Apparatus and Method for Electrostatic Discharge Protection

• US 20110214924A1
• Filed: 03/02/2010
• Published: 09/08/2011
• Est. Priority Date: 03/02/2010
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Perezselsky, Armando Leon, Nelson, Richard Brian
• Granted Patent: US 8,716,613 B2
• Time in Patent Office: Days
• US Class Current: 178/18.03
• CPC Class Codes: G06V 40/1306 non-optical, e.g. ultrasonic or capacitive sensing
• CPC Class Codes: G06V 40/1329 Protecting the fingerprint sensor against damage caused by the finger
• CPC Class Codes: H01L 23/481 Internal lead connections, e.g. via connections, feedthrough structures
• CPC Class Codes: H01L 23/49805 the leads being also applied on the sidewalls or the bottom of the substrate, e.g. leadless packages for surface mounting
• CPC Class Codes: H01L 23/60 Protection against electrostatic charges or discharges, e.g. Faraday shields
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H05K 1/0259 Electrostatic discharge [ESD] protection
• CPC Class Codes: H05K 1/141 One or more single auxiliary printed circuits mounted on a main printed circuit, e.g. modules, adapters H05K1/142 and H05K1/147 take precedence
• CPC Class Codes: H05K 2201/09181 Notches in edge pads
• CPC Class Codes: H05K 2201/10151 Sensor
• CPC Class Codes: H05K 3/0052 Depaneling, i.e. dividing a panel into circuit boards; Working of the edges of circuit boards
• CPC Class Codes: Y10T 29/49165 by forming conductive walled aperture in base

Abstract

Embodiments of the invention provide a substrate and a method for constructing a substrate with electrostatic discharge protection. The substrate includes an edge surface with at least one plated castellation capable of conducting electrostatic discharge. The at least one plated castellation is connected to a circuit trace on at least one of the bottom surface and the top surface of the substrate. The method includes punching holes along at least a portion of a perimeter of each of a plurality of substrates in a substrate array, plating the holes with a conductive material, and cutting each of the plurality of substrates along cut lines that bisect at least some of the holes.

Claims

1. A substrate capable of receiving electrostatic discharge, the substrate comprising:

an edge surface including at least one plated castellation capable of conducting the electrostatic discharge;

a bottom surface;

a top surface; and

a circuit trace along at least one of the bottom surface and the top surface, the circuit trace electrically connected to the at least one plated castellation.

2. The substrate of claim 1 and further comprising a coating applied to the top surface.

3. The substrate of claim 1 and further comprising a ball grid array coupled to the bottom surface.

4. The substrate of claim 1 wherein the at least one plated castellation is plated with a conductive material including one of copper, aluminum, nickel, and gold.

5. The substrate of claim 1 wherein the at least one plated castellation includes a plurality of plated castellations that are positioned to one of partially surround and completely surround the edge surface.

6. The substrate of claim 5 wherein the plurality of plated castellations are electrically connected to a known potential.

7. The substrate of claim 1 and further including a sensing circuit for receiving touch or press from a part of a living body, the sensing circuit is coupled to one of the bottom surface and the top surface via a one of a direct coupling and an indirect coupling, wherein the indirect coupling is through a second substrate.

8. The substrate of claim 7 wherein the sensing circuit includes at least one sensor coupled to one of the top surface and the bottom surface, and a sensing integrated circuit coupled to the bottom surface, wherein the at least one sensor is capable of transmitting information to the sensing integrated circuit.

9. The substrate of claim 7 wherein the sensing circuit is a fingerprint sensing circuit.

10. The substrate of claim 9 wherein the top surface provides an area for a finger to be swiped.

11. The method of claim 10 and further comprising applying a circuit trace around a substrate surface of each of the plurality of substrates that electrically connects the via holes.

12. The method of claim 11 and further comprising electrically connecting the circuit trace to power source ground.

13. The method of claim 10 and further comprising electrically connecting a sensing integrated circuit to each of the plurality of substrates.

14. The method of claim 10 and further comprising attaching a ball grid array to a bottom substrate surface of each of the plurality of substrates.

15. The method of claim 10 wherein the via holes are punched along the entire perimeter of each of the plurality of substrates.

16. The method of claim 10 wherein the each of the plurality of substrates includes a top substrate and a bottom substrate coupled together.

10-1. A method of constructing a substrate for a touch electronics circuit intended for receiving touch or press from a part of a living body, the method comprising:

providing a surface for receiving the touch or press from the part of the living body;

providing a substrate array including a plurality of substrates;

punching via holes along at least a portion of a perimeter of each of the plurality of substrates;

plating the via holes with a conductive material; and

cutting each of the plurality of substrates along cut lines that bisect at least some of the via holes.

17. A method of constructing a substrate with electrostatic discharge protection, the method comprising:

providing a substrate array including a plurality of substrates;

punching holes along at least a portion of a perimeter of each of the plurality of substrates;

plating the holes with a conductive material;

cutting each of the plurality of substrates along cut lines that bisect at least some of the holes; and

connecting the conductive material to a known potential.

18. The method of claim 17 and further comprising providing a circuit trace for connecting the conductive material to a known potential.

19. The method of claim 18 and further comprising applying the circuit trace to at least one of a top, bottom and inner surface of the plurality of substrates.

20. The method of claim 17 wherein the holes are punched along the entire perimeter of each of the plurality of substrates.