Light-Weight Flash Hard Drive With Plastic Frame
A light-weight flash hard drive includes a printed circuit board assembly (PCBA) mounted in a housing formed by a plastic frame and a pair of metal panels that are mounted on the plastic frame over the PCBA. The PCBA includes a PC board and a plug connector that is mounted on a front edge of the PCB. The plastic frame includes first and second parallel side rails and a back end rail extending between back ends of the first and second side rails. The frame defines an open front end and a longitudinal platform for receiving and supporting the PCBA such that the plug connector is exposed through the open front end. The metal panels are either snap-coupled to the plastic frame or to each other. Alternatively, or in addition, an adhesive or insulating film is provided between the metal panels and the IC devices mounted on the PCBA.
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This application is a divisional of U.S. patent application Ser. No. 10/990,887, entitled “Light-Weight Flash Hard Drive With Plastic Frame” filed Nov. 16, 2004.
FIELD OF THE INVENTIONThe present invention generally pertains to flash hard drive-like devices, and more particularly to housing structures for flash hard drives, and to methods for assembling flash hard drives using such housing structures.
BACKGROUND OF THE INVENTIONIntegrated Drive Electronics (IDE) hard-disk drive (HDD) devices have been used for mass data storage in computer systems for many years. While the use of IDE HDD devices is still a method of choice in stationary “desk top” computer systems (e.g., “desktop” personal computers (PCs)), IDE HDD devices have been found less desirable in portable computer systems (e.g., laptop computers), which require combination of high durability, high reliability, and low weight. Accordingly, in such portable systems, flash hard drives have been used in place of IDE HDD devices due to their advantage of exhibiting better survivability in rugged environments, higher durability, higher reliability, higher performance, lower power consumption, and lower weight than IDE HDD devices.
Flash hard drives are solid-state IC devices without any moving parts because, unlike IDE HDD devices which access data stored on a spinning disk, all data is stored on flash memory integrated circuit (IC) devices that are accessed electronically by one or more “controller” IC devices. The flash memory and controller IC devices are typically mounted on the printed circuit board (PCB) of a printed circuit board assembly (PCBA), which typically includes a standardized plug connector for connecting the flash hard drive to a host system. Flash hard drives currently range in size from 4 Mega-byte to 8 Gig-byte, but it is anticipated that their size will increase in the future. Flash hard drives are currently available in TSOP, WSOP, TBGA, and FBGA packages. Flash hard drives currently run on 3.3V, 2.5V or 1.8V supply voltages, depending on the device selected. Flash hard drives typically have operating currents 1 mA,max for stand-by operations and 30 mA,max for operating current. Each flash memory IC “block” (i.e., IC device) of the flash hard drive can typically endure 100 K or more Program/Erase cycles. The operating life of flash hard drives can be further extended using technologies such as Wear-Leveling.
Flash hard drives are produced to be a pluggable replacement for existing IDE HDD devices in certain applications (e.g., laptop computers). Thus, flash hard drives are typically produced according to the common form factors for current IDE HDD devices (e.g., 3.5″, 2.5″, and 1.8″), and data transmissions to and from flash hard drives of each form factor size is consistent with its counterpart IDE HDD devices. For example, both 3.5″ flash hard drive and 3.5″ IDE HDD devices use a standard 40-pin 0.100″ IDE connector and a separate 4-pin power connector. In contrast, 2.5″ and 1.8″ flash hard drives and IDE HDD devices use a 44-pin 2 mm IDE connector, with pins 41-43 of the connector being used for power connection. For use in host system with 3.5″ HDD environment, the 2.5″ and 1.8″ flash hard drives and IDE HDD devices need an adapter to change the standard 40-pin 0.100″ IDE connector and power connector to 44-pin 2 mm IDE connector.
Flash hard drive production typically involves forming a printed circuit board assembly (PCBA), and then housing the PCBA inside of a metal case. The PCBA is produced by mounting selected IC components (i.e., one or more flash memory IC devices and one or more controller IC devices) as well as a suitable connector onto a PCB. The PCBA is then typically mounted into a metal case formed by a pair of metal covers that mount over the PCBA such that the connector is exposed at one end. Unlike production of the PCBA, which is typically produced using well-known automated assembly systems, the process of mounting the flash hard drive housing over the PCBA is typically performed manually. This manual process typically involves placing the PCBA onto one of the two metal covers, and then connecting the second metal cover to the first metal cover using screw or other fasteners such that the PCBA is housed inside.
A problem associated with conventional flash hard drives is that the existing metal cases and metal screws are still too heavy for many light-weight computing systems. However, simply removing the metal casing is not an option because this would expose the delicate electronics (i.e., the flash memory IC devices) to shock and/or corrosion damage. In addition, the conventional manual assembly process can be tedious and time consuming, which can lead to production delays and associated increased production costs.
What is needed is an assembly structure for housing a flash hard drive that addresses the above problems associated with conventional flash hard drives. In particular, what is needed is a light-weight flash hard drive for portable applications that is highly durable and easy to assemble.
SUMMARY OF THE INVENTIONThe present invention is directed to method for assembling a flash hard drive that addresses the problems associated with conventional flash hard drives by providing a light-weight plastic frame for housing a printed circuit board assembly (PCBA), and two thin metal panels that are secured to the edges of the plastic frame over the PCBA. The plastic frame includes side and back end rails that define a longitudinal platform for supporting the PCBA such that its plug connector is exposed through an open end of the frame. The metal panels are then fitted into grooves or steps formed along the rails of the plastic frame such that outer surfaces of the metal panels are flush with the upper and lower edges of the plastic frame rails. According to an embodiment of the invention, the metal panels are secured to the plastic frame by way of connecting structures formed along outer edges of the panels, and/or is attached directly to the plastic frame or to the integrated circuit (IC) devices of the PCBA by way of an electric isolation (insulating) or adhesive contact layer. By forming flash hard drives using a plastic frame and thin metal panels that are reliably secured over the PCBA, a flash hard drive formed in accordance with the present invention is both light-weight and durable, thereby providing a highly desirable storage device for portable computing systems, such as laptop computers. In particular, the light-weight flash hard drive eliminates the heavy metal casing and screws required by conventional flash hard drive structures while providing effective protection for the enclosed electronic components and a firm and secure platform for the plug connector (so that the plug connector will not become loose and separated from the housing after extended usage), and also simplifies assembly work.
According to another embodiment of the present invention, each metal panel includes connection fingers that are snap-coupled either directly to the plastic frame, or to corresponding connection structures provided in the opposing panel. In one specific embodiment, identical metal panels include male-type connection structures that are snap-coupled into engagement holes formed in the plastic frame. In an alternative embodiment, each connection finger forms one part of a self-engaging member such that the connection structure of one of the metal panels engages with a corresponding connection structure formed on the opposing metal panel, thereby securing the two panels to the plastic frame.
According to another embodiment, an adhesive or insulating contact layer is provided between inside surfaces of the metal panels and upper surfaces of the IC devices mounted on the PCBA. In one embodiment, the contact layer comprises a thermal transfer or shock absorbing material, thereby facilitating thinner metal panels and a shorter overall profile. In addition, or in the alternative, the metal panels are secured to the PCBA (e.g., to the upper surfaces of the integrated circuit (IC) devices of the PCBA) or to other structures of the PCBA by way of an adhesive layer.
According to an embodiment of the present invention, the side rails of the plastic frame define a longitudinal shelf (platform) that supports the outer edges of the PCBA when it is inserted therein, and the end rail also defines an end portion of the longitudinal shelf that receives and supports a back end edge of the PCB. In accordance with an alternative embodiment, the longitudinal platform provided in the plastic frame is a longitudinal slot that slidably receives the PCBA, thereby minimizing handling of and damage to the PCBA during the assembly process, and thus reducing overall manufacturing costs. In addition, the longitudinal slot provides a reliable structure for securing the PCBA inside the flash hard drive, thereby resisting damage caused, for example, when the flash hard drive is dropped or otherwise subjected to mechanical shock.
According to another embodiment of the present invention, a method for producing a flash hard drive includes producing the various components, sliding or otherwise mounting the PCBA into the plastic frame, and then securing the top and bottom panels to cover and protect the PCBA. In one embodiment. In addition, a heat-activated or heat-cured adhesive is provided between inner surfaces of the metal panels and the upper surfaces of the IC devices, and the assembly is mounted in a fixture that presses the metal panels against the plastic frame and PCBA. The fixture is then inserted into an oven to activate/cure the adhesive.
According to various other aspects of the invention, the housing is based on either of a 2.51, and 1.8″ form factor, and/or allows Thin Small Outline Package (TSOP) or Very Very Small Outline Package (WSOP), or Ball Grid Array (BGA), or die with die bonding to PCB, etc. to be used. The aforementioned hard-disk drive interface is Integrated Drive Electronics (IDE) and according to various other aspects of the invention can be applied to Serial Advanced Technology Attachment (SATA), Small Computer Systems Interface (SCSI), etc.
BRIEF DESCRIPTION OF THE DRAWINGSThese and other features, aspects and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings, where:
FIGS. 4(A) and 4(B) are partially exploded and fully assembled cross-sectional end views taken along section line 4-4 of
FIGS. 7(A), 7(B), and 7(C) are perspective views showing two-dimensional (2D) connection members utilized by the flash hard drive shown in
FIGS. 8(A), 8(B), and 8(C) are perspective views showing 2D connection members according to another embodiment of the present invention;
FIGS. 9(A), 9(B), and 9(C) are perspective views showing 2D connection members according to yet another embodiment of the present invention;
FIGS. 10(A) and 10(B) are cross-sectional side views showing a plastic frame and assembled flash hard drive according to another embodiment of the present invention;
FIGS. 15(A), 15(B), and 15(C) are partial cross-sectional side views showing the connection finger of
PCBA 50 generally includes a PCB 51 and a connector 55. PCB 51 is sized and constructed according to a predefined form factor, and includes one or more IC devices 60 (e.g., flash memory IC devices and one or more controller IC devices) and other optional electronic components mounted thereon. Each IC 60 has a substantially planar upper surface 62 that is spaced from and parallel to the surfaces of PCB 51. Connector 55, which also conforms to the selected form factor, is mounted onto a front edge 53 of PCB 51, and includes pins that communicate with ICs 60 via corresponding traces (not shown) formed on PCB 51 according to well-known practices. PCB 51 also includes a back edge 52 that is inserted into frame 120 in the manner described below. Several optional alignment notches 56 are defined along one or more edges of PCB 51.
Plastic frame 120, top panel 130 and bottom panel 140 collectively form housing 110, which is cooperatively assembled with PCBA 50 to protect ICs 60 and other components mounted on PCB 51. Plastic frame 120 supports PCB 51 in the manner described below. Top panel 130 and bottom panel 140 are stamped or otherwise formed from a suitably rigid material (e.g., sheet metal), and are respectively secured to the upper and lower edges of frame 120. Top panel 130 includes a substantially flat (planar) cover plate 131 having a back edge 132 and a front edge 133. The side edges 134 of wall 131 may be bent downward (i.e., substantially perpendicular to the plane defined by cover plate 131), and back edge 132 may also be bent downward to form an end wall (not shown). Extending downward from side edges 134 and end edge 132 are connection fingers 136 that secure top panel 130 to plastic frame 120 in the manner described below. Cover plate 131 includes a planar peripheral region 131-P surrounding a planar indented section 131-IN. In one embodiment, planar indented section 131-IN has a size that is substantially equal to a “footprint” collectively defined by IC devices 60. Similar to top panel 130, bottom panel 140 includes a substantially flat (planar) cover plate 141 having back edge 142 and a front edge 143, with side edges 144 of cover plate 141 including connection fingers 146 extending upward for connection to plastic frame 120. Cover plate 141 includes a planar peripheral region 141-P surrounding a planar indented section 141-IN.
Plastic frame 120 generally includes parallel side rails 121A and 121B (collectively referred to as side rails 121), a “closed” back end rail 122, and an “open” front end 124. End rail 122 extends between and rigidly connects back edges of side rails 121, and forms a closed end of frame 120. Open front end 124 is defined at front ends of side rails 121, and serves to expose connector 55 when PCBA 50 is mounted inside plastic frame 120. Plastic frame 120 provides a longitudinal shelf (platform) 125 for supporting PCB 51 along side edges 54 and back edge 52 in the manner described below. Several alignment protrusions 126 are located along side walls 121 that mate with alignment notches 56 formed in PCB 51 during the assembly process, as described below. Formed on an upper surface of side rails 121 and end rail 122 is an elongated groove or step 127 for receiving side edges 134 and back edge 132 of top panel 130 in the manner described in additional detail below. A similar elongated groove/step (not shown) is formed on a lower surface of side rails 121 and end rail 122 for receiving side edges 144 and back edge 142 of bottom panel 140. One or more holes (shown in
Referring again to
As discussed above and shown again in
As indicated in FIGS. 4(A), 4(B) and 5, support shelf 125 is defined by side rails 121A and 121B and end rail 122, and is located in an X-Y plane extending across a central region of plastic frame 120 between side rails 121A and 121B. In particular, as indicated on the left side of
In addition,
Referring to the center of
As mentioned above, according to an aspect of the present embodiment, a series of engagement holes 128 (see, e.g.,
According to an embodiment of the present invention, both top panel 130 and bottom panel 140 include substantially identical (e.g., male-type) connection structures (e.g., connection fingers 136 and 146) that are snap-coupled directly to plastic frame 120 (i.e., not to a corresponding female connector of the opposite panel). By providing substantially identical connection structures, both the top and bottom panel can be produced using the same stamping machine such that top panel 130 and bottom panel 140 are interchangeable), thereby reducing manufacturing costs because only a single tool (e.g., a stamping press) and a single set of tooling (e.g., a die) are required to produce both top panel 130 and bottom panel 140. In contrast, when different connection structures (e.g., male-type on a top panel and female-type on a bottom panel that engage when both panels are mounted onto the frame), two different stamping presses are required, which increases production costs.
Referring again to
FIGS. 10(A), 10(B) and 11 show a second flash hard drive 100-2 according to an alternative embodiment of the present invention. Referring to
Although the present invention is described above with reference to panel structures having male/female and/or self-locking connection structures connection structures, certain aspects of the present invention may be included in flash hard drives utilizing substantially identical (e.g., male-type) that facilitate convenient and low cost connection of the panels to the frame during the flash hard drive assembly process.
FIGS. 15(A) through 15(C) are simplified cross-sectional side views showing connection finger 336A during connection of top panel 330 (e.g., side edge 334) to the frame 320. As indicated in
The metal material used for the top and bottom cover plates mentioned above can be replaced by plastics, as there is fewer Electrical Magnetic Interference (EMI) issues with the flash memory devices than with the mechanical spinning hard disk drives.
The IC devices such as flash memory controller, flash memory chip, etc. mentioned above can be in the die form using the die bonding technique to attach them to the PCB. Due to the situation that there is a limit to the size of the PCB and the flash memory hard drive, the new technique allows the memory capacity of the flash memory hard drive to increase. In additional, the less packaging material used for the IC devices translate to reduced total weight of the flash memory hard drive.
Although the present invention has been described with respect to certain specific embodiments, it will be clear to those skilled in the art that the inventive features of the present invention are applicable to other embodiments as well, all of which are intended to fall within the scope of the present invention. For example, the 2D self-engaging connection structure arrangement associated with flash hard drive 300 may be replaced with other male-female type connecting structures that are known in the art. Further, the various embodiments described with reference to a longitudinal shelf may utilize the slot-based longitudinal platform described herein with reference to
Claims
1. A method for manufacturing a flash hard drive comprising:
- forming a printed circuit board assembly (PCBA) including a plurality of integrated circuit (IC) devices, a plastic frame, and first and second metal panels;
- mounting the PCBA inside of the plastic frame;
- applying an adhesive to one of: (a) an upper surface of each of the plurality of IC devices, and (b) an inside surface of each of the first and second metal panels; and
- mounting the first and second metal panels onto the plastic frame such that the upper surface of each of the plurality of IC devices contacts the inside surface of an associated one of the first and second metal panels by way of the adhesive.
2. The method according to claim 1, wherein mounting the first and second metal panels further comprises:
- mounting the plastic frame, the PCBA, and the first and second metal panels into a fixture such that the inside surface of each of the first and second metal panels is pressed against the upper surface of the associated IC devices with the adhesive pressed therebetween;
- heating the fixture to a first relatively high temperature; and
- cooling the fixture to a second, relatively low temperature.
3. The method according to claim 2, wherein the adhesive comprises a heat-activated adhesive material exhibiting a first, relatively low adherence prior to being heated to the first, relatively high temperature, and exhibiting a second, relatively high adherence when subsequently cooled to the second, relatively low temperature.
4. The method according to claim 1, wherein the adhesive comprises a heat-cured adhesive material exhibiting an initial, relatively low adherence when applied, and exhibiting a second, relatively high adherence when heated to the first, relatively high temperature, and then subsequently cooled to the second, relatively low temperature.
5. The method according to claim 1, wherein mounting the first and second metal panels further comprises inserting connection fingers extending from outer edges of the first and second metal panels into engagement holes formed in the plastic frame.
Type: Application
Filed: Oct 15, 2007
Publication Date: Feb 14, 2008
Applicant: Super Talent Electronics, Inc. (San Jose, CA)
Inventors: Kuang-Yu Wang (Saratoga, CA), Jim Ni (San Jose, CA), Ren-Kang Chiou (Fremont, CA), I-Kang Yu (Palo Alto, CA)
Application Number: 11/872,685
International Classification: H01L 21/00 (20060101);