Simulation of printed circuit board impedance variations and crosstalk effects

• US 8,289,043 B2
• Filed: 03/26/2010
• Issued: 10/16/2012
• Est. Priority Date: 03/26/2010
• Status: Expired due to Fees

• Current Assignee: Lenovo International Limited (Lenovo Group Ltd.)
• Original Assignee: International Business Machines Corporation
• Inventors: Herrman, Bradley D., Mutnury, Bhyrav M., Rodrigues, Terence
• Primary Examiner(s): NGUYEN, VINH P
• Application Number:
  US12/732,255
• Publication Number:
  US 20110234238A1
• Time in Patent Office: 935 Days
• Field of Search: None
• US Class Current: 324/763.01
• CPC Class Codes: G01R 31/2896 Testing of IC packages; Test features related to IC packages containers per se H01L23/02, encapsulations per se H01L23/28

Abstract

A method for altering an impedance of a conductive pathway on a microelectronic package includes applying a magnetic field to the conductive pathway. The microelectronic package may be, for example, a printed circuit board. The method also includes controlling a magnitude of the magnetic field at the conductive pathway for altering the impedance of the conductive pathway. The magnetic field may be applied by, for example, an electromagnet or a permanent magnet. A magnetic field may also be applied for simulating crosstalk effects on a conductive pathway.

Claims

1. A method comprising:

using a magnetic field generator to apply a magnetic field to a conductive pathway on a microelectronic package;

measuring an impedance of the conductive pathway while the magnetic field is being applied to the conductive pathway;

calibrating the magnetic field generator based on the measured impedance;

using the magnetic field generator to control the magnitude of the magnetic field to alter the impedance of the conductive pathway to be within a predetermined impedance range; and

testing the microelectronic package while the impedance of the conductive pathway is altered.

2. The method of claim 1, wherein the microelectronic package is a printed circuit board.

3. The method of claim 1, wherein the magnetic field generator comprises:

an electromagnet; and

a computing device coupled to the electromagnet and configured to control a magnitude of electric current passing through the electromagnet for controlling the magnitude of the magnetic field at the conductive pathway.