Wafer container having electrically conductive kinematic coupling groove to detect the presence of the wafer container on a support surface, the support surface, and method

• US 6,389,707 B1
• Filed: 08/17/2000
• Issued: 05/21/2002
• Est. Priority Date: 08/17/2000
• Status: Expired due to Term

• Current Assignee: Infineon Technologies AG, NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Peiter, Martin, Haris, Clinton
• Primary Examiner(s): BENNETT, GEORGE B
• Application Number:
  US09/641,153
• Time in Patent Office: 642 Days
• Field of Search: 336/13, 336/23, 336/45, 248/542, 414/935, 340/568.1, 340/568.4, 340/686.2
• US Class Current: 33/645
• CPC Class Codes: H01L 21/67259 Position monitoring, e.g. misposition detection or presence detection
• CPC Class Codes: H01L 21/67379 characterised by coupling elements, kinematic members, handles or elements to be externally gripped

Abstract

In a transportation system (100, 200) for wafers, a wafer container (100) has kinematic coupling grooves, and a support surface (200) has kinematic coupling pins. Grooves and pins are at least partially electrically conductive to allow monitoring the correct position of the container by measuring electrical resistance, as well as to allow signal exchange to and from the container (100). The kinematic coupling pins have first and second surface areas that are electrically isolated.

Claims

1. A wafer container, comprising:

in a base plate, at least a first kinematic coupling groove with a first groove surface that is at least partially electrically conductive; and

in said base plate, a second kinematic coupling groove with a second groove surface that is also at least partially electrically conductive, wherein an electrical conductive path extends from said first groove surface to said second groove surface so that the presence of said wafer container on a support surface provides an electrically conductive loop having a predetermined electrical resistance between kinematic coupling pins of the support surface.

2. The wafer container of claim 1 wherein the electrical conductive path is formed by said base plate.

3. The wafer container of claim 1 wherein the electrical conductive path is formed by an electrical device.

4. Wafer container of claim 1 being a Front Opening Unified Pod (FOUP).

5. A kinematic coupling pin to provide kinematic coupling with a kinematic coupling groove in a wafer container, said pin characterized in that a first surface area and a second surface area kinematically couple to said groove and that said first surface area is substantially electrically isolated from said second surface area.

6. The kinematic coupling pin of claim 5, wherein electrical isolation is provided by an isolation member.

7. A support surface for holding a wafer container, said support surface having at least a first kinematic coupling pin to couple to a corresponding first kinematic coupling groove in a base plate of said wafer container, said support surface characterized in that said kinematic coupling pin comprises at least first and second electrically isolated surface areas to exchange electrical signals with said container via said first kinematic coupling groove.

8. The support surface of claim 7 wherein said first and second electrically isolated surface areas of said kinematic coupling pin are electrically coupled to an evaluation circuit that measures the electrical resistance between said first and second surface areas to indicate the kinematic coupling between said groove in said container when the electrical conductive path is established via said first surface area, said groove and said second surface area.

9. A support surface for holding a wafer container, said support surface having first and second kinematic coupling pins to couple to corresponding first and second kinematic coupling grooves in a base plate of said wafer container, said support surface characterized in that said kinematic coupling pins each are electrically conductive but electrically isolated from each other to exchange electrical signals with said container via said first and second kinematic coupling grooves.

10. The support surface of claim 9, wherein said electrical signals with said container represent a measured resistance between said first and second pins and thereby selectively indicate the presence or the absence of said wafer container on said surface.

11. Method for operating a transportation system of a wafer container and a support surface, said method comprising the following first and second steps:

first, placing said wafer container having a plurality of kinematic coupling grooves that are least partially electrically conductive on said support surface that has a plurality of corresponding kinematic coupling pins that are also at least partially electrically conductive to kinematically couple said grooves with said pins,

and second, at least one step selected from a group of the following steps;

measuring the electrical resistance across a single groove via a single pin that has electrically isolated parts; and

measuring the electrical resistance between two grooves via two corresponding pins.