Test heads having contact pairs

Abstract

A test head 90 having a plurality of contact pairs 81 is formed in a simple monolithic manner. A plurality of first conductors 74 are aligned in a first row and, spaced therefrom, a plurality of second conductors 80 are aligned in a second row. Each conductor has a circuit end and a contact end and each first conductor 74 registers with a mating second conductor 80 to form a plurality of contact pairs 81 at the contact ends. A common base insulator 88 is formed transversely of the conductors 74 and 80 at the circuit ends to maintain conductor spacing in an electrically insulated manner. A common bar insulator 86 is formed transversely of the second conductors 80 to maintain the contact spacing within the pairs 81 when the conductors are flexed toward a device 27 to be tested. In a method of making a test head 90, the conductors are made in patterns 56 from sheet 55 having a substantially uniform metallurgical composition and each pattern 56 includes a member 72 connected to the circuit ends of the conductors. After assembly, the connective member 72 is removed; therefore the position of each conductor relative to other conductors in a pattern 56 is maintained constant from the sheet 55 to the test head 90. The sheet 55 is advantageously made from a beryllium copper alloy which is susceptible to precipitation aging for hardness to obtain spring temper.