Abstract:
In an embodiment of the present invention, the hollow shell of a mid-seam memory card is composed of three, independently formed, plastic pieces—a bottom plastic piece, a top plastic piece, and a plastic lid. The plastic pieces are cross-linked using, for example, ultraviolet light (UV) activated epoxy, or ultrasonic-press methods. A printed circuit board (PCB) assembly, including memory, is positioned within the cavity of the plastic pieces, and the lid is attached. The PCB assembly can be made using chip on board (COB) or surface mount technology (SMT) components attached using ball grid array (BGA) or thin and small outline package (TSOP) connections. Various read-write/write-protect devices are possible, and can be implemented in the form of a physical feature present on one of the lateral sides of the bottom and top plastic pieces. Such devices allow the card to be read from, or written to, when in read-write mode; and upon action by the user, cause the card to function in a write-protect mode, where no more information can be written to the card&#39;s memory. These devices may be manifested as dynamic switches, removably connectible plugs, or permanently removable fin-structures.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a continuation-in-part of U.S. patent application Ser. No. 10/888,282 filed on Jul. 8, 2004, and entitled “MANUFACTURING METHOD FOR MEMORY CARD”; a continuation-in-part of U.S. patent application Ser. No. 10/913,868 filed on Aug. 6, 2004, and entitled “REMOVABLE FLASH INTEGRATED MEMORY MODULE CARD AND METHOD OF MANUFACTURE”; a continuation-in-part of U.S. Pat. No. 7,174,628 B1, filed Feb. 13, 2007, and entitled “MEMORY CARD PRODUCTION USING PREFABRICATED COVER AND MOLDED CASING PORTION”; a continuation-in-part of U.S. patent application Ser. No. 11/466,759, filed Aug. 23, 2006, and entitled “FLASH MEMORY CONTROLLER FOR ELECTRONIC DATA FLASH CARD” which is a continuation-in-part of U.S. patent application Ser. No. 09/478,720, filed Jan. 6, 2000, and entitled “ELECTRONIC DATA STORAGE MEDIUM WITH FINGERPRINT VERIFICATION CAPABILITY”; a continuation-in-part of U.S. patent application Ser. No. 10/761,853, filed Jan. 20, 2004, and entitled “HIGHLY INTEGRATED MASS STORAGE DEVICE WITH AN INTELLIGENT FLASH CONTROLLER”; and a continuation-in-part of U.S. application Ser. No. 10/789,333, filed Feb. 26, 2004, and entitled “SYSTEM AND METHOD FOR CONTROLLING FLASH MEMORY”, the disclosures of which are incorporated herein by reference as though set forth in full.  
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates generally to the field of chip on board (COB) and surface mount technology (SMT) memory cards, and particularly to a method for manufacturing memory cards using ultraviolet light (UV) activated epoxy.  
         [0004]     2. Description of the Prior Art  
         [0005]     As computers have gained enormous popularity in recent decades, so has the need for better and more efficient ways of storing memory. Notable among memory devices are the portable ones such as memory cards that may be carried around by the user to access their information at different locations. For other electronic devices such as iPods, Personal Digital Assistants (PDA), Digital cameras/camcorders, and cellular phones, memory cards are also used for storing of information. This is particularly common in the case of personal computers (PC) where the need often arises to transfer data from one PC to another. Examples of portable memory devices include nonvolatile memory devices such as secure digital cards (SD) that are removably connectible to a computer.  
         [0006]     Physical size limitations, due to industry standards that must be met regarding total package size of the memory card, place restrictions on the outer dimensions of the memory card. Ultimately, this can result in capacity limitations.  
         [0007]     Thus, it is desirable to manufacture a memory card that where the outer package assembly is more efficiently designed so that the internal electronics are given more physical space, and thus memory capacity can be increased, allowing users to store increasing amounts of information within. Assembly of a mid-seam memory card using techniques such as ultraviolet light epoxy and ultrasonic-press, combined with smaller footprint electronic components, such as those employing ball grid array connectors, better allows such benefits to be realized. In addition, the memory card should have a low cost of manufacturing, with an improved aesthetic quality, to appeal to a wide range of potential users.  
       SUMMARY OF THE INVENTION  
       [0008]     Briefly, an embodiment of the present invention includes a memory card having a bottom plastic piece and a top plastic piece, both with a plurality of lateral sides, and a cavity interposed along the lateral sides of both plastic pieces when permanently joined. The bottom and top plastic pieces are cross-linked, and a printed circuit board (PCB) assembly, including memory, is positioned in the cavity. A third plastic piece is then positioned as a lid, or alternatively, created by an injection molding step. Cross-linking of the plastic pieces can be done using various technologies, such as ultraviolet light (UV) activated epoxy, or ultrasonic-press methods.  
         [0009]     Various read-write protection devices can be implemented through the modification of one of the said lateral sides. Such devices may be embodied as dynamically located switches, permanently removable fins, or removably connectible caps. Switches are attached to the card after the manufacturing process, as a final assembly step; and depending on their user-selectable position within the read-write/write-protect notch-region, cause the card to function in either read-write or write-protect mode. Fins, made during the manufacturing process of the top and bottom plastic pieces, are located in the read-write/write-protect notch-region of the memory card and cause the memory card to function in read-write mode when the fins are present, and in write-protect mode when the fins are removed by the user, and the notch is exposed. Alternatively, a removable cap is inserted into a notch, configuring the card to function in a read-write mode when the cap is present in the notch, and in a write-protect mode when the notch is exposed.  
         [0010]     The foregoing and other objects, features, and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments, which make reference to several figures of the drawings.  
     
    
     IN THE DRAWINGS  
       [0011]      FIG. 1 ( a ) shows an angular view of memory card  10 .  
         [0012]      FIG. 1 ( b ) shows a top view of memory card  10 .  
         [0013]      FIG. 1 ( c ) shows a bottom view of memory card  10 .  
         [0014]      FIG. 2 ( a ) shows an exploded view of the casing components of memory card  10 .  
         [0015]      FIG. 2 ( b ) is a side-view showing the alignment of top plastic piece  12  and bottom plastic piece  11  for creation of sub-assembly  25 .  
         [0016]      FIG. 2 ( c ) shows a rear-angular view of sub-assembly  25  of memory card  10 .  
         [0017]      FIG. 2 ( d ) is a cross-sectional side view of sub-assembly  25  and shoe-shaped cavity  26 .  
         [0018]      FIG. 3 ( a ) shows an angular view of memory card  30 , an alternative embodiment of the present invention.  
         [0019]      FIG. 3 ( b ) shows an exploded view of memory card  30 .  
         [0020]      FIG. 4  shows a bottom angular view of printed circuit board assembly (PCBA)  40 .  
         [0021]      FIG. 5 ( a ) shows a top view of chip on board (COB) PCBA  50 .  
         [0022]      FIG. 5 ( b ) shows a top view of surface mounted technology (SMT) PCBA  54 .  
         [0023]      FIG. 6 ( a ) shows PCBA  50  being inserted into shoe-shaped cavity  26 .  
         [0024]      FIG. 6 ( b ) shows PCBA  50  being positioned within shoe-shaped cavity  26 .  
         [0025]      FIG. 7  shows an exploded view of completed memory card  10 .  
         [0026]      FIG. 8 ( a ) shows memory card  80 , with dynamic read-write/write-protect switch  84 , an alternative embodiment of the present invention.  
         [0027]      FIG. 8 ( b ) shows memory card  85 , with ribbed edge  86  instead of a read-write/write-protect mechanism, an alternative embodiment of the present invention.  
         [0028]      FIG. 8 ( c ) shows memory card  87 , with ribbed edge  89  and smooth edge  89  instead of a read-write/write-protect mechanism, an alternative embodiment of the present invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0029]     Referring now to  FIG. 1 ( a ), an angular view of assembled memory card  10  is shown to include bottom plastic piece  11 , top plastic piece  12 , and lid  13 , which are visible. Bottom plastic piece  11  and top plastic piece  12  are situated in the final assembly of memory card  10 , so that one lies on top of the other, and each pieces&#39; plurality of lateral sides are aligned with the corresponding lateral sides on the other plastic piece. For example, lateral side  15  of bottom plastic piece  11  is aligned with corresponding lateral side  16  of top plastic piece  12 . Lid  13  is inserted into hole  24  of top plastic piece  12 , as will be further explained shortly.  
         [0030]      FIG. 1 ( b ) shows a top view of lid  13  and top plastic piece  12 , of memory card  10 . In an embodiment of the present invention, the dimensions of top plastic piece  12  and bottom plastic piece  11  are the same, such that when memory card  10  is viewed directly from the top or bottom, with the pieces properly aligned, only one of either top plastic piece  12  or bottom plastic piece  11  is visible. In an embodiment of the present invention, plastic lid  13  is located substantially in the center of top plastic piece  12 , and is surrounded on all four sides by top plastic piece  12 ; however, in other embodiments lid  13  may be located less centrally to lid  12 , or be unbounded on one or more sides by top plastic piece  12 .  
         [0031]      FIG. 1 ( c ) shows a bottom view of memory card  10 , where top plastic piece  12  is fully obstructed from view by bottom plastic piece  11 . Multi-pin connector  19  interfaces memory card  10  with a host device and facilitates the transfer of information therebetween, as will be discussed in more detail shortly. In the present embodiment of the current invention, multi-pin connector  19  is comprised of eight pins, although other configurations, with more or less pins, are possible.  
         [0032]     Referring now to  FIG. 2 ( a ), an exploded view of bottom plastic piece  11 , top plastic piece  12 , and lid  13  of memory card  10  is shown. Bottom plastic piece  11 , top plastic piece  12 , and lid  13  are each created by separate processes. Such processes may be, for example, independent auto-mold or injection-molding steps. The final assembly of memory card  10  is such that bottom plastic piece  11  and top plastic piece  12  are situated directly above/beneath each other, and lid  13  is used to seal rectangular hole  22 , creating a cavity within.  
         [0033]      FIG. 2 ( b ) further illustrates how bottom plastic piece  11  and top plastic piece  12  are permanently cross-linked to form sub-assembly  25 . After pieces  11  and  12  are formed, if an epoxy is to be used to cross-link pieces  11  and  12 , it is dispensed on top face  28  of bottom plastic piece  11 , or bottom face  29  of top plastic piece  12 , or both. If the epoxy to be used is ultraviolet light activated epoxy (UV epoxy), then at least one of the plastic pieces ( 11  or  12 ) must be molded using transparent plastic resin so that light can pass thru, to allow for activation of the UV epoxy.  
         [0034]     As shown in  FIG. 2 ( c ), top piece  12  and bottom piece  11  are then placed, by machine or by hand, for example, so that faces  29  and  28 , and rectangular hole  22  and rectangular cavity  21  respectively, are aligned and adjacent. If UV epoxy is used, UV light is shone on plastic pieces  11  and  12  to activate the epoxy, which cures and cross-links bottom plastic piece  11  to top plastic piece  12 , creating a permanent lower sub-assembly  25 .  FIG. 2 ( d ) shows a cross-sectional view of bottom plastic piece  11  cross-linked to top plastic piece  12 , also known as lower sub-assembly  25 , whereby shoe-shaped cavity  26  is created from the merging of rectangular hole  22  and rectangular cavity  21 . In other embodiments of the present invention, shoe-shaped cavity  26  may have other shapes such as rectangular, parallel-piped, or cubic; hole  22  and cavity  21  may also have other shapes, such as rounded, or any geometric shape with three or more sides.  
         [0035]     In an alternative embodiment of the present invention, ultrasonic-press is used to cross-link bottom plastic piece  11  to top plastic piece  12 . If ultrasonic-press is used, instead of UV epoxy, the use of a transparent plastic resin for creating any of the plastic pieces is no longer necessary, as light does not need to reach interface of faces  28  and  29 . Instead, bottom plastic piece  11  and top plastic piece  12  are placed so that the corresponding lateral sides (i.e. lateral sides  15  and  16  in  FIG. 1 ( a )) are directly above/beneath each other, and so that bottom face  29  is adjacent and aligned with top face  28 , and ultrasonic waves then vibrates pieces  11  and  12  at a high frequency. Because of the vibrations, friction heats and melt faces  29  and  28 , causing the plastic pieces to bind, permanently cross-linking pieces  11  and  12  and forming sub-assembly  25 .  
         [0036]     Referring now to FIGS.  3 ( a ) and  3 ( b ), an alternative embodiment of memory card  10  is shown. Memory card  30  contains a read-write/write-protect device—fin-structure  34 . Memory card  30  is manufactured with fin-structure  34  in place, and while present, fin-structure  34  allows the user to read from or write to the memory card. When the user desires for memory card  30  to become permanently write-protected, he/she snaps off fin-structure  34 , and the host device will no longer allow for the information contained within card  30  to be overwritten.  FIG. 3 ( b ) shows that despite the presence of physical structures providing a write-protection method, the interfacing and cross-linking of bottom plastic piece  31  to top plastic piece  32  is the same process of cross-linking bottom plastic piece  11  to top plastic piece  12  in memory card  10 . Lid  33  serves the same function, and is cross-linked in the same manner as lid  13 , as will be discussed shortly herein.  
         [0037]     As seen in  FIG. 3 ( a ), fin-structure  34  is composed of three fins—fins  37 ,  38 , and  39 .  FIG. 3 ( b ) shows that prior to the cross-linking of bottom plastic piece  31  and top plastic piece  32 , fin  37  exists as two halves,  37   a  and  37   b ; fin  38  exists as two halves,  38   a  and  38   b ; and fin  39  exists as two halves,  39   a  and  39   b . Similarly, in alternative embodiments of the present invention, a feature present on one of the plurality of lateral sides, such as a read-write/write-protect mechanism, may not be present entirely on either the bottom or top plastic piece, but may instead start as two separate entities, which subsequent to the cross-linking step, become one solid entity.  
         [0038]      FIG. 4  shows a bottom view of internal printed circuit board (PCB) assembly  40  of a memory card, of any of the embodiments of the present invention. PCB assembly  40  is shown to include decline corner  41  for proper positioning within the bottom plastic piece, and a multi-pin connector  42 , on substrate  43 , for communicating with the host device. In an embodiment of the present invention, PCB assembly  40  contains the memory, controller, and any other electronic devices necessary for the function of the memory card it is inserted into, as will be discussed shortly. Multi-pin connector  42  is substantially the same as multi-pin connector  19  on memory card  10 , as seen in  FIG. 1 ( c ), except multi-pin connector  42  is shown as utilizing 9 pins, instead of 8. Multi-pin connector  42  couples the host device to the memory card using a wide range of protocols, examples of which are presented in U.S. Patent Publication No. US2005/0197017 A1, publication date Sep. 8, 2005 entitled, “EXTENDED SECURE DIGITAL (SD) DEVICES AND HOSTS,” the disclosure of which is herein incorporated by reference as though set forth in full. Examples of protocols used to couple the memory card with a host device through interface connector  42  include, but are not limited to, Multi-Media Card (MMC), Serial Peripheral Interface (SPI), Secure Digital (SD), Enhanced Multi-Media Card (EMMC), Universal Serial Bus (USB), Enhanced Universal Serial Bus (EUSB), Peripheral Component Interconnect Express (PCIE), Serial Advanced Technology Attachment (SATA) and the IEEE 1394 interface (also referred to as “firewire”). In other embodiments of the present invention: multi-pin connector  42  may have any number of pins; and decline corner  41  may not be present, or may be present in multiplicity on any number or combination of the corners of substrate  43 .  
         [0039]      FIG. 5 ( a ) shows a top angular view of internal PCB assembly  50 , employing chip on board (COB) electronics. PCB assembly  50  is composed of electronic devices, for example  51  and  52 , mounted to substrate  53 . Examples of electronic devices include flash memory units, controllers, and passive components. In addition to electronic devices  51  and  52 , COB PCB assembly  50  may contain other components, such as passive components for example, such as resistors, capacitors, and inductors.  
         [0040]      FIG. 5 ( b ) shows a top angular view of an alternative PCB assembly  54 , employing surface mounted technology (SMT) electronics. Assembly  54  is composed of, for example, electronic devices  55  and  56 , and passive components  57 - 58 , mounted on substrate  59 . Electronic devices  55  and  56  may include, for example, flash memory die or controller die. Passive components  57 - 58  may include, for example, resistors, capacitors, and inductors. In other embodiments of the present invention, electronic devices  55  and  56 , and passive components  57  and  58  can be mounted on both sides, or on the bottom-side of substrate  59 .  
         [0041]     PCB assemblies  50  and  54  are manufactured independent from the molding steps of the bottom and top plastic pieces. Electronic devices  55  and  56  of PCB Assembly  54  may be attached to substrate  59  using a variety of technologies, using, for example, thin and small outline package (TSOP) or ball grid array (BGA) methods. In either processes, substrate  59  first passes through a stencil printer, printing a layer of solder paste thereon. A pick-and-place machine then mounts electronic devices  55  and  56 , and passive components  57 - 58 . After mounting, the PCB assembly passes through an IR-reflow oven which melts the solder, connecting the pins of the substrate  59 , electronic devices  55  and  56 , and passive components  57 - 58 .  
         [0042]     Referring now to  FIG. 6 ( a ), PCB assembly  50  is being inserted into shoe-shaped cavity  26  of sub-assembly  25 , which is comprised of bottom plastic piece  11  and top plastic piece  12 . PCB assembly  50  is first pushed into shoe-shaped cavity  26 , by force  61 ; and is then pushed down by force  62 , which ensures that assembly  50  is located snugly between the plurality of lateral sides of bottom plastic piece  11 , as can be better seen in  FIG. 6 ( b ). Following the full insertion of PCB assembly  50  within shoe-shaped cavity  26 , lid  13  is attached.  
         [0043]     Lid  13  may be created from a variety of manufacturing methods. In one embodiment of the present invention, lid  13  is created as part of a separate injection-molding or auto-molding step, similar to that of bottom and top plastic pieces  11  and  12 ; and then attached to top plastic piece  12  using UV epoxy or ultrasonic-press. If UV epoxy is to be used, then either lid  13  or top plastic piece  12  must be molded from a transparent plastic resin in order to ensure that UV light can reach the UV epoxy to activate and cross-link top plastic piece  12  to lid  13 . In an alternative embodiment, lid  13  is created as part of an injection molding process, whereby the remaining void of shoe-shaped cavity  26  is filled with molten plastic, which subsequently hardens to form a solid top lid. The glass-transition temperature of the plastic material of lid  13  should be higher than the glass-transition temperature of top plastic piece  12 , in order to ensure adequate cross-linking between the two plastic components. In another alternative embodiment, lid  13  is only physically pressed into place, into rectangular hole  22 , and frictional forces hold it secure within top plastic piece  12 .  
         [0044]     Referring to  FIG. 7 , an overview of the complete assembly process, of memory card  10 , can be seen. In addition to the components mentioned herein prior, label  71  may be affixed to lid  13  of memory card  10 , hiding the seam that is created as a result of attaching lid  13 , and enhancing the overall aesthetic appeal of memory card  10 . In an embodiment of the present invention, label  71  is attached using an adhesive surface on one side, but other methods of attachment are possible. Printed on label  71  may be a custom designed logo and other information. In addition, label  71  enhances moisture and water resistance of the memory card  10  to protect the electronic devices within.  
         [0045]     FIGS.  8 ( a )- 8 ( c ) show various alternative sample embodiments of molded bottom plastic piece  11  and molded top plastic piece  12 . In  FIG. 8 ( a ) the notch-region  15  of memory card  10  has been replaced by a dynamically configurable switch device  84  on memory card  80 . Depending upon the position of switch device  84 , memory card  80  functions in either read-write, or write-protected mode.  
         [0046]     In  FIG. 8 ( b ), memory card  85  lacks any read-write/write-protect device, and instead has ribs  86  to provide the user with a surface that assists with insertion of memory card  85  into, and removal of memory card  85  out of, a host device. In  FIG. 8 ( c ), memory card  87  combines ribs  88 , for easier user handling, with a flattened region  89 , for smoother insertion and removal into a host device.  
         [0047]     FIGS.  8 ( a )- 8 ( c ) serve to illustrate alternative embodiments of memory cards that can be manufactured using the mid-seam UV-cure or ultrasonic-press methods of manufacturing, and is not intended to be exhaustive of all potential package designs.  
         [0048]     Although the present invention has been described in terms of specific embodiment, it is anticipated that alterations and modifications thereof will no doubt become apparent to those more skilled in the art. It is therefore intended that the following claims be interpreted as covering all such alterations and modification as fall within the true spirit and scope of the invention.