A device for forming an encapsulated end of a wire bonded to a metal
surface. The device includes a clamp being an end surface of a bar is
pressed against a surface of a plate. The end surface has a ridge formed
around its edge. Therefore, when a clamping force is applied to the bar
against the plate, the metal sheet clamped between the plate surface and
end surface of the bar, the clamping force is concentrated at an interface
between the metal surface and ridge. When encapsulate is injected into the
contact region, the ridge prevents contaminating material from migrating
over interface between bar and plate where the welding step is to be
performed. The bar is then withdrawn leaving a tunnel through which the
wire is positioned with the end of the wire in contact bondable to the
clean surface of metal. The wire is positioned in the tunnel and bonded to
the metal surface.
