Thin power device and preparation method thereof

• US 9,006,901 B2
• Filed: 07/19/2013
• Issued: 04/14/2015
• Est. Priority Date: 07/19/2013
• Status: Active Grant

• Current Assignee: Alpha & Omega Semiconductor, Ltd.
• Original Assignee: Alpha & Omega Semiconductor, Inc. (Alpha & Omega Semiconductor, Ltd.)
• Inventors: Gong, Yuping, Xue, Yan Xun, Lu, Ming-Chen, Huang, Ping, Lu, Jun, Yilmaz, Hamza
• Primary Examiner(s): CLARK, JASMINE JHIHAN B
• Application Number:
  US13/946,949
• Publication Number:
  US 20150021780A1
• Time in Patent Office: 634 Days
• Field of Search: 257/678, 257/693, 257/675, 257/706, 257/707, 257/718, 257/726, 257/727, 257/676, 257/691, 257/698, 257/773, 257/E23.001, 257/E23.02
• US Class Current: 257/773
• CPC Class Codes: H01L 2224/04042 Bonding areas specifically adapted for wire connectors, e.g. wirebond pads
• CPC Class Codes: H01L 2224/0603 Bonding areas having different sizes, e.g. different heights or widths
• CPC Class Codes: H01L 2224/24101 Connecting bonding areas at the same height
• CPC Class Codes: H01L 2224/24147 the HDI interconnect not connecting to the same level of the lower semiconductor or solid-state body at which the upper semiconductor or solid-state body is mounted, e.g. the upper semiconductor or solid-state body being mounted in a cavity or on a protrusion of the lower semiconductor or solid-state body
• CPC Class Codes: H01L 2224/29101 the principal constituent melting at a temperature of less than 400°C
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/371 with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof
• CPC Class Codes: H01L 2224/40095 Kinked
• CPC Class Codes: H01L 2224/40225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/40245 the item being metallic
• CPC Class Codes: H01L 2224/4103 Connectors having different sizes
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 2224/49111 the connectors connecting two common bonding areas, e.g. Litz or braid wires
• CPC Class Codes: H01L 2224/73221 Strap and wire connectors
• CPC Class Codes: H01L 2224/73267 Layer and HDI connectors
• CPC Class Codes: H01L 2224/82101 by additive methods, e.g. direct writing
• CPC Class Codes: H01L 2224/82102 using jetting, e.g. ink jet
• CPC Class Codes: H01L 2224/83192 wherein the layer connectors are disposed only on another item or body to be connected to the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/83801 : Soldering or alloying
• CPC Class Codes: H01L 2224/8384 : Sintering
• CPC Class Codes: H01L 2224/8385 : using a polymer adhesive, e.g. an adhesive based on silicone, epoxy, polyimide, polyester
• CPC Class Codes: H01L 2224/8485 : using a polymer adhesive, e.g. an adhesive based on silicone, epoxy, polyimide, polyester
• CPC Class Codes: H01L 2224/85 : using a wire connector
• CPC Class Codes: H01L 2224/92224 : the second connecting process involving a build-up interconnect
• CPC Class Codes: H01L 23/13 : characterised by the shape
• CPC Class Codes: H01L 23/49827 : Via connections through the substrates, e.g. pins going through the substrate, coaxial cables H01L23/49822, H01L23/49833, H01L23/4985, H01L23/49861 take precedence
• CPC Class Codes: H01L 23/49838 : Geometry or layout
• CPC Class Codes: H01L 23/49844 : for devices being provided for in H01L29/00
• CPC Class Codes: H01L 23/49861 : Lead-frames fixed on or encapsulated in insulating substrates H01L23/4985, H01L23/49805 take precedence
• CPC Class Codes: H01L 24/06 : of a plurality of bonding areas
• CPC Class Codes: H01L 24/24 : of an individual high density interconnect connector
• CPC Class Codes: H01L 24/25 : of a plurality of high density interconnect connectors
• CPC Class Codes: H01L 24/29 : of an individual layer connector
• CPC Class Codes: H01L 24/37 : of an individual strap connector
• CPC Class Codes: H01L 24/40 : of an individual strap connector
• CPC Class Codes: H01L 24/41 : of a plurality of strap connectors
• CPC Class Codes: H01L 24/48 : of an individual wire connector
• CPC Class Codes: H01L 24/49 : of a plurality of wire connectors
• CPC Class Codes: H01L 24/82 : by forming build-up interconnects at chip-level, e.g. for high density interconnects [HDI] interconnection structure between a plurality of semiconductor chips H01L23/5389
• CPC Class Codes: H01L 24/83 : using a layer connector
• CPC Class Codes: H01L 24/84 : using a strap connector
• CPC Class Codes: H01L 24/85 : using a wire connector wire bonding in general B23K20/004
• CPC Class Codes: H01L 24/89 : using at least one connector not provided for in any of the groups H01L24/81 - H01L24/86
• CPC Class Codes: H01L 24/92 : Specific sequence of method steps
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• 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 2924/00015 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed as prior art
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/0781 : being an ohmic electrical conductor
• CPC Class Codes: H01L 2924/13091 : Metal-Oxide-Semiconductor Field-Effect Transistor [MOSFET]
• CPC Class Codes: H01L 2924/15153 : the die mounting substrate comprising a recess for hosting the device
• CPC Class Codes: H05K 3/306 : Lead-in-hole components, e.g. affixing or retention before soldering, spacing means H05K3/32 takes precedence
• CPC Class Codes: H05K 3/32 : electrically connecting electric components or wires to printed circuits
• CPC Class Codes: H05K 3/4697 : having cavities, e.g. for mounting components H05K3/4691 takes precedence
• CPC Class Codes: Y10T 29/4913 : Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49139 : by inserting component lead or terminal into base aperture
• CPC Class Codes: Y10T 29/49165 : by forming conductive walled aperture in base
• CPC Class Codes: Y10T 29/49169 : Assembling electrical component directly to terminal or elongated conductor

Abstract

A thin power device comprises a substrate having a first set of first contact pads at a front surface of the substrate electrically connecting to a second set of second contact pads at a back surface of the substrate, a through opening opened from the front surface and through the substrate exposing a third contact pad at the back surface of the substrate, a semiconductor chip embedded into the through opening with a back metal layer at a back surface of the semiconductor chip attached on the third contact pad, and a plurality of conductive structures electrically connecting electrodes at a front surface of the semiconductor chip with the corresponding first contact pads in the first sets of first contact pads.

Claims

1. A thin power device comprising:

a substrate having a first set of first contact pads arranged at a front surface of the substrate and a second set of second contact pads arranged at a back surface of the substrate, wherein each first contact pad in the first set of contact pads being electrically connected with a second contact pad in the second set of contact pads;

a through opening opened from the front surface and through the substrate thus exposing a third contact pad at the back surface of the substrate, wherein the third contact pad is one of the second set of second contact pads not electrically connected with any first contact pad in the first set of contact pads;

a semiconductor chip embedded into the through opening, wherein a back metal layer at a back surface of the chip is attached on the third contact pad; and

a plurality of conductive structures electrically connecting electrodes at a front surface of the chip with the corresponding first contact pads in the first sets of contact pads.

2. The thin power device according to claim 1, wherein an underfill is filled in a gap between edges of the through opening and a periphery of the chip;

and the conductive structure is an aerosol jet printed strip positioned atop front surfaces of the substrate, the underfill and a passivation layer at the front surface of the chip, and electrically connecting an electrode at the front surface of the chip with a corresponding first contact pad in the first set of contact pads closest to the electrode.

3. The thin power device according to claim 2 further comprising a plastic packaging layer covering the front surfaces of the substrate, the semiconductor chip, the underfill and the conductive structure.

4. The thin power device according to claim 1, wherein the conductive structure is a metal clip, a bonding wire or a conductive tape.

5. The thin power device according to claim 4 further comprising a plastic packaging layer covering the front surfaces of the substrate and the semiconductor chip and the conductive structure, wherein the plastic packaging layer is filled in the gap between edges of the through opening and the periphery of the semiconductor chip.

6. The thin power device according to claim 1, wherein a through hole or a trench is formed through the substrate between a first contact pad in the first set of contact pad and a second contact pad in the second set of contact pad underneath the first contact pad and a conductive interconnecting structure is formed in the through hole or the trench electrically connecting the first contact pad and the second contact pad.