Apparatus and method for use in mounting electronic elements

• US 7,635,915 B2
• Filed: 04/26/2006
• Issued: 12/22/2009
• Est. Priority Date: 04/26/2006
• Status: Active Grant

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Hong Kong Limited (Wolfspeed, Inc.)
• Inventors: Cheng, Siu Cheong, Xie, Jian Hui
• Primary Examiner(s): HOANG, QUOC DINH
• Application Number:
  US11/380,402
• Publication Number:
  US 20070252250A1
• Time in Patent Office: 1,336 Days
• Field of Search: 257/81, 257/99, 257/100, 257/433, 257/687, 257/672, 257/696, 257/E23.042, 257/E23.043, 257/E23.06, 257/E33.066, 257/692
• US Class Current: 257/692
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls
• CPC Class Codes: H01L 33/642 characterized by the shape
• CPC Class Codes: H01L 33/647 the elements conducting electric current to or from the semiconductor body

Abstract

Some embodiments provide surface mount devices that include a first electrode comprising a chip carrier part, a second electrode disposed proximate to the chip carrier part, and a casing encasing a portion of the first and second electrodes. The first electrode can extend from the chip carrier part toward a perimeter of the casing, and the second electrode can extend away from the chip carrier part and projects outside of the casing. In extending away from the chip carrier part the first electrode divides into a plurality of leads separated by an aperture that join into a single first joined lead portion with a first width before projecting outside of the casing and maintains the first width outside of the casing. The second electrode can attain a second width prior to projecting outside of the casing and maintains the second width outside the casing.

Claims

1. A surface mount device, comprising:

a plurality of electrodes, wherein one of said electrodes comprises a first electrode comprising a chip carrier part, and wherein another of said electrodes comprises a second electrode disposed proximate to said chip carrier part and separated from said chip carrier part by an insulation gap; and

a casing at least partially encasing a portion of said first electrode and a portion of said second electrode, said casing having a recess extending from a first surface of said casing into said casing such that at least a portion of said chip carrier part is exposed through said recess;

wherein said first electrode extends from said chip carrier part toward a perimeter of said casing and divides into a first plurality of leads, said plurality of leads joining into a single first lead portion having a first width before said first electrode projects outside said casing, maintaining said width outside said casing; and

wherein said second electrode extends away from said chip carrier part and attains a second width prior to projecting outside said casing, maintaining said second width outside said casing.

2. The device of claim 1, wherein said first electrode is positioned relative to said casing such that a portion of said chip carrier part and a first portion of an aperture between said first plurality of leads extend into a perimeter of said recess and are exposed through said recess.

3. The device of claim 2, wherein casing material forming said casing extends through a second portion of said aperture that is not exposed through said recess.

4. The device of claim 3, further comprising a fill material disposed within at least a portion of said recess where at least a portion of said fill material extends into said first portion of the aperture.

5. The device of claim 1, wherein said first electrode widens as it extends from said chip carrier part toward the perimeter of said casing, narrows as it splits into said first plurality of leads, and widens as said first plurality of leads join into said first joined lead portion to said first width before said first electrode projects outside of the casing.

6. The device of claim 5, further comprising:

a first indentation along a first edge of said first electrode defined by the widening of said chip carrier part, the narrowing of said plurality of leads and the widening of said first joined lead portion; and

a second indentation along a second edge of said first electrode defined by the widening of said chip carrier part, the narrowing of said plurality of leads and the widening of said first joined lead portion.

7. The device of claim 1, wherein said insulation gap is formed by edges of said second electrode paralleling edges of said chip carrier part.

8. A surface mount device, comprising:

a first electrode comprising a chip carrier part;

a second electrode disposed proximate to said chip carrier part and separated from said chip carrier part by an insulation gap; and

a casing encasing a portion of said first electrode and a portion of said second electrode, said casing having a recess extending from a first surface of said casing into said casing such that at least a portion of said chip carrier part is exposed through said recess, wherein said casing material forming said casing extends through a second portion of said aperture that is not exposed through said recess, wherein said recess further comprises a fill material disposed within at least a portion of said recess where at least a portion of fill material extends into said first portion of the aperture;

wherein said first electrode is positioned relative to said casing such that a portion of said chip carrier part and a first portion of an aperture extend into a perimeter of said recess and are exposed through said recess, wherein said first electrode further extends from said chip carrier part toward a perimeter of said casing and divides into a first plurality of leads separated by an aperture as the first electrode extends from the chip carrier part toward the perimeter of the casing, said first plurality of leads joining into a single first lead portion having a first width before said first electrode projects outside said casing, maintaining said width outside said casing; and

wherein said second electrode extends away from said chip carrier part and attains a second width prior to projecting outside said casing, maintaining said second width outside said casing, wherein said second electrode further comprises a second plurality of leads separated by an inlet and positioned relative to said casing such that a portion of said second plurality of leads and a first portion of said inlet extend into the perimeter of and are exposed through said recess wherein at least a portion of said fill material extends into said first portion of said inlet and said casing material extends through a second portion of said inlet not exposed by the recess.

9. A surface mount device, comprising:

a first electrode comprising a chip carrier part;

a second electrode disposed proximate to said chip carrier part and separated from said chip carrier part by an insulation gap, wherein said second electrode comprises a second plurality of leads each having a head positioned juxtaposed to said chip carrier part where an edge of each said head ends at the second plurality of leads parallel edges of said chip carrier part, and a portion of said chip carrier part extends between the head ends of said second plurality of leads; and

a casing encasing a portion of said first electrode and a portion of said second electrode, said casing having a recess extending from a first surface of said casing into said casing such that at least a portion of said chip carrier part is exposed through said recess;

wherein said first electrode extends from said chip carrier part toward a perimeter of said casing and divides into a first plurality of leads separated by an aperture as the first electrode extends from the chip carrier part toward the perimeter of the casing, said first plurality of leads joining into a single first lead portion having a first width before said first electrode projects outside said casing, maintaining said width outside said casing; and

wherein said second electrode extends away from said chip carrier part and attains a second width prior to projecting outside said casing, maintaining said second width outside said casing.

10. The device of claim 9, wherein said second plurality of leads join into a second joined lead portion, with said second electrode widening as said second plurality of leads join into said second joined lead portion before said second electrode projects outside said casing such that said second joined lead portion extends through a second surface of said casing.

11. A surface mount device, comprising:

a plurality of electrodes, wherein one of said electrodes comprises a first electrode comprising a chip carrier part and a plurality of leads extending away from said chip carrier part, wherein said plurality of leads comprises first and second leads extending generally parallel and in a first direction away from said chip carrier part, and a third lead extending away from said chip carrier part in a second direction substantially opposite said first direction, wherein said first electrode narrows as it extends into at least a first and second lead, wherein another of said electrodes comprises a second electrode positioned proximate to and extending away from said chip carrier part;

an insulation gap separating said second electrode from said first electrode; and

a casing that encases portions of said first and second electrodes, wherein the plurality of leads of said first electrode and said second electrode protrude through surfaces of said casing, the at least first and second leads of said first electrode widening to first and second widths of said predefined widths, respectively, prior to said at least first and second leads projecting outside said casing, said casing comprising a recess formed such that a portion of said chip carrier part is exposed through said recess.

12. The device of claim 11, wherein said first and second leads of said first electrode are separated by a first lead gap, and said third lead and second electrode are separated by a second lead gap, and said first and second electrodes are positioned relative to said casing such that said portion of the chip carrier part, a portion of said isolation gap, a portion of said first lead gap and a portion of said second lead gap extend into said recess and are exposed through said recess.

13. The device of claim 12, wherein said chip carrier part further comprises an extension portion and an extension indentation formed in said extension portion such that a portion of said extension indentation extends into the perimeter of said recess and is exposed through said recess.

14. The device of claim 13, further comprising:

a fill material filling at least a portion of said recess and extending into said portion of the insulation gap, said portion of the first lead gap, said portion of the second lead gap and said portion of the extension indentation that are exposed through said recess.

15. A surface mount device, comprising:

a first electrode comprising a chip carrier part;

a second electrode disposed at a distance from said chip carrier part; and

a casing encasing a portion of said first electrode and a portion of said second electrode, said casing comprising a recess extending from a surface of and into said casing such that at least a portion of said chip carrier part is exposed through said recess;

said first electrode extending from said chip carrier part toward a perimeter of said casing and projecting outside said casing;

said second electrode projecting outside said casing; and

said first electrode comprising a plurality of leads as said first electrode extends from said chip carrier part toward the perimeter of said casing, said plurality of leads having predefined widths before said plurality of leads project outside said casing and maintaining said predefined widths outside said casing, wherein said first electrode narrows as it extends into at least a first and second lead, the at least first and second leads widening to first and second widths of said predefined widths, respectively, prior to said at least first and second leads projecting outside said casing, and said second electrode attaining an additional predefined width prior to projecting outside said casing and maintaining said additional predefined width outside said casing.

16. The device of claim 15, wherein said first electrode and said second electrode in combination are generally H-shaped.

17. The device of claim 15, further comprising:

a first indentation along a first edge of said first electrode defined by the narrowing of said first electrode extending into said first lead and said first lead widening to said first width prior to projecting outside said casing, and a second indentation along a second edge of said first electrode defined by the narrowing of said first electrode extending into said second lead and said second lead widening to said second width prior to projecting outside said casing.

18. The device of claim 15, wherein said second electrode narrows as it extends away from said chip carrier part and widens to said additional predefined width before said second electrode projects outside said casing defining an indentation along a first edge of said second electrode.