Patent Application
20120204722
The present invention is directed to a filtration device for a hard disk drive and a method for making the filtration device. More specifically, the present invention is directed to a hard disk drive filtration device which includes a housing and a tunable breather filter contained within the housing that can be easily removed from, and exchanged within, the housing.
A hard disk drive (HDD) is a device used for storing and retrieving digital computer data that includes one or more rotating discs each coated with a magnetic material and a magnetic head for each disc that functions to write and read data from the disc. The discs are often referred to as platters and the magnetic heads are mounted on an actuator arm that moves the heads on an arc across the platters as the platters spin on a spindle.
Hard disc drives are classified as non-volatile, random access, digital, magnetic, data storage devices and have been the dominant device for secondary storage of data in computers for decades. Advances in hard disk drive recording capacity, cost, reliability, and speed have made them able to maintain this dominant position as secondary storage devices.
A hard-disk failure occurs when a hard disk drive malfunctions and the information stored on the hard disk drive cannot be accessed with a properly configured computer. One cause of hard-disk failure is a faulty air filter. Air filters on current hard disk drives function to equalize the atmospheric pressure and moisture between the hard-drive enclosure and its outside environment. If the hard disk drive filter fails to capture a dust particle or other particle contaminant, the particle can land on the platter thereby causing a head crash if the magnetic head sweeps over the particle. A head crash occurs when the internal read-and-write magnetic head of the hard disk device touches a platter. Each particle from a damaged platter and magnetic head that result from a head crash can cause a bad sector and result in sever data loss.
Many filter components and filter configurations have been designed in an effort to enhance hard disk drive performance and reduce hard disk drive failure. However, none of the current filter devices for hard disk drives include a filter media that can be tuned for different flow rates. In addition, none of the current filter devices for hard disk drives include a filter media that can be easily removed and exchanged without having to change the housing of the filter device. These features, along with other features of the hard disk drive filtration device of the present invention, reduce the costs for making a hard disk drive filtration device while enhancing the performance of the hard disk drive and reducing hard disk drive failure.
The present invention is directed to a hard disk drive filtration device which includes a housing and a tunable breather filter contained within the housing. The tunable breather filter comprises a porous material that can be adjusted to control air flow through the filter by controlling the pore size and density of the porous material as well as the height or depth of the porous material. The porous material of the tunable breather filter results in multidirectional airflow through the filter.
In one exemplary embodiment of the hard disk drive filtration device of the present invention, the tunable breather filter may include a porous non-carbon material positioned on top of a non-porous carbon material. In another exemplary embodiment of the hard disk drive filtration device of the present invention, the tunable media filter may include a porous non-carbon material positioned on top of a porous carbon material. In yet other exemplary embodiments of the hard disk drive filtration device of the present invention, the different embodiments of the tunable media filter described above may further include one or more flow paths or trenches formed within the non-porous carbon material and/or the porous carbon material.
In still another exemplary embodiment of the hard disk drive filtration device of the present invention, the tunable breather filter may include a carbon material layer, which may be a porous or non-porous carbon, sandwiched between first and second layers of a non-carbon porous material. Further, the carbon material layer of the tunable breather filter may include one or more trenches or flow paths formed within it. In addition, the one or more trenches or flow paths formed within the carbon material layer may intersect with one another.
In yet another exemplary embodiment of the hard disk drive filtration device of the present invention, the housing may have a bottom with an opening contained therein and an open top. Moreover, in other exemplary embodiments of the hard disk drive filtration device of the present invention, the hard disk drive filtration device may include one or more of the following: a first adhesive layer having an opening therein positioned adjacent to the bottom of the housing, a filter membrane positioned on top of the first adhesive layer, a tunable breather media portion positioned on top of the filter membrane wherein the tunable breather media portion may comprise any one of the previously described embodiments of the tunable breather filter, a second adhesive layer having an opening therein positioned on top of the tunable breather media portion, a third adhesive layer positioned on top of the second adhesive layer having an opening therein, an metal layer having a labyrinth contained therein positioned on top of the third adhesive layer; a fourth adhesive layer positioned on top of the metal layer; and a release liner positioned on top of the fourth adhesive layer.
The present invention is also directed to a method for making a hard disk drive filtration device which includes the steps of forming a housing having a bottom with an opening therein and an open top, positioning a filter membrane adjacent to the bottom of the housing, forming an exchangeable tunable breather filter and positioning it on top of the filter membrane; positioning an adhesive layer on top of the tunable breather filter, and positioning a release liner on top of the adhesive layer. In addition, a spacer may be positioned between the filter membrane and the tunable breather filter.
There are several different methods for forming the exchangeable tunable breather filter. One exemplary method for forming the exchangeable tunable breather filter includes the steps of providing a carbon based absorption material and positioning a porous non-carbon tunable media on top of the carbon material. In addition, this exemplary method may also include the optional step of forming at least one flow path or trench within at least one surface of the carbon material. Another exemplary embodiment for forming the exchangeable tunable breather filter includes the steps of providing a porous tunable carbon material, positioning a porous non-carbon tunable media on top of the porous tunable carbon material, and laminating the porous non-carbon tunable media to the porous tunable carbon material. In addition, this exemplary method may also include the optional step of forming at least one flow path or trench within at least one surface, of the porous tunable carbon material before laminating the non-carbon porous tunable media to the porous tunable carbon media. Alternatively, the exchangeable tunable breather filter may be formed from a porous tunable carbon material alone and may also include one or more flow paths or trenches formed within one or more surfaces of the porous tunable carbon material. The exchangeable tunable breathable filter made from a porous tunable carbon material may be manipulated and/or adjusted to control flow rates by adjusting the pore size, density, and height or depth of the porous carbon material.
Yet another exemplary method for making the hard disk drive filtration device of the present invention includes the steps of forming a housing having a bottom with an opening therein and an open top, placing a first adhesive layer with a central opening adjacent to the bottom of the housing, placing a filter membrane on top of the first adhesive layer, forming a tunable breather filter and placing it on top of the filter membrane, placing a second adhesive layer with a central opening on top of the tunable breather filter, placing a third adhesive layer on top of the second adhesive layer, placing a metal layer having a labyrinth on top of the third adhesive layer, placing a fourth adhesive layer on top of the metal layer, and placing a release liner on top of the fourth adhesive layer. This exemplary method may also include the step of forming at least one flow path or trench within at least one surface of tunable breather filter when forming the tunable breather filter. It should also be understood that the exchangeable breather filter may be formed by any number of methods including all of the previously described methods for forming the tunable breather filter. In addition, the tunable breather filter may be formed by stacking any number of layers of porous or non-porous carbon material and porous non-carbon material in varying orders and the carbon layer may be further formed by forming one or more flow paths or trenches in one or more surfaces of the carbon layer. Moreover, it should be further understood that some of the various adhesive layers and/or the metal layer may be omitted while making other embodiments the hard disk drive filtration device.
The exchangeable tunable breather filter portion of the hard disk drive filtration device of the present invention can be made such that the exchangeable tunable breather filter can be easily removed from the housing and exchanged with another tunable breather filter which is repositioned within the housing.
The subject invention will hereinafter be described in conjunction with the appended drawing figures, wherein like numerals denote like elements, and
The hard disk drive filtration device of the present invention generally includes a housing and a tunable breather filter contained within the housing. The tunable breather filter may be removable and exchangeable within the housing and the tunable breather filter can control air flow through the device by being “tuned” or adjusted by controlling the pore size, density, and/or height/depth of the porous material that makes up the filter. Almost any porous material may be used, including porous carbon, that can function as a filter without releasing additional contaminants as a result of carrying out the filtering process. The present invention is also directed to various methods for making the hard disk drive filtration device of the present invention as well as various methods for making the tunable breather filter that comprises part of the hard disk drive filtration device.
Another exemplary embodiment of the tunable breather filter 22 of the present invention shown positioned within a housing 24 is shown in cross-section view in
A cross-sectional view showing the air flow through another embodiment of the tunable breather filter 32 and its adjacent breathable filter membrane 50 are shown in
Housing 62 may be made from materials having an electrostatic discharge (ESD), intrinsic dissipative properties (IDP), or other like materials. Electrostatic discharge materials are important inside the hard disk drive because of the potential for non-ESD materials to create a charge that could damage the read/write heads contained within the hard disk drive. The housing material may be comprised completely of ESD material, ISP material, or the like, or the housing material may be coated with ESD material, ISP material or the like using any number of coating methods including deposition methods. The housing material may contain nano-tubes, carbon, graphite or other ESD dissipative fillers. Housing 62 can be vacuum formed or formed using other thermal forming processes. These types of processes are typically low in cost. Vacuum forming the housing 62 is especially beneficial for high volume manufacturing because the process is able to produce large quantities of housings in a short period of time and the costs for vacuum forming tooling is much less than the costs for conventional plastic molding tooling. A hole tracking system can be incorporated into housing 62 for component placement accuracy and ease of manufacturing in high volume. In addition, housing 62 can have molded vacuum formed indentations that allow for maximum air flow through the filter portion of the filtration device 60.
As previously described above and with reference to
The multi-channel tunable breather media can be made of carbon and the air can pass directly from the outside of the hard disk drive device and flow through the carbon multi-channel tunable breather media thereby eliminating the need for a labyrinth channel. The filter flow rate through the carbon multi-channel tunable breather media can be controlled by carbon pore size and density. Alternatively, as previously described above, the multi-channel tunable breather media can be a combination of non-carbon and carbon material. Porous non-carbon and porous carbon materials can be laminated together and the flow rates of the two laminated multi-channel tunable breather medias can be controlled by varying pore size, density, and/or height/depth.
Exemplary embodiments of the tunable media are discussed at length in many portions of the summary and detailed description of the present invention and can include a carbon layer or sponge or any material where you can vary the pores of the material. Carbon used for the filter media can be specifically designed for optimum water and chemical absorption. In some materials, nitrogen gas can be used to make the pores. In addition to pore size and the material used, other variables for the tunable media include height and width. The tunable media is tuned during processing of the media but it is also contemplated that configurations and materials may be used for the tunable media that could allow a user to self adjust the tunable media after manufacturing.
Adhesive layer 72 may comprise SANA-STAT electrostatic discharge (ESD) adhesive which can be used for static control. Adhesive layer 72 may contain carbon nano-tubes, graphite, or other material for ESD conductivity. Release liner 74 may comprise SANA-STA electrostatic discharge (ESD) release liner which stops tribal charges when removing the filter from the liner.
Manufacturing processes for making the hard disk drive filtration device of the present invention may use tracking mechanisms on the housing and other filter components for better dimensional control and ease of manufacturing. Manufacturing processes may also use an optical alignment system for better dimensional control and Hepa filtration over manufacturing machines for particulate control.
In the exemplary embodiment of the hard disk drive filtration device 100 shown in FIG.
8, the tunable breather media portion 110 is carbon-based and has at least one flow path or trench 111 embedded within its surface. As further shown in
The breathable filter membrane 108 may comprise a breathable ePTFE membrane and a polyethylene terephthalate (PTE) carrier is used to laminate the ePTFE filter membrane 108 to the tunable breather media portion 110. The metal layer 116 may be comprised of aluminum and the labyrinth 117 may be copper etched. A tunable breather media filter comprising carbon may have a flow path or trench 111 that is molded into the carbon portion of the filter or vacuum formed into the carbon portion of the filter. The molded or vacuum formed flow path/trench can be tuned to control air flow and humidity inside the filtration device.
A flow chart showing another exemplary method for forming a tunable breather filter for the hard disk drive filtration device of the present invention is shown in
Current prior art filter devices use PYFE for the outer housing or shell of the filter device. This material is expensive and can easily get damaged during handling and manufacturing. The current prior art also uses a special adhesive that is mandatory to stick to PTFE. This adhesive is expensive and made by very few manufacturers. Further, since PTFE is very hard to adhere to, the bond strength of the PTFE to other filter components is not very good thereby causing potential filter breakage or bond failure. The hard disk drive filtration device of the present invention uses non PTFE materials for its housing and the housing can be vacuum formed. The hard disk drive filtration device of the present invention which includes a multiple multi-directional path using tunable media and a vacuum formed (or other formed) non-PTFE housing enables stable bonding of filter components with reduced chance of breakage and failure of the filter device.
The detailed description of exemplary embodiments of the invention herein shows various exemplary embodiments and the best modes, known to the inventor at this time, of the invention. These exemplary embodiments and modes are described in sufficient detail to enable those skilled in the art to practice the invention and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the following disclosure is intended to teach both the implementation of the exemplary embodiments and modes and any equivalent modes or embodiments that are known or obvious to those reasonably skilled in the art. Additionally, all included figures are non-limiting illustrations of the exemplary embodiments and modes, which similarly avail themselves to any equivalent modes or embodiments that are known or obvious to those reasonably skilled in the art.
Other combinations and/or modifications of structures, arrangements, applications, proportions, elements, materials, or components used in the practice of the instant invention, in addition to those not specifically recited, can be varied or otherwise particularly adapted to specific environments, manufacturing specifications, design parameters, or other operating requirements without departing from the scope of the instant invention and are intended to be included in this disclosure.
This application claims priority to provisional patent application having Ser. No. 61/442,325, filed Feb. 14, 2011, and provisional patent application having Ser. No. 61/479,233, filed Apr. 26, 2011, which are both herein incorporated by reference in their entireties.
| Number | Date | Country | |
|---|---|---|---|
| 61442325 | Feb 2011 | US | |
| 61479233 | Apr 2011 | US |
