Plastic package with exposed die

• US 5,894,108 A
• Filed: 02/11/1997
• Issued: 04/13/1999
• Est. Priority Date: 02/11/1997
• Status: Expired due to Fees

• Current Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Original Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Inventors: Mostafazadeh, Shahram, Smith, Joseph O.
• Primary Examiner(s): Kincaid, Kristine
• Assistant Examiner(s): Ngo, Hung V.
• Application Number:
  US08/798,967
• Time in Patent Office: 791 Days
• Field of Search: 257/712, 257/713, 257/695, 257/735, 257/696, 257/694, 257/690, 257/693, 257/684, 361/688, 361/690, 361/692, 361/707, 361/693, 361/694, 361/714, 361/718, 174/52.1, 174/52.4
• US Class Current: 174/529
• CPC Class Codes: H01L 21/568 Temporary substrate used as encapsulation process aid H01L21/4832 and H01L21/566 take precedence
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/45015 being circular
• 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 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/85001 involving a temporary auxiliary member not forming part of the bonding apparatus, e.g. removable or sacrificial coating, film or substrate
• CPC Class Codes: H01L 23/3107 the device being completely enclosed
• 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 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 2924/00015 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 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 2924/18165 of a wire bonded chip

Abstract

A molded plastic package incorporates a lead frame which includes a plurality of leads radially aligned around a central opening. A die is mounted in the central opening and is electrically connected to the leads by wire bonding. A molded plastic casing is formed over the die, wiring and lead frame to encapsulate the package. The lower surfaces of the die and lead frame are exposed through the package. A method for making the molded plastic package includes mounting the die and lead frame onto an adhesive tape, electrically connecting the die to the leads by wire bonding, forming a molded plastic casing over the die, wire bonding and lead frame, and then removing the adhesive tape to expose the lower surfaces of the die and the lead frame.

Claims

1. An electrical device comprising:

a flat lead frame including plurality of leads and an opening, the lead frame having opposing first and second surfaces;

an integrated circuit die disposed in the opening of the lead frame, the die including opposing first and second surfaces and having a plurality of die bond pads located on the first surface;

a plurality of wires, each of the plurality of wires extending from one of the die bond pads to one of the plurality of leads; and

a plastic casing formed on the first surface of the die, the plurality of wires, and the first surface of the lead frame;

wherein;

the second surface of the die is exposed through the plastic casing, and the second surface of the die and the second surface of the lead frame are co-planar,

the plastic casing includes opposing first and second surfaces; and

the second surface of the plastic casing and the second surface of the lead frame are co-planar.

2. The electrical device of claim 1, wherein the plastic casing comprises molded plastic.

3. The electrical device of claim 1, wherein the second surface of the lead frame is exposed through the plastic casing.