Packaging system for power supplies

• US 6,943,455 B1
• Filed: 02/27/2003
• Issued: 09/13/2005
• Est. Priority Date: 02/27/2003
• Status: Expired due to Fees

• Current Assignee: Power-One Incorporated (ABB Limited)
• Original Assignee: Power One Ltd (ABB Limited)
• Inventors: Maxwell, John A.
• Primary Examiner(s): CLARK, SHEILA V
• Application Number:
  US10/377,225
• Time in Patent Office: 929 Days
• Field of Search: 257/522, 257/735, 257/736, 257/784
• US Class Current: 257/784
• CPC Class Codes: H01L 2224/29075 Plural core members
• CPC Class Codes: H01L 2224/2929 with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/293 with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/37147 Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/40095 Kinked
• CPC Class Codes: H01L 2224/40245 the item being metallic
• CPC Class Codes: H01L 2224/45124 Aluminium (Al) 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 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 2224/4903 Connectors having different sizes, e.g. different diameters
• CPC Class Codes: H01L 2224/49051 Connectors having different shapes
• CPC Class Codes: H01L 2224/73221 Strap and wire connectors
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/83205 Ultrasonic bonding
• CPC Class Codes: H01L 2224/83801 Soldering or alloying
• CPC Class Codes: H01L 2224/8385 using a polymer adhesive, e.g. an adhesive based on silicone, epoxy, polyimide, polyester
• CPC Class Codes: H01L 2224/83851 being an anisotropic conductive adhesive
• CPC Class Codes: H01L 2224/84205 Ultrasonic bonding
• CPC Class Codes: H01L 2224/84801 : Soldering or alloying
• CPC Class Codes: H01L 2224/8485 : using a polymer adhesive, e.g. an adhesive based on silicone, epoxy, polyimide, polyester
• CPC Class Codes: H01L 23/49524 : the additional leads being a tape carrier or flat leads
• CPC Class Codes: H01L 23/49562 : for devices being provided for in H01L29/00
• CPC Class Codes: H01L 23/50 : for integrated circuit devices, e.g. power bus, number of leadsH01L23/482 - H01L23/498 take precedence
• CPC Class Codes: H01L 24/37 : of an individual strap connector
• CPC Class Codes: H01L 24/40 : of an individual strap connector
• 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 24/49 : of a plurality of wire connectors
• CPC Class Codes: H01L 24/73 : Means for bonding being of different types provided for in two or more of groups H01L24/10, H01L24/18, H01L24/26, H01L24/34, H01L24/42, H01L24/50, H01L24/63, H01L24/71
• CPC Class Codes: H01L 24/83 : using a layer connector
• CPC Class Codes: H01L 24/84 : using a strap connector
• CPC Class Codes: H01L 24/91 : Methods for connecting semiconductor or solid state bodies including different methods provided for in two or more of groups H01L24/80 - H01L24/90
• 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 2924/00011 : Not relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/01005 : Boron [B]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01014 : Silicon [Si]
• CPC Class Codes: H01L 2924/01015 : Phosphorus [P]
• CPC Class Codes: H01L 2924/01028 : Nickel [Ni]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01049 : Indium [In]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/10253 : Silicon [Si]
• CPC Class Codes: H01L 2924/1305 : Bipolar Junction Transistor [BJT]
• CPC Class Codes: H01L 2924/1306 : Field-effect transistor [FET]
• CPC Class Codes: H01L 2924/13091 : Metal-Oxide-Semiconductor Field-Effect Transistor [MOSFET]
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/19041 : being a capacitor
• CPC Class Codes: H01L 2924/19042 : being an inductor
• CPC Class Codes: H01L 2924/19043 : being a resistor
• CPC Class Codes: H01L 2924/30105 : Capacitance
• CPC Class Codes: H01L 2924/30107 : Inductance
• CPC Class Codes: H01L 2924/3512 : Cracking

Abstract

A packaging system for a high current, low voltage power supply. The power supply uses two bare die field effect transistors whose input and output electrodes are solder attached to low resistance, high current posts in the package. An associated controller chip is mounted to a rigid circuit board, and the circuit board is mechanically attached to the posts. The circuit board thereby gives physical rigidity to the package, but carries no high currents. The use of low resistance, high current posts reduces the heat generated, improving the long term reliability.

Claims

1. A package for semiconductor devices comprising:

a plurality of metallic posts attached to a substrate;

at least one semiconductor die having a first and second current handling electrode;

at least one metallic strap which couples the first current handling electrode of the semiconductor die to one of the metallic posts; and

a controller chip on the substrate and electrically coupled to a control electrode of the semiconductor die.

13. The package of claim 1, wherein the controller chip, the substrate, and the semiconductor die are enclosed in plastic.

2. A package for semiconductor devices comprising:

a plurality of metallic posts attached to a substrate;

at least one semiconductor die having a first and second current handling electrode; and

at least one metallic strap which couples the first current handling electrode of the semiconductor die to one of the metallic posts, wherein one of the metallic posts carries a supply voltage to the second current handling electrode of the semiconductor die.

3. A package for semiconductor devices comprising:

a plurality of metallic posts attached to a substrate;

at least one semiconductor die having a first and second current handling electrode; and

at least one metallic strap which couples the first current handling electrode of the semiconductor die to one of the metallic posts, wherein one of the metallic posts carries a ground potential to the at least one strap.

4. A package for semiconductor devices comprising:

a plurality of metallic posts attached to a substrate;

at least one semiconductor die having a first and second current handling electrode; and

at least one metallic strap which couples the first current handling electrode of the semiconductor die to one of the metallic posts, wherein one of the metallic posts is coupled to the second current handling electrode of the semiconductor die, and also to a second metallic strap coupled to another semiconductor die.

5. A package for semiconductor devices comprising:

a plurality of metallic posts attached to a substrate;

at least one semiconductor die having a first and second current handling electrode; and

at least one metallic strap which couples the first current handling electrode of the semiconductor die to one of the metallic posts, wherein the metallic posts are about 0.5 mm to about 2.5 mm thick.

6. The package of claim 5, wherein the metallic posts are leads of a single-in-line package.

8. The package of claim 5, wherein the posts are L-shaped in cross section.

10. The package of claim 5, wherein the semiconductor die comprises an FET.

7. A package for semiconductor devices comprising:

a plurality of metallic posts attached to a substrate;

at least one semiconductor die having a first and second current handling electrode; and

at least one metallic strap which couples the first current handling electrode of the semiconductor die to one of the metallic posts, wherein two or more of the posts are shorted together.

9. A package for semiconductor devices comprising:

a plurality of metallic posts attached to a substrate;

at least one semiconductor die having a first and second current handling electrode; and

at least one metallic strap which couples the first current handling electrode of the semiconductor die to one of the metallic posts, wherein the posts comprise copper, plated with nickel and gold.

11. A package for semiconductor devices comprising:

a plurality of metallic posts attached to a substrate;

at least one semiconductor die having a first and second current handling electrode; and

at least one metallic strap which couples the first current handling electrode of the semiconductor die to one of the metallic posts, wherein the straps comprise copper, plated with nickel and gold.

12. A package for semiconductor devices comprising:

a plurality of metallic posts attached to a substrate;

at least one semiconductor die having a first and second current handling electrode; and

at least one metallic strap which couples the first current handling electrode of the semiconductor die to one of the metallic posts, wherein the straps comprise aluminum that is ultrasonically bonded to the first current handling electrode of the semiconductor die.

14. A package for semiconductor devices comprising:

a plurality of metallic posts attached to a substrate;

at least one semiconductor die having a first and second current handling electrode; and

at least one metallic strap which couples the first current handling electrode of the semiconductor die to one of the metallic posts, wherein the substrate is a thermally conductive laminated ceramic-filled polymer.

15. A power supply comprising:

a plurality of metallic posts, comprising an input post, a ground post and an output post;

a first semiconductor die whose drain electrode is coupled to the input post, and whose source electrode is coupled to a first metallic strap which is coupled to the output post; and

a second semiconductor die whose drain electrode is coupled to the output post; and

whose source electrode is coupled to the ground post by a second metallic strap.

16. The power supply of claim 15, further comprising:

a printed circuit board which is mechanically attached to the plurality of metallic posts.

17. The power supply of claim 16, further comprising a controller chip on the printed circuit board, and which outputs a control gate signal which is coupled to a gate electrode of the semiconductor die.

18. The power supply of claim 15, wherein the input post, ground post and output post are leads of a single-in-line package (SIP).

19. The power supply of claim 15, wherein the input post, ground post and output post are leads of surface mount technology (SMT) package.

20. The power supply of claim 15, wherein the first and second straps comprise copper, plated with nickel and gold.

21. The power supply of claim 15, wherein the posts are about 0.5 mm to about 2.5 mm thick and comprise aluminum or copper.

22. The power supply of claim 15, wherein the posts comprise copper, plated with nickel and gold.

23. The power supply of claim 15, further comprising:

an input capacitor coupled between the input post and the ground post.

24. The power supply of claim 15, further comprising:

an inductor coupled to the output post and a load; and

a capacitor coupled between the inductor and the ground post.

25. The power supply of claim 15, wherein the posts are L-shaped in cross section.

26. The power supply of claim 15, wherein the posts have a shape configured to provide a surface mount configuration.

27. The power supply of claim 15, wherein the posts have a gull-wing shape in cross section.

28. The power supply of claim 15, wherein at least one of the metallic posts carries a supply voltage to the drain electrode of at least one of the first semiconductor die and the second semiconductor die.

29. The power supply of claim 15, wherein at least one of the metallic posts carries a ground potential to at least one of the first metallic strap and the second metallic strap.

30. The power supply of claim 15, wherein the metallic posts are about 0.5 mm to about 2.5 mm thick.