Electricity: electrical systems and devices – Housing or mounting assemblies with diverse electrical... – For electronic systems and devices
Reexamination Certificate
2000-04-25
2001-07-24
Picard, Leo P. (Department: 2835)
Electricity: electrical systems and devices
Housing or mounting assemblies with diverse electrical...
For electronic systems and devices
C361S699000, C361S700000, C361S704000, C165S185000, C174S015200
Reexamination Certificate
active
06266242
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a mounting structure which may suitably apply to an information processing apparatus such as a personal computer, and more particularly to an information processing apparatus which is arranged to both enhance heat relase efficiency and reduce its size.
The information processing apparatus such as a personal computer has been required to increase the processing speed and reduce the bulk. In order to meet these requirements and facilitate the upgrade of a CPU built therein, the recent information processing apparatus has a tendency of providing a modular CPU. The LSI element containing a CPU is directed to larger power consumption and a larger heat relase relevant thereto because of the increase of the processing speed. Also in case the semiconductor element with a large heat developed is modularized, the semiconductor is also required to dissipate heat. The heat-dissipating structure provided with the modular CPU has been heretofore known in JP-A-5-110277 (corresponding to the U.S. Pat. No. 5,315,482), for example. This prior art describes the mounting structure wherein a radiating fin for diffusing heat is integrally molded with the CPU module.
However, the prior art is arranged to mount components and a radiating fin on both sides of a circuit module. It means that the prior art does not take into a sufficient consideration the possible use of itself in a small-sized thin information processing apparatus.
Further, it also does not make a sufficient allowance for efficient heat dissipation to be considered in the case of mounting itself to a personal computer.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a CPU module which is suitable to a small-sized information processing apparatus such as a personal computer.
It is a further object of the present invention to provide a CPU module which meets a requirement for reduction in size as positively taking the measure for heat release.
It is another object of the present invention to provide a thin information processing apparatus which provides excellent heat release.
In carrying out the objects, a CPU module having a processor, a connector to be electrically connected to the outside, a system control circuit for controlling transfer of a signal between the processor and the connector, and a printed board on which the processor, the connector and the system control circuit are mounted thereon, includes:
a heat release plate such as a metal plate or a heat pipe pasted on its one side with the printed board; and
the printed board having a cavity in which the processor is mounted in a bare-chip state, one side of which is pasted with the heat release plate.
The processor is pasted with the heat release plate in the bare-chip state, so that the heat radiated by the processor is conducted to the heat release plate from which the heat is dissipated. This results in sufficiently cooling down the processor.
In the case that the other side of the heat release plate is mounted on the information processing apparatus such as a personal computer in contact with a member such as a box of the apparatus, the heat is conducted through the box. Hence, the heat release effect is further enhanced when the CPU module is mounted on the information processing apparatus.
Since only one side of the CPU module is used for mounting the relevant components thereon, the CPU module may be made thinner. The combination of this design and the bare-chip mount makes it possible to far more reduce the CPU module in size. It leads to reduction of the overall information processing apparatus where the processor is to be mounted in size and thickness.
The CPU module is further effective in reducing the overall information processing apparatus because of the possible mount of the CPU module to a mother board so that the CPU module itself is served as part of an electromagnetic shield of the information processing apparatus.
Moreover, by sealing the cavity with a member having a lower heat conductivity than the heat release plate, it is possible to prevent the heat from being upwardly conducted and increase a heat releasing factor from the heat release plate side. The reduction of the radiation onto the side with the connector makes it possible to reduce the heat conduction to the mother board side.
On the top of the sealed cavity is mounted a second substrate with a small gap therebetween so that the necessary electronic components may be mounted on the second substrate. The small gap does not bring about any convention current of the air inside of the gap, so that the gap itself is effective in insulating the heat. Hence, the effect described in the previous paragraph is further enhanced. In addition, the stepwise mount of components on the substrate where the processor is mounted results in reducing the module itself in area.
In case the electronic components to be mounted on the second substrate are a cache memory and a cache memory control mechanism both of which are strongly associated with the processor, the necessary signal lines between those components and the processor may be reduced in length. This makes it possible to further increase the processing speed and the reliability.
Since the cache memory to be mounted on the second substrate is in the bare-chip state, the height and the area of the CPU module can be suppressed.
In place of mounting the processor in the bare-chip state, the processor may be mounted in a face-down state so that the processor is connected with the substrate by means of a metal bump and in a chip-size-package state. Though the latter two mounting states offer lower effects than the bare-chip state, the objects of the invention of the present application can be achieved to some extent.
On the other hand, the CPU module has been heretofore the highest one among the components to be mounted on the mother board of a notebook personal computer. This has been an obstacle to reducing the notebook personal computer in size.
It is another object of the present invention to make the notebook personal computer free of the restriction in height imposed by the CPU module.
In carrying out the object, the height of the CPU module to the mounting level is restricted to 10 mm. or lower. The current notebook personal computer is frequently required to have a PC card slot for accommodating two PC cards in vertical, the PC cards standardized by the PCMCIA (Personal Computer Memory Card International Association). For the convenience of this standard specification in height, the notebook personal computer cannot be lower than 10.5 mm. The present invention provides the CPU module whose height from the mounting level is equal to or lower than 10 mm. Hence, the CPU module does not put a height limitation to designing the notebook personal computer, so that the CPU module makes great contribution to implementing a thin notebook personal computer.
In order to achieve the CPU module that is equal to or lower than 10 mm, the processor is mounted in the cavity and all other components can be mounted on the side where the highest component, that is, the connector is mounted.
REFERENCES:
patent: 5315482 (1994-05-01), Tanaka et al.
patent: 5557502 (1996-09-01), Banerjee et al.
patent: 5631807 (1997-05-01), Griffin
patent: 5701231 (1997-12-01), Do et al.
patent: 5710733 (1998-01-01), Chengson et al.
patent: 5712762 (1998-01-01), Webb
patent: 5847935 (1998-12-01), Thaier et al.
patent: 6005771 (1999-12-01), Bjorndahl et al.
patent: 6069793 (2000-05-01), Maruyama et al.
Kurihara Ryoichi
Maruyama Takashi
Sakaue Masakazu
Tanaka Mikihiro
Uemura Yasuhiro
Duong Hung Van
Hitachi , Ltd.
Mattingly Stanger & Malur, P.C.
Picard Leo P.
LandOfFree
Circuit module and information processing apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Circuit module and information processing apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Circuit module and information processing apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2468492