| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to add a broad bandwidth and high signal integ rity together with a high-density channel simply at a low cost by forming circuit leads of very thin traces, and separating the traces and a ground plane by means of a low dielectric thin layer. SOLUTION: The circuit leads on a circuit board 306 of a probe head 103 are formed of very thin traces 312. Ground planes 410 and 412 and various kinds of conducting elements 214 and 215 are separated by means of dielectric layers (insulating layers) 420-422 and 427 having the dielectric constant of 5 or less. Especially, the dielectric layer 420 between the trace 312 and the ground plane 410 at the top part is made to be as thin as 4-6mil, and the input capacity is made large. Furthermore, all the active leads are separated from the other parts by means of the leads connected to the ground planes 410 and 412, and the coupling between the leads is decreased. Thus, the feedback through noises, coupling and the probe ground is eliminated. Therefore, the voltage probe having a high signal integrity and a wide frequency bandwidth is obtained, with the high-density channel maintained. |
