Low profile wire bonded USB device
A low profile USB flash memory device, and methods of forming same, are disclosed. The USB flash memory device includes an integrated circuit memory portion and a USB connector. The memory portion and the USB connector may be integrally formed on the same substrate. The USB flash memory device includes a substrate on which is mounted one or more flash memory die, a controller die, passive components and an LED for indicating when the memory is being accessed. In contrast to prior art USB memory devices which used TSOP packages mounted on a printed circuit board, the semiconductor die of the present invention are affixed to the substrate and wire bonded in a SIP configuration. Omitting the encapsulated TSOP packages allows a reduction in the overall thickness of the USB flash memory device.
1. A method of fabricating a USB flash memory device, comprising the steps of:
(a) defining a conductance pattern on a substrate;
(b) forming connector pins on the same substrate, the connector pins capable of mating within a slot of a host device;
(c) wirebonding one or more semiconductor die to the substrate; and
(d) electrically coupling the one or more semiconductor die to the connector pins via the conductance pattern.
2. A method as recited in claim 1 , said step (a) of defining a conductance pattern on a substrate comprising the step of defining the connector pins on the substrate.
3. A method as recited in claim 2 , said step (b) of forming connector pins on the substrate comprising the step of plating the connector pins defined in the conductance pattern is said step (a).
4. A method as recited in claim 1 , said step (b) of forming connector pins on the substrate comprising the step of affixing connector pins to the substrate and electrically coupling the connector pins to the conductance pattern.
5. A method as recited in claim 1 , said step (c) of wirebonding one or more semiconductor die to the substrate comprising the step of wirebonding a flash memory die and a controller die to the substrate.
6. A method as recited in claim 1 , said step (c) of wirebonding one or more semiconductor die to the substrate comprising the step of wirebonding the one or more semiconductor die to the same side of the substrate including the connector pins.
7. A method as recited in claim 1 , said step (c) of wirebonding one or more semiconductor die to the substrate comprising the step of wirebonding the one or more semiconductor die to the opposite side of the substrate than the side including the connector pins.
8. A method as recited in claim 1 , further comprising the step (e) of encapsulating the one or more semiconductor die in a molding compound.
9. A method as recited in claim 8 , further comprising the step (f) of defining a pair of notches in front corners of the encapsulated USB flash memory device.
10. A method as recited in claim 9 , further comprising the step (g) of mounting the USB flash memory device within a cover with the notches engaging front portions of the cover.
11. A method as recited in claim 9 , further comprising the steps (h) of affixing solder bumps to the connector pins and (j) permanently affixing the USB flash memory device to a motherboard of a host device.
12. A method as recited in claim 11 , said step (j) of permanently affixing the USB flash memory device to a motherboard of a host device comprising the step of affixing the USB flash memory device to the motherboard via solder reflow of the solder bumps to the host device.
13. A method as recited in claim 1 , further comprising the step (k) of affixing one or more passive components to the substrate.
14. A method as recited in claim 13 , wherein said step (k) of affixing one or more passive components to the substrate comprises the step of affixing the one or more passive components to the same side of the substrate as the one or more semiconductor die.
15. A method as recited in claim 13 , wherein said step (k) of affixing one or more passive components to the substrate comprises the step of affixing the one or more passive components to the opposite side of the substrate than the one or more semiconductor die.
16. A method of fabricating a USB flash memory device, comprising the steps of:
(a) defining a conductance pattern on a substrate of a panel of substrates;
(b) forming connector pins on the same substrate, the connector pins capable of mating within a slot of a host device;
(c) wirebonding one or more semiconductor die to the substrate;
(d) electrically coupling the one or more semiconductor die to the connector pins via the conductance pattern; and
(e) singulating the USB flash memory device from the panel.
17. A method as recited in claim 16 , further comprising the step (f) of encapsulating the one or more semiconductor die in a molding compound prior to singulating the USB flash memory device from the panel.
18. A method as recited in claim 16 , further comprising the step (g) of defining a pair of notches in front corners of the encapsulated USB flash memory device.
19. A method as recited in claim 16 , further comprising:
(h) affixing solder bumps to the connector pins; and
(i) permanently affixing the USB flash memory device to a motherboard of a host device.
20. A method as recited in claim 19 , further comprising the step (k) of affixing solder bumps to the USB flash memory device at areas other than the connector pins for adding structural support to the USB flash memory device as the USB flash memory device is permanently affixed to the motherboard in said step (i).