Travelling thermocouple method & apparatus

• US 5,820,266 A
• Filed: 12/10/1996
• Issued: 10/13/1998
• Est. Priority Date: 12/10/1996
• Status: Expired due to Fees

• Current Assignee: SPX Corporation
• Original Assignee: Tibor J. Fedak
• Inventors: Fedak, Tibor J.
• Primary Examiner(s): BENNETT, GEORGE B
• Application Number:
  US08/762,764
• Time in Patent Office: 672 Days
• Field of Search: 374/110, 374/116, 374/141, 374/149, 374/179, 374/208, 136/230, 414/150, 414/152, 414/157, 414/172, 219/210, 219/388, 219/494, 432/34, 432/45, 432/239, 432/241
• US Class Current: 374/179
• CPC Class Codes: G01K 1/026 arrangements for monitoring a plurality of temperatures, e.g. by multiplexing
• CPC Class Codes: G01K 1/146 arrangements for moving thermometers to or from a measuring position
• CPC Class Codes: G01K 13/06 in linear movement

Abstract

A travelling thermocouple dynamically profiles the actual temperature of a substrate passing through a vertical oven without entangling the thermocouple wires. Media components, such as microprocessor chips in a semiconductor wafer, are supported on a tray or plate on a driven conveyor. A thermocouple formed of two metal wires of extended length are connected at one end to the media component and at the other end to a stationary readout device and function as the temperature gauge for all trays of components passing through the oven. A C-shaped clamp or hook secured to the thermocouple wires resiliently engages a chain drive driven independently of the conveyor drive but in correlation therewith by a computer controller and pulls the wires through the oven keeping pace with the media component to which it is attached. When turning the corners at the top of the oven the hook is crossed over from the leading end of the plate to the trailing end of the plate by effecting temporary relative motion between the drives. The wires are guided in a G-shaped channel throughout their passage in the oven. After exiting the oven, the hook is disconnected from the chain, and the wires are pulled forwardly through the oven after being disconnected from the readout device for reuse in another pass. An alternate embodiment is in a horizontal oven which includes going around corners.

Claims

1. A process of continuously sensing temperature of a media component traversing an oven comprising the steps of:

(a) supporting the media component on a tray on a moving conveyor and transporting the tray in a path through the oven,

(b) attaching a thermocouple, formed of two metal wires of extended length, at one end to the media component and coupling the thermocouple at the other end to a readout device and continuously sensing the temperature of the media component during the media component'"'"'s traverse of the oven while pulling a length of the wire through the oven in trail,

(c) attaching the wires of the thermocouple to a chain moving independently of the moving conveyor but in synchronism therewith in a traverse of the oven, and

(d) temporarily moving the tray relative to the chain to cross the point of attachment of the wires to the chain from a leading end of the tray to a trailing end of the tray,

whereby the tray moves around a corner in the path without entangling the extended length of wires.

2. The process of claim 1 further comprising the step of:

retaining the length of wire in a guide channel throughout its traverse of the oven.

3. The process of claim 1 wherein the step of attaching the wires to the chain further comprises the step of:

engaging a wire holder portion upon a chain extension portion.

4. The process of claim 1 further comprising the step of:

resiliently retaining the holder engaged with the chain throughout its traverse of the oven.

5. The process of claim 4 wherein the temporarily moving step further comprises the step of:

the resilient retaining step including a spring attached at one end to the holder and the other end to the tray,

the wires having a slack portion extending between the holder and the media component and passing through the tray to the media component, and

moving the slack portion of the wires and the one end of the spring under the tray from a leading end of the tray to a trailing end of the tray.

6. The process of claim 3 wherein the temporarily moving step further comprises the step of:

moving the tray forwardly in the oven relative to the chain or moving the chain rearwardly in the oven relative to the tray.

7. The process of claim 6 wherein the step of moving the chain rearwardly relative to the attachment further comprises the step of:

stopping the chain while continuing to forwardly move the conveyor carrying the tray.

8. The process of claim 1 further comprising the steps of:

measuring the sensed temperatures, and

displaying the measured temperatures.

9. The process of claim 1 further comprising the steps of:

disengaging the wires from attachment to the chain,

uncoupling the other end of the wires from the readout device, and

pulling the length of wire forwardly through the oven.

10. The process of claim 9 wherein the disengaging step further comprises the step of:

moving the chain forwardly relative to the tray.

11. The process of claim 10 wherein the step of moving the chain forwardly relative to the tray further comprises the steps of:

stopping the conveyor supporting the tray while continuing to move the chain forwardly a predetermined distance to slacken the attachment of the wires to the chain and, then,

stopping the chain to permit the wire attachment to be easily detached from the chain.

12. The process of claim 1 further comprising the step of:

moving the tray around a corner in a vertical oven.

13. The process of claim 1 further comprising the step of:

moving the tray around a corner in a horizontal oven.

14. The process of sensing the temperature of a product being moved through an oven on a conveyor drive with a thermocouple formed of two metal wires of extended length attached to the product comprising the steps of:

engaging the wires of the thermocouple with a chain of a chain drive to pull the thermocouple wires in a path completely through the oven, and

while generally keeping the chain in pace with the product and while resiliently retaining the engagement of the thermocouple wires to the chain, temporarily moving the conveyor drive relative to the chain drive to enable the product and thermocouple to traverse a corner in the path through the oven without entangling the wires.

15. In an apparatus for heat treating a substrate having a main heating chamber with an entrance and exit, and a conveyor drive for transporting a plurality of media components supported on trays on the conveyor drive along a path through the main heating chamber, wherein the improvement comprises:

a chain drive independent of the conveyor drive for keeping pace with the conveyor drive,

a computer controller for synchronizing the heating and drives,

a thermocouple, formed of two metal wires of extended length, attached at one end to a media component supported on one of the conveyor drives and at the other end to a readout device for continuously sensing the temperature of the media component during the media component'"'"'s traverse of the main heating chamber while pulling a length of the wires through the oven in trail,

an attachment device secured to the wires of the thermocouple resiliently engaged with the chain drive for pulling the length of the wires through the main heating chamber in synchronism with the media component during the media component'"'"'s traverse of the main heating chamber, and

the computer control enabling a first temporary relative motion between the conveyor drive and chain drive to cross the attachment device from a leading end of the tray to a trailing end of the tray,

whereby as the tray moves through the main heating chamber it is enabled to move around a corner in the path without entangling the extended length of wires.

16. The apparatus of claim 15 further comprising:

a channel extending along the entire path for maintaining the extended length of the wires therein while guiding the extended length of the wires as they are being pulled through the main heating chamber without entanglement.

17. The apparatus of claim 15 further comprising:

the channel being a G-shaped guide with the open slot on its upper side, the leading end of the wires exiting the slot and passing through a hole in the support to attach to the substrate.

18. The apparatus of claim 15 further comprising:

a spring resiliently holding the attachment device in engagement with the chain of the chain drive as the attachment device is moved relative to the tray from a position near the leading edge of the tray to a position near the trailing edge of the tray.

19. The apparatus of claim 15 further comprising:

a display coupled to the other end of the thermocouple for reading out the temperatures sensed by the thermocouple.

20. The apparatus of claim 15 further comprising:

the attachment device being made easily disengageable from the chain of the chain drive by a second temporary relative motion between the chain drive and the conveyor drive in a direction opposite the first temporary relative motion.

21. The apparatus of claim 15 further comprising:

the main heating chamber comprising a vertical oven having at least one corner in the path therethrough.

22. The apparatus of claim 15 further comprising:

the main heating chamber comprising a horizontal oven having at least one corner in the path therethrough.