1. Field of the Invention
The present invention relates to a clip, and more particularly to a clip including at least two pair of pressing fingers asserting downward force evenly to a die and a substrate of a CPU chip therefore preventing potential warpage of the CPU.
2. Background of the Invention
U.S. Pat. No. 5,722,848 issued to Lai on Mar. 3, 1998 discloses a typical connector socket, and which is generally referred to as ZIF (Zero Insertion Force) socket. In generally, the socket includes a base with a plurality of contacts assembled therein, and a cover moveably attached to the base. A lever along with a cam mechanism is arranged between the base and cover at a head portion so as to drive the cover from a first position to a second position. When the lever is located in a vertical position, the cover is located at the first position, in which a hole in the cover is completely in align with a corresponding passageway in the base. In this position, a pin leg of a CPU can be inserted from the cover into the passageway without any engagement with the contact. When the CPU is properly seated on the cover, then the lever is moved from the vertical position to a horizontal position, and simultaneously driving the cover from the first position to the second position. During this process, the pin leg of the CPU is then in contact with the contact within the base. The Lai '848 is specially directed to a desk-top computer.
CPU socket used on notebook is substantially similar to what is used on the desktop computer, and the only difference is on the lever used on '848 patent was replaced by a screw with a cam mechanism. When the screw is driven or rotated, the cover is driven to move along the base, therefore he pin leg of the CPU is then in contact with the contact within the base, and no detailed description is given here.
U.S. Pat. No. 7,001,197 issued to Shirai on Feb. 21, 2006 discloses another type of connector socket, and which can be generally called LGA socket. The ration is when the performance become more and more powerful, the input/output (I/O) of the CPU is accordingly increased as well. The original pin-leg type of chip occupies more estate on the bottom surface of the CPU. In order to increase the I/O, conductive pads are introduced to replace the pin-leg so as to directly and electrically contacted with contact terminals within the socket. No doubt, more I/O are provided.
As clearly shown in Figures, this is a brand new configuration and is different to what Lai '848 disclosed. The socket generally includes a metal stiffener with a housing securely supported therein. Then a metal clip is pivotally assembled to the stiffener. On the other hand, a clip is pivotally assembled to the other side of the stiffener and when the clip is closed to the stiffener, the lever having a cam can lock the clip to a closed position. By this arrangement, if before the clip is closed, and a CPU is seated on the housing, then the clip will tightly press the CPU toward the housing ensuring proper electrical connection therebetween.
Shirai '197 can be easily applied on the desktop computer as it has robust room for the operation of the lever, while it is almost impossible to apply Shirai '197 directly to the notebook in view of its compact, and thin space.
Another factor has to be also considered in view of the configuration of CPU chip. It generally includes a substrate, and a die including chip is mounted thereon. Even it is rigid, but is still vulnerable to deform or warp if downward force applied thereon is not evenly distributed. In Shirai '197 patent, the die is not pressed by the clip which has a window for it. The die is later in direct contact with a heatsink. As a result, when applying the so-called LGA socket to notebook, how to provide a mechanism functionally similar to Shirai '197, while keep downward force evenly distribute to both die and substrate, is a motive for the present invention.
It is therefore there is a need to provide clip mechanism in which downward force are evenly distribute to both the die and the substrate thereby efficiently prevent the CPU chip from warpage.
In order to achieve the objective set forth, a clip in accordance with a preferable embodiment for pressing a CPU toward LGA contacts of a CPU socket comprises, a rigid body having an elongate base with upper and lower edges. A set of first pressing finger extend from the upper edge traversally and away from the base. Each of the first pressing fingers includes a first pressing pad located at a first plane. And a set of second pressing finger extend from and away from the base, and includes a second pressing pad located at a second plane differential to the first plane. The set of first and second pressing fingers are dimensioned to be located in two different levels so as to assert downward pressure to a die of the CPU and a substrate of the CPU, respectively.
According to one aspect of the present invention, wherein the set of first and second pressing fingers are integrally formed with the base.
According to another aspect of the present invention, wherein the set of second pressing fingers is assembled to the base.
Other objects, advantages and novel features of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which:
In the following description, for purpose of explanation, numerous details are set forth in order to provide a thorough understanding of the embodiments of the present invention. However, it will be apparent to one skilled in the art that these specific details are not required in order to practice the embodiments of the present invention.
Referring to
Individual elements of the electrical connector assembly 100 will now be described in greater detail. The electrical socket 20 includes a substantially rectangular insulating housing 201, the housing 201 includes a supporting surface to accept an electronic component, for example an IC module 30, thereon and opposite facing mounting surface to a print circuit board 10. A plurality of passageways extends from the supporting surface toward the mounting surface and a number of contacts are received in the corresponding passageways forming the contact engaging portion 202. Two pairs of opposite walls 203 extend from the supporting face around the contact engaging portion 202.
The IC module 30 including a substrate 301, and a die disposed on the substrate 302. The heatsink assembly 40 further comprises a heat spreader 401 and a heat pipe 403, wherein the heat spreader 401 has two slots 402 for receiving the corresponding heat pipe 403.
The clip set 50 comprises a rigid body having an elongate base 501 with upper and lower edges, a set of first pressing finger 502 and a set of second pressing finger 503. The base has a substantially rectangular frame having inner rim 5011 and outer peripheral 5012. The inner rim 5011 equally forms four inner sides, and each has a set of first pressing finger 502 extending inward and downward from the inner rim 5011; the outer peripheral 5012 equally forms four outer sides, and each has a second pressing fingers 503 extends outwardly and downward from the outer peripheral 5012.
The clip set 50 comprises a number of the set of first pressing finger 502 and the set of second pressing finger 503; the set of first pressing finger 502 extending firstly horizontally, and then downward so as to form the pressing pad at a first plane, and each second pressing finger 503 includes a second pressing pad located at a second plane differential to the first plane. The set of first pressing fingers 502 and the set of second pressing fingers 503 are arranged spatially from each other, respectively.
Referring to
As shown in
Referring to
In assembly, the electrical socket is located on the printed circuit board, an IC module, electrically disposed on the socket and electrically contacted with the contact engaging portions. A heatsink assembly, including a clip set securely attached to the printed circuit board for pressing the IC module toward the socket to ensure reliable electrical connection between the IC module and the contact engaging portion. In this way, the set of first pressing finger downward press the die and the set of second pressing fingers downward press the substrate.
Although the present invention has been described with reference to particular embodiments, it is not to be construed as being limited thereto. Various alterations and modifications can be made to the embodiments without in any way departing from the scope or spirit of the present invention as defined in the appended claims.