EMBEDDED PROTECTION AGAINST SPURIOUS ELECTRICAL EVENTS

• US 20110211289A1
• Filed: 04/28/2011
• Published: 09/01/2011
• Est. Priority Date: 02/26/2010
• Status: Active Grant

• Current Assignee: Littelfuse Incorporated
• Original Assignee: Littelfuse Incorporated
• Inventors: Vasquez, Daniel, Graydon, Bhret, Kosowsky, Lex, Fleming, Robert
• Granted Patent: US 9,224,728 B2
• Time in Patent Office: Days
• US Class Current: 361/91.1
• CPC Class Codes: H01L 27/0288 using passive elements as protective elements, e.g. resistors, capacitors, inductors, spark-gaps
• CPC Class Codes: H05K 1/0259 Electrostatic discharge [ESD] protection
• CPC Class Codes: H05K 2201/0738 Use of voltage responsive materials, e.g. voltage switchable dielectric or varistor materials

Abstract

Various disclosed aspects provide for protecting components (e.g., integrated circuits) from spurious electrical overvoltage events, such as electrostatic discharge. Embedded components with voltage switchable dielectric materials may protect circuits against electrostatic discharge.

Claims

1. A circuit for protecting an electronic component of an electronic device against an overvoltage signal, the circuit comprising:

a voltage switchable dielectric (VSD) material embedded in a substrate, the VSD material disposed between a first point located along an expected ESD signal path and a second point located within the device, the VSD material having a characteristic voltage level; and

a circuit element disposed between the first point and the electronic component;

wherein the VSD material is configured to transmit to the second point a first portion of the overvoltage signal present at the first point when a voltage of the overvoltage signal exceeds the characteristic voltage level;

and wherein the circuit element is configured to transmit a second portion of the overvoltage signal to the electronic component while modifying at least one signal characteristic of the second portion of the ESD signal.

2. The circuit of claim 1, wherein the second point located within the device is a ground or is in electrical communication to a ground signal level.

3. The circuit of claim 1, wherein the second point located within the device is electrically coupled to an electronic component other than the component that receives the second portion of the overvoltage signal from the circuit element.

4. The circuit of claim 1, wherein the substrate is a PCB and the VSD material is at least a part of a layer of the PCB.

5. The circuit of claim 4, wherein the layer of the PCB including the VSD material is inside the PCB or is at a surface of the PCB.

6. The circuit of claim 1, wherein the circuit element is a resistor, a capacitor, an inductor, a low-pass filter, a band-pass filter, a high-pass filter, a diode, or an active electronic component.

7. The circuit of claim 1, wherein the circuit element is embedded in the substrate.

8. The circuit of claim 1, wherein the circuit element includes a via of a PCB, or is built within a via of a PCB.

9. The circuit of claim 1, wherein the circuit element is a discrete component that is not embedded in the substrate.

10. The circuit of claim 1, wherein the VSD material is further configured to protect the circuit element against the overvoltage signal.

11. The circuit of claim 1, wherein the circuit is incorporated in a connector.

12. The circuit of claim 1, wherein the substrate and the circuit element are part of a connector, and the component is part of a device to which the connector is attached.

13. The circuit of claim 1, wherein the device is a mobile phone, electronic tablet, electronic reader, mobile computer, desktop computer, server computer, television set, music player, personal health management device, or another consumer electronic device that processes or stores data using electrical or electromechanical signals.

14. The circuit of claim 1, wherein the at least one signal characteristic that the circuit element is configured to modify includes any of a voltage value, a current intensity value, a power value, a frequency value, a bandwidth value, and a propagation delay value.

15. An electronic device comprising:

a substrate;

a component disposed on the substrate;

a voltage switchable dielectric material (VSD material) embedded in the substrate; and

a circuit element electrically connected to the VSD material and to the component, the circuit element separating the VSD material and the component; and

wherein the VSD material is configured to become substantially conductive when an input signal reaching the circuit element exceeds a characteristic voltage level of the VSD material, the VSD material thereby preventing at least a portion of the input signal from propagating to the component through the circuit element.

16. The electronic device of claim 15, wherein the substrate is a PCB and the VSD material comprises at least a portion of a layer of the PCB.

17. The electronic device of claim 15, wherein the circuit element is embedded within the substrate.

18. The electronic device of claim 15, wherein the device is a mobile phone, electronic tablet, electronic reader, mobile computer, desktop computer, server computer, television set, music player, personal health management device, or another consumer electronic device that processes or stores data using electrical or electromechanical signals.

19. The electronic device of claim 15, wherein the circuit element is configured to transmit a portion of input signal to the electronic component while modifying at least one signal characteristic of the transmitted portion of the input signal.

20. The electronic device of claim 15, wherein the component includes any of a chip, an integrated circuit, a semiconductor, a resistor, an inductor, a capacitor, and a diode.