1. A lead frame for a packaged semiconductor device, the lead frame comprising:
a heat sink structure defining a first plane;
a die paddle defining a second plane substantially parallel to and spaced from the first plane, wherein the die paddle comprises two intersecting arms forming an X-shape having four triangular openings, and the heat sink structure comprises four triangular pads corresponding to the four triangular openings in the X-shaped die paddle;
a plurality of tie bars physically and thermally interconnecting the heat sink structure and the die paddle to form a heat sinkpaddle sub-assembly, wherein the tie bars connect the die paddle to the heat sink structure at a plurality of locations along the X-shaped die paddle, and wherein the tie bars comprise:
a first plurality of tie bars located at a periphery of the two intersecting arms; and
a second plurality of tie bars located at an intersection of the two intersecting arms; and
a plurality of leads positioned adjacent to the heat sinkpaddle sub-assembly.
2. The lead frame of claim 1, wherein each tie bar comprises a down step between the second plane and the first plane.
3. The lead frame of claim 1, wherein:
the leads have an outer end located in the first plane, an inner end located in the second plane, and a middle section that extends between and connects the inner and outer ends.
4. A packaged semiconductor device, comprising:
a lead frame including,
a heat sink structure defining a first plane,
a die paddle defining a second plane substantially parallel to and spaced from the first plane, wherein the die paddle comprises two intersecting arms forming an X-shape having four triangular openings, and the heat sink structure comprises four triangular pads corresponding to the four triangular openings in the X-shaped die paddle,
a plurality of tie bars physically and thermally interconnecting the heat sink structure and the die paddle to form a heat sinkpaddle sub-assembly, wherein the tie bars connect the die paddle to the heat sink structure at a plurality of locations along the die paddle, and wherein the tie bars comprise:
a first plurality of tie bars located at a periphery of the two intersecting arms; and
a second plurality of tie bars located at an intersection of the two intersecting arms, and
a plurality of leads positioned adjacent to the heat sinkpaddle sub-assembly;
a die mounted on the die paddle;
bond wires electrically connecting the die to corresponding ones of the leads; and
mold compound encapsulating the die and the bond wires and at least a portion of the lead frame, wherein a portion of the heat sink structure and a portion of each lead are exposed.
5. The packaged semiconductor device of claim 4, further comprising:
a heat sink connected to the exposed portion of the heat sink structure.
6. The packaged semiconductor device of claim 4, wherein the leads have an outer end located in the first plane, an inner end located in the second plane, and a middle section that extends between and connects the inner and outer ends.
7. The packaged semiconductor device of claim 4, wherein each tie bar comprises a down step between the second plane and the first plane.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
We claim:
1. A test strip platform of the type used for receiving a test strip for an analytical determination, the test platform comprising:
a shroud portion comprising
a strip track being dimensioned to receive a test strip therein and for providing lateral stability to said strip while allowing said strip to be slidably inserted in a direction of a longitudinal dimension of said strip;
an optical aperture along said strip track dimensioned to underlie at least a portion of said strip and to provide optical access thereto;
at least one stabilizing member extending into said strip track in the vicinity of said optical aperture to retain a test strip therein with said portion of said test strip in a predetermined spatial orientation with respect to said optical aperture;
a hood portion permanently attached to said shroud portion over said strip track so as to protectingly overlie said optical aperture; the hood portion comprising
at least one camming member descending into said strip track and positioned so as to guide the leading edge of an inserted strip into cooperative engagement with said at least one stabilizing member.
2. The test strip platform of claim 1, wherein said at least one stabilizing member comprises at least on finger member.
3. The test strip platform of claim 2, wherein said at least one finger member further comprises a protuberance for engaging indents on a test strip.
4. The test strip platform of claim 1 further comprising structure for engaging indents on an inserted strip for providing retention of a test strip after full strip insertion.
5. The test strip platform of claim 4, wherein said structure further provides a tactile indication of full strip insertion.
6. The test strip platform of claim 3, wherein there are two fingers.
7. The test strip platform of claim 1, wherein there are two camming members.
8. A testing apparatus comprising a test strip platform according to claim 1.
9. A method of performing an analytical determination comprising the steps of:
providing a testing apparatus as set forth in claim 7;
providing a test strip having a leading edge and a color spot;
applying a material containing analyte to said test strip so as to cause an optically measurable change at said color spot;
introducing a test strip into said strip track;
advancing said test strip such that said leading edge is guided by said at least one camming member into cooperative engagement with said at least one stabilizing member until said color spot is overlying said optical aperture;
optically accessing said color spot to make the analytical determination.
10. The method of claim 9 further comprising the step of retaining said strip in position in said strip track when said color spot is overlying said optical aperture.
11. The method of claim 9 further comprising the step of providing a tactile indication when said color spot is overlying said optical aperture.