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Methodology for integrating multiple system elements in an enclosed structure using a flex film LGA connector

IP.com Disclosure Number: IPCOM000034887D
Original Publication Date: 2005-Jan-19
Included in the Prior Art Database: 2005-Jan-19
Document File: 5 page(s) / 285K

Publishing Venue

IBM

Abstract

In the design of large and small computer systems, there is a need to provide a method to insure that correctly licensed and purchased hardware is used. For instance, information of the number of processors sold in a system, maybe located on a Multi-Chip module (MCM) as design by IBM. The number of processors (CPU) can range from as few as 5 to 20 CPU?s. When added functions or the number of processors sold are turned on within the MCM, a security chip is programmed to insure compliance with the licensing and sales agreements. Also when MCM?s are moved from one system board to another, new code for this change must be loaded into the Service Element (SE) and configuration files updated for the new hardware (HW). A method to insure that the HW is configured properly is to incorporate in a special chip the monitoring or verification electronics, and then mount this chip on the MCM so that it can verify the HW. This was the accepted method in previous system designs, but as the design restrictions and the need to have a larger number of processors on the MCM, the placement of this chip has been precluded. For this reason, other methods were used in later systems. The monitoring HW was then located on the system board near the MCM, or where ever it was possible to be placed. Because the space on the system board has now becomes more dense due to mounting fixturing, memory, and other required components, the available room left may not permit use of the security HW to be near the MCM. One method to facilitate the security and to be able to add functions to the system would be to build into the carrier HW for the MCM, several compartment areas which would contain small daughter MCM?s or single chip modules (SCM?s). Interconnection of those device carriers to the system board as well as the mother MCM would be accomplished with a multi-layer flex film LGA connector. In this way the monitoring, verification electronics, as well as added functions could be completely contained with the MCM structure at all times, and would be a factory safeguard for protecting the licensed system HW.

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Methodology for integrating multiple system elements in an enclosed structure using a flex film LGA connector

The present day MCM's use a metallic frame that holds the MCM as well as aligning the electrical LGA connector to the system board. This frame is designed to hold the needed cooling structures, to supply rigidity to the MCM, and to support the forces needed to compress the LGA connectors to the system board. By its very nature, this fixture must be of substantial size to support all the stresses that are developed in a mechanical compression type structure. The method described here incorporates in this structure, added compartments that could hold a small MCM ( less then 4 chips), or a small single chip modules (SCM's). These devices can be used to contain the electronics for store keys, crypto, EPROM's, early store cache, as well as added processors. Described in Fig. 1 below, a system board (30) containing signal I/O as well as power, is located between an insulator (20) and stiffener (10) structure and the support frame (40) that holds the MCM (50 and LGA connector (100). On the MCM (50) are mounted integrated circuits (IC's) (70) which are thermally controlled by the cooling cap (60) and thermal paste (80). A secondary MCM or element (90) is incorporated into the support frame (40). Both the primary MCM (50) and the supporting secondary MCM (90) are connected to the system board (30) by a single LGA connector (100). The cooling cap (60) is extended to provide thermal cooling for the support MCM (90). The support frame (40) is physically connected to the stiffener (10) by an actuating mechanism not shown.

LGA/Flex (100/200)

Secondary MCM/Element (90)

Support

Frame (40)

Sys Board (30)

Insulator (20)

Thermopaste (80)

IC (70)

Cooling Cap (60)

Support Frame

Stiffener (10)

MCM (50)

Fig. 1

Fig. 2 provides a top down view whereby it can be easily seen that several compartments for the secondary MCM's (90) are possible. The LGA connector (100) is a single structure that would permit electrical connections between the multiple secondary MCM's (90) and the primary MCM (50). A cross sectional view of the flex film is also provided. The film in this example consists of one plane pair of wires (104,105) located between two reference planes (103A, 103B). Those reference planes could be of different voltage levels and also part of the power redistribution for the system. A plated through hole (PTH) (102) would permit access to the x-y wire layers (104,105) or to the power planes located on the system board (30).

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LGA Flex Film (200)

 Secondary MCM/Element (90A)

 Secondary MCM/Element (90A)

Primary MCM Array

Support Frame (40)

PTH (102)

Ref (103A)

Ref (103B)

X-Layer (104)

Y-Layer (105)

LGA Flex Film X-Section

Fig. 2

Fig. 3 shows a more detailed view of the interconnection structure of the flex film LGA (200) connector. The LGA connector (100) here is comprised of the f...