Microwave circuit package

A method of manufacture of a microwave circuit package having a ball grid array, BGA, soldered onto a planar major surface of a metal housing of the package for the electrical connection of the ports of the microwave circuit through RF signal paths to an adjacent electrical device, in which each of the RF signal paths comprises a pin electrically connected to a respective port of the microwave circuit, projecting normally through an opening in the said major surface from which it is electrically insulated, and soldered to a ball of the BGA;

• the pin and the surrounding balls of the BGA, which are soldered to the metal housing, constituting a coaxial RF signal path;
• each RF signal path further comprising a plastics insulator plug fitted sealingly into the opening in the metal housing to form a fluid-tight seal, the plug having an axial bore through which extends the pin with a fluid-tight seal therebetween;
• the pin having a central portion narrower than the external end of the pin that is soldered to the ball, and a conical transition surface between the central portion and the external end;
• the method comprising, for each port, fitting the insulator plug and pin into the corresponding opening in the metal housing, applying axial pressure to the external end of each pin, to cause the conical transition surface to apply a radial force to the inner wall of the bore of the plastics plug to enlarge the plug bore through plastic deformation, until the pin has moved inwardly sufficiently that the pins external end is substantially flush with the major surface;
• and soldering the BGA to the pins and to the major surface with the balls substantially coplanar.