Low cost high strength surface mount package

• US 9,392,713 B2
• Filed: 12/17/2014
• Issued: 07/12/2016
• Est. Priority Date: 10/17/2014
• Status: Active Grant

• Current Assignee: Rsm Electron Power Inc. (Sensitron Semiconductor)
• Original Assignee: Rsm Electron Power Inc. (Sensitron Semiconductor)
• Inventors: Au, Ching, Zegzula, Dennis, Peng, David
• Primary Examiner(s): Clark, S. V.
• Application Number:
  US14/573,631
• Publication Number:
  US 20160113138A1
• Time in Patent Office: 573 Days
• Field of Search: 257/678, 257/701, 257/704, 257/706, 257/707
• US Class Current: 1/1
• CPC Class Codes: H01L 2224/48091 Arched
• 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 2224/49111 the connectors connecting two common bonding areas, e.g. Litz or braid wires
• CPC Class Codes: H01L 23/043 the container being a hollow construction and having a conductive base as a mounting as well as a lead for the semiconductor body
• CPC Class Codes: H01L 23/055 the leads having a passage through the base H01L23/057 takes precedence
• CPC Class Codes: H01L 23/10 characterised by the material or arrangement of seals between parts, e.g. between cap and base of the container or between leads and walls of the container
• 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: H05K 1/0271 Arrangements for reducing stress or warp in rigid printed circuit boards, e.g. caused by loads, vibrations or differences in thermal expansion
• CPC Class Codes: H05K 1/03 Use of materials for the substrate
• CPC Class Codes: H05K 1/09 Use of materials for the conductive, e.g. metallic pattern
• CPC Class Codes: H05K 1/181 associated with surface mounted components
• CPC Class Codes: H05K 5/03 Covers
• CPC Class Codes: H05K 5/066 sealed by fusion of the joining parts without bringing material; sealed by brazing

Abstract

A hermetically sealed package has an electrically insulating substrate, a plurality of electrically and thermally conductive tabs, and a lid. The electrically insulating substrate has a plurality of apertures and an aspect ratio of about 10:1 or greater. The plurality of electrically and thermally conductive tabs is hermetically joined to a bottom surface of the electrically insulating substrate and at least one tab covers each of the apertures. The lid is hermetically joined to a top surface of the electrically insulating substrate proximate to a perimeter of the electrically insulating substrate.

Claims

1. A hermetically sealed package comprising:

an electrically insulating substrate having a plurality of apertures, the electrically insulating substrate having an aspect ratio of about 10;

1 or greater;

a plurality of electrically and thermally conductive tabs hermetically joined to a bottom surface of the electrically insulating substrate and at least one tab covering each of the apertures; and

a lid hermetically joined to a top surface of electrically insulating substrate, the lid being joined proximate a perimeter of the electrically insulating substrate.

2. The hermetically sealed package of claim 1, wherein the electrically insulating substrate includes at least one of ceramic, glass, and composite material.

3. The hermetically sealed package of claim 1, wherein the electrically insulating substrate comprises silicon nitride.

4. The hermetically sealed package of claim 1, wherein the electrically insulating substrate is a ceramic having a flexural strength greater than about 750 MPa at room temperature.

5. The hermetically sealed package of claim 1, wherein the electrically insulating substrate and the plurality of conductive tabs have a coefficient of thermal expansion, with the coefficient of thermal expansion of the tabs being within about 5 ppm/°

C. of the coefficient of thermal expansion of the electrically insulating substrate.

6. The hermetically sealed package of claim 1, wherein the plurality of tabs comprise at least one of molybdenum, tungsten, and copper.

7. The hermetically sealed package of claim 1, wherein the electrically insulating substrate is from about 10 mils to about 15 mils in thickness.

8. A hermetically sealed package comprising:

an electrically insulating substrate having a plurality of apertures;

a plurality of metallization layers formed on a bottom surface of the electrically insulating substrate, with one of the metallization layers proximate a perimeter of each of the plurality of apertures, each of the plurality of metallization layers having a width of at least about 10 mils;

a plurality of electrically and thermally conductive tabs, at least one tab covering each of the apertures and joined to the attachment layer corresponding to the aperture covered by the tab;

a frame-like metallization layer formed on a top surface of the electrically insulating substrate, the frame-like metallization layer being proximate the perimeter of the electrically insulating substrate, the frame-like metallization layer having a width of at least about 15 mils; and

a lid joined to the frame-like metallization layer.

9. The hermetically sealed package of claim 8, wherein the tabs are joined to the corresponding attachment layer by brazing or soldering.

10. The hermetically sealed package of claim 8, wherein the lid is joined to the frame-like metallization layer by brazing or soldering.

11. The hermetically sealed package of claim 8, wherein the plurality of metallization layers comprises copper.

12. The hermetically sealed package of claim 11, wherein the plurality of metallization layers has a first plating layer comprising nickel.

13. The hermetically sealed package of claim 12, wherein the plurality of metallization layers has a second plating layer, applied after the first plating layer, comprising at least one of gold and silver.

14. The hermetically sealed package of claim 8, wherein the frame-like metallization layer comprises copper.

15. The hermetically sealed package of claim 14, wherein the frame-like metallization layer has a first plating layer comprising nickel.

16. The hermetically sealed package of claim 15, wherein the frame-like metallization layer has a second plating layer, applied after the first plating layer, comprising at least one of gold and silver.

17. The hermetically sealed package of claim 8, further comprising at least one pedestal soldered to a top surface of at least one tab, the pedestal extending into the aperture covered by the at least one tab.

18. The hermetically sealed package of claim 17, further comprising a semiconductor device and a wire, the wire bonded to the pedestal and the semiconductor device.

19. The hermetically sealed package of claim 18, wherein the wire comprises aluminum, and wherein the pedestal comprises copper and has a compatible metallic layer comprising aluminum.

20. A hermetically sealed package comprising:

an electrically insulating substrate having a plurality of apertures;

a plurality of metallization layers formed on a bottom surface of the electrically insulating substrate, with one of the metallization layers proximate a perimeter of each of the plurality of apertures;

a plurality of electrically and thermally conductive tabs, at least one tab covering each of the apertures and joined to the attachment layer corresponding to the aperture covered by the tab;

a frame-like metallization layer formed on a top surface of the electrically insulating substrate, the frame-like metallization layer being proximate the perimeter of the electrically insulating substrate; and

a formed lid having a generally L-shaped perimeter, with a portion of the perimeter being generally parallel to the top surface of the electrically insulating substrate, the generally parallel portion of the lid being joined to the frame-like metallization layer.