Substrate-holding device for testing circuit arrangements on substrates
View Patent ↗A substrate-holding device is designed as a one-piece ceramic element having a number of variably heavily doped layer regions. At least one layer region is a conductive region and at least one layer region is an insulative region. A multilayer chuck structure is thereby formed which does not exhibit mechanical surface interfaces between the layers.
1. A device for holding a substrate during testing of circuit arrangements on the substrate comprising a ceramic element having a substrate receiving surface and a thickness, the ceramic element having at least one conductive layer region formed within said thickness and the ceramic element having at least one insulative layer region formed within said thickness, wherein:
the at least one conductive layer region includes a first layer, at least partially enclosing the substrate receiving surface and a third layer;
the at least one insulative layer includes a second layer interposed between the first layer and the third layer; and
the first layer is provided with an external contact connection for connection of a force potential and the third layer with an external contact connection for connection to guard potential.
2. The device for holding a substrate according to claim 1 , wherein the at least one insulating layer further comprises a fourth layer beneath said third layer.
3. The device for holding a substrate according to claim 2 , wherein the at least one conductive layer further comprises a fifth layer provided under the fourth layer.
4. The device for holding a substrate according to claim 3 , wherein the fifth layer is arranged on the outside of the ceramic element with the surface being left free.
5. The device for holding a substrate according to claim 1 , wherein the at least one conductive layer has an electrical conductivity less than 10 −1 to 10 −3 ohm-cm and the at least one insulative layer has an insulating resistance greater than 10 10 to 10 12 ohms.
6. The device for holding a substrate according to claim 1 , wherein the device is placeable on a thermochuck.
7. The device for holding a substrate according to claim 1 , further comprising a region of electric heating elements disposed in one of the at least one insulative layers.
8. The device for holding a substrate according to claim 7 , wherein the region of electric heating elements is formed in a spiral-like manner in the top view and includes external contact connections.
9. The device for holding a substrate according to claim 1 , wherein:
the first layer is introduced in the center of the surface leaving free a peripheral region on the surface,
the second layer projects in the peripheral region of the surface, and
the third layer is designed in a bowl-shaped configuration that surrounds the first layer, the third layer including side wall portions which project through the thickness of the element into the peripheral region of the surface.
10. A device for holding a circuit substrate for high frequency measurements, comprising a ceramic element, the ceramic element comprising:
a substrate receiving surface;
a first insulating layer, wherein the first insulating layer has a resistance greater than about 10 10 to 10 12 ohms and wherein the first insulating layer is disposed adjoining the substrate receiving surface;
an absorption layer disposed underneath the first insulating layer, wherein the absorption layer has high electrical conductivity less than about 10 −1 to 10 −3 ohm-cm; and
a second insulating layer disposed underneath the absorption layer, wherein the a second insulating layer has a resistance greater than about 10 10 to 10 12 ohms.