Lead frame for fabricating surface mount type semiconductor devices with high reliability

• US 6,507,093 B2
• Filed: 04/18/2001
• Issued: 01/14/2003
• Est. Priority Date: 04/19/2000
• Status: Expired due to Fees

• Current Assignee: NEC Electronics Corporation (Renesas Electronics Corporation)
• Original Assignee: NEC Corporation
• Inventors: Kaneda, Yoshiharu, Uchiyama, Tokuhiro
• Primary Examiner(s): Flynn, Nathan J.
• Assistant Examiner(s): ANDUJAR, LEONARDO
• Application Number:
  US09/836,174
• Publication Number:
  US 20010033008A1
• Time in Patent Office: 636 Days
• Field of Search: 257/666, 438/123
• US Class Current: 257/666
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/45015 being circular
• 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 2224/49171 Fan-out arrangements
• CPC Class Codes: H01L 2224/85399 Material
• CPC Class Codes: H01L 23/49562 for devices being provided for in H01L29/00
• 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 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 2924/181 Encapsulation
• CPC Class Codes: H01L 2924/18301 being an anchoring portion, i.e. mechanical interlocking between the encapsulation resin and another package part
• CPC Class Codes: H01L 2924/207 Diameter ranges

Abstract

A lead frame and a semiconductor device fabricated by using the same. The lead frame comprises: first and second band shaped members disposed parallel to each other; a plurality of island portions for mounting semiconductor pellets thereon having first end portions connected to the first band shaped member; coupling strip each provided for one of the island portions whose first end portion connects to a second end portion of each of the island portions and whose second end portion connects to the second band shaped member. The lead frame further comprises at least one electrode portion for each of the island portions and electrically coupled with a corresponding electrode of the semiconductor pellet. The at least one electrode portion is disposed between each of the island portions and the second band shaped member, a first end portion thereof is connected to the second band shaped member, and a second end portion thereof is opposed to the second end portion of each of the island portions.

Claims

1. A lead frame used for manufacturing semiconductor devices, said lead frame comprising:

first and second band shaped members disposed parallel to each other;

a plurality of island portions for mounting semiconductor pellets thereon respectively, wherein said plurality of island portions are disposed at predetermined intervals between said first and second band shaped members, and wherein a first end portion of each of said island portions is connected to said first band shaped member;

a coupling strip provided for each of said island portions, wherein said coupling strip is disposed between each of said island portions and said second band shaped member, wherein a first end portion of said coupling strip is connected to a second end portion of each of said island portions, and wherein a second end portion of said coupling strip is connected to said second band shaped member; and

at least one electrode portion which is provided for each of said island portions and which is to be electrically coupled with a corresponding electrode of said semiconductor pellet mounted on each of said island portions, wherein said at least one electrode portion is disposed between each of said island portions and said second band shaped member, wherein a first end portion of said at least one electrode portion is connected to said second band shaped member, and wherein a second end portion of said at least one electrode portion is opposed to said second end portion of each of said island portions but is not connected to said second end portion of each of said island portions, wherein the width of each of said coupling strips is smallest at said first end portion of said coupling strip and becomes gradually larger toward said second end portion of said coupling strip, and wherein the width of each of said at least one electrode portion is larger than the width of each of said coupling strips.

2. A lead frame as set forth in claim 1,

wherein each electrode portion comprises a pair of electrode subportions,

wherein the electrode subportions in one of said pairs of electrode portions correspond to the same island portion,

wherein each electrode subportion comprises a first end and a second end,

wherein the first end of a first of said electrode subportions in one of said pairs of electrode portions is connected to said second band shaped member adjacent a first side of said coupling strip, and wherein the first end of the second electrode subportion in the pair of electrode portions is connected to the second band member adjacent a second side of said of said coupling strip, the second side of said coupling strip being opposite the first side of said coupling strip.

3. A lead frame as set forth in claim 1, wherein said first band shaped member has perforations for transferring said lead frame.

4. A lead frame as set forth in claim 1, wherein the width of said second band shaped member is smaller than the width of said first band shaped member.