Lead frame having integral terminal tabs

• US 4,158,745 A
• Filed: 10/27/1977
• Issued: 06/19/1979
• Est. Priority Date: 10/27/1977
• Status: Expired due to Term

• Current Assignee: AMP Incorporated (Johnson Controls International plc)
• Original Assignee: AMP Incorporated (Johnson Controls International plc)
• Inventors: Keller, Joseph R.
• Primary Examiner(s): Reynolds, Bruce A.
• Assistant Examiner(s): Tone, D. A.
• Application Number:
  US05/846,052
• Time in Patent Office: 600 Days
• Field of Search: 174/52 FP, 174/16 HS, 357/70, 361/421, 29/589, 113/119
• US Class Current: 174/536
• CPC Class Codes: H01L 21/4842 Mechanical treatment, e.g. punching, cutting, deforming, cold welding
• CPC Class Codes: H01L 23/053 the container being a hollow construction and having an insulating or insulated base as a mounting for the semiconductor body
• CPC Class Codes: H01L 23/3107 the device being completely enclosed
• CPC Class Codes: H01L 23/49562 for devices being provided for in H01L29/00
• 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 2924/16195 Flat cap [not enclosing an internal cavity]

Abstract

A continuous strip of stamped and formed lead frames for a semi-conductor chip comprises a continuous carrier strip having three laterally extending arms integral therewith. One of the arms has a chip receiving surface to which the chip is soldered. The other arms have reversely bent end portions which extend over the chip receiving surface and which are intended to be connected to contact areas on the upwardly facing surface of the chip. Each of the arms has an integral terminal member extending therefrom in the plane of the strip and these terminal members are later bent upwardly relative to the plane of the strip so that they surround the chip receiving surface. The terminal members may comprise rectangular tabs formed by folding the stock metal of the strip and dimensioned to receive complementary contact terminals on the ends of wires thereby to connect the contact areas of the chip to external circuitry.

Claims

1. A continuous strip of stamped and formed lead frames, each lead frame of said strip being intended to receive, and establish electrical connections to, a chip having oppositely directed faces and having two contact areas on one of said faces and having one contact area on the other face, said strip comprising:

a continuous carrier strip means, said lead frames being integral with said carrier strip means at spaced-apart intervals,

each of said lead frames having a chip receiving zone which is spaced from said carrier strip means, each of said lead frames comprising first, second, and third arms, said arms being integral with said carrier strip means,

each of said arms having an integral terminal portion, each of said terminal portions being generally rectangular and comprising a plurality of thicknesses of sheet metal and being dimensioned to be mated with a complementary terminal device, said terminal portions radiating from said chip receiving zone of each lead frame,

said second arm of each lead frame having integral chip supporting surface portions in said chip receiving zone, said first and third arms having contact members which extend at least partially across said chip supporting surface portions, said contact members of said first and third arms having contact tip portions for establishing electrical contact with said two contact areas on said one face of a chip whereby,

upon placement of a chip on said chip supporting surface of one of said lead frames with said other face of said chip against said chip supporting surface and with said contact members extending across said one face of said chip, said chip supporting surface will be in electrical contact with said one contact area on said other face of said chip, and said contact tip portions of said contact members will be in electrical contact with said two contact areas on said one face of said chip, and upon severing said one lead frame from said strip and bending said terminal portions away from the plane of said strip in a common direction, said terminal portions will surround said chip receiving zone and external conductors can be connected to said chip by mating terminals in said external conductors with said terminal portions of said arms.

2. A strip as set forth in claim 1, each of said terminal portions comprising a terminal tab having two thicknesses of sheet metal.

3. A strip of stamped and formed lead frames as set forth in claim 1, two of said terminal portions of each of said lead frames extending in opposite directions and generally parallel to the length of said continuous strip, the remaining one of said terminal portions extending transversely of the length of said strip.

4. A strip as set forth in claim 3, said carrier strip means comprising a pair of spaced-apart continuous carrier strips, said lead frames being between said carrier strips.

5. A strip as set forth in claim 4, said carrier strip means further comprising spaced-apart ladder strips extending between, and integral with said spaced-apart carrier strips, each of said lead frames being between two adjacent ladder strips.

6. A strip as set forth in claim 5, two of said terminal portions of each of said lead frames extending in opposite directions and generally parallel to the length of said strip, said two terminal portions being integral with adjacent ladder strips, the third terminal portions extending towards, and being integral with, one of said carrier strips.

7. A continuous strip of stamped and formed lead frames as set forth in claim 1, said carrier strip means comprising at least one continuous carrier strip, said first, second, and third arms extending laterally in side-by-side relationship from said carrier strip, said second arm being between said first and third arms, said second arm having a free end portion which is remote from said carrier strip, said terminal portion of said second arm being at said free end portion, said chip supporting surface portions being between said free end portion and said carrier strip.

8. A continuous strip of stamped and formed lead frames as set forth in claim 1, said first and third arms having reverse bends, said contact members extending from said reverse bends towards said chip supporting surface.

9. A continuous strip of stamped and formed lead frames, each lead frame of said strip being intended to receive and establish electrical connections to a chip having oppositely directed faces and having two active areas on one of said faces and having one active area on the other face, said strip comprising:

a continuous carrier strip, said lead frames being integral with said carrier strip at spaced-apart intervals,

each of said lead frames comprising first, second, and third arms, each of said arms being integral with and extending laterally from one edge of said carrier strip, said arms being in side-by-side relationship, said second arm being between said first and third arms,

said second arm having a free end which is remote from said carrier strip and having a chip supporting zone which is between said free end and said carrier strip, said free end of said second arm having terminal means for engagement with an external conductor,

said first and third arms each being reversely bent at a location spaced from said carrier strip and having free end portions which extend to said chip supporting zone, said free end portions having contact tip portions at said chip supporting zone,

said first and third arm having integral terminal means extending therefrom in opposite directions parallel and proximate to said carrier strip whereby,

upon placement of a chip member in said chip supporting zone of one of said lead frames with said chip between said contact tip portions of said first and third arms and with said one face of said chip member beneath said contact portions of said first and third arms, said second arm will be in electrical contact with said one active area on said other face and said first and third arms will be in electrical contact with said two active areas on said one face; and

upon severing said arms from said carrier strip, said arms will be connected to said active areas by independent electrical paths.

10. A continuous strip as set forth in claim 9, said terminal means in said first, second, and third arms comprising folded portions of said sheet metal arms, said terminal means being in the form of tabs which are dimensioned to receive a complementary connecting device.

11. A package comprising a chip having oppositely directed faces, having two contact areas on one of said faces, and having one contact area in the other face, said package comprising:

substrate means, first, second, and third sheet metal arms mounted on said substrate means in parallel side-by-side spaced-apart relationship, said second arm being between said first and third arms,

said second arm having a chip supporting surface on, and extending parallel to, said substrate, said chip being on, and in electrical contact with, said chip supporting surface with said other face of said chip against said chip supporting surface,

said first and third arms having reverse bends therein intermediate their ends and each having a contact member extending from said reverse bends to said one face of said chip, said contact members having contact tip portions on their ends, said contact tip portion of said first arm being in electrical contact with one of said contact areas and said contact tip portion of said third arm being in electrical contact with the other contact area on said one face of said chip,

each of said arms having integral sheet metal terminal portions extending therefrom normally of the plane of said substrate, said terminal portions partially surrounding and forming an enclosure around said chip,

insulating housing means on said substrate in enclosing relationship to said arms and said chip, portions of said terminal members extending through said insulating housing whereby,

said chip can be electrically connected to external conductors by mating said terminal members with complementary terminal members on said external conductors.

12. A package as set forth in claim 11, said sheet metal terminal portions of said arms being folded to provide spaced-apart terminal tabs extending from said insulating housing.

13. A package as set forth in claim 12, said substrate means comprising an insulating substrate which is disposed against, and bonded to, said first, second, and third arms, and a metallic heat sink bonded to said substrate and extending laterally beyond said substrate, portions of said insulating housing means being on said heat sink.