RESISTOR WITH TEMPERATURE COEFFICIENT OF RESISTANCE (TCR) COMPENSATION

• US 20110057764A1
• Filed: 09/02/2010
• Published: 03/10/2011
• Est. Priority Date: 09/04/2009
• Status: Active Grant

• Current Assignee: Vishay Dale Electronics (Vishay Intertechnology Incorporated)
• Original Assignee: Vishay Dale Electronics (Vishay Intertechnology Incorporated)
• Inventors: Bertsch, Thomas L., Veik, Thomas L., Wyatt, Todd L., Smith, Clark L.
• Granted Patent: US 8,198,977 B2
• Time in Patent Office: Days
• US Class Current: 338/25
• CPC Class Codes: G01R 1/203 Resistors used for electric measuring, e.g. decade resistors standards, resistors for comparators, series resistors, shunts resistors in general H01C; microwave or radiowave terminations H01P1/26; coupling devices H01R
• CPC Class Codes: G01R 19/0092 measuring current only all subgroups of G01R19/00 take precedence
• CPC Class Codes: G01R 19/32 Compensating for temperature change
• CPC Class Codes: H01C 1/00 Details
• CPC Class Codes: H01C 1/148 the terminals embracing or surrounding the resistive element H01C1/142 takes precedence
• CPC Class Codes: H01C 17/232 Adjusting the temperature coefficient; Adjusting value of resistance by adjusting temperature coefficient of resistance
• CPC Class Codes: H01C 17/28 adapted for applying terminals
• CPC Class Codes: H01C 7/06 including means to minimise changes in resistance with changes in temperature
• CPC Class Codes: Y10T 29/49082 Resistor making
• CPC Class Codes: Y10T 29/49101 Applying terminal

Abstract

A current sense resistor and a method of manufacturing a current sensing resistor with temperature coefficient of resistance (TCR) compensation is disclosed. The resistor has a resistive strip disposed between two conductive strips. A pair of main terminals and a pair of voltage sense terminals are formed in the conductive strips. A pair of rough TCR calibration slots are located between the main terminals and the voltage sense terminals, each of the rough TCR calibration slots have a depth selected to obtain a negative starting TCR value observed at the voltage sense terminals. A fine TCR calibration slot is formed between the pair of voltage sense terminals. The fine TCR calibration slot has a depth selected to obtain a TCR value observed at the voltage sense terminals that approaches zero. The resistor can also have a resistance calibration slot located between the pair of main terminals. The resistance calibration slot has a depth selected to calibrate a resistance value of the resistor.

Claims

1. A resistor with temperature coefficient of resistance (TCR) compensation, the resistor comprising:

a resistive strip disposed between two conductive strips;

first and second main terminals and first and second voltage sense terminals formed in the conductive strips;

first and second rough TCR calibration slots located between the first and second main terminals and the voltage sense terminals, each of the first and second rough TCR calibration slots having a depth selected to obtain a negative starting TCR value observed at the voltage sense terminals, and

a fine TCR calibration slot formed between the first and second voltage sense terminals, wherein the fine TCR calibration slot has a depth selected to obtain a TCR value observed at the voltage sense terminals that approaches zero.

2. The resistor of claim 1 further comprising a resistance calibration slot formed between the first and second main terminals, wherein the resistance calibration slot has a depth selected to calibrate a resistance value of the resistor.

3. The resistor of claim 1 wherein each of the rough TCR calibration slots have a substantially equal depth.

4. The resistor of claim 1 wherein each of the rough TCR calibration slots have a different depth.

5. The resistor of claim 1 wherein the fine TCR calibration slot is formed in the resistive strip.

6. The resistor of claim 1 wherein the fine TCR calibration slot is formed in the resistive strip and at least one of the main terminals.

7. The resistor of claim 1 wherein the rough TCR calibration slots are formed by punching or machining.

8. The resistor of claim 1 wherein the fine TCR calibration slot is formed by laser trimming.

9. A method of manufacturing a resistor with temperature coefficient of resistance (TCR) compensation, the method comprising:

disposing a resistive strip between two conductive strips;

forming first and second main terminals and first and second voltage sense terminals in the conductive strips;

forming first and second rough TCR calibration slots between the main terminals and the voltage sense terminals, each of the first and second rough TCR calibration slots having a depth selected to obtain a negative starting TCR value observed at the voltage sense terminals, and

forming a fine TCR calibration slot between the first and second voltage sense terminals, wherein the fine TCR calibration slot has a depth selected to obtain a TCR value observed at the voltage sense terminals that approaches zero.

11. The method of claim 9 further comprising forming each of the rough TCR calibration slots with a substantially equal depth.

12. The method of claim 9 further comprising forming each of the rough TCR calibration slots with different depths.

13. The method of claim 9 further comprising forming the fine TCR calibration slot in the resistive strip.

14. The method of claim 9 further comprising forming the fine TCR calibration slot in the resistive strip and at least one of the main terminals.

15. The method of claim 9 further comprising forming the rough TCR calibration slots by punching or machining.

16. The method of claim 9 further comprising forming the fine TCR calibration slot by laser trimming.

10. The method of 9 further comprising forming a resistance calibration slot between the first and second main terminals, wherein the resistance calibration slot has a depth selected to calibrate a resistance value of the resistor.

17. A resistor with temperature coefficient of resistance (TCR) compensation, the resistor comprising:

a resistive strip disposed between two conductive strips, each of the conductive strips have a defined internal area;

first and second main terminals and first and second voltage sense terminals formed within the defined internal area of the conductive strips;

first and second TCR calibration slots, each having a first TCR calibration leg located between the first and second main terminals, the first TCR calibration legs having a length selected to obtain a rough TCR value observed at the voltage sense terminals, and

first and second TCR calibration slots each having second TCR calibration legs formed between the first and second main terminals, wherein the second TCR calibration legs have a length selected to obtain a TCR value observed at the voltage sense terminals that approaches zero.

18. The resistor of claim 17 wherein the two conductive strips define a main current path and the first TCR calibration legs are disposed generally orthogonal to the main current path.

19. The resistor of claim 17 wherein the second TCR calibration legs are disposed generally parallel to the main current path.

20. The resistor of claim 17 wherein each of the first TCR calibration legs have a substantially equal length.

21. The resistor of claim 17 wherein each of the first TCR calibration legs have a different length.

22. The resistor of claim 17 wherein the each of the first and second TCR calibration legs form junctions that define a location of the first and second voltage sense terminals.

23. The resistor of claim 17 further comprising a resistance calibration slot formed in the resistive strip.

24. The resistor of claim 17 wherein the first TCR calibration legs are formed by punching or machining.

25. The resistor of claim 17 wherein the second TCR calibration legs are formed by laser trimming.