Patent Application
20130062752
The present disclosure relates generally to semiconductor chip packages, and more particularly to ring structures for chip packaging.
In semiconductor chip packages, where a semiconductor chip is mounted onto a substrate, the chip package may suffer from reliability issues when undergoing temperature cycling and/or during normal operation. Flip chip ball grid array, a type of chip package technology mounts the active side of the chip in an upside-down manner over the substrate and bonded to the same by means of a plurality of solder bumps attached to input/output pads thereon. Due to the inherent coefficient of thermal expansion mismatches between the chip and the chip package components, such as the substrate and underfill (an adhesive flowed between the chip and substrate), package warpage and thermal stresses are frequently induced in the chip package.
These high thermal stresses and warpage not only lead to the delamination in the low dielectric constant (low-k) interconnect layer(s) in the chip, but may also cause solder bump cracks leading to failure or degrading the long term operating reliability of the chip package. One method of reducing the warpage of the chip package is to attach a ring structure inside the package. However, even with the use of the ring structure inside the package, the package may still suffer from warpage to some degree. For example, warpage and therefore stress may still exist in a region of the chip package, such as at a central region of the package where the chip resides.
The features, aspects, and advantages of the present disclosure will become more fully apparent from the following detailed description, appended claims, and accompanying drawings in which:
In the following description, numerous specific details are set forth to provide a thorough understanding of the present disclosure. However, one having an ordinary skill in the art will recognize that the disclosure can be practiced without these specific details. In some instances, well-known structures have not been described in detail to avoid unnecessarily obscuring the present disclosure.
Reference will now be made in detail to the present disclosures, examples of which are illustrated in the accompanying drawings.
The FCBGA package 10 may also include a heat spreader 80 and ring structure 2 for preventing excess warpage of the package. Heat spreader 80 is mounted on top of chip 30 to dissipate heat generated by chip 30 and to counter-balance the forces exerted by the thermal expansion mismatches between at least the chip 30 and the first substrate 20. Ring structure 2 is mounted between first substrate 20 and heat spreader 80 by means of adhesives (not shown). A top plan view of ring structure 2 is shown in
The various embodiments of ring structures of the present disclosure offer a degree of rigidity against warping and twisting higher than that of ring structure 2.
Ring structure 3 has a rigid, planar frame portion 4 for bonding on one side to first substrate 20, and on the other side to a heat dissipating element such as, for example, heat spreader 80. In some embodiments, frame portion 4 is formed of a rigid material. In at least one embodiment, frame portion 4 comprises a conductive material, metal, copper, tungsten, aluminum, polysilicon, silicide, ceramic, a material that is stronger than an adjacent dielectric material, alloys thereof, or combinations thereof. However, one skilled in the art will understand that frame portion 4 may be made from any material, which provides a sufficient degree of rigidity to the chip package against warpage and twisting.
The frame portion 4 of ring structure 3 has an opening therein for surrounding an integrated circuit device, such as chip 30. It is appreciated that the size of the opening and therefore the ring structure 3 is dependent upon the size of the integrated circuit device (chip), which ring structure 3 must receive and surround. In some embodiments, the opening and ring structure 3 are sized so as to maximize the surface area of ring structure 3 that can be mounted to first substrate 20, so as to reduce twisting and warping as much as possible.
Referring back to
In some embodiments, corner portions 6 are formed of a rigid material. In at least one embodiment, corner portions 6 comprise a conductive material, metal, copper, tungsten, aluminum, polysilicon, silicide, ceramic, a material that is stronger than an adjacent dielectric material, alloys thereof, or combinations thereof. However, one skilled in the art will understand that corner portions 6 may be made from any material, which provides a sufficient degree of rigidity to the chip package against warpage and twisting. In some embodiments, one or more of corner portions 6 comprises a same material as the frame portion 4. In other embodiments, one or more of corner portions 6 comprises a different material than the frame portion 4.
In another embodiment, as shown in
In the embodiments depicted in
According to one embodiment, a ring structure for chip packaging comprises a frame portion adaptable to bond to a substrate. The frame portion surrounds a semiconductor chip and defines an inside opening, and the inside opening exposes a portion of a surface of the substrate. At least one corner portion extends from the frame portion toward the chip, and the ends of the corner portion is free of a sharp corner.
According to another embodiment, a ring structure for chip packaging comprises a frame portion adaptable to bond to a substrate. The frame portion surrounds a semiconductor chip and defines an inside opening, and the inside opening exposes a portion of a surface of the substrate. At least one mid-section portion extends from the frame portion toward the chip, and the mid-section portion is free of a sharp corner.
According to yet another embodiment, an integrated circuit structure comprises a substrate, a semiconductor chip, and a ring structure. The ring structure has a frame portion adaptable to bond to the substrate. The frame portion surrounds a semiconductor chip and defines an inside opening, and the inside opening exposes a portion of a surface of the substrate. At least one corner portion extends from the frame portion toward the chip, and the corner portion is free of a sharp corner.
In the preceding detailed description, the present disclosure is described with reference to specifically exemplary embodiments thereof. It will, however, be evident that various modifications, structures, processes, and changes may be made thereto without departing from the broader spirit and scope of the present disclosure, as set forth in the claims. The specification and drawings are, accordingly, to be regarded as illustrative and not restrictive. It is understood that the present disclosure is capable of using various other combinations and environments and is capable of changes or modifications within the scope of the inventive concept as expressed herein.
