GB1559911A - Method of attaching coaxial electrical connectors to bonded microwave stripline structures - Google Patents

Description

(54) A METHOD OF ATTACHING COAXIAL ELECTRICAL CONNECTORS TO BONDED MICROWAVE STRIPLINE STRUCTURES (71) We, STANDARD TELEPRONES AND CABLES LIMITED, a British Company, of 190 Strand, London W.C.2, England, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a method of attaching a coaxial electrical connector to a bonded microwave stripline structure.

A bonded microwave stripline structure comprises a pair of rigid dielectric sheets, one of which is provided with a printed circuit pattern on one face, bonded together with the pattern between the sheets, the Otl'- side of the structure being provided with an overall metallic screening which has holes where required for coaxial electrical connectors, the centre pins of the connectors making electrical contact with the printed circuit pattern and the outer metal casings of the connectors making electrical contact with the screening.

Problems arise when mounting coaxial electrical connectors on the edge of the structure particularly in ensuring that the edge screening, which is applied by electroplating of the bonded structure, is complete, is not liable to leave gaps through which moisture can enter the bonded structure, and also to ensure that the connector casing is firmly anchored to the structure so that it does not move when in use.

According to the present invention there is provided a method of attaching a coaxial electrical connector having an outer metal casing. one end of which has a knurled, ribbed or otherwise roughened surface, to a bonded microwave stripline structure as hereinbefore defined including the steps of clamping the pair of rigid dielectric sheets together, forming a hole in the edge of the clamped pair of sheets, separating the sheets, coating the mating surfaces of the sheets and the roughened surface of the connector casing with a bonding adhesive, reassembling the sheets with the roughened and coated end of the connector casing in the hole, performing the bonding operation, the roughened surface of the casing ensuring a good grip in the hole, and subsequently electroplating the structure with a metal screening layer which extends over the edge of the bonded structure and part of the con nector casing.

Embodiments of the invention will now be described with reference to the accompanying drawings, in which : Fig. 1 illustrates a coaxial connector hav ing a ribbed casing.

Figs. 2 and 3 illustrate two versions of the ribbed casing, and Fig. 4 illustrates the method of attaching the connector of Fig. 1 to a bonded stripline structure.

The connector illustrated in Figs. 1 > has a centre pin 1 which protrudes at one end from a dielectric sheath 2 which is contained in a cylindrical metal outer casing 3.

One end of the casing 3, remote from the protruding end of the pin 1, is provided with a screwthread 4 by means of which the connector can be connected and disconnected from a complementary connector, e.g. on the end of a coaxial cable. The other end of the casing 3 is provided with a longi tudinally ribbed outer surface 5. As an alternative to ribbing the surface 5 may be, for example, knurled or otherwise roughened to ensure a good grip when the casing end is bonded into the stripline structure, To affix the connector to the structure two dielectric sheets 6, 7 of the structure are first clamped together and a hole is end milled into the edges of the sheets. the hole being centrally disposed with respect to the mating surfaces. The ribbed surface of the casing is first coated with a bonding medium. The protruding end of the central pin 1 is then electrically attached to the printed circuit pattern 8 on the one dielectric sheet and the dielectric sheath 2, if not already fitted, is fitted together with tlle outer metal casing 3. The two dielectric sheets are then bonded in the normal manner so that the ribbed surface of the casing is firmly secured in the hole. Next a protective cap is screwed onto the screwed end of the connector casing and the entire structure is subjected to the normal wet processing and electroplating processes to extend the external metal screening around the edges of the bonded structure and onto a part at least- of the metal casing 3.

The embodiment shown in Fig. 3-has that portion of the casing which- has the roughened surface reduced in diameter so that it can be bonded into a stripline structure in which the total thickness of the structure is insufficient to provide adequate anchorage for a normally sized connector casing.

WHAT WE CLAIM IS:- 1. A method of attaching a coaxial electrical connector having an outer metal casing. one end of which has a knurled, ribbed or otherwise roughened surface, to a bonded microwave stripline structure as hereinbefore defined including the steps of clamping the pair of rigid dielectric sheets together, forming a hole in the edge of the clamped pair of sheets, separating the sheets, coating the mating surfaces of the sheets and the roughened surface of the connector casing with a bonding adhesive, reassembling the sheets with the roughened and coated end of the connector casing in the hole, performing the bonding operation, the roughened surface of the casing ensuring a good grip in the hole, and subsequently electroplating the structure with a metal screening layer which extends over the edge of the bonded structure and part of the connector casing.

2. A method of attaching a coaxial elec trical connector to a bonded microwave stripline structure substantially as described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (2)

**WARNING** start of CLMS field may overlap end of DESC **. electrically attached to the printed circuit pattern 8 on the one dielectric sheet and the dielectric sheath 2, if not already fitted, is fitted together with tlle outer metal casing 3. The two dielectric sheets are then bonded in the normal manner so that the ribbed surface of the casing is firmly secured in the hole. Next a protective cap is screwed onto the screwed end of the connector casing and the entire structure is subjected to the normal wet processing and electroplating processes to extend the external metal screening around the edges of the bonded structure and onto a part at least- of the metal casing 3. The embodiment shown in Fig. 3-has that portion of the casing which- has the roughened surface reduced in diameter so that it can be bonded into a stripline structure in which the total thickness of the structure is insufficient to provide adequate anchorage for a normally sized connector casing. WHAT WE CLAIM IS:-

1. A method of attaching a coaxial electrical connector having an outer metal casing. one end of which has a knurled, ribbed or otherwise roughened surface, to a bonded microwave stripline structure as hereinbefore defined including the steps of clamping the pair of rigid dielectric sheets together, forming a hole in the edge of the clamped pair of sheets, separating the sheets, coating the mating surfaces of the sheets and the roughened surface of the connector casing with a bonding adhesive, reassembling the sheets with the roughened and coated end of the connector casing in the hole, performing the bonding operation, the roughened surface of the casing ensuring a good grip in the hole, and subsequently electroplating the structure with a metal screening layer which extends over the edge of the bonded structure and part of the connector casing.

2. A method of attaching a coaxial elec trical connector to a bonded microwave stripline structure substantially as described with reference to the accompanying drawings.