Resin-packaged semiconductor device with flow prevention dimples

• US 5,440,169 A
• Filed: 01/05/1994
• Issued: 08/08/1995
• Est. Priority Date: 01/08/1993
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Tomita, Yoshihiro, Abe, Shunichi
• Primary Examiner(s): Limanek, Robert P.
• Application Number:
  US08/177,380
• Time in Patent Office: 580 Days
• Field of Search: 257/730, 257/796, 257/706, 257/711, 257/717, 257/739, 257/667
• US Class Current: 257/667
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/45099 Material
• 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 2224/4826 Connecting between the body and an opposite side of the item with respect to the body
• 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 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 23/3107 the device being completely enclosed
• CPC Class Codes: H01L 23/4334 Auxiliary members in encapsulations H01L23/49568 takes precedence
• CPC Class Codes: H01L 23/49503 characterised by the die pad
• CPC Class Codes: H01L 23/49551 characterised by bent parts
• 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 2924/01068 Erbium [Er]
• CPC Class Codes: H01L 2924/01077 Iridium [Ir]
• CPC Class Codes: H01L 2924/07802 not being an ohmic electrical conductor
• 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
• CPC Class Codes: H01L 2924/1815 : Shape
• CPC Class Codes: H05K 1/0204 : using means for thermal conduction connection in the thickness direction of the substrate H05K1/0207 takes precedence
• CPC Class Codes: H05K 1/182 : associated with components mounted in the printed circuit board, e.g. insert mounted components [IMC]
• CPC Class Codes: H05K 2201/10416 : Metallic blocks or heatsinks completely inserted in a PCB metallic supports H05K3/0061
• CPC Class Codes: H05K 2201/10689 : Leaded Integrated Circuit [IC] package, e.g. dual-in-line [DIL]
• CPC Class Codes: H05K 2201/10969 : Metallic case or integral heatsink of component electrically connected to a pad on PCB
• CPC Class Codes: H05K 3/341 : Surface mounted components

Abstract

A resin-packaged semiconductor device having a semiconductor element mounted on a first surface of a mounting pad. The mounting pad has an edge molded in a frame-shaped portion of a molding material. A second surface of the mounting pad has a central portion that is not included in the edge of the mounting pad and that is not covered with the molding material, the central portion of the second surface being exposed at the outside of the device. The thickness of the molding material in the frame-shaped portion and on the second surface of the mounting pad can be readily reduced to reduce the thickness of the device. Since the molding material does not cover the entire second surface, molding characteristics as well as heat radiation characteristics are improved.

Claims

1. A resin-packaged semiconductor device comprising:

a semiconductor element having opposed first and second surfaces;

a mounting pad having a first surface on which the second surface of said semiconductor element is mounted;

inner leads extending across part of and spaced from the first surface of said semiconductor element and electrically connected to said semiconductor element;

conduction means electrically connecting said semiconductor element and said inner leads to each other;

a molding material encapsulating said semiconductor element, said mounting pad, said inner leads, and said conduction means; and

outer leads continuing from said inner leads and extending outside of said molding material wherein said mounting pad has an edge encapsulated in a frame-shaped portion of said molding material, and wherein a second surface of said mounting pad opposite the first surface has a central portion not part of said edge of said mounting pad and not covered by said molding material, said central portion of said second surface being exposed as an outside surface of said device, said mounting pad having flow prevention dimples on said second surfacer said flow prevention dimples being located at first and second locations of said second surface, said first location being included in said edge of said mounting pad covered by said frame-shaped portion of said molding material and said second location being adjacent to said first location and not covered by said molding material.

2. The resin-packaged semiconductor device according to claim 1 comprising an insulator disposed on said central portion of said second surface of said mounting pad.

3. The resin-packaged semiconductor device according to claim 1 wherein said semiconductor element is secured to said mounting pad by an electrically insulating adhesive.

4. The resin-packaged semiconductor device according to claim 1 comprising a heat radiation member disposed on said central portion of said second surface of said mounting pad.

5. The resin-packaged semiconductor device according to claim 1 comprising a heating radiating member mounted on the second surface of said mounting pad.