Patent Application
20090166844
Embodiments of the present invention generally relate to the field of integrated circuit packages, and, more particularly to a metal cover on flip-chip matrix-array (FCMX) substrate for low cost CPU assembly.
Flip-chip matrix-array (FCMX) packaging, where a plurality of integrated circuit devices are attached to a substrate and then singulated, may offer advantages for cost savings. The problems presented, however, include warpage of the substrate and heat dissipation from the die.
The present invention is illustrated by way of example and not limitation in the figures of the accompanying drawings in which like references indicate similar elements, and in which:
In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the invention. It will be apparent, however, to one skilled in the art that embodiments of the invention can be practiced without these specific details. In other instances, structures and devices are shown in block diagram form in order to avoid obscuring the invention.
Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments.
Substrate 102 represents a substrate designed to receive integrated circuit dice 104 and transmit signals to electrical connections on a backside of substrate 102 opposite die 104. In one embodiment the backside of substrate 102 contains ball grid array (BGA) connections (not shown). In another embodiment, the backside of substrate 102 contains land grid array (LGA) connections.
IC dice 104 represent any type of integrated circuit devices, such as, for example processors, controllers, memories, transceivers, and the like. IC dice 104 may be flip-chip attached to substrate 102. In one embodiment, IC dice 104 have a thickness of about 125 micrometers.
Thermal interface layers (TIM) 106 provide thermal contacts and heat conductivity between IC dice 104 and metal cover 108. In one embodiment, TIM 106 represents a solder TIM. In another embodiment, TIM 106 represents a polymer TIM.
Metal cover 108 represents a metal sheet to provide stability and thermal conductivity to the IC packages. In one embodiment, metal cover 108 represents aluminum. In another embodiment, metal cover 108 represents copper. Metal cover 108 may have a thickness in the range of from about 200 to about 1800 micrometers.
Substrate cut-lines 110 and metal cover cut-lines 112 represent lines where cutting will occur to singulate the IC device packages. In one embodiment, substrate cut-lines 110 and metal cover cut-lines 112 are partially precut before assembly. In one embodiment, cut-lines 110 and 112 include intermittent cuts through the materials. In another embodiment, cut-lines 110 and 112 include cuts partially through the materials.
Adhesive 202 may be chosen for its ability to flow into gaps and also for its ability to harden and provide mechanical support against warpage.
IC device packages 302 may undergo further processing or assembly before being integrated into an electronic device or appliance, such as a laptop, desktop, handheld or other device.
According to but one example implementation, the method of
Next, TIM 106 is applied (404) on top of IC dice 104. In one embodiment, TIM 106 has a thickness of about 200 micrometers when applied.
Next, metal cover 108 is attached (406) on top of TIM 106. In one embodiment, metal cover 108 is placed on TIM 106 and pressed, thereby compressing TIM 106 to a thickness of about 50 micrometers.
Next, adhesive 202 is flowed and cured (408) between substrate 102 and metal cover 108.
Lastly, the assembly is singulated (410) to form separate IC device packages 302. In one embodiment, singulation may involve a saw. In another embodiment, singulation may involve a water jet. Additional steps may be needed to complete the packages before they can be placed in an electronic device.
In the description above, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without some of these specific details. In other instances, well-known structures and devices are shown in block diagram form.
Many of the methods are described in their most basic form but operations can be added to or deleted from any of the methods and information can be added or subtracted from any of the described messages without departing from the basic scope of the present invention. Any number of variations of the inventive concept is anticipated within the scope and spirit of the present invention. In this regard, the particular illustrated example embodiments are not provided to limit the invention but merely to illustrate it. Thus, the scope of the present invention is not to be determined by the specific examples provided above but only by the plain language of the following claims.
