Integrated circuit package encapsulating a hermetically sealed device
An integrated circuit package is disclosed having a semiconductor chip, a hermetically sealed device supported by the semiconductor chip, and a molding compound sealing the semiconductor chip and the device together as a composite package. A method of manufacturing the package is also disclosed.
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This is a divisional of application Ser. No. 11/038,275, filed Jan. 21, 2005, which is incorporated herein by reference.
FIELD OF THE INVENTIONThis invention pertains to integrated circuits, and more specifically, to an integrated circuit package for combining a sealed device with a semiconductor chip.
BACKGROUND OF THE INVENTIONThe vast majority of integrated circuits today are sold in molded plastic resin packages. These packages leak and outgas which limit the types of devices they can contain generally to integrated circuits, and more recently stacks of integrated circuits. Examples of these packages include ball-grid array packages, flip-chip packages, dual in-line packages, and quad-flat-packages.
Many integrated circuits require other devices to operate. For example, a microprocessor device may require access to a memory device. Typically, these devices can be placed on a printed circuit board and connected, or integrated, on a single substrate as described in U.S. Pat. No. 5,031,092 to Edwards, incorporated by reference herein.
U.S. Pat. No. 6,699,730 to Kim et al. and U.S. Pat. No. 6,708,132 to Gutierrez et al., both incorporated by reference herein, disclose multiple semiconductor chips provided in a single integrated circuit package. Such devices are typically referred to as multi-chip modules (MCMs). Other MCMs provide multiple sealed packages on a substrate, which are then mounted onto another substrate, such as a WL1141 Integrated PHY Module commercially available from Agere Systems, Inc.
Integration of different types of devices while still keeping the size of the module small, however, can be difficult. Different devices can require different materials to operate, and these devices cannot be integrated together. Other devices are fragile or difficult to produce and are preferably not combined with devices that are more robust or easier to make, as that would lower manufacturing yield. For example, U.S. Pat. No. 6,635,509 to Ouellet, incorporated by reference herein, discloses wafer-level packaging of a MEMs device. Such a device is difficult to produce with a high-yield. Some devices can be modified after they are manufactured to satisfy a particular need. For example, U.S. Pat. No. 5,952,890 to Fallisgaard et al., incorporated by reference herein, discloses a programmable oscillator.
Consistent with an aspect of the present invention, different types of devices are stacked within a small package. Such integration is achieved by providing an integrated circuit package that combines a sealed device with a semiconductor chip, where the sealed device typically includes a cavity and often has hermeticity to function optimally.
SUMMARY OF THE INVENTIONIn accordance with one aspect of the invention, an integrated circuit package includes a semiconductor chip, a substrate for supporting the semiconductor chip, a sealed device supported by the semiconductor chip, and an encapsulant for sealing the semiconductor chip inside the package.
In accordance with another aspect of the invention, an integrated circuit package includes a sealed device, a substrate for supporting the device, a semiconductor chip supported by the device, and an encapsulant for sealing the semiconductor chip inside the package.
In accordance with yet another aspect of the invention, a method of manufacturing an integrated circuit package includes obtaining a sealed device, obtaining a substrate, obtaining a semiconductor chip, constructing the package such that the substrate supports the semiconductor chip and the device is supported by the device, and sealing the semiconductor chip inside the package.
In accordance with still another aspect of the invention, a method of manufacturing an integrated circuit package includes obtaining a sealed device, obtaining a substrate, obtaining a semiconductor chip, constructing the package such that the substrate supports the device and the semiconductor chip is supported by the device, and sealing the semiconductor chip inside the package.
Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the invention and together with the description, serve to explain the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference will now be made in detail to the present embodiments (exemplary embodiments) of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
A substrate 100 provides a support for the components of a package 10. The present invention is not limited as to the form of the substrate and any form may be used, including, for example, a printed circuit board, a lead-frame, or tape. Electrical contacts 110, shown as balls in the embodiment of
A semiconductor chip (or semiconductor die) 120, which is not sealed and could be unprotected, bare silicon or an unencapsulated semiconductor die with an integrated circuit formed thereon, is placed on the substrate 100 in a typical manner. For example, semiconductor chip 120 could be a digital signal processor chip, such as Texas Instruments SM320C6201, a microprocessor, or a media access controller. Also, the top of the semiconductor chip may be “passivated” (such as by being protected by a thin coating of glass) and the depth of that layer may be adjusted to accommodate the subsequent process.
A sealed device 130 is placed on semiconductor chip 120. Typically, sealed device 130 is hermetically sealed, and includes a cavity 133. As shown in
The chip 120 and device 130 can be electrically-interconnected. For example, wires 140 could connect contacts on the device 130 to bond pads on chip 120. In
Chip 120 and device 130 are preferably interconnected when the device 130 provides a necessary function for chip 120, such as a frequency source or memory.
In the preferred embodiment, device 130 includes a resonator circuit. For example, device 130 could be a programmable oscillator. Device 130 could also include quartz crystals, surface acoustic wave devices, or a MEMs structure, such as a resonator, sensor, or capacitive device. Nanotechnology devices could also be included in device 130, including quantum tunneling cooling devices, quantum tunneling power generation devices, and quantum resonant devices. Improved performance of each of these devices can be realized by hermetic packaging prior to stacking, interconnecting and molding.
The package of device 130 significantly improves electrical and reliability performance for devices, such as resonators, sealed therein. Finally, it can provide protection against injection molding and similar encapsulation processes. Further, device 130 could be independently tested, programmed, or tuned prior to incorporation into package 10.
Encapsulant 160 seals chip 120 in the package of
If the device is acceptable, then in step 530, the device is placed on a semiconductor chip. Alternatively, a chip could be placed on the device. In step 540, the device is connected to the package and/or the semiconductor chip. In step 550, the device is connected to the package. Note that the connections in steps 540 and 550 could be made in any order or simultaneously.
In step 560, the chip and device are encapsulated or sealed. In step 570, conditional processing or other post-encapsulation processes could be performed on the package, such as powering-up, programming, or testing. In step 580, a decision can be made to determine if the sealed device is acceptable. If the device is not acceptable, it is rejected. Otherwise, packaging is completed.
In each of the steps of
An attachment portion 609 is provided between housing 650 and semiconductor die 120. Attachment portion 609 is configured to attach housing 650 to semiconductor die 120. In the example shown in
As further shown in
The embodiment shown in
Since housing 650 has a surface with an area less than that of semiconductor die 120, and further since housing 650 is attached to semiconductor die 120, greater integration can be achieved and a more compact package with greater functionality can be obtained.
Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
Claims
1-32. (canceled)
33. An integrated circuit package, comprising:
- a semiconductor die having a surface, the surface of the semiconductor die having an area;
- a housing having a surface, the surface of the housing having an area less than the area of the surface of the semiconductor die, the housing being hermetically sealed;
- an attachment portion, the attachment portion being provided between the hermetic housing and the semiconductor die, the attachment portion being configured to attach the housing to the semiconductor die; and
- an encapsulant, the encapsulant collectively sealing the semiconductor die, the housing, and the attachment portion.
34. An integrated circuit package according to claim 33, wherein the attachment portion includes an adhesive.
35. An integrated circuit package according to claim 33, wherein the integrated circuit package is a first package, and the attachment portion includes an oscillator circuit, the oscillator circuit being provided in a second package.
36. An integrated circuit package according to claim 33, further comprising an oscillator circuit, the oscillator circuit being provided on the housing.
37. An integrated circuit package according to claim 36, further comprising:
- a first wiring, the first wiring being configured to electrically couple the oscillator circuit to the semiconductor die;
- a second wiring; and
- a lead frame, the second wiring being configured to electrically couple the oscillator circuit to the lead frame.
38. An integrated circuit package according to claim 33, wherein the housing includes a resonator.
39. An integrated circuit package according to claim 33, wherein the semiconductor die includes a microprocessor circuit.
40. An integrated circuit package according to claim 35, further including a plurality of solder bumps, wherein the oscillator circuit is coupled to the semiconductor die through the solder bumps.
Type: Application
Filed: Dec 13, 2006
Publication Date: Apr 26, 2007
Applicant:
Inventor: James Northcutt (Lehigh Acres, FL)
Application Number: 11/637,748
International Classification: H01L 23/28 (20060101);