SEMICONDUCTOR PACKAGE SUITABLE FOR HIGH VOLTAGE APPLICATIONS
A semiconductor package has a structure in which a leadframe pad to which a semiconductor die is attached and inner leads electrically connected to the leadframe pad are covered by a molded housing, and outer leads extending from the inner leads protrude from a side surface of the molded housing to the outside. The outer leads include a first outer lead disposed in a central portion of the molded housing, second and third outer leads respectively disposed in a right and left of the first outer lead. The second and third outer leads each have bent portions in portions where they are adjacent to the side surface of the molded housing, the bent portions protruding to increase a space between the first outer lead and the bent portions in the molded housing. At least one of the bent portions of the second and third outer leads is covered by an extended portion of the molded housing.
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This application is a continuation of U.S. application Ser. No. 10/762,075 filed Jan. 21, 2004, which claims the benefit of Korean Patent Application No. 2003-4025, filed on Jan. 21, 2003, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
BACKGROUND OF THE INVENTION1. Field of the Invention
The present invention relates to a semiconductor package, and more particularly, to a semiconductor package suitable for high voltage applications.
2. Description of the Related Art
Generally, semiconductor devices such as diodes, thyristors, or MOS gate devices, for example, metal-oxide-semiconductor field effect transistors (MOSFET) and insulated gate bipolar transistors (IGBT), are formed in a silicon semiconductor die including a device junction. The die includes a metal drain electrode at its lower portion, a metal source electrode, and a gate electrode. The die is attached to a surface of a leadframe pad, and electrodes are electrically connected to the leadframe by a wire bonding. Consequently, the electrodes are electrically connected to outer leads of the leadframe. The outer leads protrude out of a molded housing. The silicon semiconductor die and the wire are completely molded in the housing.
Creepage distance is the distance along a path that begins at one exposed lead, travels along the surface of the one exposed lead and the package and ends at the adjacent exposed lead. In a semiconductor package having a structure in which outer leads protrude out of a molded housing, there must be enough creepage distance to ensure a high voltage. If the creepage distance is insufficient, it is well-known in the art that the maximum application voltage of the semiconductor package is limited.
Referring to
Since the creepage distance between the outer leads can be increased, a higher voltage can be applied to the conventional semiconductor package. However, in order to ensure the longer creepage distance, side surface 28 in
Referring to
In the semiconductor package having the above structure, the creepage distance 52 between the outer lead 45 and the outer lead 46 increases, and the creepage distance 53 between the outer lead 47 and the outer lead 45 also increases. However, as in the semiconductor package of
The present invention provides a semiconductor package suitable for high voltage applications, having a structure in which a creepage distance between outer leads is increased without increasing a size of the semiconductor package.
According to an aspect of the present invention, there is provided a semiconductor package in which a leadframe pad to which a semiconductor die is attached and inner leads electrically connected to the leadframe pad are covered by a molded housing, and outer leads extended from the inner leads protrude from a side surface of the molded housing to the outside. The outer leads include a first outer lead disposed in a central portion of the molded housing, and second and third outer leads respectively disposed in a right and left portions of the first outer lead. The second and third outer leads each have bent portions in portions where they are adjacent to the side surface of the molded housing, the bent portions protruding to increase a space between the first outer lead and the bent portions in the molded housing. Also, at least one of the bent portions of the second and third outer leads is covered by an extended portion of the molded housing.
A portion where the first outer lead is adjacent to the side surface of the molded housing may be covered by the extended portion of the molded housing. In this case, a distance between a surface of the molded housing covering the portion of the first outer lead and a surface of the molded housing covering at least one of the bent portions of the second and third outer leads may be 1 mm or more.
A depression toward a body of the molded housing may be formed on at least one of a surface of the molded housing between the first outer lead and the second outer lead and a surface of the molded housing between the first outer lead and the third outer lead.
According to an aspect of the present invention, there is provided a semiconductor package in which a leadframe pad to which a semiconductor die is attached and inner leads electrically connected to the leadframe pad are covered by a molded housing, and outer leads extended from the inner leads protrude from a side surface of the molded housing to the outside. The outer leads include a first outer lead disposed in a central portion of the molded housing, second and third outer leads respectively disposed in a right and left of the first outer lead. The second and third outer leads each include inclinations in which a distance between the first outer lead and the inclinations becomes larger as a distance between the inclinations and the side surface of the molded housing becomes smaller. And at least one of the inclinations of the second and third outer leads is covered by an extended portion of the molded housing.
A portion where the first outer lead is adjacent to the side surface of the molded housing may be covered by the extended portion of the molded housing. In this case, a distance between a surface of the molded housing covering the portion of the first outer lead and a surface of the molded housing covering at least one of the inclinations of the second and third outer leads may be 1 mm or more.
A depression toward a body of the molded housing may be formed on at least one of a surface of the molded housing between the first outer lead and the second outer lead and a surface of the molded housing between the first outer lead and the third outer lead.
At least one of the inclinations of the second and third outer leads may include a portion which is perpendicular to a surface of the molded housing and a flat portion which is larger than a thickness of the molded housing covering the inclinations in a boundary between the inclinations and the molded housing,
BRIEF DESCRIPTION OF THE DRAWINGSThe above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:
The second and third outer leads 122 and 123 disposed at the edge portion include bent portions 124 and 126 protruding toward directions opposite to the first outer lead 121 in portions adjacent to the molded housing 110. That is, a surface of the second outer lead 122 facing the first outer lead 121 is depressed to be apart from the first outer lead 121 on one side surface 112 of the molded housing 110, and accordingly, the second outer lead 122 protrudes from the surface opposing the above surface of the second outer lead 122. A surface of the third outer lead 123 facing the first outer lead 121 is depressed to be apart from the first outer lead 121 on one side surface 112 of the molded housing 110, and accordingly, the third outer lead 123 protrudes from the surface opposing the above surface of the third outer lead 123.
The bent portions 124 and 126 of the second and third outer leads 122 and 123 are covered by the molded housing 110. Also, a portion of the first outer lead 121 is covered by the molded housing 110. That is, the molded housing 110 extends at some parts thereof so as to cover a portion of the first outer lead 121 and the bent portions 124 and 126 of the second and third outer leads 122 and 123. The thickness of the molded housing 110 covering a part of the first outer lead 121 and the bent portions 124 and 126 is not necessarily thick, but it is appropriate that the thickness of the molded housing 110 is relatively thin. A distance (d) between a surface of extended portion of the molded housing 110 covering the first outer lead 121 and a surface of extended portion of the molded housing 110 covering the bent portion 126 of the third outer lead 123 is about 1 mm or more.
In the semiconductor package 100 having the above described structure, the creepage distance (de) (as shown by the dotted line) between the first outer lead 121 and the second outer lead 122 is a surface distance of the molded housing 110 measured from a first point (a) of the first outer lead 121 to a second point (b) of the second outer lead 122. Therefore, the semiconductor package is capable of ensuring a creepage distance larger than that of the conventional semiconductor package as long as the length of extended portion of the molded housing 110 covering the surface of the bent portion 124 of the second outer lead 122. The creepage distance between the first outer lead 121 and the third outer lead 123 also increases. In the semiconductor package 100 according to the present embodiment, a size of the semiconductor package does not increase in spite of the increase of creepage distance (de). This is because the increase of the creepage distance (de) is achieved using a structure in which a portion of the molded housing 110 extends to cover the bent portions 124 and 126 of the second and third outer leads 122 and 123.
Referring to
The inclinations 224 and 226 of the second and third outer leads 122 and 123 are covered by the molded housing 110. Also, a portion of the first outer lead 121 is covered by the molded housing 110. That is, the molded housing 110 extends so as to cover the portion of the first outer lead 121 and the inclinations 224 and 226 of the second and third leads 122 and 123. The thickness of the molded housing 110 covering the portion of the first outer lead 121 and the inclinations 224 and 226 is relatively small. An interval (d′) between a surface of extended portion of the molded housing 110 covering the first outer lead 121 and a surface of extended portion of the molded housing 110 covering the inclination 226 of the third outer lead 123 is about 1 mm or more.
In the semiconductor package 200 having the above described structure, the creepage distance (dc′) between the first outer lead 121 and the second outer lead 122 is the surface distance from a first point (a′) of the first outer lead 121 to a second point (b′) of the second outer lead 122. Therefore, a length corresponding to the extended portion of the molded housing 110 covering a surface of the inclination 224 of the second outer lead 122 can be ensured as the creepage distance longer than that of the conventional art. The creepage distance between the first outer lead 121 and the third outer lead 123 also increases. In the semiconductor package 200 according to the present embodiment, a size of the semiconductor package 200 does not increase in spite of the increase of the creepage distance (dc′). This is because that the increase of the creepage distance (do′) can be achieved by extending a part of the molded housing 110 so as to cover the inclinations 224 and 226 of the second and third outer leads 122 and 123.
In the semiconductor package in FIG, 8A, the extended portion of the molded housing 110 covering a portion of the first outer lead 121 is removed, and consequently, the first outer lead 121 is completely exposed out of the molded housing 110. Thus, the semiconductor package in
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Referring to
As described above, according to the semiconductor package of the present invention, the bent portion or the inclination is formed on some parts of the outer leads which connect with a side surface of the molded housing, and the extended portion of the molded housing is covered thereon to increase the creepage distances between outer leads. Accordingly, rated voltage applicable to the outer leads of the semiconductor package can be increased, thus providing the structure suitable to the high voltage application.
While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.
Claims
1-9. (canceled)
10. A semiconductor package having a molded housing comprising:
- a) first and second leads extending both inside and outside said molded housing, said first lead having a surface between two edges of said lead;
- b) said surface having a lateral bend which is inside said molded housing and proximate to an edge of said molded housing abutting said first lead, said lateral bend being in a direction to increase the creepage distance between said surface and said second lead; and
- c) said molded housing having an edge that extends on said lateral bend and which substantially follows the contour of said lateral bend.
11. The semiconductor package of claim 10 wherein an edge of said molded housing abutting said second lead extends in a direction parallel with said longitudinal axis of said second lead.
12. The semiconductor package of claim 10 further including a third lead which is positioned laterally next to said second lead away from said first lead.
13. The semiconductor Package of claim 12 wherein said third lead has a surface between two edges of said lead, said surface of said third lead having a lateral bend which is inside said molded housing, said lateral bend in said third lead being in a direction to increase the creepage distance between said surface of said third lead and said second lead, and said molded housing having an edge that extends on said lateral bend of said third lead and which substantially follows the contour of said lateral bend of said third lead.
14. The semiconductor package of claim 13 wherein an edge of said molded housing abutting said second lead extends in a direction parallel with the extended edge of said molded housing abutting said third lead.
15. The semiconductor package of claim 10 wherein an edge of said molded housing between said first and second leads has an indentation to increase the creepage distance between said first and second leads.
16. The semiconductor package of claim 12 wherein an edge of said molded housing between said second and third leads has an indentation to increase the creepage distance between said second and third leads.
17. A semiconductor package having a molded housing comprising:
- a) first and second leads extending both inside and outside said molded housing, said first lead having a surface between two edges of said lead;
- b) said surface having a bend which is inside said molded housing and proximate to an edge of said molded housing abutting said first lead, said lateral bend being in a direction to increase the creepage distance between said surface and said second lead; and
- c) said molded housing having an edge that extends with a substantially constant thickness on said lateral bend of said first lead.
18. The semiconductor package of claim 17 wherein an edge of said molded housing abutting said second lead extends in a direction parallel with said longitudinal axis of said second lead.
19. The semiconductor package of claim 17 further including a third lead which is positioned laterally next to said second lead away from said first lead.
20. The semiconductor package of claim 17 wherein said third lead has a surface between two edges of said third lead, said surface of said third lead having a lateral bend which is inside said molded housing, said lateral bend in said third lead being in a direction to increase the creepage distance between said surface of said third lead and said second lead, and said molded housing having an edge that extends with a substantially constant thickness on said lateral bend of said third lead.
21. The semiconductor package of claim 20 wherein an edge of said molded housing abutting said second lead extends in a direction parallel with said longitudinal axis of said second lead equal to the extended edge of said molded housing abutting said third lead.
22. The semiconductor package of claim 17 wherein an edge of said molded housing between said first and second leads has an indentation to increase the creepage distance between said first and second leads.
23. The semiconductor package of claim 22 wherein an edge of said molded housing between said second and third leads has an indentation to increase the creepage distance between said second and third leads.
Type: Application
Filed: Apr 3, 2007
Publication Date: Aug 9, 2007
Applicant: Fairchild Korea Semiconductor, Ltd. (Bucheon City)
Inventors: Joon-seo Son (Gangseo-gu), Shi-baek Nam (Bucheon-city), O-seob Jeon (Seoul)
Application Number: 11/695,794
International Classification: H01L 23/495 (20060101);