Integrated circuit package and method of manufacture thereof
An integrated circuit (IC) package 100 comprises an IC 102 and leads 104 coupled to the IC. Each lead has a first end 106 configured to be coupled to the integrated circuit and a second end 108 configured to pass through one of a plurality of mounting holes 110 extending through a mounting board 112. The leads comprise at least one positioning lead 114 comprising a stop 118 being a continuous part of the positioning lead and having a lateral dimension 120 greater than a diameter 122 of a first hole 124 of the plurality of mounting holes. The leads further comprise at least one non-positioning lead 116 having a continuous uniformly shaped body 130 with a lateral dimension 132 less than a diameter 134 of a second hole 136 of the plurality of mounting holes. The stop limits an extension of the non-positioning lead through the second hole.
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The present invention is directed to integrated circuit packaging and a method for manufacturing an integrated circuit package.
BACKGROUND OF THE INVENTIONAfter the manufacture of integrated circuits on a semiconductor wafer there remains the need to protect the individual integrated circuit dies from damage and to provide connections to other devices. The enclosure surrounding and connections to the integrated circuit is referred to as an integrated circuit package. Numerous consumer electrical products demand integrated circuit packages that are subject to high cost constraints. As integrated circuits grow in complexity and capabilities, however, conventional integrated circuit packages have inadequate thermal management and connectivity requirements. Additionally, today's complex integrated circuits are highly susceptible to damage by mechanical stresses that can be imparted from the surface that the integrated circuit package is mounted on.
Accordingly, what is needed in the art is an integrated circuit package that allows a large number of connections to the integrated circuit, facilitate heat transfer away from the integrated circuit, and protect the integrated circuit from mechanical stresses.
SUMMARY OF THE INVENTIONTo address the above-discussed deficiencies of the prior art, the present invention provides in one embodiment, an integrated circuit package. The integrated circuit package comprises an integrated circuit and leads coupled to the integrated circuit. Each of the leads have a first end configured to be coupled to the integrated circuit and a second end configured to pass through one of a plurality of mounting holes extending through a mounting board. The leads comprise at least one positioning lead comprising a stop being a continuous part of the positioning lead and having a lateral dimension greater than a diameter of a first hole of the plurality of mounting holes. The leads further comprise at least one non-positioning lead having a continuous uniformly shaped body with a lateral dimension less than a diameter of a second hole of the plurality of mounting holes. The stop limits an extension of the non-positioning lead through the second hole.
Another aspect of the present invention is a method of manufacturing an integrated circuit package. The method comprises forming a plurality of leads. Each of said leads having first and second ends configured as described above. Forming the plurality of leads includes forming positioning and non-positioning leads configured as described above.
The foregoing has outlined preferred and alternative features of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiments as a basis for designing or modifying other structures for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent constructions do not depart from the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGSFor a more complete understanding of the present invention, reference is now made to the following detailed description taken in conjunction with the accompanying FIGUREs. It is emphasized that various features may not be drawn to scale. In fact, the dimensions of various features may be arbitrarily increased or reduced for clarity of discussion. In addition, it is emphasized that some circuit components may not be illustrated for clarity of discussion. Reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
Each of the leads 104 have a first end 106 configured to be coupled to the integrated circuit 102 and a second end 108 configured to pass through one of a plurality of mounting holes 110 extending through a mounting board 112. The leads 104 comprise at least one positioning lead 114 and at least one non-positioning lead 116. The positioning lead 114 comprises a stop 118. The stop 118 is a continuous part of the positioning lead 114 and has a lateral dimension 120 that is greater than a diameter 122 of a first hole 124 of the plurality of mounting holes 110. The term lateral dimension 120 as used herein refers to any number of directions 126, 127 that is parallel with a plane 128 of the mounting board 112. The non-positioning lead 116 has a continuous uniformly shaped body 130 with a lateral dimension 132 less than a diameter 134 of a second hole 136 of the plurality of mounting holes 110. The stop 118 limits an extension of the non-positioning lead 116 through the second hole 136.
The first ends 106 of the leads 104 can be configured for direct or indirect coupling to the integrated circuit 102. For the embodiment shown in
With continuing reference to
In some preferred embodiments, such as shown in
The stop 118 of the positioning lead 114 is configured to hold the integrated circuit package 100 above the plane 128 of the mounting board 112 by a fixed distance 158, for example, about 100 microns to about 2000 microns. Holding the integrated circuit package 100 above the plane 128 of the mounting board 112 advantageously protects the integrated circuit 102 against damage from mechanical stresses that can otherwise be imparted from the mounting board 112 to the integrated circuit package 100. Preferably, the stop 118 is configured to prevent a segment 160 of the positioning lead 114 from passing through the first hole 124. As illustrated in
The stop can be configured to have a number of different shapes to provide the lateral dimension greater than the diameter of its corresponding mounting hole. For example, as illustrated in
As another example, the positioning lead can have a stop that comprises a bend in the positioning lead. For instances,
With continuing reference to
As shown in
In some instances, configuring the positioning leads 205, 210 as corner leads provides the additional benefit of reducing the pitch 215 between the corner positioning lead 210 and an adjacent interior non-positioning lead 220. Reducing the pitch 215 between the corner positioning lead 210 and the adjacent interior non-positioning lead 220 is facilitated by locating the stop 118 on a side of the positioning lead 210 that is non-proximal to the adjacent non-positioning lead 220, as shown in
Corner positioning leads 205, 210 can be advantageously used in combination with a variety of surface mounting configurations to reduce the interior lead pitch 225 and thereby increase the number of connections to the integrated circuit 102. For instance, as shown in
With continuing reference to
For clarity, only a limited number of leads 104 are depicted in the embodiments of the integrated circuit packages illustrated in
Another aspect of the present invention is a method of manufacturing an integrated circuit package. The method of manufacturing an integrated circuit package can be used to produce any of the embodiments of the integrated circuit package presented in
With continuing reference to
With continuing reference to
With continuing reference to
With continuing reference to
The stop 715 of the positioning leads 710 is configured to have a lateral dimension 820 greater than the diameter 815 of a first hole 825. The stop 715 thereby limits an extension of at least one non-positioning lead 720 through a second hole 830 of the mounting holes 810. Moreover, because the stop 715 is a continuous part of the positioning lead 710, the stop 715 is less prone to deform, break or shear off while the integrated circuit package is being mounted or in use, as compared to a stop that is mechanically attached or bonded to the positioning lead 710. Returning to
For the embodiment presented in
Such an embodiment is illustrated in
With continuing reference to
While maintaining reference to
With continuing reference to
While still referring to
For clarity, the manufacture of the integrated circuit packages shown in
Although the present invention has been described in detail, those skilled in the art should understand that they could make various changes, substitutions and alterations herein without departing from the scope of the invention in its broadest form.
Claims
1. An integrated circuit package, comprising:
- an integrated circuit; and
- leads coupled to said integrated circuit, each of said leads having a first end configured to be coupled to said integrated circuit and a second end configured to pass through one of a plurality of mounting holes extending through a mounting board, and wherein said leads comprise: one or more positioning lead comprising a stop being a continuous part of said positioning lead and having a lateral dimension greater than a diameter of a first hole of said plurality of mounting holes, and one or more non-positioning lead having a continuous uniformly shaped body with a lateral dimension less than a diameter of a second hole of said plurality of mounting holes, wherein said stop limits an extension of said non-positioning lead through said second hole.
2. The integrated circuit package as recited in claim 1, further comprises a mold encompassing said integrated circuit and holding a heat sink above a top surface of said integrated circuit.
3. The integrated circuit package as recited in claim 1, further comprises a mold encompassing said integrated circuit, wherein said first end is encompassed by said mold and at least a portion of said stop is below a bottom surface of said mold.
4. The integrated circuit package as recited in claim 3, wherein said stop is configured to hold said bottom surface above said mounting board by a fixed distance.
5. The integrated circuit package as recited in claim 1, wherein said stop is configured to prevent a segment of said positioning lead from passing through said first hole, said segment being between said first end and said stop.
6. The integrated circuit package as recited in claim 1, wherein said stop comprises a bend in said positioning lead.
7. The integrated circuit package as recited in claim 6, wherein said bend has an interior angle ranging from about 70 to about 110 degrees.
8. The integrated circuit package as recited in claim 1, wherein said stop comprises an increased width in said positioning lead.
9. The integrated circuit package as recited in claim 8, wherein said increased width is at least about 5 percent greater than said diameter of said first hole.
10. The integrated circuit package as recited in claim 1, further comprises at least two of said positioning leads, wherein said positioning leads are corner leads being coupled to opposing corners of said integrated circuit.
11. The integrated circuit package as recited in claim 1, further comprises at least four of said positioning leads, wherein said positioning leads are corner leads each one of said positioning leads being coupled to different corners of said integrated circuit.
12. The integrated circuit package as recited in claim 1, wherein said stop is located on a side of said positioning lead that is non-proximal to an adjacent non-positioning lead.
13. The integrated circuit package as recited in claim 1, wherein said non-positioning lead comprises short non-positioning leads interleaved with long non-positioning leads, both said short and long non-positioning leads being coupled to a same side of said integrated circuit.
14. A method of manufacturing an integrated circuit package, comprising:
- forming a plurality of leads, each of said leads having a first end configured to be coupled to an integrated circuit and a second end configured to pass through one of a plurality of holes extending through a mounting board, including: forming a positioning lead comprising a stop being a continuous part of said positioning lead and having a lateral dimension greater than a diameter of a first hole of said plurality of mounting holes; and forming a non-positioning lead having a continuous uniformly shaped body having a lateral dimension less than a diameter of a second hole of said plurality of mounting holes, wherein said stop limits an extension of said non-positioning lead through said second hole.
15. The method recited in claim 14, wherein forming said positioning lead comprises:
- forming a layout pattern on a metal sheet, wherein said layout pattern comprises a lead layout pattern for said least one positioning lead having said stop; and
- removing portions of said metal sheet that are outside of said layout pattern to thereby form a lead frame comprising said at least one positioning lead.
16. The method as recited in claim 15, wherein said stop comprises a width greater than that of an adjacent portion of said positioning lead, said adjacent portion being configured to pass through said first hole.
17. The method of fabrication recited in claim 14, wherein forming said positioning lead comprises:
- forming a lead layout pattern on a metal sheet, wherein said layout pattern comprises a lead layout pattern for a plurality of uniformly shaped leads;
- removing portions of said metal sheet that are outside of said layout pattern to thereby form said leads that are uniformly-shaped leads; and
- bending at least one of said uniformly shaped leads to form said positioning lead comprising said stop.
18. The method as recited in claim 17, wherein said stop comprises a bend with an interior angle ranging from about 70 to about 110 degrees.
19. The method as recited in claim 14, further includes bending said positioning lead to configure said stop to be below a bottom surface of a mold encompassing said integrated circuit.
20. The method as recited in claim 14, further comprising
- coupling a heat sink to a top surface of said integrated circuit; and
- encompassing said integrated circuit in a mold.
Type: Application
Filed: Feb 25, 2005
Publication Date: Aug 31, 2006
Applicant: Texas Instruments Incorporated (Dallas, TX)
Inventors: Bernhard Lange (Garland, TX), William Boyd (Frisco, TX)
Application Number: 11/066,875
International Classification: H01L 23/48 (20060101);