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Socketless Interconnect for Land Grid Array Packages Targeting Mobile Applications

IP.com Disclosure Number: IPCOM000124926D
Publication Date: 2005-May-13
Document File: 3 page(s) / 346K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method that connects land grid array (LGA) packages to printed circuit boards (PCB), without the need for conventional sockets. Benefits include reducing assembly costs and lowering the assembly height.

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Socketless Interconnect for Land Grid Array Packages Targeting

Mobile

Applications

Disclosed is a method that connects land grid array (LGA) packages to printed circuit boards (PCB), without the need for conventional sockets. Benefits include reducing assembly costs and lowering the assembly height.

Background

The current state of the art uses conventional sockets to connect the LGA to the PCB. Figures 1 and 2 show how conventional sockets are used in the package assembly.

General Description

The disclosed method replaces the conventional sockets that connect the PCB to the package lands with springy metallic folded interconnects (see Figure 3). The bottom side of these interconnects are fixed to the PCB by soldering or another method. The top side of the interconnects are open ended, and have a specific spring constant determined by their metallurgy and physical construction. The top side makes contact with the lands of the LGA package. The physical construction of the interconnects make them compliant. Figure 4a shows an exploded view of the assembly arrangement, and Figure 4b shows the scenario after assembly.

Variations on the shape of the interconnect are possible, provided the fundamental requirements of contact between the PCB and the LGA pads are met. Figure 5 shows one variation that is a folded interconnect, but with similar springy properties, where the folded portion slides on the fixed portion of the interconnect when the package is mounted. Although more compli...