Low cycle fatigue prevention

Patent metadata

Field	Value
Publication number	US-10887979-B2
Application number	US-201815866991-A
Country	US
Kind code	B2
Filing date	Jan 10, 2018
Priority date	Jan 10, 2018
Publication date	Jan 5, 2021
Grant date	Jan 5, 2021

Abstract

A system for reducing low cycle fatigue of a soldered connection includes a controller and a heating element operatively connected to the controller. The system also includes a printed wire board soldered in connection with an electronic component. The controller is configured to retrieve a signal indicative of a temperature of the electronic component, and compare the temperature to a stored predetermined range of operating temperatures. Responsive to determining that the temperature of the electronic component is less than a lower threshold temperature of the predetermined range of operating temperatures, the controller transmits a signal to the heating element that causes the heating element to heat the electronic component. The controller then saves, to an operatively connected computer readable memory, a magnitude of temperature difference and a number of times that magnitude is reached. The controller uses the stored information to track the life of the electronic component.

First claim

What is claimed is:

1. A system for reducing low cycle fatigue of a soldered connection comprising:
a controller;
a heating element operatively connected to the controller and affixed to an electronic component; and
a printed wire board (PWB) soldered in connection with an electronic component, and a trace heater embedded in the PWB, and another heating element operatively connected to the controller and affixed to an external portion of the PWB;
wherein the controller is configured to:
get from a temperature sensor a signal indicative of a temperature of the electronic component;
compare the temperature to a stored predetermined range of operating temperatures, wherein the stored predetermined range is stored in a non-transitory memory;
responsive to determining that the temperature of the electronic component is less than a lower threshold temperature of the predetermined range of operating temperatures, transmit a signal to the heating element, the another heating element and/or the trace heater, to raise the temperature of the electronic component and reduce a magnitude of the temperature difference (dT); and
save, to an operatively connected computer readable memory, the magnitude of temperature difference and a number of times that magnitude is reached;
retrieve, from the computer readable memory, a stored value indicative of an expected component life of the electronic component and PWB;
evaluate, based on the magnitude of temperature difference (dT), the number of times (N) that magnitude is reached, and the stored value, a new cumulative value of a low cycle fatigue (LCF) to predict a remaining component life; and
output an alert when the new cumulative value of the LCF exceeds a stored value of expected component life.

2. The system of claim 1 , wherein the controller causes the heating element to raise the temperature of the electronic component with a steady state signal.

3. The system of claim 1 , wherein the controller causes the heating element to raise the temperature of the electronic component with a signal pulse having a predetermined frequency and amplitude based on the temperature of the electronic component and the stored predetermined range of operating temperatures.

4. A computer-implemented method for reducing low cycle fatigue (LCF) in a soldered connection comprising:
getting, from a temperature sensor via a processor in a controller, a signal indicative of a temperature of an electronic component soldered to a printed wire board (PWB);
comparing, via the processor, the temperature to a stored predetermined range of operating temperatures, wherein the stored predetermined range is stored in a non-transitory memory;
responsive to determining that the temperature of the electronic component is less than a lower threshold temperature of the predetermined range of operating temperatures, transmitting, via the processor, a signal to one or more of a heating element affixed to the electronic component, a trace heater embedded in the PWB, and another heating element affixed to an external portion of the PWB, to raise the temperature of the electronic component and reduce a magnitude of the temperature difference (dT); and
saving, via the processor, to an operatively connected computer readable memory, the magnitude of temperature difference and a number of times that magnitude is reached;
retrieving, from the computer readable memory, a stored value indicative of an expected component life of the electronic component and PWB;
evaluating, based on the magnitude of temperature difference (dT), the number of times (N) that magnitude is reached, and the stored value, a new cumulative value of a low cycle fatigue (LCF) to predict a remaining component life; and
outputting an alert when the new cumulative value of the exceeds a stored value of expected component life.

5. The method of claim 4 , wherein the processor causes the heating element to raise the temperature of the electronic component with a steady state signal.

6. The method of claim 4 , wherein the controller causes the heating element to raise the temperature of the electronic component with a signal pulse having a predetermined frequency and amplitude based on the temperature of the electronic component and the stored predetermined range of operating temperatures.

7. A computer program product for reducing low cycle fatigue, the computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions executable by a processor to cause the processor to perform a method comprising:
getting, from a temperature sensor via processor, a signal indicative of a temperature of an electronic component soldered to a printed wire board (PWB);
comparing, via the processor, the temperature to a stored predetermined range of operating temperatures, wherein the stored predetermined range is stored in a non-transitory memory;
responsive to determining that the temperature of the electronic component is less than a lower threshold temperature of the predetermined range of operating temperatures, transmitting, via the processor, a signal to one or more of a heating element affixed to the electronic component, a trace heater embedded in the PWB, and another heating element affixed to an external portion of the PWB, to raise the temperature of the electronic component and reduce a magnitude of the temperature difference (dT); and
saving, via the processor, to an operatively connected computer readable memory, the magnitude of temperature difference and a number of times that magnitude is reached;
retrieving, from the computer readable memory, a stored value indicative of an expected component life of the electronic component and PWB;
evaluating, based on the magnitude of temperature difference (dT), the number of times (N) that magnitude is reached, and the stored value, a new cumulative value of a low cycle fatigue (LCF) to predict a remaining component life; and
outputting an alert when the new cumulative value of the LCF exceeds a stored value of expected component life.

8. The computer program product of claim 7 , wherein the processor causes the heating element to raise the temperature of the electronic component with a steady state signal.

9. The computer program product of claim 7 , wherein the processor causes the heating element to raise the temperature of the electronic component with a signal pulse having a predetermined frequency and amplitude based on the temperature of the electronic component and the stored predetermined range of operating temperatures.

Assignees

• Hamilton Sundstrand Corp
• Hamilton Sunstrand Corp

Inventors

• Severson Mark Hamilton
• Schmid Ryan W

Classifications

• H10W40/10

  Arrangements for heating · CPC title

• H05K2201/10159

  Memory · CPC title

• H05K1/0212 Primary

  Printed circuits or mounted components having integral heating means · CPC title

• G01R31/008

  on air- or spacecraft, railway rolling stock or sea-going vessels · CPC title

• H05K1/0271

  Arrangements for reducing stress or warp in rigid printed circuit boards, e.g. caused by loads, vibrations or differences in thermal expansion · CPC title