Thomson-csf

Ludovic Michel

Alain Grancher

Jean-Yves Daden

G&eacute;rard Cachier

Vincent Jahier

Muriel Gohn-Devineau

Pascal Etourneau

The surface mounting of a backset microwave package on a printed circuit. After the package has been accurately positioned against the printed circuit the connections are produced by soldering the conducting elements in direct contact. A chip is enclosed in a sort of cage constituting a screen which replaces a conventional cover, the cage is formed by layouts borne respectively by the package and the printed circuit and is linked together by metal links. The surface mounting is particularly applicable to packages operating in millimetric microwaves.

Method for surface mounting of a microwave package on a printed circuit and package and printed circuit for implementing said method

A mechanical protection of a chip by an encapsulation product poured onto the chip and then cured. The problem is one of depositing only a small thickness of encapsulation product above the chip and above its wire bonds so as not to disturb the operation of the chip. In order to control this thickness, the chip is mounted on a tab, the height of which is chosen so that the difference in height between the top of the chip and the top of the surrounding printed circuits is equal to the desired thickness of the encapsulation. The encapsulation product is then poured onto the chip until it reaches the upper level of the printed circuits, without exceeding it. Such a mechanical protection may find particular application to electronic chips operating at microwave frequencies.

Electronic card encapsulating at least one IC chip and the method for producing the same

A flip-chip process in which the chip is positioned with its contacts facing a substrate. Small gold balls, obtained by the melting of the end of a gold wire, are soldered to the contacts of the chip and a segment of the gold wire is left attached to the ball. The mounting on the substrate is under heat, for example by means of a heating table, by positioning the chip on the substrate and by making use, for this purpose, of wire segments that are suitably arranged during an intermediate operation which consists of folding them in a predetermined way. A solder paste, deposited beforehand by means of a stencil, provides for the soldering between the balls and the facing parts of the conductors of the substrate.

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Plaisir, France

Ludovic Michel