HIGH CURRENT CAPACITY SEMICONDUCTOR DEVICE PACKAGE AND LEAD FRAME WITH LARGE AREA CONNECTION POSTS AND MODIFIED OUTLINE

• US 20010054752A1
• Filed: 06/23/1998
• Published: 12/27/2001
• Est. Priority Date: 05/05/1998
• Status: Active Grant

• Current Assignee: Infineon Technologies Americas Corp. (Infineon Technologies AG)
• Original Assignee: International Rectifier Corporation (Infineon Technologies AG)
• Inventors: EWER, PETER R., WOODWORTH, ARTHUR, TEASDALE, KEN
• Granted Patent: US 6,476,481 B2
• Time in Patent Office: Days
• US Class Current: 257/676
• CPC Class Codes: H01L 2224/0603 Bonding areas having different sizes, e.g. different heights or widths
• CPC Class Codes: H01L 2224/45012 Cross-sectional shape
• CPC Class Codes: H01L 2224/45015 being circular
• 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 2224/48472 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 2224/49171 Fan-out arrangements
• CPC Class Codes: H01L 23/49562 for devices being provided for in H01L29/00
• 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 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 2924/01013 Aluminum [Al]
• CPC Class Codes: H01L 2924/01014 Silicon [Si]
• CPC Class Codes: H01L 2924/01023 Vanadium [V]
• CPC Class Codes: H01L 2924/01028 Nickel [Ni]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/0103 : Zinc [Zn]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01204 : 4N purity grades, i.e. 99.99%
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/1301 : Thyristor
• CPC Class Codes: H01L 2924/13055 : Insulated gate bipolar transistor [IGBT]
• CPC Class Codes: H01L 2924/13091 : Metal-Oxide-Semiconductor Field-Effect Transistor [MOSFET]
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/1815 : Shape
• CPC Class Codes: H01L 2924/19043 : being a resistor
• CPC Class Codes: H01L 2924/19107 : off-chip wires
• CPC Class Codes: H01L 2924/2076 : equal to or larger than 100 microns
• CPC Class Codes: H01L 2924/30107 : Inductance
• CPC Class Codes: Y10T 29/49121 : Beam lead frame or beam lead device

Abstract

A lead frame for a high power semiconductor device die has three external lead conductors, the outer two of which are reentrantly bent outwardly from the center of the lead frame. When the lead frame is overmolded, the outer conductors are spaced from a central conductor by an increased creepage distance along the plastic surface of the housing. Further, the lead sequence of the exterior leads is gate, source, drain for a power MOSFET. The post area for wire bonding to the source post is enlarged to permit wire bonding with at least three bond wires. The external conductors can be downwardly bent to form a surface mount device. The cross-sectional area of the external conductors is substantially enlarged, although only a small enlargement of the circuit board hole is needed. The package outline has a long flat area centered over the main die area, with a tapered end surface which allows the package to pry open a mounting spring for surface mounting of the package.

Claims

1. A semiconductor device of increased current capacity without an increased size;

said semiconductor device comprising a lead frame, a semiconductor device die and a plurality of bonding wires;

said lead frame comprising a thin generally flat conductive body having a die mounting pad and a plurality of parallel spaced external conductors;

at least one of said parallel spaced external conductors having an enlarged bond wire post at one end thereof which is adjacent to but is spaced from said die mounting pad;

the bottom of said die being fixed to the top surface of said die mounting pad;

a plurality of said lead wires being bonded at one end thereof to the top surface of said die and at the other end thereof to said enlarged bond wire post;

said enlarged bond wire post having a width which is at least about one-half the width of said lead frame.

2. The device of

claim 1

wherein a second one of said external conductors has a second enlarged bond wire post for connection to a control electrode on the top surface of said die;

said enlarged bond wire post having one area substantially greater than that of said second enlarged bond wire post.

3. The device of

claim 1

wherein said die mounting pad is electrically connected to one of said external conductors.

4. The device of

claim 2

wherein said die mounting pad is electrically connected to one of said external conductors.

5. The device of

claim 1

wherein said device further includes a plastic housing for enclosing said die and at least portions of said lead frame;

said plurality of spaced conductors extending from the interior of said plastic housing, through a side wall of said housing to the exterior of said housing.

6. The device of

claim 2

wherein said device further includes a plastic housing for enclosing said die and at least portions of said lead frame;

said plurality of spaced conductors extending from the interior of said plastic housing, through a side wall of said housing to the exterior of said housing.

7. The device of

claim 3

wherein said device further includes a plastic housing for enclosing said die and at least portions of said lead frame;

said plurality of spaced conductors extending from the interior of said plastic housing, through a side wall of said housing to the exterior of said housing.

8. The device of

claim 4

wherein said device further includes a plastic housing for enclosing said die and at least portions of said lead frame;

said plurality of spaced conductors extending from the interior of said plastic housing, through a side wall of said housing to the exterior of said housing.

9. The device of

claim 1

wherein the laterally outermost two of said plurality of spaced external conductors are reentrantly bent to space the free extending ends of said conductors at a reduced spacing.

21. The device of

claim 1

wherein said enlarged bond wire post extends from one outer edge of said lead frame, and toward its center.

22. The device of

claim 21

wherein said die mounting pad is electrically connected to one of said external conductors.

23. The device of

claim 22

wherein said device further includes a plastic housing for enclosing said die and at least portions of said lead frame;

said plurality of spaced conductors extending from the interior of said plastic housing, through a side wall of said housing to the exterior of said housing.

24. The device of

claim 22

wherein the laterally outermost two of said plurality of spaced external conductors are reentrantly bent to space the free extending ends of said conductors at a reduced spacing.

27. The device of

claim 5

wherein said plastic housing is of rectangular shape and has a generally flat top surface, a generally bottom flat surface, a pair of spaced generally vertical and parallel edge walls extending between said top and bottom surfaces and said side wall and a second side wall at the side of said package which is opposite to said side wall;

said generally flat top surface overlying substantially, the full area of said die.

28. The device of

claim 27

wherein said second side wall is at an angle of about 45°

from the vertical to intersect said top surface at an interior angle of about 135°

to define a camming surface for camming said housing under a cantilevered mounting spring.

30. The device of

claim 1

wherein each of said external conductors have identical rectangular shapes, the edges of said external conductors being chamfered for at least a portion of their lengths to permit their insertion into a circuit board hole of diameter smaller than that which would accept the unchamfered conductor, and permitting the use of a larger cross-sectional area for said conductors for a given diameter circuit board opening.

10. A semiconductor device of increased current capacity without an increased size;

said semiconductor device comprising a lead frame, a semiconductor device die and a plurality of bonding wires;

said lead frame comprising a thin generally flat conductive body having a die mounting pad and a plurality of parallel spaced external conductors;

at least one of said parallel spaced external conductors having an enlarged bond wire post at one end thereof which is adjacent to but is spaced from said die mounting pad;

the bottom of said die being fixed to the top surface of said die mounting pad;

a plurality of said lead wires being bonded at one end thereof to the top surface of said die and at the other end thereof to said enlarged bond wire post;

a plastic housing for enclosing said die and at least portions of said lead frame;

said plurality of spaced conductors extending from the interior of said plastic housing, through a side wall of said housing to the exterior of said housing;

the laterally outermost two of said plurality of spaced external conductors being reentrantly bent to space the free extending ends of said conductors at a reduced spacing;

said reentrantly bent external conductors penetrating said side wall of said housing where they have their greatest spacing, thereby to increase the creepage distance along the surface of said side wall.

11. The device of

claim 10

wherein said enlarged bond wire post having a width which is at least about one-half the width of said lead frame.

12. The device of

claim 11

wherein a second one of said external conductors has a second enlarged bond wire post for connection to a control electrode on the top surface of said die;

said enlarged bond wire post having one area substantially greater than that of said second enlarged bond wire post.

13. The device of

claim 10

wherein said die mounting pad is electrically connected to one of said external conductors.

20. The device of

claim 10

in which said enlarged bond wire post is fixed to said source conductor and has a width of at least about one-half the width of said lead frame.

14. A semiconductor device of increased current capacity without an increased size;

said semiconductor device comprising a lead frame, a semiconductor device die and a plurality of bonding wires;

said lead frame comprising a thin generally flat conductive body having a die mounting pad and a plurality of parallel spaced external conductors;

at least one of said parallel spaced external conductors having an enlarged bond wire post at one end thereof which is adjacent to but is spaced from said die mounting pad;

the bottom of said die being fixed to the top surface of said die mounting pad;

a plurality of said lead wires being bonded at one end thereof to the top surface of said die and at the other end thereof to said enlarged bond wire post;

said plurality of spaced external conductors comprising three equally laterally spaced conductors which are disposed in the sequence of gate, source and drain conductors respectively for a power MOSFET and wherein said source conductor is the central conductor.

15. The device of

claim 14

in which said enlarged bond wire post is fixed to said source conductor and has a width of at least about one-half the width of said lead frame.

16. The device of

claim 14

wherein a second one of said external conductors has a second enlarged bond wire post for connection to a control electrode on the top surface of said die;

said enlarged bond wire post having one area substantially greater than that of said second enlarged bond wire post.

17. The device of

claim 16

wherein said die mounting pad is electrically connected to one of said external conductors.

18. The device of

claim 15

wherein said device further includes a plastic housing for enclosing said die and at least portions of said lead frame;

said plurality of spaced conductors extending from the interior of said plastic housing, through a side wall of said housing to the exterior of said housing.

19. The device of

claim 14

wherein the laterally outermost two of said plurality of spaced external conductors are reentrantly bent to space the free extending ends of said conductors at a reduced spacing.

25. The device of

claim 15

wherein said enlarged bond wire post extends from one outer edge of said lead frame, and toward its center.

26. The device of

claim 25

wherein said device further includes a plastic housing for enclosing said die and at least portions of said lead frame;

said plurality of spaced conductors extending from the interior of said plastic housing, through a side wall of said housing to the exterior of said housing.

29. A plastic semiconductor housing having an outline adapted to cam up a cantilevered mounting spring;

said housing having a semiconductor die mounted therein and a plurality of electrical conductors extending from said die and through a side wall of said housing to the exterior of said housing;

said plastic housing having a generally rectangular shape and having a generally flat top surface, a generally bottom flat surface, a pair of spaced generally vertical and parallel edge walls extending between said top and bottom surfaces and said side wall and a second side wall at the side of said package which is opposite to said side wall;

said generally flat top surface overlying substantially, the full area of said die, said second side wall is at an angle of about 45°

from the vertical to intersect said top surface at an interior angle of about 135°

to define a camming surface for camming said housing under a cantilevered mounting spring.