Probe apparatus
A probe apparatus of inspecting electrical characteristics of a power device having electrodes on both sides of a substrate at wafer level can reduce and uniformize a contact resistance between the electrode on a rear surface of the substrate and a mounting surface conductor of a chuck top. In the probe apparatus, an attracting device supports a semiconductor wafer W on the chuck top 12, and has many vertical fine holes in a pattern (diameter φ and pitch p) that satisfies the condition of φ<p≦2φ. For example, the diameter φ is about 0.25 mm, and the pitch p is about 0.5 mm.
1. A probe apparatus of inspecting an electrical characteristic of a power device that is formed on a substrate to be inspected and has electrodes on front and rear surfaces of the substrate, the probe apparatus comprising:
a movable chuck top configured to mount and support the substrate thereon;
a probe card that is provided above the chuck top to face the chuck top and is configured to support a probe needle having a leading end to be brought into contact with a front surface electrode of the power device exposed at the front surface of the substrate supported on the chuck top;
a first measurement line, having the probe needle, configured to electrically connect the front surface electrode of the power device to a corresponding first terminal of a tester;
a mounting surface conductor that serves as a mounting surface on the chuck top and is configured to be brought into contact with a rear surface electrode of the power device exposed at the rear surface of the substrate;
a second measurement line, having the mounting surface conductor, configured to electrically connect the rear surface electrode of the power device to a corresponding second terminal of the tester; and
an attracting device, having many vertical fine holes which are densely distributed in an attraction region set on the mounting surface and each of which is vertically extended from a surface of the mounting surface conductor to an inner portion thereof, configured to apply a vacuum attracting force to the rear surface of the substrate through the vertical fine holes,
wherein, in the attraction region, the vertical fine hole satisfies a condition of φ<p≦2φ when φ denotes a diameter of the vertical fine hole and p denotes a pitch therebetween.
2. The probe apparatus of claim 1 ,
wherein a density of the vertical fine holes is equal to or higher than about 100 holes/cm 2 .
3. The probe apparatus of claim 2 ,
wherein the density of the vertical fine holes is equal to or higher than about 400 holes/cm 2 .
4. The probe apparatus of claim 1 ,
wherein the diameter φ of the vertical fine hole is in the range from about 0.2 mm to about 0.6 mm.
5. The probe apparatus of claim 1 ,
wherein, in the attraction region, an opening ratio of the vertical fine holes is in the range from about 20% to about 60%.
6. The probe apparatus of claim 1 ,
wherein at least a surface layer of the mounting surface conductor is formed of a plurality of thin plate conductors stacked on top of each other, and each of the thin plate conductors has openings at positions corresponding to the vertical fine holes and each of the openings has the same diameter as that of each of the vertical fine holes.
7. The probe apparatus of claim 6 ,
wherein the openings of the thin plate conductor are formed by an etching process.
8. The probe apparatus of claim 6 ,
wherein the thin plate conductors are joined to each other by a diffusion bonding.
9. The probe apparatus of claim 1 ,
wherein the vertical fine holes are separated from each other in a region having a preset depth from the surface of the mounting surface conductor.
10. The probe apparatus of claim 9 ,
wherein, in an inner deep region exceeding the preset depth in the mounting surface conductor, a communication path is formed between the adjacent vertical fine holes.
11. The probe apparatus of claim 9 ,
wherein the preset depth is in the range from about 0.5 mm to about 3 mm.
12. The probe apparatus of claim 1 ,
wherein the attracting device comprises a vacuum passage that is provided in an inside of or under the mounting surface conductor to be connected to lower ends of the vertical fine holes at respective positions in the attraction region, and is connected to a vacuum source.
13. The probe apparatus of claim 12 ,
wherein the vacuum passage is extended in a spiral shape from a central portion of the mounting surface to a periphery portion thereof in a radial direction or is arranged concentrically, and
the central portion of the mounting surface is positioned at an upstream side with respect to the vacuum source, and the periphery portion of the mounting surface is positioned at a downstream side.
14. The probe apparatus of claim 1 ,
wherein, in the attracting device, the substrate is first attracted at the central portion of the mounting surface, and then, the substrate is sequentially attracted from the central portion of the mounting surface toward the periphery portion thereof.