THERMALLY AND ELECTRICALLY ENHANCED BALL GRID ARRAY PACKAGE
In one embodiment, a device package is provided. The device package can include a substrate having first and second opposing surfaces, an opening being formed through the first and second surfaces of the substrate; a stiffener coupled to the first surface of the substrate, the stiffener having an extending portion that extends into the opening of the substrate; and an integrated circuit (IC) die coupled to the extending portion of the stiffener, the IC die being electrically coupled to the substrate.
Latest Broadcom Corporation Patents:
This application is continuation of U.S. application Ser. No. 13/224,933, filed Sep. 2, 2011 (now allowed), which is a divisional of U.S. application Ser. No. 12/619,385, filed Nov. 16, 2009 (now U.S. Pat. No. 8,039,949), which is a divisional of U.S. application Ser. No. 10/963,620, filed Oct. 14, 2004 (now U.S. Pat. No. 7,629,681), which is a divisional of U.S. application Ser. No. 09/997,272, filed Nov. 30, 2001 (now U.S. Pat. No, 6,882,042), which claims the benefit of U.S. Provisional Application No. 60/250,950, filed Dec. 1, 2000, all of which are incorporated by reference herein.
BACKGROUND1. Field
The invention relates generally to the field of integrated circuit (IC) device packaging technology, and more particularly to substrate stiffening and heat spreading techniques in ball grid array (BGA) packages.
2. Background Art
Integrated circuit (IC) dies are typically mounted in or on a package that is attached to a printed circuit board (PCB). One such type of IC die package is a bail grid array (BGA) package. BGA packages provide for smaller footprints than many other package solutions available today. A BGA package has an array of solder balls located on a bottom external surface of a package substrate. The solder balls are reflowed to attach the package to the PCB. The IC die is mounted to a top surface of the package substrate. Wire bonds typically couple signals in the IC die to the substrate. The substrate has internal routing which electrically couples the IC die signals to the solder balls on the bottom substrate surface.
It would be advantageous to provide a thermally and electrically enhanced ball grid array (BGA) package that is smaller, cheaper, customizable and capable of superior performance when compared with conventional BGA packages. More specifically, it would be advantageous to provide an advanced BGA package that achieves: 1) enhanced thermal and electrical performance; 2) reduced package size; 3) increased flexibility of die configuration; 4) reduced ball pitch; 5) increased flexibility in circuit routing density; and 6) configurations with greater thermal spreading capabilities.
The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate the present invention and, together with the description, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention.
The present invention will now be described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements. Additionally, the left-most digit(s) of a reference number identifies the drawing in which the reference number first appears.
DETAILED DESCRIPTIONThe present invention provides a thermally and electrically enhanced ball grid array (BGA) packaging that is smaller, cheaper, customizable and capable of superior performance when compared with conventional BGA packages. More specifically, the present invention offers advanced BGA packages that achieve: 1) enhanced thermal and electrical performance; 2) reduced package size; 3) increased flexibility of die configuration; 4) reduced ball pitch; 5) increased flexibility in circuit routing density; and 6) optional configurations with or without the attachment of a heat sink.
Embodiments of the present invention may be used in a variety of electronic devices, including telecommunication devices, mobile phones, camcorders, digital cameras, network systems, printers, and testers.
Advantages of the various embodiments of the invention include: 1) an embedded heat spreader in the package for the silicon die to adhere onto, and a connection between the die and the heat spreader to provide thermal and electrical performance enhancement; 2) an option of a fully populated ball grid array assignment for circuit routing; 3) an option of multi-layer heat spreader structure to provide split and isolated ground; 4) an option of utilizing single, double or multi-layer metal circuitry substrate with or without plating traces and with or without conductive via connections to accommodate different thermal, electrical and design requirements; 5) exposed die attach pad for enhanced thermal performance; 6) drop-in heat slug for direct thermal and electrical conduction; 7) flexible range of ball pitch from 0.3 mm to 1.5 mm; 8) active ground connection capability from silicon die to motherboard through conductive slug attachment or through solder ball connects to the heat spreader; 9) high thermal conductive path; 10) low package profile compared with plastic ball grid array (PBGA) and other conventional BGA packages; and 11) wafer saw or punch format for maximized material utilization.
Embodiments of the present invention are described in detail below, and are designated as Designs 1 through 18.
Design 1—Fully Populated Package with Solid Grounding
Substrate 130 includes a base material/dielectric layer 102, a conductive metal layer 106, and a circuit mask 108. Metal layer 106 is attached to the bottom surface of dielectric layer 102 by an adhesive 104. Metal layer 106 is a conductive layer that is patterned with traces. Circuit mask 108 is applied to the top surface of dielectric layer 102. Dielectric layer 102 may be any one of PCB. FR4, polyimide, and ceramic dielectric materials.
Stiffener 112 is attached to the top surface of substrate 130 by an adhesive 110. Die 114 is attached to the top surface of stiffener 112 by a die attach epoxy 116. First wire connection 124 is coupled from a pin on die 114 to stiffener 112. A bondable plating surface 118 is formed on the top surface of stiffener 112 to enhance attachment of first wire connection 124 to stiffener 112. Second wire connection 126 is coupled from a pin on die 114 to a trace of metal layer 106. Mold/glob top 120 is formed over the top surface of stiffener 112 to encapsulate die 114 and first and second wire connections 124 and 126.
Preferably, copper is used to make metal layer 106, although other metals may also be used. Similarly, stiffener 112 is preferably made from copper so that it may provide a substantially rigid and planar surface, enhance the coplanarity of the different layers of substrate 130, and, at the same time, act as a heat spreader to help dissipate heat. Alternatively, other materials, such as aluminum or ceramic, may also be used to make the stiffener.
Preferably, bondable surface 118 is selectively plated, chemically deposited or electro-deposited on stiffener 112 for solid or float grounding purposes. Otherwise, stiffener 112 may be fully plated. Dielectric layer 102, preferably a polyimide tape, is patterned with openings or vias for accepting solder balls 122 so that solder balls 122 make electrical contact with the patterned conductive metal layer 106. The distance between centers of adjacent solder balls 122 is shown as ball pitch 128 in
Table 1 shows example dimensions and ranges for sonic of the elements shown in
Design 2—Fully Populated Package with Solid Grounding
Design 3—Fully Populated Package with Two Stiffeners and Symmetrical Segment Grounding
Other features of BGA package 300 are similar to the corresponding features in BGA package 200.
Design 4—Fully Populated Package with Two Stiffeners and Asymmetrical Segment Grounding
Other features of BGA package 400 are similar to the corresponding features in aforementioned designs.
Design 5—Fully Populated Package with Enhanced Routability
Other features of BGA package 500 are similar to the corresponding features in aforementioned designs.
Design 6—Fully Populated Package with Enhanced Routability
As such, BGA package 600 provides superior routing flexibility to BGA package 500, and offers excellent electrical and thermal performance. Note that more conductive layers may be used. In that case, however, both the manufacturing cost and the package size (thickness) would increase accordingly.
Other features of BGA package 600 are similar to the corresponding features in aforementioned designs.
Design 7—Fully Populated Package with Enhanced Signal Integrity
Other features of BGA package 700 are similar to the corresponding features in aforementioned designs.
Design 8—Fully Populated Package with Enhanced Signal Integrity and Routability
Other features of BGA package 800 are similar to the corresponding features in aforementioned designs.
Design 9—Partially Depopulated Package with Partially Exposed Stiffener
Other features of BGA package 900 are similar to the corresponding features in aforementioned designs.
Design 10—Partially Depopulated Package with Partially Exposed Stiffener
Other features of BGA package 1000 are similar to the corresponding features in aforementioned designs.
Design 11—Partially Depopulated Package with Drop-In Heat Slug
Other features of BGA package 1100 are similar to the corresponding features in aforementioned designs.
Design 12—Partially Depopulated Package with Drop-In Heat Slug
Other features of BGA package 1200 are similar to the corresponding features in aforementioned designs.
Design 13—Partially Depopulated Package with Drop-in Heat Slug
Other features of BGA package 1300 are similar to the corresponding features in aforementioned designs.
Design 14—Partially Depopulated Package with Drop-In Heat Slug
Other features of BGA package 1400 are similar to the corresponding features in aforementioned designs.
Design. 15—Partially Depopulated Package with Partially Exposed Down-Set Stiffener
Other features of BGA package 1500 are similar to the corresponding features in aforementioned designs.
Design 16—Partially Depopulated Package with Partially Exposed Down-Set Stiffener
Other features of BGA package 1600 are similar to the corresponding features in aforementioned designs.
Design 17—Partially Depopulated Package with a One-Piece Stiffener/Die Paddle/Heat Slug
Other features of BGA package 1700 are similar to the corresponding features in aforementioned designs.
Design 18—Partially Depopulated Package with a One-Piece Stiffener/Die Paddle/Heat Slug
Other features of BGA package 1800 are similar to the corresponding features in aforementioned designs.
Note that all of the above designs may be manufactured in wafer saw format for maximized material utilization.
Refer to Table 2 below, which provides a brief overview of the above described embodiments/designs.
Although the invention herein has been described with reference to particular embodiments, it is to be understood that the embodiments are merely illustrative of the principles and application of the present invention. It is therefore to be understood that various modifications may be made to the above mentioned embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention. For example, Design 5 could be modified to incorporate two stiffeners to achieve split grounding. In fact any of the above mentioned designs may be combined with any other design or designs to produce a new package.
Claims
1. A device package, comprising:
- a substrate having first and second opposing surfaces, wherein an opening is formed through the first and second surfaces of the substrate;
- a stiffener coupled to the first surface of the substrate, the stiffener having an extending portion that extends into the opening of the substrate; and
- an integrated circuit (IC) die coupled to the extending portion of the stiffener, the IC die being electrically coupled to the substrate.
2. The device package of claim 1, wherein the substrate comprises:
- a metal layer, wherein the IC die is electrically coupled to the metal layer.
3. The device package of claim 2, wherein the substrate further comprises:
- a circuit mask coupled to the metal layer.
4. The device package of claim 3, wherein the substrate further comprises:
- a dielectric layer coupled to the metal layer.
5. The device package of claim 4, wherein the dielectric layer is coupled to the metal layer with an adhesive.
6. The device package of claim 2, wherein the metal layer comprises a trace.
7. The device package of claim 2, wherein the metal layer is a first metal layer and wherein the the substrate further comprises a second metal layer coupled to the first metal layer.
8. The device package of claim 2, further comprising:
- a plurality of connection elements attached to the substrate and electrically coupled to the metal layer.
9. The device package of claim 8, wherein the plurality of connection elements comprise a plurality of solder balls.
10. The device package of claim 1, further comprising:
- a wire connection coupled to the IC die.
11. The device package of claim 10, wherein the wire connection is coupled to the substrate.
12. The device package of claim 11, wherein the stiffener comprises an opening formed therein and the wire connection passes through the opening.
13. The device package of claim 10, wherein the wire connection is coupled to the stiffener.
14. The device package of claim 13, wherein the stiffener comprises a plating surface and wherein the wire connection is coupled to the plating surface.
15. The device package of claim 1, wherein the extending portion of the stiffener is exposed at an outer surface of the device package.
16. The device package of claim 1, wherein the stiffener comprises a metal.
17. A device package, comprising:
- a substrate having first and second opposing surfaces;
- a stiffener coupled to the first surface of the substrate, wherein the substrate comprises a plurality of conductive paths extending between the first and second surfaces of the substrate and contacting the stiffener; and
- an integrated circuit (IC) die coupled to the stiffener and electrically coupled to the substrate.
18. The device package of claim 17, further comprising:
- a plurality of connection elements coupled to the second surface of the substrate, wherein a conductive path of the plurality of conductive paths is electrically coupled to a connection element of the plurality of connection elements.
19. The device package of claim 17, wherein the substrate comprises: a metal layer.
20. The device package of claim 19, further comprising:
- a wire connection coupled to the IC die and the metal layer.
Type: Application
Filed: Mar 28, 2014
Publication Date: Jul 31, 2014
Applicant: Broadcom Corporation (Irvine, CA)
Inventors: Sam Ziqun Zhao (Irvine, CA), Reza-ur Rahman Khan (Rancho Santa Margarita, CA), Edward Law (Tracy, CA), Marc Papageorge (Pleasanton, CA)
Application Number: 14/229,215
International Classification: H01L 23/00 (20060101); H01L 23/12 (20060101);