Electricity: electrical systems and devices – Housing or mounting assemblies with diverse electrical... – For electronic systems and devices
Reexamination Certificate
2002-06-19
2004-01-20
Chérvinsky, Boris (Department: 2835)
Electricity: electrical systems and devices
Housing or mounting assemblies with diverse electrical...
For electronic systems and devices
C361S707000, C361S710000, C361S719000, C361S760000, C257S718000, C257S719000, C257S727000
Reexamination Certificate
active
06680848
ABSTRACT:
TECHNICAL FIELD
The invention relates to a device and method for mounting an electrical component on a printed circuit card. The invention particularly applies to integrated circuits whose contact with the connection pads of the printed circuit card is produced by pressure. An integrated circuit provided with a plurality of contact terminals constituting a matrix of flat leads known as an LGA (Land Grid Array) is well adapted to the implementation of the invention, and for that reason will be used as an example to illustrate the invention.
PRIOR ART
Traditionally, an integrated circuit is placed in a package comprising contact terminals. Throughout the description below, the expression “LGA integrated circuit” will be used to designate both an LGA integrated circuit and a circuit placed in a package.
Traditionally, the LGA integrated circuit has two sides, one active and the other inactive. The active side comprises the contact terminals.
Generally, connecting the LGA integrated circuit to the printed circuit card requires stacking a certain number of elements. An insert comprising flexible electric contacts is placed between the LGA integrated circuit and the printed circuit card in order to connect them electrically. Pressure must be exerted on this system in order to produce a good electrical contact. This is done by means of a press plate applied to the non-active side of the LGA integrated circuit. The device is completed by a heat sink that serves to dissipate heat. A variant consists of forming the press plate and the heat sink in one piece. Generally, a thermal joint is inserted between the LGA integrated circuit and the heat sink for a better transfer of energy to the heat sink.
The pressure is applied, for example, by springs pressing on the plate or the plate/heat sink. These springs are generally guided by standoffs attached to the integrated circuit either by inserts or by nuts provided in the printed circuit card.
A first problem raised by this technique is that the current systems do not make it possible to mount integrated circuits, particularly integrated circuits whose electrical contact with the printed circuit card is produced by pressure, on two opposite side of the printed circuit card.
Another problem is that the inserts or nuts take up a considerable amount of space on the printed circuit card. This constitutes a limitation on the component density. The space occupied by these nuts on the printed circuit card is unacceptable in a world where miniaturization is of utmost importance.
Moreover, the inserts or nuts deform the card in places. The stress produced can cause the traces located near the inserts or nuts to break. It is therefore necessary to limit the trace width, and the routing density is consequently reduced.
SUMMARY OF THE INVENTION
A first object of the invention is to allow LGA integrated circuits to be mounted on both sides of the printed circuit card.
A second object is to use mounting means whose base does not deform the printed circuit card and takes up as little space as possible, thereby permitting a higher routing density.
A third object of the invention is to retain the ease with which the integrated circuit is mounted on the printed circuit card.
A fourth object is to reduce the financial and time cost of this type of implementation as much as possible.
To this end, the subject of the invention is a device and method for mounting at least two electrical components on a printed circuit card, the card comprising connection pads on both of its sides, characterized in that the card is traversed by holes for receiving mounting means that extend through the printed circuit card in order to mount the electrical components on opposite sides of the card.
Another subject of the invention is the tool for mounting or removing an electrical component mounted on a printed circuit card, as defined in the mounting device according to the invention, characterized in that it comprises means for exerting pressure on a first electrical component mounted on a first side of the printed circuit card, in order to mount or remove a second electrical component on the opposite side of the printed circuit card.
REFERENCES:
patent: 4159483 (1979-06-01), Bettin
patent: 5424919 (1995-06-01), Hielbronner
patent: 5730210 (1998-03-01), Kou
patent: 5793618 (1998-08-01), Chan et al.
patent: 5892245 (1999-04-01), Hilton
patent: 5978223 (1999-11-01), Hamilton et al.
patent: 6154365 (2000-11-01), Chiu et al.
patent: 6477058 (2002-11-01), Luebs et al.
patent: 6490161 (2002-12-01), Johnson
patent: 6545879 (2003-04-01), Goodwin
patent: 6549418 (2003-04-01), Deeney
Fromont Thierry
Petit Claude
Bull S.A.
Chervinsky Boris
Kondracki Edward J.
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