In a circuit board testing machine for testing a circuit board of an electrically insulating material having circuit tracks of an electrically conductive material arranged on one side surface or on opposite side surfaces, a test surface (84) or two opposite test surfaces (84,84) is or are provided. The test surface or each of the test surfaces defines a number of test points electrically insulated relative to one another and arranged in a matrix configuration. For establishing electrically conductive connection between selected test points of the test surface (84) and selected areas, e.g. circuit tracks of the circuit board (126) to be tested, a connector assembly is sandwiched between the one side surface of the circuit board to be tested and the test surface. The connector assembly comprises a double-sided circuit board (120,220) having individual connectors arranged on a first and a second side surface of the circuit board and connected through conductors extending through the circuit board in a configuration corresponding to the selected areas of the circuit board to be tested and the selected points of the test surface (84), respectively. The connector assembly further comprises a first sheet (122,222) and a second sheet (124,224) arranged on opposite side surfaces of the double-sided circuit board of the connector assembly. The sheets are of an electrically insulating material having metal fibres of high electrical conductivity extending through the sheet.
The layout of the double-sided circuit board of the connector assembly is defined only by the actual layout of the circuit board to be tested and the matrix configuration of the test points of the test surface. Consequently, it is possible to easily modify the circuit board testing machine to different circuit board layouts and even to different circuit boards, which may even have components mounted thereon.