Stackable ceramic FBGA for high thermal applications

Abstract

An apparatus package for high-temperature thermal applications for ball grid array semiconductor devices and a method of packaging ball grid array semiconductor devices.

Description

BACKGROUND OF THE INVENTION

1. Statement of the Invention

The present invention relates to an apparatus for high-temperature thermal applications for ball grid array semiconductor devices and a method of packaging ball grid array semiconductor devices.

2. State of the Art

Integrated semiconductor devices are typically constructed in wafer form with each device having the form of an integrated circuit die which is typically attached to a lead frame with gold wires. The die and lead frame are then encapsulated in a plastic or ceramic package, which is then commonly referred to as an integrated circuit (IC). ICs come in a variety of forms, such as a dynamic random access memory (DRAM), static random access memory (SRAM), read only memory (ROM), gate arrays, etc. The ICs are interconnected in many combinations on printed circuit boards by a number of techniques, such as socketing and soldering. Interconnection among ICs arrayed on a printed circuit board is typically made by conductive traces formed by photolithography and etching processes.

Such semiconductor devices typically take the form of the semiconductor die therein. The die is generally electrically attached to a lead frame within a package. The lead frame physically supports the die and provides electrical connections between the die and its operating environment. The die is generally electrically attached to the lead frame by means of fine gold wires. These fine gold wires function to connect the die to the lead frame so that the gold wires are connected electrically in series with the lead frame leads. The lead frame and die are then encapsulated. The packaged chip is then able to be installed on a circuit board by any desired manner, such as soldering, socketing, etc.

However, as the speed of the semiconductor die increases, the heat generated during operation increases. Additionally, it becomes necessary to shorten the leads between the printed circuit board on which the IC is located and the IC device itself in order to keep the impedance of the circuit from affecting the response speed of the IC device.

The wires connecting the leads of the lead frame to the bond pads on the active surface of the semiconductor die in an IC package are not an effective connection for high operating speed semiconductor dice as the wires slow down the response of the semiconductor die.

Therefore, a packaging is required for semiconductor dice which have high operating speeds and generate heat associated therewith while minimizing the lead length between the semiconductor dice and the printed circuit boards on which they are mounted.

BRIEF SUMMARY OF THE INVENTION

The present invention comprises an apparatus package for high-temperature thermal applications for ball grid array semiconductor devices and a method of packaging ball grid array semiconductor devices.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a stack of a first embodiment of the packaged semiconductor dice of the present invention on a printed circuit board;

FIG. 2 is a top view of a packaged semiconductor die of the present invention;

FIG. 3 is a bottom view of a packaged semiconductor die of the present invention;

FIG. 4 is a cross-sectional view of stacks of the packaged semiconductor dice of the present invention on both sides of a printed circuit board;

FIG. 5 is a cross-sectional view of a stack of a second embodiment of the packaged semiconductor die of the present invention on a printed circuit board; and

FIG. 6 is a cross-sectional view of stacks of the second embodiment of the present invention on both sides of a printed circuit board.

The present invention will be better understood when the drawings are taken in conjunction with the description of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to drawing FIG. 1, a plurality of assemblies 10 comprising a carrier 12 and a semiconductor device 14 located therein is illustrated installed on a substrate 2. Each carrier 12 comprises a member having a cavity 16 therein. As illustrated, the cavity 16 may be a single-level or multi-level cavity having any desired number of levels therein. The carrier 12 is formed having a plurality of contact pads 18 located on the upper surface 20 and lower surface 22 thereof which is connected by circuits 24 (not shown) and by wire bonds 26 to the bond pads 28 located on the active surface 30 of the semiconductor die or device 14. The semiconductor die or device 14 is initially retained within the cavity 16 by any suitable means, such as adhesive, etc. The circuits 24 (not shown) are formed on the upper surface 20 of the carrier 12 and portions of the walls or surfaces of the cavity 16 by any suitable well-known means, such as deposition and etching processes. The wire bonds 26 connecting the bond pads 28 of the semiconductor die or device 14 to the circuits 24 (not shown) are made using any suitable commercially available wire bonder. After the wire bonds 26 are formed, the cavity 16 is filled with suitable encapsulant material 32 covering and sealing the semiconductor die 14 in the cavity 16 and sealing the wire bonds 26 in position therein.

The carriers 12 may be of any desired geometric shape. The carrier 12 is formed having internal circuits 34 extending between the contact pads 18 on the upper surface 20 and lower surface 22 of the carrier 12. The carrier 12 is formed having frusto-conical recess surfaces 36, lips 38, and frusto-conical surfaces 40 on the upper surface 20. The surfaces 36 and 40 are formed having complementary angles so that the surfaces 36 and lips 38 of an adjacent carrier 12 mate or nest with an adjacent carrier 12 having frusta-conical surfaces 40 thereon, thereby forming a stable, self-aligning stack of carriers 12. If desired, the carriers 12 may be formed having a plurality of heat transfer fins 42 thereon. The carrier 12 may be formed of any desired suitable material, such as ceramic material, high-temperature plastic material, etc. The carrier 12 may be formed by any suitable method, such as molding, extrusion, etc.

Once a plurality of carriers 12 having semiconductor die or devices 14 therein is formed as an assembly, the assembly is connected to the substrate 2 using a plurality of reflowed solder balls 50. The substrate 2 includes circuitry thereon, on either the upper surface or lower surface or both, and therein, as well as conductive vias, if desired. The substrate 2 may be any suitable substrate, such as a printed circuit board, FR-4 board, etc. Any desired number of carriers 12 may be stacked to form an assembly on the substrate 2. As illustrated, the reflowed solder balls 50 are located in alignment with the contact pads 18 and the connecting internal circuits 34 extending between the contact pads 18 on the upper surface 20 and lower surface 22 of a carrier 12.

Referring to drawing FIG. 2, a carrier 12 having circuits 24 thereon extending between contact pads 18 on the upper surface 20 of the carrier 12 is illustrated. For purposes of clarity, only a portion of the circuits 24 extending on the upper surface 20 of the carrier 12 is illustrated.

Referring to drawing FIG. 3, the lower surface 22 of a carrier 12 is illustrated having a plurality of contact pads 18 located thereon.

Referring to drawing FIG. 4, a plurality of assemblies 10 is illustrated located on both sides of a substrate 2 being connected to the circuitry thereon by a plurality of reflowed solder balls 50.

Referring to drawing FIG. 5, a second embodiment of the present invention is illustrated. A plurality of assemblies 100 is stacked on a substrate 2, being electrically and mechanically connected thereto by reflowed solder balls 150. Each assembly 100 comprises a carrier 112 having a cavity 116 therein containing a semiconductor die or device 114 therein. The semiconductor die or device 114 is electrically connected to the circuits 134 of the carrier 112 by reflowed solder balls 126. Each carrier 112 is formed having apertures 160 therethrough connecting with circuits 134. Each carrier 112 is formed with surfaces 136 and 140 as well as lips 138 as described hereinbefore with respect to carrier 12. To connect each carrier 112 to an adjacent carrier 112, a conductive material 162, such as conductive epoxy, solder, etc., is used to fill the apertures 160 in the carriers and contact the conductive material 162 in adjacent carriers 112.

The carriers 112 are similar in construction to the carriers 12 as described hereinbefore, except for the apertures 160, conductive material 162, circuits 134, and reflowed solder balls 126 between the semiconductor die or device 114 and the circuits 134

The substrate 2 is the same as described hereinbefore.

Referring to drawing FIG. 6, a plurality of assemblies 100 is illustrated stacked on both sides of a substrate 2, being electrically and mechanically connected thereto by reflowed solder balls 150.

The present invention includes additions, deletions, modifications, and alterations which are within the scope of the claims.

Claims

1. An assembly using a stackable FBGA comprising: a first carrier having a plurality of sides, having an upper surface, having a bottom surface, having a cavity extending from the upper surface, a first frusto-conical surface on a portion of the upper surface thereof, a second frusto-conical surface on a portion of the bottom surface thereof, a lip on a portion of a bottom surface thereof, and a plurality of circuits located within a portion of the cavity;a semiconductor device having a plurality of bond pads located within the cavity of the first carrier;a first connector between at least one circuit of the plurality of circuits located within the portion of the cavity of the first carrier and at least one bond pad of the plurality of bond pads of the semiconductor device;encapsulant material filling a portion of the cavity in the first carrier; anda second connector material located within the first carrier.

2. The assembly using a stackable FBGA of claim 1, further comprising: a substrate having an upper surface, a lower surface, and a plurality of circuits on the upper surface thereof; andat least one second connector connected to the second connector material in the first carrier and at least one circuit of the plurality of circuits on the upper surface of the substrate.

3. The assembly using a stackable FBGA of claim 1, wherein the first carrier includes at least one fin on a portion thereof.

4. The assembly of claim 1, further comprising: a second carrier oriented with respect to the first carrier and positioned in the same direction as the first carrier and further having a cavity therein, an upper surface, a lower surface, at least one aperture therethrough, and a plurality of circuits located within a portion of the cavity thereon connected to the at least one aperture therethrough;a second semiconductor device having an active surface having a plurality of bond pads thereon, the second semiconductor device located within the cavity of the second carrier;another first connector between at least one circuit of the plurality of circuits located within the portion of the cavity of the second carrier and at least one bond pad of the plurality of bond pads on the active surface of the second semiconductor device located within the cavity of the second carrier;encapsulant material filling the portion of the cavity in the second carrier; anda connector material located within a second aperture in the second carrier connected to the second connector material in the at least one aperture in the first carrier.

5. An assembly for use with a FBGA substrate comprising: a first carrier having a first surface having a first frusto-conical surface and at least one connection pad thereon, having a second surface having a lip, a second frusto-conical surface connected to the lip, and at least one connection pad thereon, having a cavity extending from the upper surface therein, a first surface located in the cavity having at least one connection pad thereon, a second surface located in the cavity having at least one connection pad thereon, and a third surface located in the cavity, a circuit connecting the at least one connection pad on the first surface of the first carrier to the at least one connection pad on the second surface of the first carrier, and at least one circuit located in a portion of the cavity connected to the at least one connection pad on one of the first surface located in the cavity and the second surface located in the cavity, the at least one connection pad on the first surface of the first carrier, and the at least one connection pad on the second surface of the first carrier;a semiconductor device having an active surface having at least one bond pad thereon, the semiconductor device located on the third surface located in the cavity of the first carrier;a first connector between the at least one connection pad on one of the first surface located in the cavity and the second surface located in the cavity and the at least one bond pad on the active surface of the semiconductor device; andencapsulant material filling a portion of the cavity in the first carrier.

6. The assembly of claim 5, further comprising: a substrate having a first surface, a second surface, and at least one circuit on the first surface thereof; andat least one second connector connected to the at least one connection pad on the second surface of the first carrier and the at least one circuit on the first surface of the substrate.

7. The assembly of claim 5, wherein the first carrier includes at least one fin on a portion thereof.

8. The assembly of claim 5, further comprising: a second carrier having a cavity therein, a first surface, a second surface, at least one connection pad on the first surface, at least one connection pad on the second surface, a circuit connecting the at least one connection pad on the first surface to the at least one connection pad on the second surface, and at least one circuit located in a portion of the cavity and connected to one of the at least one connection pad on the first surface and the at least one connection pad on the second surface;a semiconductor device having an active surface having at least one bond pad thereon, the semiconductor device located within the cavity of the second carrier;a first connector between the at least one circuit located in a portion of the cavity of the second carrier and the at least one bond pad on the active surface of the semiconductor device; andencapsulant material filling a portion of the cavity in the second carrier.

9. An assembly of stacked carriers for use with a substrate comprising: a first carrier having a first frusto-conical surface on a portion of an upper surface thereof, a second frusto-conical surface on a portion of a bottom surface thereof, a lip on a portion of the bottom surface thereof, and a plurality of circuits located within a portion of a cavity having a first surface, a second surface, and a third surface, a connection pad located on one of the first surface and the second surface connected to at least one of the plurality of circuits;a semiconductor device having a plurality of bond pads located on a portion of the third surface within the cavity of the first carrier;a first connector between at least one circuit of the plurality of circuits located within the portion of the cavity of the first carrier and at least one bond pad of the plurality of bond pads of the semiconductor device;encapsulant material filling a portion of the cavity in the first carrier; anda second connector material located within the first carrier.

10. The assembly of stacked carriers for use with a substrate of claim 9, wherein the substrate includes an upper surface, a lower surface, and a plurality of circuits on the upper surface thereof, and at least one second connector connected to the second connector material in the first carrier and at least one circuit of the plurality of circuits on the upper surface of the substrate.

11. The assembly of stacked carriers for use with a substrate of claim 9, wherein the first carrier includes a heat sink on a portion thereof.

12. The assembly of claim 9, further comprising: a second carrier oriented with respect to the first carrier and positioned in the same direction as the first carrier and further having a cavity therein, an upper surface, a lower surface, at least one aperture therethrough, and a plurality of circuits located within a portion of the cavity thereon connected to the at least one aperture therethrough;a second semiconductor device having an active surface having a plurality of bond pads thereon, the second semiconductor device located within the cavity of the second carrier;another first connector between at least one circuit of the plurality of circuits located within the portion of the cavity of the second carrier and at least one bond pad of the plurality of bond pads on the active surface of the second semiconductor device located within the cavity of the second carrier;encapsulant material filling the portion of the cavity in the second carrier; anda connector material located within a second aperture in the second carrier connected to the second connector material in the at least one aperture in the second carrier.

13. An assembly formed by a plurality of carriers for high thermal usage comprising: a first carrier having an upper surface, having a lower surface, having a cavity therein extending from the upper surface, a first surface located in a portion of the cavity having at least one connection pad thereon, a second surface located in a portion of the cavity, and a third surface located within a portion of the cavity, a first frusto-conical surface on a portion of the upper surface thereof, a second frusto-conical surface on a portion of the lower surface thereof, a lip on a portion of a lower surface thereof, at least one connection pad on the upper surface, at least one connection pad on the lower surface, a circuit connecting the at least one connection pad on the upper surface to the at least one connection pad on the lower-surface, and at least one circuit located in a portion of the cavity connected to the at least one connection pad on the upper surface, to the at least one connection pad on the lower surface, and to the at least one connection pad on the first surface located in the cavity;a semiconductor device having an active surface having at least one bond pad thereon, the semiconductor device located within the cavity of the first carrier on a portion of the third surface of the cavity;a first connector between the at least one circuit located in a portion of the cavity of the first carrier and the at least one bond pad on the active surface of the semiconductor device; andencapsulant material filling a portion of the cavity in the first carrier.

14. The assembly of claim 13, further comprising: a substrate including a first surface, a second surface, and at least one circuit on the first surface thereof, and at least one second connector connected to the at least one connection pad on the second surface of the first carrier and the at least one circuit on the first surface of the substrate.

15. The assembly of claim 13, wherein the first carrier includes at least one fin on a portion thereof.

16. The assembly of claim 13, further comprising: a second carrier having a cavity therein, an upper surface, a lower surface, at least one connection pad on the upper surface, at least one connection pad on the lower surface, a circuit connecting the at least one connection pad on the upper surface to the at least one connection pad on the lower surface, and at least one circuit located in a portion of the cavity connected to one of the at least one connection pad on the upper surface and the at least one connection pad on the lower surface;a semiconductor device having an active surface having at least one bond pad thereon, the semiconductor device located within the cavity of the second carrier;a first connector between the at least one circuit located in a portion of the cavity of the second carrier and the at least one bond pad on the active surface of the semiconductor device; andencapsulant material filling a portion of the cavity in the second carrier.

17. The assembly of claim 16, further comprising: a third carrier having a cavity therein, an upper surface, a lower surface, at least one connection pad on the upper surface, at least one connection pad on the lower surface, a circuit connecting the at least one connection pad on the upper surface to the at least one connection pad on the lower surface, and at least one circuit located in a portion of the cavity connected to one of the at least one connection pad on the upper surface and the at least one connection pad on the lower surface;a semiconductor device having an active surface having at least one bond pad thereon, the semiconductor device located within the cavity of the third carrier;a first connector between the at least one circuit located in a portion of the cavity of the third carrier and the at least one bond pad on the active surface of the semiconductor device; andencapsulant material filling a portion of the cavity in the first carrier, second carrier, and third carrier.

18. The assembly of claim 17, further comprising: a fourth carrier having a cavity therein, an upper surface, a lower surface, at least one connection pad on the upper surface, at least one connection pad on the lower surface, a circuit connecting the at least one connection pad on the upper surface to the at least one connection pad on the lower surface, and at least one circuit located in a portion of the cavity connected to one of the at least one connection pad on the upper surface and the at least one connection pad on the lower surface;a semiconductor device having an active surface having at least one bond pad thereon, the semiconductor device located within the cavity of the fourth carrier;a first connector between the at least one circuit located in a portion of the cavity of the fourth carrier and the at least one bond pad on the active surface of the semiconductor device; andencapsulant material filling a portion of the cavity in the fourth carrier.