Abstract: A measuring probe can be positioned and set on signal pads 6 without providing positioning pins on a test board. An IC tester adjusting unit includes signal pads formed on a test board for testing operating characteristics of an IC to be tested by allowing the signal pads to contact the IC to be tested to input testing input signals to the IC to be tested, and by evaluating output signals outputted from the IC to be tested relative to the testing input signals.

Abstract: A measuring probe can be positioned and set on signal pads 6 without providing positioning pins on a test board. An IC tester adjusting unit includes signal pads formed on a test board for testing operating characteristics of an IC to be tested by allowing the signal pads to contact the IC to be tested to input testing input signals to the IC to be tested, and by evaluating output signals outputted from the IC to be tested relative to the testing input signals.

Abstract: It is an object of the invention to provide a low cost printed-circuit board capable of achieving high density of mounting of the surface mounting components and of designing of conductive patterns while keeping speeding up a transmission speed of a signal pattern and reducing a noise, and a method of mounting electric components on the printed-circuit board. Component mounting pads formed of conductive patterns are disposed on a surface of the printed-circuit board at two locations thereof, and through holes for connecting printed-circuit boards of a multi-layer printed-circuit board are defined in the component mounting pads. The through holes are filled up by a resist ink from the electric component non-mounting surface when the printed-circuit board is manufactured. As a result, a sealed air-layer is formed inside the through holes when a solder is pasted or soldered onto the printed-circuit board.