to avoid unnecessarily obscuring the present invention.
In this description, a hermetic seal and, methods to create the same are disclosed. The hermetic seal includes an adhesive mixed with molecular sieves or zeolites. In one embodiment, the zeolites can include aluminosilicate-structured minerals such as sodium aluminosilicate. In another embodiment, the zeolites can include microporous silicate-structured minerals. It will be appreciated that active components other than zeolites that can act as absorbing filters on a molecular level can also be used. In one embodiment, the adhesive can include an adhesive with low outgassing numbers. In other embodiments, the adhesives can include adhesives with various outgassing numbers.
In one embodiment, the zeolites are mixed with the adhesive in a weight: ratio of 50:50. In other embodiments, the zeolites are mixed with the adhesive in various weight ratios. In one embodiment, the zeolites include zeolites in the powder form. In another embodiment, the zeolites include zeolites pellets. In yet another embodiment, the zeolites include zeolites beads.
The hermetic seal of the present invention can be applied as a bead between two surfaces to seal the two surfaces. The surfaces can include glass, metal, polymer, plastic, alloy or ceramic surfaces, or a combination thereof. The amount of bead that is applied can depend on the estimated amount of moisture or contaminant gases that will have to be removed from the package during the life of the package. This amount can be calculated by considering factors such as the amount of moisture/contamination that is present inside the package when the package is formed, the permeation rate of the adhesive, and the outgassing potential of the package components.
The zeolites can absorb water molecules at high temperatures. Zeolites of different pore sizes can be selected to absorb different contaminants. In one embodiment, the zeolites are selected to absorb contaminant molecules such as aromatic branched-chain hydrocarbons that have critical diameters of up to ten angstroms. In another embodiment, zeolites of pore sizes between two and three angstroms can be selected to absorb molecules of diameters less than two angstroms, namely hydrogen and moisture molecules. In yet another embodiment, zeolites of pore sizes of fifty angstroms are used to absorb nitrogen and carbon dioxide. molecules. In yet another embodiment, the hermetic seal can include a mixture of zeolites of various pore sizes.
The hermetic seal of the present invention can be constructed in a simple manner without using techniques such as welding and soldering, or by using o-rings. The bead can be applied through a simple in-line manufacturing process. The bead occupies a negligible amount of real estate and it does not significantly bulk up the package. The hermetic seal includes active components in the form of zeolites that can trap the moisture and other contaminant gases in their pores. The hermetic seal provides mechanical support to the MEMS based device package.
FIG. 1 illustrates an exemplary embodiment of package components that can be sealed with the hermetic seal of the present invention. The components 100 for the MEMS based device in the form of a flat panel display are shown. The components include the substrate glass 110 , the mirror 120 , the hermetic seal bead 130 and the back plate glass 140 . The mirror 120 is processed on the substrate glass 110 . The bead 130 is applied to the substrate glass 110 around the perimeter of the mirror 120 . The back plate glass 140 is placed on top of the substrate glass 110 . The substrate glass 110 and the back plate glass 140 are sealed together by the bead 130 to form the package 100 . In the ensuing description, the terms components 100 and package 100 are used interchangeably. Also, in the ensuing description, the terms bead 130 and hermetic seal 130 are used interchangeably.
The mirror 120 can be referred to as the MEMS based device or the MEMS structure. The package 100 can also be referred to as the glass sandwich. The package 100 formed by the components 100 can be a component of a flat panel display. An array of mirrors such as the mirror 120 can be processed on the substrate glass 110 to form the flat panel display. The back plate glass 140 serves as the viewing surface. The back plate glass 140 also serves a mechanical function because it prevents the user from touching the mirror 110 .
The mirror 120 can be processed through conventional semiconductor technology processes. The mirror 120 can include a metallic mirror such as an aluminum mirror. It will be appreciated that in addition to the mirror 120 , the package can include other display elements. It will be appreciated that clear plastic surfaces can replace the substrate glass 110 and the back plate glass 140 .
The bead 130 can be applied around the perimeter of the mirror 120 . For the embodiments in which the substrate glass 110 includes a plurality of mirrors 130 120 , the bead 130 can be applied around the perimeter of the plurality of mirrors 120 . In one embodiment, the bead 130 thickness is one hundred angstroms. In another embodiment, the bead 130 thickness is two hundred angstroms. In yet another embodiment, the bead 130 thickness is three hundred angstroms. In still other embodiments, beads 130 of various thicknesses that maintain a low form factor for the package 100 can be applied.
It will be appreciated that the application of the hermetic seal 130 of the present invention is not limited to the MEMS based products. The hermetic seal 130 can seal various surfaces of various devices and products. The hermetic seal 130 can seal surfaces including metals, plastics, polymers, ceramics, alloys and the like. The hermetic seal 130 of the present invention is ideal for the space critical environments because it occupies negligible real estate. The prior art seals that are formed by using techniques such as welding and soldering or by using o-rings can substantially bulk up the size of the package 100 . The hermetic seal 130 can be applied through simple in-line manufacturing processes. The prior art techniques of welding and soldering require very high temperature processes that are expensive, can damage the package, and occupy valuable real estate.
The hermetic seal 130 acts as an environmental barrier by blocking humidity and chemical contaminants from entering the package 100 . The hermetic seal 130 includes an adhesive mixed with an active component such as the zeolites. The adhesive alone, even a low permeation rate adhesive, cannot serve as a perfect environmental barrier because it eventually allows the contaminants and moisture to permeate. The active component can grab the contaminants and moisture that try to permeate into the package 100 , instead of merely blocking their entry. The active component can grab the contaminant gases that result from outgassing of the components 100 after the package 100 is formed. The active component can grab the portion of the adhesive that evaporates into the package 100 while the adhesive is curing. The thickness of the bead 130 and the amount of active component that is mixed with the adhesive can depend on the package 100 estimated life time and the estimated amount of contaminants and moisture that can penetrate the package 100 during the expected life time.
In some embodiments, an outer bead 150 of adhesive is applied around the perimeter of the bead 130 . The outer bead 150 can include a low permeation rate adhesive. The outer bead 150 can provide additional environmental protection to the package 100 . The outer bead can be useful for the aggressive environment in which the bead 130 alone cannot serve as an effective hermetic seal without being loaded with an impractical amount of the active component. If the bead 130 includes a very high portion of zeolites in the zeolites-adhesive mixture, for example more than sixty percent zeolites by weight, the bead 130 can become microscopically porous. The bead 130 can also become highly non-viscous and thus difficult to apply. Also, the bead 130 with a high percentage of zeolite by weight may not provide a robust mechanical support to the package 100 . In aggressive environments, the application of the outer bead 150 can slow down the penetration process of contaminants and moisture into the package 100 .
In the foregoing specification, the invention has been described with reference to specific exemplary embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention as set forth in the claims. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.