Thomson-csf

Olivier Prevotat

Jean Chazelas

Sandrine Trombert

Jean-Andre Lhermitte

Jean-Fran&ccedil;ois Silvain

To improve the resistance of a solder to strains, especial thermal strains, superelastic particles are incorporated into the solder in a proportion by volume of 10 to 30% approximately. So that this incorporation can be done, the particles are coated with a metal, for example copper, that is wettable by the solder.

Method for the making soldering flux and resulting weld joint

In a method to fabricate a printed circuit having a surface plated with a base metal layer, an improvement including depositing a first metallic resist on the base layer to delimit at least patterns of circuit elements to be etched in a layer having a first thickness, forming metallized holes in the plated surface after depositing the first metallic resist; and depositing a second metallic resist after forming the metallized holes to delimit at least patterns of circuit elements to be etched in a layer having a second thickness greater than said first thickness, whereby more accurate etching in the metal layer having the first thickness compared to etching in the metal layer having the second thickness is possible.

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Buc, France

Olivier Prevotat