Multi-flip chip on lead frame on over molded IC package and method of assembly

• US 20050206010A1
• Filed: 03/18/2004
• Published: 09/22/2005
• Est. Priority Date: 03/18/2004
• Status: Active Grant

• Current Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Original Assignee: Fairchild Semiconductor Corporation (ON Semiconductor Corporation)
• Inventors: Noquil, Jonathan A., Choi, Seung Yong, Joshi, Rajeev, Wu, Chung-Lin
• Granted Patent: US 7,154,186 B2
• Time in Patent Office: Days
• US Class Current: 257/778
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/45124 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48472 the other connecting portion not on the bonding area also being a wedge bond, i.e. wedge-to-wedge
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/83 using a layer connector
• CPC Class Codes: H01L 2224/85 using a wire connector
• CPC Class Codes: H01L 2224/92247 the second connecting process involving 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 23/3128 the substrate having spherical bumps for external connection
• CPC Class Codes: H01L 23/49575 Assemblies of semiconductor devices on lead frames
• CPC Class Codes: H01L 24/45 of an individual wire connector
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/73 Means for bonding being of different types provided for in two or more of groups H01L24/10, H01L24/18, H01L24/26, H01L24/34, H01L24/42, H01L24/50, H01L24/63, H01L24/71
• 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 25/16 the devices being of types provided for in two or more different main groups of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N, e.g. forming hybrid circuits
• 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 2924/00012 : Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/01006 : Carbon [C]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01046 : Palladium [Pd]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/12042 : LASER
• CPC Class Codes: H01L 2924/13091 : Metal-Oxide-Semiconductor Field-Effect Transistor [MOSFET]
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/15311 : being a ball array, e.g. BGA
• CPC Class Codes: H01L 2924/1532 : the connection portion being formed on the die mounting surface of the substrate
• CPC Class Codes: H01L 2924/181 : Encapsulation

Abstract

A multichip module package uses bond wire with plastic resin on one side of a lead frame to package an integrated circuit and flip chip techniques to attach one or more mosfets to the other side of the lead frame. The assembled multichip module 30 has an integrated circuit controller 14 on a central die pad. Wire bonds 16 extend from contact areas on the integrated circuit to outer leads 2.6 of the lead frame 10. On the opposite, lower side of the central die pad, the sources and gates of the mosfets 24, 26 are bump or stud attached to the half etched regions of the lead frame. The drains 36 of the mosfets and the ball contacts 22.1 on the outer leads are soldered to a printed circuit board.

Claims

1. A multi flip chip module comprising:

a leadframe having a die pad with upper and lower surfaces and a plurality of outer leads surrounding the die pad;

an integrated circuit mounted on the upper surface of the die pad and having contact areas for receiving bond wires;

bond wires extending from the contact areas on the integrated circuit to the outer leads of the leadframe;

one or more power mosfet semiconductor devices flip chip mounted on the lower surface of the leadframe; and

a molded resin encapsulating the integrated circuit and leaving exposed at least one surface of the power mosfet semiconductor devices.

2. The multichip module of claim 1 wherein the mosfets have source bump contacts extending from the surfaces of the mosfets to the half etched die pad and one or more gate bump contacts for each mosfet extending to a corresponding outer lead.

3. The multichip module of claim 1 wherein the lead frame has leadless contacts comprising a of ball contacts extending from the outer leads for establishing an electrical connection to the contact areas of the integrated circuit via the bond wires and for providing surface mounts for connecting the semiconductor device to a surface of an electrical component board.

4. The multichip module of claim 1 wherein exposed surface(s) of the power mosfets are surface mountable on an electrical component board.

5. A multichip module having a lead frame with a central die pad and peripheral outer leads, an integrated circuit on one side of the die pad, wire bonds for connecting the integrated circuit to outer leads, one or more mosfets having their respective source and gates bump connected to the other side of the central die pad, said central die pad patterned to provide connections to the outer leads from the source and gate bump connections.

6. The multichip module of claim 5 wherein the integrated circuit is encapsulated in an insulating resin.

7. A method for manufacturing a multichip module comprising the steps of;

providing a lead frame with a central die pad having upper and lower surfaces and disposed between opposite lead rails having outer lead areas

etching the lower surface of the central die pad and the rails to provide raised lands for receiving source and gate contacts of one or more mosfets;

attaching an integrated circuit to the upper surface of the central die pad;

wire bonding contact areas of the integrated circuit to the outer lead areas on the leadframe rails;

encapsulating the integrated circuit in an electrically insulating resin;

bump attaching the source and gate of one or more mosfets to the raised lands on the lower side of the central die pad.

8. The method of claim 9 wherein the leadframe adheres to a tape and the tape is removed after the step of encapsulating.