Single Shot Molding Method For COB USB/EUSB Devices With Contact Pad Ribs

• US 20090093136A1
• Filed: 09/19/2008
• Published: 04/09/2009
• Est. Priority Date: 12/02/2003
• Status: Active Grant

• Current Assignee: Super Talent Technology, Corporation
• Original Assignee: Super Talent Electronics, Inc.
• Inventors: Nan, Nan, Ma, Abraham C., Hiew, Siew S.
• Granted Patent: US 8,102,657 B2
• Time in Patent Office: Days
• US Class Current: 439/55
• CPC Class Codes: G06F 1/1632 External expansion units, e.g. docking stations
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/85 using a wire connector
• CPC Class Codes: H01L 2224/97 the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 24/97 the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01033 Arsenic [As]
• CPC Class Codes: H01L 2924/01077 Iridium [Ir]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/01082 Lead [Pb]
• CPC Class Codes: H01L 2924/014 Solder alloys
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/19041 being a capacitor
• CPC Class Codes: H01R 12/57 surface mounting terminals
• CPC Class Codes: H05K 1/117 Pads along the edge of rigid circuit boards, e.g. for pluggable connectors
• CPC Class Codes: H05K 2201/0311 Metallic part with specific elastic properties, e.g. bent piece of metal as electrical contact
• CPC Class Codes: H05K 2201/09472 : Recessed pad for surface mounting recess in pad H05K2201/09745; Recessed electrode of component
• CPC Class Codes: H05K 2203/1316 : Moulded encapsulation of mounted components
• CPC Class Codes: H05K 3/0052 : Depaneling, i.e. dividing a panel into circuit boards; Working of the edges of circuit boards
• CPC Class Codes: H05K 3/284 : for encapsulating mounted components H05K1/185 takes precedence
• CPC Class Codes: H05K 3/326 : the printed circuit having integral resilient or deformable parts, e.g. tabs or parts of flexible circuits H05K3/365 takes precedence
• CPC Class Codes: H05K 3/4046 : using auxiliary conductive elements, e.g. metallic spheres, eyelets, pieces of wire
• CPC Class Codes: H05K 5/0278 : of USB type details relating to connectors H01R27/00
• CPC Class Codes: Y10T 29/49124 : On flat or curved insulated base, e.g., printed circuit, etc.
• CPC Class Codes: Y10T 29/49144 : by metal fusion
• CPC Class Codes: Y10T 29/49155 : Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/49158 : with molding of insulated base
• CPC Class Codes: Y10T 29/4916 : Simultaneous circuit manufacturing
• CPC Class Codes: Y10T 29/53209 : Terminal or connector

Abstract

A dual-personality extended USB (EUSB) system supports both USB and EUSB memory cards using an extended 9-pin EUSB socket. Each EUSB device 101 includes a PCBA having four standard USB metal contact pads disposed on an upper side of a PCB, and several extended purpose contact springs that extend through openings defined in the PCB. A single-shot molding process is used to form both an upper housing portion on the upper PCB surface that includes ribs extending between adjacent contact pads, and a lower molded housing portion that is formed over passive components and IC dies disposed on the lower PCB surface. The passive components are mounted using SMT methods, and the IC dies are mounted using COB methods. The extended 9-pin EUSB socket includes standard USB contacts and extended use contacts that communicate with the PCBA through the standard USB metal contacts and the contact springs.

Claims

1. An Universal-Serial-Bus (USB) device comprising:

a printed circuit board assembly (PCBA) including;

a printed circuit board (PCB) including a peripheral edge including a front edge portion, the PCB having opposing first and second surfaces,

a plurality of metal contact pads disposed on the first surface of the PCB,

at least one passive component mounted on the second surface of the PCB handle section; and

at least one integrated circuit (IC) mounted on the second surface of the PCB handle section; and

a single-shot molded housing including a first portion formed on the first surface of the PCB and a second portion formed on the second surface of the PCB such that said at least one passive component and said at least one IC are covered by said second portion,

wherein the first portion includes a plurality of elongated ribs, each said elongated rib extending between an associated pair of said plurality of metal contact pads, whereby each metal contact pad of said plurality of metal contact pads is exposed between a corresponding pair of said plurality of elongated ribs.

2. The USB device of claim 1,

wherein the printed circuit board (PCB) defines a plurality of openings extending between the opposing first and second surfaces and located adjacent to the front edge, wherein the plurality of metal contact pads are located between the front edge portion of the PCB and the plurality of openings, and

wherein the PCBA further comprises a plurality of metal contact springs, each metal contact spring extending through a corresponding opening of said plurality of openings such that a contact portion of said each metal contact spring protrudes through said corresponding opening.

3. The USB device of claim 2, wherein each of the plurality of metal contact springs comprises a pair of base portions that are secured to a substrate, and said contact portion comprises a bent structure extending between the pair of base portions.

4. The USB device of claim 1,

wherein the first portion of the molded housing includes a planar first surface extending parallel to the PCB and including upper surfaces of said plurality of ribs, and the second portion of the molded housing includes a planar second surface that is parallel to the planar first surface, and

wherein a first thickness measured between the planar first surface and the planar second surface adjacent to the metal contacts is substantially equal to a second thickness between the planar first surface and the planar second surface adjacent to the IC die.

5. The USB device of claim 4, wherein the first thickness is in the range of 2.3 to 2.5 mm.

6. The USB memory card of claim 4, wherein the second portion of said molded housing includes a peripheral wall extending perpendicular to the planar second surfaces, and wherein the peripheral wall is aligned with a peripheral edge of the PCB.

7. The USB memory card of claim 4, wherein the entire peripheral edge of the PCB is exposed between the first portion of said molded housing and the second portion of said molded housing such that the first portion is entirely disposed above first surface, and the second portion is entirely disposed below the second surface.

8. The USB device of claim 1, wherein the at least wherein said at least one IC comprises at least one unpackaged IC die that is electrically connected to the conductive traces by a plurality of wire bonds extending between said at least one unpackaged IC die and corresponding contact pads disposed on the second surface of the PCB.

9. The USB device of claim 8, wherein the at least one passive component includes a lead that is soldered to a corresponding contact pad disposed on the second surface of the PCB.

10. The USB device of claim 8, wherein the at least one integrated circuit (IC) die includes a first IC die comprising an USB controller circuit, and a second IC die comprising a flash memory circuit.

11. The USB device of claim 10, wherein the at least one integrated circuit (IC) die comprises a plurality of flash memory dies disposed in a stacked arrangement such that a first flash memory die is mounted on the second surface of the PCB, and a second flash memory die is mounted on a surface of the first flash memory die.

12. The USB device of claim 8, wherein the at least one integrated circuit (IC) die includes a single-chip controller/flash die comprising controller circuit and one or more flash block mass storage circuits that are interconnected by a bus.

13. The USB device of claim 1, wherein the first portion of the single-shot molded housing further comprises a front cross-rib extending along the front edge portion of the PCB and connects front portions of each of the plurality of elongated ribs.

14. The USB device of claim 1, further comprising plurality of raised metal rail structures, each metal rail structure being disposed on a corresponding metal contact pad of said plurality of metal contact pads.

15. An assembly comprising:

a printed circuit board assembly (PCBA) including;

a printed circuit board (PCB) including a peripheral edge including a front edge portion, the PCB having opposing first and second surfaces,

a plurality of metal contact pads disposed on the first surface of the PCB,

at least one passive component mounted on the second surface of the PCB handle section; and

at least one integrated circuit (IC) mounted on the second surface of the PCB handle section;

a single-shot molded housing including a first portion formed on the first surface of the PCB and a second portion formed on the second surface of the PCB such that said at least one passive component and said at least one IC are covered by said second portion, wherein the first portion includes a plurality of elongated ribs, each said elongated rib extending between an associated pair of said plurality of metal contact pads, whereby each metal contact pad of said plurality of metal contact pads is exposed between a corresponding pair of said plurality of elongated ribs; and

a case fixedly connected to the EUSB device such that the fixed metal contacts are accessible through a front opening defined by said case.

16. The assembly of claim 15,

wherein the printed circuit board (PCB) defines a plurality of openings extending between the opposing first and second surfaces and located adjacent to the front edge,

wherein the plurality of metal contact pads are located between the front edge portion of the PCB and the plurality of openings, and

wherein the PCBA further comprises a plurality of metal contact springs, each metal contact spring extending through a corresponding opening of said plurality of openings such that a contact portion of said each metal contact spring protrudes through said corresponding opening of said single-shot molded housing.

17. A method for producing an Universal-Serial-Bus (EUSB) device comprising:

producing a printed circuit board (PCB) including opposing first and second surfaces, a plurality of metal contact pads disposed on the first surface, a plurality of first contact pads disposed on the second surface, and a plurality of second contact pads disposed on the second surface;

attaching at least one integrated circuit (IC) to the first contact pads and at least one passive component to the second contact pads; and

forming a single-shot molded housing on both the first surface and the second surface of the PCB such that said first surface is covered by a first housing portion and said at least one passive component and said at least one IC die are covered by a second housing portion, wherein the first housing portion comprises a plurality of elongated ribs, each said elongated rib extending between an associated pair of said plurality of metal contact pads, whereby each metal contact pad of said plurality of metal contact pads is exposed between a corresponding pair of said plurality of elongated ribs.

18. The method of claim 17,

wherein producing the PCB further comprises forming a plurality of openings that extend between the first and second surfaces, and

wherein the method further comprises mounting a plurality of contact springs onto the PCB such that each contact spring extends through a corresponding opening of said plurality of openings, and such that a contact portion of each contact spring protrudes above the first surface of said PCB;

19. The method of claim 18, wherein mounting said plurality of contact springs comprises attaching base portions of each of said plurality of contact springs to a substrate, and then mounting said substrate onto the second surface of the PCB such that said contact portions protrude above the first surface, and such that the substrate covers the plurality of openings.

20. The method of claim 19, wherein forming the single-shot molded housing further comprises disposing a protrusion over the plurality of openings such that molding material is prevented from forming on said plurality of contact springs.